resin composition

Abstract

To provide a resin composition or the like that can form an insulating layer having excellent flame retardancy, dielectric properties, and high-temperature reflow expansion resistance.SOLUTION: A resin composition contains (A) curable resin, (B) inorganic filler, and (C) non-inflammable gas.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This invention relates to a resin composition. [Background technology]

[0002] As a manufacturing technique for printed circuit boards, a build-up method is known in which insulating layers and conductive layers are stacked alternately. In the build-up method, the insulating layer is generally formed by curing a resin composition (Patent Document 1). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-23714 [Overview of the project] [Problems that the invention aims to solve]

[0004] In recent years, when manufacturing multilayer printed circuit boards, the cured resin compositions used to form the insulating layer are required to have excellent flame retardancy and dielectric properties, including relative permittivity and dielectric loss tangent. However, if both flame retardancy and dielectric properties are excellent, the heat resistance after curing may decrease, and blistering may occur during reflow soldering. Therefore, there is a need for materials that are excellent in both flame retardancy and dielectric properties, as well as excellent resistance to reflow blistering at high temperatures.

[0005] The present invention was devised in view of the above-mentioned problems, and aims to provide a resin composition capable of forming an insulating layer with excellent flame retardancy, dielectric properties, and resistance to high-temperature reflow blistering; a cured product of the resin composition; a sheet-like laminated material containing the resin composition; a resin sheet having a resin composition layer formed of the resin composition; a printed circuit board comprising an insulating layer containing a cured product of the resin composition; and a semiconductor device comprising the printed circuit board. [Means for solving the problem]

[0006] The inventors diligently studied to solve the aforementioned problems. As a result, the inventors found that the aforementioned problems could be solved by incorporating (C) a non-combustible gas into the resin composition, and thus completed the present invention. In other words, the present invention includes the following:

[0007] [1] (A) Curing resin, (B) Inorganic fillers, and (C) A resin composition containing a non-flammable gas. [2] The resin composition according to [1], wherein the content of component (C) is 3% by volume or more when the nonvolatile components in the resin composition are taken as 100% by volume. [3] The resin composition according to [1] or [2], wherein component (C) is one or more selected from nitrogen gas, argon gas, carbon dioxide gas, helium gas, and neon gas. [4] The resin composition according to any one of [1] to [3], wherein component (B) comprises a hollow inorganic filler (B-1) having voids inside, and component (C) is contained within the voids of component (B-1). [5] The resin composition according to [4], wherein the average particle size of component (B-1) is 0.01 μm or more and 5 μm or less. [6] The resin composition according to [4] or [5], wherein the porosity of component (B-1) is 10% by volume or more and 80% by volume or less. [7] A resin composition according to any one of [4] to [6], wherein component (B) comprises component (B-1) and a solid inorganic filler (B-2). [8] The resin composition according to any one of [1] to [7], wherein component (A) comprises at least one selected from the group consisting of epoxy resins, phenolic resins, activated ester resins, cyanate resins, and radical polymerizable resins. [9] Furthermore, the resin composition according to any one of [1] to [8], comprising (D) organic particles.

[10] A resin composition according to any one of [1] to [9] for forming an insulating layer.

[11] A cured product of any of the resin compositions described in [1] to

[10] .

[12] A sheet-like laminated material containing the resin composition described in any of [1] to

[10] .

[13] A resin sheet having a support and a resin composition layer formed on the support with any of the resin compositions described in [1] to

[10] .

[14] A printed circuit board comprising an insulating layer containing a cured product of any of the resin compositions described in [1] to

[10] .

[15]

[14] A semiconductor device comprising a printed circuit board as described above. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a resin composition capable of forming an insulating layer with excellent flame retardancy, dielectric properties, and resistance to high-temperature reflow blistering; a cured product of the resin composition; a sheet-like laminated material containing the resin composition; a resin sheet having a resin composition layer formed of the resin composition; a printed circuit board comprising an insulating layer containing a cured product of the resin composition; and a semiconductor device comprising the printed circuit board. [Modes for carrying out the invention]

[0009] The present invention will be described below with reference to embodiments and examples. However, the present invention is not limited to the embodiments and examples shown below, and may be implemented with modifications as appropriate without departing from the scope of the claims and their equivalents.

[0010] In the following explanation, the term "(meth)acrylic" includes acrylic, methacrylic, and combinations thereof. The term "(meth)acrylate" includes acrylate, methacrylate, and combinations thereof. "(meth)acryloyloxy group" includes acryloyloxy group, methacryloyloxy group, and combinations thereof. Furthermore, the term "(meth)acrylonitrile" includes acrylonitrile, methacrylonitrile, and combinations thereof.

[0011] [Resin composition] The resin composition of the present invention comprises (A) a curable resin, (B) an inorganic filler, and (C) a non-combustible gas. A resin composition that satisfies these requirements can form an insulating layer with excellent flame retardancy, dielectric properties, and resistance to high-temperature reflow blistering. Furthermore, the resin composition typically has a low coefficient of thermal expansion, excellent dielectric properties even at high temperatures, and can form an insulating layer with excellent elongation (elongation at break).

[0012] The resin composition of the present invention may contain, in combination with (A) a curable resin, (B) an inorganic filler, and (C) a non-combustible gas, (D) organic particles, (E) a curing accelerator, (F) a thermoplastic resin, (G) a flame retardant, and (H) other additives. Each component that may be included in the resin composition will be described in detail below.

[0013] <(A) Curing resin> The resin composition includes a curable resin as component (A). The curable resin (A) can be a resin that can be cured when heat is applied. The curable resin may be used alone or in combination of two or more types.

[0014] Examples of curable resins include epoxy resins, phenolic resins, activated ester resins, cyanate resins, carbodiimide resins, acid anhydride resins, amine resins, benzoxazine resins, thiol resins, and radical polymerizable resins. Curable resins may be used individually or in combination of two or more types. In particular, it is preferable that the curable resin includes at least one selected from the group consisting of epoxy resins, activated ester resins, cyanate resins, and radical polymerizable resins.

[0015] In particular, from the viewpoint of obtaining the effects of the present invention in a remarkable manner, it is preferable to use a combination of an epoxy resin and a resin that can react with the epoxy resin to cure the resin composition. The resin that can react with the epoxy resin to cure the resin composition may be referred to below as the "curing agent". Examples of curing agents include phenol resins, activated ester resins, cyanate resins, carbodiimide resins, acid anhydride resins, amine resins, benzoxazine resins, and thiol resins. Among these, phenol resins, activated ester resins, cyanate resins, and carbodiimide resins are preferred, phenol resins, activated ester resins, and cyanate resins are more preferred, activated ester resins and cyanate resins are even more preferred, and activated ester resins are particularly preferred. Furthermore, one type of curing agent may be used alone, or two or more types may be used in combination.

[0016] Epoxy resin is a curable resin that contains epoxy groups. Examples of epoxy resins include bixylenol-type epoxy resin, bisphenol A-type epoxy resin, bisphenol F-type epoxy resin, bisphenol S-type epoxy resin, bisphenol AF-type epoxy resin, dicyclopentadiene-type epoxy resin, trisphenol-type epoxy resin, naphthol novolac-type epoxy resin, phenol novolac-type epoxy resin, tert-butyl-catechol-type epoxy resin, naphthalene-type epoxy resin, naphthol-type epoxy resin, anthracene-type epoxy resin, glycidylamine-type epoxy resin, glycidyl ester-type epoxy resin, cresol novolac-type epoxy resin, phenol aralkyl-type epoxy resin, biphenyl-type epoxy resin, linear aliphatic epoxy resin, epoxy resin having a butadiene structure, alicyclic epoxy resin, heterocyclic epoxy resin, spiro-ring-containing epoxy resin, cyclohexane-type epoxy resin, cyclohexanedimethanol-type epoxy resin, naphthylene ether-type epoxy resin, trimethylol-type epoxy resin, tetraphenylethane-type epoxy resin, isocyanurate-type epoxy resin, and phenolphthaleimidine-type epoxy resin. Epoxy resin may be used individually or in combination of two or more types.

[0017] From the viewpoint of obtaining a cured product with excellent resistance to high-temperature reflow blistering, it is preferable that the epoxy resin contains an aromatic structure. An aromatic structure is a chemical structure generally defined as aromatic, and includes polycyclic aromatics and aromatic heterocyclics. Examples of epoxy resins containing aromatic structures include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol AF type epoxy resin, dicyclopentadiene type epoxy resin, trisphenol type epoxy resin, naphthol novolac type epoxy resin, phenol novolac type epoxy resin, tert-butyl-catechol type epoxy resin, naphthalene type epoxy resin, naphthol type epoxy resin, anthracene type epoxy resin, bisquilenol type epoxy resin, glycidylamine type epoxy resin having an aromatic structure, glycidyl ester type epoxy resin having an aromatic structure, cresol novolac type epoxy resin, biphenyl type epoxy resin, linear aliphatic epoxy resin having an aromatic structure, epoxy resin having a butadiene structure having an aromatic structure, alicyclic epoxy resin having an aromatic structure, heterocyclic epoxy resin, spiro-ring containing epoxy resin having an aromatic structure, cyclohexanedimethanol type epoxy resin having an aromatic structure, naphthylene ether type epoxy resin, trimethylol type epoxy resin having an aromatic structure, and tetraphenylethane type epoxy resin having an aromatic structure.

[0018] (A) The curable resin preferably contains an epoxy resin having two or more epoxy groups in one molecule. The proportion of the epoxy resin having two or more epoxy groups in one molecule is preferably 50% by mass or more, more preferably 60% by mass or more, and particularly preferably 70% by mass or more, relative to 100% by mass of the nonvolatile component of the epoxy resin.

[0019] Epoxy resins include epoxy resins that are liquid at 20°C (hereinafter sometimes referred to as "liquid epoxy resins") and epoxy resins that are solid at 20°C (hereinafter sometimes referred to as "solid epoxy resins"). The resin composition may contain only liquid epoxy resin, or only solid epoxy resin, or a combination of liquid epoxy resin and solid epoxy resin.

[0020] As the liquid epoxy resin, a liquid epoxy resin having two or more epoxy groups in one molecule is preferred.

[0021] Preferred liquid epoxy resins include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AF type epoxy resin, naphthalene type epoxy resin, glycidyl ester type epoxy resin, glycidylamine type epoxy resin, phenol novolac type epoxy resin, alicyclic epoxy resin having an ester skeleton, cyclohexane type epoxy resin, cyclohexanedimethanol type epoxy resin, and epoxy resin having a butadiene structure, with bisphenol A type epoxy resin and naphthalene type epoxy resin being more preferred.

[0022] Specific examples of liquid epoxy resins include: DIC Corporation's "HP4032", "HP4032D", "HP4032SS" (naphthalene-type epoxy resin); Mitsubishi Chemical Corporation's "828US", "828EL", "jER828EL", "825", "Epicote 828EL" (bisphenol A-type epoxy resin); Mitsubishi Chemical Corporation's "jER807", "1750" (bisphenol F-type epoxy resin); Mitsubishi Chemical Corporation's "jER152" (phenol novolac-type epoxy resin); Mitsubishi Chemical Corporation's "630", "630LSD", "604" (glycidylamine-type epoxy resin); ADEKA Corporation's "ED-523T" (glycyrrhizol-type epoxy resin); ADEKA Corporation's "EP-3950L", "EP-3980S" ( Examples include glycidylamine-type epoxy resins; ADEKA's "EP-4088S" (dicyclopentadiene-type epoxy resin); Nippon Steel Chemical & Material's "ZX1059" (a mixture of bisphenol A-type epoxy resin and bisphenol F-type epoxy resin); Nagase ChemteX's "EX-721" (glycidyl ester-type epoxy resin); Daicel's "Celoxide 2021P" (alicyclic epoxy resin with an ester skeleton); Daicel's "PB-3600", Nippon Soda's "JP-100" and "JP-200" (epoxy resins with a butadiene structure); and Nippon Steel Chemical & Material's "ZX1658" and "ZX1658GS" (liquid 1,4-glycidylcyclohexane-type epoxy resins). These can be used individually or in combination of two or more types.

[0023] As the solid epoxy resin, a solid epoxy resin having three or more epoxy groups per molecule is preferred, and an aromatic solid epoxy resin having three or more epoxy groups per molecule is more preferred.

[0024] As solid epoxy resins, bixylenol-type epoxy resins, naphthalene-type epoxy resins, naphthalene-type tetrafunctional epoxy resins, naphthol novolac-type 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, phenol aralkyl-type epoxy resins, tetraphenylethane-type epoxy resins, and phenolphthaleimidine-type epoxy resins are preferred, with biphenyl-type epoxy resins and naphthylene ether-type epoxy resins being more preferred.

[0025] Specific examples of solid epoxy resins include DIC's "HP4032H" (naphthalene-type epoxy resin); DIC's "HP-4700" and "HP-4710" (naphthalene-type tetrafunctional epoxy resins); DIC's "N-690" (cresol novolac-type epoxy resin); DIC's "N-695" (cresol novolac-type epoxy resin); DIC's "HP-7200", "HP-7200HH", "HP-7200H", and "HP-7200L" (dicyclopentadiene-type epoxy resins); and DIC's "EXA-7311". "EXA-7311-G3", "EXA-7311-G4", "EXA-7311-G4S", "HP6000" (naphthylene ether type epoxy resin); "EPPN-502H" (trisphenol type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; "NC7000L" (naphthol novolac type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; "NC3000H", "NC3000", "NC3000L", "NC3000FH", "NC3100" (biphenyl type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; "ESN475V", "ESN4 100V (naphthalene-type epoxy resin); "ESN485" (naphthol-type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "ESN375" (dihydroxynaphthalene-type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "YX4000H", "YX4000", "YX4000HK", "YL7890" (bixylenol-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "YL6121" (biphenyl-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "YX8800" (anthracene-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "Y Examples include "X7700" (phenol aralkyl type epoxy resin); "PG-100" and "CG-500" from Osaka Gas Chemical Co., Ltd.; "YX7760" (bisphenol AF type epoxy resin) from Mitsubishi Chemical Corporation; "YL7800" (fluorene type epoxy resin) from Mitsubishi Chemical Corporation; "jER1010" (bisphenol A type epoxy resin) from Mitsubishi Chemical Corporation; "jER1031S" (tetraphenylethane type epoxy resin) from Mitsubishi Chemical Corporation; and "WHR991S" (phenolphthalein type epoxy resin) from Nippon Kayaku Co., Ltd.These can be used individually or in combination of two or more types.

[0026] When using a combination of liquid epoxy resin and solid epoxy resin as the epoxy resin, their mass ratio (liquid epoxy resin:solid epoxy resin) is preferably 1:0.01 to 1:20, more preferably 1:0.05 to 1:10, and particularly preferably 1:0.1 to 1:7.

[0027] The epoxy equivalent of the epoxy resin is preferably 50 g / eq. to 5,000 g / eq., more preferably 60 g / eq. to 3,000 g / eq., even more preferably 80 g / eq. to 2,000 g / eq., and particularly preferably 110 g / eq. to 1,000 g / eq. The epoxy equivalent represents the mass of resin per equivalent of epoxy groups. This epoxy equivalent can be measured according to JIS K7236.

[0028] The weight-average molecular weight (Mw) of the epoxy resin 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 as a polystyrene equivalent by gel permeation chromatography (GPC).

[0029] From the viewpoint of obtaining a cured product exhibiting good mechanical strength and insulation reliability, the epoxy resin content in the resin composition is preferably 1% by mass or more, more preferably 5% by mass or more, particularly preferably 10% by mass or more, preferably 50% by mass or less, more preferably 40% by mass or less, and particularly preferably 30% by mass or less, when the non-volatile components in the resin composition are considered to be 100% by mass.

