Resin composition, semiconductor device, and methods for producing same

Abstract

Provided is a resin composition that is used as a capillary underfill (CUF) capable of further reducing filament cracking.　Provided is a resin composition containing (A) an epoxy resin, (B) a curing agent, and (C) a filler. A cured product of this resin composition has a stress intensity factor range ΔKth for the fatigue crack propagation lower limit of 0.55 MPa∙m0.5 or greater.

Description

Resin composition, semiconductor device, and manufacturing method thereof

[0001] The present disclosure relates to a resin composition. More specifically, the present disclosure relates to a resin composition used as a semiconductor encapsulant, particularly as an underfill material (CUF: Capillary Underfill), a semiconductor device using the resin composition, a method for manufacturing the semiconductor device, and a method for manufacturing the resin composition.

[0002] In the mounting of flip chip connections, BGA (Ball Grid Array), or CSP (Chip Size Package), stress or strain due to curing may accumulate in the fillet or bump bond where the underfill material protrudes around a semiconductor element or other electronic component. In this case, peeling or cracking may occur due to deformation caused by thermal shock, thermal expansion / contraction, moisture absorption, or heat treatment. Therefore, peeling or cracking occurring in the fillet or bump bond can significantly affect the connection reliability between the bump bonded portions, which can be a problem.

[0003] Furthermore, the solder used to form the bumps has been replaced with lead-free solder. This has resulted in higher reflow temperatures during mounting, increasing thermal stress. Compared to eutectic solder, lead-free solder has inferior mechanical strength. In addition, the adoption of copper pillar bumps has reduced the volume of lead-free solder applied, further reducing mechanical strength.

[0004] For these reasons, conventional underfill materials have the problem that peeling or cracking is likely to occur in the fillet portion, and peeling or cracking is likely to occur in the bump bonding portion.

[0005] Furthermore, as the number of bumps increases, the bump pitch and bump height become smaller. As a result, the gaps are becoming narrower. Furthermore, as higher integration increases, larger chips are being adopted. Therefore, underfill materials (CUF) are required to have the ability to flow over a large area even in narrow gaps.

[0006] In order to address this problem, attempts have been made to reduce the stress and increase the toughness of underfill materials (CUF) (see Patent Document 1).

[0007] JP 2013-163747 A

[0008] Recently, there has been a growing demand for underfill materials that can suppress the occurrence of cracks in the fillet portion. In other words, there is a demand for underfill materials that have excellent fillet crack resistance. Conventional technologies have not been able to fully satisfy the required characteristics. Therefore, further improvements are needed.

[0009] The present disclosure aims to provide a resin composition for use as an underfill material (CUF) having superior fillet crack resistance in order to address the above-mentioned problems in the conventional technology. The present disclosure also aims to provide a semiconductor device using the resin composition, a method for manufacturing the semiconductor device, and a method for manufacturing the resin composition.

[0010] In order to achieve the above object, the resin composition according to the present embodiment is a resin composition comprising: (A) an epoxy resin; (B) a curing agent; and (C) a filler, wherein a cured product of the resin composition has a viscosity of 0.55 MPa m 0.5 The above fatigue crack propagation threshold stress intensity factor range ΔK ｔｈ It has.

[0011] The resin composition according to this embodiment preferably has a glass transition temperature (Tg) of 100° C. or higher when cured.

[0012] In the resin composition according to the present embodiment, the (A) epoxy resin preferably includes a liquid epoxy resin.

[0013] In the resin composition according to the present embodiment, the (A) epoxy resin preferably contains at least one selected from the group consisting of bisphenol F epoxy resins, bisphenol A epoxy resins, aminophenol epoxy resins, naphthalene epoxy resins, and cyclohexane epoxy resins.

[0014] In the resin composition according to this embodiment, the content of the filler (C) is preferably 40 to 80 parts by mass relative to 100 parts by mass of the total mass of all components of the resin composition.

[0015] In the resin composition according to this embodiment, the filler (C) preferably has an average particle size of 0.1 to 20.0 μm.

[0016] In the resin composition according to this embodiment, the filler (C) is preferably surface-treated with a silane coupling agent.

[0017] The resin composition according to this embodiment may further contain (D) a core-shell rubber.

[0018] The resin composition according to this embodiment preferably has a cured product that satisfies Requirement 1 described below.

[0019] The resin composition according to this embodiment preferably has a cured product that satisfies Requirement 2 described below.

[0020] The semiconductor device according to this embodiment includes a substrate, a semiconductor element disposed on the substrate, and a cured product of the resin composition according to this embodiment that encapsulates the semiconductor element.

[0021] The method for manufacturing a semiconductor device according to this embodiment includes filling a gap between a substrate and a semiconductor element disposed on the substrate with a resin composition according to this embodiment, and curing the resin composition.

[0022] The method for producing a resin composition according to the present embodiment is a method for producing the resin composition, and includes using a roll mill to mix the (A) epoxy resin, the (B) curing agent, and the (C) filler to produce a resin composition, and the inter-roll pressure of the roll mill is 3.0 MPa or more.

[0023] The underfill material (CUF) using the resin composition according to this embodiment has superior fillet crack resistance.

[0024] FIG. 1 shows the fatigue crack propagation threshold stress intensity factor range ΔK ｔｈ2 is a diagram illustrating a method for image analysis of a cross section of a test piece.

[0025] The resin composition according to this embodiment will be described in detail below. The resin composition according to this embodiment contains the following components (A) to (C) as essential components.

[0026] (A) Epoxy Resin The epoxy resin of component (A) is the main component of the resin composition according to this embodiment. From the viewpoints of viscosity, injectability, etc., the epoxy resin of component (A) preferably includes a liquid epoxy resin that is liquid at room temperature (25°C). Epoxy resins that are solid at room temperature but that are liquid when used in combination with a liquid epoxy resin can also be suitably used.

[0027] Examples of epoxy resins of component (A) include bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, 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, anthracene type epoxy resins, glycidylamine type epoxy resins having an aromatic structure, and epoxy resins having an aromatic structure. Examples of epoxy resins include glycidyl ester type epoxy resins, cresol novolac type epoxy resins, biphenyl type epoxy resins, linear aliphatic epoxy resins having an aromatic structure, epoxy resins having a butadiene structure having an aromatic structure, alicyclic epoxy resins having an aromatic structure, heterocyclic epoxy resins, spiro ring-containing epoxy resins having an aromatic structure, cyclohexanedimethanol type epoxy resins having an aromatic structure, naphthylene ether type epoxy resins, trimethylol type epoxy resins having an aromatic structure, tetraphenylmethane type epoxy resins, aminophenol type epoxy resins, and silicone-modified epoxy resins.

[0028] The epoxy resin of component (A) is preferably at least one resin selected from the group consisting of bisphenol F type epoxy resins, bisphenol A type epoxy resins, aminophenol type epoxy resins, naphthalene type epoxy resins, and cyclohexane type epoxy resins.

