JP6929069B2 - Curable resin composition for light reflection, its cured product, and optical semiconductor device - Google Patents

Description

The present invention relates to a curable resin composition for light reflection, a cured product thereof, and an optical semiconductor device having a reflector formed by the cured product and an optical semiconductor device.

In recent years, light emitting devices (optical semiconductor devices) using an optical semiconductor element (LED element) as a light source have been increasingly adopted in various indoor or outdoor display boards, image reading light sources, traffic signals, large display units, and the like. .. As such an optical semiconductor device, generally, an optical semiconductor device in which an optical semiconductor element is mounted on a substrate (a substrate for mounting the optical semiconductor element) and the optical semiconductor element is sealed with a transparent encapsulant is widely used. doing. A member (reflector) for reflecting light is formed on the substrate of such an optical semiconductor device in order to increase the efficiency of extracting light emitted from the optical semiconductor element.

The reflector is required to have high light reflectivity. Conventionally, as a constituent material of the reflector, for example, a resin composition in which an inorganic filler or the like is dispersed in a polyamide resin (polyphthalamide resin) having a terephthalic acid unit as an essential constituent unit is known ( See Patent Documents 1 to 3).

In addition, as the constituent material of the reflector, for example, a thermosetting resin containing an epoxy resin and a thermosetting for light reflection containing an inorganic oxide having a refractive index of 1.6 to 3.0 in a specific ratio are used. A sex resin composition is known (see Patent Document 4). Further, for example, it contains a thermosetting resin component and one or more filler components, the difference between the refractive index of the entire thermosetting resin component and the refractive index of each filler component, and the volume of each filler component. A thermosetting resin composition for light reflection in which a parameter calculated from a ratio is controlled within a specific range is known (see Patent Document 5). Further, a curable resin composition for light reflection in which rubber particles and a white pigment are mixed with an alicyclic epoxy compound is known (see Patent Document 6).

Japanese Unexamined Patent Publication No. 2000-204244 Japanese Unexamined Patent Publication No. 2004-75994 Japanese Unexamined Patent Publication No. 2006-257314 Japanese Unexamined Patent Publication No. 2010-235753 Japanese Unexamined Patent Publication No. 2010-235756 International Publication WO2013 / 002052 Pamphlet

Reflectors made from the materials described in Patent Documents 1 to 6 described above turn yellow over time due to light or heat emitted from a semiconductor element in an optical semiconductor device using a high-power blue optical semiconductor or white optical semiconductor as a light source. There was a problem that the light reflectivity was lowered with time due to deterioration due to the above. Further, with the adoption of lead-free solder, the heating temperature in the reflow process (solder reflow process) in the manufacture of the light emitting device tends to be higher, and the heat applied in such a manufacturing process also causes the reflector to change over time. There was also a problem that it deteriorated and the light reflectivity decreased.

Therefore, at present, there is a demand for a material having excellent heat resistance and light resistance, which is less likely to decrease in light reflectivity with time even with higher output, shorter wavelength light and high temperature.

Further, the reflector is generally manufactured by subjecting a material (resin composition) for forming the reflector to transfer molding or compression molding. However, since many of the conventional resin compositions for forming a reflector are suitable for transfer molding, the reflector formed from the resin composition has excellent heat resistance, but the reflector formed by compression molding has heat resistance. Many were relatively inferior.
Further, when the filling amount of the inorganic filler is increased in order to improve the reflectance and heat resistance of the reflectors formed with the materials described in Patent Documents 1 to 6, the viscosity of the composition increases and the composition becomes a solid state. There is also a problem that it becomes difficult to form by compression molding.

Therefore, an object of the present invention is a curable resin for light reflection capable of forming a cured product having high light reflectivity, excellent heat resistance and light resistance, and the light reflectivity does not easily decrease with time by compression molding. The purpose is to provide the composition.
Another object of the present invention is to provide a cured product which is excellent in productivity by compression molding, has high light reflectivity, is excellent in heat resistance and light resistance, and the light reflectivity does not easily decrease with time. There is.
Further, another object of the present invention is to provide a highly reliable optical semiconductor device in which the brightness of light does not easily decrease with time.

Further, the reflector is less likely to be cracked when stress is applied to the reflector due to cutting or temperature change (for example, heating at a very high temperature such as a reflow process, a cold / hot cycle, etc.). Such characteristics are sometimes referred to as "crack resistance") and are required to be tough. This is because if the reflector is cracked, the light reflectivity is lowered (that is, the light extraction efficiency is lowered), and it becomes difficult to ensure the reliability of the light emitting device.

Further, when the reflector is molded, it is required that the molded product is less likely to warp. This is because if the reflector molded product is warped, the dimensional stability is impaired and the quality of the optical semiconductor device is deteriorated.

As a result of diligent studies to solve the above problems, the present inventor contains a specific epoxy compound, rubber particles other than silicone rubber particles, an inorganic filler, a white pigment, a stress relieving agent, and a curing agent. And the curable resin composition containing a curing accelerator or a curing catalyst and liquid at 25 ° C. can be compression-molded even if the filling amount of the inorganic filler or the white pigment is increased, and has high light reflection. It has been found that a cured product having properties, excellent heat resistance and light resistance, and whose light reflectivity does not easily decrease with time can be formed. The present invention has been completed based on these findings.

That is, the present invention contains an alicyclic epoxy compound (A), rubber particles (B) other than silicone rubber particles, a white pigment (C), an inorganic filler (D), and a stress relieving agent (E). Further, the present invention provides a curable resin composition for light reflection, which contains a curing agent (F) and a curing accelerator (G), or a curing catalyst (H) and is liquid at 25 ° C.

In the curable resin composition for light reflection, the stress relaxation agent (E) may be at least one selected from the group consisting of silicone rubber particles (E1) and silicone oil (E2).

In the curable resin composition for light reflection, the silicone rubber particles (E1) may be crosslinked polydimethylsiloxane having a silicone resin on the surface.

［式中、ｘは８０〜１４０の整数、ｙは１〜５の整数、ｚは５〜２０の整数である。Ｒ⁴は炭素数２又は３のアルキレン基である。Ａは、下記式（１ａ）で表される構造を有するポリアルキレンエーテル基である。

（式中、ａ及びｂはそれぞれ独立して、０〜４０の整数である。Ｂは水素原子またはメチル基である。）］ In the light-reflecting curable resin composition, the silicone oil (E2) may be a polyalkylene ether-modified silicone compound having an epoxy equivalent of 3000 to 15000 and having a structure represented by the following formula (1).

[In the formula, x is an integer of 80 to 140, y is an integer of 1 to 5, and z is an integer of 5 to 20. R ⁴ is an alkylene group having 2 or 3 carbon atoms. A is a polyalkylene ether group having a structure represented by the following formula (1a).

(In the formula, a and b are independently integers from 0 to 40. B is a hydrogen atom or a methyl group.)]

In the curable resin composition for light reflection, the rubber particles (B) are composed of a polymer containing (meth) acrylic acid ester as a monomer component, have a hydroxy group and / or a carboxy group on the surface, and are rubber particles. The average particle size of (B) may be 10 to 500 nm, and the maximum particle size may be 50 to 1000 nm.

In the curable resin composition for light reflection, the alicyclic epoxy compound (A) may be a compound having a cyclohexene oxide group.

で表される化合物を含んでいてもよい。 In the curable resin composition for light reflection, the alicyclic epoxy compound (A) has the following formula (I-1).

It may contain a compound represented by.

In the curable resin composition for light reflection, the white pigment (C) may contain at least one selected from the group consisting of titanium oxide, zirconium oxide, zinc oxide, and barium sulfate, and further, the inorganic. The filler (D) may contain at least one selected from the group consisting of silica, alumina, silicon nitride, aluminum nitride, and boron nitride.

The curable resin composition for light reflection may be a resin composition for transfer molding or compression molding.

The curable resin composition for light reflection may be a resin composition for forming a reflector.

The present invention also provides a cured product of the curable resin composition for light reflection.

The present invention also provides an optical semiconductor device including at least an optical semiconductor device and a reflector made of a cured product of the curable resin composition for light reflection.

Since the curable resin composition for light reflection of the present invention has the above-mentioned structure, it has high light reflectivity by compression molding, is excellent in heat resistance and light resistance, and is hardened so that the light reflectivity does not easily decrease with time. Can form things. Therefore, it is possible to provide a highly reliable optical semiconductor device in which the brightness of light does not easily decrease with time.

It is the schematic which shows an example of the substrate for mounting an optical semiconductor element of this invention. The left side view (a) is a perspective view, and the right side view (b) is a cross-sectional view. It is a schematic (cross-sectional view) which shows an example of the optical semiconductor device of this invention. It is the schematic (cross-sectional view; when having a heat sink) which shows another example of the optical semiconductor device of this invention. It is a schematic diagram (when having a heat sink (radiating fin)) which shows another example of the optical semiconductor device of this invention. The left side view (a) is a top view, and the right side view (b) is a cross-sectional view taken along the line AA'in (a).

<Curable resin composition for light reflection>
The curable resin composition for light reflection of the present invention (sometimes referred to simply as "the curable resin composition of the present invention") includes an alicyclic epoxy compound (A), rubber particles (B), and a white pigment (C). ), Inorganic filler (D), and stress relieving agent (E), and further contains a curing agent (F) and a curing accelerator (G), or a curing catalyst (H), and is liquid at 25 ° C. Is a curable resin composition. In other words, the curable resin composition for light reflection of the present invention contains an alicyclic epoxy compound (A), rubber particles (B), a white pigment (C), an inorganic filler (D), and a stress relieving agent (E). , A curable resin composition that is liquid at 25 ° C., or an alicyclic epoxy compound (A), rubber particles (B), white, containing a curing agent (F) and a curing accelerator (G) as essential components. A curable resin composition that is liquid at 25 ° C. and contains a pigment (C), an inorganic filler (D), a stress relieving agent (E), and a curing catalyst (H) as essential components. The curable resin composition of the present invention may contain other components, if necessary, in addition to the above-mentioned essential components. The curable resin composition of the present invention can be used as a thermosetting composition (thermosetting epoxy resin composition) that can be cured by heating and converted into a cured product.

In the present specification, the "curable resin composition for light reflection" refers to a curable resin composition capable of forming a cured product having light reflection. Specifically, for example, a curable resin composition capable of forming a cured product having a reflectance of 50% or more (particularly 80% or more) with respect to light having a wavelength of 450 nm is preferable.

The curable resin composition of the present invention is a liquid at 25 ° C. Since the curable resin composition of the present invention is liquid at 25 ° C., it tends to be suitable for compression molding, and the cured product (reflector) formed by compression molding has excellent light reflectivity and heat resistance. And tends to be excellent in light resistance. In the present specification, "liquid at 25 ° C." means that the viscosity measured at 25 ° C. at normal pressure is 1,000,000 mPa · s or less (preferably 800,000 mPa · s or less). The viscosity is determined by using, for example, a digital viscometer (model number "DVU-EII type", manufactured by Tokimec Co., Ltd.), rotor: standard 1 ° 34'x R24, temperature: 25 ° C., rotation speed: 0. It can be measured under the condition of 5 to 10 rpm.

The curable resin composition of the present invention, which is liquid at 25 ° C., is, for example, a component to be used (for example, an alicyclic epoxy compound (A), a liquid stress relieving agent (E), a curing agent (F), a curing accelerator. (G), curing catalyst (H), etc.) can be easily obtained by using a liquid component at 25 ° C. A solid component at 25 ° C. may be used as the above component, but the content thereof is adjusted so that the curable resin composition of the present invention becomes liquid at 25 ° C. Further, the content of components that are solid at 25 ° C., such as rubber particles (B), white pigment (C), inorganic filler (D), and solid stress relaxant (E), does not impair the effects of the present invention. It is also easier to obtain by adjusting within the range.

[Alicyclic epoxy compound (A)]
The alicyclic epoxy compound (alicyclic epoxy resin) (A), which is an essential component of the curable resin composition of the present invention, has an alicyclic (aliphatic ring) structure and an epoxy group (alicyclic) in the molecule (in one molecule). It is a compound having at least an oxylanyl group). In the curable resin composition of the present invention, known or commonly used alicyclic epoxy compounds can be used. More specifically, as the alicyclic epoxy compound (A), for example, (i) an epoxy group composed of two adjacent carbon atoms and oxygen atoms constituting the alicyclic (alicyclic epoxy group). (Ii) A compound having an epoxy group directly bonded to the alicyclic with a single bond, and the like.

As the compound having the alicyclic epoxy group (i) described above, a known or commonly used compound having one or more alicyclic epoxy groups in the molecule can be used and is not particularly limited. As the alicyclic epoxy group, a cyclohexene oxide group is preferable from the viewpoint of curability of the curable resin composition, heat resistance of the cured product (reflector), and light resistance (particularly, ultraviolet resistance). In particular, from the viewpoint of heat resistance and light resistance (particularly ultraviolet resistance) of the cured product (reflector), a compound having two or more cyclohexene oxide groups in the molecule is preferable, and a compound represented by the following formula (I) is more preferable. It is a compound to be used.

In formula (I), X represents a single bond or linking group (a divalent group having one or more atoms). Examples of the linking group include a divalent hydrocarbon group, an alkenylene group in which part or all of the carbon-carbon double bond is epoxidized (sometimes referred to as "epoxidized alkenylene group"), a carbonyl group, and the like. Examples thereof include an ether bond, an ester bond, a carbonate group, an amide group, and a group in which a plurality of these are linked. A substituent such as an alkyl group may be bonded to one or more carbon atoms constituting the cyclohexane ring (cyclohexene oxide group) in the formula (I).

Examples of the compound in which X is a single bond in the formula (I) include (3,4,3', 4'-diepoxy) bicyclohexane and the like.

Examples of the divalent hydrocarbon group include a linear or branched alkylene group having 1 to 18 carbon atoms, a divalent alicyclic hydrocarbon group and the like. Examples of the linear or branched alkylene group having 1 to 18 carbon atoms include a methylene group, a methylmethylene group, a dimethylmethylene group, an ethylene group, a propylene group and a trimethylene group. Examples of the divalent alicyclic hydrocarbon group include 1,2-cyclopentylene group, 1,3-cyclopentylene group, cyclopentylidene group, 1,2-cyclohexylene group and 1,3-. Examples thereof include a cycloalkylene group (including a cycloalkylidene group) such as a cyclohexylene group, a 1,4-cyclohexylene group and a cyclohexylidene group.

Examples of the alkenylene group in the alkenylene group (epoxidized alkenylene group) in which a part or all of the carbon-carbon double bond is epoxidized include a vinylene group, a propenylene group, a 1-butenylene group, a 2-butenylene group, and a butadienylene. Examples thereof include a linear or branched alkenylene group having 2 to 8 carbon atoms such as a group, a pentenylene group, a hexenylene group, a heptenylene group and an octenylene group. In particular, as the epoxidized alkenylene group, an alkenylene group in which the entire carbon-carbon double bond is epoxidized is preferable, and more preferably, the entire carbon-carbon double bond is epoxidized and has 2 to 4 carbon atoms. It is an alkenylene group.

As the linking group in X, a linking group containing an oxygen atom is particularly preferable, and specifically, -CO-, -O-CO-O-, -COO-, -O-, -CONH-, and epoxy. Examples include a chemical alkenylene group; a group in which a plurality of these groups are linked; a group in which one or two or more of these groups and one or two or more of divalent hydrocarbon groups are linked. Examples of the divalent hydrocarbon group include those exemplified above.

