JP7290989B2 - Composite sheet for protective film formation - Google Patents

Description

TECHNICAL FIELD The present invention relates to a composite sheet for forming a protective film.

2. Description of the Related Art In the process of manufacturing a semiconductor device, a protective film may be used to protect a workpiece that needs to be processed in order to obtain a desired product.
For example, in manufacturing a semiconductor device to which a mounting method called a face down method is applied, a semiconductor wafer having electrodes such as bumps on a circuit surface is used as a work, and a semiconductor wafer and its divisions are used. In order to suppress the occurrence of cracks in a semiconductor chip, the back surface of the semiconductor wafer or semiconductor chip opposite to the circuit surface is sometimes protected with a protective film. Further, in the manufacturing process of a semiconductor device, a semiconductor device panel, which will be described later, is used as a work, and in order to suppress the generation of warpage and cracks in this panel, some part of the panel may be protected with a protective film.

In order to form such a protective film, for example, a protective film comprising a support sheet and a protective film-forming film for forming the protective film on one side of the support sheet. A forming composite sheet is used.
The protective film-forming film may function as a protective film when cured, or may function as a protective film in an uncured state. Moreover, the support sheet can be used to fix a work provided with a film for forming a protective film or a cured product thereof. For example, when a semiconductor wafer is used as the workpiece, the support sheet can be used as a dicing sheet required when dividing the semiconductor wafer into semiconductor chips. Examples of the support sheet include those comprising a base material and an adhesive layer provided on one surface of the base material; and those comprising only a base material. When the support sheet has a pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer is arranged between the substrate and the protective film-forming film in the protective film-forming composite sheet.

When the protective film-forming composite sheet described above is used, first, the protective film-forming film in the protective film-forming composite sheet is attached to a target portion of the work.
Next, the workpiece provided with such a composite sheet for forming a protective film is processed as necessary to obtain a processed workpiece. For example, when a semiconductor wafer is used as a work, after the protective film forming composite sheet is attached to the back surface of the work with the protective film forming film therein, the protective film forming film is applied at an appropriate timing. Formation of protective film by curing, cutting of protective film forming film or protective film, division of semiconductor wafer into semiconductor chips (dicing), protective film forming film after cutting or semiconductor chip with protective film on the back surface ( A semiconductor chip with a protective film forming film or a semiconductor chip with a protective film) is properly picked up from the support sheet. When the semiconductor chip with the protective film forming film is picked up, the semiconductor chip with the protective film forming film is turned into the semiconductor chip with the protective film by curing the protective film forming film, and finally the semiconductor chip with the protective film is obtained. A semiconductor device is manufactured using Then, at any stage until the desired semiconductor device is obtained, the surface of the protective film forming film or the cured product thereof opposite to the surface to be attached to the work or work piece (that is, the surface for forming the protective film) In the composite sheet, printing (laser printing) may be performed on the surface facing the support sheet by irradiating laser light. This inscription is used, for example, to identify a workpiece or workpiece with a protective coating. The printing applied to the protective film-forming film maintains the same state even after the protective film is formed by curing the film. It can be done at any stage.

Patent Literature 1 discloses a back surface protective film for protecting the back surface of a semiconductor element, which has a parallel light transmittance of 15% or more at a wavelength of 800 nm. Further, Patent Document 2 discloses a composite sheet for forming a protective film having a total light transmittance of 3% or more at a wavelength of 555 nm.

JP 2016-213244 A JP 2016-213243 A

As such a composite sheet for forming a protective film, in addition to those provided with a support sheet provided with an adhesive layer that is cured by heating, there is a support sheet provided with an adhesive layer that is cured by irradiation with energy rays such as ultraviolet rays. It's being used.
On the other hand, if a semiconductor chip or a semiconductor chip with a protective film is irradiated with energy rays, the semiconductor chip may be destroyed or malfunction may occur. Especially in a semiconductor chip with a protective film, when an energy ray-curable adhesive is used, irradiation with an energy ray is essential, and this risk becomes higher.
Furthermore, in recent years, semiconductor wafers have become thinner, and it is necessary to facilitate pickup from the support sheet so as not to damage the semiconductor chips.
In addition, when the film for forming a protective film transmits visible light, grinding marks of the semiconductor wafer may be seen and the design may be impaired. In addition, if the laser marking applied to the back surface of the semiconductor wafer for process control, which is unnecessary at the time of shipment, is visible through the protective film forming film or the protective film, the laser marking on the surface of the protective film forming film may They may appear to be overlapped, resulting in reading errors.

The back surface protective film disclosed in Patent Document 1 has a high parallel light transmittance with a wavelength of 800 nm in order to catch cracks in the semiconductor chip through the back surface protective film with an infrared camera, and protects the semiconductor chip from energy rays. It does not disclose a composite sheet for forming a protective film that can be easily picked up from the support sheet without damaging the semiconductor chip.
In addition, the protective film-forming composite sheet disclosed in Patent Document 2 has a total light transmittance of 555 nm so that the notch of the semiconductor wafer can be detected when the protective film-forming composite sheet is attached to the semiconductor wafer. A composite sheet for forming a protective film with an improved protective film that protects a semiconductor chip from energy rays and that can be easily picked up from a support sheet without damaging the semiconductor chip is disclosed. do not have.

The present invention provides a protective film-forming composite sheet comprising a support sheet and a protective film-forming film provided on one surface of the support sheet. To provide a composite sheet for forming a protective film which does not destroy a semiconductor chip or cause malfunction even when irradiated with rays.
Another object of the present invention is to provide a composite sheet for forming a protective film that allows the semiconductor chip to be easily picked up from the support sheet without damaging the semiconductor chip when the semiconductor chip is picked up from the support sheet. and
Furthermore, the present invention is excellent in design by suppressing the visibility of the grinding marks on the back surface of the wafer and the laser marking applied for process control, and also prevents reading errors of the laser marking on the surface of the protective film. An object of the present invention is to provide a composite sheet for forming a protective film with a low possibility of occurrence.

The present invention includes a support sheet and a protective film-forming film provided on one surface of the support sheet, and the protective film-forming film has a transmittance of 0.3% or less for light having a wavelength of 365 nm. A composite sheet for forming a protective film is provided.

In the protective film-forming composite sheet of the present invention, the support sheet includes a substrate and a pressure-sensitive adhesive layer provided on one surface of the substrate, and the pressure-sensitive adhesive layer comprises the substrate. It is arranged between the material and the film for forming a protective film, and the pressure-sensitive adhesive layer is preferably an energy ray-curable pressure-sensitive adhesive layer.
In the protective film-forming composite sheet of the present invention, it is preferable that the protective film-forming film has a transmittance of 5% or less for light having a wavelength of 555 nm.
In the protective film-forming composite sheet of the present invention, it is preferable that the protective film-forming film has a transmittance of less than 20% for light having a wavelength of 800 nm.

According to the present invention, there is provided a protective film-forming composite sheet comprising a support sheet and a protective film-forming film provided on one surface of the support sheet, wherein energy is applied to a semiconductor chip or a semiconductor chip with a protective film. Provided is a composite sheet for forming a protective film that does not destroy semiconductor chips or cause malfunctions even when irradiated with rays.
Further, according to the present invention, there is provided a protective film-forming composite sheet comprising a support sheet and a protective film-forming film provided on one surface of the support sheet, wherein the semiconductor chip is picked up from the support sheet. Provided is a composite sheet for forming a protective film that allows the semiconductor chip to be easily picked up from the support sheet without damaging the semiconductor chip.
Furthermore, according to the present invention, the grinding marks on the back surface of the wafer and the laser marking applied for process control are suppressed from being visible, so that the design is excellent, and the reading error of the laser marking on the surface of the protective film is prevented. Provided is a protective film-forming composite sheet with a low possibility of occurrence.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows typically an example of the composite sheet for protective film formation which concerns on one Embodiment of this invention. FIG. 4 is a cross-sectional view schematically showing another example of the protective film-forming composite sheet according to one embodiment of the present invention. FIG. 4 is a cross-sectional view schematically showing still another example of the protective film-forming composite sheet according to one embodiment of the present invention. FIG. 4 is a cross-sectional view schematically showing still another example of the protective film-forming composite sheet according to one embodiment of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view schematically illustrating an example of a method for manufacturing a semiconductor chip with a protective film when using a protective film-forming composite sheet according to an embodiment of the present invention.

◇ Protective Film-Forming Composite Sheet A protective film-forming composite sheet according to an embodiment of the present invention comprises a support sheet and a protective film-forming film provided on one surface of the support sheet, The transmittance of the protective film-forming film for light with a wavelength of 365 nm (in this specification, it may be abbreviated as “light (365 nm)”) is 0.3% or less. By setting the transmittance of light (365 nm) to 0.3% or less, even if a semiconductor chip or a semiconductor chip with a protective film is irradiated with an energy beam, the semiconductor chip will not be destroyed or malfunction will occur. do not have.
A composite sheet for forming a protective film according to one embodiment of the present invention, wherein the support sheet comprises a substrate and an adhesive layer provided on one surface of the substrate, and the adhesive It is preferable that a layer is disposed between the substrate and the protective film-forming film, and the pressure-sensitive adhesive layer is an energy ray-curable pressure-sensitive adhesive layer.

The protective film-forming film in the protective film-forming composite sheet of the present embodiment may be curable or non-curable.

In this specification, as long as the laminated structure of the support sheet and the cured product of the protective film-forming film is maintained even after the protective film-forming film is cured, the laminated structure is referred to as ""composite sheet for forming a protective film".
Moreover, in this specification, unless otherwise specified, the cured product of the film for forming a protective film is referred to as a “protective film”.

In the protective film-forming composite sheet of the present embodiment, any of the substrate, the pressure-sensitive adhesive layer, the intermediate layer, the protective film-forming film, and the release film is included within the range that does not impair the effects of the present invention. Other layers may be provided that are not applicable.
The type of the other layer is not particularly limited and can be arbitrarily selected according to the purpose.
The arrangement position, shape, size, etc. of the other layers can also be arbitrarily selected according to the type, and are not particularly limited. It is preferably larger than the size of the work to which the composite sheet for use is attached.

The thickness of the work to which the composite sheet for forming a protective film of the present embodiment is attached is not particularly limited. It is preferably 70 to 400 μm, more preferably 70 to 400 μm.

The protective film-forming composite sheet of the present embodiment is to be attached to a work, and the work to which it is attached is preferably a semiconductor wafer, for example. The composite sheet for forming a protective film is preferably used for attachment to the back surface of a semiconductor wafer.

The work to which the protective film-forming composite sheet is applied does not include the work after the processing operation. Here, the "work after machining operation" includes a target work to be processed and a work in a state in which machining has not been completed. Work pieces that have not been completely machined include, for example, work pieces that are in the process of being machined, and work pieces that are partly incompletely machined even though the work has been attempted to be machined. A work whose processing has not been completed includes, for example, a state in which division of a semiconductor wafer into semiconductor chips has been attempted, but the division is partially incomplete.

FIG. 1 is a cross-sectional view schematically showing an example of a protective film-forming composite sheet according to one embodiment of the present invention.
The composite sheet 101 for forming a protective film shown here includes a support sheet 10 and a protective film provided on one surface (in this specification, sometimes referred to as "first surface") 10a of the support sheet 10. and a forming film 13 .
The support sheet 10 includes a substrate 11 and an adhesive layer 12 provided on one surface 11 a of the substrate 11 . In the protective film-forming composite sheet 101 , the pressure-sensitive adhesive layer 12 is arranged between the substrate 11 and the protective film-forming film 13 .
That is, the composite sheet 101 for forming a protective film is configured by laminating a substrate 11, an adhesive layer 12, and a film 13 for forming a protective film in this order in the thickness direction thereof.
The surface 10a of the support sheet 10 on the protective film forming film 13 side (in this specification, may be referred to as the "first surface") is the surface of the pressure-sensitive adhesive layer 12 opposite to the substrate 11 side ( In this specification, it may be referred to as a "first surface") 12a.

The protective film-forming composite sheet 101 further includes a jig adhesive layer 16 and a release film 15 on the protective film-forming film 13 .
In the protective film-forming composite sheet 101, the protective film-forming film 13 is laminated on the entire surface or substantially the entire surface of the first surface 12a of the adhesive layer 12, and the protective film-forming film 13 is separated from the adhesive layer 12 side. A jig adhesive layer 16 is laminated on a part of the opposite surface (in this specification, sometimes referred to as a "first surface") 13a, that is, a region near the peripheral edge. Further, on the first surface 13a of the protective film forming film 13, the region where the jig adhesive layer 16 is not laminated and the side opposite to the protective film forming film 13 side of the jig adhesive layer 16 A release film 15 is laminated on the surface 16a (which may be referred to as a "first surface" in this specification).

Not only in the case of the protective film-forming composite sheet 101, but in the protective film-forming composite sheet of the present embodiment, the release film (for example, the release film 15 shown in FIG. 1) has an arbitrary configuration. The protective film-forming composite sheet may or may not have a release film.

In the protective film-forming composite sheet 101 , there may be a partial gap between the release film 15 and the layer in direct contact with the release film 15 .
For example, here, the release film 15 is in contact (laminated) with the side surface 16c of the jig adhesive layer 16, but the release film 15 is not in contact with the side surface 16c. There is also Also, here, a state is shown in which the release film 15 is in contact (laminated) in the vicinity of the jig adhesive layer 16 on the first surface 13a of the protective film forming film 13. A region may not be in contact with the release film 15 .
Also, the boundary between the first surface 16a and the side surface 16c of the jig adhesive layer 16 may not be clearly distinguishable.
The above points also apply to the composite sheet for forming a protective film according to another embodiment, which is provided with an adhesive layer for a jig.

The jig adhesive layer 16 is used to fix the protective film-forming composite sheet 101 to a jig such as a ring frame.
The jig adhesive layer 16 may have, for example, a single-layer structure containing an adhesive component, or a plurality of layers in which layers containing an adhesive component are laminated on both sides of a sheet serving as a core material. You may have a structure.

In the protective film-forming composite sheet 101, the transmittance of light (365 nm) of the support sheet 10 is preferably 40% or more.

The protective film forming composite sheet 101 is a state in which the peeling film 15 is removed, and any part of the work (not shown) is attached to the first surface 13 a of the protective film forming film 13 . The first surface 16a of the adhesive layer 16 is attached to a jig such as a ring frame for use.

FIG. 2 is a cross-sectional view schematically showing another example of the protective film-forming composite sheet according to one embodiment of the present invention.
In the drawings after FIG. 2, the same constituent elements as those shown in already explained figures are given the same reference numerals as in the already explained figures, and detailed explanations thereof will be omitted.

In the protective film forming composite sheet 102 shown here, the protective film forming film has a different shape and size, and the jig adhesive layer is not the first surface of the protective film forming film, but the first adhesive layer. It is the same as the protective film-forming composite sheet 101 shown in FIG. 1 except that it is laminated on the surface.

More specifically, in the protective film-forming composite sheet 102, the protective film-forming film 23 extends in a partial region of the first surface 12a of the adhesive layer 12, that is, in the width direction of the adhesive layer 12 (Fig. 2 in the left-right direction). Furthermore, a jig adhesive layer 16 is laminated on a region of the first surface 12a of the adhesive layer 12 where the protective film forming film 23 is not laminated, ie, a region near the peripheral edge. Then, a surface 23 a of the protective film forming film 23 on the side opposite to the adhesive layer 12 side (in this specification, may be referred to as a “first surface”) and a first surface of the jig adhesive layer 16 . A release film 15 is laminated on one surface 16a.

FIG. 3 is a cross-sectional view schematically showing still another example of the protective film-forming composite sheet according to one embodiment of the present invention.
The protective film-forming composite sheet 103 shown here is the same as that shown in FIG. It is the same as the protective film forming composite sheet 101 .
The support sheet 20 includes a substrate 11, an adhesive layer 12 provided on the first surface 11a of the substrate 11, and an intermediate layer 17 provided on the first surface 12a of the adhesive layer 12. configured as follows. In the protective film-forming composite sheet 103 , the intermediate layer 17 is arranged between the adhesive layer 12 and the protective film-forming film 23 .
That is, the protective film-forming composite sheet 103 is configured by laminating the substrate 11, the adhesive layer 12, the intermediate layer 17, and the protective film-forming film 23 in this order in the thickness direction.
A surface 20 a of the support sheet 20 on the protective film forming film 23 side (in this specification, may be referred to as “first surface”) is the same as the first surface 12 a of the pressure-sensitive adhesive layer 12 .

The area of the surface 17a of the intermediate layer 17 opposite to the pressure-sensitive adhesive layer 12 side (in this specification, may be referred to as the "first surface") is the area of the first surface 12a of the pressure-sensitive adhesive layer 12 (that is, It is smaller than the total area of the area where the protective film forming film 23 is laminated and the area where it is not laminated).
The planar shape of the first surface 17a of the intermediate layer 17 is not particularly limited, and may be circular, for example.
The shape and size of the first surface 17a of the intermediate layer 17 may be the same as or different from the shape and size of the first surface 23a of the protective film-forming film 23 . However, the entire surface 23b opposite to the first surface 23a of the protective film forming film 23 (in this specification, may be referred to as the "second surface") is covered with the intermediate layer 17. is preferred.

FIG. 4 is a cross-sectional view schematically showing still another example of the protective film-forming composite sheet according to one embodiment of the present invention.
The protective film-forming composite sheet 104 shown here is the same as the protective film-forming composite sheet 101 shown in FIG.
The support sheet 30 consists of the base material 11 only.
That is, the protective film forming composite sheet 104 is configured by laminating the substrate 11 and the protective film forming film 13 in the thickness direction thereof.
A surface 30 a of the support sheet 30 on the side of the protective film forming film 13 (in this specification, may be referred to as “first surface”) is the same as the first surface 11 a of the substrate 11 .
The base material 11 has adhesiveness at least on its first surface 11a.

The composite sheet for forming a protective film according to the present embodiment is not limited to those shown in FIGS. 1 to 4, and part of the structure shown in FIGS. Alternatively, it may be deleted, or another configuration may be added to what has been described so far. More specifically, it is as follows.

So far, only the protective film-forming composite sheet 104 shown in FIG. Examples of the protective film-forming composite sheet include a protective film-forming composite sheet 102 shown in FIG. However, this is an example of another protective film-forming composite sheet provided with a support sheet consisting only of a base material.

