Epoxy resin composition and semiconductor device

Abstract

The present invention aims to provide an epoxy resin composition that exhibits good workability when using silicone oil as a stress-relaxing agent for epoxy resins, does not impair heat resistance, and has excellent stress-relaxing properties, as well as a semiconductor device using the epoxy resin composition as a encapsulant. [Solution] The present invention relates to the following components (A) to (C). (A) Epoxy resin that is liquid at 25℃, (B) Epoxy resin curing agent, and (C) Reactive silicone oil having one or more maleimide groups in one molecule The present invention provides an epoxy resin composition characterized by containing [a certain substance], and a semiconductor device characterized by being sealed with a cured product of the epoxy resin composition.

Description

[Technical Field]

[0001] The present invention relates to an epoxy resin composition and a semiconductor device using the same. [Background technology]

[0002] Epoxy resins are used as semiconductor encapsulants for many electronic components due to their excellent adhesive and electrical properties. As electrical devices become smaller, lighter, and more functional, the performance requirements for semiconductor encapsulants are becoming increasingly stringent, and epoxy resins are required to have stress-relaxing properties.

[0003] One method for giving epoxy resins stress-relaxing properties is to add additives that have a stress-relaxing effect. Specifically, commonly known stress-relaxing additives include acrylic rubber, epoxy-modified silicone oil, amino-modified silicone oil, and silicone rubber powder.

[0004] Patent Document 1 proposes a technology that achieves a reduction in elastic modulus by adding a core-shell type silicone compound, in which silicone oil is used as the core and an organic polymer such as acrylic is used as the shell, to an epoxy resin.

[0005] Furthermore, Patent Document 2 discloses a technology that uses epoxy-modified silicone microparticles having a core-shell structure, in which spherical silicone rubber microparticles are coated with polyorganosilsesquioxane having an epoxy group-containing organic group. This technology provides silicone rubber properties, good dispersibility due to anti-aggregation, and also gives the epoxy resin chemical reaction sites. However, the addition of such microparticles still requires dispersion technology into the epoxy resin, and in some cases, the desired performance cannot be achieved.

[0006] On the other hand, when adding liquid silicone oil, its poor compatibility with epoxy resin makes it difficult to uniformly mix and disperse it with the epoxy resin if a sufficient amount of epoxy-modified silicone is to be added to obtain a stress-relaxing effect. Therefore, while it is possible to suppress the separation of silicone oil by incorporating a very high viscosity silicone oil, this requires handling a very high viscosity during the compounding process, resulting in poor workability.

[0007] The technology described in Patent Document 3 successfully suppresses the separation of silicone oil by adding a dispersant dimethylpolysiloxane containing an amino group or carboxyl group that is reactive with epoxy resin, and a phenyl group or polyether group in the side chain to improve compatibility with epoxy resin. However, although a stress relaxation effect can be obtained while maintaining the heat resistance inherent to epoxy resin, its performance is still insufficient, and there is room for improvement.

[0008] The technology described in Patent Document 4 successfully maintains the inherent heat resistance of the epoxy resin and imparts a stress-relaxing effect by adding an organopolysiloxane having a cyclic imide group to the epoxy resin. However, the epoxy resin used is limited to those that are solid at 25°C. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] Japanese Patent Publication No. 2007-146148 [Patent Document 2] Japanese Patent Publication No. 2021-075605 [Patent Document 3] Japanese Patent Application Publication No. 8-100106 [Patent Document 4] Japanese Patent Publication No. 2020-026464 [Overview of the Initiative] [Problems that the invention aims to solve]

[0010] The present invention has been made in view of the above circumstances, and aims to provide an epoxy resin composition that has good workability when using silicone oil as a stress-relaxing agent for epoxy resin, does not impair heat resistance, and has excellent stress-relaxing properties, and a semiconductor device that uses the epoxy resin composition as a encapsulant. [Means for solving the problem]

[0011] In order to solve the above problems, the inventors diligently conducted research to find a way to easily and effectively disperse silicone components in an epoxy resin composition while maintaining the inherent heat resistance of the epoxy resin. As a result, they discovered that by incorporating a reactive silicone oil having a specific organic group into the epoxy resin composition, good workability and good dispersion of the silicone components can be achieved, thus completing the present invention.

