Resin composition

Abstract

To provide a resin composition or the like capable of giving a cured product having a low dielectric loss tangent and excellent crack resistance.SOLUTION: The resin composition contains: (A) a styrene resin having a structural unit represented by the following formula (A-1) and a structural unit represented by the following formula (A-2); (B) a thermosetting resin; and (C) an inorganic filler.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a resin composition, and further to a resin sheet, a printed wiring board, and a semiconductor device obtained using the resin composition. [Background technology]

[0002] 2. Description of the Related Art A known manufacturing technique for printed wiring boards is a build-up method in which insulating layers and conductor layers are alternately stacked.

[0003] As an insulating material for a printed wiring board used in such an insulating layer, for example, Patent Document 1 discloses a resin composition. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2023-131714 Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, as printed wiring boards have become more highly functional, insulating layers of printed wiring boards are required to have a low dielectric loss tangent and excellent crack resistance.

[0006] The present invention has been devised in view of the above-mentioned problems, and aims to provide a resin composition that can give a cured product having a low dielectric tangent and excellent crack resistance; a resin sheet containing the resin composition; and a printed wiring board and a semiconductor device that have an insulating layer formed using the resin composition. [Means for solving the problem]

[0007] As a result of intensive research into the above-mentioned problems, the present inventors have found that the above-mentioned problems can be solved by incorporating a styrene resin having a specific structural unit, a thermosetting resin, and an inorganic filler in combination, and have thus completed the present invention.

[0008] That is, the present invention includes the following. [1] (A) a styrene resin having a structural unit represented by the following formula (A-1) and a structural unit represented by the following formula (A-2): (B) a thermosetting resin, and (C) A resin composition containing an inorganic filler. [ka] In formula (A-2), R 1 represents an aryl group having 6 to 20 carbon atoms which may have a substituent. * represents a bond. [2] The resin composition according to [1], wherein the component (A) has a structural unit represented by the following formula (A-1), a structural unit represented by the following formula (A-2), and a structural unit represented by the following formula (A-3): [ka] In formula (A-2), R 1 represents an aryl group having 6 to 20 carbon atoms which may have a substituent. In formula (A-3), R 2 represents an alkyl group having 2 to 15 carbon atoms which may have a substituent, or an alkoxy group having 2 to 15 carbon atoms which may have a substituent. * represents a bond. [3] R in formula (A-3) 2 The resin composition according to [2], wherein the bonding position of is the para position. [4] The resin composition according to any one of [1] to [3], wherein the number average molecular weight of component (A) is 15,000 or less. [5] The resin composition according to any one of [1] to [4], wherein the component (B) contains an active ester resin. [6] The resin composition according to any one of [1] to [5], wherein the component (B) contains a phenolic resin. [7] The resin composition according to any one of [1] to [6], wherein the component (B) contains a radical polymerizable resin. [8] The resin composition according to [7], wherein the radical polymerizable resin contains a maleimide resin. [9] A resin sheet comprising a support and a resin composition layer provided on the support, the resin composition layer comprising the resin composition according to any one of [1] to [8].

[10] A printed wiring board comprising an insulating layer formed from a cured product of the resin composition according to any one of [1] to [8].

[11] A semiconductor device comprising the printed wiring board according to

[10] . [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a resin composition that can give a cured product having a low dielectric tangent and excellent crack resistance; a resin sheet that includes the resin composition; a printed wiring board that includes an insulating layer formed using the resin composition; and a semiconductor device. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present invention will be described in detail below with reference to preferred embodiments thereof. However, the present invention is not limited to the following embodiments and examples, and can be implemented with any modifications within the scope of the claims of the present invention and their equivalents.

[0011] [Resin composition] The resin composition of the present invention contains (A) a styrene resin having a structural unit represented by formula (A-1) and a structural unit represented by formula (A-2) (hereinafter, sometimes referred to as "(A) styrene resin"), (B) a thermosetting resin, and (C) an inorganic filler. In the present invention, by incorporating the components (A), (B), and (C) in combination, a cured product having a low dielectric tangent and excellent crack resistance can be obtained. In addition, a cured product having a low coefficient of linear thermal expansion (CTE) and elastic modulus can usually be obtained.

[0012] The resin composition may further contain optional components in addition to the components (A) to (C). Examples of optional components include (D) epoxy resin, (E) high-molecular-weight component, (F) curing accelerator, (G) radical polymerization initiator, (H) organic filler, (I) other additives, and (J) solvent. Each component contained in the resin composition will be described in detail below.

[0013] <(A) Styrene resin> The resin composition contains, as component (A), a styrene resin having a structural unit represented by formula (A-1) and a structural unit represented by formula (A-2). By including component (A) in the resin composition, it is possible to obtain a cured product having a low dielectric loss tangent, a low coefficient of linear thermal expansion, and a low modulus of elasticity, and excellent crack resistance. One type of component (A) may be used alone, or two or more types may be used in combination. [ka] In formula (A-2), R 1 represents an aryl group having 6 to 20 carbon atoms which may have a substituent. * represents a bond.

[0014] The structural unit represented by formula (A-2) has an active ester moiety (-C(=O)OR 1 When the resin composition is heated to form the insulating layer, the active ester moieties undergo a crosslinking reaction with other components in the resin composition, increasing the crosslink density of the cured product of the resin composition. As a result, it is believed that it is possible to obtain a cured product that has a low dielectric loss tangent, coefficient of linear thermal expansion, and modulus of elasticity, and excellent crack resistance.

[0015] R 1 The aryl group having 6 to 20 carbon atoms represented by is preferably an aryl group having 6 to 15 carbon atoms, more preferably an aryl group having 6 to 10 carbon atoms. Examples of the aryl group include a phenyl group, a naphthyl group, and an anthracenyl group, and a phenyl group is preferred.

[0016] R 1The aryl group having 6 to 20 carbon atoms represented by may have a substituent. Examples of the substituent include, for example, a halogen atom, -OH, -O-C 1-6 alkyl group, -N(C 1-10 alkyl group)2, C 1-20 alkyl group, C 2-30 alkenyl group, C 2-30 alkynyl group, C 6-10 aryl group, C 1-7 heteroaryl group, cyano group, -NH2, -CN, -C(O)O-C 1-10 alkyl group, -COOH, -C(O)H, -NO2 and the like. Here, the term "C p-q "(p and q are positive integers and p < q is satisfied.) represents that the number of carbon atoms of the organic group described immediately after this term is p to q. For example, the expression "C 1-10 alkyl group" represents an alkyl group having 1 to 10 carbon atoms. These substituents may be bonded to each other to form a ring, and the ring structure includes a spiro ring and a condensed ring.

[0017] Specific examples of the structural unit represented by formula (A-2) include the structural unit represented by formula (A-2-1), but the present invention is not limited thereto. In the formula, * represents a bond.

Chemical formula

[0018] (A) As the styrene resin, it is preferable to use a resin having a structural unit represented by the following formula (A-1), a structural unit represented by the following formula (A-2), and a structural unit represented by the following formula (A-3).

Chemical formula

[0019] R in formula (A-2) 1 represents an aryl group having 6 to 20 carbon atoms which may have a substituent, as defined above.

[0020] R 2 The alkyl group having 2 to 15 carbon atoms represented by R is preferably an alkyl group having 3 to 15 carbon atoms, more preferably an alkyl group having 3 to 10 carbon atoms, and even more preferably an alkyl group having 3 to 6 carbon atoms. 2 The alkyl group having 2 to 15 carbon atoms represented by may be linear, branched, or cyclic, but from the viewpoint of achieving the effects of the present invention remarkably, a bulky alkyl group is preferred. 2 The alkyl group having 2 to 15 carbon atoms represented by is preferably either branched or cyclic. When the alkyl group is branched, it is preferable that the alkyl group branches off from the carbon atom directly bonded to the benzene ring in formula (A-3), and when the alkyl group is cyclic, it is preferable that the carbon atom directly bonded to the benzene ring in formula (A-3) is the carbon atom constituting the ring. Examples of the alkyl group include an ethyl group, a propyl group, an isopropyl group, a 2-methylpropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, an isopentyl group, a sec-pentyl group, a neopentyl group, a tert-pentyl group, a hexyl group, an isohexyl group, a heptyl group, an isoheptyl group, an octyl group, an isooctyl group, a tert-octyl group, a cyclopentyl group, a cyclohexyl group, and a cyclohexylmethyl group. Of these, an isopropyl group, a tert-butyl group, and a cyclohexyl group are preferred, and a tert-butyl group and a cyclohexyl group are more preferred.

[0021] R 2 The alkoxy group having 2 to 15 carbon atoms represented by R is preferably an alkoxy group having 3 to 15 carbon atoms, more preferably an alkoxy group having 3 to 10 carbon atoms, and even more preferably an alkoxy group having 3 to 6 carbon atoms. 2The alkoxy group having 2 to 15 carbon atoms represented by may be linear, branched, or cyclic, but from the viewpoint of significantly achieving the effects of the present invention, a bulky alkoxy group is preferred. 2 The alkoxy group having 2 to 15 carbon atoms represented by is preferably either branched or cyclic. When the alkoxy group is branched, it is preferable that the alkoxy group is branched from the carbon atom directly bonded to the benzene ring in formula (A-3), and when the alkoxy group is cyclic, it is preferable that the carbon atom directly bonded to the benzene ring in formula (A-3) is the carbon atom constituting the ring. Therefore, R 2 The alkoxy group having 2 to 15 carbon atoms represented by is preferably either branched or cyclic. Examples of the alkoxy group include an ethoxy group, a propyloxy group, an isopropyloxy group, a 2-methylpropyloxy group, a butyloxy group, an isobutyloxy group, a sec-butyloxy group, a tert-butyloxy group, a pentyloxy group, an isopentyloxy group, a sec-pentyloxy group, a neopentyloxy group, a tert-pentyloxy group, a hexyloxy group, an isohexyloxy group, a heptyloxy group, an isoheptyloxy group, an octyloxy group, an isooctyloxy group, a tert-octyloxy group, a cyclopentyloxy group, a cyclohexyloxy group, and a cyclohexylmethyloxy group. Among these, an isopropyloxy group, a tert-butyloxy group, and a cyclohexyloxy group are preferred, and a tert-butyloxy group and a cyclohexyloxy group are more preferred.

[0022] R 2 an alkyl group having 2 to 15 carbon atoms represented by the formula 2 The alkoxy group having 2 to 15 carbon atoms represented by may have a substituent. Examples of the substituent include R 1 These are the same as the substituents that may be possessed by the aryl group having 6 to 20 carbon atoms represented by the formula:

[0023] R in formula (A-3) 2The bonding position of may be any of the ortho, meta, and para positions, but is preferably the para position from the viewpoint of achieving the remarkable effects of the present invention.

[0024] Specific examples of the structural unit represented by formula (A-3) include structural units represented by formulas (A-3-1) and (A-3-2), but the present invention is not limited thereto. In the formula, * represents a bond. [ka]

[0025] When the number of moles of the structural units represented by formula (A-1) relative to all molecules of the component (A) is x, the number of moles of the structural units represented by formula (A-2) is z, and the number of moles of the structural units represented by formula (A-3) is y, it is preferable that either the relationship x>y+z ​​or the relationship x>y≧z is satisfied, and it is preferable that both the relationships x>y+z ​​and x>y≧z are satisfied.

[0026] x / z is preferably 3 or more, more preferably 5 or more, even more preferably 8 or more, and is preferably 45 or less, more preferably 40 or less, even more preferably 35 or less.

[0027] x / y is preferably 1 or more, more preferably 2 or more, and even more preferably 3 or more, and is preferably 15 or less, more preferably 10 or less, and even more preferably 8 or less.

[0028] y / z is preferably 1 or more, more preferably 1.5 or more, even more preferably 2 or more, and is preferably 5 or less, more preferably 3 or less, even more preferably 2.5 or less.

[0029] Furthermore, x / (y+z) is preferably 1 or more, more preferably 2 or more, and even more preferably 3 or more, and is preferably 15 or less, more preferably 10 or less, and even more preferably 8 or less.

[0030] When there are a plurality of structural units represented by formula (A-1), the structural units represented by formula (A-1) may be linked to each other as repeating units, or may not be linked to each other. When the structural units represented by formula (A-1) are not linked to each other, a structural unit represented by formula (A-2), a structural unit represented by formula (A-3), or another structural unit may be interposed between them.

[0031] The amount (mol%) of the structural unit represented by formula (A-1) relative to 100 mol% of all molecules of component (A) is preferably 50 mol% or more, more preferably 60 mol% or more, even more preferably 70 mol% or more, and is preferably 90 mol% or less, more preferably 80 mol% or less, even more preferably 70 mol% or less.