Typical examples of the compound represented by the above formula (I) are the compounds represented by the following formulas (I-1) to (I-10) and 2,2-bis (3,4-epoxycyclohexane-). 1-yl) propane, 1,2-bis (3,4-epoxycyclohexane-1-yl) ethane, 1,2-epoxy-1,2-bis (3,4-epoxycyclohexane-1-yl) ethane, Examples thereof include bis (3,4-epoxycyclohexylmethyl) ether. In addition, l and m in the following formulas (I-5) and (I-7) represent integers of 1 to 30, respectively. R in the following formula (I-5) is an alkylene group having 1 to 8 carbon atoms, and is a methylene group, an ethylene group, a propylene group, an isopropylene group, a butylene group, an isobutylene group, an s-butylene group, a pentylene group, or a hexylene. Examples thereof include a linear or branched alkylene group such as a group, a heptylene group and an octylene group. Among these, a linear or branched alkylene group having 1 to 3 carbon atoms such as a methylene group, an ethylene group, a propylene group and an isopropylene group is preferable. N1 to n6 in the following formulas (I-9) and (I-10) represent integers of 1 to 30, respectively.

Examples of the compound having an epoxy group directly bonded to the alicyclic (ii) by a single bond include a compound (epoxy resin) represented by the following formula (II).

In the above formula (II), R ¹ represents a p-valent organic group. p represents an integer of 1 to 20. Examples of the p-valent organic group include a p-valent organic group having a structure formed by removing p-hydroxy groups from the structural formula of an organic compound having p-hydroxy groups, which will be described later.

In formula (II), q represents an integer from 1 to 50. When p is an integer of 2 or more, a plurality of qs may be the same or different. The sum (sum) of q in equation (II) is an integer of 3 to 100.

In formula (II), R ² is a substituent on the cyclohexane ring represented in the formula, and represents any of the groups represented by the following formulas (IIa) to (IIc). ^{The bond position of R 2} on the cyclohexane ring is not particularly limited, but usually, when the positions of the two carbon atoms of the cyclohexane ring bonded to the oxygen atom are 1-position and 2-position, the carbon atom at the 4-position or 5-position is used. Is. When the compound represented by the formula (II) has a plurality of cyclohexane rings, ^{the bond position of R 2} in each cyclohexane ring may be the same or different. ^{At least one of R 2} in the formula (II) is a group (epoxy group) represented by the formula (IIa). When the compound represented by the formula (II) has two or more R ² , the plurality of R ² may be the same or different.

In formula (IIc), R ³ represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkylcarbonyl group, or a substituted or unsubstituted arylcarbonyl group. Examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, butyl group, isobutyl group, s-butyl group, t-butyl group, pentyl group, hexyl group, octyl group and 2-ethylhexyl. Examples thereof include a linear or branched alkyl group having 1 to 20 carbon atoms such as a group. Examples of the alkylcarbonyl group include a methylcarbonyl group (acetyl group), an ethylcarbonyl group, an n-propylcarbonyl group, an isopropylcarbonyl group, an n-butylcarbonyl group, an isobutylcarbonyl group, an s-butylcarbonyl group, and t-butyl. Examples thereof include a linear or branched alkyl-carbonyl group having 1 to 20 carbon atoms such as a carbonyl group. Examples of the arylcarbonyl group include aryl-carbonyl groups having 6 to 20 carbon atoms such as a phenylcarbonyl group (benzoyl group), a 1-naphthylcarbonyl group, and a 2-naphthylcarbonyl group.

Examples of the substituent that the above-mentioned alkyl group, alkylcarbonyl group, and arylcarbonyl group may have include a substituent having 0 to 20 carbon atoms (more preferably 0 to 10 carbon atoms). Examples of the substituent include halogen atoms such as fluorine atom, chlorine atom, bromine atom and iodine atom; hydroxy group; alkoxy group such as methoxy group, ethoxy group, propoxy group, isopropyloxy group, butoxy group and isobutyloxy group. (Preferably C _1-6 alkoxy group, more preferably C _1-4 alkoxy group); Alkenyloxy group such as allyloxy group (preferably C _2-6 alkenyloxy group, more preferably C _2-4 alkenyloxy group) Acyloxy groups such as acetyloxy group, propionyloxy group, (meth) acryloyloxy group (preferably C _1-12 acyloxy group); mercapto group; alkylthio group such as methylthio group, ethylthio group (preferably C _1-6 alkylthio) Group, more preferably C _1-4 alkylthio group); alkenylthio group such as allylthio group (preferably C _2-6 alkenylthio group, more preferably C _2-4 alkenylthio group); carboxy group; methoxycarbonyl group, Alkoxycarbonyl groups such as ethoxycarbonyl group, propoxycarbonyl group, butoxycarbonyl group (preferably C _1-6 alkoxy-carbonyl group); amino group; mono or mono such as methylamino group, ethylamino group, dimethylamino group, diethylamino group or the like. Dialkylamino group (preferably mono or di-C _1-6 alkylamino group); acylamino group such as acetylamino group, propionylamino group (preferably C _1-11 acylamino group); containing oxetanol group such as ethyloxetanyloxy group Groups; Acyl groups such as acetyl groups and propionyl groups; Oxo groups; groups in which two or more of these are _{bonded via a C 1-6} alkylene group, etc., as needed. Further, examples of the substituent that the above-mentioned arylcarbonyl group may have include the above-mentioned substituted or unsubstituted alkyl group and the above-mentioned substituted or unsubstituted alkylcarbonyl group.

The ratio of the group (epoxide group) represented by the formula (IIa) to the total amount (100 mol%) ^{of R 2 in} the compound represented by the formula (II) is not particularly limited, but is 40 mol% or more (for example,). 40 to 100 mol%), more preferably 60 mol% or more, still more preferably 80 mol% or more. When the above ratio is 40 mol% or more, the heat resistance, light resistance, mechanical properties, etc. of the cured product tend to be further improved. The above ratio can be calculated by, for example, ¹ H-NMR spectrum measurement, oxylan oxygen concentration measurement, or the like.

The compound represented by the formula (II) is not particularly limited, but for example, an organic compound [R ¹ (OH) _p ] having p hydroxy groups in the molecule is used as an initiator (that is, the hydroxy group of the compound). (Starting from (active hydrogen)), 1,2-epoxide-4-vinylcyclohexane (3-vinyl-7-oxabicyclo [4.1.0] heptane) is subjected to ring-open polymerization (cationic polymerization), and then Manufactured by epoxidation with an oxidant.

^{Examples of the organic compound [R 1} (OH) _p ] having p hydroxy groups in the molecule include aliphatic alcohols such as methanol, ethanol, propanol, butanol, pentanol, hexanol and octanol; ethylene glycol and diethylene glycol. , Triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol, pentanediol, 1,6-hexanediol, neopentyl glycol, neopentyl glycol ester, cyclohexanedi Polyhydric alcohols such as methanol, glycerin, diglycerin, polyglycerin, trimethylolpropane, pentaerythritol, dipentaerythritol, hydrogenated bisphenol A, hydrogenated bisphenol F, hydrogenated bisphenol S; polyvinyl alcohol, partial hydrolysis of polyvinyl acetate Products, starch, acrylic polyol resin, styrene-allyl alcohol copolymer resin, polyester polyol, polycaprolactone polyol, polypropylene polyol, polytetramethylene glycol, polycarbonate polyols, polybutadiene having a hydroxy group, cellulose, cellulose acetate, cellulose acetate butyrate , An oligomer or polymer having a hydroxy group such as a cellulose-based polymer such as hydroxyethyl cellulose.

The above 1,2-epoxy-4-vinylcyclohexane can be produced by a known or conventional method, and is not particularly limited. For example, 4-vinylcyclohexene obtained by a dimerization reaction of butadiene is used as an oxidizing agent such as peracetic acid. Obtained by using and partially epoxidizing. Further, as the 1,2-epoxy-4-vinylcyclohexane, a commercially available product can also be used.

Further, as the above-mentioned oxidizing agent, known or commonly used oxidizing agents such as hydrogen peroxide and organic peracid can be used and are not particularly limited. For example, examples of the organic peracid include performic acid, peracetic acid and excess. Examples thereof include benzoic acid and trifluoroperacetic acid. Of these, peracetic acid is preferable because it is industrially available at low cost and has high stability.

More specifically, the above-mentioned ring-opening polymerization and epoxidation can be carried out according to a well-known and commonly used method described in, for example, Japanese Patent Application Laid-Open No. 60-161973.

The weight average molecular weight of the compound represented by the formula (II) in terms of standard polystyrene is not particularly limited, but is preferably 300 to 100,000, more preferably 1,000 to 10,000. When the weight average molecular weight is 300 or more, the mechanical strength, heat resistance, and light resistance of the cured product tend to be further improved. On the other hand, when the weight average molecular weight is 100,000 or less, the viscosity does not become too high and the fluidity at the time of molding tends to be kept low. The weight average molecular weight is measured by a gel permeation chromatography (GPC) method.

The equivalent of the epoxy group (epoxy equivalent) of the compound represented by the formula (II) is not particularly limited, but is preferably 50 to 1000, and more preferably 100 to 500. When the epoxy equivalent is 50 or more, the cured product tends to be less likely to become brittle. On the other hand, when the epoxy equivalent is 1000 or less, the mechanical strength of the cured product tends to improve. The epoxy equivalent is measured according to JIS K7236: 2001.

In the curable resin composition of the present invention, the alicyclic epoxy compound (A) may be used alone or in combination of two or more. The alicyclic epoxy compound (A) can also be produced by a known or conventional method, and for example, the trade names "Selokiside 2021P", "Selokiside 2081", "EHPE3150" (all manufactured by Daicel Corporation). ) And other commercially available products can also be used.

The alicyclic epoxy compound (A) is preferably liquid at room temperature (25 ° C.) from the viewpoint of workability during preparation and casting. Further, even the alicyclic epoxy compound (A) which is solid at room temperature (25 ° C.) may be contained as long as it exhibits a liquid state after being blended.

Above all, the curable resin composition of the present invention contains at least (i) a compound having an alicyclic epoxy group from the viewpoint of further improving the light reflectivity, heat resistance, and light resistance of the cured product (reflector). Is preferable, and (ii) it is more preferable to contain a compound having an epoxy group directly bonded to the alicyclic in a single bond.

The content (blending amount) of the alicyclic epoxy compound (A) in the curable resin composition of the present invention is not particularly limited, but is 1.5 to 60 with respect to the curable resin composition (100% by weight). The weight is preferably%, more preferably 2 to 50% by weight, still more preferably 5 to 40% by weight. By setting the content of the alicyclic epoxy compound (A) to 1.5% by weight or more, the heat resistance (particularly yellowing resistance) and light resistance (particularly ultraviolet resistance) of the cured product (reflector) can be improved. Tends to improve. On the other hand, by setting the content of the alicyclic epoxy compound (A) to 60% by weight or less, the coefficient of linear expansion of the cured product (reflector) is reduced, and problems such as warpage of the lead frame in the substrate for mounting the optical semiconductor element are reduced. Tends to be suppressed.

In the present specification, each component contained in the curable resin composition of the present invention (for example, alicyclic epoxy compound (A), rubber particles (B), white pigment (C), inorganic filler (D)). , Stress relieving agent (E), curing agent (F), curing accelerator (G), curing catalyst (H), etc.) are within the range described so that the total content is 100% by weight or less. Can be appropriately selected from.

The ratio of the alicyclic epoxy compound (A) to the total amount (100% by weight) of the epoxy compound contained in the curable resin composition of the present invention is not particularly limited, but is 50% by weight or more (for example, 50 to 100% by weight). ) Is preferable, more preferably 60% by weight or more, still more preferably 80% by weight or more, and particularly preferably 90% by weight or more. By setting the above ratio to 50% by weight or more, the heat resistance and light resistance of the cured product (reflector) tend to be further improved.

[Rubber particles other than silicone rubber particles (B)]
The rubber particles (B) other than the silicone rubber particles which are essential components of the curable resin composition of the present invention (hereinafter, may be simply referred to as "rubber particles (B)") are other than the silicone rubber particles having rubber elasticity. It is a particle of. In the curable resin composition of the present invention, rubber particles (B) are used in combination with an alicyclic epoxy compound (A), a white pigment (C), an inorganic filler (D), and a stress relieving agent (E). Therefore, the cured product formed by compression molding tends to be excellent in light reflectivity, heat resistance, light resistance, and crack resistance. As the rubber particles (B), known and commonly used rubber particles can be used without particular limitation as long as they are other than silicone rubber particles. For example, particulate NBR (acrylonitrile-butadiene rubber), reactive terminal carboxy group. Examples thereof include rubber particles such as NBR (CTBN), metal-free NBR, and particulate SBR (styrene-butadiene rubber). The rubber particles (B) have a core portion having rubber elasticity and a shell having at least one layer covering the core portion from the viewpoint that the dispersibility is good and the effect of improving toughness (improving crack resistance) can be easily obtained. Rubber particles having a multi-layer structure (core-shell structure) composed of layers (hereinafter, may be referred to as "core-shell type rubber particles") are preferable. From the viewpoint of further improving the heat resistance and light resistance of the cured product, the rubber particles (B) are particularly composed of a polymer containing a (meth) acrylic acid ester as an essential monomer component, and have an alicyclic ring on the surface. Rubber particles having a hydroxy group and / or a carboxy group (one or both of a hydroxy group and a carboxy group) are preferable as a functional group capable of reacting with a compound having an epoxy group such as the formula epoxy compound (A). That is, it is particularly preferable that the rubber particles (B) are core-shell type rubber particles composed of a polymer (acrylic polymer) containing (meth) acrylic acid ester as an essential monomer component. In the curable resin composition of the present invention, one type of rubber particles (B) may be used alone, or two or more types may be used in combination.

When the rubber particles (B) are core-shell type rubber particles, the polymer constituting the core portion having rubber elasticity is not particularly limited as long as it is not a silicone compound, but methyl (meth) acrylate and (meth) acrylic. It is preferable that the polymer contains (meth) acrylate as an essential monomer component such as ethyl acrylate and butyl (meth) acrylate. Other polymers constituting the core portion having rubber elasticity include aromatic vinyls such as styrene and α-methylstyrene; nitriles such as acrylonitrile and methacrylonitrile; conjugated diene such as butadiene and isoprene; ethylene and propylene, Α-Olefin such as isobutene may be contained as a monomer component.

Among them, the polymer constituting the core portion having rubber elasticity is a combination of one or more selected from the group consisting of aromatic vinyl, nitrile, and conjugated diene together with (meth) acrylic acid ester as a monomer component. It is preferable to include it. That is, examples of the polymer constituting the core portion include a binary copolymer such as (meth) acrylic acid ester / aromatic vinyl, (meth) acrylic acid ester / conjugated diene, and (meth) acrylic acid ester / aromatic. Examples thereof include a ternary copolymer such as a group vinyl / conjugated diene.

The polymer constituting the core portion may contain, as other monomer components, divinylbenzene, allyl (meth) acrylate, ethylene glycol di (meth) acrylate, diallyl maleate, triallyl cyanurate, diallyl phthalate, butylene glycol diacrylate and the like. A reactive cross-linking monomer having two or more reactive functional groups may be contained in the molecule.

The core portion is, among others, a binary copolymer of (meth) acrylic acid ester / aromatic vinyl (particularly butyl acrylate / styrene) or (meth) acrylic acid ester / aromatic vinyl / other monomers. A core portion composed of a former copolymer (particularly butyl acrylate / styrene / divinylbenzene) is preferable because the refractive index of the core-shell type rubber particles can be easily adjusted.

The glass transition temperature of the polymer constituting the core portion is not particularly limited, but is preferably -100 to 10 ° C, more preferably -80 to -10 ° C, and even more preferably -60 to -20 ° C. By setting the glass transition temperature of the polymer within the above range, the crack resistance of the cured product tends to be improved. The glass transition temperature of the polymer constituting the core portion means a calculated value calculated by the following Fox formula (see Bull. Am. Phys. Soc., 1 (3) 123 (1956)). In the Fox formula below, Tg indicates the glass transition temperature (unit: K) of _{the polymer constituting the core portion, and Wi i} is the weight of the monomer i with respect to the total amount of the monomers constituting the polymer constituting the core portion. Shows the rate. Further, Tg _i indicates the glass transition temperature (unit: K) of the homopolymer of monomer i. The following Fox formula shows a formula when the polymer constituting the core is a copolymer of monomer 1, monomer 2, ..., And monomer n.
1 / Tg = W ₁ / Tg ₁ + W ₂ / Tg ₂ + ... + W _n / Tg _n
For the glass transition temperature of the homopolymer, the values described in various documents can be adopted, and for example, the values described in "POLYMER HANDBOOK 3rd Edition" (published by John Wiley & Sons, Inc.) can be adopted. For those not described in the literature, the value of the glass transition temperature measured by the DSC method of the homopolymer obtained by polymerizing the monomer by the conventional method can be adopted.

