JP6834144B2 - Resin sheet with support - Google Patents

Description

The present invention relates to a resin sheet with a support. Further, the present invention relates to a method for manufacturing a printed wiring board, a printed wiring board, and a semiconductor device.

As a method for manufacturing a printed wiring board (hereinafter, also referred to as "wiring board"), a build-up method in which circuit-formed conductor layers and insulating layers are alternately stacked is widely used, and the insulating layer is a conductor. It is known that it is formed by curing a resin composition layer composed of two layers, a side in contact with the layer and a side to be plated (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2014-17301

Since the amount of information communication has increased in recent years, fine wiring is desired in the manufacture of printed wiring boards.

In order to achieve fine wiring, the surface of the insulating layer is made low in roughness, and of the two resin composition layers, the resin composition layer on the side to be plated (the side in contact with the conductor layer) is filled with inorganic material. It is desirable to reduce the content of the material. On the one hand, from the viewpoint of lowering the coefficient of thermal expansion, it is desirable that the resin composition layer on the other side (the side in contact with the substrate) has a large content of the inorganic filler.

The present inventors have attempted to form a via hole in an insulating layer formed by curing such two resin composition layers. As a result, it was found that a constricted portion was formed in the extending direction of the interface of each cured resin composition layer on the side wall of the via hole (see FIG. 1). If such a hollowed portion is generated, voids are generated during the plating process, which may hinder the fine wiring.

An object of the present invention is to provide a resin sheet with a support, a method for manufacturing a printed wiring board, a printed wiring board, and a semiconductor device, which suppress the generation of constricted portions generated in the extending direction of the interface of each cured resin composition layer. The challenge is to provide.

As a result of diligent studies on the above problems, the present inventors have reduced the difference in thermal conductivity of the thermosetting products of the first and second resin composition layers, thereby reducing the difference in thermal conductivity of the cured resin composition layers at the interface of each cured resin composition layer. It was found that the length of the constricted portion generated in the extending direction can be reduced. As a result of further diligent studies, the present inventors have made the content of the inorganic filler in the first resin composition layer on the side to be plated smaller than the content of the inorganic filler in the second resin composition layer. By doing so, it was found that the difference in thermal conductivity could be reduced, and the present invention was completed.

That is, the present invention includes the following contents.
[1] A resin sheet with a support including a support and a resin sheet provided on the support.
The resin sheet includes a first resin composition layer formed of the first resin composition provided on the support side, and a first resin composition layer.
It has a second resin composition layer formed of the second resin composition, which is provided on the side opposite to the support side.
The first resin composition contains (a) an inorganic filler, and the content of the component (a) is 30% by mass or less when the non-volatile component in the first resin composition is 100% by mass. ,
The second resin composition contains (a) an inorganic filler, and the content of the component (a) is 60% by mass or more when the non-volatile component in the second resin composition is 100% by mass. ,
The thermal conductivity of the first thermosetting product obtained by thermally curing the first resin composition at 100 ° C. for 30 minutes and further at 190 ° C. for 90 minutes, and the second resin composition at 100 ° C. for 30 minutes. A resin sheet with a support, characterized in that the difference from the thermal conductivity of the second thermosetting product obtained by thermosetting at 190 ° C. for 90 minutes is 0.4 W / mK or less.
[2] The resin sheet with a support according to [1], wherein the thickness of the resin sheet is 40 μm or less.
[3] The resin sheet with a support according to [1] or [2], wherein the thickness of the resin sheet is 25 μm or less.
[4] When the average particle size of the component (a) in the first resin composition is R1 (μm) and the average particle size of the component (a) in the second resin composition is R2 (μm). The resin sheet with a support according to any one of [1] to [3], wherein the ratio of R1 to R2 (R2 / R1) is 1 to 15.
[5] The resin sheet with a support according to any one of [1] to [4], wherein the first resin composition contains (b) an epoxy resin and (b) has a mesogen skeleton.
[6] The component (b) is one or more selected from a bixylenol type epoxy resin, a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a biphenyl type epoxy resin, and a naphthalene type epoxy resin, [5]. The resin sheet with a support described in.
[7] The resin sheet with a support according to any one of [1] to [6], which is used for forming an insulating layer of a printed wiring board.
[8] (I) A step of laminating a second resin composition layer of the resin sheet with a support according to any one of [1] to [7] on the inner layer substrate so as to be bonded to the inner layer substrate (II). A method for manufacturing a printed wiring board, which comprises a step of thermosetting a resin sheet with a support to form an insulating layer, and (III) a step of forming a via hole in the insulating layer and removing the support.
[9] The method for manufacturing a printed wiring board according to [8], wherein via holes are formed in the insulating layer by a laser in the step (III).
[10] The method for manufacturing a printed wiring board according to [8] or [9], wherein the opening diameter of the via hole is 40 μm or less.
[11] A printed wiring board including an insulating layer formed of the resin sheet with a support according to any one of [1] to [7].
[12] A semiconductor device including the printed wiring board according to [11].

According to the present invention, a resin sheet with a support, a method for manufacturing a printed wiring board, a printed wiring board, and a semiconductor device, which suppress the generation of constricted portions generated in the extending direction of the interface of each cured resin composition layer, are provided. It is now possible to provide.

FIG. 1 is a cross-sectional photograph of an insulating layer having a hollowed portion. FIG. 2 is a schematic view showing one aspect of the resin sheet with a support of the present invention. FIG. 3 is a cross-sectional photograph for explaining the length of the hollowed portion.

Hereinafter, the resin sheet with a support, the method for manufacturing a printed wiring board, the printed wiring board, and the semiconductor device of the present invention will be described in detail.

Before describing the resin sheet with a support of the present invention in detail, when forming the first resin composition layer and the second resin composition layer contained in the resin sheet in the resin sheet with a support of the present invention. The first resin composition and the second resin composition used in the above will be described.

(First resin composition)
The first resin composition forming the first resin composition layer contains (a) an inorganic filler, and the content of the component (a) is 100% by mass of the non-volatile component in the first resin composition. As long as it is 30% by mass or less, the cured product is not particularly limited as long as it has sufficient plating peeling property and insulating property. Examples of the first resin composition include a composition containing a curable resin and a curing agent thereof in addition to the inorganic filler. As the curable resin, a conventionally known curable resin used for forming an insulating layer of a printed wiring board can be used, and an epoxy resin is particularly preferable. Therefore, in one embodiment, the first resin composition comprises (b) an epoxy resin and (c) a curing agent. The first resin composition may further contain a thermoplastic resin, a curing accelerator, a flame retardant and an organic filler, if necessary.

Hereinafter, each component that can be used as a material of the first resin composition will be described in detail.

-(A) Inorganic filler-
The material of the inorganic filler is not particularly limited, but for example, silica, alumina, 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 , Zirconium oxide, barium titanate, barium titanate, barium zirconate, calcium zirconate, zirconium phosphate, zirconium tungstate phosphate, silicon carbide and the like. Among these, silicon carbide and silica are preferable, and silica is particularly preferable. Further, as silica, spherical silica is preferable. The inorganic filler may be used alone or in combination of two or more.

The average particle size of the inorganic filler is not particularly limited, but is preferably 2 μm or less, more preferably 1.5 μm or less, still more preferably 1 μm, from the viewpoint of obtaining an insulating layer having a small surface roughness and improving the fine wiring formability. It is as follows. The lower limit of the average particle size is not particularly limited, but is preferably 0.01 μm or more, more preferably 0.1 μm or more, and further preferably 0.3 μm or more. Examples of commercially available inorganic fillers having such an average particle size include "UFP-30" manufactured by Denki Kagaku Kogyo Co., Ltd., "SPH516-05" manufactured by Nippon Steel & Sumitomo Metal Materials Co., Ltd., and Shinano Electric Smelting Co., Ltd. Examples thereof include "SER-A06" manufactured by Co., Ltd.

The average particle size of the inorganic filler 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, an inorganic filler dispersed in methyl ethyl ketone by ultrasonic waves can be preferably used. As the laser diffraction / scattering type particle size distribution measuring device, "SALD-2200" manufactured by Shimadzu Corporation or the like can be used.

From the viewpoint of enhancing moisture resistance and dispersibility, the inorganic filler is preferably surface-treated with at least one surface treatment agent of a silane coupling agent, an alkoxysilane compound, and an organosilazane compound. These may be oligomers. Examples of the surface treatment agent include aminosilane-based coupling agents, epoxysilane-based coupling agents, mercaptosilane-based coupling agents, silane-based coupling agents, organosilazane compounds, titanate-based coupling agents, and the like. Commercially available surface treatment agents include, for example, "KBM403" (3-glycidoxypropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd. and "KBM803" (3-mercaptopropyltrimethoxy) manufactured by Shin-Etsu Chemical Co., Ltd. Silane), "KBE903" (3-aminopropyltriethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., "KBM573" (N-phenyl-3-aminopropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., Shin-Etsu Chemical Co., Ltd. "SZ-31" (hexamethyldisilazane) manufactured by Shin-Etsu Chemical Co., Ltd., "KBM103" (phenyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., "KBM-4803" (long-chain epoxy type) manufactured by Shin-Etsu Chemical Co., Ltd. Silane coupling agent) and the like. One type of surface treatment agent may be used alone, or two or more types may be used in combination.

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 of the inorganic filler in the first resin composition is 30% by mass or less when the non-volatile component in the first resin composition is 100% by mass from the viewpoint of improving the plating peelability. It is preferably 25% by mass or less, more preferably 20% by mass or less. The lower limit of the content of the component (c) in the first resin composition is not particularly limited and may be 0% by mass, but usually 5% by mass or more and 10% by mass or more.