[0032] When there are a plurality of structural units represented by formula (A-2), the structural units represented by formula (A-2) may be linked to each other as repeating units, or may not be linked to each other. When they are not linked to each other, the structural units represented by formula (A-2) may be interposed between them by a structural unit represented by formula (A-1), a structural unit represented by formula (A-3), or another structural unit. When there are a plurality of structural units represented by formula (A-2), R in formula (A-2) 1 may be the same or different.

[0033] The content of the structural unit represented by formula (A-2) in component (A), when component (A) is taken as 100% by mass, is preferably 1% by mass or more, more preferably 1.5% by mass or more, and even more preferably 2% by mass or more, and is preferably 30% by mass or less, more preferably 20% by mass or less, and even more preferably 15% by mass or less, 10% by mass or less, or 8% by mass or less. The content of the structural unit represented by formula (A-2) can be determined from the charging ratio of raw materials when synthesizing the styrene resin (A).

[0034] The amount (mol%) of the structural unit represented by formula (A-2) relative to 100 mol% of all molecules of component (A) is preferably 1 mol% or more, more preferably 2 mol% or more, even more preferably 2.5 mol% or more, and is preferably 15 mol% or less, more preferably 10 mol% or less, even more preferably 8 mol% or less.

[0035] When there are a plurality of structural units represented by formula (A-3), the structural units represented by formula (A-3) may be linked to each other as repeating units, or may not be linked to each other. When they are not linked to each other, the structural units represented by formula (A-3) may be interposed between them by a structural unit represented by formula (A-1), a structural unit represented by formula (A-2), or another structural unit. When there are a plurality of structural units represented by formula (A-3), R in formula (A-3) 2 may be the same or different.

[0036] The content of the structural unit represented by formula (A-3) in component (A), when component (A) is taken as 100% by mass, is preferably 1% by mass or more, more preferably 5% by mass or more, even more preferably 10% by mass or more, and is preferably 25% by mass or less, more preferably 0% by mass or less, even more preferably 18% by mass or less, or 15% by mass or less. The content of the structural unit represented by formula (A-3) can be determined from the charging ratio of raw materials when synthesizing (A) styrene resin.

[0037] The amount (mol%) of the structural unit represented by formula (A-3) relative to 100 mol% of all molecules of component (A) is preferably 5 mol% or more, more preferably 8 mol% or more, even more preferably 10 mol% or more, and is preferably 30 mol% or less, more preferably 25 mol% or less, even more preferably 20 mol% or less.

[0038] Component (A) preferably has at least the structural unit represented by formula (A-1) and the structural unit represented by formula (A-2), more preferably the structural unit represented by formula (A-1), the structural unit represented by formula (A-2), and the structural unit represented by formula (A-3), and more preferably the structural unit represented by formula (A-1), the structural unit represented by formula (A-2), and the structural unit represented by formula (A-3). Component (A) may be a random copolymer, block copolymer, graft copolymer, or alternating copolymer having the structural unit represented by formula (A-1), the structural unit represented by formula (A-2), and the structural unit represented by formula (A-3).

[0039] Examples of the terminal structure of component (A) include an alkyl group in which a hydrogen atom is added to any of the structural units represented by formula (A-1), (A-2), and (A-3), a hydroxy group in which a hydroxyl group is added, or an alkoxy group in which an alcohol used during reprecipitation is added.

[0040] The component (A) may have a structural unit represented by the following formula (A-4). [ka] In formula (A-4), R 11 each independently represents an aryl group having 6 to 20 carbon atoms which may have a substituent, R 12 each independently represents an alkyl group having 2 to 15 carbon atoms which may have a substituent, or an alkoxy group having 2 to 15 carbon atoms which may have a substituent. x, y, and z each independently represent an integer of 1 to 50, and * represents a bond.

[0041] R in formula (A-4) 11 The optionally substituted aryl group having 6 to 20 carbon atoms represented by R 1 is the same as the optionally substituted aryl group having 6 to 20 carbon atoms represented by the following formula:

[0042] R in formula (A-4) 12 The alkyl group having 2 to 15 carbon atoms and the alkoxy group having 2 to 15 carbon atoms represented by R in formula (A-3) 2 is the same as the alkyl group having 2 to 15 carbon atoms and the alkoxy group having 2 to 15 carbon atoms represented by R.

[0043] In formula (A-4), x, y and z each independently represent an integer of 1 to 50. It is preferable that y + z < x. It is preferable that x represents an integer of 1 to 50, more preferably represents an integer of 1 to 40, still more preferably represents an integer of 1 to 40, and still more preferably represents 1 to 30, an integer of 1 to 30, 1 to 25, or an integer of 1 to 25. It is preferable that y represents 1 to 10, more preferably represents an integer of 1 to 10, still more preferably represents 1 to 6, an integer of 1 to 6, 1 to 3, or an integer of 1 to 3. It is preferable that z represents 1 to 10, more preferably represents an integer of 1 to 10, still more preferably represents 1 to 6, an integer of 1 to 6, 1 to 3, or an integer of 1 to 3. x, y and z can be determined from the charging ratio of raw materials in synthesizing the (A) styrene resin.

[0044] (A) The styrene resin may have other structural units as long as the effects of the present invention are not inhibited, in addition to the structural unit represented by formula (A-1), the structural unit represented by the following formula (A-2), and the structural unit represented by formula (A-3).

[0045] Specific examples of the component (A) include compounds represented by (A1) to (A2), but the present invention is not limited thereto. * represents a bond.

Chemical formula

[0046] There are no particular limitations on the synthesis method for the (A) styrene resin. For example, component (A) can be synthesized by polymerizing styrene with an alkylstyrene or alkoxystyrene and an aryl acrylate, or by polymerizing an alkyl acrylate, followed by appropriate transesterification. The temperature condition is preferably 30 to 120°C, more preferably 50 to 100°C. The reaction time is preferably 1 hour to 7 days, more preferably 3 to 12 hours. If necessary, polymerization may be carried out using a polymerization initiator such as 2,2'-azodiisobutyronitrile and a solvent that does not inhibit the reaction, such as tetrahydrofuran or toluene.

[0047] The active ester group equivalent of the (A) styrene resin is preferably 1000 g / eq. or more, more preferably 1200 g / eq. or more, even more preferably 1500 g / eq. or more, and is preferably 6000 g / eq. or less, more preferably 5000 g / eq. or less, even more preferably 4000 g / eq. or less. The active ester group equivalent represents the mass of the resin per equivalent of the active ester group.

[0048] The number average molecular weight of the (A) styrene resin is preferably 15,000 or less, more preferably 13,000 or less, and even more preferably 10,000 or less, and is preferably 1,000 or more, more preferably 3,000 or more, and even more preferably 5,000 or more. The number average molecular weight can be measured as a polystyrene-equivalent value by gel permeation chromatography (GPC).

[0049] The weight average molecular weight of the (A) styrene resin is preferably 15,000 or less, more preferably 13,000 or less, and even more preferably 10,000 or less, and is preferably 1,000 or more, more preferably 3,000 or more, and even more preferably 5,000 or more. The weight average molecular weight can be measured as a polystyrene-equivalent value by gel permeation chromatography (GPC).

[0050] The content of component (A), when the nonvolatile components in the resin composition are taken as 100% by mass, is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, even more preferably 1% by mass or more, 2% by mass or more, or 3% by mass or more, and is preferably 10% by mass or less, more preferably 8% by mass or less, and even more preferably 5% by mass or less.

[0051] The content of component (A), when the resin component in the resin composition is taken as 100% by mass, is preferably 1% by mass or more, more preferably 3% by mass or more, even more preferably 5% by mass or more, or 10% by mass or more, and is preferably 30% by mass or less, more preferably 25% by mass or less, even more preferably 20% by mass or less, or 15% by mass or less.

[0052] In the present invention, unless otherwise specified, the content of each component in the resin composition is a value when the nonvolatile components in the resin composition are 100 mass %, and the nonvolatile components refer to all nonvolatile components in the resin composition excluding the solvent. In addition, in the present invention, the resin components in the resin composition refer to the nonvolatile components of the resin composition excluding the inorganic filler (C).

[0053] <(B) Thermosetting resin> The resin composition contains a (B) thermosetting resin as component (B). This (B) thermosetting resin as component (B) excludes those that fall under component (A). The type of (B) thermosetting resin is not particularly limited as long as it can be cured by heat. One type of (B) thermosetting resin may be used alone, or two or more types may be used in combination.

[0054] (B) Examples of thermosetting resins include radical polymerizable resins, active ester resins, phenolic resins, carbodiimide resins, cyanate resins, acid anhydride resins, amine resins, benzoxazine resins, and thiol resins. Hereinafter, active ester resins, phenolic resins, cyanate resins, carbodiimide resins, acid anhydride resins, amine resins, benzoxazine resins, and thiol resins may be collectively referred to as "curing agents."

[0055] The (B) thermosetting resin preferably contains a curing agent, more preferably contains any one of an active ester resin, a phenol resin, and a carbodiimide resin, even more preferably contains any one of an active ester resin and a phenol resin, even more preferably contains an active ester resin and a phenol resin, and particularly preferably contains an active ester resin.

[0056] The radical polymerizable resin as component (B) is not particularly limited in type, as long as it has one or more (preferably two or more) radical polymerizable unsaturated groups in one molecule. Examples of the radical polymerizable resin include resins having one or more radical polymerizable unsaturated groups selected from maleimide, vinyl, allyl, styryl, vinylphenyl, acryloyl, methacryloyl, fumaroyl, and maleoyl groups. Among these, the radical polymerizable resin is preferably a maleimide resin, a (meth)acrylic resin, or a vinyl resin, with a maleimide resin being more preferred.

[0057] The type of maleimide resin is not particularly limited as long as it has one or more (preferably two or more) maleimide groups (2,5-dihydro-2,5-dioxo-1H-pyrrol-1-yl groups) in one molecule. Examples of maleimide resins include: (1) maleimide resins containing an aliphatic skeleton (preferably an aliphatic skeleton having 36 carbon atoms derived from dimer diamine), such as "BMI-3000J," "BMI-5000," "BMI-1400," "BMI-1500," "BMI-1700," and "BMI-689" (all manufactured by Designer Molecules Inc.), and "SLK6895-T90" (manufactured by Shin-Etsu Chemical Co., Ltd.); (2) maleimide resins containing an indane skeleton, as described in the Japan Institute of Invention and Innovation's Technical Journal Disclosure No. 2020-500211; and (3) maleimide resins containing an aromatic ring skeleton directly bonded to the nitrogen atom of the maleimide group, such as "MIR-3000-70MT" (manufactured by Nippon Kayaku Co., Ltd.), "BMI-4000" (manufactured by Daiwa Kasei Co., Ltd.), and "BMI-80" (manufactured by Keiai Kasei Co., Ltd.).

[0058] The (meth)acrylic resin may be a monomer or an oligomer, and may be any type, as long as it has one or more (preferably two or more) (meth)acryloyl groups in one molecule. Here, the term "(meth)acryloyl group" is a general term for acryloyl groups and methacryloyl groups. Examples of methacrylic resins include (meth)acrylate monomers, as well as (meth)acrylic resins such as "A-DOG" (manufactured by Shin-Nakamura Chemical Co., Ltd.), "DCP-A" (manufactured by Kyoeisha Chemical Co., Ltd.), "NPDGA," "FM-400," "R-687," "THE-330," "PET-30," "SA9000" (manufactured by SABIC), and "DPHA" (all manufactured by Nippon Kayaku Co., Ltd.).

[0059] The vinyl resin is, for example, a compound having one or more, preferably two or more, vinyl groups directly bonded to an aromatic carbon atom. Examples of the vinyl resin include low-molecular-weight (molecular-weight less than 1000) styrene 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 resins such as vinylbenzyl-modified polyphenylene ether resins and styrene-divinylbenzene copolymers. Commercially available styrene 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., "OPE-2St 1200" and "OPE-2St 2200" (vinylbenzyl-modified polyphenylene ether resins) manufactured by Mitsubishi Gas Chemical Company, Inc., "G-100C" (polystyrene resin with a weight-average molecular weight of 402,000) manufactured by Toyo Styrene Co., Ltd., and "SX-100" (polystyrene resin with a weight-average molecular weight of 2,000) manufactured by Yasuhara Chemical Co., Ltd. Vinyl resins serving as radically polymerizable resins are excluded from the category of component (A).