So far, only the protective film-forming composite sheet 103 shown in FIG. Examples of composite sheets for use include those shown below. However, these are examples of other protective film-forming composite sheets provided with an intermediate layer.
- In the protective film forming composite sheet 101 shown in FIG. 1, an intermediate layer similar to that shown in FIG. 3 is provided between the adhesive layer 12 and the protective film forming film 13.
- In the protective film forming composite sheet 102 shown in FIG. 2, an intermediate layer similar to that shown in FIG. 3 is provided between the adhesive layer 12 and the protective film forming film 23.
- In the composite sheet 104 for forming a protective film shown in FIG. 4, an intermediate layer similar to that shown in FIG. 3 is provided between the substrate 11 and the film 13 for forming a protective film.

So far, the protective film-forming composite sheet provided with the jig adhesive layer has been described with reference to the protective film-forming composite sheet 101 shown in FIG. 1, the protective film-forming composite sheet 102 shown in FIG. Although the protective film-forming composite sheet 104 shown in FIG. A jig adhesive layer similar to that shown in FIG. However, this is an example of another protective film-forming composite sheet provided with a jig adhesive layer.

In the protective film-forming composite sheet having such a jig adhesive layer, the first surface of the jig adhesive layer is the same as the protective film-forming composite sheet 101 shown in FIG. It is used by being attached to a jig such as a ring frame.
As described above, the protective film-forming composite sheet of the present embodiment may be provided with an adhesive layer for a jig, regardless of the form of the support sheet and the protective film-forming film.

Up to this point, only the protective film-forming composite sheet 103 shown in FIG. Examples of the protective film-forming composite sheet without the protective film-forming composite sheet include, for example, the protective film-forming composite sheet 102 shown in FIG. However, this is an example of another protective film-forming composite sheet that does not have a jig adhesive layer.

1 to 4 show a substrate, an adhesive layer, an intermediate layer, a film for forming a protective film, and a release film as constituents of the composite sheet for forming a protective film. The composite forming sheet may comprise the other layers, none of which are described above.
In the case where the protective film-forming composite sheet shown in FIGS. 1 to 4 includes the other layer, the arrangement position thereof is not particularly limited.

In the protective film-forming composite sheet of the present embodiment, the size and shape of each layer can be arbitrarily selected according to the purpose.
The configuration of the protective film-forming composite sheet will be described in detail below.

◇Support Sheet The support sheet according to one embodiment of the present invention can form a composite sheet for forming a protective film, for example, by being laminated with a film for forming a protective film, as described later.

The support sheet of the present embodiment can be used to fix a workpiece having a film for forming a protective film, which will be described later, or a cured product thereof, at any location.
Examples of workpieces include semiconductor wafers, semiconductor device panels, and the like. A semiconductor device panel is handled in the manufacturing process of a semiconductor device, and a specific example thereof includes a panel in which a plurality of electronic components are mounted on a single circuit board.
In this specification, a machined workpiece is referred to as a "workpiece". For example, if the workpiece is a semiconductor wafer, the workpiece may be a semiconductor chip.
For example, when the workpiece is a semiconductor wafer, the support sheet of the present embodiment can be used to fix the semiconductor wafer having a protective film forming film or a cured product thereof on the back surface.

The support sheet includes, for example, a substrate and a pressure-sensitive adhesive layer provided on one surface of the substrate; a substrate only; a substrate and one of the substrates and an intermediate layer provided on the surface of the pressure-sensitive adhesive layer opposite to the substrate; a substrate and one of the substrates and an intermediate layer provided on the surface of the When the support sheet has a pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer is arranged between the substrate and the protective film-forming film in the protective film-forming composite sheet described later.

When a support sheet comprising a base material and an adhesive layer is used, the adhesion or adhesion between the support sheet and the protective film-forming film can be easily adjusted in the protective film-forming composite sheet.
When a support sheet consisting of only a substrate is used, a composite sheet for forming a protective film can be produced at low cost.
When a support sheet comprising a substrate, an adhesive layer and an intermediate layer is used, new functions can be imparted to the support sheet or protective film-forming composite sheet. In addition, the adhesive force or adhesion between the support sheet and the film for forming a protective film can be adjusted more easily than in the case of the adhesive layer described above.

The transmittance of light of 365 nm of the support sheet is preferably 40% or more, and may be, for example, 50% or more, 60% or more, or 70% or more. When the transmittance of the support sheet is equal to or higher than the lower limit, light with a wavelength of 365 nm is applied under the conditions of an illuminance of 5 mW/cm ² and a light amount of 100 mJ/cm ² (hereinafter referred to as , sometimes abbreviated as "low illumination UV irradiation conditions"), even when ultraviolet irradiation is performed, the ultraviolet rays sufficiently reach the energy ray-curable adhesive, and the protective film-forming film and the support sheet can be more easily reduced to less than 370 mN/25 mm.

The upper limit of the transmittance of light (365 nm) of the support sheet is not particularly limited, and may be, for example, 100%. For example, a support sheet having a transmittance of 97% or less is easier to manufacture.

The light (365 nm) transmittance of the support sheet can be appropriately adjusted within a range set by arbitrarily combining any of the above lower limits and upper limits. For example, in one embodiment, the transmittance of the support sheet is preferably 40 to 97%, more preferably 50 to 97%, such as 60 to 97% and 70 to 97%. or However, these are examples of the transmittance of the support sheet.

◎ Substrate The substrate is sheet-like or film-like, and preferably has a light (365 nm) transmittance of 40% or more, for example, any of 50% or more, 60% or more, and 70% or more. or

Examples of the constituent material of the base material include various resins.
Examples of the resin include polyolefins such as low-density polyethylene (LDPE) and polypropylene (PP); ethylene-methacrylic acid copolymer (EMAA); polyvinyl chloride (PVC); polyethylene terephthalate (PET), polyethylene naphthalate ( PEN), polyester such as polybutylene terephthalate (PBT); polyether sulfone, polyacrylic acid ester; polycarbonate (PC) and the like.

The resin constituting the substrate may be of one type or two or more types, and when two or more types are used, the combination and ratio thereof can be arbitrarily selected.

The substrate may consist of one layer (single layer) or may consist of a plurality of layers of two or more layers. The combination of these multiple layers is not particularly limited.

In the present specification, not only in the case of the substrate, "multiple layers may be the same or different" means "all the layers may be the same or all the layers may be different. may be the same, or only some of the layers may be the same", and further, "the plurality of layers are different from each other" means that "at least one of the constituent materials and thickness of each layer is different from each other". means.

The thickness of the substrate is preferably 50-300 μm, more preferably 60-140 μm, and particularly preferably 80-100 μm. When the thickness of the base material is within such a range, the flexibility of the composite sheet for forming a protective film and the sticking property to a workpiece or a processed workpiece are further improved.
Here, the "thickness of the base material" means the thickness of the entire base material. means.

It is preferable that the base material has a high thickness accuracy, that is, a material in which variations in thickness are suppressed irrespective of parts. Among the constituent materials described above, examples of materials that can be used to form such a base material with high thickness accuracy include polyolefin, polyethylene terephthalate, and the like.

The substrate contains various known additives such as fillers, colorants, antistatic agents, antioxidants, organic lubricants, catalysts, softeners (plasticizers), etc., in addition to the main constituent materials such as the resins. may
For example, by adjusting the presence or absence of a filler or colorant in the base material, or the content of the filler or colorant in the case where the base material contains a filler or colorant, the light (365 nm) transmission of the base material You can easily adjust the rate.

The base material may have tackiness on at least one surface by containing a specific range of components (eg, resin, etc.).

The optical properties of the substrate are preferably such that the support sheet satisfies the previously described light (365 nm) transmittance conditions.
For example, as described above, since the support sheet may be composed only of the base material, the light (365 nm) transmittance of the base material is the same as the light (365 nm) transmittance of the support sheet exemplified above. may be

Furthermore, for the same reason as the transmittance of light (365 nm) of the support sheet described above, the transmittance of light (365 nm) of the substrate is, for example, 40% or more, 50% or more, 60% or more, and 70%. % or more.

For the same reason as the transmittance of light (365 nm) of the support sheet described above, the upper limit of the transmittance of light (365 nm) of the substrate is not particularly limited, and may be, for example, 100%. . For example, a substrate having a transmittance of 97% or less is easier to manufacture or obtain.

In addition, the transmittance of light (365 nm) of the base material can be appropriately adjusted within a range set by arbitrarily combining any of the above lower limit values and upper limit values. For example, in one embodiment, the transmittance of the substrate may be any of 40-97%, 50-97%, 60-97%, and 70-97%. However, these are examples of the transmittance of the substrate.

In order to improve adhesion with the layer provided thereon (e.g., adhesive layer, film for forming a protective film, etc.), the base material is subjected to roughening treatment such as sandblasting and solvent treatment; corona discharge treatment; The surface may be subjected to oxidation treatment such as radiation treatment, plasma treatment, ozone/ultraviolet irradiation treatment, flame treatment, chromic acid treatment, and hot air treatment. Further, the substrate may have a primer-treated surface.
In addition, the base material has an antistatic coating layer; prevents the base material from adhering to other sheets and the base material from adhering to the adsorption table when the composite sheet for forming a protective film is superimposed and stored. It may have layers and the like.

A base material can be manufactured by a well-known method. For example, a substrate containing a resin can be produced by molding a resin composition containing the resin.

◎ Adhesive layer The adhesive layer is sheet-like or film-like, and the adhesive force between the film for forming a protective film or a cured product thereof and the support sheet is preferably less than 370 mN/25 mm, more preferably 250 mN/25 mm. Less than 200 mN/25 mm is particularly preferred.
By setting the adhesive strength between the film for forming a protective film or a cured product thereof and the support sheet to be less than the upper limit, the semiconductor chip can be easily picked up from the support sheet without damaging the semiconductor chip. The semiconductor chips can be picked up from the support sheet immediately.
In particular, when the pressure-sensitive adhesive contained in the pressure-sensitive adhesive layer is an energy ray-curable pressure-sensitive adhesive, the energy ray-cured material obtained by ultraviolet irradiation under low-intensity UV irradiation conditions and the support sheet By setting the adhesive strength to be less than the upper limit, the semiconductor chip can be easily removed without damaging the semiconductor chip when picking up the semiconductor chip from the support sheet while reducing the risk of UV irradiation to the semiconductor chip. It can be picked up from the support sheet.
The lower limit of the adhesive force between the protective film-forming film or the cured product thereof and the support sheet may be 50 mN/25 mm or more. When the adhesive strength is equal to or higher than the lower limit, it is possible to prevent adjacent semiconductor chips from colliding with each other and being damaged when the semiconductor chips are conveyed.

The adhesive layer contains an adhesive.
Examples of the adhesive include adhesive resins such as acrylic resins, urethane resins, rubber resins, silicone resins, epoxy resins, polyvinyl ethers, polycarbonates, and ester resins, with acrylic resins being preferred. .

In this specification, the term "adhesive resin" includes both adhesive resins and adhesive resins. For example, the tacky resin includes not only the resin itself that has tackiness, but also a resin that exhibits tackiness when used in combination with other components such as additives, and a resin that exhibits adhesiveness due to the presence of a trigger such as heat or water. Also included are resins and the like that show

The pressure-sensitive adhesive layer may consist of one layer (single layer) or may consist of two or more layers. The combination of these multiple layers is not particularly limited.

The thickness of the adhesive layer is preferably 1-14 μm, more preferably 2-12 μm, and may be, for example, 3-8 μm. When the thickness of the pressure-sensitive adhesive layer is at least the above lower limit, the effect of providing the pressure-sensitive adhesive layer can be obtained more remarkably. When the thickness of the pressure-sensitive adhesive layer is equal to or less than the above upper limit value, the film for forming a protective film in the composite sheet for forming a protective film or its cured product can be printed more satisfactorily. Then, the print can be better visually recognized through the support sheet from the outside of the protective film-forming composite sheet on the side of the support sheet.
Here, the "thickness of the pressure-sensitive adhesive layer" means the thickness of the entire pressure-sensitive adhesive layer. means the thickness of

The adhesive layer may be formed using an energy ray-curable adhesive, or may be formed using a non-energy ray-curable adhesive. That is, the pressure-sensitive adhesive layer may be either energy ray-curable or non-energy ray-curable. The energy ray-curable pressure-sensitive adhesive layer can easily adjust physical properties before and after curing. For example, by curing the energy ray-curable adhesive layer before picking up a semiconductor chip with a protective film or a semiconductor chip with a film for forming a protective film, which will be described later, these semiconductor chips can be picked up more easily.

As used herein, the term "energy ray" means an electromagnetic wave or charged particle beam that has an energy quantum, and examples thereof include ultraviolet rays, radiation, electron beams, and the like. Ultraviolet rays can be applied by using, for example, a high-pressure mercury lamp, a fusion lamp, a xenon lamp, a black light, an LED lamp, or the like as an ultraviolet light source. The electron beam can be generated by an electron beam accelerator or the like.
Further, in this specification, "energy ray-curable" means the property of curing by irradiation with energy rays, and "non-energy ray-curable" means the property of not curing even when irradiated with energy rays. means

<<Adhesive Composition>>
The adhesive layer can be formed using an adhesive composition containing an adhesive. For example, the pressure-sensitive adhesive layer can be formed on the target site by applying the pressure-sensitive adhesive composition to the surface on which the pressure-sensitive adhesive layer is to be formed, and drying it as necessary. The content ratio of the components that do not vaporize at room temperature in the pressure-sensitive adhesive composition is usually the same as the content ratio of the components in the pressure-sensitive adhesive layer. As used herein, the term "ordinary temperature" means a temperature that is not particularly cooled or heated, that is, a normal temperature.

Coating of the pressure-sensitive adhesive composition may be performed by a known method, for example, air knife coater, blade coater, bar coater, gravure coater, roll coater, roll knife coater, curtain coater, die coater, knife coater, screen coater. , Meyer bar coater, kiss coater and the like.

Drying conditions for the pressure-sensitive adhesive composition are not particularly limited. When the pressure-sensitive adhesive composition contains a solvent, which will be described later, it is preferable to heat and dry it. The solvent-containing pressure-sensitive adhesive composition is preferably dried, for example, at 70 to 130° C. for 10 seconds to 5 minutes.

When a pressure-sensitive adhesive layer is provided on a substrate, for example, the pressure-sensitive adhesive composition may be applied onto the substrate and dried as necessary to laminate the pressure-sensitive adhesive layer on the substrate. Further, in the case of providing an adhesive layer on the substrate, for example, the adhesive composition is coated on the release film and dried as necessary to form an adhesive layer on the release film. Then, the exposed surface of the pressure-sensitive adhesive layer may be laminated on one surface of the base material to laminate the pressure-sensitive adhesive layer on the base material. In this case, the release film may be removed either during the manufacturing process or during the use process of the protective film-forming composite sheet.

When the pressure-sensitive adhesive layer is energy ray-curable, the energy ray-curable pressure-sensitive adhesive composition includes, for example, non-energy ray-curable adhesive resin (I-1a) (hereinafter referred to as “adhesive resin (I- 1a)") and an energy ray-curable compound (I-1); an unsaturated group is introduced into the side chain of the adhesive resin (I-1a). a pressure-sensitive adhesive composition (I-2) containing an energy ray-curable adhesive resin (I-2a) (hereinafter sometimes abbreviated as “adhesive resin (I-2a)”); and a pressure-sensitive adhesive composition (I-3) containing a curable resin (I-2a) and an energy ray-curable compound.

When the pressure-sensitive adhesive layer is non-energy ray-curable, the non-energy ray-curable pressure-sensitive adhesive composition includes, for example, the pressure-sensitive adhesive composition (I-4) containing the pressure-sensitive adhesive resin (I-1a). is mentioned.

[Adhesive resin (I-1a)]
The pressure-sensitive adhesive composition (I-1), the pressure-sensitive adhesive composition (I-2), the pressure-sensitive adhesive composition (I-3) and the pressure-sensitive adhesive composition (I-4) (hereinafter, including these pressure-sensitive adhesive compositions The adhesive resin (I-1a) in the "adhesive compositions (I-1) to (I-4)") is preferably an acrylic resin.

Examples of the acrylic resin include an acrylic polymer having at least a structural unit derived from a (meth)acrylic acid alkyl ester.
Examples of the (meth)acrylic acid alkyl ester include those in which the alkyl group constituting the alkyl ester has 1 to 20 carbon atoms, and the alkyl group is linear or branched. is preferred.

In this specification, "(meth)acrylic acid" is a concept that includes both "acrylic acid" and "methacrylic acid". The same applies to terms similar to (meth) acrylic acid. For example, "(meth) acryloyl group" is a concept that includes both "acryloyl group" and "methacryloyl group", and "(meth) acrylate ” is a concept that includes both “acrylate” and “methacrylate”.

It is preferable that the acrylic polymer further has a structural unit derived from a functional group-containing monomer in addition to the structural unit derived from the (meth)acrylic acid alkyl ester.
As the functional group-containing monomer, for example, the functional group reacts with a cross-linking agent described later to become a starting point for cross-linking, or the functional group reacts with an unsaturated group in the unsaturated group-containing compound described later. and those capable of introducing an unsaturated group into the side chain of the acrylic polymer.

Examples of functional group-containing monomers include hydroxyl group-containing monomers, carboxy group-containing monomers, amino group-containing monomers, and epoxy group-containing monomers.

The acrylic polymer may further have structural units derived from other monomers in addition to structural units derived from (meth)acrylic acid alkyl esters and structural units derived from functional group-containing monomers.
The other monomer is not particularly limited as long as it is copolymerizable with (meth)acrylic acid alkyl ester or the like.
Examples of the other monomers include styrene, α-methylstyrene, vinyltoluene, vinyl formate, vinyl acetate, acrylonitrile and acrylamide.

In the pressure-sensitive adhesive compositions (I-1) to (I-4), the structural units of the acrylic resin such as the acrylic polymer may be only one type, may be two or more types, or may be two or more types. , the combination and ratio thereof can be arbitrarily selected.

In the acrylic polymer, the content of structural units derived from functional group-containing monomers is preferably 1 to 35% by mass with respect to the total amount of structural units.

The pressure-sensitive adhesive resin (I-1a) contained in the pressure-sensitive adhesive composition (I-1) or the pressure-sensitive adhesive composition (I-4) may be one type, two or more types, or two or more types. In that case, their combination and ratio can be arbitrarily selected.

In the adhesive composition (I-1) or adhesive composition (I-4), the adhesive resin (I The content ratio of -1a) is preferably 5 to 99% by mass.

