WO2014119161A1

WO2014119161A1 - Sheet for optical semiconductor, and optical semiconductor device

Info

Publication number: WO2014119161A1
Application number: PCT/JP2013/083869
Authority: WO
Inventors: はるか小名; 広和松田; 片山　博之
Original assignee: 日東電工株式会社
Priority date: 2013-02-04
Filing date: 2013-12-18
Publication date: 2014-08-07
Also published as: JP2014150221A; TW201431693A; CN103965794A; CN203923079U

Abstract

This sheet for optical semiconductor is provided with: an adhesive layer formed of a first silicone resin; and a non-adhesive layer, which is provided on one surface in the thickness direction of the adhesive layer, and which is formed of a second silicone resin.

Description

Sheet for optical semiconductor and optical semiconductor device

The present invention relates to an optical semiconductor sheet and an optical semiconductor device, and more particularly to an optical semiconductor sheet including an optical semiconductor sheet and an optical semiconductor element sealed thereby.

Rubbery silicone resin sheets are used in various applications because of their excellent durability and heat resistance.

Since such a silicone resin sheet has adhesiveness on the surface, the silicone resin sheet adheres to other members during transportation, contaminates the surroundings, or separately laminates a release sheet to cover the surface. It needs to be protected. Moreover, when surface adhesiveness is too high, the release property at the time of releasing a release sheet from a silicone resin sheet may fall.

Therefore, for example, a silicone rubber sheet for thermocompression bonding obtained by dusting scaly powder such as talc or mica on the surface has been proposed (for example, see Patent Document 1 below).

The silicone rubber sheet for thermocompression bonding of Patent Document 1 is reduced in surface adhesiveness by dusted powder, reduces contamination to the surroundings, and further improves the releasability.

JP-A-10-219199

However, since the silicone rubber sheet for thermocompression bonding described in Patent Document 1 has insufficient transparency due to the dusted powder, an optical semiconductor device obtained by sealing an optical semiconductor element thereby can be obtained by: There is a problem that the luminous efficiency is lowered.

An object of the present invention is to provide an optical semiconductor sheet that is excellent in transparency while reducing non-adhesiveness by reducing contamination to the surroundings, and an optical semiconductor device in which a decrease in luminous efficiency is suppressed. is there.

The sheet for optical semiconductors of the present invention comprises an adhesive layer made of a first silicone resin, and a non-adhesive layer made of a second silicone resin, provided on one surface in the thickness direction of the adhesive layer. .

This optical semiconductor sheet is provided with a non-adhesive layer on one surface in the thickness direction of the adhesive layer, thereby reducing contamination caused by the adhesion layer adhering to surrounding members and improving non-adhesiveness. However, transparency can be improved.

In the sheet for optical semiconductors of the present invention, it is preferable that the second silicone resin is solid at room temperature and is thermoplastic.

In this optical semiconductor sheet, since the second silicone resin is thermoplastic, the non-adhesive layer can be adhered to the adhesive layer by heating. Therefore, it is possible to prevent a gap from being generated between the non-adhesive layer and the adhesive layer. As a result, the transparency of the optical semiconductor sheet can be further improved.

In the optical semiconductor sheet of the present invention, it is preferable that the first silicone resin is a B-stage thermosetting silicone resin.

According to this sheet for optical semiconductors, the first silicone resin is a B-stage thermosetting silicone resin, so that the object can be easily and reliably coated. After covering the object, the object can be reliably sealed by heating the sheet for optical semiconductors to the C stage.

In the optical semiconductor sheet of the present invention, it is preferable that the second silicone resin is silsesquioxane.

According to this optical semiconductor sheet, since the second silicone resin is silsesquioxane, it is possible to easily ensure thermoplasticity while being excellent in durability and transparency.

In the optical semiconductor sheet of the present invention, it is preferable that the silsesquioxane contains a functional group that reacts with the first silicone resin.

In this sheet for optical semiconductors, silsesquioxane contains a functional group that reacts with the first silicone resin, so that the second silicone resin reacts with the first silicone resin, thereby causing adhesion. The adhesion between the layer and the non-adhesive layer can be further improved.

The optical semiconductor sheet of the present invention is preferably used for sealing an optical semiconductor element.

Since this optical semiconductor sheet is used for sealing an optical semiconductor element, it is possible to improve the reliability of the optical semiconductor element and suppress a decrease in light emission efficiency.

In the optical semiconductor sheet of the present invention, it is preferable that the non-adhesive layer is formed of a sheet made of the second silicone resin.

According to this optical semiconductor sheet, since the non-adhesive layer is formed from a sheet made of the second silicone resin, the thickness of the non-adhesive layer can be ensured uniformly, and the long-term storage stability is excellent. .

Further, in the optical semiconductor sheet of the present invention, it is preferable that the non-adhesive layer is formed in a layer form from particles made of the second silicone resin.

According to this optical semiconductor sheet, the non-adhesive layer is formed in a layer form from the particles, so that the process can be simplified.

The optical semiconductor device of the present invention includes an optical semiconductor sheet and an optical semiconductor element sealed with the optical semiconductor sheet, and the optical semiconductor sheet includes an adhesive layer made of a first silicone resin, And a non-adhesive layer made of a second silicone resin, provided on one surface in the thickness direction of the adhesive layer.

Since this optical semiconductor device includes an optical semiconductor element sealed with an optical semiconductor sheet having excellent transparency, it is possible to suppress a decrease in light emission efficiency.

The optical semiconductor sheet of the present invention can improve the transparency while reducing the contamination caused by the adhesion layer adhering to surrounding members and improving the non-adhesiveness.

The optical semiconductor device of the present invention can suppress a decrease in light emission efficiency.

