Resin composition

Abstract

To provide a resin composition that allows formation of a cured product with low coefficient of linear thermal expansion and superior adhesion to a conductor layer, and that exhibits superior fluidity.SOLUTION: A resin composition comprising (A) a curable resin, (B) an inorganic filler having a specific surface area of 50 m2 / g or less, and (C) an aerogel having porosity of 85% or more.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a resin composition for interlayer insulating materials, a cured product thereof, a resin sheet, a circuit board, and a semiconductor device. [Background technology]

[0002] Circuit boards such as printed wiring boards are widely used in various electronic devices. A known method for manufacturing circuit boards is a build-up method in which insulating layers and conductor layers are alternately stacked on an inner layer substrate. The insulating layer is formed, for example, from a cured product of a resin composition. Specifically, a resin composition layer containing a resin composition is formed, and then the resin composition layer is cured to form an insulating layer containing a cured product of the resin composition (Patent Documents 1 to 3). Moreover, the technology of Patent Document 4 is publicly known. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7222638 [Patent Document 2] Special Publication No. 7-99646 [Patent Document 3] Japanese Patent Application Laid-Open No. 2001-98174 [Patent Document 4] Patent No. 4434687 Summary of the Invention [Problem to be solved by the invention]

[0004] In a circuit board having a multilayer structure, the insulating layer can function as an interlayer insulating material that insulates between conductor layers. When the linear thermal expansion coefficient of the insulating layer of the circuit board is large, the circuit board may be greatly warped. Therefore, in order to reduce the linear thermal expansion coefficient of the insulating layer, a resin composition containing an inorganic filler may be used. Generally, since inorganic materials have a smaller linear thermal expansion coefficient than resin materials, according to the cured product of the resin composition containing an inorganic filler, an insulating layer with a small linear thermal expansion coefficient can be formed, and thus it was expected that warping of the circuit board could be suppressed.

[0005] However, when an inorganic filler is used, the adhesion between the cured product of the resin composition and the conductor layer decreases. Regarding this, in order to suppress the decrease in adhesion due to the inorganic filler, it is conceivable to use porous silica as the inorganic filler. However, as a result of the inventor's study, it was found that when porous silica is used, the fluidity of the resin composition decreases. When the fluidity of the resin composition is low, the embedding property of the conductor layer by the resin composition may decrease.

[0006] The present invention was conceived in view of the above problems, and an object thereof is to provide a resin composition having excellent fluidity, a resin sheet containing the resin composition, a cured product of the resin composition, a circuit board containing the cured product of the resin composition, and a semiconductor device including the circuit board, which can obtain a cured product having a low linear thermal expansion coefficient and excellent adhesion to a conductor layer.

Means for Solving the Problems

[0007] The inventor diligently studied to solve the above problems. As a result, the inventor found that a resin composition appropriately combined with a curable resin, an inorganic filler, and an aerogel can solve the above problems, and completed the present invention. That is, the present invention includes the following.

[0008] <1> A resin composition containing (A) a curable resin, (B) an inorganic filler having a specific surface area of 50 m 2 / g or less, and (C) an aerogel having a porosity of 85% or more. <2> (A) the curable resin includes an epoxy resin; <1> The resin composition for an interlayer insulating material according to claim 1. <3> (B) the inorganic filler comprises silica; <1> or <2> The resin composition for an interlayer insulating material according to claim 1. <4> The total amount of the (B) inorganic filler and the (C) aerogel is 30% by volume or more and 60% by volume or less, based on 100% by volume of the nonvolatile components in the resin composition. <1> ~ <3> The resin composition for an interlayer insulating material according to any one of claims 1 to 4. <5> (C) The amount of aerogel is 1% by volume or more and 40% by volume or less relative to 100% by volume of the nonvolatile components in the resin composition; <1> ~ <4> The resin composition for an interlayer insulating material according to any one of claims 1 to 4. <6> The average linear thermal expansion coefficient of the cured product for evaluation obtained by curing the resin composition at 190°C for 90 minutes is 30 ppm / °C or less from 25°C to 150°C. <1> ~ <5> The resin composition for an interlayer insulating material according to any one of claims 1 to 4. <7> When an undulation evaluation test is conducted in which a 40 μm thick resin composition layer containing a resin composition is cured under curing conditions of 100 ° C. for 30 minutes and 180 ° C. for 30 minutes to form a cured product layer, the difference in undulation between the resin composition layer and the cured product layer is less than 1.2 μm. <1> ~ <6> The resin composition for an interlayer insulating material according to any one of claims 1 to 4. <8> A resin composition layer containing a resin composition is formed on a surface of a copper foil having an arithmetic mean roughness of 1 μm, and cured at 190°C for 90 minutes to form a cured layer. When an adhesion evaluation test is conducted in which the copper foil is peeled off in the vertical direction at a rate of 50 mm / min at 23°C, the load required to peel the copper foil from the cured layer is 0.4 kgf / cm or more. <1> ~ <7> The resin composition for an interlayer insulating material according to any one of claims 1 to 4. <9> A support and a resin composition layer provided on the support, The resin composition layer is <1> ~ <8> A resin sheet for an interlayer insulating material, comprising the resin composition for an interlayer insulating material according to any one of claims 1 to 4. <10> <1> ~ <8> A cured product of the resin composition for interlayer insulation according to any one of claims 1 to 4. <11> <1> ~ <8> A circuit board comprising a cured product of the resin composition for interlayer insulation according to any one of claims 1 to 4. <12> <11> A semiconductor device comprising the circuit board according to claim 1. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a resin composition for an interlayer insulating material that has excellent fluidity and that can give a cured product that has a low linear thermal expansion coefficient and excellent adhesion to a conductor layer; a resin sheet for an interlayer insulating material that includes the resin composition; a cured product of the resin composition; a circuit board that includes the cured product of the resin composition; and a semiconductor device that includes the circuit board. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present invention will be described below with reference to embodiments and examples. However, the present invention is not limited to the embodiments and examples shown below, and may be modified and implemented within the scope of the claims and their equivalents.

[0011] <Outline of Resin Composition> A resin composition for an interlayer insulating material according to one embodiment of the present invention contains (A) a curable resin, (B) an inorganic filler, and (C) an aerogel. A cured product can be obtained by curing this resin composition. Typically, (B) the inorganic filler and (C) the aerogel are contained in the resin composition in the form of particles, and are also contained in the cured product while maintaining this particulate state.

[0012] The resin composition according to this embodiment can have high fluidity. Therefore, the resin composition can satisfactorily embed a conductor layer in a method for manufacturing a circuit board. Furthermore, a cured product of the resin composition according to this embodiment can have a low coefficient of linear thermal expansion and excellent adhesion to the conductor layer. Therefore, by forming an insulating layer as an interlayer insulating material using a cured product of the resin composition, an insulating layer having a low coefficient of linear thermal expansion and excellent adhesion to the conductor layer can be obtained. The inventors of the present invention speculate that the mechanism by which the above-described excellent effects are obtained is as follows: However, the technical scope of the present invention is not limited by the mechanism below.

[0013] The resin composition according to this embodiment contains an inorganic filler (B) and an aerogel (C). Generally, the inorganic filler (B) and the aerogel (C) have a lower coefficient of linear thermal expansion than resin materials such as the curable resin (A). Therefore, the inorganic filler (B) and the aerogel (C) can lower the coefficient of linear thermal expansion of a cured product of the resin composition.

[0014] Conventionally, in cured resin compositions containing inorganic particles, the mechanical strength of the areas between the inorganic particles is relatively low, and destruction of the cured product occurs from these areas, easily resulting in delamination accompanied by destruction of the cured product. In contrast, the resin composition according to the present embodiment uses (C) aerogel. (C) aerogel is porous, and the surfaces of the (C) aerogel particles generally have irregularities, resulting in a large particle surface area. When the (C) aerogel particles, which have such a large surface area, are covered with a resin component, the adhesion between the particles can be improved, thereby suppressing destruction of the areas between the particles. Therefore, delamination accompanied by destruction of the cured product can be suppressed, thereby achieving high adhesion.

[0015] Furthermore, in conventional resin compositions containing porous materials such as mesoporous silica, the resin components tend to penetrate into the pores of the porous material, increasing the resistance within the resin composition and reducing the fluidity of the resin composition. In contrast, the aerogel (C) used in the resin composition of this embodiment generally has small pores, so the resin components do not easily penetrate into the pores. Therefore, the aerogel (C) particles can function as particles with a small effective surface area, reducing the resistance within the resin composition and lowering the viscosity, thereby achieving high fluidity.

[0016] <(A) Curing resin> The resin composition according to this embodiment includes a curable resin (A) as component (A). The curable resin (A) may be a thermosetting resin, a photocurable resin, or a combination thereof. The curable resin (A) may be used singly or in combination of two or more. In particular, the curable resin (A) preferably includes a thermosetting resin. The curable resin (A) may include only a thermosetting resin.

[0017] Examples of thermosetting resins include epoxy resins, active ester resins, phenolic resins, cyanate ester resins, carbodiimide resins, acid anhydride resins, amine resins, benzoxazine resins, thiol resins, and radical polymerizable resins.

[0018] The (A) curable resin preferably contains an (A-1) epoxy resin. The (A-1) epoxy resin as the (A-1) component can effectively improve the fluidity of the resin composition, as well as the linear thermal expansion coefficient and adhesion of the cured product. Since (A-1) epoxy resins may react with each other, the (A) curable resin may contain only the (A-1) epoxy resin.

[0019] The (A-1) epoxy resin may be a curable resin having an epoxy group. The (A-1) epoxy resin may be used singly or in combination of two or more. Examples of the (A-1) epoxy resin include bixylenol-type epoxy resins, bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, bisphenol S-type epoxy resins, bisphenol AF-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, and glycidyl Examples of epoxy resins include ester-type epoxy resins, cresol novolac-type epoxy resins, phenol aralkyl-type epoxy resins, biphenyl-type epoxy resins, linear aliphatic epoxy resins, epoxy resins having a butadiene structure, alicyclic epoxy resins, heterocyclic epoxy resins, spiro ring-containing epoxy resins, cyclohexane-type epoxy resins, cyclohexane dimethanol-type epoxy resins, naphthylene ether-type epoxy resins, trimethylol-type epoxy resins, tetraphenylethane-type epoxy resins, isocyanurate-type epoxy resins, and phenolphthalimidine-type epoxy resins.

[0020] From the viewpoint of obtaining a cured product having excellent heat resistance, the epoxy resin (A-1) preferably contains an epoxy resin containing an aromatic structure. The aromatic structure is a chemical structure generally defined as aromatic, and also includes polycyclic aromatic rings and aromatic heterocycles. Examples of epoxy resins containing an aromatic structure include bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, bisphenol AF 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, bisxyleneol type epoxy resins, glycidylamine type epoxy resins having an aromatic structure, glycidyl ester type epoxy resins having an aromatic structure, 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, and tetraphenylethane type epoxy resins having an aromatic structure.

[0021] Among these, bisphenol A type epoxy resins, bixylenol type epoxy resins, naphthalene type epoxy resins, biphenyl type epoxy resins and naphthylene ether type epoxy resins are preferred, and bisphenol A type epoxy resins, biphenyl type epoxy resins and bixylenol type epoxy resins are more preferred.

[0022] The epoxy resin (A-1) preferably contains an epoxy resin having two or more epoxy groups per molecule, and the proportion of the epoxy resin having two or more epoxy groups per molecule relative to 100% by mass of the non-volatile components of the epoxy resin (A-1) is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more.

[0023] (A-1) Epoxy resins include epoxy resins that are liquid at a temperature of 20°C (hereinafter sometimes referred to as "liquid epoxy resins") and epoxy resins that are solid at a temperature of 20°C (hereinafter sometimes referred to as "solid epoxy resins"). (A-1) Epoxy resins may contain only liquid epoxy resins, only solid epoxy resins, or a combination of liquid epoxy resins and solid epoxy resins.

[0024] The liquid epoxy resin is preferably a liquid epoxy resin having two or more epoxy groups per molecule, such as bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol AF epoxy resin, naphthalene epoxy resin, glycidyl ester epoxy resin, glycidyl amine epoxy resin, phenol novolac epoxy resin, alicyclic epoxy resin having an ester skeleton, cyclohexane epoxy resin, cyclohexanedimethanol epoxy resin, and epoxy resin having a butadiene structure; more preferably bisphenol A epoxy resin and naphthalene epoxy resin.

[0025] Specific examples of liquid epoxy resins include "HP-4032," "HP-4032-D," and "HP-4032-SS" (naphthalene-type epoxy resins) manufactured by DIC Corporation; "828US," "828EL," "jER828EL," "825," and "Epikote 828EL" (bisphenol A-type epoxy resins) manufactured by Mitsubishi Chemical Corporation; "jER807" and "1750" (bisphenol F-type epoxy resins) manufactured by Mitsubishi Chemical Corporation; "jER152" (phenol novolac-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "630," "630LSD," and "604" (glycidylamine-type epoxy resins) manufactured by Mitsubishi Chemical Corporation; "ED-523T" (glycirol-type epoxy resin) manufactured by ADEKA Corporation; and "EP-3950L" and "EP-398" manufactured by ADEKA Corporation. 0S" (glycidylamine type epoxy resin); ADEKA's "EP-4088S" (dicyclopentadiene type epoxy resin); Nippon Steel Chemical & Material's "ZX1059" (a mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin); Nagase ChemteX's "EX-721" (glycidyl ester type epoxy resin); Daicel's "Celloxide 2021P" (alicyclic epoxy resin with an ester skeleton); Daicel's "PB-3600," Nippon Soda's "JP-100" and "JP-200" (epoxy resins with a butadiene structure); and Nippon Steel Chemical & Material's "ZX1658" and "ZX1658GS" (liquid 1,4-glycidylcyclohexane type epoxy resin).

[0026] The solid epoxy resin is preferably a solid epoxy resin having three or more epoxy groups per molecule, more preferably an aromatic solid epoxy resin having three or more epoxy groups per molecule.The solid epoxy resin is preferably a bixylenol epoxy resin, a naphthalene epoxy resin, a naphthalene tetrafunctional epoxy resin, a naphthol novolac epoxy resin, a cresol novolac epoxy resin, a dicyclopentadiene epoxy resin, a trisphenol epoxy resin, a naphthol epoxy resin, a biphenyl epoxy resin, a naphthylene ether epoxy resin, an anthracene epoxy resin, a bisphenol A epoxy resin, a bisphenol AF epoxy resin, a phenol aralkyl epoxy resin, a tetraphenylethane epoxy resin, or a phenolphthalimidine epoxy resin; more preferably a bixylenol epoxy resin, a biphenyl epoxy resin, or a naphthylene ether epoxy resin.

[0027] Specific examples of solid epoxy resins include DIC Corporation's "HP4032H" (naphthalene-type epoxy resin); DIC Corporation's "HP-4700" and "HP-4710" (naphthalene-type tetrafunctional epoxy resins); DIC Corporation's "N-690" (cresol novolac-type epoxy resin); DIC Corporation's "N-695" (cresol novolac-type epoxy resin); DIC Corporation's "HP-7200," "HP-7200HH," "HP-7200H," and "HP-7200L" (dicyclopentadiene-type epoxy resins); and DIC Corporation's "EXA-7311." "EXA-7311-G3", "EXA-7311-G4", "EXA-7311-G4S", "HP6000" (naphthylene ether type epoxy resin); "EPPN-502H" (trisphenol type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; "NC7000L" (naphthol novolac type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; "NC3000H", "NC3000", "NC3000L", "NC3000FH", "NC3100" (biphenyl type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; "ESN475V", "ESN4" manufactured by Nippon Steel Chemical & Material Co., Ltd. 100V" (naphthalene-type epoxy resin); "ESN485" (naphthol-type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "ESN375" (dihydroxynaphthalene-type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "YX4000H", "YX4000", "YX4000HK", and "YL7890" (bixylenol-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "YL6121" (biphenyl-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "YX8800" (anthracene-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "Y" manufactured by Mitsubishi Chemical Corporation Examples include "X7700" (phenol aralkyl type epoxy resin); "PG-100" and "CG-500" manufactured by Osaka Gas Chemicals Co., Ltd.; "YX7760" (bisphenol AF type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "YL7800" (fluorene type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "jER1010" (bisphenol A type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "jER1031S" (tetraphenylethane type epoxy resin) manufactured by Mitsubishi Chemical Corporation; and "WHR991S" (phenolphthalimidine type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.

[0028] When the (A-1) epoxy resin contains a combination of a liquid epoxy resin and a solid epoxy resin, the mass ratio thereof (liquid epoxy resin:solid epoxy resin) is preferably 20:1 to 1:20, more preferably 10:1 to 1:10, and even more preferably 7:1 to 1:7.

[0029] The epoxy equivalent of the (A-1) epoxy resin is preferably in the range of 50 g / eq to 5,000 g / eq, more preferably 60 g / eq to 3,000 g / eq, even more preferably 80 g / eq to 2,000 g / eq, and particularly preferably 110 g / eq to 1,000 g / eq. The epoxy equivalent represents the mass of the resin per equivalent of epoxy groups. This epoxy equivalent can be measured according to JIS K7236.

[0030] The weight-average molecular weight (Mw) of the epoxy resin (A-1) is preferably in the range of 100 to 5,000, more preferably 250 to 3,000, and even more preferably 400 to 1,500. The weight-average molecular weight can be measured by gel permeation chromatography (GPC) as a polystyrene-equivalent value.

