Method for manufacturing printed wiring board

Abstract

To provide a method for manufacturing printed wiring boards with an insulating layer having a low arithmetic mean roughness and a low average linear thermal expansion coefficient, even when using DLC.SOLUTION: A method for manufacturing a wiring board includes (I) a step for forming a resin composition layer containing epoxy resin and a curing agent on an inner layer substrate, (II) a step for heating the resin composition layer to semi-cure the resin composition layer, (III) a step for forming a diamond-like carbon layer on the semi-cured resin composition layer, and (IV) a step for further curing the semi-cured resin composition layer.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a printed wiring board. [Background technology]

[0002] Printed wiring boards are widely used in various electronic devices. Printed wiring boards are required to have finer and denser circuit wiring in order to reduce the size and improve the functionality of electronic devices. A known method for manufacturing printed wiring boards is a build-up method in which insulating layers and conductor layers are alternately stacked on an inner layer substrate. The insulating layer is formed, for example, by forming a resin composition layer containing a resin composition on the inner layer substrate and then thermally curing the resin composition layer (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-167427 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, with the improvement in the functionality of electronic components, there has been a demand for high-performance printed wiring boards. The present inventors have discovered that diamond-like carbon (DLC) has excellent insulating properties, abrasion resistance, and gas barrier properties, and is also chemically stable, and have investigated the use of DLC as an insulating layer or solder resist.

[0005] However, when DLC is used as an insulating layer, the arithmetic mean roughness Sa increases due to the occurrence of irregularities on the DLC surface, which can make it difficult to form fine wiring.In addition, when DLC is used as an insulating layer, the mean linear thermal expansion coefficient of the insulating layer can also increase.

[0006] The present invention was devised in view of the above-mentioned problems, and aims to provide a method for manufacturing a printed wiring board having an insulating layer that has a small arithmetic mean roughness Sa and a small mean linear thermal expansion coefficient even when DLC is used. [Means for solving the problem]

[0007] The present inventors have conducted extensive research to solve the above-mentioned problems, and as a result, have found that the above-mentioned problems can be solved by semi-curing a resin composition layer, forming a diamond-like carbon layer, and then further curing the semi-cured resin composition layer to form an insulating layer, thereby completing the present invention. That is, the present invention includes the following.

[0008] [1] (I) forming a resin composition layer containing an epoxy resin and a curing agent on an inner layer substrate; (II) a step of heating the resin composition layer to semi-cure the resin composition layer; (III) forming a diamond-like carbon layer on the semi-cured resin composition layer; and (IV) A method for producing a printed wiring board, comprising the step of further curing the semi-cured resin composition layer. [2] The method for producing a printed wiring board according to [1], wherein in step (II), the resin composition layer is semi-cured so that the reaction rate of the epoxy resin is 20% or more and 80% or less. [3] The method for producing a printed wiring board according to [1] or [2], wherein in step (IV), the resin composition layer is cured so that the reaction rate of the epoxy resin is 90% or more. [4] The method for producing a printed wiring board according to any one of [1] to [3], wherein the diamond-like carbon layer has a surface with an arithmetic mean roughness Sa of less than 100 nm. [5] The method for producing a printed wiring board according to any one of [1] to [4], wherein the average linear thermal expansion coefficient of the cured product of the resin composition layer is less than 40 ppm / K. [6] The method for producing a printed wiring board according to any one of [1] to [5], wherein the resin composition layer further contains an inorganic filler. [7] The method for producing a printed wiring board according to any one of [1] to [6], wherein the curing agent includes an active ester curing agent. [8] A printed wiring board comprising an inner layer substrate, an insulating layer formed on the inner layer substrate, and a diamond-like carbon layer formed on the insulating layer, The arithmetic mean roughness (Sa) of the diamond-like carbon layer is less than 100 nm; A printed wiring board, wherein the insulating layer has an average linear thermal expansion coefficient of less than 40 ppm / K. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a method for manufacturing a printed wiring board having an insulating layer that has a small arithmetic mean roughness Sa and a small mean linear thermal expansion coefficient even when DLC is used. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is an NIR chart of the resin sheet A (resin composition layer before thermal curing) and the laminated sample B (semi-cured resin composition layer) of Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0011] 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 can be implemented with any modifications within the scope of the claims and their equivalents.

[0012] Before describing the method for producing a printed wiring board of the present invention in detail, the resin composition and resin sheet used in the method for producing a printed wiring board of the present invention will be described.

[0013] <Resin composition> It is preferable that the resin composition has sufficient hardness and insulating properties when cured. Therefore, the resin composition contains (a) an epoxy resin and (b) a curing agent. The resin composition may further contain (c) an inorganic filler, (d) a thermoplastic resin, (e) a curing accelerator, (f) other additives, and (g) a solvent, as necessary.

[0014] -(a) Epoxy resin- The resin composition contains an (a) epoxy resin as component (a). By including the (a) epoxy resin in the resin composition, a cured product exhibiting good mechanical strength and insulating reliability can be obtained. The (a) epoxy resin may be used alone or in combination of two or more types.

[0015] (a) Examples of epoxy resins include bixylenol type epoxy resins, bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, bisphenol AF type epoxy resins, dicyclopentadiene type epoxy resins, trisphenol type epoxy resins, naphthol novolac type epoxy resins, phenol novolac type epoxy resins, tert-butyl-catechol type epoxy resins, naphthalene type epoxy resins, naphthol type epoxy resins, anthracene type epoxy resins, glycidylamine type epoxy resins, and glycidyl ester type Examples of epoxy resins include glycidyl cyclohexane-type epoxy resins, alkyl diglycidyl ether-type epoxy resins, cresol novolac-type epoxy resins, biphenyl-type epoxy resins, linear aliphatic epoxy resins, epoxy resins having a butadiene structure, alicyclic epoxy resins, heterocyclic epoxy resins, spiro ring-containing epoxy resins, cyclohexane-type epoxy resins, cyclohexane dimethanol-type epoxy resins, naphthylene ether-type epoxy resins, trimethylol-type epoxy resins, tetraphenylethane-type epoxy resins, and phenolphthalimidine-type epoxy resins. Of these, epoxy resins having an aromatic ring are preferred.

[0016] The resin composition preferably contains, as component (a), an epoxy resin having two or more epoxy groups in one molecule. From the viewpoint of significantly achieving the desired effects of the present invention, the proportion of the epoxy resin having two or more epoxy groups in one molecule relative to 100% by mass of the epoxy resin (a) is preferably 50% by mass or more, more preferably 60% by mass or more, and particularly preferably 70% by mass or more.

[0017] Epoxy resins include epoxy resins that are liquid at a temperature of 20°C (hereinafter sometimes referred to as "liquid epoxy resins") and epoxy resins that are solid at a temperature of 20°C (hereinafter sometimes referred to as "solid epoxy resins"). The resin composition may contain, as component (a), only a liquid epoxy resin, only a solid epoxy resin, or a combination of a liquid epoxy resin and a solid epoxy resin. Of these, from the viewpoint of significantly achieving the effects of the present invention, it is preferable to contain a combination of a liquid epoxy resin and a solid epoxy resin. Furthermore, when component (a) contains a combination of a liquid epoxy resin and a solid epoxy resin, it is preferable that either the liquid epoxy resin or the solid epoxy resin contains an epoxy resin containing an aromatic ring, and it is more preferable that both contain epoxy resins containing aromatic rings.

[0018] The liquid epoxy resin is preferably a liquid epoxy resin having two or more epoxy groups in one molecule.

[0019] Preferred liquid epoxy resins include bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol AF type epoxy resins, naphthalene type epoxy resins, glycidyl ester type epoxy resins, glycidyl amine type epoxy resins, phenol novolac type epoxy resins, alicyclic epoxy resins having an ester skeleton, cyclohexane type epoxy resins, cyclohexane dimethanol type epoxy resins, glycidyl amine type epoxy resins, and epoxy resins having a butadiene structure, glycidyl cyclohexane type epoxy resins, phenolphthalimidine type epoxy resins, and alkyl diglycidyl ether type epoxy resins, and more preferred are bisphenol A type epoxy resins, bisphenol F type epoxy resins, and naphthalene type epoxy resins.

[0020] Specific examples of liquid epoxy resins include "HP4032", "HP4032D", and "HP4032SS" (naphthalene type epoxy resins) manufactured by DIC Corporation; "828US", "jER828EL", "825", and "Epikote 828EL" (bisphenol A type epoxy resins) manufactured by Mitsubishi Chemical Corporation; "jER807" and "1750" (bisphenol F type epoxy resins) manufactured by Mitsubishi Chemical Corporation; "jER152" (phenol novolac type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "630" and "630LSD" (glycidyl amine type epoxy resins) manufactured by Mitsubishi Chemical Corporation; and "ZX1" manufactured by Nippon Steel Chemical & Material Co., Ltd. Examples of epoxy resins that can be used include "EX-721" (a glycidyl ester epoxy resin) manufactured by Nagase ChemteX Corporation, "Celloxide 2021P" (an alicyclic epoxy resin having an ester skeleton) manufactured by Daicel Corporation, "PB-3600" (an epoxy resin having a butadiene structure) manufactured by Daicel Corporation, "ZX1658" and "ZX1658GS" (liquid 1,4-glycidylcyclohexane epoxy resins) manufactured by Nippon Steel Chemical & Material Co., Ltd., and "YED216D" (an alkyl diglycidyl ether epoxy resin) manufactured by Mitsubishi Chemical Corporation. These may be used alone or in combination of two or more.

[0021] As the solid epoxy resin, a solid epoxy resin having two or more epoxy groups in one molecule is preferred, a solid epoxy resin having three or more epoxy groups in one molecule is more preferred, and an aromatic solid epoxy resin having three or more epoxy groups in one molecule is even more preferred.

[0022] Preferred solid epoxy resins include bixylenol-type epoxy resins, naphthalene-type epoxy resins, naphthalene-type tetrafunctional epoxy resins, cresol novolac-type epoxy resins, dicyclopentadiene-type epoxy resins, trisphenol-type epoxy resins, naphthol-type epoxy resins, biphenyl-type epoxy resins, naphthylene ether-type epoxy resins, anthracene-type epoxy resins, bisphenol A-type epoxy resins, bisphenol AF-type epoxy resins, and tetraphenylethane-type epoxy resins, with naphthalene-type epoxy resins and biphenyl-type epoxy resins being more preferred.