FIG. 1 is a process diagram illustrating a method for producing the first embodiment of the optical semiconductor sheet of the present invention. FIG. 1 (a) is a process of preparing an adhesive layer and a non-adhesive layer, respectively. b) shows the process of bonding the adhesive layer and the non-adhesive layer together. FIG. 2 is a process diagram illustrating a method of manufacturing an optical semiconductor device using the optical semiconductor sheet shown in FIG. 1B as a sealing sheet, and FIG. 2A is a second release sheet. FIG. 2B shows a step of sealing the optical semiconductor element with the optical semiconductor sheet. FIG. 3 is a process diagram for explaining a modification of the method of manufacturing an optical semiconductor device using the first embodiment of the optical semiconductor sheet of the present invention as a sealing sheet, and FIG. FIG. 3B shows a step of sealing the optical semiconductor element with the optical semiconductor sheet, in which the optical semiconductor sheet and the substrate from which the release sheet 1 is peeled are disposed to face each other. FIG. 4 shows a cross-sectional view of a second embodiment of the sheet for optical semiconductors of the present invention. FIG. 5 is a process diagram for explaining a method of manufacturing an optical semiconductor device using the optical semiconductor sheet of FIG. 4 as a sealing sheet. FIG. 5A shows a state in which the second release sheet is peeled off. FIG. 5B shows a step of sealing the optical semiconductor element with the optical semiconductor sheet. FIG. 6 is a process diagram illustrating a modified example of a method of manufacturing an optical semiconductor device using the second embodiment of the optical semiconductor sheet of the present invention as a sealing sheet, and FIG. FIG. 6B shows a step of sealing the optical semiconductor element with the sheet for optical semiconductor, in which the optical semiconductor sheet from which the release sheet is peeled and the substrate are disposed to face each other.

<First Embodiment>
In FIG. 1, the vertical direction of the paper is the vertical direction (thickness direction, first direction), the horizontal direction of the paper is the horizontal direction (second direction, the direction perpendicular to the first direction), and the paper thickness direction is the front-back direction (third direction). , A direction orthogonal to the first direction and the second direction). Each figure after FIG. 2 is based on the above-mentioned direction.

1B, an optical semiconductor sheet 1 includes an adhesive layer 2 and a non-adhesive layer 3 provided on the upper surface (one surface in the thickness direction) of the adhesive layer 2. A first release sheet 4 is provided under the adhesive layer 2. A second release sheet 5 is provided on the adherend layer 3.

The pressure-sensitive adhesive layer 2 is laminated on the upper surface of the first release sheet 4 and extends from the first silicone resin in the surface direction (direction orthogonal to the thickness direction, that is, both the left-right direction and the front-rear direction). Is formed.

Examples of the first silicone resin include a thermoplastic silicone resin and a thermosetting silicone resin. Preferably, a thermosetting silicone resin is used.

Examples of the thermosetting silicone resin include a two-stage curable silicone resin and a one-stage curable silicone resin.

The two-stage curable silicone resin has a two-stage reaction mechanism, and is heat-cured by B-stage (semi-curing) by the first-stage reaction and C-stage (full-curing) by the second-stage reaction. It is a functional silicone resin. On the other hand, the one-step curable silicone resin has a one-step reaction mechanism and is a thermosetting silicone resin that is completely cured by the first-step reaction.

The B stage is a state between the A stage in which the thermosetting silicone resin is in a liquid state and the fully cured C stage. Curing and gelation proceed slightly, and the elastic modulus is that of the C stage. The state is smaller than the elastic modulus.

The thermosetting silicone resin is preferably a two-stage curable silicone resin.

The first silicone resin (specifically, thermosetting silicone resin) may be prepared from a silicone resin composition (specifically, thermosetting silicone resin composition) containing a plurality of types of components. it can.

Examples of the uncured body of the two-stage curable silicone resin composition (before the first stage curing) include a condensation reaction / addition reaction curable silicone resin composition.

The condensation reaction / addition reaction curable silicone resin composition is a thermosetting silicone resin composition that can undergo a condensation reaction and an addition reaction by heating, and more specifically, a condensation reaction by heating, Thermosetting silicone that can be B-staged (semi-cured), and then further heated to an addition reaction (specifically, for example, hydrosilylation reaction) to be C-staged (fully cured) It is a resin composition.

In such a condensation reaction / addition reaction curable silicone resin composition, an addable or condensable functional group preferably remains, and more preferably an addable functional group remains.

Examples of the functional group capable of addition reaction include alkenyl groups having 2 to 10 carbon atoms such as vinyl group, allyl group, propenyl group, butenyl group, pentenyl group, hexenyl group, heptenyl group, octenyl group, for example, cyclohexenyl group. And cycloalkenyl groups having 3 to 10 carbon atoms such as norbornenyl group. An alkenyl group having 2 to 5 carbon atoms is preferable, and a vinyl group is more preferable. Furthermore, examples of the functional group capable of addition reaction include a hydrosilyl group (—SiH).

The functional group capable of addition reaction can be used alone or in combination.

As the functional group capable of addition reaction, a combination of an alkenyl group and a hydrosilyl group is preferable.

On the other hand, examples of functional groups capable of condensation reaction include hydrosilyl groups, silanol groups (—Si—OH), halogen atoms (specifically, bromine atoms, chlorine atoms, fluorine atoms, iodine atoms, etc.), alkoxy groups ( Specific examples include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, an isobutoxy group, a pentyloxy group, and a hexyloxy group), a phenoxy group, and an acetoxy group.

Preferred examples of the functional group capable of condensation reaction include a hydrosilyl group and a silanol group.

The hydrosilyl group can also serve as a functional group capable of addition reaction and a functional group capable of condensation reaction.

The functional group capable of condensation reaction can be used alone or in combination.

The functional group capable of condensation reaction is preferably a combination of a hydrosilyl group and a silanol group.

As such a condensation reaction / addition reaction curable silicone resin composition, for example, a silicone resin composition described in JP 2012-82320 A and the like can be mentioned.

The adhesive layer 2 is preferably formed from a B-stage thermosetting silicone resin (composition).

The elastic modulus at 25 ° C. of the adhesive layer 2 is, for example, 0.01 MPa or more, preferably 0.025 MPa or more, and, for example, 1.0 MPa or less, preferably 0.5 MPa or less. The elastic modulus of the adhesive layer 2 is measured using a nanoindenter. The elastic modulus of the non-adhesive layer 3 described later is also measured by the same method.