[0031] The amount of (A-1) epoxy resin is preferably 1% by mass or more, more preferably 2% by mass or more, and even more preferably 5% by mass or more, relative to 100% by mass of the nonvolatile components in the resin composition, and is preferably 60% by mass or less, more preferably 50% by mass or less, and even more preferably 40% by mass or less. Unless otherwise specified, the nonvolatile components in the resin composition refer to the components in the resin composition excluding the solvent. When the amount of (A-1) epoxy resin is within the above range, the flowability of the resin composition and the linear thermal expansion coefficient and adhesion of the cured product can be particularly improved.

[0032] The amount of (A-1) epoxy resin is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 20% by mass or more, relative to 100% by mass of the resin components in the resin composition. It is preferably 80% by mass or less, more preferably 70% by mass or less, and even more preferably 60% by mass or less. Unless otherwise specified, the resin components in the resin composition refer to the non-volatile components in the resin composition excluding (B) inorganic filler and (C) aerogel. When the amount of (A-1) epoxy resin is within the above range, the flowability of the resin composition and the linear thermal expansion coefficient and adhesion of the cured product can be particularly improved.

[0033] The (A) curable resin preferably contains a combination of an (A-1) epoxy resin and a resin capable of reacting with and bonding to the (A-1) epoxy resin to cure the resin composition. Hereinafter, the resin capable of reacting with and bonding to the (A-1) epoxy resin to cure the resin composition may be referred to as a "curing agent." The (A-2) curing agent as the (A-2) component does not include those corresponding to the above-mentioned (A-1) component. One type of (A-2) curing agent may be used alone, or two or more types may be used in combination.

[0034] Examples of the (A-2) curing agent include active ester resins, phenol resins, carbodiimide resins, cyanate resins, benzoxazine resins, acid anhydride resins, amine resins, thiol resins, etc. Among these, active ester resins and phenol resins are preferred.

[0035] The active ester resin may be a resin having one or more, preferably two or more, active ester groups in one molecule. Among them, preferred active ester resins are those having two or more highly reactive ester groups in one molecule, such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds.

[0036] The active ester resin is preferably one obtained by a condensation reaction between a carboxylic acid compound and / or a thiocarboxylic acid compound and a hydroxy compound and / or a thiol compound. From the viewpoint of improving heat resistance in particular, an active ester resin obtained from a carboxylic acid compound and a hydroxy compound is preferred, and an active ester resin obtained from a carboxylic acid compound and a phenol compound and / or a naphthol compound is more preferred. Examples of the carboxylic acid compound include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, and pyromellitic acid. Examples of phenol compounds or naphthol compounds include hydroquinone, resorcinol, bisphenol A, bisphenol F, bisphenol S, phenolphthalene, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m-cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucin, benzenetriol, dicyclopentadiene-type diphenol compounds, and phenol novolak. Here, "dicyclopentadiene-type diphenol compounds" refers to diphenol compounds obtained by condensing one dicyclopentadiene molecule with two phenol molecules.

[0037] Specifically, the active ester resin is preferably a dicyclopentadiene-type active ester resin, a naphthalene-type active ester resin containing a naphthalene structure, an active ester resin containing an acetylated product of phenol novolac, or an active ester resin containing a benzoylated product of phenol novolac, and among these, a naphthalene-type active ester resin is more preferred. The dicyclopentadiene-type active ester resin is preferably an active ester resin containing a dicyclopentadiene-type diphenol structure.

[0038] Commercially available active ester resins include, for example, "EXB9451", "EXB9460", "EXB9460S", "EXB-8000L", "EXB-8000L-65M", "EXB-8000L-65TM", "HPC-8000L-65TM", "HPC-8000", "HPC-8000-65T", "HPC-8000H", and "HPC-8000H-65TM" (manufactured by DIC Corporation) as active ester resins containing a dicyclopentadiene-type diphenol structure; and "HP-B-8151-62T", "EXB-8100L-65T", "EXB-8150-60T", and "EXB-8150-62" as active ester resins containing a naphthalene structure. Examples of such active ester resins include "EXB9401" (manufactured by DIC Corporation), "EXB-9416-70BK", "HPC-8150-60T", "HPC-8150-62T", and "HPC-8151-62T" (manufactured by DIC Corporation), a phosphorus-containing active ester resin, "EXB9401" (manufactured by DIC Corporation), "DC808" (manufactured by Mitsubishi Chemical Corporation), an active ester resin which is an acetylated product of phenol novolac, "YLH1026", "YLH1030", and "YLH1048" (manufactured by Mitsubishi Chemical Corporation), and an active ester resin containing a styryl group and a naphthalene structure, "PC1300-02-65MA" (manufactured by Air Water Inc.).

[0039] The amount of the active ester resin is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 20% by mass or more, relative to 100% by mass of the resin components in the resin composition, and is preferably 80% by mass or less, more preferably 70% by mass or less, and even more preferably 60% by mass or less. When the amount of the active ester resin is within the above range, the flowability of the resin composition and the linear thermal expansion coefficient and adhesion of the cured product can be particularly well improved.

[0040] As the phenolic resin, a resin having one or more, preferably two or more, hydroxyl groups (phenolic hydroxyl groups) bonded to an aromatic ring such as a benzene ring or a naphthalene ring per molecule can be used. From the viewpoint of heat resistance and water resistance, a phenolic resin having a novolac structure is preferred. From the viewpoint of adhesion, a nitrogen-containing phenolic resin is preferred, and a triazine skeleton-containing phenolic resin is more preferred. Among these, a triazine skeleton-containing phenolic novolac resin is preferred from the viewpoint of highly satisfying heat resistance, water resistance, and adhesion.

[0041] Specific examples of phenolic resins include "MEH-7700", "MEH-7810", "MEH-7851", and "MEH-8000H" manufactured by Meiwa Kasei Co., Ltd.; "NHN", "CBN", and "GPH" manufactured by Nippon Kayaku Co., Ltd.; and "SN-170", "SN-180", "SN-190", "SN-475", "SN-485", "SN-495", "SN-495V", and "SN- 375" and "SN-395" manufactured by DIC Corporation; "TD-2090", "TD-2090-60M", "LA-7052", "LA-7054", "LA-1356", "LA-3018", "LA-3018-50P", "LA-1356", "TD2090", and "TD-2090-60M" manufactured by DIC Corporation; and "GDP-6115L", "GDP-6115H", and "ELPC75" manufactured by Gun-ei Chemical Co., Ltd.

[0042] The amount of the phenolic resin is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and even more preferably 1% by mass or more, relative to 100% by mass of the resin components in the resin composition, and is preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 30% by mass or less. When the amount of the phenolic resin is within the above range, the flowability of the resin composition and the linear thermal expansion coefficient and adhesion of the cured product can be particularly well improved.

[0043] As the carbodiimide resin, a resin having one or more, preferably two or more, carbodiimide structures in one molecule can be used. Specific examples of the carbodiimide resin include aliphatic biscarbodiimides such as tetramethylene-bis(t-butylcarbodiimide) and cyclohexanebis(methylene-t-butylcarbodiimide); aromatic biscarbodiimides such as phenylene-bis(xylylcarbodiimide); aliphatic polycarbodiimides such as polyhexamethylenecarbodiimide, polytrimethylhexamethylenecarbodiimide, polycyclohexylenecarbodiimide, poly(methylenebiscyclohexylenecarbodiimide), and poly(isophoronecarbodiimide); poly(phenylenecarbodiimide), poly(naphthalenecarbodiimide); Examples of polycarbodiimides include aromatic polycarbodiimides such as poly(methylenediphenylenecarbodiimide), poly(tolylenecarbodiimide), poly(methyldiisopropylphenylenecarbodiimide), poly(triethylphenylenecarbodiimide), poly(diethylphenylenecarbodiimide), poly(triisopropylphenylenecarbodiimide), poly(diisopropylphenylenecarbodiimide), poly(xylylenecarbodiimide), poly(tetramethylxylylenecarbodiimide), poly(methylenediphenylenecarbodiimide), and poly[methylenebis(methylphenylene)carbodiimide]. Commercially available carbodiimide resins include, for example, "Carbodilite V-02B," "Carbodilite V-03," "Carbodilite V-04K," "Carbodilite V-05," "Carbodilite V-07," and "Carbodilite V-09" manufactured by Nisshinbo Chemical Inc.; and "Stavaxol P," "Stavaxol P400," and "Hykasil 510" manufactured by Lanxess AG.

[0044] As the cyanate-based resin, a resin having one or more, preferably two or more, cyanate groups in one molecule can be used. Examples of cyanate resins include bifunctional cyanate resins such as bisphenol A dicyanate, polyphenol cyanate, oligo(3-methylene-1,5-phenylene cyanate), 4,4'-methylenebis(2,6-dimethylphenyl cyanate), 4,4'-ethylidene diphenyl dicyanate, hexafluorobisphenol A dicyanate, 2,2-bis(4-cyanate)phenylpropane, 1,1-bis(4-cyanatephenylmethane), bis(4-cyanate-3,5-dimethylphenyl)methane, 1,3-bis(4-cyanatephenyl-1-(methylethylidene))benzene, bis(4-cyanatephenyl)thioether, and bis(4-cyanatephenyl)ether; multifunctional cyanate resins derived from phenol novolac, cresol novolac, and the like; and prepolymers in which these cyanate resins are partially triazine converted. Specific examples of cyanate-based resins include "PT30" and "PT60" (phenol novolac-type multifunctional cyanate-based resins) manufactured by Lonza, "BA230" and "BA230S75" (prepolymers in which part or all of bisphenol A dicyanate has been triazine-converted to form a trimer).

[0045] The benzoxazine resin may be a resin having one or more, preferably two or more, benzoxazine rings in one molecule. Specific examples of the benzoxazine resin include "JBZ-OP100D" and "ODA-BOZ" manufactured by JFE Chemical Corporation, "HFB2006M" manufactured by Showa Polymer Co., Ltd., and "Pd", "Fa", and "ALP-d" manufactured by Shikoku Chemicals Corporation.

[0046] As the acid anhydride resin, a resin having one or more, preferably two or more, acid anhydride groups in one molecule can be used. Specific examples of the acid anhydride resin include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnadic anhydride, hydrogenated methylnadic anhydride, trialkyltetrahydrophthalic anhydride, dodecenyl succinic anhydride, 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, trimellitic anhydride, pyromellitic anhydride, and benzophenonetetracarboxylic dianhydride. Examples of suitable anhydrides include anhydrides, biphenyltetracarboxylic dianhydride, naphthalenetetracarboxylic dianhydride, oxydiphthalic dianhydride, 3,3'-4,4'-diphenylsulfonetetracarboxylic dianhydride, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-C]furan-1,3-dione, ethylene glycol bis(anhydrotrimellitate), and polymeric anhydrides such as styrene-maleic acid resins, which are copolymers of styrene and maleic acid. Commercially available acid anhydride resins include, for example, "HNA-100," "MH-700," "MTA-15," "DDSA," and "OSA" manufactured by New Japan Chemical Co., Ltd.; "YH-306" and "YH-307" manufactured by Mitsubishi Chemical Corporation; "HN-2200" manufactured by Resonac Corporation; and "EF-30," "EF-40," "EF-60," and "EF-80" manufactured by Cray Valley Chemical Industries, Ltd.

[0047] The amine resin may be a resin having one or more, preferably two or more, amino groups in one molecule. Examples of the amine resin include aliphatic amines, polyether amines, alicyclic amines, and aromatic amines, with aromatic amines being preferred. The amine resin is preferably a primary amine or secondary amine, with primary amines being more preferred. Specific examples of the amine resin include 4,4'-methylenebis(2,6-dimethylaniline), 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, m-phenylenediamine, m-xylylenediamine, diethyltoluenediamine, 4,4'-diaminodiphenyl ether, 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dihydroxybenzidine, and 2,2-bis(3-amino-4-hydroxyphenyl)propanol. Examples of suitable bis(4-aminophenoxy)benzene include bis(4-aminophenyl)propane, 3,3-dimethyl-5,5-diethyl-4,4-diphenylmethanediamine, 2,2-bis(4-aminophenyl)propane, 2,2-bis(4-(4-aminophenoxy)phenyl)propane, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, bis(4-(4-aminophenoxy)phenyl)sulfone, and bis(4-(3-aminophenoxy)phenyl)sulfone. Commercially available amine-based resins include, for example, "SEIKACURE-S" manufactured by Seika Corporation; "KAYABOND C-200S," "KAYABOND C-100," "KAYAHARD AA," "KAYAHARD AB," and "KAYAHARD AS" manufactured by Nippon Kayaku Co., Ltd.; "Epicure W" manufactured by Mitsubishi Chemical Corporation; and "DTDA" manufactured by Sumitomo Seika Chemicals Co., Ltd.

[0048] Examples of thiol-based resins include trimethylolpropane tris(3-mercaptopropionate), pentaerythritol tetrakis(3-mercaptobutyrate), and tris(3-mercaptopropyl)isocyanurate.

[0049] The active group equivalent of the (A-2) curing agent is preferably in the range of 50 g / eq to 3,000 g / eq, more preferably 100 g / eq to 1,000 g / eq, even more preferably 100 g / eq to 500 g / eq, and particularly preferably 100 g / eq to 300 g / eq. The active group equivalent represents the mass of the resin per equivalent of the active group. For example, the active group equivalent of a phenolic resin represents the phenolic hydroxyl group equivalent, which represents the mass of the resin per equivalent of the phenolic hydroxyl group.

[0050] The weight average molecular weight (Mw) range of the (A-2) curing agent may be the same as the weight average molecular weight (Mw) range of the (A-1) epoxy resin.

[0051] The number of active groups in the (A-2) curing agent is preferably 0.1 or more, more preferably 0.3 or more, even more preferably 0.5 or more, and preferably 5 or less, more preferably 3 or less, even more preferably 2 or less, relative to the number of epoxy groups in the (A-1) epoxy resin (defined as 1). The "number of epoxy groups in the (A-1) epoxy resin" in the resin composition refers to the sum of all values obtained by dividing the mass of the non-volatile components of the (A-1) epoxy resin present in the resin composition by its epoxy equivalent. Furthermore, the "number of active groups in the (A-2) curing agent" refers to the sum of all values obtained by dividing the mass of the non-volatile components of the (A-2) curing agent present in the resin composition by its active group equivalent. When the number of active groups in the (A-2) curing agent is within the above range, the flowability of the resin composition, as well as the linear thermal expansion coefficient and adhesion of the cured product, can be particularly improved.

[0052] The amount of (A-2) curing agent is preferably at least 1 mass%, more preferably at least 5 mass%, and even more preferably at least 10 mass%, relative to 100 mass% of the nonvolatile components in the resin composition, and is preferably at most 60 mass%, more preferably at most 50 mass%, and particularly preferably at most 40 mass%. When the amount of (A-2) curing agent is within this range, the flowability of the resin composition and the linear thermal expansion coefficient and adhesion of the cured product can be particularly effectively improved.

[0053] The amount of (A-2) curing agent is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 20% by mass or more, relative to 100% by mass of the resin components in the resin composition, and is preferably 90% by mass or less, more preferably 80% by mass or less, and even more preferably 70% by mass or less. When the amount of (A-2) curing agent is within this range, the flowability of the resin composition and the linear thermal expansion coefficient and adhesion of the cured product can be particularly effectively improved.

[0054] The (A) curable resin may contain a (A-3) radical polymerizable resin. The (A-3) radical polymerizable resin as the (A-3) component does not include those corresponding to the above-mentioned components (A-1) and (A-2). The (A-3) radical polymerizable resin may be used alone or in combination of two or more.

[0055] The radical polymerizable resin (A-3) typically contains a resin containing a non-aromatic carbon-carbon unsaturated bond. Therefore, the radical polymerizable resin (A-3) may have a radical polymerizable group containing a non-aromatic carbon-carbon unsaturated bond. Examples of the radical polymerizable group include unsaturated hydrocarbon groups such as vinyl, allyl, 1-propenyl, 3-cyclohexenyl, 3-cyclopentenyl, 2-vinylphenyl, 3-vinylphenyl, and 4-vinylphenyl; and α,β-unsaturated carbonyl groups such as acryloyl, methacryloyl, and maleimide (2,5-dihydro-2,5-dioxo-1H-pyrrol-1-yl) groups. Preferred radical polymerizable resins (A-3) include (meth)acrylic radical polymerizable resins, styrene radical polymerizable resins, allyl radical polymerizable resins, and maleimide radical polymerizable resins.

