Liquid resin composition, semiconductor sealing material, underfill material, and semiconductor device

Abstract

The present disclosure provides a liquid resin composition that has high fluidity at high temperature and can suppress abnormalities of appearance and breakage of a cured product when exposed to high temperature. A liquid resin composition contains a liquid epoxy compound (A), a liquid aromatic amine compound (B), an inorganic filler (C), a stress-lowering agent (D), and a fluidity-increasing agent (E). The stress-lowering agent (D) contains an epoxidized fatty acid ester compound (D-1). The fluidity-increasing agent (E) contains at least one selected from the group consisting of compounds (E-1) that have a quaternary phosphonium cation structure and compounds (E-2) that have a silicate anion structure.

Description

Liquid resin composition, semiconductor sealing material, underfill material and semiconductor device

[0001] The present disclosure generally relates to a liquid resin composition, a semiconductor encapsulating material, an underfill material, and a semiconductor device, and more particularly to a liquid resin composition, a semiconductor encapsulating material, an underfill material, and a semiconductor device containing an epoxy compound.

[0002] Patent Document 1 discloses an encapsulating resin composition containing (A) an epoxy resin, (B) a curing agent, (C) an inorganic filler, and (D) a triglyceride having an unsaturated fatty acid residue.

[0003] Patent Document 2 discloses an epoxy resin composition containing (A) an epoxy resin, (B) a curing agent, and a pre-mixture containing at least a portion of either or both of the (A) epoxy resin and the (B) curing agent, and (C) a silicone compound, wherein the (C) silicone compound contains both (c1) a first silicone compound which is a dual-end type epoxy-modified silicone oil and (c2) a second silicone compound which is a side-chain type epoxy-polyether-modified silicone oil.

[0004] JP 2023-113250 A Patent No. 6065358 A

[0005] As semiconductor elements become denser, larger in area, and generate more heat, encapsulating resin compositions are required to suppress defects such as cracking and discoloration of the cured product at high temperatures while ensuring moldability. However, the resin compositions described in Patent Documents 1 and 2 have the problem that it is difficult to achieve high fluidity at high temperatures and to suppress abnormal appearance and breakage of the cured product when exposed to high temperatures.

[0006] An object of the present disclosure is to provide a liquid resin composition, a semiconductor encapsulating material, an underfill material, and a semiconductor device that have high fluidity at high temperatures and can suppress abnormal appearance and damage to the cured product when exposed to high temperatures.

[0007] A liquid resin composition according to one embodiment of the present disclosure contains a liquid epoxy compound (A), a liquid aromatic amine compound (B), an inorganic filler (C), a stress-reducing agent (D), and a superfluidizer (E). The stress-reducing agent (D) contains an epoxidized fatty acid ester compound (D-1). The superfluidizer (E) contains at least one compound selected from the group consisting of a compound (E-1) having a quaternary phosphonium cation structure and a compound (E-2) having a silicate anion structure.

[0008] A semiconductor encapsulation material according to one embodiment of the present disclosure contains the liquid resin composition.

[0009] An underfill material according to one embodiment of the present disclosure contains the liquid resin composition.

[0010] A semiconductor device according to one aspect of the present disclosure includes a substrate, a semiconductor element mounted on the substrate, and a sealing portion interposed in a gap between the substrate and the semiconductor element, the sealing portion including a cured product of the underfill material.

[0011] FIG. 1 is a cross-sectional view of a semiconductor device according to an embodiment of the present disclosure.

[0012] 1. Overview: Embodiments of the present disclosure will be described. Note that the following embodiments are merely a portion of various embodiments of the present disclosure. Furthermore, the following embodiments can be modified in various ways depending on the design, etc., as long as the object of the present disclosure can be achieved. The figures referred to below are schematic diagrams, and the dimensional ratios of the components in the figures do not necessarily reflect the actual dimensional ratios. Although the mechanism of action in the embodiments may be described below, the description of the mechanism of action includes an explanation based on speculation, and the present disclosure is not bound by the description of the mechanism of action.

[0013] A liquid resin composition according to an embodiment (hereinafter also referred to as composition (X)) contains a liquid epoxy compound (A), a liquid aromatic amine compound (B), an inorganic filler (C), a stress reducing agent (D), and a fluidizing agent (E). The stress reducing agent (D) contains an epoxidized fatty acid ester compound (D-1). The fluidizing agent (E) contains at least one compound selected from the group consisting of a compound (E-1) having a quaternary phosphonium cation structure and a compound (E-2) having a silicate anion structure.

[0014] According to the embodiment, a composition (X) can be obtained that has high fluidity at high temperatures and can suppress abnormal appearance and damage to the cured product when exposed to high temperatures. Although the exact reason why composition (X) exhibits the above effects has not been clarified, it can be assumed that it is based on the following reasons.

[0015] Since the epoxidized fatty acid ester compound (D-1) has an aliphatic skeleton, it is unlikely to impair the fluidity of the composition (X) in the composition (X). Furthermore, in the cured product, the epoxidized fatty acid ester compound (D-1) increases the flexibility of the cured product, thereby suppressing damage such as cracking in the cured product. Furthermore, when the composition (X) is cured, the epoxidized fatty acid ester compound (D-1) reacts with the epoxy compound (A) and the aromatic amine compound (B) to be incorporated into the polymer skeleton in the cured product. Therefore, even when the cured product is exposed to high temperatures, the components of the polymer skeleton in the cured product are unlikely to separate, and therefore, the cured product is unlikely to have abnormal appearance.

[0016] The composition (X) contains at least one compound selected from the group consisting of a compound (E-1) having a quaternary phosphonium cation and a compound (E-2) having a silicate anion. The compound (E-1) having a quaternary phosphonium cation or the compound (E-2) having a silicate anion adheres to the surface of the inorganic filler (C), thereby suppressing the generation of ions that may be generated from the inorganic filler (C). This allows the storage stability of the composition (X) to be improved while also increasing its fluidity at high temperatures.

[0017] As described above, the composition (X) according to the embodiment has a high fluidity at high temperatures and can suppress abnormal appearance and damage to the cured product when exposed to high temperatures, by combining the epoxy compound (A), the aromatic amine compound (B), and the inorganic filler (C) with the epoxidized fatty acid ester compound (D-1) and at least one compound selected from the group consisting of the compound (E-1) having a quaternary phosphonium cation and the compound (E-2) having a silicate anion.

[0018] Composition (X) can be used to produce an encapsulation portion that encapsulates a semiconductor in a semiconductor device or the like. That is, the semiconductor encapsulation material according to the embodiment contains composition (X). In particular, composition (X) can be preferably used to produce an encapsulation portion interposed between a semiconductor element flip-chip mounted on a substrate in a semiconductor device or the like and the substrate. That is, the underfill material according to the embodiment contains composition (X). The semiconductor encapsulation material and underfill material according to the embodiment easily flow between the semiconductor element and the substrate during encapsulation production, thereby improving the manufacturing efficiency of semiconductor devices and suppressing poor filling of the encapsulation portion between the semiconductor element and the substrate.