[0060] The content of the radical polymerizable resin as the (B) thermosetting resin is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, even more preferably 1% by mass or more, 2% by mass or more, 3% by mass or more, or 5% by mass or more, and is preferably 30% by mass or less, more preferably 25% by mass or less, even more preferably 20% by mass or less, 15% by mass or less, 10% by mass or less, or 8% by mass or less, based on 100% by mass of the non-volatile components in the resin composition.

[0061] The content of the radical polymerizable resin as the (B) thermosetting resin is, when the resin component in the resin composition is taken as 100% by mass, preferably 1% by mass or more, more preferably 3% by mass or more, even more preferably 5% by mass or more, 10% by mass or more, 20% by mass or more, 30% by mass or more, or 50% by mass or more, and is preferably 80% by mass or less, more preferably 75% by mass or less, even more preferably 70% by mass or less, 60% by mass or less, 30% by mass or less, or 10% by mass or less.

[0062] As the active ester resin, compounds having two or more highly reactive ester groups per molecule, such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds, are generally preferred. Active ester resins are sometimes referred to as "active ester curing agents" because they can react with epoxy resins to cure the resin composition when combined with them. The active ester resin is preferably one obtained by the condensation reaction of a carboxylic acid compound and / or a thiocarboxylic acid compound with a hydroxy compound and / or a thiol compound. In particular, from the viewpoint of improving resistance to high-temperature reflow blistering, active ester resins obtained from a carboxylic acid compound and a hydroxy compound are preferred, and active ester resins obtained from a carboxylic acid compound and a phenol compound and / or a naphthol compound are more preferred. Examples of carboxylic acid compounds 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.

[0063] 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, at least one selected from a dicyclopentadiene-type active ester resin and a naphthalene-type active ester resin is more preferred. As the dicyclopentadiene-type active ester resin, an active ester resin containing a dicyclopentadiene-type diphenol structure is preferred.

[0064] Commercially available active ester resins include, for example, activated ester resins containing a dicyclopentadiene-type diphenol structure such as "EXB9451", "EXB9460", "EXB9460S", "EXB-8000L", "EXB-8000L-65M", "EXB-8000L-65TM", "HPC-8000L-65TM", "HPC-8000L-65T", "HPC-8000", "HPC-8000-65T", "HPC-8000H", and "HPC-8000H-65TM" (manufactured by DIC Corporation); activated ester resins containing a naphthalene structure such as "HP-B-8151-62T", "EXB-8100L-65T", and "EXB-8150-60T"; Examples of such active ester resins include "EXB-8150-62T," "EXB-9416-70BK," "HPC-8150-60T," "HPC-8150-62T," and "EXB-8" (manufactured by DIC Corporation); "EXB9401" (manufactured by DIC Corporation) as a phosphorus-containing active ester resin; "DC808" (manufactured by Mitsubishi Chemical Corporation) as an active ester resin which is an acetylated product of phenol novolac; "YLH1026," "YLH1030," and "YLH1048" (manufactured by Mitsubishi Chemical Corporation) as active ester resins which are benzoylated products of phenol novolac; and "PC1300-02-65MA" (manufactured by Air Water Inc.) as an active ester resin containing a styryl group and a naphthalene structure.

[0065] The phenolic resin may be a compound having one or more, preferably two or more, hydroxyl groups bonded to an aromatic ring such as a benzene ring or a naphthalene ring per molecule. When combined with an epoxy resin, the phenolic resin may react with the epoxy resin to cure the resin composition, and is therefore sometimes referred to as a "phenolic curing agent." From the viewpoint of achieving the remarkable effects of the present invention, the phenolic resin is preferably a phenolic resin having a novolac structure. Furthermore, from the viewpoint of adhesion, nitrogen-containing phenolic resins are preferred, and triazine skeleton-containing phenolic resins are more preferred. Of these, triazine skeleton-containing phenolic novolac resins are preferred from the viewpoint of achieving the remarkable effects of the present invention. Specific examples of phenolic resins include "MEH-7700," "MEH-7810," and "MEH-7851" manufactured by Meiwa Chemical Industry Co., Ltd.; "NHN," "CBN," and "GPH" manufactured by Nippon Kayaku Co., Ltd.; "SN-170," "SN-180," "SN-190," "SN-475," "SN-485," "SN-495," "SN-375," and "SN-395" manufactured by Nippon Steel Chemical & Material Co., Ltd.; and "LA-7052," "LA-7054," "LA-3018," "LA-3018-50P," "LA-1356," "TD2090," "TD-2090-60M," and "KA-1163" manufactured by DIC Corporation.

[0066] The carbodiimide resin may be a compound having one or more, preferably two or more, carbodiimide structures in one molecule and having no radical polymerizable group. When combined with an epoxy resin, the carbodiimide resin reacts with the epoxy resin to cure the resin composition, and is therefore sometimes called a "carbodiimide curing agent."

[0067] Specific examples of carbodiimide resins 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].

[0068] Commercially available carbodiimide resins include, for example, "Carbodilite V-02B," "Carbodilite V-03," "Carbodilite V-04K," "Carbodilite V-07," and "Carbodilite V-09" manufactured by Nisshinbo Chemical Inc.; and "Stavaxol P," "Stavaxol P100," "Stavaxol P400," and "Hykasil 510" manufactured by Lanxess AG.

[0069] The cyanate resin may be a compound having one or more, preferably two or more, cyanate groups in one molecule. When combined with an epoxy resin, the cyanate resin reacts with the epoxy resin to cure the resin composition, and therefore is sometimes called a "cyanate-based curing agent." 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 and cresol novolac; and prepolymers in which these cyanate resins are partially converted to triazine. Specific examples of cyanate resins include "PT30" and "PT60" manufactured by Lonza (both of which are phenol novolac-type multifunctional cyanate resins), "BA230" and "BA230S75" (prepolymers in which part or all of bisphenol A dicyanate has been triazine-converted to form a trimer).

[0070] As the acid anhydride resin, a compound having one or more, preferably two or more, acid anhydride groups in one molecule can be used. When combined with an epoxy group, the acid anhydride resin can react with the epoxy resin to cure the resin composition, and therefore is sometimes called an "acid anhydride curing agent." Specific examples of acid anhydride resins 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 anhydride. Examples of suitable anhydrides include hydrates, 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 resin, which is a copolymer 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" and "HN-5500" manufactured by Resonac Corporation; and "EF-30," "EF-40," "EF-60," and "EF-80" manufactured by Cray Valley Chemical Industries, Ltd.

[0071] The amine resin may be a compound having one or more, preferably two or more, amino groups in one molecule. When combined with an epoxy group, the amine resin may react with the epoxy resin to cure the resin composition, and is therefore sometimes referred to as an "amine-based curing agent." 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 amine resins 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)propionate. 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 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.

[0072] Benzoxazine resins, when combined with epoxy resins, can react with the epoxy resin to cure the resin composition, and are therefore sometimes called "benzoxazine-based curing agents." Specific examples of benzoxazine resins include "JBZ-OP100D" and "ODA-BOZ" manufactured by JFE Chemical Corporation; "HFB2006M" manufactured by Showa Polymer Co., Ltd.; and "Pd" and "Fa" manufactured by Shikoku Chemical Industry Co., Ltd.

[0073] Thiol resins are sometimes called "thiol-based curing agents" because they react with epoxy resins when combined with them to cure the resin composition. Examples of thiol resins include trimethylolpropane tris(3-mercaptopropionate), pentaerythritol tetrakis(3-mercaptobutyrate), and tris(3-mercaptopropyl)isocyanurate.

[0074] The active group equivalent of the curing agent is preferably 50 g / eq. to 3000 g / eq., more preferably 100 g / eq. to 1000 g / eq., still more preferably 100 g / eq. to 500 g / eq., and particularly preferably 100 g / eq. to 300 g / eq. The active group equivalent is the mass of the curing agent per equivalent of the active group.

[0075] The weight average molecular weight (Mw) of the curing agent is preferably 100 to 5,000, more preferably 250 to 3,000, and even more preferably 400 to 1,500. The weight average molecular weight of the resin can be measured by gel permeation chromatography (GPC) as a polystyrene-equivalent value.

[0076] When the number of epoxy groups in the (D) epoxy resin described below is taken as 1, the number of active groups in the curing agent is preferably 0.01 or more, more preferably 0.05 or more, even more preferably 0.1 or more, and preferably 5 or less, more preferably 3 or less, and particularly preferably 2 or less. The "number of epoxy groups in the epoxy resin" refers to the total value obtained by dividing the mass of the non-volatile components of the epoxy resin present in the resin composition by the epoxy equivalent. Furthermore, the "number of active groups in the curing agent" refers to the total value obtained by dividing the mass of the non-volatile components of the curing agent present in the resin composition by the active group equivalent.

[0077] The content of the curing agent as the (B) thermosetting resin is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, even more preferably 1% by mass or more, 3% by mass or more, or 5% by mass or more, and is preferably 30% by mass or less, more preferably 25% by mass or less, even more preferably 20% by mass or less, or 15% by mass or less, based on 100% by mass of the non-volatile components in the resin composition.

[0078] The content of the curing agent as (B) thermosetting resin is preferably 1% by mass or more, more preferably 10% by mass or more, even more preferably 20% by mass or more, 30% by mass or more, or 35% by mass or more, and is preferably 70% by mass or less, more preferably 65% ​​by mass or less, even more preferably 60% by mass or less, or 55% by mass or less, when the resin component in the resin composition is taken as 100% by mass.

[0079] The content of the active ester resin is preferably 0.1% by mass or more, more preferably 1% by mass or more, even more preferably 5% by mass or more, or 8% by mass or more, and is preferably 30% by mass or less, more preferably 25% by mass or less, even more preferably 20% by mass or less, or 15% by mass or less, when the non-volatile components in the resin composition are taken as 100% by mass.

[0080] When the resin component in the resin composition is taken as 100% by mass, the content of the active ester resin is preferably 1% by mass or more, more preferably 10% by mass or more, even more preferably 20% by mass or more, 30% by mass or more, or 35% by mass or more, and is preferably 70% by mass or less, more preferably 65% ​​by mass or less, even more preferably 60% by mass or less, or 58% by mass or less.

[0081] The content of the phenolic resin is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, and even more preferably 0.5% by mass or more, and is preferably 10% by mass or less, more preferably 8% by mass or less, and even more preferably 5% by mass or less, or 3% by mass or less, when the non-volatile components in the resin composition are taken as 100% by mass.

[0082] The content of the phenolic resin is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, even more preferably 0.5% by mass or more, 1% by mass or more, or 2% by mass or more, and is preferably 10% by mass or less, more preferably 8% by mass or less, and even more preferably 5% by mass or less, when the resin component in the resin composition is 100% by mass.

[0083] The content of the (B) thermosetting resin is preferably 8% by mass or more, more preferably 10% by mass or more, and even more preferably 13% by mass or more, and is preferably 35% by mass or less, more preferably 30% by mass or less, and even more preferably 25% by mass or less, assuming that the non-volatile components in the resin composition are 100% by mass.

[0084] The content of the (B) thermosetting resin is preferably 1% by mass or more, more preferably 2% by mass or more, and even more preferably 3% by mass or more, and is preferably 70% by mass or less, more preferably 65% ​​by mass or less, and even more preferably 60% by mass or less, or 55% by mass or less, when the resin component in the resin composition is 100% by mass.

[0085] <(C) Inorganic filler> The resin composition contains an inorganic filler (C) as component (C). By including the inorganic filler (C) in the resin composition, a cured product having a low dielectric loss tangent and a low linear thermal expansion coefficient can be obtained. The inorganic filler (C) is usually contained in the resin composition in the form of particles. The component (C) may be used alone or in combination of two or more.

[0086] (C) Inorganic fillers are inorganic compounds. Examples of (C) 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 is particularly preferred. Examples of silica include amorphous silica, fused silica, crystalline silica, synthetic silica, and hollow silica. Spherical silica is preferred.

[0087] (C) 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-03," and "FB-105FD" manufactured by Denka Company, Limited; "Silfil NSS-3N," "Silfil NSS-4N," and "Silfil NSS-5N" manufactured by Tokuyama Corporation; and "CellSpheres MGH-005" manufactured by Taiheiyo Cement Corporation.

[0088] The average particle size of the (C) inorganic filler is preferably 0.01 μm or more, more preferably 0.1 μm or more, even more preferably 0.3 μm or more, 0.4 μm or more, or 0.5 μm or more, and is preferably 10 μm or less, more preferably 5 μm or less, and even more preferably 3 μm or less.

[0089] (C) 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 light source wavelengths 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.

[0090] (C) The BET specific surface area of ​​the inorganic filler is preferably 0.1 m 2 / g or more, more preferably 0.5m 2 / g or more, more preferably 1m 2 / g or more, preferably 100m 2 / g or less, more preferably 70m 2 / g or less, more preferably 40m 2 / g or less.