[0030] As the phenolic resin, a compound having one or more, preferably two or more, hydroxyl groups bonded to aromatic rings such as benzene rings and naphthalene rings per molecule can be used. When combined with epoxy resins, phenolic resins can react with epoxy resins to cure the resin composition, and are therefore sometimes called "phenolic curing agents." From the viewpoint of high-temperature reflow blister resistance and water resistance, phenolic resins having a novolac structure are preferred. Furthermore, from the viewpoint of adhesion, nitrogen-containing phenolic resins are preferred, and triazine skeleton-containing phenolic resins are more preferred. Among these, triazine skeleton-containing phenol novolac resins are preferred from the viewpoint of highly satisfying high-temperature reflow blister resistance, water resistance, and adhesion. Specific examples of phenolic resins include, for example, "MEH-7700," "MEH-7810," and "MEH-7851" from Meiwa Kasei Co., Ltd., "NHN," "CBN," and "GPH" from Nippon Kayaku Co., Ltd., "SN-170," "SN-180," "SN-190," "SN-475," "SN-485," "SN-495," "SN-375," and "SN-395" from Nippon Steel Chemical & Material Co., Ltd., and "LA-7052," "LA-7054," "LA-3018," "LA-3018-50P," "LA-1356," "TD2090," and "TD-2090-60M" from DIC Corporation.

[0031] As the active ester resin, compounds having two or more highly reactive ester groups in one molecule, such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds, are generally preferred. When combined with epoxy resins, the active ester resin can react with the epoxy resin to cure the resin composition, and is therefore sometimes called an "active ester curing agent." The active ester resin is preferably obtained by a condensation reaction between a carboxylic acid compound and / or a thiocarboxylic acid compound and a hydroxy compound and / or a thiol compound. Particularly from the viewpoint of improving resistance to high-temperature reflow blistering, an active ester resin obtained from a carboxylic acid compound and a hydroxy compound is preferred, and an active ester resin obtained from a carboxylic acid compound and / or a naphthol compound is 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, phenolphthalein, 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 novolac. Here, "dicyclopentadiene-type diphenol compounds" refers to diphenol compounds obtained by the condensation of two phenol molecules with one dicyclopentadiene molecule.

[0032] Specifically, preferred active ester resins include dicyclopentadiene-type active ester resins, naphthalene-type active ester resins containing a naphthalene structure, active ester resins containing an acetylated phenol novolac, and active ester resins containing a benzoylated phenol novolac. More preferably, the active ester resin is at least one selected from dicyclopentadiene-type active ester resins and naphthalene-type active ester resins. As for the dicyclopentadiene-type active ester resin, an active ester resin containing a dicyclopentadiene-type diphenol structure is preferred.

[0033] Commercially available activated 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-8000", "HPC-8000-65T", "HPC-8000H", and "HPC-8000H-65TM" (manufactured by DIC Corporation); and activated ester resins containing a naphthalene structure such as "HP-B-8151-62T", "EXB-8100L-65T", "EXB-8150-60T", and "EXB-815 Examples include "0-62T", "EXB-9416-70BK", "HPC-8150-60T", "HPC-8150-62T", and "EXB-8" (manufactured by DIC Corporation); as a phosphorus-containing active ester resin, "EXB9401" (manufactured by DIC Corporation); as an active ester resin that is an acetylated phenol novolac, "DC808" (manufactured by Mitsubishi Chemical Corporation); as an active ester resin that is a benzoylated phenol novolac, "YLH1026", "YLH1030", and "YLH1048" (manufactured by Mitsubishi Chemical Corporation); and as an active ester resin containing a styryl group and a naphthalene structure, "PC1300-02-65MA" (manufactured by Air Water Corporation).

[0034] As the cyanate resin, a compound having one or more, preferably two or more cyanate groups in one molecule can be used. When combined with an epoxy resin, the cyanate resin can react with the epoxy resin to cure the resin composition, and is therefore sometimes referred to as 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; polyfunctional cyanate resins derived from phenol novolacs and cresol novolacs; and prepolymers in which these cyanate resins are partially triazined. Specific examples of cyanate resins include "PT30" and "PT60" (both phenol novolac type polyfunctional cyanate resins) manufactured by Lonza Japan, "BA230", and "BA230S75" (prepolymers in which part or all of bisphenol A dicyanate is triazined and trimerized).

[0035] As the carbodiimide resin, a compound having one or more, preferably two or more, carbodiimide structures in one molecule can be used. Carbodiimide resins can react with epoxy resins when combined with epoxy resins to cure the resin composition, and are therefore sometimes called "carbodiimide-based curing agents." Specific examples of carbodiimide resins include aliphatic biscarbodiimides such as tetramethylene-bis(t-butylcarbodiimide) and cyclohexanebis(methylene-t-butylcarbodiimide); biscarbodiimides such as aromatic biscarbodiimides such as phenylene-bis(xylylcarbodiimide); aliphatic polycarbodiimides such as polyhexamethylenecarbodiimide, polytrimethylhexamethylenecarbodiimide, polycyclohexylenecarbodiimide, poly(methylenebiscyclohexylenecarbodiimide), and poly(isophoronecarbodiimide); and poly(phenylenecarbodiimide), poly(na Examples of polycarbodiimides include aromatic polycarbodiimides such as phthalenecarbodiimide, poly(tylenecarbodiimide), poly(methyldiisopropylphenylenecarbodiimide), poly(triethylphenylenecarbodiimide), poly(diethylphenylenecarbodiimide), poly(triisopropylphenylenecarbodiimide), poly(diisopropylphenylenecarbodiimide), poly(xylylenecarbodiimide), poly(tetramethylxylylenecarbodiimide), poly(methylenediphenylenecarbodiimide), and poly[methylenebis(methylphenylene)carbodiimide]. Examples of commercially available carbodiimide resins include "Carbodilite V-02B," "Carbodilite V-03," "Carbodilite V-04K," "Carbodilite V-07," and "Carbodilite V-09" from Nisshinbo Chemical Co., Ltd., and "Stabaxol P," "Stabaxol P400," and "Hycazil 510" from Rhein Chemie Corporation.

[0036] 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 epoxy groups, the acid anhydride resin can react with the epoxy resin to cure the resin composition, and is therefore 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-cyclohexen-1,2-dicarboxylic acid anhydride, trimellitic anhydride, pyromellitic anhydride, and bensophenone tetracarboxylic acid dihydroanhydride. Examples include aqueous solutions, biphenyltetracarboxylic acid dianhydride, naphthalenetetracarboxylic acid dianhydride, oxydiphthalic acid dianhydride, 3,3'-4,4'-diphenylsulfonetetracarboxylic acid 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 polymer-type acid anhydrides such as styrene-maleic acid resin obtained by copolymerizing styrene and maleic acid. Examples of commercially available acid anhydride resins include "HNA-100," "MH-700," "MTA-15," "DDSA," and "OSA" from Shin Nippon Rika Co., Ltd.; "YH-306" and "YH-307" from Mitsubishi Chemical Corporation; "HN-2200" and "HN-5500" from Hitachi Chemical Co., Ltd.; and "EF-30," "EF-40," "EF-60," and "EF-80" from Clay Valley Corporation.

[0037] As the amine resin, a compound having one or more, preferably two or more, amino groups in one molecule can be used. When combined with epoxy groups, the amine resin can react with the epoxy resin to cure the resin composition, and is therefore sometimes called an "amine-based curing agent." Examples of amine resins include aliphatic amines, polyetheramines, alicyclic amines, and aromatic amines, with aromatic amines being preferred. The amine resin is preferably a primary amine or a 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'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, 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)propyl Examples include pan, 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, bis(4-(3-aminophenoxy)phenyl)sulfone, etc. Examples of commercially available amine resins include "SEIKACURE-S" from Seika Corporation; "KAYABOND C-200S," "KAYABOND C-100," "KAYAHARD AA," "KAYAHARD AB," and "KAYAHARD AS" from Nippon Kayaku Co., Ltd.; "Epicure W" from Mitsubishi Chemical Corporation; and "DTDA" from Sumitomo Seika Co., Ltd.

[0038] Benzooxazine resins can react with epoxy resins when combined with them to cure the resin composition, and are therefore sometimes referred to as "benzooxazine-based curing agents." Specific examples of benzooxazine resins include "JBZ-OP100D" and "ODA-BOZ" from JFE Chemical Corporation; "HFB2006M" from Showa Polymer Co., Ltd.; and "Pd" and "Fa" from Shikoku Chemicals Co., Ltd.

[0039] Thiol resins can react with epoxy resins when combined with them to cure the resin composition, and are therefore sometimes called "thiol-based curing agents." Examples of thiol resins include trimethylolpropane tris(3-mercaptopropionate), pentaerythritol tetrakis(3-mercaptobutyrate), and tris(3-mercaptopropyl) isocyanurate.

[0040] 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., even 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 one active group.

[0041] When the number of epoxy groups in the epoxy resin is set to 1, the number of active groups in the curing agent is preferably 0.1 or more, more preferably 0.2 or more, even more preferably 0.5 or more, preferably 5.0 or less, more preferably 4.0 or less, and particularly preferably 3.0 or less. "Number of epoxy groups in the epoxy resin" refers to the sum of all values ​​obtained by dividing the mass of nonvolatile components of the epoxy resin present in the resin composition by the epoxy equivalent. Similarly, "number of active groups in the curing agent" refers to the sum of all values ​​obtained by dividing the mass of nonvolatile components of the curing agent present in the resin composition by the active group equivalent.

[0042] From the viewpoint of significantly obtaining the effects of the present invention, the content of the curing agent in the resin composition is preferably 1% by mass or more, more preferably 2% by mass or more, particularly preferably 5% by mass or more, preferably 40% by mass or less, more preferably 30% by mass or less, and particularly preferably 25% by mass or less, when the nonvolatile components in the resin composition are considered to be 100% by mass.

[0043] As the radical polymerizable resin, compounds having ethylenically unsaturated bonds can be used. Therefore, the radical polymerizable resin may have radical polymerizable groups containing ethylenically unsaturated bonds. Examples of radical polymerizable groups include unsaturated hydrocarbon groups such as vinyl groups, allyl groups, 3-cyclohexenyl groups, 3-cyclopentenyl groups, 2-vinylphenyl groups, 3-vinylphenyl groups, and 4-vinylphenyl groups; and α,β-unsaturated carbonyl groups such as acryloyl groups, methacryloyl groups, and maleimide groups (2,5-dihydro-2,5-dioxo-1H-pyrrole-1-yl groups). The number of radical polymerizable groups contained in one molecule of the radical polymerizable resin may be one, but two or more are preferred. The radical polymerizable resin may be used alone or in combination of two or more types.

[0044] Examples of preferred radical polymerizable resins include styrene-based radical polymerizable resins. Styrene-based radical polymerizable resins may be compounds having one or more, preferably two or more, vinyl groups directly bonded to aromatic carbon atoms. Examples of styrene-based radical polymerizable resins 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 compounds such as vinylbenzyl-modified polyphenylene ether resins and styrene-divinylbenzene copolymers.

[0045] As the styrenic radical polymerizable resin, a modified polyphenylene ether resin having a vinylphenyl group is preferred. The vinylphenyl group may include a 2-vinylphenyl group, a 3-vinylphenyl group, a 4-vinylphenyl group, or a group in which the aromatic carbon atom thereof is further substituted with one or more alkyl groups. Among these, as the styrenic radical polymerizable resin, a resin represented by the following formula (A-1) is particularly preferred.

[0046]

Chemical Formula

[0047] (In formula (A-1), R 11 and R 12 each independently represent an alkyl group; R 13 , R 14 , R 21 , R 22 , R 23 and R 24 each independently represent a hydrogen atom or an alkyl group; R 31 and R 32 each independently represent a vinylphenyl group; Y 1 represents a single bond, -C(R y )2-, -O-, -CO-, -S-, -SO-, or -SO2-; R y each independently represent a hydrogen atom or an alkyl group; Y 2 represents a single bond or an alkylene group; p represents 0 or 1; q and r each independently represent an integer of 1 or greater.) The q units and r units may each be the same or different for each unit, respectively.

[0048] In formula (A-1), R 11 and R 12 each independently represent an alkyl group, and is preferably a methyl group.

[0049] In equation (A-1), R 13 and R 14 Each of these independently represents a hydrogen atom or an alkyl group, preferably a hydrogen atom.

[0050] In equation (A-1), R 21 and R 22 Each of these independently represents a hydrogen atom or an alkyl group, preferably a hydrogen atom or a methyl group, and more preferably a methyl group.

[0051] In equation (A-1), R 23 and R 24 Each of these independently represents a hydrogen atom or an alkyl group, preferably a hydrogen atom or a methyl group.

[0052] In equation (A-1), R 31 and R 32 Each of these independently represents a vinylphenyl group.

[0053] In equation (A-1), Y 2 This represents a single bond or an alkylene group. An alkylene group means a linear, branched, and / or cyclic divalent aliphatic saturated hydrocarbon group. The alkylene group is preferably an alkylene group having 1 to 14 carbon atoms, more preferably an alkylene group having 1 to 10 carbon atoms, and particularly preferably an alkylene group having 1 to 6 carbon atoms. Examples of alkylene groups include -CH2-, -CH2-CH2-, -CH(CH3)-, -CH2-CH2-CH2-, -CH2-CH(CH3)-, -CH(CH3)-CH2-, -C(CH3)2-, etc. Preferably, Y 2 However, it is an alkylene group (particularly preferably -CH2-).

[0054] In equation (A-1), Y 1 This is a single bond, -C(R y )2-, -O-, -CO-, -S-, -SO-, or -SO2-, preferably a single bond, -C(R y)2-, or -O-, and particularly preferably a single bond. y Each of these independently represents a hydrogen atom or an alkyl group, preferably a hydrogen atom or a methyl group.

[0055] In formula (A-1), p represents 0 or 1, preferably 1.

[0056] In formula (A-1), q and r each independently represent an integer of 1 or more, preferably an integer between 1 and 200, and more preferably an integer between 1 and 100.

[0057] Specific examples of resins represented by formula (A-1) include, for example, the resin represented by the following formula (A-1-1). Examples of resins represented by formula (A-1-1) include "OPE-2St 1200" and "OPE-2St 2200" (vinyl benzyl modified polyphenylene ether resin) manufactured by Mitsubishi Gas Chemical Company.

[0058] [ka]

[0059] Another preferred radical polymerizable resin is, for example, a maleimide-based radical polymerizable resin. A maleimide-based radical polymerizable resin may be a compound having one or more, preferably two or more, maleimide groups. The maleimide-based radical polymerizable resin may be an aliphatic maleimide compound containing an aliphatic amine skeleton, or an aromatic maleimide compound containing an aromatic amine skeleton. Among these, the resin represented by the following formula (A-2) is particularly preferred as the maleimide-based radical polymerizable resin.

[0060] [ka]

[0061] (In equation (A-2), R aEach of these independently represents either a hydrogen atom or an alkyl group; Rings E, F, and G each independently represent an aromatic ring which may have substituents; Z is independently a single bond, -C(R z ) indicates -2-, -O-, -CO-, -S-, -SO-, -SO2-, -CONH-, or -NHCO-; R z Each of these independently represents either a hydrogen atom or an alkyl group; s represents an integer greater than or equal to 1; Each t independently represents either 0 or 1; (Each 'u' independently represents 0, 1, 2, or 3.) The s unit, t unit, and u unit may be the same or different for each unit.

[0062] In equation (A-2), R a Each of these independently represents a hydrogen atom or an alkyl group, preferably a hydrogen atom or a methyl group, and more preferably a hydrogen atom.

[0063] In formula (A-2), rings E, F, and G each independently represent optionally substituted aromatic rings, preferably optionally substituted benzene rings, more preferably substituted benzene rings with groups selected from alkyl and aryl groups, and particularly preferably unsubstituted benzene rings.

