JP6582807B2 - Manufacturing method of resin sheet - Google Patents

Description

  The present invention relates to a method for producing a resin sheet.

  As a technique for manufacturing a printed wiring board, a build-up method in which circuit-formed conductor layers and insulating layers are alternately stacked is widely used. In the build-up method, the insulating layer is generally formed by laminating a resin sheet including a resin layer on the inner layer substrate and curing the resin layer.

  On the other hand, with the recent reduction in size and thickness of electronic devices, the resin layer is becoming thinner. For example, Patent Document 1 describes an insulating resin sheet in which a first layer (resin layer) having a thickness of 2 to 18 μm is formed on a support.

JP 2014-17301 A

When a thin resin layer is formed on a support, it is generally possible to use a resin varnish with a low concentration of non-volatile components obtained by diluting the resin composition with a large amount of solvent. Ensure sex. In recent years, from the standpoint of reducing the surface smoothness of the insulating layer and the risk of foreign matter adhesion during curing, the resin layer may be thermally cured with the support attached. In many cases, a support using a material having low strength is used. In such a situation, when the resin varnish is applied to the surface of the support, the thickness of the resin layer is more than the center due to the difference in polarity between the support surface and the resin varnish or due to the change in polarity due to volatilization of the solvent In some cases, “ear heights” or repellencies that increase in the near area occurred.
In order to solve such a problem, it is conceivable to use a coating property improving agent such as a leveling agent, but there are risks such as changes in plating characteristics and bleeding out during storage. In addition, when the polarity difference between the support surface and the coating liquid is small (when wettability is high), it may spread more wet than the set coating width, making it difficult to control the coating width and film thickness. It was.

  This invention makes it a subject to provide the manufacturing method of the resin sheet which suppresses generation | occurrence | production of the ear | edge height and repellency of a resin layer, and has favorable control of a film thickness and a coating width, when forming a resin layer.

  As a result of intensive studies on the above problems, the present inventors have applied a step of applying a resin varnish on a support so that the contact angle of the resin varnish with respect to the support is 0.1 ° to 20 °. By including, it discovered that the said subject could be solved and came to complete this invention.

That is, the present invention includes the following contents.
[1] In step (A), the method includes (A) a step of applying a resin varnish containing a resin composition and a solvent on a support, and (B) a step of drying the resin varnish to form a resin layer. The method for producing a resin sheet, wherein the contact angle of the resin varnish to the support in the droplet method is 0.1 ° to 20 °, and the thickness of the resin layer is 5 μm or less in the step (B).
[2] The method for producing a resin sheet according to [1], wherein the content of the nonvolatile component in the resin varnish is 40% by mass or less.
[3] The method for producing a resin sheet according to [1] or [2], wherein the support comprises a release layer.
[4] The method for producing a resin sheet according to any one of [1] to [3], wherein the solvent contains a polar solvent.
[5] The method for producing a resin sheet according to any one of [1] to [4], wherein the solvent includes a polar solvent having a relative dielectric constant of 12 or more and a nonpolar solvent having a relative dielectric constant of 9 or less.
[6] The method for producing a resin sheet according to any one of [1] to [5], wherein a resin varnish is applied by a gravure coating method in the step (A).
[7] The method for producing a resin sheet according to any one of [1] to [6], wherein the resin sheet is for an insulating layer of a printed wiring board.

  ADVANTAGE OF THE INVENTION According to this invention, when forming a resin layer, generation | occurrence | production of the ear | edge height and repelling of a resin layer can be suppressed, and the manufacturing method of a resin sheet with favorable control of a film thickness and coating width can be provided.

[Production method of resin sheet]
Hereinafter, the manufacturing method of the resin sheet of this invention is demonstrated.

  The method for producing a resin sheet of the present invention includes (A) a step of applying a resin varnish containing a resin composition and a solvent on a support, and (B) a step of drying the resin varnish to form a resin layer. In addition, in step (A), the contact angle of the resin varnish to the support by the droplet method is 0.1 ° to 20 °, and in step (B), the thickness of the resin layer is 5 μm or less. It is characterized by.

<Process (A)>
In the step (A), a resin varnish containing a resin composition and a solvent is applied onto a support. The resin varnish is prepared by dissolving or dispersing the resin composition in a solvent. Hereinafter, the resin composition and solvent contained in the resin varnish will be described.

(Resin composition)
As a resin composition, the composition containing curable resin and its hardening | curing agent is mentioned, for example. As curable resin, the conventionally well-known curable resin used when forming the insulating layer of a printed wiring board can be used, and an epoxy resin is especially preferable. Accordingly, in one embodiment, the resin composition includes an epoxy resin and a curing agent. The resin composition may further contain additives such as an inorganic filler, a thermoplastic resin, a curing accelerator, a flame retardant, and rubber particles as necessary.

-Epoxy resin-
As the epoxy resin, for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol type epoxy resin such as bisphenol AF type epoxy resin, dicyclopentadiene type epoxy resin, trisphenol type epoxy resin, Naphthol novolac epoxy resin, phenol novolac epoxy resin, tert-butyl-catechol epoxy resin, naphthalene epoxy resin, naphthol epoxy resin, anthracene epoxy resin, glycidyl amine epoxy resin, glycidyl ester epoxy resin, cresol novolac Type epoxy resin, biphenyl type epoxy resin, linear aliphatic epoxy resin, epoxy resin having butadiene structure, alicyclic epoxy resin, composite Cyclic epoxy resins, spiro ring-containing epoxy resins, cyclohexanedimethanol type epoxy resins, naphthylene ether type epoxy resin, trimethylol type epoxy resin, tetraphenyl ethane epoxy resin and the like. An epoxy resin may be used individually by 1 type, and may be used in combination of 2 or more type.

  Examples of the epoxy resin include a bisphenol type epoxy resin, a fluorine type epoxy resin (for example, bisphenol AF type epoxy resin), a dicyclopentadiene type epoxy resin, a naphthalene type epoxy resin, a biphenyl type epoxy resin, and a mixture of these epoxy resins. It is preferable to use one or two or more selected epoxy resins.

  The epoxy resin preferably contains an epoxy resin having two or more epoxy groups in one molecule. When the nonvolatile 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, it has two or more epoxy groups in one molecule, and has a liquid epoxy resin (hereinafter referred to as “liquid epoxy resin”) at a temperature of 20 ° C. 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 an epoxy resin, a resin composition having excellent flexibility can be obtained. Moreover, the breaking strength of the cured product of the resin composition is also improved.

  Liquid epoxy resins include bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol AF type epoxy resins, naphthalene type epoxy resins, glycidyl ester type epoxy resins, phenol novolac type epoxy resins, and alicyclic epoxy resins having an ester skeleton. And epoxy resins having a butadiene structure are preferred, and bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol AF type epoxy resins and naphthalene type epoxy resins are more preferred. Specific examples of the liquid epoxy resin include “HP4032”, “HP4032D”, “HP4032SS” (naphthalene type epoxy resin) manufactured by DIC Corporation, “828US”, “jER828EL” (bisphenol A) manufactured by Mitsubishi Chemical Corporation. Type epoxy resin), “jER807” (bisphenol F type epoxy resin), “jER152” (phenol novolac type epoxy resin), “YL7760” (bisphenol AF type epoxy resin), “ZX1059” manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. ( Bisphenol A type epoxy resin and bisphenol F type epoxy resin mixture), “EX-721” (glycidyl ester type epoxy resin) manufactured by Nagase ChemteX Corporation, “Celoxide 2021P” (ester structure) manufactured by Daicel Corporation Alicyclic Epoxy with Resin), "PB-3600" (epoxy resin having a butadiene structure) and the like. These may be used alone or in combination of two or more.

  Solid epoxy resins 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, 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), “N-690” manufactured by DIC Corporation. "(Cresol novolac type epoxy resin)", "N-695" (Cresol novolac type epoxy resin), "HP-7200" (Dicyclopentadiene type epoxy resin), "HP-7200HH", "EXA7311", "EXA7311-G3 ”,“ EXA7311-G4 ”,“ EXA7311-G4S ”,“ HP6000 ”(naphthylene ether type epoxy resin),“ EPPN-502H ”(trisphenol type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.,“ NC7000L ” (Naphthol novolac type epoxy resin), “NC3000 ”,“ NC3000 ”,“ NC3000L ”,“ NC3100 ”(biphenyl type epoxy resin),“ ESN475V ”(naphthol type epoxy resin) manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.,“ ESN485 ”(naphthol novolak type epoxy resin), Mitsubishi “YX4000H”, “YL6121” (biphenyl type epoxy resin), “YX4000HK” (bixylenol type epoxy resin), “YX8800” (anthracene type epoxy resin) manufactured by Kagaku Co., Ltd., “ “PG-100”, “CG-500”, “YL7800” (fluorene type epoxy resin) manufactured by Mitsubishi Chemical Corporation, “jER1010” (solid bisphenol A type epoxy resin) manufactured by Mitsubishi Chemical Corporation, “jER1031S” (Tetraphenylethane type epoxy resin) And the like.

