Hardening components

Abstract

This invention provides a curable composition that is easy to handle and forms a cured product with excellent electrical properties (low dielectric constant, low dielectric loss tangent, etc.), moisture resistance, mechanical properties, and insulating properties, making it useful for electronic component applications such as encapsulants or underfills for semiconductor devices. [Solution] A curable composition comprising an epoxy resin containing epoxy resin 1 with an epoxy group equivalent of more than 200 g / eq and epoxy resin 2 with an epoxy group equivalent of 200 g / eq or less, a curing agent containing amine-based curing agent 1 with an active hydrogen equivalent of more than 50 g / mol and amine-based curing agent 2 with an active hydrogen equivalent of 50 g / mol or less, and silica particles, wherein the content of epoxy resin 1 in relation to the total amount of epoxy resin is 30% by mass or more, and the content of amine-based curing agent 1 in relation to the total amount of curing agent is less than or equal to the content of amine-based curing agent 2.

Description

[Technical Field]

[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. [Background technology]

[0002] In recent years, to cope with the miniaturization of electronic devices, the acceleration of signals, and the increased density of wiring, there has been a demand for high-performance insulating materials (low dielectric constant, low dielectric loss tangent, low thermal expansion, etc.) such as sealing resin compositions, build-up substrates, adhesive films, insulating resin sheets such as prepregs, and printed circuit boards for communication equipment, and various studies are being conducted to address these issues. Furthermore, flip-chip bonding is used as a semiconductor chip mounting method that can accommodate the miniaturization of electronic devices, the acceleration of signals, and the densification of wiring. In flip-chip bonding, the gap between the semiconductor chip and the substrate is sealed with a material called underfill. Patent Document 1 proposes an underfill resin composition containing epoxy resin, aromatic amine compound, inorganic filler, and organophosphorus compound as a material for electronic component applications. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2017-071704 [Overview of the Initiative] [Problems that the invention aims to solve]

[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 composition of Patent Document 1, there is still room for improvement in order to obtain a composition that provides the physical properties of electrical properties based on inorganic fillers while also being able to handle narrow gaps and having excellent fluidity, filling ability, moldability, temperature cycle resistance, and moisture resistance. 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 using two specific epoxy resins and two specific curing agents in a predetermined mixing ratio, the dispersion state of the 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 a cured product with excellent electrical properties (low dielectric constant, low dielectric loss tangent, etc.) and moisture resistance, as well as mechanical properties and insulating properties, and is also easy to handle. [Means for solving the problem]

[0005] The present invention has the following aspects. [1] A curable composition comprising an epoxy resin containing epoxy resin 1 having an epoxy group equivalent of more than 200 g / eq and epoxy resin 2 having an epoxy group equivalent of 200 g / eq or less, a curing agent containing amine-based curing agent 1 having an active hydrogen equivalent of more than 50 g / mol and amine-based curing agent 2 having an active hydrogen equivalent of 50 g / mol or less, and silica particles, wherein the content of epoxy resin 1 in relation to the total amount of epoxy resin is 30% by mass or more, and the content of amine-based curing agent 1 in relation to the total amount of curing agent is less than or equal to the content of amine-based curing agent 2. [2] The curable composition of [1], wherein the content of epoxy resin 1 in relation to the total amount of epoxy resin is less than or equal to the content of epoxy resin 2. [3] The curable composition of [1] or [2], wherein the difference between the epoxy group equivalent of epoxy resin 1 and the epoxy group equivalent of epoxy resin 2 is 100 g / eq or more. [4] A curable composition according to any of [1] to [3], wherein the content of amine-based curing agent 1 in relation to the total amount of the curing agent is 35% by mass or less. [5] A curable composition according to any one of [1] to [4], wherein the amine-based curing agent 1 and the amine-based curing agent 2 of the curing agent are both aromatic amine compounds. [6] A curable composition according to any of [1] to [5], wherein the curing agent is bisaniline 1 and amine curing agent 2 is diaminobenzene. [7] A curable composition according to any one of [1] to [6], wherein the silica particles include solid silica particles and hollow silica particles. [8] The curable composition of [7], wherein the silica particles contain 10 to 99% by volume of solid silica particles and 1 to 90% by volume of hollow silica particles. [9] The curable composition of [7] or [8], wherein the average particle size (D50) of the solid silica particles is 0.01 to 10 μm.