If the elastic modulus of the adhesive layer 2 is not less than the above lower limit, the shape retaining property of the adhesive layer 2 can be secured and the handleability of the adhesive layer 2 can be improved. If the elastic modulus of the adhesive layer 2 is less than or equal to the above upper limit, the optical semiconductor element 8 can be reliably covered when the optical semiconductor element 8 (see FIG. 2) described later is sealed.

Further, when the thickness is 600 μm, the light transmittance of the adhesive layer 2 is, for example, 80% or more, preferably 85% or more, more preferably 90% or more, further preferably, with respect to light having a wavelength of 500 nm. , 95% or more, and 99.99% or less. The light transmittance of the adhesive layer 2 is measured by a spectrophotometer equipped with an integrating sphere according to the description of “Testing method of total light transmittance of plastic-transparent material” of JIS K 7361-1 (1997 edition). Is done. The light transmittance of the non-adhesive layer 3 to be described later is also measured by the same method.

The adhesive layer 2 has tack (adhesiveness) at room temperature (specifically, 25 ° C., the same applies hereinafter). For example, the peel adhesive strength at 25 ° C. with respect to the polypropylene (PP) sheet (non-stretched, thickness 50 μm) of the adhesive layer 2 is, for example, 0.3 N / 2 cm or more, preferably 1 N / 2 cm or more. It is 8 N / 2 cm or less, preferably 5 N / 2 cm or less.

In addition, the peeling adhesive force of the adhesive layer 2 will be described in detail in a later example. The peeling adhesive strength of the non-adhesive layer 3 and the optical semiconductor sheet 1 described later is also measured by the same method.

The thickness of the adhesive layer 2 is, for example, 50 μm or more, preferably 100 μm or more, and, for example, 2000 μm or less, preferably 1500 μm or less.

The non-adhesive layer 3 is formed from a sheet made of the second silicone resin.

Examples of the second silicone resin include silsesquioxane and silicone particles. Preferably, silsesquioxane is used.

The structure of the “Si—O—Si” skeleton of silsesquioxane is not particularly limited, and examples thereof include a cage shape, a ladder shape, and a random shape.

Examples of the silsesquioxane include polymethylsilsesquioxane, polymethylphenylsilsesquioxane, polyphenylsilsesquioxane, and the like. Preferably, polymethylsilsesquioxane is used.

Silsesquioxane can also contain a functional group that reacts with the functional group of the first silicone resin in the molecule. Specifically, silsesquioxane can contain a functional group that reacts with an addable or condensable functional group of the first silicone resin in the molecule.

Examples of the functional group contained in silsesquioxane include a vinyl group and a hydroxyl group. Preferably, a vinyl group is used.

As the second silicone resin, a commercially available product can be used. Specific examples of polymethylsilsesquioxane include KR-220L (manufactured by Shin-Etsu Chemical Co., Ltd.), and vinyl group-containing polymethylsil Examples of sesquioxane include product number 52365-8 (manufactured by Aldrich), OL1123 (manufactured by Hybrid Plastics), and the like.

The second silicone resin is solid at room temperature and is thermoplastic.

Specifically, the softening point of the second silicone resin is, for example, 60 ° C. or higher, preferably 70 ° C. or higher, and for example, 200 ° C. or lower, preferably 150 ° C. or lower.

If the softening point is not more than the above upper limit, the non-adhesive layer 3 can be surely softened during thermocompression bonding described later. Furthermore, when the non-adhesive layer 3 is easily softened and melted and an optical semiconductor element 8 described later is wire-bonded to the substrate 7, damage to the wire can be prevented. On the other hand, if the softening point is not less than the above lower limit, the handleability at room temperature can be improved.

The softening point of the second silicone resin is that about 1 g of the second silicone resin is placed on the hot plate, and the hot silicone is heated at a temperature rising temperature of 5 ° C./min, so that the second silicone resin is softened. This is measured by visually observing this.

Further, the non-adhesive layer 3 is tack-free at normal temperature (that is, has no adhesiveness).

The elastic modulus at 25 ° C. of the non-adhesive layer 3 is, for example, 0.5 MPa or more, preferably 1 MPa or more, and for example, 15 MPa or less, preferably 10 MPa or less.

When the thickness is 10 μm, the light transmittance of the non-adhesive layer 3 is, for example, 80% or more, preferably 85% or more, more preferably 90% or more, further preferably, with respect to light having a wavelength of 500 nm. It is 95% or more and 99.99% or less.

The thickness of the non-adhesive layer 3 is, for example, 0.1 μm or more, preferably 1 μm or more, and for example, 100 μm or less, preferably 50 μm or less.

Examples of the first release sheet 4 include polymer sheets such as polyolefin sheets (such as polyethylene sheets and PP sheets) and polyester sheets (such as PET sheets), such as ceramic sheets, such as metal foil. Preferably, a polymer sheet is used. Further, the surface (lower surface) of the first release sheet 4 can be subjected to a peeling treatment such as a fluorine treatment.

The second release sheet 5 is formed from the same material as the first release sheet 4. Further, the second release sheet 5 can be subjected to the same release treatment as that of the first release sheet 4.

Next, a method for manufacturing the optical semiconductor sheet 1 will be described.

In this method, first, the adhesive layer 2 is laminated on the first release sheet 4 as shown in the lower view of FIG.

Specifically, the adhesive layer 2 is formed on the first release sheet 4 by applying a varnish made of the first silicone resin to the upper surface of the first release sheet 4 and then heating the coating film. To do. In the case where the first silicone resin contains a condensation reaction / addition reaction curable silicone resin composition, the condensation reaction is advanced by heating the coating film. Thereby, the adhesion layer 2 is formed from the thermosetting silicone resin of a B stage.

Separately, a non-adhesive layer 3 is prepared.

Specifically, as shown in the upper view of FIG. 1A, the non-adhesive layer 3 is placed on the second release sheet 5 (however, in FIG. 1A, the relative position with the adhesive layer 2 is clearly shown). In order to achieve this, for convenience, it is laminated “under”.