[Adhesive resin (I-2a)]
The adhesive resin (I-2a) in the adhesive compositions (I-2) and (I-3) is, for example, a functional group in the adhesive resin (I-1a), an energy ray polymerizable unsaturated It is obtained by reacting an unsaturated group-containing compound having a group.

The unsaturated group-containing compound is capable of bonding with the adhesive resin (I-1a) by reacting with a functional group in the adhesive resin (I-1a) in addition to the energy ray-polymerizable unsaturated group. It is a compound having a group.
Examples of the energy ray polymerizable unsaturated group include (meth)acryloyl group, vinyl group (ethenyl group), allyl group (2-propenyl group) and the like, and (meth)acryloyl group is preferred.
Groups capable of bonding with functional groups in the adhesive resin (I-1a) include, for example, an isocyanate group and a glycidyl group capable of bonding with a hydroxyl group or an amino group, and a hydroxyl group and an amino group capable of bonding with a carboxy group or an epoxy group. etc.

Examples of the unsaturated group-containing compound include (meth)acryloyloxyethyl isocyanate, (meth)acryloylisocyanate, glycidyl (meth)acrylate, and the like.

The pressure-sensitive adhesive resin (I-2a) contained in the pressure-sensitive adhesive composition (I-2) or (I-3) may be of one type or two or more types. Any combination and ratio can be selected.

In the adhesive composition (I-2) or (I-3), the content ratio of the adhesive resin (I-2a) to the total mass of the adhesive composition (I-2) or (I-3) is preferably 5 to 99% by mass.

[Energy ray-curable compound]
Examples of the energy ray-curable compound in the pressure-sensitive adhesive compositions (I-1) and (I-3) include monomers or oligomers having an energy ray-polymerizable unsaturated group and curable by energy ray irradiation. be done.
As the energy ray-curable compound, in order to reduce the influence of energy ray irradiation on the semiconductor chip, the energy ray cured product and the support sheet are cured even when irradiated with ultraviolet rays under low-illuminance UV irradiation conditions. It is preferable that the compound has an adhesive force between the and less than 370 mN/25 mm. The low illuminance UV irradiation conditions are the conditions described above.

Among energy ray-curable compounds, monomers include, for example, trimethylolpropane tri(meth)acrylate, pentaerythritol (meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,4 -polyvalent (meth)acrylates such as butylene glycol di(meth)acrylate, 1,6-hexanediol (meth)acrylate; urethane (meth)acrylates; polyester (meth)acrylates; polyether (meth)acrylates; meth)acrylate and the like.
Among energy ray-curable compounds, oligomers include, for example, oligomers obtained by polymerizing the above-exemplified monomers.

The energy ray-curable compound contained in the pressure-sensitive adhesive composition (I-1) or (I-3) may be one kind or two or more kinds. Any ratio can be selected.

In the pressure-sensitive adhesive composition (I-1), the content of the energy ray-curable compound is preferably 1 to 95% by mass with respect to the total weight of the pressure-sensitive adhesive composition (I-1).
In the adhesive composition (I-3), the content of the energy ray-curable compound is 0.01 to 300 parts by mass with respect to 100 parts by mass of the adhesive resin (I-2a). is preferred.

[Crosslinking agent]
As the adhesive resin (I-1a), in addition to the structural unit derived from the (meth)acrylic acid alkyl ester, when using the acrylic polymer having a structural unit derived from a functional group-containing monomer, the adhesive composition ( I-1) or (I-4) preferably further contains a cross-linking agent.
Further, as the adhesive resin (I-2a), for example, when using the acrylic polymer having the same structural unit derived from a functional group-containing monomer as in the adhesive resin (I-1a), the adhesive composition The product (I-2) or (I-3) may further contain a cross-linking agent.

The cross-linking agent, for example, reacts with the functional group to cross-link the adhesive resins (I-1a) or the adhesive resins (I-2a).
Examples of cross-linking agents include tolylene diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, isocyanate-based cross-linking agents (cross-linking agents having isocyanate groups) such as adducts of these diisocyanates; epoxy-based cross-linking agents such as ethylene glycol glycidyl ether ( aziridinyl cross-linking agents such as hexa[1-(2-methyl)-aziridinyl]triphosphatriazine (cross-linking agents having an aziridinyl group); metal chelate cross-linking agents such as aluminum chelate (metal cross-linking agents having a chelate structure); isocyanurate-based cross-linking agents (cross-linking agents having an isocyanuric acid skeleton);

The cross-linking agent contained in the pressure-sensitive adhesive composition (I-1), (I-2) or (I-4) may be of only one type, or may be of two or more types. Any combination and ratio can be selected.

In the adhesive composition (I-1) or (I-4), the content of the cross-linking agent is 0.01 to 50 parts by mass with respect to 100 parts by mass of the adhesive resin (I-1a). For example, it may be either 0.01 to 35 parts by mass or 0.01 to 20 parts by mass.
In the adhesive composition (I-2) or (I-3), the content of the cross-linking agent is 0.01 to 50 parts by mass with respect to 100 parts by mass of the adhesive resin (I-2a). For example, it may be any one of 0.01 to 35 parts by mass, 0.01 to 20 parts by mass, and 0.01 to 10 parts by mass.

[Photoinitiator]
Adhesive compositions (I-1), (I-2) and (I-3) (hereinafter, these adhesive compositions are collectively referred to as "adhesive compositions (I-1) to (I-3) ”) may further contain a photopolymerization initiator. The adhesive compositions (I-1) to (I-3) containing a photopolymerization initiator undergo sufficient curing reaction even when irradiated with relatively low-energy energy rays such as ultraviolet rays.

Examples of the photopolymerization initiator include benzoin compounds such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin benzoic acid, benzoin methyl benzoate, and benzoin dimethyl ketal; acetophenone, 2-hydroxy -2-methyl-1-phenyl-propan-1-one, 2,2-dimethoxy-1,2-diphenylethan-1-one, 2-hydroxy-1-(4-(4-(2-hydroxy-2 Acetophenone compounds such as -methylpropionyl)benzyl)phenyl)-2-methylpropan-1-one; bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide Acylphosphine oxide compounds such as; benzylphenyl sulfide, sulfide compounds such as tetramethylthiuram monosulfide; α-ketol compounds such as 1-hydroxycyclohexylphenyl ketone; azo compounds such as azobisisobutyronitrile; compounds; thioxanthone compounds such as thioxanthone; peroxide compounds; diketone compounds such as diacetyl; benzyl; (1-methylvinyl)phenyl]propanone; and quinone compounds such as 1-chloroanthraquinone and 2-chloroanthraquinone.
Moreover, as said photoinitiator, photosensitizers, such as an amine, etc. can also be used, for example.

The photopolymerization initiators contained in the pressure-sensitive adhesive compositions (I-1) to (I-3) may be only one kind, or may be two or more kinds, and when they are two or more kinds, their combination and ratio are Can be selected arbitrarily.

In the adhesive composition (I-1), the content of the photopolymerization initiator is preferably 0.01 to 20 parts by mass with respect to 100 parts by mass of the energy ray-curable compound.
In the adhesive composition (I-2), the content of the photopolymerization initiator is preferably 0.01 to 20 parts by mass with respect to 100 parts by mass of the adhesive resin (I-2a). , for example, 0.01 to 10 parts by mass, and 0.01 to 5 parts by mass.
In the adhesive composition (I-3), the content of the photopolymerization initiator is 0.01 to 0.01 with respect to 100 parts by mass of the total content of the adhesive resin (I-2a) and the energy ray-curable compound. It is preferably 20 parts by mass.

[Other additives]
The pressure-sensitive adhesive compositions (I-1) to (I-4) may contain other additives that do not fall under any of the above components within the range that does not impair the effects of the present invention.
Examples of other additives include antistatic agents, antioxidants, softeners (plasticizers), fillers, rust inhibitors, colorants (pigments, dyes), sensitizers, and tackifiers. , a reaction retardant, a cross-linking accelerator (catalyst), and other known additives.
In addition, the reaction retarder is, for example, the action of a catalyst mixed in the adhesive compositions (I-1) to (I-4) during storage, the pressure-sensitive adhesive compositions (I-1) to ( In I-4), it suppresses the progress of an unintended cross-linking reaction. Examples of the reaction retarder include those that form a chelate complex by chelating the catalyst, more specifically those having two or more carbonyl groups (-C(=O)-) in one molecule. mentioned.

The other additives contained in the pressure-sensitive adhesive compositions (I-1) to (I-4) may be one type or two or more types, and when there are two or more types, their combination and ratio are Can be selected arbitrarily.

The content of other additives in the pressure-sensitive adhesive compositions (I-1) to (I-4) is not particularly limited, and may be appropriately selected according to the type.

[solvent]
The adhesive compositions (I-1) to (I-4) may contain a solvent. Since the pressure-sensitive adhesive compositions (I-1) to (I-4) contain a solvent, the coating suitability to the surface to be coated is improved.
In this specification, unless otherwise specified, the concept of "solvent" includes not only a solvent that dissolves the target component but also a dispersion medium that disperses the target component.

The solvent is preferably an organic solvent, and examples of the organic solvent include ketones such as methyl ethyl ketone and acetone; esters (carboxylic acid esters) such as ethyl acetate; ethers such as tetrahydrofuran and dioxane; cyclohexane, n-hexane, and the like. aromatic hydrocarbons such as toluene and xylene; alcohols such as 1-propanol and 2-propanol.

The solvents contained in the pressure-sensitive adhesive compositions (I-1) to (I-4) may be of one type or two or more types, and when there are two or more types, the combination and ratio thereof may be arbitrarily selected. can.

The solvent content of the pressure-sensitive adhesive compositions (I-1) to (I-4) is not particularly limited, and may be adjusted as appropriate.

<<Method for producing pressure-sensitive adhesive composition>>
Adhesive compositions such as adhesive compositions (I-1) to (I-4) are the adhesive and, if necessary, components other than the adhesive, etc., for constituting the adhesive composition. Obtained by blending each component.
There are no particular restrictions on the order of addition of each component when blending, and two or more components may be added at the same time.
The method of mixing each component at the time of blending is not particularly limited, and may be selected from known methods such as a method of mixing by rotating a stirrer or stirring blade; a method of mixing using a mixer; a method of mixing by applying ultrasonic waves. It can be selected as appropriate.
The temperature and time at which each component is added and mixed are not particularly limited as long as each compounded component does not deteriorate, and may be adjusted as appropriate, but the temperature is preferably 15 to 30°C.

◎ Intermediate layer The intermediate layer is in the form of a sheet or film, and preferably has a light (365 nm) transmittance of 40% or more, for example, any one of 50% or more, 60% or more, and 70% or more. may be

The intermediate layer is arranged between the pressure-sensitive adhesive layer and the protective film-forming film in the protective film-forming composite sheet.
The type of intermediate layer can be arbitrarily selected according to the purpose, and is not particularly limited.

The optical properties of the intermediate layer are preferably such that the support sheet satisfies the transmittance conditions for that light (365 nm) explained above.

The intermediate layer can be formed by a known method depending on its type. For example, an intermediate layer containing a resin as a main component can be formed by molding a resin composition containing the resin.

Examples of the intermediate layer include a peelability improving layer having one surface subjected to a peeling treatment.

O Releasability-improving layer Examples of the releasability-improving layer include a multi-layered layer including a resin layer and a release treatment layer formed on the resin layer.
In the protective film-forming composite sheet, the peelability improving layer is arranged with the release treatment layer facing the protective film-forming film side.

Among the peelability improving layers, the resin layer can be produced by molding a resin composition containing a resin.
The peelability improving layer can be produced by subjecting one surface of the resin layer to a peeling treatment.

The release treatment of the resin layer can be performed using various known release agents such as alkyd-based, silicone-based, fluorine-based, unsaturated polyester-based, polyolefin-based, and wax-based release agents.
The release agent is preferably an alkyd-based, silicone-based, or fluorine-based release agent in that it has heat resistance.

The resin, which is the constituent material of the resin layer, may be appropriately selected depending on the purpose, and is not particularly limited.
Preferred resins include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), polyethylene (PE), polypropylene (PP), and the like.

The resin layer may consist of one layer (single layer), or may consist of a plurality of layers of two or more layers. They may be different, and the combination of these multiple layers is not particularly limited.

The thickness of the peelability improving layer (the total thickness of the resin layer and the peeling treatment layer) is preferably 10 to 2000 nm, more preferably 25 to 1500 nm, and particularly preferably 50 to 1200 nm. . When the thickness of the peelability-improving layer is at least the above lower limit, the effect of the peelability-improving layer becomes more pronounced, and the effect of suppressing breakage such as cutting of the peelability-improving layer becomes higher. When the thickness of the releasability improving layer is equal to or less than the above upper limit, it is possible to more easily pick up a semiconductor chip having a protective film or a film for forming a protective film, which will be described later, on the back surface.

◇Film for forming a protective film The film for forming a protective film of the present embodiment can form a composite sheet for forming a protective film, for example, by being laminated with a support sheet as described later.

The protective film-forming film forms a protective film for protecting any part of the work or the processed work. When the workpiece is a semiconductor wafer, the protective film forming film of the present embodiment can be used to form the surface of the semiconductor wafer and the semiconductor chip opposite to the circuit forming surface (in this specification, in either case, A protective film can be formed on the "back surface"). In this specification, a work piece having a protective film is sometimes referred to as a "work piece with a protective film", and a semiconductor chip having a protective film on its back surface is referred to as a "semiconductor chip with a protective film". sometimes referred to as
The protective film-forming film is soft and can be easily attached to an application target such as a work or a processed work.

The protective film-forming film may function as a protective film when cured, or may function as a protective film in an uncured state. The film for forming a protective film, which functions as a protective film in an uncured state, can be regarded as having formed a protective film, for example, at the stage when it is attached to a target portion of a workpiece.

The protective film-forming film has a transmittance of light (365 nm) of 0.3% or less. Therefore, even when the semiconductor chip is irradiated with ultraviolet rays, it is possible to prevent the semiconductor chip from being destroyed or malfunctioning. In particular, the adhesive is an energy ray-curable adhesive, and even when the adhesive is irradiated with ultraviolet rays for curing, the semiconductor chip is prevented from being destroyed or malfunctioning. can do.
The protective film-forming film and its cured product (that is, the protective film) exhibit approximately the same transmittance with respect to light of the same wavelength.

The transmittance of light (365 nm) of the film for forming a protective film is, for example, 0.3% or less, 0.25% or less, 0.2% or less, 0.15% or less, 0.1% or less, and 0 .05%. When the transmittance of the film for forming a protective film is equal to or less than the upper limit, it is possible to suppress damage or malfunction of the semiconductor chip even when the film is irradiated with ultraviolet rays.

The lower limit of the transmittance of light (365 nm) of the protective film-forming film is not particularly limited, and may be, for example, 0%. For example, a protective film-forming film having a transmittance of 0% or more is easier to manufacture.

The light (365 nm) transmittance of the film for forming a protective film can be appropriately adjusted within a range set by arbitrarily combining the above lower limit and any upper limit. For example, in one embodiment, the transmittance of the protective film-forming film is preferably 0 to 0.3%, for example, 0 to 0.25%, 0 to 0.2%, 0 to 0.3%. It may be either 15%, 0-0.1%, and 0-0.05%. However, these are examples of the transmittance of the protective film-forming film.

As described above, the protective film-forming film may be curable or non-curable.
The curable protective film-forming film may be either thermosetting or energy ray curable, or may have both thermosetting and energy ray curable properties. In order to reduce the risk of energy ray irradiation, it is preferably thermosetting or non-curing.
As used herein, the term "non-curing" means the property of not being cured by any means such as heating or energy ray irradiation.

In the case of forming a protective film by thermosetting the film for forming a protective film, unlike the case of curing by irradiation with energy rays, the film for forming a protective film can be cured by heating even if its thickness increases. Since it cures sufficiently, a protective film with high protective performance can be formed. Moreover, by using a normal heating means such as a heating oven, a large number of protective film-forming films can be collectively heated and thermally cured.
When the film for forming a protective film is cured by irradiation with energy rays to form a protective film, unlike the case of thermosetting, the composite sheet for forming a protective film does not need to have heat resistance, and can be used in a wide range of applications. A composite sheet for forming a protective film can be constructed. Moreover, it can be cured in a short time by irradiation with energy rays.
When the film for forming a protective film is used as a protective film without being cured, the curing step can be omitted, so that a workpiece with a protective film can be manufactured in a simplified process.

Regardless of whether the protective film-forming film is curable or non-curable, and if it is curable, regardless of whether it is thermosetting or energy ray curable, the protective film The forming film may consist of one layer (single layer) or may consist of two or more layers. When the protective film-forming film consists of multiple layers, these multiple layers may be the same or different, and the combination of these multiple layers is not particularly limited.

Regardless of whether the protective film-forming film is curable or non-curable, and if it is curable, regardless of whether it is thermosetting or energy ray curable, the protective film The thickness of the forming film is preferably 1 to 100 μm, more preferably 3 to 80 μm, particularly preferably 5 to 60 μm, for example, 5 to 40 μm or 5 to 20 μm. may be When the thickness of the film for forming a protective film is at least the lower limit, a protective film with higher protective ability can be formed. When the thickness of the film for forming a protective film is equal to or less than the upper limit, excessive thickness can be avoided.
Here, the "thickness of the protective film-forming film" means the thickness of the entire protective film-forming film. means the total thickness of all the layers that make up the

The transmittance of the protective film-forming film for light with a wavelength of 555 nm (hereinafter sometimes abbreviated as “light (555 nm)” in this specification) is preferably 5% or less, more preferably 4% or less. % or less is particularly preferred. When the transmittance of light (555 nm) of the film for forming a protective film is equal to or less than the upper limit, grinding marks on the back surface of the wafer and laser printing for process control are suppressed from being visible, and the design is excellent. , the possibility of poor reading of the laser marking on the surface of the protective film is reduced.

The transmittance of light with a wavelength of 800 nm (hereinafter, sometimes abbreviated as "light (800 nm") in the present specification) of the film for forming a protective film is preferably less than 20%, more preferably less than 17%, and 15% It is particularly preferable that the transmittance of the film for forming a protective film (800 nm) is less than the upper limit, so that grinding marks on the back surface of the wafer and laser marking for process control are more suppressed from being visible, The design is more excellent, and the possibility of causing poor readability of the laser marking on the surface of the protective film is reduced.