[0029] Specific examples of liquid epoxy resins include "YDF8170" (bisphenol F type epoxy resin), "YDF8125" (bisphenol A type epoxy resin), "ZX1658" and "ZX1658GS" (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 A type epoxy resin) manufactured by Mitsubishi Chemical Corporation. Examples of epoxy resins that can be used include "jER152" (phenol novolac type epoxy resin), "jER630" and "jER630LSD" (aminophenol type epoxy resin), "YX7400" (high impact resilience epoxy resin), "ZX1059" (a mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin) manufactured by Nippon Steel & Sumitomo Metal Chemical Co., Ltd., "EX-721" (glycidyl ester type epoxy resin) manufactured by Nagase ChemteX Corporation, and "Celloxide 2021P" (alicyclic epoxy resin having an ester skeleton) manufactured by Daicel Corporation.

[0030] 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", "HP-7200HHH" (dicyclopentadiene type epoxy resin), "EXA7311", and "EXA 7311-G3, EXA7311-G4, EXA7311-G4S, HP6000 (naphthylene ether type epoxy resin), Nippon Kayaku's "EPPN-502H" (trisphenol type epoxy resin), "NC-7000-L" (naphthol novolac type epoxy resin), "NC-3000-H", "NC-3000", "NC-3000-L", "NC-3100" (biphenyl type epoxy resin), Nippon Steel Chemical & Material's "ESN475V" (naphthol type epoxy resin), "ESN4 85" (naphthol novolac type epoxy resin), Mitsubishi Chemical Corporation's "YX4000H", "YL6121" (biphenyl type epoxy resin), "YX4000HK" (bixylenol type epoxy resin), "YL7760" (bisphenol AF type epoxy resin), "YX8800" (anthracene type epoxy resin), Osaka Gas Chemicals' "PG-100", "CG-500", Mitsubishi Chemical Corporation's "YL7800" (fluorene type epoxy resin), Mitsubishi Chemical Corporation's "jER1010" (solid bisphenol A type epoxy resin), Examples of epoxy resins include "jER1031S" (tetraphenylethane type epoxy resin), "jER157S70" (bisphenol novolac type epoxy resin), "YX4000HK" (bixylenol type epoxy resin) and "YX8800" (anthracene type epoxy resin) manufactured by Mitsubishi Chemical Corporation, "PG-100" and "CG-500" manufactured by Osaka Gas Chemicals Co., Ltd., "YL7800" (fluorene type epoxy resin) manufactured by Mitsubishi Chemical Corporation, and "jER1031S" (tetraphenylethane type epoxy resin) manufactured by Mitsubishi Chemical Corporation.

[0031] The epoxy resin of component (A) can be used alone, or two or more epoxy resins can be used in combination. The amount of the epoxy resin of component (A) is preferably 5 to 50 parts by mass, more preferably 10 to 45 parts by mass, per 100 parts by mass of the total mass of all components of the resin composition.

[0032] (B) Curing Agent The curing agent for component (B) is not particularly limited as long as it is a curing agent for epoxy resins. Known curing agents can be used. Examples of curing agents for component (B) include amine-based curing agents, acid anhydride-based curing agents, phenol-based curing agents, hydrazide-based curing agents, polymercaptan-based curing agents, and Lewis acid-amine complexes. The curing agent for component (B) is preferably at least one curing agent selected from the group consisting of amine-based curing agents, acid anhydride-based curing agents, and phenol-based curing agents.

[0033] Examples of the amine-based curing agent include aliphatic amines such as diethylenetriamine, triethylenetetraamine, tetraethylenepentamine, trimethylhexamethylenediamine, m-xylenediamine, and 2-methylpentamethylenediamine; alicyclic polyamines such as isophoronediamine, 1,3-bisaminomethylcyclohexane, bis(4-aminocyclohexyl)methane, norbornenediamine, and 1,2-diaminocyclohexane; piperazine-type heterocyclic aliphatic amines such as N-aminoethylpiperazine and 1,4-bis(2-amino-2-methylpropyl)piperazine; and aromatic amines such as diaminodiphenylmethane, m-phenylenediamine, diaminodiphenylsulfone, diethyltoluenediamine, dimethylthiotoluenediamine, trimethylenebis(4-aminobenzoate), polytetramethyleneoxide-di-p-aminobenzoate, and 4,4'-diamino-3,3'-diethyldiphenylmethane. Among these, 4,4'-diamino-3,3'-diethyldiphenylmethane, diethyltoluenediamine, and dimethylthiotoluenediamine are preferred.

[0034] The acid anhydride curing agent is not particularly limited, and examples of the acid anhydride curing agent include methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, aralkylated tetrahydrophthalic anhydride, methylhimic anhydride, alkenyl-substituted succinic anhydride, and glutaric anhydride. Particularly preferred are 3,4-dimethyl-6-(2-methyl-1-propenyl)-4-cyclohexene-1,2-dicarboxylic anhydride, 3,4-dimethyl-6-(2-methyl-1-propenyl)-1,2,3,6-tetrahydrophthalic anhydride, 1-isopropyl-4-methyl-bicyclo[2.2.2]oct-5-ene-2,3-dicarboxylic anhydride, norbornane-2,3-dicarboxylic anhydride, methylnorbornane-2,3-dicarboxylic anhydride, hydrogenated methylnadic anhydride, alkenyl-substituted succinic anhydride, and diethylglutaric anhydride.

[0035] The phenolic curing agent generally refers to a monomer, oligomer, or polymer having a phenolic hydroxyl group. Examples of the phenolic curing agent include phenol novolac resin and its alkylated or allylated derivatives, cresol novolac resin, phenol aralkyl (containing a phenylene or biphenylene skeleton) resin, naphthol aralkyl resin, triphenolmethane resin, and dicyclopentadiene-type phenolic resin. Among these, allylphenol novolac resin is preferred.

[0036] The curing agent of component (B) can be used alone, or two or more curing agents can be used in combination.

[0037] The curing agent of component (B) is blended so that the stoichiometric equivalent ratio (curing agent equivalent / epoxy group equivalent) between the curing agent of component (B) and the epoxy resin of component (A) is preferably 0.5 to 1.5, more preferably 0.8 to 1.2. When the curing agent is a compound having active hydrogen, such as an amine-based curing agent, the ratio of the active hydrogen equivalent of the curing agent to the epoxy equivalent of the epoxy resin (active hydrogen equivalent / epoxy equivalent) is preferably within the above range.

[0038] (C) Filler The filler of component (C) is not particularly limited as long as it has the effect of lowering the linear expansion coefficient when added. Examples of the filler of component (C) include silica (silicon dioxide) filler, alumina (aluminum oxide) filler, and aluminum nitride filler. In particular, silica (silicon dioxide) filler is preferred because it allows for a high loading. The filler of component (C) may be surface-treated with, for example, a silane coupling agent.

[0039] The average particle size of the filler of component (C) is preferably 0.1 to 20.0 μm, more preferably 0.3 to 10.0 μm. Two or more fillers having different average particle sizes may be used in combination to adjust the viscosity of the resin composition according to this embodiment.

[0040] The shape of the filler of component (C) is not particularly limited. The shape of the filler of component (C) may be any of spherical, irregular, and flaky. The filler of component (C) may be used alone. Alternatively, two or more fillers may be used in combination. The amount of the filler of component (C) is preferably 40 to 80 parts by mass, more preferably 40 to 75 parts by mass, per 100 parts by mass of the total mass of all components of the resin composition.

[0041] The resin composition according to the present embodiment may contain the following components as needed, in addition to the above components (A) to (C).

