JP7371590B2 - Manufacturing method of printed wiring board - Google Patents

Description

The present invention relates to a method for manufacturing a printed wiring board, and a resin composition for forming via holes or trenches by plasma treatment.

In recent years, in printed wiring boards, build-up layers have become multilayered, and there is a demand for finer wiring and higher density wiring. The build-up layer is formed by a build-up method in which insulating layers and conductor layers are stacked alternately. In the build-up manufacturing method, the insulating layer is generally formed by thermosetting a resin composition. It is.

Many proposals have been made for resin compositions suitable for forming the insulating layer of the inner layer circuit board, including, for example, the resin composition described in Patent Document 1.

JP 2017-59779 Publication

By the way, in manufacturing printed wiring boards, via holes or trenches are sometimes formed in an insulating layer. A "via hole" typically refers to a hole that passes through an insulating layer. Further, the term "trench" generally refers to a groove that does not penetrate an insulating layer. A method using a laser can be considered as a method of forming a via hole or trench.

The present inventors have discovered that when laser irradiation generates heat, this heat is transmitted to the insulating layer and the underlying metal of the inner layer circuit board, resulting in the haloing phenomenon. The haloing phenomenon refers to the occurrence of peeling between the insulating layer and the inner layer circuit board around the via hole. Such a haloing phenomenon usually occurs when the resin around the via hole is degraded by heat, and the degraded portion is eroded by a chemical solution such as a roughening solution. Note that the deteriorated portion is usually observed as a discolored portion.

In addition, the present inventors discovered that when a via hole is formed using a laser, the hardened resin component and inorganic filler are excavated on the side and bottom surfaces of the via hole, resulting in unevenness and unevenness. I found out that this is a very important aspect. For this reason, it has been found that when a conductor layer is formed in this via hole by sputtering, the thickness of the conductor layer becomes non-uniform.

The object of the present invention is to provide a method for manufacturing a printed wiring board that can suppress the haloing phenomenon and suppress the occurrence of unevenness on the side and bottom surfaces of via holes and trenches, and a resin composition for forming via holes or trenches by plasma treatment. Our goal is to provide the following.

As a result of intensive studies to solve the above problems, the inventors of the present invention found that the above problems could be solved by forming via holes or trenches by plasma treatment, and thus completed the present invention.

That is, the present invention includes the following contents.
[1] (A) A step of forming an insulating layer containing a cured resin composition on the inner layer circuit board, and (B) A step of performing plasma treatment on the surface of the insulating layer to form a via hole or trench. including,
The resin composition contains an inorganic filler, and the content of the inorganic filler is 60% by mass or more when the nonvolatile components in the resin composition are 100% by mass,
A method for manufacturing a printed wiring board, wherein the gas used for plasma processing contains SF ₆ .
[2] (A) A step of forming an insulating layer containing a cured resin composition on the inner layer circuit board, and (B) A step of performing plasma treatment on the surface of the insulating layer to form a via hole or trench. including,
The resin composition contains an inorganic filler, and the content of the inorganic filler is 40% by volume or more when the nonvolatile components in the resin composition are 100% by volume,
A method for manufacturing a printed wiring board, wherein the gas used for plasma processing contains SF ₆ .
[3] The method for manufacturing a printed wiring board according to [1] or [2], further including the step of (D) forming a conductor layer.
[4] The method for manufacturing a printed wiring board according to [3], wherein the step (D) forms a conductor layer by sputtering.
[5] The printed wiring according to any one of [1] to [4], wherein the gas used for plasma processing includes a mixed gas containing SF ₆ and one or more gases selected from Ar and O ₂ . Method of manufacturing the board.
[6] The method for producing a printed wiring board according to any one of [1] to [5], wherein the resin composition contains a curable resin.
[7] Contains an inorganic filler,
A resin composition for forming via holes or trenches by plasma treatment in an insulating layer of a printed wiring board, wherein the content of the inorganic filler is 60% by mass or more when the nonvolatile components in the resin composition are 100% by mass. thing.
[8] Contains an inorganic filler,
A resin composition for forming a via hole or trench by plasma treatment in an insulating layer of a printed wiring board, wherein the content of the inorganic filler is 40% by volume or more when the nonvolatile components in the resin composition are 100% by volume. thing.
[9] The resin composition according to [7] or [8], further comprising a curable resin.

According to the present invention, there is provided a method for manufacturing a printed wiring board that can suppress the haloing phenomenon and suppress the occurrence of unevenness on the side and bottom surfaces of via holes and trenches, and a resin composition for forming via holes or trenches by plasma treatment. can be provided.

FIG. 1 is a schematic cross-sectional view showing an example of how a via hole is formed in step (C). FIG. 2 is a plan view schematically showing an insulating layer immediately before forming a conductor layer of a printed wiring board in which via holes are formed by conventional laser processing. FIG. 3 is a cross-sectional view schematically showing an insulating layer immediately before forming a conductor layer of a printed wiring board in which via holes are formed by conventional laser processing.

Hereinafter, the present invention will be described in detail by showing embodiments and examples. However, the present invention is not limited to the embodiments and examples listed below, and may be implemented with arbitrary changes within the scope of the claims of the present invention and equivalents thereof.

Before explaining in detail the method for producing a printed wiring board of the present invention, the "resin composition" and "resin sheet" used in the method for producing a printed wiring board of the present invention will be explained. The resin composition is suitable for forming via holes or trenches in insulating layers of printed wiring boards by plasma treatment. Further, the resin composition contains an inorganic filler, and the content of the inorganic filler is 60% by mass or more when the nonvolatile components in the resin composition are 100% by mass, and the content of the inorganic filler is When the nonvolatile component in the resin composition is 100% by volume, it is either 40% by volume or more. By using such a resin composition, it is possible to suppress the haloing phenomenon when forming via holes or trenches by plasma treatment, and to prevent the side walls and bottom surfaces of via holes and trenches from becoming uneven surfaces. can.

[Resin composition]
The resin composition used to form the cured product may be one used in the step of forming via holes or trenches by subjecting the surface of the insulating layer, which is the cured product of the resin composition, to plasma treatment. In one embodiment, the resin composition includes (a) an inorganic filler. In addition to component (a), the resin composition further contains (b) a curable resin, (c) a curing accelerator, (d) a thermoplastic resin, and (e) other additives, if necessary. May contain. Each component contained in the resin composition will be explained in detail below.

<(a) Inorganic filler>
The resin composition contains (a) an inorganic filler, and the content of the (a) inorganic filler is 60% by mass or more when the nonvolatile components in the resin composition are 100% by mass. The resin composition (a) contains a large amount of inorganic filler, so even if the inorganic filler is scraped off by plasma irradiation with a predetermined gas and the cured resin component is dug out, the frequency of unevenness on the bottom and side walls of the via hole can be reduced. Therefore, it is possible to suppress the side walls and the bottom surface from becoming non-uniform surfaces. As a result, it becomes possible to make the thickness of the conductor layer uniform. Here, the term "resin component" refers to components other than the inorganic filler among the nonvolatile components contained in the resin composition, unless otherwise specified.

The content of component (a) is 60% by mass or more, preferably 63% by mass, when the nonvolatile components in the resin composition are 100% by mass, from the viewpoint of reducing unevenness on the bottom and side walls of the via hole or trench. % or more, more preferably 65% by mass or more, preferably 95% by mass or less, more preferably 90% by mass or less, still more preferably 80% by mass or less. In the present invention, the content of each component in the resin composition is a value based on 100% by mass of nonvolatile components in the resin composition, unless otherwise specified.

The content of component (a) is 38% by volume or more, preferably 40% by volume, when the nonvolatile component in the resin composition is 100% by volume, from the viewpoint of reducing unevenness on the bottom and side walls of the via hole or trench. % or more, more preferably 42% by volume or more, preferably 70% by mass or less, more preferably 65% by mass or less, still more preferably 60% by mass or less.

(a) An inorganic compound is used as the material for the inorganic filler. Examples of inorganic filler materials include silica, alumina, aluminosilicate, glass, cordierite, silicon oxide, barium sulfate, barium carbonate, talc, clay, mica powder, zinc oxide, hydrotalcite, boehmite, and water. Aluminum oxide, 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, calcium carbonate and silica are preferred, and silica is particularly preferred. Examples of silica include amorphous silica, fused silica, crystalline silica, synthetic silica, and hollow silica. Further, as the silica, spherical silica is preferable. (a) One type of inorganic filler may be used alone, or two or more types may be used in combination.

Commercial products of component (a) include, for example, "SP60-05" and "SP507-05" manufactured by Nippon Steel & Sumikin Materials; "YC100C", "YA050C", and "YA050C-MJE" manufactured by Admatex; “YA010C”; “UFP-30” manufactured by Denka; “Silfill NSS-3N”, “Silfill NSS-4N”, “Silfill NSS-5N” manufactured by Tokuyama; “SC2500SQ”, “SO” manufactured by Admatex -C4'', ``SO-C2'', ``SO-C1'', ``SC2050-SXF'', and the like.

The average particle diameter of component (a) is preferably greater than 0.1 μm, more preferably 0.15 μm or more, particularly preferably 0.2 μm or more, from the viewpoint of significantly obtaining the desired effects of the present invention. is 5 μm or less, more preferably 2 μm or less, even more preferably 1 μm or less.

The average particle size of component (a) can be measured by a laser diffraction/scattering method based on Mie scattering theory. Specifically, it can be measured by creating the particle size distribution of the inorganic filler on a volume basis using a laser diffraction scattering type particle size distribution measuring device, and using the median diameter as the average particle size. The measurement sample can be obtained by weighing 100 mg of the inorganic filler and 10 g of methyl ethyl ketone into a vial and dispersing them using ultrasonic waves for 10 minutes. The measurement sample was measured using a laser diffraction particle size distribution measuring device using a light source wavelength of blue and red, and the volume-based particle size distribution of the inorganic filler was measured using a flow cell method. The average particle size is calculated as the median diameter. Examples of the laser diffraction particle size distribution measuring device include "LA-960" manufactured by Horiba, "SALD-2200" manufactured by Shimadzu Corporation, and the like.