[0064] In equation (A-2), Z is independently a single bond, -C(R z )2-, -O-, -CO-, -S-, -SO-, -SO2-, -CONH-, or -NHCO-, preferably a single bond, -C(R z )2-, or -O-, more preferably a single bond, or -C(R z )2-, and particularly preferably a single bond. z Each of these independently represents a hydrogen atom or an alkyl group, preferably a hydrogen atom or a methyl group.

[0065] In formula (A-2), s represents an integer of 1 or more, preferably an integer between 1 and 10.

[0066] In formula (A-2), t independently represents either 0 or 1, and is preferably 1.

[0067] In formula (A-2), u independently represents 0, 1, 2, or 3, preferably 0, 1, or 2, more preferably 0 or 1, and particularly preferably 1.

[0068] Specific examples of resins represented by formula (A-2) include, for example, the resin represented by formula (A-2-1) below. Examples of resins represented by formula (A-2-1) include "MIR-3000-70MT" manufactured by Nippon Kayaku Co., Ltd.

[0069] [ka]

[0070] Further preferred radical polymerizable resins include, for example, (meth)acrylic radical polymerizable resins. (Meth)acrylic radical polymerizable resins may be compounds having one or more, preferably two or more, acryloyl groups and / or methacryloyl groups. Examples of (meth)acrylic radical polymerizable resins include cyclohexane-1,4-dimethanol di(meth)acrylate, cyclohexane-1,3-dimethanol di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,8-octanediool di(meth)acrylate, and 1,9- Low molecular weight (molecular weight less than 1000) aliphatic (meth)acrylic acid ester compounds such as nandiol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, glycerin tri(meth)acrylate, pentaerythritol tetra(meth)acrylate; dioxaneglycol di(meth)acrylate, 3,6-dioxa-1,8-octanediol di( Examples include low molecular weight (molecular weight less than 1000) ether-containing (meth)acrylic acid ester compounds such as meth)acrylate, 3,6,9-trioxaundecane-1,11-diol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, 9,9-bis[4-(2-acryloyloxyethoxy)phenyl]fluorene, ethoxylated bisphenol A di(meth)acrylate, and propoxylated bisphenol A di(meth)acrylate; low molecular weight (molecular weight less than 1000) isocyanurate-containing (meth)acrylic acid ester compounds such as tris(3-hydroxypropyl) isocyanurate tri(meth)acrylate, tris(2-hydroxyethyl) isocyanurate tri(meth)acrylate, and ethoxylated isocyanurate tri(meth)acrylate; and high molecular weight (molecular weight 1000 or more) acrylic acid ester compounds such as (meth)acrylic-modified polyphenylene ether resins.Examples of commercially available (meth)acrylic radical polymerizable resins include "A-DOG" (dioxane glycol diacrylate) from Shin Nakamura Chemical Industry Co., Ltd., "DCP-A" (tricyclodecane dimethanol diacrylate) and "DCP" (tricyclodecane dimethanol dimethacrylate) from Kyoeisha Chemical Co., Ltd., "KAYARAD R-684" (tricyclodecane dimethanol diacrylate) and "KAYARAD R-604" (dioxane glycol diacrylate) from Nippon Kayaku Co., Ltd., and "SA9000" and "SA9000-111" (methacrylic modified polyphenylene ether) from SABIC Innovative Plastics Co., Ltd.

[0071] Another preferred radical polymerizable resin is, for example, an allyl-based radical polymerizable resin. The allyl-based radical polymerizable resin may be a compound having one or more, preferably two or more, allyl groups. Examples of allyl-based radical polymerizable resins include aromatic carboxylic acid allyl ester compounds such as diallyl diphenate, triallyl trimellitate, diallyl phthalate, diallyl isophthalate, diallyl terephthalate, diallyl 2,6-naphthalenedicarboxylic acid, and diallyl 2,3-naphthalenecarboxylic acid; isocyanuric acid allyl ester compounds such as 1,3,5-trialyl isocyanurate and 1,3-diallyl-5-glycidyl isocyanurate; epoxy-containing aromatic allyl compounds such as 2,2-bis[3-allyl-4-(glycidyloxy)phenyl]propane; benzoxazine-containing aromatic allyl compounds such as bis[3-allyl-4-(3,4-dihydro-2H-1,3-benzoxazine-3-yl)phenyl]methane; ether-containing aromatic allyl compounds such as 1,3,5-trialyl etherbenzene; and allyl silane compounds such as diallyldiphenylsilane. Examples of commercially available allyl-based radical polymerizable resins include "TAIC" (1,3,5-triallyl isocyanurate) from Nippon Chemical Industries, Ltd., "DAD" (diallyl diphenate) from Nichishoku Techno Fine Chemicals Co., Ltd., "TRIAM-705" (triallyl trimellitate) from Wako Pure Chemical Industries, Ltd., "DAND" (2,3-diallyl naphthalenecarboxylate) from Nippon Distillation Industry Co., Ltd., "ALP-d" (bis[3-allyl-4-(3,4-dihydro-2H-1,3-benzoxazine-3-yl)phenyl]methane) from Shikoku Chemicals, Ltd., "RE-810NM" (2,2-bis[3-allyl-4-(glycidyloxy)phenyl]propane) from Nippon Kayaku Co., Ltd., and "DA-MGIC" (1,3-diallyl-5-glycidyl isocyanurate) from Shikoku Chemicals, Ltd.

[0072] The ethylenically unsaturated bond equivalent of the radical polymerizable resin is preferably 20 g / eq. to 3000 g / eq., more preferably 50 g / eq. to 2500 g / eq., even more preferably 70 g / eq. to 2000 g / eq., and particularly preferably 90 g / eq. to 1500 g / eq. The ethylenically unsaturated bond equivalent represents the mass of the radical polymerizable resin per equivalent of ethylenically unsaturated bonds.

[0073] The weight-average molecular weight (Mw) of the radical polymerizable resin is preferably 40,000 or less, more preferably 10,000 or less, even more preferably 5,000 or less, and particularly preferably 3,000 or less. The lower limit is not particularly limited, but may be, for example, 150 or more.

[0074] The content of radical polymerizable resin in the resin composition is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, particularly preferably 1.0% by mass or more, preferably 10% by mass or less, more preferably 5.0% by mass or less, and particularly preferably 3.0% by mass or less, when the non-volatile components in the resin composition are considered to be 100% by mass. When the amount of radical polymerizable resin is within the above range, the impact peel resistance and impact crack resistance of the insulating layer containing the cured product of the resin composition can be effectively improved.

[0075] From the viewpoint of significantly obtaining the effects of the present invention, the content of (A) curable resin in the resin composition is preferably 10% by mass or more, more preferably 20% by mass or more, particularly preferably 25% by mass or more, preferably 50% by mass or less, more preferably 40% by mass or less, and particularly preferably 30% by mass or less, when the nonvolatile components in the resin composition are taken as 100% by mass.

[0076] <(B) Inorganic filler> The resin composition contains (B) an inorganic filler as component (B). The inorganic filler (B) is usually included in the resin composition in particulate form.

[0077] (B) Inorganic compounds can be used as materials for inorganic fillers. (B) Examples of materials for inorganic fillers 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 zirconate titanate, barium zirconate, calcium zirconate, zirconium phosphate, and zirconium tungstate phosphate.

[0078] Furthermore, (B) an inorganic composite oxide may be used as the material for the inorganic filler. An inorganic composite oxide refers to an oxide containing two or more atoms selected from the group consisting of metal atoms and metalloid atoms. As such an inorganic composite oxide, an oxide containing a combination of silicon and one or more atoms selected from the group consisting of metal atoms and metalloid atoms other than silicon is preferred. Examples of metal atoms to be combined with silicon include aluminum, lead, nickel, cobalt, copper, zinc, zirconium, iron, lithium, magnesium, barium, potassium, calcium, titanium, boron, sodium, etc., with aluminum being particularly preferred. Therefore, as an inorganic composite oxide, an oxide containing silicon and aluminum is preferred, and aluminosilicate is particularly preferred.

[0079] Among these inorganic filler materials (B), silica, alumina, and aluminosilicate are preferred, with silica being particularly preferred. The inorganic filler (B) may be used individually or in combination of two or more types.

[0080] (B) Inorganic fillers can be classified into (B-1) hollow inorganic fillers having voids inside and (B-2) solid inorganic fillers not having voids inside. (B) Inorganic fillers preferably include (B-1) hollow inorganic fillers and (B-2) solid inorganic fillers. Furthermore, (B-2) solid inorganic fillers preferably contain (C) non-combustible gas, which will be described later, inside their voids.

[0081] (B-1) The hollow inorganic filler may be a single hollow particle having only one void inside, or a multi-hollow particle having two or more voids inside, or a combination of single hollow particles and other hollow particles.

[0082] (B-1) Since the hollow inorganic filler has voids, it usually has a porosity greater than 0 volume%. From the viewpoint of containing component (C) inside the voids of component (B-1), the porosity of the (B-1) hollow inorganic filler is preferably 10 volume% or more, more preferably 15 volume% or more, and particularly preferably 20 volume% or more. Furthermore, from the viewpoint of the mechanical strength of the cured resin composition, the porosity of the (B-1) hollow inorganic filler is preferably 80 volume% or less, more preferably 75 volume% or less, and particularly preferably 70 volume% or less.

[0083] The porosity P (volume %) of a particle is defined as the volume-based ratio of the total volume of one or more voids inside the particle to the total volume of the particle, relative to the outer surface of the particle (total volume of voids / volume of particle). This porosity P is measured by the actual density D of the particle. M (g / cm 3 ), and the theoretical value D of the material density of the material forming the particles. T (g / cm 3 Using ), it can be calculated by the following formula (X2).

[0084]

number

[0085] (B) Hollow inorganic particles generally have voids formed within the particle and an outer shell made of inorganic material surrounding these voids. Typically, the voids are separated from the outside of the particle by the outer shell. In this case, it is desirable that the voids do not communicate with the outside of the particle. Therefore, it is desirable that the outer shell is a non-porous shell that does not have pores that connect the voids to the outside of the particle. The non-porous nature of the outer shell can be confirmed by observation with a transmission electron microscope (TEM).

[0086] (B-1) The average particle size of the hollow inorganic filler is preferably 0.01 μm or more, more preferably 0.1 μm or more, particularly preferably 0.3 μm or more, preferably 5 μm or less, more preferably 4 μm or less, and particularly preferably 3 μm or less, from the viewpoint of obtaining the effects of the present invention in a remarkable manner.

[0087] The average particle size can be measured by the laser diffraction-scattering method based on Mie scattering theory. Specifically, a volume-based particle size distribution can be created using a laser diffraction-scattering particle size distribution analyzer, and the median diameter can be used as the average particle size. For inorganic fillers, a sample consisting of 100 mg of inorganic filler and 10 g of methyl ethyl ketone can be weighed into a vial and dispersed using ultrasound for 10 minutes. The sample can be measured using a laser diffraction-type particle size distribution analyzer with blue and red light source wavelengths, using a flow cell method to measure the volume-based particle size distribution of the inorganic filler, and the average particle size can be calculated as the median diameter from the obtained particle size distribution. An example of a laser diffraction-type particle size distribution analyzer is the "LA-960" manufactured by Horiba, Ltd.

[0088] (B-1) The BET specific surface area of ​​the hollow inorganic filler is preferably 1 m² from the viewpoint of significantly obtaining the effects of the present invention. 2 / g or more, more comfortably 2m 2 / g or more, particularly preferably 5m 2 It is 100m or more / g, preferably 100m 2 / g or less, more preferably 50m 2 / g or less, particularly preferably 30m 2The value is less than / g. The BET specific surface area of ​​a particle 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 Mountec Co., Ltd.) and calculating the specific surface area using the BET multi-point method.

[0089] (B-1) The hollow inorganic filler may be a commercially available product. An example of a commercially available (B-1) hollow inorganic filler is "MG-005" manufactured by Taiheiyo Cement Corporation. The (B-1) hollow inorganic filler may also be manufactured by, for example, the method described in Japanese Patent Publication No. 5940188 or a similar method. To give a specific example, hollow silica particles as an example of (B-1) hollow inorganic filler can be manufactured by a method including the steps of: preparing an aqueous solution containing a substance that can form pores and a basic compound; mixing the aqueous solution with an alkoxysilane and stirring to precipitate silica particles; removing the substance that can form pores from the silica particles to obtain a hollow silica precursor; and calcining the hollow silica precursor.

[0090] (B-1) The hollow inorganic filler is preferably treated with a surface treatment agent from the viewpoint of improving moisture resistance and dispersibility. Examples of surface treatment agents include fluorine-containing silane coupling agents, aminosilane coupling agents, epoxysilane coupling agents, mercaptosilane coupling agents, silane coupling agents, alkoxysilanes, organosilazane compounds, titanate coupling agents, etc. One type of surface treatment agent may be used alone, or two or more types may be used in any combination.

[0091] Examples of commercially available surface treatment agents include "KBM403" (3-glycidoxypropyltrimethoxysilane), "KBM803" (3-mercaptopropyltrimethoxysilane), "KBE903" (3-aminopropyltriethoxysilane), "KBM573" (N-phenyl-3-aminopropyltrimethoxysilane), "SZ-31" (hexamethyldisilazane), "KBM103" (phenyltrimethoxysilane), "KBM-4803" (long-chain epoxy-type silane coupling agent), and "KBM-7103" (3,3,3-trifluoropropyltrimethoxysilane), all manufactured by Shin-Etsu Chemical Co., Ltd.

[0092] From the viewpoint of improving dispersibility, the degree of surface treatment by the surface treatment agent is preferably within a specific range. Specifically, 100% by mass of the inorganic filler is preferably surface-treated with 0.2% to 8% by mass of the surface treatment agent, more preferably with 0.2% to 5% by mass of the surface treatment agent, and even more preferably with 0.3% to 3% by mass of the surface treatment agent.

[0093] The degree of surface treatment by a 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 should be 0.02 mg / m². 2 The above is preferred, and 0.1 mg / m² 2 The above is more preferable, 0.2 mg / m² 2 The above is even more preferable. On the other hand, from the viewpoint of preventing an increase in the melt viscosity of the resin composition, 1.0 mg / m² 2 The following is preferred: 0.8 mg / m² 2 The following is more preferable: 0.5 mg / m² 2 The following are even more preferable.

[0094] The amount of carbon per unit surface area of ​​an inorganic filler can be measured after surface treatment of the inorganic filler with a solvent (e.g., methyl ethyl ketone (MEK)). Specifically, a sufficient amount of MEK 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 solids, the amount of carbon per unit surface area of ​​the inorganic filler can be measured using a carbon analyzer. A carbon analyzer such as the "EMIA-320V" manufactured by Horiba, Ltd. can be used.

[0095] From the viewpoint of significantly obtaining the effects of the present invention, the amount (by mass) of the (B-1) hollow inorganic filler in the resin composition is preferably 1% by mass or more, more preferably 3% by mass or more, particularly preferably 5% by mass or more, preferably 60% by mass or less, more preferably 50% by mass or less, and particularly preferably 40% by mass or less, when the nonvolatile components in the resin composition are considered to be 100% by mass.

[0096] From the viewpoint of obtaining the effects of the present invention, the amount (vol %) of the (B-1) hollow inorganic filler in the resin composition is preferably 1 vol % or more, more preferably 3 vol % or more, particularly preferably 5 vol % or more, preferably 70 vol % or less, more preferably 60 vol % or less, and particularly preferably 50 vol % or less, when the non-volatile components in the resin composition are considered to be 100 vol %.

[0097] (B-1) The specific gravity of component (B-1) is preferably 3.50 g / cm³ from the viewpoint of obtaining the effects of the present invention. 3 More preferably, 3.00 g / cm³ 3 More preferably, 2.50 g / cm³ 3 The following, preferably 0.05 g / cm³ 3 More preferably 0.5 g / cm³ 3 The above is particularly preferably 1.0 g / cm³. 3 That concludes the explanation. Specific gravity can be measured using the method described in the examples below.

