JP7210901B2 - Resin composition layer - Google Patents

Description

The present invention relates to a resin composition layer. Furthermore, the present invention relates to a resin sheet containing the resin composition layer; and a printed wiring board and a semiconductor device containing an insulating layer formed of a cured product of the resin composition layer.

In recent years, in order to achieve miniaturization of electronic devices, printed wiring boards have been further thinned. Along with this, miniaturization of the wiring circuit in the inner layer substrate is being promoted. For example, Patent Literature 1 describes a resin sheet (adhesive film) that includes a support and a resin composition layer and is compatible with low dielectric loss tangent.

JP 2014-5464 A

The present inventors have studied thinning the resin composition layer of the resin sheet in order to achieve further miniaturization and thinning of electronic devices. As a result of investigation, the present inventors have found that when a thin resin composition layer is applied to an insulating layer, if the insulating layer is roughened after via holes are formed, haloing occurs. . Here, the haloing phenomenon means that delamination occurs between the insulating layer and the inner layer substrate around the via hole. Such a haloing phenomenon usually occurs when the resin around the via hole deteriorates during formation of the via hole, and the deteriorated portion is eroded during roughening treatment. The deteriorated portion is usually observed as a discolored portion.

Furthermore, the present inventors have found that when a thin resin composition layer is applied to the insulating layer, it becomes difficult to control the shape of via holes, making it difficult to obtain via holes with good shapes. Here, the "good" shape of the via hole means that the taper ratio of the via hole is close to one. Also, the taper rate of a via hole means the ratio of the bottom diameter to the top diameter of the via hole.

All of the above-mentioned problems arise only when the thickness of the resin composition layer is reduced, and are new problems that have not been known in the past. From the viewpoint of improving the reliability of electrical connection between layers of a printed wiring board, it is desirable to solve these problems.

The present invention has been invented in view of the above-mentioned problems, and provides a resin composition layer capable of suppressing the haloing phenomenon and providing an insulating layer capable of forming well-shaped via holes even when the thickness is thin. a resin sheet comprising the above resin composition layer; a printed wiring board comprising a thin insulating layer capable of suppressing the haloing phenomenon and forming via holes of good shape; and a semiconductor device comprising the above printed wiring board. ; is intended to provide

As a result of intensive studies to solve the above problems, the present inventors have found that at least one of (A) an epoxy resin, (B) a curing agent, and (C) an average particle diameter of 100 nm or less and a specific surface area of 15 m ² /g or more and (D) a pigment in combination, it was found that the above problems can be solved, and the present invention has been completed.
That is, the present invention includes the following contents.

[1] A resin composition layer having a thickness of 15 μm or less containing a resin composition,
A resin composition layer containing (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.
[2] A resin composition layer having a thickness of 15 μm or less containing a resin composition,
A resin composition layer containing (A) an epoxy resin, (B) a curing agent, (C) an inorganic filler having a specific surface area of 15 m ² /g or more, and (D) a colorant.
[3] The resin composition layer according to [1] or [2], wherein the component (D) is a black or chromatic colorant.
[4] The resin composition layer according to any one of [1] to [3], wherein component (D) is a black or blue colorant.
[5] The resin composition layer according to any one of [1] to [4], wherein the component (D) is a pigment.
[6] 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 with respect to 100% by mass of non-volatile components in the resin composition The resin composition layer described in .
[7] The resin composition according to any one of [1] to [6], wherein the amount of component (C) is 60% by mass or less with respect to 100% by mass of non-volatile components in the resin composition. layer.
[8] The resin composition layer according to any one of [1] to [7], which contains, as component (A), at least one selected from the group consisting of bixylenol-type epoxy resins and fluorine-containing epoxy resins. .
[9] The resin composition layer according to any one of [1] to [8], which is used for forming an insulating layer for forming a conductor layer.
[10] The resin composition layer according to any one of [1] to [9], which is used for forming an interlayer insulating layer of a printed wiring board.
[11] The resin composition layer according to any one of [1] to [10], which is for forming an insulating layer having via holes with a top diameter of 35 μm or less.
[12] a support;
A resin sheet comprising a resin composition layer according to any one of [1] to [11] provided on a support.
[13] A printed wiring board comprising an insulating layer formed of a cured product of the resin composition layer according to any one of [1] to [11].
[14] A semiconductor device comprising the printed wiring board according to [13].

According to the present invention, a resin composition layer capable of suppressing the haloing phenomenon and forming an insulating layer capable of forming a via hole with a good shape even if the thickness is thin; a resin containing the resin composition layer; It is possible to provide a sheet; a printed wiring board including a thin insulating layer capable of suppressing the haloing phenomenon and forming a via hole with a good shape; and a semiconductor device including the printed wiring board.

FIG. 1 is a cross-sectional view schematically showing an insulating layer obtained by curing a resin composition layer according to the first embodiment of the present invention together with an inner layer substrate. FIG. 2 is a plan view schematically showing the surface of the insulating layer obtained by curing the resin composition layer according to the first embodiment of the present invention, opposite to the conductor layer. FIG. 3 is a cross-sectional view schematically showing an insulating layer after roughening treatment, which is obtained by curing the resin composition layer according to the first embodiment of the present invention, together with an inner layer substrate. FIG. 4 is a schematic cross-sectional view of a printed wiring board according to a second embodiment of the invention.

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below with reference to embodiments and examples. However, the present invention is not limited to the following embodiments and examples, and can be arbitrarily modified without departing from the scope of the claims of the present invention and their equivalents.

In the following description, the "resin component" of the resin composition refers to non-volatile components contained in the resin composition, excluding the inorganic filler and the colorant.

[1. Overview of resin composition layer]
The resin composition layer of the present invention is a thin resin composition layer having a thickness equal to or less than a predetermined value. The resin composition contained in the resin composition layer of the present invention contains at least one of (A) an epoxy resin, (B) a curing agent, and (C) an average particle diameter of 100 nm or less and a specific surface area of 15 m ² /g or more. and (D) a coloring agent.
Therefore, the resin composition contained in the resin composition layer of the present invention can include both the following first resin composition and second resin composition.

A first resin composition comprising (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.

A second resin composition comprising (A) an epoxy resin, (B) a curing agent, (C) an inorganic filler having a specific surface area of 15 m ² /g or more, and (D) a colorant.

Here, (D) colorants refer to pigments, dyes, and combinations thereof. Pigments and dyes include components that can correspond to the above components (A) to (C), but in the present invention, pigments and dyes are classified as (D) colorants. For example, carbon black having an average particle size of 100 nm or less is classified as a coloring agent (D) rather than a component (C) because it is a pigment. In that sense, the resin composition contained in the resin composition layer of the present invention is a composition containing (D) a coloring agent in combination with components (A) to (C) other than the coloring agent (D). It can be said.

A thin insulating layer can be obtained by using such a resin composition layer. Then, the desired effect of the present invention is that a via hole having a good shape can be formed in the obtained insulating layer, and furthermore, the haloing phenomenon can be suppressed when the insulating layer in which the via hole is formed is subjected to a roughening treatment. Obtainable.

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

The resin composition preferably contains an epoxy resin having two or more epoxy groups in one molecule as (A) the epoxy resin. From the viewpoint of obtaining the desired effects of the present invention remarkably, the ratio of the epoxy resin having two or more epoxy groups in one molecule to 100% by mass of the non-volatile components of the epoxy resin (A) is preferably 50% by mass. % or more, more preferably 60 mass % or more, and particularly preferably 70 mass % or more.

Epoxy resins include epoxy resins that are liquid at a temperature of 20°C (hereinafter sometimes referred to as "liquid epoxy resins") and epoxy resins that are solid at a temperature of 20°C (sometimes referred to as "solid epoxy resins"). There is. As the epoxy resin (A), the resin composition may contain only a liquid epoxy resin or only a solid epoxy resin, but may contain a combination of a liquid epoxy resin and a solid epoxy resin. is preferred. (A) By using a combination of a liquid epoxy resin and a solid epoxy resin as the epoxy resin, the flexibility of the resin composition layer is improved, and the breaking strength of the cured product of the resin composition layer is improved. can.

The liquid epoxy resin is preferably a liquid epoxy resin having two or more epoxy groups per molecule, more preferably an aromatic liquid epoxy resin having two or more epoxy groups per molecule. Here, the “aromatic” epoxy resin means an epoxy resin having an aromatic ring in its molecule.

Examples of liquid epoxy resins include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AF type epoxy resin, naphthalene type epoxy resin, glycidyl ester type epoxy resin, glycidyl amine type epoxy resin, phenol novolak type epoxy resin, ester skeleton. An alicyclic epoxy resin having a Resin is more preferred.

Specific examples of liquid epoxy resins include "HP4032", "HP4032D", and "HP4032SS" (naphthalene-type epoxy resins) manufactured by DIC; 828EL" (bisphenol A type epoxy resin); Mitsubishi Chemical Corporation "jER807", "1750" (bisphenol F type epoxy resin); Mitsubishi Chemical Corporation "jER152" (phenol novolac type epoxy resin); Mitsubishi Chemical Corporation "630", "630LSD" (glycidylamine type epoxy resin); Nippon Steel & Sumikin Chemical Co., Ltd. "ZX1059" (mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin); Nagase ChemteX Co., Ltd. "EX -721" (glycidyl ester type epoxy resin); Daicel's "Celoxide 2021P" (alicyclic epoxy resin having an ester skeleton); Daicel's "PB-3600" (epoxy resin having a butadiene structure); Nippon Steel "ZX1658" and "ZX1658GS" (liquid 1,4-glycidylcyclohexane type epoxy resin) manufactured by Sumikin Chemical Co., Ltd., and the like can be mentioned. These may be used individually by 1 type, and may be used in combination of 2 or more types.

The solid epoxy resin is preferably a solid epoxy resin having 3 or more epoxy groups per molecule, more preferably an aromatic solid epoxy resin having 3 or more epoxy groups per molecule.

Solid epoxy resins include bixylenol type epoxy resin, naphthalene type epoxy resin, naphthalene type tetrafunctional epoxy resin, cresol novolak type epoxy resin, dicyclopentadiene type epoxy resin, trisphenol type epoxy resin, naphthol type epoxy resin, biphenyl type epoxy resin, naphthylene ether type epoxy resin, anthracene type epoxy resin, bisphenol A type epoxy resin, bisphenol AF type epoxy resin, tetraphenylethane type epoxy resin, bixylenol type epoxy resin, naphthalene type epoxy resin, bisphenol AF type epoxy resins and naphthylene ether type epoxy resins are more preferred.

Specific examples of solid epoxy resins include "HP4032H" (naphthalene-type epoxy resin) manufactured by DIC; "HP-4700" and "HP-4710" (naphthalene-type tetrafunctional epoxy resin) manufactured by DIC; "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; DIC's "HP-7200HH", "HP-7200H", "EXA-7311", "EXA-7311-G3", "EXA-7311-G4", "EXA-7311-G4S", "HP6000" ( Naphthylene ether type epoxy resin); Nippon Kayaku Co., Ltd. "EPPN-502H" (trisphenol type epoxy resin); Nippon Kayaku Co., Ltd. "NC7000L" (naphthol novolac type epoxy resin); "NC3000H", "NC3000", "NC3000L", "NC3100" (biphenyl type epoxy resin); Nippon Steel & Sumikin Chemical Co., Ltd. "ESN475V" (naphthalene type epoxy resin); Nippon Steel & Sumikin Chemical Co., Ltd. "ESN485" (naphthol novolac type epoxy resin); "YX4000H", "YX4000", "YL6121" (biphenyl type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "YX4000HK" (bixylenol type epoxy resin) manufactured by Mitsubishi Chemical Corporation; YX8800" (anthracene type epoxy resin); Osaka Gas Chemicals Co., Ltd. "PG-100", "CG-500"; Mitsubishi Chemical Co., Ltd. "YL7760" (bisphenol AF type epoxy resin); Mitsubishi Chemical Co., Ltd. "YL7800 (fluorene type epoxy resin); "jER1010" (solid bisphenol A type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "jER1031S" (tetraphenylethane type epoxy resin) manufactured by Mitsubishi Chemical Corporation; These may be used individually by 1 type, and may be used in combination of 2 or more types.

