JP2002226798A - Adhesive sheet, semiconductor device, and method of manufacturing semiconductor device - Google Patents

Abstract

(57) [abstract] (with correction) [Problem] Highly adhesiveness can be achieved by controlling the fixing force of a wafer during dicing and the peeling property at the time of pick-up, applying an adhesive for a semiconductor element and applying a film for a dicing process all at once. ,
An adhesive sheet having excellent reflow crack resistance, a method for manufacturing a semiconductor device capable of manufacturing a semiconductor device in a simple process, and a semiconductor device having excellent solder reflow crack resistance and reliability. An adhesive sheet comprising a base material layer and an adhesive layer containing (A) an energy ray-curable component and (B) a thermosetting component. The layer has an elastic modulus at 250 ° C. of 10 MPa or less, and is irradiated with an amount of energy rays equivalent to fixing the adhesive layer to the semiconductor element, and further has a water absorption of 1.5 vol% or less after heat curing. And a semiconductor device manufactured using the adhesive sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an adhesive sheet and a semiconductor device.

[0002]

2. Description of the Related Art Semiconductor wafers such as silicon and gallium arsenide are manufactured in a large-diameter state, and are transferred to the next mounting step through a dicing step of cutting and separating the wafer into semiconductor elements (IC chips). At this time, the semiconductor wafer is sent to the next die bonding step through dicing, washing, drying, expanding, and pick-up steps in a state in which the semiconductor wafer is attached to the adhesive sheet in advance.

[0003] Such an adhesive sheet used in the steps from the dicing step to the pickup of a semiconductor wafer has a sufficient adhesive force to the wafer or IC chip from the dicing step to the drying step. Is desired to have an adhesive strength such that it does not adhere to an IC chip.

In the subsequent die bonding step, that is, the bonding step between the semiconductor element and the semiconductor supporting substrate, a paste-like adhesive has been mainly used, but in recent years, the size and density of the semiconductor element have been reduced. Accordingly, a support substrate to be used is also required to be smaller and finer. However, the paste adhesive causes problems such as sticking out from the edge of the semiconductor chip and the semiconductor chip being inclined and bonding, and also causes a problem at the time of wire bonding. Further, it is difficult to control the thickness of the adhesive layer. There were problems such as generation of voids from the agent layer.

In order to solve such problems, in recent years,
Film-like adhesives have come to be used. The film adhesive is mainly used in an individual piece sticking method or a wafer backside sticking method.

The individual piece sticking method is a method in which a reel-shaped adhesive film is cut into individual pieces by cutting or punching, and then bonded to a support substrate. The semiconductor element singulated by the dicing step is joined to the supporting substrate with the adhesive film to produce a supporting substrate with the semiconductor element. Thereafter, the semiconductor device is completed through a wire bonding step, a sealing step, and the like. However, the individual sticking method requires the introduction of a dedicated assembling apparatus for cutting out the adhesive film and bonding it to the supporting substrate, and has a problem that the assembling cost is higher than using silver paste.

On the other hand, in the wafer backside bonding method, an adhesive film is laminated on a semiconductor wafer, and a dicing tape is bonded to the obtained semiconductor wafer with the adhesive film.
It is separated into individual pieces by a dicing process. The singulated semiconductor element with the adhesive is bonded to the supporting substrate, and the semiconductor device is completed through the subsequent steps. In the wafer backside bonding method, since an adhesive-attached semiconductor element is bonded to a supporting substrate, a device for separating the adhesive film is unnecessary, and a conventional assembly device for a paste-like adhesive can be used as it is or heat can be applied. Because it can be used by making some improvements such as adding a board,
It is attracting attention as an assembling method in which the assembling cost is relatively low.

[0008] The individualization of the semiconductor element of the wafer backside bonding method is performed in a dicing step after a dicing tape is attached to the film adhesive side of the semiconductor wafer on which the film adhesive is laminated. The dicing tape used at that time is roughly classified into a pressure-sensitive type and a UV type. The pressure-sensitive type is obtained by applying an adhesive to a vinyl chloride or polyolefin base film.

[0009] However, the assembly process of the wafer backside bonding method can be performed by a simpler process than the individual piece bonding method, but the film bonding process up to the dicing process is performed twice, ie, the bonding of the semiconductor device adhesive and the dicing tape. It is necessary to carry out the method, and a more efficient attaching method is desired.

In order to meet such demands, various adhesive sheets for attaching a wafer having both a wafer fixing function and an IC chip attaching function have been devised (for example, JP-A-2-32181).

JP-A-2-32181 discloses a composition comprising a (meth) acrylate copolymer, an epoxy resin, a photopolymerizable low-molecular compound, a heat-active latent epoxy resin curing agent and a photopolymerization initiator. An adhesive sheet comprising an adhesive layer formed from a product and a substrate is disclosed. This adhesive layer has a function of fixing the wafer at the time of wafer dicing, and when irradiated with energy rays after completion of dicing, the photopolymerizable component is cured, and the adhesive strength with the base material is reduced.
Therefore, when the chip is picked up, the adhesive layer immediately peels off from the substrate together with the chip. By heating and pressing the IC chip with the adhesive layer to a support member such as a lead frame, the adhesive layer develops an adhesive force, and the bonding between the IC chip and the support member is completed.

In the pressure-sensitive adhesive sheet for wafer bonding disclosed in the above publication, the step of applying the IC chip bonding adhesive can be omitted by forming the adhesive layer on the back surface of the IC chip.

By the way, in the adhesive layer of the adhesive sheet described above, all components are cured after die bonding after energy beam curing and thermal curing, and the IC chip and the supporting member can be firmly bonded. As semiconductor devices become more sophisticated, there is a strong demand for further improvements in characteristics such as toughness and impact resistance.

[0014] Further, with the advancement of the functions and integration of the device,
The C chip itself has also become highly integrated and sophisticated, and the number of pins, the size of the chip, and the power consumption have been increasing. However, with the conventional adhesive for wafer bonding, which has both a wafer fixing function and an IC chip bonding function at the same time,
Since a sufficient adhesive force cannot be obtained, such a demand for miniaturization and thinning cannot be achieved. For this reason, an adhesive composition having an excellent balance between adhesive strength and peel strength has been desired.

As a pressure-sensitive adhesive sheet provided with an adhesive having an excellent balance between the adhesive strength and the peel strength, Japanese Patent Laid-Open No. 8-
JP-A-239636 or JP-A-9-100450 or JP-A-10-8001 discloses that (A) an energy ray-curable adhesive component and (B)
An adhesive sheet having an adhesive layer formed of a thermosetting adhesive component and (C) a flexible component has been proposed. Although this adhesive sheet is effective in solving the above-mentioned technical problems, improvement and improvement are constantly demanded in the semiconductor industry, which is a state-of-the-art technical field that is constantly evolving.

In particular, the adhesive for die bonding incorporated in a semiconductor package as a final product is required to maintain sufficient adhesive properties, and improvement is being studied.

In particular, improvement in heat resistance has become an important issue as the mounting method of a semiconductor package has become mainstream, instead of the conventional pin insertion type, and the surface mounting type suitable for high-density mounting has become mainstream.

This surface mount package is mounted by heating the entire package by infrared reflow, vapor phase reflow, solder dip, or the like in order to directly solder the leads to a printed circuit board or the like. At this time, since the entire package is exposed to a high temperature of 210 to 260 ° C., if moisture exists inside the package, explosive vaporization of the moisture causes a package crack (hereinafter referred to as a reflow crack). The reflow crack significantly reduces the reliability of the semiconductor package, and is a serious problem and technical problem.