-(B) Epoxy resin-
Examples of the epoxy resin 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, dicyclopentadiene type epoxy resin, and trisphenol type epoxy resin. Naftor 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, cyclohexanedimethanol type epoxy resin, naphthylene Examples thereof include ether type epoxy resin, trimethylol type epoxy resin, and tetraphenylethane type epoxy resin. One type of epoxy resin may be used alone, or two or more types may be used in combination. From the viewpoint of increasing the thermal conductivity, the component (b) is preferably an epoxy resin having a mesogen skeleton, and a bixyleneol type epoxy resin, a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a biphenyl type epoxy resin, And more preferably, it is one or more selected from the naphthalene type epoxy resin. The mesogen skeleton is a general term for groups having a rod-like or plate-like shape and containing a rigid group (aromatic ring) that exhibits liquid crystallinity.

The epoxy resin preferably contains an epoxy resin having two or more epoxy groups in one molecule. When the non-volatile component of the epoxy resin is 100% by mass, at least 50% by mass or more is preferably an epoxy resin having two or more epoxy groups in one molecule. Among them, an epoxy resin having two or more epoxy groups in one molecule and liquid at a temperature of 20 ° C. (hereinafter referred to as "liquid epoxy resin") and three or more epoxy groups in one molecule. It is preferable to contain a solid epoxy resin (hereinafter referred to as "solid epoxy resin") at a temperature of 20 ° C. By using a liquid epoxy resin and a solid epoxy resin in combination as the epoxy resin, a resin composition having excellent flexibility can be obtained. In addition, the breaking strength of the cured product of the resin composition is also improved.

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. The alicyclic epoxy resin, cyclohexanedimethanol type epoxy resin, glycidylamine type epoxy resin, and epoxy resin having a butadiene structure are preferable, and glycidylamine type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, and bisphenol AF Type epoxy resin and naphthalene type epoxy resin are more preferable. Specific examples of the liquid epoxy resin include "HP4032", "HP4032D", "HP4032SS" (naphthalene type epoxy resin) manufactured by DIC Co., Ltd., "828US", "jER828EL", and "825" manufactured by Mitsubishi Chemical Corporation. (Bisphenol A type epoxy resin), "jER807", "1750" (bisphenol F type epoxy resin), "jER152" (phenol novolac type epoxy resin), "630", "630LSD" (glycidylamine type epoxy resin), "ZX1059" (mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin) manufactured by Nippon Steel & Sumitomo Metal Chemical Co., Ltd., "EX-721" (glycidyl ester type epoxy resin) manufactured by Nagase ChemteX Corporation, ( "Selokiside 2021P" (alicyclic epoxy resin having an ester skeleton), "PB-3600" (epoxy resin having a butadiene structure) manufactured by Daicel Co., Ltd., "ZX1658", "ZX1658GS" manufactured by Nippon Steel Chemical Co., Ltd. (Liquid 1,4-glycidylcyclohexane), "630LSD" (glycidylamine type epoxy resin) manufactured by Mitsubishi Chemical Corporation, and the like. These may be used individually by 1 type, and may be used in combination of 2 or more type.

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 Co., Ltd. (Cresol novolac type epoxy resin), "N-695" (cresol novolac type epoxy resin), "HP-7200" (dicyclopentadiene type epoxy resin), "HP-7200HH", "HP-7200H", "EXA" -7311 "," EXA-7311-G3 "," EXA-7311-G4 "," EXA-7311-G4S "," HP6000 "(naphthylene ether type epoxy resin)," EPPN "manufactured by Nippon Kayaku Co., Ltd. -502H "(Trisphenol type epoxy resin)," NC7000L "(Naftor novolac type epoxy resin)," NC3000H "," NC3000 "," NC3000L "," NC3100 "(biphenyl type epoxy resin), Nippon Steel & Sumitomo Metal Corporation "ESN475V" (naphthalene type epoxy resin), "ESN485" (naphthol novolac type epoxy resin), "YX4000H", "YL6121" (biphenyl type epoxy resin), "YX4000HK" (bixilenol) manufactured by Mitsubishi Chemical Corporation Type epoxy resin), "YX8800" (anthracene type epoxy resin), Osaka Gas Chemical Co., Ltd. "PG-100", "CG-500", Mitsubishi Chemical Co., Ltd. "YL7760" (bisphenol AF type epoxy resin) Resin), "YL7800" (fluorene type epoxy resin), "jER1010" (solid bisphenol A type epoxy resin) manufactured by Mitsubishi Chemical Corporation, "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 epoxy resin, their quantity ratio (liquid epoxy resin: solid epoxy resin) is in the range of 0: 0.1 to 1:15 in terms of mass ratio. preferable. By setting the amount ratio of the liquid epoxy resin to the solid epoxy resin within such a range, i) when used in the form of a resin sheet, appropriate adhesiveness is provided, and ii) when used in the form of a resin sheet. Sufficient flexibility can be obtained, handleability is improved, and iii) a cured product having sufficient breaking strength can be obtained. From the viewpoint of the effects of i) to iii) above, the quantitative ratio of the liquid epoxy resin to the solid epoxy resin (liquid epoxy resin: solid epoxy resin) is in the range of 0: 0.3 to 1:10 in terms of mass ratio. Is more preferable, and the range of 0: 0.6 to 1: 8 is even more preferable.

The content of the epoxy resin in the first resin composition is preferably 1% by mass or more, more preferably 2% by mass or more, still more preferably 2% by mass or more, from the viewpoint of obtaining an insulating layer exhibiting good mechanical strength and insulation reliability. It is 3% by mass or more. The upper limit of the content of the epoxy resin is not particularly limited as long as the effect of the present invention is exhibited, but is preferably 80% by mass or less, more preferably 70% by mass or less, and further preferably 60% 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 epoxy equivalent of the epoxy resin is preferably 50 to 5000, more preferably 50 to 3000, still more preferably 80 to 2000, and even more preferably 110 to 1000. Within this range, the crosslink density of the cured product becomes sufficient, and an insulating layer having a small surface roughness can be provided. The epoxy equivalent can be measured according to JIS K7236, and is the mass of the resin containing 1 equivalent of the epoxy group.

The weight average molecular weight of the epoxy resin is preferably 100 to 5000, more preferably 250 to 3000, and even more preferably 400 to 1500. Here, 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.

-(C) Hardener-
The curing agent is not particularly limited as long as it has a function of curing the epoxy resin, and for example, a phenol-based curing agent, a naphthol-based curing agent, an active ester-based curing agent, a benzoxazine-based curing agent, a cyanate ester-based curing agent, and a curing agent. Examples include carbodiimide-based curing agents. The curing agent may be used alone or in combination of two or more. The component (c) is preferably one or more selected from a phenol-based curing agent, a naphthol-based curing agent, an active ester-based curing agent, a carbodiimide-based curing agent, and a cyanate ester-based curing agent.

As the phenol-based curing agent and the naphthol-based curing agent, a phenol-based curing agent having a novolak structure or a naphthol-based curing agent having a novolak structure is 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 curing agent is more preferable. Of these, a triazine skeleton-containing phenol novolac curing agent is preferable from the viewpoint of highly satisfying heat resistance, water resistance, and adhesion to the conductor layer.

Specific examples of the phenol-based curing agent and the naphthol-based curing agent include "MEH-7700", "MEH-7810", "MEH-7851", "MEH-7851H" manufactured by Meiwa Kasei Co., Ltd. "NHN", "CBN", "GPH" manufactured by Yakuhin Co., Ltd., "SN170", "SN180", "SN190", "SN475", "SN485", "SN495", "SN495" manufactured by Nippon Steel & Sumitomo Metal Corporation "SN375", "SN395", "TD-2090", "LA-7052", "LA-7554", "LA-1356", "LA-3018-50P", "EXB-9500" manufactured by DIC Corporation. And so on.

An active ester-based curing agent is also preferable from the viewpoint of obtaining an insulating layer having excellent adhesion to the conductor layer. The active ester-based curing agent is not particularly limited, but generally contains one molecule of an ester group having high reactive activity such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds. A compound having two or more of them is preferably used. The active ester-based curing agent is preferably obtained by a condensation reaction between a carboxylic acid compound and / or a thiocarboxylic acid compound and a hydroxy compound and / or a thiol compound. In particular, from the viewpoint of improving heat resistance, an active ester-based curing agent obtained from a carboxylic acid compound and a hydroxy compound is preferable, and an active ester-based curing agent 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, trihydroxybenzophenol, 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.

Specifically, an active ester compound containing a dicyclopentadiene-type diphenol structure, an active ester compound containing a naphthalene structure, an active ester compound containing an acetylated product of phenol novolac, and an active ester compound containing a benzoylated product of phenol novolac are preferable. Of these, an active ester compound containing a naphthalene structure and an active ester compound 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 active ester-based curing agents include "EXB9451", "EXB9460", "EXB9460S", "HPC-8000-65T", and "HPC-8000H-" as active ester compounds containing a dicyclopentadiene type diphenol structure. "65TM", "EXB-8000L-65TM" (manufactured by DIC Co., Ltd.), "EXB9416-70BK" (manufactured by DIC Co., Ltd.) as an active ester compound containing a naphthalene structure, as an active ester compound containing an acetylated product of phenol novolac. "DC808" (manufactured by Mitsubishi Chemical Co., Ltd.), "YLH1026" (manufactured by Mitsubishi Chemical Co., Ltd.) as an active ester compound containing a benzoylated product of phenol novolac, and "DC808" as an active ester-based curing agent which is an acetylated product of phenol novolac. (Made by Mitsubishi Chemical Co., Ltd.), "YLH1026" (manufactured by Mitsubishi Chemical Co., Ltd.), "YLH1030" (manufactured by Mitsubishi Chemical Co., Ltd.), "YLH1048" as an active ester-based curing agent which is a benzoylated product of phenol novolac. (Manufactured by Mitsubishi Chemical Co., Ltd.) and the like.

