Epoxy resin composition, cured object, semiconductor device, and method for producing semiconductor device

Abstract

Provided is an epoxy resin composition which is less apt to form voids caused by air inclusion. Also provided are a cured object formed from the epoxy resin composition, a semiconductor device including the cured object, and a method for producing the semiconductor device.　The epoxy resin composition comprises an epoxy resin (A), a hardener (B), and an inorganic filler (C), wherein the inorganic filler (C) includes an inorganic filler (C1) surface-treated with a silane coupling agent having a C4-C15 hydrocarbon group.

Description

Epoxy resin composition, cured product, semiconductor device, and method for manufacturing semiconductor device

[0001] The present invention relates to an epoxy resin composition, a cured product, a semiconductor device, and a method for producing a semiconductor device.

[0002] As electronic devices become smaller, lighter, and more powerful, semiconductor packaging has shifted from wire-bonding to flip-chip mounting. Flip-chip semiconductor devices have a structure in which electrodes on a substrate are connected to a semiconductor element via bump electrodes. When such semiconductor devices are subjected to thermal loads, stress is applied to the bump electrodes due to the difference in thermal expansion coefficients between the substrate and the semiconductor element, increasing the risk of cracks and other defects in the bump electrodes. To prevent such defects, a semiconductor encapsulant called underfill is widely used. Underfill fills the gap between the substrate and the semiconductor element and hardens to secure the two together, thereby improving thermal cycling resistance. Therefore, high reliability is required of underfill, and this requirement is becoming more stringent as semiconductor devices become more powerful. While underfills are available in liquid and solid forms, liquid underfills are generally selected due to their ability to fill (inject) into gaps.

[0003] In recent years, with the increasing precision and miniaturization of semiconductor devices, there has been a demand for underfill to be applied to even narrower gaps (e.g., gaps of 20 μm). However, there has been a problem in that voids are generated when underfill is injected into such gaps. The presence of such voids in the gap adversely affects the durability and reliability of the cured product (encapsulant).

[0004] Patent Document 1 discloses an underfill material made of a resin composition having low viscosity characteristics, which is intended to suppress the generation of voids due to solvent scattering during heat treatment.

[0005] JP 2010-132793 A

[0006] However, even when the underfill material described in Patent Document 1 was used, voids were generated when the underfill material was injected into the narrow gap. As a result of the inventor's investigation, it was found that the voids that are generated when the underfill material is injected into the narrow gap (hereinafter referred to as "entangled voids") are different from the "voids caused by solvent scattering during heat treatment" that Patent Document 1 was intended to solve.

[0007] Here, we will explain "entrapment voids." Entrapment voids are thought to occur when underfill material is injected into the narrow gap described above, resulting in differences in the tip speed of the injected underfill material, causing the gap to be insufficiently filled with underfill material. The reason for this difference in tip speed of the underfill material is not clear, but it is thought that the difference in injection speed between the resin and inorganic filler in the composition is closely related to the above phenomenon.

[0008] The entrapment void will be explained using Figure 2. Reference numeral 11 denotes a plan view of the gap. Reference numerals 12 and 14 denote inorganic fillers, 13 denotes an underfill material (resin), and 15 denotes a void. Figures 2(a) to 2(d) show the change in the filling state of the underfill material over time when the underfill material is injected into the gap 11 from the top to the bottom of the figure. Because the injection rate of the resin in the underfill material is faster than that of the inorganic filler, the inorganic filler lags behind the resin, causing the inorganic filler to aggregate and associate as shown by 14 (Figure 2(c)). The aggregation and aggregation of the inorganic filler causes a difference in the injection rate of the underfill material, resulting in the formation of a void 15 (Figure 2(d)). This void 15 is an entrapment void.

[0009] Here, it is thought that lowering the viscosity of the resin composition will improve the injection speed into the gap, thereby uniforming the tip speed of the underfill material, which will lead to a reduction in the occurrence of entrapment voids. However, as mentioned above, even low-viscosity resin compositions such as those described in Patent Document 1 have had little effect in reducing the occurrence of entrapment voids. For this reason, although lowering the viscosity of the resin composition may have some correlation with the occurrence of entrapment voids, it is considered difficult to sufficiently suppress the occurrence of entrapment voids by lowering the viscosity alone. From this perspective, too, an epoxy resin composition that is less likely to cause entrapment voids has not been found to date.

[0010] Therefore, an object of the present invention is to provide an epoxy resin composition that is less likely to cause entrapment voids, a cured product of the epoxy resin composition, a semiconductor device including the cured product, and a method for manufacturing the same.

[0011] As a result of extensive research to achieve the above object, the present inventors have found that the above problems can be solved by blending a specific inorganic filler into an epoxy resin composition, thereby achieving high compatibility between the epoxy resin and the inorganic filler. The present invention was completed based on these findings. Hereinafter, unless otherwise specified, the compatibility between an epoxy resin and an inorganic filler will be simply referred to as "compatibility."

[0012] That is, the present invention provides an epoxy resin composition comprising an epoxy resin (A), a curing agent (B), and an inorganic filler (C), wherein the inorganic filler (C) is an inorganic filler (C1) that has been surface-treated with a silane coupling agent (S1) having a hydrocarbon group having 4 to 15 carbon atoms.

[0013] The silane coupling agent (S1) preferably has a reactive functional group.

[0014] The silane coupling agent (S1) is a compound represented by the following formula (I): [In formula (I), n is an integer of 4 to 15. R １ ~R ３are the same or different and are a methyl group, an ethyl group, a methoxy group, or an ethoxy group. ４ is a group containing a reactive functional group.]

[0015] The molecular weight of the silane coupling agent (S1) is preferably 250 to 500.

[0016] The content of the inorganic filler (C1) relative to the epoxy resin composition (100% by mass) is preferably 5 to 75% by mass.

[0017] The epoxy resin composition preferably further contains, as the inorganic filler (C), an inorganic filler (C2) that has been surface-treated with a silane coupling agent (S2) having a hydrocarbon group having 3 or less carbon atoms.

[0018] The silane coupling agent (S2) is a compound represented by the following formula (II): [In formula (II), m is an integer of 1 to 3. R １１ ~R １３ are the same or different and are a methyl group, an ethyl group, a methoxy group, or an ethoxy group. １４ is a group containing a reactive functional group.]

[0019] The epoxy resin composition preferably contains an inorganic filler having an average particle size different from that of the inorganic filler (C1).

[0020] The inorganic filler (C1) preferably has an average particle size of 0.5 to 3 μm.

[0021] The inorganic filler (C2) preferably has an average particle size of 0.01 to 0.4 μm.

[0022] The content of the inorganic filler (C1) relative to the inorganic filler (C) is preferably 10 to 100% by mass.

[0023] The content of the inorganic filler (C2) relative to the inorganic filler (C) is preferably 5 to 90 mass %.

[0024] The epoxy resin composition is preferably an underfill material.

[0025] The present invention also provides a cured product of the above epoxy resin composition.

[0026] The present invention also provides a semiconductor device comprising: a substrate; a semiconductor element disposed on the substrate; and the cured product that encapsulates the semiconductor element.

[0027] The present invention also provides a method for manufacturing a semiconductor device, comprising the steps of: filling a gap between a substrate and a semiconductor element disposed on the substrate with the epoxy resin composition; and heating and curing the epoxy resin composition.

[0028] The epoxy resin composition of the present invention is less likely to cause entrapment voids, and therefore a semiconductor device comprising a cured product of the epoxy resin composition exhibits high reliability.

[0029] 1A to 1C are diagrams illustrating "Evaluation 3: Gap filling test" in an example; an explanatory diagram of entrapped voids; a diagram illustrating "Evaluation 6: Entrapped void evaluation" (void evaluation: C) in comparative example 4; and a diagram illustrating "Evaluation 6: Entrapped void evaluation" (void evaluation: A) in example 1.

[0030] (Epoxy Resin Composition) The epoxy resin composition of the present invention comprises an epoxy resin (A), a curing agent (B), and an inorganic filler (C), and the inorganic filler (C) comprises an inorganic filler (C1) that has been surface-treated with a silane coupling agent (S1) having a hydrocarbon group having 4 to 15 carbon atoms. The epoxy resin composition may further comprise, as the inorganic filler (C), one or more of an inorganic filler (C2) that has been surface-treated with a silane coupling agent (S2) having a hydrocarbon group having 3 or less carbon atoms, a coupling agent (D), and another component (E).

[0031] Epoxy Resin (A) The epoxy resin composition contains the epoxy resin (A), which can impart high electrical insulation to the cured product. The number of epoxy groups in the epoxy resin (A) is not particularly limited as long as it is one or more, but it is preferably two or more (i.e., a polyfunctional epoxy resin). The epoxy resin (A) can be used alone or in combination of two or more.

[0032] The epoxy resin (A) may be liquid or solid at room temperature (25° C.), but is preferably liquid from the viewpoint of the viscosity of the epoxy resin composition. A solid epoxy resin can also be preferably used when it is used in combination with a liquid epoxy resin to form a liquid mixture.

[0033] The epoxy resin (A) is not particularly limited, and examples thereof include bisphenol type epoxy resins such as bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, and bisphenol AF type epoxy resins, bixylenol type epoxy resins, cyclohexane type epoxy resins, dicyclopentadiene type epoxy resins, trisphenol type epoxy resins, naphthol novolac type epoxy resins, phenol novolac type epoxy resins, tert-butyl-catechol type epoxy resins, naphthalene type epoxy resins, naphthol type epoxy resins, and anthracene type epoxy resins. , glycidyl amine type epoxy resins, glycidyl ester type epoxy resins, cresol novolac type epoxy resins, biphenyl type epoxy resins, fluorene type epoxy resins, biphenyl aralkyl epoxy resins, aliphatic epoxy resins, epoxy resins having a butadiene structure, alicyclic epoxy resins, heterocyclic epoxy resins, spiro ring-containing epoxy resins, cyclohexane dimethanol type epoxy resins, naphthylene ether type epoxy resins, trimethylol type epoxy resins, tetraphenylmethane type epoxy resins, aminophenol type epoxy resins, and silicone-modified epoxy resins.