[0091] (C) The specific surface area of ​​the inorganic filler can be measured according to the BET method by adsorbing nitrogen gas onto the sample surface 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.

[0092] The (C) 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 any combination.

[0093] 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).

[0094] 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.

[0095] 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:

[0096] (C) 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. An "EMIA-320V" manufactured by Horiba, Ltd., or the like can be used as the carbon analyzer.

[0097] The degree of surface treatment with a surface treatment agent can be evaluated by the amount of carbon per unit mass of the inorganic filler. The amount of carbon per unit mass of the inorganic filler is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and even more preferably 0.1% by mass or more, and is preferably 1.0% by mass or less, more preferably 0.8% by mass or less, and even more preferably 0.5% by mass or less. The amount of carbon per unit mass of (C) inorganic filler can be measured using a carbon analyzer, just like the amount of carbon per unit surface area of ​​(C) inorganic filler.

[0098] The content of (C) inorganic filler is preferably 50% by mass or more, more preferably 55% by mass or more, even more preferably 60% by mass or more, 65% by mass or more, or 70% by mass or more, and is preferably 90% by mass or less, more preferably 85% by mass or less, and even more preferably 80% by mass or less, assuming that the non-volatile components in the resin composition are 100% by mass.

[0099] <(D) Epoxy resin> The resin composition may contain a (D) epoxy resin as the (D) component. The (D) epoxy resin as the (D) component does not include those corresponding to the (A) to (C) components. By including the (D) epoxy resin in the resin composition, a cured product exhibiting good mechanical strength and insulation reliability can be obtained. One type of (D) epoxy resin may be used alone, or two or more types may be used in combination.

[0100] (D) Epoxy resins include, for example, 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 ester type Examples of epoxy resins include epoxy resins, glycidyl cyclohexane-type epoxy resins, alkyl diglycidyl ether-type epoxy resins, cresol novolac-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, and phenolphthalimidine-type epoxy resins.

[0101] The resin composition preferably contains, as component (D), an epoxy resin having two or more epoxy groups per molecule. From the viewpoint of significantly achieving the desired effects of the present invention, the proportion of the epoxy resin having two or more epoxy groups per molecule relative to 100% by mass of the epoxy resin (D) is preferably 50% by mass or more, more preferably 60% by mass or more, and particularly preferably 70% by mass or more.

[0102] 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"). The resin composition may contain, as component (D), only a liquid epoxy resin, only a solid epoxy resin, or a combination of a liquid epoxy resin and a solid epoxy resin. Of these, from the viewpoint of significantly achieving the effects of the present invention, it is preferable to contain a combination of a liquid epoxy resin and a solid epoxy resin.

[0103] The liquid epoxy resin is preferably a liquid epoxy resin having two or more epoxy groups in one molecule.

[0104] Preferred liquid epoxy resins include bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol AF type epoxy resins, naphthalene type epoxy resins, glycidyl ester type epoxy resins, glycidyl amine type epoxy resins, phenol novolac type epoxy resins, alicyclic epoxy resins having an ester skeleton, cyclohexane type epoxy resins, cyclohexane dimethanol type epoxy resins, glycidyl amine type epoxy resins, and epoxy resins having a butadiene structure, glycidyl cyclohexane type epoxy resins, phenolphthalimidine type epoxy resins, and alkyl diglycidyl ether type epoxy resins, and more preferred are bisphenol A type epoxy resins, bisphenol F type epoxy resins, and naphthalene type epoxy resins.

[0105] Specific examples of liquid epoxy resins include "HP4032", "HP4032D", and "HP4032SS" (naphthalene type epoxy resins) manufactured by DIC Corporation; "828US", "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" and "630LSD" (glycidyl amine type epoxy resins) manufactured by Mitsubishi Chemical Corporation; and "ZX1" manufactured by Nippon Steel Chemical & Material Co., Ltd. Examples of epoxy resins that can be used include "EX-721" (a glycidyl ester epoxy resin) manufactured by Nagase ChemteX Corporation, "Celloxide 2021P" (an alicyclic epoxy resin having an ester skeleton) manufactured by Daicel Corporation, "PB-3600" (an epoxy resin having a butadiene structure) manufactured by Daicel Corporation, "ZX1658" and "ZX1658GS" (liquid 1,4-glycidylcyclohexane epoxy resins) manufactured by Nippon Steel Chemical & Material Co., Ltd., and "YED216D" (an alkyl diglycidyl ether epoxy resin) manufactured by Mitsubishi Chemical Corporation. These may be used alone or in combination of two or more.

[0106] As the solid epoxy resin, a solid epoxy resin having two or more epoxy groups in one molecule is preferred, a solid epoxy resin having three or more epoxy groups in one molecule is more preferred, and an aromatic solid epoxy resin having three or more epoxy groups in one molecule is even more preferred.

[0107] Preferred solid epoxy resins include bixylenol-type epoxy resins, naphthalene-type epoxy resins, naphthalene-type tetrafunctional epoxy resins, cresol novolac-type epoxy resins, dicyclopentadiene-type epoxy resins, trisphenol-type epoxy resins, naphthol-type epoxy resins, biphenyl-type epoxy resins, naphthylene ether-type epoxy resins, anthracene-type epoxy resins, bisphenol A-type epoxy resins, bisphenol AF-type epoxy resins, and tetraphenylethane-type epoxy resins, and biphenyl-type epoxy resins are more preferred.

[0108] Specific examples of solid epoxy resins include "HP4032H" (naphthalene type epoxy resin), "HP-4700", "HP-4710" (naphthalene type tetrafunctional epoxy resin), "N-690" (cresol novolac type epoxy resin), "N-695" (cresol novolac type epoxy resin), "HP-7200", "HP-7200HH", "HP-7200H" (dicyclopentadiene type epoxy resin), "EXA-7311", "EXA-7311-G3", "EXA-7311-G4", "EXA-7311-G4S", "HP6000", "HP6000L" (naphthylene ether type epoxy resin), manufactured by DIC Corporation; "EPPN-502H" (trisphenol type epoxy resin), "NC7000L" (naphthol novolac type epoxy resin), "NC3000H", "NC3000", "NC3000L" manufactured by Nippon Kayaku Co., Ltd.; Examples include "NC3100" (biphenyl-type epoxy resin); "ESN475V" (naphthalene-type epoxy resin) and "ESN485" (naphthol novolac-type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "YX4000H", "YL6121" (biphenyl-type epoxy resin), "YX4000HK" (bixylenol-type epoxy resin), and "YX8800" (anthracene-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "PG-100" and "CG-500" manufactured by Osaka Gas Chemical Co., Ltd.; "YL7760" (bisphenol AF-type epoxy resin), "YL7800" (fluorene-type epoxy resin), "jER1010" (solid bisphenol A-type epoxy resin), and "jER1031S" (tetraphenylethane-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; and "WHR-991S" (phenolphthalimidine-type epoxy resin) manufactured by Nippon Kayaku Co., Ltd. These may be used alone or in combination of two or more.

[0109] When a liquid epoxy resin and a solid epoxy resin are used in combination as component (D), the ratio by mass of the liquid epoxy resin to the solid epoxy resin (liquid epoxy resin:solid epoxy resin) is preferably 1:0.1 to 1:20, more preferably 1:0.15 to 1:10, and particularly preferably 1:0.2 to 1:5. When the ratio by mass of the liquid epoxy resin to the solid epoxy resin is within this range, the desired effects of the present invention can be significantly achieved.

[0110] The epoxy equivalent of component (D) is preferably 50 g / eq. to 5000 g / eq., more preferably 50 g / eq. to 3000 g / eq., even more preferably 80 g / eq. to 2000 g / eq., and even more preferably 110 g / eq. to 1000 g / eq. By keeping it within this range, a cured product of the resin composition can be obtained with sufficient crosslink density. The epoxy equivalent is the mass of an epoxy resin containing one equivalent of epoxy groups. This epoxy equivalent can be measured according to JIS K7236.

[0111] The weight average molecular weight (Mw) of component (D) is preferably 100 to 5000, more preferably 150 to 3000, and even more preferably 200 to 1500. The weight average molecular weight of the epoxy resin is a weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC).

[0112] The content of component (D) is preferably 1% by mass or more, more preferably 3% by mass or more, and even more preferably 5% by mass or more, based on 100% by mass of the nonvolatile components in the resin composition, and the upper limit is preferably 25% by mass or less, more preferably 20% by mass or less, and even more preferably 15% by mass or less.

[0113] The content of component (D) is preferably 10% by mass or more, more preferably 15% by mass or more, and even more preferably 20% by mass or more, based on 100% by mass of the resin component in the resin composition, and the upper limit is preferably 60% by mass or less, more preferably 55% by mass or less, even more preferably 50% by mass or less, 45% by mass or less, or 40% by mass or less.

[0114] <(E) Polymer component> The resin composition may further contain a polymer component (E) as an optional component. The polymer component (E) as the component (E) excludes components (A) to (D). By including the component (E) in the resin composition, stress in the resin composition is alleviated, making it possible to obtain a cured product with a low elastic modulus. The component (E) may be used alone or in combination of two or more.

[0115] Component (E) can be one having a high weight-average molecular weight, such as polyimide resin, phenoxy resin, polyimide resin, polyvinyl acetal resin, polyolefin resin, polybutadiene resin, polyamideimide resin, polyetherimide resin, polysulfone resin, polyethersulfone resin, polyphenylene ether resin, polycarbonate resin, polyetheretherketone resin, polyester resin, etc.

[0116] The weight average molecular weight (Mw) of component (E) is preferably greater than 5,000, more preferably 8,000 or more, even more preferably 10,000 or more, and particularly 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, and particularly preferably 50,000 or less.

[0117] The polyimide resin refers to a resin containing a repeating unit containing an imide bond. Typically, the polyimide resin contains a repeating unit having a structure obtained by reacting a diamine compound with an acid anhydride (imidization reaction).

[0118] Examples of the diamine compound include aliphatic diamine compounds and aromatic diamine compounds, among which aromatic diamine compounds are preferred. Examples of the aromatic diamine compound include phenylenediamine compounds, naphthalenediamine compounds, and dianiline compounds, among which dianiline compounds are preferred.

[0119] A dianiline compound refers to a compound containing two aniline structures in the molecule. Each benzene ring in the aniline structure may have 1 to 3 optional substituents. The two aniline structures in the dianiline compound may be directly bonded to each other or may be bonded to each other via a linker structure having 1 to 100 skeletal atoms selected from the group consisting of carbon atoms, oxygen atoms, sulfur atoms, and nitrogen atoms.

[0120] Specific examples of the "linker structure" in the dianiline compound include -NHCO-, -CONH-, -OCO-, -COO-, -CH2-, -CH2CH2-, -CH2CH2CH2-, -CH2CH2CH2CH2-, -CH2CH2CH2CH2CH2-, -CH(CH3)-, -C(CH3)2-, -C(CF3)2-, -CH=CH-, -O-, -S-, -CO-, -SO2-, -NH Examples of suitable groups include -, -Ph-, -Ph-Ph-, -C(CH3)2-Ph-C(CH3)2-, -O-Ph-O-, -O-Ph-Ph-O-, -O-Ph-SO2-Ph-O-, -O-Ph-C(CH3)2-Ph-O-, -Ph-CO-O-Ph-, -C(CH3)2-Ph-C(CH3)2-, groups represented by the following formula (I), groups represented by the following formula (II), and groups formed by combinations thereof. Unless otherwise specified, "Ph" in this specification represents a 1,4-phenylene group, a 1,3-phenylene group, or a 1,2-phenylene group. In the following formulas (I) and (II), "*" represents a bond. [ka]

[0121] Examples of the dianiline compound include 4,4'-diamino-2,2'-ditrifluoromethyl-1,1'-biphenyl, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfide, 4-aminophenyl 4-aminobenzoate, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 2,2-bis(4-aminophenyl)propane, 4,4'-(hexafluoroisopropylidene)dianiline, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, [4-(4-aminophenoxy)phenyl]hexafluoropropane, α,α-bis[4-(4-aminophenoxy)phenyl]-1,3-diisopropylbenzene, α,α-bis[4-(4-aminophenoxy)phenyl]-1,4-diisopropylbenzene, 4,4'-(9-fluorenylidene)dianiline, 2,2-bis(3-methyl-4-aminophenyl)propane, 2,2-bis(3-methyl-4-aminophenyl)benzene, 4,4'-diamino-3,3'-dimethyl-1,1'-biphenyl, 4,4'-diamino-2,2'-dimethyl-1,1'-biphenyl, 9,9'-bis(3-methyl-4-aminophenyl)fluorene, 5-(4-aminophenoxy)-3-[4-(4-aminophenoxy)phenyl]-1,1,3-trimethylindane, and the like. The diamine compounds may be used singly or in combination of two or more.