<<Composition for Forming Protective Film>>
The protective film-forming film can be formed using a protective film-forming composition containing its constituent materials. For example, the film for forming a protective film can be formed by applying a composition for forming a protective film on the surface to be formed, and drying it as necessary. The content ratio of the components that do not vaporize at room temperature in the protective film-forming composition is usually the same as the content ratio of the components in the protective film-forming film.
The thermosetting protective film-forming film can be formed using the thermosetting protective film-forming composition, and the energy ray-curable protective film-forming film can be formed using the energy ray-curable protective film-forming composition. A non-curable protective film-forming film can be formed using a non-curable protective film-forming composition. In the present specification, when the protective film-forming film has both thermosetting and energy ray-curable properties, the contribution of thermosetting of the protective film-forming film to the formation of the protective film is , the protective film-forming film is treated as a thermosetting film if the contribution is greater than the contribution of the energy beam curing. Conversely, when the contribution of energy ray curing of the protective film-forming film to the formation of the protective film is greater than the contribution of thermal curing, the protective film-forming film is treated as energy ray-curable.

The protective film-forming composition can be applied, for example, by the same method as in the case of applying the pressure-sensitive adhesive composition described above.

Regardless of whether the protective film-forming film is curable or non-curable, and if it is curable, regardless of whether it is thermosetting or energy ray curable, the protective film Drying conditions for the forming composition are not particularly limited. However, when the composition for forming a protective film contains a solvent, which will be described later, it is preferable to heat and dry the composition. The protective film-forming composition containing a solvent is preferably dried by heating, for example, at 70 to 130° C. for 10 seconds to 5 minutes. However, the composition for forming a thermosetting protective film is preferably dried by heating so that the composition itself and the film for forming a thermosetting protective film formed from this composition are not thermally cured.

Hereinafter, the thermosetting protective film-forming film, the energy ray-curable protective film-forming film, and the non-curable protective film-forming film will be described in order.

◎Film for forming a thermosetting protective film The film for forming a thermosetting protective film is attached to the target part of the workpiece and heat-cured to form a protective film. There is no particular limitation as long as the curing degree is such that the function can be exhibited, and an appropriate selection may be made according to the type of the thermosetting protective film-forming film.
For example, the heating temperature during thermosetting of the film for forming a thermosetting protective film is preferably 100 to 200°C, more preferably 110 to 180°C, and particularly preferably 120 to 170°C. . The heating time during thermosetting is preferably 0.5 to 5 hours, more preferably 0.5 to 3 hours, and particularly preferably 1 to 2 hours.

Preferred thermosetting protective film-forming films include, for example, those containing a polymer component (A) and a thermosetting component (B). The polymer component (A) is a component that can be regarded as being formed by a polymerization reaction of a polymerizable compound. The thermosetting component (B) is a component that can undergo a curing (polymerization) reaction with heat as a reaction trigger. In addition, in this specification, a polycondensation reaction is also included in the polymerization reaction.

<Composition for forming a thermosetting protective film (III-1)>
Preferred thermosetting protective film-forming compositions include, for example, the thermosetting protective film-forming composition (III-1) containing the polymer component (A) and the thermosetting component (B) (this specification In the literature, it may be simply abbreviated as "composition (III-1)") and the like.

[Polymer component (A)]
The polymer component (A) is a component for imparting film-forming properties, flexibility, and the like to the thermosetting protective film-forming film.
The polymer component (A) contained in the composition (III-1) and the film for forming a thermosetting protective film may be of one type or two or more types, and when there are two or more types, combinations thereof. and ratio can be selected arbitrarily.

Examples of the polymer component (A) include acrylic resins, polyesters, urethane resins, acrylic urethane resins, silicone resins, rubber resins, phenoxy resins, thermosetting polyimides, etc. Acrylic resins are preferred. .

Examples of the acrylic resin in the polymer component (A) include known acrylic polymers.
The weight average molecular weight (Mw) of the acrylic resin is preferably from 10,000 to 2,000,000, more preferably from 100,000 to 1,500,000. When the weight-average molecular weight of the acrylic resin is at least the lower limit, the shape stability (stability over time during storage) of the film for forming a thermosetting protective film is improved. Further, when the weight average molecular weight of the acrylic resin is equal to or less than the above upper limit, the film for forming a thermosetting protective film can easily follow the uneven surface of the adherend, and the adherend and the thermosetting protective film can be formed. The occurrence of voids and the like between the film and the film for use is further suppressed.
In addition, in this specification, the "weight average molecular weight" is a polystyrene conversion value measured by a gel permeation chromatography (GPC) method, unless otherwise specified.

The glass transition temperature (Tg) of the acrylic resin is preferably -60 to 70°C, more preferably -30 to 50°C. When the Tg of the acrylic resin is equal to or higher than the above lower limit, for example, the adhesive force between the cured product of the protective film-forming film and the support sheet is suppressed, and the releasability of the support sheet is moderately improved. Further, when the Tg of the acrylic resin is equal to or less than the above upper limit, the adhesive strength of the thermosetting protective film-forming film and its cured product to the adherend is improved.

The acrylic resin has m types (m is an integer of 2 or more) of structural units, and for m types of monomers that derive these structural units, any non-overlapping number from 1 to m are sequentially assigned and named as "monomer m", the glass transition temperature (Tg) of the acrylic resin can be calculated using the Fox equation shown below.

（式中、Ｔｇはアクリル系樹脂のガラス転移温度であり；ｍは２以上の整数であり；Ｔｇ_ｋはモノマーｍのホモポリマーのガラス転移温度であり；Ｗ_ｋはアクリル系樹脂における、モノマーｍから誘導された構成単位ｍの質量分率であり、ただし、Ｗ_ｋは下記式を満たす。）

(Wherein, Tg is the glass transition temperature of the acrylic resin; m is an integer of 2 or more; Tg _k is the glass transition temperature of the homopolymer of the monomer m; W _k is the monomer m in the acrylic resin is the mass fraction of the structural unit m derived from, where W _k satisfies the following formula.)

（式中、ｍ及びＷ_ｋは、前記と同じである。）

(Wherein, m and _Wk are the same as above.)

As the Tg _k , values described in the Polymer Data Handbook or Adhesive Handbook can be used. For example, the Tg _k of a homopolymer of methyl acrylate is 10°C, the Tg _k of a homopolymer of methyl methacrylate is 105°C, and the Tg _k of a homopolymer of 2-hydroxyethyl acrylate is -15°C. .

Examples of acrylic resins include polymers of one or more (meth)acrylic acid esters; selected from (meth)acrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene, N-methylolacrylamide, and the like. Examples thereof include copolymers of two or more monomers.

Examples of the (meth)acrylic acid esters constituting the acrylic resin include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, (meth)acrylate, ) n-butyl acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, (meth)acrylic heptyl acid, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, n-octyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate , undecyl (meth)acrylate, dodecyl (meth)acrylate (lauryl (meth)acrylate), tridecyl (meth)acrylate, tetradecyl (meth)acrylate (myristyl (meth)acrylate), (meth)acrylic acid An alkyl group constituting an alkyl ester such as pentadecyl, hexadecyl (meth)acrylate (palmityl (meth)acrylate), heptadecyl (meth)acrylate, octadecyl (meth)acrylate (stearyl (meth)acrylate), A (meth)acrylic acid alkyl ester having a chain structure having 1 to 18 carbon atoms;
Cycloalkyl (meth)acrylates such as isobornyl (meth)acrylate and dicyclopentanyl (meth)acrylate;
(meth)acrylic acid aralkyl ester such as benzyl (meth)acrylate;
(meth)acrylic acid cycloalkenyl esters such as (meth)acrylic acid dicyclopentenyl ester;
(meth)acrylic acid cycloalkenyloxyalkyl ester such as (meth)acrylic acid dicyclopentenyloxyethyl ester;
(meth)acrylic acid imide;
glycidyl group-containing (meth)acrylic acid esters such as glycidyl (meth)acrylate;
Hydroxymethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, (meth) ) hydroxyl group-containing (meth)acrylic acid esters such as 3-hydroxybutyl acrylate and 4-hydroxybutyl (meth)acrylate;
Examples thereof include substituted amino group-containing (meth)acrylic acid esters such as N-methylaminoethyl (meth)acrylate. Here, "substituted amino group" means a group in which one or two hydrogen atoms of an amino group are substituted with groups other than hydrogen atoms.

The acrylic resin is, for example, one or more monomers selected from (meth)acrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene, N-methylolacrylamide, etc., in addition to the (meth)acrylic acid ester. may be copolymerized.

Monomers constituting the acrylic resin may be of one type or two or more types, and in the case of two or more types, the combination and ratio thereof can be arbitrarily selected.

Acrylic resins may have functional groups capable of bonding with other compounds, such as vinyl groups, (meth)acryloyl groups, amino groups, hydroxyl groups, carboxy groups, and isocyanate groups. The functional group of the acrylic resin may be bonded to another compound via a cross-linking agent (F), which will be described later, or may be directly bonded to another compound without the cross-linking agent (F). . By bonding the acrylic resin to other compounds via the functional group, there is a tendency for the reliability of the package obtained using the protective film-forming composite sheet to improve.

In the present invention, as the polymer component (A), a thermoplastic resin other than an acrylic resin (hereinafter sometimes simply referred to as "thermoplastic resin") is used alone without using an acrylic resin. Alternatively, it may be used in combination with an acrylic resin. By using the thermoplastic resin, the peelability of the protective film from the support sheet is improved, and the thermosetting protective film forming film easily follows the uneven surface of the adherend, and the adherend and thermosetting are improved. Occurrence of voids and the like between the film and the film for forming a protective film may be further suppressed.

The weight average molecular weight of the thermoplastic resin is preferably 1,000 to 100,000, more preferably 3,000 to 80,000.

The glass transition temperature (Tg) of the thermoplastic resin is preferably -30 to 150°C, more preferably -20 to 120°C.

Examples of the thermoplastic resin include polyester, polyurethane, phenoxy resin, polybutene, polybutadiene, polystyrene and the like.

The thermoplastic resin contained in the composition (III-1) and the film for forming a thermosetting protective film may be of only one type, or may be of two or more types. can be chosen arbitrarily.

In the composition (III-1), the ratio of the content of the polymer component (A) to the total content of all components other than the solvent (that is, the thermosetting protective film forming film in the thermosetting protective film forming film The ratio of the content of the polymer component (A) to the total mass of the film for film) is preferably 10 to 85% by mass, preferably 15 to 70% by mass, regardless of the type of the polymer component (A). more preferably 20 to 60% by mass, for example, 20 to 45% by mass, and may be either 20 to 35% by mass, 35 to 60% by mass, and 45 to Any of 60 mass % may be sufficient.

The polymer component (A) may also correspond to the thermosetting component (B). In the present invention, when the composition (III-1) contains components corresponding to both the polymer component (A) and the thermosetting component (B), the composition (III-1) is , a polymeric component (A) and a thermosetting component (B).

[Thermosetting component (B)]
The thermosetting component (B) is a component for curing the thermosetting protective film-forming film.
The composition (III-1) and the thermosetting component (B) contained in the film for forming a thermosetting protective film may be of one type or two or more types. Any combination and ratio can be selected.

Examples of the thermosetting component (B) include epoxy thermosetting resins, thermosetting polyimides, polyurethanes, unsaturated polyesters, and silicone resins, with epoxy thermosetting resins being preferred.

(epoxy thermosetting resin)
The epoxy thermosetting resin consists of an epoxy resin (B1) and a thermosetting agent (B2).
The epoxy thermosetting resin contained in the composition (III-1) and the film for forming a thermosetting protective film may be only one type, or may be two or more types, and when there are two or more types, a combination thereof. and ratio can be selected arbitrarily.

・Epoxy resin (B1)
Examples of the epoxy resin (B1) include known ones, such as polyfunctional epoxy resins, biphenyl compounds, bisphenol A diglycidyl ether and hydrogenated products thereof, ortho-cresol novolak epoxy resins, dicyclopentadiene type epoxy resins, Biphenyl-type epoxy resins, bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, phenylene skeleton-type epoxy resins, and other epoxy compounds having a functionality of two or more can be used.

As the epoxy resin (B1), an epoxy resin having an unsaturated hydrocarbon group may be used. Epoxy resins having unsaturated hydrocarbon groups have higher compatibility with acrylic resins than epoxy resins having no unsaturated hydrocarbon groups. Therefore, by using an epoxy resin having an unsaturated hydrocarbon group, the reliability of a workpiece with a protective film obtained by using the composite sheet for forming a protective film is improved.

The epoxy resin having an unsaturated hydrocarbon group includes, for example, a compound obtained by converting a part of the epoxy groups of a polyfunctional epoxy resin into a group having an unsaturated hydrocarbon group. Such a compound can be obtained, for example, by addition reaction of (meth)acrylic acid or a derivative thereof to an epoxy group.
Examples of the epoxy resin having an unsaturated hydrocarbon group include compounds in which a group having an unsaturated hydrocarbon group is directly bonded to an aromatic ring or the like that constitutes the epoxy resin.
Unsaturated hydrocarbon group is a polymerizable unsaturated group, specific examples thereof include ethenyl group (vinyl group), 2-propenyl group (allyl group), (meth) acryloyl group, (meth) An acrylamide group and the like can be mentioned, and an acryloyl group is preferred.

The number average molecular weight of the epoxy resin (B1) is not particularly limited. preferably 300 to 10,000, particularly preferably 300 to 3,000.
The epoxy equivalent of the epoxy resin (B1) is preferably 100-1000 g/eq, more preferably 150-950 g/eq.

The epoxy resin (B1) may be used alone or in combination of two or more. When two or more are used in combination, the combination and ratio thereof can be arbitrarily selected.

・Heat curing agent (B2)
The thermosetting agent (B2) functions as a curing agent for the epoxy resin (B1).
Examples of the thermosetting agent (B2) include compounds having two or more functional groups capable of reacting with epoxy groups in one molecule. Examples of the functional group include a phenolic hydroxyl group, an alcoholic hydroxyl group, an amino group, a carboxyl group, and an anhydrided group of an acid group. is preferably a group, more preferably a phenolic hydroxyl group or an amino group.

Among thermosetting agents (B2), phenol-based curing agents having phenolic hydroxyl groups include, for example, polyfunctional phenolic resins, biphenols, novolac-type phenolic resins, dicyclopentadiene-type phenolic resins, aralkyl-type phenolic resins, and the like. .
Among the thermosetting agents (B2), amine-based curing agents having an amino group include, for example, dicyandiamide.

The thermosetting agent (B2) may have an unsaturated hydrocarbon group.
Examples of the thermosetting agent (B2) having an unsaturated hydrocarbon group include, for example, a compound obtained by substituting a portion of the hydroxyl groups of a phenolic resin with a group having an unsaturated hydrocarbon group, an aromatic ring of the phenolic resin having an unsaturated Examples thereof include compounds in which a group having a saturated hydrocarbon group is directly bonded.
The unsaturated hydrocarbon group in the thermosetting agent (B2) is the same as the unsaturated hydrocarbon group in the above epoxy resin having an unsaturated hydrocarbon group.

When a phenol-based curing agent is used as the heat curing agent (B2), the heat curing agent (B2) should have a high softening point or glass transition temperature in order to improve the peelability of the protective film from the support sheet. preferable.

Of the thermosetting agent (B2), the number average molecular weight of resin components such as polyfunctional phenolic resins, novolac-type phenolic resins, dicyclopentadiene-type phenolic resins, and aralkyl-type phenolic resins is preferably 300 to 30,000. , 400 to 10,000, and particularly preferably 500 to 3,000.
Among the thermosetting agent (B2), the molecular weight of non-resin components such as biphenol and dicyandiamide is not particularly limited, but is preferably 60 to 500, for example.

The thermosetting agent (B2) may be used alone or in combination of two or more. When two or more are used in combination, the combination and ratio thereof can be arbitrarily selected.

In the composition (III-1) and the film for forming a thermosetting protective film, the content of the thermosetting agent (B2) is 0.1 to 100 parts by mass with respect to 100 parts by mass of the epoxy resin (B1). parts, more preferably 0.5 to 50 parts by mass, for example, any one of 0.5 to 25 parts by mass, 0.5 to 10 parts by mass, and 0.5 to 5 parts by mass may be When the content of the thermosetting agent (B2) is at least the lower limit, curing of the film for forming a thermosetting protective film proceeds more easily. When the content of the thermosetting agent (B2) is equal to or less than the upper limit, the moisture absorption rate of the thermosetting protective film-forming film is reduced, and the package obtained using the protective film-forming composite sheet is improved. Better reliability.

In the composition (III-1) and the film for forming a thermosetting protective film, the content of the thermosetting component (B) (for example, the total content of the epoxy resin (B1) and the thermosetting agent (B2)) is It is preferably 5 to 120 parts by mass, more preferably 5 to 80 parts by mass, with respect to 100 parts by mass of the content of the polymer component (A). 5 to 10 parts by mass, or 40 to 80 parts by mass, 50 to 75 parts by mass, or 60 to 75 parts by mass. When the content of the thermosetting component (B) is within such a range, for example, the adhesive force between the cured product of the protective film-forming film and the support sheet is suppressed, and the peelability of the support sheet is improved. do.

[Curing accelerator (C)]
The composition (III-1) and the film for forming a thermosetting protective film may contain a curing accelerator (C). The curing accelerator (C) is a component for adjusting the curing speed of composition (III-1).
Preferred curing accelerators (C) include, for example, tertiary amines such as triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, tris(dimethylaminomethyl)phenol; 2-methylimidazole, 2-phenylimidazole. , 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole (one or more hydrogen atoms other than hydrogen atoms) imidazole substituted with a group); organic phosphines such as tributylphosphine, diphenylphosphine, triphenylphosphine (phosphines in which one or more hydrogen atoms are substituted with an organic group); tetraphenylphosphonium tetraphenylborate, triphenylphosphine Tetraphenylboron salts such as tetraphenylborate and the like are included.

The curing accelerator (C) contained in the composition (III-1) and the film for forming a thermosetting protective film may be only one type, or may be two or more types, and when there are two or more types, combinations thereof and ratio can be selected arbitrarily.

When the curing accelerator (C) is used, the content of the curing accelerator (C) in the composition (III-1) and the film for forming a thermosetting protective film is equal to the content of the thermosetting component (B) of 100 It is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 7 parts by mass. When the content of the curing accelerator (C) is at least the lower limit, the effect of using the curing accelerator (C) can be obtained more remarkably. When the content of the curing accelerator (C) is equal to or less than the upper limit, for example, the highly polar curing accelerator (C) is coated in the thermosetting protective film-forming film under high temperature and high humidity conditions. The effect of suppressing segregation by moving to the adhesive interface side with the adherend is enhanced. As a result, the reliability of the work piece with a protective film obtained using the composite sheet for forming a protective film is further improved.