The mechanism of occurrence of reflow cracks caused by the die bonding material is as follows. In the semiconductor package, (1) the die bonding material absorbs moisture during storage, (2) the water is vaporized by heating during mounting of reflow soldering, and (3) the die bonding layer is broken by the vapor pressure. Peeling occurs,
(4) Reflow cracks occur.

While the reflow crack resistance of the sealing material has been improved, the reflow crack caused by the die bonding material has become a serious problem especially in a thin package, and the improvement of the reflow crack resistance is strongly. Has been requested.

[0021]

According to the first aspect of the present invention, it is possible to control the fixing force of a wafer at the time of dicing and the releasability at the time of pickup, and to apply the adhesive for a semiconductor element and the film for the dicing step all together. The object of the present invention is to provide a pressure-sensitive adhesive sheet which can be stuck and has high adhesiveness and excellent reflow crack resistance.

The second aspect of the present invention provides the pressure-sensitive adhesive sheet having the effect of the first aspect of the invention and having higher solder reflow crack resistance. The third aspect of the present invention is to provide a pressure-sensitive adhesive sheet having the effects of the first and second aspects of the present invention, and having excellent adhesive strength and excellent impact resistance. The invention described in claim 4 has the effects of the inventions described in claims 1, 2, and 3, and provides an adhesive sheet having higher solder reflow crack resistance. The invention described in claim 5 has the effects of the inventions described in claims 1 to 4 and provides an adhesive sheet having higher solder reflow crack resistance.

The invention described in claim 6 has the effects of the inventions described in claims 1 to 5 and provides an adhesive sheet having excellent workability. The inventions according to claims 7 and 8 exhibit the effects of the inventions according to claims 1 to 6, and provide a pressure-sensitive adhesive sheet having more excellent workability. The invention described in claim 9 has the effects of the inventions described in claims 1 to 8 and provides a pressure-sensitive adhesive sheet having more excellent adhesive strength.

According to a tenth aspect of the present invention, there is provided a semiconductor device manufacturing method capable of manufacturing a semiconductor device with simple steps. The invention according to claim 11 or 12 provides a semiconductor device having high solder reflow crack resistance and excellent reliability.

[0025]

The present invention provides a base material layer,
An adhesive sheet comprising: (A) an adhesive layer containing an energy ray-curable component and (B) a thermosetting component, wherein the adhesive layer has an elastic modulus at 250 ° C. 10MPa
The present invention relates to a pressure-sensitive adhesive sheet having a water absorption of 1.5% by volume or less after irradiating an amount of energy rays corresponding to fixing the pressure-sensitive adhesive layer to a semiconductor element and further heating and curing.

Further, the present invention provides the above adhesive layer, wherein the adhesive layer has a residual volatile content of 3.0% by weight or less after irradiating an energy beam corresponding to fixing the semiconductor element to the adhesive layer. Regarding the wearing sheet. Also, the present invention provides the adhesive layer,
An energy beam corresponding to fixing the semiconductor element to the adhesive layer is irradiated, and the obtained semiconductor element with the adhesive layer is adhered to a support member, and the peel strength after heat curing is 4.9 N /. The present invention relates to the above adhesive sheet having a size of 5 mm × 5 mm chip or more.

The present invention also relates to the above adhesive sheet, wherein the adhesive layer has a saturated moisture absorption of 1.0% by volume or less after heat curing. Further, the present invention provides, at the stage where the adhesive layer adheres the semiconductor element and the support member via the adhesive layer and is cured by heating, the inside of the adhesive layer and the adhesive layer and the support member The void volume fraction of the voids present at the interface is 10
% Or less.

The present invention also relates to the above-mentioned adhesive sheet, wherein the substrate is of an energy ray transmission type. The present invention also relates to the above-mentioned adhesive sheet, wherein the adhesive layer further contains a film-forming polymer. The present invention also relates to the above adhesive sheet, wherein the film-forming polymer is a polyimide resin. The present invention also relates to the above-mentioned adhesive sheet, wherein the adhesive layer further contains a filler.

Also, the present invention provides (I) a step of mounting a semiconductor wafer on the adhesive layer of the adhesive sheet, (II) a step of irradiating an energy ray from the base material side and fixing the semiconductor wafer to the semiconductor wafer, (III) dicing the semiconductor wafer with the adhesive layer to obtain a semiconductor element with the adhesive layer, (IV) picking up the semiconductor element with the adhesive layer from the base material,
(V) a step of bonding the semiconductor element with the adhesive layer to the supporting substrate by applying heat or pressure to the supporting substrate.

The present invention also relates to a semiconductor device having a structure in which a semiconductor element and a semiconductor support member are bonded via the adhesive layer of the adhesive sheet. The present invention also relates to a semiconductor device manufactured by using the method for manufacturing a semiconductor device.

[0031]

BEST MODE FOR CARRYING OUT THE INVENTION The adhesive sheet of the present invention comprises (A)
An adhesive sheet having an adhesive layer containing an energy ray-curable component and a (B) thermosetting component, and can be used as a dicing tape at the time of dicing by adopting such a configuration. It can be used as an adhesive when mounting. Therefore, the adhesive sheet of the present invention is suitable for simplifying the manufacturing process of the semiconductor device.

The adhesive layer has an elastic modulus at 250 ° C. of 10 MPa or less. In addition, the adhesive layer is irradiated with an amount of energy rays equivalent to fixing the semiconductor element and further heated and cured to obtain a water absorption coefficient. Is 1.5% by volume or less.

Although the above water absorption is 1.5% by volume or less,
1.0 vol% or less is more preferable, and 0.5 vol% or less is particularly preferable. When the water absorption exceeds 1.5% by volume, the solder reflow crack resistance is reduced due to the water absorbed.

If the elastic modulus of the adhesive layer at 250 ° C. is 10 MPa or less, the temperature is 150 to 250 ° C., the time is 0.1 second or more and less than 2 seconds, and the pressure is 0.1 to 4 gf / mm ² . Die bonding can be performed under the conditions, and a sufficient peel strength can be obtained. Therefore, a semiconductor device manufactured using the adhesive sheet of the present invention has excellent reliability.

The energy ray for irradiating the adhesive sheet of the present invention includes, for example, an electron beam and an ultraviolet ray, but an ultraviolet ray is preferred because the irradiation amount can be easily controlled and the handling is excellent.

In the pressure-sensitive adhesive sheet of the present invention, (A) an energy ray-curable component refers to a component whose components are cured by irradiation with energy rays to increase the adhesive force. Various such energy ray-curable pressure-sensitive adhesive components are known, and various conventionally known energy ray-curable pressure-sensitive adhesive components can be used in the present invention without any particular limitation.

The amount of the energy ray-curable pressure-sensitive adhesive component (A) used is preferably 15 to 100 parts by weight based on 100 parts by weight of the resin composition of the thermosetting component (B) and the polyimide resin described below. And more preferably 70 to 70 parts by weight.
Particularly preferred is 0 to 50 parts by weight. If it is less than 15 parts by weight, there is a tendency that sufficient energy ray curability cannot be obtained,
If it exceeds 100 parts by weight, the film-forming properties tend to be poor.

The energy ray-curable component contains, for example, (A-1) an acrylic pressure-sensitive adhesive, (A-2) an energy ray-polymerizable compound and, if necessary, (A-3) a photopolymerization initiator. And the like.