[0056] The (meth)acrylic radical polymerizable resin may be a resin having one or more, preferably two or more, acryloyl groups and / or methacryloyl groups in one molecule. Examples of the (meth)acrylic radical polymerizable resin include cyclohexane-1,4-dimethanol di(meth)acrylate, cyclohexane-1,3-dimethanol di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,8-octanediol di(meth)acrylate, and 1,9-nonane dimethanol di(meth)acrylate. Low molecular weight (molecular weight less than 1000) aliphatic (meth)acrylic acid ester compounds such as diol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, glycerin tri(meth)acrylate, and pentaerythritol tetra(meth)acrylate; dioxane glycol di(meth)acrylate, 3,6-dioxa-1,8-octanediol di(meth)acrylate, ) acrylate, 3,6,9-trioxaundecane-1,11-diol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, 9,9-bis[4-(2-acryloyloxyethoxy)phenyl]fluorene, ethoxylated bisphenol A di(meth)acrylate, propoxylated bisphenol A di(meth)acrylate, and other low molecular weight (molecular weight less than 1000) ether-containing (meth)acrylic acid ester compounds; low molecular weight (molecular weight less than 1000) isocyanurate-containing (meth)acrylic acid ester compounds such as tris(3-hydroxypropyl)isocyanurate tri(meth)acrylate, tris(2-hydroxyethyl)isocyanurate tri(meth)acrylate, and ethoxylated isocyanuric acid tri(meth)acrylate; and high molecular weight (molecular weight 1000 or more) acrylic acid ester compounds such as (meth)acrylic-modified polyphenylene ether resins. As used herein, the term "(meth)acrylic acid" includes acrylic acid, methacrylic acid, and combinations thereof.The term "(meth)acrylate" encompasses acrylate, methacrylate, and combinations thereof. Commercially available (meth)acrylic radical polymerizable resins include "A-DOG" (dioxane glycol diacrylate) manufactured by Shin-Nakamura Chemical Co., Ltd., "DCP-A" (tricyclodecane dimethanol diacrylate), "DCP" (tricyclodecane dimethanol dimethacrylate), and "BPE-1300N" (ethoxylated bisphenol A dimethacrylate) manufactured by Kyoeisha Chemical Co., Ltd., "KAYARAD R-684" (tricyclodecane dimethanol diacrylate) and "KAYARAD R-604" (dioxane glycol diacrylate) manufactured by Nippon Kayaku Co., Ltd., and "SA9000" and "SA9000-111" (methacrylic-modified polyphenylene ether) manufactured by SABIC.

[0057] The styrene-based radical polymerizable resin may be a resin having one or more, preferably two or more, vinyl groups directly bonded to an aromatic carbon atom in one molecule. Examples of the styrene-based radical polymerizable resin include low-molecular-weight (molecular-weight less than 1000) styrene-based compounds such as divinylbenzene, 2,4-divinyltoluene, 2,6-divinylnaphthalene, 1,4-divinylnaphthalene, 4,4'-divinylbiphenyl, 1,2-bis(4-vinylphenyl)ethane, 2,2-bis(4-vinylphenyl)propane, and bis(4-vinylphenyl)ether; and high-molecular-weight (molecular-weight 1000 or more) styrene-based compounds such as vinylbenzyl-modified polyphenylene ether resin and styrene-divinylbenzene copolymer. Commercially available styrene-based radical polymerizable resins include, for example, "ODV-XET(X03)", "ODV-XET(X04)", and "ODV-XET(X05)" (styrene-divinylbenzene copolymers) manufactured by Nippon Steel Chemical & Material Co., Ltd.; and "OPE-2St 1200" and "OPE-2St 2200" (vinylbenzyl-modified polyphenylene ether resins) manufactured by Mitsubishi Gas Chemical Company, Inc.

[0058] As the allyl radical polymerizable resin, a resin having one or more, preferably two or more, allyl groups in one molecule can be used. Examples of allyl radical polymerizable resins include aromatic carboxylic acid allyl ester compounds such as diallyl diphenate, triallyl trimellitate, diallyl phthalate, diallyl isophthalate, diallyl terephthalate, diallyl 2,6-naphthalenedicarboxylate, and diallyl 2,3-naphthalenecarboxylate; isocyanuric acid allyl ester compounds such as 1,3,5-triallyl isocyanurate and 1,3-diallyl-5-glycidyl isocyanurate; epoxy-containing aromatic allyl compounds such as 2,2-bis[3-allyl-4-(glycidyloxy)phenyl]propane; benzoxazine-containing aromatic allyl compounds such as bis[3-allyl-4-(3,4-dihydro-2H-1,3-benzoxazin-3-yl)phenyl]methane; ether-containing aromatic allyl compounds such as 1,3,5-triallyl ether benzene; and allyl silane compounds such as diallyldiphenylsilane. Commercially available allyl radical polymerizable resins include "TAIC" (1,3,5-triallyl isocyanurate) manufactured by Nippon Kasei Chemical Industry Co., Ltd., "DAD" (diallyl diphenate) manufactured by Nisshoku Techno Fine Chemical Co., Ltd., "TRIAM-705" (triallyl trimellitate) manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., "DAND" (2,3-naphthalene carboxylic acid diallyl) manufactured by Nisshoku Techno Fine Chemical Co., Ltd., "ALP-d" (bis[3-allyl-4-(3,4-dihydro-2H-1,3-benzoxazin-3-yl)phenyl]methane) manufactured by Shikoku Chemical Industry Co., Ltd., "RE-810NM" (2,2-bis[3-allyl-4-(glycidyloxy)phenyl]propane) manufactured by Nippon Kayaku Co., Ltd., and "DA-MGIC" (1,3-diallyl-5-glycidyl isocyanurate) manufactured by Shikoku Chemical Industry Co., Ltd.

[0059] The maleimide radical polymerizable resin may be a resin having one or more, preferably two or more, maleimide groups in one molecule. The maleimide radical polymerizable resin may be an aromatic maleimide resin having a maleimide group directly bonded to an aromatic ring, or an aliphatic maleimide resin having no maleimide group directly bonded to an aromatic ring. Commercially available maleimide radical polymerizable resins include, for example, "SLK-2600" manufactured by Shin-Etsu Chemical Co., Ltd.; "BMI-1500," "BMI-1700," "BMI-3000J," "BMI-689," and "BMI-2500" (dimer diamine structure-containing maleimide compounds) manufactured by Designer Molecules Inc.; "BMI-6100" (aromatic maleimide compound) manufactured by Designer Molecules Inc.; "MIR-5000-60T" and "MIR-3000-70MT" (biphenylaralkyl maleimide compounds) manufactured by Nippon Kayaku Co., Ltd.; "BMI-70" and "BMI-80" manufactured by K.I. Chemical Industry Co., Ltd.; and "BMI-2300" and "BMI-TMH" manufactured by Daiwa Kasei Kogyo Co., Ltd. Furthermore, as the maleimide-based radical polymerizable resin, a maleimide resin (maleimide compound containing an indane ring skeleton) disclosed in the Japan Institute of Invention and Innovation's Disclosure Technical Bulletin No. 2020-500211 may be used.

[0060] The radical polymerizable group equivalent of the (A-3) radical polymerizable resin is preferably 20 g / eq. to 3,000 g / eq., more preferably 50 g / eq. to 2,500 g / eq., even more preferably 70 g / eq. to 2,000 g / eq., and particularly preferably 90 g / eq. to 1,500 g / eq. The radical polymerizable group equivalent represents the mass of the resin per equivalent of the radical polymerizable group.

[0061] The weight average molecular weight (Mw) of the radical polymerizable resin (A-3) is preferably 40,000 or less, more preferably 10,000 or less, even more preferably 5,000 or less, and particularly preferably 3,000 or less. The lower limit is not particularly limited, but can be, for example, 150 or more.

[0062] The amount of the radical polymerizable resin (A-3) is preferably at least 1 mass%, more preferably at least 5 mass%, and even more preferably at least 10 mass%, relative to 100 mass% of the nonvolatile components in the resin composition, and is preferably at most 70 mass%, more preferably at most 60 mass%, and even more preferably at most 50 mass%. When the amount of the radical polymerizable resin (A-3) is within this range, the flowability of the resin composition and the linear thermal expansion coefficient and adhesion of the cured product can be particularly effectively improved.

[0063] The amount of the radical polymerizable resin (A-3) is preferably 10% by mass or more, more preferably 20% by mass or more, and even more preferably 30% by mass or more, relative to 100% by mass of the resin components in the resin composition, and is preferably 98% by mass or less, more preferably 95% by mass or less, and even more preferably 93% by mass or less. When the amount of the radical polymerizable resin (A-3) is within the above range, the flowability of the resin composition and the linear thermal expansion coefficient and adhesion of the cured product can be particularly effectively improved.

[0064] The amount of (A) curable resin is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 20% by mass or more, and is preferably 90% by mass or less, more preferably 80% by mass or less, even more preferably 70% by mass or less, and particularly preferably 60% by mass or less, based on 100% by mass of the nonvolatile components in the resin composition. When the amount of (A) curable resin is within this range, the flowability of the resin composition and the linear thermal expansion coefficient and adhesion of the cured product can be particularly well improved.

[0065] The amount of (A) curable resin is preferably 70% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more, relative to 100% by mass of the resin components in the resin composition, and is usually 100% by mass or less, preferably 99% by mass or less, and more preferably 98% by mass or less. When the amount of (A) curable resin is within this range, the flowability of the resin composition and the linear thermal expansion coefficient and adhesion of the cured product can be particularly well improved.

[0066] <(B) Inorganic filler> The resin composition according to this embodiment includes a (B) inorganic filler as component (B). The (B) inorganic filler is particles of an inorganic material having a specific surface area equal to or less than a certain threshold, and is usually included in the cured product while maintaining the particle state. The (B) inorganic filler does not include those corresponding to the above-mentioned component (A).

[0067] (B) Inorganic filler materials include inorganic compounds. Examples of (B) inorganic filler materials include silica, alumina, glass, cordierite, silicon oxide, barium sulfate, barium carbonate, talc, clay, mica powder, zinc oxide, hydrotalcite, boehmite, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum nitride, manganese nitride, aluminum borate, strontium carbonate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, zirconium oxide, barium titanate, barium titanate zirconate, barium zirconate, calcium zirconate, zirconium phosphate, and zirconium tungstate phosphate. Among these, silica, alumina, and boron nitride are preferred, silica and alumina are more preferred, and silica is even more preferred. Therefore, (B) inorganic filler preferably contains silica, and may contain only silica. Examples of silica include amorphous silica, fused silica, crystalline silica, synthetic silica, and hollow silica. Spherical silica is preferred. (B) The inorganic filler may be used alone or in combination of two or more.

[0068] (B) The specific surface area of inorganic fillers is usually 50m 2 / g or less, preferably 40m 2 / g or less, more preferably 30m 2 The lower limit is preferably 0.1 m / g or less. 2 / g or more, more preferably 0.5m 2 / g or more, more preferably 1m 2 / g or more, particularly preferably 3m 2(B) The specific surface area of particles such as inorganic fillers can be measured in accordance with the BET method by adsorbing nitrogen gas onto the surface of a sample using a specific surface area measuring device (Macsorb HM-1210 manufactured by Mountech Co., Ltd.) and calculating the specific surface area using the BET multipoint method.

[0069] (B) Examples of commercially available inorganic fillers include "SP60-05" and "SP507-05" manufactured by Nippon Steel Chemical & Material Co., Ltd.; "YC100C," "YA050C," "YA050C-MJE," "YA010C," "SC2500SQ," "SO-C4," "SO-C2," and "SO-C1" manufactured by Admatechs Co., Ltd.; "UFP-30," "DAW-01," "DAW-03," "FB-105FD," and "Spherical Nanosize BN" manufactured by Denka Co., Ltd.; "Silfil NSS-3N," "Silfil NSS-4N," and "Silfil NSS-5N" manufactured by Tokuyama Corporation; and "CellSpheres MGH-005" manufactured by Taiheiyo Cement Corporation.

[0070] The average particle size of (B) the inorganic filler is preferably 0.01 μm or more, more preferably 0.05 μm or more, even more preferably 0.1 μm or more, and is preferably 10 μm or less, more preferably 5 μm or less, even more preferably 3 μm or less.

[0071] (B) The average particle size of an inorganic filler can be measured by a laser diffraction / scattering method based on Mie scattering theory. Specifically, a volumetric particle size distribution of the inorganic filler is created using a laser diffraction / scattering particle size distribution analyzer, and the median diameter is used as the average particle size. A measurement sample can be prepared by weighing 100 mg of inorganic filler and 10 g of methyl ethyl ketone into a vial and dispersing the mixture ultrasonically for 10 minutes. The volumetric particle size distribution of the inorganic filler is measured using a laser diffraction particle size distribution analyzer with blue and red wavelength light sources using a flow cell system, and the average particle size can be calculated as the median diameter from the particle size distribution obtained. Examples of laser diffraction particle size distribution analyzers include the LA-960 manufactured by Horiba, Ltd.

[0072] (B) The inorganic filler is preferably treated with a surface treatment agent from the viewpoint of improving moisture resistance and dispersibility. Examples of the surface treatment agent include a fluorine-containing silane coupling agent, an aminosilane coupling agent, an epoxysilane coupling agent, a mercaptosilane coupling agent, a silane coupling agent, an alkoxysilane, an organosilazane compound, and a titanate coupling agent. One type of surface treatment agent may be used alone, or two or more types may be used in combination.

[0073] Examples of commercially available surface treatment agents include Shin-Etsu Chemical Co., Ltd.'s "KBM403" (3-glycidoxypropyltrimethoxysilane), Shin-Etsu Chemical Co., Ltd.'s "KBM803" (3-mercaptopropyltrimethoxysilane), Shin-Etsu Chemical Co., Ltd.'s "KBE903" (3-aminopropyltriethoxysilane), Shin-Etsu Chemical Co., Ltd.'s "KBM573" (N-phenyl-3-aminopropyltrimethoxysilane), Shin-Etsu Chemical Co., Ltd.'s "SZ-31" (hexamethyldisilazane), Shin-Etsu Chemical Co., Ltd.'s "KBM103" (phenyltrimethoxysilane), Shin-Etsu Chemical Co., Ltd.'s "KBM-4803" (long-chain epoxy-type silane coupling agent), and Shin-Etsu Chemical Co., Ltd.'s "KBM-7103" (3,3,3-trifluoropropyltrimethoxysilane).

[0074] The degree of surface treatment with the surface treatment agent preferably falls within a specific range from the viewpoint of improving the dispersibility of the inorganic filler. Specifically, 100% by mass of the inorganic filler is preferably surface-treated with 0.2% to 5% by mass of the surface treatment agent, more preferably with 0.2% to 3% by mass of the surface treatment agent, and even more preferably with 0.3% to 2% by mass of the surface treatment agent.

[0075] The degree of surface treatment with the surface treatment agent can be evaluated by the amount of carbon per unit surface area of the inorganic filler. From the viewpoint of improving the dispersibility of the inorganic filler, the amount of carbon per unit surface area of the inorganic filler is set to 0.02 mg / m 2 More than 0.1 mg / m is preferable. 2More preferably, 0.2 mg / m or more 2 On the other hand, from the viewpoint of preventing an increase in the melt viscosity of the resin composition, it is more preferable that the content be 1.0 mg / m 2 Preferably less than 0.8 mg / m 2 Less than 0.5 mg / m is more preferable. 2 The following is even more preferred:

[0076] (B) The amount of carbon per unit surface area of the inorganic filler can be measured after the surface-treated inorganic filler is washed with a solvent (e.g., methyl ethyl ketone (MEK)). Specifically, a sufficient amount of MEK as a solvent is added to the inorganic filler that has been surface-treated with a surface treatment agent, and ultrasonic cleaning is performed at 25°C for 5 minutes. After removing the supernatant and drying the solid content, the amount of carbon per unit surface area of the inorganic filler can be measured using a carbon analyzer. The carbon analyzer that can be used is the "EMIA-320V" manufactured by Horiba, Ltd.

[0077] The range of the amount of (B) inorganic filler by mass, based on 100 mass% of the nonvolatile components in the resin composition, is preferably 5 mass% or more, more preferably 10 mass% or more, particularly preferably 20 mass% or more, and is preferably 90 mass% or less, more preferably 80 mass% or less, and even more preferably 75 mass% or less. When the amount of (B) inorganic filler is within this range, the flowability of the resin composition and the linear thermal expansion coefficient and adhesion of the cured product can be particularly well improved.

[0078] The range of the amount of (B) inorganic filler by volume, relative to 100% by volume of nonvolatile components in the resin composition, is preferably 1% by volume or more, more preferably 4% by volume or more, particularly preferably 10% by volume or more, and is preferably 80% by volume or less, more preferably 70% by volume or less, and even more preferably 60% by volume or less. When the amount of (B) inorganic filler is within this range, the flowability of the resin composition and the linear thermal expansion coefficient and adhesion of the cured product can be particularly well improved.

[0079] <(C) Aerogel> The resin composition according to this embodiment contains a (C) aerogel as component (C). The (C) aerogel is a gel material with high porosity and is usually contained in the resin composition as porous particles. The (C) aerogel can be contained in the cured product while maintaining its particle state. The (C) aerogel does not include those corresponding to the above-mentioned components (A) and (B). One type of (C) aerogel may be used alone, or two or more types may be used in combination.

[0080] The porosity of the (C) aerogel is usually 85% or more, preferably 90% or more, and more preferably 92% or more. There is no particular upper limit, and it can be, for example, 99% or less, 98% or less, or 97% or less. Here, "porosity" refers to the volume fraction of voids in the (C) aerogel.

[0081] (C) The porosity of the aerogel is determined by the bulk density (ρ b ) and the true density of the aerogel (ρ s ) can be calculated using the following formula (M1). Porosity (%)=(1-ρ b / ρ s )×100 (M1)

[0082] The bulk density of the aerogel (ρ b ) can be calculated by measuring the weight and volume of the aerogel. The volume of the aerogel can be measured, for example, by the rapeseed displacement method. The true density of the aerogel can be measured, for example, by the pycnometer method using helium gas.

