JP2010159411A - Semi-cured silicone resin sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a silicone resin sheet with a semi-cured form, excellent in light resistance, heat resistance and sealable an optical semiconductor element and excellent in handleability; a method for producing the sheet; a resin cured product obtained by curing the sheet; and a sealing material for an optical semiconductor element including the sheet; and an optical semiconductor device sealed by the sealing material. <P>SOLUTION: The semi-cured silicone resin sheet is obtained by performing a condensation reaction of a composition for a silicone resin containing a silicon compound having a substituent enabling a condensation reaction, and a silicon compound having a substituent enabling an addition reaction. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a semi-cured silicone resin sheet. More specifically, a silicone resin sheet having a semi-cured state that is excellent in light resistance and heat resistance and capable of sealing an optical semiconductor element, a method for producing the sheet, a cured resin product obtained by curing the sheet, and The present invention relates to an optical semiconductor element sealing material including the sheet, and an optical semiconductor device sealed with the sealing material.

  For high-power white LED devices that are being studied for application to general lighting, sealing materials that are excellent in light resistance and heat resistance are required, and in recent years, so-called “addition-curable silicones” are frequently used.

  This addition-curable silicone is obtained by thermally curing a mixture of a silicone derivative having a vinyl group in the main chain and a silicone derivative having a SiH group in the main chain in the presence of a platinum catalyst. For example, in Patent Document 1, by introducing an organopolysiloxane into a composition and setting the molar ratio of hydrogen atoms and alkenyl groups bonded to silicon in the composition to a specific range, transparency and insulation are achieved. A resin composition capable of obtaining a cured product having excellent properties is disclosed.

  In Patent Document 2, a silicone resin having at least two alkenyl groups bonded to a silicon atom in one molecule, an organohydrogensilane having at least two hydrogen atoms bonded to a silicon atom in one molecule, and / or A resin composition containing an organohydrogenpolysiloxane is disclosed.

  In Patent Document 3, as a silicone resin component having a SiH group, a linear polyorganohydrogensiloxane having a silicon atom-bonded hydrogen atom (Si—H group) in the middle of a molecular chain, and a linear Si— A composition that provides a cured product with excellent strength by using a specific amount of polyorganohydrogensiloxane having H groups at both ends of the molecular chain is disclosed.

  On the other hand, addition-curing silicone resins usually use a highly active platinum catalyst, so once the curing reaction starts, it is extremely difficult to stop the reaction halfway, and form a semi-cured state (B stage). It is difficult. Therefore, it is known that it is effective to add phosphorus, nitrogen, sulfur compounds and acetylenes as reaction inhibitors in order to reduce the catalytic activity of the platinum catalyst (see, for example, Patent Document 4).

  In general, a white LED device emits white light by combining a near-ultraviolet or blue LED and a phosphor that emits light when excited by the wavelength of the light source. For example, a type in which an LED is sealed with a resin containing a fluorescent material as in Patent Document 5, and a resin containing a fluorescent material is sprayed and applied after the LED is sealed with a transparent resin as in Patent Document 6 There is a type to do. Further, Patent Document 7 discloses an apparatus in which a sheet-like resin layer in which a fluorescent material is uniformly distributed is provided on a light-transmitting resin layer from the viewpoint of improving emission luminance and reducing emission color unevenness. .

JP 2000-198930 A JP 2004-186168 A JP 2008-150437 A JP-A-6-118254 JP-A-7-99345 Japanese Patent Laid-Open No. 10-200165 JP 2004-343149 A

  However, although conventional addition-curable silicones are excellent in durability, they are made of a viscous liquid before the curing reaction, so that handling becomes complicated and the viscosity may change depending on the surrounding environment. It is still not satisfactory.

  In addition, since compounds known as reaction inhibitors affect the durability of the resin, further reaction control methods are required.

  An object of the present invention is to provide a silicone resin sheet having a semi-cured state that is excellent in light resistance and heat resistance and capable of encapsulating an optical semiconductor element and excellent in handleability, a method for producing the sheet, and curing the sheet. Another object of the present invention is to provide a cured resin product, an optical semiconductor element sealing material including the sheet, and an optical semiconductor device sealed with the sealing material.

The present invention
[1] A semi-cured silicone resin obtained by condensation reaction of a silicon compound having a substituent capable of condensation reaction and a silicone resin composition containing a silicon compound having a substituent capable of addition reaction Sheet,
[2] The silicone resin sheet according to [1], wherein the silicone resin composition further contains phosphor inorganic powder,
[3] The silicone resin sheet according to [2], wherein the silicone resin composition further contains fine particles,
[4] A semi-cured form comprising a step of heating a silicon resin composition containing a silicon compound having a substituent capable of condensation reaction and a silicon compound having a substituent capable of addition reaction at 40 to 120 ° C. Manufacturing method of silicone resin sheet,
[5] A cured silicone resin obtained by completely curing the silicone resin sheet according to any one of [1] to [3],
[6] An optical semiconductor element sealing material comprising the silicone resin sheet according to any one of [1] to [3],
[7] An optical semiconductor device formed by sealing an optical semiconductor element using the optical semiconductor element sealing material according to [4] [8] The silicone resin sheet according to [2] or [3] is completely cured. A silicone resin sheet obtained by laminating the semi-cured silicone resin sheet described in [1] on the cured silicone resin layer, and [9] a semi-cured silicone resin sheet encapsulates the optical semiconductor element. Thus, the present invention relates to an optical semiconductor device that is sealed using the silicone resin sheet described in [8].

  Since the silicone resin sheet of the present invention is excellent in light resistance and heat resistance and is in a semi-cured state, it has an excellent effect that the optical semiconductor element can be easily sealed.

  The silicone resin sheet of the present invention is obtained by subjecting a silicone compound having a substituent capable of a condensation reaction and a silicone resin composition containing a silicon compound having a substituent capable of an addition reaction to a condensation reaction. It has a great feature in that the resin is in a semi-cured state.