Epoxy resin, if it contains solid epoxy resin and a liquid epoxy resin, the ratio of the mass M _S of a solid epoxy resin to the weight M _L of the liquid epoxy resin (M S _{/ M L)} is 1 to 10 is preferably in the range of . The M S _/ M _L, With such a range, i) moderate tackiness is brought when used in the form of a resin sheet, ii) sufficient flexibility when used in the form of a resin sheet Is obtained, the handleability is improved, and iii) a cured product having sufficient breaking strength can be obtained.

The content of the epoxy resin in the resin composition is preferably 0.1% by mass or more, more preferably 5% by mass or more, and further preferably 10% from the viewpoint of obtaining an insulating layer exhibiting good mechanical strength and insulation reliability. It is at least mass%. Although the upper limit of content of an epoxy resin is not specifically limited as long as the effect of this invention is show | played, Preferably it is 50 mass% or less, More preferably, it is 45 mass% or less, More preferably, it is 40 mass% or less.
In addition, in this invention, content of each component in a resin composition is a value when the non-volatile component in a resin composition is 100 mass% unless there is separate description.

  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. By becoming this range, the crosslinked density of hardened | cured material becomes sufficient and it can bring about an insulating layer with small surface roughness. The epoxy equivalent can be measured according to JIS K7236, and is the mass of a resin containing 1 equivalent of an epoxy group.

  The weight average molecular weight of an epoxy resin becomes like this. Preferably it is 100-5000, More preferably, it is 250-3000, More preferably, it is 400-1500. Here, the weight average molecular weight of the epoxy resin is a weight average molecular weight in terms of polystyrene measured by a gel permeation chromatography (GPC) method.

-Curing agent-
The curing agent is not particularly limited as long as it has a function of curing an epoxy resin. For example, a phenolic curing agent, a naphthol curing agent, an active ester curing agent, a benzoxazine curing agent, a cyanate ester curing agent, and a carbodiimide. System curing agent. A hardening | curing agent may be used individually by 1 type, or may use 2 or more types together.

  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 (circuit wiring), a nitrogen-containing phenol-based curing agent or a nitrogen-containing naphthol-based curing agent is preferable, and a triazine structure-containing phenol-based curing agent or a triazine structure-containing naphthol-based curing agent is more preferable. . Among these, from the viewpoint of highly satisfying heat resistance, water resistance, and adhesiveness (peel strength) to the conductor layer, it is preferable to use a phenol novolac-based curing agent containing a triazine structure.

  Specific examples of the phenol-based curing agent and the naphthol-based curing agent include, for example, “MEH-7700”, “MEH-7810”, “MEH-7785” manufactured by Meiwa Kasei Co., Ltd., and Nippon Kayaku Co., Ltd. “NHN”, “CBN”, “GPH”, “SN170”, “SN180”, “SN190”, “SN475”, “SN485”, “SN495”, “SN375”, “SN395” manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. ”,“ LA7052 ”,“ LA7054 ”,“ LA3018 ”manufactured by DIC Corporation, and the like.

  Although there is no restriction | limiting in particular as an active ester type hardening | curing agent, Generally ester groups with high reaction activity, such as phenol ester, thiophenol ester, N-hydroxyamine ester, ester of heterocyclic hydroxy compound, are in 1 molecule. A compound having two or more in the above is preferably used. The active ester curing agent is preferably obtained by a condensation reaction between a carboxylic acid compound and / or a thiocarboxylic acid compound and a hydroxy compound and / or a thiol compound. In particular, from the viewpoint of improving heat resistance, an active ester curing agent obtained from a carboxylic acid compound and a hydroxy compound is preferable, and an active ester 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, and pyromellitic acid. 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, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucin, Benzenetriol, dicyclopentadienyl diphenol, phenol novolac and the like.

  Specifically, an active ester compound containing a dicyclopentadienyl diphenol structure, an active ester compound containing a naphthalene structure, an active ester compound containing an acetylated product of a phenol novolak, and an active ester compound containing a benzoylated product of a phenol novolak are preferred. Of these, active ester compounds containing a naphthalene structure and active ester compounds containing a dicyclopentadienyl diphenol structure are more preferred.

  Commercially available active ester curing agents include "EXB9451", "EXB9460", "EXB9460S", "HPC-8000-65T" (DIC Corporation) as active ester compounds containing a dicyclopentadienyl diphenol structure. Manufactured product), "EXB9416-70BK" (manufactured by DIC Corporation) as an active ester compound containing a naphthalene structure, "DC808" (manufactured by Mitsubishi Chemical Corporation) as an active ester compound containing an acetylated product of phenol novolac, Examples of the active ester compound containing a benzoylated compound include “YLH1026” (manufactured by Mitsubishi Chemical Corporation).

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

  Examples of the cyanate ester curing agent include bisphenol A dicyanate, polyphenol cyanate (oligo (3-methylene-1,5-phenylene cyanate)), 4,4′-methylene bis (2,6-dimethylphenyl cyanate), 4, 4'-ethylidenediphenyl dicyanate, hexafluorobisphenol A dicyanate, 2,2-bis (4-cyanate) phenylpropane, 1,1-bis (4-cyanatephenylmethane), bis (4-cyanate-3,5- Bifunctional cyanate resins such as dimethylphenyl) methane, 1,3-bis (4-cyanatephenyl-1- (methylethylidene)) benzene, bis (4-cyanatephenyl) thioether, and bis (4-cyanatephenyl) ether; Phenol novolac and Polyfunctional cyanate resin derived from resol novolac, these cyanate resins and partially triazine of prepolymer. Specific examples of the cyanate ester curing agent include “PT30” and “PT60” (both phenol novolak polyfunctional cyanate ester resins) and “BA230” (part or all of bisphenol A dicyanate) manufactured by Lonza Japan Co., Ltd. And the like, and the like, and the like.

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

  In this invention, it is preferable that the hardening | curing agent contains 1 or more types selected from a phenol type hardening | curing agent, a cyanate ester type hardening | curing agent, and an active ester type hardening | curing agent, a triazine structure containing phenol type hardening | curing agent, a cyanate ester type | system | group. It is more preferable that at least one selected from a curing agent and an active ester curing agent is included.

  Although content of the hardening | curing agent in a resin composition is not specifically limited, Preferably it is 0.1 mass% or more, More preferably, it is 1 mass% or more, More preferably, it is 5 mass% or more. Although the upper limit of content of a hardening | curing agent is not specifically limited as long as the effect of this invention is show | played, Preferably it is 30 mass% or less, More preferably, it is 25 mass% or less, More preferably, it is 20 mass% or less.

  The amount ratio of the epoxy resin and the curing agent is preferably a ratio of [total number of epoxy groups of the epoxy resin]: [total number of reactive groups of the curing agent] in the range of 1: 0.2 to 1: 2. 1: 0.3-1: 1.5 are more preferable, and 1: 0.4-1: 1 are further more preferable. Here, the reactive group of the curing agent is an active hydroxyl group, an active ester group or the like, and varies depending on the type of the curing agent. Moreover, the total number of epoxy groups of the epoxy resin is a value obtained by dividing the solid content mass of each epoxy resin by the epoxy equivalent for the epoxy resin, and the total number of reactive groups of the curing agent is each curing The value obtained by dividing the solid content mass of the agent by the reactive group equivalent is the sum of all the curing agents. By setting the amount ratio of the epoxy resin and the curing agent in such a range, the heat resistance of the cured product of the resin composition is further improved.

  The resin composition may contain additives such as an inorganic filler, a thermoplastic resin, a curing accelerator, a flame retardant, and rubber particles in addition to the epoxy resin and the curing agent.

-Inorganic filler-
The material of the inorganic filler is not particularly limited. 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 zirconate titanate, barium zirconate, calcium zirconate, zirconium phosphate, and zirconium tungstate phosphate. Of these, silica is particularly preferred. Moreover, spherical silica is preferable as the silica. An inorganic filler may be used individually by 1 type, and may be used in combination of 2 or more type. Examples of commercially available inorganic fillers include “SO-C2”, “SO-C1”, and “SO-C4” manufactured by Admatechs Corporation.

  The average particle diameter of the inorganic filler is not particularly limited, but is preferably 5 μm or less, more preferably 4 μm or less, and even more preferably 3 μm or less, from the viewpoint of obtaining an insulating layer having a small surface roughness and improving the fine wiring formability. 1 μm or less, 0.7 μm or less, 0.5 μm or less, or 0.3 μm or less is even more preferable. On the other hand, from the viewpoint of obtaining a resin varnish having an appropriate viscosity and good handleability when forming a resin varnish using the resin composition, from the viewpoint of preventing an increase in the melt viscosity of the resin sheet, The average particle diameter is preferably 0.01 μm or more, more preferably 0.03 μm or more, and further preferably 0.05 μm or more, 0.07 μm or more, or 0.1 μm or more.