In order to form the non-adhesive layer 3 on the second release sheet 5, as shown in the upper view of FIG. 1A, first, the second silicone resin is dissolved in a solvent, Then, the solution is applied to the upper surface of the second release sheet 5 to form a coating film.

Examples of the solvent include hydrocarbon solvents such as hexane and heptane, and ketone solvents such as acetone and methyl ethyl ketone.

The solid content (second silicone resin) concentration in the solution is, for example, 10% by mass or more, preferably 25% by mass or more, and for example, 90% by mass or less, preferably 75% by mass or less.

Thereafter, the solvent in the coating film is removed by heating.

The heating time is, for example, 0.1 minute or more, preferably 0.5 minutes or more, and for example, 100 minutes or less, preferably 50 minutes or less. Moreover, heating temperature is 50 degreeC or more, for example, Preferably, it is 75 degreeC or more, for example, is 150 degrees C or less, Preferably, it is 120 degrees C or less.

Thereby, the non-adhesive layer 3 is formed on the upper surface of the second release sheet 5.

Next, as shown in FIG. 1B, the adhesive layer 2 and the non-adhesive layer 3 are bonded together.

Specifically, the adhesive layer 2 laminated on the first release sheet 4 and the non-adhesive layer 3 laminated on the second release sheet 5 (non-adhesive layer laminated on the upper surface of the second release sheet 5) 3) is attached.

In adhering the adhesive layer 2 and the non-adhesive layer 3, they are pressure-bonded. The pressure in the pressure bonding is, for example, 0.001 MPa or more, and, for example, 300 MPa or less, preferably 50 MPa or less.

On the other hand, in sticking the adhesive layer 2 and the non-adhesive layer 3, the non-adhesive layer 3 may be simply laminated (specifically, placed) on the adhesive layer 2 based on the adhesiveness of the adhesive layer 2. it can.

Thus, the optical semiconductor sheet 1 composed of the adhesive layer 2 and the non-adhesive layer 3 is obtained by being sandwiched between the first release sheet 4 and the second release sheet 5 in the thickness direction. A second release sheet 5 is laminated on the upper surface of the non-adhesive layer 3, and a first release sheet 4 is laminated on the lower surface of the adhesive layer 2.

Immediately after production (specifically, within 30 minutes from production, hereinafter the same), the upper surface of the optical semiconductor sheet 1, that is, a polypropylene (PP) sheet (non-stretched, thickness 50 μm) on the side surface of the non-adhesive layer 3 is 25 ° C. The peel adhesive strength is, for example, 0.40 N / 2 cm or less, preferably 0.20 N / 2 cm or less, more preferably 0.10 N / 2 cm or less, and further preferably 0.05 N / 2 cm or less. For example, it is 0.001 N / 2 cm or more.

The light transmittance of the optical semiconductor sheet 1 immediately after manufacture (the optical semiconductor sheet 1 excluding the first release sheet 4 and the second release sheet 5) with respect to light having a wavelength of 500 nm is, for example, 80.0% or more, preferably Is 90.0% or more, more preferably 92.5% or more, still more preferably 95.0% or more, and less than 100%.

Thereafter, the optical semiconductor sheet 1 shown in FIG. 1B immediately after manufacture is handled, that is, specifically, stored and / or transported (distributed) for a long period of time. In other words, at least the second release sheet 5 is provided on the optical semiconductor sheet 1 from the production of the optical semiconductor sheet 1 shown in FIG. In other words, immediately before using the optical semiconductor sheet 1 of FIG. 1B, the second release sheet 5 is peeled from the non-adhesive layer 3 as indicated by the phantom line of FIG.

Next, a method for manufacturing the optical semiconductor device 6 by sealing the optical semiconductor element 8 using the optical semiconductor sheet 1 as a sealing sheet will be described with reference to FIG.

In this method, first, the second release sheet 5 is peeled from the non-adhesive layer 3 as shown by the phantom line in FIG.

Thereafter, as shown in FIG. 2A, the optical semiconductor sheet 1 from which the second release sheet 5 has been peeled and the substrate 7 are arranged to face each other.

Specifically, the optical semiconductor sheet 1 (see FIG. 2A) obtained by inverting the optical semiconductor sheet 1 from which the second release sheet 5 shown by the phantom line in FIG. The adhesive layer 3 and the optical semiconductor element 8 mounted on the upper surface of the substrate 7 are opposed to each other.

The substrate 7 has a substantially flat plate shape. Specifically, a conductor layer (not shown) including electrode pads (not shown) and wiring (not shown) is laminated on the insulating substrate as a circuit pattern. It is formed from the laminated board. The insulating substrate is made of, for example, a silicon substrate, a ceramic substrate, a polyimide resin substrate, or the like, and is preferably made of a ceramic substrate, specifically, a sapphire substrate.

The conductor layer is formed of a conductor such as gold, copper, silver, or nickel. The electrode pad is preferably made of silver or copper from the viewpoint of electrical conductivity. The thickness of the board | substrate 7 is 30 micrometers or more, for example, Preferably, it is 50 micrometers or more, for example, is 1500 micrometers or less, Preferably, it is 1,000 micrometers or less.

The optical semiconductor element 8 is a light emitting diode element or a laser diode provided on the upper surface of the substrate 7. The optical semiconductor element 8 is connected to the electrode pad of the substrate 7 by flip chip mounting or wire bonding, thereby being electrically connected to the conductor layer. The optical semiconductor element 8 is, for example, an element that emits blue light (specifically, a blue LED). The thickness of the optical semiconductor element 8 is, for example, not less than 0.05 mm and not more than 1 mm.

Next, as shown in FIG. 2B, the optical semiconductor element 8 is embedded (covered) with the optical semiconductor sheet 1.

Specifically, the optical semiconductor sheet 1 is thermocompression bonded to the substrate 7.

Preferably, the optical semiconductor sheet 1 and the substrate 7 are pressed flat.