[0034] The epoxy resin (A) can be classified into aromatic epoxy resins and aliphatic epoxy resins. Examples of aromatic epoxy resins include bisphenol-type epoxy resins such as bisphenol A-type epoxy resins such as 2,2-bis(4-glycidyloxyphenyl)propane, bisphenol F-type epoxy resins, bisphenol S-type epoxy resins, and bisphenol AF-type epoxy resins; novolac-type epoxy resins such as naphthol novolac-type epoxy resins, phenol novolac-type epoxy resins, and cresol novolac-type epoxy resins; fluorene-type epoxy resins; biphenyl aralkyl epoxy resins; diepoxy resins having a phenyl group such as p-tert-butylphenyl glycidyl ether and 1,4-phenyldimethanol diglycidyl ether; biphenyl-type epoxy resins such as 3,3',5,5'-tetramethyl-4,4'-diglycidyloxybiphenyl; aminophenol-type epoxy resins such as diglycidyl aniline, diglycidyl toluidine, triglycidyl-p-aminophenol, and tetraglycidyl-m-xylylenediamine; naphthalene-type epoxy resins; and epoxy resins having a plant-derived skeleton. Examples of aliphatic epoxy resins include monofunctional aliphatic epoxy compounds having one epoxy group in the molecule, such as alkyl glycidyl ethers (e.g., butyl glycidyl ether, 2-ethylhexyl glycidyl ether) and alkenyl glycidyl ethers (e.g., vinyl glycidyl ether, allyl glycidyl ether); difunctional aliphatic epoxy compounds having two epoxy groups in the molecule, such as polyalkylene glycol diglycidyl ethers (e.g., alkylene glycol diglycidyl ether, polytetramethylene glycol diglycidyl ether), and alkenylene glycol diglycidyl ether; and polyfunctional aliphatic epoxy compounds having three or more epoxy groups in the molecule, such as polyglycidyl ethers of trifunctional or higher alcohols, such as trimethylolpropane, pentaerythritol, and dipentaerythritol (e.g., trimethylolpropane triglycidyl ether, pentaerythritol (tri- or tetra-)glycidyl ether, and dipentaerythritol (tri-, tetra-, penta-, or hexa-)glycidyl ether).

[0035] Among these, the epoxy resin (A) preferably contains at least one selected from the group consisting of bisphenol-type epoxy resins, naphthalene-type epoxy resins, and aminophenol-type epoxy resins.

[0036] Specific examples of liquid epoxy resins include "YDF-8170" (bisphenol F type epoxy resin), "YDF-8125" (bisphenol A type epoxy resin), "ZX-1658" and "ZX-1658GS" (liquid 1,4-glycidylcyclohexane) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "HP-4032", "HP-4032D", and "HP-4032SS" (naphthalene type epoxy resin) manufactured by DIC Corporation; and "jER828US", "jER828EL" (bisphenol A type epoxy resin), "jER806", and "jER807" (bisphenol F type epoxy resin) manufactured by Mitsubishi Chemical Corporation. resin), "jER152" (phenol novolac type epoxy resin), "jER630", "jER630LSD", "EP3980S" (aminophenol type epoxy resin), "YX7400" (high impact resilience epoxy resin), "ZX1059" manufactured by Nippon Steel Chemical & Material Co., Ltd., "EXA-835LV" manufactured by DIC Corporation (a mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin), "EX-721" (glycidyl ester type epoxy resin) manufactured by Nagase ChemteX Corporation, and "Celloxide 2021P" (alicyclic epoxy resin) manufactured by Daicel Corporation.

[0037] Specific examples of solid epoxy resins include "HP-4032H" (naphthalene type epoxy resin), "HP-4700", "HP-4710" (naphthalene type tetrafunctional epoxy resin), "N-690" (cresol novolac type epoxy resin), "N-695" (cresol novolac type epoxy resin), "HP-7200", "HP-7200L", "HP-7200HH", "HP-7200H", and "HP-7200HH" manufactured by DIC Corporation. H" (dicyclopentadiene type epoxy resin), "EXA7311", "EXA7311-G3", "EXA7311-G4", "EXA7311-G4S", "HP6000" (naphthylene ether type epoxy resin), "EPPN-502H" (trisphenol type epoxy resin), "NC-7000-L" (naphthol novolac type epoxy resin), "NC-3000-H", "NC-3000", "NC-3000" manufactured by Nippon Kayaku Co., Ltd. -L," "NC-3100" (biphenyl type epoxy resin), "ESN475V" (naphthol type epoxy resin), "ESN485" (naphthol novolac type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd., "YX4000H," "YL6121" (biphenyl type epoxy resin), "YX4000HK" (bixylenol type epoxy resin), "YL7760" (bisphenol AF type epoxy resin), "YX Examples of epoxy resins that can be used include "8800" (anthracene-type epoxy resin), "PG-100" and "CG-500" manufactured by Osaka Gas Chemicals Co., Ltd., "YL7800" (fluorene-type epoxy resin) manufactured by Mitsubishi Chemical Corporation, and "jER1010" (solid bisphenol A-type epoxy resin), "jER1031S" (tetraphenylethane-type epoxy resin), and "jER157S70" (bisphenol novolac-type epoxy resin) manufactured by Mitsubishi Chemical Corporation.

[0038] The epoxy equivalent of the epoxy resin (A) is not particularly limited, but is preferably, for example, 30 to 500 g / eq, more preferably 40 to 400 g / eq, and even more preferably 50 to 300 g / eq.

[0039] The content of the epoxy resin (A) relative to the epoxy resin composition (100% by mass) is not particularly limited, but is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, and particularly preferably 20% by mass or more. It is also preferably 60% by mass or less, more preferably 50% by mass or less, even more preferably 40% by mass or less, and particularly preferably 35% by mass or less. That is, the content of the epoxy resin (A) relative to the epoxy resin composition (100% by mass) is preferably 5 to 60% by mass, more preferably 10 to 50% by mass, even more preferably 15 to 40% by mass, and particularly preferably 20 to 35% by mass. By having the content of the epoxy resin (A) within the above range, the thermal expansion of the cured product tends to be reduced and the toughness tends to be improved.

[0040] Curing Agent (B) The curing agent (B) is not particularly limited as long as it initiates, progresses, or accelerates the polymerization of the epoxy resin, and examples thereof include amine-based curing agents, acid anhydride-based curing agents, and phenol-based curing agents. The curing agent (B) may be solid or liquid at room temperature (25°C), and is preferably liquid. The curing agent (B) may be used alone or in combination of two or more.

[0041] Examples of the amine-based curing agent include aliphatic polyamines such as triethylenetetraamine, tetraethylenepentamine, trimethylhexamethylenediamine, and 2-methylpentamethylenediamine; alicyclic polyamines such as isophoronediamine, 1,3-bisaminomethylcyclohexane, bis(4-aminocyclohexyl)methane, norbornenediamine, and 1,2-diaminocyclohexane; piperazine-type polyamines such as N-aminoethylpiperazine and 1,4-bis(2-amino-2-methylpropyl)piperazine; m-xylenediamine, ethyltoluenediamine, and diethyltoluenediamine (3,5-diethyltoluene-2,4-diamine and 3,5-diethyltoluene-2,6-diamine); amine, etc.), dimethylthiotoluenediamine, bis(methylthio)toluenediamine, diaminodiphenylmethane, m-phenylenediamine, diaminodiphenylsulfone, trimethylenebis(4-aminobenzoate), polytetramethyleneoxide-di-p-aminobenzoate, 4,4'-methylenebis(2-ethylaniline), 1-methyl-3,5-diethyl-2,4-diaminobenzene, 1-methyl-3,5-diethyl-2,6-diaminobenzene, 1,3,5-triethyl-2,6-diaminobenzene, 3,3'-diethyl-4,4'-diaminodiphenylmethane, and 3,5,3',5'-tetramethyl-4,4'-diaminodiphenylmethane are examples of aromatic amines. Examples of the acid anhydride curing agent include alkylated tetrahydrophthalic anhydrides such as methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, hexahydrophthalic anhydride, methylhimic anhydride, alkenyl-substituted succinic anhydride, methylnadic anhydride, glutaric anhydride, phthalic anhydride, dodecenyl succinic anhydride, and methylnadic anhydride. Examples of the phenolic curing agent include phenol novolac resins and alkylated or allylated products thereof, cresol novolac resins, phenol aralkyl resins (e.g., resins containing a phenylene skeleton or a biphenylene skeleton), naphthol-modified phenolic resins (e.g., naphthol aralkyl resins), triphenolmethane resins, dicyclopentadiene-modified phenolic resins, and p-xylene-modified phenolic resins.From the viewpoint of temperature cycle resistance, moisture resistance, and reliability of the semiconductor device, the curing agent (B) is preferably the above-mentioned amine-based curing agent, more preferably an aromatic amine, and even more preferably a liquid aromatic amine.

[0042] The equivalent weight (molecular weight per functional group) of the curing agent (B) is not particularly limited, but is, for example, preferably 10 to 300 g / eq, more preferably 20 to 160 g / eq, and even more preferably 30 to 100 g / eq.

[0043] The content of the curing agent (B) is not particularly limited, but is preferably an amount such that the stoichiometric equivalent ratio (curing agent equivalent / epoxy group equivalent) with the epoxy resin (A) is, for example, 0.5 to 1.6, more preferably 0.6 to 1.3.

[0044] The content of the curing agent (B) relative to the epoxy resin composition (100% by mass) is not particularly limited, but is preferably 2% by mass or more, more preferably 4% by mass or more, and even more preferably 5% by mass or more. It is also preferably 30% by mass or less, more preferably 20% by mass or less, even more preferably 15% by mass or less, and particularly preferably 12% by mass or less. That is, the content of the curing agent (B) relative to the epoxy resin composition (100% by mass) is preferably 2 to 30% by mass, more preferably 4 to 20% by mass, even more preferably 5 to 15% by mass, and particularly preferably 5 to 12% by mass. By having the content of the curing agent (B) within the above range, the thermal expansion of the cured product tends to be reduced and the toughness tends to be improved.

[0045] The content of the curing agent (B) relative to the epoxy resin (A) (100% by mass) in the epoxy resin composition is not particularly limited, but is preferably 10% by mass or more, more preferably 20% by mass or more, and even more preferably 25% by mass or more. It is also preferably 80% by mass or less, more preferably 60% by mass or less, even more preferably 50% by mass or less, and particularly preferably 40% by mass or less. That is, the content of the curing agent (B) relative to the epoxy resin (A) (100% by mass) in the epoxy resin composition is preferably 10 to 80% by mass, more preferably 20 to 60% by mass, even more preferably 25 to 50% by mass, and particularly preferably 25 to 40% by mass. By having the content of the curing agent (B) within the above range, the thermal expansion of the cured product tends to be reduced and the toughness tends to be improved.

[0046] Inorganic Filler (C) The inorganic filler (C) is not particularly limited, but is preferably (1) a filler having the property of suppressing volumetric shrinkage (cure shrinkage) resulting from the curing reaction of the epoxy resin composition, (2) a filler having the property of suppressing volumetric change (thermal shrinkage) due to heating of the cured product, i.e., a filler having the effect of lowering the thermal expansion coefficient when added, or (3) a filler having both of these properties.

