Resin composition layer

Abstract

The present invention aims to provide a resin composition layer that can suppress the halo phenomenon and form a well-shaped through-hole even with a thin thickness. The resin composition layer is a resin composition layer having a thickness of 15 μm or less, wherein the resin composition comprises (A) an epoxy resin, (B) a curing agent, and (C) a resin having an average particle size of 100 nm or less and a particle size of 15 μm or less. 2 an inorganic filler having at least one specific surface area of ​​1000 Å / g or more, and (D) a colorant.

Description

[0001] This application is a divisional application of the Chinese patent application with application number 201810659539.6, application date June 25, 2018, and invention name “Resin Composition Layer”. Technical Field

[0002] The present invention relates to a resin composition layer, a resin sheet comprising the resin composition layer, and a printed wiring board and a semiconductor device comprising an insulating layer formed from a cured product of the resin composition layer. Background Art

[0003] In recent years, printed wiring boards have been further thinned to achieve miniaturization of electronic devices. Consequently, the wiring circuits in inner substrates have become increasingly miniaturized. For example, Patent Document 1 describes a resin sheet (adhesive film) comprising a support and a resin composition layer that is capable of achieving a low dielectric loss tangent.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2014-5464. Summary of the Invention

[0007] Problems to be solved by the invention

[0008] In order to achieve further miniaturization and thinning of electronic devices, the present inventors have studied a solution for thinning the resin composition layer of a resin sheet. As a result of the study, the present inventors found that when a thin resin composition layer is applied to an insulating layer, if a through hole is formed on the insulating layer and then roughened, a halo phenomenon occurs. The so-called halo phenomenon here refers to the phenomenon of interlayer peeling between the insulating layer and the inner substrate around the through hole. Such a halo phenomenon is usually caused by the following reasons: when the through hole is formed, the resin around the through hole deteriorates, and the deteriorated part is eroded during the roughening treatment. It should be noted that the aforementioned deteriorated part is usually observed as a discolored portion.

[0009] Furthermore, the present inventors have discovered that when a thin resin composition layer is applied to an insulating layer, it becomes difficult to control the shape of the through-holes, making it difficult to obtain well-shaped through-holes. The term "well-shaped through-holes" herein refers to a through-hole taper ratio close to 1. Furthermore, the so-called through-hole taper ratio refers to the ratio of the bottom diameter of the through-hole to the top diameter of the through-hole.

[0010] The above-mentioned problems are all caused for the first time by reducing the thickness of the resin composition layer and are new problems that have not been known so far. From the viewpoint of improving the interlayer conduction reliability of a printed wiring board, it is desired to solve these problems.

[0011] The present invention is made in view of the above-mentioned problems, and its purpose is to provide a resin composition layer that can obtain an insulating layer that can suppress the halo phenomenon even if the thickness is thin and can form a through-hole with a good shape; a resin sheet containing the above-mentioned resin composition layer; a printed wiring board containing a thin insulating layer that can suppress the halo phenomenon and can form a through-hole with a good shape; and a semiconductor device containing the above-mentioned printed wiring board.

[0012] Means for solving problems

[0013] The present inventors have conducted intensive research to solve the above-mentioned problems and have found that a combination of (A) an epoxy resin, (B) a curing agent, and (C) a granular material having an average particle size of 100 nm or less and an average particle size of 15 nm or less can be used. 2 The present invention has been completed by the inventors of the present invention and the inventors of the present invention. The inventors of the present invention have the following invention: a resin composition comprising an inorganic filler having at least one of a specific surface area of ​​1000 Å / g or more and a pigment (D) which can solve the above-mentioned problems.

[0014] That is, the present invention includes the following contents,

[0015] [1] a resin composition layer having a thickness of 15 μm or less and containing a resin composition,

[0016] The resin composition comprises (A) an epoxy resin, (B) a curing agent, (C) an inorganic filler having an average particle size of 100 nm or less, and (D) a colorant;

[0017] [2] a resin composition layer having a thickness of 15 μm or less and containing a resin composition,

[0018] The resin composition comprises (A) epoxy resin, (B) curing agent, (C) a specific surface area of ​​15m 2 / g or more inorganic filler, and (D) a colorant;

[0019] [3] The resin composition layer according to [1] or [2], wherein the component (D) is a black or chromatic colorant;

[0020] [4] The resin composition layer according to any one of [1] to [3], wherein the component (D) is a black or blue colorant;

[0021] [5] The resin composition layer according to any one of [1] to [4], wherein the component (D) is a pigment;

[0022] [6] The resin composition layer according to any one of [1] to [5], wherein the amount of component (D) is 0.1% by mass or more and 5% by mass or less relative to 100% by mass of the non-volatile components in the resin composition;

[0023] [7] The resin composition layer according to any one of [1] to [6], wherein the amount of component (C) is 60% by mass or less relative to 100% by mass of the non-volatile components in the resin composition;

[0024] [8] The resin composition layer according to any one of [1] to [7], wherein the component (A) comprises at least one selected from a biphenylol-type epoxy resin and a fluorine-containing epoxy resin;

[0025] [9] The resin composition layer according to any one of [1] to [8], which is used to form an insulating layer for forming a conductor layer;

[0026]

[10] The resin composition layer according to any one of [1] to [9], which is used to form an interlayer insulating layer of a printed wiring board;

[0027]

[11] The resin composition layer according to any one of [1] to

[10] , which is used to form an insulating layer having a through-hole with a top diameter of 35 μm or less;

[0028]

[12] A resin sheet comprising a support and a resin composition layer according to any one of [1] to

[11] provided on the support;

[0029]

[13] A printed wiring board comprising an insulating layer formed from a cured product of the resin composition layer described in any one of [1] to

[11] ;

[0030]

[14] A semiconductor device comprising the printed wiring board described in

[13] .

[0031] Effects of the Invention

[0032] The present invention can provide a resin composition layer that can obtain an insulating layer that can suppress the halo phenomenon even if the thickness is thin and can form a through-hole with a good shape; a resin sheet containing the aforementioned resin composition layer; a printed wiring board containing a thin insulating layer that can suppress the halo phenomenon and can form a through-hole with a good shape; and a semiconductor device containing the aforementioned printed wiring board. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a cross-sectional view schematically showing an insulating layer obtained by curing the resin composition layer according to the first embodiment of the present invention together with an inner layer substrate;

[0034] Figure 2This is a plan view (top view) schematically showing the surface of the insulating layer opposite to the conductor layer, which is obtained by curing the resin composition layer according to the first embodiment of the present invention;

[0035] Figure 3 This is a cross-sectional view schematically showing a roughened insulating layer obtained by curing the resin composition layer according to the first embodiment of the present invention together with an inner layer substrate;

[0036] Figure 4 This is a schematic cross-sectional view of a printed wiring board according to a second embodiment of the present invention. DETAILED DESCRIPTION

[0037] The present invention will be described in detail below with reference to the embodiments and examples. However, the present invention is not limited to the embodiments and examples listed below and can be implemented with any modifications within the scope of the claims and their equivalents.

[0038] In the following description, the "resin component" of the resin composition refers to the components other than the inorganic filler and the colorant among the non-volatile components contained in the resin composition.

[0039] [1. Overview of Resin Composition Layer]

[0040] The resin composition layer of the present invention is a thin resin composition layer having a thickness below a predetermined value. In addition, the resin composition contained in the resin composition layer of the present invention comprises (A) an epoxy resin, (B) a curing agent, and (C) a resin having an average particle size of 100 nm or less and a particle size of 15 nm or less. 2 an inorganic filler having at least one specific surface area of ​​1000 Å / g or more, and (D) a colorant.

[0041] Therefore, the resin composition contained in the resin composition layer of the present invention may include both the first resin composition and the second resin composition described below.

[0042] A first resin composition includes (A) an epoxy resin, (B) a curing agent, (C) an inorganic filler having an average particle size of 100 nm or less, and (D) a colorant.

[0043] The second resin composition comprises (A) epoxy resin, (B) curing agent, (C) a specific surface area of ​​15m 2 / g or more inorganic filler, and (D) a colorant.

[0044] The so-called (D) colorant here refers to pigments, dyes, and combinations thereof. In addition, although pigments and dyes contain components that may belong to the aforementioned (A) to (C) components, in the present invention, pigments and dyes are classified as (D) colorants. For example, carbon black with an average particle size of 100 nm or less is a pigment and is therefore not a (C) component, but is classified as a (D) colorant. In this sense, the resin composition contained in the resin composition layer of the present invention can be said to be a composition comprising a combination of (D) colorants and (A) to (C) components other than the aforementioned (D) colorants.

[0045] By using such a resin composition layer, a thin insulating layer can be obtained. Furthermore, the following desired effects of the present invention can be achieved: through-holes of good shape can be formed in the obtained insulating layer, and the halo phenomenon can be suppressed when the insulating layer with the through-holes is roughened.

[0046] [2. (A) Component: Epoxy resin]

[0047] Examples of the epoxy resin as component (A) include bixylene epoxy resins, bisphenol A epoxy resins, bisphenol F epoxy resins, bisphenol S epoxy resins, bisphenol AF epoxy resins, dicyclopentadiene epoxy resins, trisphenol epoxy resins, naphthol novolac epoxy resins, phenol novolac epoxy resins, tert-butyl-catechol epoxy resins, naphthalene epoxy resins, naphthol epoxy resins, anthracene epoxy resins, and cyclopentadiene epoxy resins. Epoxy resins include epoxy resins, glycidylamine epoxy resins, glycidyl ester epoxy resins, cresol novolac epoxy resins, biphenyl epoxy resins, linear aliphatic epoxy resins, epoxy resins having a butadiene structure, alicyclic epoxy resins, heterocyclic epoxy resins, epoxy resins containing a spiro ring, cyclohexane epoxy resins, cyclohexanedimethanol epoxy resins, naphthylene ether epoxy resins, trimethylol epoxy resins, tetraphenylethane epoxy resins, and the like. The epoxy resins may be used alone or in combination of two or more.

[0048] In the resin composition, the epoxy resin (A) preferably contains an epoxy resin having two or more epoxy groups per molecule. From the viewpoint of significantly achieving the desired effects of the present invention, the proportion of the epoxy resin having two or more epoxy groups per molecule relative to 100% by mass of the non-volatile component 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.

[0049] Epoxy resins include those that are liquid at 20°C (hereinafter sometimes referred to as "liquid epoxy resins") and those that are solid at 20°C (sometimes referred to as "solid epoxy resins"). The resin composition may contain only a liquid epoxy resin or only a solid epoxy resin as the epoxy resin (A), but preferably contains a combination of a liquid epoxy resin and a solid epoxy resin. By using a combination of a liquid epoxy resin and a solid epoxy resin as the epoxy resin (A), the flexibility of the resin composition layer can be improved, or the fracture strength of the cured product of the resin composition layer can be improved.

[0050] The liquid epoxy resin is preferably a liquid epoxy resin having two or more epoxy groups in one molecule, and more preferably an aromatic liquid epoxy resin having two or more epoxy groups in one molecule. The "aromatic" epoxy resin herein refers to an epoxy resin having an aromatic ring in its molecule.

[0051] As liquid epoxy resins, preferred are bisphenol A epoxy resins, bisphenol F epoxy resins, bisphenol AF epoxy resins, naphthalene epoxy resins, glycidyl ester epoxy resins, glycidyl amine epoxy resins, phenol novolac epoxy resins, alicyclic epoxy resins having an ester skeleton, cyclohexane epoxy resins, cyclohexanedimethanol epoxy resins, glycidyl amine epoxy resins, and epoxy resins having a butadiene structure, and more preferred are bisphenol A epoxy resins, bisphenol F epoxy resins, and cyclohexane epoxy resins.

[0052] Specific examples of liquid epoxy resins include “HP4032,” “HP4032D,” and “HP4032SS” (naphthalene-type epoxy resins) manufactured by DIC Corporation; “828US,” “jER828EL,” “825,” and “EPIKOTE828EL” (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” (glycidylamine-type epoxy resins) manufactured by Mitsubishi Chemical Corporation; “ZX1059” (a mixture of bisphenol A-type epoxy resin and bisphenol F-type epoxy resin) manufactured by Nippon Steel & Sumikin Chemicals; “EX-721” (glycidyl ester-type epoxy resin) manufactured by Nagase ChemteX Corporation; and “Celloxide 600” (glycidyl ester-type epoxy resin) manufactured by Daicel Corporation. 2021P" (alicyclic epoxy resin with an ester skeleton); "PB-3600" manufactured by Daicel Corporation (epoxy resin with a butadiene structure); "ZX1658" and "ZX1658GS" (liquid 1,4-glycidylcyclohexane type epoxy resin) manufactured by Nippon Steel & Sumikin Chemicals Co., Ltd. These can be used alone or in combination of two or more.

[0053] The solid epoxy resin is preferably a solid epoxy resin having three or more epoxy groups in one molecule, and more preferably an aromatic solid epoxy resin having three or more epoxy groups in one molecule.