The core portion can be produced by a commonly used method, for example, by a method of polymerizing the monomer by an emulsion polymerization method or the like. In the emulsification polymerization method, the entire amount of the above-mentioned monomers may be charged in a batch and polymerized, or a part of the above-mentioned monomers may be polymerized and then the rest may be continuously or intermittently added for polymerization. Further, a polymerization method using seed particles may be used.

When rubber particles having no core-shell structure are used as the rubber particles (B), for example, rubber particles composed of only the core portion can be used.

The polymer constituting the shell layer of the core-shell type rubber particles is preferably a polymer different from the polymer constituting the core portion (polymer having a different monomer composition). Further, as described above, the shell layer preferably has a hydroxy group and / or a carboxy group as a functional group capable of reacting with a compound having an epoxy group such as an alicyclic epoxy compound (A). Thereby, in particular, the adhesiveness can be improved at the interface with the alicyclic epoxy compound (A), and the cured product obtained by curing the curable resin composition containing the core-shell type rubber particles having the shell layer can be obtained. Therefore, excellent crack resistance can be exhibited. In addition, it is possible to prevent a decrease in the glass transition temperature of the cured product.

The polymer constituting the shell layer is preferably a polymer containing (meth) acrylate as an essential monomer component such as methyl (meth) acrylate, ethyl (meth) acrylate, and butyl (meth) acrylate. .. For example, when butyl acrylate is used as the (meth) acrylate in the core portion, the monomer component of the polymer constituting the shell layer is, for example, a (meth) acrylate other than butyl acrylate (for example, (for example, It is preferable to use methyl (meth) acrylate, ethyl (meth) acrylate, butyl methacrylate, etc.). Examples of the monomer component that may be contained in addition to the (meth) acrylic acid ester include aromatic vinyls such as styrene and α-methylstyrene; and nitriles such as acrylonitrile and methacrylonitrile. In the core-shell type rubber particles, it is preferable that the above-mentioned monomers are contained alone or in combination of two or more kinds together with the (meth) acrylic acid ester as the monomer component constituting the shell layer, and in particular, at least aromatic vinyl is contained. This is preferable because the refractive index of the core-shell type rubber particles can be easily adjusted.

Further, the polymer constituting the shell layer is used to form a hydroxy group and / or a carboxy group as a functional group capable of reacting with a compound having an epoxy group such as an alicyclic epoxy compound (A) as a monomer component. , Hydroxyl group-containing monomers (eg, hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate) and carboxy group-containing monomers (eg, α, β-unsaturated acids such as (meth) acrylic acid; It is preferable to contain α, β-unsaturated acid anhydride such as maleic acid anhydride).

The polymer constituting the shell layer preferably contains, as a monomer component, one or a combination of two or more selected from the above monomers together with the (meth) acrylic acid ester. That is, the shell layer is a ternary copolymer of, for example, (meth) acrylic acid ester / aromatic vinyl / hydroxyalkyl (meth) acrylate, (meth) acrylic acid ester / aromatic vinyl / α, β-unsaturated acid and the like. It is preferably a shell layer composed of a polymer or the like.

In addition to the above-mentioned monomer, the polymer constituting the shell layer contains divinylbenzene, allyl (meth) acrylate, ethylene glycol di (meth) acrylate, diallyl maleate, and trily as other monomer components, as in the case of the core portion. A reactive cross-linking monomer having two or more reactive functional groups may be contained in the molecule such as allyl cyanurate, diallyl phthalate, and butylene glycol diacrylate.

The glass transition temperature of the polymer constituting the shell layer is not particularly limited, but is preferably 20 to 200 ° C, more preferably 40 to 180 ° C, and even more preferably 60 to 160 ° C. By setting the glass transition temperature of the polymer to 20 ° C. or higher, the heat resistance and light resistance of the cured product tend to be further improved. On the other hand, by setting the glass transition temperature of the polymer to 200 ° C. or lower, the dispersibility of the rubber particles (B) and the crack resistance of the cured product tend to be improved. The glass transition temperature of the polymer constituting the shell layer means a calculated value calculated by the Fox formula, and can be measured in the same manner as the glass transition temperature of the polymer constituting the core, for example.

The core-shell type rubber particles are obtained by coating the core portion with a shell layer. As a method of coating the core portion with the shell layer, for example, a method of coating the surface of the core portion having rubber elasticity obtained by the above method by applying a polymer constituting the shell layer; obtained by the above method. Examples thereof include a method in which the core portion having rubber elasticity is used as a trunk component and each component constituting the shell layer is used as a branch component for graft polymerization.

The average particle size of the rubber particles (B) is not particularly limited, but is preferably 10 to 500 nm, and more preferably 20 to 400 nm. The maximum particle size of the rubber particles (B) is not particularly limited, but is preferably 50 to 1000 nm, more preferably 100 to 800 nm. By setting the average particle size to 500 nm or less (or the maximum particle size to 1000 nm or less), the dispersibility of the rubber particles (B) in the cured product tends to be improved, and the crack resistance tends to be improved. On the other hand, when the average particle size is 10 nm or more (or the maximum particle size is 50 nm or more), the crack resistance of the cured product tends to be improved.

The refractive index of the rubber particles (B) is not particularly limited, but is preferably 1.40 to 1.60, and more preferably 1.42 to 1.58. Further, the difference between the refractive index of the rubber particles (B) and the refractive index of the cured product obtained by curing the curable resin composition (curable resin composition of the present invention) containing the rubber particles (B) is It is preferably within ± 0.03. By setting the difference in refractive index within ± 0.03, excellent light reflectivity of the cured product is ensured, and the luminous intensity of the optical semiconductor device tends to be kept high.

The refractive index of the rubber particles (B) is, for example, 1 g of the rubber particles (B) cast into a mold and compression-molded at 210 ° C. and 4 MPa to obtain a flat plate having a thickness of 1 mm. × A multi-wavelength Abbe refractometer (trade name “DR-M2”, Atago Co., Ltd.) with a 6 mm wide test piece cut out and the prism and the test piece in close contact with each other using monobromonaphthalene as an intermediate solution. It can be obtained by measuring the refractive index of the sodium D line at 20 ° C. using (manufactured by).

The refractive index of the cured product of the curable resin composition of the present invention is, for example, a test piece having a length of 20 mm, a width of 6 mm, and a thickness of 1 mm from the cured product obtained by the heat curing method described in the section of the cured product below. 20 It can be obtained by measuring the refractive index at ° C. and sodium D line.

The content (blending amount) of the rubber particles (B) in the curable resin composition of the present invention is not particularly limited, but is 0.05 to 20% by weight with respect to the curable resin composition (100% by weight). It is preferably 0.1 to 15% by weight, more preferably 0.2 to 10% by weight. By setting the content of the rubber particles (B) to 0.05% by weight or more, the light reflectivity, heat resistance, and light resistance of the cured product tend to be more excellent. In addition, the crack resistance of the cured product tends to be improved. On the other hand, when the content of the rubber particles (B) is 20% by weight or less, the heat resistance and light resistance of the cured product tend to be further improved.

The content (blending amount) of the rubber particles (B) in the curable resin composition of the present invention is not particularly limited, but is based on 100 parts by weight of the total amount of the compound having an epoxy group contained in the curable resin composition. It is preferably 0.5 to 30 parts by weight, more preferably 1 to 20 parts by weight. When the content of the rubber particles (B) is 0.5 parts by weight or more, the light reflectivity, heat resistance, and light resistance of the cured product tend to be more excellent. In addition, the crack resistance of the cured product tends to be improved. On the other hand, when the content of the rubber particles (B) is 30 parts by weight or less, the heat resistance and light resistance of the cured product tend to be further improved.

[White pigment (C)]
The white pigment (C), which is an essential component of the curable resin composition of the present invention, mainly imparts high light reflectivity to the cured product (reflector) and also has a function of reducing the coefficient of linear expansion thereof. Have. As the white pigment (C), a known or commonly used white pigment can be used and is not particularly limited, but for example, glass, clay, mica, talc, kaolinite (kaolin), halloysite, zeolite, acidic white clay, activity. Inorganic white pigments such as white clay, boehmite, pseudo-boehmite, inorganic oxides, metal salts [for example, alkaline earth metal salts, etc.]; styrene resin, benzoguanamine resin, urea-formalin resin, melamine-formalin resin, amide Organic white pigments such as resin pigments such as based resins (plastic pigments and the like); hollow particles having a hollow structure (balloon structure) and the like can be mentioned.

As the white pigment (C), it is preferable to use a white pigment having a high refractive index in order to increase the reflectance of the reflector. For example, a white pigment having a refractive index of 1.5 or more is preferable. However, since the white pigment having a hollow particle structure contains a gas having a low refractive index inside (core) and has a very large surface reflectance, the shell portion may be made of a material having a refractive index lower than 1.5. .. Among those exemplified as the white pigment (C), those corresponding to the inorganic filler (D) have a refractive index of 1.5 or more as the white pigment (C) and a refractive index of 1.5. The smaller one is the inorganic filler (D).

Examples of the inorganic oxide include aluminum oxide (alumina), magnesium oxide, antimony oxide, titanium oxide [for example, rutile type titanium oxide, anatase type titanium oxide, broccite type titanium oxide, etc.], zirconium oxide, zinc oxide and the like. Can be mentioned. Examples of the alkaline earth metal salt include magnesium carbonate, calcium carbonate, barium carbonate, magnesium silicate, calcium silicate, magnesium hydroxide, magnesium phosphate, magnesium hydrogen phosphate, magnesium sulfate, calcium sulfate, and sulfuric acid. Barium and the like can be mentioned. Examples of metal salts other than alkaline earth metal salts include aluminum silicate, aluminum hydroxide, zinc sulfide and the like.

The hollow particles are not particularly limited, but for example, inorganic glass [for example, sodium silicate glass, aluminum silicate glass, sodium borosilicate glass, quartz, etc.], metal oxides such as silica and alumina, calcium carbonate, barium carbonate, etc. Inorganic hollow particles composed of inorganic substances such as metal salts such as nickel carbonate and calcium silicate (including natural substances such as silas balloon); styrene resin, acrylic resin, silicone resin, acrylic-styrene resin, vinyl chloride Polymers such as based resins, vinylidene chloride resins, amide resins, urethane resins, phenol resins, styrene-conjugated diene resins, acrylic-conjugated diene resins, olefin resins (including crosslinked products of these polymers), etc. Organic hollow particles composed of the above organic substances; inorganic-organic hollow particles composed of a hybrid material of an inorganic substance and an organic substance, and the like can be mentioned. The hollow particles may be composed of a single material or may be composed of two or more kinds of materials. Further, the hollow portion of the hollow particles (the space inside the hollow particles) may be in a vacuum state or may be filled with a medium, but the refractive index is particularly low from the viewpoint of improving the reflectance. Hollow particles filled with a medium (eg, an inert gas such as nitrogen or argon, air, etc.) are preferred.

The white pigment (C) is subjected to a known or conventional surface treatment [for example, a surface treatment with a surface treatment agent such as a metal oxide, a silane coupling agent, a titanium coupling agent, an organic acid, a polyol, or silicone]. It may be the one that has been done. By applying such a surface treatment, it may be possible to improve the compatibility and dispersibility with other components in the curable resin composition.

Among them, the white pigment (C) is an inorganic oxide or an inorganic oxide from the viewpoint of availability, heat resistance, light resistance, high reflectance of the cured product (reflector), and increase rate of light reflectivity with respect to the amount of addition. Hollow particles are preferable, and aluminum oxide, magnesium oxide, antimony oxide, titanium oxide, zirconium oxide, zinc oxide, barium sulfate, and inorganic hollow particles are more preferable, and titanium oxide, zirconium oxide, zinc oxide, and barium sulfate are more preferable. In particular, as the white pigment (C), titanium oxide is preferable because it has a higher refractive index.

The shape of the white pigment (C) is not particularly limited, and examples thereof include a spherical shape, a crushed shape, a fibrous shape, a needle shape, and a scale shape. Among them, spherical titanium oxide is preferable from the viewpoint of dispersibility, and true spherical titanium oxide (for example, spherical titanium oxide having an aspect ratio of 1.2 or less) is particularly preferable.

The central particle size of the white pigment (C) is not particularly limited, but is preferably 0.1 to 50 μm from the viewpoint of improving the light reflectivity of the cured product (reflector). In particular, when titanium oxide is used as the white pigment (C), the central particle size of the titanium oxide is not particularly limited, but is preferably 0.1 to 50 μm, more preferably 0.1 to 30 μm, and even more preferably 0. .1 to 20 μm, particularly preferably 0.1 to 10 μm, most preferably 0.1 to 5 μm. On the other hand, when hollow particles (particularly inorganic hollow particles) are used as the white pigment (C), the central particle size of the hollow particles is not particularly limited, but is preferably 0.1 to 50 μm, more preferably 0.1 to 1. It is 30 μm. The central particle size means the particle size (median diameter) at an integrated value of 50% in the particle size distribution measured by the laser diffraction / scattering method.

In the curable resin composition of the present invention, the white pigment (C) may be used alone or in combination of two or more. The white pigment (C) can also be produced by a known or conventional method, and for example, the trade names "SR-1", "R-42", "R-45M", "R-650", "R-32", "R-5N", "GTR-100", "R-62N", "R-7E", "R-44", "R-3L", "R-11P", "R" -21 ”,“ R-25 ”,“ TCR-52 ”,“ R-310 ”,“ D-918 ”,“ FTR-700 ”(all manufactured by Sakai Chemical Industry Co., Ltd.), product name“ Typake CR -50 "," CR-50-2 "," CR-60 "," CR-60-2 "," CR-63 "," CR-80 "," CR-90 "," CR-90-2 " , "CR-93", "CR-95", "CR-97" (all manufactured by Ishihara Sangyo Co., Ltd.), product names "JR-301", "JR-403", "JR-405", "JR-600A", "JR-605", "JR-600E", "JR-603", "JR-805", "JR-806", "JR-701", "JRNC", "JR-800" , "JR" (above, manufactured by Teika Co., Ltd.), product names "TR-600", "TR-700", "TR-750", "TR-840", "TR-900" (above, Fuji Titanium Industry Co., Ltd.), Product names "KR-310", "KR-380", "KR-380N", "ST-410WB", "ST-455", "ST-455WB", "ST-457SA" , "ST-457EC", "ST-485SA15", "ST-486SA", "ST-495M" (all manufactured by Titanium Industry Co., Ltd.), etc. "TCA-123E", "A-190", "A-197", "SA-1", "SA-1L", "SSP series", "CSB series" (all manufactured by Sakai Chemical Industry Co., Ltd.) , Product names "JA-1", "JA-C", "JA-3" (all manufactured by Teika Co., Ltd.), Product names "KA-10", "KA-15", "KA-20", "STT-65C-S", "STT-30EHJ" (all manufactured by Titanium Industry Co., Ltd.), product names "DCF-T-17007", "DCF-T-17008", "DCF-T-17050" ( As described above, commercially available products such as anatase-type titanium oxide manufactured by Regino Color Industry Co., Ltd. can also be used.

Among them, as the white pigment (C), trade names "R-62N", "CR-60", and "DCF-T-17007" are used, especially from the viewpoint of improving the light reflectivity and yellowing resistance of the cured product (reflector). , "DCF-T-17008", "DCF-T-17050", "FTR-700" are preferable.