(A) When a liquid epoxy resin and a solid epoxy resin are used in combination as the epoxy resin, the ratio by mass (liquid epoxy resin: solid epoxy resin) is preferably 1:1 to 1:20. , more preferably 1:2 to 1:15, particularly preferably 1:5 to 1:13. The desired effect of the present invention can be remarkably obtained by setting the amount ratio of the liquid epoxy resin to the solid epoxy resin within such a range. In addition, it usually provides moderate tackiness when used in the form of a resin sheet. In addition, when used in the form of a resin sheet, sufficient flexibility is usually obtained, and handleability is improved. Furthermore, usually, a cured product having sufficient breaking strength can be obtained.

Furthermore, the resin composition preferably contains at least one selected from the group consisting of bixylenol-type epoxy resins and fluorine-containing epoxy resins as (A) the epoxy resin. Some (D) colorants, such as pigments, have the effect of increasing the viscosity of the resin composition. It is possible to suppress the increase in viscosity due to this. Further, a fluorine-containing epoxy resin such as a bisphenol AF type epoxy resin can enhance the dispersibility of the (D) colorant in the resin composition.

(A) The epoxy equivalent of the epoxy resin is preferably 50-5000, more preferably 50-3000, even more preferably 80-2000, still more preferably 110-1000. Within this range, the crosslink density of the cured product of the resin composition layer is sufficient, and an insulating layer with a small surface roughness can be obtained. Epoxy equivalent weight is the mass of resin containing one equivalent of epoxy groups. This epoxy equivalent can be measured according to JIS K7236.

(A) The weight average molecular weight (Mw) of the epoxy resin is preferably 100 to 5000, more preferably 250 to 3000, still more preferably 400 to 1500, from the viewpoint of significantly obtaining the desired effects of the present invention.
The weight average molecular weight of the resin can be measured as a polystyrene-equivalent value by a gel permeation chromatography (GPC) method.

The amount of (A) epoxy resin in the resin composition is preferably 10% by mass with respect to 100% by mass of the resin component in the resin composition from the viewpoint of obtaining an insulating layer exhibiting good mechanical strength and insulation reliability. Above, more preferably 20% by mass or more, still more preferably 30% by mass or more. 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 viewpoint of significantly obtaining the desired effects of the present invention.

[3. (B) component: curing agent]
The resin composition contains a curing agent as the (B) component. (B) Curing agent usually has a function of reacting with (A) epoxy resin to cure the resin composition.

As the (B) curing agent, one having a function of curing the (A) epoxy resin can be used. (B) Curing agents include, for example, active ester curing agents, phenol curing agents, naphthol curing agents, benzoxazine curing agents, cyanate ester curing agents, and carbodiimide curing agents. Moreover, one type of curing agent may be used alone, or two or more types may be used in combination.

A compound having one or more active ester groups in one molecule can be used as the active ester curing agent. Among them, active ester curing agents include phenol esters, thiophenol esters, N-hydroxyamine esters, esters of heterocyclic hydroxy compounds, and the like, and have two or more ester groups per molecule with high reaction activity. Preferred are compounds having The active ester curing agent is preferably obtained by a condensation reaction between a carboxylic acid compound and/or a thiocarboxylic acid compound and a hydroxy compound and/or a thiol compound. In particular, from the viewpoint of improving heat resistance, an active ester curing agent obtained from a carboxylic acid compound and a hydroxy compound is preferred, and an active ester curing agent obtained from a carboxylic acid compound and a phenol compound and/or a naphthol compound is more preferred. .

Examples of carboxylic acid compounds include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, and pyromellitic acid.

Examples of phenol compounds or naphthol compounds include hydroquinone, resorcinol, bisphenol A, bisphenol F, bisphenol S, phenolphthalin, 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, phloroglucine, Benzenetriol, dicyclopentadiene-type diphenol compound, phenol novolak, and the like. Here, the term "dicyclopentadiene-type diphenol compound" refers to a diphenol compound obtained by condensing one molecule of dicyclopentadiene with two molecules of phenol.

Preferred specific examples of the active ester curing agent include an active ester compound containing a dicyclopentadiene type diphenol structure, an active ester compound containing a naphthalene structure, an active ester compound containing an acetylated phenol novolac, and a benzoylated phenol novolac. active ester compounds containing Among them, an active ester compound containing a naphthalene structure and an active ester compound containing a dicyclopentadiene-type diphenol structure are more preferable. "Dicyclopentadiene-type diphenol structure" represents a divalent structural unit consisting of phenylene-dicyclopentylene-phenylene.

Commercially available active ester curing agents include, as active ester compounds containing a dicyclopentadiene type diphenol structure, "EXB9451", "EXB9460", "EXB9460S", "HPC-8000-65T", and "HPC-8000H- 65TM", "EXB-8000L-65TM", "EXB-8150-65T" (manufactured by DIC); "EXB9416-70BK" (manufactured by DIC) as an active ester compound containing a naphthalene structure; including acetylated phenol novolak "DC808" (manufactured by Mitsubishi Chemical Corporation) as an active ester compound; "YLH1026" (manufactured by Mitsubishi Chemical Corporation) as an active ester compound containing a benzoylated phenol novolak; and "DC808" as an active ester curing agent that is an acetylated phenol novolak. " (manufactured by Mitsubishi Chemical Corporation); "YLH1026" (manufactured by Mitsubishi Chemical Corporation), "YLH1030" (manufactured by Mitsubishi Chemical Corporation), and "YLH1048" (manufactured by Mitsubishi Chemical Corporation) as active ester curing agents that are benzoyl compounds of phenol novolak. ; and the like.

From the viewpoint of heat resistance and water resistance, the phenol-based curing agent and naphthol-based curing agent preferably have a novolac structure. From the viewpoint of adhesion to the conductor layer, a nitrogen-containing phenolic curing agent is preferable, and a triazine skeleton-containing phenolic curing agent is more preferable.

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

Specific examples of the benzoxazine-based curing agent include "HFB2006M" manufactured by Showa High Polymer Co., Ltd., and "Pd" and "Fa" manufactured by Shikoku Kasei Kogyo Co., Ltd.

Examples of cyanate ester curing agents include bisphenol A dicyanate, polyphenolcyanate, oligo(3-methylene-1,5-phenylenecyanate), 4,4′-methylenebis(2,6-dimethylphenylcyanate), 4,4 '-ethylidene diphenyl dicyanate, hexafluorobisphenol A dicyanate, 2,2-bis(4-cyanate)phenylpropane, 1,1-bis(4-cyanatophenylmethane), bis(4-cyanate-3,5-dimethyl Bifunctional cyanate resins such as phenyl)methane, 1,3-bis(4-cyanatophenyl-1-(methylethylidene))benzene, bis(4-cyanatophenyl)thioether, and bis(4-cyanatophenyl)ether; polyfunctional cyanate resins derived from phenol novolak, cresol novolak, etc.; prepolymers obtained by partially triazinizing these cyanate resins; and the like. Specific examples of cyanate ester curing agents include "PT30" and "PT60" (phenol novolac type polyfunctional cyanate ester resins), "ULL-950S" (polyfunctional cyanate ester resins) and "BA230" manufactured by Lonza Japan. , "BA230S75" (a prepolymer in which part or all of bisphenol A dicyanate is triazined to form a trimer), and the like.

Specific examples of carbodiimide curing agents include "V-03" and "V-07" manufactured by Nisshinbo Chemical Co., Ltd., and the like.

Among the above-described curing agents (B), active ester curing agents are preferable from the viewpoint of significantly obtaining the desired effects of the present invention. When an active ester-based curing agent is used, the content of the active ester-based curing agent with respect to 100% by mass of the curing agent (B) is preferably 40% by mass or more, more preferably 40% by mass or more, from the viewpoint of significantly obtaining the desired effects of the present invention. is 50% by mass or more, more preferably 60% by mass or more, preferably 75% by mass or less, more preferably 73% by mass or less, and even more preferably 70% by mass or less.

From the viewpoint of significantly obtaining the desired effect of the present invention, the amount of (B) the curing agent in the resin composition is preferably 0.1% by mass or more, or more, relative to 100% by mass of the resin component in the resin composition. It is preferably 0.5% by mass or more, more preferably 1% by mass or more, preferably 30% by mass or less, more preferably 25% by mass or less, and still more preferably 20% by mass or less.

When the number of epoxy groups in (A) the epoxy resin is 1, the number of active groups in (B) the curing agent is preferably 0.1 or more, more preferably 0.2 or more, and still more preferably 0.24 or more. is 2 or less, more preferably 1.5 or less, still more preferably 1 or less, and particularly preferably 0.5 or less. Here, "the number of epoxy groups of (A) the epoxy resin" is the sum of all the values obtained by dividing the mass of the non-volatile component of the (A) epoxy resin present in the resin composition by the epoxy equivalent. In addition, "(B) the number of active groups of the curing agent" is a value obtained by dividing the mass of the non-volatile component of the (B) curing agent present in the resin composition by the active group equivalent and totaling all the values. When the number of active groups of (B) the curing agent is within the above range when the number of epoxy groups of (A) the epoxy resin is 1, the desired effect of the present invention can be remarkably obtained. The heat resistance of the cured product of the material layer is further improved.

[4. (C) Component: Inorganic filler having at least one of an average particle diameter of 100 nm or less and a specific surface area of 15 m ² /g or more]
The resin composition contains an inorganic filler as the (C) component. Since the thermal expansion coefficient of the cured product of the resin composition layer can be reduced by using the inorganic filler, it is possible to obtain an insulating layer in which reflow warpage is suppressed. In addition, the inorganic filler as component (C) has at least one of an average particle size of 100 nm or less and a specific surface area of 15 m ² /g or more. By using the component (C) having at least one of the average particle size and specific surface area within such ranges as an inorganic filler in combination with (A) an epoxy resin, (B) a curing agent and (D) a colorant , it is possible to realize an insulating layer capable of forming a well-shaped via hole.

An inorganic compound is used as the material of the inorganic filler. Examples of inorganic filler materials include silica, alumina, glass, cordierite, silicon oxide, barium sulfate, barium carbonate, talc, clay, mica powder, zinc oxide, hydrotalcite, boehmite, aluminum hydroxide, Magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum nitride, manganese nitride, aluminum borate, strontium carbonate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, zirconium oxide , barium titanate, barium zirconate titanate, barium zirconate, calcium zirconate, zirconium phosphate, and zirconium tungstate phosphate. Among these, silica is particularly suitable. Examples of silica include amorphous silica, fused silica, crystalline silica, synthetic silica, and hollow silica. Moreover, as silica, spherical silica is preferable. An inorganic filler may be used individually by 1 type, and may be used in combination of 2 or more types.