As the acrylic pressure-sensitive adhesive (A-1), for example, a (meth) acrylate monomer and a (meth) acrylate
A (meth) acrylate copolymer having a structural unit derived from an acrylic acid derivative is exemplified. As the (meth) acrylate monomer, an alkyl (meth) acrylate having an alkyl group having 1 to 18 carbon atoms is preferable. For example, methyl acrylate,
Methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate,
Butyl acrylate, butyl methacrylate and the like are used. As the (meth) acrylic acid derivative, for example, (meth) acrylic acid, glycidyl (meth) acrylate,
Hydroxyethyl (meth) acrylate and the like.
In this specification, for example, (meth) acrylic acid refers to both acrylic acid and methacrylic acid.

The weight average molecular weight of the acrylic pressure-sensitive adhesive (A-1) is not particularly limited, but is preferably 100,000 or more, more preferably 150,000 to 1,000,000. The glass transition temperature of the acrylic pressure-sensitive adhesive is not particularly limited as long as it has tackiness at normal temperature (23 ° C.), but is usually 20 ° C. or less, and is −70 to 0 ° C.
The degree is preferred. In addition, the weight average molecular weight in the present invention is a value measured by gel permeation chromatography and converted by a standard polystyrene calibration curve.

The energy ray polymerizable compound (A-2) is
It is a compound that polymerizes and cures when irradiated with energy rays such as ultraviolet rays and electron beams. Examples of such a compound include compounds having at least one polymerizable double bond in the molecule and having a molecular weight of about 100 to 30,000 (preferably about 300 to 10,000). More specifically, for example, trimethylolpropane triacrylate, tetramethylolmethanetetraacrylate, pentaerythritol triacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate, 1,
4-butylene glycol diacrylate, 1,6-hexanediol diacrylate, polyethylene glycol diacrylate, acrylate compounds such as commercially available oligoester acrylate, polyester-type or polyether-type urethane acrylate oligomer, polyester acrylate, polyether acrylate, Epoxy-modified acrylates and the like can be mentioned, and these can be used alone or in combination of two or more.

The components (A-1) and (A-
The adhesive composition containing 2) is cured by irradiation with energy rays. When ultraviolet rays are used as energy rays, it is preferable to further use a photopolymerization initiator (A-3) for the purpose of reducing the polymerization curing time and the amount of light irradiation.

When an acrylic compound is used as the energy ray polymerizable compound (A-2), examples of such a photopolymerization initiator (A-3) include benzophenone, acetophenone, benzoin, benzoin methyl ether, and benzoin ethyl. Ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin benzoic acid, methyl benzoin benzoate, benzoin dimethyl ketal, 2,4-diethylthioxanthone, α
-Hydroxycyclohexyl phenyl ketone, benzyl diphenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, benzyl,
Dibenzyl, diacetyl, β-chloranthraquinone and the like.

The energy ray-curable pressure-sensitive adhesive component (A) used in the present invention is preferably composed of the above components (A-1) to (A-3), and the compounding ratio thereof is appropriately determined according to the characteristics of each component. Usually, the component (A-2) is preferably 50 to 150 parts by weight, more preferably 80 to 125 parts by weight, based on 100 parts by weight of the component (A-1). Ingredient (A
-3) is based on 100 parts by weight of component (A-1).
The amount is preferably 5 to 4.5 parts by weight, more preferably 2.4 to 3.8 parts by weight.

The thermosetting component (B) is not cured by energy rays, but becomes three-dimensional when heated.
A component having a property of firmly bonding an adherend is shown. Examples of such a thermosetting component (B) include epoxy resin, cyanate resin, bismaleimide resin, phenol resin, urea resin, melamine resin, alkyd resin, acrylic resin, unsaturated polyester resin, diallyl phthalate resin, and silicone. Resin, resorcinol formaldehyde resin, xylene resin, furan resin, polyurethane resin, ketone resin, triallyl cyanurate resin, polyisocyanate resin, tris (2-hydroxyethyl)
Examples of the resin include a resin containing isocyanurate, a resin containing triallyl trimellitate, a resin synthesized from cyclopentadiene, and a thermosetting resin obtained by trimerizing aromatic dicyanamide. Among them, epoxy resin, cyanate resin, and bismaleimide resin are preferable, and epoxy resin is more preferable, since they can have excellent adhesive strength at high temperatures. In addition, these thermosetting resins can be used alone or in combination of two or more.

The adhesive sheet of the present invention may contain a polyimide resin for the purpose of imparting high adhesive strength, heat resistance and film formability. Such a polyimide resin can be obtained, for example, by subjecting a tetracarboxylic dianhydride and a diamine to a condensation reaction by a known method. That is, in an organic solvent, tetracarboxylic dianhydride and diamine are used in an equimolar or almost equimolar manner (addition order of each component is arbitrary), and the reaction is carried out at a reaction temperature of 80 ° C or lower, preferably 0 to 50 ° C. As the reaction proceeds, the viscosity of the reaction solution gradually increases, and polyamic acid, which is a precursor of the polyimide resin, is generated.

The polyimide resin can be obtained by dehydrating and cyclizing a polyamic acid. Dehydration ring closure is 120 ° C to 25
It can be performed by a method of heat treatment at 0 ° C. or a chemical method using a dehydrating agent such as acetic anhydride.

Examples of the tetracarboxylic dianhydride used as a raw material of the polyimide resin include, for example, 1,2
-(Ethylene) bis (trimellitate anhydride), 1,3
-(Trimethylene) bis (trimellitate anhydride),
1,4- (tetramethylene) bis (trimellitate anhydride), 1,5- (pentamethylene) bis (trimellitate anhydride), 1,6- (hexamethylene) bis (trimellitate anhydride), 1,7- ( Heptamethylene) bis (trimellitate anhydride), 1,8- (octamethylene) bis (trimellitate anhydride), 1,9- (nonamethylene) bis (trimellitate anhydride), 1,10-
(Decamethylene) bis (trimellitate anhydride), 1,
12- (dodecamethylene) bis (trimellitate anhydride), 1,16- (hexadecamethylene) bis (trimellitate anhydride), 1,18- (octadecamethylene)
Bis (trimellitate anhydride), pyromellitic dianhydride, 3,3 ', 4,4'-diphenyltetracarboxylic dianhydride, 2,2', 3,3'-diphenyltetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, 2,2-bis (2,3-
Dicarboxyphenyl) propane dianhydride, 1,1-bis (2,3-dicarboxyphenyl) ethane dianhydride,
1,1-bis (3,4-dicarboxyphenyl) ethane dianhydride, bis (2,3-dicarboxyphenyl) methane dianhydride, bis (3,4-dicarboxyphenyl) methane dianhydride, bis (3,4-dicarboxyphenyl)
Sulfone dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, benzene-1,2,3,4-
Tetracarboxylic dianhydride, 3,4,3 ', 4'-benzophenonetetracarboxylic dianhydride, 2,3,2',
3-benzophenonetetracarboxylic dianhydride, 2,
3,3 ', 4'-benzophenonetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1, 2,4,5-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,6-dichloronaphthalene-1,4,
5,8-tetracarboxylic dianhydride, 2,7-dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride, 2,3,6,7-tetrachloronaphthalene-1,
4,5,8-tetracarboxylic dianhydride, phenanthrene-1,8,9,10-tetracarboxylic dianhydride, pyrazine-2,3,5,6-tetracarboxylic dianhydride,
Thiophene-2,3,4,5-tetracarboxylic dianhydride, 2,3,3 ', 4'-biphenyltetracarboxylic dianhydride, 3,4,3', 4'-biphenyltetracarboxylic dianhydride Anhydride, 2,3,2 ', 3'-biphenyltetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) dimethylsilane dianhydride, bis (3,4-dicarboxyphenyl) methylphenylsilane Dianhydride, bis (3,4-dicarboxyphenyl) diphenylsilane dianhydride, 1,4-bis (3,4-dicarboxyphenyldimethylsilyl) benzene dianhydride, 1,3-bis (3,4 -Dicarboxyphenyl) -1,1,3,3-
Tetramethyldicyclohexane dianhydride, p-phenylenebis (trimellitate anhydride), ethylene tetracarboxylic dianhydride, 1,2,3,4-butanetetracarboxylic dianhydride, decahydronaphthalene-1,4, 5,8
-Tetracarboxylic dianhydride, 4,8-dimethyl-1,
2,3,5,6,7-hexahydronaphthalene-1,
2,5,6-tetracarboxylic dianhydride, cyclopentane-1,2,3,4-tetracarboxylic dianhydride, pyrrolidine-2,3,4,5-tetracarboxylic dianhydride,
1,2,3,4-cyclobutanetetracarboxylic dianhydride, bis (exo-bicyclo [2,2,1] heptane-
2,3-dicarboxylic dianhydride) sulfone, bicyclo-
(2,2,2) -oct-7-ene-2,3,5,6-
Tetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride, 2,2-bis [4- (3,4-dicarboxyphenyl) phenyl] hexafluoropropane Dianhydride, 4,
4'-bis (3,4-dicarboxyphenoxy) diphenyl sulfide dianhydride, 1,4-bis (2-hydroxyhexafluoroisopropyl) benzenebis (trimellitic anhydride). 1,3-bis (2-hydroxyhexafluoroisopropyl) benzenebis (trimellitic anhydride), 5- (2,5-dioxotetrahydrofuryl) -3-methyl-3-cyclohexene-1,2-dicarboxylic acid Dianhydride, tetrahydrofuran-2,3,4
5-tetracarboxylic dianhydride and the like can be mentioned, and these can be used alone or in combination of two or more.