[0054] As solid epoxy resins, preferred are biphenylol-type epoxy resins, naphthalene-type epoxy resins, naphthalene-type tetrafunctional epoxy resins, cresol novolac-type epoxy resins, dicyclopentadiene-type epoxy resins, trisphenol-type epoxy resins, naphthol-type epoxy resins, biphenyl-type epoxy resins, naphthylene ether-type epoxy resins, anthracene-type epoxy resins, bisphenol A-type epoxy resins, bisphenol AF-type epoxy resins, and tetraphenylethane-type epoxy resins, and more preferred are biphenylol-type epoxy resins, naphthalene-type epoxy resins, bisphenol AF-type epoxy resins, and naphthylene ether-type epoxy resins.

[0055] Specific examples of solid epoxy resins include “HP4032H” (naphthalene-type epoxy resin) manufactured by DIC Corporation; “HP-4700” and “HP-4710” (naphthalene-type tetrafunctional epoxy resins) manufactured by DIC Corporation; “N-690” (cresol novolac-type epoxy resin) manufactured by DIC Corporation; “N-695” (cresol novolac-type epoxy resin) manufactured by DIC Corporation; “HP-7200” (dicyclopentadiene-type epoxy resin) manufactured by DIC Corporation; “HP-7200HH”, “HP-7200H”, “EXA-7311”, “EXA-7311-G3”, “EXA-7311-G4”, “EXA-7311-G4S”, and “HP6000” (naphthylene ether-type epoxy resin) manufactured by DIC Corporation; and “E-7200” (dicyclopentadiene-type epoxy resin) manufactured by DIC Corporation. PPN-502H (trisphenol type epoxy resin); NC7000L (naphthol novolac type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; NC3000H, NC3000, NC3000L, NC3100 (biphenyl type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; ESN475V (naphthalene type epoxy resin) manufactured by Nippon Steel & Sumitomo Metal Chemical Co., Ltd.; ESN485 (naphthol novolac type epoxy resin) manufactured by Nippon Steel & Sumitomo Metal Chemical Co., Ltd.; YX4000H, YX4000, YL6121 (biphenyl type epoxy resin) manufactured by Mitsubishi Chemical Corporation; YX4000HK (dimethylphenol type epoxy resin) manufactured by Mitsubishi Chemical Corporation; YX8800 (anthracene type epoxy resin) manufactured by Mitsubishi Chemical Corporation; Osaka Gas Chemical Co., Ltd. Gas Chemicals Co., Ltd.'s "PG-100" and "CG-500"; Mitsubishi Chemical Corporation's "YL7760" (bisphenol AF type epoxy resin); Mitsubishi Chemical Corporation's "YL7800" (fluorene type epoxy resin); Mitsubishi Chemical Corporation's "jER1010" (solid bisphenol A type epoxy resin); Mitsubishi Chemical Corporation's "jER1031S" (tetraphenylethane type epoxy resin). These may be used alone or in combination of two or more.

[0056] When a liquid epoxy resin and a solid epoxy resin are used in combination as the epoxy resin (A), the mass ratio of the liquid epoxy resin to the solid epoxy resin is preferably 1:1 to 1:20, more preferably 1:2 to 1:15, and particularly preferably 1:5 to 1:13. By adjusting the mass ratio of the liquid epoxy resin to the solid epoxy resin within the above range, the desired effect of the present invention can be significantly achieved. In addition, when the epoxy resin is usually used in the form of a resin sheet, moderate adhesiveness can be achieved. In addition, when the epoxy resin is usually used in the form of a resin sheet, sufficient flexibility can be achieved, and the handleability is improved. In addition, a cured product with sufficient breaking strength can usually be obtained.

[0057] Furthermore, the resin composition preferably includes at least one selected from a bixylenol-type epoxy resin and a fluorine-containing epoxy resin as the epoxy resin (A). The colorant (D) includes, for example, a pigment that increases the viscosity of the resin composition. However, the use of a bixylenol-type epoxy resin can suppress the increase in viscosity caused by the use of the colorant (D). Furthermore, fluorine-containing epoxy resins such as bisphenol AF epoxy resins can improve the dispersibility of the colorant (D) in the resin composition.

[0058] The epoxy equivalent of the epoxy resin (A) is preferably 50 to 5000, more preferably 50 to 3000, even more preferably 80 to 2000, and even more preferably 110 to 1000. By adjusting the epoxy equivalent within this range, the cured product of the resin composition layer has a sufficient crosslinking density, enabling the formation of an insulating layer with minimal surface roughness. The epoxy equivalent is the mass of a resin containing one equivalent of epoxy groups. This epoxy equivalent can be measured in accordance with JIS K7236.

[0059] From the viewpoint of remarkably obtaining the desired effects of the present invention, the weight average molecular weight (Mw) of the epoxy resin (A) is preferably 100 to 5,000, more preferably 250 to 3,000, and even more preferably 400 to 1,500.

[0060] The weight average molecular weight of the resin can be measured as a value in terms of polystyrene by gel permeation chromatography (GPC).

[0061] The amount of the epoxy resin (A) in the resin composition is preferably 10% by mass or more, more preferably 20% by mass or more, and even more preferably 30% by mass or more, relative to 100% by mass of the resin component in the resin composition, from the perspective of obtaining an insulating layer exhibiting good mechanical strength and insulation reliability. The upper limit of the epoxy resin content is preferably 90% by mass or less, more preferably 85% by mass or less, and particularly preferably 83% by mass or less, from the perspective of significantly obtaining the desired effects of the present invention.

[0062] [3. (B) Component: Curing Agent]

[0063] The resin composition contains a curing agent as the component (B). The curing agent (B) generally reacts with the epoxy resin (A) to cure the resin composition.

[0064] As the curing agent (B), a substance that can cure the epoxy resin (A) can be used. Examples of the curing agent (B) include active ester curing agents, phenol curing agents, naphthol curing agents, benzoxazine curing agents, cyanate curing agents, and carbodiimide curing agents. The curing agent may be used alone or in combination of two or more.

[0065] As active ester curing agent, the compound with more than 1 active ester group in 1 molecule can be used.Wherein, as active ester curing agent, preferably phenol ester (phenol ester) class, thiophenol ester (thiophenol ester) class, N-hydroxylamine ester class, heterocyclic hydroxy compound ester class etc. have the compound of ester group with more than 2 reactive high activity in 1 molecule.This active ester curing agent is preferably obtained by the condensation reaction of carboxylic acid compound and / or thiocarboxylic acid compound and hydroxy compound and / or thiol compound.Especially, from the viewpoint of improving heat resistance, the active ester curing agent preferably obtained by carboxylic acid compound and hydroxy compound, more preferably the active ester curing agent obtained by carboxylic acid compound and phenol compound and / or naphthol compound.

[0066] 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.

[0067] Examples of the phenolic compound or naphthol compound include hydroquinone, resorcinol, bisphenol A, bisphenol F, bisphenol S, phenolphthalein, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m-cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucinol, pyrogallol, dicyclopentadiene-type diphenolic compounds, and phenol novolac. The term "dicyclopentadiene-type diphenolic compound" herein refers to a diphenolic compound obtained by condensing two molecules of phenol onto one molecule of dicyclopentadiene.

[0068] Preferred specific examples of active ester curing agents include active ester compounds containing a dicyclopentadiene-type diphenol structure, active ester compounds containing a naphthalene structure, active ester compounds containing acetylated products of phenol novolac resins, and active ester compounds containing benzoylated products of phenol novolac resins. Among these, active ester compounds containing a naphthalene structure and active ester compounds containing a dicyclopentadiene-type diphenol structure are more preferred. The term "dicyclopentadiene-type diphenol structure" refers to a divalent structural unit composed of phenylene-dicyclopentylene-phenylene.

[0069] Examples of commercially available active ester curing agents include "EXB9451", "EXB9460", "EXB9460S", "HPC-8000-65T", "HPC-8000H-65TM", "EXB-8000L-65TM", and "EXB-8150-65T" (manufactured by DIC Corporation), which are active ester compounds containing a dicyclopentadiene-type diphenol structure; "EXB9416-70BK" (manufactured by DIC Corporation), which are active ester compounds containing a naphthalene structure; and "acetyl phenol resin" (manufactured by DIC Corporation). "DC808" (manufactured by Mitsubishi Chemical Corporation) as an active ester compound of a benzoylated product of a phenol novolac resin; "YLH1026" (manufactured by Mitsubishi Chemical Corporation) as an active ester compound of a benzoylated product of a phenol novolac resin; "DC808" (manufactured by Mitsubishi Chemical Corporation) as an active ester curing agent of an acetylated product of a phenol novolac resin; "YLH1026" (manufactured by Mitsubishi Chemical Corporation), "YLH1030" (manufactured by Mitsubishi Chemical Corporation), "YLH1048" (manufactured by Mitsubishi Chemical Corporation) as active ester curing agents of a benzoylated product of a phenol novolac resin; and the like.

[0070] As phenolic curing agents and naphthol curing agents, curing agents having a phenolic structure are preferred from the viewpoint of heat resistance and water resistance. In addition, from the viewpoint of adhesion to the conductor layer, nitrogen-containing phenolic curing agents are preferred, and phenolic curing agents containing a triazine skeleton are more preferred.

[0071] Specific examples of phenol-based curing agents and naphthol-based curing agents include "MEH-7700", "MEH-7810", and "MEH-7851" manufactured by Meiwa Chemicals; "NHN", "CBN", and "GPH" manufactured by Nippon Kayaku Co., Ltd.; "SN170", "SN180", "SN190", "SN475", "SN485", "SN495", "SN-495V", and "SN375" manufactured by Nippon Steel & Sumikin Chemicals; "TD-2090", "LA-7052", "LA-7054", "LA-1356", "LA-3018-50P", and "EXB-9500" manufactured by DIC Corporation; and the like.

[0072] Specific examples of the benzoxazine-based curing agent include "HFB2006M" manufactured by Showa Highpolymer Co., Ltd., and "Pd" and "Fa" manufactured by Shikoku Chemicals Co., Ltd.

[0073] Examples of cyanate curing agents include difunctional cyanate resins such as bisphenol A dicyanate, polyphenol cyanate, oligo(3-methylene-1,5-phenylene cyanate), 4,4'-methylenebis(2,6-dimethylphenylcyanate), 4,4'-ethylenediphenyl 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-(methylethylene))benzene, bis(4-cyanatephenyl)sulfide, and bis(4-cyanatephenyl)ether; polyfunctional cyanate resins derived from phenol novolac resins and cresol novolac resins; and prepolymers obtained by triazinization of a portion of these cyanate resins. Specific examples of cyanate curing agents include "PT30" and "PT60" manufactured by Lonza Japan Co., Ltd. (phenol novolac-type multifunctional cyanate resins), "ULL-950S" (multifunctional cyanate resin), "BA230", and "BA230S75" (prepolymers obtained by triazinizing part or all of bisphenol A dicyanate to form a trimer), etc.

[0074] Specific examples of the carbodiimide-based curing agent include "V-03" and "V-07" manufactured by Nisshinbo Chemical Co., Ltd.

[0075] Among the above, active ester curing agents are preferred as curing agents (B) from the viewpoint of significantly achieving the desired effects of the present invention. When using an active ester curing agent, from the viewpoint of significantly achieving the desired effects of the present invention, the content of the active ester curing agent relative to 100% by mass of the curing agent (B) is preferably 40% by mass or more, more preferably 50% by mass or more, even more preferably 60% by mass or more, and preferably 75% by mass or less, more preferably 73% by mass or less, and even more preferably 70% by mass or less.

[0076] The amount of the (B) curing agent in the resin composition 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 30% by mass or less, more preferably 25% by mass or less, and even more preferably 20% by mass or less, relative to 100% by mass of the resin component in the resin composition, from the viewpoint of significantly obtaining the desired effect of the present invention.

[0077] When the number of epoxy groups of the (A) epoxy resin is set to 1, the number of active groups of the (B) curing agent is preferably 0.1 or more, more preferably 0.2 or more, further preferably 0.24 or more, preferably 2 or less, more preferably 1.5 or less, further preferably 1 or less, and particularly preferably 0.5 or less. The so-called "number of epoxy groups of the (A) epoxy resin" herein refers to the value obtained by summing up all the values ​​obtained by dividing the mass of the non-volatile components of the (A) epoxy resin present in the resin composition by the epoxy equivalent. In addition, the so-called "number of active groups of the (B) curing agent" refers to the value obtained by summing up all the values ​​obtained by dividing the mass of the non-volatile components of the (B) curing agent present in the resin composition by the active group equivalent. By setting the number of active groups of the (B) curing agent when the number of epoxy groups of the (A) epoxy resin is set to 1 within the aforementioned range, the desired effect of the present invention can be significantly obtained, and the heat resistance of the cured product of the resin composition layer is generally further improved.

[0078] [4. (C) component: having an average particle size of 100 nm or less and 15 nm 2 / g or more of the specific surface area of ​​at least one inorganic filler]

[0079] The resin composition includes an inorganic filler as component (C). The inorganic filler can reduce the thermal expansion coefficient of the cured product of the resin composition layer, thereby obtaining an insulating layer that suppresses reflow soldering warpage. In addition, the inorganic filler as component (C) has an average particle size of less than 100 nm and a particle size of 15 nm. 2 By using component (C) as an inorganic filler having at least one of an average particle size and a specific surface area within the above-mentioned ranges in combination with (A) an epoxy resin, (B) a curing agent, and (D) a colorant, an insulating layer capable of forming through-holes of a good shape can be realized.