[0019] The use of composition (X) is not limited to the production of semiconductor devices, but composition (X) can be used for various purposes other than the production of semiconductor devices.

[0020] 2. Composition 2.1 Composition of the Composition In an embodiment, the composition (X) contains a liquid epoxy compound (A), a liquid aromatic amine compound (B), an inorganic filler (C), an epoxidized fatty acid ester compound (D-1), and at least one compound selected from the group consisting of a compound (E-1) having a quaternary phosphonium cation structure and a compound (E-2) having a silicate anion structure.

[0021] (Epoxy Compound) As described above, the epoxy compound (A) is liquid. Liquid means that it has the property of flowing at 25°C. All components contained in the epoxy compound (A) may be liquid. However, for example, the epoxy compound (A) may contain a liquid component and a solid component, and by mixing the components, the epoxy compound (A) as a whole may be liquid. The liquid epoxy compound (A) can impart fluidity to the composition (X).

[0022] The viscosity of the epoxy compound (A) at 25°C is preferably 100 Pa s or less. This viscosity is more preferably 50 Pa s or less, and even more preferably 20 Pa s or less. Furthermore, the viscosity of the epoxy compound (A) at 25°C is, for example, 0.01 Pa s or more. This viscosity is more preferably 0.02 Pa s or more.

[0023] The epoxy compound (A) preferably contains a compound having two or more epoxy groups in one molecule, which can enhance the reactivity of the epoxy compound (A) with the aromatic amine compound (B).

[0024] The epoxy equivalent of the epoxy compound (A) is, for example, 50 g / eq. or more and 500 g / eq. or less. In this case, the reactivity of the epoxy compound (A) with the aromatic amine compound (B) can be increased. The epoxy equivalent of this epoxy compound (A) is preferably 80 g / eq. or more. The epoxy equivalent of this epoxy compound (A) is preferably 300 g / eq. or less.

[0025] The epoxy compound (A) includes at least one selected from the group consisting of, for example, silicone-modified epoxy compounds (a1), glycidylamine-type epoxy compounds (a2), bisphenol-type epoxy compounds (a3), p-aminophenol-type epoxy compounds, naphthalene-type epoxy compounds, bisphenol-type epoxy compounds, epoxy compounds obtained by epoxidizing novolac compounds obtained by reacting phenols, such as orthocresol novolac-type epoxy compounds, with aldehydes, glycidyl ester-type epoxy compounds obtained by reacting polybasic acids, such as phthalic acid and dimer acid, with epichlorohydrin, and aminodiphenylmethane and isocyanuric acid-type epoxy compounds. The epoxy compound (A) preferably includes at least one selected from the group consisting of silicone-modified epoxy compounds (a1) and glycidylamine-type epoxy compounds (a2).

[0026] The silicone-modified epoxy compound (a1) can easily maintain the performance of the cured product when exposed to high temperatures and can easily increase the fluidity of the composition (X) under heating. This is thought to be because the silicone skeleton of the silicone-modified epoxy compound (a1) has high heat resistance, and the silicon-oxygen bond in the silicone skeleton flexibly modifies the molecular chain of the silicone-modified epoxy compound (a1), thereby lowering the viscosity of the composition (X).

[0027] The glycidylamine epoxy compound (a2) also contains a nitrogen atom in its molecule. The nitrogen atom contained in the glycidylamine epoxy compound (a2) can react with the epoxy group contained in the epoxy compound (A). This can appropriately increase the number of crosslinking points in the cured product. As a result, abnormal appearance and damage to the cured product when exposed to high temperatures can be more easily prevented.

[0028] The number of epoxy groups in one molecule of the glycidylamine epoxy compound (a2) is preferably 3 or more. In this case, the performance of the cured product is more likely to be maintained when exposed to high temperatures. Furthermore, the number of epoxy groups is preferably 10 or less. In this case, the number of crosslinking points in the cured product does not become excessively large, making it easier to suppress destruction of the cured product. The number of epoxy groups is more preferably 6 or less, and even more preferably 4 or less.

[0029] It is more preferred that the epoxy compound (A) further contains a bisphenol-type epoxy compound (a3) ​​in addition to containing at least one selected from the group consisting of a silicone-modified epoxy compound (a1) and a glycidylamine-type compound (a2). In other words, it is more preferred that the epoxy compound (A) contains at least one selected from the group consisting of a silicone-modified epoxy compound (a1), a glycidylamine-type epoxy compound (a2), and a bisphenol-type epoxy compound (a3).

[0030] The bisphenol epoxy compound (a3) ​​can improve the heat resistance of the cured product and the fluidity of the composition (X) in a well-balanced manner. The bisphenol epoxy compound (a3) ​​includes, for example, at least one selected from the group consisting of bisphenol A epoxy compounds, bisphenol F epoxy compounds, and bisphenol S epoxy compounds.

[0031] When the epoxy compound (A) contains at least one selected from the group consisting of a silicone-modified epoxy compound (a1), a glycidylamine-type epoxy compound (a2), and a bisphenol-type epoxy compound (a3), the total proportion of the silicone-modified epoxy compound (a1), the glycidylamine-type epoxy compound (a2), and the bisphenol-type epoxy compound (a3) ​​is preferably 30% by mass or more relative to the epoxy compound (A). In this case, a composition (X) is easily obtained that has higher fluidity at high temperatures and can further suppress abnormal appearance and damage to the cured product when exposed to high temperatures. This proportion is more preferably 50% by mass or more, and even more preferably 70% by mass or more.

[0032] (Aromatic Amine Compound) The aromatic amine compound (B) can improve the heat resistance of the cured product. As described above, the aromatic amine compound (B) is liquid. All components contained in the aromatic amine compound (B) may be liquid. However, for example, the aromatic amine compound (B) may contain a liquid component and a solid component, and by mixing the components, the aromatic amine compound (B) as a whole may be liquid. Note that the liquid aromatic amine compound (B) can impart fluidity to the composition (X).

[0033] The aromatic amine compound (B) preferably contains an aromatic amine compound having two or more amino groups in one molecule. In this case, the reactivity of the epoxy compound (A) with the aromatic amine compound (B) can be further enhanced. As a result, the curability of the composition (X) and the heat resistance of the cured product can be further enhanced.