[0042] (D): Core-shell rubber The resin composition according to this embodiment may contain a core-shell rubber as component (D). In the resin composition according to this embodiment, the core-shell rubber as component (D) is used for the purpose of suppressing the occurrence and progression of fillet cracks when the resin composition is used as an underfill material (CUF). Specifically, when the resin composition according to this embodiment is used as an underfill material (CUF), the inclusion of component (D) (core-shell rubber) reduces the modulus of elasticity. This reduces the stress generated in the fillet portion. Therefore, the occurrence of fillet cracks can be suppressed. Furthermore, when fillet cracks occur, the core-shell rubber as component (D) acts as a stress relaxation agent. Therefore, the progression of fillet cracks can be suppressed.

[0043] In this specification, core-shell rubber refers to a rubber material with a multilayer structure composed of rubber particles forming a core portion and one or more shell layers covering the core portion. As described below, the core portion of the core-shell rubber can be composed of a material with excellent flexibility. At the same time, the shell layer of the core-shell rubber can be composed of a material with excellent affinity for components other than component (D) contained in the resin composition, particularly the epoxy resin as component (A). This makes it possible to achieve a low modulus of elasticity by incorporating the rubber component, while also achieving good dispersibility in the resin composition.

[0044] The rubber particles forming the core are made of a material with excellent flexibility, such as silicone rubber, butadiene rubber, styrene rubber, acrylic rubber, polyolefin rubber, and silicone / acrylic composite rubber.

[0045] On the other hand, the shell layer is made of a material that has excellent affinity with the components other than component (D) contained in the resin composition according to this embodiment, particularly with the epoxy resin as component (A). Examples of such a material include acrylic resins and epoxy resins such as bisphenol A epoxy resins and bisphenol F epoxy resins.

[0046] Specific examples of core-shell rubbers include "Kane Ace MX-153," "Kane Ace MX-257," "Kane Ace MX-154," "Kane Ace MX-960," "Kane Ace MX-136," "Kane Ace MX-137," "Kane Ace MX-965," "Kane Ace MX-217," "Kane Ace MX-227M75," "Kane Ace MX-334M75," "Kane Ace MX-416," and "Kane Ace MX-451" manufactured by Kaneka Corporation; and "Metablen C-223A," "Metablen C-140A," "Metablen E-860A," "Metablen E-870A," "Metablen E-875A," "Metablen S-2100," and "Metablen E-875A" manufactured by Mitsubishi Chemical Corporation. Examples of suitable core materials include "Staphyloid S-2200" and "Metablen S-2260" manufactured by Aica Kogyo Co., Ltd., "Staphyloid IM-203," "Staphyloid IM-401," "Staphyloid IM-601," "Staphyloid AC3355," and "Staphyloid AC3816" manufactured by Aica Kogyo Co., Ltd., and "Acryset BPA328" and "Acryset BPF307" manufactured by Nippon Shokubai Co., Ltd. In particular, silicone-based and butadiene-based cores are preferably used from the viewpoints of toughness, heat resistance, durability, and crack resistance.

[0047] The core-shell rubber of component (D) can be used alone. Alternatively, two or more types of core-shell rubber can be used in combination. The amount of the core-shell rubber of component (D) is preferably 0.3 to 10.0 parts by mass, more preferably 0.5 to 8.0 parts by mass, per 100 parts by mass of the total mass of all components of the resin composition.

[0048] (E): Curing Accelerator The resin composition according to this embodiment may contain a curing accelerator as component (E). The curing accelerator as component (E) is not particularly limited as long as it is a curing accelerator for epoxy resins. Known curing accelerators can be used. The curing accelerator as component (E) imparts an appropriate curing rate to the epoxy resin as component (A). Examples of curing accelerators include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, and 2-phenyl-4-methylimidazole. Examples of commercially available products include 2-phenyl-4-methylimidazole (manufactured by Shikoku Chemical Industries, Ltd., trade name: 2P4MZ) and 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine (manufactured by Shikoku Chemical Industries, Ltd., trade name: 2MZA). Alternatively, encapsulated imidazoles known as microencapsulated imidazoles or epoxy adduct imidazoles may be used. Examples of encapsulated imidazoles include HX3941HP, HXA3942HP, HXA3922HP, HXA3792, HX3748, HX3721, HX3722, HX3088, HX3741, HX3742, and HX3613 (all manufactured by Asahi Kasei Chemicals Corporation, trade names), PN-23J, PN-40J, and PN-50 (manufactured by Ajinomoto Fine-Techno Co., Ltd., trade names), and FXR-1121 (manufactured by Fuji Chemical Industry Co., Ltd., trade name). The curing accelerator of component (E) may be used alone. Alternatively, two or more curing accelerators may be used in combination. The amount of the curing accelerator of component (E) added is preferably 0.1 to 5.0 parts by mass, more preferably 0.2 to 3.0 parts by mass, per 100 parts by mass of the total mass of all components of the resin composition.

[0049] (Other Compounding Agents) The resin composition according to this embodiment may further contain other components as necessary, in addition to the above components (A) to (E). Examples of such compounding agents include coupling agents, ion trapping agents, leveling agents, antioxidants, antifoaming agents, flame retardants, colorants, and reactive diluents. The amount of each compounding agent can be determined according to a conventional method.

[0050] Examples of coupling agents include silane coupling agents such as vinyl-based, glycidoxy-based, methacrylic-based, amino-based, mercapto-based, and imidazole-based coupling agents; titanium coupling agents such as alkoxide-based, chelate-based, and acylate-based coupling agents; and long-chain spacer coupling agents such as glycidoxyoctyltrimethoxysilane and methacrylooctyltrimethoxysilane. The above coupling agents can be used alone. Alternatively, two or more coupling agents can be used in combination.

[0051] (Preparation of Resin Composition) The resin composition according to this embodiment can be produced by a conventional method. For example, the resin composition is prepared by mixing components (A) to (C), and, if necessary, components (D), (E), or the other compounding ingredients described above. When the epoxy resin of component (A) is solid, component (A) is preferably liquefied or fluidized by heating or the like and mixed with the other components. When it is difficult to uniformly disperse the filler of component (C) in the epoxy resin of component (A), the epoxy resin of component (A) and the filler of component (C) may be mixed first, and the remaining components may be mixed later. When mixing the components, they may be mixed simultaneously. Alternatively, some of the components may be mixed first, and the remaining components may be mixed later. The method for mixing components (A) to (C) is not particularly limited. Known mixing methods may be employed. In particular, the ΔK ｔｈ A roll mill is preferably used from the viewpoint that it is easy to adjust the ΔK. That is, components (A) to (C), and, if necessary, components (D), (E), and the other compounding ingredients are mixed using a roll mill. In this way, the resin composition can be suitably produced. The roll mill is preferably composed of three or more rolls. There is no particular limitation on the pressure between the rolls in the roll mill. ΔK ｔｈThe inter-roll pressure is preferably 2 MPa or more, more preferably 3 MPa or more, in that it is easy to adjust the pressure between the rolls to a predetermined range. The upper limit of the inter-roll pressure is not particularly limited. In many cases, the upper limit of the inter-roll pressure is 30 MPa or less. More often, the upper limit of the inter-roll pressure is 20 MPa or less.