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

Examples of the cyanate ester-based curing agent include bisphenol A disicianate, polyphenol cyanate, oligo (3-methylene-1,5-phenylene cyanate), 4,4'-methylenebis (2,6-dimethylphenylcyanate), and 4,4. '-Etilidene diphenyl disianate, hexafluorobisphenol A disyanate, 2,2-bis (4-cyanate) phenylpropane, 1,1-bis (4-cyanate phenylmethane), bis (4-cyanate-3,5-dimethyl) Bifunctional cyanate resins such as phenyl) methane, 1,3-bis (4-cyanatephenyl-1- (methylethylidene)) benzene, bis (4-cyanatephenyl) thioether, and bis (4-cyanatephenyl) ether, phenol Examples thereof include polyfunctional cyanate resins derived from novolak and cresol novolak, and prepolymers in which these cyanate resins are partially triazined. Specific examples of the cyanate ester-based curing agent include "PT30" and "PT60" (both phenol novolac type polyfunctional cyanate ester resins), "BA230", and "BA230S75" (bisphenol A disocyanate) manufactured by Lonza Japan Co., Ltd. Prepolymers in which some or all of them are triazined to form a trimer) and the like.

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

The amount ratio of the epoxy resin to the curing agent is a ratio of [total number of epoxy groups in the epoxy resin]: [total number of reactive groups in the curing agent], preferably in the range of 1: 0.01 to 1: 2. 1: 0.015 to 1: 1.5 is more preferable, and 1: 0.02 to 1: 1 is even more preferable. Here, the reactive group of the curing agent is an active hydroxyl group, an active ester group, or the like, and differs depending on the type of the curing agent. The total number of epoxy groups in the epoxy resin is the total number of all epoxy resins obtained by dividing the solid content mass of each epoxy resin by the epoxy equivalent, and the total number of reactive groups in the curing agent is The value obtained by dividing the solid content mass of each curing agent by the reaction group equivalent is the total value for all curing agents. By setting the amount ratio of the epoxy resin and the curing agent within such a range, the heat resistance of the cured product of the resin composition is further improved.

In one embodiment, the first resin composition comprises the aforementioned (b) epoxy resin and (c) curing agent. The resin composition is (b) a mixture of a liquid epoxy resin and a solid epoxy resin as the epoxy resin (the mass ratio of the liquid epoxy resin: the solid epoxy resin is preferably 0: 0.1 to 1:15, more preferably. 0: 0.3 to 1:12, more preferably 0: 0.6 to 1:10) as (c) a phenol-based curing agent, a naphthol-based curing agent, an active ester-based curing agent, and a carbodiimide-based curing agent. It is preferable to contain at least one selected from the group consisting of the agent and the cyanate ester-based curing agent.

The content of the curing agent in the first resin composition is not particularly limited, but is preferably 45% by mass or less, more preferably 43% by mass or less, still more preferably 40% by mass or less. The lower limit is not particularly limited, but is preferably 10% by mass or more, and more preferably 15% by mass or more.

-(D) Thermoplastic resin-
The first resin composition may contain (d) a thermoplastic resin in addition to the components (a) to (c).

Examples of the thermoplastic resin include phenoxy resin, polyvinyl acetal resin, polyolefin resin, polybutadiene resin, polyimide resin, polyamideimide resin, polyetherimide resin, polysulfone resin, polyethersulfone resin, polyphenylene ether resin, polycarbonate resin, and polyether. Examples thereof include ether ketone resin and polyester resin, 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 thermoplastic resin is preferably in the range of 8,000 to 70,000, more preferably in the range of 10,000 to 60,000, and even more preferably in the range of 20,000 to 60,000. The polystyrene-equivalent weight average molecular weight of the thermoplastic resin is measured by gel permeation chromatography (GPC). Specifically, the polystyrene-equivalent weight average molecular weight of the thermoplastic resin is determined by using LC-9A / RID-6A manufactured by Shimadzu Corporation as a measuring device and Shodex K-800P / K- by Showa Denko Corporation as a column. 804L / 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 a phenoxy resin having one or more skeletons selected from the group consisting of a skeleton and a trimethylcyclohexane skeleton. The terminal of the phenoxy resin may be any functional group such as a phenolic hydroxyl group or an epoxy group. 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" manufactured by Mitsubishi Chemical Corporation. Bisphenol acetophenone skeleton-containing phenoxy resin), and in addition, "FX280" and "FX293" manufactured by Nippon Steel & Sumitomo Metal Corporation, "YX6954BH30", "YX7553", "YX7553BH30" manufactured by Mitsubishi Chemical Corporation, Examples thereof include "YL7769BH30", "YL6794", "YL7213", "YL7290", "YL7891BH30" 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", and "Electrified Butyral 6000-EP" manufactured by Denki Kagaku Kogyo Co., Ltd. , Sekisui Chemical Co., Ltd. Eslek BH series, BX series (for example, BX-5Z), KS series (for example, KS-1), BL series, BM series and the like.

Specific examples of the polyimide resin include "Ricacoat SN20" and "Ricacoat 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 Toyo Spinning 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 polysulfone resin include polysulfones "P1700" and "P3500" manufactured by Solvay Advanced Polymers Co., Ltd.

Specific examples of the polyphenylene ether resin include oligophenylene ether styrene resin "OPE-2St1200" manufactured by Mitsubishi Gas Chemical Company, Inc.

Among them, as the 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.

When the first resin composition contains a thermoplastic resin, the content of the thermoplastic resin is preferably 0.5% by mass to 15% by mass, more preferably 0.6% by mass to 12% by mass, still more preferably. Is 0.7% by mass to 10% by mass.

-(E) Curing accelerator-
The first resin composition may contain (e) a curing accelerator in addition to the components (a) to (c).

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, and phosphorus-based curing accelerators and amine-based curing accelerators. Curing accelerators, imidazole-based curing accelerators, and metal-based curing accelerators are preferable, and amine-based curing accelerators, imidazole-based curing accelerators, and metal-based curing accelerators are 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 (5,4,0) -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, trimethylguanidine, and the like. 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-octadecylbiguanide, 1,1-dimethylbiguanide, 1,1-diethylbiguanide, 1-cyclohexylbiguanide, 1 -Allyl biguanide, 1-phenylbiguanide, 1- (o-tolyl) biguanide and the like can be mentioned, with dicyandiamide and 1,5,7-triazabicyclo [4.4.0] deca-5-ene being preferred.

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 in the first resin composition is not particularly limited, but is preferably 0.01% by mass to 3% by mass when the non-volatile components of the epoxy resin and the curing agent are 100% by mass.

-(F) Flame retardant-
The first resin composition may contain (f) a flame retardant. Examples of the flame retardant include an organic phosphorus flame retardant, an organic nitrogen-containing phosphorus compound, a nitrogen compound, a silicone flame retardant, and a metal hydroxide. The flame retardant may be used alone or in combination of two or more.

As the flame retardant, 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.

When the first resin composition contains a flame retardant, the content of the flame retardant is not particularly limited, but is preferably 0.5% by mass to 20% by mass, more preferably 0.5% by mass to 15% by mass. More preferably, 0.5% by mass to 10% by mass is further preferable.

-(G) Organic filler-
The resin composition may contain (g) an organic filler from the viewpoint of improving elongation. 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 Co., Ltd. and "AC3816N" manufactured by Ganz Kasei Co., Ltd.

When the first resin composition contains an organic filler, the content of the organic filler is preferably 0.1% by mass to 20% by mass, more preferably 0.2% by mass to 10% by mass, still more preferably. Is 0.3% by mass to 5% by mass, or 0.5% by mass to 3% by mass.

-(H) Any additive-
The first resin composition may further contain other additives, if necessary, and such other additives include, for example, organic copper compounds, organic zinc compounds, organic cobalt compounds and the like. Examples thereof include metal compounds, thickeners, defoaming agents, leveling agents, adhesion-imparting agents, resin additives such as colorants, and the like.

(Second resin composition)
The second resin composition forming the second resin composition layer contains (a) an inorganic filler, and the content of the component (a) is 100% by mass of the non-volatile component in the second resin composition. However, the content is not particularly limited as long as it is 60% by mass or more, that is, if the composition is different from that of the first resin composition, but the second resin composition includes an inorganic filler, an epoxy resin, and a curing agent. Those containing are preferable.

Examples of the inorganic filler in the second resin composition include those similar to the inorganic filler described in the (1st resin composition) column.

The average particle size of the inorganic filler in the second resin composition is not particularly limited, but from the viewpoint of the uniformity of the side wall shape of the via, it is preferably 2.5 μm or less, more preferably 2.0 μm or less, still more preferably 1. It is 5.5 μm or less. The lower limit of the average particle size is not particularly limited, but is preferably 0.8 μm or more, more preferably 0.9 μm or more, and further preferably 1.0 μm or more. Examples of commercially available inorganic fillers having such an average particle size include "SP60-05" and "SP507-05" manufactured by Nippon Steel & Sumitomo Metal Materials Co., Ltd., and "YC100C" and "YC100C" manufactured by Admatex Co., Ltd. "YA050C", "YA050C-MJE", "YA010C", "UFP-30" manufactured by Denki Kagaku Kogyo Co., Ltd., "Silfil NSS-3N", "Silfil NSS-4N", "Silfil NSS-5N" manufactured by Tokuyama Co., Ltd. , "SC2500SQ" manufactured by Admatex Co., Ltd., "SO-C4", "SO-C2", "SO-C1" and the like.

The relationship of R1 ≤ R2 when the average particle size of the inorganic filler in the first resin composition is R1 (μm) and the average particle size of the inorganic filler in the second resin composition is R2 (μm). It is preferable to satisfy. The ratio of R1 to R2 (R2 / R1) is preferably 1 or more, more preferably 1.1 or more, still more preferably 1.5 or more, or 2 or more. The upper limit of R2 / R1 is not particularly limited, but is preferably 15 or less, more preferably 10 or less, and further preferably 8 or less. For example, when a plurality of inorganic fillers are contained in the first resin composition, the average value of the average particle diameters of the plurality of inorganic fillers is set to R1 (the same applies to the second resin composition). ).

As the second resin composition, from the viewpoint of suppressing warpage, the content of the inorganic filler is 60% by mass or more when the non-volatile component in the second resin composition is 100% by mass, and 65% by mass. It is preferably% or more, and more preferably 67% by mass or more. The upper limit of the content of the inorganic filler in the second resin composition is preferably 95% by mass or less, more preferably 90% by mass or less, still more preferably 80% by mass or less.

