Curable composition

Abstract

[Problem] To provide a curable composition that makes it possible to form a cured product equipped with mechanical properties, insulating properties, and the like and exhibiting excellent adhesive strength to a metal such as copper, electrical properties (a low relative dielectric constant, a low dielectric loss tangent, and the like), and moisture resistance, said curable composition additionally having excellent handling properties and narrow gap penetration properties useful for electronic component device applications such as sealing materials for semiconductor devices, build-up films, and underfill materials. [Solution] A curable composition containing: an epoxy resin that contains a bisphenol C epoxy resin or an isocyanurate epoxy resin; a curing agent; and silica particles, wherein the proportion of the silica particles relative to the total volume is 40% by volume or more.

Description

curable composition

[0001] The present invention relates to a curable composition. More specifically, the present invention relates to a curable composition comprising an epoxy resin, a curing agent, and inorganic particles.

[0002] In recent years, to cope with the miniaturization of electronic devices, the acceleration of signals, and the increase in wiring density, there has been a demand for high-performance insulating materials (low dielectric constant, low dielectric loss tangent, low thermal expansion, etc.) for encapsulating resin compositions, build-up substrates, adhesive films, insulating resin sheets such as prepregs, and printed circuit boards for communication equipment, and various studies have been conducted. As encapsulating materials for semiconductor elements, Patent Document 1 proposes a resin composition containing epoxy resin, a curing agent, an inorganic filler, and black titanium oxide particles of a specific particle size, while Patent Document 2 proposes a resin composition containing epoxy resin, a curing agent, spherical silica, and a coloring agent containing carbon black and black titanium oxide. Furthermore, flip-chip bonding is used as a semiconductor chip mounting method that can cope with the miniaturization of electronic devices, the acceleration of signals, and the increase in wiring density. In flip-chip bonding, the gap between the semiconductor chip and the substrate is sealed with a material called underfill. Patent Document 3 proposes a curable composition containing bisphenol C type glycidyl ether and a curing agent as a material for electronic component applications such as underfill materials. Patent Document 4 proposes a resin composition as such a material, which contains an epoxy resin having epoxy groups and isocyanurate rings, a curing agent, and an inorganic filler, wherein the mass reduction rate of the cured product under predetermined conditions is within a specific range.

[0003] Japanese Patent Publication No. 2021-147559, Japanese Patent Publication No. 2023-012946, Japanese Patent Publication No. 2023-036020, International Publication No. 2019 / 225408

[0004] In such resin compositions, the physical properties of the epoxy resin form the basis for various properties such as workability, moldability, electrical properties, moisture resistance, heat resistance, and mechanical properties. On the other hand, when increasing the content of inorganic fillers to improve electrical properties (relative permittivity, low dielectric loss tangent, etc.) while ensuring the uniformity of the resulting cured product, the dispersibility of the constituent components tends to decrease, and the effect is not fully obtained. Even in the resin compositions of Patent Documents 1 to 3, there is still room for improvement in order to obtain a composition that is excellent in fluidity, filling ability, moldability, temperature cycle resistance, and moisture resistance, while also providing the electrical properties based on inorganic fillers and being able to handle narrow gaps. The resin composition of Patent Document 4 is said to have excellent heat resistance derived from the isocyanurate ring, and the toughness of its cured product is improved, suppressing fillet cracks. However, there is still room for improvement in order to obtain a composition that is excellent in fluidity, filling ability, moldability, temperature cycle resistance, and heat resistance, while also providing the electrical properties based on inorganic fillers and being able to handle narrow gaps. The inventors focused on the physical properties of the three components of such a resin composition: epoxy resin, curing agent, and silica particles, and conducted a detailed study of the behavior between the components. As a result, they found that by specifically blending certain components, the dispersion state of silica particles in the composition can be improved, making it easier to handle and eliminating the aforementioned tendencies. Furthermore, they found that such a composition can form cured products (including molded products such as films) with excellent electrical properties (low dielectric constant, low dielectric loss tangent, etc.) and moisture resistance, leading to the present invention. The object of the present invention is to provide a curable composition that can form cured products with excellent adhesion strength to metals such as copper, excellent electrical properties (low dielectric constant, low dielectric loss tangent, etc.), moisture resistance, and also possesses mechanical properties and insulating properties, and is useful for electronic component device applications such as encapsulants, build-up films, or underfill materials for semiconductor devices, and is also excellent in handling and penetration into narrow gaps.

[0005] The present invention has the following embodiments: [1A] A curable composition comprising an epoxy resin containing a bisphenol C type epoxy resin, a curing agent, silica particles having an average particle diameter (D50) of 0.01 to 10 μm, and black particles selected from carbon black or titanium oxide having an average particle diameter (D50) of 0.01 to 5 μm, wherein the content of the bisphenol C type epoxy resin in the total amount of the epoxy resin is 25% by mass or more. [2A] The curable composition of [1A], wherein the bisphenol C type epoxy resin is a bisphenol C type diglycidyl ether that is liquid at 25°C and has a melt viscosity of 0.4P or less at 150°C. [3A] The curable composition of [1A] or [2A], wherein the bisphenol C type epoxy resin is a bisphenol C type diglycidyl ether with an epoxy equivalent of 184 to 250 g / eq. [4A] A curable composition according to any one of [1A] to [3A], wherein the ratio of the average particle diameter of the silica particles to the average particle diameter of the black particles is greater than 0.8. [5A] A curable composition according to any one of [1A] to [4A], wherein the difference in average particle diameter between the silica particles and the black particles is greater than 0.1 μm. [6A] A curable composition according to any one of [1A] to [5A], wherein the content of the black particles relative to the total amount of the silica particles is 0.1 to 1 volume%. [7A] A curable composition according to any one of [1A] to [6A], wherein the total content of the silica particles in the entire curable composition is 40 to 80 volume%. [8A] A curable composition according to any one of [1A] to [7A], wherein the silica particles include solid silica particles and hollow silica particles. [9A] A curable composition according to any one of [1A] to [11A], wherein the curing agent is one or more selected from amine-based curing agents or acid anhydride-based curing agents. [10A] A curable composition according to any one of [1A] to [9A], wherein the curing agent is phthalic anhydrides or norbornenedicarboxylic acid anhydrides. [11A] A curable composition comprising an epoxy resin containing a bisphenol C type epoxy resin and a glycidylamine type epoxy resin, a curing agent, and silica particles having an average particle size (D50) of 0.01 to 10 μm, wherein the content of the bisphenol C type epoxy resin and the content of the glycidylamine type epoxy resin in relation to the total amount of the epoxy resin is 25% by mass or more.[12A] A curable composition of [11A], wherein the ratio of the content of the bisphenol C type epoxy resin to the content of the glycidylamine type epoxy resin is 0.5 to 2.5. [13A] A cured product of any of the curable compositions of [1A] to [12A]. [14A] A curable composition of any of [1A] to [12A] for use in electronic component devices. [15A] A curable composition of any of [1A] to [12A] for use as a encapsulant, build-up film, or underfill material for semiconductor devices.

[0006] [1B] A curable composition comprising an epoxy resin containing an isocyanurate-type epoxy resin, a curing agent having an amino group or an acid anhydride group, and hollow silica particles having an average particle size (D50) of more than 0.5 μm, wherein the content of the isocyanurate-type epoxy resin in relation to the total amount of the epoxy resin is more than 10% by mass, and the content of the hollow silica particles is 2.5% by volume or more. [2B] The curable composition of [1B], wherein the isocyanurate-type epoxy resin is an epoxy resin having an epoxy group and an isocyanurate ring, and the epoxy group and the isocyanurate ring are linked by a chain-type hydrocarbon group having 1 or more carbon atoms. [3B] The curable composition of any of [1B] to [2B], wherein the curing agent having an amino group is an aromatic amine compound having an active hydrogen equivalent of 40 to 80 g / mol. [4B] The curable composition of any of [1B] to [3B], wherein the curing agent having an amino group is a bisaniline or a diaminobenzene. [5B] A curable composition according to any one of [1B] to [4B], further comprising solid silica particles. [6B] The curable composition according to [5B], wherein the total content of solid silica particles and hollow silica particles in the entire curable composition is 50% by volume or more. [7B] The curable composition according to [5B] or [6B], wherein the ratio of hollow silica particles to the total amount of solid silica particles and hollow silica particles is 5% by volume or more. [8B] A curable composition according to any one of [5B] to [7B], wherein the average particle diameter (D50) of the solid silica particles is 0.01 to 10 μm. [9B] A curable composition according to any one of [5B] to [8B], wherein the average particle diameter (D50) of the solid silica particles is smaller than the average particle diameter (D50) of the hollow silica particles. [10B] A curable composition comprising an epoxy resin containing an isocyanurate-type epoxy resin and a glycidylamine-type epoxy resin, a curing agent having an amino group or an acid anhydride group, and silica particles, wherein the content of the isocyanurate-type epoxy resin and the glycidylamine-type epoxy resin in relation to the total amount of the epoxy resin is greater than 10% by mass each, and the sum of the content of the isocyanurate-type epoxy resin and the glycidylamine-type epoxy resin in relation to the total amount of the epoxy resin is greater than 50% by mass.[11B] A curable composition of [10B] wherein the content of the glycidylamine-type epoxy resin is greater than the content of the isocyanurate-type epoxy resin. [12B] A cured product of any of the curable compositions of [1B] to [11B]. [13B] A curable composition of any of [1B] to [11B] for use in electronic component devices. [14B] A curable composition of any of [1B] to [11B] for use as a encapsulant, build-up film, or underfill material for semiconductor devices.

[0007] According to the present invention, it is possible to form a cured product that has excellent adhesive strength to metals such as copper, electrical properties (low dielectric constant, low dielectric loss tangent, etc.), moisture resistance, mechanical properties, and insulating properties, and provides a curable composition that is useful for electronic component devices such as encapsulants, build-up films, or underfill materials for semiconductor devices, and also has excellent handling properties and penetration into narrow gaps.

[0008] In this specification, numerical ranges indicated using "~" include the numbers before and after "~" as the minimum and maximum values, respectively. Furthermore, in numerical ranges described in this specification, the upper or lower limit of one numerical range may be replaced with the upper or lower limit of another numerical range described in stages.

[0009] The present invention relates to a curable composition (hereinafter also referred to as "the composition") comprising an epoxy resin containing a bisphenol C type epoxy resin or an isocyanurate type epoxy resin, a curing agent, and silica particles, wherein the proportion of the silica particles to the total volume is 40% by volume or more.

[0010] Examples of the present composition include a curable composition (hereinafter also referred to as "the present composition 1") comprising an epoxy resin containing a bisphenol C type epoxy resin, a curing agent, silica particles having an average particle diameter (D50; median diameter) of 0.01 to 10 μm, and black particles selected from carbon black or titanium oxide having an average particle diameter (D50) of 0.01 to 5 μm, wherein the content of the bisphenol C type epoxy resin in relation to the total amount of the epoxy resin is 25% by mass or more, and the proportion of the silica particles in relation to the total volume is 40% by volume or more.

[0011] Composition 1 can form a cured product that exhibits excellent adhesive strength to metals such as copper, electrical properties (low dielectric constant, low dielectric loss tangent, etc.), moisture resistance, and also possesses mechanical properties and insulating properties. Furthermore, Composition 1 has excellent handling properties and penetration into narrow gaps. Composition 1 can be effectively used in various applications that take advantage of these properties, and can be effectively used in electronic component devices such as encapsulants, build-up films, or underfill materials for semiconductor devices. The reason why Composition 1 has excellent handling properties and can form a cured product with excellent adhesive strength to metals such as copper, electrical properties (low dielectric constant, low dielectric loss tangent, etc.), and moisture resistance is not entirely clear, but it is thought to be as follows.

[0012] Bisphenol C type epoxy resins, due to their three-dimensional structure, tend to form cured products with excellent dielectric properties and heat resistance. However, they are susceptible to the influence of interactions between components when other particles are present in the reaction system. In particular, when two or more different types of particles are present in the reaction system, it is thought that the reaction system is also susceptible to the influence of the physical properties of the particles themselves, such as their specific gravity and specific surface area, in addition to the chemical interactions between components. Composition 1 contains a predetermined amount of bisphenol C type epoxy resin as the epoxy resin, as well as silica particles of a specific particle size and black particles of a specific particle size. When the particle size of the black particles is within a predetermined particle size range relative to the silica particles, it is presumed that the black particles suppress the aggregation of the silica particles while improving their dispersibility. In other words, it is presumed that the black particles improve the rheology of Composition 1 and promote multiphase flow in the composition. As a result, Composition 1 exhibits excellent handling properties and penetration into narrow gaps. In this highly fluid state, the epoxy resin undergoes high-density crosslinking to form a cured product. Therefore, it is believed that Composition 1 yields a cured product with excellent electrical properties, moisture resistance, and adhesive strength, based on bisphenol C type epoxy resin and silica particles. This tendency becomes even more pronounced when the silica particles include hollow silica particles.