[0052] The properties of the resin composition according to this embodiment will be described below. (Fatigue crack propagation threshold stress intensity factor range ΔK ｔｈ ) Fatigue crack propagation threshold stress intensity factor range ΔK ｔｈ is known as an index for evaluating fatigue crack propagation performance (threshold stress intensity factor range ΔK ｔｈ (A Study on a Simple Identification Method of the Welding Society, Koji Murakami and Koji Goto, Journal of the Japan Welding Society, Vol. 35, No. 4, pp. 149-153 (2017), JP 6-82353 A)

[0053] In a fatigue crack propagation test, the crack propagation rate da / dN, which is determined from the relationship between the number of repeated load cycles N and the crack length a, is given as a function of the stress intensity factor width ΔK. The stress intensity factor K is expressed by the following equation: K = f(a / W)σ(πa) 1 / 2 Here, W is the width of the test piece, a is the crack length, σ is the applied stress, and f is a constant determined by the ratio of a to W. Specifically, f is calculated by the following formula.

[0054]

[0055] A fatigue crack propagation test can be carried out according to the procedure described below. When the relationship between the crack propagation rate da / dN obtained from the test results and the stress intensity factor range ΔK is plotted, it is found that when the stress intensity factor range ΔK is below a specific value, the crack propagation rate da / dN becomes 0, and the fatigue crack does not grow. This specific value is usually called the fatigue crack propagation lower limit stress intensity factor range ΔK. ｔｈ The stress intensity factor range ΔK is defined as the fatigue crack propagation threshold stress intensity factor range ΔK ｔｈIn the above, the crack propagation rate da / dN increases as the stress intensity factor range ΔK increases. At this time, the relationship between log da / dN and log ΔK is approximately linear. It is known that the Paris law expressed by the following equation holds for this relationship: da / dN = C ΔK'. However, in the present disclosure, da / dN = 1.0 × 10 -9 m / cycle is the fatigue crack propagation threshold stress intensity factor range ΔK ｔｈ It is defined as follows.

[0056] Fatigue crack propagation threshold stress intensity factor range ΔK of the cured product of the resin composition according to this embodiment ｔｈ is 0.55 MPa m 0.5 That's all. ｔｈ is 0.55 MPa m 0.5 If ΔK is 100% or more, the fillet crack resistance is improved. ｔｈ is preferably 0.56 MPa m 0.5 More preferably, 0.60 MPa m 0.5 That's all. ｔｈ In most cases, the upper limit is 0.9 MPa m 0.5 More often, this upper limit is 0.8 MPa m 0.5 The following is true: ΔK ｔｈ can be adjusted by the following items (1) to (5). Note that ΔK can be adjusted by only one of the following items (1) to (5). ｔｈ Alternatively, two or more items can be used in combination to adjust ΔK ｔｈ You can also adjust the

[0057] (1) Glass transition temperature (Tg) ΔK of the cured product of the resin composition ｔｈ can be adjusted by the glass transition temperature (Tg) of the cured product of the resin composition. The lower the glass transition temperature (Tg) of the cured product of the resin composition described later, the ｔｈ (See, for example, Examples 1 and 6 described later.) A lower Tg reduces the crosslink density of the resin skeleton. This increases flexibility. As a result, the stress applied to the cured product of the resin composition can be more effectively alleviated. In this way, ΔK ｔｈThe preferred range of the glass transition temperature (Tg) of the cured product of the resin composition will be described later.

[0058] (2) Component (C) Filler Blend Amount ΔK ｔｈ can be adjusted by the amount of filler of component (C). The greater the amount of filler of component (C), the greater the ΔK ｔｈ (See, for example, Examples 1 and 2 described later.) By blending a large amount of filler, the elastic modulus and strength of the cured resin composition are improved. Therefore, the energy required for crack propagation per unit area increases. In this way, ΔK ｔｈ It is thought that it is possible to increase

[0059] (3) Compounding of core-shell rubber of component (D) ΔK ｔｈ can also be adjusted by compounding the core-shell rubber of component (D). When the core-shell rubber of component (D) is compounded, ΔK ｔｈ The core-shell rubber reduces the stress applied to the cured product of the resin composition, which tends to increase ΔK ｔｈ It is thought that it is possible to increase

[0060] (4) Use of an epoxy resin having a flexible skeleton as the epoxy resin of component (A) ΔK ｔｈ can also be adjusted by using an epoxy resin having a flexible skeleton as the epoxy resin of component (A). When an epoxy resin having a flexible skeleton is used as the epoxy resin of component (A), ΔK ｔｈ (See, for example, Examples 1 and 7 below.) The flexible skeleton in the epoxy resin relieves the stress applied to the cured product of the resin composition, which increases ΔK ｔｈIt is believed that this can increase the tensile strength. Here, the term "flexible skeleton" refers to a molecular skeleton, such as an alkyl chain or siloxane, that has a structure that allows for easy movement. Examples of epoxy resins with flexible skeletons include (poly)alkylene glycol-modified epoxy resins such as (poly)ethylene glycol-modified epoxy resins, (poly)propylene glycol-modified epoxy resins, (poly)tetramethylene glycol-modified epoxy resins, and (poly)hexamethylene glycol-modified epoxy resins. Other examples include epoxy resins with siloxane skeletons, such as bis(2-(3,4-epoxycyclohexyl)ethyl)polydimethylsiloxane and polydimethylsiloxane diglycidyl ether, as well as polyisobutylene diglycidyl ether.

[0061] (5) Uniformity of Resin Composition ΔK ｔｈ can also be adjusted by the uniformity of the composition in the resin composition. When kneading the resin composition using a three-roll mill with strong pressure, ΔK ｔｈ tends to be large (see, for example, Example 3 and Comparative Example 5 described below). If the composition of the resin composition is non-uniform, stress will concentrate at one location in the cured product of the resin composition. Cracks will then be more likely to develop from that location. By making the composition of the resin composition uniform, stress will be propagated evenly throughout the cured product of the resin composition. In this way, it is believed that the strength of the cured product of the resin composition can be maximized.