[0098] (B) The inorganic filler preferably includes (B-1) a hollow inorganic filler and (B-2) a solid inorganic filler. Examples of commercially available solid inorganic fillers (B-2) include "UFP-30" from Denka Chemical Industries, Ltd.; "SP60-05" and "SP507-05" from Nippon Steel & Sumitomo Metal Materials Corporation; "YC100C", "YA050C", "YA050C-MJE", and "YA010C" from Admatex Corporation; "UFP-30" from Denka Corporation; "Silfil NSS-3N", "Silfil NSS-4N", and "Silfil NSS-5N" from Tokuyama Corporation; "SC2500SQ", "SO-C4", "SO-C2", and "SO-C1" from Admatex Corporation; and "DAW-03" and "FB-105FD" from Denka Corporation.

[0099] (B-2) The average particle size of the solid inorganic filler is preferably 0.01 μm or more, more preferably 0.1 μm or more, particularly preferably 0.3 μm or more, preferably 10 μm or less, more preferably 5 μm or less, and particularly preferably 3 μm or less. The average particle size of component (B-2) can be measured in the same manner as the average particle size of the hollow inorganic filler (B-1).

[0100] (B-2) The BET specific surface area of ​​the solid inorganic filler is preferably 0.1 m². 2 / g or more, more preferably 0.5m 2 / g or more, particularly preferably 1m 2 It is 100m or more / g, preferably 100m 2 / g or less, more preferably 70m 2 / g or less, particularly preferably 40m 2 It is less than or equal to / g. The BET specific surface area of ​​component (B-2) can be measured using the same method as the BET specific surface area of ​​component (B-2).

[0101] (B-2) The solid inorganic filler is preferably treated with a surface treatment agent, similar to (B-1) the hollow inorganic filler.

[0102] The amount (by mass%) of the (B-2) solid inorganic filler in the resin composition may be 0% by mass or more than 0% by mass, preferably 10% by mass or more, more preferably 20% by mass or more, particularly preferably 30% by mass or more, preferably 50% by mass or less, more preferably 45% by mass or less, and particularly preferably 40% by mass or less.

[0103] The amount (volume %) of the (B-2) solid inorganic filler in the resin composition may be 0 volume%, or more than 0 volume%, preferably 5 volume% or more, more preferably 10 volume% or more, particularly preferably 20 volume% or more, preferably 50 volume% or less, more preferably 40 volume% or less, and particularly preferably 30 volume% or less, when the nonvolatile components in the resin composition are considered to be 100 volume%.

[0104] The proportion of voids contained in the entire (B) inorganic filler, which includes both (B-1) hollow inorganic filler and (B-2) solid inorganic filler, is determined as the porosity (volume %) of the (B) inorganic filler. The porosity (volume %) of the (B) inorganic filler is a representative value that expresses the proportion of voids in the volume of the (B) inorganic filler on a volume basis, and is expressed as "total volume of voids / total volume of (B) inorganic filler". The specific range of the porosity of the (B) inorganic filler is preferably 10 volume% or more, more preferably 15 volume% or more, particularly preferably 20 volume% or more, preferably 80 volume% or less, more preferably 70 volume% or less, and particularly preferably 60 volume% or less.

[0105] The average particle size of the entire inorganic filler (B), which includes both (B-1) hollow inorganic filler and (B-2) solid inorganic filler, is preferably 0.01 μm or more, more preferably 0.1 μm or more, particularly preferably 0.3 μm or more, preferably 5 μm or less, more preferably 4 μm or less, and particularly preferably 3 μm or less, from the viewpoint of significantly obtaining the effects of the present invention.

[0106] (B-1) The total BET specific surface area of ​​the inorganic filler (B), which includes both hollow inorganic filler and solid inorganic filler (B-2), is preferably 1 m² from the viewpoint of significantly obtaining the effects of the present invention.2 / g or more, more comfortably 2m 2 / g or more, particularly preferably 5m 2 It is 100m or more / g, preferably 100m 2 / g or less, more preferably 50m 2 / g or less, particularly preferably 30m 2 It is less than / g.

[0107] From the viewpoint of significantly obtaining the effects of the present invention, the content (mass%) of inorganic filler (B) in the resin composition is preferably 20% by mass or more, more preferably 30% by mass or more, particularly preferably 40% by mass or more, preferably 80% by mass or less, more preferably 70% by mass or less, and particularly preferably 65% ​​by mass or less, when the non-volatile components in the resin composition are taken as 100% by mass. Even if component (C) is contained inside the pores of component (B-1), the mass of component (C) itself is negligibly light, so the content (mass%) of inorganic filler (B) can be determined by the sum of the content of component (B-1) and the content of component (B-2).

[0108] From the viewpoint of significantly obtaining the effects of the present invention, the content (vol%) of (B) inorganic filler in the resin composition is preferably 20 vol% or more, more preferably 30 vol% or more, particularly preferably 40 vol% or more, preferably 80 vol% or less, more preferably 75 vol% or less, and particularly preferably 70 vol% or less, when the nonvolatile components in the resin composition are considered to be 100 vol%.

[0109] <(C) Non-combustible gas> The resin composition contains (C) non-combustible gas as component (C). Component (C) typically functions as a flame retardant. By including component (C) in the resin composition, it is possible to improve the flame retardancy of the cured resin composition. Conventionally, it has been said that the presence of gases such as non-combustible gases in a resin composition adversely affects the cured resin composition. However, in the present invention, it is possible to improve the flame retardancy of the cured resin composition by including component (C) in the resin composition. Furthermore, since gases such as non-combustible gases have almost no polarization, including component (C) in the resin composition can lower the dielectric properties such as the relative permittivity and dielectric loss tangent of the cured resin composition.

[0110] Component (C) can be a chemically stable gas that does not react easily with other compounds. Examples of such gases include inert gases and noble gases. In particular, component (C) is preferably one or more selected from nitrogen gas, argon gas, carbon dioxide gas, helium gas, and neon gas.

[0111] In order to ensure that component (C) is stably present in the resin composition and in the cured product of the resin composition, it is preferable that it be contained within the pores of the hollow inorganic filler (B-1) which has pores inside. The hollow inorganic filler (B-1) is as described above.

[0112] The content (volume %) of component (C) contained within the pores of component (B-1) is, from the viewpoint of significantly obtaining the effects of the present invention, preferably 80 volume% or more, more preferably 85 volume% or more, even more preferably 90 volume% or more, 95 volume% or more, and preferably 100 volume% or less (the entire pore is component (C)), when the volume inside the pores of component (B-1) is taken as 100 volume%. The content of component (C) can be calculated from the specific gravity of component (B-1) before containing component (C) and the specific gravity of component (B-1) after containing component (C).

[0113] One method for incorporating component (C) into the pores of component (B-1) is, for example, a manufacturing method including the following steps (a) and (b). (a) A step of encapsulating a non-combustible gas inside the pores of a precursor of a hollow inorganic filler (i.e., a precursor of component (B-1)), (b) A process of calcining a precursor of a hollow inorganic filler material containing non-combustible gas inside the voids.

[0114] (a) As one embodiment of the process, a precursor of component (B-1) is placed in a sealed container such as a desiccator, and a non-combustible gas purge is performed to replace the atmosphere inside the sealed container with a non-combustible gas atmosphere. The precursor of component (B-1) represents a material from which component (B-1) can be obtained by calcination. The precursor of component (B-1) usually has a hollow portion that is open to the outside. Therefore, by performing a non-combustible gas purge, non-combustible gas can be introduced into the hollow portion. The non-combustible gas purge may be performed only once or multiple times.

[0115] The duration of the non-combustible gas purging varies depending on the content of component (C) contained within the pores of component (B-1), but is preferably 0.5 hours or more, more preferably 1 hour or more, even more preferably 2 hours or more, preferably 24 hours or less, more preferably 20 hours or less, and even more preferably 15 hours or less.

[0116] Non-combustible gas purging is preferably carried out under reduced pressure. For example, the reduced pressure conditions are such that the target pressure is preferably 1000 Pa or less, more preferably 300 Pa or less, even more preferably 100 Pa or less, preferably 0.01 Pa or more, more preferably 0.03 Pa or more, and even more preferably 0.1 Pa or more. The temperature during reduced pressure is preferably 20°C or higher, more preferably 30°C or higher, even more preferably 40°C or higher, preferably 200°C or lower, more preferably 120°C or lower, and even more preferably 80°C or lower.

[0117] (b) As one embodiment of the process, after the non-combustible gas purging is completed, the precursor of component (B-1) containing component (C) inside the pores is removed from the sealed container and fired in a non-combustible gas atmosphere using an electric furnace or the like. By performing this process, component (B-1) is obtained from the precursor, and at the same time, component (C) is sealed inside component (B-1), allowing it to exist stably in the resin composition and in the cured product of the resin composition. The non-combustible gas atmosphere during firing may be the same non-combustible gas as component (C) contained inside the pores, or it may be a different non-combustible gas.

[0118] The calcination temperature of the precursor of component (B-1) containing component (C) inside the pores is preferably 600°C or higher, more preferably 750°C or higher, even more preferably 900°C or higher, preferably 1200°C or lower, more preferably 1100°C or lower, and even more preferably 1000°C or lower.

[0119] The calcination time for the precursor of component (B-1) containing component (C) inside the pores is preferably 12 hours or more, more preferably 24 hours or more, even more preferably 48 hours or more, preferably 200 hours or less, more preferably 150 hours or less, and even more preferably 100 hours or less.

[0120] From the viewpoint of obtaining a cured product with excellent flame retardancy, high-temperature reflow blister resistance, and dielectric properties, the content of component (C) in the resin composition is preferably 1% by volume or more, more preferably 2% by volume or more, even more preferably 3% by volume or more, preferably 50% by volume or less, more preferably 40% by volume or less, and particularly preferably 30% by volume or less, when the non-volatile components in the resin composition are taken as 100% by volume. The content of component (C) can be calculated from the specific gravity of the cured product of the resin composition before and after the inclusion of component (C), assuming that the mass of component (C) itself is negligibly light.

[0121] <(D) Organic particles> The resin composition preferably contains, as an optional component, (A) a curable resin, (B) an inorganic filler, and (C) a non-combustible gas, in combination with (D) organic particles as component (D). The (D) organic particles exist in particulate form in the resin composition and are usually included in the cured product while maintaining their particulate form. Component (D) does not include components (A) to (C) described above.

[0122] (D) Organic particles, because they contain organic materials, typically have a higher coefficient of thermal expansion and a lower specific gravity than (B) inorganic fillers. Therefore, by using component (D), the coefficient of thermal expansion and specific gravity of the cured resin composition can be adjusted. In addition, since component (D) generally tends to have higher flexibility than component (B), component (D) can be used to increase the stress resistance of the cured resin composition.

[0123] Component (D) may be a particle having a uniform composition throughout, or it may be a particle having a non-uniform composition. For example, a multilayer particle having a shell portion and an internal portion formed within the shell portion is preferred. The multilayer particle may also include portions other than the shell portion and the internal portion. For example, the multilayer particle may further include any portion within the internal portion. Also, for example, the multilayer particle may include any layer between the shell portion and the internal portion. Since the internal portion is usually covered by the shell portion, the multilayer particle can be highly dispersed in the resin composition regardless of the composition of the internal portion, and therefore the degree of freedom in the composition of the internal portion can be increased. Therefore, an internal portion having a composition suitable for the insulating layer can be used, and the properties of the insulating layer can be improved. The multilayer particle referred to here does not necessarily refer only to those in which the shell portion and the internal portion can be clearly distinguished, but also includes those in which the boundary between the shell portion and the internal portion is unclear, and the internal portion does not have to be completely covered by the shell portion.

[0124] The shell portion of the multilayer particles is usually formed by a polymer. The polymer forming the shell portion may be a homopolymer as a polymer of one type of monomer, or a copolymer as a copolymer of two or more types of monomers. The type of polymer and its monomer that form the shell portion is preferably selected to suppress aggregation of component (D) and disperse well in the resin composition. The specific type may depend on the composition of the curable resin (A), but preferred examples of monomers 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; maleimides; 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. These monomers may be used individually or in combination of two or more types.

[0125] The internal part of the multilayer particle preferably contains an organic material different from that contained in the shell part. A multilayer particle having such an internal part containing an organic material may have a core part corresponding to the internal part and a shell part covering this core part, and is therefore sometimes called a "core-shell particle". In particular, the internal part preferably contains a rubber component. When the (C) organic particle contains a multilayer particle with a rubber component in the internal part, the impact peel resistance and impact crack resistance of the insulating layer containing the cured resin composition can be effectively improved. As the rubber component, for example, a resin exhibiting an elastic modulus of 1 GPa or less when subjected to a tensile test at a temperature of 25°C and a humidity of 40% RH in accordance with the Japanese Industrial Standard (JIS K7161) can be used. Furthermore, as the rubber component, for example, a resin having a glass transition temperature preferably of 0°C or lower, more preferably of -10°C or lower, even more preferably of -20°C or lower, and particularly preferably of -30°C or lower can be used. The glass transition temperature can be measured by DSC (Differential Scanning Calorimetry) at a heating rate of 10°C / min. These rubber components can be prepared, for example, as resins having one or more structures selected from polybutadiene, polysiloxane, poly(meth)acrylate, polyalkylene, polyalkylene oxy, polyisoprene, polyisobutylene, and polycarbonate structures within their molecules.

[0126] Specific examples of rubber components include silicone elastomers such as polydimethylsiloxane; olefin-based thermoplastic elastomers such as polybutadiene, polyisoprene, polychlorobutadiene, ethylene-vinyl acetate copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-isobutylene copolymer, acrylonitrile-butadiene copolymer, isoprene-isobutylene copolymer, isobutylene-butadiene copolymer, ethylene-propylene-diene terpolymer, and ethylene-propylene-butene terpolymer; and thermoplastic elastomers such as acrylic-based thermoplastic elastomers such as propyl poly(meth)acrylate, butyl poly(meth)acrylate, cyclohexyl poly(meth)acrylate, and octyl poly(meth)acrylate. Furthermore, silicone-based rubbers such as polyorganosiloxane rubber may be mixed into the rubber component.

[0127] In the multilayer particles containing rubber components, the amount of rubber components is preferably 40% by mass or more, more preferably 50% by mass or more, and particularly preferably 60% by mass or more. There is no particular upper limit, but from the viewpoint of sufficiently covering the internal components with the shell components, it may be, for example, 95% by mass or less, or 90% by mass or the like.

[0128] Multilayer particles with an internal component containing rubber can be manufactured, for example, by a manufacturing method that includes the steps of preparing core particles containing rubber and forming a shell by graft copolymerization of monomer components copolymerizable with the rubber component contained in the core particles. Alternatively, commercially available multilayer particles with an internal component containing rubber may be used. Examples of commercially available products include "CHT" from Chail Industries, Inc.; "B602" from UMGABS Inc.; and "Paraloid EXL-2602", "Paraloid EXL-2603", "Paraloid EXL-2655", "Paraloid EXL-2311", "Paraloid-EXL2313", "Paraloid EXL-2315", "Paraloid KM-330", "Paraloid KM-336P", and "Paraloid KCZ-" from Dow Chemical Japan Inc. Examples include "Metablen C-223A", "Metablen E-901", "Metablen S-2001", "Metablen W-450A", and "Metablen SRK-200" from Mitsubishi Rayon; "KaneAce M-511", "KaneAce M-600", "KaneAce M-400", "KaneAce M-580", and "KaneAce MR-01" from Kaneka Corporation; and "Stafiloid AC3832" and "AC3816N" from Aica Kogyo Co., Ltd.

[0129] The internal portion of the multilayer particles may preferably be a hollow portion. That is, the multilayer particles may preferably have a hollow portion as a void surrounded by a shell portion. Multilayer particles having a hollow portion as an internal portion in this way are sometimes called "hollow organic particles". When component (D) contains multilayer particles with a hollow portion as an internal portion, the impact peel resistance and impact crack resistance of the insulating layer containing the cured resin composition can be effectively improved.