[0023] Specific examples of solid epoxy resins include "HP4032H" (naphthalene type epoxy resin), "HP-4700", "HP-4710" (naphthalene type tetrafunctional epoxy resin), "N-690" (cresol novolac type epoxy resin), "N-695" (cresol novolac type epoxy resin), "HP-7200", "HP-7200HH", "HP-7200H" (dicyclopentadiene type epoxy resin), "EXA-7311", "EXA-7311-G3", "EXA-7311-G4", "EXA-7311-G4S", "HP6000", "HP6000L" (naphthylene ether type epoxy resin), manufactured by DIC Corporation; "EPPN-502H" (trisphenol type epoxy resin), "NC7000L" (naphthol novolac type epoxy resin), "NC3000H", "NC3000", "NC3000L" manufactured by Nippon Kayaku Co., Ltd.; Examples include "NC3100" (biphenyl-type epoxy resin); "ESN475V" (naphthalene-type epoxy resin) and "ESN485" (naphthol novolac-type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "YX4000H", "YL6121" (biphenyl-type epoxy resin), "YX4000HK" (bixylenol-type epoxy resin), and "YX8800" (anthracene-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "PG-100" and "CG-500" manufactured by Osaka Gas Chemical Co., Ltd.; "YL7760" (bisphenol AF-type epoxy resin), "YL7800" (fluorene-type epoxy resin), "jER1010" (solid bisphenol A-type epoxy resin), and "jER1031S" (tetraphenylethane-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; and "WHR-991S" (phenolphthalimidine-type epoxy resin) manufactured by Nippon Kayaku Co., Ltd. These may be used alone or in combination of two or more.

[0024] When a liquid epoxy resin and a solid epoxy resin are used in combination as component (a), the ratio by mass of the liquid epoxy resin to the solid epoxy resin (liquid epoxy resin:solid epoxy resin) is preferably 1:0.1 to 1:20, more preferably 1:0.15 to 1:10, and particularly preferably 1:0.2 to 1:5. When the ratio by mass of the liquid epoxy resin to the solid epoxy resin is within this range, the desired effects of the present invention can be significantly achieved.

[0025] The epoxy equivalent of component (a) is preferably 50 g / eq. to 5000 g / eq., more preferably 50 g / eq. to 3000 g / eq., even more preferably 80 g / eq. to 2000 g / eq., and even more preferably 110 g / eq. to 1000 g / eq. By keeping it within this range, a cured product of the resin composition can be obtained with sufficient crosslink density. The epoxy equivalent is the mass of an epoxy resin containing one equivalent of epoxy groups. This epoxy equivalent can be measured according to JIS K7236.

[0026] The weight average molecular weight (Mw) of the component (a) is preferably 100 to 5000, more preferably 150 to 3000, and even more preferably 200 to 1500. The weight average molecular weight of the epoxy resin is a weight average molecular weight measured by gel permeation chromatography (GPC) in terms of polystyrene.

[0027] The content of component (a) is preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more, based on 100% by mass of the nonvolatile components in the resin composition, and the upper limit is preferably 25% by mass or less, more preferably 20% by mass or less, and even more preferably 15% by mass or less.

[0028] The content of component (a) is preferably 40% by mass or more, more preferably 45% by mass or more, and even more preferably 50% by mass or more, based on 100% by mass of the resin component in the resin composition, and the upper limit is preferably 70% by mass or less, more preferably 65% ​​by mass or less, and even more preferably 60% by mass or less.

[0029] In the present invention, unless otherwise specified, the content of each component in the resin composition is a value when the nonvolatile components in the resin composition are 100 mass %, and the nonvolatile components refer to all nonvolatile components in the resin composition excluding the solvent. Furthermore, the resin components in the resin composition refer to the nonvolatile components in the resin composition excluding (c) the inorganic filler.

[0030] <(b) Hardener> The resin composition contains a (b) curing agent as component (b). This (b) curing agent as component (b) excludes those that fall under component (a). Component (b) usually has the function of reacting with component (a) to cure the resin composition. Component (b) may be used alone or in combination of two or more types in any ratio.

[0031] As the component (b), a compound capable of reacting with the component (a) to cure the resin composition can be used, and examples thereof include active ester curing agents, phenolic curing agents, benzoxazine curing agents, carbodiimide curing agents, acid anhydride curing agents, amine curing agents, cyanate ester curing agents, etc. Among these, the component (b) preferably contains any one of an active ester curing agent, a phenolic curing agent, and a carbodiimide curing agent, and more preferably contains an active ester curing agent.

[0032] Examples of active ester curing agents include curing agents having one or more active ester groups per molecule. Among these, preferred active ester curing agents are compounds having two or more highly reactive ester groups per molecule, such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds. The active ester curing agent is preferably one obtained by a condensation reaction between a carboxylic acid compound and / or a thiocarboxylic acid compound and a hydroxy compound and / or a thiol compound. In particular, from the viewpoint of improving heat resistance, active ester curing agents obtained from a carboxylic acid compound and a hydroxy compound are preferred, and active ester curing agents obtained from a carboxylic acid compound and a phenol compound and / or a naphthol compound are more preferred.

[0033] Examples of the carboxylic acid compound include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, and pyromellitic acid.

[0034] Examples of phenol compounds or naphthol compounds include hydroquinone, resorcinol, bisphenol A, bisphenol F, bisphenol S, phenolphthalene, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m-cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucin, benzenetriol, dicyclopentadiene-type diphenol compounds, and phenol novolak. Here, "dicyclopentadiene-type diphenol compounds" refers to diphenol compounds obtained by condensing one dicyclopentadiene molecule with two phenol molecules.

[0035] Preferred specific examples of active ester curing agents include dicyclopentadiene-type active ester curing agents, naphthalene-type active ester curing agents containing a naphthalene structure, active ester curing agents containing an acetylated product of phenol novolac, active ester curing agents containing a benzoylated product of phenol novolac, active ester curing agents that are acetylated products of phenol novolac, and active ester curing agents containing a styryl group and a naphthalene structure. As the dicyclopentadiene-type active ester curing agent, an active ester curing agent containing a dicyclopentadiene-type diphenol structure is preferred. The "dicyclopentadiene-type diphenol structure" refers to a divalent structural unit consisting of phenylene-dicyclopentylene-phenylene.

[0036] Among them, the active ester curing agent is preferably at least one selected from an active ester curing agent containing a styryl group and a naphthalene structure, and a naphthalene-type active ester curing agent containing a naphthalene structure.

[0037] Commercially available active ester curing agents include active ester curing agents containing a dicyclopentadiene-type diphenol structure such as "EXB9451," "EXB9460," "EXB9460S," "HPC-8000-65T," "HPC-8000H-65TM," and "EXB-8000L-65TM" (manufactured by DIC Corporation); naphthalene-type active ester curing agents containing a naphthalene structure such as "HP-B-8151-62T," "EXB9416-70BK," "EXB-8100L-65T," "EXB-8150L-65T," "EXB-8150-65T," "HPC-8150-60T," and "HPC-8151-62T" (manufactured by DIC Corporation); phosphorus-containing active ester compounds such as "EXB9401" (manufactured by DIC Corporation); and phenol novolac Examples of such curing agents include "DC808" (manufactured by Mitsubishi Chemical Corporation) as an active ester-based curing agent containing an acetylated product of phenol novolac; "YLH1026" (manufactured by Mitsubishi Chemical Corporation) as an active ester-based curing agent containing a benzoylated product of phenol novolac; "DC808" (manufactured by Mitsubishi Chemical Corporation) as an active ester-based curing agent which is an acetylated product of phenol novolac; "YLH1026" (manufactured by Mitsubishi Chemical Corporation), "YLH1030" (manufactured by Mitsubishi Chemical Corporation), and "YLH1048" (manufactured by Mitsubishi Chemical Corporation) as active ester-based curing agents which are benzoylated products of phenol novolac; "EXB-8500-65T" (manufactured by DIC Corporation); and "PC1300-02-65MA" (manufactured by Air Water Inc.) as an active ester-based curing agent containing a styryl group and a naphthalene structure.

[0038] Examples of phenolic curing agents include curing agents having one or more, preferably two or more, hydroxyl groups bonded to an aromatic ring (such as a benzene ring or a naphthalene ring) per molecule. Among these, compounds having a hydroxyl group bonded to a benzene ring are preferred. Furthermore, from the viewpoint of heat resistance and water resistance, phenolic curing agents having a novolac structure are preferred. Furthermore, from the viewpoint of adhesion, nitrogen-containing phenolic curing agents are preferred, and triazine skeleton-containing phenolic curing agents are more preferred. In particular, from the viewpoint of achieving high levels of heat resistance, water resistance, and adhesion, triazine skeleton-containing phenolic novolac curing agents are preferred.

[0039] Specific examples of phenol-based curing agents and naphthol-based curing agents include "MEH-7700," "MEH-7810," and "MEH-8000H" manufactured by Meiwa Kasei Co., Ltd.; "NHN," "CBN," and "GPH" manufactured by Nippon Kayaku Co., Ltd.; "SN-170," "SN-180," "SN-190," "SN-475," "SN-495," "SN-495V," "SN-375," and "SN-395" manufactured by Nippon Steel Chemical & Material Co., Ltd.; Examples include "TD-2090," "TD-2090-60M," "LA-7052," "LA-7054," "LA-1356," "LA-3018," "LA-3018-50P," "EXB-9500," "HPC-9500," "KA-1160," "KA-1163," and "KA-1165" manufactured by DIC Corporation; and "GDP-6115L," "GDP-6115H," and "ELPC75" manufactured by Gun-ei Chemical Co., Ltd.

[0040] Specific examples of carbodiimide curing agents include "V-03," "V-05," "V-07," and "V-11S" manufactured by Nisshinbo Chemical Inc.; and Stavaxol (registered trademark) P manufactured by Rhein Chemie.

[0041] Specific examples of benzoxazine curing agents include "ODA-BOZ" manufactured by JFE Chemical Corporation, "HFB2006M" manufactured by Showa Polymer Co., Ltd., and "Pd" and "Fa" manufactured by Shikoku Chemicals Corporation.

[0042] Examples of acid anhydride curing agents include curing agents having one or more acid anhydride groups in one molecule. Specific examples of acid anhydride curing agents include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, 4-methylhexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnadic anhydride, hydrogenated methylnadic anhydride, trialkyltetrahydrophthalic anhydride, dodecenyl succinic anhydride, 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, trimellitic anhydride, pyromellitic anhydride, and benzophenone. Examples of suitable curing agents include tetracarboxylic dianhydrides, biphenyltetracarboxylic dianhydride, naphthalenetetracarboxylic dianhydride, oxydiphthalic dianhydride, 3,3'-4,4'-diphenylsulfonetetracarboxylic dianhydride, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-C]furan-1,3-dione, ethylene glycol bis(anhydrotrimellitate), and polymeric acid anhydrides such as styrene-maleic acid resins (copolymers of styrene and maleic acid). Commercially available acid anhydride curing agents are also available, such as "MH-700" manufactured by New Japan Chemical Co., Ltd.

[0043] Examples of the amine curing agent include curing agents having one or more amino groups in one molecule, such as aliphatic amines, polyether amines, alicyclic amines, and aromatic amines. Among these, aromatic amines are preferred from the viewpoint of achieving the desired effects of the present invention. The amine curing agent is preferably a primary amine or a secondary amine, and more preferably a primary amine. Specific examples of amine-based curing agents include 4,4'-methylenebis(2,6-dimethylaniline), diphenyldiaminosulfone, 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-hydroxybenzoyl). Examples of suitable amine curing agents include 4,4'-bis(4-aminophenoxy)biphenyl, bis(4-(4-aminophenoxy)phenyl)propane, 3,3-dimethyl-5,5-diethyl-4,4-diphenylmethanediamine, 2,2-bis(4-aminophenyl)propane, 2,2-bis(4-(4-aminophenoxy)phenyl)propane, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, bis(4-(4-aminophenoxy)phenyl)sulfone, and bis(4-(3-aminophenoxy)phenyl)sulfone. Commercially available amine curing agents may be used, such as "KAYABOND C-200S," "KAYABOND C-100," "KAYAHARD AA," "KAYAHARD AB," and "KAYAHARD AS" manufactured by Nippon Kayaku Co., Ltd., and "Epicure W" manufactured by Mitsubishi Chemical Corporation.

