JP2020140990A - Manufacturing method of print circuit board - Google Patents

Abstract

To provide a manufacturing method of a print circuit board that has excellent operability even when a via hole has a small diameter and suppresses the haloing phenomenon.SOLUTION: A manufacturing method of a print circuit board includes (A) a step of forming via holes in an insulating layer by performing a sandblasting process with abrasive grains, and the thickness of the insulating layer is 25 μm or less, and the average particle size of the abrasive grains is 0.5 μm or more and 3 μm or less.SELECTED DRAWING: None

Description

The present invention relates to a method for manufacturing a printed wiring board.

Printed wiring boards, which are widely used in various electronic devices, are required to have finer circuit wiring and higher densities in order to reduce the size and enhance the functionality of the electronic devices. Printed wiring boards are generally manufactured by performing a build-up method in which insulating layers and conductor layers are alternately stacked on an inner layer substrate, and by forming via holes in the insulating layer in order to electrically connect each conductor layer. ..

For example, Patent Document 1 discloses a method for manufacturing a wiring board that forms a via hole by sandblasting.

Japanese Unexamined Patent Publication No. 2008-41932

In recent years, the miniaturization of electronic devices has been promoted. Along with this, it is required to form a via hole having a smaller diameter.

As a method of forming a via hole having a small diameter in the insulating layer, a method using a laser and a method using sandblasting as in Patent Document 1 can be considered.

The present inventor has found that it is difficult to form a via hole having a top diameter (opening diameter) of 20 μm or less. It was found that a via hole with a top diameter of 30 μm or more can be formed with a CO ₂ laser, but a large amount of resin residue (smear) remains on the bottom surface and side surfaces of the via hole. The smaller the diameter of the via hole, the more difficult it is to remove smear.

Further, it has been found that, in general, heat is generated when a laser such as a CO ₂ laser or a UV-YAG laser is irradiated, and this heat is transferred to the base metal of the insulating layer and the inner layer circuit board to cause a haloing phenomenon. The haloing phenomenon means that peeling occurs 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 deteriorated by heat and the deteriorated portion is eroded by a chemical solution such as a roughening solution. The deteriorated portion is usually observed as a discolored portion.

Patent Document 1 describes that a via hole having a hole diameter of 30 μm or more and 300 μm or less can be produced by sandblasting, but in the examples of Patent Document 1, it is described that a via hole having a hole diameter of 100 μm is formed. However, it is not described whether it is possible to satisfactorily form a via hole having a smaller diameter.

As a result of examining Patent Document 1, the present inventor has found that it is effective in the case of forming a via hole of about 100 μm by sandblasting, but there is still a problem in forming a via hole having a smaller diameter, and the application is applicable. I found it difficult.

The present invention has been made in view of the above circumstances, and provides a method for manufacturing a printed wiring board in which the workability of the via hole is excellent and the haloing phenomenon is suppressed even if the via hole has a small diameter.

As a result of diligent studies to solve the above-mentioned problems, the present inventor has found that the above-mentioned problems can be solved by keeping the thickness of the insulating layer and the average particle size of the abrasive grains used for the sandblasting within a predetermined range. The present invention has been completed.

That is, the present invention includes the following contents.
[1] (A) Including a step of performing sandblasting using abrasive grains to form via holes in the insulating layer.
The thickness of the insulating layer is 25 μm or less,
A method for manufacturing a printed wiring board in which the average particle size of abrasive grains is 0.5 μm or more and 3 μm or less.
[2] The insulating layer contains a cured product of the resin composition containing an inorganic filler, and the modified Mohs hardness of the inorganic filler in the resin composition is A, and the modified Mohs hardness of the abrasive grains in the sandblasting treatment is B. The method for manufacturing a printed wiring board according to [1], which satisfies the relationship of BA ≧ 2.
[3] The method for manufacturing a printed wiring board according to [2], wherein the average particle size of the inorganic filler is 0.1 μm or more and 1 μm or less.
[4] The method for producing a printed wiring board according to [2] or [3], wherein the content of the inorganic filler is 90% by mass or less when the non-volatile component in the resin composition is 100% by mass.
[5] The method for manufacturing a printed wiring board according to any one of [1] to [4], wherein the top diameter of the via hole is 20 μm or less.
[6] The method for producing a printed wiring board according to any one of [1] to [5], wherein the abrasive grains contain any one of alumina, silicon carbide, and silica.
[7] Further, any of [1] to [6], which includes (1) a step of forming an insulating layer on the main surface of the inner layer circuit board, and the arithmetic mean roughness (Ra) of the main surface is 500 nm or less. Manufacturing method of printed wiring board described in.
[8] The method for manufacturing a printed wiring board according to [7], wherein the ten-point average roughness (Rz) of the main surface is 4000 nm or less.

According to the present invention, it is possible to provide a method for manufacturing a printed wiring board in which the workability of the via hole is excellent and the haloing phenomenon is suppressed even if the via hole has a small diameter.

FIG. 1 is a schematic cross-sectional view showing an example of an insulating layer formed on the main surface of an inner layer circuit board. FIG. 2 is a schematic cross-sectional view showing an example of a state in which a dry film is laminated on an insulating layer. FIG. 3 is a schematic cross-sectional view showing an example of how the photomask is provided on the dry film. FIG. 4 is a schematic cross-sectional view showing an example of the state after exposure and development. FIG. 5 is a schematic cross-sectional view showing an example of a state after sandblasting. FIG. 6 is a schematic cross-sectional view showing an example of the state after the step of roughening the insulating layer. FIG. 7 is a schematic cross-sectional view showing an example of the state after the step of forming the conductor layer. FIG. 8 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. 9 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 with reference to embodiments and examples. However, the present invention is not limited to the embodiments and examples listed below, and can be arbitrarily modified and implemented without departing from the scope of claims of the present invention and the equivalent scope thereof.

[Resin composition]
Before explaining in detail the method for producing a printed wiring board of the present invention, the "resin composition" and the "adhesive film" used in the method for producing a printed wiring board of the present invention will be described.

The resin composition used for forming the insulating layer may have a cured product having sufficient elastic modulus, hardness and insulating property. In one embodiment, the resin composition comprises (A) an inorganic filler and (B) a curable resin. If necessary, the resin composition may further contain (C) a curing accelerator, (D) a thermoplastic resin, and (E) other additives. Hereinafter, each component contained in the resin composition will be described in detail.

<(A) Inorganic filler>
The resin composition contains (A) an inorganic filler. An inorganic compound is used as the material of the inorganic filler. Examples of materials for inorganic fillers are silica, alumina, aluminosilicate, glass, cordierite, silicon oxide, barium sulfate, barium carbonate, talc, clay, mica powder, zinc oxide, hydrotalcite, boehmite, 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 , Zirconate oxide, barium titanate, barium zirconate titanate, barium zirconate, calcium zirconate, zirconate titanate, zirconate titnate phosphate and the like. Among these, calcium carbonate and silica are preferable, and silica is particularly preferable. Examples of silica include amorphous silica, fused silica, crystalline silica, synthetic silica, hollow silica and the like. Further, as silica, spherical silica is preferable. (A) The inorganic filler may be used alone or in combination of two or more.

Examples of commercially available components (A) include "UFP-30" manufactured by Denka Co., Ltd .; "SP60-05", "SP507-05", "SPH516-05" manufactured by Nippon Steel Chemical & Materials Co., Ltd .; Admatex. "YC100C", "YA050C", "YA050C-MJE", "YA010C" manufactured by Tokuyama Corporation; "Silfil NSS-3N", "Silfil NSS-4N", "Silfil NSS-5N" manufactured by Tokuyama Corporation; "SC2500SQ", "SO-C4", "SO-C2", "SO-C1"; and the like.

The modified Mohs hardness of the inorganic filler (A) is preferably 11 or less, more preferably 10 or less, still more preferably 9 or less, preferably 1 or more, from the viewpoint of forming small-diameter via holes by sandblasting. It is preferably 1.5 or more, more preferably 2 or more, and 3 or more. (A) The modified Mohs hardness of the inorganic filler can be measured using, for example, a Mohs hardness meter.

The specific surface area of the component (A) is preferably 1 m ² / g or more, more preferably 2 m ² / g or more, and particularly preferably 3 m ² / g or more. The upper limit is not particularly limited, but 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 is obtained by adsorbing nitrogen gas on the sample surface using a specific surface area measuring device (Macsorb HM-1210 manufactured by Mountech) according to the BET method, and calculating the specific surface area using the BET multipoint method. ..

The average particle size of the component (A) is preferably 0.01 μm or more, more preferably 0.05 μm or more, still more preferably 0.1 μm or more, and preferably 0.1 μm or more, from the viewpoint of remarkably obtaining the desired effect of the present invention. It is 5 μm or less, more preferably 2 μm or less, still more preferably 1 μm or less.

The average particle size of the component (A) can be measured by a laser diffraction / scattering method based on the Mie scattering theory. Specifically, it can be measured by creating a particle size distribution of the inorganic filler on a volume basis with a laser diffraction / scattering type particle size distribution measuring device and using the median diameter as the average particle size. As the measurement sample, 100 mg of an inorganic filler and 10 g of methyl ethyl ketone can be weighed in a vial and dispersed by ultrasonic waves for 10 minutes. The measurement sample was measured using a laser diffraction type particle size distribution measuring device, the wavelengths of the light sources used were blue and red, and the volume-based particle size distribution of component (A) was measured by the flow cell method, and the obtained particle size distribution was obtained. The average particle size can be calculated as the median diameter from. Examples of the laser diffraction type particle size distribution measuring device include "LA-960" manufactured by HORIBA, Ltd.

The component (A) is preferably treated with a surface treatment agent from the viewpoint of enhancing moisture resistance and dispersibility. Examples of the surface treatment agent include vinylsilane-based coupling agents, (meth) acrylic-based coupling agents, fluorine-containing silane coupling agents, aminosilane-based coupling agents, epoxysilane-based coupling agents, and mercaptosilane-based coupling agents. Examples thereof include silane-based coupling agents, epoxysilanes, organosilazane compounds, and titanate-based coupling agents. Of these, vinylsilane-based coupling agents, (meth) acrylic-based coupling agents, and aminosilane-based coupling agents are preferable, and aminosilane-based coupling agents are more preferable, from the viewpoint of remarkably obtaining the effects of the present invention. In addition, 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 Co., Ltd., "KBM503" (3-methacryloxypropyltriethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., and Shin-Etsu Chemical Co., Ltd. "KBM403" (3-glycidoxypropyltrimethoxysilane), "KBM803" (3-mercaptopropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., "KBE903" (3-aminopropyltriethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd. , "KBM573" (N-phenyl-3-aminopropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., "SZ-31" (hexamethyldisilazane) manufactured by Shin-Etsu Chemical Co., Ltd., "KBM103" (phenyl) manufactured by Shin-Etsu Chemical Co., Ltd. Trimethoxysilane), "KBM-4803" manufactured by Shin-Etsu Chemical Co., Ltd. (long-chain epoxy type silane coupling agent), "KBM-7103" manufactured by Shin-Etsu Chemical Co., Ltd. (3,3,3-trifluoropropyltrimethoxysilane) And so on.

