TWI707898B - Manufacturing method of resin sheet - Google Patents

Abstract

The present invention provides a method for manufacturing a resin sheet that can suppress the occurrence of high sides and shrinkage holes of the resin layer and control the film thickness and coating width well when forming a resin layer.

A method for manufacturing a resin sheet, which includes the following steps: (A) a step of coating a resin varnish containing a resin composition and a solvent on a support, and (B) drying the resin varnish to form a resin layer Steps; wherein in step (A), the contact angle of the resin varnish on the support by the dropping method is 0.1°-20°, and in step (B), the thickness of the resin layer is 5 μm or less.

Description

Manufacturing method of resin sheet

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

As a manufacturing technique of a printed wiring board, a build-up method in which a conductor layer on which a circuit is formed and an insulating layer are alternately overlapped is known. In the build-up method, the insulating layer is generally formed by laminating a resin sheet including a resin layer in an inner substrate and hardening the resin layer.

On the other hand, in response to the miniaturization and thinning of electronic devices in recent years, there has been progress towards thinner resin layers. 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.

[Prior Technical Literature] [Patent Literature]

[Patent Document 1] JP 2014-17301 A

When a thin resin layer is formed on a support, a resin varnish with a low concentration of non-volatile components obtained by diluting the resin composition with a large amount of solvent is generally used to ensure coating stability by increasing the thickness of the coating film. In recent years, from the viewpoint of the surface smoothness of the insulating layer and the reduction of the risk of foreign matter adhesion during curing, there are cases where the thermosetting resin layer is carried out in a state where the support is attached. In such cases, the mold release is mostly used. The support of the layer or the support of a material with low adhesion 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 near the end due to the difference in polarity between the surface of the support and the resin varnish, or the polarity changes due to the volatilization of the solvent. The area of ?? will produce a "high-edge" or cissing that is larger than the center.

In order to solve such problems, it is considered that coatability improvers such as leveling agents can be used, but there is a risk of changes in plating characteristics or bleeding during storage. In addition, if the difference between the polarity of the support surface and the coating liquid is small (if the wettability is high), it will be more wetted and spread than the set coating width, and the coating width or film thickness control will also become Difficult situation.

The subject of the present invention is to provide a method for manufacturing a resin sheet that can suppress the occurrence of high sides and shrinkage holes in the resin layer and control the film thickness and coating width well when forming the resin layer.

The inventor of the present invention has conducted in-depth research on the above subject and found that by including the method of applying the resin varnish to the support when the contact angle when the resin varnish is dropped on the support by the dropping method becomes 0.1°~20° Steps can solve the above-mentioned problems, thus completing the present invention.

That is, the present invention includes the following contents.

[1]. A method of manufacturing a resin sheet, which includes the following steps: (A) a step of coating a resin varnish containing a resin composition and a solvent on a support, and (B) drying the resin varnish The step of forming a resin layer; wherein in step (A), the contact angle when the resin varnish is dropped on the support by the dropping method is 0.1°-20°, and in step (B), the thickness of the resin layer is Below 5μm.

[2]. The method for producing a resin sheet according to [1], wherein the non-volatile content in the resin varnish is 40% by mass or less.

[3]. The method for manufacturing a resin sheet as in [1] or [2], wherein the support system is provided with a release layer.

[4]. The method for manufacturing a resin sheet according to any one of [1] to [3], wherein the solvent includes 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 with a specific permittivity of 12 or more and a non-polar solvent with a permittivity of 9 or less.

[6]. The method of manufacturing a resin sheet according to any one of [1] to [5], wherein in step (A), the resin varnish is coated by a gravure coating method.

[7]. The method of manufacturing a resin sheet according to any one of [1] to [6], wherein the resin sheet is used for the insulating layer of a printed circuit board.

According to the present invention, it is possible to provide a method for manufacturing a resin sheet that can suppress the occurrence of high sides and shrinkage of the resin layer, and control the film thickness and coating width well when forming the resin layer.

[Best form to implement invention] [Method of manufacturing resin sheet]

Hereinafter, the method of manufacturing the resin sheet of the present invention will be described.

The method for producing a resin sheet of the present invention is characterized by comprising the following steps: (A) a step of coating a resin varnish containing a resin composition and a solvent on a support, and (B) drying the resin varnish to form The step of the resin layer; wherein in step (A), the contact angle when the resin varnish is dropped on the support by the dropping method is 0.1°~20°, and in step (B), the thickness of the resin layer is 5μm the following.