The average particle size of the component (C) is usually 100 nm or less, preferably 90 nm or less, more preferably 80 nm, from the viewpoints of thinning the insulating layer and realizing a favorable shape by enabling control of the shape of the via hole. It is below. Although the lower limit of the average particle diameter is not particularly limited, it is preferably 50 nm or more, 60 nm or more, or 70 nm or more. Examples of commercially available inorganic fillers having such an average particle size include "UFP-30" and "UFP-40" manufactured by Denki Kagaku Kogyo.

The average particle size of the inorganic filler can be measured by a laser diffraction/scattering method based on Mie scattering theory. Specifically, the particle size distribution of the inorganic filler is prepared on a volume basis using a laser diffraction/scattering type particle size distribution measuring device, and the median diameter can be used as the average particle size for measurement. As a measurement sample, one obtained by dispersing an inorganic filler in methyl ethyl ketone by ultrasonic waves can be preferably used. As the laser diffraction/scattering type particle size distribution analyzer, "LA-500" manufactured by Horiba Ltd., "SALD-2200" manufactured by Shimadzu Corporation, etc. can be used.

The specific surface area of component (C) is usually 15 m ² /g or more, preferably 20 m ² /g or more, and particularly preferably 30 m ² /g or more, from the viewpoint of facilitating control of the shape of the via hole and realizing a favorable shape. is. In addition, since the component (C), which has such a large specific surface area, generally has a small particle size, the insulating layer can be made thinner. Although there is no particular upper limit, it is preferably 60 m ² /g or less, 50 m ² /g or less, or 40 m ² /g or less. The specific surface area of the inorganic filler can be measured by the BET method.

The inorganic filler as component (C) is preferably treated with a surface treatment agent from the viewpoint of enhancing moisture resistance and dispersibility. Examples of surface treatment agents include fluorine-containing silane coupling agents, aminosilane coupling agents, epoxysilane coupling agents, mercaptosilane coupling agents, silane coupling agents, alkoxysilanes, organosilazane compounds, and titanate compounds. A coupling agent etc. are mentioned. Moreover, one type of surface treatment agent may be used alone, or two or more types may be used in combination.

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., Shin-Etsu Chemical Industry Co., Ltd. "KBE903" (3-aminopropyltriethoxysilane), Shin-Etsu Chemical Co., Ltd. "KBM573" (N-phenyl-3-aminopropyltrimethoxysilane), Shin-Etsu Chemical Co., Ltd. "SZ-31" ( Hexamethyldisilazane), Shin-Etsu Chemical Co., Ltd. "KBM103" (phenyltrimethoxysilane), Shin-Etsu Chemical Co., Ltd. "KBM-4803" (long-chain epoxy type silane coupling agent), Shin-Etsu Chemical Co., Ltd. "KBM- 7103” (3,3,3-trifluoropropyltrimethoxysilane).

From the viewpoint of improving the dispersibility of the inorganic filler, the degree of surface treatment with the surface treatment agent is preferably within a predetermined range. Specifically, 100 parts by mass of the inorganic filler is preferably surface-treated with 0.2-5 parts by mass of a surface treatment agent, and is surface-treated with 0.2-3 parts by mass. preferably 0.3 parts by mass to 2 parts by mass of the surface treatment.

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. The amount of carbon per unit surface area of the inorganic filler is preferably 0.02 mg/m ² or more, more preferably 0.1 mg/m ² or more, and more preferably 0.2 mg/m ² from the viewpoint of improving the dispersibility of the inorganic filler. The above is more preferable. On the other hand, from the viewpoint of suppressing the melt viscosity of the resin varnish and the melt viscosity in the sheet form, it is preferably 1 mg/m ² or less, more preferably 0.8 mg/m ² or less, and further preferably 0.5 mg/m ² or less. preferable.

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

From the viewpoint of lowering the dielectric loss tangent of the insulating layer, the amount of component (C) in the resin composition is preferably 30% by mass or more, more preferably 35% by mass, based on 100% by mass of non-volatile components in the resin composition. above, more preferably 40% by mass or more. In addition, conventionally, when the layer of the resin composition containing such a large amount of inorganic filler is thin, it is difficult to improve the shape of the via hole. When the amount of the material is 50% by mass or more, it is particularly difficult to form well-shaped via holes. Therefore, from the viewpoint of effectively utilizing the advantage of the present invention that it is possible to form a well-shaped via hole, which has been particularly difficult in the past, the amount of component (C) relative to 100% by mass of non-volatile components in the resin composition is is preferably 50% by mass or more, particularly preferably 55% by mass or more. In addition, the upper limit of the amount of component (C) with respect to 100% by mass of non-volatile components in the resin composition is preferably 90% by mass or less, more preferably 85% by mass or less, and even more preferably, from the viewpoint of increasing the mechanical strength of the insulating layer. is 80% by mass or less, or 75% by mass or less. Furthermore, the amount of component (C) is particularly preferably 60% by mass or less with respect to 100% by mass of non-volatile components in the resin composition, since the shape of the via hole can be made particularly good.

[5. (D) Component: Colorant]
The resin composition contains a colorant as component (D). Since the resin composition contains the (D) colorant, the resin composition layer usually has the color of the (D) colorant.

As the coloring agent (D), an achromatic coloring agent or a chromatic coloring agent may be used. Among them, (D) the coloring agent is preferably a non-white coloring agent from the viewpoint of significantly obtaining the desired effects of the present invention. Among them, the (D) colorant is preferably a black or chromatic colorant, more preferably a black, blue or green colorant, and more preferably a black or blue colorant, from the viewpoint of particularly effectively suppressing the haloing phenomenon. Colorants are more preferred.

As the coloring agent (D), a pigment may be used, a dye may be used, or a combination of a pigment and a dye may be used. Among them, pigments are preferable as (D) the colorant. Since the pigment has a high coloring ability, it can effectively color the resin composition layer. Therefore, the pigment can enhance the light-absorbing ability of the resin composition layer, so that the haloing phenomenon can be particularly effectively suppressed.

Examples of pigments include blue pigments such as phthalocyanine pigments, anthraquinone pigments, and dioxazine pigments. Examples of yellow pigments include monoazo pigments, disazo pigments, condensed azo pigments, benzimidazolone pigments, isoindolinone pigments, and anthraquinone pigments. Examples of red pigments include monoazo pigments, disazo pigments, azo lake pigments, benzimidazolone pigments, perylene pigments, diketopyrrolopyrrole pigments, condensed azo pigments, anthraquinone pigments, and quinacridone pigments. mentioned. Examples of black pigments include carbon black and graphite. Examples of green pigments include phthalocyanine pigments.

The pigment usually does not dissolve in (A) the epoxy resin in the resin composition and exists as particles. The average particle size of the pigment particles is preferably within the same range as the average particle size range of the component (C). Moreover, the specific surface area of the pigment particles is preferably within the same range as the range of the specific surface area of the component (C). As a result, the insulating layer can be made thinner, and the shape of the via hole can be controlled to achieve a favorable shape. The average particle size and specific surface area of the pigment can be measured in the same manner as for component (C).

(D) Colorants may be used singly or in combination of two or more at any ratio.

The amount of the (D) colorant in the resin composition is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and particularly preferably 1% by mass with respect to 100% by mass of non-volatile components in the resin composition. 0% by mass or more, preferably 5% by mass or less, more preferably 4% by mass or less, and particularly preferably 3% by mass or less. (D) When the amount of the coloring agent is within the above range, the haloing phenomenon can be effectively suppressed.

[6. (E) component: thermoplastic resin]
The resin composition may further contain (E) a thermoplastic resin as an optional component in addition to the components described above.

Examples of thermoplastic resins as component (E) include phenoxy resins, polyvinyl acetal resins, polyolefin resins, polybutadiene resins, polyimide resins, polyamideimide resins, polyetherimide resins, polysulfone resins, polyethersulfone resins, and polyphenylene ether resins. , polycarbonate resins, polyetheretherketone resins, polyester resins, and the like. Among them, the phenoxy resin is preferable from the viewpoint of obtaining the desired effects of the present invention remarkably and from the viewpoint of obtaining an insulating layer having a small surface roughness and particularly excellent adhesion to the conductor layer. Further, the thermoplastic resin may be used singly or in combination of two or more.

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

Specific examples of phenoxy resins include Mitsubishi Chemical's "1256" and "4250" (both bisphenol A skeleton-containing phenoxy resins); Mitsubishi Chemical's "YX8100" (bisphenol S skeleton-containing phenoxy resin); "YX6954" (bisphenolacetophenone skeleton-containing phenoxy resin) manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.; "FX280" and "FX293" manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.; "YL7769BH30", "YL6794", "YL7213", "YL7290" and "YL7482";

Examples of polyvinyl acetal resins include polyvinyl formal resins and polyvinyl butyral resins, and polyvinyl butyral resins are preferred. Specific examples of polyvinyl acetal resins include Denka Butyral 4000-2, Denka Butyral 5000-A, Denka Butyral 6000-C, and Denka Butyral 6000-EP manufactured by Sekisui Chemical Co., Ltd. S-LEC BH series, BX series (eg BX-5Z), KS series (eg KS-1), BL series, BM series;

Specific examples of the polyimide resin include "Ricacoat SN20" and "Ricacoat PN20" manufactured by Shin Nippon Rika. Specific examples of polyimide resins also include linear polyimides obtained by reacting bifunctional hydroxyl group-terminated polybutadiene, diisocyanate compounds and tetrabasic acid anhydrides (polyimides described in JP-A-2006-37083), and polysiloxane skeletons. Examples include modified polyimides such as polyimide containing (polyimides described in JP-A-2002-12667 and JP-A-2000-319386).

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

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

Specific examples of the polyphenylene ether resin include oligophenylene ether/styrene resin "OPE-2St 1200" manufactured by Mitsubishi Gas Chemical Company, Inc., and the like.

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

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

(E) When using a thermoplastic resin, the amount of the (E) thermoplastic resin in the resin composition is, from the viewpoint of significantly obtaining the desired effect of the present invention, relative to 100% by mass of the resin component in the resin composition is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, still more preferably 1% by mass or more, preferably 15% by mass or less, more preferably 12% by mass or less, further preferably 10% by mass or less. % by mass or less.

[7. (F) Component: Curing accelerator]
The resin composition may further contain (F) a curing accelerator as an optional component in addition to the components described above.

Examples of curing accelerators include phosphorus-based curing accelerators, amine-based curing accelerators, imidazole-based curing accelerators, guanidine-based curing accelerators, metal-based curing accelerators, and the like. Among them, phosphorus curing accelerators, amine curing accelerators, imidazole curing accelerators, and metallic curing accelerators are preferred, and amine curing accelerators, imidazole curing accelerators, and metallic curing accelerators are more preferred. The curing accelerator may be used singly or in combination of two or more.

Phosphorus curing accelerators include, for example, triphenylphosphine, phosphonium borate compounds, tetraphenylphosphonium tetraphenylborate, n-butylphosphonium tetraphenylborate, tetrabutylphosphonium decanoate, (4-methylphenyl)triphenylphosphonium thiocyanate. , tetraphenylphosphonium thiocyanate, and butyltriphenylphosphonium thiocyanate, and triphenylphosphine and tetrabutylphosphonium decanoate are preferred.

Examples of amine curing accelerators include trialkylamines such as triethylamine and tributylamine, 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, 1,8-diazabicyclo (5,4,0)-undecene and the like, with 4-dimethylaminopyridine and 1,8-diazabicyclo(5,4,0)-undecene being preferred.