[0062] The above ΔK ｔｈWhen measuring the tensile strength, the resin composition according to this embodiment is first cured. This results in a test specimen. In the curing process, the applied resin composition is heated at 165°C for two hours. A test specimen is produced by the above-described heating process. The size of the test specimen is 20 mm (L) x 2 mm (W) x 0.5 mm (T). A crack (0.3 mm long) was previously created in the test specimen. More specifically, FIG. 1 is a top view of a test specimen 10. A surface having a length L and a width W is observed in FIG. 1. As shown in FIG. 1, a crack 12 extending from one side to the other side is created in the center of the length L of the test specimen 10. The direction of extension of the crack 12 is parallel to the width direction of the test specimen 10. The crack 12 is created so as to penetrate the thickness direction of the test specimen. In the test described below, stress is applied to the test specimen in the direction indicated by the arrow. A microload testing machine (LMH207-10 manufactured by Saginomiya Seisakusho) is used to apply repeated loads (stress). A microscope (SZX-16 manufactured by Olympus) and a long-term video / still image (time lapse) acquisition system are used to observe cracks. The load waveform generated by the microload testing machine is a sine wave. Its frequency is 2 Hz. However, the fatigue crack propagation threshold stress intensity factor range ΔK ｔｈDue to the characteristics of the test, the test is preferably conducted at a low stress to confirm the crack propagation behavior under small stresses. Then, only if no cracks propagate, the test stress is gradually increased. Therefore, in the test, a load is first applied repeatedly to the test specimen under one-cycle loading conditions in which the load waveform is a sine wave, the frequency is 2 Hz, the minimum stress is 0 (N), and the maximum stress is X (N), while the value of X is changed. In this way, the value of X at which no cracks of 1 μm or more propagate after 20,000 cycles is found. Next, the value of X is increased by 0.1 N from the found value of X, and the test specimen is repeatedly loaded. Then, the minimum value of X at which a crack of 1 μm or more propagates after 20,000 cycles (hereinafter also referred to as "value Y") is determined. For example, a load is first applied repeatedly to the test specimen under the above loading conditions with a maximum stress X of 14 (N). If no crack of 1 μm or more has grown after 20,000 cycles, the test specimen is subjected to repeated loading under the above loading conditions at a maximum stress X of 14.1 N, which is 0.1 N higher than the previous value. It is then confirmed whether or not a crack of 1 μm or more has grown after 20,000 cycles. If no crack has grown, the same test is performed at a maximum stress X of 14.2 N, which is 0.1 N higher than the previous value. In this manner, the test is repeated with the maximum stress X increased by 0.1 N each time until crack growth of 1 μm or more is confirmed after 20,000 cycles. This allows the minimum value Y of the maximum stress X to be determined. Next, a repeated load is applied to the test specimen under the condition where X is the value Y. At this time, crack growth is confirmed on the surface consisting of the length L and width W of the test specimen. The length Lc of this crack (see FIG. 1 ) is measured. The relationship between the crack propagation rate da / dN and the stress intensity factor ΔK is plotted. Here, da / dN=1.0×10 -9 ΔK at m / cycle is ΔK ｔｈ The stress intensity factor range ΔK is defined as the maximum value ΔK of the stress intensity factor K during one cycle. ｍａｘ and the minimum value ΔK ｍｉｎ In the above measurement, the minimum value of stress during one cycle ΔK ｍｉｎis 0. From this, ΔK = ΔK ｍａｘ The following relationship is obtained.

[0063] (Glass Transition Temperature (Tg)) The glass transition temperature (Tg) of the cured product of the resin composition according to this embodiment is preferably 100°C or higher. The underfill material desirably has good bump crack resistance in addition to good fillet crack resistance. A Tg of 100°C or higher improves bump crack resistance. The Tg of the cured product of the resin composition according to this embodiment is more preferably 103°C or higher, and even more preferably 105°C or higher. The upper limit of the Tg of the cured product of the resin composition according to this embodiment is not particularly limited. In many cases, the upper limit of this Tg is 200°C or lower. More often, the upper limit of this Tg is 180°C or lower. When measuring the glass transition temperature, a test piece is first obtained by curing the resin composition according to this embodiment. For the curing treatment, the applied resin composition is heated at 165°C for 2 hours. The film thickness of the resulting cured product is adjusted to be in the range of 2000±100 μm. The glass transition temperature of the resulting cured product can then be determined using a dynamic thermomechanical analyzer (DMA) by a double-support bending method under conditions of a temperature range of -20 to 260°C, a frequency of 1 Hz, and a heating rate of 3°C / min. The glass transition temperature (Tg) can be determined from the peak temperature of the loss tangent (tan δ) calculated from the loss modulus (E") / storage modulus (E').

[0064] (Viscosity) The resin composition according to this embodiment has a low viscosity. Therefore, when the resin composition is used as an underfill material (CUF), it exhibits good injectability by capillary flow. Specifically, the viscosity measured at 25°C and 50 rpm using a rotational viscometer is preferably 100 Pa·s or less, more preferably 80 Pa·s or less. The lower limit is not particularly limited. In many cases, the lower limit is 1 Pa·s or more. More often, the lower limit is 10 Pa·s or more.

[0065] (Requirement 1) The cured product of the resin composition according to the present embodiment preferably satisfies the following Requirement 1. Requirement 1: In a cross section of the cured product of the resin composition, the area occupied by the filler in each of six randomly selected regions of 37.8 μm width × 18.9 μm length (μm ２ When the standard deviation of the area (filler area) of each of the six fillers obtained was 0.36 μm ２ Here, the filler area is obtained by observing a cross section of a cured resin composition with a scanning electron microscope at a magnification of 1000 times. Requirement 1 will be described in detail below.

[0066] In requirement 1, the standard deviation of the filler area in the cross section of the cured resin composition is calculated. The smaller the standard deviation, the more uniform the size of the filler contained in the resin composition and / or the distribution of the filler. In other words, a small standard deviation means that the composition of the resin composition is highly uniform. In other words, the standard deviation is related to the above-mentioned (5) uniformity of the resin composition. Therefore, the smaller the standard deviation calculated in requirement 1, the higher the ΔK ｔｈ The standard deviation calculated in requirement 1 is preferably 0.36 μm. ２ Less than or equal to 0.27 μm, more preferably ２ The lower limit of the standard deviation is not particularly limited. In many cases, the standard deviation is 0 μm or less. ２ More often, this standard deviation is 0.02 μm or more. ２ An example of a method for calculating the standard deviation of the area occupied by the filler in requirement 1 will be described in detail below.

[0067] First, a test specimen is obtained by curing the resin composition according to this embodiment. Specifically, a glass plate is fixed onto an organic substrate (FR-4 substrate) with a gap of 100 μm between them. The organic substrate with the fixed glass plate is then placed on a hot plate set to 110°C. The resin composition according to this embodiment is then injected into the gap. The injection width is 10 mm. The injection length is 20 mm. Subsequently, as a curing treatment, the injected resin composition is heated at 165°C for 2 hours. Next, the obtained test specimen (cured resin composition) is cleaved. The cross section exposed at the 10 mm injection distance is observed. A scanning electron microscope (Hitachi Scanning Electron Microscope System S-3400N) is used for observation. The observation magnification is 1000x. The image size during observation is 122.4 μm horizontally and 93.4 μm vertically. The resolution is 1280 x 960. Next, the acquired observation image is subjected to image analysis using image analysis software WinROOF2018 (Mitani Corporation, Ver. 4.5.5). The range of image analysis is a range of 113.4 μm horizontally and 37.8 μm vertically in the acquired observation image. The number of pixels is 1200 × 400. As a specific procedure for image analysis, in order to reduce noise, the cross-sectional observation image of the cured product is filtered using a median filter (5 × 5 pixels) using the above software. Furthermore, the observation image is subjected to monochrome image processing and then binarization processing. In the binarization processing, images having shadings less than a predetermined threshold are cut off. The image is processed by setting images having shadings equal to or greater than the threshold as 1 and images having shadings less than the threshold as 0. The binarization is performed using Otsu's method (discriminant analysis method). Next, the filler area (μm ) in a region of 37.8 μm horizontally × 18.9 μm vertically in the binarized observation image is calculated. ２) is calculated. The above-mentioned region of 37.8 μm in width and 18.9 μm in height corresponds to the region of 400×200 pixels in the binarized observation image 20 in FIG. 2 (region indicated as A in FIG. 2). Specifically, the number of pixels contained in the filler in one region selected from regions A to F in FIG. 2 is calculated. Then, this number of pixels is multiplied by the area of ​​one pixel. The obtained value is defined as the filler area. The filler area in each selected region is found by the above procedure. Furthermore, the average value of these six filler areas is calculated. The calculated average value is used as the average filler area (μm ２ ) is defined as follows. By the above process, the filler area is calculated for each of six regions (regions indicated by A to F in FIG. 2) in the binarized observation image 20 shown in FIG. 2. The standard deviation is calculated using the six filler area values ​​obtained. The obtained value is 0.36 μm ２ Requirement 1 is satisfied if the following is true. In the above, when the standard deviation is calculated, a range wider than the 37.8 μm wide × 18.9 μm high region is binarized. However, the 37.8 μm wide × 18.9 μm high region selected from regions A to F may itself be binarized. The filler area of ​​the selected region may then be calculated by the above process. The standard deviation can also be calculated by performing this process on six different locations. Furthermore, the six randomly selected regions corresponding to the calculated standard deviation refer to six regions that do not overlap with one another. Note that the number of pixels contained in the filler in each of the 37.8 μm wide × 18.9 μm high regions can be calculated. Then, the standard deviation of the number of pixels contained in the filler in each region (hereinafter also referred to as the "standard deviation of the number of pixels") can be calculated. In this case, the standard deviation of the number of pixels is preferably 40 pixels or less. The lower limit of the standard deviation of the number of pixels is not particularly limited. For example, the lower limit is 0 pixels.