[0080] As the material of the inorganic filler, an inorganic compound is used. As examples of the material of the inorganic filler, silicon dioxide, aluminum oxide, glass, cordierite, silicon oxide, barium sulfate, barium carbonate, talc, clay, mica powder, zinc oxide, hydrotalcite, boehmite, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum nitride, manganese nitride, aluminum borate, strontium carbonate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, zirconium oxide, barium titanate, barium zirconate, calcium zirconate, zirconium phosphate, and zirconium tungstate phosphate, etc., can be mentioned. Among these, silicon dioxide is particularly preferred. As silicon dioxide, for example, amorphous silicon dioxide, fused silica, crystalline silicon dioxide, synthetic silicon dioxide, hollow silica, etc. can be mentioned. In addition, spherical silicon dioxide is preferred as silicon dioxide. One inorganic filler can be used alone or in combination of two or more.

[0081] For the average grain size of (C) component, from the viewpoint that makes insulating layer thinning and makes the control of through-hole shape become possible and realize good shape, be usually below 100nm, preferably below 90nm, more preferably below 80nm.For the lower limit of this average grain size, there is no particular restriction, preferably more than 50nm, more than 60nm or more than 70nm.As the commercially available product of the inorganic filler with such average grain size, can enumerate for example Electric Chemical Industry Co., Ltd. system " UFP-30 ", " UFP-40 " etc.

[0082] The average particle size of the inorganic filler can be measured using a laser diffraction-scattering method based on Mie scattering theory. Specifically, it can be measured in the following manner: using a laser diffraction scattering particle size distribution measuring device, the particle size distribution of the inorganic filler is made according to a volume basis, and its median particle size is used as the average particle size. Regarding the measurement sample, it is preferred to use a sample obtained by dispersing the inorganic filler in methyl ethyl ketone using ultrasonic waves. As a laser diffraction scattering particle size distribution measuring device, "LA-500" manufactured by Horiba Manufacturing Co., Ltd., "SALD-2200" manufactured by Shimadzu Manufacturing Co., Ltd., etc. can be used.

[0083] The specific surface area of ​​the component (C) is usually 15 m2 from the viewpoint of facilitating the control of the through-hole shape and achieving a good shape. 2 / g or more, preferably 20m 2 / g or more, particularly preferably 30m 2 / g or more. In addition, for the component (C) with a large specific surface area as described above, the particle size is usually small, so the insulating layer can be made thinner. There is no particular limit on the upper limit, but it is preferably 60m 2 / g or less, 50m 2 / g or less or 40m 2 The specific surface area of ​​the inorganic filler can be measured by the BET method.

[0084] For the inorganic filler as (C) component, from the viewpoint of improving moisture resistance and dispersibility, it is preferably processed using a surface treatment agent. As the surface treatment agent, for example, fluorine-containing silane coupling agents, aminosilane coupling agents, epoxysilane coupling agents, mercaptosilane coupling agents, silane coupling agents, alkoxysilanes, organosilazane compounds, titanate coupling agents, etc. can be enumerated. In addition, the surface treatment agent can be used alone or in combination of two or more.

[0085] Examples of commercially available surface treatment agents include “KBM403” (3-glycidoxypropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., “KBM803” (3-mercaptopropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., “KBE903” (3-aminopropyltriethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., “KBM573” (N-phenyl-3-aminopropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., “SZ-31” (hexamethyldisilazane) manufactured by Shin-Etsu Chemical Co., Ltd., “KBM103” (phenyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., “KBM-4803” (long-chain epoxy-type silane coupling agent) manufactured by Shin-Etsu Chemical Co., Ltd., and “KBM-7103” (3,3,3-trifluoropropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd.

[0086] The degree of surface treatment performed using a surface treatment agent is preferably limited to a specified range from the viewpoint of improving the dispersibility of the inorganic filler. Specifically, for 100 parts by mass of the inorganic filler, the surface treatment agent is preferably used in an amount of 0.2 to 5 parts by mass, preferably 0.2 to 3 parts by mass, and preferably 0.3 to 2 parts by mass.

[0087] The degree of surface treatment by the surface treatment agent can be evaluated by the amount of carbon per unit surface area of ​​the inorganic filler. From the perspective of improving the dispersibility of the inorganic filler, the amount of carbon per unit surface area of ​​the inorganic filler is preferably 0.02 mg / m 2 More than 0.1 mg / m 2 More preferably, 0.2 mg / m 2 On the other hand, from the viewpoint of suppressing the increase in the melt viscosity of the resin varnish and the melt viscosity in the sheet form, it is preferably 1 mg / m 2 Below, more preferably 0.8 mg / m 2 Below, more preferably 0.5 mg / m 2 the following.

[0088] The amount of carbon per unit surface area of ​​the inorganic filler can be measured after washing the surface-treated inorganic filler with a solvent (e.g., methyl ethyl ketone (MEK)). Specifically, the measurement can be performed as follows: a sufficient amount of MEK as a solvent is added to the inorganic filler surface-treated with a surface treatment agent, and ultrasonic washing is performed at 25°C for 5 minutes. The supernatant is removed, the solid component is dried, and then the amount of carbon per unit surface area of ​​the inorganic filler is measured using a carbon analyzer. As a carbon analyzer, "EMIA-320V" manufactured by Horiba, Ltd. or the like can be used.

[0089] From the viewpoint of reducing the dielectric loss tangent of the insulating layer, relative to the non-volatile component 100% by mass in the resin combination, the amount of (C) component in the resin combination is preferably more than 30% by mass, more preferably more than 35% by mass, more preferably more than 40% by mass. In addition, when the layer of the resin combination comprising a large amount of inorganic fillers as described above is thinner in the past, it is difficult to make the shape of the through hole good, especially relative to the non-volatile component 100% by mass in the resin combination, when the amount of inorganic fillers is more than 50% by mass, it is particularly difficult to form a well-shaped through hole. Therefore, from the viewpoint of the advantage of the present invention that can effectively play the through hole (particularly difficult in the past as described above) that can form a well-shaped through hole, relative to the non-volatile component 100% by mass in the resin combination, the amount of (C) component is preferably more than 50% by mass, particularly preferably more than 55% by mass. In addition, from the viewpoint of improving the mechanical strength of the insulating layer, relative to the non-volatile component 100% by mass in the resin combination, the upper limit of the amount of (C) component is preferably less than 90% by mass, more preferably less than 85% by mass, more preferably less than 80% by mass, or less than 75% by mass. Furthermore, from the viewpoint of achieving particularly good shapes of the through-holes, the amount of the component (C) is particularly preferably 60% by mass or less relative to 100% by mass of the nonvolatile components in the resin composition.

[0090] [5. (D) Ingredient: Colorant]

[0091] The resin composition contains a colorant as the component (D). Since the resin composition contains the colorant (D), the resin composition layer usually exhibits the color of the colorant (D).

[0092] As the colorant (D), both achromatic and chromatic colorants can be used. Among them, the colorant (D) is preferably a non-white colorant from the viewpoint of significantly achieving the desired effect of the present invention. Among them, the colorant (D) is preferably a black or chromatic colorant from the viewpoint of particularly effectively suppressing the halo phenomenon, more preferably a black, blue, or green colorant, and even more preferably a black or blue colorant.

[0093] Furthermore, the colorant (D) may be a pigment, a dye, or a combination of a pigment and a dye. Among these, pigments are preferred as the colorant (D). Pigments have a high coloring power and thus effectively impart color to the resin composition layer. Therefore, the use of pigments can enhance the light absorption capacity of the resin composition layer, thereby being particularly effective in suppressing the halo phenomenon.

[0094] If examples of pigments are given, blue pigments include, for example, phthalocyanine pigments, anthraquinone pigments, dioxazine pigments, etc. As yellow pigments, monoazo pigments, disazo pigments, condensed azo pigments, benzimidazolone pigments, isoindolinone pigments, anthraquinone pigments, etc. can be given. As red pigments, monoazo pigments, disazo pigments, azo lake pigments, benzimidazolone pigments, perylene pigments, diketopyrrolopyrrole pigments, condensed azo pigments, anthraquinone pigments, quinacridone pigments, etc. can be given. As black pigments, carbon black, graphite, etc. can be given. As green pigments, phthalocyanine pigments, etc. can be given.

[0095] For pigment, it is usually insoluble in (A) epoxy resin in resin combination and exists as particles. The average particle size of the pigment particles is preferably limited to the same range as the average particle size range of (C) component and the range described. In addition, the specific surface area of ​​the pigment particles is preferably limited to the same range as the specific surface area range of (C) component and the range described. Thus, the insulating layer can be thinned, and the control of the through-hole shape can be made possible, and a good shape can be achieved. The average particle size and specific surface area of ​​the pigment can be measured using the same method as (C) component.

[0096] (D) The colorant may be used alone or in combination of two or more at any ratio.

[0097] The amount of the colorant (D) in the resin composition is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and particularly preferably 1.0% by mass or more, relative to 100% by mass of the non-volatile components in the resin composition. It is preferably 5% by mass or less, more preferably 4% by mass or less, and particularly preferably 3% by mass or less. By setting the amount of the colorant (D) within the aforementioned range, the halo phenomenon can be effectively suppressed.

[0098] [6. (E) Component: Thermoplastic resin]

[0099] The resin composition may contain (E) a thermoplastic resin as an optional component in addition to the above-mentioned components.

[0100] As the thermoplastic resin of component (E), for example, phenoxy resin, polyvinyl acetal resin, polyolefin resin, polybutadiene resin, polyimide resin, polyamide-imide resin, polyetherimide resin, polysulfone resin, polyethersulfone resin, polyphenylene ether resin, polycarbonate resin, polyetheretherketone resin, polyester resin, etc. can be mentioned. Among them, phenoxy resin is preferred from the viewpoint of significantly obtaining the desired effect of the present invention and the viewpoint of obtaining an insulating layer with low surface roughness and particularly excellent adhesion to the conductor layer. In addition, the thermoplastic resin can be used alone or in combination of two or more.

[0101] Examples of phenoxy resins include phenoxy resins having one or more skeletons selected from the group consisting of bisphenol A skeletons, bisphenol F skeletons, bisphenol S skeletons, bisphenol acetophenone skeletons, phenolic skeletons, biphenyl skeletons, fluorene skeletons, dicyclopentadiene skeletons, norbornene skeletons, naphthalene skeletons, anthracene skeletons, adamantane skeletons, terpene skeletons, and trimethylcyclohexane skeletons. The termini of the phenoxy resins may be any functional group such as a phenolic hydroxyl group or an epoxy group.

[0102] Specific examples of phenoxy resins include "1256" and "4250" manufactured by Mitsubishi Chemical Corporation (both are phenoxy resins containing a bisphenol A skeleton); "YX8100" manufactured by Mitsubishi Chemical Corporation (a phenoxy resin containing a bisphenol S skeleton); "YX6954" manufactured by Mitsubishi Chemical Corporation (a phenoxy resin containing a bisphenol acetophenone skeleton); "FX280" and "FX293" manufactured by Nippon Steel & Sumikin Chemical Corporation; "YL7500BH30", "YX6954BH30", "YX7553", "YX7553BH30", "YL7769BH30", "YL6794", "YL7213", "YL7290" and "YL7482" manufactured by Mitsubishi Chemical Corporation; and the like.

[0103] Examples of the polyvinyl acetal resin include polyvinyl formal resin and polyvinyl butyral resin, with polyvinyl butyral resin being preferred. Specific examples of the polyvinyl acetal resin 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.

[0104] Specific examples of polyimide resins include "RIKACOAT SN20" and "RIKACOAT PN20" manufactured by Shin Nippon Chemical Co., Ltd. Specific examples of polyimide resins include modified polyimides such as linear polyimides obtained by reacting difunctional hydroxyl-terminated polybutadiene, a diisocyanate compound, and a tetrabasic acid anhydride (polyimides described in JP-A-2006-37083), and polyimides containing a polysiloxane skeleton (polyimides described in JP-A-2002-12667 and JP-A-2000-319386).

[0105] Specific examples of polyamide-imide resins include "VYLOMAX HR11NN" and "VYLOMAX HR16NN" manufactured by Toyobo Co., Ltd. Specific examples of polyamide-imide resins include modified polyamide-imides such as "KS9100" and "KS9300" (polyamide-imides containing a polysiloxane skeleton) manufactured by Hitachi Chemical Co., Ltd.

[0106] Specific examples of the polyethersulfone resin include "PES5003P" manufactured by Sumitomo Chemical Co., Ltd. and the like.

[0107] Specific examples of the polyphenylene ether resin include oligomeric polyphenylene ether-styrene resin "OPE-2St 1200" manufactured by Mitsubishi Gas Chemical Co., Ltd.

[0108] Specific examples of the polysulfone resin include polysulfone "P1700" and "P3500" manufactured by Solvay Advanced Polymers.

[0109] From the viewpoint of significantly achieving the desired effects of the present invention, the weight average molecular weight (Mw) of the thermoplastic resin (E) is preferably 8,000 or more, more preferably 10,000 or more, and particularly preferably 20,000 or more, and is preferably 70,000 or less, more preferably 60,000 or less, and particularly preferably 50,000 or less.