As the pressing condition, the temperature is a temperature at which the non-adhesive layer 3 is plasticized or higher, specifically, the softening point of the second silicone resin of the non-adhesive layer 3 or higher, and more specifically, for example, It is 80 ° C. or higher, preferably 100 ° C. or higher, and for example, 220 ° C. or lower, preferably 200 ° C. or lower. The pressure is, for example, 0.01 MPa or more, and for example, 1 MPa or less, preferably 0.5 MPa or less. The pressing time is, for example, 1 to 10 minutes.

By this thermocompression bonding, as shown in FIG. 2 (b), the non-adhesive layer 3 is softened and melted to be compatible with the adhesive layer 2, and more specifically, the sealing layer 9 that is harmoniously integrated is formed. Form. Then, the optical semiconductor element 8 is embedded in the sealing layer 9. That is, the upper surface and side surfaces of the optical semiconductor element 8 are covered with the sealing layer 9.

Note that the upper surface of the substrate 7 exposed from the optical semiconductor element 8 is covered with a sealing layer 9.

Thus, the optical semiconductor sheet 1 (sealing layer 9) is adhered to the optical semiconductor element 8 and the substrate 7.

Then, by this thermocompression bonding, when the adhesive layer 2 contains a B-stage thermosetting silicone resin, the adhesive layer 2 becomes a C-stage state (completely cured).

More specifically, when the pressure-sensitive adhesive layer 2 is a condensation reaction / addition reaction curable silicone resin composition, when a remaining functional group capable of addition reaction (specifically, a hydroxyl group) remains, When the addition reaction proceeds in the adhesive layer 2 and the non-adhesive layer 3 contains the above-described functional groups (specifically, vinyl groups), the functional groups of the adhesive layer 2 and the functionalities of the non-adhesive layer 3 The group undergoes an addition reaction (specifically, a hydrosilyl addition reaction).

The sealing layer 9 is tack free at room temperature. The elastic modulus at 25 ° C. of the sealing layer 9 is, for example, 0.001 MPa or more, and, for example, 0.3 MPa or less, preferably 0.1 MPa or less.

In addition, as the elastic modulus at 25 ° C. of the sealing layer 9, the elastic modulus of the sealing layer 9 after heating the optical semiconductor sheet 1 at 150 ° C. for 3 hours, as referred to in the evaluation of examples described later. In this case, the elastic modulus is, for example, 0.5 MPa or more, preferably 1 MPa or more, and for example, 15 MPa or less, preferably 10 MPa or less.

The light transmittance for light having a wavelength of 500 nm when the thickness of the sealing layer 9 is 600 μm is, for example, 80% or more, preferably 85% or more, and for example, 99.9% or less, preferably 99% or less.

Thereby, the optical semiconductor device 6 in which the optical semiconductor element 8 is sealed by the optical semiconductor sheet 1 is obtained.

Thereafter, if necessary, the first release sheet 4 is peeled off from the non-adhesive layer 3 as indicated by the phantom lines in FIG.

And since this non-adhesive layer 3 is provided in the upper surface of the adhesion layer 2 in this sheet | seat 1 for optical semiconductors as shown in FIG.1 (b), it originates in the adhesion layer 2 adhering to a surrounding member. It is possible to reduce contamination and improve non-stickiness. Specifically, non-adhesiveness to the second release sheet 5 and non-adhesiveness to the first release sheet 4 (non-adhesiveness when the optical semiconductor sheet 1 is pulled out from the winding roll) can be improved. it can.

Further, in the optical semiconductor sheet 1 shown in FIG. 1B, the second release sheet 5 prevents foreign substances such as dust from adhering to the adhesive layer 2, and further prevents light from external impact during transportation. The semiconductor sheet 1 can also be protected.

Further, a space necessary for transporting the optical semiconductor sheet 1, specifically, conventionally, a space for preventing adhesion to other members is narrowed or eliminated, so that a large amount of the optical semiconductor sheet 1 can be efficiently used. Can be well stored or transported.

Moreover, the transparency of the optical semiconductor sheet 1 can be improved.

Moreover, in this sheet | seat 1 for optical semiconductors, since the 2nd silicone resin is thermoplasticity, the non-adhesion layer 3 may closely_contact | adhere to the adhesion layer 2 by the heating at the time of sealing in sealing of the optical semiconductor element 8. FIG. it can. Therefore, it is possible to prevent a gap from being generated between the non-adhesive layer 3 and the adhesive layer 2. As a result, the transparency of the optical semiconductor sheet 1 can be further improved.

In the optical semiconductor sheet 1, if the first silicone resin is a B-stage thermosetting silicone resin, the object, specifically, the optical semiconductor element 8 can be embedded (covered) easily and reliably. can do. Then, after the covering of the object, specifically, after the optical semiconductor element 8 is sealed, the optical semiconductor element 8 can be reliably sealed by heating the optical semiconductor sheet 1 to a C stage. it can.

Moreover, in this sheet | seat 1 for optical semiconductors, when the 2nd silicone resin of the non-adhesion layer 3 is silsesquioxane, it can ensure the above-mentioned thermoplasticity easily, being excellent in durability and transparency. it can.

In this sheet for optical semiconductors 1, if the silsesquioxane contains a functional group that reacts with the first silicone resin, the second silicone resin reacts with the first silicone resin. The adhesion between the adhesive layer 2 and the non-adhesive layer 3 can be further improved.

In addition, since the optical semiconductor sheet 1 is used for sealing the optical semiconductor element 8, it is possible to improve the reliability of the optical semiconductor element 8 and to suppress a decrease in light emission efficiency.

Moreover, according to this optical semiconductor sheet 1, since the non-adhesive layer 3 is formed from a sheet made of the second silicone resin, the thickness of the non-adhesive layer 3 can be ensured uniformly, Excellent long-term storage.

Moreover, since this optical semiconductor device 6 includes the optical semiconductor element 8 sealed with the optical semiconductor sheet 1 having excellent transparency, it is possible to suppress a decrease in light emission efficiency.

<Modification>
In the first embodiment, as shown by the solid line in FIG. 1B, the optical semiconductor sheet 1 in which the second release sheet 5 is laminated on the non-adhesive layer 3 is handled (specifically, long-term storage). And / or transport). In other words, at least the second release sheet 5 is provided on the optical semiconductor sheet 1 from the production of the optical semiconductor sheet 1 shown by the solid line in FIG. .