  The average particle diameter of the inorganic filler can be measured by a laser diffraction / scattering method based on Mie scattering theory. Specifically, the particle size distribution of the inorganic filler can be prepared on a volume basis by a laser diffraction / scattering particle size distribution measuring apparatus, and the median diameter can be measured as the average particle diameter. As the measurement sample, an inorganic filler dispersed in water by ultrasonic waves can be preferably used. As the laser diffraction / scattering particle size distribution measuring apparatus, “LA-500” manufactured by Horiba, Ltd. or the like can be used.

  Inorganic fillers are aminosilane coupling agents, epoxysilane coupling agents, mercaptosilane coupling agents, silane coupling agents, organosilazane compounds, titanate coupling agents from the viewpoint of improving moisture resistance and dispersibility. It is preferable that it is processed with 1 or more types of surface treating agents. Examples of commercially available surface treatment agents include “KBM403” (3-glycidoxypropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., and “KBM803” (3-mercaptopropyltrimethoxy manufactured by Shin-Etsu Chemical Co., Ltd.). Silane), Shin-Etsu Chemical "KBE903" (3-aminopropyltriethoxysilane), Shin-Etsu Chemical "KBM573" (N-phenyl-3-aminopropyltrimethoxysilane), Shin-Etsu Chemical "SZ-31" (hexamethyldisilazane) manufactured by KK, "KBM103" (phenyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., "KBM-4803" manufactured by Shin-Etsu Chemical Co., Ltd. (long-chain epoxy type) Silane coupling agent).

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, 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 more preferable from the viewpoint of preventing an increase in the melt viscosity of the resin varnish or the sheet form. 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 the surface treatment agent and ultrasonically cleaned at 25 ° C. for 5 minutes. After removing the supernatant and drying the solid, the carbon amount 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. can be used.

  The content of the inorganic filler in the resin composition is preferably 70% by mass or less, more preferably 60% by mass or less, and more preferably 50% by mass or less, from the viewpoint of obtaining an insulating layer on which fine wiring can be formed. Or it is 40 mass% or less. The lower limit of the content of the inorganic filler in the resin composition is not particularly limited, and may be 0% by mass, but is usually 5% by mass or more, 10% by mass or more, 20% by mass or more.

-Thermoplastic resin-
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. Thermoplastic resins such as ether ketone resins and polyester resins can be mentioned. A thermoplastic resin may be used individually by 1 type, or may be used in combination of 2 or more type.

  The polystyrene equivalent weight average molecular weight of the thermoplastic resin is preferably in the range of 5,000 to 100,000, more preferably in the range of 10,000 to 60,000, and still more preferably in the range of 20,000 to 60,000. The weight average molecular weight in terms of polystyrene of the thermoplastic resin is measured by a gel permeation chromatography (GPC) method. Specifically, the polystyrene-reduced weight average molecular weight of the thermoplastic resin is LC-9A / RID-6A manufactured by Shimadzu Corporation as a measuring device, and Shodex K-800P / K- manufactured by Showa Denko KK as a column. 804L / K-804L can be calculated using a standard polystyrene calibration curve by measuring the column temperature at 40 ° C. using chloroform or the like as a mobile phase.

  Examples of the phenoxy resin include bisphenol A skeleton, bisphenol F skeleton, bisphenol S skeleton, bisphenolacetophenone skeleton, novolac skeleton, biphenyl skeleton, fluorene skeleton, dicyclopentadiene skeleton, norbornene skeleton, naphthalene skeleton, anthracene skeleton, adamantane skeleton, terpene Examples thereof include phenoxy resins having a skeleton and one or more skeletons selected from the group consisting of a trimethylcyclohexane skeleton. The terminal of the phenoxy resin may be any functional group such as a phenolic hydroxyl group or an epoxy group. A phenoxy resin may be used individually by 1 type, and may be used in combination of 2 or more type. 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). In addition, “FX280” and “FX293” manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., “YL6954BH30”, “YX7553”, “YL7769BH30” manufactured by Mitsubishi Chemical Co., Ltd., “YL6794”, “YL7213”, “YL7290”, “YL7482” and the like.

  Examples of the polyvinyl acetal resin include a polyvinyl formal resin and a polyvinyl butyral resin, and a polyvinyl butyral resin is preferable. Specific examples of the polyvinyl acetal resin include, for example, “Electrical butyral 4000-2”, “Electrical butyral 5000-A”, “Electrical butyral 6000-C”, and “Electrical butyral 6000-EP” manufactured by Denki Kagaku Kogyo Co., Ltd. Sekisui Chemical Co., Ltd.'s S-REC BH series, BX series, KS series, BL series, BM series and the like.

  Specific examples of the polyimide resin include “Rika Coat SN20” and “Rika Coat PN20” manufactured by Shin Nippon Rika Co., Ltd. Specific examples of the polyimide resin include 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), a polysiloxane skeleton. Examples thereof include modified polyimides such as containing polyimide (polyimides described in JP-A Nos. 2002-12667 and 2000-319386).

  Specific examples of the polyamide-imide resin include “Bilomax HR11NN” and “Bilomax HR16NN” manufactured by Toyobo Co., Ltd. Specific examples of the polyamideimide resin also include modified polyamideimides such as “KS9100” and “KS9300” (polysiloxane skeleton-containing polyamideimide) manufactured by Hitachi Chemical Co., Ltd.

  Specific examples of the polyethersulfone resin include “PES5003P” manufactured by Sumitomo Chemical Co., Ltd.

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

  Among these, phenoxy resin and polyvinyl acetal resin are preferable as the thermoplastic resin from the viewpoint of obtaining an insulating layer having a lower surface roughness and superior adhesion to the conductor layer in combination with other components. Therefore, in one suitable embodiment, a thermoplastic resin component contains 1 or more types selected from the group which consists of a phenoxy resin and a polyvinyl acetal resin.

  The content of the thermoplastic resin in the resin composition is preferably 0% by mass to 20% by mass, more preferably 0.5% by mass to 10% by mass, further from the viewpoint of appropriately adjusting the melt viscosity of the resin sheet. Preferably they are 1 mass%-8 mass%.

-Curing accelerator-
Examples of the curing accelerator include phosphorus-based curing accelerators, amine-based curing accelerators, imidazole-based curing accelerators, guanidine-based curing accelerators, phosphorus-based curing accelerators, amine-based curing accelerators, and imidazole-based accelerators. A curing accelerator is preferable, and an amine-based curing accelerator and an imidazole-based curing accelerator are more preferable. A hardening accelerator may be used individually by 1 type, and may be used in combination of 2 or more type.

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

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

  Examples of the imidazole curing accelerator include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate, 1-cyanoethyl- 2 Phenylimidazolium trimellitate, 2,4-diamino-6- [2'-methylimidazolyl- (1 ')]-ethyl-s-triazine, 2,4-diamino-6- [2'-undecylimidazolyl- (1 ′)]-ethyl-s-triazine, 2,4-diamino-6- [2′-ethyl-4′-methylimidazolyl- (1 ′)]-ethyl-s-triazine, 2,4-diamino- 6- [2′-Methylimidazolyl- (1 ′)]-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl- 4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo [1,2-a] benzimidazole, 1-dodecyl-2-methyl Examples include imidazole compounds such as 3-benzylimidazolium chloride, 2-methylimidazoline, and 2-phenylimidazoline, and adducts of imidazole compounds and epoxy resins, such as 2-ethyl-4-methylimidazole and 1-benzyl-2-phenyl. Imidazole is preferred.

  Commercially available products may be used as the imidazole curing accelerator, and examples thereof include “P200-H50” manufactured by Mitsubishi Chemical Corporation.

  Examples of the guanidine curing accelerator include dicyandiamide, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, 1- (o-tolyl) guanidine, dimethylguanidine, diphenylguanidine, trimethylguanidine, Tetramethylguanidine, pentamethylguanidine, 1,5,7-triazabicyclo [4.4.0] dec-5-ene, 7-methyl-1,5,7-triazabicyclo [4.4.0] Deca-5-ene, 1-methyl biguanide, 1-ethyl biguanide, 1-n-butyl biguanide, 1-n-octadecyl biguanide, 1,1-dimethyl biguanide, 1,1-diethyl biguanide, 1-cyclohexyl biguanide, 1 -Allyl biguanide, 1-phenyl biguanide, 1- ( - tolyl) biguanide, and the like, dicyandiamide, 1,5,7-triazabicyclo [4.4.0] dec-5-ene are preferred.