[0034] Examples of the aromatic amine compound (B) include aliphatic aromatic amine compounds such as m-xylenediamine; aromatic amine compounds having one aromatic ring such as metaphenylenediamine, 1,3-diaminotoluene, 1,4-diaminotoluene, 2,4-diaminotoluene, 3,5-diethyl-2,4-diaminotoluene, 3,5-diethyl-2,6-diaminotoluene, 2,4-diaminoanisole, and dimethylthiotoluenediamine; and aromatic amine compounds having one aromatic ring such as 2,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone, 4,4'-methylenebis(2-ethylaniline). and at least one selected from the group consisting of aromatic amine compounds having two aromatic rings, such as 3,3'-dimethyl-4,4'-diaminodiphenylmethane, 3,3'-diethyl-4,4'-diaminodiphenylmethane, 3,3',5,5'-tetramethyl-4,4'-diaminodiphenylmethane, 3,3',5,5'-tetraethyl-4,4'-diaminodiphenylmethane, and polytetramethylene oxide diparaaminobenzoate; condensates of aromatic diamines and epichlorohydrin; and reaction products of aromatic diamines and styrene.

[0035] The amine active hydrogen equivalent of the aromatic amine compound (B) is, for example, 20 g / eq. or more and 500 g / eq. or less. In this case, the reactivity of the epoxy compound (A) and the aromatic amine compound (B) can be increased. The amine active hydrogen equivalent means the mass (g) of the aromatic amine compound (B) containing 1 mole of amine active hydrogen. The amine active hydrogen equivalent of the aromatic amine compound (B) is preferably 30 g / eq. or more. The amine active hydrogen equivalent of the aromatic amine compound (B) is preferably 100 g / eq. or less.

[0036] The equivalent ratio of the amine active hydrogen of the aromatic amine compound (B) to the epoxy group of the epoxy compound (A) is preferably 0.5 or more and 1.5 or less. In this case, the epoxy compound (A) and the aromatic amine compound (B) can react particularly efficiently. Therefore, the heat resistance of the cured product can be appropriately improved. This equivalent ratio is more preferably 0.6 or more, and even more preferably 0.7 or more. This equivalent ratio is more preferably 1.3 or less, and even more preferably 1.2 or less.

[0037] (Inorganic filler) The inorganic filler (C) contains at least one selected from the group consisting of silica powders such as fused silica powder, synthetic silica powder and crystalline silica powder; metal oxide powders such as alumina powder and titanium oxide powder; sulfate powders or sulfite powders such as barium sulfate powder, calcium sulfate powder and calcium sulfite powder; borate powders such as zinc borate powder, barium metaborate powder, aluminum borate powder, calcium borate powder and sodium borate powder; and nitride powders such as aluminum nitride powder, boron nitride powder and silicon nitride powder.It is more preferable that the inorganic filler (C) contains silica powder.Silica powder can particularly contribute to reducing the linear expansion coefficient of the cured product.

[0038] The shape of the inorganic filler (C) is not particularly limited and may be crushed, needle-like, scaly, spherical, etc. In order to improve the dispersibility of the inorganic filler (C) in the composition (X) and to control the viscosity of the composition (X), the shape of the inorganic filler (C) is preferably spherical.

[0039] The inorganic filler (C) is preferably surface-treated with a surface treatment agent. In this case, the dispersibility of the inorganic filler (C) in the composition (X) can be improved. This can suppress a decrease in the fluidity of the composition (X) due to the inorganic filler (C). The surface treatment agent includes, for example, at least one selected from the group consisting of silane compounds, titanium compounds, aluminum chelates, and aluminum / zirconium compounds. The silane compound includes, for example, at least one selected from the group consisting of silane compounds having an amino group, silane compounds having an acrylic group, silane compounds having a methacryl group, silane compounds having an epoxy group, mercaptosilane, alkylsilane, ureidosilane, and vinylsilane. Among these, the silane compound preferably includes at least one selected from the group consisting of silane compounds having an amino group, silane compounds having a methacryl group, and silane compounds having an epoxy group. Furthermore, the silane compound having an amino group preferably contains a silane compound having a phenylamino group. Therefore, it is particularly preferred that the inorganic filler (C) contains silica powder surface-treated with a silane compound having at least one group selected from the group consisting of a phenylamino group, a methacryl group, and an epoxy group, which can particularly enhance the dispersibility of the inorganic filler (C) in the composition (X).

[0040] The inorganic filler (C) preferably includes a first inorganic filler (c1) having an average particle size of less than 0.1 μm and a second inorganic filler (c2) having an average particle size of 0.4 μm or more and 2.0 μm or less. In this case, the increase in viscosity of the composition (X) due to the inorganic filler (C) can be suppressed, thereby maintaining good fluidity of the composition (X). The average particle size of the first inorganic filler (c1) is more preferably 0.08 μm or less, and even more preferably 0.06 μm or less. The average particle size of the second inorganic filler (c2) is more preferably 0.6 μm or more, and even more preferably 0.8 μm or more. The average particle size of the second inorganic filler (c2) is more preferably 1.6 μm or less, and even more preferably 1.3 μm or less.

[0041] When the inorganic filler (C) contains the first inorganic filler (c1) and the second inorganic filler (c2), the total proportion of the first inorganic filler (c1) and the second inorganic filler (c2) is preferably 20% by mass or more, more preferably 50% by mass or more, and even more preferably 70% by mass or more, relative to the inorganic filler (C).

[0042] The proportion of the inorganic filler (C) is preferably 45% by mass or more and 80% by mass or less relative to the total amount of the composition (X). When the proportion of the inorganic filler (C) is 45% by mass or more, destruction of the cured product can be further suppressed. When the proportion of the inorganic filler (C) is 80% by mass or less, the fluidity of the composition (X) can be maintained well. This proportion is more preferably 55% by mass or more, and even more preferably 60% by mass or more. This proportion is more preferably 76% by mass or less, and even more preferably 72% by mass or less.

[0043] The content of the inorganic filler (C) is preferably 100 parts by mass or more and 500 parts by mass or less, relative to 100 parts by mass of the total of the epoxy compound (A), the aromatic amine compound (B), and the epoxidized fatty acid ester compound (D-1). In this case, high fluidity can be easily achieved at high temperatures, and abnormal appearance and destruction of the cured product when exposed to high temperatures can be further suppressed. This content is more preferably 150 parts by mass or more, and even more preferably 200 parts by mass or more. This content is more preferably 400 parts by mass or less, and even more preferably 350 parts by mass or less.

[0044] (Stress Reducing Agent) The stress reducing agent (D) is a component that can increase the flexibility of the cured product and suppress fracture of the cured product. In an embodiment, the composition (X) contains the stress reducing agent (D), and the stress reducing agent (D) contains an epoxidized fatty acid ester compound (D-1). Note that the epoxidized fatty acid ester compound (D-1) is a different compound from the epoxy compound (A), and therefore, in the present disclosure, the epoxidized fatty acid ester compound (D-1) is not included in the epoxy compound (A).

