JP2009084511A - Optical semiconductor sealing sheet and optical semiconductor element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical semiconductor sealing sheet presenting a cured product having highly tight adhesiveness, high heat resistance and light resistance, and to provide an optical semiconductor element using the same. <P>SOLUTION: The optical semiconductor sealing sheet comprises a sealing sheet composition comprising a silicone resin A, liquid at 25°C and having cyclic ether-containing groups in molecules, a heat curing agent reacting with the cyclic ether-containing groups, and a silicone resin B having 30-150°C softening point. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to an encapsulating sheet for optical semiconductors capable of obtaining a cured product having high adhesion, heat resistance and light resistance, and an optical semiconductor element using the same.

A light emitting element of an optical semiconductor element such as a light emitting diode (LED) usually has a sealed structure because its light emission characteristics are rapidly deteriorated due to moisture in the atmosphere or floating dust when directly in contact with the atmosphere. Yes. Until now, as a method for sealing a light emitting element, a method of placing a light emitting element such as a light emitting diode in a cup and filling a liquid sealant into the cup using a dispenser or the like has been mainly used. .

However, in recent years, when light-emitting elements are used for lighting or the like, there are increasing cases in which several to several tens of individual light-emitting element packages are required to be arranged side by side. In such an application that requires the arrangement of a large number of light emitting device packages, when individually sealed light emitting device packages are mounted on a substrate, there is a problem that the manufacturing takes a lot of man-hours and the productivity is inferior.

In order to solve such a problem, a method of arranging a plurality of light emitting elements on a printed circuit board, dropping a liquid sealant on the printed circuit board, and then curing the sealant can be considered. However, according to such a method, dripping of the encapsulant occurs at the time of thermosetting, and the application height of the encapsulant changes greatly for each light emitting element, and the application height of the encapsulant varies. is expected. If the coating height of the sealant changes and varies, problems such as changes in optical characteristics and gold wires that electrically connect the light emitting elements go out of the sealant. Will be.

In order to solve this problem, a method is conceivable in which a plurality of light emitting elements on a substrate are first surrounded by a bank, a liquid sealant is dropped in the bank, the sealant is cured, and then the bank is removed. If it carries out like this, about each light emitting element, the application | coating height of a sealing agent will not change a lot. However, this method has a problem that it is inferior in productivity.
In addition, it is conceivable to increase the viscosity of the sealant to such an extent that the coating height of the sealant does not vary greatly, but if the viscosity of the sealant is increased, the productivity may decrease, especially the wire. In the case of the bonding type, problems such as wire damage may occur.

In order to solve the problem of using such a liquid sealing agent, a method of sealing a light emitting element using a sheet-like sealing material has been studied. For example, Patent Documents 1 to 4 propose a sealing sheet for an optical semiconductor having a layer made of a polycarbodiimide resin, and Patent Document 5 discloses an ethylene-vinyl acetate copolymer, polyvinyl butyral, polyurethane, and the like. A sealing sheet made of a transparent thermoplastic resin and an adhesive resin has been proposed. According to such a method, it is possible to seal a plurality of light emitting elements at the same time, and there is no problem such as variation in coating height caused by the liquid sealant.
However, these encapsulating sheets have a problem that the cured product obtained for each of them is inferior in adhesion to the substrate and cannot exhibit sufficient heat resistance and light resistance.
JP 2004-238441 A JP 2005-294733 A JP 2006-140362 A JP 2007-110053 A Japanese Patent Laid-Open No. 2007-123452

The present invention has been made in view of the above-described situation, and an object thereof is to provide an optical semiconductor encapsulating sheet capable of obtaining a cured product having high adhesion, heat resistance and light resistance, and an optical semiconductor element using the same. And

A sealing sheet containing a silicone resin A having a cyclic ether-containing group in a liquid molecule at 25 ° C., a thermosetting agent that reacts with the cyclic ether-containing group, and a silicone resin B having a softening point of 30 to 150 ° C. It is the sealing sheet for optical semiconductors which consists of a composition for a semiconductor.
The present invention is described in detail below.

As a result of intensive studies, the inventors of the present invention are excellent in sheet shape moldability by using a composition for a sealing sheet containing a predetermined silicone resin A, a thermosetting agent, and a silicone resin B. The present inventors have found that an encapsulating sheet for optical semiconductors capable of obtaining a cured product excellent in adhesion, heat resistance and light resistance can be produced, and the present invention has been completed.

The composition for sealing sheets contains a silicone resin A having a cyclic ether-containing group in a molecule that is liquid at 25 ° C. (hereinafter, also simply referred to as “silicone resin A”).
By containing such a silicone resin A, the encapsulating sheet for optical semiconductors of the present invention exhibits initial tackiness and can exhibit excellent heat resistance, light resistance and adhesion after curing.

In the silicone resin A, a preferable lower limit of a viscosity at 1 rpm at 25 ° C. using an E-type viscometer is 10 mPa · s, and a preferable upper limit is 1,000,000 mPa · s. If it is less than 10 mPa · s, it may be difficult to form a sheet shape of the obtained sealing sheet for optical semiconductors. If it exceeds 1,000,000 mPa · s, the adhesiveness of the cured product of the obtained sealing sheet for optical semiconductors may be lowered.

In the silicone resin A, the cyclic ether-containing group is not particularly limited, and examples thereof include a glycidyl group, an epoxycyclohexyl group, and an oxetane group. Of these, a glycidyl group and / or an epoxycyclohexyl group are preferable, and an epoxycyclohexyl group is particularly preferable.

The glycidyl group is not particularly limited. For example, 2,3-epoxypropyl group, 3,4-epoxybutyl group, 4,5-epoxypentyl group, 2-glycidoxyethyl group, 3-glycidoxypropyl Group, 4-glycidoxybutyl group and the like.

The epoxycyclohexyl group is not particularly limited, and examples thereof include 2- (3,4-epoxycyclohexyl) ethyl group, 3- (3,4-epoxycyclohexyl) propyl group, and the like.

The silicone resin A is not particularly limited as long as it has one or more cyclic ether-containing groups in the molecule. For example, a resin component having an average composition formula represented by the following general formula (1) is used. What is contained is preferable.

In the general formula (1), a, b, c and d are a / (a + b + c + d) = 0 to 0.2, b / (a + b + c + d) = 0.3 to 1.0, c / (a + b + c + d) = 0 to 0.5 and d / (a + b + c + d) = 0 to 0.3 are satisfied, and R ^{1 to} R ⁶ each represent at least one cyclic ether-containing group, and R ^{1 to} R ⁶ other than the cyclic ether-containing group. Represents a linear or branched hydrocarbon having 1 to 8 carbon atoms or a fluorinated product thereof, and these may be the same or different.

When the silicone resin A contains a resin component having an average composition formula represented by the general formula (1), the encapsulating sheet for optical semiconductors of the present invention has a blue to ultraviolet region of the cured product. Light-emitting elements of optical semiconductor elements such as light-emitting diodes have high transparency to short-wavelength light, have no heat generation or discoloration due to light emission when the optical semiconductor element is sealed, and have excellent heat resistance and light resistance. When sealed, the optical semiconductor element has excellent adhesion to the housing material and the like.
In addition, the said average composition formula is represented by the said Formula (1) only when the silicone resin A of the sealing sheet for optical semiconductors of this invention contains only the resin component represented by the said Formula (1). In addition, in the case of a mixture containing resin components having various structures, it means the case represented by the above formula (1) when the average of the composition of the resin components contained is taken.

In the silicone resin A, the preferable lower limit of the content of the cyclic ether-containing group is 0.1 mol%, and the preferable upper limit is 50 mol%. If it is less than 0.1 mol%, the reactivity between the silicone resin A and the thermosetting agent described later may be significantly reduced, and the curability of the optical semiconductor encapsulating sheet of the present invention may be insufficient. When it exceeds 50 mol%, the cyclic ether containing group which does not participate in reaction with the said silicone resin A and a thermosetting agent will increase, and the heat resistance of the sealing sheet for optical semiconductors of this invention may fall. A more preferred lower limit is 5 mol%, and a more preferred upper limit is 30 mol%.
In the present specification, the content of the cyclic ether-containing group means the amount of the cyclic ether-containing group contained in the average composition of the silicone resin A.

In the silicone resin A represented by the general formula (1), R ^{1 to} R ⁶ other than the cyclic ether-containing group represent a linear or branched hydrocarbon having 1 to 8 carbon atoms or a fluorinated product thereof. .

The linear or branched hydrocarbon having 1 to 8 carbon atoms is not particularly limited, and examples thereof include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, and an n-hexyl group. N-heptyl group, n-octyl group, isopropyl group, isobutyl group, sec-butyl group, t-butyl group, isopentyl group, neopentyl group, t-pentyl group, isohexyl group, cyclohexyl group, phenyl group, etc. Can be mentioned.

In the silicone resin A represented by the general formula (1), the structural unit represented by (R ⁴ R ⁵ SiO _2/2 ) (hereinafter also referred to as a bifunctional structural unit) has the following general formula (1-2) ), That is, a structure in which one of oxygen atoms bonded to a silicon atom in the bifunctional structural unit constitutes a hydroxyl group or an alkoxy group.

(R ⁴ R ⁵ SiXO _1/2 ) (1-2)
In the general formula (1-2), X represents OH or OR, and OR represents a linear or branched alkoxy group having 1 to 4 carbon atoms.

In the silicone resin A represented by the general formula (1), the structural unit represented by (R ⁶ SiO _3/2 ) (hereinafter also referred to as trifunctional structural unit) is represented by the following general formula (1-3 ) Or (1-4), that is, a structure in which two oxygen atoms bonded to a silicon atom in a trifunctional structural unit each constitute a hydroxyl group or an alkoxy group, or a structure in a trifunctional structural unit It includes a structure in which one of oxygen atoms bonded to a silicon atom constitutes a hydroxyl group or an alkoxy group.

(R ⁶ SiX ₂ O _1/2 ) (1-3)
(R ⁶ SiXO _2/2 ) (1-4)
In the general formulas (1-3) and (1-4), X represents OH or OR, and OR represents a linear or branched alkoxy group having 1 to 4 carbon atoms.

In the silicone resin A represented by the general formula (1), the structural unit represented by (SiO _4/2 ) (hereinafter also referred to as tetrafunctional structural unit) is represented by the following general formula (1-5), A structure represented by (1-6) or (1-7), that is, a structure in which three or two oxygen atoms bonded to a silicon atom in a tetrafunctional structural unit constitute a hydroxyl group or an alkoxy group, or It includes a structure in which one of oxygen atoms bonded to a silicon atom in a tetrafunctional structural unit constitutes a hydroxyl group or an alkoxy group.
(SiX ₃ O _1/2 ) (1-5)
_{(SiX 2 O 2/2) (1-6} )
(SiXO _3/2 ) (1-7)
In the general formulas (1-5), (1-6), and (1-7), X represents OH or OR, and OR represents a linear or branched alkoxy group having 1 to 4 carbon atoms. To express.

In the general formulas (1-2) to (1-7), the linear or branched alkoxy group having 1 to 4 carbon atoms is not particularly limited, and examples thereof include a methoxy group, an ethoxy group, and an n-propoxy group. N-butoxy group, isopropoxy group, isobutoxy group, sec-butoxy group, t-butoxy group and the like.

In the general formula (1), a is a numerical value that satisfies the relationship that the lower limit of a / (a + b + c + d) is 0 and the upper limit is 0.2. If it exceeds 0.2, the heat resistance of the encapsulating sheet for optical semiconductors of the present invention may deteriorate.