[0044] Examples of cyanate ester curing agents 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 novolac, cresol novolac, etc.; and prepolymers in which these cyanate resins are partially converted to triazine. Specific examples of cyanate ester curing agents include "PT30" and "PT60" manufactured by Lonza Japan Co., Ltd. (both are phenol novolac type multifunctional cyanate ester resins); "ULL-950S" (multifunctional cyanate ester resin); "BA230" and "BA230S75" (prepolymers in which part or all of bisphenol A dicyanate has been triazine converted to a trimer); and the like.

[0045] When the number of epoxy groups in component (a) is taken as 1, the number of active groups in (b) curing agent is preferably 0.01 or more, more preferably 0.05 or more, even more preferably 0.1 or more, and preferably 10 or less, more preferably 5 or less, and even more preferably 3 or less. Here, "the number of epoxy groups in component (a)" refers to the total value obtained by dividing the mass of the non-volatile components of component (a) present in the resin composition by the epoxy equivalent. Furthermore, "the number of active groups in (b) curing agent" refers to the total value obtained by dividing the mass of the non-volatile components of (b) curing agent present in the resin composition by the active group equivalent.

[0046] The content of (b) the curing agent is preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more, and is preferably 25% by mass or less, more preferably 20% by mass or less, and even more preferably 15% by mass or less, assuming that the non-volatile components in the resin composition are 100% by mass.

[0047] The content of (b) the curing agent is preferably 10% by mass or more, more preferably 20% by mass or more, even more preferably 30% by mass or more, and is preferably 60% by mass or less, more preferably 55% by mass or less, even more preferably 50% by mass or less, assuming that the resin component in the resin composition is 100% by mass.

[0048] When the (b) curing agent contains an active ester curing agent, the content of the active ester curing agent is preferably 1% by mass or more, more preferably 3% by mass or more, and even more preferably 5% by mass or more, based on 100% by mass of the non-volatile components in the resin composition, and is preferably 25% by mass or less, more preferably 20% by mass or less, and even more preferably 15% by mass or less.

[0049] When the (b) curing agent contains an active ester curing agent, the content of the active ester curing agent is preferably 10% by mass or more, more preferably 20% by mass or more, even more preferably 30% by mass or more, and is preferably 60% by mass or less, more preferably 55% by mass or less, even more preferably 50% by mass or less, based on 100% by mass of the resin component in the resin composition.

[0050] The content of curing agents other than active ester-based curing agents is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and even more preferably 1% by mass or more, based on 100% by mass of the non-volatile components in the resin composition, and is preferably 10% by mass or less, more preferably 5% by mass or less, and even more preferably 3% by mass or less.

[0051] The content of components other than the active ester-based curing agent is preferably 1% by mass or more, more preferably 2% by mass or more, and even more preferably 3% by mass or more, and is preferably 15% by mass or less, more preferably 10% by mass or less, and even more preferably 8% by mass or less, when the resin component in the resin composition is taken as 100% by mass.

[0052] <(c) Inorganic filler> The resin composition may further contain (c) an inorganic filler as an optional component. By including (c) an inorganic filler in the resin composition, an insulating layer having a low average linear thermal expansion coefficient can be obtained. The (c) inorganic filler is usually included in the resin composition in the form of particles. The (c) component may be used alone or in combination of two or more.

[0053] (c) Inorganic compounds are used as the inorganic filler material. Examples of (c) inorganic filler materials include silica, alumina, glass, cordierite, silicon oxide, barium sulfate, barium carbonate, talc, clay, mica powder, zinc oxide, hydrotalcite, boehmite, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum nitride, manganese nitride, aluminum borate, strontium carbonate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, zirconium oxide, barium titanate, barium titanate zirconate, barium zirconate, calcium zirconate, zirconium phosphate, and zirconium tungstate phosphate. Among these, silica is particularly preferred. Examples of silica include amorphous silica, fused silica, crystalline silica, synthetic silica, and hollow silica. Spherical silica is preferred.

[0054] (c) Examples of commercially available inorganic fillers include "SP60-05" and "SP507-05" manufactured by Nippon Steel Chemical & Material Co., Ltd.; "YC100C," "YA050C," "YA050C-MJE," "YA010C," "SC2500SQ," "SO-C4," "SO-C2," and "SO-C1" manufactured by Admatechs Co., Ltd.; "UFP-30," "DAW-03," and "FB-105FD" manufactured by Denka Co., Ltd.; "Silfil NSS-3N," "Silfil NSS-4N," and "Silfil NSS-5N" manufactured by Tokuyama Corporation; "CellSpheres" and "MGH-005" manufactured by Taiheiyo Cement Corporation; and "Sfereek" and "BA-1" manufactured by JGC Catalysts and Chemicals Co., Ltd.

[0055] The average particle size of the (c) inorganic filler is preferably 0.01 μm or more, more preferably 0.1 μm or more, even more preferably 0.3 μm or more, and is preferably 10 μm or less, more preferably 5 μm or less, even more preferably 3 μm or less.

[0056] (c) The average particle size of an inorganic filler can be measured by a laser diffraction / scattering method based on Mie scattering theory. Specifically, a volumetric particle size distribution of the inorganic filler is created using a laser diffraction / scattering particle size distribution analyzer, and the median diameter is used as the average particle size. A measurement sample can be prepared by weighing 100 mg of inorganic filler and 10 g of methyl ethyl ketone into a vial and dispersing them ultrasonically for 10 minutes. The measurement sample is measured using a laser diffraction particle size distribution analyzer with blue and red light source wavelengths using a flow cell system to measure the volumetric particle size distribution of the inorganic filler, and the average particle size can be calculated as the median diameter from the particle size distribution obtained. Examples of laser diffraction particle size distribution analyzers include the LA-960 manufactured by Horiba, Ltd.

[0057] (c) The BET specific surface area of ​​the inorganic filler is preferably 0.1 m 2 / g or more, more preferably 0.5m 2 / g or more, more preferably 1m 2 / g or more, preferably 100m 2 / g or less, more preferably 70m 2 / g or less, more preferably 40m 2 / g or less.

[0058] (c) The specific surface area of ​​the inorganic filler can be measured according to the BET method by adsorbing nitrogen gas onto the sample surface using a specific surface area measuring device (Macsorb HM-1210 manufactured by Mountech Co., Ltd.) and calculating the specific surface area using the BET multipoint method.

[0059] (c) The inorganic filler is preferably treated with a surface treatment agent from the viewpoint of improving moisture resistance and dispersibility. Examples of the surface treatment agent include a fluorine-containing silane coupling agent, an aminosilane coupling agent, an epoxysilane coupling agent, a mercaptosilane coupling agent, a silane coupling agent, an alkoxysilane, an organosilazane compound, and a titanate coupling agent. One type of surface treatment agent may be used alone, or two or more types may be used in any combination.

[0060] Examples of commercially available surface treatment agents include Shin-Etsu Chemical Co., Ltd.'s "KBM403" (3-glycidoxypropyltrimethoxysilane), Shin-Etsu Chemical Co., Ltd.'s "KBM803" (3-mercaptopropyltrimethoxysilane), Shin-Etsu Chemical Co., Ltd.'s "KBE903" (3-aminopropyltriethoxysilane), Shin-Etsu Chemical Co., Ltd.'s "KBM573" (N-phenyl-3-aminopropyltrimethoxysilane), Shin-Etsu Chemical Co., Ltd.'s "SZ-31" (hexamethyldisilazane), Shin-Etsu Chemical Co., Ltd.'s "KBM103" (phenyltrimethoxysilane), Shin-Etsu Chemical Co., Ltd.'s "KBM-4803" (long-chain epoxy-type silane coupling agent), and Shin-Etsu Chemical Co., Ltd.'s "KBM-7103" (3,3,3-trifluoropropyltrimethoxysilane).

[0061] The degree of surface treatment with the surface treatment agent preferably falls within a specific range from the viewpoint of improving the dispersibility of the inorganic filler. Specifically, 100% by mass of the inorganic filler is preferably surface-treated with 0.2% to 5% by mass of the surface treatment agent, more preferably with 0.2% to 3% by mass of the surface treatment agent, and even more preferably with 0.3% to 2% by mass of the surface treatment agent.

[0062] The degree of surface treatment with the surface treatment agent can be evaluated by the amount of carbon per unit surface area of ​​the inorganic filler. From the viewpoint of improving the dispersibility of the inorganic filler, the amount of carbon per unit surface area of ​​the inorganic filler is set to 0.02 mg / m 2 More than 0.1 mg / m is preferable. 2 More preferably, 0.2 mg / m or more 2 On the other hand, from the viewpoint of preventing an increase in the melt viscosity of the resin composition, it is more preferable that the content be 1.0 mg / m 2 Preferably less than 0.8 mg / m 2 Less than 0.5 mg / m is more preferable. 2 The following is even more preferred:

[0063] (c) The amount of carbon per unit surface area of ​​the inorganic filler can be measured after the surface-treated inorganic filler is washed with a solvent (e.g., methyl ethyl ketone (MEK)). Specifically, a sufficient amount of MEK as a solvent is added to the inorganic filler that has been surface-treated with a surface treatment agent, and ultrasonic cleaning is performed at 25°C for 5 minutes. After removing the supernatant and drying the solid content, the amount of carbon per unit surface area of ​​the inorganic filler can be measured using a carbon analyzer. The carbon analyzer that can be used is the "EMIA-320V" manufactured by Horiba, Ltd.

[0064] The degree of surface treatment with a surface treatment agent can be evaluated by the amount of carbon per unit mass of the inorganic filler. The amount of carbon per unit mass of the inorganic filler is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and even more preferably 0.1% by mass or more, and is preferably 1.0% by mass or less, more preferably 0.8% by mass or less, and even more preferably 0.5% by mass or less. The amount of carbon per unit mass of (c) the inorganic filler can be measured using a carbon analyzer, just like the amount of carbon per unit surface area of ​​(c) the inorganic filler.

[0065] The content of (c) inorganic filler is preferably 55% by mass or more, more preferably 60% by mass or more, particularly preferably 65% ​​by mass or more, and is preferably 85% by mass or less, more preferably 80% by mass or less, and even more preferably 75% by mass or less, assuming that the non-volatile components in the resin composition are 100% by mass.

[0066] <(d) Thermoplastic resin> The resin composition may further contain a (d) thermoplastic resin as an optional component. The (d) thermoplastic resin as component (d) does not include those corresponding to the above-mentioned components (a) to (c). The (d) thermoplastic resin may be used alone or in combination of two or more.