[0110] When the (E) thermoplastic resin is used, the amount of the (E) thermoplastic resin in the resin composition is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, even more preferably 1% by mass or more, and is preferably 15% by mass or less, more preferably 12% by mass or less, and even more preferably 10% by mass or less, relative to 100% by mass of the resin component in the resin composition, from the viewpoint of significantly achieving the desired effects of the present invention.

[0111] [7. (F) Component: Curing Accelerator]

[0112] The resin composition may contain (F) a curing accelerator as an optional component in addition to the above-mentioned components.

[0113] Examples of curing accelerators include phosphorus-based curing accelerators, amine-based curing accelerators, imidazole-based curing accelerators, guanidine-based curing accelerators, and metal-based curing accelerators. Among these, phosphorus-based curing accelerators, amine-based curing accelerators, imidazole-based curing accelerators, and metal-based curing accelerators are preferred, and amine-based curing accelerators, imidazole-based curing accelerators, and metal-based curing accelerators are more preferred. One curing accelerator may be used alone, or two or more may be used in combination.

[0114] Examples of the phosphorus-based curing accelerator include triphenylphosphine, phosphonium borate compounds, tetraphenylphosphonium tetraphenylborate, n-butylphosphonium tetraphenylborate, tetrabutylphosphonium decanoate, (4-methylphenyl)triphenylphosphonium thiocyanate, tetraphenylphosphonium thiocyanate, and butyltriphenylphosphonium thiocyanate, with triphenylphosphine and tetrabutylphosphonium decanoate being preferred.

[0115] Examples of the amine-based curing accelerator include trialkylamines such as triethylamine and tributylamine, 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, and 1,8-diazabicyclo(5,4,0)-undecene. 4-Dimethylaminopyridine and 1,8-diazabicyclo(5,4,0)-undecene are preferred.

[0116] 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, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazole, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, and 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine. Imidazole compounds such as diamino-6-[2'-undecylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2-methylimidazoline, 2-phenylimidazoline, and adducts of imidazole compounds with epoxy resins, preferably 2-ethyl-4-methylimidazole and 1-benzyl-2-phenylimidazole.

[0117] As the imidazole-based curing accelerator, a commercially available item can be used, and examples thereof include "P200-H50" manufactured by Mitsubishi Chemical Corporation.

[0118] Examples of the guanidine-based curing accelerator 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-methylbiguanidine, 1-ethylbiguanidine, 1-n-butylbiguanidine, 1-n-octadecylbiguanidine, 1,1-dimethylbiguanidine, 1,1-diethylbiguanidine, 1-cyclohexylbiguanidine, 1-allylbiguanidine, 1-phenylbiguanidine, and 1-(o-tolyl)biguanidine. Preferred examples include dicyandiamide and 1,5,7-triazabicyclo[4.4.0]dec-5-ene.

[0119] As metal curing accelerators, organometallic complexes or organometallic salts of metals such as cobalt, copper, zinc, iron, nickel, manganese, and tin can be mentioned. Specific examples of organometallic complexes include organocobalt complexes such as cobalt acetylacetonate (II) and cobalt acetylacetonate (III), organocopper complexes such as copper acetylacetonate (II), organozinc complexes such as zinc acetylacetonate (II), organoferric complexes such as iron acetylacetonate (III), organonickel complexes such as nickel acetylacetonate (II), and organomanganese complexes such as manganese acetylacetonate (II). As organometallic salts, for example, zinc octoate, tin octoate, zinc naphthenate, cobalt naphthenate, tin stearate, and zinc stearate can be mentioned.

[0120] When the curing accelerator (F) is used, the amount of the curing accelerator (F) in the resin composition 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 preferably 3% by mass or less, more preferably 2% by mass or less, and even more preferably 1.5% by mass or less, relative to 100% by mass of the resin component of the resin composition, from the viewpoint of significantly obtaining the desired effect of the present invention.

[0121] [8. (G) Ingredients: Optional additives]

[0122] In addition to the above-mentioned components, the resin composition may also contain any additives as optional components. Examples of such additives include organic fillers; resin additives such as flame retardants, thickeners, defoamers, leveling agents, and adhesion-imparting agents; and the like. These additives may be used alone or in combination of two or more.

[0123] [9. Thickness of Resin Composition Layer]

[0124] The resin composition layer is a layer formed by the above-mentioned resin composition, and has a thickness below a specified value. The specific thickness of the resin composition layer is generally 15 μm or less, preferably 14 μm or less, and more preferably 12 μm or less. In the past, the thickness of the resin composition layer used to form the insulating layer of the printed wiring board was generally thicker than the above-mentioned thickness. Relatively speaking, the present inventors have found that when the resin composition layer of a conventional composition is thinned as described above, for such a thin resin composition layer, it becomes difficult to control the shape of the through-hole and a halo phenomenon is generated after the roughening treatment, which is a previously unknown problem. From the viewpoint of solving such new problems and contributing to the thin filmization of the printed wiring board, the resin composition layer of the present invention is set to a thinner thickness as described above. The lower limit of the thickness of the resin composition layer is arbitrary, for example, it can be 1 μm or more, or 3 μm or more.

[0125] [10. Characteristics of Resin Composition Layer]

[0126] By curing the resin composition layer of the present invention, a thin insulating layer formed from the cured resin composition layer can be obtained. Through-holes with good shapes can be formed in this insulating layer. Furthermore, when through-holes are formed and roughening is performed on this insulating layer, the halo phenomenon can be suppressed. These effects are described below with reference to the accompanying drawings.

[0127] Figure 1 This is a cross-sectional view schematically showing an insulating layer 100 obtained by curing the resin composition layer according to the first embodiment of the present invention together with an inner substrate 200. Figure 1 , a cross section of the insulating layer 100 is shown, which is obtained by cutting the insulating layer 100 along a plane that passes through the center 120C of the bottom 120 of the through-hole 110 and is parallel to the thickness direction of the insulating layer 100 .

[0128] like Figure 1 As shown, the insulating layer 100 of the first embodiment of the present invention is a layer obtained by curing a resin composition layer formed on the inner layer substrate 200 including the conductor layer 210, and is formed from the cured product of the resin composition layer. Furthermore, a through hole 110 is formed in the insulating layer 100. The through hole 110 is typically formed in a forward tapered shape (a taper shape) with a diameter increasing as it approaches the surface 100U of the insulating layer 100 opposite the conductor layer 210 and decreasing as it approaches the conductor layer 210. Ideally, the through hole 110 is formed in a columnar shape having a constant diameter in the thickness direction of the insulating layer 100. The through hole 110 can typically be formed by irradiating the surface 100U of the insulating layer 100 opposite the conductor layer 210 with a laser to remove a portion of the insulating layer 100.

[0129] The bottom of the through-hole 110 on the conductor layer 210 side is appropriately referred to as the "through-hole bottom" and is indicated by the reference numeral 120. The diameter of the through-hole bottom 120 is referred to as the bottom diameter Lb. In addition, the opening of the through-hole 110 formed on the side opposite to the conductor layer 210 is appropriately referred to as the "through-hole top" and is indicated by the reference numeral 130. The diameter of the through-hole top 130 is referred to as the top diameter Lt. Generally, the through-hole bottom 120 and the through-hole top 130 have a circular planar shape as viewed in the thickness direction of the insulating layer 100, but may also be an ellipse. When the planar shape of the through-hole bottom 120 and the through-hole top 130 is an ellipse, the bottom diameter Lb and the top diameter Lt respectively represent the major diameter of the ellipse.

[0130] At this time, the closer the taper ratio Lb / Lt (%), obtained by dividing the bottom diameter Lb by the top diameter Lt, is to 100%, the better the shape of the through hole 110. Using the resin composition layer of the present invention makes it easy to control the shape of the through hole 110, thereby achieving a through hole 110 with a taper ratio Lb / Lt close to 100%.

[0131] For example, under the conditions of a mask diameter of 1 mm, a pulse width of 16 μs, an energy of 0.2 mJ / shot, a shot number of 2, and a burst mode (10 kHz), when the insulating layer 100 obtained by heating the resin composition layer at 100°C for 30 minutes and then heating it at 180°C for 30 minutes to cure it is irradiated with a CO2 laser to form a through hole 110 with a top diameter Lt of 30 μm ± 2 μm, the tapered ratio Lb / Lt of the through hole 110 can be preferably 75% to 100%, more preferably 80% to 100%, and particularly preferably 85% to 100%.

[0132] The taper ratio Lb / Lt of the through hole 110 can be calculated from the bottom diameter Lb and the top diameter Lt of the through hole 110. Alternatively, the bottom diameter Lb and the top diameter Lt of the through hole 110 can be measured by cutting the insulating layer 100 using a FIB (focused ion beam) to reveal a cross section parallel to the thickness direction of the insulating layer 100 and passing through the center 120C of the through hole bottom 120, and then observing the cross section using an electron microscope.

[0133] Figure 2 The insulating layer 100 obtained by curing the resin composition layer of the first embodiment of the present invention and the conductive layer 210 (not in Figure 2 ) A plan view schematically showing the surface 100U on the opposite side.

[0134] like Figure 2 As shown, when observing the insulating layer 100 having the through-hole 110 formed therein, a discolored portion 140 of the insulating layer 100 may be observed around the through-hole 110. This discolored portion 140 is likely formed by degradation of the resin when forming the through-hole 110 and is usually formed continuously from the through-hole 110. Furthermore, in many cases, the discolored portion 140 is a whitened portion.

[0135] Figure 3 This is a cross-sectional view schematically showing the roughened insulating layer 100 obtained by curing the resin composition layer according to the first embodiment of the present invention together with the inner substrate 200. Figure 3 , a cross section of the insulating layer 100 is shown, which is obtained by cutting the insulating layer 100 along a plane that passes through the center 120C of the through-hole bottom 120 of the through-hole 110 and is parallel to the thickness direction of the insulating layer 100 .

[0136] like Figure 3As shown, when the insulating layer 100 having the through-hole 110 formed therein is subjected to a roughening process, a halo phenomenon may occur, whereby the insulating layer 100 in the discolored portion 140 is peeled off from the conductive layer 210, forming a gap 160 that is continuous from the edge 150 of the through-hole bottom 120. This gap 160 is generally formed by erosion of the discolored portion 140 during the roughening process.

[0137] By using the resin composition layer of the present invention, the aforementioned halo phenomenon can be suppressed, thereby suppressing the insulation layer 100 from being peeled off from the conductive layer 210 , and thus the size of the gap 160 can be reduced.

[0138] The edge 150 of the through-hole bottom 120 is equivalent to the edge portion of the inner peripheral side of the gap portion 160. Therefore, the distance Wb from the edge 150 of the through-hole bottom 120 to the end portion 170 on the outer peripheral side of the gap portion 160 (that is, the end portion farther from the center 120C of the through-hole bottom 120) is equivalent to the dimension of the in-plane direction of the gap portion 160. The in-plane direction referred to here refers to the direction perpendicular to the thickness direction of the insulating layer 100. In addition, in the following description, the aforementioned distance Wb is sometimes referred to as the halo distance Wb from the edge 150 of the through-hole bottom 120 of the through-hole 110. The degree of suppression of the halo phenomenon can be evaluated by the halo distance Wb from the edge 150 of the through-hole bottom 120. Specifically, the evaluation can be performed as follows: the smaller the halo distance Wb from the edge 150 of the through-hole bottom 120, the more effectively the halo phenomenon is suppressed.

[0139] For example, under the conditions of a mask diameter of 1 mm, a pulse width of 16 μs, an energy of 0.2 mJ / shot, a shot number of 2, and a burst mode (10 kHz), a CO2 laser is irradiated on an insulating layer 100 obtained by heating a resin composition layer at 100°C for 30 minutes and then heating it at 180°C for 30 minutes to cure it, thereby forming a through hole 110 with a top diameter Lt of 30 μm ± 2 μm. Then, the insulating layer 100 is immersed in a swelling solution at 60°C for 10 minutes, then immersed in an oxidizing agent solution at 80°C for 20 minutes, then immersed in a neutralizing solution at 40°C for 5 minutes, and then dried at 80°C for 15 minutes. If the resin composition layer of the present invention is used, the halo distance Wb of the insulating layer 100 obtained in the above manner from the edge 150 of the through hole bottom 120 of the through hole 110 can be preferably 10 μm or less, more preferably 5 μm or less, further preferably 4 μm or less, and particularly preferably 3 μm or less.

[0140] The halo distance Wb from the edge 150 of the through-hole bottom 120 can be measured by using FIB (focused ion beam) to cut the insulating layer 100 to reveal a cross section parallel to the thickness direction of the insulating layer 100 and passing through the center 120C of the through-hole bottom 120, and then observing the cross section with an electron microscope.

[0141] Furthermore, by using the resin composition layer of the present invention, the shape of through-hole 110 in insulating layer 100 before roughening can be easily controlled. Therefore, even after roughening, the shape of through-hole 110 can be easily controlled. Therefore, even after roughening, the shape of through-hole 110 can be maintained to the same high quality as before roughening. Therefore, by using the resin composition layer of the present invention, through-hole 110 having a taper ratio Lb / Lt approaching 100% can be achieved in the insulating layer after roughening.