[0013] Furthermore, an embodiment of the present composition is a curable composition (hereinafter also referred to as "the present composition 2"; the present composition 1 and the present composition 2 are collectively referred to as "the present composition 12") comprising an epoxy resin containing a bisphenol C type epoxy resin and a glycidylamine type epoxy resin, a curing agent, and silica particles having an average particle size (D50, median diameter) of 0.01 to 10 μm, wherein the content of the bisphenol C type epoxy resin and the content of the glycidylamine type epoxy resin in relation to the total amount of the epoxy resin is 25% by mass or more, and the proportion of the silica particles in relation to the total volume is 40% by volume or more.

[0014] Composition 2 can form a cured product that exhibits excellent adhesive strength to metals such as copper, electrical properties (low dielectric constant, low dielectric loss tangent, etc.), moisture resistance, and also possesses mechanical properties and insulating properties. Furthermore, Composition 2 has excellent handling properties and penetration into narrow gaps. Composition 2 can be effectively used in various applications that take advantage of these properties, and can be effectively used in electronic component devices such as encapsulants, build-up films, or underfill materials for semiconductor devices. The reason why Composition 2 has excellent handling properties and can form a cured product with excellent adhesive strength to metals such as copper, electrical properties (low dielectric constant, low dielectric loss tangent, etc.), and moisture resistance is not entirely clear, but it is thought to be as follows.

[0015] As mentioned above, bisphenol C type epoxy resins tend to form cured products with excellent dielectric properties and heat resistance. However, when other particles are present in the composition, they are susceptible to the effects of interactions between components. The inventors have found that when silica particles with a particle size of sub-μm to several μm are included in the composition, the composition tends to thicken, and its handling properties and penetration into narrow gaps may decrease. The inventors have found that by using bisphenol C type epoxy resin and glycidylamine type epoxy resin in combination, and balancing the amounts of both epoxy resins in the composition, this tendency is mitigated, and a cured product with even better dielectric properties and heat resistance can be formed. The reason for this is not entirely clear, but it is thought that the glycidylamine type epoxy resin, which can be considered highly polar, breaks the interaction between the bisphenol C type epoxy resin and the silica particles, improving the dispersibility of the individual components. This tendency is more pronounced when the silica particles include hollow silica particles.

[0016] Composition 1 contains a bisphenol C type epoxy resin as the epoxy resin, and the content of the bisphenol C type epoxy resin in relation to the total amount of epoxy resin is 25% by mass or more. Preferably, the content of the bisphenol C type epoxy resin in relation to the total amount of epoxy resin is 30% by mass or more. Such a content is preferably 60% by mass or less, and more preferably 50% by mass or less. When the content of the bisphenol C type epoxy resin in relation to the total amount of epoxy resin is within the above range, the above-described mechanism of action is easily expressed, composition 1 has excellent handling properties and penetration into narrow gaps, and the cured product of composition 1 tends to have excellent electrical properties and moisture resistance (low hygroscopicity).

[0017] The bisphenol C type epoxy resin in the composition 1 is preferably a bisphenol C type diglycidyl ether which is liquid at 25°C and has a melt viscosity of 0.4 P or less at 150°C. The melt viscosity of the bisphenol C type diglycidyl ether at 150°C is preferably 0.35 P or less, more preferably 0.3 P or less. When the bisphenol C type epoxy resin is liquid at 25°C and its melt viscosity at 150°C is within the above range, the handling property is good, the compatibility with other components in the composition 1 is likely to be good, and the cured product of the composition 1 is likely to be excellent in electrical properties (low relative permittivity, low dielectric tangent, etc.) and moisture resistance. Note that the melt viscosity at 150°C can be measured using a rotational viscometer (ICI viscometer) or the like. In this specification, the structure represented by the following formula (1) is defined as "bisphenol C", and examples of the bisphenol C type diglycidyl ether include the compound represented by the following formula (2).

[0018]

[0019] In formula (2), n represents an integer of 0 or more. The upper limit of n is preferably 10 or less. In formula (2), the proportion of the bisphenol C type diglycidyl ether with n = 0 is preferably 90 to 99% by mass, and the proportion of the bisphenol C type diglycidyl ether with n = 1 is preferably 1 to 10% by mass. The bisphenol C type diglycidyl ether may also contain a bisphenol C type diglycidyl ether with n = 2 or more. Its content is more preferably 2% by mass or less. In this case, the above-described action mechanism is more likely to be expressed.

[0020] The bisphenol C type epoxy resin is more preferably a bisphenol C type diglycidyl ether having an epoxy equivalent of 184 to 250 g / eq. Such an epoxy equivalent is preferably 185 g / eq or more, more preferably 186 g / eq or more. The epoxy equivalent is preferably 240 g / eq or less, more preferably 230 g / eq or less, and even more preferably 210 g / eq or less. When the epoxy equivalent of the bisphenol C type diglycidyl ether is within the above range, it is easy to improve the electrical properties, heat resistance, moisture resistance, etc. of the cured product of the composition 1.

[0021] Bisphenol C type diglycidyl ether is preferably obtained by reacting bisphenol C with epihalohydrin in the presence of a base, or by allylating bisphenol C and then epoxidizing the carbon-carbon double bond portion, specifically, by the method described in JP-A-2023-036020. The total chlorine content of bisphenol C type diglycidyl ether is preferably 5000 ppm or less, more preferably 2000 ppm or less. The total chlorine content can be measured according to JIS K 7243-3.

[0022] In the epoxy resin constituting the present composition 1, the other epoxy resin other than the bisphenol C type epoxy resin is preferably an epoxy resin having two or more epoxy groups in one molecule. Further, such other epoxy resin may be solid or liquid at room temperature (25°C), and is more preferably liquid at room temperature from the viewpoint of improving the handleability and filling property of the present composition 1. The viscosity of the other liquid epoxy resin is preferably 0.0001 to 10 Pa·s as measured at 25°C with an E-type viscometer. Examples of the other epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol AF type epoxy resin, glycidylamine type epoxy resin, phenol novolac type epoxy resin, alkylphenol novolac type epoxy resin, biphenyl type epoxy resin, aralkyl type epoxy resin, naphthol type epoxy resin, anthracene type epoxy resin, dicyclopentadiene type epoxy resin, naphthalene type epoxy resin, adamantane type epoxy resin, an epoxidized product of a condensate of phenols and an aromatic aldehyde having a phenolic hydroxyl group, biphenylaralkyl type epoxy resin, fluorene type epoxy resin, xanthene type epoxy resin, triglycidyl isocyanurate, and the like. The other epoxy resin may be used alone or in combination of two or more.

[0023] In this specification, epoxy equivalent is the mass of resin per epoxy group (g / eq) and is determined according to JIS K 7236. Specifically, it can be measured by weighing 0.2 g of epoxy resin, dissolving it in 10 ml of chloroform, adding 20 ml of glacial acetic acid and 10 ml of tetraethylammonium bromide acetic acid solution, and titrating with a 0.1 mol / L perchloric acid acetic acid solution.

[0024] In this composition 1, examples of curing agents include amine-based curing agents, acid anhydride-based curing agents, phenol-based curing agents, and the like, all of which are known as curing agents for epoxy resins. Among these, it is preferable that the curing agent be one or more selected from amine-based curing agents or acid anhydride-based curing agents. Furthermore, aromatic amine compounds are more preferable as amine-based curing agents. When these high-temperature curing curing agents are used, the above-described mechanism of action is particularly likely to manifest in the high-temperature range where the fluidity of this composition 1 increases, and the effects such as the electrical properties of the cured product of this composition 1 are more likely to manifest.

[0025] Examples of aromatic amine compounds used as amine-based curing agents include bisanilines such as 3,5-diethyltoluene-2,4-diamine and 3,5-diethyltoluene-2,6-diamine; diaminobenzenes such as 1-methyl-3,5-diethyl-2,4-diaminobenzene, 1-methyl-3,5-diethyl-2,6-diaminobenzene, 1,3,5-triethyl-2,6-diaminobenzene, and dimethylthiotoluenediamine; and 3,3'-diethyl-4,4'-diaminodiphenylmethane and 3,5,3',5'-tetramethyl-4,4'-diaminodiphenylmethane. Examples of acid anhydride-based curing agents include phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic dianhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnadic anhydride, hydrogenated methylnadic anhydride, trialkyltetrahydrophthalic anhydride, methylcyclohexanetetracarboxylic dianhydride, ethylene glycol bis-anhydrotrimellitate, glyceryl bis(anhydrotrimellitate) monoacetate, dodecenyl succinic anhydride, aliphatic dibasic acid polyanhydride, and chlorenic anhydride.

[0026] Among those described above, amine-based curing agents that are bisanilines or diaminobenzenes are more preferred. In this specification, "bisanilines" means compounds in which multiple structural units (aniline units) are linked together, with one of the six carbon atoms forming a benzene ring directly bonded to a primary or secondary amino group. In this specification, "diaminobenzenes" means compounds having a structure in which two of the six carbon atoms forming a benzene ring are directly bonded to a primary or secondary amino group.

[0027] Amine-based curing agents may be commercially available. Examples of bisaniline-based amine-based curing agents include "KAYAHARD® A-A" (trade name, active hydrogen equivalent 64 g / mol) manufactured by Nippon Kayaku Co., Ltd. Examples of diaminobenzene-based amine-based curing agents include "jER® Cure WA" (trade name, active hydrogen equivalent 45 g / mol) manufactured by Mitsubishi Chemical Corporation and "EH-105L" (trade name, active hydrogen equivalent 54 g / mol) manufactured by ADEKA Corporation.

[0028] Furthermore, among those described above, it is more preferable that the acid anhydride-based curing agent is phthalic anhydride or norbornene dicarboxylic acid anhydride. In this case, the viscosity of composition 1 tends to decrease more easily, and the penetration into narrow gaps tends to improve even further. In this specification, "phthalic anhydride" refers to phthalic anhydride, derivatives of phthalic anhydride in which the benzene ring of phthalic anhydride is reduced, and compounds in which the hydrogen atoms bonded to the carbon atoms forming the carbocyclic ring in these are substituted. In this specification, "norbornene dicarboxylic acid anhydride" refers to norbornene dicarboxylic acid anhydride and compounds in which the hydrogen atoms bonded to the carbon atoms forming the norbornene ring of norbornene dicarboxylic acid anhydride are substituted.

[0029] Commercially available acid anhydride-based curing agents may be used. Examples of acid anhydride-based curing agents include "HN-2200" (166 g / eq equivalent of acid anhydride) and "MHAC-P" (178 g / eq equivalent of acid anhydride) from Resonaq Corporation, "Ricacid® MH-700" (166 g / eq equivalent of acid anhydride) and "Ricacid® HNA-100" (179 g / eq equivalent of acid anhydride) from Shin Nippon Rika Co., Ltd., and "YH306" and "YH307" from Mitsubishi Chemical Corporation.

[0030] Furthermore, the equivalent ratio of epoxy resin to curing agent in this composition 1 (number of functional groups that can react with epoxy in the curing agent / number of functional groups in the epoxy resin) is preferably 1.5 to 2.0, more preferably 0.6 to 1.3, from the viewpoint of minimizing the amount of unreacted material, and even more preferably 0.8 to 1.2 from the viewpoint of curability and reliability.

[0031] The black particles in this composition 1 are selected from carbon black or titanium oxide, and their average particle size (D50) is 0.01 to 5 μm. The D50 is preferably in the range of 0.05 to 3 μm, and more preferably in the range of 0.1 to 1 μm. The Mohs hardness of the black particles is preferably less than 7. In other words, the Mohs hardness of the black particles is preferably lower than the Mohs hardness of 7 of the silica particles described later. Specifically, the Mohs hardness of graphite as carbon black is in the range of 0.5 to 1, and the Mohs hardness of black titanium oxide is usually in the range of 5.5 to 6.

[0032] In this composition 1, the ratio of the average particle diameter of the silica particles (described later) to the average particle diameter of the black particles is preferably greater than 0.8, and more preferably greater than 1. This ratio is preferably 10 or less. Furthermore, the difference in average particle diameter between the silica particles (described later) and the black particles is preferably greater than 0.1 μm. This difference in average particle diameter is preferably 1 μm or less. Moreover, in this composition 1, the content of black particles relative to the total amount of silica particles (described later) is preferably 0.1 to 1 volume%. When the average particle diameters of the black particles and the silica particles (described later) satisfy the above relationship, and the content of black particles relative to the total amount of silica particles is within the above range, it is presumed that the black particles, which have a lower Mohs hardness and are more brittle than the silica particles (which have a Mohs hardness of 7), are more easily broken in this composition 1, acting as a sacrificial phase to suppress the damage of the silica particles and thus increasing the overall fluidity of this composition 1.