[0047] The epoxy resin composition contains, as the inorganic filler (C), an inorganic filler (C1) that has been surface-treated with a silane coupling agent (S1) having a hydrocarbon group having 4 to 15 carbon atoms. The epoxy resin composition may also contain an inorganic filler other than the inorganic filler (C1).

[0048] Examples of inorganic fillers other than the inorganic filler (C1) include inorganic fillers surface-treated with a compound other than the silane coupling agent (S1), such as inorganic filler (C2) surface-treated with a silane coupling agent (S2) having a hydrocarbon group having 3 or less carbon atoms and inorganic filler (C3) surface-treated with a compound other than the silane coupling agent, and inorganic filler (C4) that has not been surface-treated.

[0049] When the epoxy resin composition further contains, as the inorganic filler (C), an inorganic filler whose surface has been treated with a compound other than the silane coupling agent (S1), the occurrence of entrapment voids tends to be further reduced. Furthermore, since the injection into gaps is improved (i.e., the injection rate is increased and the injection time is shortened), the productivity of semiconductor devices can be improved and the composition can be applied to large-area packages. This tendency is more pronounced when the epoxy resin composition contains an inorganic filler (C2) as the inorganic filler whose surface has been treated with a compound other than the silane coupling agent (S1).

[0050] The epoxy resin composition preferably contains an inorganic filler having an average particle size different from that of the inorganic filler (C1). When the epoxy resin composition contains the inorganic filler, the injectability into gaps tends to be further improved.

[0051] Examples of the inorganic filler (C) include inorganic particles such as silica (silicon dioxide), silicon carbide, silicon nitride, alumina (aluminum oxide), aluminum nitride, aluminum hydroxide, aluminum silicate, magnesium silicate, calcium silicate, calcium carbonate, barium sulfate, barium carbonate, titanium oxide, lime sulfate, potassium titanate, magnesium carbonate, zinc oxide, boron nitride, and zirconia (zirconium oxide), as well as surface-treated particles thereof. Among these, silica is preferred from the viewpoint of achieving a high loading.

[0052] The shape of the inorganic filler (C) is not particularly limited, and examples thereof include spherical (e.g., spherical, nearly spherical), polyhedral, rod-like (e.g., cylindrical, prismatic), plate-like, flaky, and irregular shapes. Among these, spherical shapes are preferred from the viewpoint of achieving a high loading amount.

[0053] The average particle size of the inorganic filler (C) is not particularly limited, but is preferably 1 nm to 5 μm, more preferably 0.1 to 3 μm, and even more preferably 0.3 to 1 μm. When the average particle size of the inorganic filler (C) is within the above range, the viscosity of the epoxy resin composition falls within an appropriate range, which tends to improve injectability into gaps. Two or more inorganic fillers with different average particle sizes may be used in combination to adjust the viscosity of the epoxy resin composition. In this specification, the average particle size of the inorganic filler (C) refers to the volume-average particle size D50 (the particle size at 50% of the cumulative size from the smallest diameter in the volume-based particle size distribution) measured using a laser diffraction / scattering particle size distribution analyzer (product name: LS 13 320, manufactured by Beckman Coulter, Inc.).

[0054] The content of the inorganic filler (C) relative to the epoxy resin composition (100% by mass) is not particularly limited, but is preferably, for example, 30% by mass or more, more preferably 40% by mass or more, and even more preferably 50% by mass or more. It is also preferably, for example, 90% by mass or less, more preferably 80% by mass or less, and even more preferably 75% by mass or less. That is, the content of the inorganic filler (C) relative to the epoxy resin composition (100% by mass) is, for example, preferably 30 to 90% by mass, more preferably 40 to 80% by mass, and even more preferably 50 to 75% by mass. By having the content of the inorganic filler (C) within the above range, the viscosity of the epoxy resin composition tends to be reduced while the thermal expansion coefficient of the cured product tends to be reduced.

[0055] The content of the inorganic filler (C) relative to the epoxy resin (A) (100% by mass) in the epoxy resin composition is not particularly limited, but is preferably 40% by mass or more, more preferably 80% by mass or more, even more preferably 120% by mass or more, and particularly preferably 150% by mass or more. It is also preferably 800% by mass or less, more preferably 600% by mass or less, even more preferably 500% by mass or less, and particularly preferably 400% by mass or less. That is, the content of the inorganic filler (C) relative to the epoxy resin (A) (100% by mass) in the epoxy resin composition is preferably 40 to 800% by mass, more preferably 80 to 600% by mass, even more preferably 120 to 500% by mass, and particularly preferably 150 to 400% by mass. By having the inorganic filler (C) content within the above range, the viscosity of the epoxy resin composition tends to be reduced while the thermal expansion coefficient of the cured product thereof tends to be reduced.

[0056] Inorganic filler (C1) The inorganic filler (C1) is an inorganic filler that has been surface-treated with a silane coupling agent (S1) having a hydrocarbon group having 4 to 15 carbon atoms. By including the inorganic filler that has been surface-treated with the silane coupling agent (S1), the epoxy resin composition has a reduced viscosity, which improves injectability into gaps and tends to reduce the occurrence of entrapment voids.

[0057] The inorganic filler (C1) is surface-treated with a silane coupling agent (S1) having a hydrocarbon group having 4 to 15 carbon atoms, thereby achieving high compatibility with the epoxy resin (A). As a result, (1) the viscosity of the epoxy resin composition containing the inorganic filler (C1) is reduced, improving injectability. Furthermore, (2) when the epoxy resin composition is injected into a gap, the occurrence of entrapment voids tends to be reduced, possibly because the difference in injection speed between the epoxy resin (A) and the inorganic filler (C1) is reduced. As mentioned above, it can be said that there is little direct correlation between the occurrence of entrapment voids when the epoxy resin composition is injected into a gap and the low viscosity of the epoxy resin composition or the high injectability into the gap (i.e., a fast injection speed or a short injection time).

[0058] The silane coupling agent (S1) is a silane coupling agent having a hydrocarbon group having 4 to 15 carbon atoms. The silane coupling agent is a silane compound having a substituent reactive with inorganic particles, and examples of the substituent include an alkylsilane group and an alkoxysilane group. The number of carbon atoms in the hydrocarbon group is not particularly limited as long as it is 4 to 15, but 5 to 10 is preferred, and 6 to 8 is more preferred. The hydrocarbon group may be a saturated hydrocarbon group or an unsaturated hydrocarbon group, but a saturated hydrocarbon group is preferred. The hydrocarbon group may be a linear hydrocarbon group, a branched hydrocarbon group, or a cyclic hydrocarbon group, but a linear hydrocarbon group is preferred from the viewpoint of compatibility. From the viewpoint of compatibility with the epoxy resin (A), it is preferable that the silane coupling agent (S1) has a reactive functional group. Examples of the reactive functional group include a hydroxy group, an amino group (particularly a phenylamino group or a 2-aminoethylamino group), an epoxy group, a carboxyl group, a (meth)acryloyl group, and a (meth)acryloyloxy group. From the viewpoint of further improving compatibility, an epoxy group, a (meth)acryloyloxy group, and a phenylamino group are preferred.

[0059] The molecular weight of the silane coupling agent (S1) is not particularly limited, but is preferably 250 to 500, more preferably 260 to 450, even more preferably 270 to 400, and particularly preferably 280 to 350. When the molecular weight of the silane coupling agent (S1) is within the above range, the compatibility with the inorganic filler (C1) is further improved, and the occurrence of entrapment voids tends to be reduced.

[0060] From the viewpoint of reducing the occurrence of entrapped voids, the silane coupling agent (S1) is preferably a compound represented by the following formula (I):

[0061] In formula (I), n is an integer of 4 to 15. n is preferably 5 to 10, and more preferably 6 to 8. R １ ~R ３ are the same or different and are a methyl group, an ethyl group, a methoxy group, or an ethoxy group. ４is a group containing a reactive functional group. ４ may be a group consisting only of the reactive functional groups described above as possessed by the silane coupling agent (S1), or may be a group having the above-mentioned reactive functional group as a part thereof. The reactive functional group is not particularly limited, but examples thereof include a hydroxy group, an amino group (particularly a phenylamino group or a 2-aminoethylamino group), an epoxy group, a carboxyl group, a (meth)acryloyl group, and a (meth)acryloyloxy group. From the viewpoint of further improving compatibility, an epoxy group, a (meth)acryloyloxy group, and a phenylamino group are preferred. Examples of groups having the above-mentioned reactive functional group as a part thereof include monovalent organic groups having the above-mentioned reactive functional group, such as a glycidoxy group, at their terminals.

[0062] Specific examples of the silane coupling agent (S1) include silane coupling agents having an epoxy group such as (9,10-epoxydecyl)trimethoxysilane, (9,10-epoxydecyl)triethoxysilane, and (11,12-epoxydodecyl)trimethoxysilane; silane coupling agents having a glycidoxy group such as 8-glycidoxyoctyltrimethoxysilane, 8-glycidoxyoctyltriethoxysilane, and 11-glycidoxyundecyltrimethoxysilane; 8-acryloxyoctyltrimethoxysilane, 8-acryloxyoctyltriethoxysilane, 8-methacryloxyoctyltrimethoxysilane, and 8-methacryloxyoctyltriethoxysilane; Examples of suitable silane coupling agents include silane coupling agents having a (meth)acryloyloxy group, such as 11-methacryloxyundecyltrimethoxysilane and 11-methacryloxyundecyltrimethoxysilane; silane coupling agents having an amino group, such as 8-aminooctyltrimethoxysilane, 11-aminoundecyltrimethoxysilane and 8-aminooctyltriethoxysilane; silane coupling agents having a phenylamino group, such as 8-phenylaminooctyltrimethoxysilane; and silane coupling agents having a 2-aminoethylamino group, such as N-(2-aminoethyl)-8-aminooctyltrimethoxysilane and N-(2-aminoethyl)-8-aminooctyltriethoxysilane. Among these, from the viewpoint of reducing the occurrence of entrapment voids, 8-glycidoxyoctyltrimethoxysilane is preferred as the silane coupling agent (S1).

[0063] The amount of the silane coupling agent (S1) used in the surface treatment of the inorganic filler (C1) is not particularly limited, but from the viewpoint of improving the injectability into the gap, it is preferably, for example, 0.3 to 4.0 mass%, more preferably 0.5 to 2.5 mass%, and even more preferably 0.8 to 2.0 mass% relative to the inorganic filler (100 mass%). By having the surface treatment amount within the above range, compatibility tends to be improved, perhaps because all or most of the surface of the inorganic filler is treated with the silane coupling agent (S1). In this specification, the surface treatment amount of the silane coupling agent in the inorganic filler is the amount (used amount) of the silane coupling agent used when surface treating the inorganic particles.