[Filler (D)]
The composition (III-1) and the film for forming a thermosetting protective film may contain a filler (D). When the thermosetting protective film-forming film contains the filler (D), the thermal expansion coefficient of the thermosetting protective film-forming film and its cured product (that is, the protective film) can be easily adjusted. By optimizing the coefficient of expansion with respect to the object on which the protective film is to be formed, the reliability of the protective film-attached workpiece obtained using the protective film-forming composite sheet is further improved. In addition, by including the filler (D) in the thermosetting protective film-forming film, the moisture absorption rate of the protective film can be reduced and the heat dissipation can be improved.

The filler (D) may be either an organic filler or an inorganic filler, but is preferably an inorganic filler.
Preferable inorganic fillers include, for example, powders of silica, alumina, talc, calcium carbonate, titanium white, iron oxide, silicon carbide, boron nitride; beads obtained by spheroidizing these inorganic fillers; and surface modification of these inorganic fillers. products; single crystal fibers of these inorganic fillers; glass fibers and the like.
Among these, the inorganic filler is preferably silica or alumina, more preferably silica.

The filler (D) contained in the composition (III-1) and the film for forming a thermosetting protective film may be only one kind, or may be two or more kinds. Any ratio can be selected.

In the composition (III-1), the ratio of the content of the filler (D) to the total content of all components other than the solvent (i.e., the thermosetting protective film-forming film in the thermosetting protective film-forming film The ratio of the content of the filler (D) to the total mass of the film for film) is preferably 15 to 70% by mass, more preferably 30 to 60% by mass, for example, 35 to 60% by mass. , 40 to 60% by mass, and 45 to 60% by mass, or 30 to 55% by mass, 30 to 50% by mass, and 30 to 45% by mass. When the ratio is within such a range, it becomes easier to adjust the coefficient of thermal expansion of the thermosetting protective film-forming film and its cured product.

[Coupling agent (E)]
The composition (III-1) and the film for forming a thermosetting protective film may contain a coupling agent (E). By using a coupling agent (E) having a functional group capable of reacting with an inorganic compound or an organic compound, the adhesiveness and adhesion of the thermosetting protective film-forming film to the adherend can be improved. can. Moreover, by using the coupling agent (E), the cured product of the film for forming a thermosetting protective film has improved water resistance without impairing its heat resistance.

The coupling agent (E) is preferably a compound having a functional group capable of reacting with the functional group of the polymer component (A), thermosetting component (B), etc., and is preferably a silane coupling agent. more preferred.
Preferred silane coupling agents include, for example, 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropylmethyldiethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-glycidyloxymethyldiethoxysilane, 2- (3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-(2-aminoethylamino)propyltrimethoxysilane, 3-(2-amino Ethylamino)propylmethyldiethoxysilane, 3-(phenylamino)propyltrimethoxysilane, 3-anilinopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyl dimethoxysilane, bis(3-triethoxysilylpropyl)tetrasulfane, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, imidazolesilane and the like.

The composition (III-1) and the coupling agent (E) contained in the film for forming a thermosetting protective film may be only one kind, or may be two or more kinds, and when there are two or more kinds, combinations thereof and ratio can be selected arbitrarily.

When the coupling agent (E) is used, the content of the coupling agent (E) in the composition (III-1) and the film for forming a thermosetting protective film is the polymer component (A) and the thermosetting component With respect to 100 parts by mass of the total content of (B), it is preferably 0.03 to 10 parts by mass, more preferably 0.05 to 5 parts by mass, and 0.1 to 2 parts by mass. is particularly preferred. When the content of the coupling agent (E) is at least the lower limit, the dispersibility of the filler (D) in the resin is improved and the adhesion of the thermosetting protective film forming film to the adherend is improved. The effects of using the coupling agent (E), such as improved properties, can be obtained more remarkably. Moreover, generation|occurrence|production of outgassing is suppressed more because the said content of a coupling agent (E) is below the said upper limit.

[Crosslinking agent (F)]
As the polymer component (A), those having a functional group such as a vinyl group, (meth)acryloyl group, amino group, hydroxyl group, carboxyl group, isocyanate group, etc., capable of bonding with other compounds, such as the acrylic resins described above. When used, the composition (III-1) and the thermosetting protective film-forming film may contain a cross-linking agent (F). The cross-linking agent (F) is a component for cross-linking by binding the functional groups in the polymer component (A) to other compounds. The initial adhesive strength and cohesive strength of the can be adjusted.

Examples of the cross-linking agent (F) include an organic polyvalent isocyanate compound, an organic polyvalent imine compound, a metal chelate cross-linking agent (a cross-linking agent having a metal chelate structure), an aziridine cross-linking agent (a cross-linking agent having an aziridinyl group), and the like. is mentioned.

The cross-linking agent (F) contained in the composition (III-1) and the film for forming a thermosetting protective film may be only one type, or may be two or more types. Any ratio can be selected.

When the cross-linking agent (F) is used, the content of the cross-linking agent (F) in the composition (III-1) is 0.01 to 20 parts by mass with respect to 100 parts by mass of the polymer component (A). parts, more preferably 0.1 to 10 parts by mass, and particularly preferably 0.5 to 5 parts by mass. When the content of the cross-linking agent (F) is at least the lower limit, the effect of using the cross-linking agent (F) can be obtained more remarkably. Moreover, excessive use of a crosslinking agent (F) is suppressed because the said content of a crosslinking agent (F) is below the said upper limit.

[Energy ray-curable resin (G)]
The composition (III-1) and the thermosetting protective film-forming film may contain an energy ray-curable resin (G). Since the thermosetting protective film-forming film contains the energy ray-curable resin (G), the properties thereof can be changed by irradiation with energy rays.

The energy ray-curable resin (G) is obtained by polymerizing (curing) an energy ray-curable compound.
Examples of the energy ray-curable compound include compounds having at least one polymerizable double bond in the molecule, and acrylate compounds having a (meth)acryloyl group are preferred.

Examples of the acrylate compounds include trimethylolpropane tri(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol monohydroxypenta ( Chain aliphatic skeleton-containing (meth)acrylates such as meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,4-butylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate; Cycloaliphatic skeleton-containing (meth)acrylates such as cyclopentanyl di(meth)acrylate; polyalkylene glycol (meth)acrylates such as polyethylene glycol di(meth)acrylate; oligoester (meth)acrylates; urethane (meth)acrylate oligomers epoxy-modified (meth)acrylates; polyether (meth)acrylates other than the polyalkylene glycol (meth)acrylates; and itaconic acid oligomers.

The energy ray-curable compound preferably has a weight average molecular weight of 100 to 30,000, more preferably 300 to 10,000.

The energy ray-curable compounds used for polymerization may be of one type or two or more types, and when two or more types are used, their combination and ratio can be arbitrarily selected.

The composition (III-1) and the energy ray-curable resin (G) contained in the film for forming a thermosetting protective film may be of only one type, or may be of two or more types. can be selected arbitrarily.

When the energy ray-curable resin (G) is used, in the composition (III-1), the content ratio of the energy ray-curable resin (G) to the total mass of the composition (III-1) is 1 to It is preferably 95% by mass, more preferably 5 to 90% by mass, and particularly preferably 10 to 85% by mass.

[Photoinitiator (H)]
When the composition (III-1) and the film for forming a thermosetting protective film contain the energy ray-curable resin (G), light is used to efficiently promote the polymerization reaction of the energy ray-curable resin (G). A polymerization initiator (H) may be contained.

Examples of the photopolymerization initiator (H) in the composition (III-1) include the same photopolymerization initiators that may be contained in the pressure-sensitive adhesive composition described above.

The photopolymerization initiator (H) contained in the composition (III-1) and the film for forming a thermosetting protective film may be only one kind, or may be two or more kinds. Any combination and ratio can be selected.

When the photopolymerization initiator (H) is used, the content of the photopolymerization initiator (H) in the composition (III-1) is It is preferably 0.1 to 20 parts by mass, more preferably 1 to 10 parts by mass, and particularly preferably 2 to 5 parts by mass.

[Colorant (I)]
The composition (III-1) and the film for forming a thermosetting protective film preferably contain the coloring agent (I). By using the coloring agent (I), a protective film-forming film having a light (365 nm) transmittance of 0.3% or less can be more easily produced.

Examples of the coloring agent (I) include known ones such as inorganic pigments, organic pigments, and organic dyes.

Examples of the organic pigments and organic dyes include aminium dyes, cyanine dyes, merocyanine dyes, croconium dyes, squalium dyes, azulenium dyes, polymethine dyes, naphthoquinone dyes, pyrylium dyes, and phthalocyanines. dyes, naphthalocyanine dyes, naphtholactam dyes, azo dyes, condensed azo dyes, indigo dyes, perinone dyes, perylene dyes, dioxazine dyes, quinacridone dyes, isoindolinone dyes, quinophthalone dyes , pyrrole dyes, thioindigo dyes, metal complex dyes (metal complex dyes), dithiol metal complex dyes, indolephenol dyes, triallylmethane dyes, anthraquinone dyes, dioxazine dyes, naphthol dyes, azomethine dyes dyes, benzimidazolone dyes, pyranthrone dyes, threne dyes, and the like;

Examples of the inorganic pigments include carbon black, cobalt-based pigments, iron-based pigments, chromium-based pigments, titanium-based pigments, vanadium-based pigments, zirconium-based pigments, molybdenum-based pigments, ruthenium-based pigments, platinum-based pigments, ITO ( indium tin oxide) dyes, ATO (antimony tin oxide) dyes, and the like.

The composition (III-1) and the colorant (I) contained in the thermosetting protective film-forming film may be of one type or two or more types. Any ratio can be selected.

When the colorant (I) is used, the content of the colorant (I) in the thermosetting protective film-forming film may be appropriately adjusted according to the purpose. For example, by adjusting the content of the coloring agent (I) in the thermosetting protective film-forming film, the light (365 nm), light (555 nm) and light (800 nm) transmittances of the thermosetting protective film-forming film are adjusted. By adjusting, it is possible to adjust the ultraviolet shielding property and the print visibility when laser printing is performed on the film for forming a thermosetting protective film or a cured product thereof. In addition, by adjusting the content of the coloring agent (I) in the film for forming a thermosetting protective film, the design of the protective film can be improved, and grinding marks on the back surface of the semiconductor wafer and laser marking for process control can be removed. It can also be made invisible. Considering these points, in the composition (III-1), the ratio of the content of the colorant (I) to the total content of all components other than the solvent (i.e., in the thermosetting protective film-forming film , the ratio of the content of the colorant (I) to the total mass of the film for forming a thermosetting protective film) is preferably 1.0 to 12% by mass, and 1.0 to 9% by mass. is more preferable, and 1.0 to 7% by mass is particularly preferable. When the ratio is equal to or higher than the lower limit, the effect of using the coloring agent (I) can be obtained more remarkably. Moreover, excessive use of the coloring agent (I) is suppressed because the ratio is equal to or less than the upper limit.

[General purpose additive (J)]
The composition (III-1) and the film for forming a thermosetting protective film may contain a general-purpose additive (J) within a range that does not impair the effects of the present invention.
The general-purpose additive (J) may be a known one, can be arbitrarily selected according to the purpose, and is not particularly limited, but preferable examples include plasticizers, antistatic agents, antioxidants, gettering agents, An ultraviolet absorber etc. are mentioned.

The composition (III-1) and the general-purpose additive (J) contained in the thermosetting protective film-forming film may be only one kind, or may be two or more kinds, and when there are two or more kinds, combinations thereof and ratio can be selected arbitrarily.
The content of the general-purpose additive (J) in the composition (III-1) and thermosetting protective film-forming film is not particularly limited, and may be appropriately selected according to the purpose.

[solvent]
Composition (III-1) preferably further contains a solvent. The composition (III-1) containing a solvent is easy to handle.
Although the solvent is not particularly limited, preferred examples include hydrocarbons such as toluene and xylene; alcohols such as methanol, ethanol, 2-propanol, isobutyl alcohol (2-methylpropan-1-ol), and 1-butanol. esters such as ethyl acetate; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran; amides (compounds having an amide bond) such as dimethylformamide and N-methylpyrrolidone;
Composition (III-1) may contain only one kind of solvent, or two or more kinds of solvents.

Preferred examples of the solvent contained in the composition (III-1) include methyl ethyl ketone, toluene, and ethyl acetate, since the components contained in the composition (III-1) can be more uniformly mixed. be done.

The content of the solvent in composition (III-1) is not particularly limited, and may be appropriately selected according to the type of components other than the solvent, for example.

<Method for producing composition for forming thermosetting protective film>
A composition for forming a thermosetting protective film such as composition (III-1) is obtained by blending each component for constituting the composition.
The composition for forming a thermosetting protective film can be produced in the same manner as the pressure-sensitive adhesive composition described above, except that, for example, the types of ingredients are different.

◎Film for forming energy ray-curable protective film The curing conditions for forming the protective film by applying the energy ray-curable protective film to the target location of the workpiece and curing with the energy ray are as follows: The degree of curing is not particularly limited as long as the degree of curing is sufficient to sufficiently exhibit its function, and it may be appropriately selected according to the type of the film for forming an energy ray-curable protective film. In order to reduce the risk of malfunction, it is preferable that the illuminance and amount of light are low during energy beam curing.
For example, the illuminance of the energy ray may be 120 to 280 mW/cm ² or may be lower when the energy ray-curable protective film-forming film is cured with the energy ray. The light quantity of the energy beam during the curing may be 100 to 1000 mJ/cm ² or may be lower.

Examples of the energy ray-curable protective film-forming film include those containing the energy ray-curable component (a), and those containing the energy ray-curable component (a) and a filler are preferred.
In the energy ray-curable protective film-forming film, the energy ray-curable component (a) is preferably uncured, preferably adhesive, and more preferably uncured and adhesive.

<Composition for forming energy ray-curable protective film (IV-1)>
Preferred energy ray-curable protective film-forming compositions include, for example, the energy ray-curable protective film-forming composition (IV-1) containing the energy ray-curable component (a) (in the present specification, may be simply abbreviated as “composition (IV-1)”) and the like.

[Energy ray-curable component (a)]
The energy ray-curable component (a) is a component that is cured by irradiation with energy rays, and imparts film-forming properties, flexibility, etc. to the film for forming an energy ray-curable protective film, and provides hard protection after curing. It is also a component for forming a film.
Examples of the energy ray-curable component (a) include a polymer (a1) having an energy ray-curable group and having a weight average molecular weight of 80,000 to 2,000,000, and a polymer (a1) having an energy ray-curable group and having a molecular weight of 100 to 80,000. A compound (a2) can be mentioned. At least a part of the polymer (a1) may be crosslinked with a crosslinking agent, or may not be crosslinked.

(Polymer (a1) having an energy ray-curable group and having a weight average molecular weight of 80,000 to 2,000,000)
Examples of the polymer (a1) having an energy ray-curable group and having a weight average molecular weight of 80,000 to 2,000,000 include an acrylic polymer (a11) having a functional group capable of reacting with a group possessed by another compound, and An acrylic resin (a1-1) obtained by reacting a functional group-reactive group and an energy ray-curable compound (a12) having an energy ray-curable group such as an energy ray-curable double bond. .

Examples of the functional group capable of reacting with a group possessed by another compound include a hydroxyl group, a carboxyl group, an amino group, and a substituted amino group (one or two hydrogen atoms of the amino group are substituted with a group other than a hydrogen atom). groups), epoxy groups, and the like. However, the functional group is preferably a group other than the carboxyl group from the viewpoint of preventing corrosion of circuits such as workpieces and processed workpieces.
Among these, the functional group is preferably a hydroxyl group.

- Acrylic polymer having a functional group (a11)
Examples of the acrylic polymer (a11) having the functional group include those obtained by copolymerizing an acrylic monomer having the functional group and an acrylic monomer having no functional group. In addition to the monomers, monomers other than acrylic monomers (non-acrylic monomers) may be copolymerized.
Further, the acrylic polymer (a11) may be a random copolymer or a block copolymer, and a known polymerization method may be employed.

Examples of acrylic monomers having functional groups include hydroxyl group-containing monomers, carboxy group-containing monomers, amino group-containing monomers, substituted amino group-containing monomers, and epoxy group-containing monomers.

Examples of the hydroxyl group-containing monomer include hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, (meth) Hydroxyalkyl (meth)acrylates such as 2-hydroxybutyl acrylate, 3-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate; Saturated alcohol (unsaturated alcohol having no (meth)acryloyl skeleton) and the like can be mentioned.

Examples of the carboxy group-containing monomer include ethylenically unsaturated monocarboxylic acids (monocarboxylic acids having an ethylenically unsaturated bond) such as (meth)acrylic acid and crotonic acid; fumaric acid, itaconic acid, maleic acid, citracone; ethylenically unsaturated dicarboxylic acids (dicarboxylic acids having an ethylenically unsaturated bond) such as acids; anhydrides of the ethylenically unsaturated dicarboxylic acids; (meth)acrylic acid carboxyalkyl esters such as 2-carboxyethyl methacrylate; be done.

The acrylic monomer having the functional group is preferably a hydroxyl group-containing monomer.

The acrylic monomer having a functional group, which constitutes the acrylic polymer (a11), may be of only one type, or may be of two or more types. You can choose.

Examples of acrylic monomers having no functional group include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, and n (meth) acrylate. -butyl, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, ( 2-ethylhexyl meth)acrylate, isooctyl (meth)acrylate, n-octyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, (meth)acrylate Undecyl acrylate, dodecyl (meth) acrylate (lauryl (meth) acrylate), tridecyl (meth) acrylate, tetradecyl (meth) acrylate (myristyl (meth) acrylate), pentadecyl (meth) acrylate, (meth) ) The alkyl group constituting the alkyl ester, such as hexadecyl acrylate (palmityl (meth) acrylate), heptadecyl (meth) acrylate, octadecyl (meth) acrylate (stearyl (meth) acrylate), has 1 carbon atom A (meth)acrylic acid alkyl ester having a chain structure of 1 to 18 and the like can be mentioned.

Examples of acrylic monomers having no functional group include alkoxy groups such as methoxymethyl (meth)acrylate, methoxyethyl (meth)acrylate, ethoxymethyl (meth)acrylate, and ethoxyethyl (meth)acrylate. Alkyl group-containing (meth)acrylic acid esters; (meth)acrylic acid esters having an aromatic group, including (meth)acrylic acid aryl esters such as phenyl (meth)acrylate; non-crosslinkable (meth)acrylamides and Derivatives thereof; (meth)acrylic acid esters having a non-crosslinkable tertiary amino group such as N,N-dimethylaminoethyl (meth)acrylate and N,N-dimethylaminopropyl (meth)acrylate; .