However, as shown by the phantom lines in FIG. 1B, first, the second release sheet 5 is peeled off from the non-adhesive layer 3 of the optical semiconductor sheet 1 immediately after manufacture, and then the second release sheet 5 The peeled sheet for optical semiconductors 1 can be handled as it is.

Moreover, the sheet | seat 1 for optical semiconductors is wound, specifically, as FIG.1 (b) refers, the adhesion layer 2 and the 1st release sheet 4 (not shown) laminated | stacked on it are laminated | stacked. Can be accommodated in a roll shape (not shown in FIG. 1B) with the non-adhesive layer 3 interposed therebetween, and the optical semiconductor sheet 1 can be smoothly drawn out from the roll. .

In such an optical semiconductor sheet 1, the second release sheet 5 is peeled in advance, so that the thickness is reduced and the optical semiconductor sheet 1 can be efficiently stored in a roll shape. it can.

In the first embodiment, the adhesive layer 2 and the non-adhesive layer 3 are compatible when the optical semiconductor element 8 is sealed. For example, as shown by the broken line in FIG. And may be distinguished. In that case, the non-adhesive layer 3 is continuously formed on the upper surface and side surface of the optical semiconductor element 8 and the upper surface of the substrate 7 exposed from the optical semiconductor element 8.

Furthermore, in the first embodiment, as shown in FIG. 2, the optical semiconductor element 8 pre-mounted on the substrate 7 is embedded and sealed with the optical semiconductor sheet 1, but for example, although not illustrated, For example, the optical semiconductor element 8 that is not yet mounted on the substrate 7 and supported by a support base (not shown) or the like can be attached to the optical semiconductor sheet 1.

In the first embodiment, the non-adhesive layer 3 and the optical semiconductor element 8 are opposed to each other as shown in FIG. 2A. For example, as shown in FIG. The semiconductor element 8 can also be opposed.

In this case, first, the optical semiconductor sheet 1 in FIG. 1B is not turned upside down, and the adhesive layer 2 in the optical semiconductor sheet 1 is indicated by an imaginary line and an imaginary line arrow in FIG. Thus, the 1st release sheet 4 is peeled. Thereby, the lower surface of the adhesion layer 2 is exposed.

Next, the adhesive layer 2 and the optical semiconductor element 8 are opposed to each other.

Next, as shown in FIG. 3B, the optical semiconductor element 8 is embedded (covered) with the optical semiconductor sheet 1. Specifically, the optical semiconductor sheet 1 is thermocompression bonded to the substrate 7.

Thereby, the adhesive layer 2 covers and seals the upper surface and side surfaces of the optical semiconductor element 8.

Thus, the optical semiconductor device 6 is obtained.

Further, a filler and / or a phosphor (described later) can be added to the first silicone resin and / or the second silicone resin.

Examples of the filler include silica (silicon dioxide), barium sulfate, barium carbonate, barium titanate, titanium oxide, zirconium oxide, magnesium oxide, zinc oxide, iron oxide, aluminum hydroxide, calcium carbonate, layered mica, and carbon black. Diatomaceous earth, glass fiber, silicone resin fine particles and the like.

The phosphor is a particle having a wavelength conversion function and is not particularly limited as long as it is a known phosphor used in the optical semiconductor device 6 (see FIG. 2B). For example, blue light is converted into yellow light. Known phosphors such as a yellow phosphor that can be converted and a red phosphor that can convert blue light into red light can be used.

The yellow phosphor, for _{_{_{example, Y 3 Al 5 O 12:}}} Ce (YAG ( yttrium aluminum _{_{_{garnet): Ce), Tb 3 Al}}} 3 O 12: Ce (TAG ( terbium-aluminum-garnet): Ce), etc. Garnet-type phosphors having a garnet-type crystal structure, such as oxynitride phosphors such as Ca-α-SiAlON.

Examples of the red phosphor include nitride phosphors such as CaAlSiN ₃ : Eu and CaSiN ₂ : Eu.

Further, the filler and the phosphor are in the form of particles, and the shape thereof is not particularly limited, and examples thereof include a substantially spherical shape, a substantially flat plate shape, and a substantially needle shape. The average value of the maximum length of the filler and the phosphor and the average particle diameter (in the case of a substantially spherical shape) is, for example, 0.1 μm or more, preferably 0.2 μm or more. For example, it is 500 μm or less, preferably 200 μm or less.

The blending ratio of the filler and the phosphor is adjusted to such an extent that the excellent effect (specifically, transparency) of the present invention is not hindered, and specifically, the first silicone resin and / or the second silicone resin. The amount is, for example, 0.01 parts by mass or more, preferably 1 part by mass or more, and for example, 80 parts by mass or less, preferably 70 parts by mass or less with respect to 100 parts by mass of the silicone resin.

Second Embodiment
4 and 5, members similar to those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

In the first embodiment, as shown in FIG. 1, the non-adhesive layer 3 is formed from a sheet, but as shown in FIG. 4, it can also be formed from particles as a layer.

As shown in FIG. 4, the optical semiconductor sheet 1 includes an adhesive layer 2 and a non-adhesive layer 3 provided in a layered manner on the upper surface of the adhesive layer 2. A second release sheet 5 is provided on the conductive layer 3. A first release sheet 4 is provided under the adhesive layer 2.

The non-adhesive layer 3 is formed in a layer shape that spreads in the surface direction from particles made of the second silicone resin.

The shape of each particle made of the second silicone resin is not particularly limited, and examples thereof include a substantially spherical shape, a substantially plate shape (or a substantially scaly shape), a substantially needle shape, and an indefinite shape (lump shape). In FIG. 4, the particles are drawn with a substantially spherical cross section, but the shape is not limited as described above.

The average value of the maximum length of particles (in the case of a spherical shape, the average particle diameter) is, for example, 0.01 μm or more, preferably 1 μm or more, and, for example, 100 μm or less, preferably 50 μm or less. It is.