The content (blending amount) of the white pigment (C) in the curable resin composition of the present invention is not particularly limited, but is 0.1 to 50% by weight with respect to the curable resin composition (100% by weight). It is preferable, more preferably 1 to 40% by weight, still more preferably 5 to 35% by weight. By setting the content of the white pigment (C) to 0.1% by weight or more, the light reflectivity of the cured product (reflector) tends to be further improved. In addition, heat resistance (particularly yellowing resistance) and light resistance (particularly ultraviolet resistance) tend to be further improved. On the other hand, when the content of the white pigment (C) is 50% by weight or less, the moldability of the cured product (reflector) is improved, and it tends to be more suitable for mass production.

The content (blending amount) of the white pigment (C) in the curable resin composition of the present invention is not particularly limited, but is based on 100 parts by weight of the total amount of the compound having an epoxy group contained in the curable resin composition. It is preferably 3 to 400 parts by weight, more preferably 10 to 350 parts by weight, and even more preferably 30 to 300 parts by weight. When the content of the white pigment (C) is 3 parts by weight or more, the light reflectivity of the cured product (reflector) tends to be further improved. In addition, heat resistance (particularly yellowing resistance) and light resistance (particularly ultraviolet resistance) tend to be further improved. On the other hand, when the content of the white pigment (C) is 400 parts by weight or less, the moldability is improved and it tends to be more suitable for mass production.

When the curable resin composition of the present invention contains titanium oxide, the amount of titanium oxide based on the total amount (100% by weight) of the white pigment (C) and the inorganic filler (D) contained in the curable resin composition of the present invention. The ratio is not particularly limited, but is preferably 5 to 70% by weight, more preferably 10 to 60% by weight, from the viewpoint of the balance between the yellowing resistance of the cured product (reflector) and the light reflectivity. By setting the proportion of titanium oxide to 5% by weight or more, the light reflectivity of the cured product (reflector) tends to be further improved. In addition, heat resistance (particularly yellowing resistance) and light resistance (particularly ultraviolet resistance) tend to be further improved. On the other hand, when the proportion of titanium oxide is 70% by weight or less, the moldability of the cured product (reflector) is improved, and it tends to be more suitable for mass production.

[Inorganic filler (D)]
The curable resin composition of the present invention contains an inorganic filler (D) as an essential component in addition to the white pigment (C). The inorganic filler (D), which is an essential component of the curable resin composition of the present invention, mainly has excellent heat resistance and light resistance to the formed cured product when the curable resin composition is formed by compression molding. Gives properties (particularly excellent heat resistance). It also has the function of reducing the coefficient of linear expansion of the cured product (reflector). Further, depending on the type of the inorganic filler (D), it may be possible to impart excellent light reflectivity to the cured product (reflector).

As the inorganic filler (D), a known or commonly used inorganic filler can be used, and is not particularly limited, but for example, silica, alumina, zircon, calcium silicate, calcium phosphate, calcium carbonate, magnesium carbonate, silicon carbide, and the like. Silicon nitride, aluminum nitride, boron nitride, aluminum hydroxide, iron oxide, zinc oxide, zirconium oxide, magnesium oxide, titanium oxide, aluminum oxide, calcium sulfate, barium sulfate, fosterite, steatite, spinel, clay, kaolin, dolomite , Hydroxyapatite, neferincinite, cristobalite, wollastonite, diatomaceous earth, powders of talc and the like, or molded bodies thereof (for example, spherical beads and the like) and the like. Further, examples of the inorganic filler (D) include those obtained by subjecting the above-mentioned inorganic filler to a known or conventional surface treatment. Among them, as the inorganic filler (D), silica, alumina, silicon nitride, aluminum nitride, and boron nitride are used from the viewpoints of heat resistance (particularly yellowing resistance), light resistance, and fluidity of the cured product (reflector). It is preferable, more preferably silica (silica filler).

The silica is not particularly limited, and for example, known or commonly used silica such as molten silica, crystalline silica, and high-purity synthetic silica can be used. The silica is one that has been subjected to a known or conventional surface treatment [for example, a surface treatment with a surface treatment agent such as a metal oxide, a silane coupling agent, a titanium coupling agent, an organic acid, a polyol, or a silicone]. Can also be used.

The shape of silica is not particularly limited, and examples thereof include powder, spherical, crushed, fibrous, needle-shaped, and scaly-shaped. Among them, spherical silica is preferable from the viewpoint of dispersibility, and true spherical silica (for example, spherical silica having an aspect ratio of 1.2 or less) is particularly preferable.

The central particle size of silica is not particularly limited, but is preferably 0.1 to 50 μm, more preferably 0.1 to 30 μm, from the viewpoint of improving the light reflectivity of the cured product (reflector). The central particle size means the particle size (median diameter) at an integrated value of 50% in the particle size distribution measured by the laser diffraction / scattering method.

In the curable resin composition of the present invention, the inorganic filler (D) may be used alone or in combination of two or more. The inorganic filler (D) can also be produced by a known or conventional production method, and for example, the trade names "FB-910", "FB-940", "FB-950", "FB-105". , "FB-105FD", "FB-5D", "FB-8S", "FB-7SDC", "FB-5SDC", "FB-3SDC", "FB-9FDC", "FB-7FDC", FB series such as "FB-5FDC", "FB-970FD", "FB-975FD", "FB-950FD", "FB-40RFD", trade names "DAW-03DC", "DAW-0525", "DAW" DAW series such as -1025, product name "SGP" (manufactured by Denka Co., Ltd.), product name "HF-05" (manufactured by Tokuyama Co., Ltd.), product name "10 μm SE-CC5" (manufactured by Tokuyama Co., Ltd.) (Made by Matex), product names "MSR-2212", "MSR-25" (above, manufactured by Ryumori Co., Ltd.), product names "HS-105", "HS-106", "HS-107" (above, Commercially available products such as Micron) can also be used.

The content (blending amount) of the inorganic filler (D) in the curable resin composition of the present invention is not particularly limited, but is preferably 10 to 90% by weight with respect to the curable resin composition (100% by weight). , More preferably 13 to 75% by weight, still more preferably 15 to 70% by weight, still more preferably 20 to 70% by weight. When the curable resin composition is formed by compression molding by setting the content of the inorganic filler (D) to 10% by weight or more, the heat resistance and light resistance (particularly excellent heat resistance) of the formed cured product are excellent. Gender) tends to improve. Further, the coefficient of linear expansion of the cured product (reflector) tends to be low, and problems such as warpage of the lead frame in the substrate for mounting the optical semiconductor element using the reflector tend to be less likely to occur. On the other hand, when the content of the inorganic filler (D) is 90% by weight or less, the curable resin composition has good fluidity, so that there is a problem such as unfilling during molding (particularly transfer molding). Tends to be suppressed.

The content (blending amount) of the inorganic filler (D) in the curable resin composition of the present invention is not particularly limited, but is based on 100 parts by weight of the total amount of the compound having an epoxy group contained in the curable resin composition. , 10 to 1500 parts by weight, more preferably 50 to 1200 parts by weight, still more preferably 70 to 1000 parts by weight. When the curable resin composition is formed by compression molding by setting the content of the inorganic filler (D) to 10 parts by weight or more, the heat resistance and light resistance (particularly excellent heat resistance) of the formed cured product are excellent. Gender) tends to improve. Further, the coefficient of linear expansion of the cured product (reflector) tends to be low, and problems such as warpage of the lead frame in the substrate for mounting the optical semiconductor element using the reflector tend to be less likely to occur. On the other hand, when the content of the inorganic filler (D) is 1500 parts by weight or less, the curable resin composition has good fluidity, so that there is a problem such as unfilling during molding (particularly transfer molding). Tends to be suppressed.

The maximum particle size of the white pigment (C) and the inorganic filler (D) in the curable resin composition of the present invention is not particularly limited, but is preferably 200 μm or less, more preferably 185 μm or less, still more preferably 175 μm or less, particularly. It is preferably 150 μm or less. When the maximum particle size is 200 μm or less, the heat resistance of the cured product formed by compression molding the curable resin composition is higher than that in the case of using a white pigment or an inorganic filler having a maximum particle size of more than 200 μm. , Light resistance, and crack resistance (particularly excellent heat resistance) tend to be further excellent. Further, by using the white pigment (C) and the inorganic filler (D) having a small maximum particle size, it is possible to increase the content thereof, and the light reflectivity, heat resistance and light resistance of the cured product are further improved. It tends to improve further. The lower limit of the maximum particle size is, for example, 0.01 μm or more. The maximum particle size is the total maximum particle size of the white pigment (C) and the inorganic filler (D) contained in the curable resin composition of the present invention. The maximum particle size means the maximum particle size in the particle size distribution measured by the laser diffraction / scattering method.

[Stress relaxation agent (E)]
The stress relaxation agent (E), which is an essential component of the curable resin composition of the present invention, is a compound capable of relaxing the internal stress in the cured product. In the curable resin composition of the present invention, the stress relieving agent (E) is used in combination with the alicyclic epoxy compound (A), the rubber particles (B), the white pigment (C), and the inorganic filler (D). Therefore, compression molding is possible even if the filling amount of the white pigment (C) or the inorganic filler (D) is increased, and the cured product formed by the compression molding has light reflectivity, heat resistance, and light resistance. Tends to excel. Further, the stress relaxation agent (E) can relax the stress inside the cured product to reduce the warp of the formed product due to compression molding.

The stress relaxation agent (E) is not particularly limited, and examples thereof include silicone rubber particles (E1), silicone oil (E2), liquid rubber component (E3), and thermoplastic resin (E4).

The silicone rubber particles (E1) are not particularly limited, and examples thereof include those composed of polysiloxanes such as polymethylsiloxane and polymethylphenylsiloxane.
Further, the polysiloxane constituting the silicone rubber particles (E1) is preferably crosslinked. The crosslinked polysiloxane is not particularly limited, and is, for example, crosslinked by a condensation reaction of a silanol group or the like, a radical reaction of a mercaptosilyl group and a vinylsilyl group, an addition reaction of a vinylsilyl group and a hydrosilyl group (SiH group), or the like. Polysiloxane and the like are exemplified, but from the viewpoint of reactivity and reaction process, a polysiloxane crosslinked by an addition reaction of a vinyl group-containing organopolysiloxane and an organohydrogenpolysiloxane in the presence of a platinum-based catalyst. Is preferable.

Further, the silicone rubber particles (E1) may be surface-treated from the viewpoint of compatibility with the resin composition, improvement of dispersibility, and adjustment of the viscosity of the resin composition after dispersion. The mode of surface treatment is not particularly limited, and examples thereof include silicone rubber particles coated with methyl methacrylate and silicone rubber particles coated with silicone resin.

The average particle size (d ₅₀ ) of the silicone rubber particles (E1) is not particularly limited, but is preferably 0.1 to 100 μm, more preferably 0.5 to 50 μm. The maximum particle size of the silicone rubber particles (E1) is not particularly limited, but is preferably 0.1 to 250 μm, more preferably 0.1 to 150 μm. By setting the average particle size to 100 μm or less (or the maximum particle size to 250 μm or less), the crack resistance of the cured product tends to be further improved. On the other hand, when the average particle size is 0.1 μm or more (or the maximum particle size is 0.1 μm or more), the dispersibility of the silicone rubber particles (E1) tends to be further improved.
Further, the shape of the silicone rubber particles (E1) is not particularly limited, but a spherical shape is preferable from the viewpoint of improving workability.

The silicone rubber particles (E1) are made of crosslinked polysiloxane from the viewpoint that a cured product having excellent light reflectivity, heat resistance, and light resistance can be formed by compression molding, or a silicone rubber particle (E1) thereof. The surface is preferably coated with a silicone resin, and the surface of the crosslinked polydimethylsiloxane is particularly preferably coated with a silicone resin from the viewpoint of compatibility between the resin component and the silicone rubber particles (E1).

In the curable resin composition of the present invention, one type of silicone rubber particles (E1) may be used alone, or two or more types may be used in combination. Further, the silicone rubber particles (E1) can be produced by a known or conventional method, and the production method thereof is, for example, the silicone rubber particles produced by the method described in JP-A-7-196815. Can be used. Alternatively, the trade names "KMP-600", "KMP-601", "KMP-602", "KMP-605", "X-52-7030", "KMP-597", "KMP-598", "KMP" Commercially available products such as "-594", "X-52-875", "KMP-590", and "KMP-701" (all manufactured by Shin-Etsu Chemical Co., Ltd.) can also be used.

The silicone oil (E2) is not particularly limited, and examples thereof include non-modified silicone oil and modified silicone oil.

The non-modified silicone oil is not particularly limited, and examples thereof include a polydimethylsiloxane type, a polymethylhydrogensiloxane type, and a polymethylphenylsiloxane type.

The modified silicone oil is not particularly limited, and for example, either a reactive silicone oil having reactivity with an epoxy resin or a non-reactive silicone oil having no reactivity with an epoxy resin may be used. Examples of the reactive silicone oil include an amino-modified type, an epoxy-modified type, a carboxyl-modified type, a carbinol-modified type, a methacryl-modified type, a mercapto-modified type, and a phenol-modified type. Examples of the non-reactive silicone oil include a polyalkylene ether-modified type, a methylstyryl-modified type, an alkyl-modified type, a fatty acid ester-modified type, an alkoxy-modified type, and a fluorine-modified type. The reactive silicone oil may have a non-reactive modifying group, and examples thereof include polyalkylene ether-amino-modified silicone oil and polyalkylene ether-epoxy-modified silicone oil. A polyalkylene ether-epoxy-modified silicone oil that has reactivity with (A) and can control fluidity and viscosity is preferable.

As the silicone oil (E2), a polyalkylene ether-epoxy-modified silicone oil is preferable, and an epoxy is particularly preferable, from the viewpoint that a cured product having excellent light reflectivity, heat resistance, and light resistance can be formed by compression molding. A polyalkylene ether-modified silicone compound having an equivalent amount of 3000 to 15000 and having a structure represented by the following formula (1) (hereinafter, may be referred to as "polyalkylene ether-modified silicone compound (1)") is preferable.

In the above formula (1), R ⁴ is an alkylene group having 2 or 3 carbon atoms. Examples of the alkylene group having 2 or 3 carbon atoms include a methylmethylene group, a dimethylmethylene group, an ethylene group, a propylene group, a trimethylene group and the like, and a trimethylene group is preferable.

In the above equation (1), x represents an integer of 80 to 140.
In the above equation (1), y represents an integer of 1 to 5. When y is an integer of 2 or more, the structures in parentheses with y may be the same or different.
In the above equation (1), z represents an integer of 5 to 20. The structures in parentheses with z may be the same or different.

In the above formula (1), A is a polyalkylene ether group having a structure represented by the following formula (1a).

In the above formula (1a), a and b are independently integers from 0 to 40. When a is 40 or less, the water resistance of the cured product tends to be improved.
On the other hand, when b is 40 or less, the fluidity of the curable resin composition tends to be improved.

The sum of a and b is not particularly limited, but is preferably an integer of 1 to 80. When the total of a and b is in the above range, it becomes easy to control the water resistance of the cured product and the fluidity of the curable resin composition.

In the above formula (1a), B is a hydrogen atom or a methyl group. From the viewpoint of water resistance of the cured product, B is preferably a methyl group.

The additional form of each structural unit in the above formula (1) may be a random type or a block type as long as the two trimethylsilyl groups in the formula (1) are present at both ends. Further, the additional form of each structural unit in the above formula (1a) may be a random type or a block type as long as B is present at the end. Further, the order of arrangement of each structural unit in the above formulas (1) and (1a) is not particularly limited.

As described above, the epoxy equivalent of the polyalkylene ether-modified silicone compound (1) is 3000 to 15000, preferably 4000 to 15000, and more preferably 5000 to 13000. When the epoxy equivalent is 3000 or more, the stress relaxation inside the cured product tends to be further improved. On the other hand, when the epoxy equivalent is 15,000 or less, the compatibility with the resin tends to be further improved.
The epoxy equivalent of the polyalkylene ether-modified silicone compound (1) can be measured according to JIS K 7236: 2001.