The acrylic monomer having no functional group, which constitutes the acrylic polymer (a11), may be only one kind, or may be two or more kinds, and when there are two or more kinds, the combination and ratio thereof are arbitrary. can be selected to

Examples of the non-acrylic monomers include olefins such as ethylene and norbornene; vinyl acetate; and styrene.
The non-acrylic monomers constituting the acrylic polymer (a11) may be of one type or two or more types, and when there are two or more types, the combination and ratio thereof can be arbitrarily selected.

In the acrylic polymer (a11), the ratio (content) of the amount of the structural units derived from the acrylic monomer having the functional group to the total amount of the structural units constituting the acrylic polymer (a11) is 0.1 to 50 mass. %, more preferably 1 to 40% by mass, particularly preferably 3 to 30% by mass. When the ratio is within such a range, the acrylic resin (a1-1) obtained by copolymerization of the acrylic polymer (a11) and the energy ray-curable compound (a12) has energy The content of the radiation-curable group makes it possible to easily adjust the degree of curing of the protective film within a preferred range.

The acrylic polymer (a11) constituting the acrylic resin (a1-1) may be of only one type, or may be of two or more types. You can choose.

In the composition (IV-1), the ratio of the content of the acrylic resin (a1-1) to the total content of the components other than the solvent (that is, the total amount of the film in the energy ray-curable protective film-forming film The ratio of the content of the acrylic resin (a1-1) to the mass) is preferably 1 to 70% by mass, more preferably 5 to 60% by mass, and 10 to 50% by mass. is particularly preferred.

- Energy ray-curable compound (a12)
In the energy ray-curable compound (a12), one or two selected from the group consisting of an isocyanate group, an epoxy group and a carboxy group as a group capable of reacting with a functional group possessed by the acrylic polymer (a11). Those having the above are preferable, and those having an isocyanate group as the group are more preferable. For example, when the energy ray-curable compound (a12) has an isocyanate group as the group, the isocyanate group readily reacts with the hydroxyl group of the acrylic polymer (a11) having the hydroxyl group as the functional group.

The number of energy ray-curable groups in one molecule of the energy ray-curable compound (a12) is not particularly limited. can be selected as appropriate.
For example, the energy ray-curable compound (a12) preferably has 1 to 5, more preferably 1 to 3, energy ray-curable groups in one molecule.

Examples of the energy ray-curable compound (a12) include 2-methacryloyloxyethyl isocyanate, meta-isopropenyl-α,α-dimethylbenzyl isocyanate, methacryloyl isocyanate, allyl isocyanate, 1,1-(bisacryloyloxymethyl) ethyl isocyanate;
An acryloyl monoisocyanate compound obtained by reacting a diisocyanate compound or polyisocyanate compound with hydroxyethyl (meth)acrylate;
An acryloyl monoisocyanate compound obtained by reacting a diisocyanate compound or polyisocyanate compound, a polyol compound, and hydroxyethyl (meth)acrylate, and the like.
Among these, the energy ray-curable compound (a12) is preferably 2-methacryloyloxyethyl isocyanate.

The energy ray-curable compound (a12) constituting the acrylic resin (a1-1) may be of only one type, or may be of two or more types. can be selected to

In the acrylic resin (a1-1), the content of energy ray-curable groups derived from the energy ray-curable compound (a12) with respect to the content of the functional groups derived from the acrylic polymer (a11). is preferably 20 to 120 mol %, more preferably 35 to 100 mol %, particularly preferably 50 to 100 mol %. When the ratio of the content is within such a range, the adhesive strength of the cured product of the energy ray-curable protective film-forming film is further increased. When the energy ray-curable compound (a12) is a monofunctional compound (having one group per molecule), the upper limit of the content ratio is 100 mol%. When the energy ray-curable compound (a12) is a polyfunctional compound (having two or more of the above groups in one molecule), the upper limit of the content ratio may exceed 100 mol %.

The weight average molecular weight (Mw) of the polymer (a1) is preferably from 100,000 to 2,000,000, more preferably from 300,000 to 1,500,000.
Here, the "weight average molecular weight" is as described above.

When the polymer (a1) is at least partially crosslinked by a crosslinking agent, the polymer (a1) is the acrylic polymer (a11) described above as constituting the acrylic polymer (a11). A monomer that does not fall under any of the monomers and has a group that reacts with a cross-linking agent may be polymerized and cross-linked at the group that reacts with the cross-linking agent, or the energy ray-curable compound ( A group derived from a12) that reacts with the functional group may be crosslinked.

The polymer (a1) contained in the composition (IV-1) and the energy ray-curable protective film-forming film may be one kind or two or more kinds. Any combination and ratio can be selected.

(Compound (a2) having an energy ray-curable group and having a molecular weight of 100 to 80,000)
Examples of the energy ray-curable group in the compound (a2) having an energy ray-curable group and having a molecular weight of 100 to 80000 include groups containing an energy ray-curable double bond, and preferred examples include (meth ) acryloyl group, vinyl group and the like.

The compound (a2) is not particularly limited as long as it satisfies the above conditions, but it is a low molecular weight compound having an energy ray-curable group, an epoxy resin having an energy ray-curable group, and an energy ray-curable group. A phenol resin etc. are mentioned.

Among the compounds (a2), low-molecular-weight compounds having an energy ray-curable group include, for example, polyfunctional monomers or oligomers, and acrylate compounds having a (meth)acryloyl group are preferred.
Examples of the acrylate compounds include 2-hydroxy-3-(meth)acryloyloxypropyl methacrylate, polyethylene glycol di(meth)acrylate, propoxylated ethoxylated bisphenol A di(meth)acrylate, 2,2-bis[4 -((meth)acryloxypolyethoxy)phenyl]propane, ethoxylated bisphenol A di(meth)acrylate, 2,2-bis[4-((meth)acryloxydiethoxy)phenyl]propane, 9,9-bis [4-(2-(meth)acryloyloxyethoxy)phenyl]fluorene, 2,2-bis[4-((meth)acryloxypolypropoxy)phenyl]propane, tricyclodecanedimethanol di(meth)acrylate, 1 , 10-decanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate ) acrylate, polypropylene glycol di(meth)acrylate, polytetramethylene glycol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, 2,2-bis [4-((meth)acryloxyethoxy)phenyl]propane, neopentyl glycol di(meth)acrylate, ethoxylated polypropylene glycol di(meth)acrylate, 2-hydroxy-1,3-di(meth)acryloxypropane, etc. a bifunctional (meth)acrylate of;
tris(2-(meth)acryloxyethyl)isocyanurate, ε-caprolactone-modified tris-(2-(meth)acryloxyethyl)isocyanurate, ethoxylated glycerin tri(meth)acrylate, pentaerythritol tri(meth)acrylate, Trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, ethoxylated pentaerythritol tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol poly(meth)acrylate, dipentaerythritol hexa( Multifunctional (meth)acrylates such as meth)acrylates;
Examples include polyfunctional (meth)acrylate oligomers such as urethane (meth)acrylate oligomers.

Among the compounds (a2), the epoxy resin having an energy ray-curable group and the phenolic resin having an energy ray-curable group are described, for example, in paragraph 0043 of "JP-A-2013-194102". can use things. Such a resin also corresponds to a resin constituting a thermosetting component to be described later, but in the present invention it is treated as the compound (a2).

The weight average molecular weight of the compound (a2) is preferably 100-30,000, more preferably 300-10,000.

The compound (a2) contained in the composition (IV-1) and the energy ray-curable protective film-forming film may be one type or two or more types, and when there are two or more types, a combination thereof. and ratio can be selected arbitrarily.

[Polymer (b) having no energy ray-curable group]
When the composition (IV-1) and the energy ray-curable protective film forming film contain the compound (a2) as the energy ray-curable component (a), the composition (IV-1) further contains a polymer having no energy ray-curable group. (b) is also preferably contained.
At least a part of the polymer (b) may be crosslinked with a crosslinking agent, or may not be crosslinked.

Examples of the polymer (b) having no energy ray-curable group include acrylic polymers, phenoxy resins, urethane resins, polyesters, rubber resins, and acrylic urethane resins.
Among these, the polymer (b) is preferably an acrylic polymer (hereinafter sometimes abbreviated as "acrylic polymer (b-1)").

The acrylic polymer (b-1) may be a known one, and may be, for example, a homopolymer of one acrylic monomer or a copolymer of two or more acrylic monomers. Alternatively, it may be a copolymer of one or more acrylic monomers and one or more monomers other than acrylic monomers (non-acrylic monomers).

Examples of the acrylic monomer constituting the acrylic polymer (b-1) include (meth)acrylic acid alkyl esters, (meth)acrylic acid esters having a cyclic skeleton, glycidyl group-containing (meth)acrylic acid esters, Examples include hydroxyl group-containing (meth)acrylic acid esters and substituted amino group-containing (meth)acrylic acid esters. Here, the "substituted amino group" is as described above.

As the (meth)acrylic acid alkyl ester, for example, the acrylic monomer having no functional group (alkyl group constituting the alkyl ester) constituting the acrylic polymer (a11) described above has a carbon number of is a chain structure of 1 to 18, (meth)acrylic acid alkyl ester, etc.).

Examples of (meth)acrylic acid esters having a cyclic skeleton include (meth)acrylic acid cycloalkyl esters such as isobornyl (meth)acrylate and dicyclopentanyl (meth)acrylate;
(meth)acrylic acid aralkyl ester such as benzyl (meth)acrylate;
(meth)acrylic acid cycloalkenyl esters such as (meth)acrylic acid dicyclopentenyl ester;
(Meth)acrylic acid cycloalkenyloxyalkyl esters such as (meth)acrylic acid dicyclopentenyloxyethyl ester and the like.

Examples of the glycidyl group-containing (meth)acrylic acid ester include glycidyl (meth)acrylate.
Examples of the hydroxyl group-containing (meth)acrylic acid ester include hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 3-hydroxy (meth)acrylate. propyl, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate and the like.
Examples of the substituted amino group-containing (meth)acrylic acid ester include N-methylaminoethyl (meth)acrylate.

Examples of the non-acrylic monomers constituting the acrylic polymer (b-1) include olefins such as ethylene and norbornene; vinyl acetate; and styrene.

As the polymer (b) having no energy ray-curable group, at least a part of which is crosslinked by a crosslinking agent, for example, a reactive functional group in the polymer (b) reacted with a crosslinking agent. mentioned.
The reactive functional group may be appropriately selected according to the type of cross-linking agent, and is not particularly limited. For example, when the cross-linking agent is a polyisocyanate compound, the reactive functional group includes a hydroxyl group, a carboxyl group, an amino group, etc. Among these, a hydroxyl group having high reactivity with the isocyanate group is preferable. When the cross-linking agent is an epoxy-based compound, examples of the reactive functional group include a carboxy group, an amino group, an amide group, etc. Among these, a carboxy group having high reactivity with the epoxy group is preferable. . However, the reactive functional group is preferably a group other than the carboxyl group from the viewpoint of preventing corrosion of the circuit of the work or the processed work.

Examples of the polymer (b) having a reactive functional group and not having an energy ray-curable group include those obtained by polymerizing a monomer having at least the reactive functional group. In the case of the acrylic polymer (b-1), one or both of the acrylic monomer and the non-acrylic monomer exemplified as monomers constituting the acrylic polymer (b-1) has the reactive functional group. You can use it. Examples of the polymer (b) having a hydroxyl group as a reactive functional group include those obtained by polymerizing a hydroxyl group-containing (meth)acrylic acid ester. Examples thereof include those obtained by polymerizing a monomer in which one or more hydrogen atoms are substituted with the reactive functional groups in the acrylic monomers or non-acrylic monomers.

In the polymer (b) having a reactive functional group, the ratio (content) of the amount of structural units derived from a monomer having a reactive functional group to the total amount of structural units constituting the polymer (b) is 1 to 20. % by mass is preferable, and 2 to 10% by mass is more preferable. When the ratio is within such a range, the degree of cross-linking in the polymer (b) is in a more preferable range.

The weight-average molecular weight (Mw) of the polymer (b) having no energy ray-curable group is preferably 10,000 to 2,000,000 from the viewpoint of better film-forming properties of the composition (IV-1). It is more preferably 100,000 to 1,500,000. Here, the "weight average molecular weight" is as described above.

The polymer (b) having no energy ray-curable group contained in the composition (IV-1) and the film for forming an energy ray-curable protective film may be of one type or two or more types. When there are more than one species, their combination and ratio can be arbitrarily selected.

Examples of the composition (IV-1) include those containing either one or both of the polymer (a1) and the compound (a2). When the composition (IV-1) contains the compound (a2), it preferably further contains a polymer (b) having no energy ray-curable group. It is also preferred to contain Further, the composition (IV-1) may contain both the polymer (a1) and the polymer (b) having no energy ray-curable group without containing the compound (a2). .

When the composition (IV-1) contains the polymer (a1), the compound (a2), and the polymer (b) having no energy ray-curable group, in the composition (IV-1), the The content of the compound (a2) is preferably 10 to 400 parts by mass with respect to 100 parts by mass of the total content of the polymer (a1) and the polymer (b) having no energy ray-curable group. , and more preferably 30 to 350 parts by mass.

In the composition (IV-1), the ratio of the total content of the energy ray-curable component (a) and the polymer (b) having no energy ray-curable group to the total content of components other than the solvent (i.e. , the ratio of the total content of the energy ray-curable component (a) and the polymer (b) having no energy ray-curable group to the total mass of the film in the energy ray-curable protective film-forming film) is , preferably 5 to 90% by mass, more preferably 10 to 80% by mass, and particularly preferably 20 to 70% by mass. When the content of the energy ray-curable component is in such a range, the energy ray-curable film for forming an energy ray-curable protective film has better energy ray curability.

The composition (IV-1), in addition to the energy ray-curable component, may contain a thermosetting component, a filler, a coupling agent, a cross-linking agent, a photopolymerization initiator, a coloring agent, and general-purpose additives depending on the purpose. It may contain one or more selected from the group consisting of:

The thermosetting components, fillers, coupling agents, cross-linking agents, photopolymerization initiators, colorants, and general-purpose additives in the composition (IV-1) are, respectively, thermosetting components in the composition (III-1). The same as the chemical component (B), filler (D), coupling agent (E), cross-linking agent (F), photopolymerization initiator (H), colorant (I) and general-purpose additive (J). be done.

For example, by using the composition (IV-1) containing the energy ray-curable component and the thermosetting component, the energy ray-curable protective film-forming film formed has an adhesive strength to the adherend by heating. is improved, and the strength of the protective film formed from this energy ray-curable protective film-forming film is also improved.
In addition, the energy ray-curable protective film-forming film formed by using the composition (IV-1) containing the energy ray-curable component and the colorant is the thermosetting protective film-forming film described above. The same effects as when the film for use contains the coloring agent (I) are exhibited.

In the composition (IV-1), each of the thermosetting component, filler, coupling agent, cross-linking agent, photopolymerization initiator, colorant and general-purpose additive may be used alone or , may be used in combination of two or more types, and when two or more types are used in combination, their combination and ratio can be arbitrarily selected.

The content of the thermosetting component, filler, coupling agent, cross-linking agent, photopolymerization initiator, colorant and general-purpose additive in the composition (IV-1) may be appropriately adjusted according to the purpose. It is not particularly limited.

The composition (IV-1) preferably further contains a solvent because its handling properties are improved by dilution.
The solvent contained in composition (IV-1) includes, for example, the same solvent as in composition (III-1).
Composition (IV-1) may contain only one solvent, or two or more solvents.
The content of the solvent in composition (IV-1) is not particularly limited, and may be appropriately selected according to the type of components other than the solvent, for example.

<Method for producing composition for forming energy ray-curable protective film>
An energy ray-curable protective film-forming composition such as composition (IV-1) is obtained by blending each component for constituting the composition.
The energy ray-curable protective film-forming composition can be produced, for example, in the same manner as the pressure-sensitive adhesive composition described above, except that the types of ingredients are different.

⊚Film for forming a non-curable protective film Preferable film for forming a non-curable protective film includes, for example, a film containing a thermoplastic resin and a filler.

<Composition for forming a non-curable protective film (V-1)>
Preferred non-curable protective film-forming compositions include, for example, the non-curable protective film-forming composition (V-1) containing the thermoplastic resin and filler (in the present specification, simply “composition (V-1)” may be abbreviated) and the like.

[Thermoplastic resin]
The thermoplastic resin is not particularly limited.
As the thermoplastic resin, more specifically, for example, acrylic resin, polyester, polyurethane, phenoxy resin, polybutene, polybutadiene, polystyrene, etc., which are listed as the components of the composition (III-1) above, can be cured. Examples of resins that are not soluble include the same resins as those described above.

The thermoplastic resin contained in the composition (V-1) and the film for forming a non-curable protective film may be of only one type, or may be of two or more types. can be chosen arbitrarily.

In the composition (V-1), the ratio of the content of the thermoplastic resin to the total content of components other than the solvent (that is, the non-curable protective film-forming film in the non-curable protective film-forming film The ratio of the content of the thermoplastic resin to the total mass) is preferably 25 to 75% by mass.

[Filling material]
A non-curable protective film-forming film containing a filler exhibits the same effect as a thermosetting protective film-forming film containing a filler (D).

The filler contained in the composition (V-1) and the non-curable protective film-forming film is the same as the filler (D) contained in the composition (III-1) and the thermosetting protective film-forming film. things are mentioned.

The composition (V-1) and the filler contained in the non-curable protective film-forming film may be of one type or two or more types, and when there are two or more types, their combination and ratio are arbitrary. can be selected to

In the composition (V-1), the ratio of the content of the filler to the total content of all components other than the solvent (that is, the non-curable protective film-forming film in the non-curable protective film-forming film The content ratio of the filler to the total mass) is preferably 25 to 75% by mass. When the ratio is within such a range, it is easier to adjust the thermal expansion coefficient of the non-curable protective film-forming film (that is, the protective film), as in the case of using the composition (III-1). becomes.

Composition (V-1) may contain other components in addition to the thermoplastic resin and filler, depending on the purpose.
The other components are not particularly limited and can be arbitrarily selected according to the purpose.
For example, the non-curable protective film-forming film (in other words, protective film) formed by using the composition (V-1) containing the thermoplastic resin and the colorant is the thermosetting film described above. The same effects as when the protective film-forming film contains the colorant (I) are exhibited.