[0012] Accordingly, the present invention provides the following epoxy resin composition and semiconductor device. 1. The following components (A) to (C) (A) Epoxy resin that is liquid at 25℃, (B) Epoxy resin curing agent, and (C) Reactive silicone oil having one or more maleimide groups in one molecule An epoxy resin composition characterized by containing the following: 2. The epoxy resin composition according to item 1 above, wherein the above component (C) is represented by the following formula (1). [ka] (In formula (1) above, R independently represents a monovalent hydrocarbon group having 1 to 10 carbon atoms, and X is a group selected from the group represented by R above, or a monovalent organic group having a maleimide group, X 1 X is a monovalent organic group having a maleimide group, where m and n are integers between 0 and 300, and m+n≧1. Furthermore, each molecule contains one or more of the above monovalent organic groups having maleimide groups. Note that if X is the group represented by R above, then m≧1. 3. Further, the epoxy resin composition according to 1 and 2 above, containing (D) a reactive silicone oil represented by the following formula (2).

Chemical formula

Advantages of the Invention

[0013] According to the present invention, it is possible to provide an epoxy resin composition that is excellent in stress relaxation simply without layer separation while maintaining the heat resistance inherent in the epoxy resin. Further, the present invention can provide a semiconductor device using an epoxy resin composition excellent in stress relaxation as a sealing agent.

Modes for Carrying Out the Invention

[0014] Hereinafter, the present invention will be described in more detail. The epoxy resin composition of the present invention contains the following components (A) to (C) (A) An epoxy resin that is liquid at 25°C, (B) An epoxy resin curing agent, and (C) A reactive silicone oil having one or more maleimide groups in one molecule and is characterized by containing them.

[0015] [(A) Epoxy resin] (A) The epoxy resin can be any known epoxy resin that is liquid at 25°C. Examples include biphenol-type epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, 3,3',5,5'-tetramethyl-4,4'-biphenol type epoxy resin, and 4,4'-biphenol type epoxy resin; phenol novolac type epoxy resin, cresol novolac type epoxy resin, bisphenol A novolac type epoxy resin, naphthalenediol type epoxy resin, trisphenylolemethane type epoxy resin, tetrakisphenyloleethane type epoxy resin, phenol biphenyl type epoxy resin, epoxy resins in which the aromatic ring of dicyclopentadiene type epoxy resin is hydrogenated, epoxy resins in which the aromatic ring of phenol dicyclopentadiene novolac type epoxy resin is hydrogenated, triazine derivative epoxy resins, and alicyclic epoxy resins. These epoxy resins may be used individually or in combination of two or more. In addition, a reactive diluent having an epoxy group may be used as needed.

[0016] [(B) Epoxy resin curing agent] The curing agent of component (B) can be any curing agent commonly used in epoxy resin compositions for sealing, and is not particularly limited. Specifically, amine-based curing agents, polymercaptan-based curing agents, imidazole-based curing agents, phenol-based curing agents, and dicyandiamide can be used, and acid anhydride-based curing agents may be used if necessary, with amine-based curing agents being preferred.

[0017] The amount of curing agent in component (B) is such that the molar ratio of groups in component (B) that are reactive with the epoxy groups to the epoxy groups in component (A) is preferably 0.7 to 1.2, more preferably 0.7 to 1.1, and even more preferably 0.80 to 1.05. For example, if component (B) is an amine-based curing agent, the amount of curing agent in component (B) is such that the molar ratio of amino groups in component (B) to epoxy groups in component (A) is preferably 0.7 to 1.2, more preferably 0.7 to 1.1, and even more preferably 0.80 to 1.05. When the amount of component (B) is such that the above molar ratio is achieved, the resulting cured product is less likely to have unreacted amino groups remaining, making it easier to prevent a decrease in glass transition temperature and adhesion, and it is less likely to become brittle because it does not become too hard.