When the content of the inorganic filler in the first resin composition is A1 (mass%) and the content of the inorganic filler in the second resin composition is A2 (mass%), the relationship of A1 <A2 It is preferable to satisfy. The difference between A1 and A2 (A2-A1) is preferably 30% by mass or more, more preferably 40% by mass or more, and further preferably 50% by mass or more. The upper limit of the difference (A2-A1) is not particularly limited, but can be usually 90% by mass or less, 80% by mass or less, or the like.

In one embodiment, the second resin composition comprises an epoxy resin and a curing agent as well as an inorganic filler. If necessary, the second resin composition may further contain additives such as a thermoplastic resin, a curing accelerator, a flame retardant, and an organic filler.

The epoxy resin, curing agent and additive contained in the second resin composition are the same as those of (b) epoxy resin, (c) curing agent and additive described in the <first resin composition> column. Can be mentioned.

The content of the epoxy resin in the second resin composition is preferably 0.1% by mass or more, more preferably 5% by mass or more, and further, from the viewpoint of obtaining an insulating layer exhibiting good mechanical strength and insulation reliability. It is preferably 10% by mass or more. The upper limit of the content of the epoxy resin is not particularly limited as long as the effect of the present invention is exhibited, but is preferably 30% by mass or less, more preferably 25% by mass or less, and further preferably 22% by mass or less. Therefore, the content of the epoxy resin (b) in the second resin composition is preferably 0.1 to 30% by mass, more preferably 5 to 25% by mass, and further preferably 8 to 22% by mass.

When the content of the epoxy resin in the first resin composition is B1 (mass%) and the content of the epoxy resin in the second resin composition is B2 (mass%), the relationship of B1> B2 is satisfied. Is preferable. The difference between B1 and B2 (B1-B2) is preferably 5% by mass or more, more preferably 8% by mass or more, and further preferably 10% by mass or more. The upper limit of the difference (B1-B2) is not particularly limited, but may be usually 60% by mass or less, 50% by mass or less, or the like.

When a liquid epoxy resin and a solid epoxy resin are used in combination as the epoxy resin, their quantity ratio (liquid epoxy resin: solid epoxy resin) is in the range of 0: 0.1 to 1:15 in terms of mass ratio. preferable. By setting the amount ratio of the liquid epoxy resin to the solid epoxy resin within such a range, i) when used in the form of a resin sheet, appropriate adhesiveness is provided, and ii) when used in the form of a resin sheet. Sufficient flexibility can be obtained, handleability is improved, and iii) a cured product having sufficient breaking strength can be obtained. From the viewpoint of the effects of i) to iii) above, the quantitative ratio of the liquid epoxy resin to the solid epoxy resin (liquid epoxy resin: solid epoxy resin) is in the range of 0: 0.3 to 1:10 in terms of mass ratio. Is more preferable, and the range of 0: 0.6 to 1: 8 is even more preferable.

The preferred ranges of the epoxy equivalent of the epoxy resin and the weight average molecular weight of the epoxy resin in the second resin composition are the same as those of the epoxy resin contained in the first resin composition.

The content of the curing agent in the second resin composition is not particularly limited, but from the viewpoint of obtaining an insulating layer having a low dielectric loss tangent, it is preferably 0.1% by mass or more, more preferably 1% by mass or more, still more preferably. It is 5% by mass or more. The upper limit of the content of the curing agent is not particularly limited as long as the effect of the present invention is exhibited, but is preferably 20% by mass or less, more preferably 15% by mass or less, and further preferably 12% by mass or less. Therefore, the content of the curing agent in the second resin composition is preferably 0.1 to 20% by mass, more preferably 1 to 15% by mass, and further preferably 5 to 12% by mass.

The amount ratio of the epoxy resin to the curing agent in the second resin composition is the ratio of [total number of epoxy groups in the epoxy resin]: [total number of reactive groups in the curing agent], which is 1: 0.2. The range of ~ 1: 2 is preferable, 1: 0.3 to 1: 1.5 is more preferable, and 1: 0.4 to 1: 1 is further preferable. By setting the amount ratio of the epoxy resin and the curing agent within such a range, the heat resistance of the cured product of the second resin composition is further improved.

The content of the thermoplastic resin in the second resin composition is not particularly limited, but is preferably 0% by mass to 10% by mass, more preferably 0.2% by mass to 8% by mass, and further preferably 0.5. It is from mass% to 5% by mass.

The content of the curing accelerator in the second resin composition is not particularly limited, but it is preferably used in the range of 0.001% by mass to 3% by mass.

The content of the flame retardant in the second resin composition is not particularly limited, but is preferably 0.2% by mass to 20% by mass, more preferably 0.5% by mass to 15% by mass, and further preferably 0.8. More preferably, it is by mass% to 10% by mass.

The content of the organic filler in the second resin composition is preferably 0.1% by mass to 20% by mass, more preferably 0.2% by mass to 10% by mass.

The second resin composition, like the first resin composition, comprises any additive, for example, an organometallic compound such as an organocopper compound, an organozinc compound and an organocobalt compound, and an organic filler. It may contain a thickener, a defoaming agent, a leveling agent, an adhesion imparting agent, a resin additive such as a colorant, and the like.

[Resin sheet with support]
The resin sheet with a support of the present invention is a resin sheet with a support including a support and a resin sheet provided on the support, and the resin sheet is the first first resin sheet provided on the support side. It has a first resin composition layer formed of a resin composition and a second resin composition layer formed of a second resin composition provided on a side opposite to the support side. The first resin composition contains (a) an inorganic filler, and the content of the component (a) is 30% by mass or less when the non-volatile component in the first resin composition is 100% by mass. The second resin composition contains (a) an inorganic filler, and the content of the component (a) is 60% by mass or more when the non-volatile component in the second resin composition is 100% by mass. Yes, the thermal conductivity of the first thermocured product obtained by thermally curing the first resin composition at 100 ° C. for 30 minutes and further at 190 ° C. for 90 minutes, and the second resin composition at 100 ° C. for 30 minutes. The difference from the thermal conductivity of the second thermally cured product obtained by thermally curing at 190 ° C. for 90 minutes is 0.4 W / mK or less.

An example of the resin sheet with a support of the present invention is shown in FIG. In FIG. 2, the resin sheet 10 with a support includes a support 11 and a resin sheet 12 provided on the support 11. In FIG. 2, the resin sheet 12 is composed of a first resin composition layer 13 provided on the support side and a second resin composition layer 14 provided on the side opposite to the support.

Hereinafter, the support and the resin sheet of the resin sheet with a support of the present invention will be described in detail.

<Support>
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 leaf 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"). ) And other polyesters, polycarbonate (hereinafter sometimes abbreviated as "PC"), acrylics such as polymethylmethacrylate (PMMA), cyclic polyolefins, triacetylcellulose (TAC), polyethersulfide (PES), polyethers. Examples thereof include ketones and polyethylene. 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.

In the support, the surface to be joined with the first resin composition layer may be matted or corona-treated.

Further, as the support, a support with a release layer having a release layer on the surface to be joined with the first 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. .. A commercially available product may be used as the support with a release layer. For example, "SK-1" manufactured by Lintec Corporation, which is a PET film having a release layer containing an alkyd resin-based release agent as a main component. , "AL-5", "AL-7" and the like.

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.

<Resin sheet>
The resin sheet has a composition different from that of the first resin composition layer provided on the support side and the first resin composition provided on the side opposite to the support and forming the first resin composition layer. It has a second resin composition layer formed by the second resin composition of the above.

In the resin sheet with a support of the present invention, the thickness of the resin sheet is preferably 3 μm or more, more preferably 5 μm or more. The upper limit of the thickness of the resin sheet is preferably 40 μm or less, more preferably 35 μm or less, still more preferably 30 μm or less, or 25 μm or less from the viewpoint of setting the thickness of the resin layer on the conductor.

The thickness of the first resin composition layer composed of the first resin composition is preferably 10 μm or less, more preferably 7 μm or less, still more preferably 8 μm or less. The lower limit of the thickness of the first resin composition layer is not particularly limited, but from the viewpoint of obtaining an insulating layer exhibiting excellent peel strength with respect to the conductor layer after the roughening treatment, and from the viewpoint of ease of manufacturing a resin sheet with a support. Usually, it can be 0.05 μm or more, 0.1 μm or more, and the like. The presence of the first resin composition layer can improve the plating peelability.

The thickness of the second resin composition layer composed of the second resin composition is preferably 2.5 μm or more, more preferably 5 μm or more, still more preferably 7 μm or more, 8 μm or more, 9 μm or more, or 10 μm or more. The upper limit of the thickness of the second resin composition layer is preferably 30 μm or less, more preferably 25 μm or less, still more preferably 20 μm or less. The presence of the second resin composition layer can suppress warpage.

The resin sheet 10 with a support of the present invention may further include a protective film on a surface of the resin sheet 12 that is not bonded to the support 11 (that is, a surface opposite to the support). The protective film contributes to the prevention of dust and the like and scratches on the surface of the resin sheet 12. As the material of the protective film, the same material as that described for the support 11 may be used. The thickness of the protective film is not particularly limited, but is, for example, 1 μm to 40 μm. The resin sheet 10 with a support can be used by peeling off the protective film when manufacturing a printed wiring board.

The thermal conductivity of the first thermosetting product obtained by thermally curing the first resin composition at 100 ° C. for 30 minutes and further at 190 ° C. for 90 minutes is preferably 1 W / mK or less, more preferably 0.7 W. It is / mK or less, more preferably 0.5 W / mK or less. The lower limit is not particularly limited, but may be 0.01 W / mK or more. The thermal conductivity can be measured according to the procedure of [Measurement of thermal conductivity of cured product] described later.

The thermal conductivity of the second thermosetting product obtained by thermally curing the second resin composition at 100 ° C. for 30 minutes and further at 190 ° C. for 90 minutes is preferably 1.5 W / mK or less, more preferably 1. It is 0.0 W / mK or less, more preferably 0.7 W / mK or less. The lower limit is not particularly limited, but may be 0.01 W / mK or more. The thermal conductivity can be measured according to the procedure of [Measurement of thermal conductivity of cured product] described later.