  A semi-cured state (hereinafter also referred to as B stage) of a general epoxy resin or the like is usually achieved by controlling the thermosetting conditions. Specifically, for example, B stage pellets are prepared by heating at 80 ° C. to partially advance the monomer crosslinking reaction. The obtained pellets are subjected to a desired molding process and then heated at 150 ° C. to be completely cured. On the other hand, an addition-curable silicone resin is obtained by hydrosilylation reaction of a silicone derivative having a vinyl group in the main chain and a silicone derivative having a SiH group in the main chain. Usually, a highly active platinum catalyst is used. In addition, once the curing reaction starts, it is very difficult to stop the reaction in the middle, and it is difficult to form the B stage. Although a method of controlling the reaction with a reaction inhibitor is also known, in the present invention, curing from the A stage (uncured state) to the B stage (semi-cured state) (first stage curing), and the B stage Curing from the (half-cured state) to the C-stage (full cured state) (second-stage curing) is performed by separate reactions, that is, the first-stage curing is performed by a condensation reaction, and the second-stage curing is performed by an addition reaction. By controlling the reaction utilizing the fact that the reaction temperature conditions of the two reactions are different, the respective curing steps are advanced step by step to obtain a semi-cured resin sheet in which the first-stage curing is completed. . Further, since the second stage curing reaction proceeds not by natural factors but by external factors, it is possible to maintain the state at the time when the first stage curing is completed, that is, the semi-cured state. Furthermore, by controlling the density of functional groups involved in each reaction, it is possible to control physical properties such as viscoelasticity, toughness, and tack of the semi-cured product and the fully cured product. In this specification, a semi-cured product, that is, a semi-cured product (B stage) is a state between a solvent-soluble A stage and a completely cured C stage, which is cured, gel Means a product that is slightly advanced, swells in a solvent but does not completely dissolve, softens by heating but does not melt, and a completely cured product (completely cured product) is a completely cured gel It means a thing in the state of progressing.

  In addition, by referring to Patent Documents 5, 6, and 7, a sheet-like resin layer in which the phosphor material is uniformly dispersed can be prepared. In general, since the specific gravity of the phosphor material is heavy and the affinity of the dispersion medium to the resin is different, it is difficult to form a completely uniform distribution state because it easily settles in the resin. In addition, there is a problem that uneven distribution of the phosphor occurs and uneven emission color occurs. However, the resin composition in the present invention has a viscosity suitable as a dispersion medium for particles and has good affinity with the phosphor particles, so that the phosphor material is well dispersed, Distribution unevenness is suppressed and emission color unevenness is reduced.

  Furthermore, when a general resin sheet has a low elastic modulus, after the temperature cycle test, there may be a problem such as peeling due to thermal expansion and contraction of the resin. Therefore, fine particles can be contained in the resin, but since the distribution in the resin is not sufficient, the effect of improving the elastic modulus is not satisfactory. However, since the resin composition in the present invention has a good affinity for fine particles, the fine particles are well dispersed, the sheet elastic modulus is increased, the sheet quality is improved, and the reliability is increased.

  The silicone resin sheet of the present invention can be obtained by subjecting a silicon compound having a substituent capable of condensation reaction and a composition for silicone resin containing a silicon compound having a substituent capable of addition reaction.

  The silicon compound having a substituent capable of condensation reaction (hereinafter also referred to as a condensation reaction monomer) is not particularly limited as long as it has the substituent.

  Examples of the substituent capable of the condensation reaction include a hydroxyl group, an amino group, an alkoxy group, a carboxyl group, an ester group, a halogen atom and the like, and preferably a hydroxyl group and an alkoxy group. There is no particular limitation on the number of substituents contained in one molecule.

  Such compounds include, for example, formula (I):

(In the formula, R ¹ represents a monovalent hydrocarbon group, n is an integer of 1 or more, provided that all R ¹ may be the same or different).
The both-end silanol type silicone oil represented by these is preferable.

R ¹ in formula (I) represents a monovalent hydrocarbon group, and examples thereof include saturated or unsaturated, straight chain, branched chain or cyclic hydrocarbon groups. The number of carbon atoms of the hydrocarbon group is preferably 1 to 20 and more preferably 1 to 10 from the viewpoint of ease of preparation and thermal stability. Specific examples include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a phenyl group, a naphthyl group, a cyclohexyl group, and a cyclopentyl group. Of these, a methyl group is preferred from the viewpoints of transparency and light resistance. In formula (I), all R ¹ groups may be the same or different, but all are preferably methyl groups.

  N in the formula (I) represents an integer of 1 or more, and is preferably an integer of 1 to 10000, more preferably an integer of 1 to 1000, from the viewpoint of stability and handleability.

Examples of the compound represented by the formula (I) include both-end silanol-type polydimethylsiloxane, both-end silanol-type polymethylphenylsiloxane, both-end silanol-type polydiphenylsiloxane, and the like. These may be used alone or in combination of two or more. Can be used in combination. Among these, compounds in which R ¹ is all a methyl group and n is an integer of 1 to 1000 are preferable.

  The compound represented by the formula (I) may be a commercially available product or may be synthesized according to a known method.

  The compound represented by the formula (I) preferably has a molecular weight of 100 to 1,000,000, more preferably 100 to 100,000, from the viewpoints of stability and handleability. In the present specification, the molecular weight of the silicone derivative is measured by gel filtration chromatography (GPC).

  The content of the compound represented by the formula (I) in the condensation reaction monomer is preferably 50% by weight or more, more preferably 80% by weight or more, and still more preferably 100% by weight.

  In the composition, the content of the condensation reaction monomer is preferably 1 to 99% by weight, more preferably 50 to 99% by weight, and still more preferably 80 to 99% by weight.

  The silicon compound having a substituent capable of addition reaction (hereinafter also referred to as addition reaction monomer) is not particularly limited as long as it has the substituent.

  Examples of the substituent capable of addition reaction include an alkenyl group, a hydrogen atom, an alkynyl group, a carbonyl group, a thiol group, an epoxy group, an amino group, a hydroxyl group, and a sulfide group, preferably a hydrogen atom and an alkenyl group. Can be mentioned. There is no particular limitation on the number of substituents contained in one molecule.

  Such compounds include, for example, formula (III):

(In the formula, A, B and C are structural units, A is a terminal unit, B and C are repeating units, R ⁴ is a monovalent hydrocarbon group, a is 0 or an integer of 1 or more, b is Represents an integer of 2 or more, provided that all R ⁴ may be the same or different.
And a compound represented by formula (IV):

(Wherein R ⁵ is a monovalent hydrocarbon group, c represents 0 or an integer of 1 or more, provided that all R ⁵ may be the same or different)
At least one organohydrogensiloxane selected from the group consisting of compounds represented by: In this specification, the organohydrogensiloxane means a general term for all compounds from low molecular weight compounds to high molecular weight compounds such as organohydrogendisiloxane and organohydrogenpolysiloxane.