[0122] As the acid anhydride, an acid dianhydride can usually be used, and an aromatic tetracarboxylic dianhydride is preferred, such as benzenetetracarboxylic dianhydride, naphthalenetetracarboxylic dianhydride, anthracenetetracarboxylic dianhydride, and diphthalic dianhydride, with diphthalic dianhydride being preferred.

[0123] Diphthalic dianhydride refers to a compound containing two phthalic anhydride structures in the molecule. Each benzene ring in the phthalic anhydride structure may optionally have 1 to 3 substituents. The two phthalic anhydride structures in the diphthalic dianhydride may be directly bonded to each other or may be bonded to each other via a linker structure having 1 to 100 skeletal atoms selected from the group consisting of carbon atoms, oxygen atoms, sulfur atoms, and nitrogen atoms.

[0124] An example of a "linker structure" in diphthalic dianhydride is -[R e -Ph] me -R e -[Ph-R e ] ne In this formula, R e each independently represents a single bond, -(substituted or unsubstituted alkylene group)-, -O-, -S-, -CO-, -SO2-, -CONH-, -NHCO-, -COO-, or -OCO-; me and ne each independently represent an integer of 0 to 2 (preferably 0 or 1). Specific examples of the linker structure include -CH2-, -CH2CH2-, -CH2CH2CH2-, -CH2CH2CH2CH2-, -CH2CH2CH2CH2CH2-, -CH(CH3)-, -C(CH3)2-, -O-, -CO-, -SO2-, -Ph-, -O-Ph-O-, -O-Ph-SO2-Ph-O-, -O-Ph-C(CH3)2-Ph-O-, and the like.

[0125] Examples of diphthalic dianhydrides include 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-diphenylethertetracarboxylic dianhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, 2,3,3',4'-biphenyltetracarboxylic dianhydride, 2,3,3',4'-benzophenonetetracarboxylic dianhydride, 2,3,3',4'-diphenylethertetracarboxylic dianhydride, 2,3,3',4'-diphenylsulfonetetracarboxylic dianhydride, 2,2'-bis(3,4-dicarboxyphenoxyphenyl)sulfone dianhydride, methylene-4,4'-diphthalic dianhydride, and 1,1-ethynylidene-4,4'-diphthalic Dianhydride, 2,2-propylidene-4,4'-diphthalic dianhydride, 1,2-ethylene-4,4'-diphthalic dianhydride, 1,3-trimethylene-4,4'-diphthalic dianhydride, 1,4-tetramethylene-4,4'-diphthalic dianhydride, 1,5-pentamethylene-4,4'-diphthalic dianhydride, 1,3-bis(3,4-dicarboxyphenyl)benzene dianhydride, 1,4-bis(3,4-dicarboxyphenyl)benzene dianhydride Examples of the acid anhydride include 1,3-bis(3,4-dicarboxyphenoxy)benzene dianhydride, 1,4-bis(3,4-dicarboxyphenoxy)benzene dianhydride, 2,2-bis(2,3-dicarboxyphenyl)propane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, and 4,4'-(4,4'-isopropylidenediphenoxy)bisphthalic dianhydride. One type of acid anhydride may be used alone, or two or more types may be used in combination.

[0126] The polyimide resin can be produced by a conventionally known method. For example, the polyimide resin may be produced by a method including heating a mixture of a diamine compound, an acid anhydride, and a solvent to cause a reaction. Alternatively, a commercially available product may be used as the polyimide resin. Specific examples of commercially available polyimide resins include "SLK-6100" manufactured by Shin-Etsu Chemical Co., Ltd., and "Rikacoat SN20" and "Rikacoat PN20" manufactured by New Japan Chemical Co., Ltd.

[0127] 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 & Sumikin Chemical Co., Ltd.; and "YL7500BH30," "YX6954BH30," "YX7553," "YX7553BH30," "YL7769BH30," "YL6794," "YL7213," "YL7290," "YL7482," and "YL7891BH30" manufactured by Mitsubishi Chemical Corporation.

[0128] 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.

[0129] 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.

[0130] 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.

[0131] 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 Resonac Corporation.

[0132] A specific example of the polyethersulfone resin is "PES5003P" manufactured by Sumitomo Chemical Co., Ltd.

[0133] Specific examples of polysulfone resins include polysulfones "P1700" and "P3500" manufactured by Solvay Advanced Polymers.

[0134] A specific example of the polyphenylene ether resin is "NORYL SA90" manufactured by SABIC Corp. A specific example of the polyetherimide resin is "Ultem" manufactured by GE Corp.

[0135] Examples of polycarbonate resins include hydroxyl group-containing carbonate resins, phenolic hydroxyl group-containing carbonate resins, carboxyl group-containing carbonate resins, acid anhydride group-containing carbonate resins, isocyanate group-containing carbonate resins, and urethane group-containing carbonate resins. 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. Specific examples of polyether ether ketone resins include "Sumiploy K" manufactured by Sumitomo Chemical Co., Ltd.

[0136] 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.

[0137] The content of the (E) polymer component is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, and even more preferably 0.5% by mass or more, and is preferably 3% by mass or less, more preferably 2% by mass or less, and even more preferably 1% by mass or less, when the non-volatile components in the resin composition are taken as 100% by mass.

[0138] The content of the (E) polymer component is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, and even more preferably 0.3% by mass or more, and is preferably 5% by mass or less, more preferably 4% by mass or less, and even more preferably 3% by mass or less, when the resin component in the resin composition is taken as 100% by mass.

[0139] <(F) Curing accelerator> The resin composition may further contain a curing accelerator (F) as an optional component. The curing accelerator (F) as the component (F) does not include those corresponding to the above-mentioned components (A) to (E). By including the component (F), it becomes possible to further accelerate the curing of the component (B) or the component (D). The component (F) may be used alone or in combination of two or more.

[0140] Examples of component (F) include phosphorus-based curing accelerators, urea-based curing accelerators, guanidine-based curing accelerators, imidazole-based curing accelerators, metal-based curing accelerators, amine-based curing accelerators, etc. Among these, curing accelerators selected from amine-based curing accelerators and metal-based curing accelerators are preferred, with amine-based curing accelerators being particularly preferred.

[0141] 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;

[0142] 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].

[0143] 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.

[0144] 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 , 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, 2-phenylimidazoline, and other imidazole compounds, as well as adducts of imidazole compounds with epoxy resins.

[0145] As the imidazole-based curing accelerator, commercially available products may be used, such as "1B2PZ", "C11Z", "2P4MZ", "2MZA-PW", "2PHZ-PW", and "C11Z-A" manufactured by Shikoku Chemical Industry Co., Ltd., and "P200-H50" manufactured by Mitsubishi Chemical Corporation.

[0146] 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.

[0147] Examples of the amine-based curing accelerator include trialkylamines such as triethylamine and tributylamine, 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, and 1,8-diazabicyclo(5,4,0)-undecene.

[0148] As the amine-based curing accelerator, commercially available products may be used, for example, "MY-25" manufactured by Ajinomoto Fine-Techno Co., Ltd.

[0149] The content of component (F) is preferably 0.01% by mass or more, more preferably 0.03% by mass or more, and even more preferably 0.05% by mass or more, and is preferably 3% by mass or less, more preferably 1% by mass or less, and even more preferably 0.8% by mass or less, assuming that the non-volatile components in the resin composition are 100% by mass.

[0150] The content of component (F) is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, and even more preferably 0.4% by mass or more, and is preferably 5% by mass or less, more preferably 3% by mass or less, and even more preferably 2% by mass or less, assuming that the resin component in the resin composition is 100% by mass.

[0151] <(G) Radical Polymerization Initiator> The resin composition may contain a (G) radical polymerization initiator as an optional component. The (G) radical polymerization initiator as this component (G) excludes those corresponding to components (A) to (F). The (G) radical polymerization initiator may be, for example, a thermal polymerization initiator that generates free radicals upon heating. The (G) radical polymerization initiator may be a polymerization initiator of a radical reactive group. The (G) radical polymerization initiator may be used alone or in any combination of two or more.

[0152] (G) Examples of the radical polymerization initiator include peroxide radical polymerization initiators, azo radical polymerization initiators, etc. Among these, peroxide radical polymerization initiators are preferred.

[0153] 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.

[0154] 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.

[0155] (H) 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.

[0156] The content of component (G), when the nonvolatile components in the resin composition are taken as 100% by mass, is preferably 0.1% by mass or more, more preferably 0.15% by mass or more, even more preferably 0.2% by mass or more, and is preferably 3% by mass or less, more preferably 1% by mass or less, even more preferably 0.5% by mass or less.

[0157] The content of component (G), when the resin component in the resin composition is taken as 100% by mass, is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, even more preferably 0.5% by mass or more, and is preferably 8% by mass or less, more preferably 5% by mass or less, even more preferably 3% by mass or less.

[0158] <(H)Organic filler> The resin composition may further contain an optional component (H), which is an organic filler (H). The organic filler (H) as component (H) does not include those corresponding to the above-mentioned components (A) to (G). The component (H) may be used alone or in combination of two or more.

[0159] The component (H) is present in the resin composition in the form of particles. Examples of the component (H) include rubber particles, polyamide fine particles, silicone particles, and core-shell particles. In the present invention, from the viewpoint of significantly achieving the desired effects of the present invention, it is preferable to use either rubber particles or core-shell particles, and it is more preferable to use rubber particles.

[0160] Examples of the rubber component contained in the rubber particles include 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 acrylic-based thermoplastic elastomers such as poly(propyl meth)acrylate, poly(butyl meth)acrylate, poly(cyclohexyl meth)acrylate, and poly(octyl meth)acrylate. Preferred are olefin-based thermoplastic elastomers, and more preferably styrene-butadiene copolymers. Furthermore, silicone-based rubbers such as polyorganosiloxane rubbers 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.

[0161] As the rubber particles, commercially available products may be used, such as "EXL2655" manufactured by Dow Chemical Japan, and "AC3401N" and "AC3816N" manufactured by Aica Kogyo Co., Ltd.

[0162] Core-shell particles are particulate organic fillers consisting of a core particle containing a rubber component as described above and one or more shell layers covering the core particle. Furthermore, the core-shell particles are preferably core-shell graft copolymer particles consisting of a core particle containing a rubber component as described above and a shell formed by graft copolymerization of a monomer component copolymerizable with the rubber component contained in the core particle. The term "core-shell" as used here does not necessarily refer only to particles in which the core particle and the shell are clearly distinguishable, but also includes particles in which the boundary between the core particle and the shell is unclear, and the core particle does not necessarily have to be completely covered by the shell.

[0163] The rubber component is preferably contained in the core-shell graft copolymer particles in an amount of 40% by mass or more, more preferably 50% by mass or more, and even more preferably 60% by mass or more. The upper limit of the rubber component content in the core-shell graft copolymer particles is not particularly limited, but from the viewpoint of sufficiently covering the core particles with the shell portion, it is preferably, for example, 95% by mass or less, and more preferably 90% by mass.

[0164] Examples of monomer components that form the shell portion of the core-shell graft copolymer particles include (meth)acrylic acid esters such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, cyclohexyl (meth)acrylate, octyl (meth)acrylate, and glycidyl (meth)acrylate; (meth)acrylic acid; N-substituted maleimides such as N-methylmaleimide and N-phenylmaleimide; maleimide; α,β-unsaturated carboxylic acids such as maleic acid and itaconic acid; aromatic vinyl compounds such as styrene, 4-vinyltoluene, and α-methylstyrene; and (meth)acrylonitrile, among which (meth)acrylic acid esters are preferred, and methyl (meth)acrylate is more preferred.

[0165] Commercially available core-shell graft copolymer particles include, for example, "CHT" manufactured by Samsung SDI; "B602" manufactured by Techno UMG; "Paraloid EXL2602," "Paraloid EXL2603," "Paraloid EXL2655," "Paraloid EXL2311," "Paraloid EXL2313," "Paraloid EXL2315," "Paraloid KM330," "Paraloid KM336P," and "Paraloid KCZ201" manufactured by Dow Chemical Japan; "Metablen C-223A," "Metablen E-901," "Metablen S-2001," "Metablen W-450A," and "Metablen SRK-200" manufactured by Mitsubishi Rayon; and "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. These may be used alone or in combination of two or more.

