Epoxy resin composition, semiconductor device, and rework method

Abstract

To provide an epoxy resin composition having superior reworkability and adhesion reliability.SOLUTION: An epoxy resin composition contains an epoxy resin (A) and a curing agent (B), the curing agent (B) including a phenolic curing agent (B1) and an acid anhydride curing agent (B2). A cured product obtained by curing the epoxy resin composition at 150°C for 30 minutes has a storage modulus of 0.01 to 0.10 GPa at 230°C.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an epoxy resin composition, a semiconductor device, and a rework method. [Background technology]

[0002] Flip-chip mounting is a technique for mounting semiconductor chips and semiconductor packages to printed circuit boards. Flip-chip mounting involves forming protruding electrodes (bumps) on the surface of a semiconductor chip or semiconductor package, orienting the bumped surface on the printed circuit board, and directly connecting the chip and the printed circuit board via the bumps. This mounting method aims to improve the reliability of semiconductor devices by sealing the gap between the semiconductor chip or the printed circuit board with an underfill material such as an epoxy resin composition. Filling and curing the underfill material into the gap between the semiconductor chip or the printed circuit board protects the bumps from external factors and improves adhesion between the semiconductor chip or the printed circuit board, reducing the likelihood of peeling or other defects during thermal cycling tests. For this reason, underfill materials are required to have high adhesive reliability.

[0003] The adhesive reliability of underfill materials is known to be correlated with the glass transition temperature of the cured product. For underfill materials for semiconductors used in portable devices such as mobile phones and wearable devices, a glass transition temperature (Tg) of 85°C or higher (obtained by curing the underfill material at 150°C for 30 minutes) is an indicator of high adhesive reliability for the underfill material in that application. For underfill materials for semiconductors used in home appliances, PCs, and servers, a glass transition temperature (Tg) of 125°C or higher is an indicator of high adhesive reliability for the underfill material in that application.

[0004] In the manufacturing process of a semiconductor device, if a package defect occurs after sealing the gap between the semiconductor package and the printed circuit board with an underfill material, the semiconductor package may be removed from the printed circuit board, the underfill material removed, and the semiconductor package remounted. This process is called a rework process. Therefore, underfill materials are required to have high workability (reworkability) in the rework process. For this reason, underfill materials with various formulations have been studied with the aim of improving reworkability (Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special Publication No. 2009-513785 Summary of the Invention [Problem to be solved by the invention]

[0006] However, there is a trade-off between the reworkability and adhesive reliability of underfill materials. For example, the underfill material described in Patent Document 1 has high reworkability, but poor adhesion between semiconductor chips and printed circuit boards, and poor heat resistance, making it inferior in terms of adhesive reliability. Furthermore, attempts to improve adhesive reliability make it difficult to remove the semiconductor package from the printed circuit board, resulting in poor reworkability. Therefore, it has been difficult to create an underfill material that has both reworkability and adhesive reliability.

[0007] Therefore, an object of the present invention is to provide an epoxy resin composition having excellent reworkability and adhesive reliability, a semiconductor device including a cured product of the epoxy resin composition, and a rework method for removing a primary mounting substrate on which a semiconductor element is mounted from the semiconductor device. [Means for solving the problem]

[0008] As a result of extensive research into achieving the above object, the present inventors have found that an epoxy resin composition having a specific structure has both excellent reworkability and adhesive reliability. The present invention was completed based on these findings.

[0009] That is, the present invention provides an epoxy resin composition comprising an epoxy resin (A) and a curing agent (B), The curing agent (B) includes a phenol-based curing agent (B1) and an acid anhydride-based curing agent (B2), The epoxy resin composition is cured at 150°C for 30 minutes, and the cured product has a storage modulus at 230°C of 0.01 to 0.10 GPa.

[0010] In the epoxy resin composition, the mass ratio of the phenolic curing agent (B1) to the acid anhydride curing agent (B2) (phenolic curing agent (B1):acid anhydride curing agent (B2)) is preferably 2:8 to 8:2.

[0011] In the epoxy resin composition, the phenolic curing agent (B1) is preferably liquid at 25°C.

[0012] The epoxy resin composition further contains an inorganic filler (C), The content of the inorganic filler (C) relative to the epoxy resin composition (100% by mass) is preferably 65% ​​by mass or less.

[0013] The epoxy resin composition preferably has a glass transition temperature Tg of 85 to 140°C, the cured product obtained by curing the epoxy resin composition at 150°C for 30 minutes.

[0014] The epoxy resin composition is preferably used for semiconductor encapsulation.

[0015] The epoxy resin composition is preferably used for reworkable purposes.

[0016] The epoxy resin composition is preferably for board level use.

[0017] The present invention also provides a semiconductor device comprising a cured product of the above-mentioned epoxy resin composition.

[0018] In the present invention, a semiconductor device is provided with a semiconductor element, a primary mounting substrate, and a secondary mounting substrate in this order, The present invention also provides a semiconductor device in which the gap between the primary mounting substrate and the secondary mounting substrate is sealed with a cured product of the epoxy resin composition.

[0019] The present invention also provides a rework method including a step of removing the primary mounting substrate on which the semiconductor element is mounted from the secondary mounting substrate after heat-treating the rework target area of ​​the semiconductor device.