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 0.2 parts by mass to 3 parts by mass is surface-treated. It is preferable that the surface is treated with 0.3 parts by mass to 2 parts by mass.

The degree of surface treatment with the surface treatment agent can be evaluated by the amount of carbon per unit surface area of the inorganic filler. Carbon content per unit surface area of the inorganic filler, from the viewpoint of improving dispersibility of the inorganic filler is preferably 0.02 mg / ^{m 2} or more, 0.1 mg / ^{m 2} or more preferably, 0.2 mg / ^{m 2} 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 the sheet form, 1 mg / m ² or less is preferable, 0.8 mg / m ² or less is more preferable, and 0.5 mg / m ² or less is further preferable. 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 surface-treated with a surface treatment agent, and ultrasonic cleaning is performed at 25 ° C. for 5 minutes. After removing the supernatant and drying the solid content, the amount of carbon per unit surface area of the inorganic filler can be measured using a carbon analyzer. As the carbon analyzer, "EMIA-320V" manufactured by HORIBA, Ltd. or the like can be used.

The content (mass%) of the component (A) is preferably 100% by mass when the non-volatile component in the resin composition is 100% by mass from the viewpoint of obtaining an insulating layer having sufficiently improved elasticity, hardness, and insulating properties. It is 30% by mass or more, more preferably 40% by mass or more, further preferably 45% 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 when the non-volatile component in the resin composition is 100% by mass, unless otherwise specified.

The content (% by mass) of the component (A) is preferably 100% by mass when the non-volatile component in the resin composition is 100% by mass from the viewpoint of obtaining an insulating layer having sufficiently improved elastic modulus, hardness, and insulating property. It is 30% by mass or more, more preferably 40% by mass or more, further preferably 50% by mass or more, preferably 80% by mass or less, more preferably 70% by mass or less, still more preferably 60% by mass or less.

<(B) Curable resin>
The resin composition contains (B) a curable resin. As the curable resin, a curable resin that can be used when forming an insulating layer of a printed wiring board can be used, and a thermosetting resin is preferable.

Examples of the thermosetting resin include epoxy resin, phenolic resin, naphthol resin, benzoxazine resin, active ester resin, cyanate ester resin, carbodiimide resin, amine resin, acid anhydride resin and the like. Can be mentioned. As the component (B), one type may be used alone, or two or more types may be used in combination at an arbitrary ratio. Hereinafter, the resin composition reacts with an epoxy resin such as a phenol-based resin, a naphthol-based resin, a benzoxazine-based resin, an active ester-based resin, a cyanate ester-based resin, a carbodiimide-based resin, an amine-based resin, and an acid anhydride-based resin. Resins that can cure objects are sometimes collectively referred to as "curing agents". The resin composition preferably contains an epoxy resin and a curing agent as the component (B), and preferably contains an epoxy resin and an active ester resin.

Examples of the epoxy resin as the component (B) include bixilenol type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol AF type epoxy resin, and 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 having a butadiene structure, alicyclic epoxy resin, heterocyclic epoxy resin, spiro ring-containing epoxy resin, cyclohexane type epoxy Examples thereof include resins, cyclohexanedimethanol type epoxy resins, naphthylene ether type epoxy resins, trimethylol type epoxy resins, and tetraphenylethane type epoxy resins. One type of epoxy resin may be used alone, or two or more types may be used in combination.

The resin composition preferably contains an epoxy resin having two or more epoxy groups in one molecule as the component (B). From the viewpoint of remarkably obtaining the desired effect of the present invention, the ratio 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 non-volatile component of the component (B). As mentioned above, it is more preferably 60% by mass or more, and particularly preferably 70% by mass or more.

The epoxy resin may be a liquid epoxy resin at a temperature of 20 ° C. (hereinafter sometimes referred to as "liquid epoxy resin") or a solid epoxy resin at a temperature of 20 ° C. (hereinafter referred to as "solid epoxy resin"). ). The resin composition may contain only the liquid epoxy resin as the component (B), may contain only the solid epoxy resin, or may contain a combination of the liquid epoxy resin and the solid epoxy resin. Good.

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

Examples of the liquid epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AF type epoxy resin, naphthalene type epoxy resin, glycidyl ester type epoxy resin, glycidylamine type epoxy resin, phenol novolac type epoxy resin, and ester skeleton. An alicyclic epoxy resin, a cyclohexane type epoxy resin, a cyclohexanedimethanol type epoxy resin, a glycidylamine type epoxy resin, and an epoxy resin having a butadiene structure are preferable, and a bisphenol A type epoxy resin and a bisphenol F type epoxy resin are more preferable.

Specific examples of the liquid epoxy resin include "HP4032", "HP4032D", and "HP4032SS" (naphthalene type epoxy resin) manufactured by DIC; "828US", "jER828EL", "825", and "Epicoat" manufactured by Mitsubishi Chemical Co., Ltd. 828EL (bisphenol A type epoxy resin); Mitsubishi Chemical's "jER807", "1750" (bisphenol F type epoxy resin); Mitsubishi Chemical's "jER152" (phenol novolac type epoxy resin); Mitsubishi Chemical's "630", "630LSD" (glycidylamine type epoxy resin); "ZX1059" manufactured by Nittetsu Chemical & Materials Co., Ltd. (mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin); manufactured by Nagase ChemteX. "EX-721" (glycidyl ester type epoxy resin); "Selokiside 2021P" manufactured by Daicel Co., Ltd. (alicyclic epoxy resin having an ester skeleton); "PB-3600" manufactured by Daicel Co., Ltd. (epoxy resin having a butadiene structure) Examples thereof include "ZX1658" and "ZX1658GS" (liquid 1,4-glycidylcyclohexane type epoxy resin) manufactured by Nittetsu Chemical & Materials Co., Ltd. These may be used individually by 1 type, and may be used in combination of 2 or more types.

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.

Examples of the solid epoxy resin include bixilenol type epoxy resin, naphthalene type epoxy resin, naphthalene type tetrafunctional epoxy resin, cresol novolac type epoxy resin, dicyclopentadiene type epoxy resin, trisphenol type epoxy resin, naphthol type epoxy resin, and biphenyl. Type epoxy resin, naphthylene ether type epoxy resin, anthracene type epoxy resin, bisphenol A type epoxy resin, bisphenol AF type epoxy resin, tetraphenylethane type epoxy resin are preferable, and naphthalene type epoxy resin is more preferable.

Examples of the solid epoxy resin include naphthalene type tetrafunctional epoxy resin, cresol novolac type epoxy resin, dicyclopentadiene type epoxy resin, trisphenol type epoxy resin, naphthol type epoxy resin, biphenyl type epoxy resin, and naphthylene ether type epoxy resin. Anthracene type epoxy resin, bisphenol A type epoxy resin, and tetraphenylethane type epoxy resin are preferable, and naphthalene type tetrafunctional epoxy resin, naphthol type epoxy resin, and biphenyl type epoxy resin are more preferable. Specific examples of the solid epoxy resin 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 Kayakusha. Trisphenol type epoxy resin), "NC7000L" (naphthol novolac type epoxy resin), "NC3000H", "NC3000", "NC3000L", "NC3100" (biphenyl type epoxy resin); "ESN475V" manufactured by Nittetsu Chemical & Materials Co., Ltd. (Naphthalene type epoxy resin), "ESN485" (naphthol novolac type epoxy resin); "YX4000H", "YL6121" (biphenyl type epoxy resin), "YX4000HK" (bixilenol type epoxy resin), " "YX8800" (anthracene type epoxy resin); "PG-100" and "CG-500" manufactured by Osaka Gas Chemical Co., Ltd., "YL7760" (bisphenol AF type epoxy resin) manufactured by Mitsubishi Chemical Co., Ltd., "YL7800" (fluorene type epoxy resin) Resin), "jER1010" (solid bisphenol A type epoxy resin), "jER1031S" (tetraphenylethane type epoxy resin) and the like. These may be used individually by 1 type, and may be used in combination of 2 or more type.

When a liquid epoxy resin and a solid epoxy resin are used in combination as the component (B), their quantity ratio (liquid epoxy resin: solid epoxy resin) is a mass ratio, preferably 1: 0.1: 1: 20, more preferably 1: 0.3 to 1:15, and particularly preferably 1: 0.5 to 1:10. When the amount ratio of the liquid epoxy resin to the solid epoxy resin is within such a range, the desired effect of the present invention can be remarkably obtained. In addition, it usually provides moderate adhesiveness when used in the form of an adhesive film. In addition, when used in the form of an adhesive film, sufficient flexibility is usually obtained and handleability is improved. Further, usually, a cured product having sufficient breaking strength can be obtained.

The epoxy equivalent of the epoxy resin as the component (B) is preferably 50 g / eq. ~ 5000 g / eq. , More preferably 50 g / eq. ~ 3000 g / eq. , More preferably 80 g / eq. ~ 2000g / eq. , Even more preferably 110 g / eq. ~ 1000 g / eq. Is. Within this range, the crosslink density of the cured product of the resin composition becomes sufficient, and an insulating layer having a small surface roughness can be provided. Epoxy equivalent is the mass of an epoxy resin containing 1 equivalent of an epoxy group. This epoxy equivalent can be measured according to JIS K7236.

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

The content of the epoxy resin as the component (B) is preferably 5% by mass when the non-volatile component in the resin composition is 100% by mass from the viewpoint of obtaining an insulating layer showing good mechanical strength and insulation reliability. As mentioned above, it is more preferably 10% by mass or more, still more preferably 15% by mass or more. The upper limit of the content of the epoxy resin is preferably 40% by mass or less, more preferably 35% by mass or less, and particularly preferably 30% by mass or less, from the viewpoint of remarkably obtaining the desired effect of the present invention.

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

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

Examples of the phenol compound or naphthol compound include hydroquinone, resorcin, bisphenol A, bisphenol F, bisphenol S, phenolphthaline, 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, dihydroxybenzophenol, trihydroxybenzophenone, tetrahydroxybenzophenone, fluoroglusin, Examples thereof include benzenetriol, dicyclopentadiene-type diphenol compounds, and phenol novolac. Here, the "dicyclopentadiene-type diphenol compound" refers to a diphenol compound obtained by condensing two phenol molecules with one dicyclopentadiene molecule.