  Although content of the hardening accelerator in a resin composition is not specifically limited, It is preferable to use in 0.05 mass%-3 mass%.

-Flame retardant-
The resin composition may contain 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. A flame retardant may be used individually by 1 type, or may use 2 or more types together.

  Commercially available products may be used as the flame retardant, and examples thereof include “HCA-HQ” manufactured by Sanko Co., Ltd.

  The content of the flame retardant in the resin composition is not particularly limited, but is preferably 0.5% by mass to 20% by mass, more preferably 1% by mass to 15% by mass, and even more preferably 1.5% by mass to 10% by mass. % Is more preferable.

-Organic filler-
The resin composition may further contain an organic filler. As the organic filler, any organic filler that can be used for forming an insulating layer of a printed wiring board may be used. Examples thereof include rubber particles, polyamide fine particles, and silicone particles, and rubber particles are preferable.

  A commercially available product may be used as the rubber particles, and examples thereof include “AC3816N” manufactured by Aika Industry Co., Ltd.

  The content of the organic filler in the resin composition is preferably 1% by mass to 20% by mass, more preferably 2% by mass to 10% by mass.

  The resin composition may further contain other additives other than the flame retardant and the organic filler, if necessary. Examples of such other additives include an organic copper compound, an organic zinc compound, and Examples include organometallic compounds such as organic cobalt compounds, and resin additives such as thickeners, antifoaming agents, leveling agents, adhesion-imparting agents, and coloring agents.

(solvent)
The solvent contained in the resin varnish is not particularly limited as long as a resin varnish showing an intended contact angle with respect to the support is obtained, and a known solvent may be used. Examples of the solvent include ketones such as acetone, methyl ethyl ketone (MEK) and cyclohexanone, acetates such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate and carbitol acetate, cellosolve and butyl carbitol, etc. Examples thereof include carbitols, aromatic hydrocarbons such as toluene, xylene and ethylbenzene, amide solvents such as dimethylformamide, dimethylacetamide (DMAc) and N-methylpyrrolidone. An organic solvent may be used individually by 1 type, may be used in combination of 2 or more type, and the thing containing 2 or more types of solvents like solvent naphtha may be used.

  From the viewpoint of suppressing repelling and ear height, the solvent preferably contains a polar solvent. In the present invention, the relative permittivity (20 to 25 ° C.) of the polar solvent is preferably 10 or more, more preferably 12 or more, 14 or more, 16 or more, 18 or more, or 20 or more. Preferably it is 50 or less. Examples of such polar solvents include ethanol (25.3), methyl ethyl ketone (18.6), cyclohexanone (16.1), DMAc (38.85), etc. (values in parentheses are relative dielectric constants). Showing).

  From the viewpoint of suppressing repellency and ear height with respect to a wide variety of supports, the solvent preferably contains a polar solvent and a nonpolar solvent. The polar solvent is as described above. In the present invention, the relative dielectric constant (20 to 25 ° C.) of the nonpolar solvent is preferably less than 10, more preferably 9 or less, 8 or less, 7 or less, 6 or less, or 5 or less. Preferably it is 1 or more or 1.5 or more. Examples of such a non-polar solvent include toluene (2.38), xylene (2.27 to 2.56 depending on the bonding position of the methyl group, that is, ortho, meta, and para positions), ethylbenzene ( 2.45), solvent naphtha (a mixed solvent of aromatic hydrocarbons mainly composed of toluene, xylene, and ethylbenzene). Among them, the solvent preferably includes a polar solvent having a relative dielectric constant of 12 or more and a nonpolar solvent having a relative dielectric constant of 9 or less, and includes a polar solvent having a relative dielectric constant of 14 or more and a nonpolar solvent having a relative dielectric constant of 8 or less. It is more preferable to include a polar solvent having a relative dielectric constant of 16 or more and a nonpolar solvent having a relative dielectric constant of 6 or less, and one or more polar solvents selected from ethanol and methyl ethyl ketone, toluene, More preferably, it contains one or two or more nonpolar solvents selected from solvent naphtha. The mass ratio [polar solvent / nonpolar solvent] of the polar solvent to the nonpolar solvent in the solvent is preferably 2/8 to 8/2, more preferably, although it depends on the relative dielectric constant of these solvents and the type of the support. Is 3/7 to 7/3.

  From the viewpoint of suppressing repellency and ear height with respect to the support, the solvent has a boiling point of 100 ° C or higher (preferably 105 ° C or higher, more preferably 110 ° C or higher, 115 ° C or higher, or 120 ° C or higher), and a boiling point of 100 ° C. Less than (preferably 95 ° C. or lower, more preferably 90 ° C. or lower, 85 ° C. or lower, or 80 ° C. or lower). The mass ratio of the solvent having a boiling point of 100 ° C. or more and the solvent having a boiling point of less than 100 ° C. [(solvent having a boiling point of 100 ° C. or more) / (solvent having a boiling point of less than 100 ° C.)] is preferably 2/8 to 8/2, more preferably 3/7 to 7/3.

  The content of the non-volatile component in the resin varnish used in the step (A) is preferably 5% by mass or more, more preferably 10% by mass or more, 15% by mass or more, or 20% by mass from the viewpoint of easy coating width control. % Or more. The upper limit value of the content of the nonvolatile component in the resin varnish is preferably 40% by mass or less, more preferably 35% by mass or less.

  As long as the desired contact angle with respect to the support is shown, the viscosity of the resin varnish is not particularly limited. From the viewpoint of easy coating width control, it is preferably 2 mPa · s or more, more preferably 2.5 mPa · s or more, or 3 mPa · s or more. The upper limit of the viscosity of the resin varnish is not particularly limited as long as it can be applied to the support. From the standpoint of being able to further enjoy the effect of the present invention that brings about good film thickness control when forming a thin resin layer, it is preferably 15 mPa · s or less, more preferably 14 mPa · s or less, 13 mPa · s or less, 12 mPa · s or less. s or less, 11 mPa · s or less, or 10 mPa · s or less.

  The viscosity of the resin varnish can be measured under a temperature condition of 25 ° C. using, for example, a rotational vibration viscometer (Viscomate VM-10A manufactured by Tech Jam Co., Ltd.).

  As a support body used at a process (A), the film, metal foil, and release paper which consist of plastic materials are mentioned, for example, The film and metal foil which consist of plastic materials are preferable.

  When a film made of a plastic material is used as the support, examples of the plastic material include polyethylene terephthalate (hereinafter sometimes abbreviated as “PET”) and polyethylene naphthalate (hereinafter abbreviated as “PEN”). .) Polyester, polycarbonate (hereinafter sometimes abbreviated as “PC”), polymethyl methacrylate (PMMA) and other acrylics, cyclic polyolefin, triacetyl cellulose (TAC), polyether sulfide (PES), polyether Examples include ketones and polyimides. Among these, polyethylene terephthalate and polyethylene naphthalate are preferable, and inexpensive polyethylene terephthalate is particularly preferable.

  When using metal foil as a support body, as metal foil, copper foil, aluminum foil, etc. are mentioned, for example, 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.). It may be used.

  As described above, during the production of a printed wiring board, in recent years, in order to reduce the surface smoothness of the insulating layer and the risk of foreign matter adhesion during curing, the resin layer may be thermally cured with the support attached. In such a case, a support with a release layer or a support using a material with low adhesion is often used, but when forming a thin resin layer on such a support, the film thickness is controlled. It can be difficult. In this regard, in the present invention, even when a thin resin layer is formed on a support with a release layer or a support using a material with low adhesion, it is possible to achieve good film thickness control. it can.

  Therefore, in one embodiment that can further enjoy the effects of the present invention, the support includes a release layer, that is, the support is a support with a release layer. As a mold release agent used for a mold release layer of a support with a mold release layer, for example, one or more mold release agents selected from the group consisting of alkyd resins, polyolefin resins, urethane resins, acrylic resins and silicone resins are used. Can be mentioned. As the support with a release layer, a commercially available product may be used. For example, “SK-1” manufactured by Lintec Corporation, which is a PET film having a release layer mainly composed of an alkyd resin release agent. , “AL-5”, “AL-7” and the like.

  Although it does not specifically limit as thickness of a support body, The range of 5 micrometers-75 micrometers is preferable, and the range of 10 micrometers-60 micrometers is more preferable. In addition, when using a support body with a release layer, it is preferable that the thickness of the whole support body with a release layer is the said range.

  In the step (A), application of the resin varnish may be performed by any conventionally known method as long as a coating film having a uniform thickness can be formed. For example, the resin varnish can be applied to the support using a die coating method, a comma coating method, a gravure coating method, a bar coating method, or the like. Of these methods, the gravure coating method is preferable from the viewpoint of being suitable for forming a resin layer having a small film thickness.