[0020] It is preferable that the rework method further includes at least one selected from the group consisting of a step of scraping off the cured product of the epoxy resin composition adhering to the surface of the primary mounting board and / or the secondary mounting board, and a step of cleaning the primary mounting board and / or the secondary mounting board with a solvent. [Effects of the Invention]

[0021] The epoxy resin composition of the present invention has both excellent reworkability and adhesive reliability. [Brief explanation of the drawings]

[0022] [Figure 1] 1A and 1B are diagrams illustrating an example of a semiconductor device. DETAILED DESCRIPTION OF THE INVENTION

[0023] (Epoxy resin composition) The epoxy resin composition of the present invention comprises an epoxy resin (A) and a curing agent (B), wherein the curing agent (B) comprises a phenolic curing agent (B1) and an acid anhydride curing agent (B2), and wherein the epoxy resin composition is cured at 150° C. for 30 minutes to obtain a cured product having a storage modulus of 0.01 to 0.10 GPa at 230° C. The epoxy resin composition may further comprise one or more of an inorganic filler (C), a curing accelerator (D), and a coupling agent (E), which will be described later.

[0024] The storage modulus of the cured product at 230°C is not particularly limited as long as it is 0.01 to 0.10 GPa, but is preferably 0.09 GPa or less, more preferably 0.08 GPa or less, and even more preferably 0.07 GPa or less. The storage modulus can be measured by the method described in the Examples below. Having the storage modulus within the above range tends to improve reworkability. This is because the heat treatment temperature in the rework step is around 230°C, and having the storage modulus within the above range at this temperature makes it easy to physically remove (for example, scrape off with a spatula or the like) the cured product from the semiconductor element or substrate.

[0025] Epoxy resin (A) The epoxy resin composition contains the epoxy resin (A), which allows it to form a cured product with high electrical insulation. The number of epoxy groups in the epoxy resin (A) is not particularly limited as long as it is one or more, but it is preferably two or more (i.e., a polyfunctional epoxy resin). The epoxy resin (A) can be used alone or in combination of two or more.

[0026] The epoxy resin (A) may be liquid or solid at room temperature (25°C), but is preferably liquid from the viewpoint of the viscosity of the epoxy resin composition. A solid epoxy resin can also be preferably used when it is used in combination with a liquid epoxy resin to form a liquid mixture.

[0027] The epoxy resin (A) is not particularly limited, and examples thereof include bisphenol-type epoxy resins such as bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, bisphenol S-type epoxy resins, and bisphenol AF-type epoxy resins, bixylenol-type epoxy resins, cyclohexane-type epoxy resins, dicyclopentadiene-type epoxy resins, trisphenol-type epoxy resins, naphthol novolac-type epoxy resins, phenol novolac-type epoxy resins, tert-butyl-catechol-type epoxy resins, naphthalene-type epoxy resins, naphthol-type epoxy resins, anthracene-type epoxy resins, glycidylamine-type epoxy resins (glycidylamine-type epoxy resins without an aromatic structure or glycidylamine-type epoxy resins with an aromatic structure), glycidyl ester-type epoxy resins (glycidyl ester-type epoxy resins without an aromatic structure or glycidyl ester-type epoxy resins with an aromatic structure), cresol novolac-type epoxy resins, biphenyl-type epoxy resins, and linear aliphatic epoxy resins (linear aliphatic epoxy resins without an aromatic structure).

[0033] Examples of the epoxy resin include aromatic or aliphatic epoxy resins such as epoxy resins having a butadiene structure (epoxy resins having a butadiene structure without an aromatic structure or epoxy resins having a butadiene structure with an aromatic structure), alicyclic epoxy resins (alicyclic epoxy resins having a butadiene structure without an aromatic structure or alicyclic epoxy resins having an aromatic structure), heterocyclic epoxy resins, spiro ring-containing epoxy resins (spiro ring-containing epoxy resins having a spiro ring without an aromatic structure or spiro ring-containing epoxy resins having an aromatic structure), cyclohexanedimethanol-type epoxy resins (cyclohexanedimethanol-type epoxy resins having a non-aromatic structure or cyclohexanedimethanol-type epoxy resins having an aromatic structure), naphthylene ether-type epoxy resins, trimethylol-type epoxy resins (trimethylol-type epoxy resins having a non-aromatic structure or trimethylol-type epoxy resins having an aromatic structure), tetraphenylmethane-type epoxy resins, aminophenol-type epoxy resins, and silicone-modified epoxy resins.

[0028] Among these, from the viewpoint of reworkability and adhesive reliability, it is more preferable that the epoxy resin (A) contains at least one selected from the group consisting of bisphenol-type epoxy resins such as bisphenol F-type epoxy resins and bisphenol A-type epoxy resins, aminophenol-type epoxy resins, and naphthalene-type epoxy resins.