[0067] Examples of the (d) thermoplastic resin 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. In one embodiment, the (d) thermoplastic resin preferably includes a phenoxy resin.

[0068] Examples of phenoxy resins include phenoxy resins having one or more skeletons selected from the group consisting of bisphenol A, bisphenol F, bisphenol S, bisphenolacetophenone, novolac, biphenyl, fluorene, dicyclopentadiene, norbornene, naphthalene, anthracene, adamantane, terpene, and trimethylcyclohexane. The terminal of the phenoxy resin may be any functional group such as a phenolic hydroxyl group or an epoxy group.

[0069] Specific examples of phenoxy resins include "1256" and "4250" manufactured by Mitsubishi Chemical Corporation (both of which are phenoxy resins containing a bisphenol A skeleton); "YX8100" manufactured by Mitsubishi Chemical Corporation (phenoxy resin containing a bisphenol S skeleton); "YX6954" manufactured by Mitsubishi Chemical Corporation (phenoxy resin containing a bisphenol acetophenone skeleton); "FX280" and "FX293" manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.; and "YL7500BH30," "YX6954BH30," "YX7553," "YX7553BH30," "YL7769BH30," "YL6794," "YL7213," "YL7290," "YL7482," and "YL7891BH30" manufactured by Mitsubishi Chemical Corporation.

[0070] Specific examples of polyimide resins include "SLK-6100" manufactured by Shin-Etsu Chemical Co., Ltd., and "Rikacoat SN20" and "Rikacoat PN20" manufactured by New Japan Chemical Co., Ltd.

[0071] Examples of polyvinyl acetal resins include polyvinyl formal resins and polyvinyl butyral resins, with polyvinyl butyral resins being preferred. Specific examples of polyvinyl acetal resins include Denka Butyral 4000-2, Denka Butyral 5000-A, Denka Butyral 6000-C, and Denka Butyral 6000-EP, manufactured by Denki Kagaku Kogyo Co., Ltd.; and S-LEC BH series, BX series (e.g., BX-5Z), KS series (e.g., KS-1), BL series, and BM series, manufactured by Sekisui Chemical Co., Ltd.

[0072] Examples of polyolefin resins include ethylene copolymer resins such as low-density polyethylene, very low-density polyethylene, high-density polyethylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, and ethylene-methyl acrylate copolymer; and polyolefin polymers such as polypropylene and ethylene-propylene block copolymer.

[0073] Examples of polybutadiene resins include hydrogenated polybutadiene skeleton-containing resins, hydroxy group-containing polybutadiene resins, phenolic hydroxy group-containing polybutadiene resins, carboxy group-containing polybutadiene resins, acid anhydride group-containing polybutadiene resins, epoxy group-containing polybutadiene resins, isocyanate group-containing polybutadiene resins, urethane group-containing polybutadiene resins, and polyphenylene ether-polybutadiene resins.

[0074] Specific examples of polyamide-imide resins include "Vylomax HR11NN" and "Vylomax HR16NN" manufactured by Toyobo Co., Ltd. Specific examples of polyamide-imide resins also include modified polyamide-imides such as "KS9100" and "KS9300" (polysiloxane skeleton-containing polyamide-imides) manufactured by Hitachi Chemical Co., Ltd.

[0075] A specific example of the polyethersulfone resin is "PES5003P" manufactured by Sumitomo Chemical Co., Ltd.

[0076] Specific examples of polysulfone resins include polysulfones "P1700" and "P3500" manufactured by Solvay Advanced Polymers.

[0077] A specific example of the polyphenylene ether resin is NORYL SA90 manufactured by SABIC, etc. A specific example of the polyetherimide resin is ULTEM manufactured by GE, etc.

[0078] Examples of polycarbonate resins include hydroxyl group-containing carbonate resins, phenolic hydroxyl group-containing carbonate resins, carboxyl group-containing carbonate resins, acid anhydride group-containing carbonate resins, isocyanate group-containing carbonate resins, and urethane group-containing carbonate resins. Specific examples of polycarbonate resins include "FPC0220" manufactured by Mitsubishi Gas Chemical Company, Inc., "T6002" and "T6001" (polycarbonate diols) manufactured by Asahi Kasei Chemicals Corporation, and "C-1090," "C-2090," and "C-3090" (polycarbonate diols) manufactured by Kuraray Co., Ltd. Specific examples of polyether ether ketone resins include "Sumiploy K" manufactured by Sumitomo Chemical Co., Ltd.

[0079] Examples of polyester resins include polyethylene terephthalate resin, polyethylene naphthalate resin, polybutylene terephthalate resin, polybutylene naphthalate resin, polytrimethylene terephthalate resin, polytrimethylene naphthalate resin, and polycyclohexane dimethyl terephthalate resin.

[0080] (d) The weight average molecular weight (Mw) of the thermoplastic resin is preferably 5,000 or more, more preferably 8,000 or more, even more preferably 10,000 or more, and particularly preferably 20,000 or more, from the viewpoint of significantly obtaining the effects of the present invention, and is preferably 100,000 or less, more preferably 70,000 or less, even more preferably 60,000 or less, and particularly preferably 50,000 or less.

[0081] The content of (d) the thermoplastic resin 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, and is preferably 3% by mass or less, more preferably 1.5% by mass or less, and even more preferably 1% by mass or less, when the non-volatile components in the resin composition are taken as 100% by mass.

[0082] The content of (d) the thermoplastic resin is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and even more preferably 1% by mass or more, and is preferably 5% by mass or less, more preferably 4% by mass or less, and even more preferably 3% by mass or less, when the resin component in the resin composition is taken as 100% by mass.

[0083] <(e) Curing accelerator> The resin composition may contain (e) a curing accelerator as an optional component. The (e) curing accelerator as component (e) does not include those corresponding to the above-mentioned components (a) to (d). The (e) curing accelerator functions as a curing catalyst that accelerates the curing of the (a) epoxy resin. The (e) component may be used alone or in combination of two or more.

[0084] Examples of the (e) curing accelerator include phosphorus-based curing accelerators, urea-based curing accelerators, guanidine-based curing accelerators, imidazole-based curing accelerators, metal-based curing accelerators, and amine-based curing accelerators. Of these, it is preferable to use either a phosphorus-based curing accelerator or an imidazole-based curing accelerator. One type of (e) curing accelerator may be used alone, or two or more types may be used in combination.

[0085] Examples of the phosphorus-based curing accelerator include aliphatic phosphonium salts such as tetrabutylphosphonium bromide, tetrabutylphosphonium chloride, tetrabutylphosphonium acetate, tetrabutylphosphonium decanoate, tetrabutylphosphonium laurate, bis(tetrabutylphosphonium)pyromellitate, tetrabutylphosphonium hydrogenhexahydrophthalate, tetrabutylphosphonium 2,6-bis[(2-hydroxy-5-methylphenyl)methyl]-4-methylphenolate, and di-tert-butyldimethylphosphonium tetraphenylborate; methyltriphenylphosphonium bromide, ethyltriphenylphosphonium bromide, propyltriphenylphosphonium bromide, butyltriphenylphosphonium bromide, benzyltriphenylphosphonium chloride, tetraphenylphosphonium bromide, p-tolyltriphenylphosphonium tetra-p-tolylborate, and tetraphenylphosphonium tetra-p-tolylborate. aromatic phosphonium salts such as tetraphenylborate, tetraphenylphosphonium tetra-p-tolylborate, triphenylethylphosphonium tetraphenylborate, tris(3-methylphenyl)ethylphosphonium tetraphenylborate, tris(2-methoxyphenyl)ethylphosphonium tetraphenylborate, (4-methylphenyl)triphenylphosphonium thiocyanate, tetraphenylphosphonium thiocyanate, and butyltriphenylphosphonium thiocyanate; aromatic phosphine-borane complexes such as triphenylphosphine-triphenylborane; aromatic phosphine-quinone adducts such as triphenylphosphine-p-benzoquinone adduct; aliphatic phosphines such as tributylphosphine, tri-tert-butylphosphine, trioctylphosphine, di-tert-butyl(2-butenyl)phosphine, di-tert-butyl(3-methyl-2-butenyl)phosphine, and tricyclohexylphosphine;Dibutylphenylphosphine, di-tert-butylphenylphosphine, methyldiphenylphosphine, ethyldiphenylphosphine, butyldiphenylphosphine, diphenylcyclohexylphosphine, triphenylphosphine, tri-o-tolylphosphine, tri-m-tolylphosphine, tri-p-tolylphosphine, tris(4-ethylphenyl)phosphine, tris(4-propylphenyl)phosphine, tris(4-isopropylphenyl)phosphine, tris(4-butylphenyl)phosphine, tris(4-tert-butylphenyl)phosphine, tris(2,4-dimethylphenyl)phosphine, tris(2,5-dimethylphenyl)phosphine, tris(2,6-dimethylphenyl)phosphine aromatic phosphines such as benzene, tris(3,5-dimethylphenyl)phosphine, tris(2,4,6-trimethylphenyl)phosphine, tris(2,6-dimethyl-4-ethoxyphenyl)phosphine, tris(2-methoxyphenyl)phosphine, tris(4-methoxyphenyl)phosphine, tris(4-ethoxyphenyl)phosphine, tris(4-tert-butoxyphenyl)phosphine, diphenyl-2-pyridylphosphine, 1,2-bis(diphenylphosphino)ethane, 1,3-bis(diphenylphosphino)propane, 1,4-bis(diphenylphosphino)butane, 1,2-bis(diphenylphosphino)acetylene, and 2,2'-bis(diphenylphosphino)diphenyl ether;

[0086] Examples of the urea-based curing accelerator include 1,1-dimethylurea; aliphatic dimethylureas such as 1,1,3-trimethylurea, 3-ethyl-1,1-dimethylurea, 3-cyclohexyl-1,1-dimethylurea, and 3-cyclooctyl-1,1-dimethylurea; 3-phenyl-1,1-dimethylurea, 3-(4-chlorophenyl)-1,1-dimethylurea, 3-(3,4-dichlorophenyl)-1,1-dimethylurea, 3-(3-chloro-4-methylphenyl)-1,1-dimethylurea, 3-(2-methylphenyl)-1,1-dimethylurea, 3-(4-methylphenyl)-1,1-dimethylurea, and 3-(3,4-dimethylphenyl)-1,1-dimethylurea. aromatic dimethylureas such as toluene bis(dimethylurea), 3-(4-isopropylphenyl)-1,1-dimethylurea, 3-(4-methoxyphenyl)-1,1-dimethylurea, 3-(4-nitrophenyl)-1,1-dimethylurea, 3-[4-(4-methoxyphenoxy)phenyl]-1,1-dimethylurea, 3-[4-(4-chlorophenoxy)phenyl]-1,1-dimethylurea, 3-[3-(trifluoromethyl)phenyl]-1,1-dimethylurea, N,N-(1,4-phenylene)bis(N',N'-dimethylurea), and N,N-(4-methyl-1,3-phenylene)bis(N',N'-dimethylurea) [toluene bisdimethylurea].