  The compound represented by the formula (III) is a compound composed of structural units A, B and C, wherein A is a terminal unit, B and C are repeating units, and hydrogen is included in the repeating units.

R ⁴ in formula ^(III), i.e., R ⁴ in the structural unit ^A, the R ⁴ in R ^4, and the structural unit C of the constituent unit B, both a monovalent hydrocarbon group, saturated or unsaturated, straight Examples include a chain, branched chain, or cyclic hydrocarbon group. The number of carbon atoms of the hydrocarbon group is preferably from 1 to 20, and more preferably from 1 to 10, from the viewpoints of ease of preparation and thermal stability. Specific examples include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a phenyl group, a naphthyl group, a cyclohexyl group, and a cyclopentyl group. Of these, a methyl group and an ethyl group are preferable from the viewpoints of transparency and light resistance. In the formula (III), all R ^{4 s} may be the same or different and each independently represents the above hydrocarbon group regardless of the structural unit.

  The structural unit A is a terminal unit and is included in the formula (III).

  The number of repeating units of the structural unit B, that is, a in the formula (III) represents 0 or an integer of 1 or more, but from the viewpoint of reactivity, it is preferably an integer of 1 to 1000, more preferably 1 to 100. is there.

  The number of repeating units of the structural unit C, that is, b in the formula (III) is an integer of 2 or more, and is preferably an integer of 2 to 10000, more preferably an integer of 2 to 1000 from the viewpoint of reactivity.

Examples of the compound represented by the formula (III) include methyl hydrogen polysiloxane, dimethyl polysiloxane-CO-methyl hydrogen polysiloxane, ethyl hydrogen polysiloxane, methyl hydrogen polysiloxane-CO-methylphenyl polysiloxane, and the like. These may be used alone or in combination of two or more. Among these, a compound in which R ⁴ is a methyl group, a is 0 and b is an integer of 2 or more, and a compound in which R ⁴ is an ethyl group, a is 0 and b is an integer of 2 or more is preferable.

  The compound represented by the formula (III) preferably has a molecular weight of 100 to 1,000,000, more preferably 100 to 100,000, from the viewpoints of stability and handleability.

  The compound represented by the formula (IV) is a compound having hydrogen as a terminal.

R ⁵ in formula (IV) represents a monovalent hydrocarbon group, and examples thereof include saturated or unsaturated, linear, branched or cyclic hydrocarbon groups. The number of carbon atoms of the hydrocarbon group is preferably from 1 to 20, and more preferably from 1 to 10, from the viewpoints of ease of preparation and thermal stability. Specific examples include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a phenyl group, a naphthyl group, a cyclohexyl group, and a cyclopentyl group. Of these, a methyl group and an ethyl group are preferable from the viewpoints of transparency and light resistance. In the formula (IV), all R ^{5 s} may be the same or different but are preferably all methyl groups or ethyl groups.

  C in the formula (IV) represents 0 or an integer of 1 or more, and is preferably an integer of 1 to 10,000, more preferably 1 to 1,000 from the viewpoint of reactivity.

Examples of the compound represented by the formula (IV) include both terminal hydrosilyl type polydimethylsiloxane, both terminal hydrosilyl type polymethylphenyl siloxane, both terminal hydrosilyl type polydiphenyl siloxane, and the like. Can be used in combination. Among these, compounds in which R ⁵ is all methyl groups and c is an integer of 1 to 1,000, and compounds in which R ⁵ is all ethyl groups and c is an integer of 1 to 1,000 are preferable.

  The compound represented by the formula (IV) preferably has a molecular weight of 100 to 1,000,000, more preferably 100 to 100,000, from the viewpoints of stability and handleability.

  As the compounds represented by the formulas (III) and (IV), commercially available products or those synthesized according to known methods may be used.

  The total content of the compounds represented by formula (III) and formula (IV) in the addition reaction system monomer is 50% by weight or more of the total content of the compounds represented by formula (III) and formula (IV) Is preferable, 80% by weight or more is more preferable, and substantially 100% by weight is further preferable.

  The content of the addition reaction system monomer is preferably 0.1 to 99% by weight, more preferably 0.1 to 90% by weight, and still more preferably 0.1 to 80% by weight in the composition.

  Further, the weight ratio of the condensation reaction system monomer to the addition reaction system monomer (condensation reaction system monomer / addition reaction system monomer) is preferably 99.9 / 0.1 to 1/99 from the viewpoint of viscoelasticity when formed into a sheet, 99.9 / 0.1-50 / 50 is more preferable, and 99.9 / 0.1-90 / 10 is more preferable.

  It is preferable that the composition for silicone resins in this invention contains a condensation catalyst and an addition reaction catalyst in addition to the said monomer.

  The condensation catalyst is not particularly limited as long as it is a compound that catalyzes the condensation reaction of the above monomers. Acids such as hydrochloric acid, acetic acid, formic acid and sulfuric acid; potassium hydroxide, sodium hydroxide, potassium carbonate, tetramethylammonium hydroxide and the like Examples of such bases include metal catalysts such as aluminum, titanium, zinc, and tin. Of these, tetramethylammonium hydroxide is preferable from the viewpoints of compatibility and thermal decomposability.

  The content of the condensation catalyst in the composition is preferably from 0.1 to 50 mol, more preferably from 1.0 to 5 mol, per 100 mol of the condensation reaction monomer.

  The addition reaction catalyst is not particularly limited as long as it is a compound that catalyzes the addition reaction of the monomer, and examples thereof include a hydrosilylation catalyst.

  The hydrosilylation catalyst catalyzes a hydrosilylation reaction between a hydrosilane compound and an alkene. Specific examples of the compound include platinum catalysts such as platinum black, platinum chloride, chloroplatinic acid, platinum-olefin complexes, platinum-carbonyl complexes, and platinum-acetyl acetate; palladium catalysts, rhodium catalysts, and the like. Of these, platinum-carbonyl complexes are preferred from the viewpoints of compatibility, transparency, and catalytic activity.