[0033] Examples of carbon black used as black particles include furnace black, channel black, thermal black, acetylene black, Ketjen black, and lamp black. When carbon black is used as black particles, the average size of the primary particles (average primary particle diameter) is preferably in the range of 0.01 to 0.3 μm, and more preferably in the range of 0.015 to 0.1 μm. The average primary particle diameter of carbon black is determined by observing the carbon black with an electron microscope and calculating its arithmetic mean diameter. The average particle diameter (D50) of the secondary particles (aggregated particles) of carbon black is 0.01 to 5 μm. This D50 is preferably in the range of 0.05 to 3 μm, and more preferably in the range of 0.1 to 1 μm. The particle size of the secondary particles of carbon black (aggregation diameter when primary particles aggregate) is determined by laser diffraction / scattering. In this invention, the average particle diameter of black particles refers to the D50 of the secondary particles when carbon black is used as black particles. The pH of carbon black is preferably in the range of 2.0 to 6.0. When the pH of carbon black is within this range, aggregation of carbon black is easily suppressed. The pH of carbon black can be measured in accordance with JIS K 5101-17-2:2004.

[0034] Examples of titanium dioxide as black particles include black titanium dioxide particles. Black titanium dioxide is a particle Ti ｍ O （２ｍ－１） There exists such that (m is a positive integer) and m is between 4 and 6, Ti ４ O ７ Ti ５ O ９ and Ti ６ O １１ It is preferable to include at least one of the following from the viewpoint of easily improving the dispersibility of composition 1. The D50 of the black titanium oxide particles is in the range of 0.01 to 5 μm, preferably in the range of 0.05 to 3 μm, and more preferably in the range of 0.1 to 1 μm. The D50 of the black titanium oxide particles can be measured, for example, using a laser diffraction particle size distribution analyzer.

[0035] The silica particles in this composition 1, having an average particle size (D50) of 0.01 to 10 μm, may be solid silica particles or hollow silica particles. When the silica particles are hollow silica particles, the above-described mechanism of action is particularly likely to manifest. The silica particle content relative to the entire composition 1, in other words, the proportion of silica particles to the total volume, is 40% by volume or more, preferably 40 to 80% by volume, and more preferably in the range of 50 to 80% by volume. When the silica particle content is within the above range, this composition 1 is easy to handle, and the electrical properties of the cured product are further improved. The silica constituting the silica particles may be fused silica or crystalline silica.

[0036] It is more preferable that the composition 1 contains solid silica particles and hollow silica particles as silica particles from the viewpoint of further improving the electrical properties of the cured product of the composition 1. When the composition 1 contains solid silica particles and hollow silica particles as silica particles, the content of solid silica particles in the silica particles is preferably 10 to 99% by volume, and the content of hollow silica particles is preferably 1 to 90% by volume. The average particle diameter (D50) of the solid silica particles is preferably 0.01 μm or more and 10 μm or less. The average particle diameter (D50) of the solid silica particles is more preferably 0.1 or more, and even more preferably 0.2 μm or more. The average particle diameter (D50) of the solid silica particles is more preferably less than 4 μm, and even more preferably 3 μm or less. The average particle diameter of the solid silica particles is determined by the laser diffraction / scattering method. That is, the particle size distribution is measured by the laser diffraction / scattering method, the cumulative curve is obtained with the total volume of the particle population as 100%, and the particle diameter at the point where the cumulative volume is 50% on the cumulative curve is D50. The specific gravity of the solid silica particles is preferably 1.6 g / cm ３ or more and 2.2 g / cm ３ or less, and more preferably 1.8 g / cm ３ or more and 2.2 g / cm ３ less. In the present specification, solid silica particles refer to particles having a hollowness of less than 10%, and are distinguished from hollow silica particles by the hollowness.

[0037] The ratio of the average particle diameter (D50) of hollow silica particles to the average particle diameter (D50) of solid silica particles is preferably 0.1 to 10. Note that the D50 of hollow silica particles refers to the D50 of secondary particles of hollow silica particles, and details will be described later. If the D50 of solid silica particles is larger than the D50 of hollow silica particles, the ratio is more preferably 0.1 to 0.8. In this case, it is presumed that the solid silica particles have the effect of buffering the stress generated in the composition 1, and also promote the flow of hollow silica particles, which are smaller than the solid silica particles, making them easier to homogenize. Therefore, the packing of silica particles when mounting the composition 1 to electronic component devices, etc., is easily improved, and the flowability into narrow gaps is also easily improved. If the D50 of solid silica particles is smaller than the D50 of hollow silica particles, the ratio is more preferably 2 to 10. In this case, it is presumed that the solid silica particles, which are in a loosely aggregated state, will buffer the stress acting on the composition 1, and will also easily flow and homogenize among the hollow silica particles, which are larger than the solid silica particles. Therefore, the packing of silica particles when mounting composition 1 into electronic components and the like is easily improved, and the fluidity into narrow gaps is also easily improved.

[0038] The hollow silica particles in this composition 1 have a shell layer (solid film) containing silica and have a space inside the shell layer. The presence of a space inside the shell layer of the hollow silica particles can be confirmed by transmission electron microscopy (TEM) observation or scanning electron microscopy (SEM) observation. In the case of SEM observation, the hollowness can be confirmed by observing a broken particle with a partial opening. Spherical particles with an internal space that can be confirmed by TEM or SEM observation are defined as "primary particles". Note that, due to the firing and drying processes during manufacturing, the primary particles are partially bonded together, so hollow silica particles are often aggregates of secondary particles formed by the aggregation of primary particles. Furthermore, "having a space inside the shell layer" means that when observing the cross-section of a single primary particle, the shell layer surrounds a single space, resulting in a hollow state. That is, one hollow particle has one large space and a shell layer surrounding it. If the hollow silica particles have a structure in which there is a space within the shell, more space can be secured in the composition containing the particles, and the dielectric constant can be lowered, so this composition 1 can be suitably used for electronic component devices.

[0039] The specific gravity of hollow silica particles is 0.3 g / cm³. ３ 1.25g / cm or more ３ Preferably, it is 0.3 g / cm³. ３ 1.00g / cm or more ３ It is more preferable to be less than 0.4 to 0.8 g / cm³. ３ It is even more preferable that this is the case. In this specification, the "specific gravity" of hollow silica particles refers to the density of the particles determined by density measurement using a dry pycnometer with argon gas (hereinafter also referred to as "Ar density"). When the Ar density is within the above range, not only is the above-described mechanism of action more easily expressed, but the dielectric constant in the cured product of composition 1 is also easily reduced.

[0040] Furthermore, the density of the hollow silica particles, as determined by density measurement using a dry pycnometer with helium gas (hereinafter also referred to as He density), is 2.00 to 2.35 g / cm³. ３This is preferable. Since helium gas permeates through fine voids, the He density can also be positioned as the density corresponding to the true density of the silica portion of silica particles that have internal space. When the He density is within the above range, the amount of silanol remaining in the hollow silica particles decreases, making it easier to reduce the dielectric loss tangent.

[0041] The specific gravity (Ar density) of hollow silica particles can be adjusted by controlling the primary particle size and shell thickness. In a sample of hollow silica particles, the proportion of perfectly hollow particles (hollow particle ratio) that have an internal space without damage to the shell layer is determined by the amount of raw material used. A higher hollow particle ratio results in a lower apparent density of the hollow silica sample, while a lower hollow particle ratio results in a higher apparent density. Using this, assuming a 100% yield, the hollow particle ratio can be determined from the theoretical density obtained from the amount of raw material used and the apparent density measured with a dry pycnometer. In this case, a hollow particle ratio of 90% or more is preferable, and 95% or more is more preferable. Furthermore, a hollow particle ratio of 100% or less is preferable.

[0042] Furthermore, the hollow particle ratio can also be determined from the weight change during heat treatment using the filtration cake before the oil core is removed when manufacturing hollow silica particles. When the filtration cake is loosened and dried overnight, the oil components in the broken particles volatilize, while the oil components in the complete hollow particles are retained. The weight change during heat treatment can be calculated from the amount of raw material used for cases where all the added oil components volatilize (0% hollow particle ratio) and cases where all of them are retained (100% hollow particle ratio). Therefore, the hollow particle ratio can be determined from the weight change when the sample, dried overnight after filtration, is heat-treated to 800°C. In this case, a hollow particle ratio of 90% or more is preferable, and 95% or more is more preferable. In this case, a hollow particle ratio of 100% or less is preferable.

[0043] The BET specific surface area of ​​hollow silica particles is 1 to 100 m². ２ It is preferable that the amount is / g, and 1 to 50m ２ / g is more preferable. When the BET specific surface area is within the above range, not only is the above-described mechanism of action more easily expressed, but the dispersibility of the hollow silica particles in Composition 1 is particularly easily improved, and the viscosity increase of Composition 1 is easily suppressed. The BET specific surface area can be measured using a specific surface area measuring device (such as Shimadzu Corporation's "Tristar II 3020"), after drying the hollow silica particles at 230°C until they reach 50 mTorr, and then measuring them using a multi-point method with nitrogen gas.

[0044] Furthermore, the specific gravity (Ar density) of hollow silica particles is A (g / cm³). ３ ) and the specific surface area of ​​BET is B (m ２ If we assume ( / g), the product of the two (A × B) is between 1 and 120 m ２ / cm ３ It is preferable that A x B is 80 m ２ / cm ３ The following is more preferable: 40m ２ / cm ３ The following is even more preferable: A x B is 2m ２ / cm ３ The above is more preferable, 2.5m ２ / cm ３ The above is even more preferable. A × B can also be considered as the specific surface area per unit volume when hollow silica particles are dispersed in a solvent. For example, when hollow silica particles are added to a resin, it represents the specific surface area of ​​the portion of a predetermined volume in the resin occupied by the hollow silica particles. When A × B is within the above range, not only is the above-described mechanism of action more easily manifested, but because the specific surface area of ​​the hollow silica particles in the composition is small, it is also easier to suppress the increase in viscosity of the composition 1. Furthermore, when A × B is within the above range, it is easier to lower the relative permittivity and dielectric loss tangent of the cured product of the composition 1 and improve its electrical properties.

[0045] The sphericity of hollow silica particles is preferably between 0.75 and 1.0. When the sphericity is within this range, the hollow silica particles are less likely to break, it is easier to maintain the Ar density and specific surface area, and it is easier to lower the dielectric loss tangent. Sphericity is expressed as the average value obtained by measuring the maximum diameter (DL) and the minimum diameter (DS) perpendicular to it for any 100 particles in an image obtained by a scanning electron microscope (SEM), and calculating the ratio of the minimum diameter (DS) to the maximum diameter (DL) (DS / DL).

[0046] The average size of the primary particles of hollow silica particles (average primary particle diameter) is preferably in the range of 50 nm to 10 μm. More preferably, the average primary particle diameter is 70 nm or more, and even more preferably 100 nm or more. More preferably, the average primary particle diameter is 5 μm or less, and even more preferably 3 μm or less. When the average primary particle diameter of hollow silica particles is within the above range, they are easy to handle and it is easy to control the specific surface area, oil absorption, pore volume, and amount of SiOH on the particle surface. The average primary particle diameter of hollow silica particles is determined by measuring the size of any 100 primary particles from SEM observation images and taking the average of these values. The average primary particle diameter can also be considered to reflect the surface state of the secondary particles (aggregated particles) of the hollow silica particles and is a parameter that determines the specific surface area and oil absorption.

[0047] The hollow silica particles have the average primary particle diameter described above, preferably 35% or more of the total primary particles have a particle diameter within ±40% of the average primary particle diameter, more preferably 50% or more of the total primary particles have a particle diameter within ±40% of the average primary particle diameter, and even more preferably 70% or more of the total primary particles have a particle diameter within ±40% of the average primary particle diameter. In this case, the size of the hollow silica particles becomes more uniform, and shell defects of the hollow silica particles are less likely to occur.

[0048] The median diameter (D50) of the secondary particles (aggregated particles) of the hollow silica particles is preferably 0.2 to 10 μm, and more preferably 0.5 to 5 μm. Such D50 is even more preferably 0.6 μm or more, and particularly preferably 0.7 μm or more. Such D50 is even more preferably 4 μm or less, and particularly preferably 3 μm or less. When D50 is within the above range, not only is the above-described mechanism of action more easily expressed, but the dispersion stability of the hollow silica particles in Composition 1 is easily improved, and the increase in viscosity of the composition is easily suppressed. In addition, granularity in the cured product of Composition 1 is easily reduced.

[0049] Furthermore, the coarse particle size (D90) of the secondary particles of the hollow silica particles is preferably 1 to 30 μm. More preferably, D90 is 3 μm or more, and even more preferably 5 μm or more. More preferably, D90 is 25 μm or less, and even more preferably 20 μm or less. When D90 is within the above range, it is easier to increase the productivity of hollow silica particles and to reduce granularity in the cured product of composition 1. The particle size of the secondary particles of the hollow silica particles (aggregation diameter when primary particles aggregate) is determined by laser diffraction and scattering. That is, the particle size distribution is measured by laser diffraction and scattering, and a cumulative curve is obtained with the total volume of the particle collection set to 100%, and the particle size at the point where the cumulative volume is 50% on that cumulative curve is D50, and the particle size at the point where the cumulative volume is 90% is D90.