[0018] [(C) Reactive silicone oil containing maleimide groups] Component (C) is a reactive silicone oil having one or more maleimide groups in one molecule, and is preferably represented by the following formula (1).

[0019] [ka]

[0020] In formula (1) above, R is independently a monovalent hydrocarbon group having 1 to 10 carbon atoms, preferably a monovalent hydrocarbon group having 1 to 6 carbon atoms. Examples of monovalent hydrocarbon groups having 1 to 10 carbon atoms include alkyl groups such as methyl, ethyl, propyl, and butyl groups, cycloalkyl groups such as cyclohexyl groups, and aryl groups such as phenyl groups. Among these, the methyl group is preferred.

[0021] In formula (1) above, X is selected from the group represented by R above, or a monovalent organic group having a maleimide group. Examples of monovalent organic groups having a maleimide group include the 3-maleimidopropyl group. 1 This is a monovalent organic group having a maleimide group, and examples of groups similar to X above include this group.

[0022] In formula (1) above, m and n, which represent the number of repeating units of the siloxane bond, are integers that satisfy 0 to 300, preferably in the range of 2 to 300, and more preferably in the range of 4 to 150. If the number of repeating units is less than 2, component (C) will become miscible with the epoxy resin, and will have too much of an effect on the physical properties after curing. On the other hand, if the number of repeating units is greater than 300, the dispersibility of component (C) in the epoxy resin will be poor, or the viscosity will become too high, and as a result, the desired effects of the present invention, such as excellent workability and excellent dispersibility, will not be achieved.

[0023] Furthermore, in equation (1) above, m and n satisfy m+n≧1, and preferably 2≦m+n≦60. Note that if X is the base represented by R above, then m≧1.

[0024] When X in formula (1) above is a 3-maleimidopropyl group and m=0, the silicone oil of formula (1) above is specifically represented by the following formula (1-a). [ka]

[0025] In the above equation (1-a), R 1 The same explanations for R and n in equation (1) above apply. In equation (1-a) above, R 2 R independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. 2 Examples of these groups include methyl groups, ethyl groups, propyl groups, butyl groups, and pentyl groups. Among these, hydrogen atoms, methyl groups, and ethyl groups are preferred, hydrogen atoms or methyl groups are more preferred, and hydrogen atoms are even more preferred.

[0026] The above-mentioned maleimide group-containing organopolysiloxanes can be produced, for example, by the following methods, but are not particularly limited. One manufacturing method involves mixing an acid anhydride compound and an organopolysiloxane containing primary amino groups at both ends in an organic solvent capable of dissolving these raw materials, and then carrying out an imidation reaction. Catalysts and dehydrating agents may be used during the reaction process as needed. The reaction is preferably carried out at low temperatures, provided that the desired reaction proceeds without impairing productivity.

[0027] The organic solvent is not particularly limited as long as it is a liquid organic compound that can sufficiently dissolve the raw material without reacting with it, but examples include aprotic polar solvents such as dimethyl sulfone, dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide, 1,3-dimethyl-2-imidazolidinone, and N-methylpyrrolidone; sulfones such as tetramethylene sulfone; ether solvents such as tetrahydrofuran, 4-methyltetrahydropyran, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, propylene glycol monomethyl ether monoacetate, and cyclopentyl methyl ether; ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, and cyclohexanone; and aromatic solvents such as toluene and xylene. Among these, ether solvents and aprotic polar solvents are preferred in terms of reactivity and solubility. The organic solvent can be used alone or in appropriate mixtures of two or more.

[0028] The catalyst is not particularly limited, but examples include organometallic salts such as tin octylate, zinc octylate, dibutyltin dimaleate, zinc naphthenate, cobalt naphthenate, and tin oleate; metal chlorides such as zinc chloride, aluminum chloride, and tin chloride; and tertiary amine compounds. Among these, cobalt naphthenate is preferred in thermal imidation without the use of a dehydrating agent from the viewpoint of reactivity, and the use of a tertiary amine is preferred in chemical imidation with a dehydrating agent, as described later. The catalyst can be used alone or in appropriate mixtures of two or more types.