In the present invention, the difference in thermal conductivity between the first and second thermosetting products is 0.4 W / mK or less. As described above, by setting the difference in thermal conductivity between the first and second thermosetting products to 0.4 W / mK or less, the length of the constricted portion generated in the extending direction of the interface of each cured product. Can be made smaller. It is considered that this mechanism is due to the fact that the difference in thermal conductivity between the first and second thermosetting products is small, and the thermal decomposition properties of the first and second thermosetting products by the laser are made uniform.

In the present invention, the difference in thermal conductivity between the first and second thermosetting products is 0.4 W / mK or less, preferably 0.35 W / mK or less, and more preferably 0.3 W / mK or less. is there. The lower limit is not particularly limited, but may be 0.01 W / mK or more.

The length of the hollowed part in the extending interface direction is defined as follows. When observing the vertical cross section of the via hole, a straight line extrapolated to the side wall of the via hole is drawn, and the distance from the straight line to the interface between the first resin composition layer and the second resin composition layer is the length of the hollowed portion. It was set to d. Specifically, the length of the hollowed portion draws a straight line as shown in FIG. 3 as an example, and the distance d from the interface between the first resin composition layer and the second resin composition layer to the straight line d. It means that.

The length of the hollowed portion is preferably 2.0 μm or less, more preferably 1.8 μm or less, still more preferably 1.5 μm or less, or 1.4 μm or less, from the viewpoint of suppressing the generation of voids during plating. .. The lower limit is not particularly limited, but is 0.01 μm or more. The length of the hollow portion can be measured according to the procedure of "confirmation of the shape of the via hole (evaluation of the length of the hollow portion and laser workability)" described later.

In the resin sheet with a support of the present invention, the length of the constricted portion generated in the extending direction of the interface of each cured resin composition layer can be reduced, so that the opening diameter (top diameter) is 40 μm or less. Also exhibits the property of being excellent in laser workability. This makes it possible to make the printed wiring board finer.

[Manufacturing method of resin sheet with support]
Hereinafter, an example of the method for manufacturing the resin sheet with a support of the present invention will be described.

First, a first resin composition layer made of the first resin composition and a second resin composition layer made of the second resin composition are formed on the support.

As a method for forming the first resin composition layer and the second resin composition layer, for example, a method of laminating the first resin composition layer and the second resin composition layer so as to join each other is used. Can be mentioned. As a method of laminating the first resin composition layer and the second resin composition layer so as to be bonded to each other, for example, the first resin composition is applied to the support, the coating film is dried, and the coating film is dried. A method of applying the second resin composition on the first resin composition layer after forming the first resin composition layer, drying the coating film, and providing the second resin composition layer can be mentioned.

In this method, for the first resin composition layer, a resin varnish in which the first 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 to form a resin. It can be made by drying the varnish.

Examples of the organic solvent include ketones such as acetone, methyl ethyl ketone and cyclohexanone, acetic acid esters such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate and carbitol acetate, and carbitol such as cellosolve and butyl carbitol. Examples include aromatic hydrocarbons such as toluene and xylene, and amide solvents such as dimethylformamide, dimethylacetamide and N-methylpyrrolidone. The organic solvent may be used alone or in combination of two or more.

The resin varnish may be dried by a known drying method such as heating or blowing hot air. 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, it is dried at 50 ° C. to 150 ° C. for 1 minute to 10 minutes to support the support. A first resin composition layer can be formed on top of it.

In the above method, for the second resin composition layer, a resin varnish in which the second resin composition is dissolved in an organic solvent is prepared, and the resin varnish is formed on the support using a die coater or the like. It can be produced by applying it on the resin composition layer of the above and drying the resin varnish.

As the organic solvent used for preparing the resin varnish in which the second resin composition is dissolved, the same organic solvent as that used for preparing the resin varnish in which the first resin composition is dissolved can be used, and the second resin can be used. The resin varnish in which the composition is dissolved can be dried by the same method as the method for drying the resin varnish in which the first resin composition is dissolved.

In addition to the above coating method, the resin sheet may be formed by a tandem coating method in which two types of resin varnishes are sequentially coated on one coating line. Further, as for the resin sheet, a method of applying the first resin composition on the second resin composition layer and drying the coating film to provide the first resin composition layer, and a separately prepared first resin sheet. It can also be formed by a method of laminating the resin composition layer and the second resin composition layer so as to be bonded to each other.

Further, in the present invention, for example, after forming the second resin composition layer and the first resin composition layer in order on the protective film, the support is laminated and supported on the first resin composition layer. A resin sheet with a body may be produced.

[Manufacturing method of printed wiring board and printed wiring board]
The printed wiring board of the present invention includes an insulating layer formed by a cured product of the resin sheet in the resin sheet with a support of the present invention. Moreover, the manufacturing method of the printed wiring board of this invention
(I) A step of laminating the second resin composition layer of the resin sheet with a support of the present invention on the inner layer substrate so as to be bonded to the inner layer substrate (II) The resin sheet with a support is thermosetting and an insulating layer. (III) A step of forming a via hole in the insulating layer and removing the support.

The "inner layer substrate" used in the step (I) is mainly a glass epoxy substrate, a metal substrate, a polyester substrate, a polyimide substrate, a BT resin substrate, a heat-curable polyphenylene ether substrate or the like, or one or both sides of the substrate. A circuit board on which a patterned conductor layer (circuit) is formed. Further, the inner layer circuit board of the intermediate product in which the insulating layer and / or the conductor layer should be further formed when the printed wiring board is manufactured is also included in the "inner layer board" in the present invention. When the printed wiring board is a circuit board with built-in parts, an inner layer board with built-in parts may be used (the conductor layer is also called a wiring layer).

Lamination of the inner layer substrate and the resin sheet with the support can be performed, for example, by heat-pressing the resin sheet with the support to the inner layer substrate from the support side. Examples of the member for heat-pressing the resin sheet with the support to the inner layer substrate (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). Be done. Instead of pressing the heat-bonded member directly onto the resin sheet with support, it is better to press it through an elastic material such as heat-resistant rubber so that the resin sheet with support sufficiently follows the surface irregularities of the inner layer substrate. preferable.

The inner layer substrate and the resin sheet with a support 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 the commercially available vacuum laminator include a vacuum pressurized laminator manufactured by Meiki Seisakusho Co., Ltd., a vacuum applicator manufactured by Nikko Materials Co., Ltd., and the like.

After laminating, the laminated resin sheet 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.

In step (II), the resin sheet of the resin sheet with a support is thermally cured to form an insulating layer.

The thermosetting conditions of the resin sheets (first and second resin composition layers) 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 sheet differ depending on the types of the first and second resin compositions, but the curing temperature is in the range of 120 ° C. to 240 ° C. (preferably in the range of 150 ° C. to 220 ° C., more preferably. Can be in the range of 170 ° C. to 200 ° C., and the curing time can be in the range of 5 minutes to 120 minutes (preferably 10 minutes to 100 minutes, more preferably 15 minutes to 90 minutes).

Before the resin sheet is thermally cured, the resin sheet may be preheated at a temperature lower than the curing temperature. For example, prior to thermosetting the resin sheet, the resin sheet is placed at a temperature of 50 ° C. or higher and lower than 120 ° C. (preferably 60 ° C. or higher and 110 ° C. or lower, more preferably 70 ° C. or higher and 100 ° C. or lower) for 5 minutes or longer (preferably 60 ° C. or higher and 110 ° C. or lower). Preheating may be carried out (preferably for 5 to 150 minutes, more preferably for 15 to 120 minutes).

In step (III), via holes are formed in the insulating layer and the support is removed. The formation of the via hole is not particularly limited, and examples thereof include laser irradiation, etching, and mechanical drilling, but it is preferably performed by laser irradiation. The support is preferably peeled off after forming a via hole in the insulating layer from the viewpoint of further suppressing the occurrence of a hollowed portion, and more specifically, the support can be peeled off after forming a via hole in the insulating layer by a laser. preferable.

This laser irradiation can be performed by using an arbitrary suitable laser processing machine that uses a carbon dioxide gas laser, a YAG laser, an excimer laser, or the like as a light source. Examples of the laser processing machine that can be used include a CO ₂ laser processing machine "LC-2k212 / 2C" manufactured by Via Mechanics Co., Ltd., 605GTWIII (-P) manufactured by Mitsubishi Electric Corporation, and Matsushita Welding System Co., Ltd. Laser processing machine can be mentioned.

The conditions of laser irradiation are not particularly limited, and laser irradiation can be carried out by any suitable step according to a conventional method according to the selected means.

The shape of the via hole, that is, the shape of the contour of the opening when viewed in the extending direction is not particularly limited, but is generally circular (substantially circular). Hereinafter, the term "diameter" of the via hole means the diameter (diameter) of the contour of the opening when viewed in the extending direction. In the present specification, the opening diameter (top diameter) refers to the diameter of the contour on the insulating layer (cured product of the first resin composition layer) side of the via hole, and the bottom diameter r2 refers to the contour of the contour on the wiring layer side of the via hole. Refers to the diameter.

It is preferable to form the via hole so that the opening diameter r1 of the via hole is preferably 40 μm or less, more preferably 35 μm or less, still more preferably 30 μm or less, or 25 μm or less.

The via hole may be formed so that the opening diameter r1 is larger than the bottom diameter r2, or the via hole may be formed so that the opening diameter r1 of the via hole is the same as the bottom diameter r2 of the via hole. By doing so, the embedding property of the via hole is improved and the generation of voids can be suppressed.

In manufacturing the printed wiring board, (IV) the step of roughening the insulating layer and (V) the step of forming the conductor layer may be further carried out. These steps (IV) to (V) may be carried out according to various methods known to those skilled in the art used for manufacturing a printed wiring board.