The specific surface area of component (a) is preferably 1 m ² /g or more, more preferably 2 m ² /g or more, particularly preferably 3 m ² /g or more. Although there is no particular limit to the 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 can be obtained by adsorbing nitrogen gas on the sample surface using a specific surface area measuring device (Macsorb HM-1210 manufactured by Mountec) according to the BET method, and calculating the specific surface area using the BET multi-point method. .

Component (a) is preferably treated with a surface treatment agent from the viewpoint of improving moisture resistance and dispersibility. Examples of the surface treatment agent include vinyl silane coupling agents, (meth)acrylic coupling agents, fluorine-containing silane coupling agents, aminosilane coupling agents, epoxysilane coupling agents, mercaptosilane coupling agents, Examples include silane coupling agents, alkoxysilanes, organosilazane compounds, titanate coupling agents, and the like. Among these, from the viewpoint of significantly obtaining the effects of the present invention, vinylsilane coupling agents, (meth)acrylic coupling agents, and aminosilane coupling agents are preferred, and aminosilane coupling agents are more preferred. Moreover, one type of surface treatment agent may be used alone, or two or more types may be used in any combination.

Commercially available surface treatment agents include, for example, "KBM1003" (vinyltriethoxysilane) manufactured by Shin-Etsu Chemical, "KBM503" (3-methacryloxypropyltriethoxysilane) manufactured by Shin-Etsu Chemical, and "KBM503" (3-methacryloxypropyltriethoxysilane) manufactured by Shin-Etsu Chemical. "KBM403" (3-glycidoxypropyltrimethoxysilane), "KBM803" (3-mercaptopropyltrimethoxysilane) manufactured by Shin-Etsu Chemical, "KBE903" (3-aminopropyltriethoxysilane) manufactured by Shin-Etsu Chemical , "KBM573" (N-phenyl-3-aminopropyltrimethoxysilane) manufactured by Shin-Etsu Chemical, "SZ-31" (hexamethyldisilazane) manufactured by Shin-Etsu Chemical, "KBM103" (phenyl trimethoxysilane), "KBM-4803" (long chain epoxy type silane coupling agent) manufactured by Shin-Etsu Chemical, "KBM-7103" (3,3,3-trifluoropropyltrimethoxysilane) manufactured by Shin-Etsu Chemical etc.

The degree of surface treatment with the surface treatment agent is preferably within a predetermined range from the viewpoint of improving the dispersibility of the inorganic filler. Specifically, 100 parts by mass of the inorganic filler is preferably surface-treated with 0.2 parts by mass to 5 parts by mass of a surface treatment agent, and preferably 0.2 parts by mass to 3 parts by mass. Preferably, the surface treatment is carried out in an amount of 0.3 parts by mass to 2 parts by mass.

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 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 an increase in the melt viscosity of the resin varnish and the melt viscosity in sheet form, it is preferably 1 mg/m ² or less, more preferably 0.8 mg/m ² or less, and even more 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 (for example, methyl ethyl ketone (MEK)). Specifically, a sufficient amount of MEK as a solvent is added to the inorganic filler whose surface has been treated with a surface treatment agent, and the mixture is subjected to ultrasonic cleaning at 25° C. for 5 minutes. After removing the supernatant liquid and drying the solid content, the amount of carbon per unit surface area of the inorganic filler can be measured using a carbon analyzer. As the carbon analyzer, "EMIA-320V" manufactured by Horiba, Ltd., etc. can be used.

<(b) Curable resin>
The resin composition may contain (b) a curable resin. (b) Examples of the curable resin include thermosetting resins and photocurable resins, and thermosetting resins that can be used when forming the insulating layer of printed wiring boards are preferred.

Examples of thermosetting resins include epoxy resins, phenol resins, naphthol resins, benzoxazine resins, active ester resins, cyanate ester resins, carbodiimide resins, amine resins, and acid anhydride resins. Can be mentioned. Component (b) may be used alone or in combination of two or more in any ratio. The following resins are formed by reacting with epoxy resins, such as phenol resins, naphthol resins, benzoxazine resins, active ester resins, cyanate ester resins, carbodiimide resins, amine resins, and acid anhydride resins. Resins that can harden things are sometimes collectively referred to as "hardening agents." From the viewpoint of forming an insulating layer, the resin composition preferably contains an epoxy resin and a curing agent as component (b), and preferably contains any one of an epoxy resin, an active ester resin, and a phenol resin. More preferably, it contains an epoxy resin and an active ester resin.

(b) As the epoxy resin as the component, for example, bixylenol type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol AF type epoxy resin, dicyclopentadiene type epoxy resin, Trisphenol type epoxy resin, naphthol novolac type epoxy resin, phenol novolac type epoxy resin, tert-butyl-catechol type epoxy resin, naphthalene type epoxy resin, naphthol type epoxy resin, anthracene type epoxy resin, glycidylamine type epoxy resin, glycidyl ester type epoxy resin, cresol novolac type epoxy resin, biphenyl type epoxy resin, linear aliphatic epoxy resin, epoxy resin with butadiene structure, alicyclic epoxy resin, heterocyclic epoxy resin, spiro ring-containing epoxy resin, cyclohexane type epoxy resin, cyclohexanedimethanol type epoxy resin, naphthylene ether type epoxy resin, trimethylol type epoxy resin, tetraphenylethane type epoxy resin and the like. One type of epoxy resin may be used alone, or two or more types may be used in combination.

It is preferable that the resin composition contains, as component (b), an epoxy resin having two or more epoxy groups in one molecule. From the viewpoint of significantly obtaining the desired effects of the present invention, the proportion of the epoxy resin having two or more epoxy groups in one molecule is preferably 50% by mass with respect to 100% by mass of the nonvolatile components of component (b). The content is more preferably 60% by mass or more, particularly preferably 70% by 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 (hereinafter sometimes referred to as "solid epoxy resins"). ). The resin composition may contain only a liquid epoxy resin as the component (b), or may contain only a solid epoxy resin, but from the viewpoint of significantly obtaining the effects of the present invention, the resin composition may contain only a liquid epoxy resin and a liquid epoxy resin. It is preferable to include it in combination with a solid epoxy resin.

As the liquid epoxy resin, a liquid epoxy resin having two or more epoxy groups in one molecule is preferable.

Liquid epoxy resins include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AF type epoxy resin, naphthalene type epoxy resin, glycidyl ester type epoxy resin, glycidylamine type epoxy resin, phenol novolak type epoxy resin, and ester skeleton. Alicyclic epoxy resins, cyclohexane-type epoxy resins, cyclohexanedimethanol-type epoxy resins, glycidylamine-type epoxy resins, and epoxy resins having a butadiene structure are preferred, and bisphenol A-type epoxy resins and bisphenol F-type epoxy resins are more preferred.

Specific examples of liquid epoxy resins include "HP4032", "HP4032D", "HP4032SS" (naphthalene type epoxy resin) manufactured by DIC; "828US", "jER828EL", "825", and "Epicoat" manufactured by Mitsubishi Chemical Corporation. 828EL" (bisphenol A type epoxy resin); "jER807", "1750" (bisphenol F type epoxy resin) manufactured by Mitsubishi Chemical; "jER152" (phenol novolac type epoxy resin) manufactured by Mitsubishi Chemical; manufactured by Mitsubishi Chemical “630” and “630LSD” (glycidylamine type epoxy resin); “ZX1059” manufactured by Nippon Steel Chemical & Materials (mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin); manufactured by Nagase ChemteX Co., Ltd. "EX-721" (glycidyl ester type epoxy resin); Daicel's "Celoxide 2021P" (alicyclic epoxy resin with ester skeleton); Daicel's "PB-3600" (epoxy resin with butadiene structure) Examples include "ZX1658" and "ZX1658GS" (liquid 1,4-glycidylcyclohexane type epoxy resin) manufactured by Nippon Steel Chemical & Materials. These may be used alone or in combination of two or more.

As the solid epoxy resin, a solid epoxy resin having three or more epoxy groups in one molecule is preferable, and an aromatic solid epoxy resin having three or more epoxy groups in one molecule is more preferable.

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, and biphenyl. Type epoxy resins, naphthylene ether type epoxy resins, anthracene type epoxy resins, bisphenol A type epoxy resins, bisphenol AF type epoxy resins, and tetraphenylethane type epoxy resins are preferred, and naphthalene type epoxy resins are more preferred.

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

When using a combination of liquid epoxy resin and solid epoxy resin as component (b), their quantitative ratio (liquid epoxy resin: solid epoxy resin) is preferably 1:0.1 to 1: 20, more preferably 1:0.3 to 1:15, particularly preferably 1:0.5 to 1:10. When the ratio of the liquid epoxy resin to the solid epoxy resin is within this range, the desired effects of the present invention can be significantly obtained. Furthermore, when used in the form of a resin sheet, adequate tackiness is usually provided. Further, when used in the form of a resin sheet, sufficient flexibility is usually obtained and handling properties are improved. Furthermore, it is usually possible to obtain a cured product having sufficient breaking strength.

The epoxy equivalent of the epoxy resin as component (b) is preferably 50 g/eq. ～5000g/eq. , more preferably 50g/eq. ～3000g/eq. , more preferably 80g/eq. ～2000g/eq. , even more preferably 110 g/eq. ～1000g/eq. It is. By falling within this range, a cured product of the resin composition can be provided with a sufficient crosslinking density. Epoxy equivalent is the mass of epoxy resin containing one equivalent of epoxy groups. This epoxy equivalent can be measured according to JIS K7236.

The weight average molecular weight (Mw) of the epoxy resin as component (b) is preferably 100 to 5000, more preferably 250 to 3000, and even more preferably 400 to 1500, from the viewpoint of significantly obtaining the desired effects of the present invention. be. The weight average molecular weight of the epoxy resin is the weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC).

From the viewpoint of obtaining a cured product exhibiting good mechanical strength and insulation reliability, the content of the epoxy resin as component (b) is preferably 10% by mass when the nonvolatile components in the resin composition are 100% by mass. The content is more preferably 15% by mass or more, still more preferably 20% by mass or more. The upper limit of the content of the epoxy resin is preferably 45% by mass or less, more preferably 40% by mass or less, particularly preferably 35% by mass or less, from the viewpoint of significantly obtaining the desired effects of the present invention.

From the viewpoint of significantly obtaining the effects of the present invention, the content of the epoxy resin as component (b) is preferably 50% by mass or more, more preferably The content is 60% by mass or more, more preferably 70% by mass or more, preferably 95% by mass or less, more preferably 90% by mass or less, even more preferably 88% by mass or less. The resin component refers to the nonvolatile components in the resin composition excluding (a) the inorganic filler.