[0166] The average particle size (average primary particle size) of the core-shell graft copolymer particles is not particularly limited, but is preferably 20 nm or more, more preferably 50 nm or more, even more preferably 80 nm or more, particularly preferably 100 nm or more, and preferably 5,000 nm or less, more preferably 2,000 nm or less, even more preferably 1,000 nm or less, particularly preferably 500 nm or less. The average particle size (average primary particle size) of the core-shell graft copolymer particles can be measured using a zeta potential particle size distribution analyzer or the like.

[0167] The content of component (H) is preferably 0.1% by mass or more, more preferably 0.15% by mass or more, and even more preferably 0.2% by mass or more, and is preferably 3% by mass or less, more preferably 1% by mass or less, and even more preferably 0.5% by mass or less, assuming that the non-volatile components in the resin composition are 100% by mass.

[0168] The content of component (H) is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, and even more preferably 0.5% by mass or more, and is preferably 8% by mass or less, more preferably 5% by mass or less, and even more preferably 3% by mass or less, assuming that the resin component in the resin composition is 100% by mass.

[0169] <(I) Other additives> In addition to the components described above, the resin composition may further contain other additives as optional components. (I) Examples of other additives include polymerization initiators; 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 silane; adhesion promoters such as triazole-based adhesion promoters, tetrazole-based adhesion promoters, and triazine-based adhesion promoters; and hindered phenol-based antioxidants. 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; 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; photopolymerization initiation aids such as tertiary amines; and photosensitizers such as pyrarizones, anthracenes, coumarins, xanthones, and thioxanthones. (I) Other additives may be used singly or in combination of two or more.

[0170] <(J) Solvent> In addition to the nonvolatile components described above, the resin composition may further contain an arbitrary solvent as a volatile component. As the (J) solvent, any known solvent can be used appropriately, and the type is not particularly limited, but an organic solvent is preferred. Examples of the (J) 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. (J) Solvents may be used singly or in combination of two or more in any ratio.

[0171] The resin composition preferably contains 0.5% by mass or more and 3% by mass or less of the (J) solvent, relative to 100% by mass of all components of the resin composition. Specifically, the (J) solvent is preferably contained in an amount of 3% by mass or less, more preferably 2% by mass or less, and even more preferably 1.5% by mass or less, relative to 100% by mass of all components of the resin composition, and is preferably contained in an amount of 0.5% by mass or more, more preferably 0.8% by mass or more, and even more preferably 1% by mass or more.

[0172] The method for preparing the resin composition of the present invention is not particularly limited, and examples thereof include a method in which the blending components are mixed and dispersed using a rotary mixer or the like, with the addition of a solvent or the like as necessary.

[0173] <Physical properties and applications of resin compositions> Since the resin composition contains a combination of components (A), (B), and (C), it is possible to obtain a cured product with a low dielectric tangent and excellent crack resistance, and also, in general, a low coefficient of linear thermal expansion (CTE) and modulus of elasticity.

[0174] A cured product obtained by thermally curing the resin composition at 190°C for 90 minutes exhibits the characteristic of a low dielectric loss tangent. Therefore, the cured product provides an insulating layer with a low dielectric loss tangent. The dielectric loss tangent is preferably 0.005 or less, more preferably 0.004 or less, and even more preferably 0.003 or less, or 0.0028 or less. There is no particular lower limit, but it can be 0.00001 or more. The dielectric loss tangent can be measured according to the method described in the examples below.

[0175] A cured product obtained by thermally curing a resin composition at 190°C for 90 minutes typically exhibits the property of a low coefficient of linear thermal expansion (CTE). Therefore, the cured product provides an insulating layer with a low coefficient of linear thermal expansion. The coefficient of linear thermal expansion is preferably 30 ppm / °C or less, more preferably 25 ppm / °C or less, and even more preferably 23 ppm / °C or less. There is no particular lower limit, but it can be 1 ppm / °C or more. The coefficient of linear thermal expansion can be measured according to the method described in the examples below.

[0176] A cured product obtained by thermally curing a resin composition at 190°C for 90 minutes typically exhibits a low modulus of elasticity (tensile modulus). Therefore, the cured product provides an insulating layer with a low modulus of elasticity. The modulus of elasticity is preferably 13 GPa or less, more preferably 13.4 GPa or less, and even more preferably 13 GPa or less. There is no particular lower limit, but it can be 1 GPa or more. The modulus of elasticity can be measured according to the method described in the Examples below.

[0177] A cured product obtained by thermally curing a resin composition at 130°C for 30 minutes and then at 170°C for 30 minutes exhibits excellent crack resistance. Therefore, the cured product provides an insulating layer with excellent crack resistance. Crack resistance is evaluated by forming an insulating layer on a circuit board having a conductor layer on its surface on which a wiring pattern is formed, performing a roughening treatment, and determining the yield, according to the method described in the Examples below. In this case, the yield can be increased. The specific yield range is preferably 40% or more, more preferably 60% or more, and even more preferably 80% or more. Crack resistance can be measured according to the method described in the Examples below.

[0178] The resin composition of the present invention can be thermally cured to give a cured product. The resin composition of the present invention can also give a cured product having a low dielectric loss tangent and excellent crack resistance. Furthermore, the resin composition of the present invention can also give a cured product having a low linear thermal expansion coefficient and elastic modulus. Therefore, the resin composition of the present invention can be suitably used as a resin composition for insulating purposes. Specifically, the resin composition of the present invention can be suitably used as a resin composition for forming an insulating layer (including a rewiring layer) to be formed on an insulating layer (resin composition for forming an insulating layer).

[0179] Furthermore, in the multilayer printed wiring board described below, the resin composition can be suitably used as a resin composition for forming an insulating layer of the multilayer printed wiring board (resin composition for forming an insulating layer of a multilayer printed wiring board) and as a resin composition for forming an interlayer insulating layer of the printed wiring board (resin composition for forming an interlayer insulating layer of a printed wiring board).

[0180] Furthermore, for example, when a semiconductor chip package is manufactured through the following steps (1) to (6), the resin composition of the present invention can be suitably used as a resin composition for a rewiring formation layer (resin composition for forming a rewiring formation layer) as an insulating layer for forming a rewiring layer, and as a resin composition for encapsulating a semiconductor chip (resin composition for encapsulating a semiconductor chip). When a semiconductor chip package is manufactured, a rewiring layer may be further formed on the encapsulating layer. (1) a step of laminating a temporary fixing film on a substrate; (2) a step of temporarily fixing a semiconductor chip on a temporary fixing film; (3) forming an encapsulation layer on the semiconductor chip; (4) peeling the substrate and the temporary fixing film from the semiconductor chip; (5) forming a rewiring formation layer as an insulating layer on the surface of the semiconductor chip from which the base material and the temporary fixing film have been peeled off; and (6) A step of forming a rewiring layer as a conductor layer on the rewiring formation layer.

[0181] [Resin sheet] The resin sheet of the present invention includes a support and a resin composition layer formed from the resin composition of the present invention and provided on the support.

[0182] The thickness of the resin composition layer is preferably 100 μm or less, more preferably 80 μm or less, and even more preferably 50 μm or less, from the viewpoint of making the printed wiring board thinner and being able to provide a cured product of the resin composition that has excellent insulating properties even when the cured product is thin. The lower limit of the thickness of the resin composition layer is not particularly limited, but can usually be 5 μm or more.

[0183] Examples of the support include films made of plastic materials, metal foils, and release papers, with films made of plastic materials and metal foils being preferred.

[0184] When a film made 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.

[0185] 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.).

[0186] The surface of the support that is to be bonded to the resin composition layer may be subjected to a matte treatment, a corona treatment, or an antistatic treatment.

[0187] The support may also be a support with a release layer, which has a release layer on the surface that bonds to 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 resins, polyolefin resins, urethane resins, and silicone resins. Commercially available products may also be used as the support with a release layer, including, for example, "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, which are PET films having a release layer primarily composed of an alkyd resin-based release agent.

[0188] The thickness of the support is not particularly limited, but is preferably in the range of 5 μm to 75 μm, more preferably 10 μm to 60 μm. When a support with a release layer is used, it is preferable that the thickness of the entire support with a release layer is in the above range.

[0189] In one embodiment, the resin sheet may further include other layers as necessary. Examples of such other layers include a protective film conforming to the support and provided on the surface of the resin composition layer that is not bonded to the support (i.e., the surface opposite the support). The thickness of the protective film is not particularly limited, but is, for example, 1 μm to 40 μm. By laminating the protective film, adhesion of dust and the like to the surface of the resin composition layer and scratches can be suppressed.

[0190] The resin sheet can be produced, for example, by preparing a resin varnish by dissolving a resin composition in a solvent, applying the resin varnish to a support using a die coater or the like, and then drying the applied resin varnish to form a resin composition layer. The solvent is as described above.

[0191] Drying may be carried out by known methods such as heating or hot air blowing. Drying conditions are not particularly limited, but drying is carried out so that the solvent content in the resin composition layer becomes 10% by mass or less, preferably 5% by mass or less. Although this varies depending on the boiling point of the solvent in the resin varnish, for example, when a resin varnish containing 30% by mass to 60% by mass of solvent is used, the resin composition layer can be formed by drying at 50°C to 150°C for 3 to 10 minutes.

[0192] The resin sheet can be stored in a rolled state. When the resin sheet has a protective film, it can be used by peeling off the protective film.

[0193] [Printed wiring board] The printed wiring board of the present invention includes an insulating layer formed from a cured product of the resin composition of the present invention.

[0194] The printed wiring board can be produced, for example, by using the above-mentioned resin sheet by a method including the following steps (I) and (II). (I) A step of laminating the resin sheet on the inner layer substrate so that the resin composition layer of the resin sheet is bonded to the inner layer substrate. (II) Step of thermally curing the resin composition layer to form an insulating layer

[0195] The "inner layer substrate" used in step (I) is a member that will become the substrate of a printed wiring board, and examples thereof include glass epoxy substrates, metal substrates, polyester substrates, polyimide substrates, BT resin substrates, and thermosetting polyphenylene ether substrates. The substrate may have a conductor layer on one or both sides, and this conductor layer may be patterned. An inner layer substrate having a conductor layer (circuit) formed on one or both sides of the substrate may be referred to as an "inner layer circuit board." Furthermore, the "inner layer substrate" of the present invention also includes intermediate products on which an insulating layer and / or a conductor layer is to be further formed during the production of a printed wiring board. When the printed wiring board is a circuit board with built-in components, an inner layer substrate with built-in components may be used.

[0196] The inner layer substrate and the resin sheet can be laminated, 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 end plate) or a metal roll (SUS roll). Note that rather than pressing the thermocompression bonding member directly onto the resin sheet, it is preferable to press it via 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.

[0197] 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.

[0198] The lamination can 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 vacuum pressure laminator.

[0199] After lamination, the laminated resin sheets may be smoothed under normal pressure (atmospheric pressure), for example, by pressing a thermocompression member from the support side. The pressing conditions for the smoothing treatment may be the same as the thermocompression conditions for lamination. The smoothing treatment may be performed using a commercially available laminator. Note that lamination and smoothing treatment may be performed consecutively using the commercially available vacuum laminator.

[0200] The support may be removed between step (I) and step (II), or may be removed after step (II).

[0201] In step (II), the resin composition layer is thermally cured to form an insulating layer. The conditions for thermally curing the resin composition layer are not particularly limited, and conditions typically employed for forming insulating layers for printed wiring boards may be used.

[0202] For example, although the thermal curing conditions for the resin composition layer vary depending on the type of resin composition, 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.

[0203] Before thermally curing the resin composition layer, the resin composition layer may be preheated at a temperature lower than the curing temperature. For example, prior to thermally curing the resin composition layer, the resin composition layer may be preheated at a temperature of 50°C or higher but lower than 120°C (preferably 60°C or higher but 115°C or lower, more preferably 70°C or higher but 110°C or lower) for 5 minutes or longer (preferably 5 to 150 minutes, more preferably 15 to 120 minutes, and even more preferably 15 to 100 minutes).

[0204] When manufacturing a printed wiring board, the following steps may be further performed: (III) drilling holes in the insulating layer, (IV) roughening the insulating layer, and (V) forming a conductor layer. These steps (III) to (V) may be performed according to various methods known to those skilled in the art and used in manufacturing printed wiring boards. When the support is removed after step (II), the removal of the support may be performed between steps (II) and (III), between steps (III) and (IV), or between steps (IV) and (V). Furthermore, if necessary, the formation of the insulating layer and the conductor layer in steps (II) to (V) may be repeated to form a multilayer wiring board.