In the curable resin composition of the present invention, the silicone oil (E2) may be used alone or in combination of two or more. Further, as the silicone oil (E2), a silicone oil (E2) which can be produced by a known or conventional method, for example, a silicone oil (E2) produced by the method described in JP-A-2008-201904 is used. Or use commercially available products such as product name "SF8421" (manufactured by Toray Dow Corning Co., Ltd.) and product name "Y-19268" (manufactured by Momentive Performance Materials Japan Co., Ltd.). You can also.

The liquid rubber component (E3) is not particularly limited, and is, for example, polybutadiene, maleated polybutadiene, acrylicized polybutadiene, methacrylated polybutadiene, epoxidized polybutadiene, acrylonitrile butadiene rubber, carboxy-terminated acrylonitrile butadiene rubber, and amino-terminated acrylonitrile butadiene rubber. , Vinyl-terminated acrylonitrile butadiene rubber, styrene butadiene rubber and the like.
The liquid rubber component (E3) may be used alone or in combination of two or more.

The thermoplastic resin (E4) is not particularly limited, and for example, a polyimide resin, a polyamide resin, a polyetherimide resin, a polyester resin, a polyesterimide resin, a phenoxy resin, a polysulfone resin, a polyethersulfone resin, a polyphenylene sulfide resin, and the like. Examples thereof include polyether ketone resins. Among these, phenoxy resin and polyimide resin are preferable from the viewpoint of heat resistance. These thermoplastic resins may be used alone or in combination of two or more.

The glass transition temperature (Tg) of the thermoplastic resin (E4) is not particularly limited, but is preferably 200 ° C. or lower.

The stress relaxation agent (E) may be used alone or in combination of two or more.
The stress relieving agent (E) is made of silicone rubber particles (E1) and silicone oil (E2) from the viewpoint that a cured product having excellent light reflectivity, heat resistance, and light resistance can be formed by compression molding. At least one selected from the above group is preferable, in particular, the silicone rubber particles (E1) are preferably crosslinked polydimethylsiloxane having a silicone resin on the surface, and the silicone oil (E2) is modified with polyalkylene ether. The silicone compound (1) is preferred.

The content (blending amount) of the stress relaxation agent (E) of the present invention is not particularly limited, but is preferably 1 to 200 parts by weight, more preferably 5 parts by weight, based on 100 parts by weight of the alicyclic epoxy compound (A). It is ~ 150 parts by weight, more preferably 8 to 120 parts by weight. By setting the content of the stress relaxation agent (E) to 1 part by weight or more, compression molding is possible even if the filling amount of the white pigment (C) or the inorganic filler (D) is increased, and the molding is possible. The light reflectivity, heat resistance, and light resistance of the cured product tend to be further improved. In addition, the warp of the molded product is alleviated, and the dimensional stability tends to be improved. On the other hand, when the content of the stress relaxation agent (E) is 200 parts by weight or less, the curability of the curable resin composition tends to be further improved.

The content of the stress relaxation agent (E) with respect to the curable resin composition (100% by weight) of the present invention is not particularly limited, but is preferably 0.1 to 20% by weight, more preferably 0.3 to 18% by weight. , More preferably 0.5 to 15% by weight. By setting the content of the stress relaxation agent (E) to 0.1% by weight or more, compression molding is possible even if the filling amount of the white pigment (C) or the inorganic filler (D) is increased, and the molding is possible. The light reflectivity, heat resistance, and light resistance of the cured product tend to be further improved. In addition, the warp of the molded product is alleviated, and the dimensional stability tends to be improved. On the other hand, when the content of the stress relaxation agent (E) is 20% by weight or less, the curability of the curable resin composition tends to be further improved.

[Curing agent (F)]
The curing agent (F) in the curable resin composition of the present invention reacts with a compound having an epoxy group such as an alicyclic epoxy compound (A) and an epoxy-modified silicone oil as a stress relieving agent (E). It is a compound having a function of curing a curable resin composition. As the curing agent (F), a known or commonly used curing agent for epoxy resin can be used, and is not particularly limited. For example, acid anhydrides (acid anhydride-based curing agent) and amines (amine-based curing agent) can be used. Agents), polyamide resins, imidazoles (imidazole-based curing agents), polypeptides (polymercaptan-based curing agents), phenols (phenol-based curing agents), polycarboxylic acids, dicyandiamides, organic acid hydrazides and the like.

As the acid anhydride (acid anhydride-based curing agent) as the curing agent (F), a known or commonly used acid anhydride-based curing agent can be used, and is not particularly limited, but for example, methyltetrahydrophthalic anhydride (4). -Methyltetrahydrophthalic anhydride, 3-methyltetrahydrophthalic anhydride, etc.), Methylhexahydrophthalic anhydride (4-methylhexahydrophthalic anhydride, 3-methylhexahydrophthalic anhydride, etc.), dodecenyl succinic anhydride, methyl Endomethylenetetrahydrophthalic anhydride, phthalic anhydride, maleic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylcyclohexendicarboxylic acid anhydride, pyromellitic anhydride, trimellitic anhydride, benzophenone tetracarboxylic anhydride, anhydrous Nasic acid, methylnadic anhydride, hydride methylnadic anhydride, 4- (4-methyl-3-pentenyl) phthalic anhydride, phthalic anhydride, adipic anhydride, sebacic anhydride, dodecanediochloride, methyl Cyclohexene tetracarboxylic anhydride, vinyl ether-phthalic anhydride copolymer, alkylstyrene-phthalic anhydride copolymer and the like can be mentioned. Among them, 25 from the viewpoint that a uniform curable resin composition can be efficiently prepared, and from the viewpoint that it can be easily mixed with the alicyclic epoxy compound (A) to form a liquid mixture (curing agent composition) at 25 ° C. Acid anhydrides that are liquid at ° C. [eg, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, dodecenylsuccinic anhydride, methylendomethylenetetrahydrophthalic anhydride, etc.] are preferred. On the other hand, with respect to the acid anhydride solid at 25 ° C., for example, the curing agent (F) in the curable resin composition of the present invention can be obtained by dissolving it in a liquid acid anhydride at 25 ° C. to obtain a liquid mixture. There is a tendency for the handleability to be improved. As the acid anhydride-based curing agent, an anhydride of a saturated monocyclic hydrocarbon dicarboxylic acid (including one in which a substituent such as an alkyl group is bonded to a ring) is preferable from the viewpoint of heat resistance and light reflectivity of the cured product. ..

As the amines (amine-based curing agent) as the curing agent (F), known or conventional amine-based curing agents can be used and are not particularly limited, but for example, ethylene diamine, diethylene triamine, triethylene tetramine, tetraethylene pentamine, and the like. Aliper polyamines such as dipropylene diamine, diethylaminopropylamine, polypropylenetriamine; mensene diamine, isophorone diamine, bis (4-amino-3-methyldicyclohexyl) methane, diaminodicyclohexylmethane, bis (aminomethyl) cyclohexane, N-amino Alicyclic polyamines such as ethyl piperazine, 3,9-bis (3-aminopropyl) -3,4,8,10-tetraoxaspiro [5,5] undecane; m-phenylenediamine, p-phenylenediamine, trilene -2,4-diamine, trilen-2,6-diamine, mesitylen-2,4-diamine, 3,5-diethyltrilen-2,4-diamine, 3,5-diethyltrilen-2,6-diamine Mononuclear polyamines such as, biphenylenediamine, 4,4-diaminodiphenylmethane, 2,5-naphthylenediamine, 2,6-naphthylenediamine and other aromatic polyamines and the like can be mentioned.

As the phenols (phenol-based curing agent) as the curing agent (F), known or conventional phenol-based curing agents can be used, and the present invention is not particularly limited. Examples thereof include resins, aralkyl resins such as paraxylylene / metaxylylene-modified phenolic resins, terpene-modified phenolic resins, dicyclopentadiene-modified phenolic resins, and triphenolpropanes.

Examples of the polyamide resin as the curing agent (F) include a polyamide resin having either or both of a primary amino group and a secondary amino group in the molecule.

As the imidazoles (imidazole-based curing agent) as the curing agent (F), known or commonly used imidazole-based curing agents can be used, and the present invention is not particularly limited, but for example, 2-methylimidazole and 2-ethyl-4-methylimidazole. , 2-Undecylimidazole, 2-heptadecylimidazole, 2-phenylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1, -Cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-undecylimidazolium trimerite, 1-cyanoethyl-2-phenylimidazolium trimerite, 2-methylimidazolium isocyanurate, 2-phenylimidazolium isociate Nurate, 2,4-diamino-6- [2-methylimidazolyl- (1)]-ethyl-s-triazine, 2,4-diamino-6- [2-ethyl-4-methylimidazolyl- (1)]- Ethyl-s-triazine and the like can be mentioned.

Examples of the polyether captans (polymercaptan-based curing agent) as the curing agent (F) include liquid polyethercaptan and polysulfide resin.

Examples of the polycarboxylic acid as the curing agent (F) include adipic acid, sebacic acid, terephthalic acid, trimellitic acid, carboxy group-containing polyester and the like.

Among them, as the curing agent (F), acid anhydrides (acid anhydride-based curing agent) are preferable from the viewpoint of heat resistance, light resistance, and light reflectivity of the cured product. In the curable resin composition of the present invention, the curing agent (F) may be used alone or in combination of two or more. The curing agent can also be produced by a known or conventional method, and for example, the trade names "Ricacid MH-700", "Ricacid MH-700F", "Recasid MH-700G", "Recasid TH", "Recasid". "HH", "Recasid HNA-100" (above, manufactured by Shin Nihon Rika Co., Ltd.); Product name "HN-5500" (manufactured by Hitachi Kasei Kogyo Co., Ltd.); Product name "H-TMAn-S", "H" -TMAn "(above, manufactured by Mitsubishi Gas Chemical Co., Ltd.); commercially available products such as the trade name" YH1120 "(manufactured by Mitsubishi Chemical Corporation) can also be used.

When the curable resin composition of the present invention contains a curing agent (F), the content (blending amount) of the curing agent (F) is not particularly limited, but is based on the curable resin composition (100% by weight). It is preferably 1 to 40% by weight, more preferably 3 to 35% by weight, still more preferably 5 to 30% by weight. By setting the content of the curing agent (F) to 1% by weight or more, the curing tends to be more sufficient and the crack resistance of the cured product tends to be improved. On the other hand, when the content of the curing agent (F) is 40% by weight or less, coloring tends to be further suppressed and a cured product (reflector) having an excellent hue tends to be easily obtained.

When the curable resin composition of the present invention contains a curing agent (F), the content (blending amount) of the curing agent (F) in the curable resin composition of the present invention is not particularly limited, but is a curable resin. It is preferably 40 to 200 parts by weight, more preferably 50 to 150 parts by weight, based on 100 parts by weight of the total amount of the epoxy group-containing compound contained in the composition. More specifically, when acid anhydrides are used as the curing agent (F), 0.5 to 0.5 to 1 equivalent of the epoxy group in the compound having all the epoxy groups contained in the curable resin composition of the present invention. It is preferable to use it at a ratio of 1.5 equivalents. By setting the content of the curing agent (F) to 40 parts by weight or more, the curing tends to be more sufficient and the crack resistance of the cured product tends to be improved. On the other hand, when the content of the curing agent (F) is 200 parts by weight or less, coloring tends to be further suppressed and a cured product (reflector) having an excellent hue tends to be easily obtained.

[Curing accelerator (G)]
The curing accelerator (G) in the curable resin composition of the present invention is a compound having a function of accelerating the reaction rate of a compound having an epoxy group when it reacts with the curing agent (F). As the curing accelerator (G), a known or commonly used curing accelerator can be used, for example, 1,8-diazabicyclo [5.4.0] undecene-7 (DBU) or a salt thereof (for example, phenol). Salts, octylates, p-toluenesulfonates, formates, tetraphenylborate salts, etc.); 1,5-diazabicyclo [4.3.0] Nonen-5 (DBN) or salts thereof (eg, phenol salts, Octylate, p-toluenesulfonate, formate, tetraphenylborate salt, etc.); benzyldimethylamine, 2,4,6-tris (dimethylaminomethyl) phenol, N, N-dimethylcyclohexylamine, etc. Secondary amines; imidazoles such as 2-ethyl-4-methylimidazole and 1-cyanoethyl-2-ethyl-4-methylimidazole; phosphines such as phosphate esters and triphenylphosphines; tetraphenylphosphonium tetra (p-tolyl) borates Phosphonium compounds such as; organic metal salts such as zinc octylate and tin octylate; metal chelate and the like.

In the curable resin composition of the present invention, the curing accelerator (G) may be used alone or in combination of two or more. The curing accelerator (G) can also be produced by a known or conventional method, and for example, trade names "U-CAT SA 506", "U-CAT SA 102", "U-CAT 5003", etc. "U-CAT 18X", "12XD" (developed product) (above, manufactured by Sun Appro Co., Ltd.); Product name "TPP-K", "TPP-MK" (above, manufactured by Hokuko Kagaku Kogyo Co., Ltd.); Commercially available products such as the name "PX-4ET" (manufactured by Nippon Chemical Industrial Co., Ltd.) can also be used.

When the curable resin composition of the present invention contains a curing accelerator (G), the content (blending amount) of the curing accelerator (G) in the curable resin composition of the present invention is not particularly limited, but is cured. It is preferably 0.0001 to 5% by weight, more preferably 0.001 to 1% by weight, based on the sex resin composition (100% by weight). By setting the content of the curing accelerator (G) to 0.0001% by weight or more, the curing reaction tends to proceed more efficiently. On the other hand, by setting the content of the curing accelerator (G) to 5% by weight or less, the storage stability of the curable resin composition is further improved, coloring is further suppressed, and a cured product (reflector) having an excellent hue is produced. It tends to be easy to obtain.

When the curable resin composition of the present invention contains a curing accelerator (G), the content (blending amount) of the curing accelerator (G) in the curable resin composition of the present invention is not particularly limited, but is cured. 0.05 to 15 parts by weight, more preferably 0.1 to 12 parts by weight, still more preferably 0.2 to 10 parts by weight, based on 100 parts by weight of the total amount of the compound having an epoxy group contained in the sex resin composition. It is by weight, particularly preferably 0.25 to 8 parts by weight. By setting the content of the curing accelerator (G) to 0.05 parts by weight or more, the curing reaction tends to proceed more efficiently. On the other hand, by setting the content of the curing accelerator (G) to 15 parts by weight or less, a cured product (reflector) having a more improved storage stability of the curable resin composition, more suppressed coloring, and an excellent hue can be obtained. It tends to be easy to obtain.

[Curing catalyst (H)]
The curing catalyst (H) in the curable resin composition of the present invention is a curing reaction (polymerization reaction) of a cationically polymerizable compound such as an alicyclic epoxy compound (A) and an epoxy-modified silicone oil as a stress relieving agent (E). Is a compound having a function of curing the curable resin composition by initiating and / or accelerating. The curing catalyst (H) is not particularly limited, but for example, a cationic polymerization initiator (photocationic polymerization initiator, thermal cationic polymerization) that generates a cationic species by subjecting it to light irradiation, heat treatment, or the like to initiate polymerization. Initiators, etc.), Lewis acid / amine complexes, blended acid salts, imidazoles, etc. can be mentioned.

Examples of the photocationic polymerization initiator as the curing catalyst (H) include hexafluoroantimonate salt, pentafluorohydroxyantimonate salt, hexafluorophosphate salt, hexafluoroarsenate salt and the like, and more specifically, they. , For example, sulfonium salts such as triarylsulfonium hexafluorophosphate (eg, p-phenylthiophenyldiphenylsulfonium hexafluorophosphate), triarylsulfonium hexafluoroantimonate (particularly triarylsulfonium salt); diaryliodonium hexafluorophosphate. , Diaryliodonium hexafluoroantimonate, bis (dodecylphenyl) iodonium tetrakis (pentafluorophenyl) borate, iodonium [4- (4-methylphenyl-2-methylpropyl) phenyl] hexafluorophosphate and other iodonium salts; tetrafluorophosphonium Phenylsium salts such as hexafluorophosphate; pyridinium salts such as N-hexylpyridinium tetrafluoroborate and the like can be mentioned. Examples of the photocationic polymerization initiator include the trade name "UVACURE1590" (manufactured by Daicel Cytec Co., Ltd.); the trade names "CD-1010", "CD-1011", and "CD-1012" (above, USA). (Manufactured by Sartmer); trade name "Irgacure 264" (manufactured by BASF); trade name "CIT-1682" (manufactured by Nippon Soda Co., Ltd.) and other commercially available products can also be preferably used.