[0083] The material constituting the (C) aerogel is not limited, and examples include silica, carbon, and metal oxides such as alumina and titania. However, siloxane materials are preferred. Siloxane materials refer to materials containing siloxane bonds (Si-O-Si). These siloxane materials generally contain structural units such as M units, each of which has one siloxane bond bonded to a silicon atom; D units, each of which has two siloxane bonds bonded to a silicon atom; T units, each of which has three siloxane bonds bonded to a silicon atom; and Q units, each of which has four siloxane bonds bonded to a silicon atom. The combination of these M units, D units, T units, and Q units forms a three-dimensional network, resulting in an aerogel with a porous structure. The (C) aerogel is preferably formed from a siloxane material containing T units and Q units; it may also be formed from a siloxane material containing D units, T units, and Q units. The aerogel (C) containing a siloxane material usually has a bulk portion formed by the siloxane material and pore portions as voids formed in a three-dimensional network within the bulk portion.

[0084] (C) The specific surface area of the aerogel is preferably 250 m 2 / g or more, more preferably 400m 2 / g or more, more preferably 500m 2 / g or more, preferably 1000m 2 / g or less, more preferably 950m 2 / g or less, more preferably 900m 2 (C) The specific surface area of the aerogel can be measured by a nitrogen adsorption method using the BET method.

[0085] The average pore diameter of the (C) aerogel is preferably 5 nm or more, more preferably 10 nm or more, and even more preferably 20 nm or more, and is preferably 200 nm or less, more preferably 100 nm or less, and even more preferably 50 nm or less. The average pore diameter of the (C) aerogel can be measured, for example, by obtaining an isotherm through nitrogen adsorption / desorption measurement and applying the BJH method.

[0086] (C) The pore volume of the aerogel is preferably 1 cm 3 / g or more, more preferably 2 cm 3 / g or more, more preferably 3 cm 3 / g or more, preferably 10 cm 3 / g or less, more preferably 9cm 3 / g or less, more preferably 8cm 3 (C) The pore volume of the aerogel can be determined, for example, by obtaining an isotherm by nitrogen adsorption measurement and converting the amount of adsorbed gas at a relative pressure of about 1 into a liquid.

[0087] As described above, the (C) aerogel is usually contained in the resin composition in the form of particles. The average particle size of the (C) aerogel particles may be smaller than that of the (B) inorganic filler, but is preferably larger than that of the (B) inorganic filler. The specific range of the average particle size of the (C) aerogel particles is preferably 0.01 μm or more, more preferably 0.1 μm or more, even more preferably 1 μm or more, and preferably 50 μm or less, more preferably 30 μm or less, and even more preferably 20 μm or less. The use of such a (C) aerogel can particularly effectively improve the fluidity of the resin composition, as well as the linear thermal expansion coefficient and adhesion of the cured product. The average particle size of the (C) aerogel particles can be measured by the following method. Aerogel particles are observed using a scanning electron microscope (SEM) (e.g., Hitachi High-Technologies Corporation's "S-4800") and their minor and major diameters are measured. The average of the minor and major diameters of the aerogel particles is defined as the particle size of the particles. This operation is carried out on 30 randomly selected aerogel particles, and the average particle size of these particles is obtained as the average particle size.

[0088] (C) aerogels can be produced by hydrolyzing tetrafunctional silane compounds (e.g., tetraalkoxysilane, tetraacetoxysilane), trifunctional silane compounds (e.g., trialkoxysilane, triacetoxysilane), and bifunctional silane compounds (e.g., dialkoxysilane, diacetoxysilane) in an acid-catalyzed aqueous solution to form a sol, followed by appropriate gel formation, solvent exchange, drying, and pulverization. Typically, Q units, T units, and D units of siloxane materials are formed from tetrafunctional silane compounds, trifunctional silane compounds, and bifunctional silane compounds. A specific production method is described in Japanese Patent No. 6764050. (C) aerogels may also be commercially available products, such as "SUFA Powder Type" manufactured by TM Factory.

[0089] The amount of (C) aerogel based on mass, relative to 100 mass% of the nonvolatile components in the resin composition, is preferably 0.01 mass% or more, more preferably 0.1 mass% or more, even more preferably 0.2 mass% or more, and is preferably 20 mass% or less, more preferably 10 mass% or less, and particularly preferably 4 mass% or less. When the amount of (C) aerogel is within this range, the flowability of the resin composition and the linear thermal expansion coefficient and adhesion of the cured product can be particularly improved.

[0090] The amount of (C) aerogel by mass is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, even more preferably 0.2% by mass or more, and is preferably 70% by mass or less, more preferably 30% by mass or less, and particularly preferably 10% by mass or less, relative to 100% by mass of (B) inorganic filler in the resin composition. When the amount of (C) aerogel is within this range, the flowability of the resin composition and the linear thermal expansion coefficient and adhesion of the cured product can be particularly improved.

[0091] The amount of (C) aerogel by mass is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, even more preferably 0.2% by mass or more, and is preferably 20% by mass or less, more preferably 10% by mass or less, and particularly preferably 5% by mass or less, relative to 100% by mass of (A) curable resin in the resin composition. When the amount of (C) aerogel is within this range, the flowability of the resin composition and the linear thermal expansion coefficient and adhesion of the cured product can be particularly improved.

[0092] When the (A) curable resin contains the (A-1) epoxy resin, the amount of the (C) aerogel, based on the mass of the (A-1) epoxy resin in the resin composition, is preferably at least 0.01 mass%, more preferably at least 0.1 mass%, and even more preferably at least 1 mass%, and is preferably at most 50 mass%, more preferably at most 30 mass%, and particularly preferably at most 15 mass%. When the amount of the (C) aerogel is within this range, the flowability of the resin composition and the linear thermal expansion coefficient and adhesion of the cured product can be particularly improved.

[0093] The volumetric amount of (C) aerogel is preferably 1% by volume or more, more preferably 1.5% by volume or more, and even more preferably 2% by volume or more, relative to 100% by volume of the nonvolatile components in the resin composition, and is preferably 40% by volume or less, more preferably 30% by volume or less, and particularly preferably 20% by volume or less. When the amount of (C) aerogel is within this range, the flowability of the resin composition and the linear thermal expansion coefficient and adhesion of the cured product can be particularly improved.

[0094] The total volume of the (B) inorganic filler and the (C) aerogel is preferably 30% by volume or more, more preferably 31% by volume or more, and even more preferably 32% by volume or more, and is preferably 60% by volume or less, more preferably 59% by volume or less, and even more preferably 58% by volume or less, based on 100% by volume of the nonvolatile components in the resin composition. When the total volume of the (B) inorganic filler and the (C) aerogel is within this range, the flowability of the resin composition and the linear thermal expansion coefficient and adhesion of the cured product can be particularly improved.

[0095] The total amount of the (A) curable resin, (B) inorganic filler, and (C) aerogel, based on mass, is preferably 70 mass% or more, more preferably 80 mass% or more, and even more preferably 90 mass% or more, relative to 100 mass% of the nonvolatile components in the resin composition. The upper limit is usually 100 mass% or less, and may be 99 mass% or less.

[0096] <(D) Polymerization initiator> The resin composition according to this embodiment may contain a polymerization initiator (D) as an optional component. The polymerization initiator (D) as component (D) is preferably contained in the resin composition in combination with a radically polymerizable resin (A-3). The polymerization initiator (D) does not include those corresponding to components (A) to (C). One type of polymerization initiator (D) may be used alone, or two or more types may be used in combination.

[0097] As the (D) polymerization initiator, a radical polymerization initiator is usually used, and examples of the radical polymerization initiator include peroxide-based radical polymerization initiators and azo-based radical polymerization initiators.

[0098] Examples of the peroxide radical polymerization initiator include hydroperoxide compounds such as 1,1,3,3-tetramethylbutyl hydroperoxide; dialkyl peroxide compounds such as tert-butylcumyl peroxide, di-tert-butyl peroxide, di-tert-hexyl peroxide, dicumyl peroxide, 1,4-bis(1-tert-butylperoxy-1-methylethyl)benzene, and 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane; and diacyl peroxide compounds such as dilauroyl peroxide, didecanoyl peroxide, dicyclohexyl peroxydicarbonate, and bis(4-tert-butylcyclohexyl)peroxydicarbonate. peroxyester compounds such as tert-butyl peroxyacetate, tert-butyl peroxybenzoate, tert-butylperoxyisopropyl monocarbonate, tert-butylperoxy-2-ethylhexanoate, tert-butylperoxyneodecanoate, tert-hexylperoxyisopropyl monocarbonate, tert-butyl peroxylaurate, (1,1-dimethylpropyl) 2-ethylperhexanoate, tert-butyl 2-ethylperhexanoate, tert-butyl 3,5,5-trimethylperhexanoate, tert-butylperoxy-2-ethylhexyl monocarbonate, and tert-butylperoxymaleic acid; and the like.

[0099] Examples of the azo radical polymerization initiator include azonitrile compounds such as 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 1,1'-azobis(cyclohexane-1-carbonitrile), 1-[(1-cyano-1-methylethyl)azo]formamide, and 2-phenylazo-4-methoxy-2,4-dimethyl-valeronitrile; 2,2'-azobis[2-methyl-N-[1,1-bis(hydroxymethyl)-2-hydroxyethyl]propionamide], and 2,2'-azobis[2-methyl-N-[1,1-bis(hydroxymethyl)-2-hydroxyethyl]propionamide]. azoamide compounds such as 2,2'-azobis[2-methyl-N-[2-(1-hydroxybutyl)]-propionamide], 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)-propionamide], 2,2'-azobis(2-methylpropionamide) dihydrate, 2,2'-azobis[N-(2-propenyl)-2-methylpropionamide], 2,2'-azobis(N-butyl-2-methylpropionamide), and 2,2'-azobis(N-cyclohexyl-2-methylpropionamide); alkyl azo compounds such as 2,2'-azobis(2,4,4-trimethylpentane) and 2,2'-azobis(2-methylpropane); and the like.

[0100] Commercially available radical polymerization initiators include, for example, "Perbutyl C," "Perbutyl A," "Perbutyl P," "Perbutyl L," "Perbutyl O," "Perbutyl ND," "Perbutyl Z," "Perbutyl I," "Percumyl P," "Percumyl D," "Perhexyl D," "Perhexyl A," "Perhexyl I," "Perhexyl Z," "Perhexyl ND," "Perhexyl O," and "Perhexyl PV," all manufactured by NOF Corporation.

[0101] The amount of (D) polymerization initiator 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, relative to 100% by mass of the resin component in the resin composition, and is preferably 10% by mass or less, preferably 5% by mass or less, and more preferably 2% by mass or less.

[0102] <(E) Curing accelerator> The resin composition according to the present embodiment may contain a curing accelerator (E) as an optional component. The curing accelerator (E) as component (E) acts as a catalyst for the reaction of the epoxy resin (A-1) to accelerate the curing of the resin composition, and is therefore preferably included in the resin composition in combination with the epoxy resin (A-1). The curing accelerator (E) does not include components (A) to (D). One type of curing accelerator (E) may be used alone, or two or more types may be used in combination.

[0103] Examples of the (E) curing accelerator include phosphorus-based curing accelerators, urea-based curing accelerators, guanidine-based curing accelerators, imidazole-based curing accelerators, metal-based curing accelerators, and amine-based curing accelerators.

[0104] Examples of the phosphorus-based curing accelerator include aliphatic phosphonium salts such as tetrabutylphosphonium bromide, tetrabutylphosphonium chloride, tetrabutylphosphonium acetate, tetrabutylphosphonium decanoate, tetrabutylphosphonium laurate, bis(tetrabutylphosphonium)pyromellitate, tetrabutylphosphonium hydrogenhexahydrophthalate, tetrabutylphosphonium 2,6-bis[(2-hydroxy-5-methylphenyl)methyl]-4-methylphenolate, and di-tert-butyldimethylphosphonium tetraphenylborate; methyltriphenylphosphonium bromide, ethyltriphenylphosphonium bromide, propyltriphenylphosphonium bromide, butyltriphenylphosphonium bromide, benzyltriphenylphosphonium chloride, tetraphenylphosphonium bromide, p-tolyltriphenylphosphonium tetra-p-tolylborate, and tetraphenylphosphonium tetra-p-tolylborate. aromatic phosphonium salts such as tetraphenylborate, tetraphenylphosphonium tetra-p-tolylborate, triphenylethylphosphonium tetraphenylborate, tris(3-methylphenyl)ethylphosphonium tetraphenylborate, tris(2-methoxyphenyl)ethylphosphonium tetraphenylborate, (4-methylphenyl)triphenylphosphonium thiocyanate, tetraphenylphosphonium thiocyanate, and butyltriphenylphosphonium thiocyanate; aromatic phosphine-borane complexes such as triphenylphosphine-triphenylborane; aromatic phosphine-quinone adducts such as triphenylphosphine-p-benzoquinone adduct; aliphatic phosphines such as tributylphosphine, tri-tert-butylphosphine, trioctylphosphine, di-tert-butyl(2-butenyl)phosphine, di-tert-butyl(3-methyl-2-butenyl)phosphine, and tricyclohexylphosphine;Dibutylphenylphosphine, di-tert-butylphenylphosphine, methyldiphenylphosphine, ethyldiphenylphosphine, butyldiphenylphosphine, diphenylcyclohexylphosphine, triphenylphosphine, tri-o-tolylphosphine, tri-m-tolylphosphine, tri-p-tolylphosphine, tris(4-ethylphenyl)phosphine, tris(4-propylphenyl)phosphine, tris(4-isopropylphenyl)phosphine, tris(4-butylphenyl)phosphine, tris(4-tert-butylphenyl)phosphine, tris(2,4-dimethylphenyl)phosphine, tris(2,5-dimethylphenyl)phosphine, tris(2,6-dimethylphenyl)phosphine aromatic phosphines such as benzene, tris(3,5-dimethylphenyl)phosphine, tris(2,4,6-trimethylphenyl)phosphine, tris(2,6-dimethyl-4-ethoxyphenyl)phosphine, tris(2-methoxyphenyl)phosphine, tris(4-methoxyphenyl)phosphine, tris(4-ethoxyphenyl)phosphine, tris(4-tert-butoxyphenyl)phosphine, diphenyl-2-pyridylphosphine, 1,2-bis(diphenylphosphino)ethane, 1,3-bis(diphenylphosphino)propane, 1,4-bis(diphenylphosphino)butane, 1,2-bis(diphenylphosphino)acetylene, and 2,2'-bis(diphenylphosphino)diphenyl ether;

[0105] Examples of the urea-based curing accelerator include 1,1-dimethylurea; aliphatic dimethylureas such as 1,1,3-trimethylurea, 3-ethyl-1,1-dimethylurea, 3-cyclohexyl-1,1-dimethylurea, and 3-cyclooctyl-1,1-dimethylurea; 3-phenyl-1,1-dimethylurea, 3-(4-chlorophenyl)-1,1-dimethylurea, 3-(3,4-dichlorophenyl)-1,1-dimethylurea, 3-(3-chloro-4-methylphenyl)-1,1-dimethylurea, 3-(2-methylphenyl)-1,1-dimethylurea, 3-(4-methylphenyl)-1,1-dimethylurea, and 3-(3,4-dimethylphenyl)-1,1-dimethylurea. aromatic dimethylureas such as toluene bis(dimethylurea), 3-(4-isopropylphenyl)-1,1-dimethylurea, 3-(4-methoxyphenyl)-1,1-dimethylurea, 3-(4-nitrophenyl)-1,1-dimethylurea, 3-[4-(4-methoxyphenoxy)phenyl]-1,1-dimethylurea, 3-[4-(4-chlorophenoxy)phenyl]-1,1-dimethylurea, 3-[3-(trifluoromethyl)phenyl]-1,1-dimethylurea, N,N-(1,4-phenylene)bis(N',N'-dimethylurea), and N,N-(4-methyl-1,3-phenylene)bis(N',N'-dimethylurea) [toluene bisdimethylurea].

[0106] Examples of guanidine curing accelerators include dicyandiamide, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, 1-(o-tolyl)guanidine, dimethylguanidine, diphenylguanidine, trimethylguanidine, tetramethylguanidine, pentamethylguanidine, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, 1-methylbiguanide, 1-ethylbiguanide, 1-n-butylbiguanide, 1-n-octadecylbiguanide, 1,1-dimethylbiguanide, 1,1-diethylbiguanide, 1-cyclohexylbiguanide, 1-allylbiguanide, 1-phenylbiguanide, and 1-(o-tolyl)biguanide.

[0107] Examples of the imidazole curing accelerator include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, and 1-benzyl-2-methylimidazole. Phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazolium trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6-[2'-methylimidazolyl -(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-undecylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct Examples of imidazole compounds include 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2-methylimidazoline, and 2-phenylimidazoline, as well as adducts of imidazole compounds with epoxy resins. Commercially available imidazole curing accelerators include "1B2PZ," "2E4MZ," "2MZA-PW," "2MZ-OK," "2MA-OK," "2MA-OK-PW," "2PHZ," "2PHZ-PW," "Cl1Z," "Cl1Z-CN," "Cl1Z-CNS," and "C11Z-A" manufactured by Shikoku Chemicals Corporation; and "P200-H50" manufactured by Mitsubishi Chemical Corporation.

[0108] Examples of metal-based curing accelerators include organometallic complexes or organometallic salts of metals such as cobalt, copper, zinc, iron, nickel, manganese, and tin. Specific examples of organometallic complexes include organic cobalt complexes such as cobalt(II) acetylacetonate and cobalt(III) acetylacetonate, organic copper complexes such as copper(II) acetylacetonate, organic zinc complexes such as zinc(II) acetylacetonate, organic iron complexes such as iron(III) acetylacetonate, organic nickel complexes such as nickel(II) acetylacetonate, and organic manganese complexes such as manganese(II) acetylacetonate. Examples of organometallic salts include zinc octoate, tin octoate, zinc naphthenate, cobalt naphthenate, tin stearate, and zinc stearate.