  In the step (A), the contact angle of the resin varnish to the support in the droplet method is 0.1 ° to 20 °. With such a configuration, repelling and ear height can be suppressed. The contact angle is preferably 0.2 ° or more, more preferably 0.4 ° or more. The upper limit of the contact angle is preferably 18 ° or less, more preferably 16 ° or less, 14 ° or less, 12 ° or less, 11 ° or less, or 10 ° or less.

  The contact angle of the resin varnish to the support by the droplet method can be measured using an automatic contact angle meter (DropMaster DMs-401 manufactured by Kyowa Interface Science Co., Ltd.). Specifically, it can be measured according to the method described later (Method of measuring contact angle by droplet method).

<Process (B)>
In the step (B), the resin varnish is dried to form a resin layer. Thereby, a resin layer is formed on the support.

  In the present invention, a thin resin layer having a thickness of 5 μm or less can be formed with an intended coating width without problems of ear height and repellency. The thickness of the resin layer may be 4 μm or less and 3 μm or less. Although the minimum of the thickness of a resin layer is not specifically limited, Usually, it is 1 micrometer or more.

  The resin varnish may be dried by a known drying method such as heating or hot air blowing. The drying conditions may be determined according to the boiling point of the solvent contained in the resin varnish. The drying conditions are not particularly limited, but drying is performed so that the content of the organic solvent in the resin layer is 10% by mass or less, preferably 5% by mass or less.

  The drying process may be performed only once or a plurality of times. When the drying treatment is performed a plurality of times, the respective drying conditions may be the same or different.

  When the drying treatment is performed only once, for example, 50 to 200 ° C. (preferably 80 to 200 ° C., more preferably 90 to 200 ° C.) for 1 to 30 minutes (preferably 1 to 20 minutes, More preferably, the resin layer may be formed by drying the resin varnish for 1 minute to 15 minutes.

  When the drying process is performed a plurality of times, for example, the second and subsequent drying processes may be performed at a higher temperature than the first drying process. For example, the first drying process is performed at a temperature of 50 ° C. or higher and lower than 150 ° C. (preferably 70 ° C. or higher and 140 ° C. or lower, more preferably 80 ° C. or higher and 130 ° C. or lower, or 90 ° C. or higher and 120 ° C. or lower). The second and subsequent drying treatments may be performed at a temperature of 200 ° C. or lower (preferably 160 ° C. or higher and 200 ° C. or lower, 170 ° C. or higher and 200 ° C. or lower, or 180 ° C. or higher and 200 ° C. or lower). When the drying treatment is performed a plurality of times, each drying treatment time is, for example, 1 minute to 30 minutes (preferably 1 minute to 20 minutes, more preferably 1 minute to 15 minutes, or 1 minute to 10 minutes). Good.

  In the resin sheet, a protective film according to the support can be further provided on the surface of the resin layer that is not bonded to the support (that is, the surface opposite to the support). Therefore, in one embodiment, the method for producing a resin sheet of the present invention includes a step of providing a protective film so as to be further bonded to the resin layer after the step (B) (hereinafter also referred to as “step (C)”). Including.

  In the step (C), the protective film is preferably laminated on the resin layer by a roll, press-bonding or the like. Lamination treatment can be performed using a commercially available vacuum laminator. Examples of the commercially available vacuum laminator include a vacuum pressure laminator manufactured by Meiki Seisakusho, a vacuum applicator manufactured by Nichigo Morton, and the like.

  Although the thickness of a protective film is not specifically limited, For example, they are 1 micrometer-40 micrometers. By laminating the protective film, it is possible to prevent dust from adhering to the surface of the resin layer and scratching. The resin sheet can be stored in a roll. When the resin sheet has a protective film, it can be used by peeling off the protective film.

  The resin sheet manufactured by the method of the present invention can be used as a resin sheet (resin sheet for an insulating layer of a printed wiring board) for forming an insulating layer of a printed wiring board. In particular, in the production of printed wiring boards by the build-up method, it can be suitably used as a resin sheet (resin sheet for build-up insulating layers of printed wiring boards) for forming an insulating layer, and on the plating process It can be more suitably used as a resin sheet for forming an insulating layer on which a circuit is formed (a resin sheet for a build-up insulating layer of a printed wiring board on which a circuit is formed by a plating process).

[Laminated sheet and manufacturing method thereof]
In one embodiment, a laminated sheet can be formed by bonding various films including an insulating resin layer to the resin layer of the resin sheet obtained by the present invention.

  As the insulating resin layer, a conventionally known insulating resin layer can be used when forming the insulating layer of the printed wiring board. The thickness of the insulating resin layer is preferably 70 μm or less, more preferably 60 μm or less, 50 μm or less, 40 μm or less, 30 μm or less, or 20 μm or less from the viewpoint of reducing the thickness of the insulating layer. Although the minimum of the thickness of an insulating resin layer is not specifically limited, Usually, 1 micrometer or more, 5 micrometers or more, 10 micrometers or more etc. can be used.

  From the viewpoint of obtaining a thin insulating layer having excellent mechanical strength, the insulating resin layer is preferably a prepreg, but a thermosetting resin composition layer (hereinafter simply referred to as “thermosetting resin composition” not containing a sheet-like fiber base material). May be used). The thermosetting resin composition layer is not particularly limited as long as it exhibits sufficient hardness and insulation after curing, but generally contains an epoxy resin and a curing agent. The types and contents of the epoxy resin and the curing agent are as described for the epoxy resin and the curing agent in the above (resin composition).

  From the viewpoint of reducing the coefficient of thermal expansion of the resulting insulating layer and preventing the occurrence of cracks and circuit distortion due to the difference in thermal expansion between the insulating layer and the conductor layer, the thermosetting resin composition layer contains an inorganic filler. Furthermore, it is preferable to include. As the inorganic filler, the inorganic filler in the above (resin composition) may be used. The content of the inorganic filler in the thermosetting resin composition layer is, from the viewpoint of reducing the coefficient of thermal expansion of the resulting insulating layer, when the nonvolatile component in the thermosetting resin composition layer is 100% by mass, Preferably they are 50 mass% or more, More preferably, they are 55 mass% or more, More preferably, they are 60 mass% or more, 65 mass% or more, 70 mass% or more, or 75 mass% or more. The upper limit of the content of the inorganic filler is preferably 95% by mass or less, more preferably 90% by mass or less or 85% by mass or less, from the viewpoint of mechanical strength of the obtained insulating layer. Examples of other components that can be contained in the thermosetting resin composition layer include additives such as thermoplastic resins, curing accelerators, flame retardants, and rubber particles described in the above (resin composition). .

  In a preferred embodiment, a laminated sheet can be produced by bonding a resin layer of a resin sheet obtained by the production method of the present invention and a prepreg.

  A prepreg is formed by impregnating a thermosetting resin composition in a sheet-like fiber base material.

  The thermosetting resin composition used for the prepreg is not particularly limited as long as the cured product has sufficient hardness and insulation, and a conventionally known thermosetting resin composition used for forming an insulating layer of a printed wiring board. May be used. For example, you may use the resin composition used for formation of said thermosetting resin composition layer. Alternatively, the thermosetting resin composition used for the prepreg may be the same as the resin composition used for forming the resin layer in the resin sheet of the present invention.

  The sheet-like fiber base material used for a prepreg is not specifically limited, What is used normally as base materials for prepregs, such as a glass cloth, an aramid nonwoven fabric, a liquid crystal polymer nonwoven fabric, can be used. From the viewpoint of reducing the thickness of the insulating layer, the thickness of the sheet-like fiber substrate is preferably 50 μm or less, more preferably 40 μm or less, still more preferably 30 μm or less, 25 μm or less, or 20 μm or less. Although the minimum of the thickness of a sheet-like fiber base material is not specifically limited, Usually, you may be 5 micrometers or more, 10 micrometers or more.

  The prepreg can be produced by a known method such as a hot melt method or a solvent method.

  The thickness of the prepreg may be 70 μm or less, 60 μm or less, 50 μm or less, 40 μm or less, or 30 μm or less. Although the minimum of the thickness of a prepreg is not specifically limited, Usually, it may be 10 micrometers or more, 12 micrometers or more, etc. The thickness of the prepreg can be easily changed by adjusting the amount of impregnation of the thermosetting resin composition.

  The laminated sheet can be produced by laminating such that the resin layer of the resin sheet and the insulating resin layer (preferably prepreg) are joined. For example, a laminated sheet can be produced by laminating a resin sheet obtained by the present invention on an insulating resin layer so that the resin layer of the resin sheet is bonded to the insulating resin layer.

  Lamination can be performed using a commercially available vacuum laminator. The commercially available vacuum laminator is as described above.

  In the production of the laminated sheet, the insulating resin layer may be used in the form of an adhesive sheet including a support and an insulating resin layer bonded to the support. As the support, the same support as described for the resin sheet may be used.