As such particles, those previously formed into the above shape can be used, or relatively large particles can be formed into the above shape by pulverization (including grinding). Preferably, relatively large particles are formed into the above shape by pulverization.

The particles cover the upper surface of the pressure-sensitive adhesive layer 2 without substantially exposing the particles, and the particles are laminated in close contact with the upper surface of the pressure-sensitive adhesive layer 2. The plurality of particles are arranged adjacent to each other in the plane direction. Furthermore, although not shown in FIG. 4, the particles may overlap each other in the thickness direction.

The average thickness of the non-adhesive layer 3 is, for example, 0.1 μm or more, preferably 1 μm or more, and for example, 50 μm or less, preferably 30 μm or less. The average thickness of the non-adhesive layer 3 is calculated, for example, by observing the cross section of the layer.

Next, a method for manufacturing the optical semiconductor sheet 1 shown in FIG. 4 will be described.

First, as shown in FIG. 4, the adhesive layer 2 is laminated on the first release sheet 4.

Next, the non-adhesive layer 3 is laminated on the upper surface of the adhesive layer 2.

In order to laminate the non-adhesive layer 3 on the upper surface of the adhesive layer 2, particles made of the second silicone resin are applied to the upper surface of the adhesive layer 2. Specifically, particles are adhered and absorbed in advance on a cotton cloth such as gauze, and the gauze is rubbed against the upper surface of the adhesive layer 2. Alternatively, the particles are sprinkled from above the adhesive layer 2.

Thereafter, the second release sheet 5 is laminated on the non-adhesive layer 3.

Thus, the optical semiconductor sheet 1 composed of the adhesive layer 2 and the non-adhesive layer 3 is obtained by being sandwiched between the first release sheet 4 and the second release sheet 5 in the thickness direction.

The optical transmittance of the optical semiconductor sheet 1 immediately after production (the optical semiconductor sheet 1 excluding the first release sheet 4 and the second release sheet 5) with respect to light having a wavelength of 500 nm is such that the non-adhesive layer 3 is layered from particles. In consideration of the formation, it is lower than the light transmittance of the first embodiment, and is, for example, 95% or less, further 90% or less with respect to the light transmittance of the first embodiment. % Or more. Specifically, the light transmittance of the optical semiconductor sheet 1 with respect to light having a wavelength of 500 nm is, for example, 60% or more, preferably 70% or more, and, for example, 99% or less, preferably 90% or less. It is.

The peel adhesive strength at 25 ° C. with respect to the upper surface of the optical semiconductor sheet 1 immediately after manufacture, that is, the polypropylene (PP) sheet (non-stretched, thickness 50 μm) on the side surface of the non-adhesive layer 3 is, for example, 0.40 N / 2 cm or less, preferably Is 0.20 N / 2 cm or less, for example, 0.001 N / 2 cm or more.

Then, using this optical semiconductor sheet 1 as a sealing sheet, the optical semiconductor element 8 is sealed to manufacture the optical semiconductor device 6 except that the first release sheet 4 is peeled off. This is the same as in the first embodiment.

The elastic modulus at 25 ° C. of the sealing layer 9 is, for example, 0.5 MPa or more, preferably 1 MPa or more, and for example, 15 MPa or less, preferably 10 MPa or less.

The light transmittance of the sealing layer 9 with respect to light having a wavelength of 500 nm is, for example, 80% or more, preferably 90% or more, and, for example, 99.9% or less, preferably 99% or less. .

And according to the sheet 1 for optical semiconductors, the non-adhesive layer 3 is formed in a layer form from particles, and therefore the process can be simplified. That is, since the non-adhesive layer 3 can be formed by applying particles, the manufacturing process can be simplified.

<Modification>
In the second embodiment, the second release sheet 5 is provided on the optical semiconductor sheet 1 as shown by the solid line in FIG. 4. For example, as shown by the virtual line in FIG. The second release sheet 5 can be peeled from the sheet 1 for use, and then the optical semiconductor sheet 1 from which the second release sheet 5 has been peeled can be handled (specifically, long-term storage and / or transportation). .

In the second embodiment, the non-adhesive layer 3 and the optical semiconductor element 8 are opposed to each other as shown in FIG. 5A. For example, as shown in FIG. And the optical semiconductor element 8 can be made to face each other.

In this case, first, the adhesive layer 2 and the optical semiconductor element 8 are opposed to each other.

Next, as shown in FIG. 6B, the optical semiconductor element 8 is embedded (covered) by the optical semiconductor sheet 1. Specifically, the optical semiconductor sheet 1 is thermocompression bonded to the substrate 7.

Thus, the optical semiconductor device 6 is obtained.

The numerical values in the following examples and the like can be substituted for the numerical values (that is, the upper limit value or the lower limit value) described in the above embodiment.

Example 1
(Corresponding to the first embodiment)
1. Preparation of Adhesive Layer An adhesive layer was formed on the upper surface of the first release sheet made of a PET sheet according to Example 1 of JP2012-82320A (see the lower diagram in FIG. 1 (a)). .

The adhesive layer was prepared with a thickness of 600 μm from a B-stage thermosetting silicone resin (first silicone resin, condensation reaction / addition reaction curable silicone resin composition, unreacted hydrosilyl group remained) ( (See the lower view of FIG. 1 (a)).
2. Preparation of non-adhesive layer KR-220L (second silicone resin, polymethylsilsesquioxane, softening point 75 ° C.) was dissolved in acetone to a solid content concentration of 50 mass% to prepare a solution, Then, the prepared solution was apply | coated to the non-processed surface of the 2nd release sheet which consists of PET sheets so that the thickness after a heating might be set to about 10 micrometers.

Thereafter, the coating film was heated at 100 ° C. for 30 minutes to remove acetone, thereby preparing a non-adhesive layer on the upper surface of the second release sheet (see the upper view of FIG. 1A).
3. Production of Sheet for Optical Semiconductor Thereafter, the adhesive layer and the non-adhesive layer were bonded together at a pressure of 0.01 MPa (see FIG. 1B).

Thus, an optical semiconductor sheet composed of an adhesive layer and a non-adhesive layer was produced between the first release sheet and the second release sheet.