[0142] For example, under the conditions of a mask diameter of 1 mm, a pulse width of 16 μs, an energy of 0.2 mJ / shot, a shot count of 2, and a burst mode (10 kHz), a CO2 laser is irradiated on an insulating layer 100 obtained by heating a resin composition layer at 100°C for 30 minutes and then curing it at 180°C for 30 minutes to form a through-hole 110 with a top diameter Lt of 30 μm ± 2 μm. The layer is then immersed in a swelling solution at 60°C for 10 minutes, then immersed in an oxidizing agent solution at 80°C for 20 minutes, then immersed in a neutralizing solution at 40°C for 5 minutes, and finally dried at 80°C for 15 minutes. Using the resin composition layer of the present invention, the through-hole 110 formed in the insulating layer 100 thus obtained can have a taper ratio Lb / Lt of preferably 76% to 100%, more preferably 80% to 100%, and particularly preferably 85% to 100%.

[0143] The taper ratio Lb / Lt of the through hole 110 can be calculated from the bottom diameter Lb and the top diameter Lt of the through hole 110. Furthermore, the bottom diameter Lb and the top diameter Lt of the through hole 110 can be measured by cutting the insulating layer 100 using a FIB (focused ion beam) to reveal a cross section parallel to the thickness direction of the insulating layer 100 and passing through the center 120C of the through hole bottom 120, and then observing the cross section using an electron microscope.

[0144] Furthermore, through the research of the present inventors, it was found that there is generally the following tendency: the larger the diameter of the through-hole 110, the easier it is for the size of the discoloration portion 140 to become larger, and therefore the size of the gap portion 160 is also easier to become larger. Therefore, the degree of suppression of the halo phenomenon can be evaluated by the ratio of the size of the gap portion 160 to the diameter of the through-hole 110. For example, it can be evaluated by the halo ratio Hb relative to the bottom radius Lb / 2 of the through-hole 110. The bottom radius Lb / 2 of the through-hole 110 referred to here refers to the radius of the through-hole bottom 120 of the through-hole 110. In addition, the so-called halo ratio Hb relative to the bottom radius Lb / 2 of the through-hole 110 refers to the ratio obtained by dividing the halo distance Wb from the edge 150 of the through-hole bottom 120 by the bottom radius Lb / 2 of the through-hole 110. The smaller the halo ratio Hb relative to the bottom radius Lb / 2 of the through-hole 110, the more effectively the halo phenomenon is suppressed.

[0145] For example, under the conditions of a mask diameter of 1 mm, a pulse width of 16 μs, an energy of 0.2 mJ / shot, a shot count of 2, and a burst mode (10 kHz), an insulating layer 100 obtained by heating a resin composition layer at 100°C for 30 minutes and then curing it at 180°C for 30 minutes is irradiated with a CO2 laser to form a through-hole 110 having a top diameter Lt of 30 μm ± 2 μm. The insulating layer 100 is then immersed in a swelling solution at 60°C for 10 minutes, then immersed in an oxidizing agent solution at 80°C for 20 minutes, then immersed in a neutralizing solution at 40°C for 5 minutes, and then dried at 80°C for 15 minutes. Using the resin composition layer of the present invention, the halo ratio Hb relative to the bottom radius Lb / 2 of the through-hole 110 formed in the insulating layer 100 obtained in the above manner can be preferably 50% or less, more preferably 40% or less, and even more preferably 30% or less.

[0146] The halo ratio Hb with respect to the bottom radius Lb / 2 of the through hole 110 may be calculated from the bottom diameter Lb of the through hole 110 and the halo distance Wb from the edge 150 of the through hole bottom 120 of the through hole 110 .

[0147] Furthermore, by generally using the resin composition layer of the present invention, the formation of the discolored portion 140 when forming the through hole 110 can be suppressed. Figure 2 As shown, the size of the discoloration portion 140 can be reduced, and ideally, can be eliminated. The size of the discoloration portion 140 can be evaluated by the halo distance Wt from the edge 180 of the through-hole top 130 of the through-hole 110.

[0148] Edge 180 of through-hole top 130 corresponds to the inner peripheral edge of discoloration portion 140. The halo distance Wt from edge 180 of through-hole top 130 represents the distance from edge 180 of through-hole top 130 to outer peripheral edge 190 of discoloration portion 140. This can be evaluated as follows: the smaller the halo distance Wt from edge 180 of through-hole top 130, the more effectively the formation of discoloration portion 140 is suppressed.

[0149] For example, under the conditions of a mask diameter of 1 mm, a pulse width of 16 μs, an energy of 0.2 mJ / shot, an shot number of 2, and a group mode (10 kHz), when the insulating layer 100 obtained by heating the resin composition layer at 100°C for 30 minutes and then heating it at 180°C for 30 minutes to cure it is irradiated with a CO2 laser to form a through hole 110 with a top diameter Lt of 30 μm ± 2 μm, the halo distance Wt from the edge 180 of the through hole top 130 can be preferably less than 6 μm, more preferably less than 5 μm.

[0150] The halo distance Wt from the edge 180 of the via top 130 can be measured by observation using an optical microscope.

[0151] In addition, through the research of the present inventors, it was found that there is generally the following tendency: the larger the diameter of the through-hole 110, the easier it is for the size of the discoloration portion 140 to become larger. Therefore, the degree of suppression of the formation of the discoloration portion 140 can be evaluated by the ratio of the size of the discoloration portion 140 to the diameter of the through-hole 110. For example, it can be evaluated by the halo ratio Ht relative to the top radius Lt / 2 of the through-hole 110. The top radius Lt / 2 of the through-hole 110 referred to here refers to the radius of the through-hole top 130 of the through-hole 110. In addition, the halo ratio Ht relative to the top radius Lt / 2 of the through-hole 110 refers to the ratio obtained by dividing the halo distance Wt from the edge 180 of the through-hole top 130 by the top radius Lt / 2 of the through-hole 110. The smaller the halo ratio Ht relative to the top radius Lt / 2 of the through-hole 110, the more effectively the formation of the discoloration portion 140 is suppressed.

[0152] For example, under the conditions of a mask diameter of 1 mm, a pulse width of 16 μs, an energy of 0.2 mJ / shot, an shot number of 2, and a group mode (10 kHz), when the insulating layer 100 obtained by heating the resin composition layer at 100°C for 30 minutes and then heating it at 180°C for 30 minutes to cure it is irradiated with a CO2 laser to form a through hole 110 with a top diameter Lt of 30 μm±2 μm, the halo ratio Ht relative to the top radius Lt / 2 of the through hole 110 can be preferably less than 45%, more preferably less than 40%, and further preferably less than 35%.

[0153] The halo ratio Ht with respect to the top radius Lt / 2 of the via 110 may be calculated from the top diameter Lt of the via 110 and the halo distance Wt from the edge 180 of the via top 130 of the via 110 .

[0154] During the manufacturing process of a printed wiring board, the through-hole 110 is usually formed in a state where no additional conductive layer (not shown) is provided on the surface 100U of the insulating layer 100 on the side opposite to the conductive layer 210. Therefore, if one understands the manufacturing process of a printed wiring board, one can clearly understand the structure in which the through-hole bottom 120 is provided on the conductive layer 210 side and the through-hole top 130 is open on the side opposite to the conductive layer 210. However, in the completed printed wiring board, there may be a case where the conductive layer is provided on both sides of the insulating layer 100. In this case, it may sometimes be difficult to distinguish the through-hole bottom 120 and the through-hole top 130 by their positional relationship with the conductive layer. However, the top diameter Lt of the through-hole top 130 is usually not less than the bottom diameter Lb of the through-hole bottom 120. Therefore, in the aforementioned case, the through-hole bottom 120 and the through-hole top 130 can be distinguished by the size of the diameter.

[0155] The present inventors have speculated as follows on the mechanism by which the resin composition layer of the present invention can achieve the aforementioned effects. However, the technical scope of the present invention is not limited to the mechanism described below.

[0156] Typically, when forming the through-hole 110, energy such as heat and light is applied to the portion of the insulating layer 100 where the through-hole 110 is to be formed. A portion of the energy applied at this time is transferred to the periphery of the portion where the through-hole 110 is to be formed, which may degrade the resin. If the resin deteriorates as described above, the insulating layer discolors in the deteriorated portion and becomes susceptible to erosion. Therefore, erosion during the roughening treatment may cause a halo phenomenon, causing the insulating layer to peel off from the conductor layer. In contrast, for the resin composition layer of the present invention, due to the effect of the (D) colorant, the resin composition can effectively absorb energy. In particular, due to the effect of the (D) colorant, the resin composition has a greatly improved absorption performance for a wide range of lasers that can be used industrially. Therefore, the applied energy is effectively absorbed by the resin composition, which can suppress the energy reaching the bottom 120 of the through-hole from becoming too large, thereby suppressing the degradation of the resin around the bottom 120 of the through-hole. Therefore, for the insulating layer 100 obtained using the resin composition layer of the present invention, the halo phenomenon can be suppressed.

[0157] In addition, as can be seen from the description of average particle size and specific surface area, the particle size of the (C) component contained in the resin composition layer is usually smaller. Since the particle size of the (C) component is small, the energy applied to the insulating layer 100 can be well transmitted in the thickness direction of the insulating layer 100. For example, if heat or light energy is applied to the surface 100U of the insulating layer 100, the energy will not diffuse over a large range in the in-plane direction and can be effectively transmitted in the thickness direction. Therefore, a through hole 110 with a large taper ratio can be easily formed, so the shape of the through hole 110 can be made good.

[0158] [11. Application of resin composition layer]

[0159] The resin composition layer of the present invention can be suitably used as a resin composition layer for insulating purposes. Specifically, the resin composition layer of the present invention can be suitably used as: a resin composition layer for forming an insulating layer of a printed wiring board (a resin composition layer for forming an insulating layer of a printed wiring board); and furthermore, it can be more suitably used as: a resin composition layer for forming an interlayer insulating layer of a printed wiring board (a resin composition layer for forming an interlayer insulating layer of a printed wiring board). In addition, the resin composition layer of the present invention can be suitably used as: a resin composition layer for forming the insulating layer for forming a conductor layer (including a redistribution layer) on the insulating layer (a resin composition layer for forming an insulating layer for forming a conductor layer).

[0160] In particular, from the perspective of effectively utilizing the advantages of being able to suppress the halo phenomenon and form through-holes of good shape, the aforementioned resin composition layer is suitable as: a resin composition layer for forming an insulating layer having through-holes (resin composition layer for forming an insulating layer having through-holes), and is particularly suitable as: a resin composition layer for forming an insulating layer having through-holes with a top diameter of less than 35 μm.

[0161] [12. Resin sheet]

[0162] The resin sheet of the present invention includes a support and the resin composition layer of the present invention provided on the support.

[0163] Examples of the support include films made of plastic materials, metal foils, and release papers, and films made of plastic materials and metal foils are preferred.

[0164] When a film formed of a plastic material is used as the support, examples of the plastic material include polyesters such as polyethylene terephthalate (hereinafter sometimes referred to as "PET") and polyethylene naphthalate (hereinafter sometimes referred to as "PEN"), acrylic polymers such as polycarbonate (hereinafter sometimes referred to as "PC") and polymethyl methacrylate (hereinafter sometimes referred to as "PMMA"), cyclic polyolefins, triacetyl cellulose (hereinafter sometimes referred to as "TAC"), polyether sulfide (hereinafter sometimes referred to as "PES"), polyether ketone, and polyimide. Among them, polyethylene terephthalate and polyethylene naphthalate are preferred, and inexpensive polyethylene terephthalate is particularly preferred.

[0165] When a metal foil is used as a support, examples of the metal foil include copper foil and aluminum foil, with copper foil being preferred. The copper foil may be made of copper alone or an alloy of copper and other metals (e.g., tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.).

[0166] The surface of the support to be in contact with the resin composition layer may be subjected to treatment such as matte treatment, corona treatment, and antistatic treatment.

[0167] In addition, as the support, a support with a release layer having a release layer on the surface bonded to the resin composition layer can be used. As a release agent for the release layer of the support with a release layer, for example, one or more release agents selected from alkyd resins, polyolefin resins, polyurethane resins, and silicone resins can be mentioned. The support with a release layer can be a commercially available product, for example, a PET film having a release layer with an alkyd resin-based release agent as the main component, i.e., "SK-1", "AL-5", and "AL-7" manufactured by Lintec; "Lumirror T60" manufactured by Toray Industries; "Purex" manufactured by Teijin; "Unipeel" manufactured by UNITIKA; etc.

[0168] The thickness of the support is not particularly limited, but is preferably in the range of 5 μm to 75 μm, more preferably in the range of 10 μm to 60 μm. When a support with a release layer is used, the thickness of the entire support with a release layer is preferably in the above range.

[0169] In addition, as needed, the resin sheet may include any layer other than the support and the resin composition layer. As the arbitrary layer, for example, a protective film based on the support is provided on the surface of the resin composition layer that is not bonded to the support (i.e., the surface on the opposite side of the support). The thickness of the protective film is not particularly limited, for example, 1 μm to 40 μm. The protective film can prevent dust from adhering to the surface of the resin composition layer or from being damaged.

[0170] The resin sheet can be produced, for example, by preparing a resin varnish containing an organic solvent and a resin composition, applying the resin varnish on a support using a coating apparatus such as a die coater, and drying the varnish to form a resin composition layer.