As the active ester resin as component (b), a resin having one or more active ester groups in one molecule can be used. Among these, active ester resins include those having two or more ester groups with high reaction activity in one molecule, such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds. Resins are preferred. The active ester resin is preferably one obtained by a condensation reaction between a carboxylic acid compound and/or a thiocarboxylic acid compound and a hydroxy compound and/or a thiol compound. In particular, from the viewpoint of improving heat resistance, active ester resins obtained from a carboxylic acid compound and a hydroxy compound are preferred, and active ester resins obtained from a carboxylic acid compound and a phenol compound and/or a naphthol compound are more preferred.

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

Examples of phenolic 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, phloroglucin, Examples include benzenetriol, dicyclopentadiene type diphenol compounds, and phenol novolacs. Here, the term "dicyclopentadiene type diphenol compound" refers to a diphenol compound obtained by condensing two molecules of phenol with one molecule of dicyclopentadiene.

Preferred specific examples of active ester resins include active ester resins containing a dicyclopentadiene type diphenol structure, active ester resins containing a naphthalene structure, active ester resins containing an acetylated product of phenol novolak, and benzoyl phenol novolac. Examples include active ester resins containing compounds. Among these, active ester resins containing a naphthalene structure and active ester resins containing a dicyclopentadiene type diphenol structure are more preferable. "Dicyclopentadiene type diphenol structure" refers to a divalent structural unit consisting of phenylene-dicyclopentylene-phenylene.

Commercially available active ester resins include "EXB9451," "EXB9460," "EXB9460S," "HPC-8000-65T," and "HPC-8000H-" as active ester resins containing a dicyclopentadiene diphenol structure. 65TM", "EXB-8000L-65TM" (manufactured by DIC Corporation); "EXB9416-70BK", "EXB-8100L-65T", "EXB-8150L-65T", " EXB-8150-65T”, “HPC-8150-60T”, “HPC-8150-62T” (manufactured by DIC), “PC1300-02-65T” (manufactured by Air Water); Contains acetylated phenol novolak "DC808" (manufactured by Mitsubishi Chemical Corporation) as an active ester resin; "YLH1026" (manufactured by Mitsubishi Chemical Corporation) as an active ester resin containing a benzoylated product of phenol novolak; "DC808" (manufactured by Mitsubishi Chemical Company); "YLH1026" (manufactured by Mitsubishi Chemical Company), "YLH1030" (manufactured by Mitsubishi Chemical Company), and "YLH1048" (manufactured by Mitsubishi Chemical Company) as active ester resins that are benzoylated products of phenol novolak. ; "EXB-8500-65T" (manufactured by DIC Corporation); and the like.

From the viewpoint of significantly obtaining the effects of the present invention, the content of the active ester resin as component (b) is preferably 1% by mass or more, more preferably The content is 3% by mass or more, more preferably 5% by mass or more, preferably 20% by mass or less, more preferably 15% by mass or less, even more preferably 10% by mass or less.

From the viewpoint of significantly obtaining the effects of the present invention, the content of the active ester resin as component (b) is preferably 3% by mass or more, more preferably 3% by mass or more when the resin component in the resin composition is 100% by mass. is 5% by mass or more, more preferably 8% by mass or more, preferably 25% by mass or less, more preferably 20% by mass or less, even more preferably 15% by mass or less.

As the phenol resin and naphthol resin as component (b), those having a novolac structure are preferred from the viewpoint of heat resistance and water resistance. Further, from the viewpoint of adhesion to the conductor layer, nitrogen-containing phenolic resins are preferred, and triazine skeleton-containing phenolic resins are more preferred.

Specific examples of phenolic resins and naphthol resins include "MEH-7700", "MEH-7810", and "MEH-7851" manufactured by Meiwa Kasei Co., Ltd., and "NHN" and "CBN" manufactured by Nippon Kayaku Co., Ltd. ", "GPH", "SN170", "SN180", "SN190", "SN475", "SN485", "SN495", "SN-495V", "SN375", "SN395" manufactured by Nippon Steel Chemical & Materials. , "TD-2090", "LA-7052", "LA-7054", "LA-1356", "LA-3018-50P", and "EXB-9500" manufactured by DIC Corporation.

Specific examples of the benzoxazine resin as component (b) include "JBZ-OD100" (benzoxazine ring equivalent: 218), "JBZ-OP100D" (benzoxazine ring equivalent: 218), and "ODA-" manufactured by JFE Chemical Co., Ltd. BOZ” (benzoxazine ring equivalent 218); “P-d” (benzoxazine ring equivalent 217) manufactured by Shikoku Kasei Kogyo Co., “Fa” (benzoxazine ring equivalent 217); “HFB2006M manufactured by Showa Kobunshi Co., Ltd. (benzoxazine ring equivalent: 432).

Examples of the cyanate ester resin as component (b) include bisphenol A dicyanate, polyphenol cyanate, oligo(3-methylene-1,5-phenylene cyanate), and 4,4'-methylenebis(2,6-dimethylphenyl cyanate). ), 4,4'-ethylidene diphenyl dicyanate, hexafluorobisphenol A dicyanate, 2,2-bis(4-cyanate) phenylpropane, 1,1-bis(4-cyanate phenylmethane), bis(4-cyanate- 3,5-dimethylphenyl)methane, 1,3-bis(4-cyanatophenyl-1-(methylethylidene))benzene, bis(4-cyanatophenyl)thioether, and bis(4-cyanatophenyl)ether, etc. Bifunctional cyanate resins; polyfunctional cyanate resins derived from phenol novolacs, cresol novolacs, etc.; prepolymers in which these cyanate resins are partially triazine-formed; and the like. Specific examples of cyanate ester resins include "PT30", "PT30S" and "PT60" (phenol novolak type polyfunctional cyanate ester resin), "ULL-950S" (polyfunctional cyanate ester resin) manufactured by Lonza Japan, Examples include "BA230" and "BA230S75" (a prepolymer in which part or all of bisphenol A dicyanate is triazinized to form a trimer).

Specific examples of the carbodiimide resin as component (b) include Carbodilite (registered trademark) V-03 (carbodiimide group equivalent: 216), V-05 (carbodiimide group equivalent: 216), V-07 (carbodiimide group equivalent: 216), manufactured by Nisshinbo Chemical Co., Ltd. Carbodiimide group equivalent: 200); V-09 (carbodiimide group equivalent: 200); Stabaxol (registered trademark) P manufactured by Rhein Chemie (carbodiimide group equivalent: 302).

Examples of the amine resin as component (b) include resins having one or more amino groups in one molecule, such as aliphatic amines, polyether amines, alicyclic amines, aromatic amines, etc. Examples include amines, among which aromatic amines are preferred from the viewpoint of achieving the desired effects of the present invention. The amine resin is preferably a primary amine or a secondary amine, and more preferably a primary amine. Specific examples of the amine curing agent include 4,4'-methylenebis(2,6-dimethylaniline), diphenyldiaminosulfone, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone, and 3,3' - Diaminodiphenylsulfone, m-phenylenediamine, m-xylylenediamine, diethyltoluenediamine, 4,4'-diaminodiphenyl ether, 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl- 4,4'-diaminobiphenyl, 3,3'-dihydroxybenzidine, 2,2-bis(3-amino-4-hydroxyphenyl)propane, 3,3-dimethyl-5,5-diethyl-4,4-diphenylmethane Diamine, 2,2-bis(4-aminophenyl)propane, 2,2-bis(4-(4-aminophenoxy)phenyl)propane, 1,3-bis(3-aminophenoxy)benzene, 1,3- Bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, bis(4-(4-aminophenoxy)phenyl)sulfone, Examples include bis(4-(3-aminophenoxy)phenyl)sulfone. Commercially available amine resins may be used, such as "KAYABOND C-200S", "KAYABOND C-100", "KAYA HARD AA", "KAYA HARD AB", and "KAYA HARD" manufactured by Nippon Kayaku Co., Ltd. Examples include "A-S" and "Epicure W" manufactured by Mitsubishi Chemical Corporation.

Examples of the acid anhydride resin as component (b) include resins having one or more acid anhydride groups in one molecule. Specific examples of acid anhydride resins include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnadic anhydride, and hydrogenated methylnadic anhydride. trialkyltetrahydrophthalic anhydride, dodecenyl succinic anhydride, 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, trimellitic anhydride Acid, pyromellitic anhydride, bensophenonetetracarboxylic dianhydride, biphenyltetracarboxylic dianhydride, naphthalenetetracarboxylic dianhydride, oxydiphthalic dianhydride, 3,3'-4,4'-diphenyl Sulfone tetracarboxylic dianhydride, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-C]furan-1, Examples include polymeric acid anhydrides such as 3-dione, ethylene glycol bis(anhydrotrimellitate), and styrene-maleic acid resin, which is a copolymer of styrene and maleic acid.

When containing an epoxy resin and a curing agent as components (b), the ratio of the epoxy resin to all curing agents is [total number of epoxy groups in the epoxy resin]:[total number of reactive groups in the curing agent]. The ratio is preferably in the range of 1:0.01 to 1:5, more preferably 1:0.05 to 1:3, and even more preferably 1:0.1 to 1:2. Here, "the number of epoxy groups in the epoxy resin" is the sum of all the values obtained by dividing the mass of nonvolatile components of the epoxy resin present in the resin composition by the epoxy equivalent. Moreover, "the number of active groups of a curing agent" is the total value of all the values obtained by dividing the mass of nonvolatile components of the curing agent present in the resin composition by the active group equivalent. By controlling the ratio of the epoxy resin and curing agent as component (b) within this range, a cured product with excellent flexibility can be obtained.

The content of the curing agent as component (b) is preferably 1% by mass or more, more preferably 3% by mass based on 100% by mass of the nonvolatile components in the resin composition, from the viewpoint of significantly obtaining the effects of the present invention. % or more, more preferably 5% by mass or more, preferably 20% by mass or less, more preferably 15% by mass or less, even more preferably 10% by mass or less.