  In another embodiment, it is also possible to produce a laminated sheet by forming an insulating resin layer on the resin layer of the resin sheet obtained by the present invention by applying an insulating resin composition and drying the coating film. is there.

  In this method, the insulating resin layer is prepared by dissolving an insulating resin composition in an organic solvent to prepare an insulating resin varnish, and applying the insulating resin varnish on a support using a die coater or a gravure coater. It can be produced by drying the resin varnish.

  As the insulating resin composition, a composition containing an epoxy resin and a curing agent is preferable. The types and contents of the epoxy resin and the curing agent are as described for the epoxy resin and the curing agent in the above (resin composition). As an organic solvent, the thing similar to the solvent contained in said resin varnish can be used.

  The insulating resin varnish may be dried by a known drying method such as heating or hot air blowing.

  The laminated sheet can be used as a laminated sheet for forming an insulating layer of a printed wiring board (a laminated sheet for an insulating layer of a printed wiring board). Above all, in the production of printed wiring boards by the build-up method, it can be suitably used as a laminated sheet for forming an insulating layer (a laminated sheet for a build-up insulating layer of a printed wiring board), and on top of that by a plating process It can be more suitably used as a laminated sheet for forming an insulating layer on which a circuit is formed (a laminated sheet for a build-up insulating layer of a printed wiring board on which a circuit is formed by a plating process).

  When the insulating resin layer is used in the form of the adhesive sheet in the production of the laminated sheet, the obtained laminated sheet is a surface of the insulating resin layer that is not bonded to the resin sheet of the present invention (that is, the resin of the present invention). A support derived from an adhesive sheet is provided on the surface opposite to the sheet. When manufacturing a laminated board or a printed wiring board, it can be used by peeling off the support derived from such an adhesive sheet.

[Laminated plate and manufacturing method thereof]
The resin sheet obtained by the production method of the present invention can be used in the production of laminated boards such as printed wiring boards. In one embodiment, the laminate can be produced by a method including the following step (I-1) using the resin sheet and the insulating resin layer obtained by the production method of the present invention (hereinafter referred to as “No. Also referred to as “one embodiment”).
(I-1) One or more insulating resin layers are arranged between two resin sheets arranged so that the resin layers face each other, and are integrally molded by heating and pressing at 200 ° C. or higher under reduced pressure. Process

  The resin sheet and insulating resin layer used in the first embodiment are as described above. In the first embodiment, the insulating resin layer is preferably a prepreg.

  Step (I-1) can be performed, for example, using a vacuum hot press apparatus according to the following procedure.

  First, a laminated structure in which one or more insulating resin layers are arranged between two resin sheets arranged so that the resin layers face each other is set in a vacuum hot press apparatus.

  Next, a vacuum hot press process is performed in which the laminated structure is thermocompression bonded under reduced pressure conditions. The vacuum hot press treatment can be performed using a conventionally known vacuum hot press apparatus that presses the laminated structure from both sides thereof with a heated metal plate such as an SUS plate. Examples of commercially available vacuum heat press apparatuses include “MNPC-V-750-5-200” manufactured by Meiki Seisakusho, “VH1-1603” manufactured by Kitagawa Seiki Co., Ltd., and the like.

  The conditions for the vacuum hot press treatment are not particularly limited, and known conditions used for producing a laminated plate may be used.

  The step (I-1) may be performed by using two or more insulating resin layers and further disposing an inner layer substrate between the insulating resin layers. Two or more insulating resin layers may be the same or different.

  In the present invention, the “inner layer substrate” is mainly a glass epoxy substrate, a metal substrate, a polyester substrate, a polyimide substrate, a BT resin substrate, a thermosetting polyphenylene ether substrate, or a pattern process on one or both sides of the substrate. A circuit board on which a conductive layer (circuit) is formed. Further, when the printed wiring board is manufactured, an inner layer circuit board of an intermediate product in which an insulating layer and / or a conductor layer is further formed is also included in the “inner layer board” in the present invention.

  By the step (I-1), the resin layer of the resin sheet and the insulating resin layer are integrated to form an insulating layer.

In another embodiment, the laminate can be produced by a method including the following steps (II-1) and (II-2) using the above-described laminate sheet (hereinafter, also referred to as “second embodiment”). Say.).
(II-1) A step of laminating the laminated sheet on the inner layer substrate so that the insulating resin layer is in contact with the inner layer substrate (II-2) A step of thermosetting the laminated sheet to form an insulating layer

  The laminated sheet and inner layer substrate used in the second embodiment are as described above.

  In step (II-1), the laminated sheet is laminated on the inner layer substrate such that the insulating resin layer is in contact with the inner layer substrate.

  Lamination of the laminated sheet and the inner layer substrate in the step (II-1) can be performed, for example, by thermocompression bonding the laminated sheet to the inner layer substrate from the support side. Examples of the member that heat-presses the laminated sheet to the inner layer substrate (hereinafter also referred to as “heat-pressing member”) include a heated metal plate (SUS end plate, etc.) or a metal roll (SUS roll). In addition, it is preferable not to press the thermocompression bonding member directly on the laminated sheet but to press the laminated sheet through an elastic material such as heat-resistant rubber so that the laminated sheet sufficiently follows the surface irregularities of the inner layer substrate.

The lamination of the laminated sheet and the inner layer substrate may be performed by a vacuum laminating method. In the vacuum laminating method, the heating temperature is preferably in the range of 60 ° C. to 160 ° C., more preferably in the range of 80 ° C. to 140 ° C., and the pressure bonding pressure is preferably 1 kgf / cm ^{2 to} 18 kgf / cm ² (0.098 MPa to 1.77MPa), more preferably in the range of ^{3kgf / cm 2 ~15kgf / cm 2} (0.29MPa~1.47MPa), bonding time is preferably 20 seconds to 400 seconds, more preferably 30 seconds to 300 The range of seconds. Lamination is preferably performed under reduced pressure conditions with a pressure of 26.7 hPa or less.

  In step (II-1), the laminated sheet may be laminated on one side of the inner layer substrate, or may be laminated on both sides of the inner layer substrate.

  Lamination | stacking of a lamination sheet and an inner layer board | substrate can be performed with a commercially available vacuum laminator. The commercially available vacuum laminator is as described above.

  In step (II-2), the laminated sheet is thermally cured to form an insulating layer. The conditions for thermosetting are not particularly limited, and the conditions normally employed when forming the insulating layer of the printed wiring board may be used.

  By the step (II-2), both the resin layer and the insulating resin layer in the laminated sheet are thermally cured to form an integrated insulating layer.

  Regardless of whether the first embodiment or the second embodiment is different, (III) a step of drilling the insulating layer, (IV) a step of roughening the insulating layer, and (V) a step of forming a circuit on the surface of the insulating layer. May be further implemented. Accordingly, in one embodiment, the laminate includes a circuit formed on the surface of the insulating layer.

  The support may be removed before the circuit is formed on the surface of the insulating layer, regardless of whether the first embodiment or the second embodiment is used, but the surface smoothness of the obtained insulating layer and the time of curing are not limited. From the viewpoint of reducing the risk of foreign matter adhesion, it is preferable to remove the resin layer after thermosetting. In detail, in 1st Embodiment, a support body is between process (I-1) and process (III), between process (III) and process (IV), or process (IV) and process ( V) may be removed. In 2nd Embodiment, a support body is between process (II-2) and process (III), between process (III) and process (IV), or process (IV) and process (V). Remove it in between.

  Step (III) is a step of making a hole in the insulating layer, whereby holes such as via holes and through holes can be formed in the insulating layer. Step (III) may be performed using, for example, a drill, a laser, plasma, or the like according to the resin layer used for forming the insulating layer and the composition of the insulating resin layer. The dimensions and shape of the holes may be appropriately determined according to the design of the printed wiring board.

  Step (IV) is a step of roughening the insulating layer. The procedure and conditions for the roughening treatment are not particularly limited, and known procedures and conditions that are usually used when forming an insulating layer of a printed wiring board can be employed. 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. Although it does not specifically limit as a swelling liquid, An alkaline solution, surfactant solution, etc. are mentioned, Preferably it is an alkaline solution, As this alkaline solution, a sodium hydroxide solution and a potassium hydroxide solution are more preferable. Examples of commercially available swelling liquids include “Swelling Dip Securigans P” and “Swelling Dip Securigans SBU” manufactured by Atotech Japan Co., Ltd. Although the swelling process by a swelling liquid is not specifically limited, For example, it can carry out by immersing an insulating layer for 1 minute-20 minutes in 30-90 degreeC swelling liquid. Although it does not specifically limit as an oxidizing agent, For example, the alkaline permanganate solution which melt | dissolved potassium permanganate and sodium permanganate in the aqueous solution of sodium hydroxide is mentioned. The roughening treatment with an oxidizing agent such as an alkaline permanganic acid solution is preferably performed by immersing the insulating layer in an oxidizing agent solution heated to 60 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 oxidizing agents include alkaline permanganic acid solutions such as “Concentrate Compact CP” and “Dosing Solution Securigans P” manufactured by Atotech Japan Co., Ltd. The neutralizing solution is preferably an acidic aqueous solution. Examples of commercially available products include “Reduction Solution Securigant P” manufactured by Atotech Japan Co., Ltd. The treatment with the neutralizing solution can be performed by immersing the treated surface subjected to the roughening treatment with the oxidizing agent in the neutralizing solution at 30 to 80 ° C. for 5 to 30 minutes.