[0064] In addition, the method of surface treatment of inorganic filler with silane coupling agent is not particularly limited, and can be carried out by known and commonly used methods.Surface treatment can be exemplified by the mode that the alkoxy group etc. of silane coupling agent is hydrolyzed to become hydroxyl group, and this hydroxyl group reacts with the surface of inorganic filler or the substituent (for example, hydroxyl group) present on the surface, and inorganic filler and silane coupling agent are covalently bonded.However, the surface treatment described above is not necessarily determined only by the presence or absence of covalent bond between inorganic filler and silane coupling agent, but also includes the mode that inorganic filler and silane coupling agent are bonded by weak attractive force such as intermolecular force.

[0065] In the inorganic filler (C1), the inorganic particles to be surface-treated with the silane coupling agent (S1) can be the inorganic particles exemplified in the inorganic filler (C), and are not particularly limited, but silica (silicon dioxide) is preferred. The shape of the inorganic filler (C1) may be any of the shapes exemplified in the inorganic filler (C), and is not particularly limited, but is preferably spherical.

[0066] The average particle size of the inorganic filler (C1) is not particularly limited, but is, for example, preferably 0.01 to 5 μm, more preferably 0.05 to 3 μm, and even more preferably 0.1 to 1 μm. When the epoxy resin composition contains an inorganic filler (C2), the average particle size of the inorganic filler (C1) is preferably 0.5 to 3 μm, and even more preferably 0.5 to 1 μm.

[0067] The content of the inorganic filler (C1) relative to the epoxy resin composition (100% by mass) is not particularly limited, but is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 20% by mass or more, even more preferably 25% by mass or more, even more preferably 30% by mass or more, and particularly preferably 35% by mass or more. It is also preferably 75% by mass or less, more preferably 70% by mass or less, even more preferably 65% ​​by mass or less, and particularly preferably 60% by mass or less. That is, the content of the inorganic filler (C1) relative to the epoxy resin composition (100% by mass) is preferably 5 to 75% by mass, more preferably 10 to 70% by mass, even more preferably 20 to 65% by mass, even more preferably 25 to 60% by mass, even more preferably 30 to 60% by mass, and particularly preferably 35 to 60% by mass.

[0068] The content of the inorganic filler (C1) relative to the epoxy resin (A) (100% by mass) in the epoxy resin composition is not particularly limited, but is, for example, preferably 10% by mass or more, more preferably 20% by mass or more, even more preferably 30% by mass or more, and particularly preferably 40% by mass or more. Furthermore, it is, for example, preferably 600% by mass or less, more preferably 500% by mass or less, even more preferably 400% by mass or less, and particularly preferably 300% by mass or less. That is, the content of the inorganic filler (C1) relative to the epoxy resin (A) (100% by mass) in the epoxy resin composition is, for example, preferably 10 to 600% by mass, more preferably 20 to 500% by mass, even more preferably 30 to 400% by mass, and particularly preferably 40 to 300% by mass.

[0069] The content of the inorganic filler (C1) relative to the inorganic filler (C) (100% by mass) in the epoxy resin composition is not particularly limited, but is, for example, preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, and particularly preferably 20% by mass or more. It is also, for example, 100% by mass or less, preferably 90% by mass or less, and more preferably 85% by mass or less. That is, the content of the inorganic filler (C1) relative to the inorganic filler (C) (100% by mass) in the epoxy resin composition is, for example, preferably 5 to 100% by mass, more preferably 10 to 90% by mass, even more preferably 15 to 85% by mass, and particularly preferably 20 to 85% by mass.

[0070] Inorganic Filler (C2) The inorganic filler (C2) is an inorganic filler surface-treated with a silane coupling agent (S2) having a hydrocarbon group having 3 or less carbon atoms (1 to 3 carbon atoms). When the above-mentioned epoxy resin composition further contains an inorganic filler (C2) surface-treated with a silane coupling agent (S2) as the inorganic filler (C), the viscosity is reduced, the injectability is further improved, and the occurrence of entrapment voids tends to be further reduced. The silane coupling agent (S2) is a silane coupling agent containing a hydrocarbon group having 3 or less carbon atoms (1 to 3 carbon atoms). The number of carbon atoms in the hydrocarbon group is not particularly limited as long as it is 1 to 3, but 3 is preferred. The hydrocarbon group may be a saturated hydrocarbon group or an unsaturated hydrocarbon group, but a saturated hydrocarbon group is preferred. The silane coupling agent (S2) preferably has a reactive functional group from the viewpoint of improving compatibility with the epoxy resin (A). The reactive functional group is not particularly limited, but examples thereof include a hydroxy group, an amino group (particularly a phenylamino group or a 2-aminoethylamino group), an epoxy group, a carboxyl group, a (meth)acryloyl group, and a (meth)acryloyloxy group. From the viewpoint of further improving compatibility, an epoxy group, a (meth)acryloyloxy group, and a phenylamino group are preferred.

[0071] The molecular weight of the silane coupling agent (S2) is not particularly limited, but is preferably 200-290, more preferably 210-280, even more preferably 220-270, and particularly preferably 230-260.

[0072] The silane coupling agent (S2) is preferably a compound represented by the following formula (II):

[0073] In formula (II), m is an integer of 1 to 3, and is preferably 3. １１ ~R １３ are the same or different and are a methyl group, an ethyl group, a methoxy group, or an ethoxy group. １４ is a group containing a reactive functional group. １４ may be a group consisting only of the reactive functional groups described above as possessed by the silane coupling agent (S2), or may be a group having the above-mentioned reactive functional group as a part thereof. The reactive functional group is not particularly limited, but examples thereof include a hydroxy group, an amino group (particularly a phenylamino group or a 2-aminoethylamino group), an epoxy group, a carboxyl group, a (meth)acryloyl group, and a (meth)acryloyloxy group. From the viewpoint of further improving compatibility, an epoxy group, a (meth)acryloyloxy group, and a phenylamino group are preferred. Examples of groups having the above-mentioned reactive functional group as a part thereof include monovalent organic groups having the above-mentioned reactive functional group, such as a glycidoxy group, at their terminals.

[0074] Specific examples of the silane coupling agent (S2) include 3-glycidyloxypropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, and N-phenyl-3-aminopropyltrimethoxysilane.

[0075] The amount of the silane coupling agent (S2) used for surface treatment of the inorganic filler (C2) is not particularly limited, but is preferably 0.3 to 4.0 mass%, and more preferably 0.5 to 2.5 mass%, relative to the inorganic filler (100 mass%).

[0076] In the inorganic filler (C2), the inorganic particles to be surface-treated with the silane coupling agent (S2) can be the inorganic particles exemplified in the inorganic filler (C), and are not particularly limited, but silica (silicon dioxide) is preferred. The shape of the inorganic filler (C2) may be any of the shapes exemplified in the inorganic filler (C), and is not particularly limited, but is preferably spherical.

[0077] The average particle size of the inorganic filler (C2) is not particularly limited, but is, for example, preferably 0.01 to 5 μm, more preferably 0.05 to 3 μm, and even more preferably 0.1 to 1 μm. When the epoxy resin composition contains the inorganic filler (C1), the average particle size of the inorganic filler (C2) is preferably 0.01 to 0.4 μm, and more preferably 0.1 to 0.35 μm.

[0078] The content of the inorganic filler (C2) relative to the epoxy resin composition (100% by mass) is not particularly limited, but is preferably, for example, 3% by mass or more, more preferably 5% by mass or more, and even more preferably 8% by mass or more. It is also preferably, for example, 75% by mass or less, more preferably 60% by mass or less, even more preferably 50% by mass or less, even more preferably 40% by mass or less, and particularly preferably 30% by mass or less. That is, the content of the inorganic filler (C2) relative to the epoxy resin composition (100% by mass) is, for example, preferably 3 to 75% by mass, more preferably 5 to 60% by mass, even more preferably 8 to 50% by mass, even more preferably 8 to 40% by mass, and particularly preferably 8 to 30% by mass.

[0079] The content of the inorganic filler (C2) relative to the epoxy resin (A) (100% by mass) in the epoxy resin composition is not particularly limited, but is, for example, preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, and particularly preferably 20% by mass or more. Furthermore, it is, for example, preferably 600% by mass or less, more preferably 400% by mass or less, even more preferably 300% by mass or less, and particularly preferably 250% by mass or less. That is, the content of the inorganic filler (C2) relative to the epoxy resin (A) (100% by mass) in the epoxy resin composition is, for example, preferably 5 to 600% by mass, more preferably 10 to 400% by mass, even more preferably 15 to 300% by mass, and particularly preferably 20 to 250% by mass.

[0080] The content of the inorganic filler (C2) relative to the inorganic filler (C) (100% by mass) in the epoxy resin composition is not particularly limited, but is, for example, 0% by mass or more, preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, and particularly preferably 20% by mass or more. It is also, for example, preferably 100% by mass or less, more preferably 90% by mass or less, and even more preferably 85% by mass or less. That is, the content of the inorganic filler (C2) relative to the inorganic filler (C) (100% by mass) in the epoxy resin composition is, for example, 0 to 100% by mass, preferably 5 to 90% by mass, more preferably 10 to 85% by mass, even more preferably 15 to 85% by mass, and particularly preferably 20 to 85% by mass.

[0081] Inorganic filler (C3) The inorganic filler (C3) is an inorganic filler that has been surface-treated with a compound other than a silane coupling agent. The compound other than the silane coupling agent is not particularly limited, but is preferably a titanium coupling agent that may have a reactive functional group such as an epoxy group, a (meth)acryloyl group, a (meth)acryloyloxy group, or an amino group (particularly a phenylamino group or a 2-aminoethylamino group).

[0082] In the inorganic filler (C3), the inorganic particles to be surface-treated with a compound other than a silane coupling agent can be the inorganic particles exemplified in the inorganic filler (C), and are not particularly limited, but silica (silicon dioxide) is preferred. The shape of the inorganic filler (C3) may be any of the shapes exemplified in the inorganic filler (C), and are not particularly limited, but are preferably spherical.

[0083] The average particle size of the inorganic filler (C3) is not particularly limited and is, for example, 0.01 to 5 μm. The content of the inorganic filler (C3) relative to the epoxy resin composition (100% by mass) is not particularly limited.

[0084] Inorganic filler (C4) Examples of the inorganic filler (C4) include the inorganic particles described in the inorganic filler (C), but silica (silicon dioxide) is preferred. The shape of the inorganic filler (C4) is not particularly limited as long as it is one of the shapes exemplified for the inorganic filler (C), but a spherical shape is preferred.