[0205] Step (III) is a step of drilling holes in the insulating layer, thereby forming holes such as via holes and through holes in the insulating layer. Step (III) may be performed using, for example, a drill, a laser, plasma, or the like, depending on the composition of the resin composition used to form the insulating layer. The dimensions and shape of the holes may be determined appropriately depending on the design of the printed wiring board.

[0206] Step (IV) is a step of roughening the insulating layer. Smear removal is usually also performed in this step (IV). The roughening procedure and conditions are not particularly limited, and known procedures and conditions commonly used in forming insulating layers for printed wiring boards can be employed. For example, the insulating layer can be roughened by performing a swelling treatment with a swelling liquid, a roughening treatment with an oxidizing agent, and a neutralization treatment with a neutralizing liquid in this order. The swelling liquid used in the roughening treatment is not particularly limited, but examples include alkaline solutions and surfactant solutions. Alkaline solutions are preferred, and sodium hydroxide solutions and potassium hydroxide solutions are more preferred. Commercially available swelling liquids include "Swelling Dip Securigans P," "Swelling Dip Securigans SBU," and "Swelling Dip Securigant P," both manufactured by Atotech Japan. The swelling treatment using a swelling liquid is not particularly limited, but can be carried out, for example, by immersing the insulating layer in a swelling liquid at 30°C to 90°C for 1 to 20 minutes. From the viewpoint of suppressing 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. The oxidizing agent used in the roughening treatment is not particularly limited, but examples thereof include alkaline permanganate solutions prepared by dissolving potassium permanganate or sodium permanganate in an aqueous solution of sodium hydroxide. The roughening treatment using an oxidizing agent such as an 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 Securiganth P" manufactured by Atotech Japan. The neutralizing solution used for the roughening treatment is preferably an acidic aqueous solution, and a commercially available product thereof is, for example, "Reduction Solution Securiganth P" manufactured by Atotech Japan. Treatment with a neutralizing solution can be carried out by immersing the surface that has been roughened with an oxidizing agent in the neutralizing solution at 30°C to 80°C for 1 to 30 minutes.From the viewpoint of workability, a preferred method is to immerse the object that has been subjected to roughening treatment with an oxidizing agent in a neutralizing solution at 40°C to 70°C for 5 to 20 minutes.

[0207] In one embodiment, the arithmetic mean roughness (Ra) of the insulating layer surface after roughening treatment is preferably 300 nm or less, more preferably 250 nm or less, and even more preferably 200 nm or less. There is no particular lower limit, but it is preferably 30 nm or more, more preferably 40 nm or more, and even more preferably 50 nm or more. The arithmetic mean roughness (Ra) of the insulating layer surface can be measured using a non-contact surface roughness meter.

[0208] Step (V) is a step of forming a conductor layer, and the conductor layer is formed on the insulating layer. The conductor 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, etc., a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, or an alloy layer of a nickel-chromium alloy, a copper-nickel alloy, or a 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.

[0209] The conductor layer may have a single layer structure or a multi-layer structure in which two or more single metal layers or alloy layers made of different types of metals or alloys are laminated. 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.

[0210] The thickness of the conductor layer depends on the desired design of the printed wiring board, but is generally 3 μm to 35 μm, preferably 5 μm to 30 μm.

[0211] In one embodiment, 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, it is preferable to form the conductor layer by a semi-additive method. An example of forming the conductor layer by a semi-additive method will be described below.

[0212] First, a plating seed layer is formed on the surface of an insulating layer by electroless plating. Next, a mask pattern is formed on the formed plating seed layer, exposing a portion of the plating seed layer corresponding to the desired wiring pattern. After a metal layer is formed on the exposed plating seed layer by electrolytic plating, the mask pattern is removed. Thereafter, unnecessary plating seed layer is removed by etching or the like, thereby forming a conductor layer having the desired wiring pattern.

[0213] [Semiconductor Devices] The semiconductor device of the present invention includes the printed wiring board of the present invention. The semiconductor device of the present invention can be manufactured using the printed wiring board of the present invention.

[0214] Examples of semiconductor devices include various semiconductor devices used in electrical appliances (for example, computers, mobile phones, digital cameras, and televisions) and vehicles (for example, motorcycles, automobiles, trains, ships, and aircraft).

[0215] The semiconductor device of the present invention can be manufactured by mounting a component (semiconductor chip) on a conductive portion of a printed wiring board. The "conductive portion" refers to a portion of the printed wiring board that transmits an electrical signal, and the portion may be either on the surface or embedded. The semiconductor chip is not particularly limited as long as it is an electrical circuit element made of a semiconductor material.

[0216] The method of mounting a semiconductor chip when manufacturing a semiconductor device is not particularly limited as long as the semiconductor chip functions effectively, but specific examples include wire bonding mounting, flip chip mounting, bumpless buildup layer (BBUL) mounting, anisotropic conductive film (ACF) mounting, non-conductive film (NCF) mounting, etc. Here, the "bumpless buildup layer (BBUL) mounting method" refers to "a mounting method in which a semiconductor chip is directly embedded in a recess in a printed wiring board and the semiconductor chip is connected to the wiring on the printed wiring board." [Example]

[0217] The present invention will be described in more detail below using examples, but the present invention is not limited to these examples. In the following description, unless otherwise specified, "parts" and "%" mean "parts by mass" and "% by mass", respectively.

[0218] (GPC measurement conditions for measuring number average molecular weight and weight average molecular weight) Measuring device: Tosoh Corporation "HLC-8420GPC" Column: Tosoh guard column "HXL-L" + Tosoh "TSK-GEL SuperHZ2000" + Tosoh "TSK-GEL SuperHZ2000" + Tosoh "TSK-GEL SuperHZ3000" + Tosoh "TSK-GEL SuperHZ4000" Detector: RI (differential refractometer) Data processing: Tosoh Corporation's "GPC Workstation EcoSEC-WorkStation" Column temperature: 40℃ Developing solvent: tetrahydrofuran Flow rate: 0.35mL / min Standard: The following monodisperse polystyrenes with known molecular weights were used in accordance with the measurement manual for the GPC Workstation EcoSEC-WorkStation. TSKgel F-10, F-4, F-1, A-5000, A-1000, A-500 (manufactured by Tosoh Corporation) Sample: 10 μL of a tetrahydrofuran solution containing 0.2% by mass of resin solids filtered through a microfilter

[0219] Example 1A: Synthesis of styrene resin 1 A recovery flask was charged with 10.0 g of styrene, 2.84 g of 4-tert-butylstyrene, 0.62 g of tert-butyl acrylate, 0.31 g of 2,2'-azodiisobutyronitrile, and 45 mL of tetrahydrofuran, and the mixture was stirred at 70 °C for 3 hours under an argon atmosphere. After cooling to room temperature, the reaction mixture was added dropwise to methanol, and the precipitated solid was collected by filtration and dried under reduced pressure to obtain 4.11 g of a white solid. The resulting solid was dissolved in 20 mL of dichloromethane, and 5 mL of trifluoroacetic acid was added dropwise. The mixture was stirred at room temperature for 1 hour and then concentrated under reduced pressure. The resulting residue was dissolved in 5 mL of dichloromethane, and 5 mL of thionyl chloride and one drop of N,N'-dimethylformamide were added. The mixture was stirred for 2 hours and then concentrated under reduced pressure. The resulting residue was dissolved in 20 mL of tetrahydrofuran, and 415 μL of phenol and 1.0 mL of triethylamine were added. The mixture was stirred at room temperature overnight. The reaction solution was added dropwise to methanol, and the precipitated solid was collected by filtration and dried under reduced pressure to obtain 2.6 g of a white solid styrene resin 1. The solid was dissolved in toluene to obtain the target styrene resin 1 (number average molecular weight 9,100, weight average molecular weight 12,400, non-volatile content 50%) with a solids concentration of 50% by mass. The styrene resin 1 was identified using an NMR apparatus (nuclear magnetic resonance apparatus: Bruker AVANCE 400 (400 MHz)) and confirmed to have structural units represented by the following formulas (A-1), (A-2), and (A-3). (In the formulas, * represents a bond. The molar ratio x:y:z, where x is the number of moles of the structural unit represented by formula (A-1), y is the number of moles of the structural unit represented by formula (A-3), and z is the number of moles of the structural unit represented by formula (A-2), was 20:3:1. The molar ratio of the structural units was calculated from the feed ratio.) 1 H-NMR(400MHz,Chloroform-d)δ 7.24-6.11(m,100H),4.03-3.70(m,1H),2.42-0.74(m,123H) [ka]

[0220] Example 2A: Synthesis of styrene resin 2 A recovery flask was charged with 10.0 g of styrene, 3.16 g of 4-tert-butylstyrene, 0.41 g of tert-butyl acrylate, 0.31 g of 2,2'-azodiisobutyronitrile, and 45 mL of tetrahydrofuran, and the mixture was stirred at 70 °C for 3 hours under an argon atmosphere. After cooling to room temperature, the reaction mixture was added dropwise to methanol, and the precipitated solid was collected by filtration and dried under reduced pressure to obtain 3.57 g of a white solid. The resulting solid was dissolved in 20 mL of dichloromethane, and 5 mL of trifluoroacetic acid was added dropwise. The mixture was stirred at room temperature for 1 hour and then concentrated under reduced pressure. The resulting residue was dissolved in 5 mL of dichloromethane, and 5 mL of thionyl chloride and one drop of N,N'-dimethylformamide were added. The mixture was stirred for 2 hours and then concentrated under reduced pressure. The resulting residue was dissolved in 20 mL of tetrahydrofuran, and 400 μL of phenol and 1.0 mL of triethylamine were added. The mixture was stirred at room temperature overnight. The reaction solution was added dropwise to methanol, and the precipitated solid was collected by filtration and dried under reduced pressure to obtain 1.96 g of a white solid styrene resin 2. The solid was dissolved in toluene to obtain the target styrene resin 2 (number average molecular weight 8,100, weight average molecular weight 10,800, non-volatile content 50%) with a solids concentration of 50% by mass. The styrene resin 2 was identified using an NMR apparatus (nuclear magnetic resonance apparatus: Bruker AVANCE 400 (400 MHz)) and confirmed to have structural units represented by the following formulas (A-1), (A-2), and (A-3) (where * represents a bond. The molar ratio x:y:z, where x is the number of moles of the structural unit represented by formula (A-1), y is the number of moles of the structural unit represented by formula (A-3), and z is the number of moles of the structural unit represented by formula (A-2), was 30:5:1; the molar ratio of the structural units was calculated from the feed ratio). 1 H-NMR(400MHz,Chloroform-d)δ 7.26-6.18(m,162H),4.05-3.74(m,1H),2.41-0.76(m,191H) [ka]

[0221] Example 3A: Synthesis of styrene resin 3 A recovery flask was charged with 10.0 g of styrene, 3.79 g of 4-tert-butylstyrene, 1.23 g of tert-butyl acrylate, 0.33 g of 2,2'-azodiisobutyronitrile, and 45 mL of tetrahydrofuran, and the mixture was stirred at 70 °C for 3 hours under an argon atmosphere. After cooling to room temperature, the reaction mixture was added dropwise to methanol, and the precipitated solid was collected by filtration and dried under reduced pressure to obtain 4.52 g of a white solid. The resulting solid was dissolved in 20 mL of dichloromethane, and 5 mL of trifluoroacetic acid was added dropwise. The mixture was stirred at room temperature for 1 hour and then concentrated under reduced pressure. The resulting residue was dissolved in 5 mL of dichloromethane, and 5 mL of thionyl chloride and one drop of N,N'-dimethylformamide were added. The mixture was stirred for 2 hours and then concentrated under reduced pressure. The resulting residue was dissolved in 20 mL of tetrahydrofuran, and 800 μL of phenol and 2.0 mL of triethylamine were added. The mixture was stirred at room temperature overnight. The reaction solution was added dropwise to methanol, and the precipitated solid was collected by filtration and dried under reduced pressure to obtain 3.1 g of a white solid styrene resin 3. The solid was dissolved in toluene to obtain the target styrene resin 3 (number average molecular weight 7,700, weight average molecular weight 9,800, non-volatile content 50%) with a solids concentration of 50% by mass. The styrene resin 3 was identified using an NMR apparatus (nuclear magnetic resonance apparatus: Bruker AVANCE 400 (400 MHz)) and confirmed to have structural units represented by the following formulas (A-1), (A-2), and (A-3). (In the formulas, * represents a bond. The molar ratio x:y:z, where x is the number of moles of the structural unit represented by formula (A-1), y is the number of moles of the structural unit represented by formula (A-3), and z is the number of moles of the structural unit represented by formula (A-2), is 10:2:1. The molar ratio of the structural units was calculated from the feed ratio.) 1 H-NMR(400MHz,Chloroform-d)δ 7.24-6.13(m,62H),4.02-3.74(m,1H),2.44-0.73(m,68H) [ka]