[0087] Examples of guanidine curing accelerators include dicyandiamide, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, 1-(o-tolyl)guanidine, dimethylguanidine, diphenylguanidine, trimethylguanidine, tetramethylguanidine, pentamethylguanidine, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, 1-methylbiguanide, 1-ethylbiguanide, 1-n-butylbiguanide, 1-n-octadecylbiguanide, 1,1-dimethylbiguanide, 1,1-diethylbiguanide, 1-cyclohexylbiguanide, 1-allylbiguanide, 1-phenylbiguanide, and 1-(o-tolyl)biguanide.

[0088] Examples of the imidazole curing accelerator include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, and 1-benzyl-2-methylimidazole. Phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazolium trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6-[2'-methylimidazolyl -(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-undecylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct Examples of imidazole compounds include 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2-methylimidazoline, and 2-phenylimidazoline, as well as adducts of imidazole compounds with epoxy resins. Commercially available imidazole curing accelerators include "1B2PZ," "2E4MZ," "2MZA-PW," "2MZ-OK," "2MA-OK," "2MA-OK-PW," "2PHZ," "2PHZ-PW," "Cl1Z," "Cl1Z-CN," "Cl1Z-CNS," and "C11Z-A" manufactured by Shikoku Chemicals Corporation; and "P200-H50" manufactured by Mitsubishi Chemical Corporation.

[0089] Examples of metal-based curing accelerators include organometallic complexes or organometallic salts of metals such as cobalt, copper, zinc, iron, nickel, manganese, and tin. Specific examples of organometallic complexes include organic cobalt complexes such as cobalt(II) acetylacetonate and cobalt(III) acetylacetonate, organic copper complexes such as copper(II) acetylacetonate, organic zinc complexes such as zinc(II) acetylacetonate, organic iron complexes such as iron(III) acetylacetonate, organic nickel complexes such as nickel(II) acetylacetonate, and organic manganese complexes such as manganese(II) acetylacetonate. Examples of organometallic salts include zinc octoate, tin octoate, zinc naphthenate, cobalt naphthenate, tin stearate, and zinc stearate.

[0090] Examples of the amine curing accelerator include trialkylamines such as triethylamine and tributylamine, 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, 1,8-diazabicyclo(5,4,0)-undecene, etc. Commercially available amine curing accelerators may be used, such as "MY-25" manufactured by Ajinomoto Fine-Techno Co., Inc.

[0091] The content of (e) the curing accelerator is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, even more preferably 0.1% by mass or more, and is preferably 1% by mass or less, more preferably 0.5% by mass or less, even more preferably 0.3% by mass or less, when the non-volatile components of the resin composition are taken as 100% by mass.

[0092] The content of (e) the curing accelerator is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, even more preferably 0.5% by mass or more, and is preferably 3% by mass or less, more preferably 1.5% by mass or less, even more preferably 1% by mass or less, when the resin component of the resin composition is taken as 100% by mass.

[0093] <(f) Optional Additives> The resin composition may contain (f) an optional additive as an optional component. Examples of the optional additive (f) include organic fillers such as rubber particles; elastomers (excluding those corresponding to component (d)); organometallic compounds such as organocopper compounds, organozinc compounds, and organocobalt compounds; colorants such as phthalocyanine blue, phthalocyanine green, iodine green, diazo yellow, crystal violet, titanium oxide, and carbon black; polymerization inhibitors such as hydroquinone, catechol, pyrogallol, and phenothiazine; leveling agents such as silicone-based leveling agents and acrylic polymer-based leveling agents; thickeners such as bentone and montmorillonite; antifoaming agents such as silicone-based antifoaming agents, acrylic-based antifoaming agents, fluorine-based antifoaming agents, and vinyl resin-based antifoaming agents; ultraviolet absorbers such as benzotriazole-based ultraviolet absorbers; adhesion improvers such as urea silane; triazole-based adhesion promoters, tetrazole-based antifoaming agents, and the like. Examples of the additives include adhesion promoters such as phenol-based adhesion promoters and triazine-based adhesion promoters; antioxidants such as hindered phenol-based antioxidants; fluorescent brighteners such as stilbene derivatives; surfactants such as fluorine-based surfactants and silicone-based surfactants; flame retardants such as phosphorus-based flame retardants (e.g., phosphate ester compounds, phosphazene compounds, phosphinic acid compounds, and red phosphorus), nitrogen-based flame retardants (e.g., melamine sulfate), halogen-based flame retardants, and inorganic flame retardants (e.g., antimony trioxide); dispersants such as phosphate ester-based dispersants, polyoxyalkylene-based dispersants, acetylene-based dispersants, silicone-based dispersants, anionic dispersants, and cationic dispersants; and stabilizers such as borate-based stabilizers, titanate-based stabilizers, aluminate-based stabilizers, zirconate-based stabilizers, isocyanate-based stabilizers, carboxylic acid-based stabilizers, and carboxylic anhydride-based stabilizers. (f) Optional additives may be used alone or in combination of two or more.

[0094] <(g) Solvent> The resin composition may further contain (g) a solvent as an optional volatile component in addition to the non-volatile components (a) to (f) described above. The (g) solvent is typically an organic solvent. Examples of organic solvents include ketone-based solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ester-based solvents such as methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, isoamyl acetate, methyl propionate, ethyl propionate, and γ-butyrolactone; ether-based solvents such as tetrahydropyran, tetrahydrofuran, 1,4-dioxane, diethyl ether, diisopropyl ether, dibutyl ether, diphenyl ether, and anisole; alcohol-based solvents such as methanol, ethanol, propanol, butanol, and ethylene glycol; 2-ethoxyethyl acetate, propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl diglycol acetate, γ-butyrolactone, and methyl methoxypropionate. Examples of suitable solvents include ether ester solvents such as ethyl acetate; ester alcohol solvents such as methyl lactate, ethyl lactate, and methyl 2-hydroxyisobutyrate; ether alcohol solvents such as 2-methoxypropanol, 2-methoxyethanol, 2-ethoxyethanol, propylene glycol monomethyl ether, and diethylene glycol monobutyl ether (butyl carbitol); amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone; sulfoxide solvents such as dimethyl sulfoxide; nitrile solvents such as acetonitrile and propionitrile; aliphatic hydrocarbon solvents such as hexane, cyclopentane, cyclohexane, and methylcyclohexane; and aromatic hydrocarbon solvents such as benzene, toluene, xylene, ethylbenzene, and trimethylbenzene. (g) The solvent may be used singly or in combination of two or more.

[0095] The amount of (g) solvent is not particularly limited, but 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, or even 0% by mass, relative to 100% by mass of all components of the resin composition.

[0096] The resin composition can be produced, for example, by mixing the above-mentioned components. Some or all of the above-mentioned components may be mixed simultaneously, or they may be mixed sequentially. In the process of mixing each component, the temperature may be appropriately set, and thus heating and / or cooling may be performed temporarily or throughout. Furthermore, stirring or shaking may be performed in the process of mixing each component.

[0097] <Resin sheet> The resin sheet includes a support and a resin composition layer formed from a resin composition provided on the support.

[0098] The thickness of the resin composition layer is preferably 100 μm or less, more preferably 80 μm or less, and even more preferably 50 μm or less, from the viewpoint of making the printed wiring board thinner and being able to provide a cured product of the resin composition that has excellent insulating properties even when the cured product is thin. The lower limit of the thickness of the resin composition layer is not particularly limited, but can usually be 5 μm or more.

[0099] Examples of the support include films made of plastic materials, metal foils, and release papers, with films made of plastic materials and metal foils being preferred.

[0100] When a film made of a plastic material is used as the support, examples of the plastic material include polyesters such as polyethylene terephthalate (hereinafter sometimes abbreviated as "PET") and polyethylene naphthalate (hereinafter sometimes abbreviated as "PEN"), polycarbonate (hereinafter sometimes abbreviated as "PC"), acrylics such as polymethyl methacrylate (PMMA), cyclic polyolefins, triacetyl cellulose (TAC), polyether sulfide (PES), polyether ketone, polyimide, etc. Among these, polyethylene terephthalate and polyethylene naphthalate are preferred, with inexpensive polyethylene terephthalate being particularly preferred.

[0101] When a metal foil is used as the support, examples of the metal foil include copper foil and aluminum foil, with copper foil being preferred. The copper foil may be a foil made of a single metal, copper, or an alloy of copper and another metal (e.g., tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.).

[0102] The surface of the support that is to be bonded to the resin composition layer may be subjected to a matte treatment, a corona treatment, or an antistatic treatment.

[0103] The support may also be a support with a release layer, which has a release layer on the surface that bonds to the resin composition layer. Examples of the release agent used in the release layer of the support with a release layer include one or more release agents selected from the group consisting of alkyd resins, polyolefin resins, urethane resins, and silicone resins. Commercially available products may also be used as the support with a release layer, including, for example, "SK-1," "AL-5," and "AL-7" manufactured by Lintec Corporation, "Lumirror T60" manufactured by Toray Industries, Inc., "Purex" manufactured by Teijin Limited, and "Uni-Peel" manufactured by Unitika Limited, which are PET films having a release layer primarily composed of an alkyd resin-based release agent.

[0104] The thickness of the support is not particularly limited, but is preferably in the range of 5 μm to 75 μm, more preferably 10 μm to 60 μm. When a support with a release layer is used, it is preferable that the thickness of the entire support with a release layer is in the above range.

[0105] In one embodiment, the resin sheet may further include other layers as necessary. Examples of such other layers include a protective film conforming to the support and provided on the surface of the resin composition layer that is not bonded to the support (i.e., the surface opposite the support). The thickness of the protective film is not particularly limited, but is, for example, 1 μm to 40 μm. By laminating the protective film, adhesion of dust and the like to the surface of the resin composition layer and scratches can be suppressed.

[0106] The resin sheet can be produced, for example, by preparing a resin varnish by dissolving a resin composition in a solvent, applying the resin varnish to a support using a die coater or the like, and then drying the applied resin varnish to form a resin composition layer. The solvent is as described above.

[0107] Drying may be carried out by known methods such as heating or hot air blowing. Drying conditions are not particularly limited, but drying is carried out so that the solvent content in the resin composition layer becomes 10% by mass or less, preferably 5% by mass or less. Although this varies depending on the boiling point of the solvent in the resin varnish, for example, when a resin varnish containing 30% by mass to 60% by mass of solvent is used, the resin composition layer can be formed by drying at 50°C to 150°C for 3 to 10 minutes.

[0108] The resin sheet can be stored in a rolled state. When the resin sheet has a protective film, it can be used by peeling off the protective film.

[0109] [Printed wiring board manufacturing method] The method for producing a printed wiring board of the present invention comprises: (I) forming a resin composition layer containing an epoxy resin and a curing agent on an inner layer substrate; (II) a step of heating the resin composition layer to semi-cure the resin composition layer; (III) forming a diamond-like carbon layer (DLC layer) on the semi-cured resin composition layer; and and (IV) a step of further curing the semi-cured resin composition layer. Steps (I), (II), (III), and (IV) are preferably performed in this order. By performing steps (I) to (IV), the arithmetic mean roughness Sa of the diamond-like carbon layer can be reduced, making it possible to form fine wiring and produce a printed wiring board having an insulating layer with a low thermal expansion coefficient. Furthermore, it is usually possible to reduce the oxygen permeability of the insulating layer.