Examples of the diamine used as a raw material of the polyimide resin include, for example, o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 3,3'-diaminodiphenyl ether, 3,4 '
-Diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-
Diaminodiphenylmethane, bis (4-amino-3,5
-Dimethylphenyl) methane, bis (4-amino-3,
5-diisopropylphenyl) methane, 3,3'-diaminodiphenyldifluoromethane, 3,4'-diaminodiphenyldifluoromethane, 4,4'-diaminodiphenyldifluoromethane, 3,3'-diaminodiphenylsulfone, 3,4 ' -Diaminodiphenyl sulfone,
4,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfide, 3,4'-diaminodiphenylsulfide, 4,4'-diaminodiphenylsulfide, 3,3'-diaminodiphenylketone, ,
4'-diaminodiphenyl ketone, 4,4'-diaminodiphenyl ketone, 2,2-bis (3-aminophenyl) propane, 2,2 '-(3,4'-diaminodiphenyl) propane, 2,2-bis (4-aminophenyl)
Propane, 2,2-bis (3-aminophenyl) hexafluoropropane, 2,2- (3,4'-diaminodiphenyl) hexafluoropropane, 2,2-bis (4-
Aminophenyl) hexafluoropropane, 1,3-bis (3-aminophenoxy) benzene, 1,4-bis (3-aminophenoxy) benzene, 1,4-bis (4
-Aminophenoxy) benzene, 3,3 '-(1,4-
Phenylenebis (1-methylethylidene)) bisaniline, 3,4 '-(1,4-phenylenebis (1-methylethylidene)) bisaniline, 4,4'-(1,4-phenylenebis (1-methylethylidene) ) Bisaniline, 2,2-bis (4- (3-aminophenoxy) phenyl) propane, 2,2-bis (4- (4-aminophenoxy) phenyl) propane, 2,2-bis (4-3-
(Aminophenoxy) phenyl) hexafluoropropane, 2,2-bis (4- (4-aminophenoxy) phenyl) hexafluoropropane, bis (4- (3-aminophenoxy) phenyl) sulfide, bis (4- (4
-Aminophenoxy) phenyl) sulfide, bis (4
Aromatic diamines such as-(3-aminophenoxy) phenyl) sulfone and bis (4- (4-aminophenoxy) phenyl) sulfone; 1,2-diaminoethane;
-Diaminopropane, 1,4-diaminobutane, 1,5
-Diaminopentane, 1,6-diaminohexane, 1,
7-diaminoheptane, 1,8-diaminooctane,
1,9-diaminononane, 1,10-diaminodecane,
Examples thereof include aliphatic diamines such as 1,11-diaminoundecane and 1,12-diaminododecane, and these can be used alone or in combination of two or more.

The adhesive layer composed of each of the above components has energy ray curability and heat curability, and can be used as an adhesive for fixing a wafer during dicing.
At the time of mounting, it can be used as an adhesive for bonding the chip and the lead frame. And, through thermal curing, finally a cured product with high impact resistance can be given, and also excellent in the balance between shear strength and peel strength,
Sufficient adhesive properties can be maintained even under severe hot and humid conditions.

The adhesive layer in the adhesive sheet of the present invention has the following features. (1) The elastic modulus at 250 ° C. is 10 MPa or less, in order to further improve the reflow crack resistance of the semiconductor device.
In addition, after irradiating an amount of energy rays corresponding to fixing the semiconductor element and further heating and curing, the water absorption rate must satisfy a physical property value of 1.5% by volume or less. In order to obtain a high semiconductor device, it is preferable to satisfy any of the following conditions (2) to (5).

(2) The condition of (1) is satisfied, and the residual volatile matter after irradiating an energy beam corresponding to fixing the semiconductor element to the adhesive layer is 3.0% by weight or less. (3) Supporting the obtained semiconductor device with an adhesive layer, which satisfies any one of the conditions (1) and (2) and irradiates the adhesive layer with an energy ray corresponding to fixing the semiconductor element to the adhesive layer. Peel strength after bonding to the member and heat curing is not less than 5.0N / 5mm x 5mm chip. (4) Satisfy any of the conditions of (1), (2) or (3) and have a saturated moisture absorption of 1.0% by volume or less. (5) When any of the conditions of (1) to (4) is satisfied and the semiconductor element is bonded to the support member, the inside of the adhesive layer and the interface between the adhesive layer and the support member The void volume ratio of the voids existing in (1) is 10% or less.

Further, the adhesive layer of the adhesive sheet of the present invention may be formed of gold,
A conductive filler such as silver, copper, nickel, aluminum, stainless steel, carbon, ceramic, or nickel or aluminum coated with silver can be added. In addition, gold, silver,
Copper, nickel, aluminum, stainless steel, silicon,
A heat conductive substance such as a metal material such as germanium or an alloy thereof can also be added.

Further, a coupling agent can be further added to the adhesive layer of the adhesive sheet of the present invention for the purpose of improving the adhesion and adhesion to the adherend after curing. The coupling agent is considered to have an organic functional group that reacts with the thermosetting component (B), and can improve the adhesiveness and adhesion without impairing the heat resistance of the cured product. The effect of improving also is exhibited. As the coupling agent, for example, a silane coupling agent,
Titanium coupling agents and the like can be mentioned, and among them, silane coupling agents are preferable in terms of versatility and cost merit.

Further, an organic polyvalent isocyanate compound, an organic polyvalent imine compound and the like can be added to the adhesive layer for the purpose of adjusting the initial adhesive strength and cohesive strength before irradiation with energy rays.