[10] A curable composition according to any of [7] to [9], wherein the average particle size (D50) of the hollow silica particles is 0.2 to 10 μm.

[11] A curable composition according to any of [7] to

[10] , wherein the ratio of the average particle diameter (D50) of the hollow silica particles to the average particle diameter (D50) of the solid silica particles is 0.1 to 10.

[12] A curable composition according to any of [1] to

[11] , wherein the silica particles are contained in 40 to 80% by volume relative to the entire composition.

[13] A cured product of any of the curable compositions [1] to

[12] .

[14] A curable composition of any of [1] to

[12] for use in electronic component devices.

[15] A curable composition according to any one of [1] to

[12] , which is used for a sealing material or an underfill material of a semiconductor device.

Advantages of the Invention

[0006] According to the present invention, a cured product excellent in electrical properties (low relative permittivity, low dielectric tangent, etc.) and moisture resistance, and also having mechanical properties, insulation properties, etc. can be formed, and a curable composition excellent in handleability can be provided.

Embodiments for Carrying Out the Invention

[0007] In this specification, in the numerical range indicated by using "~", the numerical values described before and after "~" are included as the minimum value and the maximum value, respectively. Also, in the numerical range described in this specification, the upper limit value or the lower limit value described in one numerical range may be replaced with the upper limit value or the lower limit value of the numerical range described in other stepwise descriptions.

[0008] The present invention includes an epoxy resin containing an epoxy resin 1 having an epoxy equivalent weight of more than 200 g / eq and an epoxy resin 2 having an epoxy equivalent weight of 200 g / eq or less, a curing agent containing an amine-based curing agent 1 having an active hydrogen equivalent weight of more than 50 g / mol and an amine-based curing agent 2 having an active hydrogen equivalent weight of 50 g / mol or less, and silica particles, wherein the content of the epoxy resin 1 in the total amount of the epoxy resin is 30% by mass or more, and the content of the amine-based curing agent 1 in the total amount of the curing agent is not more than the content of the amine-based curing agent 2, which is a curable composition (hereinafter, also referred to as "the present composition").

[0009] From the present composition, a cured product excellent in electrical properties (low relative permittivity, low dielectric tangent, etc.) and moisture resistance, and also having mechanical properties, insulation properties, etc. can be formed, and the handleability (pot life) is also excellent. The present composition can be effectively used for various applications taking advantage of such properties, and can be effectively used for applications of electronic component devices such as a sealing material or an underfill material of a semiconductor device, for example. The reason why the present composition is excellent in handleability and can form a cured product excellent in electrical properties (low relative permittivity, low dielectric tangent, etc.) and moisture resistance is not necessarily clear, but it is considered as follows.

[0010] When an epoxy resin reacts by the action of an amine-based curing agent, hydroxyl groups are generated in the reactant along with the ring-opening of the epoxy ring. When the content of such hydroxyl groups increases, the hydrophilicity of the reactant increases, and its hygroscopicity increases and the electrical properties tend to deteriorate. This composition contains a predetermined amount of an epoxy resin 1 as an epoxy resin, the epoxy equivalent of which is more than 200 g / eq, in other words, the hydrophobic part is relatively larger than that of epoxy resin 2, and as an amine-based curing agent, an amine-based curing agent 2 having an active hydrogen equivalent of 50 g / mol or less, in other words, the number of amino groups in the molecule is relatively larger than that of amine-based curing agent 1 and can also be regarded as having high hydrophilicity, in a larger amount than amine-based curing agent 1. Therefore, the reactant that can be contained in this composition and the cured product generated with the curing reaction of this composition can also be regarded as having a large hydrophobic part derived from epoxy resin 1 and a hydrophilic part derived from hydroxyl groups and amino groups, and it is presumed that its surfactant action enhances the interaction between the constituent components, particularly the interaction between the epoxy resin and the silica particles. As a result, it is considered that the dispersibility of the silica particles in this composition or its cured product is improved. Further, since the epoxy equivalent of each of epoxy resin 1 and epoxy resin 2 in the epoxy resin constituting this composition is within the above-mentioned range, the total amount of cross-linking points during curing can be reduced, and the amount of hydroxyl groups generated during curing is reduced. Therefore, it is considered that a cured product having good electrical properties, moisture resistance, etc. based on the epoxy resin and silica particles can be obtained from this composition. Such a tendency becomes more prominent when the silica particles contain hollow silica particles.