[0029] Chemical imidation using a dehydrating agent has the advantage of lowering the reaction temperature compared to thermal imidation. The dehydrating agent used is designed not to react with the substrate in the reaction system, but to react with the water generated. The chemical species produced by the reaction with water are not reactive with the resulting imide compound and can be removed in a subsequent step.

[0030] Examples of dehydrating agents include carboxylic acid anhydrides, specifically acetic anhydride, propionic anhydride, succinic anhydride, and maleic anhydride, but are not limited to these. When using a carboxylic acid anhydride, it is preferable to use it in combination with an equimolar amount of a tertiary amine. The tertiary amine is not particularly limited, but triethylamine is preferred from the viewpoint of market availability and ease of removal in subsequent processes.

[0031] Regarding the reaction ratio of the substrate, it is preferable that the amount of acid anhydride for imidization is 0.8 to 1.5 moles per mole of primary amino group. If the amount of acid anhydride per mole of primary amino group is 0.8 moles or less, or 1.5 moles or more, an excess of unreacted functional groups will remain, which may reduce the yield of the desired imide compound.

[0032] Regarding the amount of dehydrating agent used in chemical imidation, it is preferable to use 1 to 2 moles per mole of primary amino group, and simultaneously, an equimolar amount of tertiary amine should also be used. From the viewpoint of productivity, the amount of tertiary amine used is preferably in the range of 1.2 to 1.6 moles.

[0033] Regarding the method for producing the maleimide group-containing organopolysiloxane of formula (1-a) described above, the reaction time for the raw materials, such as primary amino group-containing organopolysiloxanes and acid anhydride compounds, is preferably 10 minutes to 24 hours. The above reaction time should be sufficient to consume the raw materials as the reaction progresses, but preferably 1 to 10 hours, more preferably 2 to 7 hours. If the reaction time is less than 10 minutes, the raw materials may not be consumed sufficiently, and if it exceeds 24 hours, the raw materials may already be completely consumed, making it an unnecessary step and potentially reducing production efficiency.

[0034] The amount of component (C) is preferably in the range of 1 to 40 parts by mass, and more preferably in the range of 2 to 30 parts by mass, relative to 100 parts by mass of the total of components (A) and (B).

[0035] [(D) Reactive silicone oil] The epoxy resin composition of the present invention may further contain a reactive silicone oil represented by the following formula (2) as component (D).

[0036] [ka]

[0037] In formula (2) above, Y is selected from the group represented by R above, a monovalent organic group having an epoxy group, and a monovalent organic group that is reactive with an epoxy group. Examples of monovalent organic groups having an epoxy group include 3-glycidylpropyl group and 2-(3,4-epoxycyclohexyl)ethyl group. Examples of monovalent organic groups that are reactive with an epoxy group include 3-aminopropyl group and 3-(2-succinic anhydride)propyl group. Furthermore, Y1 is a group selected from a monovalent organic group having an epoxy group and a monovalent organic group that is reactive with an epoxy group, and examples of groups similar to Y above are given.

[0038] In formula (2) above, p and q, which represent the number of repeating units of the siloxane bond, are integers that satisfy 0 to 300, preferably in the range of 2 to 300, and more preferably in the range of 4 to 150. If the number of repeating units is less than 2, component (D) will become miscible with the epoxy resin, and will have too much of an effect on the physical properties after curing. On the other hand, if the number of repeating units is greater than 300, the dispersibility of component (D) in the epoxy resin will be poor, or the viscosity will become too high, and as a result, the desired effects of the present invention, such as excellent workability and excellent dispersibility, will not be achieved.

[0039] Furthermore, in equation (2) above, p and q satisfy p+q≧1, and preferably 2≦p+q≦60. Note that if Y is the base represented by R above, then p≧1.