In the general formula (1), b is a numerical value that satisfies the relationship that the lower limit of b / (a + b + c + d) is 0.3 and the upper limit is 1.0. When it is less than 0.3, the cured product of the encapsulating sheet for optical semiconductors of the present invention becomes too hard, and cracks and the like may occur.

In the general formula (1), c is a numerical value that satisfies the relationship that c / (a + b + c + d) has a lower limit of 0 and an upper limit of 0.5. If it exceeds 0.5, it may be difficult to maintain an appropriate viscosity as the composition for a sealing sheet.

Furthermore, in the general formula (1), d is a numerical value that satisfies the relationship that the lower limit of d / (a + b + c + d) is 0 and the upper limit is 0.3. If it exceeds 0.3, it may be difficult to maintain an appropriate viscosity as the composition for a sealing sheet.

When the silicone resin A represented by the above general formula (1) is subjected to ²⁹ Si-nuclear magnetic resonance analysis (hereinafter referred to as NMR) based on tetramethylsilane (hereinafter referred to as TMS), it varies slightly depending on the type of substituent. Although a peak corresponding to the structural unit represented by (R ¹ R ² R ³ SiO _1/2 ) _a in the general formula (1) appears in the vicinity of +10 to 0 ppm, (R ⁴ R ⁵ SiO _2/2 ) Each peak corresponding to the bifunctional structural unit of _b and (1-2) appears in the vicinity of −10 to −30 ppm, and (R ⁶ SiO _{3 / 2} ) Each peak corresponding to the trifunctional structural units of _c , (1-3) and (1-4) appears in the vicinity of −50 to −70 ppm, and (SiO _4/2 ) _{d of} the above general formula (1), Tetrafunctional structure of (1-5), (1-6) and (1-7) Each peak corresponding to a unit appears in the vicinity of -90 to-120 ppm.
Therefore, it is possible to measure the ratio of the general formula (1) by measuring ²⁹ Si-NMR and comparing the peak areas of the respective signals.
However, when the ²⁹ Si-NMR measurement based on the TMS cannot be distinguished from the functional structural unit of the general formula (1), not only the ²⁹ Si-NMR measurement result but also 1H-NMR or 19F The ratio of the structural units can be discriminated by using the results measured by -NMR as necessary.

The silicone resin A preferably has a structural unit of R ⁷ R ⁸ SiO _2/2, a structural unit of R ⁹ SiO _3/2 and / or a structural unit of SiO _4/2 . By having a structural unit of R ⁷ R ⁸ SiO _2/2, a structural unit of R ⁹ SiO _3/2 and / or a structural unit of SiO _4/2 , the encapsulating sheet for optical semiconductors of the present invention further comprises It has excellent heat resistance and can prevent problems such as film loss under use conditions. Moreover, it becomes easy to adjust the viscosity of the said composition for sealing sheets to a desired range by having a structural unit of _{SiO4 / 2} suitably, and is preferable. When the silicone resin A contains only a structural unit of R ⁷ R ⁸ SiO _2/2 , the encapsulating sheet for optical semiconductors of the present invention is insufficient in heat resistance or is three-dimensional. Cross-linking tends to be insufficient, and film loss may occur after curing.
At least one of R ^{7 to} R ⁹ is a cyclic ether-containing group, and R ^{7 to} R ⁹ other than the cyclic ether-containing group are linear or branched hydrocarbons having 1 to 8 carbon atoms or fluorine thereof. Which may be the same or different from each other. Examples of such R ^{12 to} R ¹⁴ include the same as R ^{4 to} R ⁶ described above. Furthermore, the structural unit of R ⁷ R ⁸ SiO _2/2 , the structural unit of R ⁹ SiO _3/2 , and the structural unit of SiO _4/2 include the above general formulas (1-2) to (1-7 The same structure as the bifunctional structural unit, trifunctional structural unit and tetrafunctional structural unit represented by

In the composition for encapsulating sheets, having a structural unit of R ⁷ R ⁸ SiO _{2/2 and} a structural unit of R ⁹ SiO _3/2 and / or a structural unit of SiO _4/2 is uncured. A resin having a structural unit of R ⁷ R ⁸ SiO _{2/2 and} a structural unit of R ⁹ SiO _3/2 and / or a structural unit of SiO _4/2 in a skeleton of one molecule in a state may be used, A mixture of a resin having a structural unit of only R ⁷ R ⁸ SiO _2/2 and a resin having a structural unit of R ⁹ SiO _3/2 and / or a resin having a structural unit of SiO _4/2 may be used. Of these, a resin having a structural unit of R ⁷ R ⁸ SiO _{2/2 and} a structural unit of R ⁹ SiO _3/2 in the skeleton of one molecule of the resin is preferable.

The resin having a structural unit of R ⁷ R ⁸ SiO _{2/2 and} a structural unit of R ⁹ SiO _3/2 in the skeleton of one molecule is represented by a = d = 0 in the general formula (1). Can be used.
In this case, the preferable lower limit of b / (a + b + c + d) is 0.5, the preferable upper limit is 0.95, the more preferable lower limit is 0.6, and the more preferable upper limit is 0.9 (hereinafter, condition (1)) Also called). The preferable lower limit of c / (a + b + c + d) is 0.05, the preferable upper limit is 0.5, the more preferable lower limit is 0.1, and the more preferable upper limit is 0.4 (hereinafter also referred to as condition (2)).

Specific examples of the resin having the structural unit of R ⁷ R ⁸ SiO _{2/2 and} the structural unit of R ⁹ SiO _3/2 in the skeleton of one molecule of the silicone resin A include, for example, the following average composition formula: Resins represented by the formula (2), (3), (4) or (5) can be used.

In the general formula (2), R ¹² is a cyclic ether-containing group, R ¹⁰ and R ¹¹ represent a linear or branched hydrocarbon having 1 to 8 carbon atoms or a fluorinated product thereof. These may be the same as or different from each other. e / (e + f) satisfies the above condition (1), and f / (e + f) satisfies the above condition (2).

In the general formula (3), R ¹⁴ and / or R ¹⁵ is a cyclic ether-containing group, and R ¹³ represents a linear or branched hydrocarbon having 1 to 8 carbon atoms or a fluorinated product thereof. When only one of R ^{14 and} R ¹⁵ is a cyclic ether, the other represents a linear or branched hydrocarbon having 1 to 8 carbon atoms or a fluorinated product thereof. g / (g + h) satisfies the above condition (1), and h / (g + h) satisfies the above condition (2).

In the general formula (17), R ⁶⁰ is a cyclic ether-containing group, and R ⁵⁶ , R ⁵⁷ , R ⁵⁸ , and R ⁵⁹ are linear or branched hydrocarbons having 1 to 8 carbon atoms or fluorine thereof. Which may be the same or different from each other. (B + C) / (B + C + D) satisfies the above condition (1), and D / (B + C + D) satisfies the above condition (2). However, (R ⁵⁶ R ⁵⁷ SiO _2/2 ) and (R ⁵⁸ R ⁵⁹ SiO _2/2 ) have different structures.

In the general formula (4), R ¹⁸ and / or R ¹⁹ is a cyclic ether-containing group, and R ¹⁶ , R ¹⁷ , and R ²⁰ are linear or branched hydrocarbons having 1 to 8 carbon atoms or It represents the fluorinated product, and these may be the same or different from each other. Further, when only one of R ¹⁸ or R ¹⁹ is a cyclic ether and the other represents a straight or branched chain hydrocarbon or a fluorinated compound having 1 to 8 carbon atoms. (I + j) / (i + j + k) satisfies the above condition (1), and k / (i + j + k) satisfies the above condition (2).

In the general formula (5), R ²³ is a cyclic ether-containing group, and R ²¹ , R ²² , and R ^{24 each} represent a linear or branched hydrocarbon having 1 to 8 carbon atoms or a fluorinated product thereof. These may be the same as or different from each other. l / (l + m + n) satisfies the condition (1), and (m + n) / (l + m + n) satisfies the condition (2).

Especially, it is preferable to contain the resin component represented by the said General formula (2), (5) or (17). In the general formulas (2) to (5), the cyclic ether-containing group preferably contains either one of a glycidyl group or an epoxycyclohexyl group.

The resin having a structural unit of R ⁷ R ⁸ SiO _{2/2 and} a structural unit of R ⁹ SiO _3/2 in the skeleton of one molecule is a cyclic ether-containing group in the structural unit of R ⁹ SiO _3/2. It is preferable to have. When the cyclic ether-containing group is contained in the structural unit of R ⁹ SiO _3/2 , the cyclic ether-containing group is likely to come out of the polysiloxane skeleton of the silicone resin A, and the curing of the encapsulating sheet for optical semiconductors of the present invention is achieved. The product has a sufficient three-dimensional cross-linked structure to have sufficient heat resistance, and it is possible to suitably prevent the film from being reduced in the cured product.

A resin having a structural unit of R ⁷ R ⁸ SiO _{2/2 and} a structural unit of R ⁹ SiO _3/2 in the skeleton of one molecule, wherein the cyclic ether-containing group is contained in the structural unit of R ⁹ SiO _3/2 As the resin having, for example, the average composition formula is preferably represented by the following general formula (6), (7) or (8).

一般式（６）中、ｏ、ｐは、ｏ／（ｏ＋ｐ）＝０．６〜０．９５、ｐ／（ｏ＋ｐ）＝０．０５〜０．４を満たし、Ｒ^２７が環状エーテル含有基であり、Ｒ^２５、Ｒ^２６は、炭素数１〜８の炭化水素或いはフッ素化物であり、これらは互いに同一であってもよく、異なっていてもよい。

In the general formula (6), o and p satisfy o / (o + p) = 0.6 to 0.95, p / (o + p) = 0.05 to 0.4, and R ²⁷ is a cyclic ether-containing group. R ²⁵ and R ²⁶ are hydrocarbons or fluorinated compounds having 1 to 8 carbon atoms, and these may be the same or different.

一般式（７）中、ｑ、ｒ、ｓは、（ｑ＋ｒ）／（ｑ＋ｒ＋ｓ）＝０．６〜０．９５、ｓ／（ｑ＋ｒ＋ｓ）＝０．０５〜０．４を満たし、Ｒ^３２が環状エーテル含有基であり、Ｒ^２８〜Ｒ^３１は、炭素数１〜８の炭化水素或いはフッ素化物であり、これらは互いに同一であってもよく、異なっていてもよい。ただし、（Ｒ^２８Ｒ^２９ＳｉＯ_２／２）と（Ｒ^３０Ｒ^３１ＳｉＯ_２／２）とは構造が異なるものである。

In general formula (7), q, r, and s satisfy (q + r) / (q + r + s) = 0.6 to 0.95, s / (q + r + s) = 0.05 to 0.4, and R ³² is cyclic It is an ether-containing group, and R ^{28 to} R ³¹ are hydrocarbons or fluorinated compounds having 1 to 8 carbon atoms, and these may be the same or different. However, (R ²⁸ R ²⁹ SiO _2/2 ) and (R ³⁰ R ³¹ SiO _2/2 ) have different structures.