Preferred specific examples of the active ester-based resin include an active ester-based resin containing a dicyclopentadiene-type diphenol structure, an active ester-based resin containing a naphthalene structure, an active ester-based resin containing an acetylated product of phenol novolac, and a benzoyl of phenol novolac. Examples thereof include active ester-based resins containing compounds. Of these, an active ester resin containing a naphthalene structure and an active ester resin containing a dicyclopentadiene type diphenol structure are more preferable. The "dicyclopentadiene-type diphenol structure" represents a divalent structural unit composed of phenylene-dicyclopentylene-phenylene.

Commercially available products of the active ester resin include "EXB9451", "EXB9460", "EXB9460S", "HPC-8000-65T", and "HPC-8000H-" as active ester resins containing a dicyclopentadiene type diphenol structure. "65TM", "EXB-8000L-65TM" (manufactured by DIC); "EXB9416-70BK", "EXB-8150-65T" (manufactured by DIC) as an active ester resin containing a naphthalene structure; acetylated phenol novolac. As an active ester resin containing "DC808" (manufactured by Mitsubishi Chemical Co., Ltd.); "YLH1026" (manufactured by Mitsubishi Chemical Co., Ltd.) as an active ester resin containing a benzoylate of phenol novolac; as an active ester resin which is an acetylated product of phenol novolac "DC808" (manufactured by Mitsubishi Chemical Co., Ltd.); "YLH1026" (manufactured by Mitsubishi Chemical Co., Ltd.), "YLH1030" (manufactured by Mitsubishi Chemical Co., Ltd.), "YLH1048" (manufactured by Mitsubishi Chemical Co., Ltd.) as active ester-based resins that are benzoylated phenol novolacs. ); Etc. can be mentioned.

As the phenolic resin and the naphthol resin as the component (B), those having a novolak structure are preferable from the viewpoint of heat resistance and water resistance. Further, from the viewpoint of adhesion to the conductor layer, a nitrogen-containing phenol-based curing agent is preferable, and a triazine skeleton-containing phenol-based resin is more preferable.

Specific examples of the phenolic resin and the naphthol resin include "MEH-7700", "MEH-7810", "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 Co., Ltd. , DIC Corporation "TD-2090", "LA-7052", "LA-7054", "LA-1356", "LA-3018-50P", "EXB-9500" and the like.

Specific examples of the benzoxazine-based resin as the 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); "Pd" (benzoxazine ring equivalent 217), "FA" (benzoxazine ring equivalent 217) manufactured by Shikoku Kasei Kogyo Co., Ltd .; "HFB2006M" manufactured by Showa Polymer Co., Ltd. (Benzooxazine ring equivalent 432) and the like.

Examples of the cyanate ester-based resin as the component (B) include bisphenol A cyanate, polyphenol cyanate, oligo (3-methylene-1,5-phenylene cyanate), and 4,4'-methylenebis (2,6-dimethylphenylcyanoate). ), 4,4'-Etilidendiphenyl disianate, hexafluorobisphenol A disyanate, 2,2-bis (4-cyanate) phenylpropane, 1,1-bis (4-cyanate phenylmethane), bis (4-cyanate-) 3,5-Dimethylphenyl) methane, 1,3-bis (4-cyanatephenyl-1- (methylethylidene)) benzene, bis (4-cyanatephenyl) thioether, bis (4-cyanatephenyl) ether, etc. Bifunctional cyanate resin; polyfunctional cyanate resin derived from phenol novolac, cresol novolak and the like; prepolymer in which these cyanate resins are partially triazine; and the like. Specific examples of the cyanate ester resin include "PT30" and "PT60" (phenol novolac type polyfunctional cyanate ester resin), "ULL-950S" (polyfunctional cyanate ester resin), and "BA230" manufactured by Ronza Japan. Examples thereof include "BA230S75" (a prepolymer in which part or all of bisphenol A disyanate is triazined to form a trimer).

Specific examples of the carbodiimide-based resin as the component (B) include carbodilite (registered trademark) V-03 (carbodiimide group equivalent: 216, V-05 (carbodiimide group equivalent: 216)) and V-07 (registered trademark) manufactured by Nisshinbo Chemical Co., Ltd. Carbodiimide group equivalent: 200); V-09 (carbodiimide group equivalent: 200); Stavaxol® P (carbodiimide group equivalent: 302) manufactured by Rheinchemy.

Examples of the amine-based resin as the component (B) include resins having one or more amino groups in one molecule, for example, aliphatic amines, polyether amines, alicyclic amines, and aromatics. Examples thereof include amines, and among them, aromatic amines are preferable from the viewpoint of achieving the desired effect of the present invention. The amine-based resin is preferably a primary amine or a secondary amine, more preferably a primary amine. Specific examples of amine-based curing agents include 4,4'-methylenebis (2,6-dimethylaniline), diphenyldiaminosulfone, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone, 3,3'. -Diaminodiphenylsulfone, m-phenylenediamine, m-xylylenediamine, diethyltoluenediamine, 4,4'-diaminodiphenyl ether, 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl- 4,4'-Diaminobiphenyl, 3,3'-dihydroxybenzidine, 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 thereof include bis (4- (3-aminophenoxy) phenyl) sulfone. Commercially available products may be used as the amine resin, for example, "KAYABOND C-200S", "KAYABOND C-100", "Kayahard A-A", "Kayahard AB", "Kayahard" manufactured by Nippon Kayaku Corporation. Examples include "AS" and "Epicure W" manufactured by Mitsubishi Chemical Corporation.

Examples of the acid anhydride-based resin as the component (B) include a resin having one or more acid anhydride groups in one molecule. Specific examples of the acid anhydride-based resin include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnadic acid anhydride, and methylnadic hydride anhydride. Trialkyltetrahydrophthalic anhydride, succinic anhydride, 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic acid anhydride, trimerit anhydride Acid, pyromellitic anhydride, benzophenone tetracarboxylic acid dianhydride, biphenyltetracarboxylic acid dianhydride, naphthalenetetracarboxylic acid dianhydride, oxydiphthalic acid dianhydride, 3,3'-4,4'-diphenyl Sulphontetracarboxylic dianhydride, 1,3,3a,4,5,9b-hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-C] furan-1, Examples thereof include 3-dione, ethylene glycol bis (anhydrotrimeritate), and polymer-type acid anhydrides such as styrene / maleic acid resin in which styrene and maleic acid are copolymerized.

When the component (B) contains an epoxy resin and a curing agent, the amount ratio of the epoxy resin to all the 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: 0.5 to 1: 3, and even more preferably 1: 1 to 1: 2. Here, the "number of epoxy groups in the epoxy resin" is a total value obtained by dividing the mass of the non-volatile component of the epoxy resin present in the resin composition by the epoxy equivalent. The "number of active groups of the curing agent" is a total value obtained by dividing the mass of the non-volatile component of the curing agent present in the resin composition by the active group equivalent. By setting the amount ratio of the epoxy resin and the curing agent within such a range as the component (B), an insulating layer having excellent flexibility can be obtained.

The content of the curing agent as the component (B) is preferably 10% by mass or more, more preferably 15% by mass, based on 100% by mass of the non-volatile component in the resin composition from the viewpoint of obtaining an insulating layer having excellent flexibility. % Or more, more preferably 20% by mass or more, preferably 50% by mass or less, more preferably 45% by mass or less, still more preferably 40% by mass or less.

<(C) Curing accelerator>
The resin composition may contain (C) a curing accelerator as an arbitrary component. 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, and the like, as well as amine-based curing accelerators and imidazole-based curing agents. A curing accelerator is preferable, and an amine-based curing accelerator is more preferable. The curing accelerator may be used alone or in combination of two or more.

Examples of the phosphorus-based curing accelerator include triphenylphosphine, phosphonium borate compound, tetraphenylphosphonium tetraphenylborate, n-butylphosphonium tetraphenylborate, tetrabutylphosphonium decanoate, and (4-methylphenyl) triphenylphosphonium thiocyanate. , Tetraphenylphosphonium thiocyanate, butyltriphenylphosphonium thiocyanate and the like, and triphenylphosphine and tetrabutylphosphonium decanoate are preferable.

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

Examples of the imidazole-based curing accelerator include 2-methylimidazole, 2-undecyl imidazole, 2-heptadecyl imidazole, 1,2-dimethyl imidazole, 2-ethyl-4-methyl imidazole, 1,2-dimethyl imidazole, and the like. 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 trimerite, 1-cyanoethyl- 2-Phenylimidazolium trimerite, 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 the imidazole compound and an epoxy resin are mentioned, with 2-ethyl-4-methylimidazole and 1-benzyl-2-phenylimidazole being preferred.

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

Examples of the guanidine-based curing accelerator include dicyandiamide, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, 1- (o-tolyl) guanidine, dimethylguanidine, diphenylguanidine, and trimethylguanidine. Tetramethylguanidine, pentamethylguanidine, 1,5,7-triazabicyclo [4.4.0] deca-5-ene, 7-methyl-1,5,7-triazabicyclo [4.4.0] Deca-5-ene, 1-methylbiguanide, 1-ethylbiguanide, 1-n-butylbiguanide, 1-n-octadesylbiguanide, 1,1-dimethylbiguanide, 1,1-diethylbiguanide, 1-cyclohexylbiguanide, 1 Examples thereof include −allyl biguanide, 1-phenylbiguanide, 1- (o-tolyl) biganide, and dicyandiamide, 1,5,7-triazabicyclo [4.4.0] deca-5-ene is preferable.

Examples of the metal-based curing accelerator include organometallic complexes or organometallic salts of metals such as cobalt, copper, zinc, iron, nickel, manganese, and tin. Specific examples of the organic metal complex include an organic cobalt complex such as cobalt (II) acetylacetonate and cobalt (III) acetylacetonate, an organic copper complex such as copper (II) acetylacetonate, and zinc (II) acetylacetonate. Examples thereof include organic zinc 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, zinc stearate and the like.

The content of the curing accelerator (C) is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and particularly preferably 0.% by mass, when the non-volatile component in the resin composition is 100% by mass. It is 1% by mass or more, preferably 3% by mass or less, more preferably 1% by mass or less, and particularly preferably 0.5% by mass or less.

<(D) Thermoplastic resin>
The resin composition may contain (D) a thermoplastic resin as an arbitrary component. Examples of the thermoplastic resin include phenoxy resin, polyvinyl acetal resin, polyolefin resin, polyimide resin, polyamideimide resin, polyetherimide resin, polysulfone resin, polyethersulfone resin, polyphenylene ether resin, and polyetheretherketone resin. , Polyimide resin and the like, and phenoxy resin is preferable. The thermoplastic resin may be used alone or in combination of two or more.