Examples of imidazole curing accelerators include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate, 1-cyanoethyl- 2-phenylimidazolium trimellitate, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-undecyl imidazolyl-(1′)]-ethyl-s-triazine, 2,4-diamino-6-[2′-ethyl-4′-methylimidazolyl-(1′)]-ethyl-s-triazine, 2,4- Diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanurate, 2-phenylimidazole isocyanurate, 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 the like, and adducts of imidazole compounds and epoxy resins, with 2-ethyl-4-methylimidazole and 1-benzyl-2-phenylimidazole being preferred.

As the imidazole-based curing accelerator, a commercially available product may be used, and examples thereof include "P200-H50" manufactured by Mitsubishi Chemical Corporation.

Guanidine curing accelerators include, for example, dicyandiamide, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, 1-(o-tolyl)guanidine, dimethylguanidine, diphenylguanidine, trimethylguanidine, Tetramethylguanidine, Pentamethylguanidine, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7-methyl-1,5,7-triazabicyclo[4.4.0] Dec-5-ene, 1-methylbiguanide, 1-ethylbiguanide, 1-n-butylbiguanide, 1-n-octadecylbiguanide, 1,1-dimethylbiguanide, 1,1-diethylbiguanide, 1-cyclohexylbiguanide, 1 -allylbiguanide, 1-phenylbiguanide, 1-(o-tolyl)biguanide and the like, with dicyandiamide and 1,5,7-triazabicyclo[4.4.0]dec-5-ene being preferred.

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

(F) When using a curing accelerator, the amount of (F) curing accelerator in the resin composition is, from the viewpoint of significantly obtaining the desired effect of the present invention, relative to 100% by mass of the resin component of the resin composition , preferably 0.01% by mass or more, more preferably 0.05% by mass or more, still more preferably 0.1% by mass or more, preferably 3% by mass or less, more preferably 2% by mass or less, further preferably It is 1.5% by mass or less.

[8. (G) Component: optional additive]
The resin composition may further contain optional additives as optional components in addition to the components described above. Such additives include, for example, organic fillers; resin additives such as flame retardants, thickeners, antifoaming agents, leveling agents, adhesion imparting agents; and the like. These additives may be used singly or in combination of two or more.

[9. Thickness of resin composition layer]
The resin composition layer is a layer formed of the resin composition described above and has a thickness equal to or less than a predetermined value. A specific thickness of the resin composition layer is usually 15 μm or less, preferably 14 μm or less, more preferably 12 μm or less. Conventionally, the thickness of a resin composition layer for forming an insulating layer of a printed wiring board was generally thicker than this. In contrast, when the inventor of the present invention thinned a resin composition layer having a general composition as described above, with such a thin resin composition layer, it became difficult to control the shape of the via hole, and roughening treatment It was found that a hitherto unknown problem of occurrence of the subsequent haloing phenomenon occurs. From the viewpoint of solving such a new problem and contributing to the thinning of the printed wiring board, the resin composition layer of the present invention is provided thinly as described above. The lower limit of the thickness of the resin composition layer is arbitrary, and can be, for example, 1 μm or more and 3 μm or more.

[10. Properties of Resin Composition Layer]
By curing the resin composition layer of the present invention, a thin insulating layer formed of the cured resin composition layer can be obtained. A well-shaped via hole can be formed in this insulating layer. Further, when a via hole is formed in this insulating layer and a roughening treatment is performed, the haloing phenomenon can be suppressed. These effects will be described below with reference to the drawings.

FIG. 1 is a cross-sectional view schematically showing an insulating layer 100 obtained by curing a resin composition layer according to the first embodiment of the present invention together with an inner layer substrate 200. FIG. 1 shows a cross section of insulating layer 100 taken along a plane passing through center 120C of bottom 120 of via hole 110 and parallel to the thickness direction of insulating layer 100. FIG.
As shown in FIG. 1, the insulating layer 100 according to the first embodiment of the present invention is a layer obtained by curing a resin composition layer formed on an inner layer substrate 200 including a conductor layer 210, It consists of the hardened|cured material of the said resin composition layer. A via hole 110 is formed in the insulating layer 100 . Via hole 110 generally has a larger diameter closer to surface 100U of insulating layer 100 opposite conductor layer 210 and a smaller diameter closer to conductor layer 210. Ideally, via hole 110 is formed in a forward tapered shape. It is formed in a columnar shape having a constant diameter in the thickness direction of 100 . The via hole 110 is usually formed by irradiating the surface 100U of the insulating layer 100 opposite to the conductor layer 210 with a laser beam to partially remove the insulating layer 100 .

The bottom of the via hole 110 on the side of the conductor layer 210 is appropriately called a “via bottom” and denoted by reference numeral 120 . The diameter of the via bottom 120 is called a bottom diameter Lb. An opening formed on the side of the via hole 110 opposite to the conductor layer 210 is appropriately called a “via top” and denoted by reference numeral 130 . The diameter of the via top 130 is called a top diameter Lt. Generally, the via bottom 120 and the via top 130 are circular when viewed in the thickness direction of the insulating layer 100, but they may be oval. When the planar shapes of the via bottom 120 and the via top 130 are elliptical, the bottom diameter Lb and the top diameter Lt respectively represent the longer diameters of the elliptical shapes.

At this time, the closer to 100% the taper ratio Lb/Lt (%) obtained by dividing the bottom diameter Lb by the top diameter Lt, the better the shape of the via hole 110 . By using the resin composition layer of the present invention, it is possible to easily control the shape of via hole 110, and thus via hole 110 having a taper ratio Lb/Lt close to 100% can be realized.

For example, the resin composition layer is heated at 100° C. for 30 minutes, and then heated at 180° C. for 30 minutes to cure. Equation 2, when a via hole 110 having a top diameter Lt of 30 μm±2 μm is formed by irradiating CO ₂ laser light under burst mode (10 kHz) conditions, the taper ratio Lb/Lt of the via hole 110 is preferably 75%. ~100%, more preferably 80% to 100%, particularly preferably 85% to 100%.

The taper ratio Lb/Lt of via hole 110 can be calculated from bottom diameter Lb and top diameter Lt of via hole 110 . In addition, the bottom diameter Lb and the top diameter Lt of the via hole 110 are obtained by using FIB (focused ion beam) to measure the insulating layer 100 so that a cross section parallel to the thickness direction of the insulating layer 100 and passing through the center 120C of the via bottom 120 appears. It can be measured by observing the cross section with an electron microscope after shaving as described above.

FIG. 2 schematically shows a surface 100U of the insulating layer 100 obtained by curing the resin composition layer according to the first embodiment of the present invention, opposite to the conductor layer 210 (not shown in FIG. 2). is a plan view shown in FIG.
As shown in FIG. 2 , when looking at the insulating layer 100 with the via hole 110 formed therein, a discolored portion 140 where the insulating layer 100 is discolored may be observed around the via hole 110 . This discolored portion 140 may be formed by deterioration of the resin during formation of the via hole 110 , and is normally formed continuously from the via hole 110 . Moreover, in many cases, the discolored portion 140 is a whitened portion.

FIG. 3 is a cross-sectional view schematically showing the insulating layer 100 after roughening treatment, which is obtained by curing the resin composition layer according to the first embodiment of the present invention, together with the inner layer substrate 200 . 3 shows a cross section of insulating layer 100 taken along a plane passing through center 120C of via bottom 120 of via hole 110 and parallel to the thickness direction of insulating layer 100. FIG.
As shown in FIG. 3, when the insulating layer 100 having the via hole 110 formed therein is roughened, a haloing phenomenon occurs, the insulating layer 100 at the discolored portion 140 is separated from the conductive layer 210, and the edge of the via bottom 120 is peeled off. A gap 160 continuous from 150 may be formed. The gap 160 is usually formed by eroding the discolored portion 140 during the roughening process.

By using the resin composition layer of the present invention, the haloing phenomenon can be suppressed. Therefore, the separation of the insulating layer 100 from the conductor layer 210 can be suppressed, so that the size of the gap 160 can be reduced.

The edge 150 of the via bottom 120 corresponds to the inner edge of the gap 160 . Therefore, the distance Wb from the edge 150 of the via bottom 120 to the edge 170 on the outer peripheral side of the gap 160 (that is, the edge on the far side from the center 120C of the via bottom 120) is the size of the gap 160 in the in-plane direction. Equivalent to. Here, the in-plane direction means a direction perpendicular to the thickness direction of the insulating layer 100 . Further, in the following description, the distance Wb may be referred to as a haloing distance Wb of the via hole 110 from the edge 150 of the via bottom 120 . The degree of suppression of the haloing phenomenon can be evaluated by the haloing distance Wb from the edge 150 of the via bottom 120 . Specifically, it can be evaluated that the smaller the haloing distance Wb from the edge 150 of the via bottom 120 is, the more effectively the haloing phenomenon can be suppressed.

For example, the resin composition layer is heated at 100° C. for 30 minutes, and then heated at 180° C. for 30 minutes to cure. Formula 2: A via hole 110 having a top diameter Lt of 30 μm±2 μm is formed by irradiating CO ₂ laser light under burst mode (10 kHz) conditions. After that, it is immersed in a swelling solution at 60°C for 10 minutes, then in an oxidizing agent solution at 80°C for 20 minutes, then in a neutralizing solution at 40°C for 5 minutes, and then dried at 80°C for 15 minutes. By using the resin composition layer of the present invention, the haloing distance Wb from the edge 150 of the via bottom 120 of the via hole 110 of the insulating layer 100 thus obtained is preferably 10 μm or less, more preferably 5 μm or less, and further It is preferably 4 μm or less, particularly preferably 3 μm or less.

The haloing distance Wb from the edge 150 of the via bottom 120 is measured by using an FIB (focused ion beam) to cut the insulating layer 100 so that a cross section parallel to the thickness direction of the insulating layer 100 and passing through the center 120C of the via bottom 120 appears. It can be measured by observing the cross section with an electron microscope after shaving it out.

In addition, by using the resin composition layer of the present invention, the shape of via hole 110 in insulating layer 100 before roughening treatment can be easily controlled. The shape can be easily controlled. Therefore, even after the roughening process, the shape of the via hole 110 can be made as good as before the roughening process. Therefore, by using the resin composition layer of the present invention, via holes 110 having a taper ratio Lb/Lt close to 100% can be realized in the insulating layer after the roughening treatment.

For example, the resin composition layer is heated at 100° C. for 30 minutes, and then heated at 180° C. for 30 minutes to cure. Formula 2: A via hole 110 having a top diameter Lt of 30 μm±2 μm is formed by irradiating CO ₂ laser light under burst mode (10 kHz) conditions. After that, it is immersed in a swelling solution at 60°C for 10 minutes, then in an oxidizing agent solution at 80°C for 20 minutes, then in a neutralizing solution at 40°C for 5 minutes, and then dried at 80°C for 15 minutes. By using the resin composition layer of the present invention, the taper ratio Lb/Lt of the via hole 110 formed in the insulating layer 100 thus obtained is preferably 76% to 100%, more preferably 80% to 100%. %, particularly preferably 85% to 100%.

The taper ratio Lb/Lt of via hole 110 can be calculated from bottom diameter Lb and top diameter Lt of via hole 110 . In addition, the bottom diameter Lb and the top diameter Lt of the via hole 110 are obtained by using FIB (focused ion beam) to measure the insulating layer 100 so that a cross section parallel to the thickness direction of the insulating layer 100 and passing through the center 120C of the via bottom 120 appears. It can be measured by observing the cross section with an electron microscope after shaving as described above.