一般式（８）中、ｔ、ｕ、ｖは、ｔ／（ｔ＋ｕ＋ｖ）＝０．６〜０．９５を満たし、（ｕ＋ｖ）／（ｔ＋ｕ＋ｖ）＝０．０５〜０．４を満たし、Ｒ^３６が環状エーテル含有基であり、Ｒ^３３、Ｒ^３４、Ｒ^３５は、炭素数１〜８の炭化水素或いはフッ素化物であり、これらは互いに同一であってもよく、異なっていてもよい。

In general formula (8), t, u, and v satisfy t / (t + u + v) = 0.6 to 0.95, satisfy (u + v) / (t + u + v) = 0.05 to 0.4, and R ³⁶ Is a cyclic ether-containing group, and R ³³ , R ³⁴ , and R ³⁵ are hydrocarbons or fluorinated compounds having 1 to 8 carbon atoms, and these may be the same or different.

Moreover, in the said composition for sealing sheets, it is preferable that the said silicone resin A has the cyclic ether containing group and the polysiloxane skeleton couple | bonded through the silicon-carbon bond. Since the cyclic ether-containing group and the polysiloxane skeleton are bonded via a silicon-carbon bond, the encapsulating sheet for optical semiconductors of the present invention is excellent in heat resistance, light resistance, and film reduction. preferable. For example, when a resin obtained by an addition reaction in which an OH group is reacted is used, a cyclic ether-containing group and a polysiloxane skeleton are bonded via a silicon-oxygen bond. Not only may heat resistance and light resistance not be obtained sufficiently, film thickness may be deteriorated.

The silicone resin A preferably contains an alkoxy group with a lower limit of 0.5 mol% and an upper limit of 10 mol%. By containing such an alkoxy group, heat resistance and light resistance are drastically improved. This is presumably because the silicone resin A contains an alkoxy group, and thus the curing rate can be dramatically improved, thereby preventing thermal deterioration during curing.

In addition, since the curing speed is dramatically improved in this way, sufficient curability can be obtained even when the amount of the curing accelerator described later is relatively small.

If the alkoxy group is less than 0.5 mol%, the curing rate may not be sufficiently obtained and the heat resistance may be deteriorated. If it exceeds 10 mol%, the silicone resin A or the composition for sealing sheet is stored. Stability deteriorates and heat resistance deteriorates. A more preferred lower limit is 1 mol%, and a more preferred upper limit is 5 mol%.

In the present specification, the content of the alkoxy group means the amount of the alkoxy group contained in the average composition of the silicone resin A.

It is preferable that the silicone resin A does not contain a silanol group. The silanol group is not preferable because the storage stability of the polymer is remarkably deteriorated and the storage stability when the resin composition is obtained is also remarkably deteriorated. Such silanol groups can be reduced by heating under vacuum, and the amount of silanol groups can be measured using infrared spectroscopy or the like.

In the composition for a sealing sheet, the preferable lower limit of the number average molecular weight (Mn) of the silicone resin A is 1000, and the preferable upper limit is 50,000. If it is less than 1000, volatile components increase at the time of thermal curing, and the film loss of the cured product increases, which is not preferable. If it exceeds 50,000, viscosity adjustment becomes difficult, which is not preferable. A more preferred lower limit is 1500, and a more preferred upper limit is 15000.
In the present specification, the number average molecular weight (Mn) is a value obtained using polystyrene as a standard using gel permeation chromatography (GPC), and is a measuring device manufactured by Waters (column: manufactured by Showa Denko KK). It means a value measured using Shodex GPC LF-804 (length: 300 mm) × 2, measurement temperature: 40 ° C., flow rate: 1 mL / min, solvent: tetrahydrofuran, standard substance: polystyrene.

The method for synthesizing the silicone resin A is not particularly limited. For example, (1) a substituent is introduced by a hydrosilylation reaction between a silicone resin A (a) having a SiH group and a vinyl compound having a cyclic ether group. Examples thereof include (2) a method in which a siloxane compound and a siloxane compound having a cyclic ether-containing group are subjected to a condensation reaction.

In the above method (1), the hydrosilylation reaction is a method of reacting a SiH group and a vinyl group in the presence of a catalyst as necessary.

The silicone resin A (a) having the SiH group has a structure represented by the general formula (1) described above after reacting a vinyl compound having a SiH group in the molecule and the cyclic ether-containing group. Preferably, a material having a structure represented by any of the above general formulas (2) to (8) or (17) may be used.

The vinyl compound having a cyclic ether-containing group is not particularly limited as long as it is a vinyl compound having one or more cyclic ether-containing groups in the molecule. For example, vinyl glycidyl ether, allyl glycidyl ether, glycidyl (meth) acrylate , Epoxy group-containing compounds such as butadiene monooxide, vinylcyclohexene oxide, and allylcyclohexene oxide. In addition, the said (meth) acryl means acryl or methacryl.

Examples of the catalyst used as necessary during the hydrosilylation reaction include, for example, a simple substance of Group 8 metal, a metal solid supported on a carrier such as alumina, silica, carbon black, and the like. Examples include salts and complexes. Specifically, as the metal of Group 8 of the periodic table, for example, platinum, rhodium, and ruthenium are preferable, and platinum is particularly preferable.
As the hydrosilation reaction catalyst using platinum, for example, chloroplatinic acid, chloroplatinic acid and alcohol, aldehyde, ketone complex, platinum-vinylsiloxane complex, platinum-phosphine complex, platinum-phosphite complex, And dicarbonyldichloroplatinum.

The reaction conditions during the hydrosilylation reaction are not particularly limited, but the reaction temperature is preferably 10 ° C. and the preferred upper limit is 200 ° C. in consideration of the reaction rate and yield. A more preferred lower limit is 30 ° C., a more preferred upper limit is 150 ° C., a still more preferred lower limit is 50 ° C., and a still more preferred upper limit is 120 ° C.

Moreover, the said hydrosilylation reaction may be performed without a solvent and may be performed using a solvent.
The solvent is not particularly limited, and examples thereof include ether solvents such as dioxane, tetrahydrofuran and propylene glycol monomethyl ether acetate; ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone; hydrocarbon solvents such as toluene, xylene and cyclohexane; acetic acid Examples include ester solvents such as ethyl and butyl acetate; alcohol solvents such as butyl cellosolve and butyl carbitol. Of these, ether solvents, ester solvents, ketone solvents, and hydrocarbon solvents are preferred. preferable.

In the above method (2), examples of the siloxane compound include alkoxysilanes having a siloxane unit represented by the following general formulas (9), (10), (11), and (12), or partial hydrolysates thereof.

In the general formulas (9) to (12), R ^{37 to} R ⁴² represent a linear or branched hydrocarbon having 1 to 8 carbon atoms or a fluorinated product thereof, and OR represents a linear or branched chain. Represents an alkoxy group having 1 to 4 carbon atoms.

In the general formulas (9) to (12), when R ^{37 to} R ⁴² are linear or branched hydrocarbons having 1 to 8 carbon atoms, specifically, for example, a methyl group, an ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, isopropyl group, isobutyl group, sec-butyl group, t-butyl group, isopentyl group, neopentyl group Group, t-pentyl group, isohexyl group, cyclohexyl group, phenyl group and the like.

In the general formulas (9) to (12), the linear or branched alkoxy group having 1 to 4 carbon atoms represented by OR is specifically, for example, a methoxy group, an ethoxy group, n -Propoxy group, n-butoxy group, isopropoxy group, isobutoxy group, sec-butoxy group, t-butoxy group and the like.

In the siloxane compound, the compounding ratio of the alkoxysilane having a siloxane unit represented by the general formulas (9) to (12) or a partial hydrolyzate thereof is subjected to a condensation reaction with a siloxane compound having a cyclic ether-containing group described later. The silicone resin A synthesized in this manner is appropriately selected so as to have a structure represented by the above general formula (1), preferably a structure represented by any one of the above general formulas (2) to (8) or (17). adjust.

Examples of the siloxane compound having a cyclic ether-containing group include alkoxysilanes having a cyclic ether-containing group represented by the following general formulas (13) and (14) or partial hydrolysates thereof.

In the general formulas (13) and (14), R ⁴³ and / or R ⁴⁴ and R ⁴⁵ are cyclic ether-containing groups, and only one of R ^{43 and} R ⁴⁴ is a cyclic ether-containing group. The other represents a linear or branched hydrocarbon having 1 to 8 carbon atoms or a fluorinated product thereof, and OR represents a linear or branched alkoxy group having 1 to 4 carbon atoms.

In general formulas (13) and (14), R ⁴³ and / or R ⁴⁴ and the cyclic ether-containing group represented by R ⁴⁵ are not particularly limited, and examples thereof include a glycidyl group, an epoxycyclohexyl group, and an oxetane group. Is mentioned. Of these, a glycidyl group and / or an epoxycyclohexyl group are preferable.

The glycidyl group is not particularly limited. For example, 2,3-epoxypropyl group, 3,4-epoxybutyl group, 4,5-epoxypentyl group, 2-glycidoxyethyl group, 3-glycidoxypropyl Group, 4-glycidoxybutyl group and the like.

The epoxycyclohexyl group is not particularly limited, and examples thereof include 2- (3,4-epoxycyclohexyl) ethyl group, 3- (3,4-epoxycyclohexyl) propyl group, and the like.

In the general formula (13), when either one of R ⁴³ and / or R ⁴⁴ is a straight-chain or branched hydrocarbon or a fluorinated compound having 1 to 8 carbon atoms, specifically, for example, the The thing similar to what was demonstrated in General formula (1) is mentioned.

In the general formulas (13) and (14), the linear or branched alkoxy group having 1 to 4 carbon atoms represented by OR is specifically the general formula (1-2) described above. The thing similar to what was demonstrated in-(1-7) is mentioned.

Specific examples of the siloxane compound having a cyclic ether-containing group represented by the general formula (13) include 3-glycidoxypropyl (methyl) dimethoxysilane and 3-glycidoxypropyl (methyl) di Ethoxysilane, 3-glycidoxypropyl (methyl) dibutoxysilane, 2,3-epoxypropyl (methyl) dimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyl (methyl) dimethoxysilane, 2- (3 4-epoxycyclohexyl) ethyl (methyl) diethoxysilane and the like.

Specific examples of the siloxane compound having a cyclic ether-containing group represented by the general formula (14) include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3- Glycidoxypropyltributoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltriethoxysilane, 2,3-epoxypropyltrimethoxysilane, 2, Examples include 3-epoxypropyltriethoxysilane.

In the method (2), as a specific method for the condensation reaction of the siloxane compound and the siloxane compound having a cyclic ether-containing group, for example, the siloxane compound and the compound having a cyclic ether group are mixed with water and an acid. Alternatively, a method of synthesizing the silicone resin A by reacting in the presence of a basic catalyst can be mentioned.
The siloxane compound may be reacted in advance in the presence of water and an acid or basic catalyst, and then the siloxane compound having a cyclic ether group may be reacted.

In the method (2), when the siloxane compound and the compound having a cyclic ether-containing group are reacted in the presence of water and an acid or a basic catalyst, the compound having the cyclic ether-containing group is It mix | blends so that a lower limit may be 0.1 mol% and an upper limit may be 50 mol% with respect to all the organic groups couple | bonded with the silicon atom of the said siloxane compound and the compound which has a cyclic ether containing group.

The blending amount of the water is not particularly limited as long as it is an amount capable of hydrolyzing the alkoxy group bonded to the silicon atom in the siloxane compound having the cyclic ether-containing group, and is appropriately adjusted.

The acidic catalyst is a catalyst for reacting the siloxane compound with a siloxane compound having a cyclic ether-containing group. For example, inorganic acids such as phosphoric acid, boric acid, and carbonic acid; formic acid, acetic acid, propionic acid, and lactic acid , Lactic acid, malic acid, tartaric acid, citric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, fumaric acid, maleic acid, oleic acid and other organic acids; their acid anhydrides or derivatives .