[0130] Multilayer particles containing hollow portions typically have a porosity greater than 0 volume%. From the viewpoint of effectively improving the impact peel resistance and impact crack resistance of the insulating layer containing the cured resin composition, the porosity of the multilayer particles is preferably 10 volume% or more, more preferably 15 volume% or more, and particularly preferably 20 volume% or more. Furthermore, from the viewpoint of the mechanical strength of the cured resin composition, the porosity of the multilayer particles is preferably 90 volume% or less, more preferably 90 volume% or less, and particularly preferably 80 volume% or less.

[0131] Multilayered particles including hollow portions can be manufactured by methods described in, for example, Japanese Patent Publication No. 2006-265394, Japanese Patent Publication No. 2007-238792, International Publication No. 2011 / 040376, Japanese Patent Publication No. 2016-190980, International Publication No. 2018 / 051794, and Japanese Patent Publication No. 2020-189978. Alternatively, commercially available multilayered particles including hollow portions may be used. An example of a commercially available product is "XX-5598Z" manufactured by Sekisui Chemical Co., Ltd.

[0132] (D) Component may be used alone or in combination of two or more types.

[0133] Component (D) may be treated with a surface treatment agent. Examples of surface treatment agents for component (D) include inorganic acids such as hydrochloric acid, nitric acid, and sulfuric acid; carboxylic acids such as acetic acid, propionic acid, butyric acid, and acrylic acid; sulfonic acids such as p-toluenesulfonic acid, ethylsulfonic acid, and dodecylbenzenesulfonic acid; phosphoric acids such as polyoxyethylene alkyl ether phosphate; organic acids such as phosphonic acid and phosphinic acid; silane coupling agents such as tetraethoxysilane, methyltrimethoxysilane, phenyltrimethoxysilane, 3-(meth)acryloxypropyltrimethoxysilane, and 8-(meth)acryloxyoctyltrimethoxysilane; and isocyanate compounds such as ethyl isocyanate.

[0134] The average particle size of component (D) is preferably smaller than the average particle size of the hollow inorganic filler (B-1). The specific average particle size of component (D) is preferably 0.01 μm or more, more preferably 0.05 μm or more, even more preferably 0.10 μm or more, preferably 5 μm or less, more preferably 2 μm or less, and even more preferably 1 μm or less. The average particle size of component (D) can be measured using a zeta potential particle size distribution analyzer.

[0135] From the viewpoint of significantly obtaining the effects of the present invention, the amount (mass%) of component (D) in the resin composition is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, particularly preferably 1% by mass or more, preferably 20% by mass or less, more preferably 10% by mass or less, and particularly preferably 5% by mass or less, when the nonvolatile components in the resin composition are considered to be 100% by mass.

[0136] From the viewpoint of significantly obtaining the effects of the present invention, the amount (vol %) of component (D) in the resin composition is preferably 0.5 vol % or more, more preferably 1.5 vol % or more, particularly preferably 2.0 vol % or more, preferably 20 vol % or less, more preferably 15 vol % or less, and particularly preferably 10 vol % or less, when the non-volatile components in the resin composition are considered to be 100 vol %.

[0137] (D) The specific gravity of component (D) is preferably 2.5 g / cm³ from the viewpoint of obtaining the effects of the present invention. 3 More preferably, 2.0 g / cm³ 3 The following, preferably 0.8 g / cm³ 3 More preferably 0.9 g / cm³ 3 The above is particularly preferably 1.0 g / cm³. 3 That concludes the explanation. Specific gravity can be measured using the method described in the examples below.

[0138] <(E) Curing accelerator> The resin composition may further include, as an optional component, (E) a curing accelerator in combination with the components (A) to (C) described above. This curing accelerator (E) does not include any of the components (A) to (D) described above. The curing accelerator (E) functions as a curing catalyst that accelerates the curing of the curable resin (A).

[0139] (E) As the curing accelerator, an appropriate one may be used depending on the type of curable resin (A). For example, if the curable resin (A) contains epoxy resin, examples of curing accelerators (E) that can accelerate the curing of the epoxy resin 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. (E) The curing accelerator may be used alone or in combination of two or more types.

[0140] Examples of phosphorus-based curing accelerators include aliphatic phosphonium salts such as tetrabutylphosphonium bromide, tetrabutylphosphonium chloride, tetrabutylphosphonium acetate, tetrabutylphosphonium decanoate, tetrabutylphosphonium laurate, bis(tetrabutylphosphonium) pyromelitate, tetrabutylphosphonium hydrogen hexahydrophthalate, 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 bromide. 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 addition products such as triphenylphosphine-p-benzoquinone addition products; 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 Examples include aromatic phosphines such as 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.

[0141] Examples of urea-based curing accelerators include aliphatic dimethylureas such as 1,1-dimethylurea, 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 toluenebisdimethylurea, 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) [toluenebisdimethylurea] are examples.

[0142] Examples of guanidine-based 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]deca-5-ene, 7-methyl-1,5,7-triazabicyclo[4.4.0]deca-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.

[0143] Examples of imidazole-based curing accelerators 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, 1-benzyl-2- Phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazolium 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 isocyanurate adduct, 2-phenylimidazole isocyanurate adduct Examples of imidazole compounds include 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2-methylimidazoline, and 2-phenylimidazoline, as well as adducts of imidazole compounds with epoxy resins. Examples of commercially available imidazole-based curing accelerators include "1B2PZ", "2E4MZ", "2MZA-PW", "2MZ-OK", "2MA-OK", "2MA-OK-PW", "2PHZ", "2PHZ-PW", "Cl1Z", "Cl1Z-CN", "Cl1Z-CNS", and "C11Z-A" from Shikoku Chemicals, Inc., and "P200-H50" from Mitsubishi Chemical Corporation.

[0144] Examples of metal-based hardening 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 organocobalt complexes such as cobalt(II) acetylacetonate and cobalt(III) acetylacetonate, organocopper complexes such as copper(II) acetylacetonate, organozinc complexes such as zinc(II) acetylacetonate, organoiron complexes such as iron(III) acetylacetonate, organonickel complexes such as nickel(II) acetylacetonate, and organomanganese complexes such as manganese(II) acetylacetonate. Examples of organometallic salts include zinc octoate, tin octoate, zinc naphthenate, cobalt naphthenate, tin stearate, and zinc stearate.

[0145] Examples of amine-based curing accelerators include trialkylamines such as triethylamine and tributylamine, 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, and 1,8-diazabicyclo(5,4,0)-undecene. Commercially available amine-based curing accelerators may also be used, such as "MY-25" manufactured by Ajinomoto Fine Techno Co., Ltd.

[0146] The amount of (E) curing accelerator in the resin composition may be 0% by mass or greater than 0% by mass, when the non-volatile components in the resin composition are considered to be 100% by mass, preferably 0.01% by mass or more, more preferably 0.02% by mass or more, particularly preferably 0.05% by mass or more, preferably 1.0% by mass or less, more preferably 0.5% by mass or less, particularly preferably 0.2% by mass or less.

[0147] <(F)Thermoplastic resin> The resin composition may further include, as an optional component, (F) a thermoplastic resin in combination with the components (A) to (C) described above. This (F) thermoplastic resin does not include any of the components (A) to (E) described above.

[0148] (F) Examples of thermoplastic resins include 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. (F) A single thermoplastic resin may be used, or two or more types may be used in combination.

[0149] Examples of phenoxy resins include phenoxy resins having one or more skeletons selected from the group consisting of bisphenol A skeleton, bisphenol F skeleton, bisphenol S skeleton, bisphenolacetophenone skeleton, novolac skeleton, biphenyl skeleton, fluorene skeleton, dicyclopentadiene skeleton, norbornene skeleton, naphthalene skeleton, anthracene skeleton, adamantane skeleton, terpene skeleton, and trimethylcyclohexane skeleton. The terminal end 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" (both phenoxy resins containing a bisphenol A skeleton) manufactured by Mitsubishi Chemical Corporation; "YX8100" (phenoxy resin containing a bisphenol S skeleton) manufactured by Mitsubishi Chemical Corporation; "YX6954" (phenoxy resin containing a bisphenol acetophenone skeleton) manufactured by Mitsubishi Chemical Corporation; "FX280" and "FX293" manufactured by Nippon Steel & Sumitomo Metal Chemical Corporation; and "YL7500BH30", "YX6954BH30", "YX7553", "YX7553BH30", "YL7769BH30", "YL6794", "YL7213", "YL7290", "YL7482", and "YL7891BH30" manufactured by Mitsubishi Chemical Corporation.

[0150] Specific examples of polyimide resins include "SLK-6100" manufactured by Shin-Etsu Chemical Co., Ltd., and "Ricacoat SN20" and "Ricacoat PN20" manufactured by Shin-Nippon Rika Co., Ltd.

[0151] Examples of polyvinyl acetal resins include polyvinyl formal resin and polyvinyl butyral resin, with polyvinyl butyral resin being preferred. Specific examples of polyvinyl acetal resins include "Denka Butyral 4000-2", "Denka Butyral 5000-A", "Denka Butyral 6000-C", and "Denka Butyral 6000-EP" from Denki Kagaku Kogyo Co., Ltd.; and S-Rec BH series, BX series (e.g., BX-5Z), KS series (e.g., KS-1), BL series, and BM series from Sekisui Chemical Co., Ltd.

[0152] Examples of polyolefin resins include ethylene-based copolymer resins such as low-density polyethylene, ultra-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.

[0153] Examples of polybutadiene resins include hydrogenated polybutadiene skeleton-containing resins, hydroxyl group-containing polybutadiene resins, phenolic hydroxyl group-containing polybutadiene resins, carboxyl 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.

[0154] Specific examples of polyamide-imide resins include "Viromax HR11NN" and "Viromax HR16NN" manufactured by Toyobo Co., Ltd. Other specific examples of polyamide-imide resins include modified polyamide-imides such as "KS9100" and "KS9300" (polysiloxane skeleton-containing polyamide-imide) manufactured by Hitachi Chemical Co., Ltd.

[0155] Specific examples of polyethersulfone resins include "PES5003P" manufactured by Sumitomo Chemical Co., Ltd.

[0156] Specific examples of polysulfone resins include Solvay Advanced Polymers' polysulfones "P1700" and "P3500".

[0157] Specific examples of polyphenylene ether resins include "NORYL SA90" manufactured by SABIC. Specific examples of polyetherimide resins include "Ultem" manufactured by GE.

[0158] 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" from Mitsubishi Gas Chemical Co., Ltd., "T6002" and "T6001" (polycarbonate diols) from Asahi Kasei Chemicals Corporation, and "C-1090," "C-2090," and "C-3090" (polycarbonate diols) from Kuraray Co., Ltd. Specific examples of polyether ether ketone resins include "Sumiproi K" from Sumitomo Chemical Co., Ltd.

[0159] Examples of polyester resins include polyethylene terephthalate resin, polyethylene naphthalate resin, polybutylene terephthalate resin, polybutylene naphthalate resin, polytrimethylene terephthalate resin, polytrimethylene naphthalate resin, and polycyclohexanedimethyl terephthalate resin.

[0160] (F) The weight-average molecular weight (Mw) of the thermoplastic resin is preferably greater than 5,000, more preferably 8,000 or more, even more preferably 10,000 or more, particularly preferably 20,000 or more, 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.

[0161] The amount of (F) thermoplastic resin in the resin composition is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, particularly preferably 1% by mass or more, preferably 20% by mass or less, more preferably 10% by mass or less, and particularly preferably 5% by mass or less, when the nonvolatile components in the resin composition are considered to be 100% by mass.

[0162] <(G) Flame retardant> The resin composition may also contain, as an optional component, a (G) flame retardant in combination with the components (A) to (C) described above. This (G) flame retardant does not include those corresponding to the components (A) to (F) described above. Examples of (G) flame retardants include phosphazene compounds, organophosphorus flame retardants, organic nitrogen-containing phosphorus compounds, nitrogen compounds, silicone flame retardants, metal hydroxides, etc., with phosphazene compounds being preferred. The flame retardant may be used alone or in combination of two or more types.

[0163] The phosphazene compound is not particularly limited as long as it is a cyclic compound with nitrogen and phosphorus as constituent elements, but it is preferable that the phosphazene compound is a phosphazene compound having a phenolic hydroxyl group.

[0164] Specific examples of phosphazene compounds include, for example, "SPH-100," "SPS-100," "SPB-100," and "SPE-100" manufactured by Otsuka Chemical Co., Ltd., and "FP-100," "FP-110," "FP-300," and "FP-400" manufactured by Fushimi Pharmaceutical Co., Ltd., with "SPH-100" manufactured by Otsuka Chemical Co., Ltd. being preferred.

[0165] As a flame retardant other than a phosphazene compound, commercially available products may be used, such as "HCA-HQ" manufactured by Sanko Co., Ltd. and "PX-200" manufactured by Daihachi Chemical Industry Co., Ltd. As a flame retardant, one that is not easily hydrolyzed is preferred, such as 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide.

[0166] (G) From the viewpoint of significantly obtaining the effects of the present invention, the content of the flame retardant is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, and even more preferably 0.3% by mass or more, when the nonvolatile components in the resin composition are considered to be 100% by mass. The upper limit is preferably 5% by mass or less, more preferably 3% by mass or less, and even more preferably 1% by mass or less.

[0167] <(H) Any additives> The resin composition may further contain (H) any additive as an optional non-volatile component in combination with the components (A) to (C) described above. Examples of optional additives (H) 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 dioxide, 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 bentonite and montmorillonite; defoamers such as silicone-based defoamers, acrylic-based defoamers, fluorine-based defoamers, and vinyl resin-based defoamers; ultraviolet absorbers such as benzotriazole-based ultraviolet absorbers; adhesion improvers such as urea silane; adhesion ferrants such as triazole-based adhesion ferrants, tetrazole-based adhesion ferrants, and triazine-based adhesion ferrants; and hindered phenol-based antioxidants. Examples include antioxidants such as phosphate esters; fluorescent whitening agents such as stilbene derivatives; surfactants such as fluorine-based surfactants and silicone-based surfactants; flame retardants such as phosphorus-based flame retardants (e.g., phosphate ester compounds, phosphazene compounds, phosphinic acid compounds, 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 acid anhydride-based stabilizers; photopolymerization initiators such as tertiary amines; and photosensitizers such as pyrarizones, anthracenes, coumarins, xanthones, and thioxanthones. (H) Any additive may be used alone or in combination of two or more types.

[0168] <(I) Solvent> The resin composition may also contain (I) solvent as an optional volatile component in combination with the non-volatile components such as components (A) to (H) described above. Typically, an organic solvent is used as the (I) solvent. Examples of organic solvents include: ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ester solvents such as methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, isoamyl acetate, methyl propionate, ethyl propionate, and γ-butyrolactone; ether solvents such as tetrahydropyran, tetrahydrofuran, 1,4-dioxane, diethyl ether, diisopropyl ether, dibutyl ether, diphenyl ether, and anisole; alcohol 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 include ether ester solvents such as tyl; ester alcohol solvents such as methyl lactate, ethyl lactate, and methyl 2-hydroxyisobutyrate; ether alcohol solvents such as 2-methoxypropanol, 2-methoxyethanol, 2-ethoxyethanol, propylene glycol monomethyl ether, and diethylene glycol monobutyl ether (butyl carbitol); amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone; sulfoxide solvents such as dimethyl sulfoxide; nitrile solvents such as acetonitrile and propionitrile; aliphatic hydrocarbon solvents such as hexane, cyclopentane, cyclohexane, and methylcyclohexane; and aromatic hydrocarbon solvents such as benzene, toluene, xylene, ethylbenzene, and trimethylbenzene. (I) A single solvent may be used alone, or two or more may be used in combination.