[0110] Further, the method for producing a printed wiring board of the present invention includes the steps of: (V) forming holes; (VI) roughening the insulating layer; and (VII) A step of forming a conductor layer. Each step will be described in detail below.

[0111] <Process (I)> Step (I) is a step of forming a resin composition layer on an inner layer substrate. In step (I), the resin composition layer is usually formed on a main surface of the inner layer substrate. The main surface of the inner layer substrate refers to the surface of the inner layer circuit board on which an insulating layer is provided.

[0112] The step (I) may include a step (I-1) of preparing an inner layer substrate. The inner layer substrate is a component that serves as the substrate of a printed wiring board, and examples thereof include a glass epoxy substrate, a metal substrate, a polyester substrate, a polyimide substrate, a BT resin substrate, and a thermosetting polyphenylene ether substrate. The substrate may have a conductor layer on one or both sides, and this conductor layer may be patterned. An inner layer substrate having a conductor layer (circuit) formed on one or both sides of the substrate may be referred to as an "inner layer circuit board." In addition, an intermediate product on which an insulating layer and / or a conductor layer is to be further formed during the production of a printed wiring board is also included in the inner layer substrate of the present invention. When the printed wiring board is a circuit board with built-in components, an inner layer substrate with built-in components may be used.

[0113] In addition, a preferred embodiment of step (I) may include (I-2) a step of preparing a resin sheet, and (I-3) a step of laminating an inner layer substrate and the resin sheet. The resin sheet is as described above.

[0114] In step (I-3), for example, a resin composition layer of a resin sheet is laminated on a main surface of the inner layer substrate. The lamination of the inner layer substrate and the resin sheet can be carried out, for example, by thermocompression bonding the resin sheet to the inner layer substrate from the support side. Examples of a member for thermocompression bonding the resin sheet to the inner layer substrate (hereinafter also referred to as a "thermocompression bonding member") include a heated metal plate (such as a SUS panel) or a metal roll (SUS roll). Note that rather than pressing the thermocompression bonding member directly onto the resin sheet, it is preferable to press it via an elastic material such as heat-resistant rubber so that the resin sheet can sufficiently conform to the surface irregularities of the inner layer substrate.

[0115] The lamination of the inner layer substrate and the resin sheet may be carried out by a vacuum lamination method. In the vacuum lamination method, the thermocompression temperature is preferably in the range of 60°C to 160°C, more preferably 80°C to 140°C, the thermocompression pressure is preferably in the range of 0.098MPa to 1.77MPa, more preferably 0.29MPa to 1.47MPa, and the thermocompression time is preferably in the range of 20 seconds to 400 seconds, more preferably 30 seconds to 300 seconds. The lamination is preferably carried out under reduced pressure conditions of 26.7hPa or less.

[0116] The lamination can be performed using a commercially available vacuum laminator, such as a vacuum pressure laminator manufactured by Meiki Seisakusho Co., Ltd., a vacuum applicator manufactured by Nikko Materials Co., Ltd., or a batch vacuum pressure laminator.

[0117] After lamination, the laminated resin sheets may be smoothed under normal pressure (atmospheric pressure), for example, by pressing a thermocompression member from the support side. The pressing conditions for the smoothing treatment may be the same as the thermocompression conditions for lamination. The smoothing treatment may be performed using a commercially available laminator. Note that lamination and smoothing treatment may be performed consecutively using the commercially available vacuum laminator.

[0118] The support of the resin sheet may be removed after step (I) or after step (II).

[0119] In another embodiment of step (I), a resin composition layer may be formed by applying a resin composition to an inner layer substrate and drying it. The resin composition may be applied using an appropriate application device such as a die coater. Drying may be performed by heating, blowing hot air, or other methods. The drying conditions are not particularly limited, but the resin composition is typically dried so that the solvent content is 10% by mass or less, preferably 5% by mass or less. Although this varies depending on the boiling point of the solvent in the resin composition, for example, when a resin composition containing 30% by mass to 60% by mass of solvent is applied, the resin composition layer can be formed by drying at 50°C to 150°C for 3 to 10 minutes.

[0120] <Process (II)> In step (II), the resin composition layer is heated to semi-cure the resin composition layer. Specifically, after the resin composition layer is formed on the inner layer circuit board, the resin composition layer is heated to semi-cure the resin composition layer.

[0121] The resin composition contained in the resin composition layer contains (a) an epoxy resin and (b) a curing agent. The (b) curing agent reacts with the (a) epoxy resin to form a bond, thereby curing the resin composition layer. Therefore, the degree of curing of the resin composition layer can be evaluated by measuring the reaction rate of the epoxy groups in the epoxy resin. The reaction rate of the epoxy resin when the resin composition layer is semi-cured, i.e., the reaction rate of the epoxy resin after step (II) is preferably 80% or less, more preferably 75% or less, and even more preferably 70% or less. The lower limit is preferably 20% or more, more preferably 25% or more, and even more preferably 30% or more, 35% or more, or 40% or more. By semi-curing the resin composition layer so that the reaction rate of the epoxy resin is within this range, the effects of the present invention can be significantly achieved.

[0122] The reaction rate of the epoxy resin can be determined by measuring the NIR (near-infrared spectroscopy) of the resin composition layer before and after step (II). Specifically, the area of ​​the peak derived from the aromatic ring (benzene ring) of the epoxy resin before semi-curing and the area of ​​the peak derived from the epoxy group are determined, and the ratio of each area is calculated (this area ratio is referred to as the "area ratio before step (B)"). After semi-curing, the ratio of each area is also calculated in the same manner as before step (II) (this area ratio is referred to as the "area ratio after step (B)"). The reaction rate of the epoxy resin can be determined by applying the area ratio before and after step (II) to the following formula. Details can be described using the method described in the Examples below. As a near-infrared spectrometer for measuring NIR, for example, JASCO's FT / IR-4600 can be used. Epoxy resin reaction rate (%) = 100 x {1 - area rate after step (B)} / area rate before step (B)

[0123] The conditions for semi-curing the resin composition layer in step (II) vary depending on the type of resin composition constituting the resin composition layer, but the semi-curing temperature is preferably 120°C or higher, more preferably 130°C or higher, even more preferably 140°C or higher, and preferably 240°C or lower, more preferably 210°C or lower, even more preferably 200°C or lower.

[0124] The semi-curing time is preferably 5 minutes or more, more preferably 10 minutes or more, and even more preferably 15 minutes or more, and is preferably 60 minutes or less, more preferably 50 minutes or less, and even more preferably 40 minutes or less.

[0125] In step (II), the resin composition layer is preferably preheated at a temperature lower than the semi-curing temperature before semi-curing. The preheating temperature is preferably 50°C or higher, more preferably 60°C or higher, and even more preferably 70°C or higher, and is preferably 150°C or lower, more preferably 140°C or lower, and even more preferably 135°C or lower.

[0126] The preheating time is preferably 5 minutes or more, more preferably 10 minutes or more, even more preferably 15 minutes or more, and is preferably 60 minutes or less, more preferably 50 minutes or less, even more preferably 40 minutes or less.

[0127] <Process (III)> Step (III) is a step of forming a diamond-like carbon layer on the semi-cured resin composition layer. The diamond-like carbon layer is formed of sp 3 Carbon atoms with covalent bonds via hybrid orbitals and sp corresponding to the graphite structure 2 The diamond-like carbon layer is an amorphous thin film having an intermediate structure in which carbon atoms having covalent bonds formed by hybrid orbitals are mixed. The diamond-like carbon layer may contain either hydrocarbon or metal atoms in addition to carbon atoms.

[0128] Methods for forming the diamond-like carbon layer include chemical vapor deposition methods such as chemical vapor deposition (CVD method); and physical vapor deposition methods such as sputtering and ion plating, with chemical vapor deposition being preferred.

[0129] Examples of the CVD method include plasma CVD, thermal CVD, and cat-CVD, with plasma CVD being preferred.

[0130] When forming a diamond-like carbon layer by CVD, examples of the raw material gas include alkanes such as methane, ethane, and propane; alkenes such as ethylene and propylene; alkynes such as acetylene and methylacetylene; alkadienes such as pentadiene and butadiene; aromatic hydrocarbons such as benzene, toluene, and xylene; cycloalkanes such as cyclopropane and cyclohexane; and cycloalkenes such as cyclopentene and cyclohexene, with alkynes being preferred. The raw material gas may be used alone or in combination of two or more.

[0131] The pressure (partial pressure) of the acetylene gas when forming a diamond-like carbon layer by the CVD method is preferably 20 Pa or less, more preferably 10 Pa or less, even more preferably 5 Pa or less, and is preferably 0.01 Pa or more, more preferably 0.05 Pa or more, even more preferably 0.1 Pa or more.

[0132] The output conditions (power) when forming a diamond-like carbon layer by the CVD method are preferably 100 W or more, more preferably 200 W or more, even more preferably 300 W or more, or 400 W or more, and preferably 1000 W or less, more preferably 800 W or less, even more preferably 600 W or less.

[0133] The vacuum condition in the chamber of the CVD apparatus is preferably 100 Pa or less, more preferably 50 Pa or less, and even more preferably 20 Pa or less.

[0134] When forming a diamond-like carbon layer by plasma CVD, the plasma generation time is preferably 10 seconds or more, more preferably 30 seconds or more, even more preferably 1 minute or more, and is preferably 3 hours or less, more preferably 2 hours or less, even more preferably 1 hour or less.

[0135] The thickness of the diamond-like carbon layer is preferably 1 μm or less, more preferably 0.5 μm or less, and even more preferably 0.3 μm or less, and is preferably 1 nm or more, more preferably 10 nm or more, and even more preferably 50 nm or more. When using a CVD method, the thickness of the diamond-like carbon layer can be adjusted within this range by controlling the output, pressure of the raw material gas, plasma generation time, etc.

[0136] <Process (IV)> Step (IV) is a step of forming a diamond-like carbon layer on the semi-cured resin composition layer, and then further thermally curing the semi-cured resin composition layer to form an insulating layer.

[0137] The heat curing conditions in step (IV) vary depending on the type of resin composition, but 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.

[0138] The reaction rate of the epoxy resin after step (IV) is more than 80%, preferably 85% or more, more preferably 90% or more, or 95% or more. The upper limit is 100%, preferably 100% or less, more preferably 99% or less, and even more preferably 98% or less. The reaction rate of the epoxy resin after step (IV) can be measured by the same method as the reaction rate of the epoxy resin in step (II).

[0139] <Process (V)> The method for manufacturing a printed wiring board according to this embodiment may include, after step (IV), step (V) of forming holes in the insulating layer and the diamond-like carbon layer. In step (V), for example, via holes are formed as the holes. The concept of holes includes via holes and trenches.