The content of the hydrosilylation catalyst in the composition is preferably 1.0 × 10 ^{−4 to} 0.5 part by weight, more preferably 1.0 × 10 ^{−3 to} 0.05 part by weight, based on 100 parts by weight of the addition reaction monomer. When a platinum catalyst is used, 1.0 × 10 ^{−4 to} 1.0 part by weight, preferably 1.0 × 10 ^{−4 to} 0.5 part by weight, and preferably 1.0 × 10 ⁻⁴ to 1.0 part by weight in terms of platinum, based on 100 parts by weight of the addition reaction monomer 10 ^{−3 to} 0.05 parts by weight are more preferable.

  The silicone resin sheet of the present invention is obtained by reacting the composition containing the condensation reaction monomer and the addition reaction monomer under conditions suitable for the condensation reaction, so that the condensation reaction monomer forms a crosslinked structure. In addition, an addition reaction system monomer is dispersed therein. In the present invention, from the viewpoint of the strength of a cured product obtained by carrying out a curing reaction, the composition for a silicone resin in the present invention further reacts with both the condensation reaction system monomer and the addition reaction system monomer in addition to the above. It is preferable to contain a compound to be obtained (hereinafter also referred to as a condensation / addition monomer). When all the curing reactions are performed by using such a composition, the monomers of the condensation reaction system monomer and the addition reaction system monomer are cross-linked. In addition to this, a cured product having a structure in which the condensation reaction monomer and the addition reaction monomer are cross-linked is obtained.

  The condensation / addition monomer has a functional group capable of reacting with the condensation reaction system monomer and a functional group capable of reacting with the addition reaction system monomer in one molecule.

  Examples of the functional group capable of reacting with the condensation reaction monomer include the same substituents as those described above that can undergo the condensation reaction, and the number of functional groups in one molecule is not particularly limited.

  Examples of the functional group capable of reacting with the addition reaction monomer include the same substituents as those described above that can undergo the addition reaction, and the number of functional groups in one molecule is not particularly limited.

Such compounds include, for example, formula (II):
R ² —Si (OR ³ ) ₃ (II)
(Wherein R ² represents a substituted or unsubstituted alkenyl group, R ³ represents a monovalent hydrocarbon group, provided that three R ³ may be the same or different)
The alkenyl group containing trialkoxysilane represented by these is preferable. In the above compound, an alkenyl group undergoes an addition reaction with an addition reaction monomer, and an alkoxy group undergoes a condensation reaction with a condensation reaction monomer.

R ² in formula (II) represents a substituted or unsubstituted alkenyl group, and is an organic group containing an alkenyl group in the skeleton. The number of carbon atoms of the organic group is preferably 1-20, more preferably 1-10, from the viewpoint of ease of preparation and thermal stability. Specific examples include a vinyl group, an allyl group, a propenyl group, a butenyl group, a pentenyl group, a hexenyl group, a heptenyl group, an octenyl group, a norbornenyl group, and a cyclohexenyl group. Among these, a vinyl group is preferable from the viewpoint of reactivity with respect to the hydrosilylation reaction.

R ³ in the formula (II) is a monovalent hydrocarbon group, that is, an alkyl group, and OR ³ represents an alkoxy group. The number of carbon atoms of the hydrocarbon group is preferably 1 to 10 and more preferably 1 to 6 from the viewpoint of reactivity. Specific examples include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group. Of these, a methyl group is preferred from the viewpoint of reactivity to the condensation reaction. In the formula (II), all R ^{3 s} may be the same or different but are preferably all methyl groups.

Examples of the compound represented by the formula (II) include vinyltrimethoxysilane, vinyltriethoxysilane, allyltrimethoxysilane, propenyltrimethoxysilane, norbornenyltrimethoxysilane, octenyltrimethoxysilane, and the like. These can be used alone or in combination of two or more. Among these, vinyltrimethoxysilane, in which R ² is a vinyl group and R ³ is all a methyl group, is preferable.

  The compound represented by the formula (II) may be a commercially available product or may be synthesized according to a known method.

  The content of the compound represented by the formula (II) in the condensation / addition monomer is preferably 50% by weight or more, more preferably 80% by weight or more, and still more preferably 100% by weight.

  The content of the condensation / addition monomer is preferably 0.01 to 90% by weight, more preferably 0.01 to 50% by weight, and still more preferably 0.01 to 10% by weight in the composition.

When both-end silanol type silicone oil represented by the formula (I) is used as the condensation reaction system monomer and the alkenyl group-containing trialkoxysilane represented by the formula (II) is used as the condensation / addition monomer, the weight of both The molar ratio of the functional groups (SiOH / SiOR ³ ) is from 20/1 to 20% from the viewpoint of reacting the SiOH groups of both-end silanol type silicone oil and the SiOR ³ groups of the alkenyl group-containing trialkoxysilane without excess or deficiency. 0.2 / 1 is preferable, 10/1 to 0.5 / 1 is more preferable, and substantially equivalent (1/1) is further preferable. When the molar ratio is 20/1 or less, the silicone resin sheet of the present invention has appropriate toughness, and when it is 0.2 / 1 or more, the alkenyl group-containing trialkoxysilane is not excessively obtained. The heat resistance of the resin is improved.

Furthermore, in the above, when the organohydrogensiloxane represented by the formula (III) or formula (IV) is used as the addition reaction monomer, the weight ratio of the alkenyl group-containing trialkoxysilane and the organohydrogensiloxane is: From the viewpoint of reacting the SiR ² group of the alkenyl group-containing trialkoxysilane and the SiH group of the organohydrogensiloxane without excess or deficiency, the molar ratio of the functional groups (SiR ² / SiH) is preferably 20/1 to 0.1 / 1. 10/1 to 0.2 / 1 is more preferable, 10/1 to 0.5 / 1 is further preferable, and substantially equivalent (1/1) is further preferable. If the molar ratio is 20/1 or less, the silicone resin sheet of the present invention has appropriate toughness, and if it is 0.1 / 1 or more, the organohydrogensiloxane does not increase too much, and the resulting resin Heat resistance and toughness are improved.

  Moreover, the silicone resin sheet obtained by carrying out the condensation reaction of the composition for silicone resins containing fluorescent substance inorganic powder other than the said component as another aspect of this invention is provided.

The phosphor inorganic powder is not particularly limited, and phosphor inorganic powders known in the art such as oxide phosphors, oxynitride phosphors, nitride phosphors, sulfide phosphors, silicate compounds, and the like. Can be mentioned. Specifically, as a suitable commercially available phosphor having a function of converting blue to yellow, yellow phosphors (α-sialon, average particle diameter 20 μm), YAG, TAG, etc. are exemplified, and the function of converting to red Examples of suitable commercially available phosphors having Ca include SiAlN ₃ .