The basic catalyst is a catalyst for reacting the siloxane compound with a siloxane compound having a cyclic ether-containing group, and examples thereof include alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, cesium hydroxide; Examples include alkali metal alkoxides such as sodium-t-butoxide, potassium-t-butoxide, and cesium-t-butoxide; and alkali metal silanol compounds such as sodium silanolate compounds, potassium silanolate compounds, and cesium silanolate compounds. Of these, potassium-based catalysts and cesium-based catalysts are preferred.

The addition amount of the acid or basic catalyst is not particularly limited, but the preferred lower limit is 10 ppm and the preferred upper limit is 10,000 ppm with respect to the total amount of the siloxane compound and the siloxane compound having a cyclic ether-containing group, A more preferred lower limit is 100 ppm, and a more preferred upper limit is 5000 ppm.
The acid or basic catalyst may be added as it is, or may be added after dissolving in a small amount of water or the siloxane compound.

In the condensation reaction of the siloxane compound and the siloxane compound having a cyclic ether-containing group, the synthesized silicone resin A can be prevented from precipitating from the reaction system, and the water and free water by the condensation reaction are removed by azeotropic distillation. It is preferable to use an organic solvent because it can be used.
Examples of the organic solvent include aromatic organic solvents such as toluene and xylene; ketone organic solvents such as acetone and methyl isobutyl ketone; aliphatic organic solvents such as hexane, heptane and octane. Of these, aromatic organic solvents are preferably used.

Although it does not specifically limit as reaction temperature at the time of the said condensation reaction, A preferable minimum is 40 degreeC and a preferable upper limit is 200 degreeC, A more preferable minimum is 50 degreeC and a more preferable upper limit is 150 degreeC. Moreover, when using the said organic solvent, the said condensation reaction can be easily performed at reflux temperature by using what has a boiling point in the range of 40-200 degreeC as this organic solvent.

From the viewpoint of adjusting the amount of the alkoxy group, it is preferable to synthesize the silicone resin A by the above method (2).
In order to bring the alkoxy group into an appropriate range, the above method (2) can bring the alkoxy group into an appropriate range by adjusting the reaction temperature, reaction time, amount of catalyst and amount of water. is there.

The sealing sheet composition preferably contains a bifunctional silicone resin A having one or more glycidyl-containing groups in the molecule.
By containing such a bifunctional silicone resin A, the sealing sheet for optical semiconductors of the present invention significantly improves the crack resistance of the cured product. This is because in the cured product, the bifunctional skeleton is more flexible than the silicone resin A in the gap between the crosslinking points generated by the reaction of the cyclic ether-containing group of the silicone resin A having a cyclic ether-containing group in the molecule. It is assumed that this is because the silicone resin A enters.

In the present specification, the glycidyl-containing group only needs to contain a glycidyl group as at least a part of the group, and may contain, for example, another skeleton such as an alkyl group or an alkyl ether group and a glycidyl group. Means group.
The glycidyl-containing group is not particularly limited. For example, 2,3-epoxypropyl group, 3,4-epoxybutyl group, 4,5-epoxypentyl group, 2-glycidoxyethyl group, 3-glycidoxy A propyl group, 4-glycidoxybutyl group, etc. are mentioned.

As the bifunctional silicone resin A, for example, a resin represented by a = c = d = 0 in the general formula (1) can be used. Specifically, the average composition formula is represented by the following general formula ( It is preferable to contain the resin component represented by 15) or (16). When the bifunctional silicone resin A contains a resin component represented by the following general formula (15) or (16), the cured product of the encapsulating sheet for optical semiconductors of the present invention has appropriate flexibility. Thus, the crack resistance is extremely excellent. The bifunctional silicone resin A has an average composition formula represented by the following general formula (15) or (16). The bifunctional silicone resin A has the following general formula (15). ) Or (16) not only containing only the resin component represented, but also in the case of a mixture containing resin components of various structures, the following general formula ( It also means the case represented by 15) or (16).

一般式（１５）中、Ｒ^４８及び／又はＲ^４９は、グリシジル含有基であり、Ｒ^４６、Ｒ^４７は、直鎖状又は分岐状の炭素数１〜８の炭化水素或いはそのフッ素化物を表し、これらは、互いに同一であってもよく、異なっていてもよい。また、Ｒ^４８又はＲ^４９のいずれか一方のみがグリシジル含有基である場合、他方は、直鎖状又は分岐状の炭素数１〜８の炭化水素或いはそのフッ素化物を表す。また、ｗ／（ｗ＋ｘ）の好ましい下限は０．６、好ましい上限は０．９５、より好ましい下限は０．７、より好ましい上限は０．９であり、ｘ／（ｗ＋ｘ）の好ましい下限は０．０５、好ましい上限は０．４、より好ましい下限は０．１、より好ましい上限は０．３である。

In the general formula (15), R ⁴⁸ and / or R ⁴⁹ is a glycidyl-containing group, and R ⁴⁶ and R ⁴⁷ represent a linear or branched hydrocarbon having 1 to 8 carbon atoms or a fluorinated product thereof. These may be the same as or different from each other. When only one of R ^{48 and} R ⁴⁹ is a glycidyl-containing group, the other represents a linear or branched hydrocarbon having 1 to 8 carbon atoms or a fluorinated product thereof. The preferred lower limit for w / (w + x) is 0.6, the preferred upper limit is 0.95, the more preferred lower limit is 0.7, the more preferred upper limit is 0.9, and the preferred lower limit for x / (w + x) is 0. 0.05, a preferred upper limit is 0.4, a more preferred lower limit is 0.1, and a more preferred upper limit is 0.3.

一般式（１６）中、Ｒ^５４及び／又はＲ^５５は、グリシジル含有基であり、Ｒ^５０、Ｒ^５１、Ｒ^５２、Ｒ^５３は、直鎖状又は分岐状の炭素数１〜８の炭化水素或いはそのフッ素化物を表し、これらは、互いに同一であってもよく、異なっていてもよい。また、Ｒ^５４又はＲ^５５のいずれか一方のみがグリシジル含有基である場合、他方は、直鎖状又は分岐状の炭素数１〜８の炭化水素或いはそのフッ素化物を表す。また、ｙ＋ｚ／（ｙ＋ｚ＋Ａ）の好ましい下限は０．６、好ましい上限は０．９５、より好ましい下限は０．７、より好ましい上限は０．９であり、Ａ／（ｙ＋ｚ＋Ａ）の好ましい下限は０．０５、好ましい上限は０．４、より好ましい下限は０．１、より好ましい上限は０．３である。ただし、（Ｒ^５０Ｒ^５１ＳｉＯ_２／２）と（Ｒ^５２Ｒ^５３ＳｉＯ_２／２）とは構造が異なるものである。

In the general formula (16), R ⁵⁴ and / or R ⁵⁵ is a glycidyl-containing group, and R ⁵⁰ , R ⁵¹ , R ⁵² , and R ⁵³ are linear or branched hydrocarbons having 1 to 8 carbon atoms. Or the fluoride is represented, and these may be the same as each other or different. When only one of R ^{54 and} R ⁵⁵ is a glycidyl-containing group, the other represents a linear or branched hydrocarbon having 1 to 8 carbon atoms or a fluorinated product thereof. The preferred lower limit of y + z / (y + z + A) is 0.6, the preferred upper limit is 0.95, the more preferred lower limit is 0.7, the more preferred upper limit is 0.9, and the preferred lower limit of A / (y + z + A) is 0. 0.05, a preferred upper limit is 0.4, a more preferred lower limit is 0.1, and a more preferred upper limit is 0.3. However, (R ⁵⁰ R ⁵¹ SiO _2/2 ) and (R ⁵² R ⁵³ SiO _2/2 ) have different structures.

The preferable lower limit of the number average molecular weight (Mn) of the bifunctional silicone resin A is 1500, and the preferable upper limit is 50,000. If it is less than 1500, the crack resistance of the cured product of the encapsulating sheet for optical semiconductors of the present invention may be insufficient, and if it exceeds 50,000, it is difficult to adjust the viscosity of the composition for encapsulating sheet. May be. A more preferable lower limit is 2000, and a more preferable upper limit is 20,000.

A method for synthesizing such a bifunctional silicone resin A is not particularly limited, and examples thereof include the same method as the method for synthesizing silicone resin A described above. That is, a method of introducing a substituent by a hydrosilylation reaction between a silicone resin A (b) having a SiH group and a vinyl compound having a glycidyl-containing group (method (3)), having an alkoxysilane compound and a glycidyl-containing group Examples thereof include a method (method (4)) for causing a condensation reaction with an alkoxysilane compound.

When the bifunctional silicone resin A is synthesized by the method (3), the silicone resin A (b) having the SiH group includes, for example, a vinyl compound having a SiH group in the molecule and the glycidyl-containing group. After the reaction, those having a structure represented by the above general formula (15) or (16) can be mentioned.

The vinyl compound having a glycidyl-containing group is not particularly limited as long as it is a vinyl compound having one or more glycidyl-containing groups in the molecule. For example, vinyl glycidyl ether, allyl glycidyl ether, glycidyl (meth) acrylate, butadiene A monooxide etc. are mentioned.

Moreover, at the time of the hydrosilylation reaction, as in the case of synthesizing the silicone resin A described above, a catalyst may be used as necessary, or it may be carried out without a solvent, or using a solvent. May be.

When the bifunctional silicone resin A is synthesized by the method (4), the alkoxysilane compound is not particularly limited, and examples thereof include the same compounds as the dialkoxysilane compound of the general formula (10) described above.
Moreover, as an alkoxysilane compound which has the said glycidyl containing group, the thing similar to the dialkoxysilane compound of General formula (13) mentioned above is mentioned, for example.

Specific examples of the dialkoxysilane having a glycidyl-containing group include 3-glycidoxypropyl (methyl) dimethoxysilane, 3-glycidoxypropyl (methyl) diethoxysilane, 3-glycidoxypropyl ( And methyl) dibutoxysilane and 2,3-epoxypropyl (methyl) dimethoxysilane.

As a specific method for the condensation reaction of the alkoxysilane compound and the alkoxysilane compound having a glycidyl-containing group, for example, the alkoxysilane compound and the alkoxysilane compound having a cyclic ether-containing group in the case of synthesizing the silicone resin A described above. The same method as in the case of reacting with is mentioned.

In the composition for a sealing sheet, the amount of the bifunctional silicone resin A to the silicone resin A described above is not particularly limited, but the preferred lower limit is 10 parts by weight and the preferred upper limit with respect to 100 parts by weight of the silicone resin A. Is 120 parts by weight. If it is less than 10 parts by weight, the crack resistance of the cured product of the encapsulating sheet for optical semiconductors of the present invention may not be sufficiently exhibited. If it exceeds 120 parts by weight, the encapsulating sheet for optical semiconductors of the present invention The cured product is inferior in heat resistance, and the cured product may be easily yellowed in a thermal environment. A more preferred lower limit is 15 parts by weight, and a more preferred upper limit is 100 parts by weight.