[0045] <Epoxidized Fatty Acid Ester Compound> The epoxidized fatty acid ester compound (D-1) includes a compound in which an unsaturated bond in an unsaturated fatty acid has been epoxidized (hereinafter also referred to as an epoxidized fatty acid) and a polyhydric alcohol such as glycerin are linked via an ester bond. Such a compound can be produced by epoxidizing the unsaturated bond in the unsaturated fatty acid in a compound in which an unsaturated fatty acid and a polyhydric alcohol are ester-linked (hereinafter also referred to as a fatty acid ester compound). The epoxidized fatty acid may be obtained by epoxidizing only a portion of the unsaturated bonds in the unsaturated fatty acid per molecule; not all of the unsaturated bonds need to be epoxidized. The epoxy equivalent of the epoxidized fatty acid ester compound (D-1) is not particularly limited, but is preferably 150 g / eq. or more, more preferably 180 g / eq. or more, and even more preferably 210 g / eq. or more, from the viewpoint of further suppressing abnormalities in the appearance of the cured product. The upper limit of this epoxy equivalent is not particularly limited, but is preferably 1000 g / eq. or less, and more preferably 700 g / eq. or less. It is more preferably 500 g / eq. or less, and even more preferably 500 g / eq. or less.

[0046] The polyhydric alcohol forming the fatty acid ester compound is not limited to glycerin, and may include at least one selected from the group consisting of glycerin, diglycerin, polyglycerin, sorbitol, maltitol, glyceryl glycoside, and the like.

[0047] The number of carbon atoms of the unsaturated fatty acid is preferably 4 or more and 40 or less. In this case, the fluidity of the composition (X) at high temperatures can be further improved, while the flexibility of the cured product can be further improved and the breakage of the cured product can be further suppressed. The number of carbon atoms is more preferably 8 or more, and even more preferably 12 or more. The number of carbon atoms is more preferably 36 or less, and even more preferably 32 or less. Specific examples of unsaturated fatty acids include crotonic acid, myristoleic acid, palmitoleic acid, sapienic acid, oleic acid, elaidic acid, vaccenic acid, gadoleic acid, eicosenoic acid, erucic acid, nervonic acid, linoleic acid, eicosadienoic acid, docosadienoic acid, linolenic acid, pinolenic acid, eleostearic acid, mead acid, dihomo-γ-linolenic acid, eicosatrienoic acid, stearidonic acid, arachidonic acid, eicosatetraenoic acid, adrenic acid, bosseopentaenoic acid, eicosapentaenoic acid, osbondo acid, sardine acid, tetracosapentaenoic acid, docosahexaenoic acid, and herring acid. The unsaturated fatty acid preferably includes at least one selected from the group consisting of oleic acid, linoleic acid, linolenic acid, etc.

[0048] The fatty acid ester compound may be a fat or oil. Therefore, the fatty acid ester compound includes at least one selected from the group consisting of, for example, rapeseed oil, soybean oil, linseed oil, castor oil, coconut oil, palm oil, palm kernel oil, sunflower oil, rice bran oil, safflower oil, beef tallow, and lard. Therefore, the epoxidized fatty acid ester compound (D-1) includes at least one epoxidized fat or oil (hereinafter also referred to as epoxidized oil) selected from the group consisting of, for example, epoxidized rapeseed oil, epoxidized soybean oil, epoxidized linseed oil, epoxidized castor oil, epoxidized coconut oil, epoxidized palm oil, epoxidized palm kernel oil, epoxidized sunflower oil, epoxidized rice bran oil, epoxidized safflower oil, epoxidized beef tallow, and epoxidized lard. General rapeseed oil contains 63.5% oleic acid, an unsaturated fatty acid with 18 carbon atoms, 19.3% linoleic acid, an unsaturated fatty acid with 18 carbon atoms, 9.0% linolenic acid, an unsaturated fatty acid with 18 carbon atoms, 4.1% palmitic acid, a saturated fatty acid with 16 carbon atoms, and 1.7% stearic acid, a saturated fatty acid with 18 carbon atoms. General flaxseed oil contains 18.3% oleic acid, an unsaturated fatty acid with 18 carbon atoms, 14.3% linoleic acid, an unsaturated fatty acid with 18 carbon atoms, 53.4% ​​linolenic acid, an unsaturated fatty acid with 18 carbon atoms, 5.1% palmitic acid, a saturated fatty acid with 16 carbon atoms, and 3.4% stearic acid, a saturated fatty acid with 18 carbon atoms.

[0049] The epoxy fatty acid ester compound (D-1) also includes an epoxidized fatty acid alkyl ester compound in which an epoxidized fatty acid and an alkyl alcohol are bonded together. The epoxidized fatty acid alkyl ester has a structure in which an epoxidized fatty acid and an alkyl alcohol are linked together via an ester bond.

[0050] For example, an epoxidized fatty acid alkyl ester compound can be obtained by isolating an epoxidized fatty acid from an epoxidized oil and then esterifying the isolated epoxidized fatty acid with an alkyl alcohol. Examples of methods for isolating an epoxidized fatty acid include saponifying the epoxidized oil. The production procedure is not particularly limited as long as an epoxidized fatty acid alkyl ester compound can be obtained. For example, an epoxidized fatty acid alkyl ester compound can be obtained by isolating an unsaturated fatty acid from a fatty acid ester compound before epoxidation, reacting the unsaturated fatty acid with an alkyl alcohol, and then epoxidizing the unsaturated fatty acid. Alternatively, an epoxidized fatty acid alkyl ester compound can be obtained by isolating an unsaturated fatty acid from a fatty acid ester compound before epoxidation, epoxidizing the unsaturated fatty acid, and then reacting the unsaturated fatty acid with an alkyl alcohol. The alkyl alcohol is not particularly limited, but an alkyl alcohol having 1 to 20 carbon atoms can be used, for example. Examples of the alkyl alcohol include at least one selected from the group consisting of methanol, ethanol, propanol, butanol, pentanol, hexanol, isobutyl alcohol, heptanol, octanol, and 2-ethylhexyl alcohol.

[0051] It is particularly preferred that the epoxidized fatty acid ester compound (D-1) contains at least one selected from the group consisting of epoxidized rapeseed fatty acid 2-ethylhexyl and epoxidized linseed oil, which makes it particularly easy to reduce the viscosity of the composition (X).

[0052] The proportion of the epoxidized fatty acid ester compound (D-1) is preferably 0.2% by mass or more and 4% by mass or less relative to the composition (X). If this proportion is 0.2% by mass or more, destruction of the cured product can be further suppressed. If this proportion is 4.0% by mass or less, the enhanced fluidity of the composition (X) can be maintained. This proportion is more preferably 0.4% by mass or more, and even more preferably 0.6% by mass or more. This proportion is more preferably 3.0% by mass or less, and even more preferably 2.0% by mass or less.