[0068] (Requirement 2) The cured product of the resin composition according to this embodiment preferably satisfies the following Requirement 2. Requirement 2: When the number of fillers is calculated in each of six randomly selected regions measuring 37.8 μm wide x 18.9 μm long in a cross section of the cured product of the resin composition, the standard deviation of the six obtained numbers of fillers is 80 or less. Here, the number of fillers is obtained by observing the cross section of the cured product of the resin composition with a scanning electron microscope at 1000x magnification. Requirement 2 will be described in detail below.

[0069] In requirement 2, the standard deviation of the number of fillers in the cross section of the cured resin composition is calculated. The smaller this standard deviation, the higher the uniformity of the composition of the resin composition. In other words, this standard deviation is related to the above-mentioned (5) uniformity of the resin composition. Therefore, the smaller the standard deviation in requirement 2, the higher the ΔK ｔｈ becomes larger. The standard deviation of requirement 2 is preferably 60 or less, more preferably 55 or less. The lower limit of the standard deviation is not particularly limited. In many cases, this standard deviation is 0 or more. More often, this standard deviation is 5 or more. An example of a method for calculating the standard deviation of the number of fillers in the subregion where the fillers are located, as required in requirement 2, will be described in detail below.

[0070] In calculating the standard deviation of requirement 2, a binarized observation image is obtained according to the same procedure as described for requirement 1. Next, the number of fillers in a 37.8 μm wide × 18.9 μm long region in the binarized observation image is calculated. Through the above process, the number of fillers in each of six regions (regions A to F in FIG. 2) in the binarized observation image 20 shown in FIG. 2 is calculated. The standard deviation is calculated using the six obtained numbers of fillers. Requirement 2 is met if the obtained value is 80 or less. In the above process, when calculating the standard deviation, a binarized observation image wider than the 37.8 μm wide × 18.9 μm long region is binarized. However, the 37.8 μm wide × 18.9 μm long region selected from regions A to F may itself be binarized. The number of fillers in the selected region may then be calculated through the above process. The standard deviation may be calculated by performing this process on six different regions. The six randomly selected regions corresponding to the standard deviation thus determined refer to six regions that do not overlap with each other.

[0071] The semiconductor device according to the present embodiment includes a substrate, a semiconductor element disposed on the substrate, and a cured product of the resin composition according to the present embodiment that encapsulates the semiconductor element. The semiconductor element is not particularly limited. Examples of the semiconductor element include an integrated circuit, a large-scale integrated circuit, a transistor, a thyristor, a diode, and a capacitor.

[0072] The method for manufacturing a semiconductor device according to this embodiment includes filling a gap between a substrate and a semiconductor element disposed on the substrate with a resin composition according to this embodiment, and curing the resin composition.

[0073] In filling the resin composition, for example, the resin composition according to this embodiment is applied to one end of the semiconductor element while the substrate is heated to 70 to 120°C. Then, capillary action causes the gap between the substrate and the semiconductor element to be filled with the resin composition according to this embodiment. At this time, the substrate may be tilted to shorten the time required to fill the resin composition according to this embodiment. Alternatively, a pressure difference may be generated between the inside and outside of the gap.

[0074] In curing the resin composition, after the gap is filled with the resin composition according to this embodiment, the substrate is heated at a predetermined temperature for a predetermined time, for example, at 150 to 165°C for 0.5 to 2 hours. In this way, the resin composition is heated and cured, thereby sealing the gap.

[0075] The present embodiment will be described in detail below with reference to examples, although the present embodiment is not limited to these examples.

[0076] (Examples 1 to 13, Comparative Examples 1 to 5) Using a roll mill (three-roll mill), raw materials were kneaded in the blending ratios shown in the table below. In this manner, the resin compositions of Examples 1 to 13 and Comparative Examples 1 to 5 were prepared. The pressure (pressure between the rolls) during roll mill kneading was 3 MPa except for Comparative Example 5, which was 1 MPa. The numerical values ​​for each composition in the table represent parts by mass.

[0077] The components used in preparing the resin composition are as follows:

[0078] Component (A): Epoxy resin Epoxy resin A-1: ​​Liquid bisphenol F type epoxy resin, product name YDF8170, manufactured by Nippon Steel Chemical & Material Co., Ltd., epoxy equivalent 158 ​​g / eq. Epoxy resin A-2: Liquid aminophenol type epoxy resin, product name jER630, manufactured by Mitsubishi Chemical Corporation, epoxy equivalent 98 g / eq. Epoxy resin A-3: Liquid naphthalene type epoxy resin, product name HP-4032D, manufactured by DIC Corporation, epoxy equivalent 140 g / eq. Epoxy resin A-4: Liquid cyclohexane type epoxy resin, product name EP-4085S, manufactured by ADEKA Corporation, epoxy equivalent 145 g / eq.

[0079] Component (B): Curing agent Curing agent B-1: Amine-based curing agent, 4,4'-diamino-3,3'-diethyldiphenylmethane, product name HDAA, active hydrogen equivalent 63.5 g / eq, manufactured by Nippon Kayaku Co., Ltd. Curing agent B-2: Amine-based curing agent, diethyltoluenediamine, product name Ethacure 100, active hydrogen equivalent 44.5 g / eq, manufactured by Albemarle Co., Ltd. Curing agent B-3: Amine-based curing agent, dimethylthiotoluenediamine, product name Ethacure 300, active hydrogen equivalent 53.5 g / eq, manufactured by Albemarle Co., Ltd. Curing agent B-4: Acid anhydride-based curing agent, 3,4-dimethyl-6-(2-methyl-1-propenyl)-4-cyclohexene-1,2-dicarboxylic anhydride, product name YH307, active hydrogen equivalent 117 g / eq, manufactured by Mitsubishi Chemical Corporation

[0080] Component (C): Filler Filler C-1: 3-glycidoxypropyltrimethoxysilane surface-treated silicon dioxide, average particle size 0.5 μm, product name SE2200-SEJ, manufactured by Admatechs Co., Ltd. Filler C-2: Silicon dioxide, average particle size 0.5 μm, product name SO-E2, manufactured by Admatechs Co., Ltd. Filler C-3: 3-glycidoxypropyltrimethoxysilane surface-treated silicon dioxide, average particle size 1.5 μm, product name SE5050-SEJ, manufactured by Admatechs Co., Ltd. Filler C-4: 3-glycidoxypropyltrimethoxysilane surface-treated silicon dioxide, product name SE1050-SEO, average particle size 0.3 μm, manufactured by Admatechs Co., Ltd. Filler C-5: Aluminum oxide, product name A9-SX-E2, average particle size 10 μm, manufactured by Admatechs Co., Ltd.