The composition for sealing sheets contains a thermosetting agent that reacts with the cyclic ether-containing group (hereinafter also simply referred to as a thermosetting agent).
The thermosetting agent is not particularly limited as long as it can react with the cyclic ether-containing group of the silicone resin. For example, ethylenediamine, triethylenepentamine, hexamethylenediamine, dimer acid-modified ethylenediamine, N-ethylamino Aliphatic amines such as piperazine and isophoronediamine, metaphenylenediamine, paraphenylenediamine, 3,3′-diaminodiphenylsulfone, 4,4′-diaminodiphenolsulfone, 4,4′-diaminodiphenormethane, Aromatic amines such as 4,4'-diaminodiphenol ether, mercaptans such as mercaptopropionic acid esters, terminal mercapto compounds of epoxy resins, bisphenol A, bisphenol F, bisphenol AD, bisphenol S, tetramethylbisphenol A, tetramethylbisphenol F, tetramethylbisphenol AD, tetramethylbisphenol S, tetrabromobisphenol A, tetrachlorobisphenol A, tetrafluorobisphenol A, biphenol, dihydroxynaphthalene, 1,1,1-tris (4-hydroxyphenyl) ) Methane, 4,4- (1- (4- (1- (4-hydroxyphenyl) -1-methylethyl) phenyl) ethylidene) bisphenol, phenol novolak, cresol novolak, bisphenol A novolak, brominated phenol novolak, bromine Phenolic resins such as bisphenol A novolac; polyols obtained by hydrogenating aromatic rings of these phenolic resins, polyazeline acid anhydride, methyltetrahydrophthalic anhydride, tetrahydride Phthalic anhydride, methylhexahydrophthalic anhydride, hexahydrophthalic anhydride, 5-norbornene-2,3-dicarboxylic anhydride, norbornane-2,3-dicarboxylic anhydride, methyl-5-norbornene-2,3- Dicarboxylic anhydride, methyl-norbornane-2,3-dicarboxylic anhydride, cyclohexane-1,2,3-tricarboxylic acid-1,2 anhydride, cyclohexane-1,2,4-tricarboxylic acid-1,2 anhydride 3-alkylglutaric anhydride having an optionally branched alkyl group having 1 to 8 carbon atoms, such as alicyclic acid anhydrides, 3-methylglutaric anhydride, etc., 2-ethyl-3- 2,3-dialkylglutaric anhydride, 2,4-diethylglutar having a C1-C8 alkyl group which may be branched, such as propylglutaric anhydride Alkyl-substituted glutaric anhydrides such as 2,4-dialkylglutaric anhydride having an alkyl group having 1 to 8 carbon atoms which may be branched, such as anhydride, 2,4-dimethylglutaric anhydride, anhydrous Aromatic acid anhydrides such as phthalic acid, trimellitic anhydride, pyromellitic anhydride, imidazoles such as 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, and salts thereof, the above aliphatic Amines, aromatic amines, and / or amine adducts obtained by reaction of imidazoles with epoxy resins, hydrazines such as adipic acid dihydrazide, dimethylbenzylamine, 1,8-diazabicyclo [5.4.0] Tertiary amines such as undecene-7, organic phosphines such as triphenylphosphine, dicyandiamide, etc. Can be mentioned. These thermosetting agents may be used independently and 2 or more types may be used together. In addition, when it contains the said bifunctional silicone resin, such as the resin component represented by the said General formula (15) or (16), the said thermosetting agent can also react with the glycidyl containing group of this bifunctional silicone resin. .

Among these, acid anhydrides such as alicyclic acid anhydrides, alkyl-substituted glutaric acid anhydrides, and aromatic acid anhydrides are preferable, and alicyclic acid anhydrides and alkyl-substituted glutaric acid anhydrides are more preferable. And particularly preferably methylhexahydrophthalic anhydride, hexahydrophthalic anhydride, norbornane-2,3-dicarboxylic anhydride, methyl-norbornane-2,3-dicarboxylic anhydride, cyclohexane-1,2. , 3-tricarboxylic acid-1,2 anhydride, cyclohexane-1,2,4-tricarboxylic acid-1,2 anhydride, 2,4-diethylglutaric anhydride.

The blending amount of the thermosetting agent is not particularly limited, but a preferable lower limit is 10 parts by weight and a preferable upper limit is 200 parts by weight with respect to 100 parts by weight of the silicone resin A. Within this range, the encapsulating sheet for optical semiconductors of the present invention sufficiently undergoes a crosslinking reaction, is excellent in heat resistance and light resistance, and has a sufficiently low moisture permeability. A more preferred lower limit is 20 parts by weight, and a more preferred upper limit is 150 parts by weight.

The composition for sealing sheets contains a silicone resin B having a softening point of 30 to 150 ° C. (hereinafter also simply referred to as silicone resin B).
By containing such silicone resin B, it becomes possible to shape | mold the said composition for sealing sheets in a sheet form.

The lower limit of the softening point of the silicone resin B is 30 ° C., and the upper limit is 150 ° C.
When the temperature is less than 30 ° C., it may be difficult to form a composition for a sealing sheet obtained by blending with the silicone resin A, or the handleability may be inferior even if a sheet is obtained. When the softening point exceeds 150 ° C., it becomes too hard when formed into a sheet, and the light emitting element or the like may be damaged during sealing. Especially in the case of a wire bonding type, the wire may be damaged.
A preferred lower limit is 50 ° C and a preferred upper limit is 120 ° C.
In the present specification, the softening point refers to the temperature at which the resin softens, and is measured according to the ring and ball method of JIS K7234.

The silicone resin B is not particularly limited as long as the softening point is 30 to 150 ° C. For example, dimethyl silicone resin, diphenyl silicone resin, methyl phenyl silicone resin, methyl silsesquioxane, phenyl silsesquioxane, methyl Phenyl silsesquioxane, dimethyl silicone resin having functional group, methyl phenyl silicone resin having functional group, methyl silsesquioxane having functional group, phenyl silsesquioxane having functional group, methyl phenyl sil having functional group Examples include sesquioxane.

The functional group that the silicone resin B has is not particularly limited, and examples thereof include a hydroxyl group, an amino group, a (meth) acryl group, a cyclic ether group, and a carboxyl group. Especially, since the sealing sheet for optical semiconductors obtained has the outstanding adhesiveness, it is preferable that it is a cyclic ether group.
In the present specification, the (meth) acryl group means an acryl group or a methacryl group.

Examples of commercially available products of the silicone resin B include, for example, PPSQ-H, PPSQ-E, PPSQ-T, PMPSQ-E (manufactured by Konishi Chemical Co., Ltd.), SILRES 603, SILRES 604, SILRES 605, SILRES 610, SILRES MK. , SILRES H44, SILRES REN100, SILRES SY430, SILRES IC836 (manufactured by Asahi Kasei Wacker Silicone).

The blending amount of the silicone resin B is not particularly limited, but a preferable lower limit is 5 parts by weight and a preferable upper limit is 120 parts by weight with respect to 100 parts by weight of the silicone resin A. If the amount is less than 5 parts by weight, it may be difficult to maintain the sheet shape. If the amount exceeds 120 parts by weight, the sheet may become too hard to follow the shape, or the adhesion may decrease. There is. A more preferred lower limit is 10 parts by weight, and a more preferred upper limit is 100 parts by weight.

The encapsulating sheet composition preferably contains silicon oxide fine particles.
By containing the silicon oxide fine particles, it becomes possible to impart tough sheet properties of the composition for encapsulating sheets constituting the encapsulating sheet for optical semiconductors of the present invention.

The said silicon oxide microparticles | fine-particles have a preferable minimum of BET specific surface area of 30 m < ² > / g, and a preferable upper limit of 400 m < ² > / g. If it is less than 30 m ² / g, the viscosity of the resulting composition for sealing sheets may decrease. When it exceeds 400 m ² / g, aggregation of the silicon oxide fine particles may occur and dispersibility may deteriorate.

The preferable lower limit of the primary particle diameter of the silicon oxide fine particles is 5 nm, and the preferable upper limit is 200 nm. If it is less than 5 nm, the dispersibility of fine silica obtained by surface-treating silicon oxide fine particles with an organosilicon compound is lowered, and the transparency of the cured product of the resulting thermosetting composition for optical semiconductors may be inferior. . If it exceeds 200 nm, light scattering caused by finely divided silica formed by surface-treating silicon oxide fine particles with an organosilicon compound is likely to occur, and the transparency of the cured product of the resulting thermosetting composition for optical semiconductors is reduced. There are things to do. A more preferred lower limit is 8 nm, and a more preferred upper limit is 150 nm.
In the present specification, the primary particle diameter of the silicon oxide fine particles means an average value of the diameter of the silicon oxide fine particles when the silicon oxide fine particles are spherical, and silicon oxide when the silicon oxide fine particles are non-spherical. It means the average value of the major axis of fine particles.

The silicon oxide fine particles are not particularly limited, and examples thereof include silica produced by a dry method such as fumed silica and fused silica; silica produced by a wet method such as colloidal silica, sol-gel silica and precipitated silica. . Especially, since there are few volatile components and transparency is high, fumed silica is used suitably.

The fumed silica is not particularly limited. For example, Aerosil 50 (specific surface area: 50 m ² / g), Aerosil 90 (specific surface area: 90 m ² / g), Aerosil 130 (specific surface area: 130 m ² / g), Aerosil 200 (specific surface area: 200 m ² / g), Aerosil 300 (specific surface area: 300 m ² / g), Aerosil 380 (specific surface area: 380 m ² / g) (all manufactured by Nippon Aerosil Co., Ltd.) and the like.

The silicon oxide fine particles are preferably surface-treated with an organosilicon compound. By subjecting the surface of the silicon oxide fine particles to such surface treatment, the viscosity of the sealing sheet composition can be easily adjusted to a desired range.

The organosilicon compound is not particularly limited, and examples thereof include a silane compound having an alkyl group, a silicon compound having a siloxane skeleton such as dimethylsiloxane, a silicon compound having an amino group, and a silicon having a (meth) acryl group. Examples thereof include silicon compounds and silicon compounds having an epoxy group. Among these, a compound having a trimethylsilyl group or a silane compound having a polydimethylsiloxane group is preferable, and an alkoxy compound is more preferable.
In addition, in this specification, the said (meth) acryl means acryl or methacryl.

Specific examples of the compound having a trimethylsilyl group include hexamethyldisilazane, trimethylsilyl chloride, and trimethylmethoxysilane.

Examples of commercially available silicon oxide fine particles surface-treated with the compound having a trimethylsilyl group include RX200 (specific surface area: 140 m ² / g), R8200 (specific surface area: 140 m ² / g) (all manufactured by Nippon Aerosil Co., Ltd.), etc. Is mentioned.

Specific examples of the silane compound having a polydimethylsiloxane group include compounds having a silanol group at the terminal of polydimethylsiloxane, cyclic siloxane, and the like.

RY200 (specific surface area: 120 m ² / g) (manufactured by Nippon Aerosil Co., Ltd.) can be mentioned as a commercial product of silicon oxide fine particles surface-treated with a silane compound having a polydimethylsiloxane group.

The method for treating the surface of the silicon oxide fine particles with the organosilicon compound is not particularly limited. For example, the silicon oxide fine particles are added to a mixer capable of high-speed stirring such as a Henschel mixer and a V-type mixer while stirring. A dry method in which an organosilicon compound is added directly or as an alcohol aqueous solution, an organic solvent solution or an aqueous solution, a slurry method in which an organosilicon compound is added to a slurry of silicon oxide fine particles, and a step of drying the silicon oxide fine particles Direct treatment method such as spray method for spraying an organosilicon compound; organosilicon during mixing of silicon oxide fine particles and a matrix resin such as a silicone resin described later in preparing the thermosetting composition for optical semiconductors of the present invention Examples include an integral blend method in which a system compound is directly added.