Examples of the thermal cationic polymerization initiator as the curing catalyst (H) include aryldiazonium salt, aryliodonium salt, arylsulfonium salt, allen-ion complex and the like, and trade names "PP-33" and "CP-66". , "CP-77" (manufactured by ADEKA Co., Ltd.); product name "FC-509" (manufactured by 3M); product name "UVE1014" (manufactured by GE); product name "Sun Aid SI-60L", "Sun Aid SI-80L", "Sun Aid SI-100L", "Sun Aid SI-110L", "Sun Aid SI-150L" (all manufactured by Sanshin Chemical Industry Co., Ltd.); Product name "CG-24-61" ( Commercially available products such as (manufactured by BASF) can be preferably used. Further, as the thermal cationic polymerization initiator, a chelate compound of a metal such as aluminum or titanium and acetacetic acid or diketones and a compound of silanol such as triphenylsilanol, or a metal such as aluminum or titanium and acetacetic acid or diketone. Examples thereof include a chelate compound with the like and a compound with a phenol such as bisphenol S.

As the Lewis acid / amine complex as the curing catalyst (H), a known or commonly used Lewis acid / amine complex-based curing catalyst can be used, and is not particularly limited, but for example, BF ₃ · n-hexylamine, BF. _3. Monoethylamine, BF ₃ benzylamine, BF ₃ diethylamine, BF ₃ piperidine, BF ₃ triethylamine, BF ₃ aniline, BF ₄ n-hexylamine, BF ₄ monoethylamine, BF ₄ benzylamine , BF ₄ / diethylamine, BF ₄ / piperidine, BF ₄ / triethylamine, BF ₄ / aniline, PF ₅ / ethylamine, PF ₅ / isopropylamine, PF ₅ / butylamine, PF ₅ / laurylamine, PF ₅ / benzylamine, AsF _5. Laurylamine and the like can be mentioned.

As the Bronsted salts as the curing catalyst (H), known or commonly used Bronsted acid salts can be used and are not particularly limited, but for example, aliphatic sulfonium salts, aromatic sulfonium salts, iodonium salts and phosphoniums. Examples include salt.

As the imidazoles as the curing catalyst (H), known or commonly used imidazoles can be used, and the imidazoles are not particularly limited, and are, for example, 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-undecyl. Imidazole, 2-heptadecylimidazole, 2-phenylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2- Undecylimidazole, 1-cyanoethyl-2-undecylimidazolium trimerite, 1-cyanoethyl-2-phenylimidazolium trimerite, 2-methylimidazolium isocyanurate, 2-phenylimidazolium isocyanurate, 2,4 -Diamino-6- [2-methylimidazolyl- (1)]-ethyl-s-triazine, 2,4-diamino-6- [2-ethyl-4-methylimidazolyl- (1)]-ethyl-s-triazine And so on.

In the curable resin composition of the present invention, the curing catalyst (H) may be used alone or in combination of two or more. As described above, a commercially available product can also be used as the curing catalyst (H).

When the curable resin composition of the present invention contains a curing catalyst (H), the content (blending amount) of the curing catalyst (H) in the curable resin composition of the present invention is not particularly limited, but is a curable resin. It is preferably 0.0001 to 5% by weight, more preferably 0.001 to 1% by weight, based on the composition (100% by weight). By using the curing catalyst (H) within the above range, a cured product having excellent heat resistance and light resistance can be obtained.

When the curable resin composition of the present invention contains a curing catalyst (H), the content (blending amount) of the curing catalyst (H) in the curable resin composition of the present invention is not particularly limited, but is a curable resin. 0.0001 to 15 parts by weight, more preferably 0.01 to 12 parts by weight, still more preferably 0.05 to 10 parts by weight, based on 100 parts by weight of the total amount of the cationically polymerizable compound contained in the composition. Particularly preferably, it is 0.05 to 8 parts by weight. By using the curing catalyst (H) within the above range, a cured product having excellent heat resistance and light resistance can be obtained.

The curable resin composition of the present invention may further contain an epoxy compound other than the alicyclic epoxy compound (A) (sometimes referred to as "other epoxy compounds"). As the other epoxy compound, a known or commonly used compound having one or more epoxy groups (oxylan rings) in the molecule can be used, and the present invention is not particularly limited, but for example, an aromatic epoxy compound (aromatic epoxy resin). ), An aliphatic epoxy compound (aliphatic epoxy resin), a heterocyclic epoxy compound (heterocyclic epoxy resin), a siloxane derivative having one or more epoxy groups in the molecule, and the like. The above-mentioned other epoxy compounds may be used alone or in combination of two or more.

Examples of the heterocyclic epoxy compound include isocyanuric acid derivatives having one or more epoxy groups in the molecule. When the curable resin composition of the present invention contains the above-mentioned isocyanuric acid derivative, the adhesion, heat resistance, and moisture absorption / reflow resistance of the cured product to the electrodes tend to be improved.

[Release agent]
The curable resin composition of the present invention may further contain a mold release agent. By including the release agent, continuous molding by a molding method using a mold such as transfer molding and compression molding becomes easy, and a cured product (reflector) can be manufactured with high productivity. As the release agent, a known or commonly used release agent can be used, and is not particularly limited, but for example, a fluorine-based release agent (fluorine atom-containing compound; for example, fluorine oil, polytetrafluoroethylene, etc.), Silicone-based release agents (silicone compounds; for example, silicone oils, silicone waxes, silicone resins, polyorganosiloxanes having polyoxyalkylene units, etc.), wax-based release agents (waxes; for example, vegetable waxes such as carnauba wax) , Animal wax such as wool wax, paraffins such as paraffin wax, polyethylene wax, polyethylene oxide wax, etc.), higher fatty acids or salts thereof (for example, metal salts, etc.), higher fatty acid esters, higher fatty acid amides, mineral oils, etc. ..

In the curable resin composition of the present invention, one type of mold release agent may be used alone, or two or more types may be used in combination. Further, the release agent can be produced by a known or conventional method, or a commercially available product can be used.

When the curable resin composition of the present invention contains a release agent, the content (blending amount) of the release agent in the curable resin composition of the present invention is not particularly limited, but is included in the curable resin composition. It is preferably 1 to 12 parts by weight, more preferably 2 to 10 parts by weight, based on 100 parts by weight of the total amount of the compound having an epoxy group. By setting the content of the release agent to 1 part by weight or more, the releasability of the cured product (reflector) tends to be further improved, and the productivity of the reflector tends to be further improved. On the other hand, by setting the content of the release agent to 12 parts by weight or less, there is a tendency that good adhesion of the reflector to the lead frame of the substrate for mounting the optical semiconductor element can be ensured.

[Antioxidant]
The curable resin composition of the present invention may contain an antioxidant. By including an antioxidant, it becomes possible to produce a cured product (reflector) having further excellent heat resistance (particularly, yellowing resistance). As the antioxidant, a known or commonly used antioxidant can be used, and is not particularly limited. For example, a phenol-based antioxidant (phenolic compound), a hindered amine-based antioxidant (hindered amine-based compound), or phosphorus. Examples thereof include based antioxidants (phosphorus compounds) and sulfur-based antioxidants (sulfur-based compounds).

Examples of the phenolic antioxidant include 2,6-di-t-butyl-p-cresol, butylated hydroxyanisol, 2,6-di-t-butyl-p-ethylphenol, and stearyl-β- (3). , 5-Di-t-butyl-4-hydroxyphenyl) propionates and other monophenols; 2,2'-methylenebis (4-methyl-6-t-butylphenol), 2,2'-methylenebis (4-ethyl- 6-t-butylphenol), 4,4'-thiobis (3-methyl-6-t-butylphenol), 4,4'-butylidenebis (3-methyl-6-t-butylphenol), 3,9-bis [1 , 1-Dimethyl-2- {β- (3-t-butyl-4-hydroxy-5-methylphenyl) propionyloxy} ethyl] 2,4,8,10-tetraoxaspiro [5.5] undecane, etc. Bisphenols; 1,1,3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-) t-butyl-4-hydroxybenzyl) benzene, tetrakis- [methylene-3- (3', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane, bis [3,3'-bis- (4'-Hydroxy-3'-t-Butylphenyl) Butyric Acid] Glycolester, 1,3,5-Tris (3', 5'-di-t-Butyl-4'-Hydroxybenzyl) -s- Examples thereof include high molecular weight phenols such as triazine-2,4,6- (1H, 3H, 5H) trione and tocophenol.

Examples of the hindered amine antioxidant include bis (1,2,2,6,6-pentamethyl-4-piperidyl) [[3,5-bis (1,1-dimethylethyl) -4-hydroxyphenyl] methyl. ] Butylmalonate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, methyl-1,2,2,6,6-pentamethyl-4-piperidyl sebacate, 4-benzoyloxy- Examples thereof include 2,2,6,6-tetramethylpiperidine.

Examples of phosphorus-based antioxidants include triphenylphosphite, diphenylisodecylphosphite, phenyldiisodecylphosphite, tris (nonylphenyl) phosphite, diisodecylpentaerythritol phosphite, and tris (2,4-di-t-). Butylphenyl) phosphite, cyclic neopentanetetraylbis (octadecyl) phosphite, cyclic neopentanetetraylbis (2,4-di-t-butylphenyl) phosphite, cyclic neopentanetetraylbis (2) , 4-Di-t-Butyl-4-methylphenyl) Phenyl Phenyl, Bis [2-t-Butyl-6-Methyl-4- {2- (Octadecyloxycarbonyl) Ethyl} Phenyl] Hydrogen Phenyl Phenyl, etc. Fights; 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10- (3,5-di-t-butyl-4-hydroxybenzyl) -9,10-dihydro-9- Examples thereof include oxaphosphaphenylanthrene oxides such as oxa-10-phosphaphenylanthrene-10-oxide.

Examples of the sulfur-based antioxidant include dodecanethiol, dilauryl-3,3'-thiodipropionate, dimyristyl-3,3'-thiodipropionate, distearyl-3,3'-thiodipropionate and the like. Can be mentioned.

In the curable resin composition of the present invention, one type of antioxidant may be used alone, or two or more types may be used in combination. Further, the antioxidant can be produced by a known or conventional method, and for example, the trade name "Irganox 1010" (manufactured by BASF, phenol-based antioxidant), the trade names "AO-60", "AO-80". (Made by ADEKA Co., Ltd., phenolic antioxidant), trade name "Irgafos168" (manufactured by BASF, phosphorus-based antioxidant), trade name "Adecastab HP-10", "Adecastab PEP-36" (Co., Ltd.) Commercial products such as ADEKA (made by ADEKA, phosphorus-based antioxidant) and trade name "HCA" (manufactured by Sanko Co., Ltd., phosphorus-based antioxidant) can also be used.

When the curable resin composition of the present invention contains an antioxidant, the content (blending amount) of the antioxidant in the curable resin composition of the present invention is not particularly limited, but is included in the curable resin composition. The amount is preferably 0.1 to 5 parts by weight, more preferably 0.5 to 3 parts by weight, based on 100 parts by weight of the total amount of the compound having an epoxy group. By setting the content of the antioxidant to 0.1 parts by weight or more, oxidation of the cured product (reflector) is efficiently prevented, and heat resistance and yellowing resistance tend to be further improved. On the other hand, when the content of the antioxidant is 5 parts by weight or less, coloring is suppressed and a reflector having a better hue tends to be easily obtained.

[Additive]
The curable resin composition of the present invention may contain various additives in addition to the above-mentioned components as long as the effects of the present invention are not impaired. When a compound having a hydroxy group (particularly, an aliphatic polyhydric alcohol) such as ethylene glycol, diethylene glycol, propylene glycol, and glycerin is contained as the additive, the reaction can be allowed to proceed slowly. In addition, defoaming agents, leveling agents, silane coupling agents such as γ-glycidoxypropyltrimethoxysilane and 3-mercaptopropyltrimethoxysilane, and surfactants, as long as the viscosity and light reflectivity are not impaired. , A flame retardant, a colorant, an ion adsorbent, an ultraviolet absorber, a light stabilizer, a fluorescent whitening agent, a pigment other than the white pigment (C), and other conventional additives can be used. The content of these additives is not particularly limited and can be appropriately selected.

As the fluorescent whitening agent, a known or commonly used fluorescent whitening agent can be used. When the curable resin composition of the present invention contains a fluorescent whitening agent, it tends to be more excellent in light reflectivity, heat resistance, light resistance, and crack resistance of the cured product formed by compression molding. Examples of the fluorescent whitening agent include pyrazoline derivatives, stillben derivatives, triazine derivatives, thiazole derivatives, benzoxazole derivatives, xanthone derivatives, triazole derivatives, oxazole derivatives, thiophene derivatives, coumarin derivatives, naphthalimide derivatives and the like.

The curable resin composition of the present invention comprises an alicyclic epoxy compound (A), rubber particles (B), white pigment (C), inorganic filler (D), stress relieving agent (E), and curing agent (F). , And, when the curing accelerator (G) is contained, a mixture of the alicyclic epoxy compound (A), rubber particles (B), stress relieving agent (E), curing agent (F), and curing accelerator (G). The viscosity of the above at 25 ° C. is not particularly limited, but is preferably 5000 mPa · s or less. The curable resin composition of the present invention may contain the above-mentioned aliphatic polyhydric alcohol such as ethylene glycol, and in this case, the above-mentioned mixture is an alicyclic epoxy compound (A) and rubber particles (B). , A mixture of a stress relieving agent (E), a curing agent (F), a curing accelerator (G), and an aliphatic polyhydric alcohol. On the other hand, the curable resin composition of the present invention comprises an alicyclic epoxy compound (A), rubber particles (B), a white pigment (C), an inorganic filler (D), a stress relieving agent (E), and a curing catalyst. When (H) is contained, the viscosity of the mixture of the alicyclic epoxy compound (A), the rubber particles (B), the stress relieving agent (E), and the curing catalyst (H) at 25 ° C. is not particularly limited. It is preferably 5000 mPa · s or less. In the present specification, the viscosities of the above two types of mixtures at 25 ° C. may be collectively referred to as "resin viscosity".

The resin viscosity is a viscosity measured at 25 ° C. under normal pressure. The resin viscosity is preferably 5000 mPa · s or less, more preferably 4000 mPa · s or less, still more preferably 3500 mPa · s or less, and particularly preferably 3000 mPa · s or less. When the resin viscosity is 5000 mPa · s or less, the heat resistance, light resistance, and resistance of the cured product formed by compression molding the curable resin composition are higher than those when the resin viscosity exceeds 5000 mPa · s. Crackability (particularly excellent heat resistance) tends to be even better. Further, since the resin viscosity is relatively low, the content of other components such as the white pigment (C) and the inorganic filler (D) can be increased, and the cured product has light reflectivity, heat resistance, and heat resistance. Light resistance tends to be further improved. The lower limit of the resin viscosity is, for example, 100 mPa · s or more. The resin viscosity is determined by using, for example, a digital viscometer (model number "DVU-EII type", manufactured by Tokimec Co., Ltd.), rotor: standard 1 ° 34'x R24, temperature: 25 ° C., rotation speed: 0. It can be measured under the condition of 5 to 10 rpm.

The resin viscosity is determined by, for example, the components used (for example, alicyclic epoxy compound (A), liquid stress relieving agent (E), curing agent (F), curing accelerator (G), curing catalyst (H), etc.). As a result, it becomes easier to obtain by using a liquid component at 25 ° C. A solid component at 25 ° C. may be used as the component, but the content thereof is preferably adjusted so that the resin viscosity is 5000 mPa · s or less. Further, it can be easily obtained by adjusting the contents of the rubber particles (B) and the solid stress relaxant (E) within a range that does not impair the effect of the present invention.