[0081] Component (D): Core-shell rubber Core-shell rubber D-1: Product name MX-137 (core-shell type butadiene rubber particles, manufactured by Kaneka Corporation) Core-shell rubber D-2: Product name MX-965 (core-shell type silicone rubber particles, manufactured by Kaneka Corporation)

[0082] Component (E): Curing accelerator Curing accelerator E-1: 2-phenyl-4-methylimidazole, product name 2P4MZ, manufactured by Shikoku Chemical Industries, Ltd.

[0083] (Viscosity) The viscosity (Pa·s) of the evaluation sample immediately after preparation was measured using a Brookfield viscometer at a liquid temperature of 25° C. and 50 rpm.

[0084] (Tg) Using a dynamic viscoelasticity apparatus, the storage modulus and loss modulus of the cured resin compositions of each Example and Comparative Example were measured. The peak value of tan δ, which is the ratio of these moduli, was measured as Tg. The above modulus was measured in accordance with Japanese Industrial Standard JIS C6481. More specifically, first, spacers consisting of overlapping heat-resistant tape were placed in two locations on a Teflon (registered trademark) sheet attached to the surface of a 3 mm thick glass plate. At this time, the thickness of the spacers was adjusted so that the thickness of the cured resin composition, as described below, was 2000 ± 100 μm. Next, the resin composition was applied to the Teflon sheet between the spacers. While taking care to avoid trapping air bubbles, the applied resin composition was sandwiched between other glass plates with Teflon (registered trademark) sheets attached to their surfaces. In this state, the resin composition was cured at 165 °C for 2 hours. Finally, the cured product obtained in this manner was peeled off from the Teflon (registered trademark) sheet. The cured product was then cut into pieces of specified dimensions (10 mm x 50 mm) using a cutter. Test specimens were obtained in this manner. The cut edges of the cured product were smoothed with sandpaper. The Tg of this test specimen was measured by the double-support bending method using a dynamic thermomechanical analyzer (DMA) (manufactured by Hitachi High-Tech Science Corporation) in the range of -20 to 260°C, at a frequency of 1 Hz, and at a heating rate of 3°C / min. Tg was determined from the peak temperature (°C) of tan δ, which was calculated from E'' / E'.

[0085] (ΔK ｔｈ ) ΔK in the following steps ｔｈ A fatigue crack propagation test was carried out, and the stress intensity factor width ΔK, expressed by the following formula, was calculated: ΔK = f(a / W)σ(πa) 1 / 2W: width of the test piece, a: crack length, σ: load stress, f: constant determined by the ratio of a to W. Test pieces were prepared by curing the resin compositions of each example and comparative example at 165°C for 2 hours. The test piece dimensions were 20 mm (L) x 2 mm (W) x 0.5 mm (T). As described in Figure 1, a 0.3 mm long crack was created in the test piece. A microload tester (LMH207-10, manufactured by Saginomiya Seisakusho) was used as the test equipment. A microscope (SZX-16, manufactured by Olympus) and a long-term video / still image (time lapse) acquisition system were used for crack observation. The load waveform generated by the microload tester was a sine wave. The frequency was 2 Hz. Next, as described above, tests were repeated under one cycle of loading conditions: a sine wave load waveform, a frequency of 2 Hz, a minimum stress of 0 (N), and a maximum stress of X (N), with the value of X being varied. The minimum value of X was determined when crack growth of 1 μm or more was observed in the test specimen after 20,000 cycles of loading under the same loading conditions. By repeatedly loading the test specimen at the determined minimum value, the relationship between the obtained crack propagation rate da / dN and the stress intensity factor width ΔK was plotted. The obtained da / dN = 1.0 × 10 -9 ΔK at m / cycle is ΔK ｔｈ It was defined as follows.

[0086] (Reliability Test) The resin compositions of each example and comparative example were applied to a test piece consisting of a Walts-KIT FC150 01A150P-10 substrate manufactured by Walts Corporation and a Walts-TEG FC150JY silicon chip mounted on the test piece. The applied resin composition was cured at 165°C for 2 hours. A preconditioning test was carried out under JEDEC Level 3 conditions. Thereafter, a test was carried out under Condition B conditions. Ｔｈ A thermal cycle was performed for 1000 cycles. After that, the fillet portion was observed under a microscope to evaluate fillet crack resistance. In this way, the presence or absence of fillet cracks was observed. In addition, the presence or absence of breaks in the daisy chain in the test piece was observed using a resistance meter to evaluate bump crack resistance. The reliability test was performed five times using different test pieces.

[0087] In Tables 1 to 3, "Filler Addition Amount" represents the amount of filler (parts by mass) per 100 parts by mass of the resin composition. In Tables 1 to 3, "Rubber Particle Addition Amount" represents the amount of core-shell rubber (parts by mass) per 100 parts by mass of the resin composition. In Tables 1 to 3, "Equivalent Ratio" represents the ratio of the active hydrogen equivalent of the curing agent to the epoxy equivalent of the epoxy resin (active hydrogen equivalent / epoxy equivalent). In Tables 1 to 3, "Fillet Crack" represents the number of test pieces with fillet cracks observed in the reliability test. For example, "0 / 5" means that when the reliability test described above was performed five times using different test pieces, no fillet cracks were observed in any of the test pieces. "1 / 5" means that fillet cracks were observed in one test piece. In Tables 1 to 3, "Conduction Failure (Open)" represents the number of test pieces exhibiting daisy chain breaks observed in the reliability test. For example, "0 / 5" means that when the above-mentioned reliability test was performed five times using different test specimens, no breaks in the daisy chain were observed in any of the test specimens. "1 / 5" means that a break in the daisy chain was observed in one test specimen. In Tables 1 to 3, "pressure between rolls (MPa)" represents the pressure (MPa) between the rolls during roll milling.