[0171] Examples of the organic solvent include ketone solvents such as acetone, methyl ethyl ketone, and cyclohexanone; acetate solvents such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, and carbitol acetate; carbitol solvents such as cellosolve and butyl carbitol; aromatic hydrocarbon solvents such as toluene and xylene; and amide solvents such as dimethylformamide, dimethylacetamide (DMAc), and N-methylpyrrolidone. These organic solvents may be used alone or in combination of two or more.

[0172] Drying can be performed by heating, blowing hot air, or other methods. Drying conditions are not particularly limited; drying is performed so that the organic solvent content in the resin composition layer is generally 10% by mass or less, preferably 5% by mass or less. While this varies depending on the boiling point of the organic solvent in the resin varnish, for example, when using a resin varnish containing 30% to 60% by mass of an organic solvent, the resin composition layer can be formed by drying at 50°C to 150°C for 3 to 10 minutes.

[0173] The resin sheet can be stored in a roll. If the resin sheet has a protective film, it can usually be used by peeling off the protective film.

[0174] [13. Printed wiring board]

[0175] As described above, the printed wiring board of the present invention includes an insulating layer formed from a cured product of a thin resin composition layer. Furthermore, this insulating layer can suppress the halo phenomenon and form well-shaped through-holes. Therefore, by using the resin composition layer of the present invention, it is possible to achieve a thinner printed wiring board while suppressing performance degradation caused by the halo phenomenon or degradation of the through-hole shape.

[0176] A through-hole is typically provided to provide electrical continuity between conductive layers disposed on both sides of an insulating layer having the through-hole. Therefore, the printed wiring board of the present invention typically includes a first conductive layer, a second conductive layer, and an insulating layer formed between the first and second conductive layers. Furthermore, a through-hole is formed in the insulating layer, allowing electrical continuity between the first and second conductive layers.

[0177] By utilizing the advantages of a resin composition layer, such as its ability to suppress haloing and form well-shaped through-holes, a specific printed wiring board, which has been difficult to achieve in the past, can be realized. This specific printed wiring board comprises a first conductor layer, a second conductor layer, and an insulating layer formed between the first and second conductor layers, and satisfies all of the following conditions (i) to (v):

[0178] (i) The thickness of the insulating layer is 15 μm or less;

[0179] (ii) the insulating layer has a through hole with a top diameter of 35 μm or less;

[0180] (iii) the through hole has a taper ratio of 80% or more;

[0181] (iv) the halo distance of the through hole from the edge of the through hole bottom is 5 μm or less;

[0182] (v) The halo ratio of the through hole relative to the bottom radius is 35% or less.

[0183] Hereinafter, a specific printed wiring board will be described with reference to the drawings. Figure 4 : is a schematic cross-sectional view of a printed wiring board 300 according to a second embodiment of the present invention. Figure 4 , a cross section of the printed wiring board 300 is shown, which is obtained by cutting the printed wiring board 300 along a plane that passes through the center 120C of the through-hole bottom 120 of the through-hole 110 and is parallel to the thickness direction of the insulating layer 100. Figure 4 In the Figures 1 to 3 For the parts corresponding to the elements recorded in Figures 1 to 3 The same reference numerals used in the drawings are used to represent the same figures.

[0184] like Figure 4 As shown, a specific printed wiring board 300 according to the second embodiment of the present invention includes a first conductive layer 210, a second conductive layer 220, and an insulating layer 100 formed between the first conductive layer 210 and the second conductive layer 220. Through-holes 110 are formed in the insulating layer 100. Furthermore, the second conductive layer 220 is typically provided after the through-holes 110 are formed. Therefore, the second conductive layer 220 is typically formed not only on the surface 100U of the insulating layer 100 but also within the through-holes 110, and the first conductive layer 210 and the second conductive layer 220 are electrically connected via the through-holes 110.

[0185] The thickness T of the insulating layer 100 included in the specific printed wiring board 300 is generally 15 μm or less, preferably 12 μm or less, more preferably 10 μm or less, and particularly preferably 5 μm or less. The specific printed wiring board 300 includes such a thin insulating layer 100, thereby enabling the specific printed wiring board 300 itself to be thinner. The lower limit of the thickness T of the insulating layer 100 is preferably 1 μm or more, more preferably 2 μm or more, and particularly preferably 3 μm or more, from the perspective of improving the insulating performance of the insulating layer 100. The thickness T of the insulating layer 100 referred to herein refers to the dimension of the insulating layer 100 between the first conductive layer 210 and the second conductive layer 220, and does not refer to the dimension of the insulating layer 100 at locations where the first conductive layer 210 or the second conductive layer 220 is not present. The thickness T of the insulating layer 100 generally matches the distance between the principal surface 210U of the first conductive layer 210 and the principal surface 220D of the second conductive layer 220 , which face each other across the insulating layer 100 , and also matches the depth of the through hole 110 .

[0186] The top diameter Lt of through-hole 110 in insulating layer 100 included in specific printed wiring board 300 is typically 35 μm or less, preferably 33 μm or less, and particularly preferably 32 μm or less. Because specific printed wiring board 300 includes insulating layer 100 having through-hole 110 having such a small top diameter Lt, miniaturization of the wiring including first conductor layer 210 and second conductor layer 220 can be promoted. The lower limit of top diameter Lt of through-hole 110 is preferably 3 μm or greater, more preferably 10 μm or greater, and particularly preferably 15 μm or greater, from the perspective of facilitating the formation of through-hole 110.

[0187] The taper ratio Lb / Lt (%) of through-holes 110 in insulating layer 100 included in specific printed wiring board 300 is typically 80% to 100%. Specific printed wiring board 300 includes insulating layer 100 having well-shaped through-holes 110 with a high taper ratio Lb / Lt as described above. Therefore, specific printed wiring board 300 typically improves the electrical continuity reliability between first conductor layer 210 and second conductor layer 220.

[0188] The halo distance Wb of through-hole 110 in insulating layer 100 included in specific printed wiring board 300 from edge 150 of through-hole bottom 120 is typically 5 μm or less, preferably 4 μm or less, and more preferably 3 μm or less. As described above, in specific printed wiring board 300, the halo distance Wb from edge 150 of through-hole bottom 120 is small, thereby minimizing separation of insulating layer 100 from first conductive layer 210. Consequently, specific printed wiring board 300 generally improves the electrical continuity reliability between first conductive layer 210 and second conductive layer 220.

[0189] The halo ratio Hb of the through-hole 110 of the insulating layer 100 included in the specific printed wiring board 300 relative to the bottom radius Lb / 2 is typically 35% or less, preferably 30% or less, and more preferably 25% or less. As described above, the halo ratio Hb of the specific printed wiring board 300 relative to the bottom radius Lb / 2 is small, thereby minimizing separation of the insulating layer 100 from the first conductive layer 210. The specific printed wiring board 300 including the insulating layer 100 having such a small halo ratio Hb generally improves the electrical conduction reliability between the first conductive layer 210 and the second conductive layer 220. The lower limit of the halo ratio Hb relative to the bottom radius Lb / 2 is ideally 0, but is typically 5% or greater.

[0190] The number of through-holes 110 included in insulating layer 100 of specific printed wiring board 300 may be one or two or more. When insulating layer 100 has two or more through-holes 110, some of them may satisfy conditions (ii) to (v), but preferably all of them satisfy conditions (ii) to (v). Furthermore, it is preferable that, for example, five randomly selected through-holes 110 in insulating layer 100 satisfy conditions (ii) to (v) on average.

[0191] The above-mentioned specific printed wiring board 300 can be realized by forming the insulating layer 100 from the cured product of the resin composition layer of the present invention. In this case, the planar shapes of the through-hole bottom 120 and the through-hole top 130 of the through-hole 110 formed in the insulating layer 100 are arbitrary, but are generally circular or elliptical, preferably circular.

[0192] A printed wiring board such as a specific printed wiring board can be produced, for example, by using a resin sheet and performing a production method including the following steps (I) to (IV).

[0193] (I) a step of laminating a resin sheet on the inner substrate so that the resin composition layer is bonded to the inner substrate;

[0194] (II) a step of thermally curing the resin composition layer to form an insulating layer;

[0195] (III) forming a through hole in the insulating layer;

[0196] (IV) A step of roughening the insulating layer.

[0197] The "inner substrate" used in step (I) is a member that becomes the substrate of the printed wiring board. As the inner substrate, for example, a glass epoxy substrate, a metal substrate, a polyester substrate, a polyimide substrate, a BT resin substrate, a thermosetting polyphenylene ether substrate, etc. can be cited. Usually, as the inner substrate, a substrate having a conductor layer on one or both sides is used. Then, an insulating layer is formed on the conductor layer. In order to make the conductor layer function, for example, in the form of a circuit, it can also be patterned. Sometimes an inner substrate having a conductor layer formed in the form of a circuit on one or both sides of the substrate is referred to as an "inner circuit substrate". In addition, an intermediate product to be further formed with an insulating layer and / or a conductor layer when manufacturing a printed wiring board is also included in the "inner substrate". When the printed wiring board is a circuit board with built-in components, an inner substrate with built-in components can also be used.

[0198] The lamination of the inner substrate and the resin sheet can be carried out, for example, by the following method: the resin composition layer is attached to the inner substrate by heat-pressing the resin sheet to the inner substrate from the support body side. As a component for heat-pressing the resin sheet to the inner substrate (hereinafter sometimes referred to as "heat-pressing component"), for example, a heated metal plate (SUS end plate (mirror plate) etc.) or a metal roller (SUS roller) etc. can be cited. It should be noted that in order to make the resin sheet fully follow the surface unevenness of the inner substrate, it is preferred that the heat-pressing component is not directly pressurized to the resin sheet, but pressurized via an elastic material such as heat-resistant rubber.

[0199] Lamination of the inner layer substrate and the resin sheet can be performed, for example, by vacuum lamination. In vacuum lamination, the heating and pressing temperature is preferably 60°C to 160°C, more preferably 80°C to 140°C, the heating and pressing pressure is preferably 0.098 MPa to 1.77 MPa, more preferably 0.29 MPa to 1.47 MPa, and the heating and pressing time is preferably 20 seconds to 400 seconds, more preferably 30 seconds to 300 seconds. Lamination is preferably performed under reduced pressure conditions of 26.7 hPa or less.

[0200] Lamination can be performed using a commercially available vacuum laminator. Examples of commercially available vacuum laminators include a vacuum pressure laminator manufactured by Meiki Manufacturing Co., Ltd., a vacuum applicator manufactured by Nikko Materials Co., Ltd., and a batch vacuum pressure laminator.

[0201] After lamination, the laminated resin sheet can be smoothed by, for example, applying pressure to the heat-pressing member from the support side under normal pressure (atmospheric pressure). The pressurizing conditions for the smoothing treatment can be set to the same conditions as the heat-pressing conditions for the above-mentioned lamination. The smoothing treatment can be carried out using a commercially available laminator. It should be noted that the lamination and smoothing treatment can be carried out continuously using the above-mentioned commercially available vacuum laminator.

[0202] In step (II), the resin composition layer is thermally cured to form an insulating layer. The thermal curing conditions of the resin composition layer are not particularly limited, and any conditions used when forming an insulating layer of a printed wiring board can be used.

[0203] For example, the thermal curing conditions of the resin composition layer vary depending on the type of resin composition, etc. The curing temperature can generally be set in the range of 120°C to 240°C (preferably in the range of 150°C to 220°C, more preferably in the range of 170°C to 200°C), and the curing time can generally be set in the range of 5 minutes to 120 minutes (preferably 10 minutes to 100 minutes, more preferably 15 minutes to 90 minutes).

[0204] Before heat-curing the resin composition layer, the resin composition layer may be preheated at a temperature lower than the curing temperature. For example, before heat-curing the resin composition layer, the resin composition layer is preheated at a temperature of generally 50°C or higher and lower than 120°C (preferably 60°C or higher and 115°C or lower, more preferably 70°C or higher and 110°C or lower) for generally 5 minutes or more (preferably 5 minutes to 150 minutes, more preferably 15 minutes to 120 minutes, and even more preferably 15 minutes to 100 minutes).

[0205] In step (III), a through hole is formed in the insulating layer. Examples of methods for forming the through hole include laser irradiation, etching, and mechanical drilling. Laser irradiation is generally prone to causing a halo phenomenon. Therefore, from the perspective of effectively utilizing the effect of suppressing the halo phenomenon, laser irradiation is preferred.

[0206] The laser irradiation can be performed using, for example, a laser processing machine having a laser light source such as a carbon dioxide laser, a YAG laser, or an excimer laser. Examples of usable laser processing machines include the CO2 laser processing machine "LC-2k212 / 2C" manufactured by Via Mechanics, the 605GTWIII(-P) manufactured by Mitsubishi Electric, and the laser processing machine manufactured by Panasonic Welding Systems.

[0207] Laser irradiation conditions, such as laser wavelength, pulse number, pulse width, and output power, are not particularly limited and can be set to appropriate conditions corresponding to the type of laser light source. Furthermore, from the perspective of significantly achieving the desired effects of the present invention, the laser wavelength is preferably within the absorption wavelength range of the colorant (D).