[0085] The average particle size of the inorganic filler (C4) is not particularly limited and is, for example, 0.01 to 5 μm. The content of the inorganic filler (C4) relative to the epoxy resin composition (100% by mass) is not particularly limited.

[0086] Coupling Agent (D) The coupling agent (D) is not particularly limited, and examples thereof include vinyl-based, glycidoxy-based, methacrylic-based, amino-based, mercapto-based, imidazole-based, etc. Coupling agents (D) may be used singly or in combination of two or more.

[0087] Examples of the silane coupling agent include silane coupling agents having a hydrocarbon group, such as those described as silane coupling agent (S1) and silane coupling agent (S2). Examples include 3-glycidoxypropyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 8-glycidoxyoctyltrimethoxysilane, 8-methacryloxyoctyltrimethoxysilane, and 8-phenylaminooctyltrimethoxysilane.

[0088] The content of the coupling agent (D) relative to the epoxy resin composition (100% by mass) is not particularly limited, but is preferably 0.01% by mass or more, more preferably 0.03% by mass or more, even more preferably 0.05% by mass or more, and particularly preferably 0.1% by mass or more. It is also preferably 3.0% by mass or less, more preferably 1.5% by mass or less, even more preferably 1.0% by mass or less, and particularly preferably 0.5% by mass or less. That is, the content of the coupling agent (D) relative to the epoxy resin composition (100% by mass) is preferably 0.01 to 3.0% by mass, more preferably 0.03 to 1.5% by mass, even more preferably 0.05 to 1.0% by mass, and particularly preferably 0.1 to 0.5% by mass.

[0089] Other Components (E) The epoxy resin composition may or may not contain components other than the epoxy resin (A), curing agent (B), inorganic filler (C), and coupling agent (D) (hereinafter referred to as "other components (E)"). Examples of other components (E) include curable compounds other than the epoxy resin (A), thermoplastic resins such as acrylic resins, polyethylene resins, polyester resins, polyurethane resins, and polyamide resins, thermal radical polymerization initiators such as organic peroxides, thermal cationic polymerization initiators such as acid generators, photopolymerization initiators such as photoradical polymerization initiators and photocationic polymerization initiators, curing accelerators, core-shell rubber particles, conductive particles, ion-trapping agents, surfactants, antioxidants, defoamers, flame retardants, colorants, reactive diluents, solvents, etc. The other components (E) may be used alone or in combination of two or more.

[0090] The content of the solvent relative to the epoxy resin composition (100% by mass) is, for example, 3% by mass or less, 1% by mass or less, 0.1% by mass or less, or 0.01% by mass or less, and, for example, 0.01% by mass or more, 0.1% by mass or more, or 1% by mass or more.

[0091] The content of the other component (E) relative to the epoxy resin composition (100% by mass) is not particularly limited as long as it does not impair the effects of the present invention, but is, for example, preferably 10% by mass or less, more preferably 5% by mass or less, even more preferably 3% by mass or less, and particularly preferably 1% by mass or less. Also, for example, it is preferably 0.001% by mass or more, more preferably 0.01% by mass or more, and even more preferably 0.1% by mass or more.

[0092] (Physical Properties and Production Method of Epoxy Resin Composition) The viscosity of the epoxy resin composition at 25°C is not particularly limited, but is, for example, preferably 0.1 Pa·s or more, more preferably 1 Pa·s or more, even more preferably 3 Pa·s or more, and particularly preferably 5 Pa·s or more. Furthermore, it is, for example, preferably 250 Pa·s or less, more preferably 200 Pa·s or less, even more preferably 150 Pa·s or less, and particularly preferably 100 Pa·s or less. That is, the viscosity of the epoxy resin composition at 25°C is, for example, preferably 0.1 to 250 Pa·s, more preferably 1 to 200 Pa·s, even more preferably 3 to 150 Pa·s, and particularly preferably 5 to 100 Pa·s. Having a viscosity within the above range tends to result in good handleability. The viscosity can be measured using a Brookfield viscometer (model number: HBDV-1, manufactured by Brookfield) at a liquid temperature of 25°C and rotated at 50 rpm for 1 minute, as described in the Examples below.

[0093] The viscosity of the epoxy resin composition at 110°C is not particularly limited, but is, for example, preferably 0.001 Pa·s or more, more preferably 0.005 Pa·s or more, even more preferably 0.01 Pa·s or more, and particularly preferably 0.05 Pa·s or more. Furthermore, it is, for example, preferably 5 Pa·s or less, more preferably 1 Pa·s or less, even more preferably 0.5 Pa·s or less, and particularly preferably 0.3 Pa·s or less. That is, the viscosity of the epoxy resin composition at 110°C is, for example, preferably 0.001 to 5 Pa·s, more preferably 0.005 to 1 Pa·s, even more preferably 0.01 to 0.5 Pa·s, and particularly preferably 0.05 to 0.3 Pa·s. Having a viscosity within the above range tends to facilitate gap filling. The viscosity can be measured at a liquid temperature of 110° C. using a HAAKE MARS60 (viscosity / viscoelasticity measuring device, manufactured by HAAKE Co., Ltd.) as described in the Examples below.

[0094] The epoxy resin composition can be prepared by a known, conventional method. For example, the epoxy resin (A), curing agent (B), inorganic filler (C), and, optionally, coupling agent (D), and at least one component selected from the group consisting of other components (E), can be simultaneously or separately introduced into an appropriate mixer and stirred and mixed while melting by heating as needed. If the epoxy resin (A) is solid, it is preferably liquefied or fluidized by heating before mixing. If it is difficult to uniformly disperse the inorganic filler (C) in the epoxy resin composition, the epoxy resin (A) and inorganic filler (C) can be heated and mixed to uniformly disperse the inorganic filler (C) in the epoxy resin (A), followed by cooling as needed, and then mixing with components such as the curing agent (B). This allows the epoxy resin composition to be prepared.

[0095] The mixer is not particularly limited, and examples thereof include a roll mill equipped with a stirrer and a heater, a Raikai mixer, a Henschel mixer, a tumbler, a planetary mixer, etc. The mixing ratio of each component is appropriately set depending on the content of each component in the epoxy resin composition.

[0096] The epoxy resin composition can be preferably used as a material for encapsulating semiconductor elements, wiring, solder (solder bumps), and other materials disposed on a substrate in a semiconductor device (an epoxy resin composition for semiconductor encapsulation). By using the epoxy resin composition as an epoxy resin composition for semiconductor encapsulation, a highly reliable semiconductor device can be manufactured. The epoxy resin composition can also be preferably used as a material for encapsulating semiconductor elements, etc., disposed on a substrate in a flip-chip semiconductor device (an epoxy resin composition for flip-chip semiconductor encapsulation). Specifically, by filling the gap between the semiconductor element, etc., and the substrate with the epoxy resin composition and subjecting it to thermal curing, the bump electrodes present in the gap can be encapsulated while the semiconductor element and the substrate are fixed together as an encapsulant, thereby improving reliability.

[0097] The epoxy resin composition for semiconductor encapsulation can be used as a liquid encapsulant at 25°C, and is used, for example, as an underfill material such as a capillary underfill, a liquid mold underfill, a secondary underfill, or a pre-applied underfill, a grab-top material, or a liquid compression molding material. The epoxy resin composition is not limited to the above-mentioned use as an epoxy resin composition for semiconductor encapsulation, and can also be used, for example, as an adhesive for fixing, joining, or protecting components that constitute electronic components. Among these, the epoxy resin composition is preferably used as an underfill material.

[0098] (Cured Product of Epoxy Resin Composition) A cured product is formed by curing the epoxy resin composition. The curing method is not particularly limited, but for example, the curing can be carried out by subjecting the epoxy resin composition to a heat treatment. The temperature of the heat treatment is not particularly limited, but for example, 60 to 200°C is preferred, and 80 to 180°C is more preferred. The time of the heat treatment is not particularly limited, but for example, 0.1 to 5 hours is preferred, and 0.5 to 3 hours is more preferred.

[0099] The glass transition temperature Tg of the cured product is not particularly limited, but is preferably 90°C or higher, more preferably 95°C or higher, even more preferably 100°C or higher, and particularly preferably 105°C or higher. Furthermore, it is not particularly limited, but is preferably 145°C or lower, more preferably 135°C or lower, even more preferably 125°C or lower, and particularly preferably 120°C or lower. That is, the glass transition temperature Tg of the cured product is preferably 90 to 145°C, more preferably 95 to 135°C, even more preferably 100 to 125°C, and particularly preferably 105 to 120°C. Having a glass transition temperature within the above range tends to result in excellent adhesive reliability of the resulting cured product. The glass transition temperature (Tg) can be measured using a cured product obtained by heat-curing the epoxy resin composition at 165°C for 120 minutes, and more specifically, can be measured by the method described in the Examples below.

[0100] (Semiconductor Device) The semiconductor device of the present invention comprises a substrate, a semiconductor element disposed on the substrate, and a cured product of the epoxy resin composition that encapsulates the semiconductor element. The semiconductor device is preferably a flip-chip type semiconductor device. A flip-chip type semiconductor device has a structure in which an electrode portion on a substrate and the semiconductor element are connected via bump electrodes. In addition, in the semiconductor device, the gap between the semiconductor element and the substrate is encapsulated with a cured product (encapsulant) of the epoxy resin composition.

[0101] A semiconductor device can be manufactured by filling the gap between the substrate and a semiconductor element disposed on the substrate with the epoxy resin composition (filling step) and then heating and curing the epoxy resin composition (sealing step). The method for filling the gap with the epoxy resin composition is not particularly limited; for example, the epoxy resin composition can be applied to one end of the substrate or the semiconductor element while heating the substrate to 50 to 120°C, thereby filling the gap between the substrate and the semiconductor element with the epoxy resin composition by capillary action. After filling the gap with the epoxy resin composition, the substrate is heated at a predetermined temperature for a predetermined time, specifically, at the temperature and for the time described above for the heat treatment in forming the cured product, thereby sealing the gap.

[0102] The present invention will be described in more detail below based on examples, but the present invention is not limited to these examples.

[0103] The epoxy resin compositions of Examples 1 to 11 and Comparative Examples 1 to 5 were prepared by appropriately selecting and mixing the components so as to obtain the blending ratios shown in Table 1. The numerical values ​​for each component in Table 1 indicate parts by mass.