[0029] Specific examples of liquid epoxy resins include "YDF-8170" (bisphenol F type epoxy resin), "YDF-8125" (bisphenol A type epoxy resin), "ZX-1658", and "ZX-1658GS" (liquid 1,4-glycidylcyclohexane) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "HP-4032", "HP-4032D", and "HP-4032SS" (naphthalene type epoxy resin) manufactured by DIC Corporation; and "jER828US", "jER828EL" (bisphenol A type epoxy resin), "jER806", and "jER807" (bisphenol A type epoxy resin) manufactured by Mitsubishi Chemical Corporation. Examples include "bisphenol F type epoxy resin," "jER152" (phenol novolac type epoxy resin), "jER630," "jER630LSD," "EP3980S" (aminophenol type epoxy resin), "YX7400" (high resilience epoxy resin), "ZX1059" (a mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin) manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., "EX-721" (glycidyl ester type epoxy resin) manufactured by Nagase ChemteX Corporation, and "Celloxide 2021P" (alicyclic epoxy resin) 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), "EXA850CRP", "EXA7311" manufactured by DIC Corporation. "EXA7311-G3", "EXA7311-G4", "EXA7311-G4S", "HP6000" (naphthylene ether type epoxy resin), "EPPN-502H" (trisphenol type epoxy resin), "NC-7000-L" (naphthol novolac type epoxy resin), "NC-3000-H", "NC-3000", "NC-3000-L", "NC-3100" (biphenyl type epoxy resin) manufactured by Nippon Kayaku Co., Ltd., "ESN475V" (naphthol type epoxy resin) and "ESN48" manufactured by Nippon Steel Chemical & Material Co., Ltd. 5" (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 Co., Ltd.'s "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 equivalent of the epoxy resin (A) is not particularly limited, but is preferably 30 to 1000 g / eq, more preferably 40 to 500 g / eq, and even more preferably 50 to 300 g / eq.

[0032] The content of the epoxy resin (A) relative to the epoxy resin composition (100% by mass) is not particularly limited, but is preferably 5% by mass or more, more preferably 8% by mass or more, even more preferably 12% by mass or more, particularly preferably 15% by mass or more, and most preferably 18% by mass or more. It is also preferably 80% by mass or less, more preferably 70% by mass or less, even more preferably 60% by mass or less, and particularly preferably 50% by mass or less. When the content of the epoxy resin (A) is within the above range, both reworkability and adhesion reliability tend to improve.

[0033] Hardener (B) The curing agent (B) is an agent that initiates, advances, or accelerates the polymerization of the epoxy resin and includes a phenolic curing agent (B1) and an acid anhydride curing agent (B2). By simultaneously including both the phenolic curing agent (B1) and the acid anhydride curing agent (B2) as the curing agent (B), excellent reworkability and adhesive reliability are exhibited. The curing agent (B) may further include at least one selected from the group consisting of an amine curing agent (B3) and an imidazole curing agent (B4). However, the inclusion of the amine curing agent (B3) is not preferred because it tends to prolong the curing time. The curing agents (B) can be used singly or in combination of two or more.

[0034] The phenolic curing agent (B1) has the property of improving reworkability. The phenolic curing agent (B1) may be any of a monomer, oligomer, and polymer having a phenolic hydroxyl group. Examples include phenol novolac resins, alkylated phenol novolac resins, allylated phenol novolac resins, cresol novolac resins, phenol aralkyl resins (e.g., resins containing a phenylene skeleton and / or a biphenylene skeleton), naphthol aralkyl resins, triphenolmethane resins, and dicyclopentadiene-type phenolic resins. The phenolic curing agent (B1) may be used alone or in combination of two or more. The phenolic curing agent (B1) may be liquid or solid at room temperature (25°C). Liquid curing agents are preferred from the viewpoint of workability in epoxy resin compositions. Furthermore, phenolic novolac resins are particularly preferred from the viewpoint of improving reworkability. This is thought to be due to the fact that phenolic novolac resins have little steric hindrance due to their structure.

[0035] The acid anhydride curing agent (B2) is defined as a curing agent having one or more acid anhydride groups in one molecule. It has the property of reducing the viscosity of the epoxy resin composition and increasing the glass transition temperature (Tg) of the cured product. Examples of the acid anhydride curing agent (B2) include acid anhydrides, hydrated acid anhydrides, and modified acid anhydrides, such as phthalic anhydride curing agents, succinic anhydride curing agents, and glutaric anhydride curing agents. The acid anhydride curing agent (B2) can be used alone or in combination of two or more. Among these acid anhydride curing agents (B2), phthalic anhydride is preferred because of its excellent electrical insulation properties and heat resistance, and because it is liquid at room temperature (25°C).

[0036] The phthalic anhydride curing agent is defined as a curing agent having a skeleton derived from phthalic anhydride in the molecule. The phthalic anhydride curing agent is not particularly limited, but examples thereof include phthalic anhydrides which may have a substituent (preferably a hydrocarbon group) such as trimellitic anhydride, pyromellitic anhydride, and benzophenone tetracarboxylic dianhydride; hydrogenated phthalic anhydrides which may have a substituent (preferably a hydrocarbon group, more preferably an alkyl group or an alkenyl group) such as tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, 3,4-dimethyl-6-(2-methyl-1-propenyl)-4-cyclohexene-1,2-dicarboxylic anhydride, 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, and nadic anhydride. The succinic anhydride curing agent is not particularly limited, but examples thereof include succinic anhydride which may have a substituent (preferably a hydrocarbon group, more preferably an alkyl group or an alkenyl group). The glutaric anhydride curing agent is not particularly limited, but examples thereof include glutaric anhydride which may have a substituent (preferably a hydrocarbon group, more preferably an alkyl group or an alkenyl group).