The blending amount of the silicon oxide fine particles is not particularly limited, but a preferable lower limit is 0.1 parts by weight and a preferable upper limit is 30 parts by weight with respect to 100 parts by weight of the sealing resin composition. If it is less than 1 part by weight, the blending effect may not be sufficiently obtained. If it exceeds 30 parts by weight, problems such as a decrease in adhesion may occur.

It is preferable that the said composition for sealing sheets contains a dispersing agent.
By containing the said dispersing agent, the dispersibility of the said silicon oxide microparticles | fine-particles improves, and the sealing sheet for optical semiconductor elements with higher transparency is obtained.

Examples of the dispersant include polyalkylene oxide surfactants, poly (meth) acrylate surfactants, fluorine surfactants, and silicone surfactants.

As a content of the dispersing agent, a preferable lower limit is 0.01 part by weight and a preferable upper limit is 5 parts by weight with respect to 100 parts by weight of the silicone resin. When the amount is less than 0.01 part by weight, the effect of blending the dispersant can hardly be obtained. May be off. A more preferred lower limit is 0.05 parts by weight, and a more preferred upper limit is 3 parts by weight.

It is preferable that the said composition for sealing sheets contains a hardening accelerator.
By containing the said hardening accelerator, the sealing sheet for optical semiconductors of this invention can be hardened early after a heating.
The curing accelerator is not particularly limited, and examples thereof include imidazoles such as 2-methylimidazole and 2-ethyl-4-methylimidazole; and third compounds such as 1,8-diazabicyclo (5,4,0) undecene-7. Phosphines such as triphenylphosphine; phosphonium salts such as triphenylphosphonium bromide; tins such as aminotriazoles, tin octylate and dibutyltin dilaurate, zincs such as zinc octylate, aluminum, And metal catalysts such as acetylacetonate such as chromium, cobalt, and zirconium. These hardening accelerators may be used independently and may use 2 or more types together.

Although it does not specifically limit as a compounding quantity of the said hardening accelerator, A preferable minimum is 0.01 weight part with respect to 100 weight part of said silicone resins, and a preferable upper limit is 5 weight part. If it is less than 0.01 part by weight, the effect of adding the curing accelerator cannot be obtained, and if it exceeds 5 parts by weight, the coloration of the cured product, heat resistance, and light resistance are significantly reduced, which is not preferable. A more preferred lower limit is 0.05 parts by weight, and a more preferred upper limit is 1.5 parts by weight.

It is preferable that the said composition for sealing sheets contains antioxidant.
Examples of the antioxidant include a phosphorus compound having at least one skeleton selected from the group consisting of a phosphite skeleton, a phosphonite skeleton, a phosphate skeleton, and a phosphinate skeleton (hereinafter also simply referred to as a phosphorus compound), and A phenolic compound which is a substituted phenol derivative having an alkyl group at least at the second position (hereinafter also simply referred to as a phenolic compound) is preferably used.
By containing the above phosphorus compound and phenol compound as an antioxidant, the encapsulating sheet for optical semiconductors of the present invention has excellent heat resistance without yellowing in the cured product under the usage environment. It becomes. This is considered to be due to the following reasons.

That is, yellowing that occurs in a cured product of a thermosetting composition containing a conventional epoxy silicone resin is a substance that causes yellowing that is generated from radicals, peroxides, and the like that are generated in a high-temperature environment (use conditions). On the other hand, the phenolic compound has a function of stabilizing radicals generated under a high temperature environment (use conditions), and the phosphorus compound has a function of decomposing the peroxide. . When the composition for sealing sheets uses the phosphorus compound and the phenol compound together as an antioxidant, a synergistic effect of the functions of the phenol compound and the phosphorus compound is born, and the yellowing cause substance It is considered that can be efficiently stabilized or decomposed.
More specifically, in the composition for encapsulating sheets, since the phosphorus compound has an oxygen atom adjacent to the phosphorus atom as described later, the oxygen atom and the hydroxyl group of the phenol compound are By forming a hydrogen bond, the interaction between the phenol compound and the phosphorus compound increases. As a result, it is considered that the function of stabilizing and decomposing the yellowing cause substance is enhanced, and the heat resistance is extremely excellent as compared with a thermosetting composition containing a conventional epoxy silicone.
Furthermore, when the phosphorus compound has a structure having an aromatic ring, which will be described later, an interaction occurs with the aromatic ring of the phenol compound, and the function of stabilizing and decomposing the yellowing cause substance is further enhanced. It is thought that it is raised.

The phosphorus compound has at least one skeleton selected from the group consisting of a phosphite skeleton, a phosphonite skeleton, a phosphate skeleton, and a phosphinate skeleton. By having these skeletons, the phosphorus compound has an oxygen atom adjacent to the phosphorus atom, and can efficiently decompose the yellowing cause substance generated in the composition for a sealing sheet. Of these, phosphorus compounds having a phosphite skeleton and / or a phosphonite skeleton are preferable.

The phosphorus compound having the phosphite skeleton is not particularly limited. For example, 1,1,3-tris (2-methyl-4-ditridecylphosphite-5-tert-butylphenyl) butane, distearyl pentaerythritol Diphosphite, bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, phenylbisphenol A penta Erythritol diphosphite, dicyclohexylpentaerythritol diphosphite, tris (diethylphenyl) phosphite, tris (di-isopropylphenyl) phosphite, tris (di-n-butylphenyl) phosphite, tris (2,4-di-) tert Butylphenyl) phosphite, tris (2,6-di-tert-butylphenyl) phosphite, tris (2,6-di-tert-butylphenyl) phosphite, 2,2′-methylenebis (4,6-di) -Tert-butylphenyl) (2,4-di-tert-butylphenyl) phosphite, 2,2'-methylenebis (4,6-di-tert-butylphenyl) (2-tert-butyl-4-methylphenyl) ) Phosphite, 2,2′-methylenebis (4-methyl-6-tert-butylphenyl) (2-tert-butyl-4-methylphenyl) phosphite, 2,2′-ethylidenebis (4-methyl-6) -Tert-butylphenyl) (2-tert-butyl-4-methylphenyl) phosphite.

The phosphorus compound having the phosphonite skeleton is not particularly limited, and examples thereof include tetrakis (2,4-di-tert-butylphenyl) -4,4′-biphenylenediphosphonite, tetrakis (2,4-di-tert). -Butylphenyl) -4,3'-biphenylenediphosphonite, tetrakis (2,4-di-tert-butylphenyl) -3,3'-biphenylenediphosphonite, tetrakis (2,6-di-tert-butyl) Phenyl) -4,4′-biphenylenediphosphonite, tetrakis (2,6-di-tert-butylphenyl) -4,3′-biphenylenediphosphonite, tetrakis (2,6-di-tert-butylphenyl) -3,3'-biphenylenediphosphonite, bis (2,4-di-tert-butylphenyl) -4-fe Ru-phenylphosphonite, bis (2,4-di-tert-butylphenyl) -3-phenyl-phenylphosphonite, bis (2,6-di-n-butylphenyl) -3-phenyl-phenylphosphonite, Bis (2,6-di-tert-butylphenyl) -4-phenyl-phenylphosphonite, bis (2,6-di-tert-butylphenyl) -3-phenyl-phenylphosphonite, tetrakis (2,4- And di-tert-butyl-5-methylphenyl) -4,4′-biphenylenediphosphonite.

The phosphorus compound having the above phosphate skeleton is not particularly limited, and examples thereof include tributyl phosphate, trimethyl phosphate, tricresyl phosphate, triphenyl phosphate, trichlorophenyl phosphate, triethyl phosphate, diphenyl cresyl phosphate, diphenyl monoorthoxenyl phosphate. , Tributoxyethyl phosphate, dibutyl phosphate, dioctyl phosphate, diisopropyl phosphate and the like.

The phosphorus compound having the phosphinate skeleton is not particularly limited, and examples thereof include 9,10-di-hydro-9-oxa-10-phosphaphenanthroline-10-oxide.

The phosphorus compound is preferably a compound having one or more aromatic rings in the molecule. Such a phosphorus-based antioxidant having one or more aromatic rings in the molecule causes an interaction between the aromatic ring in the molecule and the aromatic ring of the phenolic compound described later, and the phosphorus-based compound described above. The interaction between the compound and the phenolic compound is further increased. As a result, the function of stabilizing or decomposing the yellowing cause substance described above can be further enhanced, and the heat resistance of the sealing sheet composition can be further enhanced.
In addition, in the said composition for sealing sheets, the phosphorus compound mentioned above may be used independently, and 2 or more types may be used together.

The amount of the phosphorus compound is not particularly limited, but a preferable lower limit is 0.01 part by weight and a preferable upper limit is 2.0 parts by weight with respect to 100 parts by weight of the silicone resin. If the amount is less than 0.01 parts by weight, the effect of adding the phosphorus compound may not be obtained. If the amount exceeds 2.0 parts by weight, the light resistance is significantly lowered, which is not preferable. A more preferred lower limit is 0.05 parts by weight, and a more preferred upper limit is 1.0 part by weight.

The phenolic compound is a substituted phenol derivative having an alkyl group at least at the second position. If the phenolic compound does not have an alkyl group at the second position, the function of stabilizing radicals generated in a high temperature environment will not be observed.
In the present specification, the position numbers of the substituents such as alkyl groups in the substituted phenol derivatives are the second, third, and fourth positions clockwise or counterclockwise with the carbon bonded to the OH group as the first position. , 5 and 6 means the number when numbered. Therefore, it does not necessarily match the IUPAC nomenclature.

The alkyl group in the substituted phenol derivative may have a branch point, and is preferably an alkyl group having 1 to 8 carbon atoms.
Specific examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a tert-pentyl group, and a tert-octyl group. Can be mentioned. Of these, a methyl group, a tert-butyl group, or a tert-pentyl group is preferable.

The substituted phenol derivative having an alkyl group at least at the second position is not particularly limited. For example, a substituted phenol derivative having an alkyl group at the second position and the sixth position, an alkyl group at the second position, At least one selected from the group consisting of a substituted phenol derivative having a methylene group or a methine group at the position and a substituted phenol derivative having an alkyl group at the 2nd and 5th positions is preferably used.

The substituted phenol derivative having an alkyl group at the second position and the sixth position is not particularly limited, and examples thereof include 2,6-di-tert-butyl-4-methylphenol, n-octadecyl-3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate, tetrakis [methylene-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] methane, 2,4-di-tert-butyl -6-methylphenol, 1,6-hexanediol-bis- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], tris (3,5-di-tert-butyl-4 -Hydroxybenzyl) -isocyanurate, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl- -Hydroxybenzyl) benzene, pentaerythrityl-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 3,9-bis- [2- [3- (3-tert- Butyl-4-hydroxy-5-methylphenyl) -propionyloxy] -1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro [5,5] undecane, triethylene glycol-bis [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate] and the like.

The substituted phenol derivative having an alkyl group at the 2nd position and a methylene group or a methine group at the 6th position is not particularly limited. For example, 2,2′-butylidenebis (4,6-di-tert-butylphenol ), 4,4′-butylidenebis (3-methyl-6-tert-butylphenol), 2,2′-methylenebis (4-methyl-6-tert-butylphenol), 2,2′-methylenebis (4-ethyl-6) -Tert-butylphenol), 2-tert-butyl-6- (3-tert-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenol acrylate, 2- [1- (2-hydroxy-3,5 -Di-tert-pentylphenyl) ethyl] -4,6-di-tert-pentylphenyl acrylate and the like.