[0169] (I) The amount of solvent is not particularly limited, but when the total components in the resin composition are considered to be 100% by mass, it may be, for example, 60% by mass or less, 40% by mass or less, 30% by mass or less, 20% by mass or less, 15% by mass or less, 10% by mass or less, etc., and may also be 0% by mass.

[0170] From the viewpoint of obtaining the effects of the present invention, the specific gravity of the resin component in the cured product of the resin composition is preferably 1.58 g / cm³. 3 More preferably, 1.56 g / cm³ 3 The following applies: The lower limit of the specific gravity of the cured product is preferably 1.0 g / cm³. 3 More preferably 1.02 g / cm³ 3 In particular, 1.05 g / cm³ is preferred. 3 This concludes the explanation. The resin component refers to the non-volatile components of the resin composition, excluding (B) inorganic fillers and (D) organic particles. Specific gravity can be measured using the method described in the examples below.

[0171] From the viewpoint of significantly obtaining the effects of the present invention, the content (volume %) of the resin component in the cured product obtained by heating the resin composition at 180°C for 90 minutes is preferably 20% by volume or more, more preferably 30% by volume or more, even more preferably 40% by volume or more, preferably 80% by volume or less, more preferably 70% by volume or less, and even more preferably 60% by volume or less.

[0172] A resin composition can be manufactured, for example, by mixing components that may be included in the resin composition. The above-mentioned components may be mixed some or all at the same time, or sequentially. The temperature may be set appropriately during the mixing of each component, and thus heating and / or cooling may be performed temporarily or throughout the process. Furthermore, stirring or shaking may be performed during the mixing of each component.

[0173] The thermal expansion coefficient of the cured resin composition can be adjusted by the composition of the resin composition. For example, (B) increasing the amount of inorganic filler can reduce the thermal expansion coefficient. Conversely, increasing the amount of resin component can increase the thermal expansion coefficient. Furthermore, the thermal expansion coefficient may be changed by adjusting the types of inorganic filler and resin component.

[0174] Cured products obtained by heating a resin composition at 180°C for 90 minutes can have a low dielectric constant. Therefore, an insulating layer with a low dielectric constant can be formed using these cured resin compositions. In one example, the dielectric constant of the cured product measured by cavity resonance perturbation at a measurement frequency of 5.8 GHz and a measurement temperature of 23°C is preferably less than 3.30, more preferably 3.15 or less, and particularly preferably 3.00 or less. There is no particular limit to the lower limit, and it may be, for example, 2.00 or more. The dielectric constant can be measured according to the method described in the examples below.

[0175] Cured products obtained by heating a resin composition at 180°C for 90 minutes can have a low dielectric constant. Therefore, an insulating layer with a low dielectric constant can be formed using these cured resin compositions. In one example, the dielectric constant of the cured product measured by cavity resonance perturbation at a measurement frequency of 5.8 GHz and a measurement temperature of 90°C is preferably less than 3.30, more preferably 3.15 or less, and particularly preferably 3.00 or less. There is no particular limit to the lower limit, and it may be, for example, 2.00 or more. The dielectric constant can be measured according to the method described in the examples below.

[0176] Cured products obtained by heating a resin composition at 180°C for 90 minutes can have a low dielectric loss tangent. Therefore, these cured resin compositions can form an insulating layer with a low dielectric loss tangent. In one example, the dielectric loss tangent of the cured product measured by cavity resonance perturbation at a measurement frequency of 5.8 GHz and a measurement temperature of 23°C is preferably 0.020 or less, more preferably 0.018 or less, and particularly preferably 0.015 or less. There is no particular limit to the lower limit, and it may be, for example, 0.001 or more, 0.002 or more, etc. The dielectric loss tangent can be measured according to the method described in the examples below.

[0177] Cured products obtained by heating a resin composition at 180°C for 90 minutes can have a low dielectric loss tangent. Therefore, these cured resin compositions can form an insulating layer with a low dielectric loss tangent. In one example, the dielectric loss tangent of the cured product measured by cavity resonance perturbation at a measurement frequency of 5.8 GHz and a measurement temperature of 90°C is preferably 0.020 or less, more preferably 0.018 or less, and particularly preferably 0.015 or less. There is no particular limit to the lower limit, and it may be, for example, 0.001 or more, 0.002 or more, etc. The dielectric loss tangent can be measured according to the method described in the examples below.

[0178] Cured products obtained by heating a resin composition at 180°C for 90 minutes typically exhibit a low rate of change in dielectric loss tangent between the dielectric loss tangent of the cured product at a measurement temperature of 90°C and the dielectric loss tangent of the cured product at a measurement temperature of 23°C. Therefore, these cured resin compositions can form insulating layers with a low rate of change in dielectric loss tangent. In one example, the rate of change in dielectric loss tangent of the cured resin composition is preferably less than 30%, more preferably 29% or less, and particularly preferably 25% or less. There is no particular limit to the lower limit, and it may be, for example, 1% or more, 2% or more, etc. The rate of change in dielectric loss tangent can be measured according to the method described in the examples below.

[0179] The cured product obtained by heat-curing the resin composition of the present invention at 180°C for 90 minutes exhibits excellent flame retardancy. Therefore, a flame-retardant insulating layer can be formed using the cured product of these resin compositions. The flame retardancy is preferably "V-1", "V-0", or better in the UL flame resistance test (UL94V). The flame retardancy can be measured according to the method described in the examples below.

[0180] A cured product obtained by heat-curing the resin composition at 100°C for 30 minutes, followed by 190°C for 120 minutes, exhibits excellent resistance to high-temperature reflow blistering. Therefore, it is possible to form an insulating layer that exhibits the characteristic of not showing abnormalities such as blistering even when a reflow process is performed (reflow resistance). Even when the cured product is passed through a reflow apparatus that reproduces a solder reflow temperature of 260°C peak temperature 10 times, no abnormalities such as blistering are observed in small pieces of the insulating layer. High-temperature reflow blister resistance can be measured according to the method described in the examples below.

[0181] The cured product obtained by heating the resin composition at 180°C for 90 minutes typically has a coefficient of thermal expansion within a specific range. The specific range of the coefficient of thermal expansion of the cured product is usually 40 ppm or less, preferably 30 ppm or less, and more preferably 25 ppm or less. The lower limit of the coefficient of thermal expansion of the cured product is preferably 5 ppm or more, more preferably 10 ppm or more, and particularly preferably 15 ppm or more.

[0182] Cured products obtained by heating a resin composition at 180°C for 90 minutes can usually have a large elongation (elongation at break). Therefore, an insulating layer with a large elongation at break can be formed using the cured products of these resin compositions. In one example, the elongation at break of the cured product is preferably 0.5% or more, more preferably 1.0% or more, and particularly preferably 1.2% or more. There is no particular upper limit, and it may be, for example, 10% or less, 5.0% or less, etc. The elongation can be measured according to the method described in the examples below.

[0183] The resin compositions described above can be used as resin compositions for insulating applications, and are particularly suitable for use as resin compositions for forming insulating layers (resin compositions for forming insulating layers). For example, the resin compositions described above can be used as resin compositions for forming insulating layers of printed circuit boards, and are particularly suitable for use as resin compositions for forming interlayer insulating layers (resin compositions for interlayer insulating applications).

[0184] Furthermore, the resin composition described above may also be used as a resin composition for forming a redistribution layer (resin composition for forming a redistribution layer). The redistribution layer refers to an insulating layer for forming a redistribution layer. The redistribution layer also refers to a conductive layer formed on the redistribution layer as an insulating layer. For example, when a semiconductor chip package is manufactured through the following steps (1) to (6), the resin composition described above may be used as a resin composition for forming a redistribution layer. Furthermore, when a semiconductor chip package is manufactured through the following steps (1) to (6), a redistribution layer may be further formed on the sealing layer. (1) A step of laminating a temporary fixing film onto the substrate, (2) A step of temporarily fixing the semiconductor chip onto a temporary fixing film, (3) A step of forming a sealing layer on a semiconductor chip, (4) Steps to peel off the substrate and temporary fixing film from the semiconductor chip, (5) A step of forming a rewiring layer as an insulating layer on the surface from which the substrate and temporary fixing film of the semiconductor chip have been peeled off, and (6) Step of forming a redistribution layer as a conductor layer on the redistribution formation layer.

[0185] Furthermore, the above-mentioned resin compositions can be used in a wide range of applications where resin compositions are used, such as sheet-like laminated materials like resin sheets and prepregs, solder resists, underfill materials, die bonding materials, semiconductor encapsulants, hole-filling resins, and component-embedding resins.

[0186] [Sheet-like laminated material] The resin composition described above may be used by applying it in a varnish state, but industrially, it is preferable to use it in the form of a sheet-like laminate material containing the resin composition.

[0187] As sheet-like laminated materials, the following resin sheets and prepregs are preferred.

[0188] In one embodiment, the resin sheet includes a support and a resin composition layer provided on the support. The resin composition layer is formed of the resin composition described above. Therefore, the resin composition layer usually contains the resin composition, and preferably contains only the resin composition.

[0189] The thickness of the resin composition layer is preferably 50 μm or less, more preferably 40 μm or less, from the viewpoint of thinning the printed circuit board and providing a cured product with excellent insulating properties even if the cured product of the resin composition is a thin film. The lower limit of the thickness of the resin composition layer is not particularly limited, but may be 5 μm or more, 10 μm or more, etc.

[0190] Examples of support materials include films made of plastic materials, metal foils, and release paper, with films made of plastic materials and metal foils being preferred.

[0191] When using a film made of plastic material as a support, examples of plastic materials 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, triacetylcellulose (TAC), polyether sulfide (PES), polyether ketones, and polyimides. Among these, polyethylene terephthalate and polyethylene naphthalate are preferred, and inexpensive polyethylene terephthalate is particularly preferred.

[0192] When using metal foil as a support, examples of metal foil include copper foil and aluminum foil, with copper foil being preferred. As for copper foil, foil made of single-metal copper may be used, or foil made of an alloy of copper with another metal (for example, tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.) may be used.

[0193] The support may have a matte finish, corona treatment, or antistatic treatment applied to the surface that bonds with the resin composition layer.

[0194] As a support, a support with a release layer may be used, which has a release layer on the surface that is bonded to the resin composition layer. Examples of release agents 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 be used as the support with a release layer, for example, PET films having a release layer mainly composed of an alkyd resin-based release agent, such as "SK-1", "AL-5", and "AL-7" from Lintec Corporation, "Lumirror T60" from Toray Industries, Inc., "Purex" from Teijin Corporation, and "Unipeel" from Unitika Corporation.

[0195] The thickness of the support is not particularly limited, but is preferably in the range of 5 μm to 75 μm, and more preferably in the range of 10 μm to 60 μm. When using a support with a release layer, it is preferable that the overall thickness of the support with the release layer is within the above range.

[0196] In one embodiment, the resin sheet may further include any additional layer as needed. Such an additional layer may be, for example, a protective film similar to the support, provided on the side of the resin composition layer that is not bonded to the support (i.e., the side opposite to 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, the adhesion of dust and scratches to the surface of the resin composition layer can be suppressed.

[0197] Resin sheets can be manufactured, for example, by applying a liquid (varnish-like) resin composition as is, or by dissolving the resin composition in a solvent to prepare a liquid (varnish-like) resin composition, applying this to a support using a coating device such as a die coater, and then drying it to form a resin composition layer.

[0198] Examples of solvents include those similar to those described as components of the resin composition. A single solvent may be used, or two or more solvents may be used in combination.

[0199] Drying may be carried out by methods such as heating or blowing hot air. The drying conditions are not particularly limited, but the drying is carried out so that the solvent content in the resin composition layer is usually 10% by mass or less, preferably 5% by mass or less. Although it also depends on the boiling point of the solvent in the resin composition, for example, when using a resin composition containing 30% to 60% by mass of solvent, the resin composition layer can be formed by drying at 50°C to 150°C for 3 to 10 minutes.

[0200] Resin sheets can be stored by rolling them up. If the resin sheet has a protective film, it can usually be used after removing the protective film.

[0201] In one embodiment, the prepreg is formed by impregnating a sheet-like fibrous substrate with the above-mentioned resin composition.

[0202] The sheet-like fibrous substrate used in the prepreg can be one of those commonly used as prepreg substrates, such as glass cloth, aramid nonwoven fabric, or liquid crystal polymer nonwoven fabric. From the viewpoint of thinning the printed circuit board, the thickness of the sheet-like fibrous substrate is preferably 50 μm or less, more preferably 40 μm or less, even more preferably 30 μm or less, and particularly preferably 20 μm or less. The lower limit of the thickness of the sheet-like fibrous substrate is not particularly limited, and is usually 10 μm or more.

[0203] Prepregs can be manufactured by methods such as the hot melt method and the solvent method.

[0204] The thickness of the prepreg can be in the same range as the resin composition layer in the resin sheet described above.

[0205] The sheet-like laminated material can be suitably used to form an insulating layer of a printed circuit board (for the insulating layer of a printed circuit board), and more suitably used to form an interlayer insulating layer of a printed circuit board (for the interlayer insulating layer of a printed circuit board).

[0206] [Printed wiring board] A printed circuit board according to one embodiment of the present invention comprises an insulating layer containing a cured product obtained by curing the above-described resin composition. This printed circuit board can be manufactured, for example, using the above-described resin sheet by a method including the following steps (I) and (II). (I) A step of laminating a resin sheet onto an inner layer substrate such that the resin composition layer of the resin sheet is bonded to the inner layer substrate. (II) A step of curing the resin composition layer to form an insulating layer.

[0207] The "internal layer substrate" used in process (I) refers to a material that serves as the substrate for a printed circuit board, and examples include glass epoxy substrates, metal substrates, polyester substrates, polyimide substrates, BT resin substrates, thermosetting polyphenylene ether substrates, etc. The substrate may also have a conductive layer on one or both sides, and this conductive layer may be patterned. An internal layer substrate in which a conductive layer (circuit) is formed on one or both sides of the substrate is sometimes called an "internal layer circuit board." Intermediate products on which an insulating layer and / or a conductive layer is further formed when manufacturing a printed circuit board are also included in the above-mentioned "internal layer substrate." If the printed circuit board is a component-embedded circuit board, an internal layer substrate with embedded components may be used.

[0208] Lamination of the inner layer substrate and the resin sheet can be performed, for example, by heating and pressing the resin sheet onto the inner layer substrate from the support side. Examples of the member used to heat and press the resin sheet onto the inner layer substrate (hereinafter also referred to as the "heat-pressing member") include a heated metal plate (such as a SUS end plate) or a metal roll (such as a SUS roll). It is preferable to press the resin sheet via an elastic material such as heat-resistant rubber, rather than directly pressing the heat-pressing member onto the resin sheet, so that the resin sheet can adequately follow the surface irregularities of the inner layer substrate.

[0209] 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 heat-pressure temperature is preferably in the range of 60°C to 160°C, more preferably in the range of 80°C to 140°C, the heat-pressure pressure is preferably in the range of 0.098 MPa to 1.77 MPa, more preferably in the range of 0.29 MPa to 1.47 MPa, and the heat-pressure time is preferably in the range of 20 seconds to 400 seconds, more preferably in the range of 30 seconds to 300 seconds. Lamination is preferably carried out under reduced pressure conditions of 26.7 hPa or less.

[0210] Lamination can be performed using a commercially available vacuum laminator. Examples of commercially available vacuum laminators include vacuum pressure laminators manufactured by Meiki Seisakusho Co., Ltd., vacuum applicators manufactured by Nikko Materials Co., Ltd., and batch-type vacuum pressure laminators.

[0211] After lamination, the laminated resin sheets may be smoothed by pressing a heat-sealing member from the support side under normal pressure (atmospheric pressure). The pressing conditions for the smoothing process can be the same as the heat-sealing conditions for lamination. The smoothing process can be performed using a commercially available laminator. Lamination and smoothing may be performed continuously using the commercially available vacuum laminator mentioned above.