[0050] The shell thickness of hollow silica particles is preferably 0.01 to 0.3, more preferably 0.02 or greater, and even more preferably 0.03 or greater, when the diameter of the primary particle is set to 1. Furthermore, the shell thickness of hollow silica particles is more preferably 0.2 or less, and even more preferably 0.1 or less, when the diameter of the primary particle is set to 1. When the shell thickness relative to the diameter of the primary particle is within the above range, it is easier to maintain the strength of the hollow silica particles and to exhibit properties based on their hollow shape. The shell thickness is determined by measuring the shell thickness of individual particles using a transmission electron microscope (TEM).

[0051] SiO in hollow silica particles ２The content is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 99% by mass or more. SiO in hollow silica particles ２ The content may be 100% by mass, and is preferably 99.99% by mass or less. Here, SiO in hollow silica particles ２ The content refers to the amount of silica (SiO₂) contained in the shell layer that makes up the hollow silica particles. ２ This is the content of SiO in hollow silica particles, for example, "SiO in hollow silica particles" ２ "Having a content of 99% by mass or more" means that 99% by mass or more of the shell layer constituting the hollow silica particles is silica (SiO₂ ２ This means that it contains ). Residues in hollow silica particles include alkali metal oxides and silicates, alkaline earth metal oxides and silicates, carbon, etc. In other words, hollow silica particles may contain one or more metals M selected from the group consisting of Li, Na, K, Rb, Cs, Mg, Ca, Sr, and Ba. When metal M is included in hollow silica particles, it acts as a flux during firing, which reduces the specific surface area and tends to lower the dielectric loss tangent.

[0052] Metal M is incorporated into the hollow silica particles between the reaction step and the washing step during the manufacturing process. For example, metal M can be incorporated into the hollow silica particles by adding a metal salt of metal M to the reaction solution used to form the silica shell during the reaction step, or by washing the hollow silica precursor with a solution containing metal ions of metal M before firing. In the hollow silica particles of this composition 1, the concentration of metal M is preferably 50 ppm by mass or more and 1% by mass or less, more preferably 100 ppm by mass or more, even more preferably 150 ppm by mass or more, and also preferably 1% by mass or less, more preferably 5000 ppm by mass or less, and even more preferably 1000 ppm by mass or less. When the total concentration of metal M is within the above range, the flux effect during firing promotes the condensation of bonded silanol groups, reducing the number of remaining silanol groups and thus lowering the dielectric loss tangent.

[0053] In the hollow silica particles of this composition 1, the metal M is at least Na, and it is preferable that the Na content is less than 1000 ppm by mass. In other words, in this composition 1, the SiO in the hollow silica particles is ２ It is particularly preferable that the content is 99% by mass or more, and the Na content is less than 1000 ppm by mass. In this case, not only is the above-described mechanism of action more easily expressed, but the hollow silica particles have an excellent balance of electrical properties and strength, and cracking is also easily suppressed. The composition of the shell layer of the hollow silica particles can be measured by ICP emission spectrometry or flame atomic absorption spectrometry, etc.

[0054] The hollow silica particles are preferably obtained by a manufacturing method that includes, for example, preparing an oil-in-water emulsion in which the oil phase is dispersed in water, containing an aqueous phase, an oil phase, and a surfactant; obtaining a hollow silica precursor in which a shell layer containing silica is formed on the outer circumference of the core in this oil-in-water emulsion; removing the core from this precursor; and heat-treating it. Specifically, the method described in International Publication No. 2023 / 100676 is preferred. When alkali metal silicates are used as the silica raw material for forming the shell layer, the amount of carbon (C) component derived from the raw material in the shell layer of the resulting hollow silica particles will be less compared to when silicon alkoxides are used as the silica raw material.

[0055] The pore volume of the hollow silica particles is set to 0.2 cm² from the viewpoint of suppressing moisture adsorption and not degrading the electrical properties of the cured product of Composition 1. ３ It is preferable that the amount is less than or equal to / g. The pore volume is determined by the BJH method based on nitrogen adsorption using a specific surface area and pore distribution measuring device (for example, "BELSORP-mini II" from Microtrac-Bel, "Tristar II" from Micromeritic, etc.).

[0056] The surface of the hollow silica particles may be treated with a silane coupling agent. In this case, the amount of silane coupling agent attached is preferably in the range of 1 to 10 parts by mass per 100 parts by mass of hollow silica particles. When the surface of the hollow silica particles is treated with a silane coupling agent, the amount of remaining surface silanol groups is reduced, the surface becomes hydrophobic, moisture adsorption is suppressed and dielectric loss can be improved, and the affinity with the epoxy resin in Composition 1 is increased, making it easier to disperse and improving the strength of the cured product of Composition 1. Examples of silane coupling agents include aminosilane coupling agents, epoxysilane coupling agents, mercaptosilane coupling agents, silane coupling agents, organosilazane compounds, etc. These may be used individually or in combination of two or more. The treatment of the surface of the hollow silica particles with a silane coupling agent can be confirmed by detecting peaks due to substituents of the silane coupling agent using IR. The amount of silane coupling agent attached can be measured by the amount of carbon.

[0057] The relative permittivity of hollow silica particles at 1 GHz is preferably 1.0 to 5.0, and more preferably 1.3 to 3.5. Furthermore, the dielectric loss tangent of hollow silica particles at 1 GHz is preferably 0.0001 to 0.05. The relative permittivity and dielectric loss tangent can be measured, for example, using a Keycom "Vector Network Analyzer E5063A" by the perturbation resonator method.

[0058] The silica particle content in the entire composition 1 is preferably 40% by volume or more, and more preferably 50% by volume or more. The silica particle content is preferably 80% by volume or less. In the case where the silica particles include solid silica particles and hollow silica particles, the silica particle content refers to the total content of solid silica particles and hollow silica particles. The epoxy resin content, including bisphenol C type epoxy resin, in the entire composition 1 is preferably 10% by mass or more, and more preferably 20% by mass or more. The epoxy resin content is preferably 40% by mass or less. The curing agent content in the entire composition 1 is preferably 5% by mass or more. The curing agent content is preferably 15% by mass or less, and more preferably 10% by mass or less. Furthermore, in the composition 1, the ratio of the volume percentage of epoxy resin to the volume percentage of silica particles is preferably 0.5 or more and 1 or less, and more preferably 0.6 or more and 0.9 or less. When such a ratio is within the above range, not only is the above-described mechanism of action more easily manifested, but the silica particles and epoxy resin in composition 1 exhibit excellent dispersibility, and the properties based on the silica particles are more easily exhibited in the cured product of composition 1 (including molded products such as films).

[0059] Composition 1 may further contain a curing accelerator as needed. Examples of curing accelerators include cycloamidine compounds such as 1,8-diazabicyclo[5.4.0]undecene-7, 1,5-diazabicyclo[4.3.0]nonene, and 5,6-dibutylamino-1,8-diazabicyclo[5.4.0]undecene-7; tertiary amine compounds such as triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, and tris(dimethylaminomethyl)phenol; 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, and 1-methylimidazole. Examples of conventionally known compounds used in the curing of epoxy resins include imidazole compounds such as benzoyl-2-phenylimidazole, 1-benzyl-2-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,4-diamino-6-(2'-methylimidazolyl-(1'))-ethyl-s-triazine, and 2-heptadecylimidazole; and phenylboron salts such as 2-ethyl-4-methylimidazole tetraphenylborate and N-methylmorpholine tetraphenylborate. These may be used individually or in combination of two or more. If composition 1 contains a curing accelerator, its content is not particularly limited and can be appropriately selected as long as it is an amount that exhibits a curing-accelerating effect between the epoxy resin and the curing agent. For example, it is preferably 0.1 to 40% by mass relative to the total amount of epoxy resin and curing agent.

[0060] Composition 1 may further contain a coupling agent. When a coupling agent is included, the interfacial adhesion between the epoxy resin constituting Composition 1 and the silica particles, and the interfacial adhesion between Composition 1 and the components of electronic parts tend to become stronger, and the filling properties also tend to improve. Examples of coupling agents include aminosilanes having one or more selected from the group consisting of primary, secondary, and tertiary amino groups; epoxysilanes such as β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-glycidoxypropylmethyldimethoxysilane; silane compounds such as mercaptosilane, alkylsilane, ureidosilane, and vinylsilane; titanium compounds; aluminum chelates; and aluminum / zirconium compounds. These may be used individually or in combination of two or more. Among these, silane compounds are preferred from the viewpoint of reactivity with silica particles. If composition 1 contains a coupling agent, its content is preferably 0.05 to 10% by mass relative to the total mass of the epoxy resin and curing agent constituting composition 1.

[0061] Composition 1 may further contain a plasticizer as needed. When a plasticizer is included, the thermal shock resistance of Composition 1 and the stress on semiconductor elements are easily reduced. Examples of plasticizers include rubber particles such as styrene-butadiene rubber, nitrile-butadiene rubber, butadiene rubber, urethane rubber, acrylic rubber, and silicone rubber. These may be used individually or in combination of two or more. The average primary particle diameter of such rubber particles is preferably 0.05 to 10 μm, and more preferably 0.1 to 5 μm. When the average primary particle diameter is within the above range, the dispersibility in the resin composition and the stress reduction effect are easily improved, and the penetration into fine gaps and fluidity of Composition 1 are improved, making it easier to suppress the occurrence of voids and unfilled portions. When Composition 1 further contains a plasticizer, its content is preferably 1 to 30% by mass relative to the total components of Composition 1 other than silica particles.

[0062] Composition 1 may further contain an ion trapping agent as needed. When an ion trapping agent is included, the migration resistance, moisture resistance, and high-temperature storage characteristics of semiconductor devices such as ICs to which Composition 1 is applied tend to improve.

[0063] Composition 1 may further contain other additives, such as colorants, leveling agents, surfactants, inorganic fillers, thixotropic agents, viscosity modifiers, defoaming agents, weathering agents, antioxidants, heat stabilizers, lubricants, antistatic agents, whitening agents, conductive agents, mold release agents, and flame retardants, to the extent that they do not impair the effects of the present invention.

[0064] Composition 1 is obtained by mixing silica particles in which D50 is within the specified range described above, an epoxy resin containing bisphenol C type epoxy resin, a curing agent, black particles in which D50 is within the specified range described above, and additives as needed. Composition 1 may be obtained by mixing the silica particles, epoxy resin, curing agent, and black particles all at once, or by mixing them in multiple stages. When mixing, it is preferable to mix in such a way that the total mass of the silica particles, epoxy resin, curing agent, black particles, and any additives added as needed does not change substantially, and it is preferable to mix in a closed system. As a result, a composition 1 is obtained in which each component is uniformly mixed and highly degassed.

[0065] The mixing apparatus for obtaining Composition 1 is not particularly limited as long as it can sufficiently disperse and mix each component. Examples include stirring devices equipped with blades such as Henschel mixers, pressure kneaders, Banbury mixers, and planetary mixers; grinding devices equipped with media such as ball mills, attritors, basket mills, sand mills, sand grinders, Dino mills, disper mats, SC mills, spike mills, and agitator mills; and dispersion devices equipped with other mechanisms such as roll mills, microfluidizers, nanomizers, ultimateizers, ultrasonic homogenizers, desolvers, dispersers, high-speed impellers, thin-film swirling high-speed mixers, rotational and revolving agitators, and V-type mixers. The mixing method may be batch or continuous.

[0066] The content of bisphenol C type epoxy resin in the total amount of epoxy resin in Composition 2 is 25% by mass or more. Preferably, the content is 30% by mass or more. Furthermore, it is preferable that the content is 60% by mass or less, and preferably 50% by mass or less. The physical properties (viscosity, epoxy equivalent, chlorine content, etc.) and molecular structure of the bisphenol C type epoxy resin in Composition 2 are the same as those of the bisphenol C type epoxy resin in Composition 1, including preferred embodiments.

[0067] The content of glycidylamine-type epoxy resin in the total amount of epoxy resin in Composition 2 is 25% by mass or more. Preferably, the content is 30% by mass or more. Preferably, the content is 80% by mass or less, and preferably 60% by mass or less. The epoxy group equivalent of the glycidylamine-type epoxy resin in Composition 2 is preferably 75 to 250 g / eq, and more preferably 75 g / eq or more and less than 125 g / eq. Preferably, each glycidylamine-type epoxy resin in Composition 2 is an epoxy resin having two or more epoxy groups in one molecule. Furthermore, the glycidylamine-type epoxy resin is preferably liquid at 25°C, and preferably has a viscosity of 0.0001 to 10 Pa·s as measured by an E-type viscometer at 25°C.