Step (IV) is a step of roughening the insulating layer. 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 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. Examples of commercially available swelling liquids include "Swelling Dip Security SBU" and "Swelling Dip Security SBU" manufactured by Atotech Japan Co., Ltd. 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 cured product in a swelling solution at 40 ° C. to 80 ° C. for 5 minutes to 15 minutes. The oxidizing agent (coagulant) 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 permanganate solution is preferably carried out by immersing the insulating layer in an oxidizing agent solution heated to 60 ° C. to 80 ° C. for 10 to 30 minutes. The concentration of permanganate in the alkaline permanganate solution is preferably 5% by mass to 10% by mass. Examples of commercially available oxidants include alkaline permanganate solutions such as "Concentrate Compact CP", "Concentrate Compact P", and "Dosing Solution Security P" manufactured by Atotech Japan Co., Ltd. Can be mentioned. Further, the neutralizing solution is preferably an acidic aqueous solution, and examples of commercially available products include "Reduction Solution Security P" manufactured by Atotech Japan Co., Ltd. The treatment with the neutralizing solution can be performed by immersing the treated surface that has been roughened with an oxidizing agent in the neutralizing solution at 30 ° C. to 80 ° C. for 5 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.

Step (V) is a step of forming a conductor layer.

The conductor material used for the conductor layer is not particularly limited. In a preferred embodiment, the conductor layer 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 single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper, or an alloy layer of a nickel-chromium alloy is more preferable, and a single copper layer 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 a 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. 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.

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

Examples of semiconductor devices include various semiconductor devices used in electrical 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 the semiconductor device of the present invention 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 no bumps. Examples thereof include a mounting method using a build-up layer (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, but the present invention is not limited to these Examples. In the following description, "parts" and "%" mean "parts by mass" and "% by mass", respectively, unless otherwise specified.

[Manufacturing of resin sheet with support]
Using the resin varnish (resin composition) prepared by the following procedure, resin sheets with supports of Examples and Comparative Examples were prepared.

(Preparation of resin varnish 1)
10 parts of bixyleneol type epoxy resin ("YX4000HK" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent of about 185), 25 parts of biphenyl type epoxy resin ("NC3000L" manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent of 288), and phenoxy resin (YX7553BH30 manufactured by Mitsubishi Chemical Corporation, cyclohexanone with a solid content of 30% by mass: 1: 1 solution of methyl ethyl ketone (MEK)) 20 parts are dissolved by heating in a mixed solvent of 5 parts of solvent naphtha and 5 parts of cyclohexanone while stirring. I let you. After cooling to room temperature, there, 10 parts of a triazine skeleton-containing phenol novolac curing agent (hydroxyl equivalent 125, "LA-7054" manufactured by DIC Co., Ltd., MEK solution having a solid content of 60%), a biphenyl novolac curing agent. (Moxide equivalent 218, "MEH-7851H" manufactured by Meiwa Kasei Co., Ltd., MEK solution with 60% solid content), 15 parts, polyvinyl butyral resin (glass transition temperature 105 ° C., "KS-1" manufactured by Sekisui Chemical Industry Co., Ltd. 10 parts of a 1: 1 mixed solution of ethanol and toluene with a solid content of 15%, 1 part of an amine-based curing accelerator (4-dimethylaminopyridine (DMAP), MEK solution with a solid content of 5% by mass), imidazole-based curing Surface treatment with 2 parts of accelerator (“P200-H50” manufactured by Mitsubishi Chemical Corporation, propylene glycol monomethyl ether solution with 50% by mass of solid content) and aminosilane coupling agent (“KBM573” manufactured by Shinetsu Chemical Industry Co., Ltd.) 22 parts of spherical silica (“SPH516-05” manufactured by Nippon Steel & Sumitomo Metal Materials Co., Ltd., average particle size 0.2 μm, carbon amount 0.43 mg / m ² per unit surface area) were mixed and uniformed with a high-speed rotating mixer. Then, the resin varnish 1 was prepared by filtering with a cartridge filter (“SHP020” manufactured by ROKITECHNO).

(Preparation of resin varnish 2)
Bisphenol F type epoxy resin ("1750" manufactured by Mitsubishi Chemical Co., Ltd., epoxy equivalent about 159) 5 parts, bixilenol type epoxy resin ("YX4000HK" manufactured by Mitsubishi Chemical Co., Ltd., epoxy equivalent about 185) 10 parts, biphenyl type 20 parts of epoxy resin ("NC3000L" manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent 288), 3 parts of naphthalene type epoxy resin ("HP-4710" manufactured by DIC Co., Ltd., epoxy equivalent of about 170), and phenoxy resin (Mitsubishi) 5 parts of "YX7553BH30" manufactured by Kagaku Co., Ltd. (1: 1 solution of cyclohexanone: methyl ethyl ketone (MEK) having a solid content of 30% by mass) was heated and dissolved in a mixed solvent of 20 parts of solvent naphtha and 5 parts of cyclohexanone while stirring. .. After cooling to room temperature, there, 5 parts of a triazine skeleton-containing phenol novolac curing agent (hydroxyl equivalent 125, DIC Co., Ltd. "LA-7054", MEK solution having a solid content of 60%), triazine skeleton-containing cresol novolac. 10 parts of a curing agent (hydroxyl equivalent 151, "LA-3018-50P" manufactured by DIC Co., Ltd., 2-methoxypropanol solution having a solid content of 50%), a naphthol-based curing agent ("SN485" manufactured by Nippon Steel & Sumitomo Metal Corporation) , 215 hydroxyl group equivalent, 60% solid content MEK solution) 10 parts, amine-based curing accelerator (4-dimethylaminopyridine (DMAP), MEK solution with 5% by mass solid content), flame retardant (Sanko Co., Ltd.) Manufactured by "HCA-HQ", 10- (2,5-dihydroxyphenyl) -10-hydro-9-oxa-10-phosphaphenanslen-10-oxide, average particle size 1.5 μm) 3 parts, aminosilane system Spherical silica (“SP60-05” manufactured by Nippon Steel & Sumitomo Metal Materials Co., Ltd., average particle size 1.3 μm, carbon content per unit surface area) surface-treated with a coupling agent (“KBM573” manufactured by Shinetsu Chemical Industry Co., Ltd.) 0.30 mg / m ² ) 190 parts were mixed, uniformly dispersed with a high-speed rotary mixer, and then filtered with a cartridge filter (“SHP050” manufactured by ROKITECHNO) to prepare a resin varnish 2.

(Preparation of resin varnish 3)
Naphthalene type epoxy resin (epoxy equivalent 144, "HP4032SS" manufactured by DIC Co., Ltd.) 5 parts, biphenyl type epoxy resin (Nippon Kayaku Co., Ltd. "NC3100", epoxy equivalent 258) 5 parts, naphthylene ether type epoxy resin (EXA-7311 manufactured by DIC Co., Ltd., epoxy equivalent 277), 20 parts, and phenoxy resin ("YX7553BH30" manufactured by Mitsubishi Chemical Co., Ltd., cyclohexanone: methyl ethyl ketone (MEK) 1: 1 solution having a solid content of 30% by mass. ) 6 parts were dissolved by heating in a mixed solvent of 5 parts of solvent naphtha and 5 parts of cyclohexanone with stirring. After cooling to room temperature, 5 parts of an active ester compound (“HPC-8000-65T” manufactured by DIC Co., Ltd., a toluene solution having a weight average molecular weight of about 2700 and an active group equivalent of about 223 and a non-volatile content of 65% by mass), carbodiimide 5 parts of resin ("V-03" manufactured by Nisshinbo Chemical Co., Ltd., toluene solution of 50% by mass of non-volatile component), prepolymer of bisphenol A disicanate ("BA230S75" manufactured by Ronza Japan Co., Ltd., cyanate equivalent of about 232, non-volatile content 30 parts of 75% by mass MEK solution, 1 part of curing accelerator (4-dimethylaminopyridine (DMAP), MEK solution with 5% by mass of solid content), imidazole-based curing accelerator (Mitsubishi Chemical Co., Ltd. "P200-" H50 ”, 0.1 part of propylene glycol monomethyl ether solution having a solid content of 50% by mass, curing accelerator (manufactured by Tokyo Kasei Co., Ltd., cobalt (III) acetylacetonate [Co (III) Ac, solid content 1% by mass) MEK solution] 3 parts, rubber particles (Dow Chemical Japan Co., Ltd., PARALOID EXL2655) 2 parts, phenylaminosilane coupling agent (Shinetsu Chemical Industry Co., Ltd., "KBM573") 12 parts of silica (“SPH516-05” manufactured by Nippon Steel & Sumikin Materials Co., Ltd., average particle size 0.2 μm, carbon content 0.43 mg / m ² per unit surface area) was mixed and uniformly dispersed with a high-speed rotating mixer. Later, the resin varnish 3 was prepared by filtering with a cartridge filter (“SHP020” manufactured by ROKITECHNO).

(Preparation of resin varnish 4)
Bisphenol A type epoxy resin ("825" manufactured by Mitsubishi Chemical Co., Ltd., epoxy equivalent about 176) 10 parts, naphthylene ether type epoxy resin ("EXA-7311" manufactured by DIC Co., Ltd., epoxy equivalent 277) 20 parts, and While stirring 12 parts of a phenoxy resin (“YX7553BH30” manufactured by Mitsubishi Chemical Corporation, a 1: 1 solution of cyclohexanone: methyl ethyl ketone (MEK) having a solid content of 30% by mass) in a mixed solvent of 12 parts of solvent naphtha and 5 parts of cyclohexanone. It was melted by heating. After cooling to room temperature, 30 parts of an active ester compound ("HPC-8000-65T" manufactured by DIC Co., Ltd., a toluene solution having a weight average molecular weight of about 2700 and an active group equivalent of about 223 and a non-volatile content of 65% by mass) was cured. 2 parts of accelerator (4-dimethylaminopyridine, MEK solution with 5% by mass solid content), imidazole-based curing accelerator ("1B2PZ" 1-benzyl-2-phenylimidazole manufactured by Shikoku Kasei Kogyo Co., Ltd., 5% solid content) MEK solution) 0.5 part, flame retardant ("HCA-HQ" manufactured by Sanko Co., Ltd., 10- (2,5-dihydroxyphenyl) -10-hydro-9-oxa-10-phosphaphenanthrene- Spherical silica (“SP507-05” manufactured by Nippon Steel & Sumitomo Metal Materials Co., Ltd.) surface-treated with 3 parts of 10-oxide (average particle size 2 μm) and an aminosilane-based coupling agent (“KBM573” manufactured by Shin-Etsu Chemical Industry Co., Ltd.) , Average particle size 1.0 μm, carbon amount per unit surface area 0.35 mg / m ² ) 120 parts are mixed, uniformly dispersed with a high-speed rotating mixer, and then filtered with a cartridge filter (“SHP050” manufactured by ROKITECHNO). , Resin varnish 4 was prepared.