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

Examples of the phenoxy resin include bisphenol A skeleton, bisphenol F skeleton, bisphenol S skeleton, bisphenol acetphenone skeleton, novolak skeleton, biphenyl skeleton, fluorene skeleton, dicyclopentadiene skeleton, norbornene skeleton, naphthalene skeleton, anthracene skeleton, adamantan skeleton, and terpen Examples thereof include phenoxy resins having one or more skeletons selected from the group consisting of skeletons and trimethylcyclohexane skeletons. The terminal of the phenoxy resin may be any functional group such as a phenolic hydroxyl group or an epoxy group. The phenoxy resin may be used alone or in combination of two or more. Specific examples of the phenoxy resin include "1256" and "4250" (both bisphenol A skeleton-containing phenoxy resin), "YX8100" (bisphenol S skeleton-containing phenoxy resin), and "YX6954" (bisphenol acetophenone) manufactured by Mitsubishi Chemical Corporation. (Skeletal-containing phenoxy resin), and also "FX280" and "FX293" manufactured by Nittetsu Chemical & Materials Co., Ltd., "YL7500BH30", "YX6954BH30", "YX7553", "YX7553BH30" manufactured by Mitsubishi Chemical Co., Ltd., Examples thereof include "YL7769BH30", "YL6794", "YL7213", "YL7290" and "YL7482".

Examples of the polyvinyl acetal resin include polyvinyl formal resin and polyvinyl butyral resin, and polyvinyl butyral resin is preferable. Specific examples of the polyvinyl acetal resin include "Electrified Butyral 4000-2", "Electrified Butyral 5000-A", "Electrified Butyral 6000-C", "Electrified Butyral 6000-EP", Sekisui Chemical Co., Ltd. Examples thereof include Eslek BH series, BX series (for example, BX-5Z), KS series (for example, KS-1), BL series, and BM series manufactured by Sekisui Chemical Co., Ltd.

Specific examples of the polyimide resin include "Rikacoat SN20" and "Rikacoat PN20" manufactured by New Japan Chemical Co., Ltd. Specific examples of the polyimide resin include a linear polyimide obtained by reacting a bifunctional hydroxyl group-terminated polybutadiene, a diisocyanate compound and a tetrabasic acid anhydride (polyimide described in JP-A-2006-37083), and a polysiloxane skeleton. Examples thereof include modified polyimides such as contained polyimides (polyimides described in JP-A-2002-12667 and JP-A-2000-319386).

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

Specific examples of the polyether sulfone resin include "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 Company, Ltd. Specific examples of the polyetheretherketone resin include "Sumiproi K" manufactured by Sumitomo Chemical Co., Ltd. Specific examples of the polyetherimide resin include "Ultem" manufactured by GE.

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

Examples of the polyolefin resin include ethylene-based 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: Polyolefin-based elastomers such as polypropylene and ethylene-propylene block copolymers can be mentioned.

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

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

The content of the thermoplastic resin (D) is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, still more preferably 1% by mass, when the non-volatile component in the resin composition is 100% by mass. % Or more. The upper limit is preferably 5% by mass or less, more preferably 4% by mass or less, and further preferably 3% by mass or less.

<(E) Other additives>
In addition to the above-mentioned components, the resin composition may further contain other additives as arbitrary components. Examples of such additives include flame retardant agents; organic fillers; organic metal compounds such as organic copper compounds, organozinc compounds and organocobalt compounds; thickeners; defoaming agents; leveling agents; adhesion imparting agents; Examples thereof include resin additives such as colorants. One of these additives may be used alone, or two or more of these additives may be used in combination at any ratio.

Examples of the flame retardant include a phosphazene compound, an organic phosphorus flame retardant, an organic nitrogen-containing phosphorus compound, a nitrogen compound, a silicone flame retardant, a metal hydroxide and the like, and a phosphazene compound is preferable. The flame retardant may be used alone or in combination of two or more.

The phosphazene compound is not particularly limited as long as it is a cyclic compound containing nitrogen and phosphorus as constituent elements, but the phosphazene compound is preferably a phosphazene compound having a phenolic hydroxyl group.

Specific examples of the phosphazene compound include, for example, "SPH-100", "SPS-100", "SPB-100" and "SPE-100" manufactured by Otsuka Chemical Co., Ltd., and "FP-100" manufactured by Fushimi Pharmaceutical Co., Ltd. Examples thereof include "FP-110", "FP-300", "FP-400", and "SPH-100" manufactured by Otsuka Chemical Co., Ltd. is preferable.

As the flame retardant other than the phosphazene compound, a commercially available product may be used, and examples thereof include "HCA-HQ" manufactured by Sanko Co., Ltd. and "PX-200" manufactured by Daihachi Chemical Industry Co., Ltd. As the flame retardant, one that is hard to hydrolyze is preferable, and for example, 10- (2,5-dihydroxyphenyl) -10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide and the like are preferable.

The content of the flame retardant is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, still more preferably 0.3% by mass or more, when the non-volatile component in the resin composition is 100% by mass. Is. The upper limit is preferably 3% by mass or less, more preferably 2% by mass or less, and further preferably 1% by mass or less.

As the organic filler, any organic filler that can be used when forming the insulating layer of the printed wiring board may be used, and examples thereof include rubber particles, polyamide fine particles, and silicone particles. As the rubber particles, commercially available products may be used, and examples thereof include "EXL2655" manufactured by Dow Chemical Japan, "AC3401N" and "AC3816N" manufactured by Aica Kogyo Co., Ltd. The organic filler may be used alone or in combination of two or more.

The content of the organic filler is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, still more preferably 0.3% by mass, when the non-volatile component in the resin composition is 100% by mass. That is all. The upper limit is preferably 3% by mass or less, more preferably 2% by mass or less, and further preferably 1% by mass or less.

[Adhesive film]
The adhesive film includes a support and a resin composition layer formed of the resin composition provided on the support. The resin composition is as described in the [Resin composition] column.

The thickness of the resin composition layer is preferably 25 μm or less, more preferably 20 μm or less, still more preferably 15 μm or less, and 10 μm or less from the viewpoint of forming a via hole having a small diameter. The lower limit of the thickness of the resin composition layer is not particularly limited, but may be usually 1 μm or more, 5 μm or more, or the like.

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

When a film made of a plastic material is used as the support, the plastic material may be, for example, polyethylene terephthalate (hereinafter abbreviated as "PET") or polyethylene naphthalate (hereinafter abbreviated as "PEN"). ) Etc., polyester, polycarbonate (hereinafter sometimes abbreviated as "PC"), acrylic such as polymethylmethacrylate (PMMA), cyclic polyolefin, triacetylcellulose (TAC), polyethersulfide (PES), polyether. Examples thereof include ketones and polyimides. Of these, polyethylene terephthalate and polyethylene naphthalate are preferable, and inexpensive polyethylene terephthalate is particularly preferable.

When a metal foil is used as the support, examples of the metal foil include copper foil and aluminum foil, and copper foil is preferable. As the copper foil, a foil made of a single metal of copper may be used, and a foil made of an alloy of copper and another metal (for example, tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.) may be used. You may use it.

The surface of the support to be joined to the resin composition layer may be matted, corona-treated, or antistatic-treated.

Further, as the support, a support with a release layer having a release layer on the surface to be joined with the resin composition layer may be used. Examples of the release agent used for the release layer of the support with the release layer include one or more release agents selected from the group consisting of alkyd resin, polyolefin resin, urethane resin, and silicone resin. .. As the support with a release layer, a commercially available product may be used. For example, "SK-1" and "SK-1" manufactured by Lintec Corporation, which are PET films having a release layer containing an alkyd resin-based release agent as a main component. Examples thereof include "AL-5" and "AL-7", "Lumirror T60" manufactured by Toray Industries, Inc., "Purex" manufactured by Teijin Corporation, and "Unipee" manufactured by Unitika.

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

In one embodiment, the adhesive film may further include other layers, if desired. Examples of such other layers include a protective film similar to the support provided on a surface of the resin composition layer that is not bonded to the support (that is, a surface opposite to the support). 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, it is possible to suppress the adhesion of dust and the like to the surface of the resin composition layer and scratches.

For the adhesive film, for example, a resin varnish in which a resin composition is dissolved in an organic solvent is prepared, 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 the organic solvent include ketones such as acetone, methyl ethyl ketone (MEK) and cyclohexanone; acetic acid esters such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate and carbitol acetate; cellosolve and butyl carbitol and the like. Carbitols; aromatic hydrocarbons such as toluene and xylene; amide solvents such as dimethylformamide, dimethylacetamide (DMAc) and N-methylpyrrolidone. The organic solvent may be used alone or in combination of two or more.

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

The adhesive film can be rolled up and stored. If the adhesive film 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
(A) Includes a step of performing sandblasting using abrasive grains to form via holes in the insulating layer.
The thickness of the insulating layer is 25 μm or less, and the average particle size of the abrasive grains is 0.5 μm or more and 3 μm or less.

In the present invention, by setting the thickness of the insulating layer and the average particle size of the abrasive grains used for the sandblasting within a predetermined range, the workability of the via hole is excellent and the haloing phenomenon is suppressed even if the via hole has a small diameter. It becomes possible to manufacture printed wiring boards.

Before performing the step (A), the method for manufacturing the printed wiring board may include (1) a step of forming an insulating layer on the main surface of the inner layer circuit board.

Hereinafter, each step of the method for manufacturing a printed wiring board will be described.

<Process (1)>
The step (1) preferably includes the step of preparing the inner layer circuit board (1-1). The inner layer circuit board usually includes a support board and a metal layer provided on the surface of the support board. The metal layer is exposed on the main surface of the inner layer circuit board, and via holes are formed in the area where the metal layer is located in the step (A). Therefore, on the main surface of the inner layer circuit board, the area where the via hole is formed in the step (A) is formed of the metal layer.

Examples of the material of the support 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 of the metal layer include a copper foil, a copper foil with a carrier, a material of a conductor layer described later, and the like, and a copper foil is preferable.

The arithmetic mean roughness (Ra) of the main surface of the inner layer circuit board is preferably 500 nm or less, more preferably 450 nm or less, still more preferably 400 nm or less, 350 nm or less. By setting the arithmetic mean roughness (Ra) of the main surface of the inner layer circuit board to 500 nm or less, it is possible to prevent the insulating layer formed on the main surface from penetrating deep into the inner layer circuit board, improving the workability of via holes. Can be made to. The lower limit is not particularly limited, but is preferably 10 nm or more, more preferably 50 nm or more, and further preferably 100 nm or more. The arithmetic mean roughness (Ra) of the main surface is a value measured in accordance with ISO 25178, and can be measured using a non-contact type surface roughness meter. The main surface of the inner layer circuit board represents the surface of the inner layer circuit board provided with the insulating layer.