<Step (A)>

In step (A), a resin varnish containing a resin composition and a solvent is coated on the 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)

Examples of the resin composition include a composition containing a curable resin and a curing agent. As the curable resin, a conventionally known curable resin used when forming an insulating layer of a printed wiring board can be used, and among them, epoxy resin is preferred. Therefore, in one embodiment, the resin composition includes an epoxy resin and a hardener. The resin composition may further contain additives such as inorganic fillers, thermoplastic resins, hardening accelerators, flame retardants, and rubber particles as required.

-Epoxy resin-

Examples of epoxy resins include bisphenol A epoxy resins, bisphenol F epoxy resins, bisphenol S epoxy resins, and bisphenol AF epoxy resins. Diene epoxy resin, triphenol epoxy resin, naphthol novolac epoxy resin, phenol novolac epoxy resin, tert-butyl-catechol epoxy resin, naphthalene epoxy resin, naphthalene Phenolic epoxy resin, anthracene epoxy resin, glycidylamine epoxy resin, glycidyl ester epoxy resin, cresol novolac epoxy resin, biphenyl epoxy resin, linear aliphatic epoxy resin , Epoxy resin with butadiene structure, alicyclic epoxy resin, heterocyclic epoxy resin, epoxy resin containing spiro ring, cyclohexane dimethanol type epoxy resin, naphthyl ether type epoxy resin Resin, trimethylol type epoxy resin, tetraphenylethane type epoxy resin, etc. The epoxy resin system can be used individually by 1 type or in combination of 2 or more types.

As the epoxy resin, bisphenol epoxy resin, fluorine epoxy resin (such as bisphenol AF epoxy resin), dicyclopentane One or more epoxy resins selected from the group consisting of diene epoxy resins, naphthalene epoxy resins, biphenyl epoxy resins, and mixtures of these epoxy resins are preferred.

The epoxy resin is preferably an epoxy resin having two or more epoxy groups in one molecule. When the non-volatile content 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, the system has two or more epoxy groups in one molecule, and contains a liquid epoxy resin (hereinafter referred to as "liquid epoxy resin") at a temperature of 20°C, and has 3 epoxy groups in one molecule. One or more epoxy groups and a solid epoxy resin (hereinafter referred to as "solid epoxy resin") at a temperature of 20°C are preferred. As the epoxy resin, by using a liquid epoxy resin and a solid epoxy resin in combination, 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.

As liquid epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AF type epoxy resin, naphthalene type epoxy resin, glycidyl ester type epoxy resin, phenol phenol type Epoxy resins, alicyclic epoxy resins with ester skeletons, and epoxy resins with butadiene structure are preferred, and bisphenol A type epoxy resins, bisphenol F type epoxy resins, and bisphenol AF type epoxy resins are preferred. Epoxy resins and naphthalene type epoxy resins are more preferable. Specific examples of liquid epoxy resins include "HP4032", "HP4032D", "HP4032SS" (naphthalene-type epoxy resin) manufactured by DIC Corporation, and "828US", "Mitsubishi Chemical Corporation" manufactured by Mitsubishi Chemical Corporation. "jER828EL" (bisphenol A type epoxy resin), "jER807" (bisphenol F type epoxy resin), "jER152" (Phenolic novolac type epoxy resin), "YL7760" (bisphenol AF type epoxy resin), "ZX1059" (bisphenol A type epoxy resin and bisphenol F type epoxy resin) manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. Resin mixture), "EX-721" (glycidyl ester type epoxy resin) manufactured by Nagasechemtex (Stock), "CELLOXIDE 2021P" (alicyclic epoxy resin with ester skeleton) manufactured by Daicel, "PB-3600" (epoxy resin with butadiene structure). These systems may be used individually by 1 type, or may be used in combination of 2 or more types.