[0037] Examples of the amine curing agent (B3) include aromatic amines such as 4,4'-diamino-3,3'-diethyldiphenylmethane, diethyltoluenediamine, dimethylthiotoluenediamine, methylenedianiline, m-phenylenediamine, 4,4'-diaminodiphenylsulfone, and 3,3'-diaminodiphenylsulfone. The amine curing agent (B3) can be used alone or in combination of two or more. Examples of the imidazole curing agent (B4) include 2-methylimidazole, 2-undecylimidazole, 1-cyanoethyl-2-undecylimidazole, 2-heptadecylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-ethyl-4-imidazole, 2-phenylimidazole, and 2-phenyl-4-methylimidazole. The imidazole curing agent (B4) also includes a microcapsule-type imidazole curing agent. The imidazole curing agent (B4) can be used alone or in combination of two or more.

[0038] The equivalent weight (molecular weight per functional group) of the curing agent (B) is not particularly limited, but is, for example, preferably 10 to 600 g / eq, more preferably 50 to 400 g / eq, and even more preferably 100 to 300 g / eq.

[0039] The content of the curing agent (B) relative to the epoxy resin composition of the present invention (100% by mass) is not particularly limited, but is, for example, preferably 1 to 70% by mass, more preferably 5 to 60% by mass, and even more preferably 10 to 50% by mass. When the content of the curing agent (B) is within the above range, reworkability and adhesion reliability tend to be further improved.

[0040] The mass ratio of the phenolic curing agent (B1) to the acid anhydride curing agent (B2) (phenolic curing agent (B1):acid anhydride curing agent (B2)) is not particularly limited, but is preferably 1:9 to 9:1, more preferably 2:8 to 8:2, and even more preferably 3:7 to 7:3. When the mass ratio of the phenolic curing agent (B1) to the acid anhydride curing agent (B2) is within the above range, reworkability and adhesion reliability tend to be further improved.

[0041] The content of the curing agent (B) (particularly the phenol-based curing agent (B1) and the acid anhydride-based curing agent (B2)) relative to the epoxy resin (A) is preferably 0.5 to 1.5 in equivalent ratio, more preferably 0.8 to 1.2.

[0042] ·Inorganic filler (C) The inorganic filler (C) is not particularly limited, but is preferably (1) one having the property of suppressing volumetric shrinkage (cure shrinkage) caused by the curing reaction of the epoxy resin composition, (2) one having the property of suppressing volumetric change (thermal shrinkage) caused by heating of the cured product, i.e., one having the effect of lowering the linear expansion coefficient when added, or (3) one having both of these properties.

[0043] Examples of inorganic fillers (C) include silica (silicon dioxide), silicon carbide, silicon nitride, alumina (aluminum oxide), aluminum nitride, aluminum hydroxide, aluminum silicate, magnesium silicate, calcium silicate, calcium carbonate, barium sulfate, barium carbonate, titanium oxide, lime sulfate, potassium titanate, magnesium carbonate, zinc oxide, boron nitride, zirconia (zirconium oxide), and inorganic particles having their surfaces treated. Among these, silica is preferred from the viewpoint of increasing the loading amount. The inorganic filler (C) can be used alone or in combination of two or more.

[0044] In order to maintain the viscosity of the epoxy resin composition within an appropriate range, the inorganic filler (C) may be surface-treated with a coupling agent having a functional group such as an epoxy group, a (meth)acryloyl group, or an amino group (particularly a phenylamino group). Examples of the coupling agent include silane coupling agents such as 3-glycidoxypropyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, and N-phenyl-3-aminopropyltrimethoxysilane. The surface treatment of the inorganic filler (C) can be carried out using one of the above coupling agents alone or in combination of two or more.

[0045] The shape of the inorganic filler (C) is not particularly limited, and examples thereof include spherical (e.g., spherical, nearly spherical), polyhedral, rod-like (e.g., cylindrical, prismatic), plate-like, flaky, and irregular shapes. Among these, spherical shapes are preferred from the viewpoint of achieving a high loading amount.

[0046] The average particle size of the inorganic filler (C) is not particularly limited, but is preferably 1 nm to 10 μm, more preferably 0.1 to 5 μm, and even more preferably 0.2 to 2 μm. When the average particle size of the inorganic filler (C) is within the above range, the particle size is not too large, so the injectability of the epoxy resin composition is less likely to decrease even in narrow gaps, and the viscosity of the epoxy resin composition can be adjusted to facilitate dispensing. Two or more inorganic fillers with different average particle sizes may be used in combination to adjust the viscosity of the epoxy resin composition. The method for measuring the average particle size of the inorganic filler (C) is not particularly limited herein, but can be measured, for example, using a laser diffraction / scattering particle size distribution analyzer (product name: LS 13 320, manufactured by Beckman Coulter, Inc.).

[0047] The content of the inorganic filler (C) relative to the epoxy resin composition (100% by mass) is not particularly limited, but is, for example, preferably 90% by mass or less, more preferably 80% by mass or less, even more preferably 70% by mass or less, and particularly preferably 65% ​​by mass or less. When the content of the inorganic filler (C) is within the above range, reworkability and adhesive reliability tend to be further improved.