Further, when the arithmetic mean roughness (Ra) is not constant on the main surface, the arithmetic mean roughness (Ra) of the main surface in the area where the metal layer is formed may be within the above range, and via holes are formed. It is preferable that the arithmetic mean roughness (Ra) of the main surface in the area is in the above range.

The ten-point average roughness (Rz) of the main surface of the inner layer circuit board is preferably 5000 nm or less, more preferably 4500 nm or less, and further preferably 4000 nm or less. By setting the ten-point average roughness (Rz) of the main surface of the inner layer circuit board to 5000 nm or less, it is possible to prevent the insulating layer formed on the main surface from penetrating deep into the inner layer circuit board, and the insulation reliability is improved. Can be made to. The lower limit is not particularly limited, but is preferably 50 nm or more, more preferably 100 nm or more, and further preferably 1000 nm or more. The ten-point average roughness (Rz) of the main surface is a value measured in accordance with ISO 25178, and can be measured using a non-contact type surface roughness meter.

Further, when the ten-point average roughness (Rz) is not constant on the main surface, it is preferable that the ten-point average roughness (Rz) of the main surface in the area where the metal layer is formed is in the above range. It is more preferable that the ten-point average roughness (Rz) of the main surface in the area where the via hole is formed is in the above range.

The arithmetic average roughness (Ra) and the ten-point average roughness (Rz) of the main surface of the inner layer circuit board can be adjusted within the above ranges by, for example, etching treatment and polishing.

Further, the step (1) may include a step (1-2) of preparing an adhesive film. The adhesive film is as described above.

Further, the step (1) may include a step of forming an insulating layer on the main surface of the inner layer circuit board (1-3). The insulating layer contains a cured product of a resin composition containing an inorganic filler.

As an example shown in FIG. 1, the inner layer circuit board 10 includes a support board 11 and a metal layer 12 provided on the surface of the support board 11, and an adhesive film is laminated on the main surface 10a of the inner layer circuit board 10. , The insulating layer 20 is formed. Normally, since the insulating layer 20 is provided on the surface of the metal layer 12, the surface of the metal layer 12 opposite to the surface of the support substrate 11 is the main surface 10a. Although the metal layer 12 is provided on one surface of the support substrate 11 in FIG. 1, it may be provided on both surfaces of the support substrate 11.

Lamination of the inner layer circuit board and the adhesive film can be performed, for example, by heat-pressing the adhesive film to the inner layer circuit board from the support side. Examples of the member for heat-pressing the adhesive film to the inner layer circuit board (hereinafter, also referred to as “heat-bonding member”) include a heated metal plate (SUS end plate or the like) or a metal roll (SUS roll). It is preferable not to press the heat-bonded member directly onto the adhesive film, but to press it through an elastic material such as heat-resistant rubber so that the adhesive film sufficiently follows the surface irregularities of the inner layer circuit board.

The inner layer circuit board and the adhesive film may be laminated by a vacuum laminating method. In the vacuum laminating method, the heat crimping temperature is preferably in the range of 60 ° C. to 160 ° C., more preferably 80 ° C. to 140 ° C., and the heat crimping pressure is preferably 0.098 MPa to 1.77 MPa, more preferably 0. It is in the range of .29 MPa to 1.47 MPa, and the heat crimping 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 at a pressure of 26.7 hPa or less.

Lamination can be performed by a commercially available vacuum laminator. Examples of commercially available vacuum laminators include a vacuum pressurizing laminator manufactured by Meiki Co., Ltd., a vacuum applicator manufactured by Nikko Materials, and a batch type vacuum pressurizing laminator.

After laminating, the laminated adhesive film may be smoothed by pressing the heat-bonded member from the support side under normal pressure (under atmospheric pressure), for example. The press conditions for the smoothing treatment can be the same as the heat-bonding conditions for the above-mentioned lamination. The smoothing process can be performed by a commercially available laminator. The lamination and smoothing treatment may be continuously performed using the above-mentioned commercially available vacuum laminator.

The support may be removed after laminating the adhesive film and before thermosetting, or may be removed after performing the sandblasting treatment in step (A).

After laminating the adhesive film on the inner layer circuit board, the resin composition layer is thermoset to form an insulating layer. The thermosetting conditions of the resin composition layer are not particularly limited, and the conditions usually adopted when forming the insulating layer of the printed wiring board may be used.

For example, the thermosetting conditions of the resin composition layer differ depending on the type of the resin composition and the like, but the curing temperature is preferably 120 ° C. to 240 ° C., more preferably 150 ° C. to 220 ° C., still more preferably 170 ° C. to 210. ℃. The curing time can be preferably 5 minutes to 120 minutes, more preferably 10 minutes to 100 minutes, and even more preferably 15 minutes to 100 minutes.

Before the resin composition layer is thermoset, 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 heated at a temperature of 50 ° C. or higher and lower than 120 ° C. (preferably 60 ° C. or higher and 115 ° C. or lower, more preferably 70 ° C. or higher and 110 ° C. or lower). Preheating may be performed for 5 minutes or more (preferably 5 minutes to 150 minutes, more preferably 15 minutes to 120 minutes, still more preferably 15 minutes to 100 minutes).

The thickness of the insulating layer is 25 μm or less, preferably 20 μm or less, more preferably 15 μm or less, and further preferably 10 μm or less from the viewpoint of forming a via hole having a small diameter. The lower limit of the thickness of the insulating layer is not particularly limited, but may be usually 1 μm or more, 5 μm or more, or the like.

Instead of step (1-2), the resin composition may be applied directly on the main surface of the inner layer circuit board to form an insulating layer. The conditions for forming the insulating layer at that time are the same as the conditions for forming the insulating layer using the adhesive film.

The elastic modulus of the cured product (insulating layer) obtained by curing the resin composition layer at 200 ° C. for 90 minutes is preferably 1 GPa or more, more preferably 2 GPa or more, and more preferably from the viewpoint of facilitating the processing of via holes. Is 3 GPa or more, preferably 25 GPa or less, more preferably 20 GPa or less, still more preferably 15 GPa or less. The elastic modulus can be measured by the method described in Examples described later.

<Process (A)>
The step (A) is a step of performing sandblasting using abrasive grains to form via holes in the insulating layer. The step (A) preferably includes the following steps (A-1) to (A-3) in this order.
(A-1) A step of laminating a dry film on an insulating layer or a support,
(A-2) A step of exposing and developing a dry film using a photomask to obtain a pattern dry film, and (A-3) a step of sandblasting the pattern dry film as a mask to form a via hole.

In the step (A-1), as shown in FIG. 2, the dry film 30 is laminated on the insulating layer 20 formed on the main surface 10a of the inner layer circuit board 10. The laminating conditions of the insulating layer 20 and the dry film 30 may be the same as the laminating conditions of the inner layer circuit board 10 and the adhesive film 20. In FIG. 2, the dry film 30 is laminated on the insulating layer 20, but the dry film 30 may be laminated on a support of an adhesive film (not shown).

The dry film used in the step (A-1) may be any film that can obtain a pattern dry film by exposure and development, and more preferably a film that is resistant to sandblasting. 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 novolak 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, still more preferably 20 μm or more, preferably 100 μm or less, more preferably 70 μm or less, still more preferably, from the viewpoint of improving the processability of the via hole. It is 50 μm or less.

In the step (A-2), as shown in FIG. 3, an exposure is performed by irradiating an active energy ray (not shown) through a photomask 40 having a predetermined pattern. For details of the exposure, the surface of the dry film is irradiated with active energy rays through a photomask to photo-cure the exposed portion of the dry film. Examples of the active energy ray include ultraviolet rays, visible rays, electron beams, X-rays and the like, and ultraviolet rays are preferable. The irradiation amount and irradiation time of ultraviolet rays can be appropriately set according to the dry film. Examples of the exposure method include a contact exposure method in which a mask pattern is brought into close contact with a dry film for exposure, and a non-contact exposure method in which a mask pattern is exposed using parallel light rays without being brought into close contact with a dry film.

After the exposure, as shown in FIG. 4, the exposed portion of the dry film 30 is removed by developing to form the pattern dry film 31. The development may be either wet development or dry development. Examples of the developing method include a dip method, a paddle method, a spray method, a brushing method, a scraping method and the like.

In the step (A-3), as shown in FIG. 5, a pattern dry film 31 is used as a mask and sandblasting is performed to form a via hole 50. Here, the sandblasting treatment is performed by injecting an abrasive grain or a slurry solution of abrasive grains from a nozzle onto the surface of an insulating layer or a support not covered with a pattern dry film by air jetting at a predetermined pressure, and the abrasive grains. Refers to a process of forming a via hole by colliding with an insulating layer or a support. The sandblasting treatment in the step (A-3) may be either a dry blasting treatment in which abrasive grains are sprayed or a wet blasting treatment in which a slurry solution of abrasive grains is sprayed. As the sandblasting treatment in the step (A-3), a drive lasting treatment is preferable from the viewpoint of ease of forming via holes.

The modified Mohs hardness of the abrasive grains used in the sandblasting treatment is preferably 1 or more, more preferably 5 or more, still more preferably 6 or more, or 7 or more from the viewpoint of forming a via hole having a small diameter by the sandblasting treatment. The upper limit can usually be 15 or less. The modified Mohs hardness of the abrasive grains can be measured using, for example, a Mohs hardness meter.

When the modified Mohs hardness of the inorganic filler in the insulating layer is A and the modified Mohs hardness of the abrasive grains in the sandblasting treatment is B, the following formula (1) is preferably satisfied, and the following formula (2) is satisfied. It is more preferable, and it is further preferable to satisfy the following formula (3). By satisfying the formula (1), the insulating layer can be suitably ground, and as a result, the workability of the via hole having a small diameter can be improved.
BA ≧ 2 (1)
BA ≧ 3 (2)
BA ≧ 4 (3)
The upper limit of "BA" in the formulas (1) to (3) is preferably 10 or less, more preferably 9 or less, still more preferably 8 or less, from the viewpoint of remarkably obtaining the desired effect of the present invention. It is 7 or less.

Abrasive grains include inorganic compounds such as silica and glass; metal compounds such as steel, stainless steel, zinc and copper; ceramics such as garnet, zirconia, silicon carbide, alumina and boron carbide; particles mainly composed of dry ice and the like. And so on. Among them, inorganic compounds and ceramics are preferable, and alumina, silicon carbide, and silica are preferable from the viewpoint of remarkably obtaining the desired effect of the present invention. As the silica, crystalline silica is preferable.