[0011] In this composition, the content of epoxy resin 1 in the total amount of epoxy resin is 30% by mass or more, and preferably 40% by mass or more. Further, it is preferable that the content of epoxy resin 1 in the total amount of epoxy resin is equal to or less than the content of epoxy resin 2. In other words, the ratio of the content of epoxy resin 1 to the content of epoxy resin 2 in the epoxy resin is preferably 1 or less, and more preferably 0.4 or more and 1 or less. Furthermore, it is preferable that the difference between the epoxy group equivalents of epoxy resin 1 and epoxy resin 2 in this composition is 100 g / eq or more, and more preferably 240 g / eq or more. It is preferable that the difference in epoxy equivalents is 360 eq / g or less. When the difference in epoxy group equivalents of epoxy resin 1 and epoxy resin 2 is within the above range, the above-described mechanism of action is more likely to be expressed. 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.

[0012] Epoxy resin 1 and epoxy resin 2 are preferably epoxy resins having two or more epoxy groups in one molecule. Epoxy resin 1 and epoxy resin 2 may be solid or liquid at room temperature (25°C), and are more preferably liquid at room temperature from the viewpoint of improving the handling and filling properties of the composition. The viscosity of the liquid epoxy resin is preferably 0.0001 to 10 Pa·s, as measured at 25°C using an E-type viscometer. Examples of epoxy resins 1 and 2 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, anthracene type epoxy resin, adamantane type epoxy resin, epoxidized products of condensates of phenols and aromatic aldehydes having a phenolic hydroxyl group, biphenyl aralkyl type epoxy resin, fluorene type epoxy resin, xanthene type epoxy resin, triglycidyl isocyanurate, and the like. Epoxy resin 1 and epoxy resin 2 may be used individually or in combination of two or more types.

[0013] The curing agent in this composition contains amine-based curing agent 1 having an active hydrogen equivalent of more than 50 g / mol and amine-based curing agent 2 having an active hydrogen equivalent of 50 g / mol or less. The content of amine-based curing agent 1 in relation to the total amount of curing agent is less than or equal to the content of amine-based curing agent 2. The content of amine-based curing agent 1 in relation to the total amount of curing agent is preferably 35% by mass or less, and more preferably 32% by mass or less. The content of amine-based curing agent 1 in relation to the total amount of curing agent is preferably 20% by mass or more.

[0014] It is preferable that both amine-based curing agent 1 and amine-based curing agent 2 are aromatic amine compounds. Examples of such aromatic amine compounds 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.

[0015] In particular, it is more preferable that amine-based curing agent 1 is bisaniline and amine-based curing agent 2 is diaminobenzene. In this specification, "bisanilines" refers to compounds in which multiple structural units (aniline units) are linked together, each in which a primary or secondary amino group is directly bonded to one of the six carbon atoms forming a benzene ring. The amino groups in bisanilines are located far apart, and it is presumed that the cured products are relatively less likely to exhibit properties similar to those of the surfactants described above. In this specification, "diaminobenzenes" refers to compounds having a structure in which a primary or secondary amino group is directly bonded to two of the six carbon atoms forming the benzene ring. The amino groups in the molecules of diaminobenzenes are closer together than those in bisanilines, and it is presumed that they are more likely to exhibit properties similar to those of the surfactants described above in their cured products.

[0016] Amine-based curing agent 1 and amine-based curing agent 2 may be commercially available products. Examples of amine-based curing agents that are bisanilines include "KAYAHARD(registered trademark) AA" (trade name, active hydrogen equivalent 64 g / mol) manufactured by Nippon Kayaku Co., Ltd. Examples of amine-based curing agents that are diaminobenzenes include "jER(registered trademark) 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. The curing agent in this composition may further contain other curing agents such as other amine-based curing agents, acid anhydride-based curing agents, or phenol-based curing agents that differ from the amine-based curing agent 1 and amine-based curing agent 2 described above, as long as they do not impair the effects of the present invention.

[0017] Furthermore, the equivalent ratio of the epoxy resin to the amine-based curing agent in this composition (number of functional groups in the amine-based 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 in each, and even more preferably 0.8 to 1.2 from the viewpoint of curability and reliability.