[0040] The amount of component (D) is blended such that, in terms of mass ratio with component (C), (C) / (D) = 1 / 10 to 1 / 1, more preferably 1 / 6 to 1 / 2. In this case, component (D) is blended so that the total mass parts of component (C) and component (D) are in the range of 1 to 40 parts by mass, preferably 2 to 30 parts by mass, relative to 100 parts by mass of the total of components (A) and (B).

[0041] [Other ingredients] Furthermore, the epoxy resin composition of the present invention may contain curing accelerators to promote the curing reaction between the epoxy resin and the curing agent, various inorganic fillers, and the like. In addition, known additives used in epoxy resin compositions may be added as appropriate, as long as they do not impair the effects of the present invention.

[0042] The epoxy resin composition of the present invention can be cured by known curing methods. For example, it is preferable to first mold and cure the composition at a temperature of 100 to 120°C for 0.5 hours or more, and particularly preferably 0.5 to 2 hours, and then perform post-curing in a hot oven at a temperature of 130 to 250°C for 0.5 hours or more, and particularly preferably 0.5 to 5 hours. Curing conditions of a heating temperature of 100 to 120°C for 0.5 hours or more effectively prevent the formation of voids after curing. Furthermore, curing conditions of a heating temperature of 130 to 250°C for 0.5 hours or more make it easier to obtain a cured product with sufficient properties.

[0043] The method for producing the epoxy resin composition of the present invention may be carried out according to conventionally known methods. For example, the epoxy resin composition of the present invention can be obtained by mixing the above components in accordance with conventional methods.

[0044] The epoxy resin composition of the present invention is excellent as a encapsulant from the viewpoint of stress relaxation. Therefore, the epoxy resin composition of the present invention is useful as a encapsulant for semiconductor devices and the like, and can be suitably used as a encapsulant by, for example, coating an object (such as an electronic circuit board) with the epoxy resin composition of the present invention using a known coating method. [Examples]

[0045] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. In the following formula, the kinematic viscosity is the value measured using a Cannon-Fenske viscometer as described in JIS Z8803:2011.

[0046] [Preparation of epoxy resin composition] The epoxy resins and curing agents used in the examples and comparative examples are shown below.

[0047] (1) Liquid epoxy resin • JER-828EL (Epoxy equivalent: 190g / eq, manufactured by Mitsubishi Chemical Corporation) [ka]

[0048] (2) Hardening agent: an aromatic amine-based catalyst represented by the following formula · KAYAHARD A-A (manufactured by Nippon Kayaku Co., Ltd.)

Chemical formula

[0049] (3) Silicone oil The silicone oils used in this example and comparative examples are shown below.

[0050] · Silicone oil (1) Maleimide group equivalent 550 g / mol, kinematic viscosity at 25°C 160 mm 2 / s bifunctional maleimide silicone at both ends

Chemical formula

[0051] · Silicone oil (2) Maleimide group equivalent 860 g / mol, kinematic viscosity at 25°C 130 mm 2 / s bifunctional maleimide silicone at both ends

Chemical formula

[0052] · Silicone oil (3) Product name "X-22-164AS": methacryl group equivalent 450 g / mol, kinematic viscosity at 25°C 12 mm 2 / s bifunctional methacryl silicone at both ends (manufactured by Shin-Etsu Chemical Co., Ltd.) · Silicone oil (4) Product name "KF-105": epoxy group equivalent 490 g / mol, kinematic viscosity at 25°C 15 mm 2 / s bifunctional epoxy silicone at both ends (manufactured by Shin-Etsu Chemical Co., Ltd.) · Silicone oil (5) Product name "X-22-163C": Epoxy group equivalent 2,700 g / mol, kinematic viscosity at 25°C 120 mmHg 2 / s epoxy-functional silicone at both ends (manufactured by Shin-Etsu Chemical Co., Ltd.) • Silicone oil (6) Product name "X-22-3939A": Amine equivalent 1,800 g / mol, kinematic viscosity at 25°C 3,300 mmHg 2 / s side-chain amino-polyether functional silicone (manufactured by Shin-Etsu Chemical Co., Ltd.)