[0104] Each component in Table 1 will be explained below. Epoxy resin (A) YDF-8170 (product name): bisphenol F type epoxy resin, epoxy equivalent 160 g / eq, liquid at 25°C, manufactured by Nippon Steel Chemical & Material Co., Ltd. HP-4032D (product name): naphthalene type epoxy resin, epoxy equivalent 140 g / eq, liquid at 25°C, manufactured by DIC Corporation EXA-835LV: product name / EPICLON EXA-835LV, mixture of bisphenol F type epoxy resin and bisphenol A type epoxy resin, epoxy equivalent 165 g / eq, liquid at 25°C, manufactured by DIC Corporation Curing agent (B) HD AA: product name / KAYAHARD AA, 4,4'-methylenebis(2-ethylaniline), active hydrogen equivalent 63 g / eq, liquid at 25°C, manufactured by Nippon Kayaku Co., Ltd. EH-105L (product name): modified aromatic amine curing agent, active hydrogen equivalent: 61 g / eq, liquid at 25°C, manufactured by ADEKA Corporation; inorganic filler (C1); Filler 1: silica surface-treated with KBM-4803 (product name) (8-glycidoxyoctyltrimethoxysilane, long-chain epoxy silane coupling agent, manufactured by Shin-Etsu Chemical Co., Ltd.), average particle size 0.6 μm, surface treatment amount 1.3 mass%, weight average molecular weight of the silane coupling agent 306.5; Filler 2: silica surface-treated with KBM-5803 (product name) (8-methacryloxyoctyltrimethoxysilane, long-chain methacrylsilane coupling agent, manufactured by Shin-Etsu Chemical Co., Ltd.), average particle size 0.6 μm, surface treatment amount 1.4 mass%, weight average molecular weight of the silane coupling agent 318.5. Filler 3: Silica surface-treated with a long-chain phenylamino silane coupling agent (8-phenylamino octyl trimethoxy silane), average particle size 0.6 μm, surface treatment amount 1.4 mass%, weight average molecular weight of the silane coupling agent 325.5. Filler 4: Silica surface-treated with KBM-4803 (product name) (8-glycidoxy octyl trimethoxy silane, long-chain epoxy silane coupling agent, manufactured by Shin-Etsu Chemical Co., Ltd.), average particle size 0.6 μm, surface treatment amount 2.0 mass%, weight average molecular weight of the silane coupling agent 306.5.Filler 5: Silica surface-treated with KBM-4803 (product name) (8-glycidoxyoctyltrimethoxysilane, long-chain epoxy silane coupling agent, manufactured by Shin-Etsu Chemical Co., Ltd.), average particle size 0.6 μm, surface treatment amount 0.7 mass%, weight average molecular weight of the silane coupling agent 306.5. Filler 6: Silica surface-treated with KBM-4803 (product name) (8-glycidoxyoctyltrimethoxysilane, long-chain epoxy silane coupling agent, manufactured by Shin-Etsu Chemical Co., Ltd.), average particle size 0.6 μm, surface treatment amount 2.3 mass%, weight average molecular weight of the silane coupling agent 306.5. Filler 7: Silica surface-treated with KBM-4803 (product name) (8-glycidoxyoctyltrimethoxysilane, long-chain epoxy silane coupling agent, manufactured by Shin-Etsu Chemical Co., Ltd.), average particle size 0.6 μm, surface treatment amount 1.0 mass%, weight average molecular weight of the silane coupling agent 306.5 Filler 8: Silica surface-treated with KBM-4803 (product name) (8-glycidoxyoctyltrimethoxysilane, long-chain epoxy silane coupling agent, manufactured by Shin-Etsu Chemical Co., Ltd.), average particle size 0.3 μm, surface treatment amount 2.0 mass%, weight average molecular weight of the silane coupling agent 306.5 Inorganic filler (C2) Filler 9: Silica surface-treated with KBM-403 (product name) (3-glycidyloxypropyltrimethoxysilane, short-chain epoxy silane coupling agent, manufactured by Shin-Etsu Chemical Co., Ltd.), average particle size 0.6 μm, surface treatment amount 1.0 mass%, weight average molecular weight of the silane coupling agent 236.3 Filler 10: Silica surface-treated with KBM-503 (product name) (3-methacryloxypropyltrimethoxysilane, short-chain methacryl silane coupling agent, manufactured by Shin-Etsu Chemical Co., Ltd.), average particle size 0.6 μm, surface treatment amount 1.1 mass%, weight average molecular weight of the silane coupling agent 248.4 Filler 11: Silica surface-treated with KBM-573 (product name) (N-phenyl-3-aminopropyltrimethoxysilane, short-chain phenylaminosilane coupling agent, manufactured by Shin-Etsu Chemical Co., Ltd.), average particle size 0.6 μm, surface treatment amount 1.1 mass%, weight average molecular weight of the silane coupling agent 255.4Filler 12: Silica surface-treated with KBM-403 (product name) (3-glycidyloxypropyltrimethoxysilane, short-chain epoxy silane coupling agent, manufactured by Shin-Etsu Chemical Co., Ltd.), average particle size 0.3 μm, surface treatment amount 1.5 mass%, weight average molecular weight of the silane coupling agent 236.3. Inorganic filler (C4) SE2300 (product name): silica with untreated surface, average particle size 0.6 μm, manufactured by Admatechs Co., Ltd. Coupling agent (D) KBM-4803 (product name): 8-glycidoxyoctyltrimethoxysilane, long-chain epoxy silane coupling agent, manufactured by Shin-Etsu Chemical Co., Ltd. KBM-403 (product name): 3-glycidyloxypropyltrimethoxysilane, short-chain epoxy silane coupling agent, manufactured by Shin-Etsu Chemical Co., Ltd.

[0105] (Evaluation 1: Measurement of viscosity at 25°C) The viscosity (Pa s) of the epoxy resin compositions of the Examples and Comparative Examples at 25°C was measured using a Brookfield viscometer (model number: HBDV-1, spindle: SC4-14, manufactured by Brookfield) at a liquid temperature of 25°C, rotating at 50 rpm for 1 minute. The results are shown in the "25°C viscosity" section of the evaluation results in Table 1. In this measurement, the epoxy resin composition was used immediately after preparation. Note that the viscosity of the epoxy resin composition at 25°C showed almost no change within 8 hours after preparation.

[0106] (Evaluation 2: Measurement of viscosity at 110°C) The viscosity (Pa s) of the epoxy resin compositions of the Examples and Comparative Examples at 110°C was measured using a HAAKE MARS60 (viscosity / viscoelasticity measuring device, manufactured by HAAKE Corporation). The evaluation method was as follows. 0.2 mL of the epoxy resin composition was dropped onto a stage at 110°C, and the epoxy resin composition was sandwiched between 20 mmφ plates so that a gap of 0.5 mm was maintained. Under these conditions, a stress sweep from 0 to 5 Pa was performed, and the viscosity at 5 Pa was read as the measured value. The results are shown in the "110°C viscosity" column of the evaluation results in Table 1. In this measurement, the epoxy resin composition was used immediately after preparation.

[0107] (Evaluation 3: Gap filling test) Preparation of test piece A test piece was obtained by sandwiching tape between two hemo cover glasses (16 mm x 22 mm) so that the gap between them was 20 μm, and then shifting the hemo cover glasses by 2 mm to secure an area for application of the evaluation sample.

[0108] Test and Evaluation The above test piece was placed on a hot plate set at 110°C, and about 1 g of each of the epoxy resin compositions of the Examples and Comparative Examples was applied to the sample application area, and the time (seconds) until the filling distance reached 20 mm was measured.

[0109] The gap filling test will be described using Figure 1. In Figure 1, 1 indicates a test specimen. 2 and 2' are hemocoverglasses. 3 indicates a tape. 4 indicates a gap. 5 indicates an evaluation sample. (a) is a plan view of the test specimen 1, with the longitudinal direction of the test specimen 1 being vertical and the lateral direction being horizontal. (b) is a side view of the test specimen 1 from the longitudinal direction. (c) is a side view of the test specimen 1 from the lateral direction. A hemocoverglass 2 is laminated to another hemocoverglass 2' via a tape 3. As shown in (b), the hemocoverglass 2 and the hemocoverglass 2' are laminated so that there is a 2 mm misalignment in the longitudinal direction. This misalignment is the application area (sample application area) of the evaluation sample 5. The gap 4 is a space surrounded by the hemocoverglass 2 on its upper surface, the hemocoverglass 2' on its lower surface, and two tapes 3 on its sides. In the gap 4, the distance between the hemocoverglass 2 and the hemocoverglass 2' is 20 μm, and the distance between the two tapes 3 is 10 mm. The longitudinal distance of the gap 4 is 20 mm. The test piece 1 is placed on a hot plate (not shown), and the evaluation sample 5 is applied to the sample application portion. The applied evaluation sample 5 moves downward along the gap 4 in the direction of (a) due to capillary action. The time it takes for the evaluation sample 5 to reach the end of the hemocoverglass 2' is measured and recorded as "Gap filling time (seconds)" in Table 1. The unit is seconds. The shorter the gap filling time, the better the injection property. A shorter injection time is preferable because it provides superior productivity and can be expected to be applied to large packages.

[0110] (Evaluation 4: Glass Transition Temperature, Tg) Using a dynamic viscoelasticity apparatus, the storage modulus (E') and loss modulus (E'') of the cured products of the epoxy resin compositions of the Examples and Comparative Examples were measured, and the peak value of tan δ, which is the ratio of these values, was determined as the glass transition temperature (Tg). The measurement was performed in accordance with Japanese Industrial Standard JIS C6481. First, spacers (layered with heat-resistant tape) were placed in two positions on a 3 mm thick glass plate with a release agent so that the film thickness of the cured product would be 2000 μm ± 100 μm. Next, the epoxy resin composition was applied between the spacers to a width of 40 mm, length of 70 mm, and thickness of 2 mm. The plate was sandwiched between other glass plates with a release agent, taking care not to trap air bubbles, and heated and cured at 165°C for 120 minutes to obtain a cured product. This cured product was peeled from the glass plate with the release agent and then cut into predetermined dimensions (width: 10 mm ± 0.5 mm, length: 50 mm ± 1 mm) using a cutter to obtain a test specimen. The glass transition temperature (Tg) of this test specimen was measured using a dynamic thermomechanical analyzer (DMA) (product name: DMS6100, manufactured by SII Corporation) in the range of 25 to 300°C, at a frequency of 1 Hz, at a heating rate of 3°C / min, using a double-support bending method. The results are shown in Table 1 under "Tg (°C)."