[0208] In step (IV), the insulating layer is subjected to a roughening treatment. The steps and conditions for the roughening treatment are not particularly limited, and any steps and conditions used in forming the insulating layer of a printed wiring board can be employed. For example, the insulating layer can be roughened by sequentially performing a swelling treatment with a swelling solution, a roughening treatment with an oxidizing agent, and a neutralization treatment with a neutralizing solution.

[0209] There are no particular restrictions on the swelling liquid, and examples thereof include alkaline solutions, surfactant solutions, and the like, with alkaline solutions being preferred. As the alkaline solution, sodium hydroxide solutions and potassium hydroxide solutions are more preferred. Examples of commercially available swelling liquids include "Swelling Dip Securiganth P" and "Swelling Dip Securiganth SBU" manufactured by ATOTECH JAPAN. In addition, one swelling liquid may be used alone, or two or more may be used in combination at any ratio. The swelling treatment using the swelling liquid is not particularly limited, and for example, it may be performed by immersing the insulating layer in a swelling liquid at 30°C to 90°C for 1 minute to 20 minutes. From the viewpoint of suppressing the swelling of the resin of the insulating layer to an appropriate level, it is preferred to immerse the insulating layer in a swelling liquid at 40°C to 80°C for 5 minutes to 15 minutes.

[0210] There are no particular restrictions on the oxidizing agent, and examples thereof include alkaline permanganate solutions formed by dissolving potassium permanganate or sodium permanganate in an aqueous solution of sodium hydroxide. In addition, one oxidizing agent may be used alone, or two or more oxidizing agents may be used in combination in any ratio. The roughening treatment performed using an oxidizing agent such as an alkaline permanganate solution is preferably performed by immersing the insulating layer in an oxidizing agent solution heated to 60°C to 80°C for 10 minutes to 30 minutes. In addition, the concentration of permanganate in the alkaline permanganate solution is preferably 5% by mass to 10% by mass. As commercially available oxidizing agents, examples thereof include alkaline permanganate solutions such as "Concentrate Compact CP" and "Dosing Solution Securiganth P" manufactured by ATOTECH JAPAN.

[0211] As the neutralizing solution, an acidic aqueous solution is preferred, and commercially available products include, for example, "Reduction Solution Securiganth P" manufactured by ATOTECH JAPAN. One type of neutralizing solution may be used alone, or two or more types may be used in combination at any ratio. The treatment with the neutralizing solution can be performed by immersing the surface roughened with an oxidizing agent in a neutralizing solution at a temperature of 30°C to 80°C for 5 to 30 minutes. From the perspective of operability, a method in which the object roughened with an oxidizing agent is immersed in a neutralizing solution at a temperature of 40°C to 70°C for 5 to 20 minutes is preferred.

[0212] In addition, the support may be removed between step (I) and step (II), between step (II) and step (III), between step (III) and step (IV), or after step (IV). From the perspective of further suppressing the occurrence of the notch, it is preferably removed after step (III) of forming a through hole on the insulating layer. For example, when the support is peeled off after forming a through hole on the insulating layer by laser irradiation, a through hole of a good shape is easily formed.

[0213] The method for producing a printed wiring board may further include (V) forming a conductor layer. This step (V) can be carried out by various methods that can be used in the production of a printed wiring board.

[0214] Step (V) is a step of forming a conductor layer. The conductor material used for the conductor layer is not particularly limited. In a preferred embodiment, the conductor layer comprises 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. As the alloy layer, for example, a layer formed by an alloy of two or more metals selected from the above group (for example, nickel-chromium alloy, copper-nickel alloy and copper-titanium alloy) can be mentioned. Among them, from the viewpoints of versatility, cost, ease of patterning, etc. in forming the conductor layer, a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper is preferred; or an alloy layer of nickel-chromium alloy, copper-nickel alloy or copper-titanium alloy. Furthermore, a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper is more preferred; or an alloy layer of nickel-chromium alloy, and a single metal layer of copper is particularly preferred.

[0215] The conductive layer may have a single-layer structure or a multilayer structure comprising two or more single metal layers or alloy layers formed of different metals or alloys. When the conductive layer has a multilayer 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.

[0216] The thickness of the conductor layer depends on the desired design of the printed wiring board, but is usually 3 μm to 35 μm, preferably 5 μm to 30 μm.

[0217] The conductor layer can be formed by plating. For example, a semi-additive method, a full-additive method, or other techniques can be used to plate the surface of the insulating layer to form a conductor layer having a desired wiring pattern. Of these, the semi-additive method is preferred for ease of manufacture.

[0218] The following describes an example of forming a conductor layer using a semi-additive process. First, a plating seed layer is formed on the surface of an insulating layer using chemical plating (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. A metal layer is formed on the exposed plating seed layer using electrolytic plating, and the mask pattern is then removed. The unnecessary plating seed layer is then removed using etching or the like, thereby forming a conductor layer having the desired wiring pattern.

[0219] Furthermore, if necessary, the formation of the insulating layer and the conductive layer by steps (I) to (V) can be repeated to produce a multilayer printed wiring board.

[0220] [14. Semiconductor devices]

[0221] The semiconductor device of the present invention includes the aforementioned printed wiring board. This semiconductor device can be manufactured using the printed wiring board.

[0222] Examples of semiconductor devices include various semiconductor devices used in electrical products (eg, computers, mobile phones, digital cameras, and televisions) and vehicles (eg, motorcycles, automobiles, trains, ships, and airplanes).

[0223] Semiconductor devices can be manufactured, for example, by mounting a component (semiconductor chip) at a conductive location on a printed wiring board. "Conductive location" refers to a location on the printed wiring board where electrical signals are transmitted, and can be located on the surface or embedded within the printed wiring board. Furthermore, any electrical circuit element made of semiconductors can be used as the semiconductor chip.

[0224] There are no particular restrictions on the method for mounting semiconductor chips when manufacturing semiconductor devices, as long as the semiconductor chips can function effectively. Examples of mounting methods include wire bonding mounting methods, flip chip mounting methods, mounting methods using a solderless build-up layer (BBUL), mounting methods using anisotropic conductive film (ACF), and mounting methods using a non-conductive film (NCF). Here, "mounting method using a solderless build-up layer (BBUL)" refers to "a mounting method in which a semiconductor chip is directly embedded in a recess of a printed wiring board to connect the semiconductor chip to the wiring on the printed wiring board."

[0225] Example

[0226] The present invention is described in detail below with reference to the following examples. However, the present invention is not limited to the following examples. In the following description, "parts" and "%" representing quantities represent "parts by mass" and "mass %" respectively, unless otherwise specified. Furthermore, the operations described below are performed under normal temperature and pressure, unless otherwise specified.

[0227] [Explanation of Inorganic Filler]

[0228] <Method for measuring average particle size of inorganic filler>

[0229] 100 mg of inorganic filler, 0.1 g of dispersant (Sannopco "SN9228"), and 10 g of methyl ethyl ketone were weighed into a vial and dispersed using ultrasound for 20 minutes. The particle size distribution of the inorganic filler was measured on a volume basis using a laser diffraction particle size distribution analyzer (Shimadzu Corporation "SALD-2200") in a batch cell method. The average particle size of the inorganic filler was then calculated as the median particle size from the obtained particle size distribution.

[0230] <Method for measuring the specific surface area of ​​inorganic fillers>

[0231] The specific surface area of ​​the inorganic filler was measured using a BET fully automatic specific surface area measuring apparatus ("Macsorb HM-1210" manufactured by Mountech).

[0232] <Inorganic filler 1>

[0233] Spherical silica ("UFP-30" manufactured by Denki Kagaku Kogyo Co., Ltd., with an average particle size of 0.078 μm and a specific surface area of ​​30.7 m) was prepared. 2 / g) and 100 parts of N-phenyl-3-aminopropyltrimethoxysilane ("KBM573" manufactured by Shin-Etsu Chemical Co., Ltd.) were surface-treated as inorganic filler 1.

[0234] <Inorganic filler 2>

[0235] Spherical silica (“SC2500SQ” manufactured by Admatechs, with an average particle size of 0.77 μm and a specific surface area of ​​5.9 m 2 / g) 100 parts, N-phenyl-3-aminopropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBM573) 1 part

[0236] The surface-treated product is used as the inorganic filler 2 .

[0237] [Example 1. Preparation of Resin Composition 1]

[0238] 6 parts of a bixylene epoxy resin ("YX4000HK" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent weight approximately 185), 5 parts of a naphthalene epoxy resin ("ESN475V" manufactured by Nippon Steel & Sumikin Chemical Corporation, epoxy equivalent weight approximately 332), 15 parts of a bisphenol AF epoxy resin ("YL7760" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent weight approximately 238), 2 parts of a cyclohexane epoxy resin ("ZX1658GS" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent weight approximately 135), and 2 parts of a phenoxy resin ("YL7500BH30" manufactured by Mitsubishi Chemical Corporation, a 1:1 solution of cyclohexanone and methyl ethyl ketone (MEK) with a nonvolatile content of 30% by mass, Mw = 44,000) were dissolved in a mixed solvent of 20 parts of solvent naphtha and 10 parts of cyclohexanone while stirring. The resulting solution was cooled to room temperature. Next, 6 parts of an active ester curing agent (DIC Corporation's "EXB-8000L-65™," a 1:1 toluene:MEK solution containing an active group equivalent of approximately 220 and a nonvolatile content of 65% by mass), 4 parts of a triazine skeleton-containing cresol novolac curing agent (DIC Corporation's "LA-3018-50P," a 2-methoxypropanol solution containing a hydroxyl group equivalent of approximately 151 and a nonvolatile content of 50%), 50 parts of an inorganic filler 1, 1 part of carbon black (Nippon Pigment Co., Ltd.'s "NV-7-201") as a black pigment, and 0.05 parts of an amine curing accelerator (4-dimethylaminopyridine (DMAP)) were mixed with this solution and uniformly dispersed using a high-speed rotary mixer to obtain a mixture. The mixture was filtered using a cartridge filter (ROKITECHNO Corporation's "SHP020") to obtain Resin Composition 1.

[0239] [Example 2. Preparation of Resin Composition 2]

[0240] A blue pigment ("Cyanine Blue 4920" manufactured by Dainichi Seika Co., Ltd.) was used instead of carbon black. Resin composition 2 was prepared by the same operation as that for preparing resin composition 1 except for the above matters.

[0241] [Comparative Example 1. Preparation of Resin Composition 3]

[0242] Carbon black was not used. Resin composition 3 was prepared by the same operation as that for preparing resin composition 1 except for the above matters.

[0243] [Comparative Example 2. Preparation of Resin Composition 4]

[0244] Inorganic filler 2 was used instead of inorganic filler 1. Resin composition 4 was prepared by carrying out the same operation as that for preparing resin composition 1 except for the above matters.

[0245] [Composition of resin composition]

[0246] The components used in the preparation of resin compositions 1 to 5 and their blending amounts (parts by mass of non-volatile components) are shown in Table 1 below. The abbreviations in the following table are as follows:

[0247] Curing agent content: the ratio of the curing agent content relative to 100% by mass of the resin component in the resin composition;

[0248] Active ester curing agent content: the ratio of the active ester curing agent content relative to 100% by mass of the resin component in the resin composition;

[0249] Inorganic filler content: the ratio of the content of the inorganic filler relative to 100% by mass of the non-volatile components in the resin composition;

[0250] Pigment content: The ratio of the content of the pigment relative to 100% by mass of the non-volatile components in the resin composition.

[0251] [Table 1]

[0252] [Table 1. Composition of resin composition]

[0253]

[0254] [Production of resin sheets]

[0255] As a support, a polyethylene terephthalate film ("Lumirror R80" manufactured by Toray Industries, Ltd., 38 μm thick, softening point 130° C.) subjected to release treatment with an alkyd resin-based release agent ("AL-5" manufactured by Lintec) was prepared.

[0256] Resin compositions 1 to 4 were uniformly applied to a support using a die coater so that the thickness of the dried resin composition layer was 10 μm. The layers were dried at 70°C to 95°C for 2 minutes to form resin composition layers on the support. Next, the rough surface of a polypropylene film ("ALPHAN MA-411" manufactured by Oji F-Tex Co., Ltd., 15 μm thick) was attached as a protective film to the surface of the resin composition layer not in contact with the support. This yielded a resin sheet A having a support, a resin composition layer, and a protective film in this order.

[0257] [Thickness measurement method]

[0258] The thickness of layers such as the resin composition layer was measured using a contact-type film thickness meter ("MCD-25MJ" manufactured by Mitutoyo Corporation).

[0259] [Evaluation of through-holes after laser drilling]

[0260] Using the resin sheets A produced using each of the resin compositions 1 to 4, an insulating layer having through-holes was formed by the following method, and the through-holes were evaluated.

[0261] Preparation of evaluation samples

[0262] (1) Preparation of inner substrate:

[0263] As the inner layer substrate, a glass cloth-based epoxy resin double-sided copper-clad laminate having copper foil layers on both sides was prepared (copper foil thickness 3 μm, substrate thickness 0.15 mm, "HL832NSF LCA" manufactured by Mitsubishi Gas Chemical Co., Ltd., size 255×340 mm).