[0018] The silica particles in this composition 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 occur. The silica particle content of the total composition is 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, the composition 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.

[0019] It is more preferable, from the viewpoint of further improving the electrical properties of the cured product of this composition, that the composition includes solid silica particles and hollow silica particles as silica particles. When the composition contains solid silica particles and hollow silica particles as silica particles, it is preferable that the content of solid silica particles is 10 to 99% by volume and the content of hollow silica particles is 1 to 90% by volume. The average particle size (D50) of the solid silica particles is preferably 0.01 to 10 μm. The average particle size of solid silica particles is determined by laser diffraction and scattering. Specifically, the particle size distribution is measured using laser diffraction and scattering, and a cumulative curve is obtained with the total volume of the particle collection set to 100%. The particle size at the point on this cumulative curve where the cumulative volume is 50% is defined as D50. The specific gravity of solid silica particles is 1.6 g / cm³. 3 More than 2.2g / cm 3 Preferably, it is 1.8 g / cm³ 3 More than 2.2g / cm 3 It is preferable that it be less than [a certain value]. In this specification, solid silica particles refer to particles with a hollow ratio of less than 10%, and are distinguished from hollow silica particles based on their hollow ratio.

[0020] 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, which will be explained in detail later. When the D50 of solid silica particles is greater 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, 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 into electronic components and the like is easily improved, and the flowability into narrow gaps is also easily improved. When 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 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 this composition into electronic components and the like is easily improved, and the fluidity into narrow gaps is also easily improved.

[0021] The hollow silica particles in this composition 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 hollow silica particles can be confirmed by transmission electron microscopy (TEM) 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 a space inside, which 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. In other words, 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 can be suitably used in electronic component devices.

[0022] The specific gravity of hollow silica particles is 0.3 g / cm³. 3 More than 1.00g / cm 3 It is less than 0.4-0.8 g / cm³. 3 It is preferable that this is the case. In this specification, the "specific gravity" of hollow silica particles refers to the particle density (hereinafter also referred to as "Ar density") determined by density measurement using a dry pycnometer with argon gas. When the Ar density is within the above range, the above-described mechanism of action is more easily manifested, and the dielectric constant of the cured product of this composition is also easily reduced.

[0023] Furthermore, the density of 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. 3It is preferably so. 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 the silica particles having a space inside. When the He density is within the above range, the remaining amount of silanol contained in the hollow silica particles decreases, making it easier to reduce the dielectric loss tangent.

[0024] The specific gravity (Ar density) of the hollow silica particles can be adjusted by adjusting the primary particle diameter and the shell thickness. In a sample of hollow silica particles, the ratio of complete hollow particles (hollow particle ratio) in which the shell layer is not broken and a space portion is retained inside is such that the apparent density of the hollow silica sample becomes smaller as the hollow particle ratio is higher, and the apparent density of the hollow silica sample becomes higher as the hollow particle ratio is lower. Utilizing this, when assuming a yield of 100%, the hollow particle ratio can be obtained from the theoretical density determined from the charged amount of the raw material and the apparent density measured with a dry pycnometer. In this case, the hollow particle ratio is preferably 90% or more, more preferably 95% or more. Note that the hollow particle ratio in this case is preferably 100% or less.

[0025] Also, the hollow particle ratio can be obtained from the weight change during heat treatment using the cake after filtration before removing the oil core when manufacturing the hollow silica particles. When the cake after filtration is loosened and dried overnight, the oil component in the damaged particles volatilizes, and the oil component in the complete hollow particles is retained. Since the amount of weight change during heat treatment when all the charged oil components have volatilized (hollow particle ratio 0%) and when all are retained (hollow particle ratio 100%) can be calculated from the charged amount of the raw material, the hollow particle ratio can be obtained from the weight change when the sample dried overnight after filtration is heat-treated up to 800°C. In this case, the hollow particle ratio is preferably 90% or more, more preferably 95% or more. Note that the hollow particle ratio in this case is preferably 100% or less.

[0026] The BET specific surface area of the hollow silica particles is preferably 1 to 100 m 2 / g, and preferably 1 to 50 m 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 manifested, but the dispersibility of the hollow silica particles in the composition is particularly easily improved, and the viscosity increase of the composition 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 to 50 mTorr, and then measuring by a multi-point method using nitrogen gas.