[0111] (Evaluation 5: Measurement of coefficient of thermal expansion, CTE) The epoxy resin compositions of the examples and comparative examples were heat-cured at 165°C for 120 minutes and molded into a cylindrical shape of 8 mmφ x 200 mm to prepare test specimens. The coefficient of thermal expansion of these test specimens was measured by thermomechanical analysis (TMA) using a TMA4000SA from Bruker ASX, with the measurement temperature range being -30 to 230°C and the analysis temperature range being 0 to 40°C. The results are shown in Table 1 as "CTE (ppm / °C)".

[0112] (Evaluation 6: Entrapment Void Evaluation) Evaluation 3: In the gap filling test, the evaluation sample injected into the gap was observed to check for the presence or absence of voids due to entrapment. The test was conducted on three tests (n = 3), and the absence of voids was rated as "A," the presence of 1 or more but less than 5 voids was rated as "B," and the presence of 5 or more voids was rated as "C." The results are shown in "Void Evaluation" in Table 1. Note that a void is defined as one having a diameter of 100 μm or more, and the void diameter was measured using a digital microscope (product name: VHX-8000, manufactured by Keyence Corporation).

[0113]

[0114] Variations of the present invention are described below. [Appendix 1] An epoxy resin composition comprising an epoxy resin (A), a curing agent (B), and an inorganic filler (C), wherein the inorganic filler (C) comprises an inorganic filler (C1) that has been surface-treated with a silane coupling agent (S1) having a hydrocarbon group having 4 to 15 carbon atoms. [Appendix 2] The epoxy resin composition according to Appendix 1, wherein the epoxy resin (A) comprises at least one selected from the group consisting of a bisphenol-type epoxy resin, a naphthalene-type epoxy resin, and an aminophenol-type epoxy resin. [Appendix 3] The epoxy resin composition according to Appendices 1 or 2, wherein the content of the epoxy resin (A) relative to the epoxy resin composition (100 mass%) is 5% by mass or more, 10% by mass or more, 15% by mass or more, or 20% by mass or more; 60% by mass or less, 50% by mass or less, 40% by mass or less, or 35% by mass or less; and / or 5 to 60% by mass, 10 to 50% by mass, 15 to 40% by mass, or 20 to 35% by mass. [Appendix 4] The epoxy resin composition according to any one of Appendices 1 to 3, wherein the curing agent (B) comprises at least one selected from the group consisting of an amine-based curing agent (particularly, an aromatic amine), an acid anhydride-based curing agent, and a phenol-based curing agent. [Appendix 5] The epoxy resin composition according to any one of Appendices 1 to 4, wherein the content of the curing agent (B) relative to the epoxy resin composition (100% by mass) is 2% by mass or more, 4% by mass or more, or 5% by mass or more; 30% by mass or less, 20% by mass or less, 15% by mass or less, or 12% by mass or less; and / or 2 to 30% by mass, 4 to 20% by mass, 5 to 15% by mass, or 5 to 12% by mass. [Appendix 6] The epoxy resin composition according to any one of Appendices 1 to 5, wherein the content of the curing agent (B) relative to the epoxy resin (A) (100% by mass) is 10% by mass or more, 20% by mass or more, or 25% by mass or more; 80% by mass or less, 60% by mass or less, 50% by mass or less, or 40% by mass or less; and / or 10 to 80% by mass, 20 to 60% by mass, 25 to 50% by mass, or 25 to 40% by mass.[Appendix 7] The epoxy resin composition according to any one of Appendices 1 to 6, wherein the content of the inorganic filler (C) relative to the epoxy resin composition (100 mass%) is 30 mass% or more, 40 mass% or more, or 50 mass% or more; 90 mass% or less, 80 mass% or less, or 75 mass% or less; and / or 30 to 90 mass%, 40 to 80 mass%, or 50 to 75 mass%. [Appendix 8] The epoxy resin composition according to any one of Appendices 1 to 7, wherein the content of the inorganic filler (C) relative to the epoxy resin (A) (100 mass%) is 40 mass% or more, 80 mass% or more, 120 mass% or more, or 150 mass% or more; 800 mass% or less, 600 mass% or less, 500 mass% or less, or 400 mass% or less; and / or 40 to 800 mass%, 80 to 600 mass%, 120 to 500 mass%, or 150 to 400 mass%. [Appendix 9] The epoxy resin composition according to any one of Appendices 1 to 8, wherein the hydrocarbon group in the silane coupling agent (S1) has 5 to 10 carbon atoms, or 6 to 8 carbon atoms. [Appendix 10] The epoxy resin composition according to any one of Appendices 1 to 9, wherein the hydrocarbon group in the silane coupling agent (S1) is a saturated hydrocarbon group or an unsaturated hydrocarbon group, and the hydrocarbon group is a linear hydrocarbon group, a branched hydrocarbon group, or a cyclic hydrocarbon group. [Appendix 11] The epoxy resin composition according to any one of Appendices 1 to 10, wherein the silane coupling agent (S1) has a reactive functional group. [Appendix 12] The epoxy resin composition according to Appendices 11, wherein the silane coupling agent (S1) contains, as the reactive functional group, at least one selected from the group consisting of a hydroxy group, an amino group (particularly a phenylamino group and a 2-aminoethylamino group), an epoxy group, a carboxyl group, a (meth)acryloyl group, and a (meth)acryloyloxy group. [Appendix 13] The epoxy resin composition according to any one of Appendices 1 to 12, wherein the molecular weight of the silane coupling agent (S1) is 250 to 500, 260 to 450, 270 to 400, or 280 to 350. [Appendix 14] The silane coupling agent (S1) is represented by the following formula (I): [In formula (I), n is an integer of 4 to 15, 5 to 10, or 6 to 8. R １ ~R ３are the same or different and are a methyl group, an ethyl group, a methoxy group, or an ethoxy group. ４is a group containing a reactive functional group (for example, a reactive functional group, or a group having the reactive functional group as a part thereof).] [Appendix 15] The epoxy resin composition according to any one of Appendices 1 to 13, wherein the group containing a reactive functional group in formula (I) is a hydroxy group, an amino group (particularly a phenylamino group or a 2-aminoethylamino group), an epoxy group, a carboxyl group, a (meth)acryloyl group, a (meth)acryloyloxy group, or a glycidoxy group. [Appendix 16] The silane coupling agent (S1) may be a silane coupling agent having an epoxy group such as (9,10-epoxydecyl)trimethoxysilane, (9,10-epoxydecyl)triethoxysilane, or (11,12-epoxydodecyl)trimethoxysilane; a silane coupling agent having a glycidoxy group such as 8-glycidoxyoctyltrimethoxysilane, 8-glycidoxyoctyltriethoxysilane, or 11-glycidoxyundecyltrimethoxysilane; a silane coupling agent having an epoxy ...acryloxyoctyltrimethoxysilane, 8-acryloxyoctyltriethoxysilane, 8-methacryloxyoctyltrimethoxysilane, 8-methacryloxyoctyltriethoxysilane, or 11-methacryloxyoctyltriethoxysilane; the epoxy resin composition according to any one of Appendix 1 to Appendix 15, which is a silane coupling agent having a (meth)acryloyloxy group, such as acryloyloxyundecyltrimethoxysilane; a silane coupling agent having an amino group, such as 8-aminooctyltrimethoxysilane, 11-aminoundecyltrimethoxysilane, or 8-aminooctyltriethoxysilane; a silane coupling agent having a phenylamino group, such as 8-phenylaminooctyltrimethoxysilane; or a silane coupling agent having a 2-aminoethylamino group, such as N-(2-aminoethyl)-8-aminooctyltrimethoxysilane or N-(2-aminoethyl)-8-aminooctyltriethoxysilane. [Appendix 17] The epoxy resin composition according to any one of Appendices 1 to 16, wherein the amount of the silane coupling agent (S1) used for surface treatment in the inorganic filler (C1) is 0.3 to 4.0 mass%, 0.5 to 2.5 mass%, or 0.8 to 2.0 mass%, relative to the inorganic filler (100 mass%).[Appendix 18] The epoxy resin composition according to any one of Appendices 1 to 17, wherein the inorganic filler (C1) has an average particle size of 0.01 to 5 μm, 0.05 to 3 μm, or 0.1 to 1 μm, and when the epoxy resin composition contains an inorganic filler (C2), the inorganic filler (C1) has an average particle size of 0.5 to 3 μm, or 0.5 to 1 μm. [Appendix 19] The epoxy resin composition according to any one of Appendices 1 to 18, wherein the content of the inorganic filler (C1), relative to the epoxy resin composition (100% by mass), is 5% by mass or more, 10% by mass or more, 20% by mass or more, 25% by mass or more, 30% by mass or more, or 35% by mass or more; 75% by mass or less, 70% by mass or less, 65% by mass or less, or 60% by mass or less; and / or 5 to 75% by mass, 10 to 70% by mass, 20 to 65% by mass, 25 to 60% by mass, 30 to 60% by mass, or 35 to 60% by mass. [Appendix 20] The epoxy resin composition according to any one of Appendices 1 to 19, wherein the content of the inorganic filler (C1) relative to the epoxy resin (A) (100 mass%) is 10 mass% or more, 20 mass% or more, 30 mass% or more, or 40 mass% or more; 600 mass% or less, 500 mass% or less, 400 mass% or less, or 300 mass% or less; and / or 10 to 600 mass%, 20 to 500 mass%, 30 to 400 mass%, or 40 to 300 mass%. [Appendix 21] The epoxy resin composition according to any one of Appendices 1 to 20, wherein the content of the inorganic filler (C1) relative to the inorganic filler (C) (100 mass%) is 5 mass% or more, 10 mass% or more, 15 mass% or more, or 20 mass% or more; 100 mass% or less, 90 mass% or less, or 85 mass% or less; and / or 5 to 100 mass%, 10 to 90 mass%, 15 to 85 mass%, or 20 to 85 mass%. [Appendix 22] The epoxy resin composition according to any one of Appendices 1 to 21, further comprising, as the inorganic filler (C), an inorganic filler (C2) that has been surface-treated with a silane coupling agent (S2) having a hydrocarbon group having 3 or less carbon atoms (particularly, 3 carbon atoms). [Appendix 23] The epoxy resin composition according to Appendices 22, wherein the hydrocarbon group in the silane coupling agent (S2) is a saturated hydrocarbon group or an unsaturated hydrocarbon group.[Appendix 24] The epoxy resin composition according to Appendices 22 or 23, wherein the silane coupling agent (S2) has a reactive functional group. [Appendix 25] The epoxy resin composition according to Appendices 24, wherein the silane coupling agent (S2) contains, as the reactive functional group, at least one selected from the group consisting of a hydroxy group, an amino group (particularly a phenylamino group or a 2-aminoethylamino group), an epoxy group, a carboxyl group, a (meth)acryloyl group, and a (meth)acryloyloxy group. [Appendix 26] The epoxy resin composition according to any one of Appendices 22 to 25, wherein the molecular weight of the silane coupling agent (S2) is 200 to 290, 210 to 280, 220 to 270, or 230 to 260. [Appendix 27] The silane coupling agent (S2) is represented by the following formula (II): [In formula (II), m is an integer of 1 to 3 (particularly, 3). R １１ ~R １３ are the same or different and are a methyl group, an ethyl group, a methoxy group, or an ethoxy group. １４is a group containing a reactive functional group (for example, a reactive functional group, or a group having the reactive functional group as a part thereof).] [Appendix 28] The epoxy resin composition according to any one of Appendices 22 to 26, wherein the group containing a reactive functional group in formula (II) is a hydroxy group, an amino group (particularly a phenylamino group or a 2-aminoethylamino group), an epoxy group, a carboxyl group, a (meth)acryloyl group, a (meth)acryloyloxy group, or a glycidoxy group. [Appendix 29] The epoxy resin composition according to any one of Appendices 22 to 28, wherein the silane coupling agent (S2) is 3-glycidyloxypropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, or N-phenyl-3-aminopropyltrimethoxysilane. [Appendix 30] The epoxy resin composition according to any one of Appendices 22 to 29, wherein the amount of the silane coupling agent (S2) used for surface treatment in the inorganic filler (C2) is 0.3 to 4.0 mass% or 0.5 to 2.5 mass% relative to the inorganic filler (100 mass%). [Appendix 31] The epoxy resin composition according to any one of Appendices 22 to 30, wherein the inorganic filler (C2) has an average particle size of 0.01 to 5 μm, 0.05 to 3 μm, or 0.1 to 1 μm, and when the epoxy resin composition contains an inorganic filler (C1), the inorganic filler (C2) has an average particle size of 0.01 to 0.4 μm or 0.1 to 0.35 μm. [Appendix 32] The epoxy resin composition according to any one of Appendices 22 to 31, wherein the content of the inorganic filler (C2), relative to the epoxy resin composition (100% by mass), is 3% by mass or more, 5% by mass or more, or 8% by mass or more; 75% by mass or less, 60% by mass or less, 50% by mass or less, 40% by mass or less, or 30% by mass or less; and / or 3 to 75% by mass, 5 to 60% by mass, 8 to 50% by mass, 8 to 40% by mass, or 8 to 30% by mass.[Appendix 33] The epoxy resin composition according to any one of Appendices 22 to 32, wherein the content of the inorganic filler (C2) relative to the epoxy resin (A) (100 mass%) is 5 mass% or more, 10 mass% or more, 15 mass% or more, or 20 mass% or more; 600 mass% or less, 400 mass% or less, 300 mass% or less, or 250 mass% or less; and / or 5 to 600 mass%, 10 to 400 mass%, 15 to 300 mass%, or 20 to 250 mass%. [Appendix 34] The epoxy resin composition according to any one of Appendices 22 to 33, wherein the content of the inorganic filler (C2) relative to the inorganic filler (C) (100% by mass) is 0% by mass or more, 5% by mass or more, 10% by mass or more, 15% by mass or more, or 20% by mass or more; 100% by mass or less, 90% by mass or less, or 85% by mass or less; and / or 0 to 100% by mass, 5 to 90% by mass, 10 to 85% by mass, 15 to 85% by mass, or 20 to 85% by mass. [Appendix 35] The epoxy resin composition according to any one of Appendices 1 to 34, comprising an inorganic filler having an average particle size different from that of the inorganic filler (C1). [Appendix 36] The epoxy resin composition according to any one of Appendices 1 to 35, further comprising a coupling agent (D). [Appendix 37] The epoxy resin composition according to Appendix 36, comprising as coupling agent (D) a silane coupling agent such as a vinyl-based, glycidoxy-based, methacryl-based, amino-based, mercapto-based, or imidazole-based silane coupling agent. [Appendix 38] The epoxy resin composition according to Appendix 37, comprising as the silane coupling agent at least one selected from the group consisting of 3-glycidoxypropyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 8-glycidoxyoctyltrimethoxysilane, 8-methacryloxyoctyltrimethoxysilane, and 8-phenylaminooctyltrimethoxysilane.[Appendix 39] The epoxy resin composition according to any one of Appendices 36 to 38, wherein the content of the coupling agent (D), relative to the epoxy resin composition (100% by mass), is 0.01% by mass or more, 0.03% by mass or more, 0.05% by mass or more, or 0.1% by mass or more; 3.0% by mass or less, 1.5% by mass or less, 1.0% by mass or less, or 0.5% by mass or less; and / or 0.01 to 3.0% by mass, 0.03 to 1.5% by mass, 0.05 to 1.0% by mass, or 0.1 to 0.5% by mass. [Appendix 40] The epoxy resin composition according to any one of Appendices 1 to 39, wherein the content of components other than the epoxy resin (A), the curing agent (B), the inorganic filler (C), and the coupling agent (D), i.e., other component (E), relative to the epoxy resin composition (100% by mass) is 10% by mass or less, 5% by mass or less, 3% by mass or less, or 1% by mass or less; and / or 0.001% by mass or more, 0.01% by mass or more, or 0.1% by mass or more. [Appendix 41] The epoxy resin composition according to any one of Appendices 1 to 40, wherein the content of solvent relative to the epoxy resin composition (100% by mass) is 3% by mass or less, 1% by mass or less, 0.1% by mass or less, or 0.01% by mass or more, or 0.01% by mass or more, 0.1% by mass or more, or 1% by mass or more. [Appendix 42] The epoxy resin composition according to any one of Appendices 1 to 41, wherein the viscosity of the epoxy resin composition at 25°C is 0.1 Pa s or more, 1 Pa s or more, 3 Pa s or more, or 5 Pa s or more; 250 Pa s or less, 200 Pa s or less, 150 Pa s or less, or 100 Pa s or less; and / or 0.1 to 250 Pa s, 1 to 200 Pa s, 3 to 150 Pa s, or 5 to 100 Pa s. [Appendix 43] The epoxy resin composition according to any one of Appendices 1 to 42, wherein the viscosity of the epoxy resin composition at 110°C is 0.001 Pa s or more, 0.005 Pa s or more, 0.01 Pa s or more, or 0.05 Pa s or more; 5 Pa s or less, 1 Pa s or less, 0.5 Pa s or less, or 0.3 Pa s or less; and / or 0.001 to 5 Pa s, 0.005 to 1 Pa s, 0.01 to 0.5 Pa s, or 0.05 to 0.3 Pa s.[Appendix 44] The epoxy resin composition according to any one of Appendices 1 to 43, wherein the glass transition temperature Tg of the cured product is 90°C or higher, 95°C or higher, 100°C or higher, or 105°C or higher; 145°C or lower, 135°C or lower, 125°C or lower, or 120°C or lower; and / or 90 to 145°C, 95 to 135°C, 100 to 125°C, or 105 to 120°C. [Appendix 45] The epoxy resin composition according to any one of Appendices 1 to 44, which is an underfill material. [Appendix 46] A cured product of the epoxy resin composition according to any one of Appendices 1 to 45. [Appendix 47] A semiconductor device comprising: a substrate; a semiconductor element arranged on the substrate; and the cured product according to Appendices 46 that encapsulates the semiconductor element. [Supplementary Note 48] A method for manufacturing a semiconductor device, comprising: filling a gap between a substrate and a semiconductor element disposed on the substrate with the epoxy resin composition according to any one of Supplementary Note 1 to Supplementary Note 45; and heating and curing the epoxy resin composition.