[0048] Curing accelerator (D) The curing accelerator (D) has the property of accelerating the curing of epoxy resins. The curing accelerator is not particularly limited, but examples thereof include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, and 2-phenyl-4-methylimidazole. Commercially available products include 2-phenyl-4-methylimidazole (manufactured by Shikoku Chemical Industries, Ltd., product name "2P4MZ"), 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine (manufactured by Shikoku Chemical Industries, Ltd., product name "2MZA"), and dicyandiamide. Microencapsulated imidazoles and encapsulated imidazoles, also known as epoxy adduct imidazoles, may also be used. Examples include "HX3941HP", "HXA3942HP", "HXA3922HP", "HXA3792", "HX3748", "HX3721", "HX3722", "HX3088", "HX3741", "HX3742", and "HX3613" (all manufactured by Asahi Kasei Chemicals Corporation), "PN-23J", "PN-40J", and "PN-50" (manufactured by Ajinomoto Fine-Techno Co., Ltd.), and FXR-1121 (manufactured by Fuji Chemical Industry Co., Ltd.). One type of curing accelerator (D) can be used alone, or two or more types can be used in combination.

[0049] The content of the curing accelerator (D) relative to the epoxy resin composition (100% by mass) is not particularly limited, but is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and even more preferably 1% by mass or more. Furthermore, it is not particularly limited, but is preferably 25% by mass or less, more preferably 20% by mass or less, and even more preferably 15% by mass or less.

[0050] Coupling agent (E) The coupling agent has various effects, such as improving the adhesion between the epoxy resin (A) and the inorganic filler (C) or between the epoxy resin (A) and the constituent members of electronic components. The coupling agent (E) is not particularly limited, but examples thereof 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 coupling agent (E) can be used alone or in combination of two or more.

[0051] Examples of the silane coupling agent include 3-glycidoxypropyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and 3-methacryloxypropyltrimethoxysilane.

[0052] The content of the coupling agent (E) relative to the epoxy resin composition (100% by mass) is not particularly limited, but is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, and is not particularly limited, but is preferably 5.0% by mass or less, more preferably 3.0% by mass or less.

[0053] Other ingredients (F) The epoxy resin composition may contain components other than the epoxy resin (A), curing agent (B), inorganic filler (C), curing accelerator (D), and coupling agent (E) (hereinafter referred to as "other components (F)"). Examples of other components (F) include curable compounds other than the epoxy resin (A), thermoplastic resins such as polyethylene resins, polyester resins, polyurethane resins, and polyamide resins, elastomers, surfactants, ion trapping agents, leveling agents, antioxidants, antifoaming agents, flame retardants, colorants such as carbon black, reactive diluents, and solvents. The other components (F) may be used alone or in combination of two or more.

[0054] The content of the other component (F) relative to the epoxy resin composition (100% by mass) is not particularly limited as long as it does not impair the effects of the present invention, but is, for example, preferably 10% by mass or less, more preferably 5% by mass or less, even more preferably 3% by mass or less, and particularly preferably 1% by mass or less. Furthermore, although not particularly limited, it is, for example, preferably 0.001% by mass or more, more preferably 0.01% by mass or more.

[0055] (Physical properties and production method of epoxy resin composition) The viscosity of the epoxy resin composition at 25°C is not particularly limited, but is preferably 300 Pa·s or less, more preferably 150 Pa·s or less, even more preferably 100 Pa·s or less, particularly preferably 75 Pa·s or less, and most preferably 50 Pa·s or less. Furthermore, for example, the viscosity is preferably 0.1 or more, more preferably 0.5 Pa·s or more. A viscosity within the above range tends to facilitate gap filling. As described in the examples below, the viscosity can be measured using an HB-type rotational viscometer or an RV-type rotational viscometer (both rotational viscometers have a spindle model number of SC4-14, manufactured by Brookfield) at a liquid temperature of 25°C, rotating at 50 rpm for 1 minute. When the viscosity at 25°C is 2.5 Pa·s or more but less than 20 Pa·s, an HB-type rotational viscometer is used. When the viscosity at 25°C is 20 Pa·s or more but less than 200 Pa·s, an RV-type rotational viscometer is used.

[0056] The epoxy resin composition can be prepared by a known, commonly used method. For example, the epoxy resin (A), curing agent (B), and, if necessary, at least one component selected from the group consisting of inorganic filler (C), curing accelerator (D), coupling agent (E), and other components (F) can be simultaneously or separately introduced into an appropriate mixer and stirred and mixed while melting, if necessary, by heating. If the epoxy resin (A) is solid, it is preferably liquefied or fluidized by heating before mixing. If it is difficult to uniformly disperse the inorganic filler (C) in the epoxy resin composition, the epoxy resin (A) and inorganic filler (C) can be heated and mixed to uniformly disperse the inorganic filler (C) in the epoxy resin (A), followed by cooling as necessary, and then mixing with components such as the curing agent (B) to prepare the epoxy resin composition.

[0057] The mixer is not particularly limited, and examples thereof include a roll mill equipped with a stirrer and a heater, a Raikai mixer, a Henschel mixer, a tumbler, a planetary mixer, etc. The mixing ratio of each component is appropriately set depending on the content of each component in the epoxy resin composition.

[0058] The epoxy resin composition can be preferably used as a material for encapsulating materials arranged on a substrate, such as semiconductor elements, wiring, and solder (solder bumps) in a semiconductor device (an epoxy resin composition for semiconductor encapsulation). By using the epoxy resin composition as an epoxy resin composition for semiconductor encapsulation, an encapsulated body with high adhesive reliability can be produced.