[0264] (2) Lamination of resin sheets:

[0265] The protective film was peeled off from the resin sheet A to expose the resin composition layer. Using an intermittent vacuum pressurization laminator (Nikko-Materials, 2-Stage Buildup Laminator "CVP700"), the resin composition layer was laminated to both sides of the inner substrate in such a way that the inner substrate was in contact with the resin composition layer. Lamination was performed by the following method: decompression was performed for 30 seconds to adjust the air pressure to below 13hPa, and then pressing was performed at 130°C and a pressure of 0.74MPa for 45 seconds. Next, hot pressing was performed at 120°C and a pressure of 0.5MPa for 75 seconds.

[0266] (3) Thermal curing of the resin composition layer:

[0267] The inner substrate laminated with the resin sheet was then placed in a 100°C oven for 30 minutes. The resin composition layer was then heated in a 180°C oven for 30 minutes to thermally cure, forming an insulating layer. The insulating layer had a thickness of 10 μm. The support was then peeled off, yielding a cured substrate A comprising the insulating layer, inner substrate, and insulating layer in this order.

[0268] (4) Laser drilling:

[0269] A CO2 laser processing machine (Mitsubishi Electric Corporation's "605GTWIII(-P)") was used to irradiate the insulating layer with laser light, forming multiple through-holes with a top diameter of approximately 30 μm. Laser irradiation conditions were: mask diameter 1 mm, pulse width 16 μs, energy 0.2 mJ / shot, shot count 2, and burst mode (10 kHz). The cured substrate A with through-holes formed in the insulating layer in this manner is referred to as hole-processed substrate A.

[0270] (5) Roughening treatment:

[0271] A desmear treatment as a roughening treatment was performed on the hole-formed substrate A. As the desmear treatment, the following wet desmear treatment was performed.

[0272] (Wet decontamination treatment)

[0273] The hole-forming substrate A was immersed in a swelling solution ("Swelling Dip Securiganth P" manufactured by ATOTECH JAPAN, an aqueous solution of diethylene glycol monobutyl ether and sodium hydroxide) at 60°C for 10 minutes, then immersed in an oxidizing solution ("Concentrate Compact CP" manufactured by ATOTECH JAPAN, an aqueous solution of approximately 6% potassium permanganate and 4% sodium hydroxide) at 80°C for 20 minutes, and then immersed in a neutralizing solution ("Reduction Solution Securiganth P" manufactured by ATOTECH JAPAN, an aqueous solution of sulfuric acid) at 40°C for 5 minutes, and then dried at 80°C for 15 minutes. The hole-forming substrate A subjected to this wet desmear treatment is referred to as a roughened substrate A.

[0274] <Measurement of Through-Hole Dimensions Before Roughening>

[0275] Cross-sectional observation of the hole-processed substrate A before roughening was performed using a FIB-SEM hybrid instrument (SII NanoTechnology, Inc., "SMI3050SE"). Specifically, the insulating layer was cut using a focused ion beam (FIB) to reveal a cross section parallel to the thickness of the insulating layer and passing through the center of the bottom of the through-hole. This cross section was then observed using a scanning electron microscope (SEM). The top and bottom diameters of the through-holes were measured from the observed images.

[0276] The above measurements were performed at five randomly selected through-holes. The average of the top diameters of the five through-holes measured was used as the top diameter, Lt1, of the sample before roughening. Furthermore, the average of the bottom diameters of the five through-holes measured was used as the bottom diameter, Lb1, of the sample before roughening.

[0277] <Measurement of Through-Hole Dimensions and Halo Distance After Roughening>

[0278] For the roughened substrate A, a FIB-SEM composite device ("SMI3050SE" manufactured by SII Nano Technology) was used to perform cross-sectional observation. In detail, the insulating layer was cut using FIB (focused ion beam) to reveal a cross section parallel to the thickness direction of the insulating layer and passing through the center of the bottom of the through-hole of the through-hole. The cross section was observed using SEM. The bottom diameter and top diameter of the through-hole were measured from the observed image. In addition, in the image obtained by observation using SEM, a gap portion was observed that was continuous from the edge of the bottom of the through-hole and was formed by peeling off the insulating layer from the copper foil layer of the inner substrate. Therefore, from the observed image, the distance r3 from the center of the bottom of the through-hole to the edge of the bottom of the through-hole (equivalent to the inner radius of the gap portion) and the distance r4 from the center of the bottom of the through-hole to the farther end of the aforementioned gap portion (equivalent to the outer radius of the gap portion) were measured, and the difference r4-r3 between the above-mentioned distance r3 and the distance r4 was calculated as the halo distance from the edge of the bottom of the through-hole at the measurement location.

[0279] The above measurements were performed on five randomly selected through-holes. The average of the top diameters of the five through-holes measured was used as the top diameter, Lt2, of the sample after roughening. Furthermore, the average of the bottom diameters of the five through-holes measured was used as the bottom diameter, Lb2, of the sample after roughening. Furthermore, the average of the halo distances of the five through-holes measured was used as the halo distance, Wb, from the edge of the through-hole bottom for the sample.

[0280] [result]

[0281] The evaluation results of the above-mentioned Examples and Comparative Examples are shown in Table 2 below.

[0282] In Table 2, the taper ratio refers to the ratio "Lb1 / Lt1" of the top diameter Lt1 to the bottom diameter Lb1 of the through hole before the roughening process.

[0283] In Table 2, the halo ratio Hb represents the ratio (Wb / (Lb / 2)) of the halo distance Wb from the edge of the through-hole bottom after roughening to the radius of the through-hole bottom after roughening (Lb / 2). A halo ratio Hb of 35% or less was considered "good," while a halo ratio greater than 35% was considered "poor."

[0284] [Table 2]

[0285] [Table 2. Results of Examples and Comparative Examples]

[0286]

[0287] [Investigation]

[0288] As shown in Table 2, although the insulating layer in the examples was formed using a thin resin composition layer as thin as 10 μm, through-holes with a large taper ratio were formed in the insulating layer. This result confirms that the resin composition layer of the present invention can achieve an insulating layer capable of forming well-shaped through-holes even with a thin thickness.

[0289] Furthermore, Table 2 shows that, despite using a thin resin composition layer as thin as 10 μm to form the insulating layer in the examples, the halo ratio Hb after roughening treatment is smaller. This result confirms that the resin composition layer of the present invention can achieve an insulating layer that suppresses the halo phenomenon even with a thin thickness.

[0290] In particular, an insulating layer having a thickness of 15 μm or less, a through-hole top diameter Lt of 35 μm or less, a through-hole taper ratio of 80% or greater, a halo distance Wb from the through-hole bottom edge of 5 μm or less, and a halo ratio Hb relative to the through-hole bottom radius of 35% or less, as achieved in Examples 1 and 2, has not been previously achieved. Therefore, achieving such an insulating layer has significant technical significance in recent years for printed wiring boards, where thinner insulating layers are desired.

[0291] Although the specific results when a conductive layer is formed on the insulating layer of the roughened substrate A are not shown in Examples 1 and 2, from the results of the above examples, a person skilled in the art can clearly understand that by forming a conductive layer on the insulating layer of the roughened substrate A, a specific printed wiring board that satisfies conditions (i) to (v) can be obtained.

[0292] In Examples 1 and 2, even when the components (E) to (F) were not contained, it was confirmed that the same results as those of the above-described Examples were achieved, although there were differences in degree.

[0293] Description of Reference Signs

[0294] 100 insulation layer

[0295] 100U The surface of the insulation layer opposite to the conductor layer

[0296] 110 through hole

[0297] 120 through-hole bottom

[0298] 120C Center of bottom of through hole

[0299] 130 Through-hole top

[0300] 140 Color Change Department

[0301] 150 The edge of the bottom of the through hole

[0302] 160 gap

[0303] 170 End portion of the outer peripheral side of the gap portion

[0304] 180 The edge of the top of the through hole

[0305] 190 The edge portion of the outer peripheral side of the color changing portion

[0306] 200 inner substrate

[0307] 210 conductor layer (first conductor layer)

[0308] 220 Second conductor layer

[0309] 300 printed wiring board

[0310] Lb bottom diameter of the through hole

[0311] Lt Top diameter of the through hole

[0312] T thickness of the insulation layer

[0313] Wt is the distance of the halo from the edge of the top of the via

[0314] Wb is the halo distance from the edge of the bottom of the via.

Claims

1. A resin composition layer having a thickness of 15 μm or less, for forming an interlayer insulating layer having a through-hole in a printed wiring board, comprising a resin composition. in, The resin composition comprises (A) an epoxy resin, (B) a curing agent, (C) an inorganic filler having an average particle size of 100 nm or less, and (D) a colorant. (D) the colorant is a black colorant, The amount of the component (C) is 30% by mass or more relative to 100% by mass of the non-volatile components in the resin composition. The amount of the component (D) is 0.5% by mass or more and 4% by mass or less relative to 100% by mass of the nonvolatile matter in the resin composition.

2. A resin composition layer having a thickness of 15 μm or less and containing a resin composition for forming an interlayer insulating layer having a through-hole in a printed wiring board. in, The resin composition comprises (A) epoxy resin, (B) curing agent, (C) a specific surface area of ​​15m 2 / g or more inorganic filler, and (D) colorant, (D) the colorant is a black colorant, The amount of the component (C) is 30% by mass or more relative to 100% by mass of the non-volatile components in the resin composition. The amount of the component (D) is 0.5% by mass or more and 4% by mass or less relative to 100% by mass of the nonvolatile matter in the resin composition.

3. The resin composition layer according to claim 1, wherein The average particle size of the component (C) is 80 nm or less.

4. The resin composition layer according to claim 1, wherein The average particle size of the component (C) is 50 nm or more.

5. The resin composition layer according to claim 1, wherein The average particle size of the component (C) is 70 nm or more. The resin composition layer according to claim 2, wherein The specific surface area of ​​component (C) is 30m 2 / g or above.

7. The resin composition layer according to claim 2, wherein The specific surface area of ​​component (C) is 60m 2 / g or less.

8. The resin composition layer according to claim 2, wherein The specific surface area of ​​component (C) is 40 m 2 / g or less.

9. The resin composition layer according to any one of claims 1 to 8, wherein Component (D) is a pigment.

10. The resin composition layer according to any one of claims 1 to 8, wherein The amount of the component (D) is 1.0% by mass or more relative to 100% by mass of the non-volatile matter in the resin composition.

11. The resin composition layer according to any one of claims 1 to 8, wherein The amount of the component (D) is 3% by mass or less relative to 100% by mass of the nonvolatile matter in the resin composition.

12. The resin composition layer according to any one of claims 1 to 8, wherein The amount of the component (C) is 90% by mass or less relative to 100% by mass of the non-volatile matter in the resin composition.

13. The resin composition layer according to any one of claims 1 to 8, wherein The amount of the component (C) is 60% by mass or less relative to 100% by mass of the nonvolatile matter in the resin composition.

14. The resin composition layer according to any one of claims 1 to 8, wherein The amount of the component (C) is 55% by mass or more relative to 100% by mass of the non-volatile matter in the resin composition.

15. The resin composition layer according to any one of claims 1 to 8, wherein The amount of the component (A) is 10% by mass or more and 90% by mass or less relative to 100% by mass of the resin component in the resin composition.

16. The resin composition layer according to any one of claims 1 to 8, wherein The amount of the component (A) is 30% by mass or more relative to 100% by mass of the resin component in the resin composition.

17. The resin composition layer according to any one of claims 1 to 8, wherein The amount of the component (A) is 83% by mass or less relative to 100% by mass of the resin component in the resin composition.

18. The resin composition layer according to any one of claims 1 to 8, wherein The amount of the component (B) is 0.1% by mass or more and 30% by mass or less relative to 100% by mass of the resin component in the resin composition.

19. The resin composition layer according to any one of claims 1 to 8, wherein The amount of the component (B) is 1% by mass or more relative to 100% by mass of the resin component in the resin composition.

20. The resin composition layer according to any one of claims 1 to 8, wherein The amount of the component (B) is 20% by mass or less relative to 100% by mass of the resin component in the resin composition.

21. The resin composition layer according to any one of claims 1 to 8, wherein (A) As a component, at least one selected from the group consisting of a biphenylol-type epoxy resin and a fluorine-containing epoxy resin is contained.

22. The resin composition layer according to any one of claims 1 to 8, wherein The thickness of the resin composition layer is 12 μm or less.

23. The resin composition layer according to any one of claims 1 to 8, wherein The thickness of the resin composition layer is 1 μm or more.

24. The resin composition layer according to any one of claims 1 to 8, wherein The thickness of the resin composition layer is 3 μm or more. 25 . The resin composition layer according to claim 1 , which is used to form an insulating layer for forming a conductor layer. 26 . The resin composition layer according to claim 1 , which is used for forming an insulating layer having a through-hole having a top diameter of 35 μm or less. 27 . The resin composition layer according to claim 1 , which is used for forming an insulating layer having a through-hole having a top diameter of 32 μm or less. 28 . The resin composition layer according to claim 1 , which is used for forming an insulating layer having a through-hole having a top diameter of 3 μm or more. 29 . The resin composition layer according to claim 1 , which is used for forming an insulating layer having a through-hole having a top diameter of 15 μm or more. 30 . A resin sheet comprising a support and the resin composition layer according to claim 1 provided on the support.

31. A printed wiring board comprising an insulating layer formed from a cured product of the resin composition layer according to any one of claims 1 to 29.

32. A semiconductor device comprising the printed wiring board according to claim 31.

Images