[0109] Examples of the amine curing accelerator include trialkylamines such as triethylamine and tributylamine, 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, 1,8-diazabicyclo(5,4,0)-undecene, etc. Commercially available amine curing accelerators may be used, such as "MY-25" manufactured by Ajinomoto Fine-Techno Co., Inc.

[0110] The amount of (E) curing accelerator is preferably 0.001% by mass or more, more preferably 0.01% by mass or more, even more preferably 0.1% by mass or more, relative to 100% by mass of non-volatile components in the resin composition, and is preferably 2% by mass or less, more preferably 1% by mass or less, even more preferably 0.5% by mass or less.

[0111] The amount of (E) curing accelerator is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, even more preferably 0.2% by mass or more, relative to 100% by mass of the resin component in the resin composition, and is preferably 5% by mass or less, more preferably 2% by mass or less, even more preferably 1% by mass or less.

[0112] <(F)Organic filler> The resin composition according to this embodiment may contain an organic filler (F) as an optional component. The organic filler (F) as component (F) is usually incompatible with resin components other than the organic filler (F), is contained in the resin composition in the form of particles, and is contained in the cured product while maintaining this particulate state. The organic filler (F) can usually absorb stress in the cured product, thereby increasing the toughness of the cured product. This increases the mechanical strength of the cured product, thereby improving the adhesion between the cured product and the conductor layer. The organic filler (F) does not include those corresponding to the above-mentioned components (A) to (E). One type of organic filler (F) may be used alone, or two or more types may be used in combination.

[0113] The (F) organic filler may be particles of an organic material. A rubber component is preferred as the organic material contained in the (F) organic filler. Examples of rubber components include silicone-based elastomers such as polydimethylsiloxane; olefin-based thermoplastic elastomers such as polybutadiene, polyisoprene, polychlorobutadiene, ethylene-vinyl acetate copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-isobutylene copolymer, acrylonitrile-butadiene copolymer, isoprene-isobutylene copolymer, isobutylene-butadiene copolymer, ethylene-propylene-diene terpolymer, and ethylene-propylene-butene terpolymer; and thermoplastic elastomers such as acrylic thermoplastic elastomers such as polypropyl(meth)acrylate, polybutyl(meth)acrylate, polycyclohexyl(meth)acrylate, and polyoctyl(meth)acrylate. Furthermore, silicone-based rubbers such as polyorganosiloxane rubber may be mixed into the rubber component. The rubber component contained in the rubber particles has a glass transition temperature of, for example, 0°C or lower, preferably -10°C or lower, more preferably -20°C or lower, and even more preferably -30°C or lower.

[0114] The (F) organic filler may be a core-shell type rubber particle consisting of a core particle containing the above-mentioned rubber component and a shell portion formed by graft copolymerization of a monomer component copolymerizable with the rubber component contained in the core particle. Here, the term "core-shell type" does not necessarily refer only to those in which the core particle and the shell portion are clearly distinguishable, but also includes those in which the boundary between the core particle and the shell portion is unclear, and the core particle does not necessarily have to be completely covered with the shell portion.

[0115] Specific examples of (F) organic fillers include "CHT" manufactured by Samsung SDI; "B602" manufactured by Techno UMG; "Paraloid EXL-2602", "Paraloid EXL-2603", "Paraloid EXL-2655", "Paraloid EXL-2311", "Paraloid-EXL2313", "Paraloid EXL-2315", "Paraloid KM-330", "Paraloid KM-336P", and "Paraloid KCZ-201" manufactured by Dow; and "Metabrene C-223A" and "Metabrene E- 901," "Metabrene S-2001," "Metabrene W-450A," "Metabrene SRK-200," "Kane Ace M-511," "Kane Ace M-600," "Kane Ace M-400," "Kane Ace M-580," and "Kane Ace MR-01" manufactured by Kaneka Corporation, and "Staphyloid AC3355," "Staphyloid AC3816," "Staphyloid AC3816N," "Staphyloid AC3832," "Staphyloid AC4030," and "Staphyloid AC3364" manufactured by Aica Kogyo Co., Ltd.

[0116] The amount of the (F) organic filler is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and even more preferably 1% by mass or more, relative to 100% by mass of the nonvolatile components in the resin composition, and is preferably 10% by mass or less, more preferably 6% by mass or less, and particularly preferably 3% by mass or less.

[0117] The amount of (F) organic filler is preferably 0.1% by mass or more, more preferably 1% by mass or more, and even more preferably 2% by mass or more, relative to 100% by mass of the resin component in the resin composition, and is preferably 10% by mass or less, preferably 8% by mass or less, and more preferably 5% by mass or less.

[0118] <(G) Polymer resin> The resin composition according to this embodiment may contain a (G) polymer resin as an optional component. The (G) polymer resin as the (G) component typically has thermoplastic properties. Furthermore, the (G) polymer resin is typically included in the resin composition in a state where it is compatible with resin components other than the (G) polymer resin, and is included in the cured product in this compatible state. The (G) polymer resin typically can absorb stress in the cured product, thereby increasing the toughness of the cured product. Therefore, the mechanical strength of the cured product can be increased, thereby improving the adhesion between the cured product and the conductor layer. The (G) polymer resin does not include those corresponding to the above-mentioned components (A) to (F). Furthermore, one type of (G) polymer resin may be used alone, or two or more types may be used in combination.

[0119] The (G) polymer resin usually has a large molecular weight. Specifically, the weight-average molecular weight Mw of the (G) polymer resin is preferably greater than 5,000, more preferably 8,000 or more, even more preferably 10,000 or more, even more preferably 20,000 or more, and is preferably 100,000 or less, more preferably 70,000 or less, even more preferably 60,000 or less, even more preferably 50,000 or less. The weight-average molecular weight Mw can be measured by gel permeation chromatography (GPC) in terms of polystyrene.

[0120] Examples of (G) polymer resins include phenoxy resins, polyimide resins, polyvinyl acetal resins, polystyrene-based resins, polyolefin resins, polybutadiene resins, polyamide-imide resins, polyethersulfone resins, polysulfone resins, polyetherimide resins, polyphenylene ether resins, polycarbonate resins, polyether ether ketone resins, polyester resins, etc. Among these, phenoxy resins and polystyrene-based resins are preferred.

[0121] Examples of phenoxy resins include phenoxy resins having one or more skeletons selected from the group consisting of bisphenol A, bisphenol F, bisphenol S, bisphenolacetophenone, novolac, biphenyl, fluorene, dicyclopentadiene, norbornene, naphthalene, anthracene, adamantane, terpene, and trimethylcyclohexane. The terminal of the phenoxy resin may be any functional group such as a phenolic hydroxyl group or an epoxy group. Specific examples of phenoxy resins include "1256" and "4250" manufactured by Mitsubishi Chemical Corporation (both of which are phenoxy resins containing a bisphenol A skeleton); "YX8100" manufactured by Mitsubishi Chemical Corporation (phenoxy resin containing a bisphenol S skeleton); "YX6954" manufactured by Mitsubishi Chemical Corporation (phenoxy resin containing a bisphenol acetophenone skeleton); "FX280" and "FX293" manufactured by Nippon Steel Chemical & Material Co., Ltd.; "YL7500BH30," "YX6954BH30," "YX7553," "YX7553BH30," "YL7769BH30," "YL6794," "YL7213," "YL7290," "YL7482," and "YL7891BH30" manufactured by Mitsubishi Chemical Corporation; and the like.

[0122] Specific examples of polyimide resins include "PIAD200" manufactured by Arakawa Chemical Industry Co., Ltd., "SLK-6100" manufactured by Shin-Etsu Chemical Co., Ltd., and "Rikacoat SN20" and "Rikacoat PN20" manufactured by New Japan Chemical Co., Ltd. Specific examples of polyimide resins also include modified polyimide resins such as linear polyimide resins obtained by reacting bifunctional hydroxyl group-terminated polybutadiene, a diisocyanate compound, and a tetrabasic acid anhydride (polyimide resins described in JP-A No. 2006-37083), and polysiloxane skeleton-containing polyimide resins (polyimide resins described in JP-A Nos. 2002-12667 and 2000-319386).

[0123] Examples of polyvinyl acetal resins include polyvinyl formal resins and polyvinyl butyral resins, with polyvinyl butyral resins being preferred. Specific examples of polyvinyl acetal resins include S-LEC BH series, BX series (e.g., BX-5Z), KS series (e.g., KS-1), BL series, and BM series manufactured by Sekisui Chemical Co., Ltd.

[0124] Examples of polystyrene resins include unmodified polystyrene resins, oxazoline group-containing modified polystyrene resins, and styrene block copolymers. Examples of styrene block copolymers include styrene-isoprene-styrene block copolymers (SIS resins), styrene-ethylene-butylene-styrene block copolymers (SEBS resins), styrene-ethylene-propylene-styrene block copolymers (SEPS resins), styrene-butadiene-styrene block copolymers (SBS resins), and styrene-isobutylene-styrene block copolymers (SIBS resins). Specific examples of polystyrene resins include "PX3-RP-37" and "RP-RX-61" (oxazoline group-containing modified polystyrene resins) manufactured by Nippon Shokubai; and "HYBRAR" manufactured by Kuraray Co., Ltd. 5125 (SIS resin); Asahi Kasei Corporation's "S1611" (SEBS resin); Asahi Kasei Corporation's "H1041", "Tuftec H1043", "Tuftec P2000", and "Tuftec MP10" (hydrogenated styrene-based thermoplastic resins); Daicel Corporation's "Epofriend AT501" and "CT310" (epoxidized styrene-butadiene thermoplastic resins); Kuraray Corporation's "Septon HG252" (modified polystyrene resin with hydroxyl groups); Asahi Kasei Corporation's "Tuftec N503M" (modified polystyrene resin with carboxyl groups); Asahi Kasei Corporation's "Tuftec N501" (modified polystyrene resin with amino groups); Asahi Kasei Corporation's "Tuftec M1913" (modified polystyrene resin with acid anhydride groups); Kuraray Corporation's "Septon S8104" (unmodified polystyrene resin); Kraton Corporation's "FG1924" (styrene-ethylene / butylene-styrene block copolymer); and "EF-40" (CRAY (manufactured by VALLEY Co., Ltd.)

[0125] Examples of polyolefin resins include ethylene copolymer resins such as low-density polyethylene, very low-density polyethylene, high-density polyethylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, and ethylene-methyl acrylate copolymer; and polyolefin polymers such as polypropylene and ethylene-propylene block copolymer.

[0126] Examples of polybutadiene resins include hydrogenated polybutadiene skeleton-containing resins, hydroxy group-containing polybutadiene resins, phenolic hydroxy group-containing polybutadiene resins, carboxy group-containing polybutadiene resins, acid anhydride group-containing polybutadiene resins, epoxy group-containing polybutadiene resins, isocyanate group-containing polybutadiene resins, urethane group-containing polybutadiene resins, and polyphenylene ether-polybutadiene resins.

[0127] Specific examples of polyamide-imide resins include "Vylomax HR11NN" and "Vylomax HR16NN" manufactured by Toyobo Co., Ltd. Specific examples of polyamide-imide resins also include modified polyamide-imides such as "KS9100" and "KS9300" (polysiloxane skeleton-containing polyamide-imides) manufactured by Hitachi Chemical Co., Ltd.

[0128] A specific example of the polyethersulfone resin is "PES5003P" manufactured by Sumitomo Chemical Co., Ltd.

[0129] Specific examples of polysulfone resins include polysulfones "P1700" and "P3500" manufactured by Solvay Advanced Polymers.

[0130] The polyphenylene ether resin may be, for example, a copolymer of polyphenylene ether and polybutadiene.

[0131] A specific example of the polyetherimide resin is "Ultem" manufactured by GE.

[0132] Examples of polycarbonate resins include hydroxy group-containing carbonate resins, phenolic hydroxy group-containing carbonate resins, carboxy group-containing carbonate resins, acid anhydride group-containing carbonate resins, isocyanate group-containing carbonate resins, urethane group-containing carbonate resins, etc. Specific examples of polycarbonate resins include "FPC0220" manufactured by Mitsubishi Gas Chemical Company, Inc., "T6002" and "T6001" (polycarbonate diols) manufactured by Asahi Kasei Corporation, and "C-1090," "C-2090," and "C-3090" (polycarbonate diols) manufactured by Kuraray Co., Ltd.

[0133] A specific example of the polyether ether ketone resin is "Sumiploy K" manufactured by Sumitomo Chemical Co., Ltd.

[0134] Examples of polyester resins include polyethylene terephthalate resin, polyethylene naphthalate resin, polybutylene terephthalate resin, polybutylene naphthalate resin, polytrimethylene terephthalate resin, polytrimethylene naphthalate resin, and polycyclohexane dimethyl terephthalate resin.

[0135] The amount of (G) polymer resin is preferably 0.01% by mass or more, more preferably 0.2% by mass or more, even more preferably 0.5% by mass or more, relative to 100% by mass of the nonvolatile components in the resin composition, and is preferably 20% by mass or less, more preferably 10% by mass or less, even more preferably 5% by mass or less.

[0136] The amount of the (G) polymer resin is preferably 0.1% by mass or more, more preferably 1% by mass or more, and even more preferably 2% by mass or more, relative to 100% by mass of the resin components in the resin composition, and is preferably 30% by mass or less, preferably 20% by mass or less, and more preferably 10% by mass or less.

[0137] <(H) Optional Additives> The resin composition according to this embodiment may further contain an optional additive (H) as an optional component. The optional additive (H) as component (H) does not include those corresponding to the above-mentioned components (A) to (G). Examples of the optional additive (H) include organometallic compounds such as organocopper compounds, organozinc compounds, and organocobalt compounds; colorants such as phthalocyanine blue, phthalocyanine green, iodine green, diazo yellow, crystal violet, titanium oxide, and carbon black; polymerization inhibitors such as hydroquinone, catechol, pyrogallol, and phenothiazine; leveling agents such as silicone-based leveling agents and acrylic polymer-based leveling agents; thickeners such as bentone and montmorillonite; antifoaming agents such as silicone-based antifoaming agents, acrylic-based antifoaming agents, fluorine-based antifoaming agents, and vinyl resin-based antifoaming agents; ultraviolet absorbers such as benzotriazole-based ultraviolet absorbers; adhesion improvers such as urea silanes; triazole-based adhesion promoters, tetrazole-based adhesion promoters, and triazine-based adhesion promoters. Examples of the additives include adhesion-imparting agents such as adhesion promoters, antioxidants such as hindered phenol antioxidants, fluorescent brighteners such as stilbene derivatives, surfactants such as fluorine-based surfactants and silicone-based surfactants, flame retardants such as phosphorus-based flame retardants (e.g., phosphate ester compounds, phosphazene compounds, phosphinic acid compounds, and red phosphorus), nitrogen-based flame retardants (e.g., melamine sulfate), halogen-based flame retardants, and inorganic flame retardants (e.g., antimony trioxide), dispersants such as phosphate ester-based dispersants, polyoxyalkylene-based dispersants, acetylene-based dispersants, silicone-based dispersants, anionic dispersants, and cationic dispersants, and stabilizers such as borate-based stabilizers, titanate-based stabilizers, aluminate-based stabilizers, zirconate-based stabilizers, isocyanate-based stabilizers, carboxylic acid-based stabilizers, and carboxylic anhydride-based stabilizers. (H) Optional additives may be used singly or in combination of two or more.

[0138] <(I) Solvent> The resin composition according to this embodiment may further contain (I) a solvent as an optional volatile component in addition to the non-volatile components (A) to (H) described above. The (I) solvent is typically an organic solvent. Examples of the organic solvent include ketone-based solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ester-based solvents such as methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, isoamyl acetate, methyl propionate, ethyl propionate, and γ-butyrolactone; ether-based solvents such as tetrahydropyran, tetrahydrofuran, 1,4-dioxane, diethyl ether, diisopropyl ether, dibutyl ether, diphenyl ether, and anisole; alcohol-based solvents such as methanol, ethanol, propanol, butanol, and ethylene glycol; 2-ethoxyethyl acetate, propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl diglycol acetate, γ-butyrolactone, and methyl methoxypropionate. Examples of suitable solvents include ether ester solvents such as ethyl acetate; ester alcohol solvents such as methyl lactate, ethyl lactate, and methyl 2-hydroxyisobutyrate; ether alcohol solvents such as 2-methoxypropanol, 2-methoxyethanol, 2-ethoxyethanol, propylene glycol monomethyl ether, and diethylene glycol monobutyl ether (butyl carbitol); amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone; sulfoxide solvents such as dimethyl sulfoxide; nitrile solvents such as acetonitrile and propionitrile; aliphatic hydrocarbon solvents such as hexane, cyclopentane, cyclohexane, and methylcyclohexane; and aromatic hydrocarbon solvents such as benzene, toluene, xylene, ethylbenzene, and trimethylbenzene. (I) The solvents may be used singly or in combination of two or more.

[0139] The amount of (I) solvent, relative to 100% by mass of all components in the resin composition, can be, for example, 60% by mass or less, 40% by mass or less, 30% by mass or less, 20% by mass or less, 15% by mass or less, or 10% by mass or less, or may be 0% by mass.

[0140] <Method of manufacturing resin composition> The resin composition according to the present embodiment can be produced, for example, by mixing components that can be contained in the resin composition. The above-mentioned components may be mixed in part or all at the same time, or may be mixed sequentially. In the process of mixing each component, the temperature may be appropriately set, and thus heating and / or cooling may be performed temporarily or throughout. Furthermore, stirring or shaking may be performed in the process of mixing each component.