(Preparation of resin varnish 5)
Biphenyl F type epoxy resin ("1750" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent about 159) 5 parts, biphenyl type epoxy resin ("NC3000L" manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent 288) 20 parts, biphenyl type epoxy 3 parts of resin (“NC3100” manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent 258), and phenoxy resin (“YX7553BH30” manufactured by Mitsubishi Chemical Co., Ltd., cyclohexanone with a solid content of 30% by mass: methyl ethyl ketone (MEK) 1: 1 12 parts of the solution) was dissolved by heating in a mixed solvent of 5 parts of solvent naphtha and 5 parts of cyclohexanone with stirring. After cooling to room temperature, 5 parts of a triazine skeleton-containing cresol novolac-based curing agent (hydroxyl equivalent 151, "LA-3018-50P" manufactured by DIC Co., Ltd., 2-methoxypropanol solution having a solid content of 50%), 15 parts of an active ester compound (“HPC-8000-65T” manufactured by DIC Co., Ltd., a toluene solution having a weight average molecular weight of about 2700 and an active group equivalent of about 223 and a non-volatile content of 65% by mass), an amine-based curing accelerator (4- 2 parts of dimethylaminopyridine (DMAP), MEK solution with 5% by mass of solid content), imidazole-based curing accelerator ("1B2PZ" 1-benzyl-2-phenylimidazole manufactured by Shikoku Kasei Kogyo Co., Ltd., MEK with 5% solid content) 2 parts of solution), 0.1 part of epoxy silane coupling agent ("KBM403" manufactured by Shin-Etsu Chemical Industry Co., Ltd.), finely divided silicon carbide ("SER-A06" manufactured by Shinano Electric Smelting Co., Ltd., average particle size 0 .6 μm) 5 parts were mixed, uniformly dispersed with a high-speed rotary mixer, and then filtered with a cartridge filter (“SHP030” manufactured by ROKITECHNO) to prepare a resin varnish 5.

(Preparation of resin varnish 6)
Bisphenol A type epoxy resin ("825" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent about 176) 10 parts, xylene type epoxy resin ("YX7700" manufactured by Mitsubishi Chemical Co., Ltd., epoxy equivalent 270) 25 parts, and phenoxy resin ( 20 parts of "YX7553BH30" manufactured by Mitsubishi Chemical Corporation (1: 1 solution of cyclohexanone: methyl ethyl ketone (MEK) with a solid content of 30% by mass) was dissolved by heating in a mixed solvent of 5 parts of solvent naphtha and 5 parts of cyclohexanone while stirring. It was. After cooling to room temperature, 10 parts of a triazine skeleton-containing phenol novolac-based curing agent (hydroxyl equivalent 125, "LA-7054" manufactured by DIC Co., Ltd., MEK solution having a solid content of 60%), a naphthol-based curing agent (Nittetsu Sumikin Chemical Co., Ltd.) 15 parts of "SN485" manufactured by Sekisui Chemical Co., Ltd., MEK solution having a hydroxyl group equivalent of 215 and a solid content of 60%, and a solid content of 15 parts of polyvinyl butyral resin (glass transition temperature 105 ° C., "KS-1" manufactured by Sekisui Chemical Industry Co., Ltd.) 10 parts of a 1: 1 mixed solution of% ethanol and toluene), 1 part of an amine-based curing accelerator (4-dimethylaminopyridine (DMAP), MEK solution with a solid content of 5% by mass), and an imidazole-based curing accelerator (Mitsubishi) Spherical silica surface-treated with 2 parts of "P200-H50" manufactured by Kagaku Co., Ltd., a propylene glycol monomethyl ether solution having a solid content of 50% by mass) and an aminosilane-based coupling agent ("KBM573" manufactured by Shinetsu Chemical Industry Co., Ltd.). (SO-C1 manufactured by Admatex Co., Ltd., average particle size 0.4 μm, carbon amount per unit surface area 0.35 mg / m ² ) 22 parts were mixed and uniformly dispersed with a high-speed rotating mixer, and then the cartridge. A resin varnish 6 was prepared by filtering with a filter (“SHP030” manufactured by ROKITECHNO).

(Preparation of resin varnish 7)
Bisphenol A type epoxy resin (Mitsubishi Chemical Co., Ltd. "825", epoxy equivalent about 176) 5 parts, bixylenol type epoxy resin (Mitsubishi Chemical Co., Ltd. "YX4000HK", epoxy equivalent about 185) 10 parts, biphenyl type 20 parts of epoxy resin ("NC3000L" manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent 288), 3 parts of naphthalene type epoxy resin ("HP-4710" manufactured by DIC Co., Ltd., epoxy equivalent of about 170), and phenoxy resin (Mitsubishi) 5 parts of "YX7553BH30" manufactured by Kagaku Co., Ltd. (1: 1 solution of cyclohexanone: methyl ethyl ketone (MEK) having a solid content of 30% by mass) was heated and dissolved in a mixed solvent of 10 parts of solvent naphtha and 5 parts of cyclohexanone while stirring. .. After cooling to room temperature, there, 5 parts of a triazine skeleton-containing phenol novolac curing agent (hydroxyl equivalent 125, DIC Co., Ltd. "LA-7054", MEK solution having a solid content of 60%), triazine skeleton-containing cresol novolac. 10 parts of system curing agent (hydroxyl equivalent 151, "LA3018-50P" manufactured by DIC Co., Ltd., 2-methoxypropanol solution with 50% solid content), naphthol curing agent ("SN485" manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., hydroxyl group Equivalent amount 215, 60% solid content MEK solution) 10 parts, amine-based curing accelerator (4-dimethylaminopyridine (DMAP), MEK solution with 5% by mass solid content) 1 part, flame retardant (manufactured by Sanko Co., Ltd. HCA-HQ ”, 10- (2,5-dihydroxyphenyl) -10-hydro-9-oxa-10-phosphophenanthrene-10-oxide, average particle size 1.5 μm) 3 parts, aminosilane coupling Crushed silica surface-treated with an agent ("KBM573" manufactured by Shin-Etsu Chemical Industry Co., Ltd.) ("IMSIL A-8" manufactured by Ryumori Co., Ltd., average particle size 2 μm, carbon content 0.21 mg / m per unit surface area ² ) 120 parts were mixed and uniformly dispersed with a high-speed rotating mixer, and then filtered with a cartridge filter (“SHP050” manufactured by ROKITECHNO) to prepare a resin varnish 7.

Table 1 shows the materials used for producing each resin varnish and their blending amounts (mass parts of non-volatile components).

<Example 1: Preparation of resin sheet with support>
As a support, a PET film ("Lumilar R80" manufactured by Toray Industries, Inc., thickness 38 μm, softening point 130 ° C., "Release"" was released by an alkyd resin-based mold release agent ("AL-5" manufactured by Lintec Co., Ltd.). Mold PET ") was prepared.

The resin varnish 1 is uniformly applied on the release PET with a die coater so that the thickness of the first resin composition layer after drying becomes 5 μm, and dried at 80 ° C. to 160 ° C. for 5 minutes. A first resin composition layer was obtained on the release PET. Next, the resin varnish 2 is applied onto the first resin composition layer so that the combined thickness with the first resin composition layer after drying is 20 μm, and the temperature is adjusted to 70 ° C. to 110 ° C. (average 90 ° C.). And dried for 3 minutes to form a two-layer resin composition layer (resin sheet). Next, a polypropylene film (Oji F-Tex Co., Ltd.) was used as a protective film on the surface of the resin sheet that was not bonded to the support (that is, the surface of the second resin composition layer that was not bonded to the first resin composition layer). ), The rough surface of "Alfan MA-411", thickness 15 μm) was laminated so as to be bonded to the second resin composition layer. As a result, a resin sheet 1 with a support consisting of a support, a first resin composition layer (derived from resin varnish 1), a second resin composition layer (derived from resin varnish 2), and a protective film was obtained. ..

<Example 2: Fabrication of resin sheet 2 with support>
In Example 1, 1) a resin varnish 3 was used instead of the resin varnish 1, and the first resin composition layer after drying was applied so as to have a thickness of 3 μm, and 2) a resin varnish 4 was used instead of the resin varnish 2. A resin sheet 2 with a support was obtained in the same manner as in Example 1 except that it was used.

<Example 3: Preparation of resin sheet 3 with support>
In Example 1, 1) a resin varnish 5 was used instead of the resin varnish 1, and the first resin composition layer after drying was applied so as to have a thickness of 4 μm, and 2) a resin varnish 4 was used instead of the resin varnish 2. A resin sheet 3 with a support was obtained in the same manner as in Example 1 except that it was used.

<Comparative Example 1: Fabrication of Resin Sheet 4 with Support>
In Example 1, a resin varnish 6 was used instead of the resin varnish 1, and a resin sheet with a support was applied in the same manner as in Example 1 except that the thickness of the first resin composition layer after drying was 4 μm. I got 4.

<Comparative Example 2: Fabrication of Resin Sheet 5 with Support>
In Example 1, a resin sheet 5 with a support was obtained in the same manner as in Example 1 except that the resin varnish 7 was used instead of the resin varnish 2.