  Since the degree of color mixing varies depending on the type of phosphor inorganic powder and the thickness of the resin sheet to be formed, the content of the phosphor inorganic powder is not generally determined.

  Furthermore, as another aspect of the present invention, in addition to the above components and phosphor inorganic powder, a silicone resin obtained by subjecting a silicone resin composition containing fine particles to a condensation reaction from the viewpoint of improving the elastic modulus of the resin sheet. Provide a sheet.

  The fine particles are not particularly limited as long as they are organic and inorganic fine particles known in the art, but from the viewpoint of light transmittance of the resin sheet to be obtained, transparent particles are preferable, and the affinity for the resin and the refractive index are high. From the viewpoint, silica is more preferable.

  If the particle size of the silica is too large, the resulting resin sheet becomes fragile, which is not preferable. Conversely, if the particle size is too small, the transmittance decreases, which is not preferable. The average particle diameter of silica is preferably 1 to 50 μm. From the viewpoint of sheet strength, the maximum particle size is not particularly limited as long as it is 70 μm or less. Examples of the shape of silica include a spherical shape and a crushed shape, but are not particularly limited. In the present specification, the average particle size of the inorganic particles can be measured by the method described in Examples described later.

  The content of the fine particles in the composition cannot be determined unconditionally depending on the thickness of the resin sheet to be formed, but is preferably 5% by weight or more from the viewpoint of the effect of improving the elastic modulus, and 80% by weight or less from the viewpoint of light transmittance. preferable. Therefore, 5 to 80% by weight is preferable.

  In addition to the above, the composition for a silicone resin in the present invention is an antioxidant, a modifier, a surfactant, a dye, a pigment, a discoloration inhibitor, an ultraviolet absorber, etc., as long as the effects of the present invention are not impaired. An additive may be contained.

  The silicone resin composition according to the present invention can be prepared without particular limitation as long as it contains a silicon compound having a substituent capable of condensation reaction and a silicon compound having a substituent capable of addition reaction. The reaction temperature and time are appropriately selected according to the reaction mechanism of the reaction and the addition reaction, and from the viewpoint of proceeding and completing the reaction, the components related to the condensation reaction are mixed in advance and then the components related to the addition reaction are mixed. May be.

  Mixing of the components related to the condensation reaction is performed by stirring the condensation reaction system monomer with a condensation catalyst, a condensation / addition monomer, and an additive such as an organic solvent, if necessary, preferably at 0 to 60 ° C. for 5 minutes to 24 hours. Can be performed. The condensation / addition monomer is a component related to both the condensation reaction and the addition reaction. However, since the condensation reaction starts at a lower temperature than the addition reaction, it is mixed simultaneously with the condensation reaction system monomer. It is preferable.

  Although there is no limitation in particular as an organic solvent, 2-propanol is preferable from a viewpoint of improving the compatibility of a silicone derivative and a condensation catalyst.

  The amount of the organic solvent present is preferably 3 to 20 parts by weight, more preferably 5 to 10 parts by weight, based on 100 parts by weight of the total amount of the condensation reaction system monomer and the condensation / addition monomer. When it is 3 parts by weight or more, the reaction progress is good, and when it is 20 parts by weight or less, foaming in the curing stage of the composition is reduced.

The mixing may start a part of the condensation reaction between the condensation reaction monomer and the condensation / addition monomer. The degree of progress of the condensation reaction may be determined by, for example, using an alkenyl group-containing trialkoxysilane as the condensation / addition monomer. When used, it can be confirmed by the disappearance of the peak derived from the alkoxy group in the molecule by ¹ H-NMR measurement.

  Next, in addition to the addition reaction system monomer as a component related to the addition reaction, an addition reaction catalyst is mixed with the mixture of the components related to the condensation reaction. The composition in the present invention undergoes two kinds of reactions, a condensation reaction and an addition reaction, to obtain a cured product, but only a condensation reaction is performed to prepare a semi-cured sheet. The mixing method is not particularly limited as long as it is uniformly mixed with the mixture of components relating to the condensation reaction.

  In addition, when the phosphor inorganic powder or the fine particles are contained, the components related to the addition reaction can be mixed with the mixture of the components related to the condensation reaction, respectively. When mixing both the phosphor inorganic powder and the fine particles, the phosphor inorganic powder and the fine particles may be mixed separately or premixed. When mixing separately, the mixing order of the phosphor inorganic powder and the fine particles is particularly It is not limited. Moreover, if a mixing method is also mixed uniformly, there will be no limitation in particular.

Thus, a silicone resin composition can be prepared, but in the present invention, from the viewpoint of elastic modulus and storage stability,
(1) Both ends silanol type silicone oil
(2) Alkenyl group-containing trialkoxysilane
(3) Organohydrogensiloxane
(4) condensation catalyst, and
(5) It preferably contains a hydrosilylation catalyst.

  The viscosity at 25 ° C. of the obtained composition is preferably 10 to 100,000 mPa · s, more preferably 1000 to 50,000 mPa · s. In the present specification, the viscosity can be measured using a B-type viscometer.

  The silicone resin sheet of the present invention can be obtained by subjecting the silicone resin composition obtained above to a condensation reaction.

  Specifically, the silicone resin composition is cast, spin-coated, roll-coated, for example, on a release sheet (for example, an organic polymer film such as a polyethylene substrate, ceramics, metal, etc.) whose surface is peeled off. It can be formed into a sheet by coating to an appropriate thickness by a method such as the above, and heating and drying at a temperature at which the solvent can be removed. Moreover, when the composition for silicone resins in this invention contains fluorescent substance inorganic powder, the sheet | seat obtained by apply | coating this composition like the above turns into a wavelength conversion sheet. Therefore, the silicone resin sheet of the present invention includes a sheet-like resin layer (embodiment 1) that does not contain phosphor inorganic powder, and a wavelength conversion sheet (embodiment 2) that further contains phosphor inorganic powder and, if necessary, fine particles. It is done. These sheets can be used alone, for example, by being mounted on an optical semiconductor element. However, sheets in which modes 1 and 2 are laminated directly or indirectly, that is, modes 1 and 2 are combined. It can also be used as an integrated composite sheet. Specifically, for example, a sheet in which the sheet of aspect 1 and the sheet of aspect 2 are integrated in this order on the optical semiconductor element so that the sheet of aspect 1 embeds the optical semiconductor element. The light extraction efficiency from the optical semiconductor element can be increased. In the present specification, the “directly laminated” sheet means a sheet formed by directly laminating the separator, the sheet of aspect 1 and the sheet of aspect 2, and “indirectly laminated”. Is a sheet formed by laminating another layer between the separator and the sheet of aspect 1 and / or between the sheet of aspect 1 and the sheet of aspect 2 according to a conventional method. Means that.