From the viewpoint of significantly obtaining the effects of the present invention, the content of the curing agent as component (b) is preferably 5% by mass or more, more preferably 10% by mass, when the resin component in the resin composition is 100% by mass. It is at least 15% by mass, more preferably at least 15% by mass, preferably at most 40% by mass, more preferably at most 30% by mass, even more preferably at most 25% by mass.

<(c) Curing accelerator>
The resin composition may contain (c) a curing accelerator. Examples of the curing accelerator include phosphorus-based curing accelerators, amine-based curing accelerators, imidazole-based curing accelerators, guanidine-based curing accelerators, metal-based curing accelerators, etc. Curing accelerators are preferred, and amine curing accelerators are more preferred. The curing accelerator may be used alone or in combination of two or more.

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

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

Examples of imidazole-based curing accelerators include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate, 1-cyanoethyl- 2-Phenylimidazolium trimellitate, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-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 isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2- Phenyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2-methylimidazoline , 2-phenylimidazoline and other imidazole compounds, and adducts of imidazole compounds and epoxy resins, with 2-ethyl-4-methylimidazole and 1-benzyl-2-phenylimidazole being preferred.

As the imidazole curing accelerator, commercially available products may be used, such as "P200-H50" manufactured by Mitsubishi Chemical Corporation.

Examples of the guanidine-based curing accelerator include dicyandiamide, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, 1-(o-tolyl)guanidine, dimethylguanidine, diphenylguanidine, trimethylguanidine, Tetramethylguanidine, pentamethylguanidine, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7-methyl-1,5,7-triazabicyclo[4.4.0] Dec-5-ene, 1-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, etc., and dicyandiamide and 1,5,7-triazabicyclo[4.4.0]dec-5-ene are preferred.

Examples of the metal hardening accelerator include organometallic complexes or organometallic salts of metals such as cobalt, copper, zinc, iron, nickel, manganese, and tin. Specific examples of organometallic complexes include organic cobalt complexes such as cobalt (II) acetylacetonate and cobalt (III) acetylacetonate, organic copper complexes such as copper (II) acetylacetonate, and zinc (II) acetylacetonate. Examples include organic zinc complexes such as , organic iron complexes such as iron (III) acetylacetonate, organic nickel complexes such as nickel (II) acetylacetonate, and organic manganese complexes such as manganese (II) acetylacetonate. Examples of the organic metal salt include zinc octylate, tin octylate, zinc naphthenate, cobalt naphthenate, tin stearate, and zinc stearate.

(c) From the viewpoint of significantly obtaining the effects of the present invention, the content of the curing accelerator is preferably 0.01% by mass or more, more preferably 0.01% by mass, based on 100% by mass of nonvolatile components in the resin composition. The content is .02% by weight or more, particularly preferably 0.03% by weight or more, preferably 3% by weight or less, more preferably 1% by weight or less, particularly preferably 0.5% by weight or less.

(c) From the viewpoint of significantly obtaining the effects of the present invention, the content of the curing accelerator is preferably 0.01% by mass or more, more preferably 0.01% by mass when the resin component in the resin composition is 100% by mass. The content is .05% by mass or more, more preferably 0.1% by mass or more, preferably 3% by mass or less, more preferably 2% by mass or less, even more preferably 1% by mass or less.

<(d) Thermoplastic resin>
The resin composition may contain (d) a thermoplastic resin. (d) Thermoplastic resins include, for example, phenoxy resin, polyvinyl acetal resin, polyolefin resin, polyimide resin, polyamideimide resin, polyetherimide resin, polysulfone resin, polyether sulfone resin, polyphenylene ether resin, polyether ether ketone resin. , polyester resin, etc., with phenoxy resin being preferred. The thermoplastic resins may be used alone or in combination of two or more.

(d) The weight average molecular weight of the thermoplastic resin in terms of polystyrene is preferably 38,000 or more, more preferably 40,000 or more, and still more preferably 42,000 or more. The upper limit is preferably 100,000 or less, more preferably 70,000 or less, even more preferably 60,000 or less. (d) The weight average molecular weight of the thermoplastic resin in terms of polystyrene is measured by gel permeation chromatography (GPC). Specifically, (d) the weight average molecular weight of the thermoplastic resin in terms of polystyrene was determined using LC-9A/RID-6A manufactured by Shimadzu Corporation as a measuring device and Shodex K-800P/K-804L manufactured by Showa Denko Corporation as a column. /K-804L is measured at a column temperature of 40° C. using chloroform or the like as a mobile phase, and can be calculated using a standard polystyrene calibration curve.

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 types of skeletons selected from the group consisting of a skeleton and a trimethylcyclohexane skeleton. The terminal of the phenoxy resin may be any functional group such as a phenolic hydroxyl group or an epoxy group. One type of phenoxy resin may be used alone, or two or more types may be used in combination. Specific examples of phenoxy resins include Mitsubishi Chemical's "1256" and "4250" (both phenoxy resins containing bisphenol A skeleton), "YX8100" (phenoxy resin containing bisphenol S skeleton), and "YX6954" (bisphenol acetophenone). Other examples include "FX280" and "FX293" manufactured by Nippon Steel Chemical & Materials, "YL7500BH30", "YX6954BH30", "YX7553", "YX7553BH30" manufactured by Mitsubishi Chemical Corporation, Examples include "YL7769BH30", "YL6794", "YL7213", "YL7290", and "YL7482".

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

Specific examples of the polyimide resin include "Ricacoat SN20" and "Ricacoat PN20" manufactured by Shin Nihon Rika Co., Ltd. Specific examples of polyimide resins include linear polyimides obtained by reacting bifunctional hydroxyl group-terminated polybutadiene, diisocyanate compounds, and tetrabasic acid anhydrides (polyimide described in JP-A No. 2006-37083), polysiloxane skeletons, etc. Examples include modified polyimides such as polyimides containing polyimides (polyimides described in JP-A-2002-12667 and JP-A-2000-319386, etc.).

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

A specific example of the polyether sulfone resin includes "PES5003P" manufactured by Sumitomo Chemical Co., Ltd. Specific examples of the polyphenylene ether resin include oligophenylene ether styrene resin "OPE-2St 1200" manufactured by Mitsubishi Gas Chemical Co., Ltd. Specific examples of polyetheretherketone resins include "Sumiploy K" manufactured by Sumitomo Chemical Co., Ltd., and the like. A specific example of the polyetherimide resin includes "Ultem" manufactured by GE.

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

Examples of polyolefin resins include ethylene copolymers such as low density polyethylene, ultra-low density polyethylene, high density polyethylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, and ethylene-methyl acrylate copolymer. Resin; Examples include polyolefin elastomers such as polypropylene and ethylene-propylene block copolymers.

Examples of the polyester resin include polyethylene terephthalate resin, polyethylene naphthalate resin, polybutylene terephthalate resin, polybutylene naphthalate resin, polytrimethylene terephthalate resin, polytrimethylene naphthalate resin, polycyclohexane dimethyl terephthalate resin, and the like.

Among them, as the thermoplastic resin (d), phenoxy resin and polyvinyl acetal resin are preferable. Therefore, in a preferred embodiment, the thermoplastic resin includes one or more selected from the group consisting of phenoxy resin and polyvinyl acetal resin. Among these, as the thermoplastic resin, phenoxy resin is preferable, and phenoxy resin having a weight average molecular weight of 40,000 or more is particularly preferable.

(d) From the viewpoint of significantly obtaining the effects of the present invention, the content of the thermoplastic resin is preferably 0.1% by mass or more, more preferably 0.0% when the nonvolatile component in the resin composition is 100% by mass. .3% by mass or more, more preferably 0.5% by mass or more. The upper limit is preferably 5% by mass or less, more preferably 4% by mass or less, even more preferably 3% by mass or less.

(d) From the viewpoint of significantly obtaining the effects of the present invention, the content of the thermoplastic resin is preferably 0.5% by mass or more, more preferably 1% by mass when the resin component in the resin composition is 100% by mass. It is at least 1.5% by mass, more preferably at least 1.5% by mass, preferably at most 10% by mass, more preferably at most 5% by mass, even more preferably at most 3% by mass.

<(e) Other additives>
In addition to the above-mentioned components, the resin composition may further contain other additives as optional components. Such additives include, for example, flame retardants; organic fillers; organometallic compounds such as organocopper compounds, organozinc compounds, and organocobalt compounds; thickeners; antifoaming agents; leveling agents; adhesion imparting agents; Examples include resin additives such as colorants. These additives may be used alone or in combination of two or more in any ratio. The content of each can be set as appropriate by those skilled in the art.

The method for preparing the resin composition is not particularly limited, and includes, for example, a method of mixing and dispersing the ingredients together with a solvent, if necessary, using a rotary mixer or the like.

[Resin sheet]
The resin sheet includes a support and a resin composition layer formed of a resin composition provided on the support. The resin composition is as described in the [Resin composition] section.

The thickness of the resin composition layer is preferably 100 μm or less, more preferably 100 μm or less, from the viewpoint of making the printed wiring board thinner and providing a cured product with excellent insulation even if the cured product of the resin composition is a thin film. is 50 μm or less, more preferably 40 μm or less, 30 μm or less, or 20 μm or less. The lower limit of the thickness of the resin composition layer is not particularly limited, but can usually be 1 μm or more, 5 μm or more, etc.

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 preferred.

When using a film made of a plastic material as a support, examples of the plastic material include polyethylene terephthalate (hereinafter sometimes abbreviated as "PET") and polyethylene naphthalate (hereinafter sometimes abbreviated as "PEN"). ), polyesters such as polycarbonate (hereinafter sometimes abbreviated as "PC"), acrylics such as polymethyl methacrylate (PMMA), cyclic polyolefins, triacetyl cellulose (TAC), polyether sulfide (PES), polyether Examples include ketones and polyimides. Among these, polyethylene terephthalate and polyethylene naphthalate are preferred, and inexpensive polyethylene terephthalate is particularly preferred.

When using metal foil as the support, examples of the metal foil include copper foil, aluminum foil, etc., with copper foil being preferred. As the copper foil, a foil made of a single metal such as copper may be used, or 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 surface of the support to be bonded to the resin composition layer may be subjected to matte treatment, corona treatment, or antistatic treatment.