Furthermore, according to the study of the present inventor, generally, the larger the diameter of the via hole 110, the larger the size of the discolored portion 140 tends to be, and thus the size of the gap portion 160 tends to be larger. . Therefore, the degree of suppression of the haloing phenomenon can be evaluated by the ratio of the size of the gap 160 to the diameter of the via hole 110 . For example, the haloing ratio Hb to the bottom radius Lb/2 of the via hole 110 can be used for evaluation. Here, the bottom radius Lb/2 of the via hole 110 means the radius of the via bottom 120 of the via hole 110 . The haloing ratio Hb to the bottom radius Lb/2 of the via hole 110 is a ratio obtained by dividing the haloing distance Wb of the via bottom 120 from the edge 150 by the bottom radius Lb/2 of the via hole 110 . The smaller the haloing ratio Hb with respect to the bottom radius Lb/2 of the via hole 110, the more effectively the haloing phenomenon was suppressed.

For example, the resin composition layer is heated at 100° C. for 30 minutes, and then heated at 180° C. for 30 minutes to cure. Formula 2: A via hole 110 having a top diameter Lt of 30 μm±2 μm is formed by irradiating CO ₂ laser light under burst mode (10 kHz) conditions. After that, it is immersed in a swelling solution at 60°C for 10 minutes, then in an oxidizing agent solution at 80°C for 20 minutes, then in a neutralizing solution at 40°C for 5 minutes, and then dried at 80°C for 15 minutes. When the resin composition layer of the present invention is used, the haloing ratio Hb with respect to the bottom radius Lb/2 of the via hole 110 formed in the insulating layer 100 thus obtained is preferably 50% or less, more preferably 40%. % or less, more preferably 30% or less.

The haloing ratio Hb to the bottom radius Lb/2 of the via hole 110 can be calculated from the bottom radius Lb of the via hole 110 and the haloing distance Wb of the via hole 110 from the edge 150 of the via bottom 120 .

Furthermore, normally, the formation of the discolored portion 140 during the formation of the via hole 110 can be suppressed by using the resin composition layer of the present invention. Therefore, as shown in FIG. 2, the size of the discolored portion 140 can be reduced, and ideally the discolored portion 140 can be eliminated. The size of discolored portion 140 can be evaluated by haloing distance Wt from edge 180 of via top 130 of via hole 110 .

The edge 180 of the via top 130 corresponds to the inner edge of the discolored portion 140 . The haloing distance Wt from the edge 180 of the via top 130 represents the distance from the edge 180 of the via top 130 to the outer edge 190 of the discolored portion 140 . It can be evaluated that the smaller the haloing distance Wt from the edge 180 of the via top 130, the more effectively the formation of the discolored portion 140 can be suppressed.

For example, the resin composition layer is heated at 100° C. for 30 minutes, and then heated at 180° C. for 30 minutes to cure. Formula 2: When a via hole 110 having a top diameter Lt of 30 μm±2 μm is formed by irradiating a CO ₂ laser beam under burst mode (10 kHz) conditions, the haloing distance Wt from the edge 180 of the via top 130 is preferably can be 6 μm or less, more preferably 5 μm or less.

A haloing distance Wt from the edge 180 of the via top 130 can be measured by observation with an optical microscope.

Further, according to the study of the present inventor, it has been found that generally, the larger the diameter of the via hole 110, the larger the size of the discolored portion 140 tends to be. Therefore, the degree of suppression of the formation of the discolored portion 140 can be evaluated by the ratio of the size of the discolored portion 140 to the diameter of the via hole 110 . For example, it can be evaluated by the haloing ratio Ht to the top radius Lt/2 of the via hole 110 . Here, the top radius Lt/2 of via hole 110 means the radius of via top 130 of via hole 110 . The haloing ratio Ht to the top radius Lt/2 of the via hole 110 is a ratio obtained by dividing the haloing distance Wt of the via top 130 from the edge 180 by the top radius Lt/2 of the via hole 110 . The smaller the haloing ratio Ht with respect to the top radius Lt/2 of the via hole 110, the more effectively the formation of the discolored portion 140 can be suppressed.

For example, the resin composition layer is heated at 100° C. for 30 minutes, and then heated at 180° C. for 30 minutes to cure. Equation 2, when a via hole 110 having a top diameter Lt of 30 μm±2 μm is formed by irradiating a CO ₂ laser beam under burst mode (10 kHz) conditions, the haloing ratio Ht with respect to the top radius Lt/2 of the via hole 110 is It is preferably 45% or less, more preferably 40% or less, still more preferably 35% or less.

The haloing ratio Ht to the top radius Lt/2 of the via hole 110 can be calculated from the top diameter Lt of the via hole 110 and the haloing distance Wt of the via hole 110 from the edge 180 of the via top 130 .

In the process of manufacturing a printed wiring board, via hole 110 is normally formed without another conductor layer (not shown) provided on surface 100U of insulating layer 100 opposite conductor layer 210 . Therefore, if the manufacturing process of the printed wiring board is known, the structure in which the via bottom 120 is on the conductor layer 210 side and the via top 130 is opened on the opposite side of the conductor layer 210 can be clearly recognized. However, the completed printed wiring board may have conductor layers on both sides of the insulating layer 100 . In this case, it may be difficult to distinguish between the via bottom 120 and the via top 130 depending on the positional relationship with the conductor layer. However, the top diameter Lt of the via top 130 is usually larger than the bottom diameter Lb of the via bottom 120 . Therefore, in the above case, it is possible to distinguish between the via bottom 120 and the via top 130 according to the size of the diameter.

The present inventor presumes the mechanism by which the resin composition layer of the present invention achieves the effects described above as follows. However, the technical scope of the present invention is not limited by the mechanism described below.

Generally, when forming the via hole 110, energy such as heat or light is applied to a portion of the insulating layer 100 where the via hole 110 is to be formed. Part of the energy applied at this time is transmitted to the periphery of the portion where the via hole 110 is to be formed, possibly degrading the resin. When the resin deteriorates in this way, the insulating layer is discolored at the deteriorated portion and becomes susceptible to corrosion. Therefore, erosion during the roughening treatment may cause a haloing phenomenon, and the insulating layer may separate from the conductor layer. In contrast, in the resin composition layer of the present invention, the resin composition can effectively absorb energy due to the action of (D) the colorant. In particular, due to the action of (D) the colorant, the resin composition has greatly improved absorption performance for a wide variety of industrially used laser beams. Therefore, the applied energy is efficiently absorbed by the resin composition, and the energy delivered to the via bottom 120 can be suppressed from becoming excessive, so that the deterioration of the resin around the via bottom 120 can be suppressed. Therefore, the haloing phenomenon can be suppressed in the insulating layer 100 obtained using the resin composition layer of the present invention.

Moreover, as can be seen from the description of the average particle size and specific surface area, the particle size of the component (C) contained in the resin composition layer is usually small. Since the particle size of the component (C) is small, the energy applied to the insulating layer 100 can be transmitted well in the thickness direction of the insulating layer 100 . For example, when heat energy or light energy is applied to the surface 100U of the insulating layer 100, the energy can be effectively transmitted in the thickness direction without causing large diffusion in the in-plane direction. Therefore, the via hole 110 having a large taper rate can be easily formed, and the shape of the via hole 110 can be improved.

[11. Application of resin composition layer]
The resin composition layer of the present invention can be suitably used as a resin composition layer for insulation. Specifically, the resin composition layer of the present invention is preferably 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). Furthermore, it can be used more preferably 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). Further, the resin composition layer of the present invention is a resin composition layer for forming a conductor layer (including a rewiring layer) on an insulating layer (a resin composition layer for forming a conductor layer). It can be suitably used as a resin composition layer for forming an insulating layer).

In particular, from the viewpoint of effectively utilizing the advantages of being able to suppress the haloing phenomenon and being able to form well-shaped via holes, the resin composition layer is used to form an insulating layer having via holes. It is suitable as a resin composition layer (resin composition layer for forming an insulating layer having via holes), and particularly suitable as a resin composition layer for forming an insulating layer having via holes with a top diameter of 35 μm or less.

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

Examples of the support include a film made of a plastic material, a metal foil, and a release paper, and a film made of a plastic material and a metal foil are preferable.

When a film made of a plastic material is used as the support, examples of the plastic material include polyethylene terephthalate (hereinafter sometimes abbreviated as "PET") and polyethylene naphthalate (hereinafter sometimes abbreviated as "PEN"). ) and other polyesters, polycarbonate (hereinafter sometimes abbreviated as "PC"), acrylic polymers such as polymethyl methacrylate (hereinafter sometimes abbreviated as "PMMA"), cyclic polyolefins, triacetyl cellulose (hereinafter may be abbreviated as "TAC"), polyether sulfide (hereinafter sometimes abbreviated as "PES"), polyether ketone, polyimide, and the like. Among them, polyethylene terephthalate and polyethylene naphthalate are preferable, and inexpensive polyethylene terephthalate is particularly preferable.

When a metal foil is used as the support, examples of the metal foil include copper foil and aluminum foil, with copper foil being preferred. As the copper foil, a foil made of a single metal of copper may be used, and a foil made of an alloy of copper and other metals (for example, tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.) may be used. may be used.

The support may be subjected to matte treatment, corona treatment, antistatic treatment, or the like on the surface to be bonded to the resin composition layer.

Further, as the support, a support with a release layer having a release layer on the surface to be bonded to the resin composition layer may be used. The release agent used in the release layer of the release layer-attached support includes, for example, one or more release agents selected from the group consisting of alkyd resins, polyolefin resins, urethane resins, and silicone resins. . As the support with a release layer, a commercially available product may be used, for example, "SK-1" manufactured by Lintec Co., Ltd., "SK-1", " AL-5", "AL-7"; "Lumirror T60" manufactured by Toray Industries, Inc.; "Purex" manufactured by Teijin; "Unipeel" manufactured by Unitika;

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 release layer-attached support is used, the thickness of the release layer-attached support as a whole is preferably within the above range.

Moreover, the resin sheet may contain arbitrary layers other than the support and the resin composition layer, if necessary. Examples of such an optional layer include a protective film conforming to the support provided on the surface of the resin composition layer not bonded to the support (that is, the surface opposite to the support). be done. Although the thickness of the protective film is not particularly limited, it is, for example, 1 μm to 40 μm. The protective film can prevent dust from adhering to the surface of the resin composition layer and scratches on the surface of the resin composition layer.

For the resin sheet, for example, a resin varnish containing an organic solvent and a resin composition is prepared, the resin varnish is applied onto a support using a coating device such as a die coater, and dried to form a resin composition layer. It can be manufactured by forming.

Examples of organic solvents include ketone solvents such as acetone, methyl ethyl ketone and cyclohexanone; acetic ester solvents such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate and carbitol acetate; carbitols such as cellosolve and butyl carbitol. Solvents; aromatic hydrocarbon solvents such as toluene and xylene; amide solvents such as dimethylformamide, dimethylacetamide (DMAc) and N-methylpyrrolidone; An organic solvent may be used individually by 1 type, and may be used in combination of 2 or more types.

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

The resin sheet can be wound into a roll and stored. When the resin sheet has a protective film, it can be used by peeling off the protective film.