[0027] Furthermore, the specific gravity (Ar density) of hollow silica particles is A (g / cm³). 3 Let BET be the specific surface area (m²). 2 If we assume / g, then the product of the two (A × B) is between 1 and 120m. 2 / cm 3 It is preferable that A × B is 80m 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 the specific surface area of ​​the hollow silica particles in the composition is small, making it easier to suppress the increase in viscosity of the composition. 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, thereby improving its electrical properties.

[0028] 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 scanning electron microscopy (SEM), and calculating the ratio of the minimum diameter (DS) to the maximum diameter (DL) (DS / DL).

[0029] 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 the specific surface area, oil absorption, pore volume, and OHCl content on the particle surface are easy to control. 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 measurements. 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 serves as a parameter that determines the specific surface area and oil absorption capacity.

[0030] 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.

[0031] The median diameter (D50) of the secondary particles (aggregated particles) of the hollow silica particles is 0.2 to 10 μm, preferably 0.5 to 5 μm. More preferably, D50 is 0.6 μm or more, and even more preferably 0.7 μm or more. More preferably, D50 is 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 this composition is easily improved, and the increase in viscosity of the composition is easily suppressed. In addition, granularity in the cured product of this composition is easily reduced.

[0032] 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 this composition. The particle size of secondary particles in hollow silica particles (the aggregate diameter when primary particles aggregate) is determined by laser diffraction and scattering. Specifically, 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%. On this cumulative curve, the particle size at the point where the cumulative volume reaches 50% is D50, and the particle size at the point where the cumulative volume reaches 90% is D90.

[0033] 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, the strength of the hollow silica particles is easily maintained, and the properties based on the hollow shape are easily exhibited. The shell thickness is determined by measuring the shell thickness of individual particles using a transmission electron microscope (TEM).

[0034] The SiO2 content in hollow silica particles is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 99% by mass or more. The SiO2 content in hollow silica particles may be 100% by mass, and preferably 99.99% by mass or less. Here, the SiO2 content in hollow silica particles refers to the amount of silica (SiO2) contained in the shell layer constituting the hollow silica particles. For example, "the SiO2 content in hollow silica particles is 99% by mass or more" means that 99% by mass or more of the shell layer constituting the hollow silica particles contains silica (SiO2). Residues in hollow silica particles include alkali metal oxides and silicates, alkaline earth metal oxides and silicates, and carbon. 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, reducing the specific surface area and making it easier to lower the dielectric loss tangent.

[0035] Metal M is incorporated into hollow silica particles during the manufacturing process, specifically between the reaction step and the washing step. For example, metal M can be incorporated into 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, 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 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.

[0036] In the hollow silica particles of this composition, it is preferable that the metal M is at least Na, and the Na content is less than 1000 ppm by mass. In other words, it is particularly preferable that the SiO2 content of the hollow silica particles in this composition 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-mentioned mechanism of action more easily expressed, but the hollow silica particles also have an excellent balance of electrical properties and strength, and cracking is easily suppressed. The composition of the shell layer of hollow silica particles can be measured by methods such as ICP emission spectrometry or flame atomic absorption spectrometry.

[0037] 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, comprising 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 the precursor; and heat-treating it. Specifically, it is preferable to manufacture them by the method described in International Publication No. 2023 / 100676. Furthermore, 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 is reduced in the shell layer of the resulting hollow silica particles compared to when silicon alkoxides are used as the silica raw material.

[0038] The pore volume of the hollow silica particles is set to 0.2 cm, from the viewpoint of suppressing moisture adsorption and not degrading the electrical properties of the cured product of this composition. 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 / pore distribution measuring device (for example, "BELSORP-miniII" from Microtrac-Bel, "Tristar II" from Micromeritic, etc.).

[0039] 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, which suppresses moisture adsorption and improves dielectric loss. Furthermore, the affinity with the epoxy resin in this composition increases, making it easier to disperse and thus easier to improve the strength of the cured product of this composition. Examples of silane coupling agents include aminosilane coupling agents, epoxysilane coupling agents, mercaptosilane coupling agents, silane coupling agents, and organosilazane compounds. These may be used individually or in combination of two or more. The surface of hollow silica particles being treated with a silane coupling agent can be confirmed by detecting peaks corresponding to substituents of the silane coupling agent using IR imaging. Furthermore, the amount of silane coupling agent adhering to the surface can be measured by its carbon content.