(Preparation of cured product of each resin composition)
Each resin varnish 1 to 7 was uniformly applied on the same release PET film as in Examples and Comparative Examples with a die coater so that the thickness of the resin composition layer after drying was 50 μm, and the temperature was 70 ° C. to 120 ° C. A resin film having a resin composition layer formed on the release PET film was obtained by drying in.

The untreated surface of the release PET film (Lintec Co., Ltd. "501010", thickness 38 μm, 240 mm square) is a glass cloth base material epoxy resin double-sided copper-clad laminate (Matsushita Electric Works Co., Ltd. "R5715ES", thickness. It was placed on a glass cloth base material epoxy resin double-sided copper-clad laminate so as to be in contact with (0.7 mm, 255 mm square), and the four sides of the release film were fixed with polyimide adhesive tape (width 10 mm).

Each resin film (167 × 107 mm square) having a thickness of 50 μm of the resin composition layer was subjected to a batch type vacuum pressure laminator (2-stage build-up laminator CVP700 manufactured by Nikko Materials Co., Ltd.) to be used as a resin composition layer. Was laminated in the center so that the film was in contact with the release surface of the release PET film. The laminating treatment was carried out by reducing the pressure for 30 seconds to reduce the atmospheric pressure to 13 hPa or less, and then crimping at 100 ° C. and a pressure of 0.74 MPa for 30 seconds.

Next, the support was peeled off and the resin composition layer of the same resin film was further laminated on the resin composition layer under the same conditions to obtain a resin composition layer having a thickness of 50 μm × 2 = 100 μm, and then the support was peeled off. In this state, the resin composition layer was heat-cured under the curing conditions of 100 ° C. for 30 minutes and 190 ° C. for 90 minutes.

After thermosetting, the polyimide adhesive tape was peeled off, and the resin composition layer was removed from the glass cloth-based epoxy resin double-sided copper-clad laminate. Further, the release PET film was peeled off from the resin composition layer to obtain a sheet-like cured product having a thickness of about 100 μm. The sheet-shaped cured product is referred to as an evaluation cured product.

[Measurement of thermal conductivity of cured product]
(1) Measurement of thermal diffusivity α The thermal diffusivity α (m ² / s) in the thickness direction of the cured product for evaluation was measured by a temperature wave analysis method using “ai-Phase Mobile 1u” manufactured by ai-Phase. It was measured. The same sample was measured three times and the average value was calculated.
(2) Measurement of specific heat capacity Cp Curing by raising the temperature from -40 ° C to 80 ° C at 10 ° C / min using a differential scanning calorimeter (“DSC7020” manufactured by SII Nanotechnology Co., Ltd.) and measuring it. The specific heat capacity Cp (J / kg · K) of the sample at 20 ° C. was calculated.
(3) Measurement of Density ρ The density (kg / m ³ ) of the cured product for evaluation was measured using an analytical balance XP105 (using a specific gravity measurement kit) manufactured by METTLER TOLEDO Co., Ltd.
(4) Calculation of thermal conductivity λ The thermal diffusivity α (m ² / s), the specific heat capacity Cp (J / kg · K), and the density ρ (kg / m) obtained in (1) to (3) above. ^By substituting 3) into the following formula (I), the thermal conductivity λ (W / m · K) was calculated. The results are shown in the table below.
λ = α × Cp × ρ (I)

<Evaluation of the length of the hollowed part and laser workability>
(Preparation of sample)
(1) Substrate treatment of wiring board Glass cloth base material epoxy resin laminated board (copper foil thickness 12 μm, substrate thickness 0.3 mm, size) in which a circular conductor pattern (wiring pattern) with a diameter of 150 μm is formed on both sides. Processing (i) "CZ8101" manufactured by MEC Co., Ltd. on both sides of a conductor pattern (wiring board having a conductor pattern (residual copper ratio of about 70%) formed using "R-1515A" manufactured by Panasonic Corporation, 510 mm x 340 mm). The surface of the conductor pattern was roughened by etching to a thickness of about 0.8 μm to remove the conductor pattern.

(2) Laminating Step of Resin Sheet The protective film of each resin sheet with a support (size 504 mm × 334 mm) having the two-layer resin composition produced in Examples and Comparative Examples is peeled off, and a batch type vacuum pressure laminator ( Using a 2-stage build-up laminator manufactured by Nikko Materials Co., Ltd. (CVP700), the second resin composition layer is laminated on both sides of the wiring board so as to be in contact with the wiring board treated in (1) above. did. This laminating step was carried out by reducing the pressure for 30 seconds to reduce the atmospheric pressure to 13 hPa or less, and then crimping for 30 seconds under the conditions of a temperature of 120 ° C. and a pressure of 0.74 MPa. Next, a heat pressing step was performed for 60 seconds under the conditions of a temperature of 110 ° C. and a pressure of 0.5 MPa.

(3) Curing of Resin Composition Layer A wiring board on which a resin sheet with a support is laminated is heat-cured at 100 ° C. for 30 minutes and then at 175 ° C. for 30 minutes by thermosetting the resin composition layer to form an insulating layer ( About 15 μm thick on the conductor) was formed.

(4) Formation of Via Hole A laser was irradiated from above the support side to form a small diameter via hole in the insulating layer directly above the circular conductor pattern having a diameter of 150 μm inside, and an evaluation substrate was obtained.

The via hole forming step was carried out under the conditions as shown below.
_{Using a CO 2} laser machining machine "605GTWIII (-P)" manufactured by Mitsubishi Electric Corporation, a laser was irradiated from above the support side to form a via hole with a top diameter (diameter) of 30 μm in the insulating layer. The laser irradiation conditions were a mask diameter of 1 mm, a pulse width of 16 μs, an energy of 0.20 mJ / shot, a number of shots of 2, and a burst mode (10 kHz).

(Evaluation)
(5) Confirmation of the shape of the via hole (evaluation of the length of the hollowed part and laser workability)
With respect to the evaluation substrate obtained in (4) above, the support is peeled off, cut into an appropriate size, the sample containing the via hole is embedded in a cold-embedded resin, and a sample polishing device (RotoPol manufactured by Sturers) is used. A cross section of the central part of the via was prepared in -22) and observed with a scanning electron microscope (S4800 manufactured by Hitachi High-Technologies Corporation). From the obtained image, the length (μm) of the scooped portion generated in the extending direction of the interface generated at the interface between the first resin composition layer and the second resin composition layer was measured. Specifically, a straight line extrapolated to the side wall of the via hole was drawn, and the distance d from the straight line to the interface between the first resin composition layer and the second resin composition layer was measured. Four via holes were measured, the average value was calculated for each, and the evaluation was made according to the following criteria.
◯: The length of the hollowed part is 3 μm or less ×: The length of the hollowed part exceeds 3 μm

10 Resin sheet with support 11 Support 12 Resin sheet 13 First resin composition layer 14 Second resin composition layer

Claims (13)

A resin sheet with a support including a support and a resin sheet provided on the support.
The resin sheet includes a first resin composition layer formed of the first resin composition provided on the support side, and a first resin composition layer.
It has a second resin composition layer formed of the second resin composition, which is provided on the side opposite to the support side.
The first resin composition contains (a) an inorganic filler, and the content of the component (a) is 30% by mass or less when the non-volatile component in the first resin composition is 100% by mass. ,
The second resin composition contains (a) an inorganic filler, and the content of the component (a) is 65% by mass or more when the non-volatile component in the second resin composition is 100% by mass. ,
The thermal conductivity of the first thermosetting product obtained by thermally curing the first resin composition at 100 ° C. for 30 minutes and further at 190 ° C. for 90 minutes, and the second resin composition at 100 ° C. for 30 minutes. A resin sheet with a support, characterized in that the difference from the thermal conductivity of the second thermosetting product obtained by thermosetting at 190 ° C. for 90 minutes is 0.35 W / mK or less ; however, the first A resin with a support having a resin composition layer in which a first layer having a thickness of less than 2 μm and a second layer made of a second resin composition are provided so as to be bonded to each other. Excludes seats. The resin sheet with a support according to claim 1, wherein the thickness of the resin sheet is 40 μm or less. The resin sheet with a support according to claim 1 or 2, wherein the thickness of the resin sheet is 25 μm or less. When the average particle size of the component (a) in the first resin composition is R1 (μm) and the average particle size of the component (a) in the second resin composition is R2 (μm), R1 and R2 The resin sheet with a support according to any one of claims 1 to 3, wherein the ratio (R2 / R1) to the resin sheet is 1 to 15. When the average particle size of the component (a) in the first resin composition is R1 (μm) and the average particle size of the component (a) in the second resin composition is R2 (μm), R1 and R2 The resin sheet with a support according to any one of claims 1 to 4, wherein the ratio (R2 / R1) to the resin sheet is 5 to 8. The resin sheet with a support according to any one of claims 1 to 5, wherein the first resin composition contains (b) an epoxy resin and (b) has a mesogen skeleton. The sixth aspect of claim 6, wherein the component (b) is at least one selected from a bixylenol type epoxy resin, a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a biphenyl type epoxy resin, and a naphthalene type epoxy resin. Resin sheet with support. The resin sheet with a support according to any one of claims 1 to 7, which is used for forming an insulating layer of a printed wiring board. (I) Step of laminating the second resin composition layer of the resin sheet with a support according to any one of claims 1 to 8 on the inner layer substrate so as to be bonded to the inner layer substrate (II) Support A method for manufacturing a printed wiring board, which comprises a step of thermosetting a resin sheet with a resin sheet to form an insulating layer, and (III) a step of forming a via hole in the insulating layer and removing a support. The method for manufacturing a printed wiring board according to claim 9 , wherein a via hole is formed in the insulating layer by a laser in the step (III). Opening diameter of the via hole is 40μm or less, a method for manufacturing a printed wiring board according to claim 9 or 1 0. A printed wiring board including an insulating layer formed of the resin sheet with a support according to any one of claims 1 to 8. It comprises a printed wiring board according to claim 1 2, the semiconductor device.