[0053] [Examples 1-5, Comparative Examples 1-5] The epoxy resin, curing agent, and the above-mentioned silicone oil were added in the amounts shown in Table 1 below to obtain the epoxy resin compositions of each example and comparative example.

[0054] [Table 1]

[0055] Furthermore, the epoxy resin compositions of each example and comparative example were cured according to the method described below. The bleedability of each resulting cured product was evaluated, and the flexural strength, flexural modulus, and glass transition temperature were measured. These evaluation results are shown in Table 2 below.

[0056] [Evaluation of breeding potential] After mixing each epoxy resin composition for 10 minutes, it was poured into a 4 mm thick mold. The mixture was then cured at 120°C for 0.5 hours and 165°C for 3 hours, and the cured product was removed from the mold. The surface of the cured product and the mold release surface were visually inspected to determine if there was any separation or migration of the liquid silicone component, thereby evaluating the bleedability.

[0057] [Bending test] After mixing each epoxy resin composition for 10 minutes, the mixtures were poured into a mold measuring 10 mm x 100 mm with a thickness of 4 mm. The mixtures were then cured at 120°C for 0.5 hours and 165°C for 3 hours, and the cured material was removed from the mold. The resulting cured material was subjected to a bending test, and the bending strength (MPa) and bending modulus (MPa) were measured at 25°C. The bending test was performed using an Autograph (manufactured by Shimadzu Corporation) in accordance with JIS K7171:2016. The test conditions were a support distance of 64 mm, a speed of 2 mm / min, and a sample thickness of 4 mm.

[0058] [Glass transition temperature measurement] Dynamic viscoelasticity (DMA) measurements were performed on the fractured hardened material (10 mm × 50 mm × 4 mm) after the bending test described above. The measurement device used was a "DMA7100" (manufactured by Hitachi High-Tech Science), and measurements were taken in 3-point bending mode. The glass transition temperature was determined by referring to the peak top temperature of tanδ.

[0059] [Table 2]

[0060] As shown in Table 2, the cured product obtained from the composition of the present invention was found to have no bleeding due to the efficient dispersion of the silicone component, to be stress-relieved, and furthermore, to maintain the heat resistance inherent to the epoxy resin.

[0061] It should be noted that the present invention is not limited to the embodiments described above. The embodiments described above are merely illustrative, and any configuration that is substantially identical to the technical idea described in the claims of the present invention and achieves similar effects is included within the technical scope of the present invention.

Claims

1. The following components (A) to (C) (A) Epoxy resin that is liquid at 25°C, (B) Epoxy resin curing agent, and (C) Reactive silicone oil having one or more maleimide groups in one molecule An epoxy resin composition characterized by containing the following:

2. The epoxy resin composition according to claim 1, wherein the above-mentioned component (C) is represented by the following formula (1). 【Chemistry 1】 (In the above formula (1), R independently represents a monovalent hydrocarbon group having 1 to 10 carbon atoms, and X is a group selected from the group represented by R above, or a monovalent organic group having a maleimide group, X 1 X is a monovalent organic group having a maleimide group, where m and n are integers between 0 and 300, and m + n ≥ 1. Furthermore, each molecule contains one or more of the above monovalent organic groups having a maleimide group. Note that if X is the group represented by R above, then m ≥ 1.

3. Furthermore, the epoxy resin composition according to claims 1 and 2 further comprises (D) a reactive silicone oil represented by the following formula (2). 【Chemistry 2】 (In formula (2) above, R is the same as above, and Y is a group selected from the group represented by R above, a monovalent organic group having an epoxy group, and a monovalent organic group that is reactive with an epoxy group, Y 1 The group is selected from a monovalent organic group having an epoxy group and a monovalent organic group reactive with an epoxy group, where p and q are integers satisfying 0 to 300, and p + q ≥ 1. Furthermore, each molecule contains one or more monovalent organic groups having the above epoxy group, or monovalent organic groups reactive with an epoxy group. Note that if Y is the group represented by R above, then p ≥ 1.

4. A semiconductor device characterized by being sealed with a cured product of an epoxy resin composition according to any one of claims 1 to 3.

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