[13. Printed wiring board]
The printed wiring board of the present invention includes an insulating layer formed of a cured thin resin composition layer as described above. In addition, this insulating layer can suppress the haloing phenomenon and form a via hole with a good shape. Therefore, by using the resin composition layer of the present invention, it is possible to reduce the thickness of the printed wiring board while suppressing the deterioration of the performance due to the haloing phenomenon or the deterioration of the shape of the via hole.

A via hole is usually provided to conduct conductor layers provided on both sides of an insulating layer having the via hole. Therefore, the printed wiring board of the present invention usually includes a first conductor layer, a second conductor layer, and an insulating layer formed between the first conductor layer and the second conductor layer. A via hole is formed in the insulating layer, and the first conductor layer and the second conductor layer can be electrically connected through the via hole.

By utilizing the advantages of the resin composition layer that it is possible to suppress the haloing phenomenon and to form via holes of good shape, it is possible to realize a specific printed wiring board that has been difficult to achieve in the past. can. This specific printed wiring board is a printed wiring board comprising a first conductor layer, a second conductor layer, and an insulating layer formed between the first conductor layer and the second conductor layer, All of the following requirements (i) to (v) are satisfied.
(i) The thickness of the insulating layer is 15 μm or less.
(ii) The insulating layer has a via hole with a top diameter of 35 μm or less.
(iii) The via hole has a taper ratio of 80% or more.
(iv) The haloing distance from the edge of the via bottom of the via hole is 5 μm or less.
(v) The haloing ratio to the bottom radius of the via hole is 35% or less.

The specific printed wiring board will be described below with reference to the drawings. FIG. 4 is a schematic cross-sectional view of a printed wiring board 300 according to the second embodiment of the invention. 4 shows a cross section of printed wiring board 300 taken along a plane passing through center 120C of via bottom 120 of via hole 110 and parallel to the thickness direction of insulating layer 100. FIG. Also, in FIG. 4, parts corresponding to the elements described in FIGS. 1 to 3 are denoted by the same reference numerals as used in FIGS.

As shown in FIG. 4, the specific printed wiring board 300 according to the second embodiment of the present invention includes a first conductor layer 210, a second conductor layer 220, and the first conductor layer 210 and the second conductor It includes an insulating layer 100 formed between it and layer 220 . A via hole 110 is formed in the insulating layer 100 . Also, the second conductor layer 220 is usually provided after the via hole 110 is formed. Therefore, the second conductor layer 220 is normally formed not only on the surface 100U of the insulating layer 100 but also in the via hole 110, and the first conductor layer 210 and the second conductor layer 220 are electrically connected through the via hole 110. are doing.

The thickness T of insulating layer 100 included in specific printed wiring board 300 is usually 15 μm or less, preferably 12 μm or less, more preferably 10 μm or less, and particularly preferably 5 μm or less. Since the specific printed wiring board 300 has such a thin insulating layer 100, the thickness of the specific printed wiring board 300 itself can be reduced. 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 viewpoint of enhancing the insulating performance of the insulating layer 100 . Here, the thickness T of the insulating layer 100 represents the dimension of the insulating layer 100 between the first conductor layer 210 and the second conductor layer 220. It does not represent the dimension of the insulating layer 100 at the position where there is no . The thickness T of the insulating layer 100 usually matches the distance between the main surface 210U of the first conductor layer 210 and the main surface 220D of the second conductor layer 220 facing each other with the insulating layer 100 interposed therebetween, and , corresponds to the depth of the via hole 110 .

The top diameter Lt of via hole 110 of insulating layer 100 included in specific printed wiring board 300 is usually 35 μm or less, preferably 33 μm or less, and particularly preferably 32 μm or less. Since the specific printed wiring board 300 includes the insulating layer 100 having the via hole 110 with the small top diameter Lt, it is possible to promote miniaturization of the wiring including the first conductor layer 210 and the second conductor layer 220. can. The lower limit of the top diameter Lt of via hole 110 is preferably 3 μm or more, more preferably 10 μm or more, and particularly preferably 15 μm or more, from the viewpoint of facilitating formation of via hole 110 .

The taper ratio Lb/Lt (%) of via hole 110 in insulating layer 100 included in specific printed wiring board 300 is usually 80% to 100%. The specific printed wiring board 300 includes the insulating layer 100 having the well-shaped via holes 110 with a high taper ratio Lb/Lt. Therefore, specific printed wiring board 300 can generally improve the reliability of conduction between first conductor layer 210 and second conductor layer 220 .

The haloing distance Wb from the edge 150 of the via bottom 120 of the via hole 110 of the insulating layer 100 included in the specific printed wiring board 300 is usually 5 μm or less, preferably 4 μm or less, more preferably 3 μm or less. The specific printed wiring board 300 has such a small haloing distance Wb from the edge 150 of the via bottom 120 , so that the peeling of the insulating layer 100 from the first conductor layer 210 is small. Therefore, specific printed wiring board 300 can generally improve the reliability of conduction between first conductor layer 210 and second conductor layer 220 .

The haloing ratio Hb to the bottom radius Lb/2 of via hole 110 of insulating layer 100 included in specific printed wiring board 300 is usually 35% or less, preferably 30% or less, and more preferably 25% or less. The specific printed wiring board 300 has such a small haloing ratio Hb with respect to the bottom radius Lb/2. A specific printed wiring board 300 including an insulating layer 100 having such a small haloing ratio Hb can generally improve the reliability of conduction between the first conductor layer 210 and the second conductor layer 220 . The lower limit of the haloing ratio Hb to the bottom radius Lb/2 is ideally zero, but is usually 5% or more.

The number of via holes 110 included in insulating layer 100 included in specific printed wiring board 300 may be one, or two or more. When the insulating layer 100 has two or more via holes 110, some of them may satisfy requirements (ii) to (v), but it is preferable that all of them satisfy requirements (ii) to (v). . Also, for example, five via holes 110 randomly selected from the insulating layer 100 preferably satisfy requirements (ii) to (v) on average.

The specific printed wiring board 300 described above can be realized by forming the insulating layer 100 from the cured product of the resin composition layer of the present invention. At this time, the planar shape of via bottom 120 and via top 130 of via hole 110 formed in insulating layer 100 is arbitrary, but is usually circular or elliptical, preferably circular.

A printed wiring board such as a specific printed wiring board can be manufactured, for example, by using a resin sheet and carrying out a manufacturing method including the following steps (I) to (IV).
(I) A step of laminating a resin sheet on the inner layer substrate such that the resin composition layer is bonded to the inner layer substrate.
(II) A step of thermosetting the resin composition layer to form an insulating layer.
(III) A step of forming via holes in the insulating layer.
(IV) A step of roughening the insulating layer.

The "inner layer substrate" used in step (I) is a member that serves as the substrate of the printed wiring board. Examples of inner layer substrates include glass epoxy substrates, metal substrates, polyester substrates, polyimide substrates, BT resin substrates, thermosetting polyphenylene ether substrates, and the like. Usually, as the inner layer substrate, one having a conductor layer on one side or both sides thereof is used. Then, an insulating layer is formed on this conductor layer. This conductor layer may be patterned, for example, to function as a circuit. An inner layer substrate having a conductor layer formed as a circuit on one side or both sides of the substrate is sometimes referred to as an "inner layer circuit board." In addition, an intermediate product on which an insulating layer and/or a conductor layer are further formed when manufacturing a printed wiring board is also included in the "inner layer board". When the printed wiring board is a circuit board with built-in components, an inner layer board with built-in components may be used.

Lamination of the inner layer substrate and the resin sheet can be performed, for example, by bonding the resin composition layer to the inner layer substrate by thermocompression bonding the resin sheet to the inner layer substrate from the support side. Examples of the member for thermocompression bonding the resin sheet to the inner layer substrate (hereinafter sometimes referred to as "thermocompression bonding member") include heated metal plates (such as SUS end plates) and metal rolls (SUS rolls). . Instead of pressing the thermocompression member directly onto the resin sheet, it is preferable to press through an elastic material such as heat-resistant rubber so that the resin sheet can sufficiently follow the uneven surface of the inner layer substrate.

Lamination of the inner layer substrate and the resin sheet may be performed by, for example, a vacuum lamination method. In the vacuum lamination method, the thermocompression temperature is preferably in the range of 60° C. to 160° C., more preferably 80° C. to 140° C., and the thermocompression pressure is preferably 0.098 MPa to 1.77 MPa, more preferably 0. .29 MPa to 1.47 MPa, and the heat pressing time is preferably 20 seconds to 400 seconds, more preferably 30 seconds to 300 seconds. Lamination is preferably carried out under reduced pressure conditions of 26.7 hPa or less.

Lamination can be done with a commercially available vacuum laminator. Commercially available vacuum laminators include, for example, a vacuum pressurized laminator manufactured by Meiki Seisakusho, a vacuum applicator manufactured by Nikko Materials, a batch vacuum pressurized laminator, and the like.

After lamination, the laminated resin sheets may be smoothed by, for example, pressing a thermocompression member from the support side under normal pressure (atmospheric pressure). The pressing conditions for the smoothing treatment may be the same as the thermocompression bonding conditions for the lamination described above. Smoothing treatment can be performed with a commercially available laminator. Lamination and smoothing may be performed continuously using the above-mentioned commercially available vacuum laminator.

In step (II), the resin composition layer is thermally cured to form an insulating layer. The thermosetting conditions for the resin composition layer are not particularly limited, and any conditions employed when forming an insulating layer of a printed wiring board may be used.

For example, the thermosetting conditions for the resin composition layer vary depending on the type of resin composition, etc., but the curing temperature is usually in the range of 120° C. to 240° C. (preferably 150° C. to 220° C., more preferably 170° C. C. to 200.degree. C.), and the curing time is usually in the range of 5 minutes to 120 minutes (preferably 10 minutes to 100 minutes, more preferably 15 minutes to 90 minutes).

Before thermally curing the resin composition layer, the resin composition layer may be preheated at a temperature lower than the curing temperature. For example, prior to thermosetting the resin composition layer, the resin composition layer is usually heated at a temperature of 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). may be preheated for 5 minutes or more (preferably 5 minutes to 150 minutes, more preferably 15 minutes to 120 minutes, still more preferably 15 minutes to 100 minutes).

In step (III), via holes are formed in the insulating layer. Methods for forming via holes include laser light irradiation, etching, mechanical drilling, and the like. Among them, laser light irradiation generally tends to cause a haloing phenomenon. Therefore, from the viewpoint of effectively utilizing the effect of suppressing the haloing phenomenon, laser light irradiation is preferable.

This laser beam 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 as a light source. Laser processing machines that can be used include, for example, CO ₂ laser processing machine "LC-2k212/2C" manufactured by Via Mechanics, 605 GTW III (-P) manufactured by Mitsubishi Electric, laser processing machine manufactured by Matsushita Welding Systems, etc. is mentioned.

Laser light irradiation conditions such as the wavelength, number of pulses, pulse width, and output of the laser light are not particularly limited, and appropriate conditions may be set according to the type of laser light source. Moreover, the wavelength of the laser light is preferably within the range of the absorption wavelength of the (D) colorant from the viewpoint of obtaining the desired effects of the present invention remarkably.

In step (IV), the insulating layer is roughened. The procedure and conditions of the roughening treatment are not particularly limited, and any procedure and conditions used when forming an insulating layer of a printed wiring board can be adopted. For example, the insulating layer can be roughened by performing a swelling treatment with a swelling liquid, a roughening treatment with an oxidizing agent, and a neutralizing treatment with a neutralizing liquid in this order.