[0040] The relative permittivity of the hollow silica particles at 1 GHz is preferably 1.0 to 5.0, and more preferably 1.3 to 3.5. Furthermore, it is preferable that the hollow silica particles have a dielectric loss tangent of 0.0001 to 0.05 at 1 GHz. The relative permittivity and dielectric loss tangent can be measured using the perturbation resonator method with, for example, a Keycom "Vector Network Analyzer E5063A".

[0041] The silica particle content in the total composition 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. The epoxy resin content in the total composition 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 relative to the entire composition 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.

[0042] Furthermore, in this composition, 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 the ratio is within this range, not only is the above-mentioned mechanism of action more easily expressed, but the silica particles and epoxy resin in this composition are more easily dispersed, and the properties based on the silica particles are more easily exhibited in the cured product of this composition (including molded products such as films).

[0043] This composition 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 imidazole compounds used in the curing of epoxy resins include 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 compounds may be used individually or in combination of two or more. If this composition 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.

[0044] This composition may further contain a coupling agent. When a coupling agent is included, the interfacial adhesion between the epoxy resin constituting this composition and the silica particles, as well as the interfacial adhesion between this composition and the components of electronic parts, tends to become stronger, and the filling properties also tend to improve. Examples of coupling agents include aminosilanes having one or more amino groups 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 the composition 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 the composition.

[0045] This composition may further contain a flexible agent as needed. When a flexible agent is included, the thermal shock resistance of this composition and the stress on semiconductor devices are easily reduced. Examples of flexible agents 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 this lipid composition and the stress reduction effect are easily improved, as are the penetration into fine voids and fluidity of this composition, and the generation of voids and unfilled portions is easily suppressed. If the composition further contains a flexible agent, its content is preferably 1 to 30% by mass relative to the total components of the composition other than silica particles.

[0046] This composition 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 this composition is applied tend to improve.

[0047] This composition 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.

[0048] This composition is obtained by mixing silica particles, epoxy resin (epoxy resin 1 and epoxy resin 2), curing agents (amine-based curing agent 1 and amine-based curing agent 2), and additives as needed. This composition may be obtained by mixing silica particles, epoxy resin, and curing agent all at once, or by mixing them in multiple separate steps. During mixing, it is preferable to mix the silica particles, epoxy resin, curing agent, and any additives added as needed in such a way that the total mass does not substantially change, and it is preferable to mix in a closed system. As a result, a composition is obtained in which each component is uniformly mixed and highly degassed.

[0049] The mixing apparatus for obtaining this composition is not particularly limited as long as it can sufficiently disperse and mix each component, and 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, rotating and revolving agitators and V-type mixers. The mixing method can be either batch or continuous.

[0050] The composition is preferably liquid at room temperature (25°C). The viscosity of the liquid composition is preferably 200 Pa·s or less, and more preferably 100 Pa·s or less. The viscosity of the composition is preferably 0.01 Pa·s or more, and more preferably 0.1 Pa·s or more. In this case, not only is the aforementioned mechanism of action more easily manifested, but this composition produces less foam and easily ensures fluidity and permeability that can accommodate the miniaturization of electronic components, the finer pitch of connection terminals for semiconductor elements, and the finer wiring of wiring boards in recent years. Furthermore, the cured product of this composition becomes denser, and physical properties based on silica particles are more easily manifested. The viscosity of this composition 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.

[0051] 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 a 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.

[0052] This composition can be suitably used as a encapsulant or underfill material for semiconductor devices in which electronic components such as semiconductor chips, transistors, diodes, thyristors, capacitors, resistors, resistor arrays, coils, switches, etc., 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 encapsulating or underfilling materials for semiconductor devices, comprising the present composition.

[0053] 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.

[0054] The relative permittivity (Dk) of the cured product of this composition is preferably 3.5 or less, and 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 0.012 or less, and particularly preferably 0.009 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 range, 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.

[0055] 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, Hitachi High-Tech Science's "TMA7100"), by heating the cured product with 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 tangential slope from 80°C to 100°C.