[0059] The epoxy resin composition for semiconductor encapsulation is used, for example, as an underfill such as a capillary underfill, a liquid mold underfill, a secondary underfill, or a pre-applied underfill, a grab-top material, or a liquid compression molding material. The epoxy resin composition is not limited to the use as the epoxy resin composition for semiconductor encapsulation described above, and can also be used, for example, as an adhesive for fixing, joining, or protecting components that constitute electronic components.

[0060] Furthermore, the above-mentioned epoxy resin composition can be preferably used as a material for reworkable applications (reworkable epoxy resin composition for semiconductor encapsulation). Specifically, the reworkable epoxy resin composition for semiconductor encapsulation is an epoxy resin composition that can be filled into the gap between a semiconductor element and a substrate or between substrates, cured to form an encapsulant, and then heated to soften the encapsulant, thereby making it possible to peel the semiconductor element or the substrate from it.

[0061] Furthermore, the epoxy resin composition can be preferably used as a material for board-level applications (epoxy resin composition for board-level encapsulation). In other words, it can be preferably used as a material for printed circuit board (PCB) applications or motherboard applications. Specifically, the epoxy resin composition for board-level encapsulation is an epoxy resin composition used to seal the gap between a primary mounting substrate 5 and a secondary mounting substrate 8, which are illustrated in FIG. 1 below.

[0062] (Cured product of epoxy resin composition) A cured product is formed by curing the epoxy resin composition. The curing method is not particularly limited, but for example, the curing can be carried out by subjecting the epoxy resin composition to a heat treatment. The temperature of the heat treatment is not particularly limited, but for example, 60 to 200°C is preferred, and 80 to 180°C is more preferred. The time of the heat treatment is not particularly limited, but for example, 0.1 to 5 hours is preferred, and 0.5 to 3 hours is more preferred.

[0063] The glass transition temperature Tg of the cured product obtained by curing the epoxy resin composition at 150°C for 30 minutes is not particularly limited, but is preferably, for example, 85°C or higher, more preferably 88°C or higher. Furthermore, although not particularly limited, it is, for example, preferably 140°C or lower, more preferably 130°C or lower, even more preferably 120°C or lower, and particularly preferably 115°C or lower. Having a glass transition temperature within the above range tends to result in excellent adhesive reliability of the cured product. The glass transition temperature (Tg) can be measured, for example, by the method described in the Examples below. Specifically, the glass transition temperature is measured by DMA (dynamic viscoelasticity measurement).

[0064] (Semiconductor Devices) The semiconductor device of the present invention comprises a cured product of the epoxy resin composition of the present invention. The semiconductor device preferably comprises a substrate, a semiconductor element disposed on the substrate, and a cured product of the epoxy resin composition encapsulating the semiconductor element. The semiconductor element and the substrate may be electrically and physically connected by, for example, bump electrodes such as solder bumps. Furthermore, it is preferable that the semiconductor device comprises a semiconductor element, a primary mounting substrate, and a secondary mounting substrate in this order, and that a gap between the semiconductor element and the primary mounting substrate or a gap between the primary mounting substrate and the secondary mounting substrate is sealed with a cured product of the epoxy resin composition. It is more preferable that the semiconductor device comprises a semiconductor element, a primary mounting substrate, and a secondary mounting substrate in this order, and that a gap between the primary mounting substrate and the secondary mounting substrate is sealed with a cured product of the epoxy resin composition. The semiconductor element and the primary mounting substrate may be electrically and physically connected by bump electrodes such as solder bumps, etc. Also, the primary mounting substrate and the secondary mounting substrate may be electrically and physically connected by bump electrodes such as solder balls, etc. An example of a semiconductor device will be described using Figure 1. In Figure 1, reference numeral 1 denotes a semiconductor device. Reference numeral 2 denotes a semiconductor element, 3 denotes solder bumps, 4 denotes an encapsulant, 5 denotes a primary mounting substrate, 6 denotes solder balls, 7 denotes an encapsulant (a cured product of the epoxy resin composition of the present invention), and 8 denotes a secondary mounting substrate.

[0065] The semiconductor device can be produced, for example, by filling a gap between the substrate and a semiconductor element disposed on the substrate with the epoxy resin composition of the present invention (filling step), and then curing and sealing the epoxy resin composition by heating (encapsulating step).

[0066] The semiconductor device can be manufactured, for example, by filling the gap between the primary mounting substrate and a semiconductor element disposed on the primary mounting substrate with an epoxy resin composition (filling step 1), curing the epoxy resin composition by heating to form a seal (encapsulation step 1), stacking the primary mounting substrate with the semiconductor element on a secondary mounting substrate (stacking step), filling the gap between the primary mounting substrate and the secondary mounting substrate with the epoxy resin composition (filling step 2), and curing the epoxy resin composition of the present invention by heating to form a seal (encapsulation step 2). In this embodiment, the method for manufacturing a semiconductor device includes the stacking step, filling step 2, and encapsulation step 2, and may further include filling step 1 and encapsulation step 1. The epoxy resin composition used in filling step 1 and encapsulation step 1 may be the epoxy resin composition of the present invention or another epoxy resin composition.

[0067] In filling steps 1 and 2, the method for filling the gap with the epoxy resin composition is not particularly limited, but for example, the epoxy resin composition is applied to one end of the substrate or semiconductor element while heating the substrate to 50 to 120°C, and the epoxy resin composition is then filled by capillary action into the gap between the substrate and the semiconductor element or the gap between the primary mounting substrate and the secondary mounting substrate. After filling the gap with the epoxy resin composition, the substrate is heated at a predetermined temperature for a predetermined time, specifically at the temperature and for the time described above in the heat treatment for forming the cured product, thereby sealing the gap.