Example 2
(Corresponding to the first embodiment)
A sheet for optical semiconductors was produced in the same manner as in Example 1 except that vinyl group-containing polymethylsilsesquioxane (second silicone resin, softening point 70 ° C.) was used instead of KR-220L. .

Example 3
(Corresponding to the second embodiment)
1. Preparation of adhesive layer The adhesive layer was prepared like Example 1 (refer FIG. 4).
2. Preparation of non-adhesive layer KR-220L (second silicone resin, polymethylsiloxane, softening point 75 ° C.) was ground using a mortar and pestle to form particles having an average maximum length of 10 μm. This was adhered to and absorbed by the gauze, and particulate KR-220L was uniformly (evenly) applied to the entire upper surface of the adhesive layer with the gauze.

Thereby, a non-adhesive layer was formed on the upper surface of the adhesive layer (see FIG. 4). The average thickness of the non-adhesive layer was 30 μm.

Thus, an optical semiconductor sheet composed of an adhesive layer and a non-adhesive layer was produced between the first release sheet and the second release sheet (see FIG. 4).

Example 4
(Corresponding to the second embodiment)
A sheet for optical semiconductors was produced in the same manner as in Example 3 except that vinyl group-containing polymethylsilsesquioxane (second silicone resin, softening point 70 ° C.) was used instead of KR-220L. (See FIG. 4).

Comparative Example 1
An optical semiconductor sheet was produced in the same manner as in Example 1 except that the non-adhesive layer was not provided.

Comparative Example 2
An optical semiconductor sheet was produced in the same manner as in Example 3 except that talc (particulate, spherical, average particle diameter 10 μm) was used instead of KR-220L (see FIG. 4).
(Evaluation)
The following items were evaluated. The results are shown in Table 1.
1. Light transmittance 1-1. Initial light transmittance (immediately after production) A. Optical Semiconductor Sheet Using a spectrophotometer as the initial total light transmittance, the light transmittance for light with a wavelength of 500 nm of the optical semiconductor sheet (adhesive layer and non-adhesive layer) immediately after production of each Example and each Comparative Example Measured.

Specifically, a spectrophotometer equipped with an integrating sphere (U-4100, Hitachi, in accordance with the description of “Testing method of total light transmittance of plastic-transparent material” in JIS K 7361-1 (1997 edition). The light transmittance of the sheet for optical semiconductors from which the first release sheet and the second release sheet were peeled was measured by Seisakusho Co., Ltd.

B. Adhesive layer and non-adhesive layer The light transmittances of the adhesive layer prepared in Examples 1 to 4 and Comparative Examples 1 and 2 and the non-adhesive layer prepared in Examples 1 and 2 were determined in the same manner as described above. It was measured.

1-2. Light transmittance after heating The light transmittance of the sheet for optical semiconductor of each example and each comparative example after heating at 150 ° C. for 3 hours was also measured by the same method as described above.
2. Peel test (peel adhesion)
2-1. Peeling adhesive strength of optical semiconductor sheet A sample made of PP was bonded to the side surface of the adhesive layer in the optical semiconductor sheet immediately after production of Examples 1 to 4 and Comparative Example 2, and cut into a width of 2 cm. Was prepared.

Thereafter, the sample was subjected to a 180-degree peel test in which the separator was peeled from the optical semiconductor sheet at an angle of 180 degrees using a universal testing machine (Autograph, manufactured by Shimadzu Corporation). The separator peeling rate was 30 cm / min. The temperature during the test was 25 ° C.

For Comparative Example 1, a peel test was performed by the same method as above except that a separator was bonded to the upper surface of the adhesive layer.

2-2. Peeling adhesive strength of adhesive layer The adhesive layers prepared in Examples 1 to 4 and Comparative Examples 1 and 2 were subjected to a 180-degree peeling test by the same method as described above.
3. Elastic modulus (indenter method)
3-1. Adhesive Layer The elastic modulus at 25 ° C. of the adhesive layers prepared in Examples 1 to 4 and Comparative Examples 1 and 2 was measured using a nanoindenter.

3-2. Non-adhesive layer About the non-adhesive layer prepared in Example 1 and 2, the elasticity modulus in 25 degreeC was measured using the nanoindenter.

Although the above invention has been provided as an exemplary embodiment of the present invention, this is merely an example and should not be interpreted in a limited manner. Variations of the present invention that are apparent to one of ordinary skill in the art are within the scope of the following claims.

The optical semiconductor sheet is used for sealing semiconductor elements.

DESCRIPTION OF SYMBOLS 1 Sheet | seat for optical semiconductors 2 Adhesion layer 3 Non-adhesion layer 6 Optical semiconductor device 8 Optical semiconductor element

Claims

An adhesive layer made of a first silicone resin;
A sheet for optical semiconductors, comprising: a non-adhesive layer made of a second silicone resin, provided on one surface in the thickness direction of the adhesive layer.
2. The sheet for optical semiconductors according to claim 1, wherein the second silicone resin is solid at normal temperature and is thermoplastic.
2. The optical semiconductor sheet according to claim 1, wherein the first silicone resin is a B-stage thermosetting silicone resin. 3.
The sheet for optical semiconductors according to claim 1, wherein the second silicone resin is silsesquioxane.
The sheet for optical semiconductors according to claim 4, wherein the silsesquioxane contains a functional group that reacts with the first silicone resin.
The optical semiconductor sheet according to claim 1, wherein the optical semiconductor sheet is used for sealing an optical semiconductor element.
2. The optical semiconductor sheet according to claim 1, wherein the non-adhesive layer is formed of a sheet made of the second silicone resin. 3.
2. The optical semiconductor sheet according to claim 1, wherein the non-adhesive layer is formed into a layer from particles made of the second silicone resin. 3.
A sheet for optical semiconductors;
An optical semiconductor element sealed by the optical semiconductor sheet,
The optical semiconductor sheet is:
An adhesive layer made of a first silicone resin;
An optical semiconductor device comprising: a non-adhesive layer made of a second silicone resin, provided on one surface in the thickness direction of the adhesive layer.