  Step (V) is a step of forming a circuit (conductor layer) on the surface of the insulating layer.

  The conductor material used for the conductor layer is not particularly limited. In a preferred embodiment, the conductor layer 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. As the alloy layer, for example, an alloy of two or more metals selected from the above group (for example, nickel-chromium alloy, copper- A layer formed from a nickel alloy and a copper / titanium alloy). Among them, from the viewpoint of versatility of conductor layer formation, cost, ease of patterning, etc., single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper, or nickel / chromium alloy, copper / An alloy layer of nickel alloy or 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 nickel / chromium alloy is more preferable, and a single layer of copper is preferable. A metal layer is more preferred.

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

  Although the thickness of a conductor layer is based on the design of a desired printed wiring board, it is 3 micrometers-50 micrometers normally, Preferably it is 5 micrometers-30 micrometers.

  The conductor layer can be formed by a plating process. 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.

  A laminated board can be used for various uses according to the manufacturing method and structure (For example, the presence or absence of the use of the inner layer board | substrate in 1st Embodiment, the presence or absence of the circuit in 1st and 2nd embodiment). For example, it may be used as an inner layer substrate such as an insulating core substrate or an inner layer circuit substrate used for manufacturing a printed wiring board, or may be used as a printed wiring board.

[Semiconductor device]
A semiconductor device can be manufactured using a printed wiring board made of the above laminated board or using a printed wiring board manufactured using the above laminated board.

  Examples of the semiconductor device include various semiconductor devices used for electrical products (for example, computers, mobile phones, digital cameras, and televisions) and vehicles (for example, motorcycles, automobiles, trains, ships, and aircrafts).

  EXAMPLES The present invention will be specifically described below 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.

[Preparation of resin varnish]
(Preparation of standard resin varnish)
10 parts of naphthylene ether type epoxy resin (DIC Corporation "EXA-7311-G4S", epoxy equivalent 186), bixylenol type epoxy resin (Mitsubishi Chemical Corporation "YX4000HK", epoxy equivalent of about 185) , 20 parts of biphenyl type epoxy resin (“NC3000H” manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent 288), and phenoxy resin (“YX7553BH30” manufactured by Mitsubishi Chemical Corporation), cyclohexanone: methyl ethyl ketone (MEK) with a solid content of 30% by mass 1 part solution) was dissolved by heating in a mixed solvent of 15 parts of solvent naphtha and 5 parts of cyclohexanone with stirring. After cooling to room temperature, 10 parts of a triazine skeleton-containing phenol novolac curing agent (hydroxyl equivalent 125, “LA-7054” manufactured by DIC Corporation, MEK solution with a solid content of 60%), naphthol curing agent ( 19 parts of “SN485” manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., MEK solution having a hydroxyl equivalent weight of 215 and a solid content of 60%, polyvinyl butyral resin (glass transition temperature 105 ° C., “KS-1” manufactured by Sekisui Chemical 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 curing accelerator (4-dimethylaminopyridine (DMAP), MEK solution with a solid content of 5% by mass), an imidazole curing accelerator (Mitsubishi Chemical Co., Ltd. “P200-H50”, 50 mass% solid content propylene glycol monomethyl ether solution) 2 parts, aminosilane-based coupling Grayed agent (Shin-Etsu Chemical Co., Ltd., "KBM573") surface-treated with spherical silica (Co. Admatechs Co. "SOC2", average particle size 0.5 [mu] m, the carbon amount 0.38 mg / m per unit surface area ² ) 50 parts were mixed and uniformly dispersed with a high-speed rotary mixer, and then filtered with a cartridge filter ("SHP050" manufactured by ROKITECHNO) to prepare a standard resin varnish.

(Preparation of resin varnish 1)
A resin varnish 1 was prepared by mixing a standard resin varnish with a solvent in which methyl ethyl ketone (MEK) and solvent naphtha were mixed at a ratio of 50:50 (mass ratio) and adjusting the content of nonvolatile components to 25%. .

(Preparation of resin varnish 2)
A resin varnish 2 was prepared by mixing a standard resin varnish with a solvent in which ethanol and toluene were mixed at a ratio of 50:50 (mass ratio) and adjusting the content of nonvolatile components to 25%.

(Preparation of resin varnish 3)
A resin varnish 3 was prepared by mixing a standard resin varnish with a solvent in which MEK and cyclohexanone were mixed at a ratio of 50:50 (mass ratio) and adjusting the content of nonvolatile components to 25%.

(Preparation of resin varnish 4)
Cyclohexanone was mixed with the standard resin varnish, and the content of nonvolatile components was adjusted to be 25% to prepare a resin varnish 4.

(Preparation of resin varnish 5)
A resin varnish 5 was prepared by mixing a standard resin varnish with a solvent in which MEK and solvent naphtha were mixed at a ratio of 50:50 (mass ratio) and adjusting the content of nonvolatile components to 35%.

(Preparation of resin varnish 6)
A resin varnish 6 was prepared by mixing a standard resin varnish with a solvent in which ethanol and toluene were mixed at a ratio of 50:50 (mass ratio) and adjusting the content of nonvolatile components to 35%.

(Preparation of resin varnish 7)
A resin varnish 7 was prepared by mixing a standard resin varnish with a solvent in which MEK and cyclohexanone were mixed at a ratio of 50:50 (mass ratio) and adjusting the content of nonvolatile components to 35%.

(Preparation of resin varnish 8)
Cyclohexanone was mixed with the standard resin varnish and adjusted so that the content of nonvolatile components was 35%, thereby preparing a resin varnish 8.

(Preparation of resin varnish 9)
A resin varnish 9 was prepared by mixing a standard resin varnish with a solvent in which MEK and solvent naphtha were mixed at 50:50 (mass ratio) and adjusting the content of the nonvolatile component to 15%.

(Preparation of resin varnish 10)
Resin varnish 10 was prepared by mixing dimethylacetamide (DMAc) with the standard resin varnish and adjusting the nonvolatile component content to 25%.

(Preparation of resin varnish 11)
DMAc was mixed with the standard resin varnish, and the resin varnish 11 was prepared by adjusting the nonvolatile component content to 35%.

(Measurement of viscosity of resin varnish)
The viscosities of the resin varnishes 1 to 11 were measured under a temperature condition of 25 ° C. using a rotary vibration viscometer (Viscomate VM-10A manufactured by Techjam Co., Ltd.). The value 2 minutes after the start of measurement was taken as the viscosity of each resin varnish, and the results are shown in Table 1.

[Examples 1 to 25 and Comparative Examples 1 to 8]
After applying the resin varnishes 1 to 11 to the supports 1 to 3 and measuring the contact angle by the method described later, the resin varnish applied to the support is dried by the following method to form a resin layer. An evaluation test was conducted on the ear height and the coating width.