Commercially available products can be used as the abrasive grains. Examples of commercially available products include "DAW-03" manufactured by Denka, "AY2-75" (alumina) manufactured by Nippon Steel Chemical & Materials Co., Ltd .; "GP # 4000" and "SER-A06" manufactured by Shinano Electric Smelting Co., Ltd. (carbide). Silicon); "IMSIL A-8" (crystalline silica) manufactured by Ryumori Co., Ltd .; "Fuji Random WA" (molten alumina) manufactured by Fuji Seisakusho.

The average particle size of the abrasive grains is 0.5 μm or more, preferably 0.55 μm or more, and more preferably 0.6 μm or more. By setting the lower limit of the average particle size of the abrasive grains within such a range, the machining time of the via hole can be shortened and the workability of the via hole can be improved. Further, it is possible to suppress the blowback of abrasive grains in the sandblasting process, and it is possible to suppress the grinding of the pattern dry film. Blow-back of abrasive grains is a phenomenon in which abrasive grains sprayed into holes such as via holes and dents on the main surface reduce the collision speed by the action of the air flow that enters the holes and returns, and the average particle size is particularly small. It is remarkable in the abrasive grains. The upper limit of the average particle size of the abrasive grains is 3 μm or less, preferably 2.5 μm or less, and more preferably 2 μm or less. By setting the upper limit of the average particle size of the abrasive grains within such a range, the workability of a via hole having a small diameter can be improved. The average particle size of the abrasive grains can be measured, for example, by observing with a scanning electron microscope, and the details can be measured by the method described in JP-A-2008-41932.

A via hole having a small diameter can be formed by adjusting the processing pressure in the sandblasting process, the scanning speed of the nozzle, and the like.

The pressure (machining pressure) for injecting the abrasive grains is preferably 0.05 MPa or more, more preferably 0.1 MPa or more, still more preferably 0.15 MPa or more, preferably 1 MPa or less, more preferably 0.8 MPa or less. , More preferably 0.5 MPa or less. By setting the processing pressure within such a range, the processing of the insulating layer can be performed in a realistic time. The processing pressure here is a value on the surface of the insulating layer.

Usually, the sandblasting process is performed while moving the nozzle for ejecting abrasive grains so as to scan the main surface. The scanning speed of the nozzle is preferably 20 mm / s or more, more preferably 25 mm / s or more, and further preferably 30 mm / s or more. By setting the lower limit value within such a range, the abrasive grains do not penetrate the insulating layer in one scan, so that the damage given to the inner layer circuit board by the sandblasting process can be reduced. The upper limit of the operation speed is preferably 150 mm / s or less, more preferably 130 mm / s or less, and further preferably 120 mm / s or less. By setting the upper limit value within such a range, the number of times the nozzle is scanned can be reduced, and via holes can be efficiently formed. Normally, the nozzle scans parallel to the surface of the insulating layer while keeping a certain distance from the insulating layer to be processed. Further, a mechanism in which the insulating layer side moves instead of the nozzle may be used.

The diameter of the nozzle is preferably 5 mm or less, more preferably 4 mm or less, and further preferably 3 mm or less. By setting the upper limit value within such a range, it is possible to suppress a pressure drop due to insufficient air. Further, the lower limit value is preferably 0.5 mm or more, more preferably 0.6 mm or more, and further preferably 0.7 mm or more from the viewpoint of injecting abrasive grains into a wide range. As the shape of the nozzle, a wide-angle nozzle that injects abrasive grains over a wide range, a nozzle with a sharp point, or the like can be used.

The number of nozzles is preferably 15 or less. By setting the number of nozzles within such a range, it is possible to increase the processing speed while suppressing the pressure drop due to insufficient air. The sandblasting process causes less damage to the inner layer circuit board. The lower limit is not particularly limited, but is one or more.

The distance between the nozzle and the insulating layer is preferably 200 mm or less, more preferably 190 mm or less, further preferably 180 mm or less, preferably 10 mm or more, more preferably 15 mm or more, still more preferably 20 mm or more. By keeping the above distance within such a range, via holes can be efficiently formed.

The shape of the via hole formed by performing the step (A) is not particularly limited, but is generally circular (substantially circular). The top diameter of the via hole that can be formed by performing the step (A) is preferably 25 μm or less, more preferably 20 μm or less, still more preferably 15 μm or less, preferably 3 μm or more, preferably 5 μm or more, and more. It is preferably 8 μm or more. Here, the top diameter of the via hole means the diameter of the opening of the via hole on the surface of the insulating layer. A small diameter via hole means a via hole having a top diameter of 20 μm or less.

When the arithmetic mean roughness (Ra) of the main surface of the inner layer circuit board is R and the average particle size of the abrasive grains is r, R / r is preferable from the viewpoint of remarkably obtaining the desired effect of the present invention. It is 65 or more, more preferably 70 or more, still more preferably 75 or more, preferably 1000 or less, more preferably 800 or less, still more preferably 700 or less.

When the elastic modulus of the insulating layer is E and the average particle size of the abrasive grains is r, E / r is preferably 0.5 or more, more preferably 0, from the viewpoint of significantly obtaining the desired effect of the present invention. It is .7 or more, more preferably 1.0 or more, preferably 30 or less, more preferably 25 or less, still more preferably 20 or less.

<Other processes>
In manufacturing the printed wiring board, after the step (A) is completed, (B) a step of roughening the insulating layer and (C) a step of forming a conductor layer may be further carried out. These steps (B) and (C) may be carried out according to various methods known to those skilled in the art used for manufacturing a printed wiring board. Further, if necessary, the formation of the insulating layer and the conductor layer in the steps (A) to (C) may be repeated to form the multilayer wiring board.

The step (B) is a step of roughening the insulating layer (also referred to as desmear treatment). Normally, in this step (B), as shown by an example in FIG. 6, abrasive grains and pattern dry film 31 (not shown) are also removed. The procedure and conditions of the roughening treatment are not particularly limited, and known procedures and conditions usually used when forming the insulating layer of the printed wiring board can be adopted. For example, the insulating layer can be roughened by performing a swelling treatment with a swelling liquid, a roughening treatment with an oxidizing agent, and a neutralization treatment with a neutralizing liquid in this order. The swelling solution used for the roughening treatment is not particularly limited, and examples thereof include an alkaline solution and a surfactant solution, preferably an alkaline solution, and the alkaline solution is more preferably a sodium hydroxide solution or a potassium hydroxide solution. preferable. Examples of commercially available swelling solutions include "Swelling Dip Security SBU" and "Swelling Dip Security P" manufactured by Atotech Japan. Be done. The swelling treatment with the swelling liquid is not particularly limited, but can be performed, for example, by immersing the insulating layer in the swelling liquid at 30 ° C. to 90 ° C. for 1 minute to 20 minutes. From the viewpoint of suppressing the swelling of the resin of the insulating layer to an appropriate level, it is 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, and examples thereof include 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 carried out by immersing the insulating layer in an oxidizing agent solution heated to 60 ° C. to 100 ° C. for 10 to 30 minutes. The concentration of permanganate in the alkaline permanganate solution is preferably 5% by mass to 10% by mass. Examples of commercially available oxidizing agents include alkaline permanganic acid solutions such as "Concentrate Compact CP" and "Dosing Solution Security P" manufactured by Atotech Japan. Further, the neutralizing solution used for the roughening treatment is preferably an acidic aqueous solution, and examples of commercially available products include "Reduction Solution Security P" manufactured by Atotech Japan. The treatment with the neutralizing solution can be carried out by immersing the treated surface that has been roughened with the oxidizing agent in the neutralizing solution at 30 ° C. to 80 ° C. for 1 minute to 30 minutes. From the viewpoint of workability and the like, a method of immersing the object roughened with an oxidizing agent in a neutralizing solution at 40 ° C. to 70 ° C. for 5 to 20 minutes is preferable. When the support is removed after the step (A) is completed, the pattern dry film 31 may be removed together with the support.

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, 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 further preferably 50 nm or more. The arithmetic mean roughness (Ra) of the insulating layer surface can be measured using a non-contact surface roughness meter.

The step (C) is a step of forming the conductor layer, and the conductor layer 60 is formed on the insulating layer 20 as shown in FIG. 7 as an example. The conductor material used for the conductor layer is not particularly limited. In a preferred embodiment, the conductor layer is 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, nickel-chromium alloy, copper, etc.). A layer formed from a nickel alloy and a copper / titanium alloy) can be mentioned. Among them, from the viewpoint of versatility of conductor layer formation, cost, ease of patterning, etc., a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper, or a nickel-chromium alloy, copper, etc. An alloy layer of a nickel alloy or a copper-titanium alloy is preferable, and a monometal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper, or an alloy layer of a nickel-chromium alloy is more preferable, and a single copper is preferable. A metal layer is more preferred.

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

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

In one embodiment, the conductor layer may be formed by plating. For example, the surface of the insulating layer can be plated by a conventionally known technique such as a semi-additive method or a full-additive method to form a conductor layer having a desired wiring pattern, and the semi-additive can be manufactured from the viewpoint of ease of manufacture. It is preferably formed by the method. Hereinafter, an example of forming the conductor layer by the semi-additive method will be shown.

First, a plating seed layer is formed on the surface of the insulating layer by electroless plating. Next, a mask pattern is formed on the formed plating seed layer to expose a part of the plating seed layer corresponding to a desired wiring pattern. After forming a metal layer by electrolytic plating on the exposed plating seed layer, the mask pattern is removed. After that, the unnecessary plating seed layer can be removed by etching or the like to form a conductor layer having a desired wiring pattern.

The method for manufacturing a printed wiring board of the present invention exhibits a characteristic that the workability of the via hole is excellent even if the via hole has a small diameter. Specifically, the wiring board subjected to the step (A) is prepared, and the wiring board is subjected to desmear treatment. At this time, even if the top diameter of the via hole is as small as 20 μm, the opening diameter of the via top can be reduced by an electron microscope, and the resin residue on the via bottom can be reduced. The details can be carried out by the method described in Examples described later.

The method for manufacturing a printed wiring board of the present invention exhibits a characteristic that the haloing phenomenon is suppressed. Specifically, even if the top diameter of the via hole is as small as 20 μm, the haloing phenomenon can be suppressed. Hereinafter, the haloing phenomenon will be described with reference to the drawings.