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. Examples of the release agent used in the release layer of the support with a release layer include one or more release agents selected from the group consisting of alkyd resins, polyolefin resins, urethane resins, and silicone resins. . As the support with a release layer, commercially available products may be used, such as "SK-1", "AL-5", "AL-7" manufactured by Lintec, "Lumirror T60" manufactured by Toray Industries, Inc., and "Lumirror T60" manufactured by Teijin Corporation. Examples include PET films with a release layer containing an alkyd resin mold release agent as a main component, such as "Purex" manufactured by Co., Ltd. and "Unipeel" manufactured by Unitika; "U2-NR1" manufactured by DuPont Films; It will be done.

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. In addition, when using the support body with a mold release layer, it is preferable that the thickness of the whole support body with a mold release layer is in the said range.

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

For the resin sheet, for example, a resin varnish is prepared by dissolving a resin composition in an organic solvent, and this resin varnish is applied onto a support using a die coater or the like, and further dried to form a resin composition layer. It can be manufactured by

Examples of organic solvents include ketones such as acetone, methyl ethyl ketone (MEK), and cyclohexanone; acetate esters such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, and carbitol acetate; cellosolve and butyl carbitol, etc. carbitols; aromatic hydrocarbons such as toluene and xylene; and amide solvents such as dimethylformamide, dimethylacetamide (DMAc) and N-methylpyrrolidone. One type of organic solvent may be used alone, or two or more types may be used in combination.

Drying may be performed by a known method such as heating or blowing hot air. Although drying conditions are not particularly limited, drying is performed so that the content of organic solvent in the resin composition layer is 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% to 60% by mass of organic solvent, the resin composition can be adjusted by drying at 50°C to 150°C for 3 to 10 minutes. A material layer can be formed.

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

[Manufacturing method of printed wiring board]
The method for manufacturing a printed wiring board of the present invention includes:
(A) forming an insulating layer containing a cured resin composition on the inner layer circuit board; and (B) performing plasma treatment on the surface of the insulating layer to form via holes or trenches. The gas used for this includes SF ₆ .

In the present invention, via holes or trenches are formed in the insulating layer by plasma processing instead of laser processing. Therefore, the haloing phenomenon can be suppressed, and the occurrence of unevenness on the side and bottom surfaces of the via hole and trench can be suppressed.

Moreover, in addition to step (A) and step (B), the method for manufacturing a printed wiring board of the present invention includes, as necessary,
(C) a step of roughening the surface of the insulating layer;
(D) The method may include a step of forming a conductor layer on the surface of the insulating layer.

It is preferable that step (A) and step (B) are performed in this order, and it is more preferable that step (A), step (B), step (C), and step (D) are performed in this order. Each step of the printed wiring board manufacturing method will be described below.

<Process (A)>
Step (A) is a step of forming an insulating layer containing a cured product of the resin composition on the inner layer circuit board. In step (A), an insulating layer is usually formed on the main surface of the inner layer circuit board. The main surface of the inner layer circuit board refers to the surface of the inner layer circuit board on which the insulating layer is provided. The resin composition used here is the resin composition explained above.

The step (A) may include the step of (A-1) preparing an inner layer circuit board. The inner layer circuit board typically includes a support substrate and a metal layer provided on the surface of the support substrate. The metal layer is exposed on the main surface of the inner layer circuit board.

Examples of the material of the supporting substrate include a glass epoxy substrate, a metal substrate, a polyester substrate, a polyimide substrate, a BT resin substrate, a thermosetting polyphenylene ether substrate, and the like. Examples of the material for the metal layer include copper foil, copper foil with a carrier, and materials for the conductor layer described below, with copper foil being preferred.

Further, in carrying out step (A), the step (A-2) of preparing a resin sheet may be included. The resin sheet is as described above.

In step (A), for example, a resin composition layer of a resin sheet is laminated on the main surface of the inner layer circuit board, and the resin composition layer is thermally cured to form an insulating layer.

Lamination of the inner layer circuit board and the resin sheet can be performed, for example, by heat-pressing the resin sheet to the inner layer circuit board from the support side. Examples of the member for heat-pressing the resin sheet to the inner layer circuit board (hereinafter also referred to as "heat-pressing member") include heated metal plates (SUS mirror plate, etc.), metal rolls (SUS rolls), and the like. Note that, instead of pressing the thermocompression bonding member directly onto the resin sheet, it is preferable to press it through an elastic material such as heat-resistant rubber so that the resin sheet sufficiently follows the surface irregularities of the inner layer circuit board.

The inner circuit board and the resin sheet may be laminated by vacuum lamination. In the vacuum lamination method, the heat-pressing temperature is preferably in the range of 60°C to 160°C, more preferably 80°C to 140°C, and the heat-pressing pressure is preferably in the range of 0.098 MPa to 1.77 MPa, more preferably 0. The pressure is in the range of .29 MPa to 1.47 MPa, and the heat-pressing time is preferably in the range of 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 performed using a commercially available vacuum laminator. Examples of commercially available vacuum laminators include a vacuum pressure laminator manufactured by Meiki Seisakusho, a vacuum applicator manufactured by Nikko Materials, and a batch vacuum pressure laminator.

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

The support may be removed before the resin sheets are laminated and thermally cured, or may be removed after step (A).

After laminating the resin sheet on the inner layer circuit board, 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 conditions that are normally 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 preferably 120°C to 240°C, more preferably 150°C to 220°C, and even more preferably 170°C to 210°C. It is ℃. The curing time can be preferably 5 minutes to 120 minutes, more preferably 10 minutes to 100 minutes, even more preferably 15 minutes to 100 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 cured 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). Preheating may be performed for 5 minutes or more (preferably 5 minutes to 150 minutes, more preferably 15 minutes to 120 minutes, even more preferably 15 minutes to 100 minutes).

The thickness of the insulating layer is preferably 100 μm or less, more preferably 50 μm or less, still more preferably 40 μm or less, 30 μm or less, or 20 μm or less, preferably 1 μm or more, and more preferably 5 μm or more.

Note that instead of forming the insulating layer using a resin sheet, the insulating layer may be formed by directly applying a resin composition onto the main surface of the inner layer circuit board. The conditions for forming the insulating layer at this time are the same as those for forming the insulating layer using a resin sheet. Moreover, the resin composition to be applied is as explained above.

After completing step (A) and before performing step (B), in order to effectively form a via hole or trench in the insulating layer, (A-3) laminating a dry film on the insulating layer or on the support; and (A-4) exposing and developing the dry film using a photomask to obtain a patterned dry film.

In step (A-3), a dry film is laminated on the insulating layer or support formed on the main surface of the inner layer circuit board. The conditions for laminating the insulating layer and the dry film may be the same as those for laminating the inner circuit board and the resin sheet.

The dry film used in step (A-3) may be any film that can yield a patterned dry film through exposure and development, and even better if it is resistant to the plasma treatment in step (B). . Further, as the dry film, a photosensitive dry film made of a photoresist composition can be used. As such a dry film, for example, a dry film formed of a resin such as a novolac resin or an acrylic resin can be used.

The thickness of the dry film is preferably 10 μm or more, more preferably 15 μm or more, even more preferably 20 μm or more, and preferably 100 μm or less, more preferably 70 μm or less, and even more preferably It is 50 μm or less.

In step (A-4), exposure is performed by irradiating active energy rays through a photomask having a predetermined pattern. The details of the exposure include irradiating the surface of the dry film with active energy rays through a photomask to photocure the exposed portions of the dry film. Examples of active energy rays include ultraviolet rays, visible rays, electron beams, and X-rays, with ultraviolet rays being preferred. The irradiation amount and irradiation time of ultraviolet rays can be appropriately set depending on the dry film. Examples of the exposure method include a contact exposure method in which the mask pattern is exposed to light by bringing it into close contact with the dry film, and a non-contact exposure method in which the mask pattern is exposed using parallel light without being brought into close contact with the dry film.

After exposure, one of the exposed and non-exposed portions (usually the non-exposed portion) of the dry film is removed by development to form a patterned dry film. Development may be performed by either wet development or dry development. Examples of the developing method include a dip method, a paddle method, a spray method, a brushing method, and a scraping method.

In step (B), which will be described later, plasma treatment is performed using the patterned dry film as a mask to form via holes or trenches.

<Process (B)>
Step (B) is a step of performing plasma treatment on the surface of the insulating layer to form via holes or trenches on the surface of the insulating layer. (B) The details of the process are as shown in FIG. 1 as an example, by removing the cured product 1020 of the resin composition contained in the insulating layer 100 and scraping the inorganic filler 1010 using plasma using a predetermined gas to form the via hole. 110 is formed. Usually, the cured resin component 1020 and the inorganic filler 1010 are etched by plasma. When plasma treatment is continued to etch the inorganic filler 1010, a portion of the cured resin component 1020 is dug out. The cured product 1020 of the resin component that has been dug out may fall off the side wall or bottom surface of the via hole 110, and a portion 1030 (unevenness) where the cured product 1020 of the resin component is dug out may occur on the side wall or bottom surface of the via hole 110. Usually, no depression is formed in the portion where the inorganic filler 1010 is etched. The content of the inorganic filler 1010 is 60% by mass or more when the nonvolatile component in the resin composition is 100% by mass, and the content of the inorganic filler 1010 is greater than the resin component, so the bottom and side walls of the via hole 110 are The frequency of locations 1030 where the cured product 1020 of the resin component is excavated can be reduced. That is, the number of irregularities on the bottom surface and side walls can be reduced, and the formation of non-uniform surfaces can be suppressed. As a result, it becomes possible to make the thickness of the conductor layer formed in the via hole 110 uniform in step (D) described below.

In the plasma treatment, a via hole or trench is formed on the surface of the insulating layer by treating the surface of the insulating layer with plasma generated by introducing gas into a plasma generator. There are no particular restrictions on the method of generating plasma, and examples include microwave plasma that generates plasma using microwaves, high-frequency plasma that uses high frequency waves, atmospheric pressure plasma that generates under atmospheric pressure, and atmospheric pressure plasma that generates under vacuum. Atmospheric pressure plasma generated under vacuum is preferred.

Further, the plasma used in step (C) is preferably RF plasma excited by high frequency.

As the gas to be turned into plasma, a gas containing SF ₆ that can etch the resin component and inorganic filler in the insulating layer is used. The gas to be turned into plasma only needs to contain SF ₆ , and may be a mixed gas containing other gases such as Ar and O ₂ in addition to SF ₆ . The gas to be turned into plasma is preferably a mixed gas containing SF ₆ and at least one of Ar and O ₂ , more preferably a mixed gas containing SF ₆ , Ar, and O ₂ .