Examples of the swelling liquid include, but are not limited to, alkaline solutions, surfactant solutions, and the like, preferably alkaline solutions. As the alkaline solution, a sodium hydroxide solution and a potassium hydroxide solution are more preferable. Examples of commercially available swelling liquids include "Swelling Dip Securigans P" and "Swelling Dip Securigans SBU" manufactured by Atotech Japan. Moreover, one type of swelling liquid may be used alone, or two or more types may be used in combination at an arbitrary ratio. The swelling treatment with the swelling liquid is not particularly limited, but can be performed, for example, by immersing the insulating layer in the swelling liquid at 30.degree. C. to 90.degree. C. for 1 to 20 minutes. From the viewpoint of suppressing the swelling of the resin of the insulating layer to an appropriate level, it is preferable to immerse the insulating layer in a swelling liquid at 40° C. to 80° C. for 5 minutes to 15 minutes.

Examples of the oxidizing agent include, but are not limited to, an alkaline permanganate solution in which potassium permanganate or sodium permanganate is dissolved in an aqueous solution of sodium hydroxide. Moreover, one type of oxidizing agent may be used alone, or two or more types may be used in combination at an arbitrary ratio. The roughening treatment with an oxidizing agent such as an alkaline permanganate solution is preferably carried out by immersing the insulating layer in an oxidizing agent solution heated to 60° C. to 80° C. for 10 to 30 minutes. The permanganate concentration in the alkaline permanganate solution is preferably 5% by mass to 10% by mass. Examples of commercially available oxidizing agents include alkaline permanganate solutions such as "Concentrate Compact CP" and "Dosing Solution Security P" manufactured by Atotech Japan.

As the neutralizing liquid, an acidic aqueous solution is preferable, and commercially available products include, for example, "Reduction Solution Securigant P" manufactured by Atotech Japan. Further, the neutralizing liquid may be used singly, or two or more types may be used in combination at an arbitrary ratio. The treatment with the neutralizing solution can be carried out by immersing the treated surface roughened with the oxidizing agent in the neutralizing solution at 30° C. to 80° C. for 5 to 30 minutes. From the viewpoint of workability, etc., a method of immersing an object roughened with an oxidizing agent in a neutralizing solution at 40° C. to 70° C. for 5 to 20 minutes is preferable.

By the way, the support may be removed between step (I) and step (II), may be removed between step (II) and step (III), or may be removed between step (III) and step ( IV), or after step (IV). In particular, from the viewpoint of further suppressing the generation of gouged portions, it is preferable to remove after the step (III) of forming via holes in the insulating layer. For example, if a via hole is formed in an insulating layer by irradiation with a laser beam and then the support is peeled off, it is easy to form a well-shaped via hole.

The printed wiring board manufacturing method may further include (V) the step of forming a conductor layer. This step (V) may be carried out according to various methods used in the manufacture of printed wiring boards.

Step (V) is a step of forming a conductor layer. A conductor material used for the conductor layer is not particularly limited. In a preferred embodiment, the conductor layer contains one or more selected from the group consisting of gold, platinum, palladium, silver, copper, aluminum, cobalt, chromium, zinc, nickel, titanium, tungsten, iron, tin and indium. Contains metal. The conductor layer may be a single metal layer or an alloy layer. The alloy layer includes, for example, a layer formed from an alloy of two or more metals selected from the above group (for example, a nickel-chromium alloy, a copper-nickel alloy, and a copper-titanium alloy). Among them, from the viewpoint of versatility of conductor layer formation, cost, ease of patterning, etc., a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper; or nickel-chromium alloy, copper - An alloy layer of a nickel alloy or a copper-titanium alloy; is preferable. Furthermore, a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper; or an alloy layer of a nickel-chromium alloy; is more preferred, and a single metal layer of copper is particularly preferred.

The conductor layer may have a single layer structure, or may have a multi-layer structure including two or more single metal layers or alloy layers made of different kinds of metals or alloys. When the conductor 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 nickel-chromium alloy.

The thickness of the conductor layer is generally 3 μm to 35 μm, preferably 5 μm to 30 μm, depending on the desired printed wiring board design.

The conductor layer may be formed by plating. For example, a conductive layer having a desired wiring pattern can be formed by plating the surface of the insulating layer by techniques such as a semi-additive method and a full-additive method. Among them, the semi-additive method is preferable from the viewpoint of manufacturing simplicity.

An example of forming a conductor layer by a semi-additive method is shown below. First, a plating seed layer is formed on the surface of the insulating layer by electroless plating. Next, a mask pattern is formed on the formed plating seed layer to expose a portion of the plating seed layer corresponding to a desired wiring pattern. After forming a metal layer on the exposed plating seed layer by electroplating, the mask pattern is removed. After that, the unnecessary plating seed layer is removed by etching or the like, and a conductor layer having a desired wiring pattern can be formed.

Further, if necessary, the formation of the insulating layer and the conductor layer in steps (I) to (V) may be repeated to produce a multilayer printed wiring board.

[14. semiconductor device]
A semiconductor device of the present invention includes the printed wiring board described above. This semiconductor device can be manufactured using a printed wiring board.

Examples of semiconductor devices include various semiconductor devices used in electrical appliances (eg, computers, mobile phones, digital cameras, televisions, etc.) and vehicles (eg, motorcycles, automobiles, trains, ships, aircraft, etc.).

A semiconductor device can be manufactured, for example, by mounting a component (semiconductor chip) on a conductive portion of a printed wiring board. A "conducting part" is a "part where an electric signal is transmitted on a printed wiring board", and the place may be a surface or an embedded part. Moreover, the semiconductor chip can arbitrarily use an electric circuit element made of a semiconductor.

A method for mounting a semiconductor chip when manufacturing a semiconductor device is not particularly limited as long as the semiconductor chip functions effectively. Examples of mounting methods include wire bonding mounting method, flip chip mounting method, mounting method by bumpless build-up layer (BBUL), mounting method by anisotropic conductive film (ACF), and mounting by non-conductive film (NCF). methods, and the like. Here, "a mounting method using a build-up layer without bumps (BBUL)" means "a mounting method in which a semiconductor chip is directly embedded in a concave portion of a printed wiring board and the semiconductor chip and wiring on the printed wiring board are connected." is.

EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to the following examples. In the following description, "parts" and "%" representing amounts mean "parts by mass" and "% by mass", respectively, unless otherwise specified. In addition, unless otherwise specified, the operations described below were performed in an environment of normal temperature and normal pressure.

[Explanation of inorganic filler]
<Method for measuring average particle size of inorganic filler>
100 mg of an inorganic filler, 0.1 g of a dispersant (“SN9228” manufactured by San Nopco), and 10 g of methyl ethyl ketone were weighed into a vial and dispersed by ultrasonic waves for 20 minutes. Using a laser diffraction particle size distribution analyzer ("SALD-2200" manufactured by Shimadzu Corporation), the particle size distribution of the inorganic filler was measured on a volume basis by a batch cell method. Then, from the obtained particle size distribution, the average particle size of the inorganic filler was calculated as the median size.

<Method for measuring specific surface area of inorganic filler>
The specific surface area of the inorganic filler was measured using a BET fully automatic specific surface area measuring device ("Macsorb HM-1210" manufactured by Mountec).

<Inorganic filler 1>
N-phenyl- ³ -aminopropyltrimethoxysilane (Shin-Etsu Chemical An inorganic filler 1 was prepared by surface-treating with 2 parts of “KBM573” manufactured by Kogyo Co., Ltd.).

<Inorganic filler 2>
N-phenyl- ³ -aminopropyltrimethoxysilane (Shin-Etsu Chemical Co., Ltd., , KBM573) 1 part was prepared as the inorganic filler 2 .

[Example 1. Preparation of resin composition 1]
Bixylenol type epoxy resin (manufactured by Mitsubishi Chemical Corporation "YX4000HK", epoxy equivalent of about 185) 6 parts, naphthalene type epoxy resin (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. "ESN475V", epoxy equivalent of about 332) 5 parts, bisphenol AF type epoxy resin ( Mitsubishi Chemical "YL7760", epoxy equivalent about 238) 15 parts, cyclohexane type epoxy resin (Mitsubishi Chemical "ZX1658GS", epoxy equivalent about 135) 2 parts, and phenoxy resin (Mitsubishi Chemical "YL7500BH30", 2 parts of a 1:1 solution of cyclohexanone:methyl ethyl ketone (MEK) containing 30% by mass of non-volatile components (Mw=44000) was heated and dissolved in a mixed solvent of 20 parts of solvent naphtha and 10 parts of cyclohexanone with stirring. The resulting solution was cooled to room temperature. After that, to this solution, 6 parts of an active ester curing agent ("EXB-8000L-65TM" manufactured by DIC, an active group equivalent of about 220, a 1:1 solution of toluene:MEK with a nonvolatile content of 65% by mass), containing a triazine skeleton 4 parts of cresol novolac curing agent (DIC's "LA-3018-50P", hydroxyl equivalent of about 151, 2-methoxypropanol solution with 50% non-volatile component), 50 parts of inorganic filler 1, carbon black as black pigment ("NV-7-201" manufactured by Nippon Pigment Co., Ltd.) and 0.05 parts of an amine-based curing accelerator (4-dimethylaminopyridine (DMAP)) were mixed and uniformly dispersed with a high-speed rotating mixer. to obtain a mixture. This mixture was filtered through a cartridge filter (“SHP020” manufactured by ROKITECHNO) to obtain a resin composition 1.

[Example 2. Preparation of resin composition 2]
A blue pigment (“Cyanine Blue 4920” manufactured by Dainichi Seika Co., Ltd.) was used instead of carbon black. Resin composition 2 was prepared in the same manner as resin composition 1 except for the above.

[Comparative Example 1. Preparation of resin composition 3]
No carbon black was used. Resin composition 3 was prepared in the same manner as resin composition 1 except for the above.

[Comparative Example 2. Preparation of resin composition 4]
Inorganic filler 2 was used instead of inorganic filler 1. Resin composition 4 was prepared in the same manner as resin composition 1 except for the above.

[Composition of resin composition]
Table 1 below shows the components used in the preparation of Resin Compositions 1 to 5 and their blending amounts (mass parts of non-volatile matter). Abbreviations in the table below are as follows.
Curing agent content: The ratio of the curing agent content to 100% by mass of the resin component in the resin composition.
Content of active ester curing agent: Ratio of content of active ester curing agent to 100% by mass of the resin component in the resin composition.
Inorganic filler content: ratio of inorganic filler content to 100% by mass of non-volatile components in the resin composition.
Pigment content: ratio of pigment content to 100% by mass of non-volatile components in the resin composition.

[Production of resin sheet]
As a support, a polyethylene terephthalate film (“Lumirror R80” manufactured by Toray Industries, Inc., thickness 38 μm, softening point 130° C.) subjected to release treatment with an alkyd resin release agent (“AL-5” manufactured by Lintec) was prepared. .

Each of the resin compositions 1 to 4 was uniformly coated on the support with a die coater so that the thickness of the resin composition layer after drying was 10 μm, and dried at 70° C. to 95° C. for 2 minutes. , a resin composition layer was formed on the support. Next, a rough surface of a polypropylene film (“Alphan MA-411” manufactured by Oji F-Tex Co., Ltd., thickness 15 μm) was attached as a protective film to the surface of the resin composition layer not bonded to the support. As a result, a resin sheet A having a support, a resin composition layer, and a protective film in this order was obtained.

[Method for measuring thickness]
The thickness of the layer such as the resin composition layer was measured using a contact film thickness gauge ("MCD-25MJ" manufactured by Mitutoyo Corporation).