[0212] The support may be removed between steps (I) and (II), or after step (II).

[0213] In step (II), the resin composition layer is cured to form an insulating layer made of the cured resin composition. The specific curing conditions for the resin composition layer may be those commonly used when forming the insulating layer of a printed circuit board, and are usually heat-cured by heating.

[0214] The thermal curing conditions for the resin composition layer may vary depending on the type of resin composition. For example, the curing temperature is preferably 120°C to 240°C, more preferably 150°C to 220°C, and even more preferably 170°C to 210°C. The curing time is preferably 5 minutes to 120 minutes, more preferably 10 minutes to 100 minutes, and even more preferably 15 minutes to 100 minutes.

[0215] Furthermore, when the resin composition layer is heat-cured, the method for manufacturing the printed circuit board preferably includes preheating the resin composition layer at a temperature lower than the curing temperature before heat curing. For example, prior to heat curing the resin composition layer, the resin composition layer may be preheated at a temperature of typically 50°C to 150°C, preferably 60°C to 140°C, more preferably 70°C to 130°C for typically 5 minutes or more, preferably 5 minutes to 150 minutes, more preferably 15 minutes to 120 minutes, and even more preferably 15 minutes to 100 minutes.

[0216] In manufacturing printed circuit boards, the following steps may be further performed: (III) drilling holes in the insulating layer, (IV) roughening the insulating layer, and (V) forming the conductor layer. These steps (III) through (V) may be carried out according to various methods known to those skilled in the art that are used in the manufacture of printed circuit boards. If the support is removed after step (II), the removal of the support may be carried out 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 (I) through (V) may be repeated to form a multilayer circuit board.

[0217] In other embodiments, the printed circuit board can be manufactured using the prepreg described above. The manufacturing method may be basically the same as that used when a resin sheet is used.

[0218] 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 carried out using, for example, a drill, laser, plasma, etc., depending on the composition of the resin composition used to form the insulating layer. The dimensions and shape of the holes may be appropriately determined according to the design of the printed circuit board.

[0219] Step (IV) is a process for roughening the insulating layer. Typically, smear removal is also performed in this step (IV). The procedure and conditions for the roughening process are not particularly limited, and known procedures and conditions commonly used when forming the insulating layer of a printed circuit board can be adopted. For example, the insulating layer can be roughened by performing swelling treatment with a swelling solution, roughening treatment with an oxidizing agent, and neutralization treatment with a neutralizing solution in this order.

[0220] Examples of swelling solutions used for roughening treatment include alkaline solutions and surfactant solutions, with alkaline solutions being preferred. Sodium hydroxide solution and potassium hydroxide solution are more preferred as the alkaline solution. Examples of commercially available swelling solutions include "Swelling Dip Securing P" and "Swelling Dip Securing SBU" manufactured by Atotec Japan. The swelling treatment with the swelling solution can be carried out, for example, by immersing the insulating layer in a swelling solution at 30°C to 90°C for 1 to 20 minutes. From the viewpoint of suppressing the swelling of the resin of the insulating layer to an appropriate level, it is preferable to immerse the insulating layer in a swelling solution at 40°C to 80°C for 5 to 15 minutes.

[0221] Examples of oxidizing agents used in the roughening treatment include alkaline permanganate solutions obtained 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. Furthermore, the concentration of permanganate in the alkaline permanganate solution is preferably 5% to 10% by mass. Examples of commercially available oxidizing agents include alkaline permanganate solutions such as "Concentrate Compact CP" and "Dosing Solution Securigans P" manufactured by Atotec Japan.

[0222] As the neutralizing solution used for roughening treatment, an acidic aqueous solution is preferred, and a commercially available example is "Reduction Solution Securigant P" manufactured by Attec Japan. Treatment with the neutralizing solution can be carried out by immersing the treated surface, which has been roughened with an oxidizing agent, in a neutralizing solution at 30°C to 80°C for 5 to 30 minutes. From the viewpoint of workability, it is preferable to immerse the object that has been roughened with an oxidizing agent in a neutralizing solution at 40°C to 70°C for 5 to 20 minutes.

[0223] Step (V) is a step of forming a conductive layer, in which a conductive layer is formed on an insulating layer. The conductive material used for the conductive layer is not particularly limited. In a preferred embodiment, the conductive 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 conductive layer may be a single-metal layer or an alloy layer, and examples of alloy layers include layers formed from alloys of two or more metals selected from the above group (e.g., nickel-chromium alloy, copper-nickel alloy, and copper-titanium alloy). In particular, from the viewpoint of versatility in conductor layer formation, cost, and ease of patterning, single metal layers of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, or alloy layers of nickel-chromium alloy, copper-nickel alloy, or copper-titanium alloy are preferred, single metal layers of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, or alloy layers of nickel-chromium alloy are more preferred, and single metal layers of copper are even more preferred.

[0224] The conductive layer may be a single-layer structure, or it may be a multi-layer structure in which two or more single-metal layers or alloy layers made of different types of metals or alloys are stacked. When the conductive layer is 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 nickel-chromium alloy.

[0225] The thickness of the conductor layer depends on the desired printed circuit board design, but is generally 3 μm to 35 μm, preferably 5 μm to 30 μm.

[0226] 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 conventionally known techniques such as the semi-additive method or the fully additive method. From the viewpoint of ease of manufacture, the semi-additive method is preferred. An example of forming the conductor layer by the semi-additive method is shown below.

[0227] First, a plating seed layer is formed on the surface of the 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 forming a metal layer on the exposed plating seed layer by electroplating, the mask pattern is removed. Then, the unnecessary plating seed layer can be removed by etching or other means to form a conductor layer having the desired wiring pattern.

[0228] In other embodiments, the conductor layer may be formed using metal foil. When forming the conductor layer using metal foil, step (V) is preferably performed between steps (I) and (II). For example, after step (I), the support is removed and the metal foil is laminated onto the surface of the exposed resin composition layer. The lamination of the resin composition layer and the metal foil may be carried out by a vacuum lamination method. The lamination conditions may be the same as those described for step (I). Next, step (II) is performed to form an insulating layer. Subsequently, the metal foil on the insulating layer can be used to form a conductor layer having a desired wiring pattern by conventional known techniques such as the subtractive method or the modified semi-additive method.

[0229] Metal foils can be manufactured by known methods such as electrolysis and rolling. Examples of commercially available metal foils include HLP foil and JXUT-III foil manufactured by JX Metals, and 3EC-III foil and TP-III foil manufactured by Mitsui Mining & Smelting Co., Ltd.

[0230] [Semiconductor device] A semiconductor device according to one embodiment of the present invention includes the printed circuit board described above. The semiconductor device can be manufactured using the printed circuit board.

[0231] Examples of semiconductor devices include various types of semiconductor devices used in electrical products (e.g., computers, mobile phones, digital cameras, and televisions) and vehicles (e.g., motorcycles, automobiles, trains, ships, and aircraft). [Examples]

[0232] The present invention will be specifically described below with reference to examples. However, the present invention is not limited to these examples. In the following description, "parts" and "%" representing quantities mean "parts by mass" and "mass%", respectively, unless otherwise specified. In addition, unless a specific temperature is specified, the temperature and pressure conditions were room temperature (25°C) and atmospheric pressure (1 atm). Furthermore, a hollow inorganic filler containing non-combustible gas inside the void may be referred to as a "flame retardant".

[0233] <Synthesis Example 1: Manufacturing of Flame Retardant 1> In a reaction vessel, 40 g of methanol, 0.3 g of 25% solids tetramethylammonium hydroxide aqueous solution, 0.7 g of dodecyltrimethylammonium chloride, and 0.4 g of hexane were added and stirred until dissolved. 120 g of deionized water was added to the methanol solution to precipitate emulsion droplets of hexane. Then, 0.85 g of tetramethoxysilane was slowly added, stirred at room temperature (25°C) for 8 hours, and then aged for 12 hours. Next, the obtained white precipitate was filtered through Advantec filter paper (5C), washed with 300 mL of water, and dried at 90°C for 8 hours to obtain a dried powder. The obtained dried powder was heated to 600°C at a rate of 1°C / min with airflow (3 L / min) using a high-speed electric furnace (Motoyama "SK-2535E"), and calcined at 600°C for 2 hours to remove organic components and obtain hollow silica precursor particles. 0.5 g of these hollow silica precursor particles were placed in an alumina crucible, transferred to a desiccator, and subjected to five nitrogen purging cycles using nitrogen gas (N2 gas) with a purity exceeding 99.999% under reduced pressure. Afterward, the alumina crucible was removed from the desiccator and fired in the aforementioned electric furnace at 1000°C under a nitrogen atmosphere for 72 hours, thereby obtaining flame retardant 1 (average particle size 1.6 μm, BET specific surface area 12 m²) in which the inside of the pores was completely replaced with N2 gas. 2 A porosity of 50% per liter was obtained.

[0234] <Synthesis Example 2: Manufacturing of Flame Retardant 2> In Synthesis Example 1, nitrogen gas with a purity exceeding 99.999% was replaced with carbon dioxide gas (CO₂ gas) with a purity exceeding 99.995%. Except for the above matters, Flame Retardant 2 in which the entire interior of the pores was replaced with CO₂ gas (average particle diameter: 1.6 μm, BET specific surface area: 12 m 2 / g, porosity: 50 vol%) was obtained.

[0235] <Synthesis Example 3. Production of Flame Retardant 3> In Synthesis Example 1, nitrogen gas with a purity exceeding 99.999% was replaced with helium gas (He gas) with a purity exceeding 99.999%. Except for the above matters, Flame Retardant 3 in which the entire interior of the pores was replaced with He gas (average particle diameter: 1.6 μm, BET specific surface area: 12 m 2 / g, porosity: 50 vol%) was obtained.

[0236] <Synthesis Example 4. Production of Flame Retardant 4> In Synthesis Example 1, nitrogen gas with a purity exceeding 99.999% was replaced with neon gas (Ne gas) with a purity exceeding 99.999%. Except for the above matters, Flame Retardant 4 in which the entire interior of the pores was replaced with Ne gas (average particle diameter: 1.6 μm, BET specific surface area: 12 m 2 / g, porosity: 50 vol%) was obtained.

[0237] <Synthesis Example 5. Production of Flame Retardant 5> In Synthesis Example 1, nitrogen gas with a purity exceeding 99.999% was replaced with argon gas (Ar gas) with a purity exceeding 99.999%. Except for the above matters, Flame Retardant 5 in which the entire interior of the pores was replaced with Ar gas (average particle diameter: 1.6 μm, BET specific surface area: 12 m 2 / g, porosity: 50 vol%) was obtained.

[0238] <Synthesis Example 6. Production of Flame Retardant 6> Flame Retardant 6 was synthesized in accordance with the description in Japanese Patent No. 5940188. Specifically, Flame Retardant 6 was synthesized by the following procedure. 300 g of a water glass aqueous solution (SiO2 / Na2O molar ratio 3.2, SiO2 concentration 24 wt%) was used, and silica particle precursor particles (1) were obtained by spraying hot air at an inlet temperature of 400°C into one of two-fluid nozzles at a flow rate of 0.12 kg / hr and into the other nozzle at a flow rate of 31800 L / hr (air / liquid volume ratio 31800). At this time, the outlet temperature was 150°C. Next, 50 g of silica particle precursor particles (1) were immersed in 500 g of a 10 wt% sulfuric acid aqueous solution and stirred for 2 hours. Then, the mixture was dried and heat-treated in a dryer at 90°C for 12 hours to obtain a dried powder. The obtained dried powder was heated to 600°C at a rate of 1°C / min while maintaining an airflow of 3 L / min using a high-speed electric furnace (Motoyama "SK-2535E"), and then calcined at 600°C for 2 hours to obtain hollow silica particles. 0.5 g of these hollow silica particles were placed in an alumina crucible, transferred to a desiccator, and subjected to five rounds of nitrogen purging with reduced pressure and nitrogen gas of purity >99.999%. After that, the alumina crucible was removed from the desiccator and calcined in the aforementioned electric furnace at 1000°C under a nitrogen atmosphere for 72 hours, thereby obtaining flame retardant 6 (average particle size 2.0 μm, BET specific surface area 3.8 m²) in which the inside of the pores was completely replaced with N2 gas. 2 A porosity of 20% per liter was obtained.

[0239] <Example 1> 25 parts of bisphenol A type epoxy resin (Mitsubishi Chemical Corporation's "828EL," epoxy equivalent approximately 180g), 10 parts of biphenyl type epoxy resin (Nippon Kayaku Co., Ltd.'s "NC3000L," epoxy equivalent approximately 269g / eq.), and 50 parts of methyl ethyl ketone were added and heated while stirring until dissolved. This was then cooled to room temperature to prepare the epoxy resin solution composition. To this dissolution composition: 10 parts of triazine skeleton-containing phenolic curing agent (DIC Corporation "LA-3018-50P", active group equivalent approximately 151 g / eq., 2-methoxypropanol solution with 50% non-volatile content), 10 parts of naphthol-type curing agent (Nippon Steel Chemical & Material Co., Ltd. "SN-485", hydroxyl group equivalent approximately 205 g / eq.), 15 parts of phenoxy resin (Mitsubishi Chemical Corporation "YX7553BH30", 1:1 solution of MEK and cyclohexanone with 30% by mass of non-volatile content), and silane coupling agent (Shin-Etsu Chemical Co., Ltd. "KBM-573" A resin varnish was prepared by mixing 80 parts of spherical silica (SO-C2, manufactured by Admatex, average particle size 0.5 μm) surface-treated with a silane coupling agent (KBM-573, manufactured by Shin-Etsu Chemical Co., Ltd.) with a flame retardant (average particle size 1.6 μm, contains N2 gas, porosity 50 vol%), 3 parts of rubber particles (Stafloid AC3816N, manufactured by Aica Kogyo Co., Ltd.) and 4 parts of an amine-based curing accelerator (4-dimethylaminopyridine (DMAP), MEK solution with 5% solids by mass), and uniformly dispersing them in a high-speed rotary mixer.

[0240] Next, a resin varnish was uniformly applied to the release surface of a release-treated polyethylene terephthalate film (Lintec Corporation's "AL5", 38 μm thick), which served as the support, so that the resin composition layer had a thickness of 40 μm. The film was then dried at 80-120°C (average 100°C) for 5 minutes to produce a resin sheet with a support.

[0241] <Example 2> In Example 1, 10 parts of flame retardant 1 (average particle size 1.6 μm, N2 gas-containing, 50 vol. porosity) surface-treated with a silane coupling agent (Shin-Etsu Chemical Co., Ltd. "KBM-573") were replaced with 10 parts of flame retardant 2 (average particle size 1.6 μm, CO2 gas-containing, 50 vol. porosity) surface-treated with a silane coupling agent (Shin-Etsu Chemical Co., Ltd. "KBM-573"). Except for the above, resin varnish and resin sheets were prepared in the same manner as in Example 1.

[0242] <Example 3> In Example 1, 10 parts of flame retardant 1 (average particle size 1.6 μm, N2 gas-containing, 50 vol. porosity) surface-treated with a silane coupling agent ("KBM-573" manufactured by Shin-Etsu Chemical Co., Ltd.) were replaced with 10 parts of flame retardant 3 (average particle size 1.6 μm, He gas-containing, 50 vol. porosity) surface-treated with a silane coupling agent ("KBM-573" manufactured by Shin-Etsu Chemical Co., Ltd.). Except for the above, resin varnish and resin sheets were prepared in the same manner as in Example 1.