The mixing ratio of the mixed gas with SF ₆ and other gases (SF ₆ /other gases: unit: sccm) is preferably 1 from the viewpoint of making the thickness of the conductor layer formed in the via hole or trench uniform. /0.01 to 1/1, more preferably 1/0.05 to 1/1, more preferably 1/0.1 to 1/1.

When the gas to be turned into plasma is a mixed gas containing SF ₆ , Ar and O ₂ , the mixing ratio of Ar and O ₂ (Ar/O ₂ : unit is sccm) is determined from the viewpoint of significantly obtaining the effects of the present invention. , 1/0.01 to 1/1, more preferably 1/0.05 to 1/1, more preferably 1/0.1 to 1/1.

The irradiation time in the plasma treatment is not particularly limited, but is preferably 1 minute or more, more preferably 2 minutes or more, and even more preferably 3 minutes or more. The upper limit is not particularly limited, but is preferably 20 minutes or less, more preferably 15 minutes or less, and even more preferably 10 minutes or less.

In the present invention, the via hole or trench is formed by plasma treatment, so the opening diameter of the via hole or trench can be reduced. The opening diameter is preferably 50 μm or less, more preferably 40 μm or less, still more preferably 30 μm or less, and even more preferably 20 μm or less. The lower limit is not particularly limited, but may be 1 μm or more.

<Step (C)>
Step (C) is a step of roughening the surface of the insulating layer, and in detail, foreign matter such as solids of the resin component of the resin composition that fell off in step (B) is removed from the via hole or trench using a treatment liquid. This is the process of Foreign matter is present on the surface of the insulating layer after step (B). This foreign material may include, for example, solid resin components of the resin composition excavated by plasma treatment. This foreign material may cause a decrease in the adhesion strength of the conductor layer. Therefore, step (C) is performed to remove these foreign substances. The details of step (C) are, after step (B) is completed, the surface of the insulating layer is brought into contact with a treatment liquid to remove the foreign matter. Step (C) may be performed once or multiple times.

The procedure and conditions of step (C) are not particularly limited, and known procedures and conditions commonly used in 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 using a swelling liquid, a roughening treatment using an oxidizing agent, and a neutralization treatment using a neutralizing liquid in this order. The swelling liquid used in the roughening treatment is not particularly limited, but includes alkaline solutions, surfactant solutions, etc., preferably alkaline solutions, and more preferably sodium hydroxide solutions and potassium hydroxide solutions. preferable. Examples of commercially available swelling liquids include "Swelling Dip Securigance P", "Swelling Dip Securigance SBU", and "Swelling Dip Securigant P" manufactured by Atotech Japan. It will be done. Swelling treatment with a swelling liquid is not particularly limited, but can be carried out, for example, by immersing the insulating layer in a swelling liquid at 30° C. to 90° C. for 1 minute to 20 minutes. From the viewpoint of suppressing the swelling of the resin in the insulating layer to an appropriate level, it is preferable to immerse the insulating layer in a swelling liquid at 40° C. to 80° C. for 5 minutes to 15 minutes. The oxidizing agent used in the roughening treatment is not particularly limited, but includes, for example, an alkaline permanganate solution in which potassium permanganate or sodium permanganate is dissolved in an aqueous solution of sodium hydroxide. The roughening treatment with an oxidizing agent such as an alkaline permanganic acid solution is preferably performed by immersing the insulating layer in an oxidizing agent solution heated to 60° C. to 100° C. for 10 minutes to 30 minutes. Further, the concentration of permanganate in the alkaline permanganic acid 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 Securigance P" manufactured by Atotech Japan. Further, as the neutralizing liquid used for the roughening treatment, an acidic aqueous solution is preferable, and a commercially available product includes, for example, "Reduction Solution Securigant P" manufactured by Atotech Japan. The treatment with the neutralizing liquid can be carried out by immersing the treated surface, which has been roughened with an oxidizing agent, in the neutralizing liquid at 30° C. to 80° C. for 1 minute to 30 minutes. From the viewpoint of workability, it is preferable to immerse the object that has been roughened with an oxidizing agent in a neutralizing solution at 40° C. to 70° C. for 5 minutes to 20 minutes.

In one embodiment, the arithmetic mean roughness (Ra) of the surface of the insulating layer after the roughening treatment is preferably 500 nm or less, more preferably 400 nm or less, and still more preferably 300 nm or less. The lower limit is not particularly limited, but is preferably 30 nm or more, more preferably 40 nm or more, and still more preferably 50 nm or more. The arithmetic mean roughness (Ra) of the surface of the insulating layer can be measured using a non-contact surface roughness meter.

<Step (D)>
Step (D) is a step of forming a conductor layer on the surface of the insulating layer. The conductor material used for the conductor layer is not particularly limited. In a preferred embodiment, the conductor layer includes 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, and the alloy layer may be, for example, an alloy of two or more metals selected from the above group (for example, a nickel-chromium alloy, a copper-chromium alloy, a copper-chromium alloy, etc.). nickel alloys and copper-titanium alloys). Among these, from the viewpoint of versatility in forming conductor layers, cost, ease of patterning, etc., monometallic layers of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, nickel-chromium alloys, copper, etc. An alloy layer of nickel alloy or copper/titanium alloy is preferable, a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper, or an alloy layer of nickel/chromium alloy is more preferable, and a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper is more preferable. More preferred is a metal layer.

The conductor layer may have a single layer structure or a multilayer structure in which two or more single metal layers or alloy layers made of different types of metals or alloys are laminated. When the conductor layer has a multilayer structure, the layer in contact with the hardened body 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 depends on the desired printed wiring board design, but is generally between 3 μm and 35 μm, preferably between 5 μm and 30 μm.

In a preferred embodiment of step (D), the conductor layer is formed by sputtering. In the present invention, since the resin composition contains an inorganic filler having an average particle size of 0.1 μm or less, the difference in unevenness at the bottom and side walls of the via hole where the inorganic filler is excavated is reduced. As a result, it becomes possible to make the thickness of the conductor layer formed in the via hole or trench uniform.

When forming a conductive layer by sputtering, usually, a conductive seed layer is first formed on the surface of an insulating layer by sputtering, and then a conductive sputtered layer is formed on the conductive seed layer by sputtering. Before forming the conductive seed layer by sputtering, the surface of the insulating layer may be cleaned by reverse sputtering. Various gases can be used for the reverse sputtering, but Ar, O ₂ and N ₂ are preferred among them. If the seed layer is Cu and Cu alloy, use Ar or O ₂ or Ar, O ₂ mixed gas, if the seed layer is Ti, use Ar or N ₂ or Ar, N ₂ mixed gas, if the seed layer is Cr or Cr alloy (nichrome). etc.), Ar or O ₂ or a mixed gas of Ar and O ₂ is preferable. Sputtering can be performed using various sputtering devices such as magnetron sputtering and mirrortron sputtering. Examples of metals forming the conductive seed layer include Cr, Ni, Ti, and nichrome. Particularly preferred are Cr and Ti. The thickness of the conductive seed layer is usually preferably 5 nm or more, more preferably 10 nm or more, and preferably 1000 nm or less, more preferably 500 nm or less. Examples of metals forming the conductor sputtered layer include Cu, Pt, Au, and Pd. Particularly preferred is Cu. The thickness of the conductor sputtered layer is usually preferably 50 nm or more, more preferably 100 nm or more, and preferably 3000 nm or less, more preferably 1000 nm or less.

After forming the conductor layer by sputtering, a copper plating layer may be further formed on the conductor layer by electrolytic copper plating. The thickness of the copper plating layer is usually preferably 5 μm or more, more preferably 8 μm or more, and preferably 75 μm or less, more preferably 35 μm or less. Known methods such as a subtractive method and a semi-additive method can be used for circuit formation.

The printed wiring board manufacturing method of the present invention exhibits the characteristic that the haloing phenomenon is suppressed. The haloing phenomenon will be explained below with reference to the drawings.

FIG. 2 shows a surface 100U of an insulating layer 100, opposite to a metal layer 210 (not shown in FIG. 2), immediately before a conductor layer is formed, of a conventional printed wiring board in which via holes are formed with a laser. FIG. FIG. 3 is a cross-sectional view schematically showing an insulating layer 100 of a conventional printed wiring board in which via holes are formed with a laser, just before a conductor layer is formed, together with a metal layer 210 of an inner circuit board 200. FIG. 3 shows a cross section of the insulating layer 100 taken along a plane that passes through the center 120C of the via bottom 120 of the via hole 110 and is parallel to the thickness direction of the insulating layer 100.

As shown in FIG. 2, when a via hole is formed using a laser, a discolored portion 140 may occur due to deterioration of the resin due to the heat of the laser. This discolored portion 140 is eroded by a chemical during the roughening treatment, and the insulating layer 100 may peel off from the metal layer 210, forming a gap 160 continuous from the edge 150 of the via bottom 120 (via hole phenomenon).

In the present invention, since the via holes or trenches are formed by plasma treatment that hardly generates heat, deterioration of the resin can be suppressed. Therefore, peeling of the insulating layer 100 from the metal layer 210 can be suppressed, the size of the gap 160 can be reduced, and ideally the discolored part 140 and the gap 160 can be eliminated.

The size of the discolored portion 140 can be evaluated by the harrowing distance Wt of the via hole 110 from the edge 180 of the via top 130.

The edge 180 of the via top 130 corresponds to the inner edge of the discolored portion 140. The harrowing 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 peripheral 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 is, the more effectively the formation of the discolored portion 140 can be suppressed.

For example, plasma is irradiated onto an insulating layer 100 formed on a copper foil, which is obtained by heating and curing a resin sheet at 100° C. for 30 minutes, then at 180° C. for 30 minutes, and the top diameter Lt is approximately 15 μm. A via hole 110 is formed. The haloing distance Wt of the thus obtained insulating layer 100 from the edge 180 of the via top 130 can be preferably 15 μm or less, more preferably 10 μm or less, and still more preferably 5 μm or less. The lower limit is not particularly limited, but may be 0 μm or more, 0.01 μm or more, etc.