[Evaluation of via hole after laser via processing]
Using the resin sheet A produced using each of the resin compositions 1 to 4, an insulating layer having via holes was formed by the following method, and the via holes were evaluated.

<Preparation of sample for evaluation>
(1) Preparation of inner layer substrate:
Glass cloth-based epoxy resin double-sided copper-clad laminate having copper foil layers on both sides as an inner layer substrate (copper foil thickness 3 μm, substrate thickness 0.15 mm, “HL832NSF LCA” manufactured by Mitsubishi Gas Chemical Company, 255 × 340 mm size ) was prepared.

(2) Lamination of resin sheets:
The protective film was peeled off from the resin sheet A to expose the resin composition layer. Both surfaces of the inner layer substrate were laminated so that the resin composition layer was in contact with the inner layer substrate using a batch-type vacuum pressure laminator (manufactured by Nikko Materials Co., Ltd., 2-stage build-up laminator "CVP700"). Lamination was carried out by pressure bonding for 45 seconds at 130° C. and pressure of 0.74 MPa after reducing the pressure for 30 seconds to adjust the atmospheric pressure to 13 hPa or less. Then, hot pressing was performed at 120° C. and a pressure of 0.5 MPa for 75 seconds.

(3) Thermosetting of resin composition layer:
After that, the inner layer substrate laminated with the resin sheet is placed in an oven at 100° C. and heated for 30 minutes, then transferred to an oven at 180° C. and heated for 30 minutes to thermally cure the resin composition layer, An insulating layer was formed. The thickness of the insulating layer was 10 μm. After that, the support was peeled off to obtain a cured substrate A having an insulating layer, an inner layer substrate and an insulating layer in this order.

(4) Laser via processing:
Using a CO ₂ laser processing machine (“605GTWIII(-P)” manufactured by Mitsubishi Electric Corporation), the insulating layer is irradiated with a laser beam to form a plurality of via holes with a top diameter (diameter) of about 30 μm in the insulating layer. formed. The irradiation conditions of the laser light were mask diameter 1 mm, pulse width 16 μs, energy 0.2 mJ/shot, number of shots 2, and burst mode (10 kHz). The cured substrate A in which via holes are formed in the insulating layer in this way is called a via-processed substrate A. As shown in FIG.

(5) Roughening treatment:
A desmear treatment was performed as a roughening treatment on the via-processed substrate A. As shown in FIG. As the desmear treatment, the following wet desmear treatment was performed.

(Wet desmear treatment)
Via-processed substrate A is immersed in a swelling liquid (“Swelling Dip Securigant P” manufactured by Atotech Japan Co., Ltd., an aqueous solution of diethylene glycol monobutyl ether and sodium hydroxide) at 60° C. for 10 minutes, and then immersed in an oxidizing agent solution (Atotech Japan company "Concentrate Compact CP", an aqueous solution with a potassium permanganate concentration of about 6% and a sodium hydroxide concentration of about 4%) at 80 ° C. for 20 minutes, then a neutralizing solution (Atotech Japan Co., Ltd. "Reduction Solution Securigant P", sulfuric acid aqueous solution) at 40°C for 5 minutes, and then dried at 80°C for 15 minutes. The via-processed substrate A subjected to this wet desmearing process is called a roughened substrate A. As shown in FIG.

<Measurement of dimensions of via hole before roughening>
The cross-section of the via-processed substrate A before the roughening treatment was observed using an FIB-SEM composite apparatus ("SMI3050SE" manufactured by SII Nanotechnology Inc.). Specifically, an FIB (focused ion beam) was used to shave the insulating layer so that a cross section parallel to the thickness direction of the insulating layer and passing through the center of the via bottom of the via hole appeared. This cross section was observed by SEM (scanning electron microscope). From the observed image, the top diameter and bottom diameter of the via hole were measured.

The above measurements were performed at five randomly selected via holes. Then, the average of the top diameters of the five measured via holes was adopted as the top diameter Lt1 of the sample before roughening treatment. In addition, the average of the measured bottom diameters of the five via holes was adopted as the bottom diameter Lb1 of the sample before roughening treatment.

<Dimensions of via hole after roughening treatment and measurement of haloing distance>
The cross-section of the roughened substrate A was observed using an FIB-SEM composite device ("SMI3050SE" manufactured by SII Nanotechnology). Specifically, an FIB (focused ion beam) was used to shave the insulating layer so that a cross section parallel to the thickness direction of the insulating layer and passing through the center of the via bottom of the via hole appeared. This cross section was observed by SEM. The bottom diameter and top diameter of the via hole were measured from the observed image. Further, in the image observed by SEM, a gap was observed continuously from the edge of the via bottom and formed by peeling the insulating layer from the copper foil layer of the inner layer substrate. Therefore, from the observed image, the distance r3 from the center of the via bottom to the edge of the via bottom (corresponding to the inner radius of the gap) and the distance r3 from the center of the via bottom to the far end of the gap (gap The difference r4-r3 between the distance r3 and the distance r4 was calculated as the haloing distance from the edge of the beer bottom at the measurement point.

The above measurements were performed at five randomly selected via holes. Then, the average of the measured top diameters of the five via holes was adopted as the top diameter Lt2 of the sample after the roughening treatment. In addition, the average of the measured bottom diameters of the five via holes was adopted as the bottom diameter Lb2 of the sample after the roughening treatment. Furthermore, the average of the measured haloing distances of five via holes was adopted as the haloing distance Wb from the edge of the via bottom of the sample.

[result]
The evaluation results of the above examples and comparative examples are shown in Table 2 below.
In Table 2, the taper ratio represents the ratio "Lb1/Lt1" between the top diameter Lt1 and the bottom diameter Lb1 of the via hole before roughening treatment.

In Table 2, the haloing ratio Hb is the ratio of the haloing distance Wb from the edge of the via bottom after roughening to the radius of the via bottom of the via hole after roughening (Lb/2) "Wb/(Lb /2)”. If the haloing ratio Hb was 35% or less, it was determined as "good", and if the haloing ratio Ht was greater than 35%, it was determined as "defective".

[Consideration]
As can be seen from Table 2, in Examples, a via hole having a large taper rate can be formed in an insulating layer using a thin resin composition layer having a thickness of 10 μm. From these results, it was confirmed that the resin composition layer of the present invention can realize an insulating layer capable of forming a via hole with a good shape even if the thickness is small.

Further, as can be seen from Table 2, in Examples, the haloing ratio Hb after the roughening treatment is small, although the insulating layer is formed using a thin resin composition layer having a thickness of 10 μm. From this result, it was confirmed that the resin composition layer of the present invention can realize an insulating layer capable of suppressing the haloing phenomenon even if the thickness is thin.

In particular, the thickness is 15 μm or less, the top diameter Lt of the via hole is 35 μm or less, the taper rate of the via hole is 80% or more, and the bottom edge of the via hole is as obtained in Examples 1 and 2 above. Conventionally, an insulating layer having a haloing distance Wb of 5 μm or less and a haloing ratio Hb to the bottom radius of the via hole of 35% or less has not been realized. Therefore, the realization of such an insulating layer has a significant technical significance in the recent printed wiring board, where thinning of the insulating layer is desired.

Examples 1 and 2 do not show specific results when the conductor layer is formed on the insulating layer of the roughened substrate A, but the results of the above-described examples show that the insulation of the roughened substrate A Those skilled in the art will clearly understand that forming a conductor layer on a layer results in a specific printed wiring board that satisfies requirements (i) to (v).
Further, in Examples 1 and 2, even if the components (E) to (F) are not contained, although there is a difference in degree, it has been confirmed that results similar to those of the above examples are obtained. .

REFERENCE SIGNS LIST 100 Insulating layer 100U Side of insulating layer opposite to conductor layer 110 Via hole 120 Via bottom 120C Center of via bottom 130 Via top 140 Discolored portion 150 Edge of via bottom of via hole 160 Gap 170 Edge of gap on outer peripheral side 180 Via hole Edge of via top 190 Edge on outer peripheral side of discolored portion 200 Inner layer substrate 210 Conductor layer (first conductor layer)
220 second conductor layer 300 printed wiring board Lb bottom diameter of via hole Lt top diameter of via hole T thickness of insulating layer Wt haloing distance from via top edge Wb haloing distance from via bottom edge

Claims (15)

A resin composition layer having a thickness of 15 μm or less containing a resin composition for forming an interlayer insulating layer of a printed wiring board ,
The resin composition contains (A) an epoxy resin, (B) a curing agent, (C) an inorganic filler having an average particle size of 100 nm or less, (D) a colorant, and (E) a thermoplastic resin,
The amount of component (C) is 30% by mass or more with respect to 100% by mass of non-volatile components in the resin composition,
(E) A resin composition layer in which the amount of component is 12% by mass or less with respect to 100% by mass of the resin component in the resin composition. A resin composition layer having a thickness of 15 μm or less containing a resin composition for forming an interlayer insulating layer of a printed wiring board ,
The resin composition comprises (A) an epoxy resin, (B) a curing agent, (C) an inorganic filler having a specific surface area of 15 m ² /g or more as measured by the BET method, (D) a colorant, and (E) including a thermoplastic resin,
The amount of component (C) is 30% by mass or more with respect to 100% by mass of non-volatile components in the resin composition,
(E) A resin composition layer in which the amount of component is 12% by mass or less with respect to 100% by mass of the resin component in the resin composition. 3. The resin composition layer according to claim 1, which is for forming an insulating layer for forming a conductor layer. A resin composition layer having a thickness of 15 μm or less containing a resin composition for forming an interlayer insulating layer of a printed wiring board,
The resin composition contains (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 coloring agent,
A resin composition layer in which the amount of component (C) is 30% by mass or more with respect to 100% by mass of non-volatile components in the resin composition. A resin composition layer having a thickness of 15 μm or less containing a resin composition for forming an interlayer insulating layer of a printed wiring board,
The resin composition contains (A) an epoxy resin, (B) a curing agent, (C) an inorganic filler having a specific surface area of 15 m ² /g or more as measured by the BET method, and (D) a colorant,
A resin composition layer in which the amount of component (C) is 30% by mass or more with respect to 100% by mass of non-volatile components in the resin composition. The resin composition layer according to any one of claims 1 to 5 , wherein component (D) is a black or chromatic colorant. The resin composition layer according to any one of claims 1 to 6 , wherein component (D) is a black or blue colorant. The resin composition layer according to any one of claims 1 to 7 , wherein component (D) is a pigment. The resin composition according to any one of claims 1 to 8 , wherein the amount of component (D) is 0.1% by mass or more and 5% by mass or less with respect to 100% by mass of non-volatile components in the resin composition. layers. The resin composition layer according to any one of claims 1 to 9 , wherein the amount of component (C) is 60% by mass or less with respect to 100% by mass of non-volatile components in the resin composition. The resin composition layer according to any one of claims 1 to 10 , wherein the component (A) contains at least one selected from the group consisting of bixylenol-type epoxy resins and fluorine-containing epoxy resins. The resin composition layer according to any one of claims 1 to 11 , which is for forming an insulating layer having via holes with a top diameter of 35 µm or less. a support;
A resin sheet comprising a resin composition layer according to any one of claims 1 to 12 provided on a support. A printed wiring board comprising an insulating layer formed of a cured product of the resin composition layer according to any one of claims 1 to 12 . A semiconductor device comprising the printed wiring board according to claim 14 .

Images