The organic polyvalent isocyanate compound includes, for example, aromatic polyvalent isocyanate compounds, aliphatic polyvalent isocyanate compounds, alicyclic polyvalent isocyanate compounds, and trimer of these polyvalent isocyanate compounds. And isocyanate-terminated urethane prepolymers obtained by reacting these polyvalent isocyanate compounds with polyol compounds.

The organic polyvalent isocyanate compound includes, for example, 2,4-tolylene diisocyanate,
6-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylene diisocyanate,
Diphenylmethane-4,4'-diisocyanate, diphenylmethane-2,4'-diisocyanate, 3-methyldiphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-di Isocyanates, dicyclohexylmethane-2,4'-diisocyanate,
Lysine isocyanate and the like can be mentioned.

The organic polyvalent imine compound includes, for example, N, N'-diphenylmethane-4,4'-bis (1
-Aziridinecarboxamide), trimethylolpropane-tri-β-aziridinylpropionate, tetramethylolmethane-tri-β-aziridinylpropionate, N, N′-toluene-2,4-bis (1 -Aziridinecarboxamide) triethylenemelamine and the like.

The adhesive layer may further contain a compound which is colored by irradiation with energy rays.
By including such a compound in the adhesive layer,
After the adhesive sheet is irradiated with energy rays, the adhesive sheet is colored, which increases the detection accuracy when detecting a wafer chip with an optical sensor and significantly reduces the incidence of malfunction during wafer chip pickup. Can be done. Further, there is obtained an effect that whether or not the adhesive sheet is irradiated with the energy ray can be immediately determined by visual observation.

Further, an expanding agent can be further added to the adhesive layer. By adding the expanding agent, the expansion after the polymerization and curing of the adhesive layer is further facilitated.

Further, an antistatic agent can be further added to the adhesive layer. By adding the antistatic agent, the static electricity generated at the time of expansion or at the time of pickup can be suppressed, and as a result, the reliability of the chip is improved.

The pressure-sensitive adhesive sheet of the present invention has a pressure-sensitive adhesive layer comprising the above-mentioned components, and the pressure-sensitive adhesive sheet of the present invention having such a pressure-sensitive adhesive layer comprises a support. Without using
It may be a self-supporting thin film of a composition comprising the above components, or may have a multilayer structure containing a base material layer and an adhesive layer formed using the above composition. .

As the base material of the adhesive sheet, for example, when ultraviolet rays are used as energy rays, polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride film Copolymer film, polyethylene terephthalate film, polybutylene terephthalate film, polyurethane film, ethylene vinyl acetate film, ionomer resin film, ethylene- (meth) acrylic acid copolymer film, ethylene- (meth) acrylate copolymer film, Transparent films such as a polystyrene film and a polycarbonate film may be mentioned, and a crosslinked film thereof may be used, and a laminated film thereof may be used.

When an electron beam is used as the energy beam, the support does not need to be transparent. Therefore, in addition to the above transparent film, an opaque film, a fluororesin film, or the like obtained by coloring them can be used. .

The substrate has a surface tension of preferably 4.0 Pa or less, more preferably 3.7 Pa or less, and particularly preferably 3.5 Pa or less.
Such a substrate having a low surface tension can be obtained by appropriately selecting the material, or can be obtained by applying a silicone resin or the like to the surface of the support and subjecting it to a release treatment.

The thickness of such a support is not particularly limited, but is usually 10 to 300 μm,
00 μm is preferable, and 50 to 150 μm is more preferable. Further, abrasive grains may be dispersed in the base material. By including the abrasive grains in the support, even if the cutting blade is cut into the support and an adhesive adheres to the cutting blade, clogging can be easily removed by the polishing effect of the abrasive grains. .

The adhesive sheet according to the present invention is prepared, for example, by coating an adhesive composition comprising the above components on a substrate by a known method such as a comma coater, a gravure coater, a die coater or a reverse coater. And dried.

There is no particular limitation on the thickness of the adhesive layer formed in this manner, and the size of the semiconductor element to be attached,
Although it can be appropriately selected according to the required conditions and the like, it is usually 3 to 100 μm, and preferably 10 to 60 μm.

Next, the adhesive sheet of the present invention and the method of using the same will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view of an adhesive sheet 1 of the present invention, in which an adhesive layer 3 is formed on a substrate 2. As shown in FIG. 2, when the peelable sheet 4 is provided on the upper surface of the adhesive sheet on the side of the adhesive layer, the peelable sheet 4 is removed before use.

Hereinafter, an example of a method of using the adhesive sheet 1 of the present invention will be described with reference to FIG. First, as shown in (I), the semiconductor wafer A is placed on the adhesive layer 3,
After bonded at room temperature or under heating, when dicing with a cutting means such as a dicing saw, a plurality of semiconductor elements A _1, as shown in _{(II), A 2, ...} , A 4 is pressure-sensitive adhesive layer 3 It can be obtained while being held on top, and various steps such as washing and drying are added as it is. Semiconductor wafer A at this time
The adhesive force between the adhesive layer 3 and the adhesive layer 3 is preferably 50 to 2000 g / 25 mm, more preferably 100 to 1500 g / 25 mm.
On the other hand, the adhesive force between the adhesive layer 3 and the base material 2 is usually 500 g / 2.
5 mm or less.

Next, as shown in (III), the adhesive layer 3 is irradiated with radiation B such as ultraviolet rays (UV) and electron beams (EB) from the substrate 2 side of the adhesive sheet 1. The attachment layer 3 is cured. When using ultraviolet rays as energy rays,
Usually, the illuminance is set in the range of 20 to 500 mW / cm ² , the irradiation time is set in the range of 0.1 to 150 seconds, and the center wavelength is set to about 36.
Preferably, it is 5 nm. Also, for example, when irradiating with an electron beam, various conditions can be set according to the above-described case of irradiating with ultraviolet rays. In addition, heating can be supplementarily performed during energy beam irradiation.

As described above, by irradiating the adhesive layer 3 with an energy ray, the energy ray-curable adhesive component (A) is cured and adheres to the semiconductor elements A ₁ , A ₂ ,..., A ₄ . The adhesive strength with the adhesion layer 3 increases. Adhesion value is 50-40
00 g / 25 mm is preferred, and 100-3000 g / 25 mm is more preferred. On the other hand, the adhesive strength between the adhesive layer 3 and the base material 2 is usually 1 to 500 g / 25 mm, preferably 100 g / 2
5 mm or less.

Therefore, by irradiating the energy ray B, the adhesive force between the semiconductor elements A ₁ , A ₂ ,..., A ₄ and the adhesive layer 3 is reduced. Is larger than the adhesive force between the semiconductor elements A ₁ ,
A ₂ ,..., A ₄ can be fixed and left on one side and peeled off from the support.

In the use of the pressure-sensitive adhesive sheet of the present invention, the irradiation with the energy beam B may be performed before the dicing step in order to suppress chip flying during the dicing step. That is, the semiconductor wafer A
Is placed on the adhesive layer 3 of the adhesive sheet, and then radiated with energy rays to increase the adhesive force between the semiconductor wafer A and the adhesive layer 3 and then diced (II) As shown in ( ₁₎ , semiconductor devices A ₁ , A ₂ ,..., A ₄ are obtained. This method
When the adhesive layer does not have sufficient adhesive force to hold the semiconductor wafer A, when the impact given to the semiconductor wafer at the time of dicing is large, when the desired size of the semiconductor element is small, etc. It is preferably applied to

Next, as shown in (IV), a desired chip interval is obtained by expanding the adhesive sheet.
As shown in (V), the semiconductor elements A ₁ , A ₂ ,..., A ₄ to be picked up by the push-up needle 5 from the lower surface of the substrate 2.
The push-up, the semiconductor device A _1, A _2, ..., a A _4, for example, picked up by the suction collet 6, as shown in (VI).