FIG. 8 shows a surface 20U of the insulating layer 20 immediately before the conductor layer is formed on the conventional printed wiring board in which the via hole is formed by the laser, opposite to the metal layer 12 (not shown in FIG. 8). Is a plan view schematically showing. FIG. 9 is a cross-sectional view schematically showing the insulating layer 20 immediately before the conductor layer is formed in the conventional printed wiring board in which the via hole is formed by the laser, together with the metal layer 12 of the inner layer circuit board. FIG. 9 shows a cross section of the insulating layer 20 cut through a plane passing through the center 220C of the via bottom 220 of the via hole 50 and parallel to the thickness direction of the insulating layer 20.

As shown in FIG. 9, when a via hole is formed by a laser, a discolored portion 240 may occur due to deterioration of the resin due to the heat of the laser. The discolored portion 240 may be eroded by a chemical during the roughening treatment, the insulating layer 20 may be peeled from the metal layer 12, and a gap portion 260 continuous from the edge 250 of the via bottom 220 may be formed (via hole phenomenon).

In the present invention, since the sandblasting treatment that does not easily generate heat is adopted, deterioration of the resin can be suppressed. Therefore, the peeling of the insulating layer 20 from the metal layer 12 can be suppressed, and the size of the gap 260 can be reduced.

The edge 250 of the via bottom (via bottom (via bottom)) 220 corresponds to the inner peripheral edge of the gap 260. Therefore, the distance Wb from the edge 250 of the via bottom 220 to the outer peripheral end of the gap 260 (that is, the end far from the center 220C of the via bottom 220) 270 is the size of the gap 260 in the in-plane direction. Equivalent to. Here, the in-plane direction means a direction perpendicular to the thickness direction of the insulating layer 20. Further, in the following description, the distance Wb may be referred to as a haloing distance Wb from the edge 250 of the beer bottom 220 of the via hole 50. The degree of suppression of the haloing phenomenon can be evaluated from the haloing distance Wb from the edge 250 of the via bottom 220. Specifically, it can be evaluated that the smaller the haloing distance Wb from the edge 250 of the via bottom 220, the more effectively the haloing phenomenon can be suppressed.

According to the production method of the present invention, even if a via hole having a top diameter of 25 μm or less is formed, the haloing distance Wb from the edge 250 of the via bottom 220 of the via hole 110 of the insulating layer 20 is preferably 5 μm or less, more preferably 5 μm or less. It can be 4 μm or less, more preferably 3 μm or less. The lower limit is not particularly limited, but may be 0 μm or more, 0.1 μm or more, and the like.

According to the manufacturing method of the present invention, even if the top diameter is a small via hole, the via hole is excellent in workability. The top diameter is preferably 25 μm or less, more preferably 20 μm or less, still more preferably 15 μm or less, preferably 3 μm or more, preferably 5 μm or more, and more preferably 8 μm or more.

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

Examples of semiconductor devices include various semiconductor devices used in electric products (for example, computers, mobile phones, digital cameras, televisions, etc.) and vehicles (for example, motorcycles, automobiles, trains, ships, aircraft, etc.).

The semiconductor device of the present invention can be manufactured by mounting a component (semiconductor chip) on a conductive portion of a printed wiring board. The "conduction point" is a "place for transmitting an electric signal in the printed wiring board", and the place may be a surface or an embedded place. Further, the semiconductor chip is not particularly limited as long as it is an electric circuit element made of a semiconductor.

The mounting method of the semiconductor chip in manufacturing a semiconductor device is not particularly limited as long as the semiconductor chip functions effectively, but specifically, a wire bonding mounting method, a flip chip mounting method, and a bumpless build-up layer. Examples thereof include a mounting method using (BBUL), a mounting method using an anisotropic conductive film (ACF), and a mounting method using a non-conductive film (NCF). Here, the "mounting method using the bumpless build-up layer (BBUL)" means "a mounting method in which the semiconductor chip is directly embedded in the recess of the printed wiring board and the semiconductor chip is connected to the wiring on the printed wiring board". Is.

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

<Measurement of modified Mohs hardness>
Known values can be used for the modified Mohs hardness of the inorganic filler and abrasive grains, or the Mohs hardness identification kit (manufactured by Mistral) may be used to measure the modified Mohs hardness according to JIS K 5600-5-4. ..

<Preparation of adhesive film 1>
10 parts of biphenyl type epoxy resin ("NC3000L" manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent of about 269), 10 parts of liquid 1,4-glycidylcyclohexane ("ZX1658" manufactured by Nittetsu Chemical & Materials Co., Ltd., epoxy equivalent of about 135), bi 10 parts of xylenol type epoxy resin (Mitsubishi Chemical's "YX4000H", epoxy equivalent about 185), active ester resin (DIC's "HPC-8000-65T", active group equivalent about 223, non-volatile component 65% by mass toluene 50 parts of solution), 6 parts of triazine skeleton-containing phenolic resin (“LA-3018-50P” manufactured by DIC, 2-methoxypropanol solution having a hydroxyl group equivalent of about 151 and a solid content of 50%), phenoxy resin (“LA-3018-50P” manufactured by Mitsubishi Chemical Co., Ltd. YL7553BH30 ”, 10 parts of MEK with a solid content of 30% by mass and a 1: 1 solution of cyclohexanone), carbodiimide-based resin (“V-03” manufactured by Nisshinbo Chemical Co., Ltd., active group equivalent of about 216, toluene solution with a solid content of 50% by mass) 10 parts, 75 parts of spherical silica (average particle size 0.5 μm, modified moth hardness 7, Admatex “SO-C2”) surface-treated with an aminosilane-based coupling agent (“KBM573” manufactured by Shinetsu Chemical Industry Co., Ltd.) , Phosphorus flame retardant ("HCA-HQ" manufactured by Sanko Co., Ltd., 10- (2,5-dihydroxyphenyl) -10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide), 1 part, rubber 1 part of particles (Staffyloid AC3816N manufactured by Ganz Kasei Co., Ltd.), 5 parts of curing accelerator (4-dimethylaminopyridine (DMAP), MEK solution having a solid content of 5% by mass), 15 parts of methyl ethyl ketone, and 10 parts of cyclohexanone were mixed. A resin varnish was prepared by uniformly dispersing it with a high-speed rotating mixer.

Next, a dried resin composition layer is placed on the release surface of a polyethylene terephthalate film with a mold release treatment (“AL5” manufactured by Lintec Corporation, thickness 38 μm, (hereinafter, may be referred to as “release PET”)). The resin varnish was uniformly applied so that the thickness of the film was 20 μm, and dried at 80 to 120 ° C. (average 100 ° C.) for 6 minutes to prepare an adhesive film 1.

<Preparation of adhesive film 2>
In the production of the adhesive film 1, spherical silica surface-treated with an aminosilane-based coupling agent (“KBM573” manufactured by Shin-Etsu Chemical Industry Co., Ltd.) (average particle size 0.5 μm, modified Mohs hardness 7, “SO-C2” manufactured by Admatex Co., Ltd. ”) 75 parts of spherical silica (average particle size 0.3 μm, modified Mohs hardness 7, Nittetsu Chemical & Materials Co., Ltd.“ SPH516 ”) surface-treated with an aminosilane-based coupling agent (“KBM573” manufactured by Shin-Etsu Chemical Industry Co., Ltd.) -05 ") Changed to 75 copies. The adhesive film 2 was produced in the same manner as the adhesive film 1 except for the above items.

<Preparation of adhesive film 3>
In the production of the adhesive film 1, spherical silica surface-treated with an aminosilane-based coupling agent (“KBM573” manufactured by Shin-Etsu Chemical Industry Co., Ltd.) (average particle size 0.5 μm, modified Mohs hardness 7, “SO-C2” manufactured by Admatex Co., Ltd. ”) 75 parts was changed to 32 parts by mass of calcium carbonate (average particle size 1.0 μm, modified Mohs hardness 3, “Nanox # 30” manufactured by Maruo Calcium Co., Ltd.). The adhesive film 3 was produced in the same manner as the adhesive film 1 except for the above items.

<Preparation of adhesive film 4>
In the preparation of the adhesive film 1, the thickness of the resin composition layer after drying was changed from 20 μm to 40 μm. An adhesive film 4 was produced in the same manner as the adhesive film 1 except for the above items.

[Measurement of elastic modulus of cured product of resin composition layer]
<Preparation of cured product for evaluation>
On the release agent-treated PET film (Lintec "501010", thickness 38 μm, 240 mm square), a glass cloth-based epoxy resin double-sided copper-clad laminate (Panasonic "R5715ES"), (Thickness 0.7 mm, 255 mm square) was overlapped and the four sides were fixed with polyimide adhesive tape (width 10 mm) (hereinafter, may be referred to as "fixed PET film").

Each of the produced adhesive films was laminated on the release-treated surface of the above-mentioned "fixed PET film" using a batch type vacuum pressure laminator (MVLP-500 manufactured by Meiki Co., Ltd.). Lamination was carried out by reducing the pressure for 30 seconds to a pressure of 13 hPa or less, and then pressing at 100 ° C. and a pressure of 0.74 MPa for 30 seconds.

Next, the polyethylene terephthalate film with mold release treatment (“AL5” manufactured by Lintec Corporation, thickness 38 μm) was peeled off, and the adhesive film was thermoset under curing conditions of 90 minutes after being placed in an oven at 200 ° C.

After thermosetting, the polyimide adhesive tape is peeled off, the cured product is removed from the glass cloth base material epoxy resin double-sided copper-clad laminate, and the PET film (Lintec Corporation "501010") is also peeled off to obtain a sheet-shaped cured product. It was. The obtained cured product is referred to as an "evaluation cured product".

<Measurement of elastic modulus>
The obtained cured product for evaluation is subjected to a tensile test of the cured product using a Tensilon universal testing machine (manufactured by A & D Co., Ltd.) in accordance with Japanese Industrial Standards (JIS K7127), and the cured product of the resin composition layer is subjected to a tensile test. The elastic modulus at 23 ° C. was measured.

[Example 1]
(1) Lamination of Adhesive Film Using a batch type vacuum pressurizing laminator (MVLP-500 manufactured by Meiki Co., Ltd.), roughening the copper surface with a micro-etching agent ("CZ8201" manufactured by Mech Co., Ltd.) (copper etching amount: It was prepared on both sides of a glass cloth base material epoxy resin double-sided copper laminated plate (manufactured by Panasonic, "R-1766") subjected to surface roughness Ra: 310 nm, Rz: 3920 nm after roughening treatment at 0.5 μm. The resin composition layer of the adhesive film 1 was laminated so as to be in contact with each other. Lamination was carried out by reducing the pressure for 30 seconds to a pressure of 13 hPa or less, and then pressing at 100 ° C. and a pressure of 0.74 MPa for 30 seconds.