[0140] Via holes are typically provided for electrical connection between layers and penetrate the insulating layer and the diamond-like carbon layer. Therefore, the via holes have an opening on the surface opposite the inner layer substrate, which is in contact with the insulating layer. Furthermore, the inner layer substrate may be exposed at the bottom of the via hole. Since the inner layer conductor layer of the inner layer substrate is typically exposed at the bottom of the via hole, the bottom of the via hole is formed by the inner layer conductor layer.

[0141] The holes can be formed by drilling, laser, plasma, or other methods depending on the characteristics of the insulating layer and the diamond-like carbon layer. For example, holes can be formed in the insulating layer by irradiating the insulating layer with laser light through the support. The size of the hole opening can be selected depending on the fineness of the components to be mounted, and an opening diameter in the range of 30 μm to 500 μm is preferred. Unless otherwise specified, the hole opening diameter refers to the diameter of the hole opening, specifically, the diameter of the hole opening on the surface of the insulating layer opposite the inner layer substrate.

[0142] Examples of laser light sources include carbon dioxide laser (hereinafter also referred to as "CO2 laser") devices, YAG laser devices, and excimer laser devices. Among these, carbon dioxide laser devices are preferred from the viewpoints of processing speed and cost. When a carbon dioxide laser device is used as the laser light source, laser light with a wavelength of 9.3 μm to 10.6 μm is generally used.

[0143] The conditions for irradiating the laser beam are desirably set so as to form holes having the desired depth and opening diameter. In one example, the number of shots is usually selected in the range of 1 to 10 shots. From the viewpoint of increasing the processing speed and improving the productivity of printed wiring boards, a smaller number of shots is preferable, preferably in the range of 1 to 5 shots, and more preferably in the range of 1 to 3 shots. In particular, when a CO2 laser device is used, the number of shots is preferably within the above range. When the number of shots is 2 or more, the laser may be irradiated in either burst mode or cycle mode.

[0144] The energy of the laser beam depends on conditions such as the number of shots, the depth of the hole, and the thickness of the support. From the viewpoint of smoothly forming holes, the energy of the laser beam per shot is set to preferably 0.25 mJ or more, more preferably 0.5 mJ or more, and even more preferably 1 mJ or more. From the viewpoint of suppressing damage to the insulating layer due to excessive energy, the upper limit of the energy of the laser beam is preferably 20 mJ or less, more preferably 15 mJ or less, and even more preferably 10 mJ or less. In particular, when a CO2 laser device is used, it is preferable that the energy be in the above range.

[0145] Holes may be formed using a laser beam using a commercially available carbon dioxide laser device, such as Hitachi Via Mechanics' "LC-2E21B / 1C," Hitachi's "LC-K212," Mitsubishi Electric's "ML605GTWII," or Matsushita Welding Systems' board drilling laser processing machine.

[0146] <Process (VI)> The method for manufacturing a printed wiring board according to this embodiment may include a step (VI) of roughening the insulating layer (desmearing). Typically, smear removal is also performed in this step (VI). The procedure and conditions for the roughening treatment are not particularly limited, and known procedures and conditions commonly used in forming insulating layers for printed wiring boards can be used. For example, the insulating layer can be roughened by performing a swelling treatment using a swelling liquid, a roughening treatment using an oxidizing agent, and a neutralization treatment using a neutralizing liquid in this order.

[0147] Examples of swelling liquids used in the roughening treatment include alkaline solutions and surfactant solutions, with alkaline solutions being preferred. Examples of the alkaline solution include sodium hydroxide solution and potassium hydroxide solution. Examples of commercially available swelling liquids include "Swelling Dip Securigance P" and "Swelling Dip Securigance SBU" manufactured by Atotech Japan. Swelling treatment using a swelling liquid can be performed by immersing the insulating layer in the swelling liquid at 30°C to 90°C for 1 to 20 minutes. From the viewpoint of suppressing swelling of the resin in the insulating layer to an appropriate level, it is preferable to immerse the insulating layer in the swelling liquid at 40°C to 80°C for 5 to 15 minutes.

[0148] Examples of oxidizing agents used in the roughening treatment include alkaline permanganate solutions prepared by dissolving potassium permanganate or sodium permanganate in an aqueous solution of sodium hydroxide. Roughening treatment using an oxidizing agent such as alkaline permanganate solution is preferably carried out by immersing the insulating layer in an oxidizing agent solution heated to 60°C to 100°C for 10 to 30 minutes. The concentration of permanganate in the alkaline permanganate solution is preferably 5% by mass to 10% by mass. Commercially available oxidizing agents include alkaline permanganate solutions such as "Concentrate Compact CP" and "Dosing Solution Securigance P" manufactured by Atotech Japan.

[0149] The neutralizing solution used in the roughening treatment is preferably an acidic aqueous solution, and a commercially available product such as "Reduction Solution Securigant P" manufactured by Atotech Japan can be cited. Treatment with a neutralizing solution can be carried out by immersing the surface that has been roughened with an oxidizing agent in a neutralizing solution at 30°C to 80°C for 5 to 30 minutes. From the standpoint of workability, a preferred method is to immerse the object that has been roughened with an oxidizing agent in a neutralizing solution at 40°C to 70°C for 5 to 20 minutes.

[0150] <Process (VII)> The method for producing a printed wiring board according to this embodiment may include a step (VII) of forming a conductor layer on the diamond-like carbon layer.

[0151] The conductive material used for the conductor layer is not particularly limited. In a preferred embodiment, the conductor layer contains one or more metals selected from the group consisting of gold, platinum, palladium, silver, copper, aluminum, cobalt, chromium, zinc, nickel, titanium, tungsten, iron, tin, and indium. The conductor layer may be a single metal layer or an alloy layer. Examples of alloy layers include layers formed from an alloy of two or more metals selected from the above group (e.g., nickel-chromium alloy, copper-nickel alloy, and copper-titanium alloy). Among these, from the viewpoints of versatility in forming the conductor layer, cost, ease of patterning, etc., 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.

[0152] The conductor layer may have a single layer structure or a multi-layer structure in which two or more single metal layers or alloy layers made of different types of metals or alloys are laminated. When the conductor layer has a multi-layer structure, the layer in contact with the insulating layer is preferably a single metal layer of chromium, zinc, or titanium, or an alloy layer of a nickel-chromium alloy.

[0153] The thickness of the conductor layer depends on the desired design of the printed wiring board, but is generally 3 μm to 35 μm, preferably 5 μm to 30 μm.

[0154] 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 diamond-like carbon layer using a conventionally known technique such as a semi-additive method or a full-additive method. From the viewpoint of ease of production, it is preferable to form the conductor layer by the semi-additive method. An example of forming the conductor layer by the semi-additive method will be described below.

[0155] First, a plating seed layer is formed on the surface of the diamond-like carbon layer by electroless plating. Next, a mask pattern is formed on the formed plating seed layer, exposing a portion of the plating seed layer corresponding to the desired wiring pattern. After a metal layer is formed on the exposed plating seed layer by electrolytic plating, the mask pattern is removed. Thereafter, unnecessary plating seed layer is removed by etching or the like, thereby forming a conductor layer having the desired wiring pattern.

[0156] Alternatively, an adhesion layer containing either hydrocarbon or metal atoms may be formed on the diamond-like carbon layer, and a conductor layer may be formed on the adhesion layer. The adhesion layer can be removed together with any unnecessary plating seed layer by etching or the like.

[0157] The above steps may be repeated two or more times. For example, the steps (I) to (VII) may be repeated to form insulating layers and conductive layers, thereby producing a multilayer printed wiring board having a multilayer structure.

[0158] <Printed wiring board> According to the above-mentioned method for manufacturing a printed wiring board, it is possible to manufacture a printed wiring board comprising an inner layer substrate, an insulating layer formed on the inner layer substrate, and a diamond-like carbon layer formed on the insulating layer. In this printed wiring board, the arithmetic mean roughness (Sa) of the diamond-like carbon layer is less than 100 nm, and the mean linear thermal expansion coefficient of the insulating layer is less than 40 ppm / K. Furthermore, when the method for manufacturing a printed wiring board includes step (VII), the manufactured printed wiring board comprises a conductor layer on the diamond-like carbon layer.

[0159] According to the above-described manufacturing method, steps (I) to (IV) are performed, so that the arithmetic mean roughness (Sa) of the diamond-like carbon layer can be reduced. This makes it possible to manufacture a printed wiring board with fine wiring. The arithmetic mean roughness (Sa) of the diamond-like carbon layer is preferably less than 100 nm, more preferably 80 nm or less, and even more preferably 50 nm or less. There is no particular lower limit, but it can be 0.1 nm or more, for example. Unless otherwise specified, the arithmetic mean roughness Sa is a value measured in accordance with ISO 25178 and can be measured using a non-contact surface roughness meter. The arithmetic mean roughness of the surface of the diamond-like carbon layer can be measured specifically according to the method described in the Examples below.

[0160] According to the above-described manufacturing method, steps (I) to (IV) are performed, so that the average coefficient of linear thermal expansion (CTE) can be reduced even if a diamond-like carbon layer is present. This makes it possible to manufacture a printed wiring board having an insulating layer with a low average coefficient of linear thermal expansion. The average coefficient of linear thermal expansion is preferably less than 40 ppm / K, more preferably 39 ppm / K or less, and even more preferably 38 ppm / K or less. There is no particular lower limit, but it can be 0.01 ppm / K or more. The average coefficient of linear thermal expansion can be measured according to the method described in the examples below.

[0161] The manufactured printed wiring board has a diamond-like carbon layer, and therefore can generally have a low oxygen permeability. As a result, it has high gas barrier properties. Therefore, the diamond-like carbon layer effectively blocks oxygen, and deterioration of the insulating layer can be suppressed. The oxygen permeability of the printed wiring board manufactured by carrying out steps (I) to (IV) can be evaluated by the permeability coefficient, which is obtained by dividing the oxygen permeability by the thickness. The permeability coefficient is 0.1 cc / m 2 mm -1 There is no particular lower limit, but it is 0.0001 cc / m 2 mm -1The oxygen permeability can be measured according to the method described in the Examples below.

[0162] <Applications of printed wiring boards> The printed wiring board manufactured by the manufacturing method of the present invention can be used, for example, in the manufacture of a semiconductor device. A semiconductor device typically includes a printed wiring board and a semiconductor chip mounted on the printed wiring board. The printed wiring board manufactured by the above-described manufacturing method can realize finer and higher-density conductor layers as circuit wiring, thereby realizing miniaturization and high functionality of electronic devices equipped with semiconductor devices.

[0163] Examples of semiconductor devices include various semiconductor devices used in electrical appliances (for example, computers, mobile phones, digital cameras, and televisions) and vehicles (for example, motorcycles, automobiles, trains, ships, and aircraft).

[0164] A semiconductor device can be manufactured by mounting a semiconductor chip on a conductive portion of a printed wiring board. A "conductive portion" is a portion of a printed wiring board that transmits an electrical signal, and the portion may be either on the surface or embedded. The semiconductor chip may be an electrical circuit element made of a semiconductor material.