The curable resin composition of the present invention is B-staged, which is obtained by heating and reacting a part of the alicyclic epoxy compound (A) and the curing agent (F) in the curable resin composition. It may be a cured curable resin composition (a curable resin composition in a B stage state).

As described above, since the curable resin composition of the present invention is excellent in light reflectivity, heat resistance, and light resistance after curing, it can be particularly preferably used as a resin composition for transfer molding or a resin composition for compression molding. .. Above all, the curable resin composition of the present invention is particularly excellent in light reflectivity, heat resistance, and light resistance of the cured product (reflector) formed by compression molding, and therefore, it may be a resin composition for compression molding. Especially preferable.

The curable resin composition of the present invention is not particularly limited, but can be prepared by stirring and mixing each of the above components in a heated state, if necessary. The curable resin composition of the present invention can be used as a one-component composition in which each component is mixed in advance and is used as it is. For example, two or more separately stored compositions can be used. It can also be used as a multi-component (for example, two-component) composition in which the components are mixed at a predetermined ratio before use. The method of stirring / mixing is not particularly limited, and for example, known or conventional stirring / mixing means such as various mixers such as a dissolver and a homogenizer, a kneader, a roll, a bead mill, and a self-revolving stirring device can be used. Further, after stirring and mixing, defoaming may be performed under vacuum.

Although not particularly limited, the rubber particles (B) are blended in the state of a composition previously dispersed in the alicyclic epoxy compound (A) (the composition may be referred to as a "rubber particle-dispersed epoxy compound"). It is preferable to do so. That is, the curable resin composition of the present invention comprises the rubber particle-dispersed epoxy compound, a white pigment (C), an inorganic filler (D), a stress relieving agent (E), a curing agent (F), and curing. It is preferable to prepare by mixing the accelerator (G) or the curing catalyst (H) with other components as needed. By such a preparation method, the dispersibility of the rubber particles (B) in the curable resin composition can be improved. However, the method of blending the rubber particles (B) is not limited to the above method, and may be a method of blending the rubber particles (B) alone.

(Rubber particle dispersed epoxy compound)
The rubber particle-dispersed epoxy compound is obtained by dispersing the rubber particles (B) in the alicyclic epoxy compound (A). The alicyclic epoxy compound (A) in the rubber particle-dispersed epoxy compound may be the total amount or a part of the alicyclic epoxy compound (A) constituting the curable resin composition. You may. Similarly, the rubber particles (B) in the rubber particle-dispersed epoxy compound may be the total amount or a part of the rubber particles (B) constituting the curable resin composition.

The viscosity of the rubber particle-dispersed epoxy compound can be adjusted, for example, by using a reactive diluent in combination (that is, the rubber particle-dispersed epoxy compound may further contain a reactive diluent). As the reactive diluent, for example, an aliphatic polyglycidyl ether having a viscosity at room temperature (25 ° C.) of 200 mPa · s or less can be preferably used. Examples of the aliphatic polyglycidyl ether having a viscosity (25 ° C.) of 200 mPa · s or less include cyclohexanedimethanol diglycidyl ether, cyclohexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, and 1,6-hexanediol diglycidyl ether. , Trimethylol propan triglycidyl ether, polypropylene glycol diglycidyl ether and the like.

The amount of the reactive diluent used can be appropriately adjusted and is not particularly limited, but is preferably 30 parts by weight or less, more preferably 25 parts by weight or less, based on 100 parts by weight of the total amount of the rubber particle-dispersed epoxy compound. (For example, 5 to 25 parts by weight). When the amount used is 30 parts by weight or less, it tends to be easy to obtain desired performance such as toughness (improved crack resistance).

The method for producing the rubber particle-dispersed epoxy compound is not particularly limited, and a well-known and commonly used method can be used. For example, a method in which rubber particles (B) are dehydrated and dried into powder and then mixed with an alicyclic epoxy compound (A) to be dispersed, or an emulsion of rubber particles (B) and an alicyclic epoxy compound (A). ) And the like, followed by dehydration.

The viscosity of the curable resin composition of the present invention at 25 ° C. is not particularly limited, but is preferably 100 to 1000000 mPa · s, more preferably 200 to 800,000 mPa · s, and even more preferably 300 to 800,000 mPa · s. By setting the viscosity at 25 ° C. to 100 mPa · s or more, the workability at the time of casting tends to be improved, and the heat resistance and light resistance of the cured product tend to be further improved.

<Cured product>
By curing the curable resin composition of the present invention by heating, a cured product having excellent light reflectivity, heat resistance, light resistance, and crack resistance can be obtained. A cured product obtained by curing the curable resin composition of the present invention, that is, a cured product of the curable resin composition of the present invention may be referred to as a "cured product of the present invention". The heating temperature (curing temperature) at the time of curing is not particularly limited, but is preferably 50 to 200 ° C, more preferably 80 to 180 ° C. The heating time (curing time) at the time of curing is not particularly limited, but is preferably 60 to 1800 seconds, more preferably 90 to 900 seconds. If the curing temperature and curing time are lower than the lower limit of the above range, the curing is insufficient, and conversely, if it is higher than the upper limit of the above range, yellowing due to thermal decomposition occurs, which is not preferable. The curing conditions depend on various conditions, and can be appropriately adjusted, for example, by shortening the curing time when the curing temperature is high and lengthening the curing time when the curing temperature is low. Further, the curing treatment may be performed in one step (for example, compression molding only), or in multiple steps (for example, after compression molding, further heating in an oven or the like as post-cure (secondary curing)). May be good. When post-cure is performed, the heating temperature at this time is preferably 50 to 200 ° C, more preferably 60 to 180 ° C, and more preferably a temperature similar to the curing temperature. The time for post-cure is preferably 0.5 to 10 hours, more preferably 1 to 8 hours.

The cured product of the present invention has high light reflectivity and is excellent in heat resistance and light resistance. Therefore, the cured product is less likely to deteriorate, and the reflectance is less likely to decrease over time. Therefore, the curable resin composition of the present invention is used for LED packages (components of LED packages, for example, reflector materials in optical semiconductor devices, housing materials, etc.), for bonding electronic components, and for liquid crystal displays (for example, reflectors). Etc.), can be preferably used as an ink for a white substrate, a sealer, or the like. Above all, it can be particularly preferably used as a curable resin composition for an LED package (particularly, a curable resin composition for a reflector in an optical semiconductor device (that is, a curable resin composition for forming a reflector)).

The reflectance (initial reflectance) of the cured product of the present invention is not particularly limited, but for example, the reflectance of light having a wavelength of 450 nm is preferably 90% or more, more preferably 91% or more, still more preferably. It is 92% or more, particularly preferably 95% or more. In particular, the reflectance of light at 450 to 800 nm is preferably 90% or more, more preferably 91% or more, still more preferably 92% or more, and particularly preferably 95% or more.

Retention rate of the reflectance of light having a wavelength of 450 nm after heating at 120 ° C. for 250 hours (sometimes referred to as “reflectance after heating aging”) of the cured product of the present invention with respect to the initial reflectance ([heating aging]. The subsequent reflectance] / [initial reflectance] × 100) is not particularly limited, but is preferably 70% or more, more preferably 75% or more, still more preferably 80% or more, and particularly preferably 90% or more. Is. In particular, the retention rate in the case of light of 450 to 800 nm is preferably 70% or more, more preferably 75% or more, still more preferably 80% or more, and particularly preferably 90% or more. According to the curable resin composition of the present invention, the cured product formed by compression molding can have the above-mentioned retention rate of 90% or more as described above.

Retention of the reflectance (sometimes referred to as "reflectance after UV aging") of the cured product of the present invention to ^{light having a wavelength of 450 nm after being irradiated with ultraviolet rays having an intensity of 10 mW / cm 2 for 250 hours with respect to the initial reflectance.} The rate ([reflectance after ultraviolet aging] / [initial reflectance] × 100) is not particularly limited, but is preferably 80% or more, more preferably 85% or more, still more preferably 90% or more. .. In particular, the retention rate in the case of light of 450 to 800 nm is preferably 80% or more, more preferably 85% or more, still more preferably 90% or more.

The reflectance is measured, for example, by using a cured product (thickness: 3 mm) of the present invention as a test piece and using a spectrophotometer (trade name "spectrophotometer UV-2450", manufactured by Shimadzu Corporation). can do.

When the curable resin composition of the present invention is a curable resin composition for a reflector in an optical semiconductor device, the curable resin composition of the present invention is a substrate of an optical semiconductor element in an optical semiconductor device (for mounting an optical semiconductor device). It is a molding material (material used for molding with a mold or the like) used for forming a reflector (light reflecting member) of a substrate). Therefore, by molding (and curing) the curable resin composition of the present invention, it has high light reflectivity, excellent heat resistance and light resistance, and high quality having a reflector having excellent crack resistance. A substrate for mounting an optical semiconductor device (for example, with high durability) can be manufactured. The reflector is a member for reflecting light emitted from an optical semiconductor element in an optical semiconductor device to increase the directivity and brightness of the light and improve the light extraction efficiency. A substrate used for mounting an optical semiconductor device, which has at least a reflector formed of the cured product of the present invention, may be referred to as a "board for mounting an optical semiconductor device of the present invention".

<Substrate for mounting optical semiconductor devices>
The substrate for mounting an optical semiconductor device of the present invention is a reflector (white reflector) formed of a cured product of the curable resin composition of the present invention (cured product obtained by curing the curable resin composition of the present invention). It is a substrate having at least. 1A and 1B are schematic views showing an example of a substrate for mounting an optical semiconductor element of the present invention, in which FIG. 1A is a perspective view and FIG. 1B is a cross-sectional view. In FIG. 1, 100 is a white reflector, 101 is a metal wiring (lead frame), 102 is a mounting area for an optical semiconductor element, and 103 is a package substrate. A metal wiring 101 and a white reflector 100 are attached to the package substrate 103, and the optical semiconductor element 107 is placed in the center (mounting area 102 of the optical semiconductor element) and die-bonded to form the optical semiconductor element 107. And the metal wiring 101 on the package substrate 103 are connected by wire bonding. As the material of the package substrate 103, resin, ceramic, or the like is used, but it may be the same as that of the white reflector. The upper white reflector 100 in the substrate for mounting an optical semiconductor device of the present invention has a concave shape that surrounds the mounting area 102 of the optical semiconductor device in an annular shape and is inclined so that the diameter of the ring expands upward. Have. In the substrate for mounting an optical semiconductor device of the present invention, the inner surface of the concave shape may be formed at least by a cured product of the curable resin composition of the present invention. Further, as shown in FIG. 1, the portion surrounded by the metal wiring 101 (lower part of 102) may be the package substrate 103 or the white reflector 100 (that is, “100/103” in FIG. "Can be the white reflector 100 or the package substrate 103). However, the substrate for mounting an optical semiconductor device of the present invention is not limited to the mode shown in FIG.

As a method for forming the white reflector on the substrate for mounting the optical semiconductor element of the present invention, a known or conventional molding method (for example, compression molding or the like) can be used, and the curing is not particularly limited, but for example, the curing of the present invention. Examples thereof include a method of attaching the sex resin composition to various molding methods such as transfer molding, compression molding, injection molding, LIM molding (injection molding), and dam molding by dispense. The curing conditions for forming the reflector can be appropriately selected from, for example, the conditions for forming the cured product described above. In the present invention, in particular, heat treatment is performed in multiple stages in that foaming due to a rapid curing reaction can be prevented, stress strain due to curing can be relaxed, and toughness (crack resistance) can be improved. It is preferable to cure the material.

The optical semiconductor device of the present invention can be obtained by using the optical semiconductor device mounting substrate of the present invention as a substrate in an optical semiconductor device and mounting the optical semiconductor element on the substrate.

<Optical semiconductor device>
The optical semiconductor device of the present invention is an optical semiconductor device including at least an optical semiconductor device as a light source and a reflector (reflecting material) made of a cured product of the curable resin composition of the present invention. More specifically, the optical semiconductor device of the present invention is an optical semiconductor device having at least the substrate for mounting the optical semiconductor element of the present invention and the optical semiconductor element mounted on the substrate. Since the optical semiconductor device of the present invention has a reflector formed of a cured product of the curable resin composition of the present invention as a reflector, the brightness of light does not easily decrease over time and is highly reliable. FIG. 2 is a schematic view (cross-sectional view) showing an example of the optical semiconductor device of the present invention. In FIG. 2, 100 is a white reflector, 101 is a metal wiring (lead frame), 103 is a package substrate, 104 is a bonding wire, 105 is a sealing material, 106 is die bonding, and 107 is an optical semiconductor element (LED element). In the optical semiconductor device shown in FIG. 2, since the light emitted from the optical semiconductor element 107 is reflected by the surface (reflecting surface) of the white reflector 100, the light from the optical semiconductor element 107 is extracted with high efficiency. As shown in FIG. 2, the optical semiconductor element in the optical semiconductor device of the present invention is usually sealed with a transparent sealing material (105 in FIG. 2).

3 and 4 are diagrams showing another example of the optical semiconductor device of the present invention. Reference numerals 108 in FIGS. 3 and 4 indicate a heat sink (case heat sink), and by having such a heat sink 108, the heat dissipation efficiency in the optical semiconductor device is improved. FIG. 3 shows an example in which the heat dissipation path of the heat sink is located directly under the optical semiconductor element, and FIG. 4 shows an example in which the heat dissipation path of the heat sink is located in the lateral direction of the optical semiconductor device [(a) is a top view, (B) shows a cross-sectional view of AA'in (a)]. The heat sink 108 projecting from the side surface of the optical semiconductor device in FIG. 4 may be referred to as a heat radiation fin. Further, 109 in FIG. 4 indicates a cathode mark. However, the optical semiconductor device of the present invention is not limited to the aspects shown in FIGS. 2 to 4.

Hereinafter, the present invention will be described in more detail based on Examples, but the present invention is not limited to these Examples. The unit of the blending amount of each component of the curable resin composition in Tables 1 to 3 is a part by weight. Further, "-" in Tables 1 to 3 means that the component was not blended.

Manufacturing example 1
(Manufacturing of rubber particles)
500 g of ion-exchanged water and 0.68 g of sodium dioctyl sulfosuccinate were charged in a 1 L polymerization vessel equipped with a reflux condenser, and the temperature was raised to 80 ° C. while stirring under a nitrogen stream. Here, a monomer mixture consisting of 9.5 g of butyl acrylate, 2.57 g of styrene, and 0.39 g of divinylbenzene, which corresponds to about 5% by weight of the amount required to form the core portion of the rubber particles. Was added all at once and stirred for 20 minutes for emulsification, then 9.5 mg of potassium persulfate was added and stirred for 1 hour for the first seed polymerization. Subsequently, 180.5 mg of potassium persulfate was added, and the mixture was stirred for 5 minutes. Here, the remaining amount (about 95% by weight) required to form the core portion is 180.5 g of butyl acrylate, 48.89 g of styrene, and 7.33 g of divinylbenzene, and 0.95 g of sodium dioctyl sulfosuccinate. The monomer mixture obtained by dissolving the above was continuously added over 2 hours, seed polymerization was carried out for the second time, and then aged for 1 hour to obtain a core portion.
Next, 60 mg of potassium persulfate was added and stirred for 5 minutes, in which 0.3 g of sodium dioctyl sulfosuccinate was dissolved in 60 g of methyl methacrylate, 1.5 g of acrylic acid, and 0.3 g of allyl methacrylate. The monomer mixture was continuously added over 30 minutes for seed polymerization. Then, it was aged for 1 hour to form a shell layer covering the core portion.
Then, the mixture was cooled to room temperature (25 ° C.) and filtered through a plastic net having a mesh size of 120 μm to obtain a latex containing rubber particles having a core-shell structure. The obtained latex was frozen at −30 ° C., dehydrated and washed with a suction filter, and then air-dried at 60 ° C. for 24 hours to obtain rubber particles. The average particle size of the obtained rubber particles was 108 nm, and the maximum particle size was 289 nm.