The arithmetic average roughness (Ra) after the roughening treatment of the copper surface of the glass cloth base material epoxy resin double-sided copper laminated plate and the arithmetic ten-point average roughness (Rz) after the roughening treatment are non-contact type surface roughness meters. (Measured using "WYKO NT3300" manufactured by Becoin Sturments). The arithmetic average roughness (Ra) and the arithmetic ten-point average roughness (Rz) are values measured in accordance with ISO 25178.

(2) Curing of Resin Composition Layer The release PET was peeled off from the laminated adhesive film 1, and the resin composition layer was cured under curing conditions of 180 ° C. for 30 minutes to form an insulating layer.

(3) Formation of Pattern Dry Film A dry film with a thickness of 20 μm (“ALPHO 20A263” manufactured by Nikko Materials Co., Ltd.) is attached to the surface of the insulating layer of the inner layer circuit board on which the above insulating layer is formed. To laminate the dry film, use a batch type vacuum pressurizing laminator (“MVLP-500” manufactured by Meiki Co., Ltd.) to reduce the pressure for 30 seconds to reduce the atmospheric pressure to 13 hPa or less, and then set the pressure to 0.1 MPa and the temperature to 70 ° C. Then, pressurization was performed for 20 seconds. Then, a glass mask having a via pattern was placed on a polyethylene terephthalate film which is a protective layer of a dry film, and UV irradiation was performed with a UV lamp at an irradiation intensity of 150 mJ / cm ² . After UV irradiation, a spray treatment was performed for 30 seconds at an injection pressure of 0.15 MPa using a 1% sodium carbonate aqueous solution at 30 ° C. Then, it was washed with water and patterned so that a via hole having a top diameter of 20 μm was formed.

(4) Sandblasting Next, the insulating layer is sandblasted 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 Smelting Co., Ltd.) as abrasive grains. The treatment was performed to form a via hole, and a wiring board for evaluation was prepared.

[Example 2]
In Example 1, the adhesive film 1 was changed to the adhesive film 2. A wiring board for evaluation was produced in the same manner as in Example 1 except for the above items.

[Example 3]
In Example 1, silicon carbide (average particle size 0.6 μm, modified Mohs hardness 13, “SER-A06” manufactured by Shinano Electric Smelting Co., Ltd.) was used as alumina (average particle size 3.0 μm, modified Mohs hardness 12, Nittetsu Chemical Co., Ltd.). & Material Co., Ltd. "AY2-75") was changed. A wiring board for evaluation was produced in the same manner as in Example 1 except for the above items.

[Example 4]
In Example 1, the adhesive film 1 was changed to the adhesive film 3, and silicon carbide (average particle size 0.6 μm, modified Mohs hardness 13, “SER-A06” manufactured by Shinano Electric Smelting Co., Ltd.) was used as crystalline silica (average particle size). It was changed to 2.0 μm, modified Mohs hardness 8, and Ryumori Co., Ltd. “IMSIL A-8”). A wiring board for evaluation was produced in the same manner as in Example 1 except for the above items.

[Comparative Example 1]
In Example 1, silicon carbide (average particle size 0.6 μm, modified Mohs hardness 13, “SER-A06” manufactured by Shinano Electric Smelting Co., Ltd.) was introduced into alumina (average particle size 4.0 μm, modified Mohs hardness 12, manufactured by Denka Co., Ltd.). Changed to "DAW-03"). A wiring board for evaluation was produced in the same manner as in Example 1 except for the above items.

[Comparative Example 2]
In Example 1, instead of performing (3) pattern dry film formation and (4) sandblasting treatment, via holes were formed by (A) CO ₂ laser shown below. A wiring board for evaluation was produced in the same manner as in Example 1 except for the above items.

(A) Formation of Via Hole by CO ₂ Laser A via hole was formed in the insulating layer by using a CO ₂ laser processing machine (“LC-2E21B / 1C” manufactured by Hitachi Via Mechanics). The top diameter (diameter) of the via hole on the surface of the insulating layer was 30 μm, and it was not possible to form a via hole smaller than that. After the shape of the via hole, the release PET was peeled off.

[Comparative Example 3]
In Example 1, instead of performing (3) pattern dry film formation and (4) sandblasting treatment, via holes were formed by (B) UV-YAG laser shown below. A wiring board for evaluation was produced in the same manner as in Example 1 except for the above items.

(B) Formation of Via Hole by UV-YAG Laser A via hole was formed in the insulating layer by using a UV-YAG laser processing machine (“LU-2L212 / M50L” manufactured by Via Mechanics, Ltd.). The top diameter (diameter) of the via hole on the surface of the insulating layer was 20 μm. After the shape of the via hole, the release PET was peeled off.

[Comparative Example 4]
In Example 1, the adhesive film 1 was changed to the adhesive film 4, and silicon carbide (average particle size 0.6 μm, modified Mohs hardness 13, “SER-A06” manufactured by Shinano Electric Smelting Co., Ltd.) was used as alumina (average particle size 3). It was changed to 0.0 μm, modified Mohs hardness of 12, and “AY2-75” manufactured by Nittetsu Chemical & Materials Co., Ltd.). A wiring board for evaluation was produced in the same manner as in Example 1 except for the above items.

[Evaluation of workability of via holes]
The evaluation wiring boards produced in Examples and Comparative Examples were immersed in a swollen liquid, a swirling dip seculant P containing diethylene glycol monobutyl ether manufactured by Atotech Japan, at 60 ° C. for 5 minutes, and then as a roughening liquid. , Atotech Japan's Concentrate Compact P (KMnO ₄ : 60 g / L, NaOH: 40 g / L aqueous solution) at 80 ° C. for 15 minutes, and finally as a neutralizing solution, Atotech Japan's reduction sho It was immersed in Ryucin Securigant P at 40 ° C. for 5 minutes. After that, the bottom of the via (bottom of the via hole) is observed with an electron microscope, and if the opening diameter of the top of the via is 25 μm or less and no resin residue is found on the bottom of the via, it is evaluated as “○”, and the opening diameter of the top of the via is Those exceeding 25 μm or having a resin residue on the bottom of the via were evaluated as “x”.

<Evaluation of haloing>
The evaluation wiring board after the evaluation of the workability of the via hole was cross-sectionally observed using a FIB-SEM composite device (“SMI3050SE” manufactured by SII Nanotechnology Co., Ltd.). Specifically, using a FIB (focused ion beam), the insulating layer was carved so that a cross section parallel to the thickness direction of the insulating layer and passing through the center of the via bottom of the via hole appeared. This cross section was observed by SEM. In some of the observed images, gaps formed by peeling the insulating layer from the copper foil layer of the glass cloth-based epoxy resin double-sided copper laminate were seen continuously from the edge of the via bottom. Therefore, from the observed image, the distance from the edge of the via bottom to the end on the outer peripheral side of the gap was measured as a haloing distance and evaluated according to the following criteria. The haloing distance is measured at five randomly selected via holes, and the haloing distance is the average value of the top diameters of the five measured via holes.

(Evaluation criteria for haloing)
◯: Haloing distance is less than 6 μm ×: Haloing distance is 6 μm or more

表中、「ＳＢ」はサンドブラスト処理によりビアホールを形成、「ＣＯ_２」はＣＯ_２レーザーによりビアホールを形成、及び「ＵＶ−ＹＡＧ」はＵＶ−ＹＡＧレーザーによりビアホールを形成したことを表す。

In the table, "SB" indicates that a via hole was formed by sandblasting, "CO ₂ " indicates that a via hole was formed by a CO ₂ laser, and "UV-YAG" indicates that a via hole was formed by a UV-YAG laser.

It can be seen that in Examples 1 to 4, even if the via hole is 20 μm, the workability of the via hole is excellent and the haloing phenomenon is suppressed.
On the other hand, Comparative Example 1 in which the average particle size of the abrasive grains exceeds 3 μm could not be ground because the abrasive grains did not enter the portion where the via was to be formed and had a diameter of 20 μm without the pattern dry film. Therefore, it was not possible to evaluate haloing.
In Comparative Example 2, a via hole of 20 μm or less could not be formed. Therefore, it was not possible to evaluate haloing. In addition, many smear remained on the bottom and sides of the beer hall.
In Comparative Example 3, a via hole of 20 μm or less could be formed, but it can be seen that the haloing phenomenon cannot be suppressed due to the influence of the heat of the UV-YAG laser.
In Comparative Example 4, since the thickness of the insulating layer exceeded 25 μm, all the pattern dry film was ground before the end of the step (A), and via holes could not be formed. Therefore, it was not possible to evaluate haloing.

10 Inner layer Circuit board 11 Support board 12 Metal layer 10a Main surface 20 Insulation layer 30 Dry film 31 Pattern dry film 40 Photomask 50 Via hole 60 Conductor layer 20U Surface of insulation layer opposite to metal layer 220 Via bottom 220C Center of via bottom 230 Beer top 240 Discoloration part 250 Beer bottom edge of via hole 260 Gap 270 Outer edge of gap 280 Beer top edge 290 Outer peripheral edge of discoloration Wb Helloning distance from beer bottom edge

Claims (8)

(A) Includes a step of performing sandblasting using abrasive grains to form via holes in the insulating layer.
The thickness of the insulating layer is 25 μm or less,
A method for manufacturing a printed wiring board in which the average particle size of abrasive grains is 0.5 μm or more and 3 μm or less. When the insulating layer contains a cured product of the resin composition containing the inorganic filler, the modified Mohs hardness of the inorganic filler in the resin composition is A, and the modified Mohs hardness of the abrasive grains in the sandblasting treatment is B, B. The method for manufacturing a printed wiring board according to claim 1, which satisfies the relationship of −A ≧ 2. The method for manufacturing a printed wiring board according to claim 2, wherein the average particle size of the inorganic filler is 0.1 μm or more and 1 μm or less. The method for producing a printed wiring board according to claim 2 or 3, wherein the content of the inorganic filler is 90% by mass or less when the non-volatile component in the resin composition is 100% by mass. The method for manufacturing a printed wiring board according to any one of claims 1 to 4, wherein the top diameter of the via hole is 20 μm or less. The method for producing a printed wiring board according to any one of claims 1 to 5, wherein the abrasive grains contain any one of alumina, silicon carbide, and silica. The method according to any one of claims 1 to 6, further comprising (1) a step of forming an insulating layer on the main surface of the inner layer circuit board, and the arithmetic average roughness (Ra) of the main surface is 500 nm or less. How to manufacture printed wiring boards. The method for manufacturing a printed wiring board according to claim 7, wherein the ten-point average roughness (Rz) of the main surface is 4000 nm or less.

Images