[0141] <Characteristics of the resin composition and its cured product> The resin composition according to this embodiment can have high fluidity, and therefore, by using this resin composition, the conductor layer can be embedded well in the method for manufacturing a circuit board.

[0142] The fluidity of a resin composition can be evaluated by undulation. Specifically, an undulation evaluation test is performed in which a resin composition layer containing the resin composition is pressure-bonded to the surface of a copper foil, hot-pressed, and cured to form a cured layer. The cured layer corresponds to an insulating layer formed using the resin composition. The difference between the maximum height and the minimum height of the surface of the resin composition layer (the surface opposite the copper foil) formed when this undulation evaluation test is performed represents the "undulation" of the resin composition layer. Furthermore, the difference between the maximum height and the minimum height of the surface of the cured layer (the surface opposite the copper foil) formed when this undulation evaluation test is performed represents the "undulation" of the cured layer. The smaller the undulation, the better the fluidity of the resin composition.

[0143] For example, an undulation evaluation test is performed in which a 40 μm-thick resin composition layer is pressure-bonded to the surface of copper foil at 100°C and 0.74 MPa for 30 seconds, and then hot-pressed at 100°C and 0.5 MPa for 60 seconds to form a cured product layer. When this undulation evaluation test is performed, the undulation range of the resin composition layer is preferably less than 0.7 μm, more preferably 0.5 μm or less. The lower limit is ideally 0 μm, but may be 0.1 μm or more. Furthermore, when this undulation evaluation test is performed, the undulation range of the cured product layer is preferably less than 2 μm, more preferably less than 1.8 μm, and even more preferably 1.5 μm or less. The lower limit is ideally 0 μm, but may be 0.1 μm or more. The specific method for the undulation evaluation test can be the method described in <Test 2. Undulation Evaluation Test> in the Examples below.

[0144] The resin composition according to this embodiment can usually suppress deformation due to curing. Specifically, it can reduce the difference in undulation between a resin composition layer formed from the resin composition and a cured layer corresponding to an insulating layer formed by curing the resin composition layer. Hereinafter, the difference in undulation may be referred to as "amount of change in undulation." The amount of change in undulation corresponds to the amount of change in undulation of the resin composition layer that can occur due to curing of the resin composition.

[0145] For example, an undulation evaluation test is conducted in which a 40 μm-thick resin composition layer is cured under curing conditions of 100°C for 30 minutes and 180°C for 30 minutes to form a cured product layer. The amount of undulation change when this undulation evaluation test is conducted is expressed as the difference between the undulation of the resin composition layer and the undulation of the cured product layer. The range of this undulation change is preferably less than 1.2 μm, more preferably 1.0 μm or less. The lower limit is ideally 0 μm, but may be 0.1 μm or more. The specific method for the undulation evaluation test can be the method described in <Test 2. Undulation Evaluation Test> in the Examples below.

[0146] By curing the resin composition according to this embodiment, a cured product of the resin composition can be obtained. An insulating layer can be formed from this cured product. Since heat is typically applied during curing of the resin composition, volatile components, such as (I) the solvent, contained in the resin composition can volatilize due to the heat during curing. Therefore, the cured product obtained by curing the resin composition can contain non-volatile components, such as components (A) to (H), or reaction products thereof.

[0147] The cured product of the resin composition according to this embodiment can have a low coefficient of linear thermal expansion. Therefore, when the cured product is used to form an insulating layer of a circuit board, warping of the circuit board can be suppressed. In one example, the average coefficient of linear thermal expansion of the cured product at temperatures between 25°C and 150°C is preferably 40 ppm / °C or less, more preferably 30 ppm / °C or less. The lower limit can be 5 ppm / °C or more, 10 ppm / °C or more, etc. When the sample is a resin composition before curing, the cured product for evaluation (hereinafter sometimes referred to as the "cured product for evaluation") obtained by curing the resin composition under curing conditions of 190°C for 90 minutes preferably has an average coefficient of linear thermal expansion within the above range. The specific method for measuring the average coefficient of linear thermal expansion of the cured product can be the method described in "Test 3. Measurement of Average Coefficient of Linear Thermal Expansion (CTE)" in the Examples section below.

[0148] The cured product of the resin composition according to this embodiment exhibits excellent adhesion to a conductor layer. Therefore, when an insulating layer is formed on a conductor layer of a circuit board using the cured product, peeling between the conductor layer and the insulating layer can be suppressed. The adhesion can be evaluated by the magnitude of the load required to peel the conductor layer from the cured product layer when the conductor layer on the cured product layer formed from the cured product of the resin composition is pulled in the vertical direction. Hereinafter, the load may be referred to as "peel strength." The higher the peel strength, the better the adhesion.

[0149] For example, an adhesion evaluation test is conducted by peeling a cured material layer formed on a surface of copper foil corresponding to the conductor layer with an arithmetic mean roughness of 1 μm at 23°C in the vertical direction at a rate of 50 mm / min. When this adhesion evaluation test is conducted, the peel strength, as the load required to peel the copper foil from the cured material layer, is preferably 0.30 kgf / cm or more, more preferably 0.32 kgf / cm or more, and even more preferably 0.34 kgf / cm or more. The upper limit is preferably higher, and may be, for example, 1 kgf / cm or less. When the sample is a resin composition before curing, a resin composition layer containing the resin composition is formed on the surface of the copper foil, and the cured material layer is cured at 190°C for 90 minutes. When an adhesion evaluation test is conducted on the resulting cured material layer, it is preferable that a peel strength within the above range is obtained. A specific method for measuring peel strength may be the method described in "Test 1. Adhesion Evaluation Test" in the Examples below.

[0150] The cured product of the resin composition according to this embodiment preferably has excellent dielectric properties, specifically, a low dielectric loss tangent Df. In one example, the dielectric loss tangent Df of the cured product is preferably 0.0050 or less, more preferably 0.0045 or less, and even more preferably 0.0040 or less. The lower limit of the dielectric loss tangent Df is not particularly limited, and may be, for example, 0.0010 or more. The dielectric loss tangent Df of the cured product of the resin composition can be measured by a cavity resonance perturbation method under measurement conditions of a measurement frequency of 5.8 GHz and a measurement temperature of 23°C. When the sample is a resin composition before curing, the resin composition may be cured at 190°C for 90 minutes to obtain a cured product, and the dielectric loss tangent Df of the cured product may be measured.

[0151] <Applications of resin composition> The resin composition according to this embodiment can be used to form an interlayer insulating material, and is particularly preferably used to form an interlayer insulating layer of a circuit board having a multilayer structure. The resin composition may also be used to manufacture a resin sheet. Typically, an insulating layer is formed using this resin sheet. The resin composition may also be used for other purposes, such as solder resist, underfill material, die bonding material, hole filling resin, sealing resin, and component embedding resin.

[0152] <Resin sheet> A resin sheet for an interlayer insulating material according to one embodiment of the present invention includes a support and a resin composition layer formed on the support. The resin composition layer contains the resin composition described above, and preferably contains only the resin composition described above.

[0153] From the viewpoint of thinning, the thickness of the resin composition layer provided in the resin sheet is preferably 200 μm or less, more preferably 150 μm or less, and even more preferably 100 μm or less. The lower limit of the thickness of the resin composition layer can be, for example, 1 μm or more, 3 μm or more, 5 μm or more, etc.

[0154] Examples of the support include plastic film, metal foil, and release paper, with plastic film and metal foil being preferred.

[0155] When a film of a plastic material is used as the support, examples of the plastic material include polyesters such as polyethylene terephthalate (hereinafter sometimes abbreviated as "PET") and polyethylene naphthalate (hereinafter sometimes abbreviated as "PEN"), polycarbonate (hereinafter sometimes abbreviated as "PC"), acrylics such as polymethyl methacrylate (PMMA), cyclic polyolefins, triacetyl cellulose (TAC), polyether sulfide (PES), polyether ketone, polyimide, etc. Among these, polyethylene terephthalate and polyethylene naphthalate are preferred, with inexpensive polyethylene terephthalate being particularly preferred.

[0156] When a metal foil is used as the support, examples of the metal foil include copper foil and aluminum foil, with copper foil being preferred. The copper foil may be a foil made of a single metal, copper, or an alloy of copper and another metal (e.g., tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.).

[0157] The surface of the support that is to be bonded to the resin composition layer may be subjected to a surface treatment such as matte treatment, corona treatment, or antistatic treatment.

[0158] The support may be a support with a release layer, which has a release layer on the surface that bonds with the resin composition layer. Examples of the release agent used in the release layer of the support with a release layer include one or more release agents selected from the group consisting of alkyd-based release agents, polyolefin-based release agents, urethane-based release agents, and silicone-based release agents. Commercially available products may be used as the support with a release layer, including PET films having a release layer primarily composed of a silicone-based release agent or an alkyd resin-based release agent, such as "PET501010," "SK-1," "AL-5," and "AL-7" manufactured by Lintec Corporation; "Lumirror T60" manufactured by Toray Industries, Inc.; "Purex" manufactured by Teijin Limited; and "Uni-Peel" manufactured by Unitika Limited.

[0159] The thickness of the support is not particularly limited, but is preferably 1 μm or more, more preferably 5 μm or more, even more preferably 10 μm or more, and is preferably 75 μm or less, more preferably 60 μm or less, even more preferably 50 μm or less. When a support with a release layer is used, it is preferable that the thickness of the entire support with a release layer is within the above range.

[0160] The resin sheet may include any optional member as needed. For example, the resin sheet may include a protective film for protecting the resin composition layer. The protective film is usually provided on the surface of the resin composition layer that is not bonded to the support (i.e., the surface opposite to the support). The thickness of the protective film is not particularly limited, but is, for example, 1 μm to 40 μm. When the protective film is provided, adhesion of dust and scratches to the surface of the resin composition layer can be suppressed.

[0161] The resin sheet can be produced, for example, by a method including forming a resin composition layer on a support. Specifically, the resin sheet can be produced by applying a liquid (varnish-like) resin composition directly or by mixing a solvent and the resin composition to prepare a liquid (varnish-like) resin composition, applying the liquid (varnish-like) resin composition to a support, and then drying it as necessary to form a resin composition layer. The solvent may be the same as the (I) solvent described as a component of the resin composition.

[0162] The resin composition can be applied using a coating device such as a die coater. Drying can be performed by a drying method such as heating or hot air blowing. The drying conditions are not particularly limited, but drying is typically performed so that the solvent content in the resin composition layer is 10% by mass or less, preferably 5% by mass or less. Although this may vary depending on the boiling point of the solvent, for example, when a resin composition containing 30% by mass to 60% by mass of solvent is used, a resin composition layer can be formed by drying at 50°C to 150°C for 3 to 10 minutes.

[0163] The produced resin sheet can be stored by being wound up in a roll. When the resin sheet has a protective film, the resin sheet can usually be used by peeling off the protective film.

[0164] <Circuit board> A circuit board according to one embodiment of the present invention includes a cured product of the resin composition described above. Typically, the circuit board includes an insulating layer, and this insulating layer includes a cured product of the resin composition. The insulating layer may include only a cured product of the resin composition. The thickness of the insulating layer is not particularly limited and may be, for example, in the same range as the thickness of the resin composition layer included in the resin sheet. Furthermore, the insulating layer can usually have properties similar to those of the cured product of the resin composition described above. Therefore, the insulating layer can have small undulations, a small average linear thermal expansion coefficient, and high adhesion to the conductor layer.

[0165] Preferably, the circuit board includes an inner layer substrate and the insulating layer is provided on the inner layer substrate. The circuit board may also include a conductor layer. For example, the conductor layer may be provided on an insulating layer. An example of a preferred method for manufacturing a circuit board will be described below.

[0166] A preferred example of a method for manufacturing a circuit board includes the steps of: Step (I) of forming a resin composition layer on an inner layer substrate; a step (II) of curing the resin composition layer; Includes.

[0167] An "inner layer substrate" is a member that serves as the base material of a circuit board, and examples thereof include glass epoxy substrates, metal substrates, polyester substrates, polyimide substrates, BT resin substrates, and thermosetting polyphenylene ether substrates. The inner layer substrate may have a conductor layer on one or both sides. The conductor layer of the inner layer substrate may be patterned. An inner layer substrate having a conductor layer (circuit) formed on one or both sides of the substrate is sometimes called an "inner layer circuit board." The term "inner layer substrate" also includes intermediate products on which insulating layers and / or conductor layers are to be further formed during the production of a circuit board. In addition, inner layer substrates with built-in components may also be used.

[0168] The resin composition layer may be formed on the inner layer substrate by, for example, a method including applying a resin composition to the inner layer substrate and drying it as necessary, but is preferably formed using a resin sheet. The method for forming a resin composition layer using a resin sheet typically includes laminating the resin sheet and the inner layer substrate. The resin sheet and the inner layer substrate are laminated so that the resin composition layer of the resin sheet and the inner layer substrate are bonded. This lamination may be performed, for example, by thermocompression bonding the resin sheet to the inner layer substrate from the support side. Examples of a member for thermocompression bonding the resin sheet to the inner layer substrate (hereinafter also referred to as a "thermocompression bonding member") include a heated metal plate (such as a SUS panel) or a metal roll (such as a SUS roll). It is preferable to press the thermocompression bonding member not directly against the resin sheet but through an elastic material such as heat-resistant rubber so that the resin sheet can sufficiently conform to the surface irregularities of the inner layer substrate.

[0169] The lamination of the inner layer substrate and the resin sheet may be carried out by a vacuum lamination method. In the vacuum lamination method, the thermocompression temperature is preferably in the range of 60°C to 160°C, more preferably 80°C to 140°C, the thermocompression pressure is preferably in the range of 0.098MPa to 1.77MPa, more preferably 0.29MPa to 1.47MPa, and the thermocompression time is preferably in the range of 20 seconds to 400 seconds, more preferably 30 seconds to 300 seconds. The lamination is preferably carried out under reduced pressure conditions of 26.7hPa or less.

[0170] The lamination may be performed using a commercially available vacuum laminator, such as a vacuum pressure laminator manufactured by Meiki Seisakusho Co., Ltd., a vacuum applicator manufactured by Nikko Materials Co., Ltd., or a batch-type vacuum pressure laminator.

[0171] The method for manufacturing a circuit board may include, after lamination, smoothing the resin sheet by pressing the support side with a thermocompression member under normal pressure (atmospheric pressure). The pressing conditions for the smoothing may be the same as the conditions for thermocompression bonding of the lamination. The smoothing may be performed using a commercially available laminator. The lamination and smoothing may be performed consecutively using the commercially available vacuum laminator.

[0172] The method for producing a circuit board according to this example includes a step (II) of curing the resin composition layer after the step (I). By curing the resin composition layer in the step (II), an insulating layer containing a cured product of the resin composition can be formed.

[0173] The resin composition layer is usually cured by thermal curing. The thermal curing conditions for the resin composition layer may vary depending on the type of resin composition. For example, the curing temperature is preferably 120°C to 240°C, more preferably 150°C to 220°C, and even more preferably 170°C to 210°C. The curing time is preferably 5 minutes to 120 minutes, more preferably 10 minutes to 100 minutes, and even more preferably 15 minutes to 100 minutes.

[0174] The method for producing a circuit board may include preheating the resin composition layer at a temperature lower than the curing temperature before thermally curing the resin composition layer. For example, prior to thermally curing the resin composition layer, the resin composition layer may be preheated for typically 5 minutes or more, preferably 5 minutes to 150 minutes, more preferably 15 minutes to 120 minutes, and even more preferably 15 minutes to 100 minutes, at a temperature of typically 50°C to 150°C, preferably 60°C to 140°C, and more preferably 70°C to 130°C. Preheating is typically carried out after step (I). Furthermore, when a smoothing treatment is carried out after laminating the inner layer substrate and the resin sheet, preheating can typically be carried out after the smoothing treatment.

[0175] When a resin sheet is used, the method for producing a circuit board may include a step of peeling off the support of the resin sheet after laminating the inner layer substrate and the resin sheet. The peeling off of the support may be performed between steps (I) and (II), or after step (II). Furthermore, when the method for producing a circuit board includes step (III) of forming holes in the insulating layer, step (IV) of roughening the insulating layer, and step (V) of forming a conductor layer, as described below, the peeling off of the support may be performed between steps (II) and (III), between steps (III) and (IV), or between steps (IV) and (V).

[0176] The method for producing a circuit board may include, after step (II), step (III) of forming holes such as via holes or through holes in the insulating layer. The method for forming the holes may be selected depending on factors such as the composition of the resin composition used to form the insulating layer. For example, holes may be formed by processing methods such as drilling, laser processing, and plasma processing, with laser processing being preferred. For example, holes may be formed by irradiating the insulating layer with laser light after peeling off the support, or by irradiating the insulating layer with laser light through the support. The dimensions and shape of the holes may be determined appropriately depending on the design of the circuit board.

[0177] The method for manufacturing a circuit board may include a step (IV) of roughening the insulating layer. The roughening treatment can roughen the surface of the insulating layer. The roughening treatment can also remove smears (resin residues) from the insulating layer. Therefore, this roughening treatment is sometimes called a "desmear treatment." For example, when holes are formed in step (III), smears may form in the holes. Therefore, it is preferable to perform the roughening treatment of step (IV) after step (III) to remove the smears.