The substituted phenol derivative having an alkyl group at the second position and the fifth position is not particularly limited. For example, 4,4′-thiobis (3-methyl-6-tert-butylphenol), 4,4′-butylidenebis ( 3-methyl-6-tert-butylphenol) and the like.

Moreover, it is preferable that the said phenol type compound is a substituted phenol derivative which does not have an alkyl group in 6th position. By containing such a substituted phenol derivative, the heat resistance of the optical semiconductor encapsulating sheet of the present invention is further improved. This is because the substituted phenol derivative having no alkyl group at the 6-position has a structure having an alkyl group only at one ortho position with respect to the OH group, so that steric hindrance around the OH group can be removed. It is considered that a hydrogen bond between the oxygen atom adjacent to the phosphorus atom of the phosphorus compound and the OH group of the phenol compound is likely to be formed. As a result, it is considered that the interaction between the phosphorus compound and the phenol compound is increased, and the function of stabilizing or decomposing the yellowing cause substance is enhanced.

The substituted phenol derivative having no alkyl group at the 6-position is not particularly limited, and examples thereof include 2-tert-butyl-4-methylphenol, 2,4-di-tert-butylphenol, 2,4-di -Tert-pentylphenol, 4,4'-thiobis (3-methyl-6-tert-butylphenol), 4,4'-butylidenebis (3-methyl-6-tert-butylphenol), bis- [3,3-bis -(4'-hydroxy-3'-tert-butylphenyl) -butanoic acid] -glycol ester and the like.

The phenolic compound preferably has a quaternary carbon-containing group at the fourth position. By containing such a phenolic compound, the heat resistance of the encapsulating sheet for optical semiconductors of the present invention is further improved. This is because a phenolic compound having no quaternary carbon at the 4th position generates a yellowing cause substance having a quinone skeleton by an intramolecular reaction or an intermolecular reaction during use under severe conditions. While this may occur, the phenolic compound having a quaternary carbon-containing group at the fourth position is considered to be able to prevent generation of the yellowing cause substance.

The phenolic compound having a quaternary carbon-containing group at the fourth position is not particularly limited. For example, 2,4-di-tert-butylphenol, 2,4-di-tert-pentylphenol, 2- [1- (2-hydroxy-3,5-di-tert-pentylphenyl) ethyl] -4,6-di-tert-pentylphenyl acrylate, bis- [3,3-bis- (4′-hydroxy-3′-tert) -Butylphenyl) -butanoic acid] -glycol ester and the like.

Among the phenolic compounds mentioned above, in particular, bis- [3,3-bis- (4′-hydroxy-3′-tert-butylphenyl) -butanoic acid] -glycol ester, 2- [1- ( 2-hydroxy-3,5-di-tert-pentylphenyl) ethyl] -4,6-di-tert-pentylphenyl acrylate is preferably used.

A commercial item can also be used for the said phenolic compound. It does not specifically limit as a phenol type compound marketed, For example, IRGANOX 1010, IRGANOX 1035, IRGANOX 1076, IRGANOX 1135, IRGANOX 245, IRGANOX 259, IRGANOX 295 (all are the Ciba Specialty Chemicals company make), ADK STAB AO-30, ADK STAB AO-40, ADK STAB AO-50, ADK STAB AO-60, ADK STAB AO-70, ADK STAB AO-80, ADK STAB AO-90, ADK STAB AO-330 (all of which are manufactured by ADEKA), Sumiliz GA-80, Sumilizer MDP-S, Sumilizer BBM-S, Sumilizer GM, Sumilizer G S (F), Sumilizer GP (all of which are manufactured by Sumitomo Chemical Co., Ltd.), HOSTANOX O10, HOSTANOX O16, HOSTANOX O14, HOSTANOX O3 (all of which are manufactured by Clariant), Antage BHT, Antage W-300, Antage W-400, Antage W500 (all are manufactured by Kawaguchi Chemical Industry Co., Ltd.), SEENOX 224M, SEENOX 326M (all are manufactured by Sipro Kasei Co., Ltd.), and the like.

The blending amount of the phenol compound is not particularly limited, but a preferable lower limit is 0.01 part by weight and a preferable upper limit is 2.0 parts by weight with respect to 100 parts by weight of the silicone resin. If the amount is less than 0.01 parts by weight, the effect of adding the phenolic compound may not be obtained. If the amount exceeds 2.0 parts by weight, the light resistance is significantly lowered, which is not preferable. A more preferred lower limit is 0.05 parts by weight, and a more preferred upper limit is 1.0 part by weight.

When the composition for a sealing sheet contains the phosphorus compound and the phenol compound, the compounding ratio of the phosphorus compound and the phenol compound is not particularly limited, but “phosphorus compound / phenol compound” A preferred lower limit (weight ratio) is 0.1, and a preferred upper limit is 20. If it is less than 0.1, the effect of adding a phosphorus compound may not be obtained, and if it exceeds 20, the effect of adding a phenol compound may not be obtained. A more preferred lower limit is 0.5, and a more preferred upper limit is 10.

It is preferable that the said composition for sealing sheets contains fluorescent substance.
The phosphor can absorb light emitted from a light emitting element encapsulated using the encapsulating sheet for optical semiconductor elements of the present invention and generate fluorescence to finally obtain light of a desired color. Any material can be used without particular limitation, and at least one phosphor can be appropriately selected and used. That is, the phosphor is excited by light emitted from the light emitting element to emit fluorescence, and light of a desired color can be obtained by a combination of light emitted from the light emitting element and fluorescence emitted from the phosphor.

The combination of the light-emitting element and the phosphor is not particularly limited. For example, when it is intended to finally obtain white light using an ultraviolet LED chip as the light-emitting element, a blue phosphor or a red phosphor The green phosphor and the green phosphor are preferably used in combination. When the blue LED chip is used as the light emitting element and the final goal is to obtain white light, the green phosphor and the red phosphor are used in combination. Or a yellow phosphor is preferably used.

The blue phosphor is not particularly limited as long as it absorbs ultraviolet rays and emits blue fluorescence. For example, (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu, (Ba , Sr) MgAl ₁₀ O ₁₇ : Eu, (Sr, Ba) ₃ MgSi ₂ O ₈ : Eu, and the like.

The red phosphor is not particularly limited. For example, (Sr, Ca) S: Eu, (Ca, Sr) ₂ SI ₅ N ₈ : Eu, CaSiN ₂ : Eu, CaAlSiN ₃ : Eu, Y ₂ O ₂ S : Eu, La ₂ O ₂ S: Eu, LiW ₂ O ₈ : (Eu, Sm), (Sr, Ca, Bs, Mg) ₁₀ (PO ₄ ) ₈ Cl ₂ : (Eu, Mn), Ba ₃ MgSi ₂ And O ₈ : (Eu, Mn).

The green phosphor is not particularly limited, and for example, Y ₃ (Al, Ga) ₅ O ₁₂ : Ce, SrGa ₂ S ₄ : Eu, Ca ₃ Sc ₂ Si ₃ O ₁₂ : Ce, SrSiON: Eu, ZnS: (Cu, Al), BaMgAl ₁₀ O ₁₇ (Eu, Mn), SrAl ₂ O ₄ : Eu, and the like.

Is not particularly restricted but includes the yellow phosphor, for _{example, Y 3 Al 5 O 12:} Ce, (Y, Gd) 3 Al 5 O 12: Ce, Tb 3 Al 5 O 12: Ce, CaGa 2 S 4: Eu , Sr ₂ SiO ₄ : Eu, and the like.

In addition to the above phosphors, perylene compounds and the like can be cited as organic phosphors.

The phosphor is preferably made into nanoparticles. By forming nanoparticles, light scattering can be reduced.

The phosphor has a preferable lower limit of the primary particle diameter of 0.1 μm and a preferable upper limit of 100 μm. If it is less than 0.1 μm, the dispersibility in the sealant may decrease. When the thickness exceeds 100 μm, the amount of light emitted from the obtained optical semiconductor element (package) may be significantly reduced.
In the present specification, the primary particle diameter of the phosphor means an average value of the diameter of the phosphor when the phosphor is spherical, and the major diameter of the phosphor when the phosphor is non-spherical. Mean value.

The blending amount of the phosphor is not particularly limited, but a preferable lower limit is 0.1 part by weight and a preferable upper limit is 20 parts by weight with respect to 100 parts by weight of the resin component. If it is less than 0.1 part by weight, light of a desired color may not be obtained. If the amount exceeds 20 parts by weight, the amount of light emitted from the resulting optical semiconductor element (package) may be significantly reduced.

The composition for sealing sheets may contain a coupling agent for imparting adhesion.
The coupling agent is not particularly limited, and examples thereof include vinyltriethoxysilane, vinyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, Examples thereof include silane coupling agents such as N-phenyl-3-aminopropyltrimethoxysilane. These coupling agents may be used independently and 2 or more types may be used together.

As a blending ratio of the coupling agent, a preferable lower limit is 0.1 part by weight and a preferable upper limit is 5 parts by weight with respect to 100 parts by weight of the silicone resin. If the amount is less than 0.1 parts by weight, the effect of blending the coupling agent may not be sufficiently exhibited. If the amount exceeds 5 parts by weight, the excess coupling agent volatilizes, and the optical semiconductor sealing sheet of the present invention is used. When cured, it may cause film loss.

The sealing sheet composition may contain additives such as an antifoaming agent, a colorant, a modifier, a leveling agent, a light diffusing agent, a heat conductive filler, and a flame retardant, as necessary.

The method for producing the composition for a sealing sheet is not particularly limited. For example, using a mixer such as a homodisper, a homomixer, a universal mixer, a planetarium mixer, a kneader, a triple roll, a bead mill, Below, the said silicone resin A, the thermosetting agent, the said silicone resin B, and the method of mixing each predetermined amount of the said silicon oxide microparticles | fine-particles, a hardening accelerator, antioxidant, etc. as needed are mentioned.

The sealing sheet for optical semiconductors of this invention consists of the said composition for sealing sheets.
It does not specifically limit as a manufacturing method of the sealing sheet for optical semiconductors of this invention, The said composition for sealing sheets is diluted with a solvent, and is mixed and degassed. Then, for example, using a method such as screen printing, the composition for a sealing sheet diluted with the above solvent is coated on a base material such as a release PET sheet, heated and dried, using a bar coater Examples include a method of coating a composition for a sealing sheet diluted with the above solvent on a substrate such as a release PET sheet, and heating and drying.
The heating / drying conditions are not particularly limited, and examples thereof include a method of drying at a temperature of 50 to 150 ° C. for 10 seconds to 30 minutes using a hot air circulating oven, a far infrared heating furnace, or the like.

In the method for producing an optical semiconductor encapsulating sheet of the present invention, the solvent used for diluting the encapsulating sheet composition is not particularly limited. For example, ether solvents such as dioxane and tetrahydrofuran; acetone, methyl ethyl ketone, methyl isobutyl Examples include ketone solvents such as ketone and cyclohexanone; hydrocarbon solvents such as hexane, toluene, xylene and cyclohexane; ester solvents such as ethyl acetate and butyl acetate; alcohol solvents such as methanol and ethanol. Of these, ester solvents and ketone solvents are preferable, and specifically, for example, ethyl acetate, methyl ethyl ketone, cyclohexanone, and the like are preferable.