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

Further, according to studies conducted by the present inventors, it has been found that, in general, 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 based on the ratio of the size of the discolored portion 140 to the diameter of the via hole 110. For example, evaluation can be made using the harrowing ratio Ht to the top radius Lt/2 of the via hole 110. Here, the top radius Lt/2 of the via hole 110 refers to the radius of the via top 130 of the via hole 110. Further, the harrowing ratio Ht to the top radius Lt/2 of the via hole 110 is a ratio obtained by dividing the harrowing distance Wt from the edge 180 of the via top 130 by the top radius Lt/2 of the via hole 110. The smaller the haloing ratio Ht to the top radius Lt/2 of the via hole 110, the more effectively the formation of the discolored portion 140 could be suppressed.

For example, an insulating layer 100 formed on copper foil, obtained by heating and curing a resin sheet at 100° C. for 30 minutes and then at 180° C. for 30 minutes, is irradiated with plasma to form a layer with a top diameter Lt of about 15 μm. A via hole 110 is formed. The harrowing ratio Ht to the top radius Lt/2 of the via hole 110 formed in the insulating layer 100 thus obtained is preferably 35% or less, more preferably 25% or less, still more preferably 10% or less, 5 % or less. The lower limit is not particularly limited, but may be 0% or more, 0.01% or more, etc.

The harrowing 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 harrowing distance Wt of the via hole 110 from the edge 180 of the via top 130.

The edge 150 of the via bottom 120 corresponds to the inner peripheral edge of the gap 160. Therefore, the distance Wb from the edge 150 of the via bottom 120 to the outer peripheral end of the gap 160 (that is, the end far from the center 120C of the via bottom 120) 170 is determined by the size of the gap 160 in the in-plane direction. Equivalent to. Here, the in-plane direction refers to 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 harrowing distance Wb of the via hole 110 from the edge 150 of the via bottom 120.

Regarding the size of the discolored portion 140, the degree of suppression of the haloing phenomenon can also be evaluated based on 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.

The harrowing distance Wb of the via hole 110 of the insulating layer 100 from the edge 150 of the via bottom 120 is preferably 10 μm or less, more preferably 5 μm or less, still more preferably 4.5 μm or less, particularly preferably 4 μm or less. The lower limit is not particularly limited, but may be 0 μm or more, 0.01 μm or more, etc. The haloing distance Wb is determined by cutting the insulating layer 100 using a focused ion beam (FIB) 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.

Furthermore, in the conventional method using a laser, it has been found that the larger the diameter of the via hole, the larger the size of the gap 160 tends to be. Therefore, the degree of suppression of the haloing phenomenon can be evaluated based on the ratio of the size of the gap 160 to the diameter of the via hole 110. For example, evaluation can be made using the harrowing ratio Hb to the bottom radius Lb/2 of the via hole 110. Here, the bottom radius Lb/2 of the via hole 110 refers to the radius of the via bottom 120 of the via hole 110. Further, the harrowing ratio Hb to the bottom radius Lb/2 of the via hole 110 is a ratio obtained by dividing the harrowing distance Wb from the edge 150 of the via bottom 120 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 can be suppressed.

The haloing ratio Hb can be made preferably 35% or less, more preferably 30% or less, even more preferably 25% or less. The harrowing ratio Hb to the bottom radius Lb/2 of the via hole 110 can be calculated from the bottom diameter Lb of the via hole 110 and the harrowing distance Wb of the via hole 110 from the edge 150 of the via bottom 120.

In the process of manufacturing a printed wiring board, via hole 110 is usually formed without another conductor layer (not shown) provided on surface 100U of insulating layer 100 opposite to metal layer 210. Therefore, if the manufacturing process of the printed wiring board is understood, the structure in which the via bottom 120 is on the metal layer 210 side and the via top 130 is open on the side opposite to the metal layer 210 can be clearly recognized. However, in the completed printed wiring board, conductor layers may be provided 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 their 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, the via bottom 120 and the via top 130 can be distinguished depending on the diameter.

The printed wiring board manufacturing method of the present invention can reduce the frequency of locations where resin components are excavated on the bottom and side walls of via holes. Therefore, a conductor layer with a uniform thickness can be formed within the via hole. When observing the cross section of the insulating layer using SEM, it can be confirmed that the copper layer is formed uniformly and without interruption on the walls of the trenches and via holes formed in the insulating layer.

[Semiconductor device]
The semiconductor device of the present invention includes a printed wiring board. The semiconductor device of the present invention can be manufactured using a printed wiring board obtained by the manufacturing method of the present invention.

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

The semiconductor device of the present invention can be manufactured by mounting components (semiconductor chips) on conductive parts of a printed wiring board. A "conducting location" is a "location on a printed wiring board that transmits electrical signals," and the location may be on the surface or embedded. Further, the semiconductor chip is not particularly limited as long as it is an electric circuit element made of a semiconductor.

The mounting method for semiconductor chips when manufacturing semiconductor devices is not particularly limited as long as the semiconductor chip functions effectively, but specifically, wire bonding mounting method, flip chip mounting method, bumpless buildup layer, etc. Examples include a mounting method using (BBUL), a mounting method using an anisotropic conductive film (ACF), a mounting method using a non-conductive film (NCF), and the like. Here, "a mounting method using a bumpless buildup layer (BBUL)" refers to a "mounting method in which a semiconductor chip is directly embedded in a recess of a printed wiring board and the semiconductor chip and wiring on the printed wiring board are connected." It is.

Hereinafter, the present invention will be specifically explained by showing 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. Further, the operations described below were performed in an environment of normal temperature and normal pressure unless otherwise specified.

<Inorganic filler used>
Inorganic filler 1: N-phenyl- ³ -aminopropyltrimethoxysilane ( Surface treated with 1 part of KBM573 (manufactured by Shin-Etsu Chemical Co., Ltd.).
Inorganic filler 2: N-phenyl-3-aminopropyltrimethoxysilane (Shin-Etsu Chemical Co., Ltd.) to 100 parts of spherical silica (“SC1500SQ” manufactured by Admatex, average particle size 0.3 μm, specific surface area 11 m ² /g) Surface treated with 2 parts of KBM573 (manufactured by Kogyo Co., Ltd.).
Inorganic filler 3: N-phenyl- ³ -aminopropyltrimethoxysilane ( Surface treated with 1 part of KBM573 (manufactured by Shin-Etsu Chemical Co., Ltd.).

<Preparation of resin composition 1>
6 parts of bixylenol type epoxy resin ("YX4000HK" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent: approximately 185), 5 parts of naphthalene type epoxy resin ("ESN475V" manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., epoxy equivalent: approximately 332), bisphenol AF type epoxy resin ( 15 parts of "YL7760" (manufactured by Mitsubishi Chemical Corporation, epoxy equivalent: approximately 238), 2 parts of naphthylene ether type epoxy resin ("HP6000L", manufactured by DIC Corporation, epoxy equivalent of approximately 213), cyclohexane type epoxy resin ("ZX1658GS", manufactured by Mitsubishi Chemical Corporation) , epoxy equivalent: about 135), 2 parts of phenoxy resin (YX7553BH30 manufactured by Mitsubishi Chemical Corporation, 1:1 solution of cyclohexanone:methyl ethyl ketone (MEK) with solid content of 30% by mass, Mw = 35000), 20 parts of solvent naphtha. and 10 parts of cyclohexanone was heated and dissolved in a mixed solvent with stirring. After cooling to room temperature, 4 parts of a triazine skeleton-containing cresol novolac curing agent (“LA-3018-50P” manufactured by DIC, 2-methoxypropanol solution with a hydroxyl equivalent of about 151 and a solid content of 50%), active 6 parts of ester resin ("EXB-8000L-65TM" manufactured by DIC Corporation, active group equivalent: about 220, 1:1 solution of toluene: methyl ethyl ketone (MEK) with 65% by mass of non-volatile components), 85 parts of inorganic filler 1, After mixing 0.05 part of an amine curing accelerator (4-dimethylaminopyridine (DMAP)) and uniformly dispersing it with a high-speed rotating mixer, it was filtered with a cartridge filter ("SHP020" manufactured by ROKITECHNO) to determine the resin composition. Product 1 was prepared.

<Preparation of resin composition 2>
In the preparation of resin composition 1,
6 parts of an active ester resin ("EXB-8000L-65TM" manufactured by DIC Corporation, a 1:1 solution of toluene:methyl ethyl ketone (MEK) with an active group equivalent of about 220 and 65% by mass of non-volatile components) was added to an active ester resin (DIC). "EXB-8200L-65T" manufactured by Co., Ltd., active group equivalent approximately 233, solid content 65% by mass toluene solution) 6 parts,
85 parts of inorganic filler 1 was replaced with 82 parts of inorganic filler 2.
Resin composition 2 was prepared in the same manner as resin composition 1 except for the above matters.

<Preparation of resin composition 3>
In the preparation of resin composition 1,
Two parts of phenoxy resin (YX7553BH30 manufactured by Mitsubishi Chemical Corporation, 1:1 solution of cyclohexanone:methyl ethyl ketone (MEK) with a solid content of 30% by mass, Mw = 35000) was mixed with phenoxy resin (YL7500BH30 manufactured by Mitsubishi Chemical Corporation, solid content 30% by weight of a 1:1 solution of cyclohexanone: methyl ethyl ketone (MEK), Mw = 44000),
85 parts of Inorganic Filler 1 was replaced with 110 parts of Inorganic Filler 3.
Resin composition 3 was prepared in the same manner as resin composition 1 except for the above matters.

<Preparation of resin composition 4>
In the preparation of resin composition 1, the amount of inorganic filler 1 was changed from 85 parts to 48 parts. Resin composition 4 was prepared in the same manner as resin composition 1 except for the above matters.

The components used in the preparation of resin compositions 1 to 4 and their blending amounts (parts by mass of non-volatile components) are shown in the table below. The content of the curing agent and active ester resin represents the content when the resin component in the resin composition is 100% by mass, and the content of component (a) represents the content of the nonvolatile component in the resin composition. The content is expressed as 100% by mass.