In the composition (V-1), the other components may be used alone or in combination of two or more. When two or more are used in combination, the combination and ratio thereof are Can be selected arbitrarily.

The content of the other components in composition (V-1) may be appropriately adjusted depending on the purpose, and is not particularly limited.

The composition (V-1) preferably further contains a solvent, since its handleability is improved by dilution.
The solvent contained in composition (V-1) includes, for example, the same solvent as in composition (III-1) described above.
Composition (V-1) may contain only one solvent, or two or more solvents.
The content of the solvent in the composition (V-1) is not particularly limited, and may be appropriately selected, for example, according to the types of components other than the solvent.

<Method for producing a composition for forming a non-curable protective film>
A non-curable protective film-forming composition such as composition (V-1) is obtained by blending each component for constituting the composition.
The non-curable protective film-forming composition can be produced, for example, in the same manner as the pressure-sensitive adhesive composition described above, except that the types of ingredients are different.

◇Method for producing a composite sheet for forming a protective film In the composite sheet for forming a protective film, the above layers are laminated so as to have a corresponding positional relationship, and if necessary, the shape of some or all of the layers is adjusted. Therefore, it can be manufactured. The method for forming each layer is as described above.

For example, when a pressure-sensitive adhesive layer is laminated on a substrate when producing a support sheet, the above-described pressure-sensitive adhesive composition may be applied onto the substrate and dried as necessary.
Alternatively, the adhesive composition is applied onto the release film and dried as necessary to form an adhesive layer on the release film, and the exposed surface of the adhesive layer is placed on one side of the substrate. A pressure-sensitive adhesive layer can also be laminated on a base material by the method of bonding to the surface of . At this time, the pressure-sensitive adhesive composition is preferably applied to the release-treated surface of the release film.
So far, the case of laminating the pressure-sensitive adhesive layer on the substrate has been exemplified, but the above-described method can also be applied, for example, to the case of laminating the intermediate layer or the other layers on the substrate.

On the other hand, for example, when a protective film-forming film is laminated on the adhesive layer already laminated on the substrate, the protective film-forming composition is applied onto the adhesive layer to form a protective film. It is possible to form the forming film directly. Layers other than the protective film-forming film can also be laminated on the pressure-sensitive adhesive layer in the same manner using the composition for forming this layer. In this way, a new layer (hereinafter abbreviated as "second layer") is formed on any layer (hereinafter abbreviated as "first layer") laminated on the base material, When forming a continuous two-layer laminated structure (in other words, a laminated structure of a first layer and a second layer), a composition for forming the second layer is applied onto the first layer. Then, if necessary, a method of drying can be applied.
However, the second layer is formed in advance on a release film using a composition for forming it, and the side opposite to the side of the formed second layer that is in contact with the release film It is preferable to form a continuous two-layer laminated structure by bonding the exposed surface of the first layer to the exposed surface of the first layer. At this time, the composition is preferably applied to the release-treated surface of the release film. The release film may be removed as necessary after the laminated structure is formed.
Here, the case of laminating the film for forming a protective film on the pressure-sensitive adhesive layer was mentioned as an example, but for example, when laminating the intermediate layer or the other layer on the pressure-sensitive adhesive layer, the target laminated structure is , can be selected arbitrarily.

In this way, all layers other than the base material constituting the protective film-forming composite sheet can be formed in advance on a release film and laminated by a method of bonding them to the surface of the desired layer. A composite sheet for forming a protective film may be produced by appropriately selecting a layer to which such a step is applied.

The protective film-forming composite sheet is usually stored in a state in which a release film is attached to the surface of the outermost layer (for example, protective film-forming film) opposite to the support sheet. Therefore, on this release film (preferably its release-treated surface), a composition for forming a layer constituting the outermost layer, such as a composition for forming a protective film, is applied and dried as necessary. Then, a layer constituting the outermost layer is formed on the release film, and the remaining layers are laminated on the exposed surface of this layer opposite to the side in contact with the release film by any of the above methods. Then, the protective film-forming composite sheet with the release film is obtained by leaving the release film in a bonded state without removing the release film.

◇Method for manufacturing workpiece with protective film (method for using composite sheet for forming protective film)
The protective film-forming composite sheet can be used for manufacturing the protective film-attached workpiece.
As an example of a method for manufacturing a protective film-attached workpiece having a protective film on any part of the workpiece, the protective film-forming film in the protective film-forming composite sheet is used as the object of the workpiece. an attaching step of producing a laminated body in which the protective film-forming composite sheet is provided (laminated) on the work by attaching it to a location; After the curing step of curing the forming film and the attaching step, the protective film-forming composite sheet is applied to the protective film-forming film in the protective film-forming composite sheet in the laminate or a cured product thereof. A printing step of printing on the protective film-forming film or a cured product thereof by irradiating a laser beam from the outside on the support sheet side through the support sheet, and processing the work after the printing step. and a processing step of producing a work processed product, wherein the protective film forming film after being attached to the work is used as a protective film without curing, or the cured product is obtained by curing. A manufacturing method using an object as a protective film is mentioned.

An example of a method for manufacturing a semiconductor chip with a protective film, that is, a semiconductor chip with a protective film when the work is a semiconductor wafer is a method for manufacturing a semiconductor chip with a protective film in which a protective film is provided on the back surface of the semiconductor chip. Then, the protective film-forming film in the protective film-forming composite sheet is attached to the back surface of a semiconductor wafer, thereby producing a laminate in which the protective film-forming composite sheet is provided on the back surface of the semiconductor wafer. an affixing step, a curing step of curing the protective film-forming film, which is optionally performed after the affixing step, and a protective film in the protective film-forming composite sheet in the laminate after the affixing step By irradiating the protective film-forming film or its cured product with a laser beam from the outside of the protective film-forming composite sheet on the support sheet side through the support sheet, the protective film-forming film or its cured product is formed. and a dividing/cutting step of, after the printing step, dividing the semiconductor wafer to produce semiconductor chips, and further cutting the film for forming a protective film or a cured product thereof. and a pick-up step of picking up the semiconductor chip provided with the cut protective film-forming film or a cured product thereof from the support sheet, wherein the protective film is formed after being attached to the semiconductor wafer. There is a production method in which the protective film is used without curing the film for the protective film, or the cured product obtained by curing is used as the protective film.

In the manufacturing method, when the work is a semiconductor wafer, the work described above can be used.

In the manufacturing method, by using the protective film-forming composite sheet of the present embodiment described above, even when the laser light having a short wavelength such as 266 nm is irradiated, the protective film-forming composite sheet (2) Good printing can be performed on the protective film-forming film or its cured product. Furthermore, this print can be well visually recognized through the support sheet from the outside of the protective film-forming composite sheet on the side of the support sheet.

The manufacturing method includes a manufacturing method with the curing step (in this specification, may be referred to as "manufacturing method (1)") and a manufacturing method without the curing step (in this specification, may be referred to as "manufacturing method (2)").
These manufacturing methods will be described in sequence below.

<<Manufacturing method (1)>>
The production method (1) is a method for producing a protective film-attached workpiece having a protective film at any part of the workpiece, wherein the protective film-forming film in the protective film-forming composite sheet is attached to the target location of the work to prepare a laminate (laminated) in which the protective film-forming composite sheet is provided on the work, and after the attachment step, the protective A curing step of curing the film-forming film, and after the attaching step, the protective film-forming composite sheet in the protective film-forming composite sheet in the laminate or a cured product thereof A printing step of printing on the protective film-forming film or a cured product thereof by irradiating a laser beam from the outside of the support sheet side through the support sheet, and processing the work after the printing step and a processing step of producing a work processed product, and a cured product obtained by curing the protective film forming film after being attached to the work is used as a protective film.

FIG. 5 is a cross-sectional view for schematically explaining an example of the manufacturing method (1) in which the workpiece is a semiconductor wafer. Here, a manufacturing method using the protective film-forming composite sheet 101 shown in FIG. 1 will be described.

<Affixing process>
In the sticking step, the protective film-forming composite sheet 101 from which the release film 15 has been removed is used, and as shown in FIG. is attached to the back surface 9b of the semiconductor wafer 9. As a result, a laminate 901 including the semiconductor wafer 9 and the protective film-forming composite sheet 101 provided on the back surface 9b of the semiconductor wafer 9 is produced.

In the attaching step, the protective film-forming film 13 may be heated to be softened and attached to the semiconductor wafer 9 .
Here, in the semiconductor wafer 9, bumps and the like on the circuit forming surface 9a are omitted from the illustration.
Further, the reference numeral 13b denotes a surface opposite to the first surface 13a of the protective film-forming film 13 (in other words, the adhesive layer 12 side) (in this specification, it may be referred to as a "second surface"). indicates

The semiconductor wafer 9 may have its back surface ground so as to have a desired thickness. That is, the back surface 9b of the semiconductor wafer 9 may be a ground surface.

In the semiconductor wafer 9, it is preferable that there is no groove penetrating between the circuit forming surface 9a and the back surface 9b.

<Curing process>
After the sticking process, in the curing process, as shown in FIG. 5B, the protective film forming film 13 is cured.
Here, the case where the curing process is performed before the printing process is shown.
In this embodiment, the cured product obtained by curing the protective film forming film 13 after being attached to the semiconductor wafer 9 is used as the protective film regardless of whether or not the film is cut.

By carrying out the curing step, the protective film forming composite sheet 101 becomes the protective film forming composite sheet 1011 in which the protective film forming film 13 is the cured product 13′, and the semiconductor wafer 9 and its back surface 9b are provided. A cured laminate 9011 is obtained, which is composed of the composite sheet 1011 for forming a protective film and the composite sheet 1011.
Reference numeral 13a′ indicates the first surface of the cured product 13′ corresponding to the first surface 13a of the protective film forming film 13, and reference numeral 13b′ corresponds to the second surface 13b of the protective film forming film 13. The second surface of the cured product 13' is shown.

In the curing step, when the protective film forming film 13 is thermosetting, the protective film forming film 13 is heated to form a cured product 13 ′. When the protective film-forming film 13 is energy ray-curable, the protective film-forming film 13 is irradiated with energy rays through the support sheet 10 to form a cured product 13 ′.

In the curing step, the curing conditions for the protective film-forming film 13, that is, the heating temperature and heating time during thermosetting, and the illuminance and light intensity of energy rays during curing with energy rays, are as described above.

<Printing process>
After the pasting step, in the printing step, as shown in FIG. By irradiating laser light L through the support sheet 10 from the outside of the composite sheet 1011 on the side of the support sheet 10, the cured product 13' is printed. A print (not shown) is applied to the second surface 13b' of the cured product 13'.

By performing the printing process, the protective film-forming composite sheet 1011 becomes a protective film-forming composite sheet 1012 having the printed cured product 13′, and the semiconductor wafer 9 and the protective film provided on the back surface 9b thereof. A printed and cured laminate 9012 is obtained comprising the forming composite sheet 1012 .

The wavelength of the laser light L is preferably shorter than that of the conventional one, and more preferably 266 nm.

<Dividing/cutting process>
After the printing process, in the dividing/cutting process, as shown in FIG. 5(d), the semiconductor wafer 9 is divided into semiconductor chips 9', and the cured product 13' is cut. do.
A semiconductor chip with a protective film, comprising a semiconductor chip 9′ and the cured product 130′ after cutting provided on the rear surface 9b′ of the semiconductor chip 9′ by performing a dividing/cutting process. A plurality of 91 are obtained. The plurality of semiconductor chips 91 with protective films are all aligned on one support sheet 10, and these semiconductor chips 91 with protective films and the support sheet 10 form a semiconductor chip group 910 with protective films. Configure.

Reference numeral 130a' indicates the first surface of the cured product 130' after cutting, which corresponds to the first surface 13a' of the cured product 13', and reference numeral 130b' indicates the second surface 13b of the cured product 13'. ' shows the second side of the cured product 130' after cutting, corresponding to .
Reference numeral 9a' denotes a circuit forming surface of the semiconductor chip 9' corresponding to the circuit forming surface 9a of the semiconductor wafer 9. FIG.

The production of semiconductor chips 9' by dividing (in other words, solidifying) the semiconductor wafer 9 can be performed by a known method.
Examples of the method for dividing the semiconductor wafer 9 include blade dicing in which the semiconductor wafer 9 is diced using a blade; laser dicing in which the semiconductor wafer 9 is diced by laser irradiation; and dicing of the semiconductor wafer 9 by spraying water containing an abrasive. A method of cutting a semiconductor wafer, such as water dicing, can be used.
When applying these methods, for example, by dividing the semiconductor wafer 9 and cutting the cured product 13 ′ at the same time, the division of the semiconductor wafer 9 and the cutting of the cured product 13 ′ are performed collectively. You can do it.

As a method for dividing the semiconductor wafer 9, methods other than the method of cutting the semiconductor wafer can be used.
That is, in this method, first, a portion to be divided is set inside the semiconductor wafer 9, and a laser beam is irradiated so as to focus on this point with this point as a focal point. Form a modified layer. Unlike other parts of the semiconductor wafer, the modified layer of the semiconductor wafer has been modified by the irradiation of the laser beam and has a weaker strength. Therefore, when a force is applied to the semiconductor wafer 9 , a crack extending in the direction of both surfaces of the semiconductor wafer 9 is generated in the modified layer inside the semiconductor wafer 9 , and becomes a starting point for dividing (cutting) the semiconductor wafer 9 . Then, a force is applied to the semiconductor wafer 9 to divide the semiconductor wafer 9 at the portion of the modified layer to fabricate semiconductor chips. A method of dividing the semiconductor wafer 9 that accompanies the formation of such a modified layer is called stealth dicing (registered trademark).
For example, a semiconductor wafer having a modified layer formed thereon can be split by expanding it in a direction parallel to its surface and applying force. Thus, when applying the method of expanding the semiconductor wafer, the cured product 13' of the protective film forming film is expanded together with the semiconductor wafer 9, and the cured product 13' is also cut at the same time. The division of the semiconductor wafer 9 and the cutting of the cured product 13' may be performed collectively. The cutting of the cured product 13' by expanding is preferably performed at a low temperature such as -20 to 5°C.

If the division of the semiconductor wafer 9 and the cutting of the cured product 13' are not performed collectively, the cured product 13' may be cut by a known method in addition to the division of the semiconductor wafer 9. good.

<Pickup process>
After the dividing/cutting process, in the picking up process, as shown in FIG. 5(e), a semiconductor chip 9' (semiconductor chip 91 with a protective film) provided with the cured product 130' after cutting is supported. It is pulled away from the sheet 10 and picked up. Here, the arrow I indicates the direction of pickup.

A well-known method can be used to pick up the semiconductor chip 91 with a protective film. For example, the separation means 8 for separating the semiconductor chip 91 with the protective film from the support sheet 10 may be a vacuum collet or the like. It should be noted that only the separating means 8 is not shown in cross section here, and this is the same for similar drawings that follow.
As described above, the desired semiconductor chip 91 with a protective film is obtained.

In the semiconductor chip 91 with the protective film which was the object of the printing process, including the picked-up one, the printing is clearly maintained on the second surface 130b' of the cured product 130' after cutting.

<Timing for performing the curing process>
Although the case where the curing process is performed between the attaching process and the printing process has been described so far, the timing of performing the curing process in the manufacturing method (1) is not limited to this. For example, in the production method (1), the curing step may be performed between the printing step and the dividing/cutting step, between the dividing/cutting step and the pick-up step, or after the pick-up step.

When the curing step is performed after the pasting step and the printing step, in the printing step, the protective film is applied to the protective film-forming film 13 in the protective film-forming composite sheet 101 in the laminate 901 shown in FIG. The protective film forming film 13 is printed by irradiating the laser light L from the outside of the forming composite sheet 101 on the support sheet 10 side through the support sheet 10 . A print (not shown) is applied to the second surface 13b of the protective film-forming film 13 .
The printing process in this case is the printing process described above, except that the object to be irradiated with the laser light L is not the cured product 13 ′ of the protective film forming film 13 but the protective film forming film 13. can be done in the same way as

<Other processes>
The manufacturing method (1) may have other processes that do not correspond to any of these processes, in addition to each of the sticking process, the curing process, the printing process, the dividing/cutting process, and the picking up process.
The types of the other steps and the timing of performing them can be arbitrarily selected according to the purpose, and are not particularly limited.

<<Manufacturing method (2)>>
The production method (2) is a method for producing a protective film-attached workpiece having a protective film at any part of the workpiece, wherein the protective film-forming film in the protective film-forming composite sheet is attached to the target location of the work to produce a laminate in which the protective film-forming composite sheet is provided on the work (laminated), and after the attachment step, the lamination By irradiating the protective film-forming film in the protective film-forming composite sheet in the body with a laser beam from the outside on the support sheet side of the protective film-forming composite sheet through the support sheet, A printing step of printing on a film for forming a protective film, and a processing step of processing the work after the printing step to produce a work processed product, and the protection after being attached to the work A production method of forming a protective film without curing the film-forming film is mentioned.
Manufacturing method (2) does not include the curing step regardless of the type of work, and is the same as manufacturing method (1) except that the protective film-forming film after being attached to the work is used as the protective film as it is. It is the same, and has the same effect as the manufacturing method (1).

Up to this point, the method for manufacturing a protective film-attached work piece using the protective film-forming composite sheet 101 shown in FIG. 1 has been mainly described. is not limited to this.
For example, even if a protective film-forming composite sheet other than the protective film-forming composite sheet 101 shown in FIG. 1, such as the protective film-forming composite sheet shown in FIGS. can be manufactured.
When using the protective film-forming composite sheet of another embodiment, based on the difference in structure between this sheet and the protective film-forming composite sheet 101, in the above-described manufacturing method, the steps are appropriately performed. Additions, changes, omissions, etc. may be made to produce a work piece with a protective film.

◇Method for Manufacturing Semiconductor Device After obtaining a work piece with a protective film by the above manufacturing method, the work piece with a protective film is used, and a semiconductor device is manufactured by a known appropriate method according to the type. can be manufactured. For example, when the workpiece with the protective film is a semiconductor chip with the protective film, the semiconductor chip with the protective film is flip-chip connected to the circuit surface of the substrate, then formed into a semiconductor package, and the semiconductor package is used. , the intended semiconductor device can be manufactured (not shown).

The present invention will be described in more detail below with reference to specific examples. However, the present invention is by no means limited to the examples shown below.