The average particle size and maximum particle size of rubber particles are determined by the "Nanotrac ^TM " type nanotrack particle size distribution measuring device (trade name "UPA-EX150", manufactured by Nikkiso Co., Ltd.) based on the dynamic light scattering method. ) Is measured, and in the obtained particle size distribution curve, the cumulative average particle size, which is the particle size at the time when the cumulative curve becomes 50%, is the average particle size, and the frequency (%) of the particle size distribution measurement result is 0. The maximum particle size at the time when it exceeded 0.00% was defined as the maximum particle size. As the sample, 1 part by weight of the rubber particle-dispersed epoxy compound obtained in Production Example 2 below was dispersed in 20 parts by weight of tetrahydrofuran.

Manufacturing example 2
(Manufacture of rubber particle dispersed epoxy compound)
Using a dissolver in a state where 5 parts by weight of the rubber particles obtained in Production Example 1 were heated to 60 ° C. under a nitrogen stream, the trade name was "Selokiside 2021P" (3,4-epoxycyclohexylmethyl (3,4). -Epoxy) Cyclohexanecarboxylate, manufactured by Daicel Co., Ltd.) Dispersed in 100 parts by weight (1000 rpm, 60 minutes) and vacuum defoamed to obtain a rubber particle-dispersed epoxy compound (viscosity at 25 ° C.: 1036 mPa · s). rice field.
The viscosity of the rubber particle-dispersed epoxy compound (5 parts by weight of rubber particles dispersed in 100 parts by weight of seroxide 2021P) obtained in Production Example 2 at 25 ° C. is determined by a digital viscometer (trade name "DVU"). -EII type ", manufactured by Tokimec Co., Ltd.) was used for measurement.

Manufacturing example 3
With the formulation (unit: parts by weight) shown in Table 1, the product name "Ricacid MH-700" (manufactured by Shin Nihon Rika Co., Ltd.), the product name "U-CAT 18X" (manufactured by Sun Appro Co., Ltd.), and ethylene Glycol (manufactured by Wako Pure Chemical Industries, Ltd.) is uniformly mixed using a self-revolving stirrer (trade name "Awatori Rentaro AR-250", manufactured by Shinky Co., Ltd.) and defoamed. A curing agent composition (sometimes referred to as "K agent") was obtained.

Example 1
First, according to the formulation (unit: parts by weight) shown in Table 1, the rubber particle-dispersed epoxy compound obtained in Production Example 2, silicone rubber particles (trade name "KMP-600" (manufactured by Shin-Etsu Chemical Co., Ltd.), oxidation) Titanium (trade name "DCF-T-17050", manufactured by Regino Color Industry Co., Ltd.) and silica (trade name "FB-970FD", manufactured by Denka Co., Ltd.) are uniformly mixed using a dissolver and rolled mill. A kneaded product was obtained by melt-kneading under predetermined conditions (roll pitch: 0.2 mm, rotation speed: 25 hertz, 3 passes).
Next, the kneaded product obtained above and the curing agent composition obtained in Production Example 3 were combined with a self-revolving stirrer (trade name “Awa”) so as to have the compounding formulation (unit: parts by weight) shown in Table 1. Tori Rentaro AR-250 ”, manufactured by Shinky Co., Ltd.) was uniformly mixed (2000 rpm, 5 minutes) and defoamed to obtain a curable resin composition (curable epoxy resin composition). ..
The curable resin composition is sandwiched between a release film made of polyester, placed in a mold for compression molding at 150 ° C., heated and pressurized at a pressure of 3.0 MPa for 600 seconds to cure, and then post-cured (post-cure). A cured product was obtained by carrying out (at 150 ° C. for 5 hours).

Examples 2-9, Comparative Examples 1-8
A curable resin composition and a cured product were prepared in the same manner as in Example 1 except that the composition of the curable resin composition was changed to the composition shown in Tables 1 and 2. In some Examples and Comparative Examples, the epoxy compounds shown in Tables 1 and 2 were used as constituents of the curable resin composition in place of or in combination with the rubber particle-dispersed epoxy compound obtained in Production Example 2. used.

Example 10
The rubber particle-dispersed epoxy compound, silicone rubber particles (trade name "KMP-600" (manufactured by Shin-Etsu Chemical Co., Ltd.), and titanium oxide (manufactured by Shin-Etsu Chemical Co., Ltd.) obtained in Production Example 2 according to the formulation (unit: parts by weight) shown in Table 3 Product name "DCF-T-17050", manufactured by Regino Color Industry Co., Ltd., and silica (trade name "FB-970FD", manufactured by Denka Co., Ltd.) are uniformly mixed using a dissolver and determined by a roll mill. Under the conditions (roll pitch: 0.2 mm, rotation speed: 25 hertz, 3 passes), melt-kneading was performed to obtain a kneaded product.
Next, the kneaded product obtained above and the curing catalyst (trade name "Sun Aid SI-100L", manufactured by Sanshin Kagaku Kogyo Co., Ltd.) were combined with the compounding formulation (unit: parts by weight) shown in Table 3. Is uniformly mixed (2000 rpm, 5 minutes) using a self-revolving stirrer (trade name "Awatori Rentaro AR-250", manufactured by Shinky Co., Ltd.), defoamed, and a curable resin composition. (Curable epoxy resin composition) was obtained.
The curable resin composition is sandwiched between a release film made of polyester, placed in a mold for compression molding at 150 ° C., heated and pressurized at a pressure of 3.0 MPa for 600 seconds to cure, and then post-cured (post-cure). A cured product was obtained by carrying out (at 150 ° C. for 5 hours).

Examples 11 and 12, Comparative Examples 9 to 13
A curable resin composition and a cured product were prepared in the same manner as in Example 10 except that the composition of the curable resin composition was changed to the composition shown in Table 3. In some examples and comparative examples, the epoxy compound shown in Table 3 was used as a constituent component of the curable resin composition in place of or in combination with the rubber particle-dispersed epoxy compound obtained in Production Example 2. ..

The curable resin compositions obtained in Examples 1 to 12 and Comparative Examples 1 to 9 were liquid at 25 ° C. On the other hand, the curable resin compositions obtained in Comparative Examples 10 to 13 were solid at 25 ° C.

<Evaluation>
The following evaluations were carried out on the cured products obtained in Examples and Comparative Examples.

[Initial reflectance]
The cured products obtained in Examples and Comparative Examples were cut to prepare test pieces having a length of 30 mm, a width of 30 mm, and a thickness of 3 mm. Next, using a spectrophotometer (trade name "Spectrophotometer UV-2450", manufactured by Shimadzu Corporation), the reflectance (referred to as "initial reflectance") of each test piece to light having a wavelength of 450 nm is measured. bottom. The results are shown in Tables 1-3.
If the initial reflectance is 95% or more, it can be said that it is particularly excellent as a material for light reflection.

[Reflectance retention before and after heating aging]
Using a test piece (cured product; length 30 mm x width 30 mm x 3 mm thickness) for which the initial reflectance was evaluated, the test piece was placed in a dryer at 120 ° C. and left for 250 hours (heat resistance test). After that, the reflectance of light having a wavelength of 450 nm was measured in the same manner as the initial reflectance. Then, the reflectance retention rate (before and after heating aging) was calculated by the following formula. The results are shown in Tables 1-3.
[Reflectance retention rate (before and after heating aging)] = ([Reflectance after heating aging] / [Initial reflectance]) x 100
It is suggested that the higher the reflectance retention rate, the better the heat resistance of the cured product. If the reflectance retention after heating at 120 ° C. for 250 hours is 90% or more, it can be said that the material is particularly excellent in heat resistance as a material for light reflection.

[Reflectance retention before and after UV aging]
Using a test piece (cured product; length 30 mm x width 30 mm x 3 mm thickness) for which the initial reflectance was evaluated, the test piece is ^{irradiated with ultraviolet rays having an intensity of 10 mW / cm 2} for 250 hours (light resistance test). ), Then the reflectance of light having a wavelength of 450 nm was measured in the same manner as the initial reflectance. Then, the reflectance retention rate (before and after ultraviolet aging) was calculated by the following formula. The results are shown in Tables 1-3.
[Reflectance retention rate (before and after UV aging)] = ([Reflectance after UV aging] / [Initial reflectance]) x 100
It is suggested that the higher the reflectance retention rate, the better the light resistance of the cured product. If the intensity is 10 mW / cm ² and the reflectance retention after 250 hours of irradiation is 90% or more, it can be said that the light resistance is particularly excellent as a material for light reflection.

[Evaluation of cracks during cutting (evaluation of toughness)]
The cured products obtained in Examples and Comparative Examples were cut to prepare test pieces having a width of 5 mm, a length of 5 mm, and a thickness of 3 mm. A micro-cutting machine (trade name "BS-300CL", manufactured by Meiwaforsis Co., Ltd.) was used to cut the cured product, and whether or not the cured product cracked during the cutting process was checked. It was observed and confirmed using a digital microscope (trade name "VHX-900", manufactured by KEYENCE CORPORATION). Tables 1 to 3 prepare 10 test pieces per sample, and show the number of test pieces [pieces / 10 pieces] in which cracks were confirmed to occur as evaluation results.

[Evaluation of cracks during reflow (evaluation of toughness)]
A reflow furnace (trade name "UNI-5016F", manufactured by Nippon Antom Co., Ltd.) was used for the test piece (width 5 mm x length 5 mm x thickness 3 mm) obtained by the above cutting process, and the maximum temperature was 260 ° C. The reflow treatment was performed with the temperature set to 5 seconds and the total reflow time set to 90 seconds. Then, whether or not the test piece was cracked by the reflow treatment was observed and confirmed using a digital microscope (trade name "VHX-900", manufactured by KEYENCE CORPORATION). Tables 1 to 3 show the number of test pieces [pieces / 10 pieces] in which cracks were confirmed to occur after 10 test pieces were reflowed per sample as evaluation results.
For those in which cracks were found during cutting, the presence or absence of cracks during reflow was not evaluated.

[Comprehensive judgment]
As a result of each test, those satisfying all of the following (1) to (5) were judged to be ◯ (good). On the other hand, when any of the following (1) to (5) is not satisfied, it is determined as x (defective).
(1) Initial reflectance: light reflectance of 95% or more (2) reflectance retention before and after heating aging: reflectance retention of 90% or more (3) reflectance retention before and after ultraviolet aging: reflectance retention 90% or more (4) Evaluation of cracks during cutting: 0 cracks (5) Evaluation of cracks during reflow: 0 cracks The results are shown in Tables 1 to 3 "Comprehensive". Shown in the "Judgment" column.

The components shown in Tables 1 to 3 will be described below.
(Epoxy compound)
Celoxide 2021P: Trade name "Ceroxide 2021P" (3,4-epoxycyclohexylmethyl (3,4-epoxy) cyclohexanecarboxylate), Epoxy group equivalent 131, Daicel Co., Ltd. YD-128: Trade name "YD-128" (Bisphenol A type epoxy resin), epoxy group equivalent 170, EHPE3150 manufactured by Nippon Steel Chemical Co., Ltd .: Trade name "EHPE3150" (2,2-bis (hydroxymethyl) -1-butanol 1,2-epoxy -4- (2-oxylanyl) cyclohexane adduct), manufactured by Daicel Co., Ltd. (hardener composition)
MH-700: Brand name "Ricacid MH-700" (4-methylhexahydrophthalic anhydride / Hexahydrophthalic anhydride), manufactured by Shin Nihon Rika Co., Ltd. 18X: Product name "U-CAT 18X" (curing accelerator) , San Appro Co., Ltd. Ethylene glycol: Wako Pure Chemical Industries, Ltd. (curing catalyst)
Sun Aid SI-100L: Brand name "Sun Aid SI-100L" (curing catalyst), manufactured by Sanshin Chemical Industry Co., Ltd. (stress relaxation agent)
KMP-600: Trade name "KMP-600" [crosslinked polydimethylsiloxane with silicone resin on the surface], KMP-602 manufactured by Shin-Etsu Chemical Co., Ltd .: Trade name "KMP-602" [silicone resin on the surface Crosslinked polydimethylsiloxane], SF8421 manufactured by Shin-Etsu Chemical Co., Ltd .: trade name "SF8421" [polyalkylene ether-modified silicone compound represented by the formula (1)], Y- manufactured by Toray Dow Corning Co., Ltd. 19268: Trade name "Y-19268" [polyalkylene ether-modified silicone compound represented by formula (1)], manufactured by Momentive Performance Materials Japan (same as above) (white pigment)
DCF-T-17050: Trade name "DCF-T-17050" (titanium oxide, average particle size 0.3 μm, maximum particle size 1 μm or less), manufactured by Regino Color Industry Co., Ltd. (inorganic filler)
FB-970FD: Product name "FB-970FD" (silica, no surface treatment, average particle size 16.7 μm, maximum particle size 70 μm), DAW-1025 manufactured by Denka Co., Ltd .: Product name “DAW-1025” (alumina, Average particle size 7.9 μm, maximum particle size 32 μm), HF-05 manufactured by Denka Co., Ltd .: Trade name “HF-05” (aluminum nitride, average particle size 5 μm, maximum particle size 5 μm), manufactured by Tokuyama Co., Ltd.

100: White reflector 101: Metal wiring (electrode)
102: Mounting area of optical semiconductor element 103: Package substrate 104: Bonding wire 105: Encapsulant for optical semiconductor element 106: Die bonding 107: Optical semiconductor element 108: Heat sink 109: Cathode mark

Claims (8)

Alicyclic epoxy compound (A), rubber particles (B), a white pigment (C), contain an inorganic filler (D), and the stress relaxation agent (E), further, the curing agent (F) and the curing accelerator agent (G), or contain a curing catalyst (H), a light reflecting curable resin composition which is a liquid at 25 ° C.,
The rubber particles (B) are composed of a polymer containing (meth) acrylic acid ester as a monomer component, have a hydroxy group and / or a carboxy group on the surface, and the average particle size of the rubber particles (B) is 10 to 500 nm. The maximum particle size is 50 to 1000 nm.
The stress relaxation agent (E) is at least one selected from the group consisting of silicone rubber particles (E1) and silicone oil (E2).
The silicone rubber particles (E1) are crosslinked polydimethylsiloxane having a silicone resin on the surface.
The silicone oil (E2) is a polyalkylene ether-modified silicone compound having an epoxy equivalent of 3000 to 15000 and having a structure represented by the following formula (1).

[In the formula, x is an integer of 80 to 140, y is an integer of 1 to 5, and z is an integer of 5 to 20. R ⁴ is an alkylene group having 2 or 3 carbon atoms. A is a polyalkylene ether group having a structure represented by the following formula (1a).

(In the formula, a and b are independently integers from 0 to 40. B is a hydrogen atom or a methyl group.)]
The content of the rubber particles (B) is 0.05 to 20% by weight with respect to the curable resin composition for light reflection (100% by weight).
A curable resin composition for light reflection, wherein the content of the stress relaxation agent (E) is 0.1 to 20% by weight with respect to the curable resin composition for light reflection (100% by weight) . The curable resin composition for light reflection according to claim 1 , wherein the alicyclic epoxy compound (A) is a compound having a cyclohexene oxide group. The alicyclic epoxy compound (A) has the following formula (I-1).

The curable resin composition for light reflection according to claim 1 or 2 , which comprises the compound represented by. The white pigment (C) contains at least one selected from the group consisting of titanium oxide, zirconium oxide, zinc oxide, and barium sulfate, and the inorganic filler (D) is silica, alumina, silicon nitride, and nitride. The curable resin composition for light reflection according to any one of claims 1 to 3 , which comprises at least one selected from the group consisting of aluminum and boron nitride. The curable resin composition for light reflection according to any one of claims 1 to 4 , which is a resin composition for transfer molding or compression molding. The curable resin composition for light reflection according to any one of claims 1 to 5 , which is a resin composition for forming a reflector. A cured product of the curable resin composition for light reflection according to any one of claims 1 to 6. An optical semiconductor device comprising at least an optical semiconductor device and a reflector made of a cured product of the curable resin composition for light reflection according to claim 7.

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