[0068] In Composition 2, the content of bisphenol C type epoxy resin and the content of glycidylamine type epoxy resin in relation to the total amount of epoxy resin are each 25% by mass or more. In other words, the total content of bisphenol C type epoxy resin and glycidylamine type epoxy resin in relation to the total amount of epoxy resin in Composition 2 is 50% by mass or more. The total content is preferably 55 to 100% by mass, and more preferably 60 to 100% by mass. Furthermore, the ratio of the content of bisphenol C type epoxy resin to the content of glycidylamine type epoxy resin is preferably 0.5 to 2.5, and more preferably 0.8 to 1.2. In this case, the above-described mechanism of action is likely to be significantly expressed.

[0069] The epoxy resin in Composition 2 may further contain other epoxy resins other than bisphenol C type epoxy resin and glycidylamine type epoxy resin. Examples of such other epoxy resins include the other epoxy resins exemplified in Composition 1.

[0070] The curing agent in Composition 2 is the same as the curing agent in Composition 1, including in preferred embodiments. Furthermore, the equivalent ratio of epoxy resin to curing agent in Composition 2 (number of functional groups that can react with epoxy in the curing agent / number of functional groups in the epoxy resin) is the same as the equivalent ratio in Composition 1, including in preferred embodiments.

[0071] Composition 2 may further contain components other than bisphenol C type epoxy resin, glycidylamine type epoxy resin, curing agent, and silica particles having an average particle size (D50) of 0.01 to 10 μm. Examples of such components include the black particles, curing accelerator, coupling agent, plasticizer, ion trapping agent, and other additives (colorants, leveling agents, surfactants, inorganic fillers different from the silica particles described above, thixotropic agents, viscosity modifiers, defoaming agents, weathering agents, antioxidants, heat stabilizers, lubricants, antistatic agents, whitening agents, conductive agents, mold release agents, flame retardants, etc.) found in Composition 1, and their preferred embodiments are the same as those of Composition 1.

[0072] Composition 2 is obtained by mixing silica particles in which D50 is within the specified range described above, an epoxy resin containing a bisphenol C type epoxy resin and a glycidylamine type epoxy resin, a curing agent, and additives as needed. The mixing to obtain Composition 2 can be carried out in the same manner as the mixing to obtain Composition 1.

[0073] The composition 12 is preferably liquid at room temperature (25°C). The viscosity of the liquid composition 12 is preferably 200 Pa·s or less, and more preferably 100 Pa·s or less. The viscosity of the composition 12 is preferably 0.01 Pa·s or more, and more preferably 0.1 Pa·s or more. In this case, not only is the above-described mechanism of action more easily expressed, but the composition 12 produces less foam, and it is easier to ensure fluidity and permeability that can accommodate the miniaturization of electronic components, the fine pitch of connection terminals of semiconductor elements, and the fine wiring of wiring boards in recent years. In addition, the cured product of the composition 12 becomes denser, and physical properties based on silica particles are more easily expressed. The viscosity of the composition 12 is determined by measuring the composition using a B-type viscometer with an appropriate rotor under conditions of 25°C and a rotation speed of 5 rpm.

[0074] Furthermore, an embodiment of the present composition is a curable composition (hereinafter also referred to as "the present composition 3") comprising an epoxy resin containing an isocyanurate-type epoxy resin, a curing agent having an amino group or an acid anhydride group, and hollow silica particles having an average particle diameter (D50, median diameter) of more than 0.5 μm, wherein the content of the isocyanurate-type epoxy resin in relation to the total amount of the epoxy resin is more than 10% by mass, the content of the hollow silica particles is 2.5% by volume or more, and the proportion of silica particles in relation to the total volume is 40% by volume or more.

[0075] Composition 3 can form a cured product with excellent electrical properties (low dielectric constant, low dielectric loss tangent, etc.) and heat resistance, as well as mechanical properties, insulation, and moisture resistance, and is also easy to handle. Composition 1 can be effectively used in various applications that take advantage of these properties, and can be effectively used in electronic component devices such as encapsulants, build-up films, or underfill materials for semiconductor devices. The reason why Composition 3 can form a cured product with excellent handling properties and excellent electrical properties (low dielectric constant, low dielectric loss tangent, etc.) and heat resistance is not entirely clear, but it is thought to be as follows.

[0076] In the reaction of epoxy resins induced by the action of a curing agent, using an isocyanurate-type epoxy resin with highly flexible epoxy groups tends to result in a dense crosslinking reaction, yielding a cured product with superior epoxy resin properties. On the other hand, curing agents having amino groups or acid anhydride groups generally have high reaction activity and promote sequential reactions. Therefore, if a large amount of silica particles are present in the reaction system, interactions between components occur, easily affecting the properties of the cured product. In particular, if the silica particles include hollow silica particles with a particle size of a certain magnitude or larger, it is thought that the chemical properties, as well as the physical properties of the particles themselves, such as specific gravity and specific surface area, will also be more easily influenced. Composition 3 contains a predetermined amount or more of isocyanurate-type epoxy resin as the epoxy resin, along with a curing agent having amino groups or acid anhydride groups, and a predetermined amount or more of hollow silica particles of a specific particle size. In this case, it is presumed that the properties of the isocyanurate-type epoxy resin, the activity of the curing agent, and the morphological properties of the hollow silica particles are balanced, and the formation of the cured product proceeds while the interactions between components are maintained throughout the reaction. As a result, it is believed that a cured product containing an epoxy resin with a high glass transition temperature was formed, while the dispersibility of hollow silica particles in composition 3 or its cured product was improved. Therefore, it is believed that a cured product with good electrical properties and heat resistance, etc., based on the epoxy resin and hollow silica particles, was obtained from composition 3. This tendency becomes even more pronounced when the silica particles include solid silica particles.

[0077] Furthermore, an embodiment of the present composition is a curable composition (hereinafter also referred to as "the present composition 4"; the present composition 3 and the present composition 4 are collectively referred to as "the present composition 34") that comprises an epoxy resin containing an isocyanurate-type epoxy resin and a glycidylamine-type epoxy resin, a curing agent having an amino group or an acid anhydride group, and silica particles, wherein the content of the isocyanurate-type epoxy resin and the glycidylamine-type epoxy resin in relation to the total amount of the epoxy resin is each greater than 10% by mass, the sum of the content of the isocyanurate-type epoxy resin and the glycidylamine-type epoxy resin in relation to the total amount of the epoxy resin is greater than 50% by mass, and the proportion of silica particles in relation to the total volume is 40% by volume or more.

[0078] Composition 4 can form a cured product with excellent electrical properties (low dielectric constant, low dielectric loss tangent, etc.) and heat resistance, as well as mechanical properties, insulation, and moisture resistance. Furthermore, it has particularly low viscosity, excellent pot life, and excellent handling properties. Composition 2 can be effectively used in various applications that take advantage of these properties, and can be effectively used in electronic component devices such as encapsulants, build-up films, or underfill materials for semiconductor devices. The reason why Composition 4 can form a cured product with excellent handling properties and excellent electrical properties (low dielectric constant, low dielectric loss tangent, etc.) and heat resistance is not entirely clear, but it is thought to be as follows.

[0079] In the reaction of epoxy resins induced by the action of a curing agent, when an isocyanurate-type epoxy resin with highly flexible epoxy groups is used in combination with a glycidylamine-type epoxy resin that can be considered highly polar, the latter epoxy resin tends to suppress viscosity increase, allowing for a dense crosslinking reaction and resulting in a cured product with superior epoxy resin properties. In this composition 2, during this crosslinking reaction, the curing agent having amino groups or acid anhydride groups generally has high reaction activity and promotes a sequential reaction. Therefore, it is thought that the epoxy resin and silica particles hybridize as curing progresses, incorporating silica particles present in the reaction system to a high degree. Consequently, it is believed that a cured product with good electrical properties and heat resistance, etc., based on the epoxy resin and silica particles, was obtained from this composition 4.

[0080] Composition 3 contains an isocyanurate-type epoxy resin as the epoxy resin, and the content of the isocyanurate-type epoxy resin in relation to the total amount of epoxy resin is more than 10% by mass. Preferably, the content of the isocyanurate-type epoxy resin in relation to the total amount of epoxy resin is 15% by mass or more, and more preferably 20% by mass or more. Such a content is preferably 50% by mass or less, and more preferably 40% by mass or less. When the content of the isocyanurate-type epoxy resin in relation to the total amount of epoxy resin is within the above range, the above-described mechanism of action is easily expressed, composition 1 has excellent handling properties and penetration into narrow gaps, and the cured product of composition 3 tends to have excellent electrical properties and heat resistance.

[0081] The isocyanurate-type epoxy resin in Composition 3 is preferably an epoxy resin having epoxy groups and isocyanurate rings. More preferably, the isocyanurate-type epoxy resin is an epoxy resin having epoxy groups and isocyanurate rings, and the epoxy groups and isocyanurate rings are linked by a chain-type hydrocarbon group having 1 or more carbon atoms. The isocyanurate-type epoxy resin may be solid or liquid at room temperature (25°C), but it is preferably liquid. Being liquid at room temperature provides good handling, good compatibility with the curing agent and hollow silica particles of a specific average particle size that constitute Composition 3, and the cured product of Composition 3 tends to have excellent electrical properties (low dielectric constant, low dielectric loss tangent, etc.) and heat resistance.

[0082] It is preferable that isocyanurate-type epoxy resins do not have carbon-oxygen single bonds other than epoxy groups within their molecules. Furthermore, the number of epoxy groups in the molecule of an isocyanurate-type epoxy resin is preferably two or more, and more preferably three. When the number of epoxy groups in the molecule of an isocyanurate-type epoxy resin is two or more, "the epoxy group and the isocyanurate ring are linked by a chain hydrocarbon group having one or more carbon atoms" means that at least one epoxy group in the molecule is linked by a chain hydrocarbon group having one or more carbon atoms. When an isocyanurate-type epoxy resin has two epoxy groups, it is preferable that the two epoxy groups in the molecule are linked by a chain hydrocarbon group having one or more carbon atoms. When an isocyanurate-type epoxy resin has three epoxy groups, it is preferable that two or more, preferably three, epoxy groups in the molecule are linked by a chain hydrocarbon group having one or more carbon atoms. When there are two or more chain hydrocarbon groups having one or more carbon atoms linking the epoxy group and the isocyanurate ring in one molecule, each chain hydrocarbon group may be the same or different from one another.

[0083] The chain hydrocarbon group having one or more carbon atoms may be linear or branched, and may be saturated or unsaturated hydrocarbon groups. The number of carbon atoms in such a chain hydrocarbon group is preferably two or more. The number of carbon atoms is preferably five or less, and more preferably four or less. Examples of chain hydrocarbon groups having one or more carbon atoms include linear alkylene groups having 1 to 5 carbon atoms, and branched alkylene groups having one or more branched chains of 1 to 5 carbon atoms attached to these linear alkylene groups. Such chain hydrocarbon groups may further have substituents such as phenyl groups and hydroxyl groups. Note that the number of carbon atoms in the chain hydrocarbon group linking the epoxy group and the isocyanurate ring refers to the number of carbon atoms on the main chain, i.e., on the chain linking the epoxy group and the isocyanurate group, and does not include the number of carbon atoms in the branched chains and substituents. Among these, isocyanurate-type epoxy resins in which the epoxy group and the isocyanurate ring are linked by a chain hydrocarbon group having two or more carbon atoms are preferred from the viewpoint of being easily liquid and having excellent handling properties.

[0084] The epoxy equivalent of the isocyanurate-type epoxy resin is preferably 100 to 300 g / eq, and more preferably 120 to 160 g / eq. In this case, composition 3 is easy to handle and the heat resistance of the cured product of composition 3 is easily improved. The viscosity of the isocyanurate-type epoxy resin at 25°C is preferably 50 Pa·s or less, and more preferably 10 Pa·s or less. Examples of such isocyanurate-type epoxy resins include triglycidyl isocyanurate compounds, with 1,3,5-tris(4,5-epoxypentyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione being preferred.

[0085] In the epoxy resin constituting Composition 3, it is preferable that the epoxy resin other than the isocyanurate-type epoxy resin is an epoxy resin having two or more epoxy groups in one molecule. Furthermore, such other epoxy resin may be solid or liquid at room temperature (25°C), and it is more preferable that it be liquid at room temperature from the viewpoint of improving the handling and filling properties of Composition 3. The viscosity of the liquid other epoxy resin is preferably 0.0001 to 10 Pa·s when measured at 25°C using an E-type viscometer. The other epoxy resin is the same as the other epoxy resin in Composition 1.

[0086] The curing agent in this composition 3 is a curing agent having an amino group or an acid anhydride group. Examples of curing agents having an amino group include aromatic amine compounds as exemplified in this composition 1. Examples of curing agents having an acid anhydride group include acid anhydride curing agents as exemplified in this composition 1.