<Raw materials for resin production>
The official names of raw materials for resin production, which are abbreviated in the present examples and comparative examples, are shown below.
BA: butyl acrylate MA: methyl acrylate GMA: glycidyl methacrylate HEA: 2-hydroxyethyl acrylate 2EHA: 2-ethylhexyl acrylate MOI: 2-methacryloyloxyethyl isocyanate

<Raw materials for manufacturing protective film-forming composition>
Raw materials used for producing the composition for forming a protective film are shown below.
[Polymer component (A)]
(A)-1: Acrylic polymer (weight average molecular weight 300,000, glass transition temperature -1°C)
[Thermosetting component (B1)]
(B1)-1: Bisphenol A type epoxy resin (“jER828” manufactured by Mitsubishi Chemical Corporation, epoxy equivalent 184 to 194 g/eq)
(B1)-2: Bisphenol A type epoxy resin (“jER1055” manufactured by Mitsubishi Chemical Corporation, epoxy equivalent 800 to 900 g/eq)
(B1)-3: Dicyclopentadiene type epoxy resin (manufactured by DIC "Epiclon HP-7200HH", epoxy equivalent 255 to 260 g/eq)
[Heat curing agent (B2)]
(B2)-1: Dicyandiamide ("ADEKA Hardener EH-3636AS" manufactured by ADEKA, heat-activated latent epoxy resin curing agent, active hydrogen content 21 g/eq; hereinafter sometimes abbreviated as "DICY")
[Curing accelerator (C)]
(C)-1: 2-phenyl-4,5-dihydroxymethylimidazole (“Curesol 2PHZ” manufactured by Shikoku Kasei Kogyo Co., Ltd.)
[Filler (D)]
(D)-1: Silica filler (“SC2050MA” manufactured by Admatechs, silica filler surface-modified with an epoxy-based compound, average particle size 0.5 μm)
(D)-2: Silica filler (“UF310” manufactured by Tokuyama, average particle size 3 μm)
(D)-3: Silica filler (manufactured by Tatsumori "SV-10", average particle size 8 μm)
[Coupling agent (E)]
(E)-1: Silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd., KBM403) (G) Inorganic coloring agent: carbon black (manufactured by Mitsubishi Chemical Corporation, #MA650, average particle size 28 nm)
[Colorant (I)]
(I)-1: Carbon black ("MA600B" manufactured by Mitsubishi Chemical Corporation)

[Example 1]
<<Production of support sheet>>
<Production of adhesive resin (I-2a)>
2 To an acrylic polymer having a weight average molecular weight of 600,000, which is a copolymer of EHA (80 parts by mass) and HEA (20 parts by mass), MOI (the total number of hydroxyl groups derived from HEA in the acrylic polymer The total number of moles of isocyanate groups in the MOI is 0.75 times the number of moles), and an addition reaction is performed at 50 ° C. for 48 hours in an air stream to obtain the desired adhesive resin. (I-2a)-1 was obtained.
Hereinafter, the acrylic polymer may be referred to as "adhesive resin (I-1a)-1".

<Production of adhesive composition (I-2)>
Adhesive resin (I-2a) -1 (100 parts by mass), hexamethylene diisocyanate-based cross-linking agent ("Coronate L" manufactured by Tosoh Corporation) (6 parts by mass), as a photopolymerization initiator, "Irgacure 184" manufactured by BASF. (1-hydroxycyclohexylphenyl ketone) (3 parts by mass) and BASF "Irgacure 127" (2-hydroxy-1-(4-(4-(2-hydroxy-2-methylpropyl)benzyl)phenyl)-2 -methylpropan-1-one) (3 parts by weight), methyl ethyl ketone as a solvent, and the total concentration of all components other than the solvent is 35% by mass. Agent composition (I-2)-1 was prepared. The contents of all the components other than methyl ethyl ketone shown here are the contents of the target product not including the solvent.

<Manufacturing of support sheet>
Using a release film ("SP-PET381031" manufactured by Lintec Co., Ltd., thickness 38 μm) in which one side of a polyethylene terephthalate film is release-treated by silicone treatment, the pressure-sensitive adhesive composition obtained above is applied to the release-treated surface ( I-2)-1 was applied and dried by heating at 100° C. for 2 minutes to form an energy ray-curable pressure-sensitive adhesive layer with a thickness of 5 μm.
Next, a polypropylene film (1) (thickness: 80 μm, colorless) is laminated as a base material to the exposed surface of the adhesive layer, so that the base material, the adhesive layer and the release film are formed in this order to their respective thicknesses. A laminate sheet was produced which was constructed by laminating in a direction, ie a support sheet with a release film.

The polypropylene film (1) was subjected to a tensile test at a tensile speed of 200 mm/min in accordance with JIS K 7127 under an environment of 23° C., and the Young's modulus was 510 MPa.

<<Production of Protective Film Forming Film>>
<Production of protective film-forming composition (III-1)>
Polymer component (A)-1 (150 parts by mass), thermosetting component (B1)-1 (60 parts by mass), (B1)-2 (10 parts by mass), (B1)-3 (30 parts by mass) , Thermosetting agent (B2) -1 (2 parts by mass), curing accelerator (C) -1 (2 parts by mass), filler (D) -1 (320 parts by mass), coupling agent (E) -1 (2 parts by mass), and coloring agent (I)-1 (5.8 parts by mass) are dissolved or dispersed in a mixed solvent of methyl ethyl ketone, toluene and ethyl acetate, and stirred at 23 ° C. to obtain a solution other than the solvent. A thermosetting protective film-forming composition (III-1)-1 having a total concentration of all components of 45% by mass was obtained. All of the blending amounts of the components other than the mixed solvent shown here are the blending amounts of the target product containing no solvent.

<Production of protective film forming film>
A release film (second release film, “SP-PET381031” manufactured by Lintec Co., Ltd., thickness 38 μm) in which one side of a polyethylene terephthalate film is release-treated by silicone treatment is used, and the release-treated surface is coated with the above-obtained A protective film forming composition (III-1)-1 was applied and dried at 100° C. for 2 minutes to produce a thermosetting protective film forming film having a thickness of 15 μm.

Furthermore, the exposed surface of the obtained film for forming a protective film on the side not provided with the second release film is treated with a release film (first release film, “SP-PET381031” manufactured by Lintec Corporation, thickness 38 μm). By bonding the surfaces together, the protective film forming film, the first release film provided on one surface of the protective film forming film, and the second release film provided on the other surface of the protective film forming film A laminated film comprising a release film was obtained.

<<Manufacturing of composite sheet for forming protective film>>
The release film was removed from the support sheet obtained above. Also, the first release film was removed from the laminated film obtained above. Then, by bonding the exposed surface of the adhesive layer produced by removing the release film and the exposed surface of the protective film forming film produced by removing the first release film, the base material, the adhesive A protective film-forming composite sheet was produced by laminating an agent layer, a protective film-forming film, and a second release film in this order in the thickness direction.

<<Evaluation of support sheet>>
<Measurement of transmittance of light (365 nm) of support sheet>
The release film was removed from the support sheet obtained above. Then, for this support sheet, the transmittance of light having a wavelength range of 190 to 1200 nm was measured using a spectrophotometer ("UV-VIS-NIR SPECTROPHOTOMETER UV-3600" manufactured by SHIMADZU). Using the large sample chamber "MPC-3100" attached to the photometer, the integrating sphere built into the spectrophotometer was used, and the transmittance of light (365 nm) was calculated from the obtained measurement results. The results are shown in Tables 1 and 2.

<<Evaluation of Protective Film Forming Film>>
<Measurement of transmittance of light (365 nm), light (555 nm) and light (800 nm)>
The film for forming a protective film obtained above was heated in an oven at 130° C. for 2 hours to thermally cure the film for forming a protective film to form a protective film. The second release film was removed from this protective film, and the transmittance of light with a wavelength range of 190 to 1200 nm was measured using a spectrophotometer ("UV-VIS-NIR SPECTROPHOTOMETER UV-3600" manufactured by SHIMADZU). At this time, the measurement was performed using the large sample chamber "MPC-3100" attached to the spectrophotometer without using the integrating sphere built into the spectrophotometer. , light (365 nm), light (555 nm) and light (800 nm) were calculated, and the results are shown in Tables 1 and 2.

<<Evaluation of Composite Sheet for Protective Film Formation>>
<Evaluation of adhesive strength between protective film-forming film and support sheet after UV irradiation under low-intensity UV irradiation conditions>
The mirror surface of the silicon wafer and the protective film forming layer surface of the protective film forming composite sheet obtained above are coated using a tape mounter (manufactured by Lintec Corporation, product name "Adwill RAD-3600 F/12"). Applied at room temperature at 70°C. Then, from the substrate side of the composite sheet for protective film forming layer, under the conditions of illuminance of 5 mW/cm ² and light amount of 100 mJ/cm ² , UV irradiation is performed with a UV irradiation machine ("UVI-1201MB7" manufactured by Omiya Industry Co., Ltd.), It was allowed to stand for 20 minutes in an environment of 23° C. and 50% RH (relative humidity).
After standing, using a universal testing machine (manufactured by Shimadzu Corporation, product name "Autograph AG-IS"), the adhesive force measurement test was performed under the conditions of a peel angle of 180 ° and a peel speed of 0.3 m / min. and measured the load when the pressure-sensitive adhesive sheet was peeled off from the protective film-forming layer. The results are shown in Tables 1 and 2.

<Pickup evaluation>
The release film was removed from the protective film-forming composite sheet obtained above, and an 8-inch silicon wafer (thickness: 100 μm, attachment surface: dry-polished finish) was placed on the exposed bonding surface of the adhesive layer at 70°C. Lamination was performed while heating, and this composite sheet for forming a protective film was fixed to a ring frame. Next, using a dicing machine ("DFD6361" manufactured by DISCO), a cutting method by blade dicing with a feed of 30 mm / sec, a rotation speed of 30000 rpm, and a blade of Z05-SD2000-D1-90 CC is applied to cut the silicon wafer. It was singulated into chips having a size of 8 mm×8 mm. At this time, a dicing blade was used to cut the surface of the protective film-forming composite sheet to a depth of 25 μm.

Then, using a pick-up device ("BESTEM-D02" manufactured by Canon Machinery), the silicon chip with the protective film was separated from the support sheet and picked up 10 times. At this time, the pick-up method was such that one silicon chip with a resin film was pushed up with one pin, the speed of pushing up was 20 mm/s, and the amount of pushing up was 200 μm. Then, the number of chips that could be normally picked up without cracking was confirmed, and the pick-up aptitude of the semiconductor processing sheet was evaluated according to the following evaluation criteria. Table 1 shows the results.
A: All chips were successfully picked up.
B: Six or more chips were successfully picked up.
C: 1 to 5 chips were successfully picked up.
D: No chips were successfully picked up.

<Evaluation of Wafer Grinding Scratches Shielding Properties>
A composite sheet for forming a protective film is attached to the ground surface of an 8-inch silicon wafer (surface: #2000, thickness 350 μm) at 70 ° C., and the composite sheet for forming a protective film and the silicon wafer are laminated to form a laminate. got a body
Then, this laminate was heated at 130° C. for 2 hours to thermally cure the protective film-forming layer in the composite sheet to form a protective film.
Next, after allowing the wafer with the protective film obtained by this thermal curing to cool, UV irradiation (illuminance of 5 mW/cm ² , light intensity of 100 mJ/cm ² ) is performed from the support sheet side, and the support sheet is peeled off from the wafer with the protective film. bottom.
Next, the wafer was observed from the side of the protective film-attached wafer to which the protective film was attached, and whether or not the grinding marks of the wafer could be seen through the protective film was evaluated according to the following criteria.
(Evaluation criteria)
5: No traces of wafer grinding are visible even when observed at a distance of 10 cm from a fluorescent lamp.
4: When observed at a distance of 10 cm under a fluorescent lamp, the grinding marks of the wafer are faint and can be recognized by the difference in shading.
3: When observed at a distance of 10 cm from a fluorescent lamp, the grinding marks of the wafer can be recognized by a clear difference in shading.
2: When observed at a distance of 10 cm under a fluorescent lamp, grinding traces of the wafer are visible.
1: Grinding traces of the wafer are visible even without irradiation with a fluorescent lamp or the like.

<Evaluation of ultraviolet (UV) shielding property>
The light (365 nm) transmittance of the protective film-forming composite sheet was calculated in the same manner as in the evaluation of the protective film-forming film. Based on the obtained transmittance, the ultraviolet (UV) shielding property was evaluated according to the following evaluation criteria.
A: transmittance of light (365 nm) is 0.05 or less B: transmittance of light (365 nm) is more than 0.5 and less than or equal to 0.1 C: transmittance of light (365 nm) is more than 0.1 and less than or equal to 0.3 D: Transmittance of light (365 nm) greater than 0.3 <<manufacture and evaluation of support sheet, protective film-forming film, and protective film-forming composite sheet>>

[Example 2]
A support sheet, a film for forming a protective film and a Composite sheets were manufactured and evaluated. Table 1 shows the results.

[Example 3]
A support sheet, a film for forming a protective film, and a Composite sheets were manufactured and evaluated. Table 1 shows the results.

[Example 4]
A support sheet, a film for forming a protective film, and a Composite sheets were manufactured and evaluated. Table 1 shows the results.

[Example 5]
(B1)-1 (60 parts by mass) and (B1)-3 (40 parts by mass) were used as thermosetting components during the production of the protective film-forming composition, and the filler (D)-1 (320 parts by mass) was used. parts by mass) in place of (D)-2 (320 parts by mass), in the same manner as in Example 1, to produce a support sheet, a film for forming a protective film, and a composite sheet for forming a protective film. ,evaluated. Table 1 shows the results.

[Example 6]
(B1)-1 (70 parts by mass) and (B1)-3 (30 parts by mass) were used as thermosetting components during the production of the protective film-forming composition, and the filler (D)-1 (320 parts by mass) was used. parts by mass) in place of (D)-3 (320 parts by mass), in the same manner as in Example 1, to produce a support sheet, a film for forming a protective film, and a composite sheet for forming a protective film. ,evaluated. Table 1 shows the results.

[Comparative Example 1]
A support sheet, a film for forming a protective film and a Composite sheets were manufactured and evaluated. Table 2 shows the results.

[Comparative Example 2]
A support sheet, a protective film-forming film, and a protective film-forming composite sheet were produced in the same manner as in Example 1, except that the coloring agent (I)-1 was not used in the production of the protective film-forming composition. and evaluated. Table 2 shows the results.

As is clear from the above results, in Examples 1 to 6, the transmittance of light (365 nm) of the film for forming a protective film was 0.3% or less, and the ultraviolet rays of the composite sheet for forming a protective film It was excellent in (UV) shielding properties. On the other hand, the light (365 nm) transmittance of the films for forming protective films in Comparative Examples 1 and 2 exceeded 0.3%, indicating that the composite sheets for forming protective films had inferior ultraviolet (UV) shielding properties. .

Further, in Examples 1 to 4, the adhesive force between the protective film-forming film and the support sheet obtained by ultraviolet irradiation under low-illuminance UV irradiation conditions of illuminance of 5 mW/cm ² and light intensity of 100 mJ/cm ² was 370 mN. /25 mm, and the pick-up property was excellent. In particular, the composite sheet for forming a protective film of Example 1 had a low adhesive force of 105 mN/25 mm between the film for forming a protective film and the support sheet obtained by irradiating ultraviolet rays under low-intensity UV irradiation conditions, and the pick-up property was particularly low. was excellent. The protective film-forming composite sheets of Examples 5 and 6 had an adhesive force of 370 mN/25 mm or more between the protective film-forming film obtained by UV irradiation under low-intensity UV irradiation conditions and the support sheet. inferior in terms of sex.

Regarding the grinding mark shielding property of the composite sheet for forming a protective film, in Examples 1 to 3, 5 and 6, the transmittance of light (555 nm) of the film for forming a protective film was 5% or less, and the light ( 800 nm) was less than 20%. Therefore, the evaluation of the grinding mark shielding property was 4 or 5 in each case, and the grinding mark shielding property was good. In Example 4, the transmittance of light (555 nm) of the protective film-forming film was 5% or less, but the transmittance of light (800 nm) was 20%. Therefore, the evaluation of the grinding mark shielding property was 3, which is slightly inferior to those of Examples 1 to 3, 5 and 6. On the other hand, in Comparative Examples 1 and 2, the light (555 nm) transmittance of the protective film forming film exceeded 5%, and the light (800 nm) transmittance was 20% or more. Therefore, the evaluation of the grinding mark shielding property was 1 or 2 in each case, and the grinding mark shielding property was inferior.

INDUSTRIAL APPLICABILITY The present invention can be used for manufacturing semiconductor devices.

101, 102, 103, 104... Protective film-forming composite sheet, 1011... Protective film-forming composite sheet with cured protective film-forming film, 1012... Protective film-forming film with cured and Printed protective film forming composite sheet 10, 20, 30 Supporting sheet 10a, 20a, 30a One surface (first surface) of supporting sheet 13, 23 Protective film formation film, 13'... Protective film (cured product of protective film forming film), 130'... Protective film after cutting (cured product of protective film forming film after cutting), 9... Semiconductor Wafer 9a circuit forming surface of semiconductor wafer 9b rear surface of semiconductor wafer 9′ semiconductor chip L laser beam

Claims (4)

A support sheet and a protective film-forming film provided on one surface of the support sheet,
The protective film-forming film has a transmittance of 0.3% or less for light with a wavelength of 365 nm,
The protective film-forming film is thermosetting or non-curable,
The protective film-forming film does not contain a component having a reactive double bond group,
Does not contain an epoxy thermosetting component containing a condensed cyclic aromatic compound having an epoxy group,
A composite sheet for forming a protective film, wherein an adhesive force between the film for forming a protective film or a cured product thereof and the support sheet is less than 370 mN/25 mm. The support sheet comprises a base material and an adhesive layer provided on one surface of the base material,
The pressure-sensitive adhesive layer is arranged between the substrate and the protective film-forming film,
2. The composite sheet for forming a protective film according to claim 1, wherein the pressure-sensitive adhesive layer is an energy ray-curable pressure-sensitive adhesive layer. 3. The composite sheet for forming a protective film according to claim 1 , wherein the film for forming a protective film has a transmittance of 5% or less for light having a wavelength of 555 nm. 4. The composite sheet for forming a protective film according to claim 1 , wherein the film for forming a protective film has a transmittance of less than 20% for light having a wavelength of 800 nm.

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