[0068] (Rework method) The rework method of the present invention is characterized by removing the primary mounting substrate on which the semiconductor element is mounted from a semiconductor device comprising a semiconductor element, a primary mounting substrate, and a secondary mounting substrate in this order, wherein the gap between the primary mounting substrate and the secondary mounting substrate is sealed with a cured product of the epoxy resin composition of the present invention. In the rework method, part or all of the cured product may adhere to the surface of the primary mounting substrate to be removed.

[0069] The rework method includes a step (removal step) of removing the primary mounting substrate on which the semiconductor element is mounted from the secondary mounting substrate after heat-treating the rework target area of ​​the semiconductor device. The temperature of the heat treatment is not particularly limited, but is preferably, for example, 200 to 250°C. The time of the heat treatment is not particularly limited, but is preferably, for example, 1 to 10 minutes, and more preferably 2 to 5 minutes.

[0070] The rework method may further include at least one step selected from the group consisting of a step of scraping off the cured product of the epoxy resin composition adhering to the surface of the primary mounting substrate and / or the secondary mounting substrate (scraping step), and a step of cleaning the primary mounting substrate and / or the secondary mounting substrate with a solvent (cleaning step). In this method, the scraping step may be performed after the removing step, or the cleaning step may be performed after the removing step. Furthermore, the method may be performed in the order of the removing step, the scraping step, and the cleaning step, or may be performed in the order of the removing step, the cleaning step, and the scraping step.

[0071] In the cleaning step, the primary mounting substrate and / or the secondary mounting substrate is cleaned with a solvent, thereby making it possible to remove the cured product of the epoxy resin composition adhering to the surfaces of the primary mounting substrate and the secondary mounting substrate. [Example]

[0072] The present invention will be described in more detail below based on examples, but the present invention is not limited to these examples.

[0073] The epoxy resin compositions of Examples 1 to 16 and Comparative Examples 1 and 2 were prepared by appropriately selecting and mixing one or more components selected from the group consisting of epoxy resin (A), curing agent (B) (phenolic curing agent (B1) and acid anhydride curing agent (B2)), inorganic filler (C), curing accelerator (D), coupling agent (E), and other components (F) so as to obtain the blending ratios shown in Table 1. The numerical values ​​for each component in Table 1 indicate parts by mass.

[0074] Each component in Table 1 will be explained below. Epoxy resin (A) YDF-8170 (product name): Bisphenol F epoxy resin, epoxy equivalent weight 158g / eq, liquid at 25℃, manufactured by Nippon Steel Chemical & Material Co., Ltd. EXA-850CRP (product name): Bisphenol A epoxy resin, epoxy equivalent 173g / eq, liquid at 25℃, manufactured by DIC Corporation jER630 (product name): Aminophenol-type epoxy resin, epoxy equivalent weight 98g / eq, liquid at 25℃, manufactured by Mitsubishi Chemical Corporation HP-4032D (product name): Naphthalene-type epoxy resin, epoxy equivalent weight 140 eq, liquid at 25°C, manufactured by DIC Corporation Phenolic hardener (B1) MEH-8005 (product name): Phenol novolac resin, hydroxyl equivalent weight 139-143g / eq, liquid at 25℃, manufactured by UBE Corporation ·Acid anhydride curing agent (B2) YH307 (product name): Phthalic anhydride curing agent, acid anhydride equivalent 234g / eq, manufactured by Mitsubishi Chemical Corporation ·Inorganic filler (C) SO-E5 (product name): Average particle size 1.5 μm, silicon dioxide, manufactured by Admatechs Co., Ltd. Curing accelerator (D) HX-3088 (product name): Microcapsule-type latent curing accelerator, manufactured by Asahi Kasei Corporation Coupling agent (E) KBM-403 (product name): 3-glycidoxypropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd. Other ingredients (F) L-1982N (product name): Antifoaming agent, manufactured by Kusumoto Chemicals Co., Ltd.

[0075] (Measurement of storage modulus at 230°C) The storage modulus of the cured epoxy resin compositions of Examples 1 to 16 and Comparative Examples 1 and 2 was measured at 230°C using a dynamic viscoelasticity analyzer. First, spacers (overlaid with heat-resistant tape) were placed in two locations on a 3-mm-thick glass plate with a release agent so that the film thickness of the cured product was 2000±100 μm. Next, the epoxy resin compositions of Examples 1 to 16 and Comparative Examples 1 and 2 were applied between the spacers, sandwiched between two glass plates with a release agent while taking care not to trap air bubbles, and cured at 150°C for 30 minutes to obtain cured products. The cured products were peeled from the glass plates and then cut to the specified dimensions (10 mm × 50 mm) using a cutter to obtain test specimens. The storage modulus of these test specimens was measured using a dynamic thermomechanical analyzer (DMA) (product name: DMA7100, manufactured by Hitachi High-Tech Science Corporation) over a temperature range of -60°C to 260°C, at a frequency of 1 Hz, at a heating rate of 3°C / min, using a double-support bending method. The results are shown in Table 1 under "230°C storage modulus [GPa]."