[0053] It is preferable that the stress reducing agent (D) in the composition (X) further contains core-shell type rubber particles (D-2). In this case, destruction of the cured product when exposed to high temperatures can be further suppressed. The core-shell type rubber particles (D-2) have a core and a shell. The core is a particulate rubber. The shell is a graft layer that covers the core.

[0054] The core contains at least one substance selected from the group consisting of, for example, a (meth)acrylic acid polymer, a (meth)acrylic acid ester polymer, an olefin compound polymer, polybutadiene, and silicone. The core of the core-shell rubber particles (D-2) preferably contains silicone. In this case, destruction of the cured product can be further suppressed.

[0055] The shell contains at least one substance selected from the group consisting of, for example, a styrene-acrylonitrile copolymer, a (meth)acrylic acid polymer, polybutadiene, and silicone. The shell of the core-shell rubber particles (D-2) preferably contains silicone. In this case, destruction of the cured product can be further suppressed.

[0056] Commercially available products can be used as the core-shell rubber (D-2). For example, silicone rubber particles include Kane Ace (registered trademark) MX-965 manufactured by Kaneka Corporation. Butadiene rubber particles include Kane Ace (registered trademark) MX-136 and MX-139 manufactured by Kaneka Corporation.

[0057] The average particle size of the core-shell rubber particles (D-2) is less than 1.0 μm. In this case, when the core-shell rubber particles (D-2) having a small average particle size as described above are contained in the composition (X), destruction of the cured product is more likely to be suppressed. The lower limit of the average particle size of the core-shell rubber particles (D-2) is not particularly limited, but is, for example, 0.1 μm or more. In the present disclosure, "average particle size" means the particle size at 50% of the integrated value in the particle size distribution determined by a laser diffraction / scattering method.

[0058] The proportion of the core-shell rubber particles (D-2) relative to the composition (X) is preferably 0.1% by mass or more and 8.0% by mass or less. If this proportion is 0.1% by mass or more, destruction of the cured product can be further suppressed. If this proportion is 8.0% by mass or less, the fluidity of the composition (X) can be easily increased. This proportion is more preferably 0.5% by mass or more. This proportion is more preferably 4.0% by mass or less.

[0059] (Superfluidizer) The superfluidizer (E) is a component that improves the fluidity of the composition (X). Examples of the superfluidizer (E) include organic salts. In an embodiment, the composition (X) contains the superfluidizer (E), and the superfluidizer (E) contains at least one selected from the group consisting of a compound (E-1) having a quaternary phosphonium cation (hereinafter also referred to as compound (E-1)) and a compound (E-2) having a silicate anion (hereinafter also referred to as compound (E-2)).

[0060] <Compound Having a Quaternary Phosphonium Cation> The compound (E-1) can reduce the viscosity of the composition (X) when it is heated, and can improve the fluidity. The quaternary phosphonium cation has, for example, a structure represented by formula (1).

[0061]

[0062] In formula (1), R １ ~R ４ are the same or different and each represents a substituted or unsubstituted hydrocarbon group having 1 to 12 carbon atoms. １ ~R ４ Each of the groups preferably has 4 to 6 carbon atoms in terms of curability, storage stability, and fluidity. Specific examples of the hydrocarbon group include a methyl group, an ethyl group, a propyl group, an n-butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, a dodecyl group, a cyclohexyl group, a phenyl group, a methoxymethyl group, and a benzyl group. Of these, an n-butyl group or a phenyl group is preferred.

[0063] The anion contained in the compound (E-1) is not particularly limited. Examples of the anion contained in the compound (E-1) include Cl. － ,Br－ , I － Monoatomic anions such as BF ４ － , P.F. ６ － inorganic anions having a fluorine atom such as NO ３ － , NO ２ － inorganic anions not containing fluorine atoms, such as CF ３ SO ３ － , (CF ３ SO ２ ) ２ N － , (CF ３ SO ２ ) ２ C － , (C ２ F ５ SO ２ ) ２ N － an organic anion having a fluorine atom, such as (CH ３ CH ２ O) ２ P.O. － , (CN) ２ N － , C.H. ３ COO － The anion contains at least one selected from the group consisting of organic anions not having a fluorine atom, such as:

[0064] <Compound Having Silicate Anion> The compound (E-2) can reduce the viscosity of the composition (X) when it is heated, and can improve the fluidity. The silicate anion has, for example, a skeleton derived from dihydroxynaphthalene or catechol. The silicate anion has, for example, a structure represented by formula (2).

[0065]

[0066] In formula (2), R ５ and R ６ are each independently a phenylene group or a naphthylene group. ７ is a phenyl group or a group represented by formula (3).

[0067]

[0068] In formula (3), n is 3 or more and 8 or less. In formula (3), X is —SH, —NH ２ , -NH-Ph, -Ph-CH=CH ２ , —NH—C ２ H ４ -NH ２ , —N═C═O, a glycidyl ether group, or a group represented by formula (4).

[0069]

[0070] In the present disclosure, "-Ph" in "-NH-Ph" means a phenyl group, and "-Ph-CH=CH ２ "-Ph-" in "" means a phenylene group.

[0071] The cation contained in the compound (E-2) is not particularly limited, and includes, for example, at least one selected from the group consisting of aliphatic onium cations such as ammonium cations, sulfonium cations, and phosphonium cations; alicyclic cations such as pyrrolidinium cations; and aromatic cations such as imidazolium cations and pyridinium cations.

[0072] The superplasticizer may include a compound having a quaternary phosphonium cation and a silicate anion. The compound having a quaternary phosphonium cation and a silicate anion corresponds to both the compound (E-1) and the compound (E-2).

[0073] The total proportion of compound (E-1) and compound (E-2) is preferably 0.01% by mass or more and 0.5% by mass or less relative to composition (X). When this proportion is 0.01% by mass or more, the viscosity of composition (X) at high temperatures can be reduced. When this proportion is 0.5% by mass or less, the storage stability of composition (X) is further improved and high curability can be sufficiently maintained. The proportion of this compound is more preferably 0.02% by mass or more, and even more preferably 0.05% by mass or more. This proportion is more preferably 0.3% by mass or less, and even more preferably 0.2% by mass or less.

[0074] (Silane Coupling Agent) The composition (X) may further contain a silane coupling agent (F). The silane coupling agent (F) adheres to the surface of the inorganic filler (C) and can suppress the generation of ions that may be generated from the inorganic filler (C). This can further reduce the viscosity of the composition (X).