Then, the semiconductor elements A ₁ , A ₂ ,..., A ₄ are mounted on the lead frame 7 via the adhesive layer 3 as shown in (VII), and a heat bonding step (die bonding step) is performed. After that, it is cured by heating. For the conditions of die bonding,
The temperature is preferably 100 to 350 ° C, and 150 to 250 ° C.
Is more preferred. The time is preferably 0.1 to 20 seconds,
0.1 second to 10 seconds are more preferable, and 0.1 second to 5 seconds are particularly preferable. The pressure is preferably 0.1 to 30 gf / mm ² ,
0.1 to 4 gf / mm ² is more preferable, and 0.3 to ² gf / mm ² is particularly preferable. The preferred conditions of temperature, time and pressure can be considered in 18 ways by the above-mentioned combinations. However, appropriate conditions are selected according to the conditions of the raw material used for the adhesive sheet of the present invention, the semiconductor element to be attached, the semiconductor supporting substrate and the like. Can be. In addition, as a condition of the thermosetting, the time is from 10 minutes to
Five hours are preferable, and the temperature is preferably 100 to 200 ° C. By such thermocompression bonding, the thermosetting adhesive component is cured, and the semiconductor elements A ₁ , A ₂ ,..., A ₄ and the lead frame 7 can be firmly bonded.

The finally cured adhesive layer 3 has high heat resistance, and the cured product does not have one of the shear strength and the peel strength which is extremely low, has an excellent balance, and has a high impact resistance. Having. Further, even under severe hot and humid conditions, sufficient adhesive properties can be maintained.

FIG. 4 shows an example of a method for measuring the peel strength of the adhesive layer of the adhesive sheet using a push-pull gauge, and the measuring conditions will be described later. In FIG. 4, reference numeral 8 denotes a push-pull gauge, reference numeral 9 denotes a hot platen, and reference numeral 10 denotes a support installed on the hot platen to prevent a measurement sample from moving.

[0079]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples. In the following examples, the following was used as the energy ray-curable component (A).

(A) Energy-Curable Component As a (meth) acrylate copolymer, 55 parts by weight of butyl acrylate, 10 parts by weight of methyl methacrylate, 20 parts by weight of glycidyl methacrylate and 15 parts by weight of 2-hydroxyethyl acrylate were used. 100 parts by weight of a copolymer obtained by polymerization, having a weight average molecular weight of 900,000 and a glass transition temperature of -28 ° C., 100 parts by weight of dipentaerythritol hexaacrylate as an energy ray polymerizable compound, and 1 part as a photoinitiator. A mixture with 3 parts by weight of hydroxycyclohexyl phenyl ketone was defined as an energy ray-curable component (A).

The polyimides used in the following examples are all obtained by mixing equimolar acid anhydrides and diamines in a solvent and polymerizing the mixture by heating. In each of the following examples, polyimide A is a polyimide synthesized from 1,2- (ethylene) bis (trimellitate anhydride) and bis (4-amino-3,5-dimethylphenyl) methane, and polyimide B Is a polyimide synthesized from 1,2- (ethylene) bis (trimellitate anhydride) and 4,4'-diaminodiphenyl ether, and polyimide C is 1,2- (ethylene) bis (trimellitate anhydride) and 1,2- (ethylene) bis (trimellitate anhydride). Polyimide synthesized from bis (4-amino-3,5-diisopropylphenyl) methane. Polyimide D is composed of 1,2- (ethylene) bis (trimellitate anhydride) and 2,2-bis [4- ( 4
-Aminophenoxy) phenyl] propane, and polyimide E is 1,2- (ethylene) bis (trimellitate anhydride) and 1,10-
A polyimide synthesized from an equimolar mixture of (decamethylene) bis (trimellitate anhydride) and 2,2-bis [4- (4-aminophenoxy) phenyl] propane, and polyimide F is 1,10- (decamethylene ) Bis (trimellitate anhydride) and 2,2-bis [4- (4
-Aminophenoxy) phenyl] propane.

Example 1 An organic solvent 2 was added to 80 g of the polyimide, 20 g of the epoxy resin and 50 g of the energy ray-curable component (A) shown in Table 1.
Add 80 g and dissolve. Here, a predetermined amount of silver powder is added, stirred well, and uniformly dispersed to obtain a coating varnish. This coating varnish has a thickness of 90 formed by laminating a plasticized polyvinyl chloride layer and an ethylene / methacrylic acid copolymer layer.
An adhesive / adhesive sheet having an adhesive / adhesive layer having the composition and water absorption shown in Table 1 was obtained by applying and drying the μm laminated film on the ethylene / methacrylic acid copolymer layer side (surface tension: 3.5 Pa).

The adhesive sheet shown in Table 1 was attached to the back surface of a silicon wafer having a thickness of 300 μm and polished with # 2000, irradiated with ultraviolet rays, diced into 8 mm × 10 mm, and picked up together with the adhesive layer. The semiconductor element with the adhesive layer was placed on the tab of the lead frame at a temperature of 300 ° C., a pressure of 12.5 gf / mm ² , and a time of 5 seconds.
For Nos. To 8, the silicon chip was mounted by heating at a temperature of 230 ° C., a pressure of 0.6 gf / mm ² , and a time of 1 second, wire bonding was performed, and a sealing material (CEL-, manufactured by Hitachi Chemical Co., Ltd.) was used. 9000) to manufacture a semiconductor device. (QFP (Quad Flat Package) package 14 × 20 × 1.4mm, chip size 8 × 10mm,
42 alloy lead frame)

The semiconductor device after sealing is subjected to 85 ° C. and 85% RH.
And then heated at 240 ° C. for 10 seconds in an IR reflow oven. Thereafter, the semiconductor device was cast with a polyester resin, and a cross section cut with a diamond cutter was observed with a microscope, and a reflow crack generation rate (%) was measured by the following formula to evaluate reflow crack resistance.

(Equation 1) Table 1 shows the evaluation results.

[0085]

[Table 1]

The method for measuring the water absorption is as follows. After irradiating the adhesive sheet with ultraviolet rays until the adhesive layer becomes a self-supporting film, the film obtained by peeling the adhesive layer from the base material and cutting it into a size of 50 × 50 mm is used as a sample, and the sample is evacuated. After drying in a drier at 120 ° C. for 3 hours, and after cooling in a desiccator, the dry weight is measured and defined as M ₁ . Samples were removed from the immersed for 24 hours at room temperature in distilled water, wipe the sample surface with a filter paper, quickly weighed to the M _2.

The water absorption was calculated as follows: [(M ₂ −M ₁ ) / (M ₁ / d)] × 100 = water absorption (volume%) d is the density of the adhesive layer.

The method of measuring the film elastic modulus (MPa) is as follows. After irradiating the adhesive sheet with ultraviolet rays until the adhesive layer becomes a self-supporting film, the film obtained by peeling the adhesive layer from the base material is used as a sample, and a rheographic solid S type manufactured by Toyo Seisakusho Co., Ltd. is used. Using a heating rate of 5 ° C./min,
The dynamic viscoelasticity was measured at a frequency of 10 Hz, and the storage elastic modulus E ′ at 250 ° C. was defined as the elastic modulus.