[0222] <Synthesis Example 1: Synthesis of Maleimide A> An MEK solution of maleimide compound A (62% by mass of nonvolatile components, t'' = 1.47 (mainly 1, 2, or 3), Mw / Mn = 1.81) synthesized by the method described in Synthesis Example 1 of the Japan Institute of Invention and Innovation's Technical Journal Disclosure No. 2020-500211 was prepared. This maleimide compound A has a structure represented by the following formula (1). [ka]

[0223] <Synthesis Example 2: Synthesis of Polyimide B> A 500 mL separable flask was prepared, equipped with a water content receiver connected to a reflux condenser, a nitrogen inlet tube, and a stirrer. 20.3 g of 4,4'-oxydiphthalic anhydride (ODPA), 200 g of γ-butyrolactone, 20 g of toluene, and 29.6 g of 5-(4-aminophenoxy)-3-[4-(4-aminophenoxy)phenyl]-1,1,3-trimethylindane were added to the flask and stirred at 45°C for 2 hours under a nitrogen stream. The reaction solution was then heated and maintained at approximately 160°C, while the condensed water was azeotropically removed with toluene under a nitrogen stream. It was confirmed that the specified amount of water had accumulated in the water content receiver and that no water was leaking out. After confirmation, the reaction solution was further heated and stirred at 200°C for 1 hour. The mixture was then cooled to obtain a polyimide solution (non-volatile content: 20% by mass) containing a polyimide resin having a 1,1,3-trimethylindane skeleton. The obtained polyimide resin had a repeating unit represented by the following formula (X1) and a repeating unit represented by the following formula (X2). The weight-average molecular weight of the polyimide resin was 12,000. [ka]

[0224] <Production of resin varnish> Each component was weighed out in the number of parts by mass shown in the table, and then mixed with 15 parts of MEK and 2 parts of cyclohexanone, and the mixture was uniformly dispersed using a high-speed rotating mixer to obtain a resin varnish. [Table 1] *1: Indicates the content when the resin component in the resin composition is 100% by mass. *2: Indicates the content when the non-volatile components in the resin composition are taken as 100% by mass.

[0225] Details of each component listed in the table are as follows: Component (A) Styrene resin 1: Synthesized in Example 1A Styrene resin 2: Synthesized in Example 2A Styrene resin 3: Synthesized in Example 3A (B) Component HPC-8150-62T: Active ester curing agent, active ester resin with naphthalene structure, functional group equivalent weight 223g / eq., manufactured by DIC Corporation HPC-8000L-65MT: Active ester resin containing dicyclopentadiene-type diphenol structure, functional group equivalent weight 229g / eq., manufactured by DIC Corporation PC1300-02-65MA: Activated ester resin with naphthalene structure, functional group equivalent weight 199g / eq., manufactured by Air Water Inc. LA-3018-50P: 1-methoxy-2-propanol solution with functional group equivalent of 151 g / eq. and non-volatile content of 50% by mass, manufactured by DIC Corporation V-03: Functional group equivalent weight 216 g / eq., toluene solution with non-volatile content of 50% by mass, manufactured by Nisshinbo Chemical Inc. Maleimide A: Synthesized in Synthesis Example 1, a maleimide-based radical polymerizable resin ODV-XET-X04: Styrene-based radical polymerizable compound, manufactured by Nippon Steel Chemical & Material Co., Ltd. OPE-2St: Vinylbenzyl-modified polyphenylene ether (Mitsubishi Gas Chemical Company, toluene solution with 65% non-volatile content) A-DOG: Dioxane glycol diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.) BA230S75: Prepolymer of bisphenol A dicyanate, functional group equivalent weight 232g / eq., manufactured by Lonza G-100C: Polystyrene resin, weight average molecular weight 402,000, manufactured by Toyo Styrene Co., Ltd. (C) Component SO-C2: Spherical silica surface-treated with an amine-based alkoxysilane compound ("KBM573" manufactured by Shin-Etsu Chemical Co., Ltd.), average particle size 0.5 μm, specific surface area 5.8 m 2 / g, manufactured by Admatechs Co., Ltd. UFP-30: Spherical silica surface-treated with an amine-based alkoxysilane compound (Shin-Etsu Chemical Co., Ltd.'s "KBM573"), with an average particle size of 0.3 μm and a specific surface area of ​​30.7 m 2 / g, manufactured by Denka (D) Component NC-3000-L: Biphenyl type epoxy resin, functional group equivalent weight 269g / eq., manufactured by Nippon Kayaku Co., Ltd. HP-4032-SS: Naphthalene-type epoxy resin, functional group equivalent weight approx. 145g / eq., manufactured by DIC Corporation ZX-1059: 1:1 mixture of bisphenol A epoxy resin and bisphenol F epoxy resin, functional group equivalent weight 169g / eq., manufactured by Nippon Steel Chemical & Material Co., Ltd. (E) Component YX7553BH30: Phenoxy resin, 1:1 solution of MEK and cyclohexanone with 30% non-volatile content, manufactured by Mitsubishi Chemical Corporation Polyimide B: Synthesized in Synthesis Example 2 (F) Component 1B2PZ: Imidazole-based reaction accelerator, manufactured by Shikoku Chemicals Corporation DMAP: Amine-based curing accelerator, manufactured by Tokyo Chemical Industry Co., Ltd. Co(III): Metallic hardening accelerator, manufactured by Tokyo Chemical Industry Co., Ltd. (G) Component Perbutyl C: Radical polymerization initiator, t-butylcumyl peroxide (NOF Corporation) (H) Component EXL2655: Core-shell graft copolymer rubber particles, manufactured by The Dow Chemical Company

[0226] <Measurement of the average particle size of inorganic fillers> 100 mg of inorganic filler, 0.1 g of dispersant (San Nopco "SN9228"), and 10 g of methyl ethyl ketone were weighed into a vial and dispersed ultrasonically for 20 minutes. The particle size distribution was measured using a laser diffraction particle size distribution analyzer (Shimadzu Corporation "SALD-2200") using a batch cell method, and the average particle size was calculated based on the median diameter.

[0227] <Measurement of dielectric loss tangent, coefficient of linear thermal expansion, and modulus of elasticity> (1) Preparation of resin sheet A having a resin composition layer thickness of 40 μm A polyethylene terephthalate film ("AL5" manufactured by Lintec Corporation, thickness 38 μm) with a release layer was prepared as a support. The resin varnishes obtained in the Examples and Comparative Examples were uniformly applied onto the release layer of this support so that the thickness of the resin composition layer after drying would be 40 μm. Thereafter, the resin composition was dried at 80°C to 100°C (average 90°C) for 2 minutes to obtain a resin sheet A including a support and a resin composition layer.

[0228] (2) Preparation of a cured resin composition layer The prepared resin sheet A was cured for 90 minutes in an oven at 190° C. The support was peeled off from the resin sheet A taken out of the oven to obtain a cured resin composition layer.

[0229] (3) Measurement of dielectric loss tangent (dielectric properties) The cured resin composition layer was cut into a piece of 80 mm long and 2 mm wide, and the dielectric loss tangent (Df value) was measured by the cavity resonance perturbation method using an Agilent Technologies HP8362B at a measurement frequency of 5.8 GHz and measurement temperatures of 23° C. and 90° C. Measurement was performed on two test pieces, and the average was calculated.

[0230] (4) Measurement of the coefficient of linear thermal expansion The cured resin composition layer was cut into test pieces approximately 5 mm wide and 15 mm long, and thermomechanical analysis was performed using a thermomechanical analyzer (Rigaku Corporation, "Thermo Plus TMA8310") using the tensile load method. Specifically, the test pieces were mounted in the analyzer and subjected to two consecutive measurements under the conditions of a 1 g load and a heating rate of 5°C / min (the first measurement was performed at 200°C, and the second measurement was performed at 260°C). The average linear thermal expansion coefficient (ppm / °C) from 25°C to 150°C was calculated in the second measurement.

[0231] (5) Measurement of elastic modulus The tensile strength of the cured resin composition layer was measured using an Orientec tensile tester "RTC-1250A," and the modulus of elasticity at 23°C was measured. The measurement was carried out in accordance with JIS K7127. The measurement was carried out five times, and the average of the top three points was calculated.

[0232] <Crack resistance evaluation> (1) Lamination of resin sheet A An inner layer substrate ("MCL-E700G" manufactured by Resonac Corporation) having circuit conductors (copper) with 100 or more L / S=8μm / 8μm wiring patterns on both sides was prepared. The conductor layer was 35μm thick, with a total thickness of 0.4mm and a residual copper ratio of 40%). Resin sheet A was laminated on both sides of this inner layer substrate so that the resin composition layer was in contact with the inner layer substrate. This lamination was performed using a vacuum pressure laminator ("MVLP-500" manufactured by Meiki Seisakusho Co., Ltd.) by vacuum suction at a temperature of 120°C for 30 seconds, followed by lamination at a temperature of 120°C and a pressure of 7.0 kg / cm. 2 Then, the substrate was pressed for 30 seconds using a heat-resistant rubber sheet under atmospheric pressure at a temperature of 120°C and a pressure of 5.5 kg / cm using a stainless steel end plate. 2 The press was performed for 60 seconds under the conditions.

[0233] (2) Thermal curing of the resin composition layer The inner layer substrate laminated with resin sheet A was heated at 130°C for 30 minutes, and then at 170°C for 30 minutes to thermally cure the resin composition layer and obtain an insulating layer. The support was then peeled off to obtain a sample substrate having a layer structure of insulating layer / inner layer substrate / insulating layer.

[0234] (3) Roughening treatment The insulating layer of the sample substrate was roughened. Specifically, the sample substrate was immersed in a swelling solution, Securiganth P (Atotech Japan), at 60°C for 10 minutes. Next, it was immersed in a roughening solution, Concentrate Compact P (Atotech Japan), at 80°C for 20 minutes. Finally, it was immersed in a neutralizing solution, Reduction Solution Securiganth P (Atotech Japan), at 40°C for 5 minutes.

[0235] (4) Evaluation of crack resistance After the roughening treatment, the insulating layer surface was observed on the L / S pattern of the inner layer substrate. The surface of 100 inner layer substrates was checked for cracks along the pattern shape, and the percentage of the number of areas on the pattern where cracks did not occur was counted. This percentage was calculated as the "yield." The calculated yield was then scored according to the following criteria. 1 point: 0% or more but less than 20%. 2 points: 20% or more but less than 40%. 3 points: 40% or more but less than 60%. 4 points: 60% or more but less than 80%. 5 points: 80% or above. A score of 3 or more was evaluated as "○", and a score of 2 or less was evaluated as "×".

[0236] [Table 2]

[0237] In Examples 1 to 11, it was confirmed that even when components (D) to (H) were not contained, the same results as those in the above Examples were obtained, although to different degrees.

Claims

1. (A) a styrene resin having a structural unit represented by the following formula (A-1) and a structural unit represented by the following formula (A-2), (B) a thermosetting resin, and (C) A resin composition containing an inorganic filler. 【Chemical 1】 In formula (A-2), R １ represents an aryl group having 6 to 20 carbon atoms which may have a substituent. * represents a bond.

2. The resin composition according to claim 1, wherein the component (A) has a structural unit represented by the following formula (A-1), a structural unit represented by the following formula (A-2), and a structural unit represented by the following formula (A-3): 【Chemistry 2】 In formula (A-2), R １ represents an aryl group having 6 to 20 carbon atoms which may have a substituent. In formula (A-3), R ２ represents an alkyl group having 2 to 15 carbon atoms which may have a substituent, or an alkoxy group having 2 to 15 carbon atoms which may have a substituent. * represents a bond.

3. R in formula (A-3) ２ The resin composition according to claim 2, wherein the bonding position of is the para position.

4. The resin composition according to claim 1, wherein the number average molecular weight of component (A) is 15,000 or less.

5. The resin composition according to claim 1 , wherein the component (B) comprises an active ester resin.

6. The resin composition according to claim 1 , wherein the component (B) comprises a phenolic resin.

7. The resin composition according to claim 1 , wherein the component (B) comprises a radical polymerizable resin.

8. The resin composition according to claim 7 , wherein the radical polymerizable resin comprises a maleimide resin.

9. A resin sheet comprising a support and a resin composition layer provided on the support, the resin composition comprising the resin composition according to any one of claims 1 to 8.

10. A printed wiring board comprising an insulating layer formed from a cured product of the resin composition according to any one of claims 1 to 8.

11. A semiconductor device comprising the printed wiring board according to claim 10.

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