[0115] REFERENCE SIGNS LIST 1 Test piece 2 Hemo cover glass 2' Hemo cover glass 3 Tape 4 Gap 5 Evaluation sample 11 Gap 12 Inorganic filler 13 Underfill material (resin) 14 Association / aggregation of inorganic filler 15 Void

Claims

1. An epoxy resin composition comprising an epoxy resin (A), a curing agent (B), and an inorganic filler (C), wherein the inorganic filler (C) is an inorganic filler (C1) that has been surface-treated with a silane coupling agent (S1) having a hydrocarbon group having 4 to 15 carbon atoms.

2. The epoxy resin composition according to claim 1, wherein the silane coupling agent (S1) has a reactive functional group.

3. The silane coupling agent (S1) is represented by the following formula (I): [In formula (I), n is an integer of 4 to 15. R １ ~R ３ are the same or different and are a methyl group, an ethyl group, a methoxy group, or an ethoxy group. ４ The epoxy resin composition according to claim 1 or 2, wherein the compound is a compound represented by the formula:

4. The epoxy resin composition according to claim 1 or 2, wherein the molecular weight of the silane coupling agent (S1) is 250 to 500.

5. The epoxy resin composition according to claim 1 or 2, wherein the content of the inorganic filler (C1) relative to the epoxy resin composition (100% by mass) is 5 to 75% by mass.

6. The epoxy resin composition according to claim 1 or 2, further comprising, as the inorganic filler (C), an inorganic filler (C2) that has been surface-treated with a silane coupling agent (S2) having a hydrocarbon group having 3 or less carbon atoms.

7. The silane coupling agent (S2) is represented by the following formula (II): [In formula (II), m is an integer of 1 to 3. R １１ ~R １３ are the same or different and are a methyl group, an ethyl group, a methoxy group, or an ethoxy group. １４ is a group containing a reactive functional group. ] The epoxy resin composition according to claim 6, 8. The epoxy resin composition according to claim 1 or 2, which contains an inorganic filler having an average particle size different from that of the inorganic filler (C1).

9. The epoxy resin composition according to claim 1 or 2, wherein the inorganic filler (C1) has an average particle size of 0.5 to 3 μm.

10. The epoxy resin composition according to claim 6, wherein the inorganic filler (C2) has an average particle size of 0.01 to 0.4 μm.

11. The epoxy resin composition according to claim 1 or 2, wherein the content of the inorganic filler (C1) relative to the inorganic filler (C) is 10 to 100 mass %.

12. The epoxy resin composition according to claim 6, wherein the content of the inorganic filler (C2) relative to the inorganic filler (C) is 5 to 90 mass %.

13. The epoxy resin composition according to claim 1 or 2, which is an underfill material.

14. A cured product of the epoxy resin composition according to claim 1 or 2.

15. A semiconductor device comprising: a substrate; a semiconductor element disposed on the substrate; and the cured product according to claim 14 that seals the semiconductor element.

16. A method for manufacturing a semiconductor device, comprising: a step of filling a gap between a substrate and a semiconductor element arranged on the substrate with the epoxy resin composition according to claim 1 or 2; and a step of heating and curing the epoxy resin composition.

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