[0088]

[0089]

[0090]

[0091] 0.55 MPa m 0.5 The above ΔK ｔｈNo fillet cracks were observed in any of Examples 1 to 13, which exhibited a Tg of 105°C or higher. The frequency of wire breakage was less than one in five tests. No wire breakage was observed in any of Examples 1 to 7 and Examples 9 to 13, which exhibited a Tg of 105°C or higher. In Examples 2 and 3, the filler blending ratio was changed from that of Example 1. In Example 4, two different epoxy resins of component (A) were used in combination. In Examples 5 and 6, the equivalent ratio of the epoxy resin of component (A) to the curing agent of component (B) was changed from that of Example 4. In Example 7, unlike Example 4, epoxy resin A-4 was used in combination with epoxy resin A-1 as component (A) instead of epoxy resin A-2. In Example 8, the equivalent ratio of the epoxy resin of component (A) to the curing agent of component (B) was changed from that of Example 7. In Example 9, two different epoxy resins of component (A) were used in combination. Furthermore, a core-shell rubber of component (D) was added to the composition. In Example 10, an epoxy resin different from that used in Example 1 is used as component (A). Furthermore, a core-shell rubber of component (D) is added to the composition. In Example 11, three different epoxy resins of component (A) are used in combination. Furthermore, two curing agents different from those used in Example 1 are used as component (B). In Example 12, a curing agent different from that used in Example 1 is used as component (B). Furthermore, two fillers different from those used in Example 1 are used in combination as component (C). In Example 13, a curing agent different from that used in Example 1 is used as component (B). Furthermore, a filler different from that used in Example 1 is used as component (C). 0.55 MPa m 0.5 Less than ΔK ｔｈ The occurrence of fillet cracks was observed in all of Comparative Examples 1 to 5 having the above.

[0092] (Evaluation of Requirement 1) Evaluation of Requirement 1 was performed using the resin compositions of Examples 3, 10, and 12, and Comparative Example 5, according to the following procedure. Table 4 shows the results. To evaluate Requirement 1, test specimens were obtained by curing the resin compositions of Examples 3, 10, and 12, and Comparative Example 5. Specifically, a glass plate was fixed onto an organic substrate (FR-4 substrate) with a gap of 100 μm between them. The organic substrate with the fixed glass plate was placed on a hot plate set at 110°C. Each of the resin compositions of Examples 3, 10, and 12, and Comparative Example 5, was then injected into the gap. The injection width was 10 mm. The injection length was 20 mm. Subsequently, the injected resin composition was heated at 165°C for 2 hours as a curing treatment. The obtained test specimens (cured resin compositions) were fractured. The exposed cross section at the 10 mm injection distance was observed. A scanning electron microscope (Hitachi Scanning Electron Microscope System S-3400N) was used for the observation. The observation magnification was 1000x. The image size during observation was 122.4 μm horizontally and 93.4 μm vertically. The resolution was 1280 × 960. Next, the acquired observation image was analyzed using image analysis software WinROOF2018 (Mitani Shoji Co., Ltd., Ver. 4.5.5). The image analysis range was a range of 113.4 μm horizontally and 37.8 μm vertically within the acquired observation image. The number of pixels was 1200 × 400. As a specific procedure for image analysis, in order to reduce noise, the cross-sectional observation image of the cured product was filtered with a median filter (5 × 5 pixels) using the above software. Furthermore, the observation image was converted to a monochrome image and then binarized. In the binarization process, images with gradations below a predetermined threshold were cut off. Images with gradations equal to or greater than the threshold were set to 1, and images with gradations below the threshold were set to 0. The binarization was performed using Otsu's method (discriminant analysis method). Next, the filler area (μm ) in an area of ​​37.8 μm wide x 18.9 μm long in the binarized observation image was calculated. ２The above process was carried out for six locations in the binarized observation image (see Figure 2). In this way, the filler area of ​​each region was calculated. Using the six filler area values ​​obtained, the standard deviation (standard deviation of area (μm ２ The standard deviation of the area (μm ２ ) and the standard deviation of the average pixel counts mentioned above were also calculated.

[0093] (Evaluation of Requirement 2) Evaluation of Requirement 2 was carried out using the resin compositions of Examples 3, 10, and 12, and Comparative Example 5, according to the procedure shown below. To evaluate Requirement 2, first, a binarized observation image was obtained in the same manner as described above (Evaluation of Requirement 1). Next, the number of fillers in a region of 37.8 μm in width and 18.9 μm in length in the binarized observation image was calculated. By the above process, the number of fillers in each of six regions (see FIG. 2 ) in the binarized observation image was calculated. Using the obtained six filler count values, the standard deviation (standard deviation of the number (pieces)) was calculated.

[0094] In Table 4, "Pressure between rolls (MPa)" represents the pressure (MPa) between the rolls during roll milling. ２ ")" is the standard deviation of the filler area calculated above (evaluation of requirement 1). In Table 4, "standard deviation of area (number of pixels)" is the standard deviation of the average value of the number of pixels described above. In Table 4, "standard deviation of number (pieces)" is the standard deviation of the number of fillers calculated above (evaluation of requirement 2).

[0095]

[0096] As shown in Table 4 above, the resin compositions of Examples 3, 10, and 12 satisfy requirements 1 and 2. It was confirmed that these compositions have excellent uniformity. It is believed that the desired effects were achieved by using resin compositions exhibiting such properties.

[0097] 10 Test piece 12 Crack 20 Binarized observation image

Claims

1. (A) an epoxy resin, (B) a curing agent, (C) a filler; The cured product of the resin composition has a viscosity of 0.55 MPa m 0.5 The above fatigue crack propagation threshold stress intensity factor range ΔK ｔｈ have Resin composition.

2. The glass transition temperature (Tg) of the cured product of the resin composition is 100° C. or higher. The resin composition according to claim 1.

3. The (A) epoxy resin includes a liquid epoxy resin. The resin composition according to claim 1 or 2.

4. The (A) epoxy resin includes at least one selected from the group consisting of bisphenol F type epoxy resins, bisphenol A type epoxy resins, aminophenol type epoxy resins, naphthalene type epoxy resins, and cyclohexane type epoxy resins. The resin composition according to claim 1 or 2.

5. The content of the (C) filler is 40 to 80 parts by mass per 100 parts by mass of the total mass of all components of the resin composition. The resin composition according to claim 1 or 2.

6. The average particle size of the (C) filler is 0.1 to 20.0 μm. The resin composition according to claim 1 or 2.

7. The (C) filler is surface-treated with a silane coupling agent. The resin composition according to claim 1 or 2.

8. Further comprising (D) a core-shell rubber, The resin composition according to claim 1 or 2.

9. The cured product of the resin composition satisfies the following requirement 1: The resin composition according to claim 1 or 2. Requirement 1: A cross section of the cured resin composition is observed with a scanning electron microscope at a magnification of 1000 times, and the average area (μm ２ When the operation of calculating the area ratio (Rp) was performed at six randomly selected locations, the standard deviation of the areas of the six fillers obtained was 0.36 μm ２ The following is the result.

10. The cured product of the resin composition satisfies the following requirement 2: The resin composition according to claim 1 or 2. Requirement 2: When a cross section of the cured resin composition is observed under a scanning electron microscope at 1000x magnification and the number of fillers in an area of ​​37.8 μm wide × 18.9 μm long is calculated at six randomly selected locations, the standard deviation of the six numbers of fillers obtained is 80 or less.

11. The present invention comprises a substrate, a semiconductor element disposed on the substrate, and a cured product of the resin composition according to claim 1 or 2 that encapsulates the semiconductor element. Semiconductor device.

12. The method includes filling a gap between a substrate and a semiconductor element disposed on the substrate with the resin composition according to claim 1 or 2, and curing the resin composition. A method for manufacturing a semiconductor device.

13. The method includes mixing the (A) epoxy resin, the (B) curing agent, and the (C) filler using a roll mill to produce a resin composition; The roll pressure of the roll mill is 3.0 MPa or more; A method for producing the resin composition according to claim 1 or 2.