[0087] In particular, it is preferable that the curing agent be one or more selected from aromatic amine compounds or acid anhydride groups. Furthermore, it is more preferable that the curing agent having an amino group is an aromatic amine compound with an active hydrogen equivalent of 40 to 80 g / mol, and even more preferable that it is a bisaniline or diaminobenzene. When these high-temperature curing curing agents are used, the above-described mechanism of action is particularly likely to manifest in the high-temperature range where the fluidity of composition 3 is increased, and the effects such as the electrical properties of the cured product of composition 3 are more likely to manifest. In addition, it is presumed that when the active hydrogen equivalent of the curing agent having an amino group is within the above range, the molecular size is relatively compact and reacts closely with the isocyanurate-type epoxy resin, which has an epoxy group and an isocyanurate ring, and the epoxy group and the isocyanurate ring are linked by a chain-like hydrocarbon group having 1 or more carbon atoms, forming a loose and highly flexible network derived from the high degree of freedom of the epoxy chain, and thus more easily buffering the cracking of hollow silica particles.

[0088] Examples of curing agents having an amino group include the commercially available products exemplified in this composition 1.

[0089] Examples of curing agents having acid anhydride groups include the commercially available products exemplified in Composition 1. Composition 3 may further contain other curing agents, such as phenolic curing agents, that differ from the above-mentioned curing agents having amino groups and curing agents having acid anhydride groups, as long as the effects of the present invention are not impaired.

[0090] Furthermore, it is preferable that the range of the equivalent ratio of epoxy resin to curing agent in composition 3 is the same as the range of the equivalent ratio in composition 1.

[0091] The structure of the hollow silica particles in Composition 3 is the same as that of the hollow silica particles in Composition 1. Because the hollow silica particles have a structure in which there is space within the shell, more space can be secured in the composition containing these particles, and the dielectric constant can be lowered, so Composition 3 can be suitably used in electronic component device applications.

[0092] In composition 3, the content of hollow silica particles is preferably 2.5% by volume or more, and more preferably 5% by volume or more. The content of hollow silica particles is preferably 40% by volume or less, and more preferably 30% by volume or less. When the content of hollow silica particles is within the above range, the above-mentioned effects are more easily expressed, the handling of composition 3 is improved, and the cured product of composition 1 tends to have excellent electrical properties, etc.

[0093] The specific gravity and He density of the hollow silica particles, including preferred ranges, are the same as those of the hollow silica particles in Composition 1. The specific gravity (Ar density) of the hollow silica particles, adjusted by the primary particle diameter and shell thickness, and the hollow particle ratio of the hollow silica particles, measured from the apparent density measured with a dry pycnometer, are the same as those of the hollow silica particles in Composition 1, including preferred ranges.

[0094] The BET specific surface area of ​​hollow silica particles and the specific gravity (Ar density) of hollow silica particles are given by A (g / cm³). ３ ) and the specific surface area of ​​BET is B (m ２ The respective ranges of the product of the two (A × B) when expressed as ( / g) are the same as those of the hollow silica particles in this composition 1, including the preferred range.

[0095] The ranges for the sphericity of the hollow silica particles and the average value of the primary particle size (average primary particle diameter) of the hollow silica particles, including preferred ranges, are the same as those for the hollow silica particles in Composition 1.

[0096] The median diameter (D50) of the secondary particles (aggregated particles) of the hollow silica particles is greater than 0.5 μm. More preferably, D50 is 0.7 μm or more. Preferably, D50 is 5 μm or less, more preferably 4 μm or less, and even more preferably 3 μm or less. When D50 is within the above range, not only is the above-described mechanism of action more easily expressed, but the dispersion stability of the hollow silica particles in composition 3 is easily improved, and the increase in viscosity of the composition is easily suppressed. In addition, granularity in the cured product of composition 3 is easily reduced.

[0097] Furthermore, the coarse particle size (D90) of the secondary particles of the hollow silica particles is preferably 1 to 30 μm. More preferably, D90 is 3 μm or more, and even more preferably 5 μm or more. More preferably, D90 is 25 μm or less, and even more preferably 20 μm or less. When D90 is within the above range, it is easier to increase the productivity of hollow silica particles and to reduce granularity in the cured product of composition 3.

[0098] Shell thickness of hollow silica particles, and SiO ２ The respective ranges of content, including preferred ranges, are the same as those for the hollow silica particles in Composition 1. Also, in the hollow silica particles, SiO ２ The types of other residues, and their content, including their preferred ranges, are the same as those of the hollow silica particles in this composition 1. Furthermore, the pore volume of the hollow silica particles, including their preferred ranges, is the same as that of the hollow silica particles in this composition 1.

[0099] The surface of the hollow silica particles may be treated with a silane coupling agent. In this case, the amount of silane coupling agent applied is preferably in the range of 1 to 10 parts by mass per 100 parts by mass of hollow silica particles. When the surface of the hollow silica particles is treated with a silane coupling agent, the amount of remaining surface silanol groups is reduced, the surface becomes hydrophobic, moisture adsorption is suppressed and dielectric loss can be improved, and the affinity with the epoxy resin in Composition 3 is increased, making it easier to improve dispersibility and thus improving the strength of the cured product of Composition 3. The embodiment of the silane coupling agent is the same as the embodiment of the silane coupling agent in Composition 1.

[0100] The relative permittivity and dielectric loss tangent of the hollow silica particles at 1 GHz, including preferred ranges, are the same as those of the hollow silica particles in Composition 1.

[0101] Composition 3 may further contain solid silica particles. A configuration in which Composition 3 includes both solid silica particles and hollow silica particles is more preferable from the viewpoint of further improving the electrical properties of the cured product of Composition 3. The solid silica particles may be surface-treated with a silane coupling agent.

[0102] When composition 3 includes solid silica particles and hollow silica particles as silica particles, the ratio of hollow silica particles to the total amount of solid silica particles and hollow silica particles is preferably more than 1 volume%, more preferably 5 volume% or more, even more preferably 10 volume% or more, and particularly preferably 15 volume% or more. Such a ratio is preferably less than 50 volume%. When the ratio of hollow silica particles to the total amount of solid silica particles and hollow silica particles is within the above range, it is more preferable from the viewpoint of further improving the electrical properties of the cured product of composition 3. The silica constituting the silica particles may be fused silica or crystalline silica. The average particle diameter (D50) of solid silica particles is preferably 0.01 μm or more and 10 μm or less. The D50 of solid silica particles is preferably 0.1 μm or more and more preferably 0.2 μm or more. The average particle diameter (D50) of solid silica particles is preferably 4 μm or less and more preferably 3 μm or less. The specific gravity of solid silica particles is 1.6 g / cm³. ３ 2.2g / cm or more ３ Preferably, it is 1.8 g / cm³. ３ 2.2g / cm or more ３ It is more preferable that it be less than . In this specification, solid silica particles refer to particles with a hollow ratio of less than 10%, and are distinguished from hollow silica particles by their hollow ratio.

[0103] The ratio of the average particle diameter (D50) of hollow silica particles to the average particle diameter (D50) of solid silica particles is preferably 0.1 to 10, and more preferably the average particle diameter (D50) of solid silica particles is smaller than the average particle diameter (D50) of hollow silica particles. Note that D50 of hollow silica particles refers to the D50 of the secondary particles of hollow silica particles as described above. If D50 of solid silica particles is larger than D50 of hollow silica particles, the ratio is more preferably 0.1 to 0.8. In this case, it is presumed that the solid silica particles have the effect of buffering the stress generated in the composition 3, and also promote the flow of hollow silica particles, which are smaller than the solid silica particles, making them easier to homogenize. Therefore, the packing performance of silica particles when mounting the composition 3 to electronic component devices, etc., is easily improved, and the fluidity into narrow gaps is also easily improved. When the D50 of solid silica particles is smaller than the D50 of hollow silica particles, it is more preferable that the ratio of the D50 of hollow silica particles to the D50 of solid silica particles is 2 to 10. In this case, it is presumed that the solid silica particles, which are in a loosely aggregated state, will buffer the stress acting on the composition 3, and will also easily flow and homogenize among the hollow silica particles, which are larger than the solid silica particles. Therefore, the packing of silica particles when mounting the composition 3 into electronic components and the like is easily improved, and the fluidity into narrow gaps is also easily improved.

[0104] The silica particle content relative to the entire composition 3, in other words, the proportion of silica particles in the total volume, is 40% by volume or more. When the composition 3 contains both solid and hollow silica particles as silica particles, the silica particle content relative to the entire composition 3, in other words, the total content of solid and hollow silica particles in the entire composition 3, is 40% by volume or more, and more preferably 50% by volume or more. The silica particle content is preferably 80% by volume or less. When the silica particle content is within the above range, the composition 3 is easy to handle, and the electrical properties of the cured product are more easily improved. The epoxy resin content relative to the entire composition 3 is preferably 10% by mass or more, and more preferably 20% by mass or more. The epoxy resin content is preferably 40% by mass or less.

[0105] The curing agent content in the total composition 3 is preferably 5% by mass or more. The curing agent content is preferably 15% by mass or less, and more preferably 10% by mass or less. Furthermore, in composition 3, the ratio of the volume percentage of epoxy resin to the total volume percentage of solid silica particles and hollow silica particles is preferably 0.5 or more and 1 or less, and more preferably 0.6 or more and 0.9 or less. When this ratio is within the above range, not only is the above-mentioned mechanism of action more easily expressed, but the silica particles and epoxy resin in composition 3 are more easily dispersed, and the properties based on the silica particles are more easily exhibited in the cured product of composition 3 (including molded products such as films).

[0106] Composition 3 may further contain a curing accelerator as needed. Examples of curing accelerators include those exemplified in Composition 1. When Composition 3 contains a curing accelerator, its content is not particularly limited and can be appropriately selected as long as it is an amount that exhibits a curing-accelerating effect between the epoxy resin and the curing agent. For example, it is preferably 0.1 to 40% by mass relative to the total amount of epoxy resin and curing agent.

[0107] Composition 3 may further contain a coupling agent. When a coupling agent is included, the interfacial adhesion between the epoxy resin constituting Composition 3 and the silica particles, and the interfacial adhesion between Composition 3 and the components of the electronic component tend to become stronger, and the filling properties also tend to improve. Examples of coupling agents include those exemplified in Composition 1. When Composition 3 contains a coupling agent, its content is preferably 0.05 to 10% by mass relative to the total mass of the epoxy resin and curing agent constituting Composition 3.

[0108] Composition 3 may further contain a plasticizer as needed. When a plasticizer is included, the thermal shock resistance of Composition 3 and the stress on semiconductor devices are easily reduced. The form of the plasticizer is the same as that of the flexible agent exemplified in Composition 1. When Composition 3 further contains a plasticizer, its content is preferably 1 to 30% by mass relative to the total components of Composition 3 other than silica particles.

[0109] Composition 3 may further contain an ion trapping agent as needed. When an ion trapping agent is included, the migration resistance, heat resistance, and high-temperature storage characteristics of semiconductor devices such as ICs to which Composition 3 is applied tend to improve.

[0110] Composition 3 may further contain other additives, such as colorants, leveling agents, surfactants, inorganic fillers different from the silica particles described above, thixotropic agents, viscosity modifiers, defoaming agents, weathering agents, antioxidants, heat stabilizers, lubricants, antistatic agents, whitening agents, conductive agents, mold release agents, and flame retardants, to the extent that they do not impair the effects of the present invention.

[0111] Composition 3 is obtained by mixing the above-mentioned silica particles, an epoxy resin containing an isocyanurate-type epoxy resin, a curing agent having an amino group or an acid anhydride group, and additives as needed. Composition 3 may be obtained by mixing the silica particles, epoxy resin, and curing agent all at once, or by mixing them in multiple stages. When mixing, it is preferable to mix in such a way that the total mass of the silica particles, epoxy resin, curing agent, and any additives added as needed does not change substantially, and it is preferable to mix in a closed system. As a result, a composition 3 is obtained in which each component is uniformly mixed and highly degassed.

[0112] An example of a mixing apparatus for obtaining composition 3 is the same apparatus listed as the mixing apparatus for obtaining composition 1.

[0113] The content of isocyanurate-type epoxy resin in the total amount of epoxy resin in Composition 4 is more than 10% by mass, preferably 15% by mass or more, and more preferably 20% by mass or more. The content is preferably 60% by mass or less, and more preferably 50% by mass or less. The physical properties (viscosity, epoxy equivalent, etc.) and molecular structure of the isocyanurate-type epoxy resin in Composition 4 are the same as those of the isocyanurate-type epoxy resin in Composition 3, including preferred embodiments.

[0114] The content of glycidylamine-type epoxy resin in the total amount of epoxy resin in Composition 4 is more than 10% by mass, preferably 20% by mass or more, and more preferably 30% by mass or more. The content is preferably 85% by mass or less, and more preferably 80% by mass or less. The epoxy group equivalent of the glycidylamine-type epoxy resin in Composition 4 is preferably 75 to 250 g / eq, and more preferably 75 g / eq or more and less than 125 g / eq. The glycidylamine-type epoxy resin in Composition 2 is preferably an epoxy resin having two or more epoxy groups in one molecule. Furthermore, the glycidylamine-type epoxy resin is preferably liquid at 25°C, and its viscosity, as measured at 25°C using an E-type viscometer, is preferably 0.0001 to 10 Pa·s.