[0075] Examples of the silane coupling agent (F) include vinyl silanes such as vinyltrimethoxysilane and vinyltriethoxysilane; epoxy silanes such as 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 3-glycidoxypropyltriethoxysilane; styryl silanes such as p-styryltrimethoxysilane; methacryl silanes such as 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, and 3-methacryloxypropyltriethoxysilane; acrylic silanes such as 3-acryloxypropyltrimethoxysilane; N-2-(acryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, and 3-methacryloxypropyltriethoxysilane; and at least one selected from the group consisting of aminosilanes such as N-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethylbutylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, and phenylaminopropyltrimethoxysilane; isocyanurate silanes; alkyl silanes; ureido silanes such as 3-ureidopropyltrialkoxysilane; mercapto silanes such as 3-mercaptopropylmethyldimethoxysilane and 3-mercaptopropyltrimethoxysilane; and isocyanate silanes such as 3-isocyanatopropyltriethoxysilane.

[0076] The proportion of the silane coupling agent (F) is 0.1 mass % or more and 2.0 mass % or less with respect to the composition (X).

[0077] (Additives) The composition (X) may contain, as necessary, a component other than the components listed above (hereinafter referred to as additive (G)). The additive (G) contains, for example, at least one selected from the group consisting of an antioxidant, a curing aid, a colorant, a thixotropic agent, an ion trapping agent, an antifoaming agent, a leveling agent, and an antioxidant. The proportion of the additive (G) is preferably 1.0 mass% or less relative to the composition (X).

[0078] (Solvent) The composition (X) may contain a solvent (H). However, it is preferable that the composition (X) does not contain a solvent (H) or contains only a trace amount of the solvent (H) that is inevitably mixed in. The proportion of the solvent (H) is preferably 1.0 mass% or less based on the solid content of the composition (X). The solid content of the composition (X) means the components contained in the composition (X) excluding volatile components such as the solvent (H).

[0079] (Viscosity) In this embodiment, composition (X) is liquid. Composition (X) being liquid means that composition (X) has fluidity at 25°C. If the viscosity of composition (X) at 25°C, measured using a Brookfield rotational viscometer (TVB-10, manufactured by Toki Sangyo Co., Ltd.) at a rotation speed of 20 rpm, is 200 Pa s or less, composition (X) can be considered liquid. The viscosity of composition (X) is preferably 100 Pa s or less, more preferably 50 Pa s or less, and even more preferably 30 Pa s or less. Furthermore, the viscosity of composition (X) at 110°C is preferably 1 Pa s or less, more preferably 0.5 Pa s or less, and even more preferably 0.3 Pa s or less. The method for measuring the 110°C viscosity will be explained in the Examples section below.

[0080] 3. Semiconductor Device (Semiconductor Encapsulating Material and Underfill Material) Composition (X) can be used in semiconductor encapsulating materials, and is particularly preferably used in underfill materials. That is, the semiconductor encapsulating material according to the embodiment contains composition (X), and the underfill material according to the embodiment contains composition (X). The semiconductor encapsulating material is a material for producing an encapsulating portion 5 that protects the semiconductor element 3 by covering part or all of the semiconductor element 3. Furthermore, the underfill material is a semiconductor encapsulating material that is used to produce the encapsulating portion 5 that is interposed in the gap between the substrate 2 and the semiconductor element 3 surface-mounted on the substrate 2.

[0081] When the encapsulating part 5 is produced from the semiconductor encapsulating material or underfill material according to the embodiment, molding defects such as insufficient filling can be suppressed because the composition (X) has high particle size at high temperatures during production of the encapsulating part 5. Furthermore, damage such as cracks in the encapsulating part 5 at high temperatures is suppressed, and the occurrence of abnormal appearance of the encapsulating part 5 at high temperatures is suppressed.

[0082] (Semiconductor Device) The semiconductor device 1 according to the embodiment includes a sealing portion 5 made from the semiconductor sealing material or underfill material according to the embodiment.

[0083] When the semiconductor device 1 has a sealing portion 5 made from an underfill material, the semiconductor device 1 has a substrate 2, a semiconductor element 3 mounted on the substrate 2, and a sealing portion 5 interposed in the gap between the substrate 2 and the semiconductor element 3, and the sealing portion 5 includes a hardened product of the underfill material.

[0084] The substrate 2 includes an insulating substrate such as a glass epoxy substrate, a polyimide substrate, a polyester substrate, or a ceramic substrate, and conductive wiring 21 overlaid on the insulating substrate. The conductive wiring 21 includes, for example, electrode pads. The substrate 2 is, for example, a motherboard, a package substrate, or an interposer substrate.

[0085] The semiconductor element 3 may be any suitable surface-mount type element. The semiconductor element 3 has bump electrodes 31 on the surface facing the substrate 2. The semiconductor element 3 may be a bare chip, a packaged component, or a wafer-level package. The semiconductor element 3 may be a flip-chip type chip such as a BGA (ball grid array), an LGA (land grid array), or a CSP (chip-size package). The semiconductor element 3 may also be a PoP (package-on-package) type chip.

[0086] A semiconductor element 3 is surface-mounted on the substrate 2. More specifically, the surface of the semiconductor element 3 having bump electrodes 31 faces the substrate 2, the bump electrodes 31 on the semiconductor element 3 are joined to the electrode pads of the conductor wiring 21 on the substrate 2 by solder bumps 4, and the bump electrodes 31 are electrically connected to the electrode pads by the solder bumps 4. Note that the manner of connection between the semiconductor element 3 and the substrate 2 is not limited to the above, as long as the semiconductor element 3 is mounted on the substrate 2 so that a gap is left between the semiconductor element 3 and the substrate 2.

[0087] The sealing portion 5 is interposed in the gap between the semiconductor element 3 and the substrate 2. Therefore, the bump electrodes 31, the solder bumps 4, and the electrode pads of the conductor wiring 21 are buried in the sealing portion 5.

[0088] (Method for Manufacturing Semiconductor Device) An example of a method for manufacturing the semiconductor device 1 will be described.

[0089] First, the substrate 2, the semiconductor element 3, and the underfill material are prepared.

[0090] Next, the semiconductor element 3 is surface-mounted on the substrate 2. Specifically, the surface of the semiconductor element 3 having the bump electrodes 31 is placed opposite the substrate 2, and solder bumps 4 are interposed between the bump electrodes 31 on the semiconductor element 3 and the electrode pads of the conductor wiring 21 on the substrate 2. The solder contained in the solder bumps 4 is a lead-free solder with a melting point of 210°C or higher, such as Sn-3.5Ag (melting point 221°C), Sn-2.5Ag-0.5Cu-1Bi (melting point 214°C), Sn-0.7Cu (melting point 227°C), or Sn-3Ag-0.5Cu (melting point 217°C). In this state, the solder bumps 4 are heated and melted by an appropriate heating method such as reflow heating, and then solidified. The heating temperature is set appropriately depending on the solder bumps 4 so that the solder bumps 4 melt, but for example, the maximum heating temperature is 180°C or higher and 300°C or lower. As a result, the conductor wiring 21 and the electrode pads are joined by the solder bumps 4, and the conductor wiring 21 and the electrode pads are electrically connected by the solder bumps 4.