[0243] <Example 4> In Example 1, 10 parts of flame retardant 1 (average particle size 1.6 μm, N2 gas-containing, 50 vol. porosity) surface-treated with a silane coupling agent ("KBM-573" manufactured by Shin-Etsu Chemical Co., Ltd.) were replaced with 10 parts of flame retardant 4 (average particle size 1.6 μm, Ne gas-containing, 50 vol. porosity) surface-treated with a silane coupling agent ("KBM-573" manufactured by Shin-Etsu Chemical Co., Ltd.). Except for the above, resin varnish and resin sheets were prepared in the same manner as in Example 1.

[0244] <Example 5> 12 parts of naphthalene-type epoxy resin (DIC Corporation's "HP-4032-SS", epoxy equivalent approximately 144) were added to 50 parts of methyl ethyl ketone, and the mixture was heated while stirring until homogenized. This was then cooled to room temperature to prepare the epoxy resin solution composition. This dissolution composition contains 30 parts of an active ester compound (DIC Corporation's "HPC-8000-65T", active ester group equivalent of approximately 223 g / eq., toluene solution with 65% non-volatile content), 2 parts of a triazine skeleton-containing phenolic curing agent (DIC Corporation's "LA-3018-50P", active group equivalent of approximately 151 g / eq., 2-methoxypropanol solution with 50% non-volatile content), 5 parts of a carbodiimide curing agent (Nisshinbo Chemical Corporation's "V-03", active group equivalent of approximately 216 g / eq., toluene solution with 50% non-volatile content), and vinyl benzyl-modified polyphenylene ether (Mitsubishi Gas Chemical Corporation's "OPE-2St Two parts of a toluene solution with a non-volatile component content of 65% (2200), 30 parts of spherical silica (SO-C2, manufactured by Admatex, average particle size 0.5 μm) surface-treated with a silane coupling agent (KBM-573, manufactured by Shin-Etsu Chemical Co., Ltd.), 30 parts of flame retardant 5 (average particle size 1.6 μm, containing Ar gas, porosity 50 vol%) surface-treated with a silane coupling agent (KBM-573, manufactured by Shin-Etsu Chemical Co., Ltd.), and 0.1 parts of an imidazole-based curing accelerator (1B2PZ, manufactured by Shikoku Chemicals, Inc., 1-benzyl-2-phenylimidazole) were mixed and uniformly dispersed in a high-speed rotary mixer to prepare a resin varnish.

[0245] Next, a resin varnish was uniformly applied to the release surface of a release-treated polyethylene terephthalate film (Lintec Corporation's "AL5", 38 μm thick), which served as the support, so that the resin composition layer had a thickness of 40 μm. The film was then dried at 80-120°C (average 100°C) for 5 minutes to produce a resin sheet with a support.

[0246] <Example 6> Twenty parts of bisphenol A type epoxy resin (Mitsubishi Chemical Corporation's "828EL," epoxy equivalent approximately 180), fifteen parts of naphthylene ether type epoxy resin (epoxy equivalent approximately 250, DIC Corporation's "HP6000"), and fifty parts of methyl ethyl ketone were added and heated and dissolved while stirring. This was then cooled to room temperature to prepare the epoxy resin solution composition. This dissolution composition contains 15 parts of an active ester compound (DIC Corporation's "HPC-8000-65T", active ester group equivalent approximately 223 g / eq., toluene solution with 65% non-volatile content), 20 parts of a bisphenol A dicyanate prepolymer (Lonza Japan's "BA230S75", cyanate equivalent approximately 232, MEK solution with 75% by mass non-volatile content), 2 parts of a biphenylaralkyl novolac type maleimide (Nippon Kayaku Co., Ltd.'s "MIR-3000-70MT", MEK / toluene mixed solution with 70% non-volatile content), 1 part of an organophosphorus flame retardant (Daihachi Chemical Industry Co., Ltd.'s "PX-200"), 8 parts of a phenoxy resin (Mitsubishi Chemical Corporation's "YX7553BH30", a 1:1 solution of MEK and cyclohexanone with 30% by mass non-volatile content), and A resin varnish was prepared by mixing 60 parts of spherical silica (SO-C2, manufactured by Admatex, average particle size 0.5 μm) surface-treated with a silane coupling agent (KBM-573, manufactured by Shin-Etsu Chemical Co., Ltd.), 48 parts of flame retardant 6 (average particle size 2.0 μm, BET specific surface area 3.8 m2 / g, N2 gas content, porosity 20 vol%) surface-treated with a silane coupling agent (KBM-573, manufactured by Shin-Etsu Chemical Co., Ltd.), 2 parts of rubber particles (Stafiloid AC3816N, manufactured by Aica Kogyo Co., Ltd.), 4 parts of an amine-based curing accelerator (4-dimethylaminopyridine (DMAP), MEK solution with 5% solids by mass), and 1 part of a 1% by mass MEK solution of cobalt(III) acetylacetonate (manufactured by Tokyo Chemical Industry Co., Ltd.), and uniformly dispersing them in a high-speed rotary mixer.

[0247] Next, a resin varnish was uniformly applied to the release surface of a release-treated polyethylene terephthalate film (Lintec Corporation's "AL5", 38 μm thick), which served as the support, so that the resin composition layer had a thickness of 40 μm. The film was then dried at 80-120°C (average 100°C) for 5 minutes to produce a resin sheet with a support.

[0248] <Comparative Example 1> In Example 1, the amount of spherical silica (SO-C2, manufactured by Admatex, average particle size 0.5 μm) surface-treated with silane coupling agent (KBM-573, manufactured by Shin-Etsu Chemical Co., Ltd.) was changed from 80 parts to 100 parts, and 10 parts of flame retardant 1 (average particle size 1.6 μm, N2 gas-containing, porosity 50 vol%) surface-treated with silane coupling agent (KBM-573, manufactured by Shin-Etsu Chemical Co., Ltd.) were omitted. Except for the above, resin varnish and resin sheets were prepared in the same manner as in Example 1.

[0249] <Comparative Example 2> In Example 1, 10 parts of flame retardant 1 (average particle size 1.6 μm, N2 gas-containing, porosity 50 vol%) surface-treated with a silane coupling agent ("KBM-573" manufactured by Shin-Etsu Chemical Co., Ltd.) were replaced with 10 parts of an organophosphorus flame retardant ("PX-200" manufactured by Daihachi Chemical Industry Co., Ltd.). Except for the above, resin varnish and resin sheets were prepared in the same manner as in Example 1.

[0250] <Measurement of specific gravity> Using a Mettler-Toledo XP105 analytical balance (with a specific gravity measurement kit), specific gravity was calculated by measuring the weight in air and water. Measurements were performed on five samples, and the average value was calculated.

[0251] <Preparation of hardened samples for evaluation> A glass cloth-based epoxy resin double-sided copper-clad laminate (Panasonic R5715ES, 0.7 mm thick, 255 mm square) was placed on the untreated side of a PET film (Lintec "501010", 50 μm thick, 240 mm square) that had been treated with a mold release agent, and the four sides were fixed with polyimide adhesive tape (10 mm wide) (hereinafter sometimes referred to as "fixed PET film").

[0252] The resin varnishes produced in Examples 1 to 6 and Comparative Examples 1 and 2 were coated onto the release-treated surface of the above-mentioned "fixed PET film" using a die coater such that the thickness of the resin composition layer after drying became 40 µm, and dried at 80°C to 120°C (average 100°C) for 10 minutes to obtain a resin sheet. Subsequently, after placing in an oven at 180°C, the resin composition layer was heat-cured under curing conditions of 90 minutes. After heat curing, the polyimide adhesive tape was peeled off, the cured product was removed from the glass cloth base epoxy resin double-sided copper-clad laminate, and the PET film ("501010" manufactured by Lintec Corporation) was also peeled off to obtain a sheet-shaped cured product. The obtained cured product is referred to as "cured product for evaluation".

[0253] <Measurement of Relative Dielectric Constant and Dielectric Loss Tangent> The cured product for evaluation was cut into a size of 80 mm in length and 2 mm in width to obtain an evaluation sample. This evaluation sample was measured for relative dielectric constant (Dk 23deg.C ) and dielectric loss tangent (Df 23deg.C ) at a measurement frequency of 5.8 GHz and a measurement temperature of 23°C, and relative dielectric constant (Dk 90deg.C ) and dielectric loss tangent (Df 90deg.C ) at a measurement temperature of 90°C by the cavity resonance perturbation method using an HP8362B apparatus manufactured by Agilent Technologies. Measurements were performed on two test pieces, and the average value was calculated. In addition, the relative dielectric constant and dielectric loss tangent at each temperature were evaluated according to the following evaluation criteria.

[0254] · Evaluation criteria for relative dielectric constant ◎: The relative dielectric constant is less than 3.00. ○: The relative dielectric constant is 3.00 or more and less than 3.30. ×: The relative dielectric constant is 3.30 or more.

[0255] · Evaluation criteria for dielectric loss tangent ◎: The rate of change of dielectric loss tangent represented by the following formula (1) is less than 30%. ×: The rate of change of dielectric loss tangent represented by the following formula (1) is 30% or more. Rate of change of dielectric loss tangent (%) = {(Df 90deg.C ) – (Df 23deg.C )} / (Df 23deg.C ) × 100 (1)

[0256] <Evaluation of the coefficient of thermal expansion> The cured material for evaluation was cut into test specimens approximately 15 mm in length and 5 mm in width, and thermomechanical analysis was performed using a Rigaku Thermo Plus TMA8310 thermomechanical analyzer by the tensile loading method. After mounting the test specimens in the apparatus, measurements were taken twice consecutively under measurement conditions of a load of 1 g and a heating rate of 5 °C / min. In the second measurement, the glass transition temperature and the coefficient of thermal expansion from 25 °C to 150 °C were calculated. The coefficient of thermal expansion was evaluated according to the following evaluation criteria. • Evaluation criteria ○: The coefficient of thermal expansion is less than 30 ppm. ×: The coefficient of thermal expansion is 30 or greater.

[0257] <Measurement of elongation (elongation at break)> The hardened material for evaluation was cut into dumbbell-shaped specimens (Type 1) to obtain test pieces. The tensile strength of these test pieces was measured using an Orientec RTC-1250A tensile testing machine, and the elongation at break at 23°C was determined. The measurements were performed in accordance with JIS K7127, and the average value of five measurements was calculated.

[0258] <Evaluation of flame retardancy> The resin sheets prepared in the examples and comparative examples were laminated to both sides of a copper-clad laminate (Hitachi Chemical Co., Ltd. "MCL-E-700G") with a substrate thickness of 0.2 mm, from which the copper foil had been etched off, using a batch-type vacuum pressure laminator MVLP-500 (product name of Meiki Co., Ltd.). Lamination was performed by reducing the pressure to 13 hPa or less for 30 seconds, and then pressing at 100°C and a pressure of 0.74 MPa for 30 seconds. After peeling off the PET film from the support, a 40 μm thick resin sheet was laminated to both sides again under the same conditions. Then, the PET film was peeled off and the sample was heat-cured at 180°C for 90 minutes to obtain a sample for flame retardancy testing. The sample was cut to a width of 12.7 mm and a length of 127 mm, and the cut surface was polished with a polishing machine (Struers, RotoPol-22). The above five samples were treated as a set, and flame retardancy tests were conducted according to the UL94 vertical flame retardancy test.

[0259] <Evaluation of High Temperature Reflow Blister Resistance> The resin varnishes prepared in Examples and Comparative Examples were applied onto a copper foil ("JDLC" manufactured by JX Nippon Mining & Metals Corporation, thickness 12 μm, 240 mm square) using a die coater such that the thickness of the resin composition layer after drying was 40 μm, and dried at 80°C to 120°C (average 100°C) for 10 minutes to obtain a copper foil sheet with resin. This copper foil sheet with resin was laminated on both sides of a copper-clad laminate using a vacuum hot press (VH1-1603, manufactured by Kitagawa Seiki Co., Ltd.) such that the resin composition layer of the copper foil sheet with resin was in contact with the copper-clad laminate. The pressing conditions were a degree of vacuum of 1×10 -3 MPa or less under reduced pressure, a pressure condition of 20 kgf / cm 2 Under the above conditions, as heating conditions, the first-stage pressing was performed at a temperature of 100°C for 30 minutes, and the second-stage pressing was performed at a temperature of 190°C for 120 minutes, to obtain a substrate for heat resistance evaluation. The evaluation substrate was cut into 100 mm × 50 mm small pieces, and passed through a reflow apparatus ("HAS-6116" manufactured by Nihon Antom Co., Ltd.) that reproduces a solder reflow temperature with a peak temperature of 260°C 10 times (the reflow temperature profile conforms to IPC / JEDEC J-STD-020C). The evaluation was performed on two small pieces, and evaluated by visual observation according to the following evaluation criteria. ○: No abnormality at all in all small pieces. △: 1 to 4 abnormalities such as blistering are observed. ×: 5 or more abnormalities such as blistering are observed.

[0260] [Table 1]

[0261] [Table 2]

[0262] [Table 3]

Claims

1. (A) Curable resin, (B) Inorganic fillers, and (C) A resin composition containing a non-combustible gas, Component (B) includes a hollow inorganic filler (B-1) having voids inside, (B-1) Component is silica, Component (C) is contained within the void of component (B-1), The content (volume %) of component (C) contained within the pores of component (B-1) is 80% or more when the volume inside the pores of component (B-1) is taken as 100% by volume. A resin composition in which component (C) is one or more selected from argon gas, carbon dioxide gas, helium gas, and neon gas.

2. The resin composition according to claim 1, wherein the average particle size of component (B-1) is 0.01 μm or more and 5 μm or less.

3. (A) Curable resin, (B) Inorganic fillers, and (C) A resin composition containing a non-combustible gas, Component (B) includes a hollow inorganic filler (B-1) having voids inside, (B-1) Component is silica, Component (C) is contained within the void of component (B-1), The content (volume %) of component (C) contained within the pores of component (B-1) is 80% or more when the volume inside the pores of component (B-1) is taken as 100% by volume. A resin composition having an average particle size of component (B-1) of 3.0 μm or less.

4. The resin composition according to claim 3, wherein component (C) is one or more selected from nitrogen gas, argon gas, carbon dioxide gas, helium gas, and neon gas.

5. (A) The resin composition according to any one of claims 1 to 4, wherein component (A) comprises an epoxy resin containing an aromatic structure.

6. The resin composition according to any one of claims 1 to 5, wherein the porosity of component (B-1) is 10% by volume or more and 80% by volume or less.

7. The resin composition according to any one of claims 1 to 6, wherein component (B) comprises component (B-1) and a solid inorganic filler (B-2).

8. (A) The resin composition according to any one of claims 1 to 7, wherein component (A) comprises at least one selected from the group consisting of epoxy resins, phenolic resins, activated ester resins, cyanate resins, and radical polymerizable resins.

9. Furthermore, the resin composition according to any one of claims 1 to 8, further comprising (D) organic particles.

10. A resin composition according to any one of claims 1 to 9, for forming an insulating layer.

11. A cured product of the resin composition according to any one of claims 1 to 10.

12. A sheet-like laminated material containing the resin composition according to any one of claims 1 to 10.

13. A resin sheet having a support and a resin composition layer formed on the support with the resin composition described in any one of claims 1 to 10.

14. A printed circuit board comprising an insulating layer containing a cured product of the resin composition according to any one of claims 1 to 10.

15. A semiconductor device comprising a printed circuit board as described in claim 14.

16. (a) (B-1) A step of encapsulating a non-combustible gas inside the pores of the precursor of the hollow inorganic filler, and A method for producing a resin composition, comprising the step of (b) calcining a precursor of a hollow inorganic filler (B-1) containing a non-combustible gas inside the pores, The resin composition is (A) Curable resin, (B) Inorganic fillers, and (C) Non-combustible gas, A method for producing a resin composition, wherein component (B) includes a hollow inorganic filler (B-1) having internal pores, component (C) is contained within the pores of component (B-1), and the content (volume %) of component (C) contained within the pores of component (B-1) is 80% by volume or more, when the volume inside the pores of component (B-1) is taken as 100% by volume.

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