As solid epoxy resin, naphthalene type tetrafunctional epoxy resin, cresol novolac type epoxy resin, dicyclopentadiene type epoxy resin, triphenol type epoxy resin, naphthol type epoxy resin, biphenyl Type epoxy resin, naphthyl ether type epoxy resin, anthracene type epoxy resin, bisphenol A type epoxy resin, tetraphenylethane type epoxy resin are preferred, and naphthalene type tetrafunctional epoxy resin, naphthalene type epoxy resin Phenolic epoxy resins and biphenyl epoxy resins are more preferable. Specific examples of solid epoxy resins include "HP4032H" (naphthalene type epoxy resin), "HP-4700", "HP-4710" (naphthalene type tetrafunctional epoxy resin) manufactured by DIC (Stock), "N-690" (cresol novolac epoxy resin), "N-695" (cresol novolac epoxy resin), "HP-7200" (dicyclopentadiene epoxy resin), "HP-7200HH ", "EXA7311", "EXA7311-G3", "EXA7311-G4", "EXA7311-G4S", "HP6000" (naphthyl ether type epoxy resin), and "EPPN-502H" manufactured by Nippon Kayaku Co., Ltd. ”(Triphenol type epoxy resin), “NC7000L” (Naphthol novolac epoxy resin), “NC3000H”, “NC3000”, “NC3000L”, “NC3100” (biphenyl type epoxy Resin), "ESN475V" (naphthol type epoxy resin), "ESN485" (naphthol novolac epoxy resin) manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., "YX4000H" manufactured by Mitsubishi Chemical Co., Ltd., and " YL6121" (biphenyl type epoxy resin), "YX4000HK" (bixylenol type epoxy resin), "YX8800" (anthracene type epoxy resin), "PG-100" manufactured by Osaka Gas Chemicals, "CG-500", "YL7800" manufactured by Mitsubishi Chemical Corporation (茀-type epoxy resin), "jER1010" (solid bisphenol A epoxy resin) manufactured by Mitsubishi Chemical Corporation, "jER1031S" ( Tetraphenylethane type epoxy resin) and so on.

If the epoxy resin contains solid epoxy resin and liquid epoxy resin, the ratio of the mass M _S of the solid epoxy resin to the mass M _L of the liquid epoxy resin (M _S /M _L ) is 1~ The range of 10 is preferable. By setting M _S /M _L within the above range, the following effects can be obtained: i) When used in the form of a resin sheet, it can bring appropriate adhesion; ii) When used in the form of a resin sheet , Can obtain sufficient flexibility, and the handling is improved; and iii) a cured product with 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, from the viewpoint of obtaining an insulating layer with good mechanical strength and insulation reliability. Preferably, it is 10% by mass or more. The upper limit of the epoxy resin content is not particularly limited as long as the effects of the present invention can be exerted, but it is preferably 50% by mass or less, more preferably 45% by mass or less, and more preferably 40% by mass or less.

Still, in the present invention, the content of each component in the resin composition is In particular, the value when the non-volatile content in the resin composition is set to 100% by mass.

The epoxy equivalent of the epoxy resin is preferably 50-5000, more preferably 50-3000, more preferably 80-2000, and still more preferably 110-1000. By being in this range, the crosslink density of the cured product becomes sufficient, and an insulating layer with a small surface roughness can be obtained. The epoxy equivalent can be measured in accordance with JIS K7236, and is the mass of the resin containing 1 equivalent of epoxy groups.

The weight average molecular weight of the epoxy resin is preferably 100 to 5000, more preferably 250 to 3000, and more preferably 400 to 1500. Here, the weight average molecular weight of the epoxy resin is the weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC).

-hardener-

系硬化劑、氰酸酯系硬化劑及碳二醯亞胺系硬化劑。硬化劑係可單獨使用1種、或亦可併用2種以上。 The curing agent is not particularly limited as long as it has the function of curing epoxy resin. Examples include phenolic curing agents, naphthol curing agents, active ester curing agents, benzo

Hardener, cyanate ester hardener and carbodiimide hardener. The hardener system may be used alone or in combination of two or more kinds.

As the phenol-based curing agent and the naphthol-based curing agent, from the viewpoint of heat resistance and water resistance, a phenol-based curing agent having a phenolic structure or a naphthol-based curing agent having a phenolic structure is preferable. Also, from the viewpoint of adhesion to the conductor layer (circuit wiring), a nitrogen-containing phenol hardener or a nitrogen-containing naphthol hardener is preferred, and a phenol hardener containing a triazine structure is preferred. A chemical agent or a naphthol hardener containing a triazine structure is more preferable. Among them, from the viewpoint of highly satisfying heat resistance, water resistance, and adhesion (peel strength) to the conductor layer, it is preferable to use a phenol-phenolic hardener containing a triazine structure.

Specific examples of phenolic hardeners and naphthol hardeners include "MEH-7700", "MEH-7810", "MEH-7851" manufactured by Meiwa Chemical Co., Ltd., and Nippon Kayaku Co., Ltd. "NHN", "CBN", "GPH", "SN170", "SN180", "SN190", "SN475", "SN485", "SN495", "SN375" manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd. , "SN395", "LA7052", "LA7054", "LA3018", etc. under the DIC (share) system.