[0178] The procedure and conditions for the roughening treatment are not particularly limited, and known procedures and conditions that are commonly used when forming an insulating layer for a circuit board can be adopted. For example, the roughening treatment may be performed by subjecting the insulating layer to a swelling treatment using a swelling liquid, an oxidation treatment using an oxidizing agent, and a neutralization treatment using a neutralizing liquid in this order.

[0179] Examples of swelling liquids used in the roughening treatment include alkaline solutions and surfactant solutions, with alkaline solutions being preferred. Sodium hydroxide solutions and potassium hydroxide solutions are more preferred as alkaline solutions. Commercially available swelling liquids include "Swelling Dip Securiganth P" and "Swelling Dip Securiganth SBU" manufactured by Atotech Japan. Swelling treatment using a swelling liquid can be performed, for example, by immersing the insulating layer in a swelling liquid at 30°C to 90°C for 1 to 20 minutes. To keep the swelling of the resin in the insulating layer to an appropriate level, it is preferable to immerse the insulating layer in a swelling liquid at 40°C to 80°C for 5 to 15 minutes.

[0180] Examples of oxidizing agents used in the roughening treatment include alkaline permanganate solutions prepared by dissolving potassium permanganate or sodium permanganate in an aqueous solution of sodium hydroxide. Oxidation treatment using an oxidizing agent such as alkaline permanganate solution is preferably carried out by immersing the insulating layer in an oxidizing agent solution heated to 60°C to 100°C for 10 to 30 minutes. The concentration of permanganate in the alkaline permanganate solution is preferably 5% by mass to 10% by mass. Commercially available oxidizing agents include alkaline permanganate solutions such as "Concentrate Compact CP" and "Dosing Solution Securigance P" manufactured by Atotech Japan.

[0181] The neutralizing solution used in the roughening treatment is preferably an acidic aqueous solution, and a commercially available product such as "Reduction Solution Securigant P" manufactured by Atotech Japan can be cited as an example. Neutralization treatment using a neutralizing solution can be carried out by immersing the surface that has been oxidized with an oxidizing agent in a neutralizing solution at 30°C to 80°C for 5 to 30 minutes. From the standpoint of workability, a preferred method is to immerse the object that has been oxidized with an oxidizing agent in a neutralizing solution at 40°C to 70°C for 5 to 20 minutes.

[0182] The method for producing a circuit board may include step (V) of forming a conductor layer on the insulating layer. When the method for producing a circuit board includes step (III) or (IV), step (V) of forming a conductor layer is usually preferably carried out after steps (III) and (IV).

[0183] The conductive material used for the conductor layer is not particularly limited. In a preferred embodiment, the conductor layer contains one or more metals selected from the group consisting of gold, platinum, palladium, silver, copper, aluminum, cobalt, chromium, zinc, nickel, titanium, tungsten, iron, tin, and indium. The conductor layer may be a single metal layer or an alloy layer. Examples of alloy layers include layers formed from alloys of two or more metals selected from the above group (e.g., nickel-chromium alloys, copper-nickel alloys, and copper-titanium alloys). Among these, from the viewpoints of versatility in forming the conductor layer, cost, ease of patterning, and the like, a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, or an alloy layer of a nickel-chromium alloy, copper-nickel alloy, or copper-titanium alloy is preferred. A single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, or an alloy layer of a nickel-chromium alloy, is more preferred, and a single metal layer of copper is even more preferred.

[0184] The conductor layer may have a single layer structure or a multi-layer structure including two or more single metal or alloy layers made of different types of metals or alloys. When the conductor layer has a multi-layer structure, the layer in contact with the insulating layer is preferably a single metal layer of chromium, zinc, or titanium, or an alloy layer of a nickel-chromium alloy.

[0185] The thickness of the conductor layer depends on the design of the circuit board, but is preferably 3 μm to 35 μm, and more preferably 5 μm to 30 μm.

[0186] The conductor layer may be formed by plating. For example, a conductor layer having a desired wiring pattern can be formed by plating the surface of the insulating layer using a conventionally known technique such as a semi-additive method or a full-additive method. From the viewpoint of ease of production, the semi-additive method is preferred. An example of forming a conductor layer by a semi-additive method will be described below.

[0187] First, an electroless plated layer (plating seed layer) is formed on the surface of the insulating layer by electroless plating. Next, a mask pattern is formed on the formed electroless plated layer, exposing a portion of the electroless plated layer corresponding to the desired wiring pattern. After forming an electroless plated layer on the exposed electroless plated layer by electrolytic plating, the mask pattern is removed. Thereafter, unnecessary electroless plated layer is removed by etching, thereby forming a conductor layer having the desired wiring pattern.

[0188] As another example, the conductor layer may be formed using a metal foil. When a metal foil is used to form the conductor layer, step (V) is preferably performed between steps (I) and (II). For example, after step (I), the support is removed, and a metal foil is laminated on the exposed surface of the resin composition layer. The lamination of the resin composition layer and the metal foil may be performed by a vacuum lamination method. The lamination conditions may be the same as those described for step (I). Next, step (II) is performed to form an insulating layer. Thereafter, a conductor layer having a desired wiring pattern can be formed using the metal foil on the insulating layer by a known technique such as a subtractive method or a modified semi-additive method. The metal foil can be manufactured by a known method such as an electrolytic method or a rolling method. Commercially available metal foils include, for example, HLP foil and JXUT-III foil manufactured by JX Nippon Mining & Smelting Co., Ltd., and 3EC-III foil and TP-III foil manufactured by Mitsui Mining & Smelting Co., Ltd.

[0189] When a conductor layer is formed on an insulating layer, the method for manufacturing a circuit board may include performing an annealing treatment after the formation of the conductor layer. The annealing treatment can improve the adhesion between the insulating layer and the conductor layer. The annealing treatment can be performed, for example, by heating at 150°C to 210°C for 20 to 180 minutes.

[0190] In the method for manufacturing a circuit board, each of the above steps may be performed only once or may be repeated two or more times. For example, steps (I) to (V) may be performed repeatedly to form a circuit board having a multilayer structure, such as a multilayer printed wiring board having a plurality of insulating layers and conductor layers.

[0191] The method for manufacturing a circuit board may include any additional steps in addition to the steps described above. For example, the method for manufacturing a circuit board may include a step of providing a semiconductor chip so that the semiconductor chip is bonded to the conductor layer. Specifically, when manufacturing a circuit board for a semiconductor chip package including a semiconductor chip, the method for manufacturing a circuit board may include a step of providing the semiconductor chip. The semiconductor chip may be bonded under appropriate conditions that allow conductive connection between the terminal electrodes of the semiconductor chip and the conductor layer formed on the insulating layer. For example, conditions used in flip-chip mounting may be used. The semiconductor chip may be bonded via an insulating adhesive or by reflow bonding. If necessary, the provided semiconductor chip may be filled with a mold underfill material. The method for manufacturing a circuit board may also include, for example, a step of forming a sealing layer, a step of forming a solder resist layer, and a step of dicing the manufactured circuit board into individual pieces.

[0192] Examples of circuit boards include printed wiring boards and semiconductor chip packages. Examples of semiconductor chip packages include FC-CSP, MIS-BGA package, ETS-BGA package, fan-out type WLP (Wafer Level Package), fan-in type WLP, fan-out type PLP (Panel Level Package), and fan-in type PLP. In these semiconductor chip packages, it is preferable to form a rewiring formation layer as an insulating layer using a cured product obtained by curing the above-mentioned resin composition. However, the circuit board is not limited to those exemplified here.

[0193] <Semiconductor device> The circuit board can be used to manufacture a semiconductor device. The semiconductor device includes the circuit board described above. Examples of the semiconductor device include various semiconductor devices used in electrical appliances (e.g., computers, mobile phones, smartphones, tablet devices, wearable devices, digital cameras, medical equipment, and televisions) and vehicles (e.g., motorcycles, automobiles, trains, ships, and aircraft). [Example]

[0194] The present invention will be specifically described below with reference to examples. However, the present invention is not limited to these examples. In the following description, "parts" and "%" representing amounts mean "parts by mass" and "% by mass", respectively, unless otherwise specified. Furthermore, unless otherwise specified, the temperature and pressure conditions were room temperature (23°C) and atmospheric pressure (1 atm). Furthermore, unless otherwise specified, "Mn" represents the number average molecular weight.

[0195] <Synthesis Example 1: Synthesis of Maleimide Resin B> An MEK solution (70% by mass of non-volatile components) of maleimide resin B (Mw / Mn = 1.81, t'' = 1.47 (mainly 1, 2, or 3)) synthesized by the method described in Synthesis Example 1 of the Japan Institute of Invention and Innovation's Technical Journal Publication No. 2020-500211 was prepared. This maleimide resin B has a structure represented by the following formula (b).

[0196] [ka]

[0197] Example 1 To 6 parts of bixylenol epoxy resin ("YX4000HK" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent weight: approximately 185 g / eq.), 10 parts of biphenyl epoxy resin ("NC3000L" manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent weight: approximately 269 g / eq.), and 6 parts of bisphenol A epoxy resin ("828EL" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent weight: approximately 180 g / eq.), 15 parts of methyl ethyl ketone (MEK) was added as a dilution solvent, and the mixture was heated and dissolved with stirring. This was then cooled to room temperature to obtain an epoxy resin dissolved composition. This epoxy resin solution composition was mixed with 3 parts of a triazine skeleton-containing phenolic resin (DIC Corporation's "LA-3018-50P," active group equivalent weight approximately 151 g / eq., non-volatile content 50% in 2-methoxypropanol solution), 60 parts of an active ester resin (DIC Corporation's "HPC-8000-65T," active group equivalent weight approximately 223 g / eq., non-volatile content 65% in toluene solution), 0.15 parts of an amine-based curing accelerator (4-dimethylaminopyridine (DMAP)), 0.1 parts of an imidazole-based curing accelerator (Shikoku Chemical Industry Co., Ltd.'s "1B2PZ," 1-benzyl-2-phenylimidazole), and spherical silica (Admatechs Co., Ltd.'s "SO-C2," average particle size 0.5 μm, specific surface area 5.8 m) surface-treated with a silane coupling agent (Shin-Etsu Chemical Co., Ltd.'s "KBM-573"). 2 / g) 70 parts, aerogel ("SUFA Powder type" manufactured by TM Factory, average particle size 9 μm, porosity 93%, specific surface area 810 m 2 / g, average pore diameter 23 nm, pore volume 4 cm 3 A resin varnish was produced as a liquid resin composition by mixing 1 part of hydroxybenzoates (1 part hydroxybenzoates / g), 5 parts of phenoxy resin ("YX7553BH30" manufactured by Mitsubishi Chemical Corporation, a 1:1 solution of MEK and cyclohexanone with a non-volatile content of 30% by mass), and 3 parts of rubber particles ("Staphyloid AC3816N" manufactured by Aica Kogyo Co., Ltd.). The mixture was uniformly dispersed using a high-speed rotating mixer.

[0198] A polyethylene terephthalate film ("AL5" manufactured by Lintec Corporation, thickness 38 μm) having a release-treated release surface was prepared as a support. A resin varnish was uniformly applied to the release surface of the support so that the thickness of the resin composition layer was 40 μm, and the film was dried at 80°C to 120°C (average 100°C) for 5 minutes to produce a resin sheet.

[0199] <Example 2> In Example 1, 1) The amount of spherical silica (Admatechs' "SO-C2") surface-treated with a silane coupling agent (Shin-Etsu Chemical's "KBM-573") was changed from 70 parts to 80 parts. 2) The amount of aerogel ("SUFA Powder type" manufactured by T.M. Factory) was changed from 1 part to 0.3 parts. A resin varnish and a resin sheet were produced in the same manner as in Example 1 except for the above.

[0200] Example 3 In Example 1, 1) The amount of spherical silica (Admatechs' "SO-C2") surface-treated with a silane coupling agent (Shin-Etsu Chemical's "KBM-573") was changed from 70 parts to 10 parts. 2) The amount of aerogel ("SUFA Powder type" manufactured by T.M. Factory) was changed from 1 part to 5 parts. A resin varnish and a resin sheet were produced in the same manner as in Example 1 except for the above.

[0201] Example 4 In Example 1, 1) The amount of spherical silica (Admatechs' "SO-C2") surface-treated with a silane coupling agent (Shin-Etsu Chemical's "KBM-573") was changed from 70 parts to 160 parts. 2) The amount of aerogel ("SUFA Powder type" manufactured by T.M. Factory) was changed from 1 part to 0.7 parts. A resin varnish and a resin sheet were produced in the same manner as in Example 1 except for the above.

[0202] <Example 5> In Example 1, a resin varnish and a resin sheet were produced in the same manner as in Example 1, except that the amount of spherical silica ("SO-C2" manufactured by Admatechs Co., Ltd.) surface-treated with a silane coupling agent ("KBM-573" manufactured by Shin-Etsu Chemical Co., Ltd.) was changed from 70 parts to 50 parts.

[0203] Example 6 In Example 1, 1) The amount of spherical silica (Admatechs' "SO-C2") surface-treated with a silane coupling agent (Shin-Etsu Chemical's "KBM-573") was changed from 70 parts to 60 parts. 2) The amount of aerogel ("SUFA Powder type" manufactured by T.M. Factory) was changed from 1 part to 8 parts. A resin varnish and a resin sheet were produced in the same manner as in Example 1 except for the above.

[0204] Example 7 In Example 1, 1) The amount of bixylenol-type epoxy resin (Mitsubishi Chemical Corporation's "YX4000HK") was changed from 6 parts to 3 parts. 2) The amount of activated ester resin (DIC HPC-8000-65T, a toluene solution with a non-volatile content of 65%) was changed from 60 parts to 30 parts. 3) The amount of triazine skeleton-containing phenolic curing agent (DIC Corporation "LA-3018-50P", 2-methoxypropanol solution with a non-volatile content of 50%) was changed from 3 parts to 1.5 parts. 4) 45 parts of vinylbenzyl-modified polyphenylene ether ("OPE-2St 2200" manufactured by Mitsubishi Gas Chemical Co., Ltd., a toluene solution with a non-volatile content of 65%) was additionally added. A resin varnish and a resin sheet were produced in the same manner as in Example 1 except for the above.

[0205] Example 8 In Example 1, 1) The amount of amine curing accelerator (4-dimethylaminopyridine (DMAP)) was changed from 0.15 parts to 0.2 parts. 2) No imidazole-based curing accelerator (1-benzyl-2-phenylimidazole, "1B2PZ" manufactured by Shikoku Chemicals Corporation) was used. A resin varnish and a resin sheet were produced in the same manner as in Example 1 except for the above.

[0206] Example 9 In Example 1, 1) No amine-based curing accelerator (4-dimethylaminopyridine (DMAP)) is used. 2) The amount of imidazole curing accelerator (1-benzyl-2-phenylimidazole, "1B2PZ" manufactured by Shikoku Chemicals Corporation) was changed from 0.1 parts to 0.4 parts. A resin varnish and a resin sheet were produced in the same manner as in Example 1 except for the above.

[0207] Example 10 A resin varnish and a resin sheet were produced in the same manner as in Example 1, except that a triazine skeleton-containing phenolic resin (DIC Corporation's "LA-3018-50P", a 2-methoxypropanol solution with a non-volatile content of 50%) was not used.

[0208] Example 11 A resin varnish and a resin sheet were produced in the same manner as in Example 1, except that the rubber particles (manufactured by Aica Kogyo Co., Ltd., "Staphyloid AC3816N") were not used.

[0209] Example 12 A resin varnish and a resin sheet were produced in the same manner as in Example 1, except that the phenoxy resin ("YX7553BH30" manufactured by Mitsubishi Chemical Corporation, a 1:1 solution of MEK and cyclohexanone with a non-volatile content of 30% by mass) was not used.

[0210] Example 13 In Example 1, 70 parts of spherical silica ("SO-C2" manufactured by Admatechs Co., Ltd.) surface-treated with a silane coupling agent ("KBM-573" manufactured by Shin-Etsu Chemical Co., Ltd.) were mixed with spherical alumina ("DAW-01" manufactured by Denka Co., Ltd., average particle size 1.9 μm, specific surface area 1.0 m) surface-treated with a silane coupling agent ("KBM-573" manufactured by Shin-Etsu Chemical Co., Ltd.). 2 / g, specific gravity 3.7g / cm 3 A resin varnish and a resin sheet were produced in the same manner as in Example 1, except that the amount of hydroxybenzoates was changed to 78 parts.

[0211] Example 14 In Example 1, 70 parts of spherical silica ("SO-C2" manufactured by Admatechs Co., Ltd.) surface-treated with a silane coupling agent ("KBM-573" manufactured by Shin-Etsu Chemical Co., Ltd.) were mixed with spherical boron nitride ("Spherical Nano-sized BN" manufactured by Denka Co., Ltd., average particle size 0.5 μm, specific surface area 15 m) surface-treated with a silane coupling agent ("KBM-573" manufactured by Shin-Etsu Chemical Co., Ltd.). 2 / g, specific gravity 2.3g / cm 3 A resin varnish and a resin sheet were produced in the same manner as in Example 1, except that the amount of hydroxybenzoate was changed to 50 parts by weight.