[0091] Next, an underfill material is injected into the gap between the semiconductor element 3 and the substrate 2 using a dispenser or the like. The underfill material flows through the gap between the semiconductor element 3 and the substrate 2 due to capillary action. When causing the composition (X) to flow, the viscosity of the composition (X) may be reduced by heating the composition (X) as needed. In this case, the heating temperature of the composition (X) is, for example, 80°C or higher and 130°C or lower. This allows the underfill material to fill the gap between the semiconductor element 3 and the substrate 2. In the embodiment, the fluidity of the underfill material can be increased when the underfill material is heated as described above. Therefore, the underfill material can be successfully filled into the gap between the semiconductor element 3 and the substrate 2. In this state, the underfill material is heated to harden it. The heating conditions in this case are appropriately set depending on the composition of the composition (X); for example, the heating temperature is 80°C or higher and 180°C or lower, and the heating time is 60 minutes or higher and 300 minutes or lower. This produces a sealing portion 5 containing a cured underfill material in the gap between the semiconductor element 3 and the substrate 2.

[0092] In the embodiment, the underfill material can have high fluidity, which can prevent insufficient filling of the composition (X) and the sealing portion 5 between the semiconductor element 3 and the substrate 2.

[0093] The method for manufacturing the semiconductor device 1 is not limited to the above.

[0094] 4. Aspects As is apparent from the above embodiments, the present disclosure includes the following embodiments.

[0095] The liquid resin composition according to the first aspect of the present disclosure contains a liquid epoxy compound (A), a liquid aromatic amine compound (B), an inorganic filler (C), a stress reducing agent (D), and a fluidizing agent (E). The stress reducing agent (D) contains an epoxidized fatty acid ester compound (D-1). The fluidizing agent (E) contains at least one compound selected from the group consisting of a compound (E-1) having a quaternary phosphonium cation structure and a compound (E-2) having a silicate anion structure.

[0096] According to this embodiment, it is possible to provide a liquid resin composition that has high fluidity at high temperatures and that can suppress abnormal appearance and damage to the cured product when exposed to high temperatures.

[0097] In the liquid resin composition according to the second aspect of the present disclosure, in the first aspect, the epoxy compound (A) has a viscosity at 25°C of 100 Pa·s or less.

[0098] In the liquid resin composition according to the third aspect of the present disclosure, in the first or second aspect, the epoxidized fatty acid ester compound (D-1) includes at least one selected from the group consisting of epoxidized rapeseed fatty acid 2-ethylhexyl and epoxidized linseed oil.

[0099] In the liquid resin composition according to the fourth aspect of the present disclosure, in any one of the first to third aspects, the stress reducing agent (D) further contains core-shell type rubber particles (D-2).

[0100] In the liquid resin composition according to the fifth aspect of the present disclosure, in any one of the first to fourth aspects, the epoxy compound (A) includes at least one selected from the group consisting of silicone-modified epoxy compounds (a1) and glycidylamine-type epoxy compounds (a2).

[0101] In the liquid resin composition according to the sixth aspect of the present disclosure, in any one of the first to fifth aspects, the epoxy compound (A) further contains a bisphenol-type epoxy compound (a3).

[0102] In any one of the first to sixth aspects of the liquid resin composition according to the seventh aspect of the present disclosure, the content of the inorganic filler (C) is 100 parts by mass or more and 500 parts by mass or less, relative to 100 parts by mass in total of the epoxy compound (A), the aromatic amine compound (B), and the epoxidized fatty acid ester compound (D-1).

[0103] In the liquid resin composition according to the eighth aspect of the present disclosure, in any one of the first to seventh aspects, the inorganic filler (C) includes a first inorganic filler (c1) having an average particle size of less than 0.1 μm and a second inorganic filler (c2) having an average particle size of 0.4 μm or more and 2.0 μm or less.

[0104] The liquid resin composition according to the ninth aspect of the present disclosure is any one of the first to eighth aspects, further comprising a silane coupling agent (F).

[0105] A semiconductor encapsulation material according to a tenth aspect of the present disclosure contains the liquid resin composition according to any one of the first to ninth aspects.

[0106] An underfill material according to an eleventh aspect of the present disclosure contains the liquid resin composition according to any one of the first to ninth aspects.

[0107] A semiconductor device (1) according to a twelfth aspect of the present disclosure includes a substrate (2), a semiconductor element (3) mounted on the substrate (2), and a sealing portion (5) interposed in a gap between the substrate (2) and the semiconductor element (3). The sealing portion (5) includes a cured product of the underfill material of the eleventh aspect.

[0108] Specific examples of the embodiments will be described below, but the present disclosure is not limited to these examples.

[0109] 1. Preparation of Compositions Compositions were prepared by mixing the components shown in the table. Details of the components in the table are as follows: (Epoxy Compounds) - Epoxy Compound #1: Manufactured by Momentive Performance Materials Japan, LLC. Product name: TSL9906. Liquid silicone-modified epoxy resin (siloxane oligomer with glycidoxypropyl groups at both ends). Epoxy equivalent: 181 g / eq. - Epoxy Compound #2: Manufactured by ADEKA Corporation. Product name: EP-3950S. Liquid glycidylamine-type epoxy resin. Epoxy equivalent: 94 g / eq. - Epoxy Compound #3: Manufactured by Nippon Steel Chemical & Material Co., Ltd. Product name: YDF8170. Liquid bisphenol F-type epoxy resin. Epoxy equivalent: 160 g / eq.

[0110] (Aromatic amine compounds) - Aromatic amine compound #1: Manufactured by Nippon Kayaku Co., Ltd. Product name: KAYAHARD AA. Liquid aromatic amine resin. Amine active hydrogen equivalent: 63.5 g / eq. - Aromatic amine compound #2: Manufactured by Mitsubishi Chemical Corporation. Product name: JER Cure WA. Liquid aromatic amine compound. Amine equivalent: 45 g / eq. - Aromatic amine compound #3: Manufactured by ADEKA Corporation. Product name: EH-105L. Liquid aromatic amine compound. Amine equivalent: 61 g / eq.

[0111] (Inorganic fillers) - Inorganic filler #1: Silica with an average particle size of 0.7 μm that has been surface-treated with N-phenyl-3-aminopropyltrimethoxysilane. - Inorganic filler #2: Silica with an average particle size of 0.1 μm that has been surface-treated with phenyltrimethoxysilane. - Inorganic filler #3: Manufactured by Admatechs Co., Ltd. Product name: YA-050A-JER. A mixture of bisphenol F epoxy resin with an epoxy equivalent of 160 g / eq. and silica with an average particle size of 50 nm. Silica concentration: 50% by mass.