Although the heating temperature is not generally determined depending on the type of solvent used, in the present invention, in addition to the removal of the solvent, the condensation reaction is completed by this heating, and a semi-cured (B stage) silicone resin is obtained. From the preparation of the sheet, 40 to 120 ° C is preferable, and 60 to 100 ° C is more preferable. The same applies even if the phosphor inorganic powder is contained. The heating time is preferably from 0.1 to 60 minutes, more preferably from 0.1 to 15 minutes. In the present specification, “completion of the reaction” means that 80% or more of the functional groups involved in the reaction have reacted. In the condensation reaction, for example, the remaining by ¹ H-NMR as described above. This can be confirmed by measuring the amount of alkoxy groups.

  Moreover, as a preferable manufacturing method of the silicone resin sheet of the present invention, a method including a step of subjecting the silicone resin composition to a condensation reaction may be mentioned.

  Specific examples of the step include, for example, a silicon compound having a substituent capable of condensation reaction and a silicone resin composition containing a silicon compound having a substituent capable of addition reaction, preferably 40 to 120 ° C. More preferably, a method of reacting with stirring at a temperature of 60 to 100 ° C. can be mentioned.

  The thickness of the silicone resin sheet is not particularly limited, but when used alone in any embodiment, 100 to 5000 μm is preferable and 100 to 2000 μm is more preferable from the viewpoint of optical semiconductor sealing properties. Further, when the silicone resin sheet of the present invention is the composite sheet of Embodiment 1 and Embodiment 2, the sheet thickness of Embodiment 1 is preferably 100 to 5000 μm, more preferably 100 to 2000 μm, from the viewpoint of sealing properties. From the viewpoint of whitening, the sheet thickness 2 is preferably 30 to 200 μm, more preferably 70 to 120 μm, and the composite sheet thickness is preferably 130 to 5200 μm, and more preferably 170 to 2120 μm.

  For example, when preparing an optical semiconductor device, the obtained silicone resin sheet completely embeds an optical semiconductor element mounted on a substrate and seals the bonding wire without deforming or damaging it. The tensile elastic modulus at 25 ° C. is preferably 1000 to 100000 a (0.001 to 1 MPa), more preferably 5000 to 20000 Pa (0.005 to 0.02 MPa). In addition, in this specification, a tensile elasticity modulus can be measured in accordance with the method as described in the below-mentioned Example.

  The silicone resin sheet of the present invention is preferably stored in a semi-cured state at 25 ° C. for 24 hours or more from the viewpoint of economy and handling properties, and the silicone resin sheet of the present invention after storage at 25 ° C. for 24 hours is When the tensile elastic modulus before storage is 100%, the elastic modulus is preferably 80 to 120%, more preferably 90 to 110%.

  In the silicone resin sheet of the present invention, for example, since the single sheet of the above embodiment is in a semi-cured state, the composite sheet is the sheet of Embodiment 1 as it is or after potting a known resin on the optical semiconductor element. After being placed and sealed so that is on the element side, the optical semiconductor device can be prepared by heating at a high temperature to completely cure the resin sheet. Therefore, this invention provides the optical semiconductor device which sealed the optical semiconductor element using the silicone resin sheet of this invention. This complete curing of the resin sheet is carried out by reaction of components relating to the addition reaction. Therefore, as another embodiment of the present invention, there is provided a cured silicone resin obtained by curing the silicone resin sheet of the present invention.

  The method for carrying out the sealing process after placing the sheet on the substrate is not particularly limited, for example, using a laminator, preferably at 100 to 200 ° C., 0.01 to 10 MPa, more preferably 120 to 160 ° C., 0.1 An example is a method in which a sealing process is performed after pressure bonding by heating at ˜1 MPa for 5 to 600 seconds.

  The heating temperature for the sealing process is preferably more than 120 ° C and not more than 250 ° C, more preferably 150 to 200 ° C. The heating time is preferably 0.5 to 24 hours, more preferably 2 to 6 hours.

  In addition, the progress of the addition reaction is confirmed by, for example, the absorption degree of the peak derived from the SiH group of the organohydrogenpolysiloxane by IR measurement when the organohydrogenpolysiloxane is used as the addition reaction monomer. When the absorption strength is less than 20% of the initial value (before the curing reaction), the hydrosilylation reaction is completed and the film is completely cured.

  Thus, by using the silicone resin sheet of the present invention, the optical semiconductor device can be easily sealed. Moreover, since the silicone resin sheet of this invention contains the silicone derivative which is excellent in heat resistance and light resistance as a main component, it is used suitably as a sealing material of an optical semiconductor element. Accordingly, the present invention provides an optical semiconductor element sealing material including the silicone resin sheet of the present invention, and an optical semiconductor device in which the optical semiconductor element is sealed using the sealing material.

  EXAMPLES Hereinafter, although this invention is demonstrated based on an Example, this invention is not limited at all by these Examples.

[Molecular weight of silicone derivatives]
Obtained in terms of polystyrene by gel filtration chromatography (GPC).

Example 1
Silanol oil of both ends silanol type (manufactured by Shin-Etsu Chemical Co., Ltd., trade name “X-21-5842”, average molecular weight 11500) 100 g (8.70 mmol), vinyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name “KBM-1003”) ) 0.86 g [5.80 mmol, molar ratio of SiOH group of both-end silanol type silicone oil to methoxy group of vinyltrimethoxysilane (SiOH / methoxy group) = 17/17], and 10 mL of 2-propanol (both end silanol type silicone) After stirring and mixing oil and vinyltrimethoxysilane (100 parts by weight in total), 0.16 mL (0.17 mmol, both-end silanol type silicone oil) as a condensation catalyst, tetramethylammonium hydroxide aqueous solution (concentration 10% by weight) 2.0 moles per 100 moles) and stirred for 2 hours at room temperature (25 ° C.) 0.75 g of organohydrogenpolysiloxane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name “KF-9901”) was added to the resulting oil. [Molar ratio of vinyl group of vinyltrimethoxysilane to SiH group of organohydrogenpolysiloxane (vinyl group / SiH) = 1/1) and platinum carbonyl complex solution (platinum concentration 2% by weight) 0.26mL as hydrosilylation catalyst (35 parts by weight with respect to 100 parts by weight of organohydrogenpolysiloxane) was added to obtain a silicone resin composition.