[0115] In this composition 4, the sum of the content of isocyanurate-type epoxy resin and glycidylamine-type epoxy resin in the total amount of epoxy resin is more than 50% by mass, and preferably between 60% and 90% by mass. Furthermore, it is preferable that the content of glycidylamine-type epoxy resin is greater than the content of isocyanurate-type epoxy resin. In this case, the above-described mechanism of action is more likely to be expressed.

[0116] The epoxy resin in this composition 4 may further contain other epoxy resins other than isocyanurate-type epoxy resins and glycidylamine-type epoxy resins. Such other epoxy resins are the same as the other epoxy resins in this composition 3.

[0117] The silica particles in this composition 4 preferably include hollow silica particles, and more preferably include both hollow silica particles and solid silica particles. The embodiments of each silica particle, including preferred embodiments, are the same as those of the hollow silica particles and solid silica particles in this composition 3.

[0118] The curing agent in Composition 4 is a curing agent having an amino group or an acid anhydride group, and is the same as the curing agent in Composition 3, including in preferred embodiments. Furthermore, the equivalent ratio of epoxy resin to curing agent in Composition 4 (number of functional groups in the curing agent that can react with epoxy / number of functional groups in the epoxy resin) is the same as the equivalent ratio in Composition 3, including in preferred embodiments.

[0119] Composition 4 may further contain components other than isocyanurate-type epoxy resin, glycidylamine-type epoxy resin, a curing agent having an amino group or an acid anhydride group, and silica particles. Examples of such components include curing accelerators, coupling agents, plasticizers, ion trapping agents, and other additives (colorants, leveling agents, surfactants, inorganic fillers different from the silica particles described above, thixotropic agents, viscosity modifiers, defoaming agents, weathering agents, antioxidants, heat stabilizers, lubricants, antistatic agents, whitening agents, conductive agents, mold release agents, flame retardants, etc.) in Composition 3, and their preferred embodiments are the same as in Composition 3.

[0120] Composition 4 is obtained by mixing silica particles, an epoxy resin containing a bisphenol C type epoxy resin and a glycidylamine type epoxy resin, a curing agent, and additives as needed. The mixing to obtain Composition 4 can be carried out in the same manner as the mixing to obtain Composition 3.

[0121] The composition 34 is preferably liquid at room temperature (25°C). The viscosity of the liquid composition 34 is preferably 200 Pa·s or less, and more preferably 100 Pa·s or less. The viscosity of the composition 34 is preferably 0.01 Pa·s or more, and more preferably 0.1 Pa·s or more. In this case, not only is the above-described mechanism of action more easily expressed, but the composition 34 produces less foam, and it is easier to ensure fluidity and permeability that can accommodate the miniaturization of electronic components, the fine pitch of connection terminals of semiconductor elements, and the fine wiring of wiring boards in recent years. In addition, the cured product of the composition 34 becomes denser, and physical properties based on silica particles are more easily expressed. The viscosity of the composition 34 is determined by measuring the composition using a B-type viscometer with an appropriate rotor under conditions of 25°C and a rotation speed of 5 rpm.

[0122] This composition can be used for electronic component devices such as encapsulants, build-up films, and underfill materials for semiconductor devices, and is preferably used as an encapsulant or underfill material for semiconductor devices. For example, a specific example of using this composition as an underfill material is to apply this composition to one end of a semiconductor element while maintaining a substrate equipped with a semiconductor element at 70 to 130°C, fill the gap between the substrate and the semiconductor element with the composition by capillary action, and then seal the gap between the substrate and the semiconductor element by curing the composition while maintaining the substrate at 80 to 200°C. The filling time is preferably within 1200 seconds. The curing time of this composition is preferably 0.1 to 6 hours.

[0123] This composition can be suitably used as a encapsulant, build-up film, or underfill material for semiconductor devices in which electronic components such as semiconductor chips, transistors, diodes, thyristors, capacitors, resistors, resistor arrays, coils, and switches are mounted on support members such as lead frames, pre-wired tape carriers, rigid and flexible wiring boards, glass, and silicone wafers. In particular, it is suitable as an underfill material for flip-chip devices, and specifically, it can be suitably used as an underfill material for semiconductor devices such as flip-chip BGA / LGA and COF (Chip On Film), in which semiconductor elements are flip-chip bonded by bump connection to wiring formed on rigid and flexible wiring boards or glass. In other words, the present invention also includes encapsulants, build-up films, or underfill materials for semiconductor devices made from this composition.

[0124] The present invention also relates to a cured product of the composition. The cured product of the composition may be a cured product used as a encapsulant or underfill material for the semiconductor device described above, or it may be in the form of a molded product such as the build-up film described above.

[0125] The relative permittivity (Dk) of the cured product of this composition is preferably 3.5 or less, more preferably 3.1 or less, at a frequency of 10 GHz. The relative permittivity is preferably 1.5 or more. Furthermore, the dielectric loss tangent (Df) of the cured product of this composition is preferably 0.022 or less, more preferably 0.020 or less, even more preferably 0.018 or less, and particularly preferably 0.015 or less, at a frequency of 10 GHz. When the relative permittivity and dielectric loss tangent of the cured product at a frequency of 10 GHz are within the above ranges, the electrical properties are excellent, and transmission loss in the circuit is easily suppressed. The relative permittivity and dielectric loss tangent can be measured, for example, using the apparatus described in the examples.

[0126] The average linear expansion coefficient of the cured product of this composition is preferably 10 to 80 ppm / °C. When the average linear expansion coefficient is within the above range, the electrical properties tend to be excellent. The average linear expansion coefficient is determined using a thermomechanical analyzer (for example, "TMA7100" manufactured by Hitachi High-Tech Science Corporation), by heating the cured product under a load of 98 mN and a heating rate of 5°C / min, measuring the temperature increase from 25°C to 230°C using the compression method, and obtaining the linear expansion coefficient from the tangent slope from 80°C to 100°C.

[0127] The glass transition temperature (Tg) of the cured product of composition 3 is preferably 110°C or higher, and more preferably 120°C or higher. A Tg of 250°C or lower is also preferable. When Tg is within this range, the cured product of composition 3 tends to exhibit excellent heat resistance, mechanical properties, etc. The glass transition temperature (Tg) of the cured product can be determined by using a thermomechanical analyzer (for example, Hitachi High-Tech Science's "DMA7100"), heating the cured product at a frequency of 1 Hz and a heating rate of 3°C / min, measuring the temperature increase from 25°C to 250°C using the three-point bending method, and reading the peak temperature of tanδ, which is the ratio of the storage modulus to the loss modulus. Alternatively, Tg may be determined using a thermomechanical analyzer (for example, Hitachi High-Tech Science's "TMA7100"), by heating the above-mentioned cured material with a load of 98 mN and a heating rate of 5°C / min, measuring the temperature from 25°C to 230°C using the compression method, and reading the temperature at the intersection of the tangent lines before and after the inflection point of the resulting chart.

[0128] Although the present composition and its cured product have been described above, the present invention is not limited to the configuration of the embodiments described above. For example, the present composition and its cured product (including molded products such as films) may have other arbitrary configurations added to the configuration of the above embodiments, or may be replaced with any arbitrary configuration that performs similar functions.

[0129] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. 1. Preparation of each component [Silica particles] Silica particle 1: Solid silica particle, "SO-C2" manufactured by Admatex, Inc., median diameter (D50) 0.5 μm Silica particle 2: Hollow silica particle, "HS-200" manufactured by AGC Inc., median diameter (D50) 2.0 μm Silica particle 3: Hollow silica particle, "HS-070" manufactured by AGC Inc., median diameter (D50) 0.5 μm The median diameter (D50) of the silica particles was measured using a diffraction scattering particle distribution analyzer (MT3300) manufactured by Microtrac-Bell, Inc., and the median value (median diameter, D50) of the particle distribution (diameter) was measured. The measurement was performed twice and the average value was calculated.

[0130] [Epoxy Resins] Epoxy Resin 1: Mitsubishi Chemical Corporation's "jER806", bisphenol F type epoxy resin, epoxy group equivalent 167 g / eq Epoxy Resin 2: Mitsubishi Chemical Corporation's "jER630", glycidylamine type epoxy resin, epoxy group equivalent 96 g / eq Epoxy Resin 3: DIC Corporation's "HP-4032D", naphthalene type epoxy resin, epoxy group equivalent 141 g / eq Epoxy Resin 4: Bisphenol C type epoxy resin (bisphenol C type glycidyl ether), epoxy group equivalent 191 g / eq Epoxy Resin 5: Nissan Chemical Industries, Ltd.'s "TEPIC-VL", isocyanurate type epoxy resin, epoxy group equivalent 135 g / eq Epoxy Resin 6: Nissan Chemical Industries, Ltd.'s "TEPIC-FL", isocyanurate type epoxy resin, epoxy group equivalent 185 g / eq

[0131] [Hardening Agents] Hardening agent 1: Amine-based hardening agent. "jER Cure WA" manufactured by Mitsubishi Chemical Corporation, diaminobenzenes, active hydrogen equivalent 45 g / mol Hardening agent 2: Amine-based hardening agent. "Kaya Hard A-A" manufactured by Nippon Kayaku Co., Ltd., bisanilines, active hydrogen equivalent 64 g / mol Hardening agent 1: Acid anhydride-based hardening agent. Resonaq HN-2200, methyltetrahydrophthalic anhydride, active hydrogen equivalent 81-85 g / mol [Black particles] Black particle 1: Mitsubishi Chemical MA-100 (carbon black, average particle size 25 nm) Black particle 2: Ako Chemical Co., Ltd. Tilack D™ B (black titanium oxide, average particle size 0.6 μm) [Other components] Coupling agent: Shin-Etsu Chemical KBM-403 (silane coupling agent) Curing accelerator: 2-ethyl-4-methylimidazole

[0132] 2. Examples of Production of Curable Compositions (Part 1) [Example 1] A curable composition 1 was obtained by mixing parts by mass of silica particles 1 such that silica particles 1 constitute 50% by volume in the composition, parts by mass of epoxy resins such that epoxy resin 1 (bisphenol F type epoxy resin), epoxy resin 2 (glycidylamine type epoxy resin), and epoxy resin 4 (bisphenol C type epoxy resin) are contained in epoxy resins such that the proportions of epoxy resin 1 (35% by mass), epoxy resin 2 (35% by mass), and epoxy resin 4 (30% by mass) in the total epoxy resin, and parts by mass of amine-based curing agent 1 and amine-based curing agent 2 are contained in amine-based curing agent 1 (70% by mass) and amine-based curing agent 2 (30% by mass) in the total curing agent. When mixing, black particles 1 (carbon black) were added in a ratio of 0.5 phr and coupling agent in a ratio of 3.0 phr relative to the total mass of epoxy resin and curing agent. The total content of silica particles, epoxy resin, and curing agent in curable composition 1 was 67% by mass, 24% by mass, and 9% by mass, respectively.

[0133] [Examples 2 to 9] Curable compositions 2 to 9 were obtained by performing the same procedure as in Example 1, except that the type and volume percentage of silica particles, the type and percentage of epoxy resin, the type and percentage of curing agent, and the type of black particles were changed as shown in Table 1.

[0134] 3. Evaluation of Curable Compositions (Part 1) The following evaluations were performed on curable compositions 1 to 9 obtained in Examples 1 to 9. 3-1. Dielectric Loss Tangent (Df) The curable compositions obtained in each example were poured into a mold and molded under conditions of a mold temperature of 150°C and a curing time of 2 hours to obtain plate-shaped cured products (80 mm long, 40 mm wide, 0.2 mm thick). The obtained cured products were used as test pieces, and the dielectric loss tangent (Df) was measured at 25 ± 3°C and 10 GHz using a dielectric constant measuring device "Network Analyzer N5227A" (manufactured by Agilent Technologies), and evaluated according to the following criteria. <Evaluation Criteria for Df> ◎: Df is 0.015 or less ○: Df is greater than 0.015 and 0.018 or less △: Df is greater than 0.018 and 0.020 or less ×: Df is greater than 0.020

[0135] 3-2. Moisture Resistance The curable compositions obtained in each example were poured into a mold and molded under the conditions of a temperature of 150°C and a curing time of 2 hours to obtain cured discs. The mass of the obtained discs was measured (M ０ ) and leave at 85°C, 85% RH for 168 hours, then measure the mass again (M １ The moisture absorption rate was calculated using the following formula, and the moisture resistance was evaluated according to the following criteria. Moisture absorption rate (mass%) = 100 × (M １ -M ０ ) / M ０ <Evaluation Criteria> ◎: Moisture absorption rate is 1.8% by mass or less ○: Moisture absorption rate is greater than 1.8% by mass and 2.0% by mass or less △: Moisture absorption rate is greater than 2.0% by mass and 2.2% by mass or less ×: Moisture absorption rate is greater than 2.2% by mass

[0136] 3-3. Adhesion Strength A 1 mm thick silicone rubber sheet with a 3 mm diameter hole was placed on a 30 mm square copper plate, which served as the adherend. The curable composition obtained in each example, filled with a syringe, was injected into the hole and cured at a temperature of 150°C for 2 hours to form a cylindrical cured object. The adhesion between this cured object and the adherend was evaluated using a Nordson T&I 4000 Plus bond tester manufactured by Nordson Advanced Technologies. The measurement conditions were a measurement speed of 50 μm / s and a measurement height of 50 μm. The maximum load at which the adhesive surface of the test piece broke and the test piece separated from the adherend was measured. The maximum load at which separation occurred was divided by the adhesive area to calculate the value for three test pieces, and the average value of the three points was taken as the adhesion strength. <Evaluation Criteria> ◎: Adhesion strength is 10 MPa or higher ○: Adhesion strength is 8.5 MPa or higher but less than 10 MPa △: Adhesion strength is 7.0 MPa or higher but less than 8.5 MPa ×: Adhesion strength is less than 7.0 MPa

[0137] The results are shown in Table 1. The cured products formed from the curable compositions of Examples 1 to 7 exhibit a good balance of dielectric loss tangent, moisture resistance, and adhesive strength.