[0076] (Viscosity measurement at 25°C) The viscosity (Pa s) at 25°C was measured for the epoxy resin compositions of Examples 1 to 16 and Comparative Examples 1 and 2 immediately after preparation. Specifically, an HB-type rotational viscometer or an RV-type rotational viscometer (both rotational viscometers had a spindle model number of SC4-14 spindle, manufactured by Brookfield) was used to measure the viscosity of the epoxy resin compositions when rotated at 50 rpm for 1 minute at a liquid temperature of 25°C. When the viscosity at 25°C was 2.5 Pa s or more but less than 20 Pa s, an HB-type rotational viscometer was used. When the viscosity at 25°C was 20 Pa s or more but less than 200 Pa s, an RV-type rotational viscometer was used. The results are shown in Table 1 under "Viscosity at 25°C (Pa s)."

[0077] (Reworkability evaluation) The epoxy resin compositions of Examples 1 to 16 and Comparative Examples 1 and 2 were applied to test substrates with a solder mask (PSR-4000 AUS703, manufactured by Taiyo Holdings Co., Ltd.) formed on an FR4 substrate and cured at 150°C for 30 minutes. The test substrates with the cured products were then left on a hot plate heated to 230°C for 1 minute, after which the cured products were scraped off using a spatula on the hot plate. Reworkability was evaluated based on damage to the solder mask (peel-off from the substrate). The results are shown in the "Reworkability" section of Table 1. The evaluation criteria were: "A" for no solder mask peeling, "B" for slight solder mask peeling, and "C" for solder mask peeling. Evaluations of A and B indicated that the epoxy resin compositions had good reworkability.

[0078] (Measurement of glass transition temperature (Tg)) The storage modulus (E') and loss modulus (E'') of the cured products of the epoxy resin compositions of Examples 1 to 16 and Comparative Examples 1 and 2 were measured using a dynamic viscoelasticity analyzer, and the peak value of tan δ, which is the ratio of these values, was determined as the glass transition temperature (Tg). The measurements were performed in accordance with Japanese Industrial Standard JIS C6481. First, spacers (heat-resistant tape laminated on top) were placed in two locations on a 3 mm thick glass plate with a release agent so that the film thickness of the cured product would be 2000±100 μm. Next, the epoxy resin composition was applied between the spacers, sandwiched between two other glass plates with a release agent while taking care not to trap air bubbles, and cured at 150°C for 30 minutes to obtain a cured product. The cured product was then peeled from the glass plate with the release agent and cut to the specified dimensions (10 mm × 50 mm) using a cutter to obtain test specimens. The glass transition temperature (Tg) of this test piece was measured using a dynamic thermomechanical analyzer (DMA) (product name: DMA7100, manufactured by Hitachi High-Tech Science Corporation) in the range of -60°C to 260°C, at a frequency of 1 Hz, at a heating rate of 3°C / min, and by a double-support bending method. The results are shown in the "Glass transition temperature (°C)" column in Table 1.

[0079] [Table 1]

[0080] 1. Semiconductor device 2. Semiconductor elements 3 Solder bumps 4 Encapsulation body 5 Primary mounting board 6 solder balls 7 Sealing body 8 Secondary mounting board

Claims

1. An epoxy resin composition comprising an epoxy resin (A) and a curing agent (B), The curing agent (B) includes a phenol-based curing agent (B1) and an acid anhydride-based curing agent (B2), The epoxy resin composition is cured at 150°C for 30 minutes, and the cured product has a storage modulus at 230°C of 0.01 to 0.10 GPa.

2. 2. The epoxy resin composition according to claim 1, wherein a mass ratio of the phenol-based curing agent (B1) to the acid anhydride-based curing agent (B2) (phenol-based curing agent (B1):acid anhydride-based curing agent (B2)) is 2:8 to 8:

2.

3. 3. The epoxy resin composition according to claim 1, wherein the phenolic curing agent (B1) is liquid at 25°C.

4. Further containing an inorganic filler (C), 3. The epoxy resin composition according to claim 1, wherein the content of the inorganic filler (C) relative to the epoxy resin composition (100% by mass) is 65% by mass or less.

5. 3. The epoxy resin composition according to claim 1, wherein the glass transition temperature Tg of a cured product obtained by curing the epoxy resin composition at 150°C for 30 minutes is 85 to 140°C.

6. 3. The epoxy resin composition according to claim 1, which is used for semiconductor encapsulation.

7. The epoxy resin composition according to claim 1 or 2, which is used for reworkable purposes.

8. 3. The epoxy resin composition according to claim 1 or 2, which is used for board level applications.

9. A semiconductor device comprising a cured product of the epoxy resin composition according to claim 1 or 2.

10. a semiconductor device, a primary mounting substrate, and a secondary mounting substrate in this order; A semiconductor device in which a gap between the primary mounting substrate and the secondary mounting substrate is sealed with a cured product of the epoxy resin composition according to claim 1 or 2.

11. 11. A rework method comprising the step of: removing the primary mounting substrate on which the semiconductor element is mounted from the secondary mounting substrate after heat-treating the rework target region of the semiconductor device according to claim 10.

12. 12. The rework method according to claim 11, further comprising at least one selected from the group consisting of a step of scraping off a cured product of the epoxy resin composition adhered to a surface of the primary mounting board and / or the secondary mounting board, and a step of cleaning the primary mounting board and / or the secondary mounting board with a solvent.

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