[0165] The mounting method for semiconductor chips is not particularly limited as long as the semiconductor chip functions effectively. For example, methods that can be used include wire bonding mounting, flip chip mounting, bumpless buildup layer (BBUL) mounting, anisotropic conductive film (ACF) mounting, and non-conductive film (NCF) mounting. Here, the term "bumpless buildup layer (BBUL) mounting" refers to a mounting method in which a semiconductor chip is directly embedded in a recess in a printed wiring board and connected to the wiring on the printed wiring board. [Example]

[0166] The present invention will be specifically described below with reference to examples. However, the present invention is not limited to these examples. In the following description, "parts" and "%" representing amounts mean "parts by mass" and "% by mass", respectively, unless otherwise specified. Furthermore, the temperature and pressure conditions were room temperature (25°C) and atmospheric pressure (1 atm), unless otherwise specified.

[0167] <Preparation of Resin Varnishes 1 to 6> Resin varnishes 1 to 6 were prepared by blending the components in the proportions shown in the table and stirring at room temperature until a homogeneous solution was obtained. [Table 1] In the table, the content is expressed when the nonvolatile components in the resin composition are taken as 100% by mass.

[0168] Details of each component listed in the table are as follows: (Epoxy resin: component (a)) ZX-1059: 1:1 mixture of bisphenol A epoxy resin and bisphenol F epoxy resin, epoxy equivalent 169g / eq., manufactured by Nippon Steel Chemical & Material Co., Ltd. NC3000H: Biphenyl type epoxy resin, epoxy equivalent 288g / eq., manufactured by Nippon Kayaku Co., Ltd. (Curing agent: component (b)) HP-B-8151-62T: toluene solution with functional group equivalent weight of 238 g / eq. and non-volatile content of 62% by mass, manufactured by DIC Corporation PC-1300-02-65MA: Methyl amyl ketone solution with a functional group equivalent weight of 210 g / eq. and a non-volatile content of 65% by mass, manufactured by Air Water Corporation LA3018-50P: 1-methoxy-2-propanol solution with functional group equivalent of 151 g / eq. and non-volatile content of 50% by mass, manufactured by DIC Corporation V-03: Functional group equivalent weight 216 g / eq., toluene solution with non-volatile content of 50% by mass, manufactured by Nisshinbo Chemical Inc. (Inorganic filler: component (c)) SO-C2: Spherical silica surface-treated with an amine-based alkoxysilane compound ("KBM573" manufactured by Shin-Etsu Chemical Co., Ltd.), average particle size 0.5 μm, specific surface area 5.8 m 2 / g, manufactured by Admatechs Co., Ltd. (Thermoplastic resin: component (d)) YX7553BH30: Phenoxy resin, 1:1 solution of MEK and cyclohexanone with 30% non-volatile content, manufactured by Mitsubishi Chemical Corporation (Curing accelerator: component (e)) DMAP: Amine-based curing accelerator, manufactured by Tokyo Chemical Industry Co., Ltd. 1B2PZ: Imidazole-based reaction accelerator, manufactured by Shikoku Chemicals Corporation (Solvent: component (g)) MEK: Methyl ethyl ketone

[0169] [Examples 1 to 6, Comparative Examples 1 to 8] <Process (I)> -Preparation of resin sheet A- The obtained resin varnishes 1 to 6 were applied to the release-treated surface of a PET film (thickness 38 μm, manufactured by Unitika Ltd.) using an applicator (manufactured by Eger Corporation, product name EGPI-1210), and then dried for 180 seconds in a gear oven at 100°C to volatilize the solvent in the resin varnish, thereby obtaining resin sheet A having a resin composition layer 25 μm thick.

[0170] -Lamination of resin composition layer- The copper foil on both sides of a glass cloth-based epoxy resin double-sided laminate (copper foil thickness 18 μm, substrate thickness 0.3 mm, size 500 mm × 500 mm, Panasonic "R5715ES") with an inner layer circuit formed was etched to create 25 copper patterns with L / S of 1 mm / 1 mm and a length of 5 cm, obtaining a textured substrate. The copper surface was then roughened by etching 1 μm using a MEC "CZ8100" to obtain an inner layer circuit board.

[0171] Each resin sheet A was laminated on both sides of the inner layer circuit board using a batch-type vacuum pressure laminator (Nichigo-Morton "CVP700", a two-stage build-up laminator). Lamination was performed by reducing the pressure to 13 hPa or less for 30 seconds, followed by pressure bonding at 100°C and a pressure of 0.74 MPa for 30 seconds. Next, a heat press was performed at 100°C and a pressure of 0.5 MPa for 60 seconds.

[0172] <Process (II)> The laminated resin sheet A was heated at the temperature and for the time shown in the table below to semi-cure the resin composition layer. The obtained laminate sample is referred to as "Laminate Sample B."

[0173] <Process (III)> Using a plasma CVD apparatus (manufactured by Kurita Manufacturing Co., Ltd.), acetylene gas was introduced into the obtained laminated sample A to set the partial pressure to 1 Pa, and CVD was performed at a power of 500 W under a vacuum of 1 Pa to form a diamond-like carbon layer having a thickness of 100 nm on the semi-cured resin layer precursor. Note that in Comparative Examples 1 to 6, step (III) was not performed.

[0174] <Process (IV)> The semi-cured resin composition layer of laminated sample C was cured by heat treatment at 200° C. for 60 minutes. The obtained laminated sample is referred to as “laminated sample C.”

[0175] <Measurement of reaction rate> The reaction rate of the epoxy resin was determined by measuring the peaks of the resin sheet A and the laminated sample B using an NIR device (manufactured by JASCO, product name FT / IR-4600). Specifically, as shown in an example in Figure 1, the peaks at 4,620 cm -1 The peak P1 around 4,530 cm is derived from the benzene ring and is constant before and after thermal curing. -1 The peak P2 in the vicinity is derived from the epoxy group, and when the epoxy group reacts by heating, the area of ​​the peak P2 derived from the epoxy group decreases.

[0176] The area S1 of peak P1 and the area S2 of peak P2 of resin sheet A and laminate sample B were calculated, respectively, to determine R = S2 / S1. The R of resin sheet A was defined as R(A) and the R of laminate sample B was defined as R(B), and the reaction rate RR was calculated using the following formula. RR(%)=100×{1-R(B) / R(A)}

[0177] <Measurement of average coefficient of linear thermal expansion (CTE) and oxygen permeability> -Preparation of evaluation sample D- In the preparation of resin sheet A, the same method was used except that the PET film (thickness 38 μm, manufactured by Unitika Ltd.) was replaced with a polyimide film ("Upilex" manufactured by UBE Corporation), to obtain a resin sheet having a resin composition layer 25 μm thick on a polyimide film.

[0178] The obtained resin sheet was heated at the temperature and for the time shown in the table below to semi-cure the resin composition layer. Using a plasma CVD apparatus (manufactured by Kurita Manufacturing Co., Ltd.), acetylene gas was introduced onto the semi-cured resin composition layer to a partial pressure of 1 Pa. CVD was performed at a power of 500 W under a vacuum of 1 Pa to form a diamond-like carbon layer with a thickness of 100 nm. After the diamond-like carbon layer was formed, the semi-cured resin composition layer was cured by heat treatment at 200°C for 60 minutes, and the polyimide film was peeled off to obtain evaluation sample D.

[0179] -Measurement of the average coefficient of linear thermal expansion (CTE)- Evaluation Sample D was cut into a width of approximately 5 mm and a length of approximately 15 mm to obtain a test specimen. A thermomechanical analysis was performed on the test specimen using a thermomechanical analyzer (Rigaku Corporation, "Thermo Plus TMA8310") using the tensile load method. Specifically, the test specimen was loaded into the thermomechanical analyzer and subjected to two consecutive thermomechanical analyses under the conditions of a 1 g load and a heating rate of 5°C / min (the first run was heated to 200°C, and the second run was heated to 260°C). Based on the results of the second run, the average linear thermal expansion coefficient (ppm / K) from 25°C (298K) to 150°C (423K) was calculated and evaluated according to the following criteria. ◯: Average linear thermal expansion coefficient is less than 40 ppm / K ×: Average linear thermal expansion coefficient is 40 ppm / K or more

[0180] -Oxygen permeability measurement- The oxygen permeability of Evaluation Sample D was measured in accordance with JIS-K7126 (constant pressure method) using an oxygen permeability measuring device (OX-TRAN2 / 21 manufactured by MOCON) under an atmosphere of 23°C and 0% RH and an atmosphere of 23°C and 90% RH. RH stands for relative humidity. Furthermore, the permeability coefficient P was calculated by dividing the oxygen permeability of Evaluation Sample D by the thickness of Evaluation Sample D (the total thickness of the resin composition layer and the diamond-like carbon layer), and evaluated according to the following criteria. ○: Permeability coefficient P is 0.1cc / m 2 mm -1 Less than a day ×: Permeability coefficient P is 0.1 cc / m 2 mm -1 ·day or more

[0181] [Sa (arithmetic mean roughness) measurement] The arithmetic mean roughness Sa of the surface of laminated sample C was determined using a non-contact surface roughness meter (VYKO NT3300 manufactured by Veeco Instruments) in VSI mode with a 50x lens over a measurement range of 121 μm x 92 μm. The average value of 10 randomly selected points was calculated as the measurement value, and the results were evaluated according to the following criteria. 〇: Arithmetic mean roughness (Sa) is less than 100 nm ×: Arithmetic mean roughness (Sa) is 100 nm or more

[0182] [Table 2] [Table 3]

Claims

1. (I) forming a resin composition layer containing an epoxy resin and a curing agent on an inner layer substrate; (II) a step of heating the resin composition layer to semi-cure the resin composition layer; (III) forming a diamond-like carbon layer on the semi-cured resin composition layer; and (IV) A method for producing a printed wiring board, comprising: a step of further curing the semi-cured resin composition layer.

2. The method for producing a printed wiring board according to claim 1, wherein in step (II), the resin composition layer is semi-cured so that the reaction rate of the epoxy resin is 20% or more and 80% or less.

3. 2. The method for producing a printed wiring board according to claim 1, wherein in step (IV), the resin composition layer is cured so that the reaction rate of the epoxy resin is 90% or more.

4. 2. The method for producing a printed wiring board according to claim 1, wherein the diamond-like carbon layer has a surface with an arithmetic mean roughness Sa of less than 100 nm.

5. The method for producing a printed wiring board according to claim 1, wherein the resin composition layer has a mean linear thermal expansion coefficient of less than 40 ppm / K after curing.

6. The method for producing a printed wiring board according to claim 1 , wherein the resin composition layer further contains an inorganic filler.

7. The method for producing a printed wiring board according to claim 1 , wherein the curing agent comprises an active ester curing agent.

8. A printed wiring board comprising an inner layer substrate, an insulating layer formed on the inner layer substrate, and a diamond-like carbon layer formed on the insulating layer, The diamond-like carbon layer has an arithmetic mean roughness (Sa) of less than 100 nm; A printed wiring board, wherein the insulating layer has an average linear thermal expansion coefficient of less than 40 ppm / K.

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