[0212] Example 15 5 parts of naphthylene ether epoxy resin (DIC Corporation "HP-6000", epoxy equivalent: approximately 250 g / eq.), 18 parts of biphenyl epoxy resin (Nippon Kayaku Co., Ltd. "NC3000L", epoxy equivalent: approximately 269 g / eq.), 8 parts of naphthalene epoxy resin (DIC Corporation "HP-4032SS", epoxy equivalent: approximately 144 g / eq.), and 10 parts of bisphenol A epoxy resin (Mitsubishi Chemical Corporation "828EL", epoxy equivalent: approximately 180 g / eq.) were added to 15 parts of methyl ethyl ketone (MEK) as a diluent, and the mixture was heated and dissolved with stirring. This was then cooled to room temperature to obtain an epoxy resin solution composition. This epoxy resin solution composition was mixed with 15 parts of a triazine skeleton-containing phenol novolac resin (DIC Corporation's "LA-7054," hydroxyl group equivalent weight approximately 125 g / eq., MEK solution with a non-volatile content of 60% by mass), 9 parts of a naphthol-based curing agent (Nippon Steel Chemical & Material Co., Ltd.'s "SN395," active group equivalent weight approximately 107 g / eq.), 0.2 parts of an amine-based curing accelerator (4-dimethylaminopyridine (DMAP)), and spherical silica (Admatechs Co., Ltd.'s "SO-C2," average particle size 0.5 μm, specific surface area 5.8 m) surface-treated with a silane coupling agent (Shin-Etsu Chemical Co., Ltd.'s "KBM-573"). 2 70 parts of cellulose acetate (cellulose acetate / g), 0.7 parts of aerogel ("SUFA Powder type" manufactured by TM Factory, average particle size 9 μm, porosity 93%), and 18 parts of phenoxy resin ("YX7553BH30" manufactured by Mitsubishi Chemical Corporation, a 1:1 solution of MEK and cyclohexanone with a non-volatile content of 30% by mass) were mixed and uniformly dispersed in a high-speed rotating mixer to produce a resin varnish as a liquid resin composition.

[0213] A polyethylene terephthalate film ("AL5" manufactured by Lintec Corporation, thickness 38 μm) having a release-treated release surface was prepared as a support. A resin varnish was uniformly applied to the release surface of the support so that the thickness of the resin composition layer was 40 μm, and the film was dried at 80°C to 120°C (average 100°C) for 5 minutes to produce a resin sheet.

[0214] Example 16 To 15 parts of a biphenylaralkyl novolac maleimide resin ("MIR-3000-70MT" manufactured by Nippon Kayaku Co., Ltd., a MEK / toluene mixed solution with a non-volatile content of 70%), 20 parts of the maleimide resin B obtained in Synthesis Example 1 (a MEK solution with a non-volatile content of 70% by mass), 10 parts of diallyl diphenate ("DAD" manufactured by Nisshoku Techno Fine Chemical Co., Ltd.), and 3 parts of a styrene-butadiene resin ("Tuftec (registered trademark) P2000" manufactured by Asahi Kasei Corporation), 15 parts of methyl ethyl ketone (MEK) was added as a diluent, and the mixture was heated and dissolved with stirring. This mixture was cooled to room temperature to obtain an epoxy resin solution composition. This epoxy resin solution composition was mixed with 0.5 parts of a radical polymerization initiator (NOF Corp.'s "Perhexyl D") and spherical silica (Admatechs Co., Ltd.'s "SO-C2", average particle size 0.5 μm, specific surface area 5.8 m) surface-treated with a silane coupling agent (Shin-Etsu Chemical Co., Ltd.'s "KBM-573"). 2 45 parts of cellulose acetate (1 / g) and 0.3 parts of aerogel (SUFA Powder type, manufactured by TM Factory, average particle size 9 μm, porosity 93%) were mixed and uniformly dispersed in a high-speed rotating mixer to produce a resin varnish as a liquid resin composition.

[0215] A polyethylene terephthalate film ("AL5" manufactured by Lintec Corporation, thickness 38 μm) having a release-treated release surface was prepared as a support. A resin varnish was uniformly applied to the release surface of the support so that the thickness of the resin composition layer was 40 μm, and the film was dried at 80°C to 120°C (average 100°C) for 5 minutes to produce a resin sheet.

[0216] <Comparative Example 1> In Example 1, 1) The amount of spherical silica (Admatechs' "SO-C2") surface-treated with a silane coupling agent (Shin-Etsu Chemical's "KBM-573") was changed from 70 parts to 85 parts. 2) Aerogel ("SUFA Powder type" manufactured by T.M. Factory) was not used. A resin varnish and a resin sheet were produced in the same manner as in Example 1 except for the above.

[0217] <Comparative Example 2> In Example 1, 1) It does not use spherical silica (Admatechs' "SO-C2") surface-treated with a silane coupling agent (Shin-Etsu Chemical's "KBM-573"), 2) The amount of aerogel ("SUFA Powder type" manufactured by T.M. Factory) was changed from 1 part to 6 parts. A resin varnish and a resin sheet were produced in the same manner as in Example 1 except for the above.

[0218] <Comparative Example 3> A resin varnish and a resin sheet were produced in the same manner as in Example 1, except that 1 part of aerogel ("SUFA Powder type" manufactured by TM Factory) was replaced with 15 parts of mesoporous silica ("Mesopure" manufactured by Nippon Kasei Co., Ltd., average particle size 5 μm, pore size 4 nm, porosity less than 85%).

[0219] <Test 1. Adhesion evaluation test> (1) Sample preparation: The shiny side of an electrolytic copper foil (Mitsui Mining & Smelting Co., Ltd., "3EC-III," 35 μm thick) was immersed in a microetching agent (Mech Co., Ltd., "CZ-8101") to roughen the copper foil surface. The arithmetic mean roughness Ra of the copper foil surface after roughening was 1 μm. The arithmetic mean roughness Ra was measured in accordance with ISO 25178 using a non-contact surface roughness meter (Veco Instruments, Inc., "WYKO NT3300"). The surface of this copper foil was then subjected to a rust prevention treatment using a rust prevention solution (Mech Co., Ltd., "CL8300"). The resulting copper foil is referred to as CZ copper foil. This CZ copper foil was then heat-treated in an oven at 130°C for 30 minutes.

[0220] A glass cloth-based epoxy resin double-sided copper-clad laminate (copper foil thickness 18 μm, substrate thickness 0.4 mm, Panasonic "R1515A") with an inner layer circuit formed thereon was prepared as an inner layer circuit board. Next, resin sheets were laminated on both sides of the inner layer circuit board using a batch-type vacuum pressure laminator (Meiki Seisakusho "MVLP-500") so that the resin composition layer was bonded to the inner layer circuit board. Lamination was performed by reducing the pressure for 30 seconds to 13 hPa or less, followed by pressure bonding at 100°C and a pressure of 0.74 MPa for 30 seconds. After lamination, the support was peeled off to expose the resin composition layer. The treated side of the CZ copper foil was laminated on the exposed resin composition layer under the same conditions as for laminating the resin sheet described above. Thereafter, the resin composition layer was cured under curing conditions of 190°C and 90 minutes to form an insulating layer as a cured product layer, thereby producing a sample having a structure of CZ copper foil / insulating layer / inner layer circuit board / insulating layer / CZ copper foil.

[0221] (2) Measurement of load (peel strength): The prepared sample was cut into small pieces measuring 150 × 30 mm. A cutter was used to make a slit in the small CZ copper foil piece, enclosing a rectangular portion measuring 10 mm in width and 100 mm in length. One longitudinal end of this rectangular portion was peeled off and gripped with a gripper (TSE Corporation, "AC-50C-SL"). The load at which 35 mm was peeled off vertically at a rate of 50 mm / min at room temperature (23°C) using an Instron universal testing machine was measured in accordance with JIS C6481. The measured load was the load required to peel the CZ copper foil from the insulating layer, and corresponds to the peel strength. A higher peel strength indicates better adhesion.

[0222] <Test 2. Undulation evaluation test> An inner layer substrate (glass cloth-based epoxy resin double-sided copper-clad laminate, copper foil thickness 18 μm, substrate thickness 0.8 mm, "R5715ES" manufactured by Matsushita Electric Works, Ltd.) was prepared. The substrate surface had a copper foil pattern (line / space = 175 μm / 175 μm comb pattern (50% copper remaining)) formed on it, as in IPC Multi-Purpose Test Board No. IPC B-25. Here, "line" refers to the wiring width of the wiring formed by the copper foil, and "space" refers to the gap between the wiring. Both sides of this inner layer substrate were etched by 1 μm with an etching agent ("CZ8100" manufactured by MEC Co., Ltd.) to roughen the copper foil surface.

[0223] The resin sheets were laminated onto both sides of the inner layer substrate using a batch-type vacuum pressure laminator (a two-stage build-up laminator "CVP700" manufactured by Nikko Materials Co., Ltd.) so that the resin composition layer was in contact with the inner layer substrate. Lamination was performed by reducing the pressure to 13 hPa or less for 30 seconds, followed by pressure bonding at 100°C and a pressure of 0.74 MPa for 30 seconds. Next, a heat press was performed at 100°C and a pressure of 0.5 MPa for 60 seconds. This procedure yielded evaluation substrate 1, which had a support, a resin composition layer, an inner layer substrate, a resin composition layer, and a support in that order.

[0224] The laminated resin sheet was then heated at 100°C for 30 minutes and then at 180°C for 30 minutes to thermally cure the resin composition layer and form an insulating layer as a cured product layer. The support of the resin sheet was then peeled off. This resulted in an evaluation substrate 2 having an insulating layer, an inner layer substrate, and another insulating layer in this order.

[0225] The evaluation substrates 1 and 2 were cut into 200 mm x 200 mm test pieces. The surface condition of the obtained test pieces was observed using an optical interference surface roughness and surface profiler (Veeco Japan, "Wyko NT9300"), and the undulation A1 of the resin composition layer of evaluation substrate 1 and the undulation A2 of the insulating layer of evaluation substrate 2 were measured. Here, the undulation A1 of the resin composition layer of evaluation substrate 1 represents the difference between the maximum height and the minimum height of the surface of the resin composition layer (the surface opposite the inner layer substrate). Furthermore, the undulation A2 of the insulating layer of evaluation substrate 2 represents the difference between the maximum height and the minimum height of the surface of the insulating layer (the surface opposite the inner layer substrate). The undulations measured in this manner were evaluated according to the following criteria. Smaller undulations indicate better fluidity of the resin composition.

[0226] The evaluation criteria for the undulation A1 of the resin composition layer of the evaluation substrate 1 are as follows. "Excellent": Undulation A1 is 0.5 μm or less "Good": Undulation A1 is greater than 0.5 μm and less than 0.7 μm "Bad" undulation A1 is 0.7μm or more

[0227] The evaluation criteria for the undulation A2 of the insulating layer of the evaluation substrate 2 are as follows. "Excellent": Undulation A2 is 1.5 μm or less "Good": Undulation A2 is greater than 1.5 μm and less than 1.8 μm "Bad" undulation A2 is 1.8 μm or more

[0228] The evaluation criteria for the amount of change in undulation from evaluation substrate 1 to evaluation substrate 2 (the difference A2-A1 between the undulation A1 of the resin composition layer of evaluation substrate 1 and the undulation A2 of the insulating layer of evaluation substrate 2) are as follows: "Excellent": Undulation change is 1.0 μm or less "Good": Undulation change is greater than 1.0 μm and less than 1.2 μm "Poor": Undulation change is 1.2 μm or more

[0229] <Test 3. Measurement test of average coefficient of linear thermal expansion (CTE)> (1) Preparation of cured product for evaluation: A PET film ("501010" manufactured by Lintec Corporation, 50 μm thick, 240 mm square) was prepared, which had a release-treated surface treated with a release agent and an untreated surface not treated with a release agent. A glass cloth-based epoxy resin double-sided copper-clad laminate ("R5715ES" manufactured by Panasonic Corporation, 0.7 mm thick, 255 mm square) was placed on the untreated surface of this PET film, and the four sides were fixed with polyimide adhesive tape (10 mm wide).

[0230] A resin varnish was applied to the release agent-treated surface of the fixed PET film using a die coater and dried at 80°C to 120°C (average 100°C) for 5 minutes to produce a resin sheet with a thickness of 40 µm.

[0231] The resin composition layer was then heat-cured by heating in an oven at 190°C for 90 minutes. After heat curing, the polyimide adhesive tape was peeled off, the glass cloth-based epoxy resin double-sided copper-clad laminate was peeled off, and the PET film ("501010" manufactured by Lintec Corporation) was also peeled off to obtain a sheet-like cured product. The obtained cured product may be referred to as the "cured product for evaluation."

[0232] (2) Average coefficient of linear thermal expansion (CTE) measurement: The cured product for evaluation was cut into a length of approximately 15 mm and a width of approximately 5 mm to obtain a test specimen. Thermomechanical analysis was performed using a thermomechanical analyzer (Rigaku Corporation, "Thermo Plus TMA8310") by the tensile load method. Specifically, the test specimen was mounted in the analyzer and measured twice consecutively under the following conditions: a load of 1 g and a heating rate of 5°C / min. The first measurement was performed by raising the temperature to 200°C, and the second measurement was performed by raising the temperature to 260°C. In the second measurement, the average coefficient of linear thermal expansion (CTE) from 25°C to 150°C was calculated. The average coefficient of linear thermal expansion measured in this manner was evaluated according to the following criteria. "Excellent": Average coefficient of linear thermal expansion (CTE) is 30 ppm / ℃ or less "Good": Average coefficient of linear thermal expansion (CTE) is greater than 30 ppm / ℃ and less than 40 ppm / ℃ "Poor": Average coefficient of linear thermal expansion (CTE) greater than 40 ppm / ℃

[0233] <Result> The results of the above-mentioned Examples and Comparative Examples are shown in the following table. In the following table, the volume-based content (vol %) of a component was calculated based on the volume obtained by dividing the mass of the component by its specific gravity. In the calculation, the specific gravity of silica "SO-C2" was 2.2 g / cm 3 The specific gravity of spherical alumina "DAW-01" is 3.7g / cm 3 The specific gravity of spherical boron nitride "spherical nano-sized BN" is 2.3g / cm 3 The specific gravity of mesoporous silica "Mesopure" is 2.2g / cm 3 The specific gravity of the aerogel "SUFA Powder type" is 0.154g / cm 3 The specific gravity of the other resin components is 1.2 g / cm 3 It was decided.

[0234] In the table below, the meanings of the abbreviations are as follows: "NVC": Non-volatile component concentration "CTE": Coefficient of mean linear thermal expansion "Content of components (B) + (C)": Ratio of the total amount of the inorganic filler (B) and the aerogel (C) to 100% by volume of the nonvolatile components of the resin composition "Silica content": The ratio of spherical silica "SO-C2" to 100% by volume of non-volatile components of the resin composition "Alumina content": The ratio of spherical alumina "DAW-01" to 100% by volume of non-volatile components of the resin composition "Boron nitride content": The ratio of spherical boron nitride (spherical nano-sized BN) to 100% by volume of the non-volatile components of the resin composition "Mesoporous silica content": The ratio of mesoporous silica "Mesopure" to 100% by volume of non-volatile components of the resin composition "Content of component (C)": Ratio of aerogel (C) to 100% by volume of non-volatile components of the resin composition

[0235]

Table 1

[0236]

Table 2

[0237]

Table 3

Claims

1. (A) Curable resin, (B) 50m ２ A resin composition for an interlayer insulating material, comprising: an inorganic filler having a specific surface area of 1 / g or less; and (C) an aerogel having a porosity of 85% or more.

2. 2. The resin composition for an interlayer insulating material according to claim 1, wherein the curable resin (A) comprises an epoxy resin.

3. 2. The resin composition for an interlayer insulating material according to claim 1, wherein the inorganic filler (B) comprises silica.

4. 2. The resin composition for interlayer insulation according to claim 1, wherein the total amount of the inorganic filler (B) and the aerogel (C) is 30% by volume or more and 60% by volume or less, based on 100% by volume of non-volatile components in the resin composition.

5. 2. The resin composition for an interlayer insulating material according to claim 1, wherein the amount of the aerogel (C) is 1% by volume or more and 40% by volume or less relative to 100% by volume of nonvolatile components in the resin composition.

6. 2. A resin composition for interlayer insulation according to claim 1, wherein the average linear thermal expansion coefficient of a cured product for evaluation obtained by curing the resin composition under conditions of 190°C for 90 minutes is 30 ppm / °C or less from 25°C to 150°C.

7. 2. The resin composition for interlayer insulation material according to claim 1, wherein when an undulation evaluation test is conducted in which a 40 μm-thick resin composition layer containing the resin composition is cured under curing conditions of 100°C for 30 minutes and 180°C for 30 minutes to form a cured product layer, the difference in undulation between the resin composition layer and the cured product layer is less than 1.2 μm.

8. 2. The resin composition for interlayer insulation according to claim 1, wherein a resin composition layer containing the resin composition is formed on a surface of a copper foil having an arithmetic mean roughness of 1 μm, the resin composition layer is cured under conditions of 190°C for 90 minutes to form a cured layer, and when an adhesion evaluation test is conducted in which the copper foil is peeled off in the vertical direction at 23°C at a rate of 50 mm / min, the load required to peel the copper foil from the cured layer is 0.3 kgf / cm or more.

9. A resin sheet for an interlayer insulating material, comprising a support and a resin composition layer provided on the support, wherein the resin composition layer contains the resin composition for an interlayer insulating material according to any one of claims 1 to 8.

10. A cured product of the resin composition for interlayer insulation according to any one of claims 1 to 8.

11. A circuit board comprising a cured product of the resin composition for interlayer insulation according to any one of claims 1 to 8.

12. A semiconductor device comprising the circuit board according to claim 11.

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