[0138]

[0139] 4. Examples of production of curable compositions (Part 2) [Examples 10-18] Curable compositions 10-18 were obtained by performing the same procedure as in Example 1, except that the type and volume % of silica particles, the type and content ratio of epoxy resin, the type and content ratio of curing agent, the type of black particles, and the amounts of curing accelerator and coupling agent were as shown in Table 2.

[0140] 5. Evaluation of Curable Compositions (Part 2) The following evaluations were performed on curable compositions 10 to 18 obtained in Examples 10 to 18. 5-1. Dielectric Loss Tangent (Df) Measured and evaluated in the same manner as in 3-1.

[0141] 5-2. Viscosity The viscosity (Pa·s; initial viscosity) of the curable compositions obtained in each example was measured immediately after preparation using a Toki Sangyo Co., Ltd. Type B viscometer "TVB-10" (rotor used: rotor H7), rotated at 25°C and 5 rpm for 1 minute, and evaluated according to the following criteria. <Evaluation Criteria> ○: Initial viscosity is 20.0 Pa·s or less △: Initial viscosity is greater than 20.0 Pa·s and 25.0 Pa·s or less ×: Initial viscosity is greater than 25.0 Pa·s

[0142] 5-3. A test specimen was prepared by fixing a narrow-gap permeable glass plate (length: 60 mm, width: 60 mm) and a glass plate simulating a semiconductor element (length: 20 mm, width: 20 mm) with a gap (length: 20 mm, width: 10 mm) between them using a 50 μm thick tape. The test specimen was placed on a hot plate set to 110°C, and the curable composition obtained in each example, filled with a syringe, was applied to one end of the gap between the horizontally held specimen. The time it took for the gap to be filled with the curable composition was measured and evaluated according to the following criteria: <Evaluation Criteria> ○: Reaching time is 200 seconds or less △: Reaching time is more than 200 seconds but 250 seconds or less ×: Reaching time is more than 250 seconds

[0143] The results are shown in Table 2. The cured products formed from the curable compositions of Examples 10 to 16 exhibit a good balance of dielectric loss tangent, viscosity, and narrow gap penetration properties.

[0144]

[0145] 6. Example of Production of Curable Composition (Part 3) [Example 19] A curable composition 19 was obtained by mixing a portion by mass of silica particles such that the composition contained 45% by volume of solid silica particles 1 and 5% by volume of hollow silica particles 2; epoxy resins such that epoxy resin 1 (bisphenol F type epoxy resin), epoxy resin 2 (glycidylamine type epoxy resin), and epoxy resin 5 (isocyanurate type epoxy resin) were contained in a proportion of 35% by mass for epoxy resin 1, 35% by mass for epoxy resin 2, and 30% by mass for epoxy resin 5 in the total epoxy resin; and curing agents 1 and 2 were contained in a proportion of 70% by mass for curing agent 1 and 30% by mass for curing agent 2 in the total curing agent. When mixing, a coloring agent and a coupling agent were also used so that the black particles 1 amounted to 0.5 phr and the coupling agent amounted to 3.0 phr relative to the total mass of epoxy resin and curing agent. The total content of silica particles, epoxy resin, and curing agent in the curable composition 19 was 67% by mass, 24% by mass, and 9% by mass, respectively.

[0146] [Examples 20 to 29] Curable compositions 20 to 29 were obtained by performing the same procedure as in Example 19, except that the type and volume percentage of silica particles, the type and percentage of epoxy resin, and the type and percentage of curing agent were changed as shown in Table 3.

[0147] 7. Evaluation of Curable Compositions (Part 3) The following evaluations were performed on curable compositions 19 to 29 obtained in Examples 19 to 29. 7-1. Relative Permittivity (Dk) The curable compositions obtained in each example were poured into a mold and molded under conditions of a mold temperature of 150°C and a curing time of 2 hours to obtain plate-shaped cured products (80 mm long, 40 mm wide, 0.2 mm thick). The obtained cured products were used as test pieces, and the relative permittivity (Dk) at 25±3°C and 10 GHz was measured using a dielectric constant measuring device "Network Analyzer N5227A" (manufactured by Agilent Technologies, Inc.), and evaluated according to the following criteria. <Evaluation Criteria for Dk> ◎: Dk is 3.1 or less ○: Dk is greater than 3.1 and 3.3 or less △: Dk is greater than 3.3 and 3.4 or less ×: Dk is greater than 3.4

[0148] 7-2. Viscosity The viscosity (Pa·s; initial viscosity) of the curable compositions obtained in each example immediately after preparation was measured using a Toki Sangyo Co., Ltd. Type B viscometer "TVB-10" (rotor used: rotor H7) by rotating at 25°C and 5 rpm for 1 minute, and evaluated according to the following criteria. <Evaluation Criteria> ◎: Initial viscosity is 15.0 Pa·s or less ○: Initial viscosity is greater than 15.0 Pa·s and 18.0 Pa·s or less △: Initial viscosity is greater than 18.0 Pa·s and 20.0 Pa·s or less ×: Initial viscosity is greater than 20.0 Pa·s

[0149] 7-3. Glass Transition Temperature (Tg) The curable compositions obtained in each example were poured into a mold and molded under the conditions of a mold temperature of 150°C and a curing time of 2 hours to obtain a prismatic cured product (50 mm long, 5 mm wide, and 2 mm thick). The obtained cured product was used as a test piece and heated using a Hitachi High-Tech Science Corporation thermomechanical analyzer "DMA7100" under the conditions of a frequency of 1 Hz and a heating rate of 3°C / min. The temperature was measured from 25°C to 250°C using the three-point bending method, and the glass transition temperature (Tg) was determined by reading the peak temperature of tanδ, which is the ratio of the storage modulus to the loss modulus, and was evaluated according to the following criteria. <Evaluation Criteria> ◎: Tg is 140°C or higher ○: Tg is 120°C or higher and less than 140°C △: Tg is 110°C or higher and less than 120°C ×: Tg is less than 110°C

[0150] The results are shown in Table 3. The curable compositions of Examples 19 to 29 exhibit good viscosity characteristics, and the resulting cured products have excellent dielectric constant and can achieve high Tg.

[0151]

[0152] 8. Examples of production of curable compositions (Part 4) [Examples 30 to 35] Curable compositions 30 to 35 were obtained by performing the same procedure as in Example 19, except that the type and volume percentage of silica particles, the type and percentage of epoxy resin, and the type and percentage of curing agent were changed as shown in Table 4.

[0153] 9. Evaluation of Curable Compositions (Part 4) The following evaluations were performed on the curable compositions 30 to 35 obtained in Examples 30 to 35. 9-1. Relative Permittivity (Dk) For the curable compositions obtained in each example, measurements were taken in the same manner as in 7-1, and the relative permittivity of the cured products formed from each curable composition was 3.1 or less in all cases.

[0154] 9-2. 150°C Gel Time The curable compositions obtained in each example were dropped onto a hot plate at 150±2°C, and the time until stringiness disappeared was measured using a stopwatch as the 150°C gel time. The results showed that the 150°C gel time for all curable compositions was less than 60 minutes.

[0155] 9-3. Viscosity The viscosity (Pa·s; initial viscosity) of the curable compositions obtained in each example was measured immediately after preparation in the same manner as in 7-2 and evaluated using the same evaluation criteria.

[0156] 9-4. Pot Life For each curable composition obtained in the pot life examples, the viscosity immediately after preparation (Pa·s; initial viscosity) and the viscosity every four hours while kept in a sealed container at 25°C were measured using a Toki Sangyo Co., Ltd. Type B viscometer "TVB-10" (rotor used: rotor H7), rotated at 25°C and 5 rpm for 1 minute. The time until the viscosity increased to more than twice the initial viscosity was determined, and the pot life was evaluated according to the following criteria. <Evaluation Criteria> ○: More than 24 hours until viscosity increased to more than twice the initial viscosity △: More than twice the initial viscosity in 24 hours or more but less than 24 hours ×: More than twice the initial viscosity in less than 8 hours

[0157] Table 4 shows the evaluation results for viscosity and pot life. The cured products formed from the curable compositions of Examples 30 to 33 exhibit a good balance of low dielectric constant, low viscosity, 150°C gel time, and pot life.

[0158]

[0159] The curable composition of the present invention is easy to handle and can form cured products with excellent adhesive strength to metals such as copper, excellent electrical properties (low dielectric constant, low dielectric loss tangent, etc.), moisture resistance, and also possesses mechanical properties and insulating properties. Taking advantage of these properties, the curable composition of the present invention can be effectively used in electronic component devices such as encapsulants, build-up films, or underfill materials for semiconductor devices.

Claims

1. A curable composition comprising an epoxy resin containing a bisphenol C type epoxy resin or an isocyanurate type epoxy resin, a curing agent, and silica particles, wherein the proportion of the silica particles to the total volume is 40% by volume or more.

2. A curable composition comprising an epoxy resin containing a bisphenol C type epoxy resin, a curing agent, silica particles having an average particle size (D50) of 0.01 to 10 μm, and black particles selected from carbon black or titanium oxide having an average particle size (D50) of 0.01 to 5 μm, wherein the silica particles account for 40% by volume or more of the total volume, and the bisphenol C type epoxy resin content in the total amount of the epoxy resin is 25% by mass or more.

3. The curable composition according to claim 2, wherein the ratio of the average particle diameter of the silica particles to the average particle diameter of the black particles is greater than 0.

8.

4. The curable composition according to claim 2, wherein the content of the black particles relative to the total amount of silica particles is 0.1 to 1 volume percent.

5. The curable composition according to claim 2, wherein the curing agent is one or more selected from amine-based curing agents or acid anhydride-based curing agents.

6. A curable composition comprising an epoxy resin containing a bisphenol C type epoxy resin and a glycidylamine type epoxy resin, a curing agent, and silica particles having an average particle size (D50) of 0.01 to 10 μm, wherein the silica particles account for 40% by volume or more of the total volume, and the content of the bisphenol C type epoxy resin and the glycidylamine type epoxy resin in relation to the total amount of the epoxy resin are each 25% by mass or more.

7. The curable composition according to claim 6, wherein the ratio of the content of the bisphenol C type epoxy resin to the content of the glycidylamine type epoxy resin is 0.5 to 2.

5.

8. A curable composition comprising an epoxy resin containing an isocyanurate-type epoxy resin, a curing agent having an amino group or an acid anhydride group, and hollow silica particles having an average particle size (D50) greater than 0.5 μm, wherein the content of the isocyanurate-type epoxy resin in relation to the total amount of the epoxy resin is greater than 10 mass, the content of the hollow silica particles is 2.5 volume% or more, and the proportion of the silica particles in relation to the total volume is 40 volume% or more.

9. The curable composition according to claim 8, further comprising solid silica particles.

10. The curable composition according to claim 9, wherein the total content of solid silica particles and hollow silica particles in the entire curable composition is 50% by volume or more.

11. The curable composition according to claim 9, wherein the average particle diameter (D50) of the solid silica particles is smaller than the average particle diameter (D50) of the hollow silica particles.

12. A curable composition comprising an epoxy resin containing an isocyanurate-type epoxy resin and a glycidylamine-type epoxy resin, a curing agent having an amino group or an acid anhydride group, and silica particles, wherein the content of the isocyanurate-type epoxy resin and the glycidylamine-type epoxy resin in relation to the total amount of the epoxy resin is greater than 10% by mass each, the sum of the content of the isocyanurate-type epoxy resin and the glycidylamine-type epoxy resin in relation to the total amount of the epoxy resin is greater than 50% by mass, and the proportion of silica particles in relation to the total volume is 40% by volume or more.

13. The curable composition according to claim 12, wherein the content of the glycidylamine-type epoxy resin is greater than the content of the isocyanurate-type epoxy resin.

14. A curable composition according to any one of claims 1 to 13, for use in electronic component devices.

15. A curable composition according to any one of claims 1 to 13, for use as a encapsulant, build-up film, or underfill material for semiconductor devices.

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