[0112] (Stress Reducing Agents) - Stress Reducing Agent #1: Kaneka Corporation, product name Kane Ace (registered trademark) MX-965, a mixture of bisphenol F epoxy resin with an epoxy equivalent of 160 g / eq. and core-shell rubber particles with a silicone rubber core, rubber particle concentration 25% by mass. - Stress Reducing Agent #2: ADEKA Corporation, product name Adeka Cizer D-32, epoxidized rapeseed fatty acid 2-ethylhexyl. Oxirane oxygen content 4.3% by mass. - Stress Reducing Agent #3: ADEKA Corporation, product name Adeka Cizer O-180A, epoxidized linseed oil. Oxirane oxygen content 8.5% by mass. - Stress Reducing Agent #4: Riken Nosan Kako Co., Ltd., product name Domestic Soybean Oil. Soybean oil (fatty acid ester compound). - Stress Reducing Agent #5: Nippun Corporation, product name Nippun Linseed Oil. Linseed oil (fatty acid ester compound).--Stress reducing agent #6: manufactured by Dow Toray Industries, Inc., product name FZ-3736, epoxy silicone compound.

[0113] (Superplasticizer) Superplasticizer #1: A compound represented by the following formula:

[0114]

[0115] Superplasticizer #2: a compound of the formula:

[0116]

[0117] Superplasticizer #3: a compound represented by the following formula:

[0118]

[0119] (Silane Coupling Agent) - Silane Coupling Agent #1: manufactured by Momentive Performance Materials Japan LLC, product name SILQUEST A-187 SILANE, 3-glycidoxypropyltrimethoxysilane.

[0120] 2. The evaluation compositions were subjected to the following evaluations, the results of which are shown in the table below.

[0121] (1) Viscosity at 25° C. The viscosity of the composition at 25° C. was measured using a B-type rotational viscometer (TVB-10, manufactured by Toki Sangyo Co., Ltd.) at a rotation speed of 20 rpm.

[0122] (2) The temperature dependence of the 110°C viscosity composition was measured using a rheometer (MCR-102, manufactured by Anton Paar) under conditions of a rotation speed of 1 rpm, a gap of 300 μm, and a temperature rise rate of 5°C / min, and the viscosity of the composition at 110°C was read from the results. If this result was 0.4 Pa s or less, the fluidity could be evaluated as good, and if it was 0.2 Pa s or less, the fluidity could be evaluated as particularly good.

[0123] (3) High-Temperature Retention Resistance 1) Method for Preparing Evaluation Samples 10 mg of the composition was applied in an X-shaped pattern to a silicon substrate measuring 25 mm × 25 mm × 775 μm. A 7 mm square (7 mm × 7 mm × 775 μm) silicon substrate was placed on the applied composition. In this state, the two silicon substrates and the composition were heated at 80°C for 60 seconds and then cooled to 25°C. As a result, the composition spread between the two silicon substrates, and a fillet of the composition protruded from the periphery of the 7 mm square silicon substrate. The silicon substrates and the composition were then heated at 100°C for 2 hours and then at 165°C for 2 hours to prepare evaluation samples.

[0124] 2) Crack Evaluation The samples prepared according to "1) Method for preparing evaluation samples" were heated at 175°C for 250 hours. The corners of the side surfaces of the 7 mm square silicon substrate and areas other than the corners were checked using an optical microscope (magnification 200x). Note that corner cracks refer to cracks that occur in the fillet portion of the cured composition in the vicinity of the 7 mm square silicon substrate.

[0125] 3) Presence or absence of separation: The samples prepared according to "1) Method for preparing samples for evaluation" were heated at 175°C for 250 hours and then observed under an optical microscope (magnification: 200x). If separated matter with a major axis length of 0.1 mm or more was observed during this observation, it was judged that separation had occurred.

[0126] 4) Presence or absence of discoloration in separated portion If it was confirmed that the color of the separated portion observed in the evaluation of "3) Presence or absence of separation" had changed compared to the color of the cured composition in the surrounding area, it was judged that discoloration had occurred. Discoloration means, for example, discoloration to black.

[0127]

[0128]

[0129] REFERENCE SIGNS LIST 1 semiconductor device 2 substrate 3 semiconductor element 5 sealing portion

Claims

1. A liquid resin composition comprising a liquid epoxy compound (A), a liquid aromatic amine compound (B), an inorganic filler (C), a stress-reducing agent (D), and a fluidity-improving agent (E), wherein the stress-reducing agent (D) comprises an epoxidized fatty acid ester compound (D-1), and the fluidity-improving agent (E) comprises at least one compound selected from the group consisting of a compound (E-1) having a quaternary phosphonium cation structure and a compound (E-2) having a silicate anion structure.

2. The liquid resin composition according to claim 1, wherein the viscosity of the epoxy compound (A) at 25°C is 100 Pa·s or less.

3. The liquid resin composition according to claim 1, wherein the epoxidized fatty acid ester compound (D-1) comprises at least one selected from the group consisting of epoxidized rapeseed fatty acid 2-ethylhexyl and epoxidized linseed oil.

4. The liquid resin composition according to claim 1, wherein the stress reducing agent (D) further contains core-shell type rubber particles (D-2).

5. The liquid resin composition according to claim 1, wherein the epoxy compound (A) comprises at least one selected from the group consisting of silicone-modified epoxy compounds (a1) and glycidylamine-type epoxy compounds (a2).

6. The liquid resin composition according to claim 5, wherein the epoxy compound (A) further contains a bisphenol-type epoxy compound (a3).

7. The liquid resin composition according to claim 1, wherein the content of the inorganic filler (C) is 100 parts by mass or more and 500 parts by mass or less relative to a total of 100 parts by mass of the epoxy compound (A), the aromatic amine compound (B), and the epoxidized fatty acid ester compound (D-1).

8. The liquid resin composition according to claim 1, wherein the inorganic filler (C) comprises a first inorganic filler (c1) having an average particle size of less than 0.1 μm and a second inorganic filler (c2) having an average particle size of 0.4 μm or more and 2.0 μm or less.

9. The liquid resin composition according to claim 1, further comprising a silane coupling agent (F).

10. A semiconductor encapsulating material containing the liquid resin composition according to any one of claims 1 to 9.

11. An underfill material containing the liquid resin composition according to any one of claims 1 to 9.

12. A semiconductor device comprising: a substrate; a semiconductor element mounted on said substrate; and a sealing portion interposed in a gap between said substrate and said semiconductor element, said sealing portion including a cured product of the underfill material according to claim 11.

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