Example 2 An organic solvent 2 was added to 80 g of the polyimide, 20 g of the epoxy resin and 50 g of the energy ray-curable component (A) shown in Table 2.
Add 80 g and dissolve. Here, a predetermined amount of silver powder is added, stirred well, and uniformly dispersed to obtain a coating varnish. This coating varnish has a thickness of 90 formed by laminating a plasticized polyvinyl chloride layer and an ethylene / methacrylic acid copolymer layer.
The layer was coated on the ethylene / methacrylic acid copolymer layer side (surface tension of 3.5 Pa) of the μm laminated film and dried to obtain a pressure-sensitive adhesive sheet having the composition shown in Table 2 and a saturated moisture absorption rate.

The adhesive sheet shown in Table 2 was attached to the back surface of a silicon wafer having a thickness of 300 μm and polished with # 2000, irradiated with ultraviolet rays, diced into 8 mm × 10 mm, picked up together with the adhesive layer, and obtained. In the No.1-6, the silicon chip with the adhesive layer was placed on the tab of the lead frame.
No. at a temperature of 300 ° C, a pressure of 12.5 gf / mm ² and a time of 5 seconds.
In No. 7, a silicon chip was mounted at a temperature of 230 ° C., a pressure of 0.6 gf / mm ² and a time of 1 second, wire bonding was performed, and a sealing material (CEL-, manufactured by Hitachi Chemical Co., Ltd.) was used.
9000) to manufacture a semiconductor device. (Q
FP (Quad Flat Package) package 14 × 20 × 1.
4mm, chip size 8 × 10mm, 42 alloy lead frame)

The semiconductor device after sealing is subjected to 85 ° C. and 85% RH.
And then heated at 240 ° C. for 10 seconds in an IR reflow oven. Thereafter, the semiconductor device was cast with a polyester resin, and a cross section cut with a diamond cutter was observed with a microscope, and a reflow crack generation rate (%) was measured by the following formula to evaluate reflow crack resistance.

(Equation 3) Table 2 shows the evaluation results.

[0091]

[Table 2]

The method of measuring the saturated moisture absorption is as follows. After irradiating the adhesive sheet with ultraviolet rays until the adhesive layer became a self-supporting film, the adhesive layer was peeled from the substrate and cut into a circular film having a diameter of 100 mm, which was used as a sample. The sample is placed in a vacuum dryer at 120 ° C, 3
Dried time, was allowed to cool in a desiccator, measuring the dry weight and M _1. The sample is taken out after absorbing moisture in a constant temperature and humidity chamber of 85 ° C. and 85% RH, and is weighed quickly. When the weighed value becomes constant, the weight is defined as M ₂ .

The saturated moisture absorption was calculated as [(M ₂ −M ₁ ) / (M ₁ / d)] × 100 = saturated moisture absorption (volume%). d is the density of the adhesive layer.

Example 3 160 g of dimethylacetamide and 160 g of cyclohexanone as solvents are added to and dissolved in 80 g of polyimide F, 20 g of epoxy resin and 50 g of energy-curable component. Here, 90 g of silver powder is added, stirred well, and uniformly dispersed to obtain a coating varnish. The coating varnish is formed by laminating a plasticized polyvinyl chloride layer and an ethylene / methacrylic acid copolymer layer on a side of the ethylene / methacrylic acid copolymer layer (with a surface tension of 3.mu.m) having a thickness of 90 .mu.m.
5Pa) and dried to obtain an adhesive sheet containing the remaining volatile components shown in Table 3.

The adhesive sheet shown in Table 3 was adhered to the back surface of a silicon wafer having a thickness of 300 μm and polished with # 2000, irradiated with ultraviolet rays, diced to 8 mm × 10 mm, and picked up together with the adhesive layer. A silicon chip with an adhesive layer is mounted on a tab of a lead frame at a temperature of 230 ° C., a pressure of 0.6 gf / mm ² , and a time of 1 second, wire bonding is performed, and a sealing material (Hitachi Chemical Industry Co., Ltd.) Made by company, trade name CEL-9000)
A semiconductor device was manufactured. (QFP (Quad Flat Package)
Package 14 × 20 × 1.4mm, chip size 8 × 1
0mm, 42 alloy lead frame)

The semiconductor device after sealing is heated to 85 ° C. and 85% RH.
And then heated at 240 ° C. for 10 seconds in an IR reflow oven. Thereafter, the semiconductor device was cast with a polyester resin, and a cross section cut with a diamond cutter was observed with a microscope, and a reflow crack generation rate (%) was measured by the following formula to evaluate reflow crack resistance.

(Equation 5) Table 3 shows the evaluation results.

[0096]

[Table 3]

The method for measuring the residual volatile matter is as follows. After irradiating the adhesive sheet with ultraviolet rays until the adhesive layer becomes a self-supporting film, the adhesive layer was peeled off from the substrate, and the film cut into a size of 50 × 50 mm was used as a sample. was a measured M _1, sample 200 ° C. in a hot air circulating constant temperature bath. after heating for 2 hours, and M ₂ as weighing,

The residual volatile content was calculated as [(M ₂ −M ₁ ) / M ₁ ] × 100 = remaining volatile content (vol%).

Example 4 160 g of dimethylacetamide and 160 g of cyclohexanone as a solvent were dissolved in 80 g of polyimide D, 20 g of epoxy resin and 50 g of an energy-curable component. Here, 90 g of silver powder is added, stirred well, and uniformly dispersed to obtain a coating varnish. The coating varnish is formed by laminating a plasticized polyvinyl chloride layer and an ethylene / methacrylic acid copolymer layer on a side of the ethylene / methacrylic acid copolymer layer (surface tension of 3.mu.m) having a thickness of 90 .mu.m.
5Pa) and dried to obtain an adhesive sheet having a void volume ratio shown in Table 4. Here, the void volume ratio is a void volume ratio of voids existing at the interface between the die bonding material and the support member when the semiconductor element is bonded to the support member.

The adhesive sheet shown in Table 4 was adhered to the back surface of a silicon wafer having a thickness of 300 μm and polished with # 2000, irradiated with ultraviolet rays, diced to 8 mm × 10 mm, and picked up together with the adhesive layer. A silicon chip with an adhesive layer is mounted on a tab of a lead frame at a temperature of 300 ° C., a pressure of 12.5 gf / mm ² and a time of 5 seconds, wire bonding is performed, and a sealing material (Hitachi Chemical Industry Co., Ltd.) A semiconductor device was manufactured by molding with a company name (CEL-9000). (QFP (Quad Flat Pack
age) Package 14 x 20 x 1.4 mm, chip size 8 x 10 mm, 42 alloy lead frame)

The semiconductor device after sealing is subjected to 85 ° C. and 85% RH.
And then heated at 240 ° C. for 10 seconds in an IR reflow oven. Thereafter, the semiconductor device was cast with a polyester resin, and a cross section cut with a diamond cutter was observed with a microscope, and a reflow crack generation rate (%) was measured by the following formula to evaluate reflow crack resistance.

(Equation 7) Table 4 shows the evaluation results.

[0101]

[Table 4]

The method for measuring the void volume ratio is as follows. The lead frame and the silicon chip were adhered with an adhesive layer to prepare a sample, and a photograph was taken of an image observed from above the sample using a soft X-ray apparatus. The area ratio of voids in the photograph was measured by an image analyzer, and the area ratio of voids as seen through from the upper surface = the volume ratio of voids (%).

Example 5 80 g of polyimide D and 20 g of epoxy resin shown in Table 5
And 50 g of energy-curable component and 320 g of organic solvent
And dissolve. Here, a predetermined amount of silver powder is added, stirred well, and uniformly dispersed to obtain a coating varnish. This coating varnish is applied on the ethylene / methacrylic acid copolymer layer side (3.5 Pa surface tension) of a 90 μm-thick laminated film formed by laminating a plasticized polyvinyl chloride layer and an ethylene / methacrylic acid copolymer layer. It was applied and dried to obtain an adhesive sheet having the composition and peel strength shown in Table 5. here,
The peel strength is the peel strength of the film-shaped organic die bonding material at the stage when the semiconductor element is bonded to the support member via the adhesive layer.