In the encapsulating sheet for optical semiconductor elements of the present invention, it is preferable that the reduction rate of the light transmittance after the light resistance test of the cured product is less than 10%. When it is 10% or more, the optical characteristics of the optical semiconductor element using the encapsulating sheet for optical semiconductor elements of the present invention may be insufficient. The light resistance test described above is a 1 mm thick cured product obtained by curing the encapsulating sheet for optical semiconductor elements of the present invention, and a high-pressure mercury lamp fitted with a filter that cuts light having a wavelength of 340 nm or less. The light transmittance after the light resistance test is a test of irradiating at cm ² for 24 hours, and the light transmittance at a wavelength of 400 nm is set to “U-4000” manufactured by Hitachi, Ltd. using the cured product after the light resistance test. It is the value measured using "."

In the encapsulating sheet for optical semiconductor elements of the present invention, it is preferable that the reduction rate of the light transmittance after the heat resistance test of the cured product is less than 10%. When it is 10% or more, the optical characteristics of the optical semiconductor element using the encapsulating sheet for optical semiconductor elements of the present invention may be insufficient. The heat resistance test is a test in which a cured product having a thickness of 1 mm obtained by curing the sealing sheet for optical semiconductor elements of the present invention is left in an oven at 150 ° C. for 500 hours. The transmittance is a value obtained by measuring the transmittance of light having a wavelength of 400 nm using “U-4000” manufactured by Hitachi, Ltd., using the cured product after the heat resistance test.

An optical semiconductor element can be manufactured by sealing a light emitting element using the sealing sheet for optical semiconductor elements of this invention. The optical semiconductor element using the sealing sheet for optical semiconductors of the present invention is also one aspect of the present invention.

The light emitting element is not particularly limited. For example, when the optical semiconductor element is a light emitting diode, for example, a semiconductor material stacked on a substrate can be used. In this case, examples of the semiconductor material include GaAs, GaP, GaAlAs, GaAsP, AlGaInP, GaN, InN, AlN, InGaAlN, and SiC.
Examples of the substrate include sapphire, spinel, SiC, Si, ZnO, and GaN single crystal. In addition, a buffer layer may be formed between the substrate and the semiconductor material as necessary. Examples of the buffer layer include GaN and AlN.

The method for laminating the semiconductor material on the substrate is not particularly limited, and examples thereof include MOCVD, HDVPE, and liquid phase growth.
Examples of the structure of the light emitting element include a homojunction having a MIS junction, a PN junction, and a PIN junction, a heterojunction, and a double heterostructure. Moreover, it can also be set as a single or multiple quantum well structure.

The method for sealing the light emitting element with the sealing sheet for optical semiconductor elements of the present invention is not particularly limited. For example, after placing the sealing sheet for optical semiconductors of the present invention on a plurality of light emitting elements, Examples thereof include a method of thermocompression bonding, a method of overheat pressure bonding after reducing the pressure to vacuum.
In any of the above methods, the encapsulating sheet for optical semiconductor elements of the present invention has initial tackiness and moderate flexibility and high laminating properties. Moreover, since the sealing sheet for optical semiconductors of this invention has a sheet | seat shape, even if it is a case where a several light emitting element is sealed, it can obtain without the height of a sealing sheet differing about each light emitting element. There is no variation in optical characteristics. Furthermore, the optical semiconductor encapsulating sheet of the present invention can exhibit excellent adhesion, heat resistance and light resistance after being cured by heating. Therefore, it is possible to efficiently seal a plurality of light emitting elements simultaneously.

Specific examples of the optical semiconductor element of the present invention include a light emitting diode, a semiconductor laser, and a photocoupler. Such an optical semiconductor element of the present invention includes, for example, a backlight such as a liquid crystal display, illumination, various sensors, a light source such as a printer and a copy machine, a vehicle measuring instrument light source, a signal light, a display light, a display device, and a planar light emission It can be suitably used for body light sources, displays, decorations, various lights, switching elements and the like.

ADVANTAGE OF THE INVENTION According to this invention, the sealing sheet for optical semiconductors which can obtain the hardened | cured material which has high adhesiveness, heat resistance, and light resistance, and an optical semiconductor element using the same can be provided.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited only to these examples.

(Synthesis Example 1)
Dimethyldimethoxysilane (440 g) and 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane (160 g) were placed in a 2000 mL thermometer and a separable flask equipped with a dropping device, and the mixture was stirred at 50 ° C. Into this, potassium hydroxide (1.2 g) / water (170 g) was slowly added dropwise, and after completion of the addition, the mixture was stirred at 50 ° C. for 6 hours. The acetic acid (1.3g) was put in it, the volatile component was removed under reduced pressure, and potassium acetate was filtered, and the polymer was obtained. The obtained polymer was washed with hexane / water and volatile components were removed under reduced pressure to obtain polymer A. The molecular weight of the polymer A is Mn = 2300, Mw = 4800, and (Me ₂ SiO _2/2 ) _0.84 (EpSiO _3/2 ) _0.16 from ²⁹ Si-NMR.
The 2- (3,4-epoxycyclohexyl) ethyl group content was 22 mol%, and the epoxy equivalent was 550 g / eq. Met.
The molecular weight of the polymer A (10 mg) was stirred until tetrahydrofuran (1 mL) was dissolved and dissolved, and a waters measuring device (column: Showa Denko, Shodex GPC LF-804 (length: 300 mm) × 2 pieces) Measurement temperature: 40 ° C., flow rate: 1 mL / min, solvent: tetrahydrofuran, standard substance: polystyrene), and measurement by GPC measurement. Moreover, the epoxy equivalent was calculated | required based on JISK-7236.

Example 1
Polymer A (60 g), SILRES H44 (methyl phenyl silicone resin having a softening point of 75 ° C., manufactured by Asahi Kasei Wacker Silicone Co., Ltd., 40 g), Rikacid MH-700G (acid anhydride, Shin Nippon Rika Co., Ltd., 20 g), 2MZA-PW ( Curing accelerator, manufactured by Shikoku Kasei Co., Ltd., 0.2 g), R8200 (fine silica [trimethylsilyl treatment, specific surface area: 160 m ² / g], Nippon Aerosil Co., Ltd., 20 g), methyl ethyl ketone (60 g) mixed and defoamed The coating liquid was prepared. The prepared coating solution was applied to a 50 μm release PET sheet and dried in an oven at 50 ° C. for 10 minutes and then at 100 ° C. for 20 minutes to prepare sealing sheets for optical semiconductors having a thickness of 100 μm and 500 μm. Two sheets of the prepared 500 μm thick sheet were laminated with a thermal laminator to prepare a 1 mm thick sealing sheet for optical semiconductors.
Moreover, this 1 mm-thick sealing sheet for optical semiconductors was heated and cured at 120 ° C. for 1 hour and 150 ° C. for 3 hours to obtain a cured product.

(Evaluation)
The following evaluation was performed about the sealing sheet for optical semiconductors and the hardened | cured material which were produced in the Example. The results are shown in Table 1.

(1) Adhesion test Using a vacuum laminator (MVLP-500, manufactured by Meiki Seisakusho Co., Ltd.), an aluminum substrate (Al substrate), a polyphthalamide resin substrate (PPA substrate), and a copper substrate subjected to silver plating (Ag Substrate) and a glass epoxy substrate (Ep substrate), the 100 μm-thick sealing sheet for optical semiconductors is laminated at 50 ° C., and heated at 120 ° C. for 1 hour and 150 ° C. for 3 hours. And cured. In accordance with JIS K-5400, an adhesion test was performed using a grid tape method with a clearance of 1 mm and 100 squares.
In Table 1, when the number of peels was 0: ◯, when the number of peels 1 to 70: Δ, and when the number of peels 71 to 100: x.

(2) Initial light transmittance A light transmittance of 400 nm was measured using U-4000 manufactured by Hitachi, Ltd. using a cured product having a thickness of 1 mm.

(3) Light transmittance after light resistance test A cured product with a thickness of 1 mm is attached to a high-pressure mercury lamp with a filter that cuts 340 nm or less, irradiated at 100 mW / cm ² for 24 hours, and has a light transmittance of 400 nm. The measurement was performed using U-4000 manufactured by the company. In Table 1, when the rate of decrease in light transmittance from the initial stage is less than 10%: ○, when less than 10-40%: Δ, when 40 or more: x.

(4) Light transmittance after heat resistance test A cured product having a thickness of 1 mm was left in an oven at 150 ° C. for 500 hours, and a light transmittance of 400 nm was measured using U-4000 manufactured by Hitachi, Ltd. In Table 1, when the rate of decrease in light transmittance from the initial stage is less than 10%: ○, when less than 10-40%: Δ, when 40 or more: x.

(5) Thickness variation Using a thickness gauge (ID-F125, manufactured by Mitutoyo Corporation), the thickness of the cured product is measured at 10 points. The thickness variation is less than 10%, and less than 20% is Δ. 20% or more was rated as x.

(6) Whether or not to emit light Using a vacuum laminator (MVLP-500, manufactured by Meiki Seisakusho Co., Ltd.), the produced 1 mm-thick sealing sheet for optical semiconductors is applied to the light-emitting element electrically connected to the substrate with a gold wire. Lamination was carried out under conditions of 50 ° C. and cured by heating under conditions of 120 ° C. for 1 hour and 150 ° C. for 3 hours to obtain an optical semiconductor element. When a voltage was applied to the obtained optical semiconductor element, a light emitting element was indicated as ◯, and a non-light emitting element was indicated as ×.

ADVANTAGE OF THE INVENTION According to this invention, the sealing sheet for optical semiconductors which can obtain the hardened | cured material which has high adhesiveness, heat resistance, and light resistance, and the optical semiconductor element using this can be provided.

Claims (8)

Silicone resin A having a cyclic ether-containing group in a molecule that is liquid at 25 ° C .;
A thermosetting agent that reacts with the cyclic ether-containing group;
The sealing sheet for optical semiconductors which consists of a composition for sealing sheets containing the silicone resin B whose softening point is 30-150 degreeC. The encapsulating sheet for optical semiconductors according to claim 1, wherein the silicone resin B having a softening point of 30 to 150 ° C has a cyclic ether-containing group. The encapsulating sheet for optical semiconductors according to claim 1 or 2, wherein the composition for encapsulating sheet further contains silicon oxide fine particles. 4. The encapsulating sheet for optical semiconductor according to claim 3, wherein the surface of the silicon oxide fine particles is surface-treated with a trimethylsilyl group or a polydimethylsiloxane group. 5. The encapsulating sheet for optical semiconductors according to claim 3, wherein the silicon oxide fine particles have a BET specific surface area of 30 to 400 m ² / g. The silicone resin A having a cyclic ether-containing group in a liquid molecule at 25 ° C. contains a resin component having an average composition formula represented by the following general formula (1): 4. A sealing sheet for optical semiconductors according to 4 or 5.

In the general formula (1), a, b, c and d are a / (a + b + c + d) = 0 to 0.2, b / (a + b + c + d) = 0.3 to 1.0, c / (a + b + c + d) = 0, respectively. To 0.5, d / (a + b + c + d) = 0 to 0.3, at least one of R ^{1 to} R ⁶ represents a cyclic ether-containing group, and R ^{1 to} R ⁶ other than the cyclic ether-containing group are Represents a linear or branched hydrocarbon having 1 to 8 carbon atoms or a fluorinated product thereof, and these may be the same or different from each other. The encapsulating sheet for optical semiconductor according to claim 1, 2, 3, 4, 5 or 6, wherein the composition for encapsulating sheet further contains a phosphor. An optical semiconductor element comprising the optical semiconductor sealing sheet according to claim 1, 2, 3, 4, 6, or 7.