The used supports 1 to 3 are as follows.
Support 1: A support prepared by providing a release layer composed of an alkyd release agent on a PET film ("Lumirror T60" manufactured by Toray Industries, Inc.) (surface roughness is 22 nm, water contact measured by a droplet method) (Angle is 90 °)
Support 2: Support prepared by providing a release layer composed of an olefin-based release agent on a PET film (“Lumirror T60” manufactured by Toray Industries, Inc.) (surface roughness is 22 nm, water contact measured by a droplet method) (Angle is 110 °)
Support 3: PET film (“Lumirror T60” manufactured by Toray Industries, Inc.) is used as it is (surface roughness is 22 nm, water contact angle measured by the droplet method is 75 °)

Example 1
The resin varnish 1 is uniformly coated on the support 1 with a gravure coater so that the thickness of the resin layer after drying is 2 μm, and dried at 100 to 120 ° C. for 3 minutes. A resin layer was formed on the substrate to prepare a resin sheet.
(Example 2)
A resin layer was formed on the support 1 in the same manner as in Example 1 except that the resin varnish 2 was used instead of the resin varnish 1 to prepare a resin sheet.
Example 3
A resin sheet was produced by forming a resin layer on the support 1 in the same manner as in Example 1 except that the resin varnish 3 was used instead of the resin varnish 1.
Example 4
A resin layer was formed on the support 1 in the same manner as in Example 1 except that the resin varnish 4 was used instead of the resin varnish 1 to prepare a resin sheet.
(Example 5)
A resin layer was formed on the support 1 in the same manner as in Example 1 except that the resin varnish 5 was used instead of the resin varnish 1 to prepare a resin sheet.
(Example 6)
A resin sheet was produced by forming a resin layer on the support 1 in the same manner as in Example 1 except that the resin varnish 6 was used instead of the resin varnish 1.
(Example 7)
A resin layer was formed on the support 1 in the same manner as in Example 1 except that the resin varnish 7 was used instead of the resin varnish 1 to prepare a resin sheet.
(Example 8)
A resin layer was formed on the support 1 in the same manner as in Example 1 except that the resin varnish 8 was used instead of the resin varnish 1 to prepare a resin sheet.
Example 9
A resin layer was formed on the support 2 in the same manner as in Example 1 except that the support 2 was used in place of the support 1 to prepare a resin sheet.
(Example 10)
A resin layer was formed on the support 2 in the same manner as in Example 9 except that the resin varnish 2 was used instead of the resin varnish 1 to prepare a resin sheet.
(Example 11)
A resin layer was formed on the support 2 in the same manner as in Example 9 except that the resin varnish 3 was used instead of the resin varnish 1 to prepare a resin sheet.
Example 12
A resin layer was formed on the support 2 in the same manner as in Example 9 except that the resin varnish 5 was used instead of the resin varnish 1 to prepare a resin sheet.
(Example 13)
A resin layer was formed on the support 2 in the same manner as in Example 9 except that the resin varnish 6 was used instead of the resin varnish 1 to prepare a resin sheet.
(Example 14)
A resin layer was formed on the support 2 in the same manner as in Example 9 except that the resin varnish 7 was used instead of the resin varnish 1 to prepare a resin sheet.
(Example 15)
A resin layer was formed on the support 2 in the same manner as in Example 9 except that the resin varnish 9 was used instead of the resin varnish 1 to prepare a resin sheet.
(Example 16)
A resin layer was formed on the support 3 in the same manner as in Example 1 except that the support 3 was used in place of the support 1 to prepare a resin sheet.
(Example 17)
A resin layer was formed on the support 3 in the same manner as in Example 16 except that the resin varnish 2 was used in place of the resin varnish 1 to prepare a resin sheet.
(Example 18)
A resin layer was formed on the support 3 in the same manner as in Example 16 except that the resin varnish 3 was used instead of the resin varnish 1 to prepare a resin sheet.
(Example 19)
A resin layer was formed on the support 3 in the same manner as in Example 16 except that the resin varnish 4 was used instead of the resin varnish 1 to prepare a resin sheet.
(Example 20)
A resin layer was formed on the support 3 in the same manner as in Example 16 except that the resin varnish 5 was used in place of the resin varnish 1 to prepare a resin sheet.
(Example 21)
A resin layer was formed on the support 3 in the same manner as in Example 16 except that the resin varnish 6 was used instead of the resin varnish 1 to prepare a resin sheet.
(Example 22)
A resin layer was formed on the support 3 in the same manner as in Example 16 except that the resin varnish 7 was used instead of the resin varnish 1 to prepare a resin sheet.
(Example 23)
A resin layer was formed on the support 3 in the same manner as in Example 16 except that the resin varnish 8 was used in place of the resin varnish 1 to prepare a resin sheet.
(Example 24)
A resin layer was formed on the support 3 in the same manner as in Example 16 except that the resin varnish 10 was used instead of the resin varnish 1 to prepare a resin sheet.
(Example 25)
A resin layer was formed on the support 3 in the same manner as in Example 16 except that the resin varnish 11 was used instead of the resin varnish 1 to prepare a resin sheet.

(Comparative Example 1)
A resin layer was formed on the support 1 in the same manner as in Example 1 except that the resin varnish 9 was used instead of the resin varnish 1 to prepare a resin sheet.
(Comparative Example 2)
A resin layer was formed on the support 1 in the same manner as in Example 1 except that the resin varnish 10 was used instead of the resin varnish 1 to prepare a resin sheet.
(Comparative Example 3)
A resin layer was formed on the support 1 in the same manner as in Example 1 except that the resin varnish 11 was used instead of the resin varnish 1 to prepare a resin sheet.
(Comparative Example 4)
A resin layer was formed on the support 2 in the same manner as in Example 9 except that the resin varnish 4 was used instead of the resin varnish 1 to prepare a resin sheet.
(Comparative Example 5)
A resin layer was formed on the support 2 in the same manner as in Example 9 except that the resin varnish 8 was used instead of the resin varnish 1 to prepare a resin sheet.
(Comparative Example 6)
A resin layer was formed on the support 2 in the same manner as in Example 9 except that the resin varnish 10 was used instead of the resin varnish 1 to prepare a resin sheet.
(Comparative Example 7)
A resin layer was formed on the support 2 in the same manner as in Example 9 except that the resin varnish 11 was used instead of the resin varnish 1 to prepare a resin sheet.
(Comparative Example 8)
A resin layer was formed on the support 3 in the same manner as in Example 16 except that the resin varnish 9 was used instead of the resin varnish 1 to prepare a resin sheet.

(Measurement method of contact angle by droplet method)
The contact angle of each resin varnish to the support by the droplet method was measured using an automatic contact angle meter (DropMaster DMs-401 manufactured by Kyowa Interface Science Co., Ltd.). Specifically, a resin varnish is filled into a syringe, a droplet of 0.8 μL is prepared, and the value after 2000 ms from the adhesion is determined by the droplet method in which the droplet is adhered to the support. The results are shown in Table 1.

(Evaluation of repelling)
The number of repellency defects in the resin layers 10 m ² formed in Examples 1 to 25 and Comparative Examples 1 to 8 was counted. “X” indicates that 10 or more repellants having a diameter of 0.1 mm or more are recognized in the resin layer 10 m ² , “△” indicates that the number of cisterns is 2 to 9, and indicates that the number of cistern is 0 to 1 The results are shown in Table 1, and the results are shown in Table 1.

(Evaluation of ear height)
The thickness of the center part of the resin layer formed in Examples 1-25 and Comparative Examples 1-8 and the thickest part (maximum thickness part) was measured using the micrometer. The difference between the thickness of the central portion and the maximum thickness portion is 10 μm or more, “×”, 2 μm to 10 μm is “Δ”, 0 to 2 μm is “◯”, and the results are shown in Table 1.

(Evaluation of coating width control)
The coating width of the resin layer formed in Examples 1 to 25 and Comparative Examples 1 to 8 was measured with a stainless ruler. The difference in the actual coating width with respect to the target coating width of 1000 mm is “X” when the difference is 5 mm or more, “△” when 2 mm to 5 mm, and “◯” when 0-2 mm, and the results are shown in Table 1. It was.

  Table 1 shows the viscosity of the resin varnish, the contact angle of the resin varnish with the droplet method, the evaluation result of repelling, the evaluation result of the ear height, the evaluation result of the coating width control, and the preparation of each resin varnish. The type and amount of the solvent used in the above, the content of nonvolatile components, etc. are shown.

Claims (8)

(A) The process of apply | coating the resin varnish containing a resin composition and a solvent on a support body,
(B) drying the resin varnish to form a resin layer;
Including
In the step (A), the contact angle of the resin varnish to the support in the droplet method is 0.1 ° to 20 °, and
In step (B), the thickness of the resin layer is Ri der less 5 [mu] m,
A method for producing a resin sheet, wherein the support is a film made of a plastic material or a release paper .   (A) The process of apply | coating the resin varnish containing a resin composition and a solvent on a support body,
  (B) drying the resin varnish to form a resin layer;
Including
  In the step (A), the contact angle of the resin varnish to the support in the droplet method is 0.1 ° to 20 °, and
  In the step (B), the thickness of the resin layer is 5 μm or less,
  A method for producing a resin sheet, wherein the support comprises a release layer. The method for producing a resin sheet according to claim 1 or 2 , wherein the content of nonvolatile components in the resin varnish is 40% by mass or less. The manufacturing method of the resin sheet of Claim 1 or Claim 3 with which a support body is provided with a mold release layer. The manufacturing method of the resin sheet of any one of Claims 1-4 in which a solvent contains a polar solvent. The method for producing a resin sheet according to any one of claims 1 to 5 , wherein the solvent includes a polar solvent having a relative dielectric constant of 12 or more and a nonpolar solvent having a relative dielectric constant of 9 or less. The process for producing a resin sheet according to any one of claims 1 to 6 , wherein in the step (A), a resin varnish is applied by a gravure coating method. The method for producing a resin sheet according to any one of claims 1 to 7 , wherein the resin sheet is for an insulating layer of a printed wiring board.