The adhesive sheet shown in Table 5 was adhered to the back surface of a silicon wafer having a thickness of 300 μm and polished with # 2000. A silicon chip with an adhesive layer was placed on a tab of a lead frame at a temperature of 300 ° C., a pressure of 12.5 gf / mm ² and a time of 5 seconds for Nos. 1 to 5,
For Nos. 6 and 7, the temperature was 230 ° C and the pressure was 0.6 gf / m.
The silicon chip was mounted, wire-bonded, and molded with a sealing material (trade name: CEL-9000, manufactured by Hitachi Chemical Co., Ltd.) at m ² for 1 second to manufacture a semiconductor device. (QFP (Quad Flat Package) package 14 × 20 × 1.4mm, chip size 8 × 10mm,
42 alloy lead frame)

The semiconductor device after sealing is subjected to 85 ° C. and 85% RH.
And then heated at 240 ° C. for 10 seconds in an IR reflow oven. Thereafter, the semiconductor device was cast with a polyester resin, and a cross section cut with a diamond cutter was observed with a microscope, and a reflow crack occurrence rate (%) was measured according to the following formula, and the reflow crack resistance was evaluated.

(Equation 8) Table 5 shows the evaluation results.

[0106]

[Table 5]

Peel Strength Measuring Method A sticky adhesive sheet was adhered to the back surface of a silicon wafer having a thickness of 300 μm and polished with # 2000, and after irradiation with ultraviolet rays, 5 mm × 5 mm
The silicon chip with the adhesive layer is picked up together with the adhesive layer, and the obtained silicon chip with the adhesive layer is bonded to a support member for supporting a semiconductor element such as a tab surface of a lead frame. Then, as shown in FIG. 4, the peel strength was measured at a test speed of 0.5 mm / min using a push-pull gauge as shown in FIG. In this case, the measurement was carried out at 240 ° C. for 20 seconds. However, when the temperature at which the semiconductor device was mounted was different depending on the intended use of the semiconductor device, the measurement was carried out at the semiconductor device mounting temperature.

[0108]

According to the first aspect of the present invention, the pressure-sensitive adhesive sheet can control the fixing force of the wafer at the time of dicing and the releasability at the time of pick-up, and can simultaneously apply the adhesive for the semiconductor element and the film for the dicing process. It has high adhesiveness and excellent reflow crack resistance.

The pressure-sensitive adhesive sheet according to the second aspect is the first aspect.
And has higher solder reflow crack resistance. The adhesive sheet according to the third aspect has the effects of the inventions according to the first and second aspects, and is excellent in adhesive strength and impact resistance. The adhesive sheet according to the fourth aspect has the effects of the inventions according to the first, second and third aspects, and has higher solder reflow crack resistance. The adhesive sheet according to the fifth aspect has the effects of the inventions according to the first to fourth aspects, and has higher solder reflow crack resistance.

The pressure-sensitive adhesive sheet according to the sixth aspect is the first aspect.
The present invention has the effects of the inventions described in (1) to (5) and is further excellent in workability. The adhesive sheet according to claims 7 and 8 has the effects of the inventions according to claims 1 to 6, and is excellent in workability. The adhesive sheet according to the ninth aspect has the effects of the inventions according to the first to eighth aspects, and is more excellent in adhesive strength.

According to the method of manufacturing a semiconductor device according to the tenth aspect, the semiconductor device can be manufactured by simple steps. The semiconductor device according to claim 11 or 12 has high solder reflow crack resistance and excellent reliability.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of the adhesive sheet of the present invention.

FIG. 2 is a cross-sectional view of the adhesive sheet of the present invention.

FIG. 3 is a process chart showing an example of a method for using the adhesive sheet of the present invention.

FIG. 4 is a cross-sectional view illustrating a peel strength measuring method using a push-pull gauge.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Adhesive sheet 2 ... Substrate 3 ... Adhesive layer 4 ... Releasable sheet 5 ... Push-up needle 6 ... Suction collet 7 ... Lead frame 8 ... Push-pull gauge 9 ... Hot plate 10 ... Support A ... Semiconductor wafer A ₁ to A ₄ ... semiconductor element B ... radiation

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Takashi Masuko 48 Wadai, Tsukuba, Ibaraki Prefecture Within Hitachi Chemical Co., Ltd. (72) Inventor Hiroyuki Kawakami 48 Wadai, Tsukuba, Ibaraki Prefecture On-site F term (reference) 4J004 AA02 AA11 AA18 AB01 AB05 AB06 FA05 FA08 4J040 EC002 EF002 FA132 FA231 JB09 KA13 NA20 5F047 AA11 BA23 BA24 BA33 BA34 BA39 BB03 BB19

Claims (12)

[Claims] 1. An adhesive sheet comprising: a base material layer; and an adhesive layer containing (A) an energy ray-curable component and (B) a thermosetting component. 250 ° C for adhesive layer
, The elasticity of which is not more than 10 MPa, the amount of energy rays corresponding to fixing the adhesive layer to the semiconductor element is irradiated, and the water absorption after heating and curing is not more than 1.5% by volume. Wearing sheet. 2. The adhesive according to claim 1, wherein the adhesive layer has a residual volatile content of 3.0% by weight or less after irradiating an energy beam corresponding to fixing the semiconductor element to the adhesive layer. Adhesive sheet. 3. The adhesive layer is irradiated with energy rays corresponding to fixing the semiconductor element to the adhesive layer, the obtained semiconductor element with the adhesive layer is adhered to a supporting member, and further heated. Peel strength after curing is 4.9N / 5mm x 5mm
3. The adhesive sheet according to claim 1, which is a chip or more. 4. The pressure-sensitive adhesive sheet according to claim 1, wherein the pressure-sensitive adhesive layer has a saturated moisture absorption after heating and curing of 1.0% by volume or less. 5. After the adhesive layer adheres the semiconductor element and the support member through the adhesive layer and further heat-curs, the inside of the adhesive layer and the adhesive layer and The adhesive sheet according to any one of claims 1 to 4, wherein a void volume ratio of voids existing at an interface of the support member is 10% or less. 6. The adhesive sheet according to claim 1, wherein the substrate is of an energy ray transmission type. 7. The adhesive sheet according to claim 1, wherein the adhesive layer further comprises a film-forming polymer. 8. The adhesive sheet according to claim 7, wherein the film-forming polymer is a polyimide resin. 9. The adhesive sheet according to claim 1, wherein the adhesive layer further contains a filler. 10. A step of (I) mounting a semiconductor wafer on the adhesive layer of the adhesive sheet according to any one of claims 1 to 9, and (II) irradiating an energy ray from the base material side. Fixing a semiconductor wafer with an adhesive layer, (III) dicing the semiconductor wafer with an adhesive layer to obtain a semiconductor element with an adhesive layer, (IV) picking up a semiconductor element with an adhesive layer from a base material, (V) adhering the semiconductor element with an adhesive layer to a supporting substrate by applying heat or pressure to the supporting element. 11. A semiconductor device having a structure in which a semiconductor element and a semiconductor support member are bonded via the adhesive layer of the adhesive sheet according to any one of claims 1 to 9. 12. A semiconductor device manufactured by using the method for manufacturing a semiconductor device according to claim 10.