[0056] Although the present composition and the cured product thereof have been described above, the present invention is not limited to the configuration of the embodiments described above. For example, the present composition and the cured product thereof may have any other configurations added to the configuration of the above embodiments, or may be replaced with any configuration that performs similar functions. [Examples]

[0057] 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, Admatex "SO-C2", median diameter (D50) 0.5 μm Silica particles 2: Hollow silica particles, AGC Corporation "HS-200", median diameter (D50) 2.0 μm Silica particles 3: Hollow silica particles, AGC Corporation "HS-070", 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. The median value (median diameter, D50) of the particle distribution (diameter) was measured. The measurement was performed twice, and the average value was calculated.

[0058] [Epoxy resin 1] Epoxy resin 11: Mitsubishi Chemical Corporation "YX8000", hydrogenated epoxy resin, epoxy group equivalent weight 205 g / eq Epoxy resin 12: Mitsubishi Chemical Corporation "YX7105", flexible epoxy resin, epoxy group equivalent 480 g / eq Epoxy resin 13: Mitsubishi Chemical Corporation's "YX7400N", high-rebound epoxy resin, epoxy base equivalent 440 g / eq [Epoxy resin 2] Epoxy resin 21: Mitsubishi Chemical Corporation's "jER806", bisphenol F type epoxy resin, epoxy group equivalent 167 g / eq Epoxy resin 22: Mitsubishi Chemical Corporation's "jER630", glycidylamine type epoxy resin, epoxy group equivalent 96 g / eq Epoxy resin 23: DIC Corporation "HP-4032D", naphthalene-type epoxy resin, epoxy group equivalent 141 g / eq [Amine-based curing agent 1] Amine-based curing agent 11: "Kayahard AA" manufactured by Nippon Kayaku Co., Ltd., bisanilines, active hydrogen equivalent 64 g / mol Amine-based curing agent 12: ADEKA Corporation "EH-105L", diaminobenzenes, active hydrogen equivalent 54 g / mol [Amine-based curing agent 2] Amine-based curing agent 21: "jER Cure WA" manufactured by Mitsubishi Chemical Corporation, diaminobenzenes, active hydrogen equivalent 45 g / mol [Other ingredients] Coloring agent: Mitsubishi Chemical Corporation "MA-100" (carbon black) Coupling agent: Shin-Etsu Chemical Co., Ltd. "KBM-403" (silane coupling agent)

[0059] 2. Examples of manufacturing curable compositions [Example 1] The mass part of silica particles 1 such that silica particles 1 are 50% by volume in the composition, epoxy resins 11, 21 and 23 as epoxy resins, and the content ratios in all epoxy resins are epoxy resin 11 (50% by mass), epoxy resin 21 (25% by mass) and epoxy resin 23 (25% by mass) were mixed with the mass parts, and amine curing agents 11 and 21 as curing agents, and the content ratios in all curing agents were amine curing agent 11 (30% by mass) and amine curing agent 21 (70% by mass) were mixed to obtain a curable composition 1. At the time of mixing, a colorant and a coupling agent were also used in combination so that the colorant was 0.5 phr and the coupling agent was 3.0 phr with respect to the total mass of the epoxy resin and the curing agent. In addition, the total content of silica particles, epoxy resin, and curing agent in the curable composition 1 was 67% by mass, 24% by mass, and 9% by mass in this order.

[0060] [Examples 2 to 12] In Example 1, the same operations as in Example 1 were performed except that the type and content volume% of silica particles, the type and content ratio of epoxy resin, and the type and content ratio of curing agent were changed as shown in Table 1, and curable compositions 2 to 12 were obtained.

[0061] 3. Evaluation of curable composition 3-1. Relative permittivity (Dk) and dielectric loss tangent (Df) 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 plate-like cured product (80 mm long, 40 mm wide, 0.2 mm thick). Using the obtained cured product as a test piece, a dielectric constant measuring device "Network Analyzer N5227A" (manufactured by Agilent Technologies) was used to measure the relative permittivity and dielectric loss tangent at 25 ± 3 °C and 10 GHz, and evaluation was performed according to the following criteria. <Evaluation criteria for Dk> ◎: Dk is 3.1 or less ○: Dk is more than 3.1 and 3.5 or less <Evaluation criteria for Df> ◎: Df is 0.009 or less ○: Df is more than 0.009 and 0.010 or less △: Df is greater than 0.010 and less than or equal to 0.012. ×: Df is greater than 0.012

[0062] 3-2. Pot Life For each curable composition obtained in the example, the viscosity immediately after preparation (Pa·s; initial viscosity) and the viscosity every 4 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 5 rpm for 1 minute at 25°C. 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> ◎: It takes more than 24 hours for the viscosity to increase to more than twice the initial viscosity. ○: Increases to more than twice the initial viscosity in 16 hours to less than 24 hours. △: Increases to more than twice the initial viscosity in 8 hours to less than 16 hours. ×: Increases to more than twice the initial viscosity in less than 8 hours.