Example 2
Silanol oil of both ends silanol type (manufactured by Shin-Etsu Chemical Co., Ltd., trade name “X-21-5842”, average molecular weight 11500) 100 g (8.70 mmol), vinyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name “KBM-1003”) ) 0.86 g [5.80 mmol, molar ratio of SiOH group of both-end silanol type silicone oil to methoxy group of vinyltrimethoxysilane (SiOH / methoxy group) = 17/17], and 10 mL of 2-propanol (both end silanol type silicone) After stirring and mixing oil and vinyltrimethoxysilane (100 parts by weight in total), 0.16 mL (0.17 mmol, both-end silanol type silicone oil) as a condensation catalyst, tetramethylammonium hydroxide aqueous solution (concentration 10% by weight) The mixture was stirred at room temperature (25 ° C.) for 2 hours, and 0.090 g of organohydrogenpolysiloxane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name “KF-99”) was added to the resulting oil. Molar ratio of vinyl trimethoxysilane to SiH groups of organohydrogenpolysiloxane (vinyl group / SiH) = 1/1] and platinum carbonyl complex solution (platinum concentration 2 wt%) 0.26mL as hydrosilylation catalyst ( 289 parts by weight based on 100 parts by weight of organohydrogenpolysiloxane was added to obtain a silicone resin composition.

Example 3
19 g of yttrium aluminum garnet phosphor (YAG phosphor) was added to 100 g of the resin composition obtained in Example 1, and the mixture was stirred at room temperature (25 ° C.) for 1 hour to obtain a phosphor-containing silicone resin composition. Obtained.

Example 4
After adding 19 g of yttrium aluminum garnet phosphor (YAG phosphor) to 100 g of the resin composition obtained in Example 1, 30 g of silica particles (DENKA, FB-7SDC, average particle size: 5.8 μm) were added. The mixture was added and stirred at room temperature (25 ° C.) for 1 hour to obtain a phosphor-silica fine particle-containing silicone resin composition.

Comparative Example 1
A two-component mixed silicone elastomer (manufactured by Asahi Kasei Wacker Silicone Co., Ltd., LR7665) was mixed well with 10 g of A solution and 10 g of B solution to obtain a silicone resin composition.

Comparative Example 2
In Example 3, except that the type of resin to which the yttrium aluminum garnet phosphor (YAG phosphor) is added is changed to a general silicone resin (manufactured by Asahi Kasei Wacker Silicone Co., Ltd., LR7665), the same as in Example 3. A phosphor-containing composition for a silicone resin was obtained.

Comparative Example 3
Example 3 is the same as Example 3 except that the type of resin to which yttrium aluminum garnet phosphor (YAG phosphor) is added is changed to a general silicone resin (KER-2500, manufactured by Shin-Etsu Chemical Co., Ltd.). Thus, a phosphor-containing composition for a silicone resin was obtained.

Comparative Example 4
Example 3 is the same as Example 3 except that the type of resin to which the yttrium aluminum garnet phosphor (YAG phosphor) is added is changed to a general silicone resin (OE-6336 manufactured by Toray Dow Corning). Thus, a phosphor-containing composition for a silicone resin was obtained.

Preparation of semi-cured silicone resin composition A semi-cured sheet was prepared using the compositions of Examples 1 and 2 and Comparative Example 1 obtained above.

  Specifically, the composition of Examples 1-2 or Comparative Example 1 was applied to a biaxially stretched polyester film (Mitsubishi Resin, 50 μm) to a thickness of 500 μm, and the compositions of Examples 1-2 Was heated at 80 ° C. for 10 minutes, and the composition of Comparative Example 1 was allowed to stand at room temperature (25 ° C.) for 16 hours to prepare a semi-cured resin sheet (thickness: 500 μm).

  In addition, the composition of Examples 3 to 4 or Comparative Examples 2 to 4 was applied to a fluorine-treated polyester film (Nippa Corp., SS4C, 50 μm) to a thickness of 100 μm and heated at 145 ° C. for 5 minutes. Thus, a semi-cured resin sheet was prepared (thickness: 100 μm).

Preparation of Completely Cured Product Using the semi-cured resin sheets of Examples 1 to 4 or Comparative Examples 1 to 4 obtained above, the resin sheet was prepared by heating at 150 ° C. for 5 hours.

Production Example 1 of Optical Semiconductor Device
Using the semi-cured resin sheet of Examples 1 or 2 or Comparative Example 1, it was placed on a substrate on which a blue LED was mounted, heated to 160 ° C. under reduced pressure, and sealed at a pressure of 0.2 MPa. The obtained apparatus was heated at 150 ° C. for 5 hours to completely cure the resin.

Fabrication example 2 of optical semiconductor device
An optical semiconductor device was fabricated by sealing the substrate on which the blue LED was mounted using the sheets of Examples 3 to 4 or Comparative Examples 2 to 4. Specifically, phosphor inorganic powder and silica fine particles from the compositions used in the preparation of the sheets of Examples 3 to 4 on the fully cured sheet of 100 μm in Examples 3 to 4 or Comparative Examples 2 to 4 The composition (phosphor / silica-free composition, i.e., the composition of Example 1) was applied at a film thickness of 500 μm, heated at 80 ° C. for 10 minutes, and then Examples 3-4 or Comparative Example 2 A semi-cured sealing layer was provided on the sheets 4 to 4 (total thickness 600 μm). The sheet obtained above was placed on the blue LED so that the semi-cured product side (phosphor / silica-free composition side) was on the LED chip side, and 160 ° C. using a vacuum press device. Was heated for 5 minutes, sealed at a pressure of 0.1 MPa, and then heated at 150 ° C. for 5 hours to completely cure the resin, thereby producing an optical semiconductor device.

  The characteristics of the obtained semi-cured sheet, completely cured product, and semiconductor device were evaluated according to the following Test Examples 1 to 9. The results are shown in Tables 1-2.