<Production of resin sheets A and B>
As a support, a PET film ("Lumirror R80" manufactured by Toray Industries, Inc., thickness 38 μm, softening point 130°C, "Release PET") treated with an alkyd resin mold release agent ("AL-5" manufactured by Lintec Corporation) was used. prepared. By uniformly applying each resin composition onto the mold release agent of the support using a die coater so that the thickness of the resin composition layer after drying is 35 μm, and drying at 70°C to 95°C for 2 minutes. A resin composition layer was obtained on the mold release PET. Next, the rough surface of a polypropylene film ("Alphan MA-411" manufactured by Oji F-Tex Co., Ltd., thickness 15 μm) was applied as a protective film to the surface of the resin sheet that was not bonded to the support, so as to bond it to the resin composition layer. Laminated on. Thereby, a resin sheet A was obtained which consisted of the release PET (support), the resin composition layer, and the protective film in this order.

Further, resin sheet B was obtained in the same manner as resin sheet A except that each resin composition was uniformly applied using a die coater so that the thickness of the resin composition layer after drying was 15 μm.

<Measurement of thickness of resin composition layer, etc.>
The thickness of the resin composition layer was measured using a contact film thickness meter (manufactured by Mitutoyo, MCD-25MJ).

-Preparation of evaluation boards A and B-
(1) Preparation of copper-clad laminate As a copper-clad laminate, a glass cloth base epoxy resin double-sided copper-clad laminate with copper foil layers laminated on both sides (copper foil thickness 3 μm, substrate thickness 0.15 mm, Mitsubishi Gas "HL832NSF LCA" (manufactured by Kagaku Co., Ltd., size 255 x 340 mm) was prepared, placed in an oven at 130°C, and dried for 30 minutes.

(2) Lamination of resin sheets The protective film is peeled off from each resin sheet A produced, and the resin composition layer is laminated using a batch vacuum pressure laminator (manufactured by Nikko Materials, 2-stage build-up laminator, CVP700). It was laminated on both sides of the copper-clad laminate so that it was in contact with the copper-clad laminate. Lamination was carried out by reducing the pressure for 30 seconds to a pressure of 13 hPa or less, and press-bonding at 130° C. and a pressure of 0.74 MPa for 45 seconds. Then, hot pressing was performed at 120° C. and a pressure of 0.5 MPa for 75 seconds.

(3) Heat curing of resin composition layer The copper clad laminate on which resin sheet A was laminated was placed in an oven at 100°C for 30 minutes, then transferred to an oven at 180°C, and then heat cured for 30 minutes. An insulating layer was formed and the support was peeled off. As a result, a copper-clad laminate A was obtained in which an insulating layer of 35 μm was formed.

Further, a copper clad laminate B having a 15 μm insulating layer formed thereon was obtained in the same manner as the production of copper clad laminate A except that resin sheet B was used.

(4) Dry film pattern formation A 20 μm thick dry film (“ALPHO 20A263” manufactured by Nikko Materials) was laminated on the surface of the insulating layer of the copper-clad laminate A on which the above insulating layer was formed. The dry film was laminated using a batch vacuum pressure laminator ("MVLP-500" manufactured by Meiki Manufacturing Co., Ltd.). After reducing the pressure to 13 hPa or less by reducing the pressure for 30 seconds, the dry film was laminated at a pressure of 0.1 MPa and a temperature of 70°C. Then, pressure was applied for 20 seconds. Thereafter, a glass mask having a trench pattern was placed on a polyethylene terephthalate film serving as a protective layer of the dry film, and UV irradiation was performed using a UV lamp at an irradiation intensity of 150 mJ/cm ² . After UV irradiation, a spray treatment was performed for 30 seconds using a 1% aqueous sodium carbonate solution at 30° C. at a spray pressure of 0.15 MPa. Thereafter, it was washed with water and patterned to form a trench pattern with a wiring width of 20 μm, thereby obtaining a trench-processed substrate.

Further, using a glass mask having a via pattern, patterning was performed on the copper clad laminate B so that a via hole having a top diameter of 15 μm was formed in the same manner as on the copper clad laminate A, thereby obtaining a via-processed substrate.

(5) Plasma processing In Examples 1 to 3 and Comparative Example 1, a plasma dry etching device (PlasmaPro 100 manufactured by Oxford Instruments) was used, and Ar/SF ₆ /O ₂ was mixed at a mixing ratio of 10:40:8. (sccm) for 5 minutes under the conditions of vacuum: 50 mTorr, RF power: 120 W, and ICP power: 0 W. A via hole with a top diameter of about 15 μm was formed in the insulating layer, and then the dry film was peeled off to obtain a trench evaluation board.

In addition, a via hole having a top diameter of approximately 15 μm was formed in the insulating layer of the via-processed substrate using the same method as in the preparation of the trench evaluation board, and then the dry film was peeled off to obtain a via evaluation board.

(6) Sandblasting Comparative Example 2 is trench processing at a processing pressure of 0.2 MPa using silicon carbide (average particle size 0.6 μm, modified Mohs hardness 13, "SER-A06" manufactured by Shinano Electric Refining Co., Ltd.) as abrasive grains. A trench was formed by sandblasting the insulating layer on the substrate, and then the dry film was peeled off to produce a sandblast trench evaluation board.

In addition, a via hole having a top diameter of approximately 15 μm was formed in the insulating layer of the via-processed substrate in the same manner as in the production of the sandblast trench evaluation board, and then the dry film was peeled off to obtain a sandblast via evaluation board.

(7) UV-YAG laser via processing In Comparative Example 3, a UV-YAG laser processing machine ("LU-2L212/M50L" manufactured by Via Mechanics Co., Ltd.) was used to apply a laser beam to the insulating layer of the copper-clad laminate B. was irradiated to form a plurality of via holes having a top diameter of approximately 15 μm. The laser light irradiation conditions were a power of 0.08 W and a number of shots of 25. This board will be used as a laser evaluation board.

<Observation of trench walls and via walls>
After heating the trench evaluation board, via evaluation board, sandblast trench evaluation board, and sandblast via evaluation board at 150°C for 30 minutes, copper was deposited on the insulating layer using a sputtering device ("E-400S" manufactured by Canon Anelva). A layer (200 nm thick) was formed. Thereafter, cross-sectional observation was performed using a FIB-SEM composite device ("SMI3050SE" manufactured by SII Nano Technology Co., Ltd.), and evaluation was made according to the following criteria.
Good: A copper layer is formed uniformly and without interruption on the wall surface of a trench formed in an insulating layer or on the wall surface of a via hole.
×: The copper layer is not uniformly formed due to unevenness.

<Measurement of via hole dimensions and harrowing distance>
The via evaluation board, the sandblast via evaluation board, and the laser evaluation board were observed using an optical microscope ("KH8700" manufactured by Hirox Corporation). Specifically, the insulating layer around the via hole was observed from above the via evaluation board using an optical microscope (CCD). The size of the via hole was observed by focusing an optical microscope on the via top. The top diameter (Lt) of the via hole was measured from the observed image. It was observed whether a donut-shaped haloing part, in which the insulating layer turned white, was observed around the via hole, continuing from the edge of the via top of the via hole. From the observed image, measure the radius r1 of the via top of the via hole (corresponding to the inner radius of the harrowing part) and the outer radius r2 of the harrowing part, and calculate the difference r2 - r1 between these radii r1 and radius r2. was calculated as the harrowing distance from the edge of the beer top at the measurement point.

The above measurements were performed in five randomly selected via holes. Then, the average of the measured values of the top diameters of the via holes at five locations was adopted as the top diameter Lt1 of the via hole of the sample. Furthermore, the average of the measured values of the harrowing distances of the five via holes was adopted as the harrowing distance Wt from the edge of the via top of the sample.

The harrowing ratio Ht represents the ratio "Wt/(Lt1/2)" between the harrowing distance Wt from the edge of the via top and the radius (Lt1/2) of the via top of the via hole before roughening treatment. If the haloing ratio Ht was 35% or less, the haloing evaluation was determined to be "○", and if the haloing ratio Ht was greater than 35%, the haloing evaluation was determined to be "x".

＊ハローイング距離の欄の「－」はハローイングが観測されないことを意味する。

*A "-" in the haloing distance column means that no haloing is observed.

100 Insulating layer 100U Surface of the insulating layer opposite to the 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 portion 170 Edge on the outer periphery of the gap portion 180 Via top edge 190 outer edge of discolored part 200 inner layer substrate 210 metal layer 1010 inorganic filler 1020 cured product of resin component 1030 location where cured product of resin component is excavated Lb bottom diameter of via hole Lt top diameter of via hole Wb Haloing distance from the edge of the via bottom Wt Haloing distance from the edge of the via top

Claims (8)

(A) Forming an insulating layer containing a cured resin composition on the inner layer circuit board, and (B) Plasma-forming a mixed gas containing SF ₆ , Ar, and O ₂ on the surface of the insulating layer. A step of performing plasma treatment to form a via hole or trench,
The resin composition contains an inorganic filler, and the content of the inorganic filler is 60% by mass or more when the nonvolatile components in the resin composition are 100% by mass,
A method for manufacturing a printed wiring board, wherein the gas used for plasma processing contains SF ₆ . (A) Forming an insulating layer containing a cured resin composition on the inner layer circuit board, and (B) Plasma-forming a mixed gas containing SF ₆ , Ar, and O ₂ on the surface of the insulating layer. A step of performing plasma treatment to form a via hole or trench,
The resin composition contains an inorganic filler, and the content of the inorganic filler is 40% by volume or more when the nonvolatile components in the resin composition are 100% by volume,
A method for manufacturing a printed wiring board, wherein the gas used for plasma processing contains SF ₆ . The method for manufacturing a printed wiring board according to claim 1 or 2, further comprising the step of (D) forming a conductor layer. The method for manufacturing a printed wiring board according to claim 3, wherein the step (D) forms the conductor layer by sputtering. The method for manufacturing a printed wiring board according to any one of claims 1 to 4 , wherein the resin composition contains a curable resin. Contains inorganic fillers,
A mixed gas containing SF ₆ , Ar and O ₂ is used in the insulating layer of the printed wiring board, where the content of the inorganic filler is 60% by mass or more when the nonvolatile components in the resin composition are 100% by mass. A resin composition for forming via holes or trenches by plasma treatment. Contains inorganic fillers,
A mixed gas containing SF ₆ , Ar and O ₂ is used in the insulating layer of a printed wiring board, where the content of the inorganic filler is 40% by volume or more when the nonvolatile components in the resin composition are 100% by volume. A resin composition for forming via holes or trenches by plasma treatment. The resin composition according to claim 6 or 7 , further comprising a curable resin.

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