[0063] 3-3. Moisture resistance The curable compositions obtained in each example were poured into a mold and molded at a temperature of 150°C for a curing time of 2 hours to obtain cured discs. The mass of the obtained discs was measured (M0), and after being left at 85°C and 60% RH for 168 hours, the mass was measured again (M1) to determine the water absorption rate using the following formula, and the moisture resistance was evaluated according to the following criteria. Water absorption rate (mass%)=100×(M1-M0) / M0 <Evaluation Criteria> ◎: Water absorption rate is less than 0.1% by mass. ○: Water absorption rate is 0.1% by mass or more and less than 0.3% by mass. △: Water absorption rate is 0.3% by mass or more and less than 0.5% by mass. ×: The water absorption rate is 0.5% by mass or more.

[0064] The results are shown in Table 1. In particular, the cured products formed from the curable compositions of Example 1, Examples 4-8, and Examples 10-11 exhibit a good balance of relative permittivity, dielectric loss tangent, pot life, and moisture resistance. [Table 1] [Industrial applicability]

[0065] The curable composition of the present invention has excellent handling properties (pot life), excellent electrical properties (low dielectric constant, low dielectric loss tangent, etc.), excellent moisture resistance, and can form cured products that also possess 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 or underfill materials for semiconductor devices.

Claims

1. A curable composition comprising an epoxy resin containing epoxy resin 1 with an epoxy group equivalent of more than 200 g / eq and epoxy resin 2 with an epoxy group equivalent of 200 g / eq or less, a curing agent containing amine-based curing agent 1 with an active hydrogen equivalent of more than 50 g / mol and amine-based curing agent 2 with an active hydrogen equivalent of 50 g / mol or less, and silica particles, wherein the content of epoxy resin 1 in relation to the total amount of epoxy resin is 30% by mass or more, and the content of amine-based curing agent 1 in relation to the total amount of curing agent is less than or equal to the content of amine-based curing agent 2.

2. The curable composition according to claim 1, wherein the content of epoxy resin 1 in relation to the total amount of epoxy resin is less than or equal to the content of epoxy resin 2.

3. The curable composition according to claim 1, wherein the difference between the epoxy group equivalent of epoxy resin 1 and the epoxy group equivalent of epoxy resin 2 is 100 g / eq or more.

4. The curable composition according to claim 1, wherein the content of amine-based curing agent 1 in relation to the total amount of the curing agent is 35% by mass or less.

5. The curable composition according to claim 1, wherein both the amine-based curing agent 1 and the amine-based curing agent 2 of the curing agent are aromatic amine compounds.

6. The curable composition according to claim 1, wherein the amine-based curing agent 1 is a bisaniline and the amine-based curing agent 2 is a diaminobenzene.

7. The curable composition according to claim 1, wherein the silica particles include solid silica particles and hollow silica particles.

8. The curable composition according to claim 7, wherein the content of solid silica particles in the silica particles is 10 to 99 volume%, and the content of hollow silica particles is 1 to 90 volume%.

9. The curable composition according to claim 7, wherein the average particle size (D50) of the solid silica particles is 0.01 to 10 μm.

10. The curable composition according to claim 7, wherein the average particle size (D50) of the hollow silica particles is 0.2 to 10 μm.

11. The curable composition according to claim 7, wherein the ratio of the average particle diameter (D50) of the hollow silica particles to the average particle diameter (D50) of the solid silica particles is 0.1 to 10.

12. The curable composition according to claim 1, wherein the content of the silica particles relative to the entire composition is 40 to 80% by volume.

13. A cured product of a curable composition according to any one of claims 1 to 12.

14. A curable composition according to any one of claims 1 to 12, for use in electronic component devices.

15. A curable composition according to any one of claims 1 to 12, for use as a encapsulant or underfill material for semiconductor devices.

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