Test example 1 (resin viscosity)
It measured using the rheometer on 25 degreeC and 1 atmosphere conditions.

Test example 2 (storability)
With a dynamic viscoelasticity measuring device (DMS-200, manufactured by SII Nano Technology), the viscoelasticity at the time of shearing is measured, and from the measurement result, the storage elastic modulus at 25 ° C. is taken as the tensile elastic modulus of the resin sheet, Each semi-cured product was allowed to stand at room temperature (25 ° C.), and the change in elastic modulus after 24 hours was examined. When the elastic modulus before storage is 100%, the change rate of elastic modulus after 24 hours is less than 3% (elastic modulus after storage is over 97% and less than 103%). When it is -20% (elasticity after storage is 80-97%, 103-120%), "○", when it exceeds 20% (elasticity after storage is less than 80%, more than 120%) × ”.

Test example 3 (elasticity)
About the obtained completely hardened | cured material sheet | seat, the tensile elasticity modulus (MPa) was calculated | required and evaluated using the autograph (made by Shimadzu Corporation). The higher the tensile modulus, the higher the elasticity and the higher the quality assurance by the thermal cycle test.

Test example 4 (luminance)
460 nm single wavelength excitation light is incident on the obtained fully cured sheet from a direction perpendicular to the sheet plane, and the excitation light transmitted through the sheet and the fluorescence emitted from the phosphor in the sheet are transmitted through an integrating sphere. And the optical spectrum of the total luminous flux was detected using an instantaneous multi-photometry system (MCPD-3000, manufactured by Otsuka Electronics Co., Ltd.). From the obtained optical spectrum, the Y value serving as a luminance index was measured.

Test Example 5 (chromaticity stability)
The obtained completely cured product sheet was irradiated with a certain blue light, and the transmitted blue light and the emitted yellow light were detected to evaluate the chromaticity. Specifically, the chromaticity was measured for any 10 points on the sheet using the CIE chromaticity y coordinate, and the difference between the maximum chromaticity and the minimum chromaticity was calculated as the maximum chromaticity difference and evaluated. A smaller maximum chromaticity difference indicates higher chromaticity stability.

Test Example 6 (Light transmittance)
The light transmittance (%) at a wavelength of 450 nm of each completely cured product was measured using a spectrophotometer (U-4100, manufactured by Hitachi High-Tech). It shows that it is excellent in light transmittance, so that light transmittance is high.

Test example 7 (heat resistance)
Each completely cured product is left in a warm air dryer at 150 ° C, the appearance of the completely cured product is visually observed after 100 hours, and “○” indicates that there is no discoloration from the state before storage. Was marked “x”.

Test Example 8 (Sealing property)
The state before and after the sealing of each optical semiconductor device was observed with an optical microscope. The optical semiconductor element was completely embedded and the bonding wire was not deformed or damaged.

Test Example 9 (Light resistance)
The LED element was turned on by supplying a current of 300 mA to each optical semiconductor device, and the luminance immediately after the start of the test was measured by an instantaneous multi-photometry system (MCPD-3000, manufactured by Otsuka Electronics Co., Ltd.). Thereafter, the LED element was left in a lit state, the luminance after 300 hours was measured in the same manner, the luminance retention rate was calculated by the following formula, and the light resistance was evaluated. It shows that it is excellent in light resistance, so that a luminance retention is high.
Luminance retention rate (%) = (Luminance after 300 hours / Luminance immediately after starting the test) x 100

  As a result, the resin sheet of the example has high storage stability even in a semi-cured state as compared with the comparative example, and can easily and well seal the LED element, and is an excellent sealing material It turns out that it is.

  Moreover, since the resin sheet of Examples 3-4 has a low maximum chromaticity difference compared with Comparative Examples 2-4, the resin composition containing each component of (1)-(5) is fluorescent. It can be seen that the dispersibility of the body material is high.

  Moreover, the elastic modulus of the fully cured silicone resin could be improved by adding silica fine particles to Example 3. Furthermore, although Example 4 contained silica fine particles compared with Example 3, the luminance was not lowered. This suggests that a sheet showing good results for reliability tests such as temperature cycles can be obtained.

  The semi-cured silicone resin sheet of the present invention produces, for example, display devices and lighting fixtures using LED light-emitting devices as light sources, backlights such as displays, traffic lights, semiconductor devices such as large outdoor displays and advertising signs. In this case, it is preferably used.

Claims (14)

  A semi-cured silicone resin sheet obtained by subjecting a silicon compound having a substituent capable of condensation reaction and a silicone resin composition containing a silicon compound having a substituent capable of addition reaction.   The silicone resin sheet according to claim 1, wherein the tensile elastic modulus at 25 ° C is 1000 to 100000Pa.   The silicone resin sheet according to claim 1 or 2, wherein the tensile elastic modulus at 25 ° C after storage at 25 ° C for 24 hours is 80 to 120% when the tensile elastic modulus before storage is 100%.   The silicone resin sheet according to any one of claims 1 to 3, wherein the silicone resin composition further comprises phosphor inorganic powder.   The silicone resin sheet according to claim 4, wherein the silicone resin composition further comprises fine particles.   The silicone resin sheet according to claim 5, wherein the fine particles are silica.   The silicone resin sheet according to claim 6, wherein the content of silica is 5 to 80% by weight in the composition for silicone resin.   The silicone resin sheet of Claim 6 or 7 whose average particle diameter of a silica is 50 micrometers or less.   A semi-cured silicone resin comprising a step of heating a silicon compound having a substituent capable of condensation reaction and a silicone resin composition containing a silicon compound having a substituent capable of addition reaction at 40 to 120 ° C. Sheet manufacturing method.   A cured silicone resin obtained by completely curing the silicone resin sheet according to claim 1.   An optical semiconductor element sealing material comprising the silicone resin sheet according to claim 1.   An optical semiconductor device obtained by sealing an optical semiconductor element using the optical semiconductor element sealing material according to claim 11.   A silicone resin sheet obtained by laminating the semi-cured silicone resin sheet according to any one of claims 1 to 3 on a cured silicone resin layer obtained by completely curing the silicone resin sheet according to any one of claims 4 to 8. .   The optical semiconductor device formed by sealing using the silicone resin sheet of Claim 13 so that a semi-hardened silicone resin sheet may seal an optical semiconductor element.