There are no particular restrictions on the active ester-based hardener. Generally, phenol esters, thiophenol esters, N-hydroxyamine esters, heterocyclic hydroxy compound esters, etc. are preferably used. A compound having two or more highly reactive ester groups in one molecule. The active ester curing agent is preferably obtained by a condensation reaction of a carboxylic acid compound and/or a thiocarboxylic acid compound and a hydroxyl compound and/or a thiol compound. Particularly from the viewpoint of improving heat resistance, active ester hardeners obtained from carboxylic acid compounds and hydroxy compounds are preferred, and those obtained from carboxylic acid compounds and phenol compounds and/or naphthol compounds are preferred. Active ester hardeners are 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 phenol compounds or naphthol compounds include hydroquinone, resorcinol, and bisphenol A, bisphenol F, bisphenol S, reduced phenolphthalein, 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, trihydroxydi Benzophenone, tetrahydroxybenzophenone, phloroglucinol, pyrogallol, dicyclopentadienyl diphenol, phenol phenol, etc.

Specifically, an active ester compound containing a dicyclopentadienyl diphenol structure, an active ester compound containing a naphthalene structure, an active ester compound containing an acetyl compound of phenolic phenol, and an active ester compound containing a phenolic phenolic compound Active ester compounds are preferable, and among them, an active ester compound containing a naphthalene structure and an active ester compound containing a dicyclopentadienyl diphenol structure are more preferable.

Examples of commercially available active ester hardeners include "EXB9451", "EXB9460", "EXB9460S", "HPC-8000-65T" (DIC) and active ester compounds containing a dicyclopentadienyl diphenol structure. (Stock), "EXB9416-70BK" (manufactured by DIC Co., Ltd.) containing an active ester compound containing naphthalene structure, and "DC808" (manufactured by Mitsubishi Chemical Co., Ltd.) containing an active ester compound containing phenolic phenolic acetamide ), "YLH1026" (manufactured by Mitsubishi Chemical Co., Ltd.), an active ester compound containing phenolic benzoic acid, etc.

系硬化劑之具體例，可舉出昭和高分子(股)製的「HFB2006M」、四國化成工業(股)製的「P-d」、「F-a」。 As benzo

Specific examples of the curing agent include "HFB2006M" manufactured by Showa Polymer Co., Ltd., and "Pd" and "Fa" manufactured by Shikoku Chemical Industry Co., Ltd.

As the cyanate ester curing agent, for example, bisphenol A dicyanide Ester, polyphenol cyanate (oligo(3-methylene-1,5-phenylene cyanate)), 4,4'-methylenebis(2,6-dimethylphenyl) Cyanate), 4,4'-ethylene diphenyl dicyanate, hexafluorobisphenol A dicyanate, 2,2-bis(4-cyanate) phenyl propane, 1,1 -Bis(4-cyanate phenylmethane), bis(4-cyanate-3,5-dimethylphenyl)methane, 1,3-bis(4-cyanatephenyl-1-( (Methylethylene)) benzene, bis(4-cyanate phenyl) sulfide, and bis(4-cyanate phenyl) ether and other bifunctional cyanate resins, made of phenol phenol and cresol phenol The derivatized polyfunctional cyanate resins, prepolymers in which part of these cyanate resins are triazineized, etc. Specific examples of cyanate ester hardeners include "PT30" and "PT60" (both phenolic novolac type polyfunctional cyanate resin) manufactured by Lonza Japan (Stock), and "BA230" (bisphenol A di Part or all of the cyanate ester is triazineized into a trimer (prepolymer) and the like.

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

In the present invention, the curing agent preferably contains one or more selected from a phenolic curing agent, a cyanate ester curing agent, and an active ester curing agent. At least one selected from an acid ester curing agent and an active ester curing agent is more preferable.

The content of the curing agent in the resin composition is not particularly limited, but is preferably 0.1% by mass or more, more preferably 1% by mass or more, and more preferably 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 can be exerted, and it is preferably 30% by mass or less, more preferably 25% by mass or less, and more preferably 20% by mass or less.

The ratio of the amount of epoxy resin to hardener is the ratio of [total number of epoxy groups of epoxy resin]: [total number of reactive groups of hardener], in the range of 1:0.2~1:2 It is better, and 1:0.3~1:1.5 is more preferred, and 1:0.4~1:1 is more preferred. Here, the reactive groups of the so-called hardener are active hydroxyl groups, active ester groups, etc., and differ depending on the type of hardener. In addition, the total number of epoxy groups of the epoxy resin is the total value obtained by dividing the solid content mass of each epoxy resin by the epoxy equivalent for the epoxy resin, the so-called total number of the reactive groups of the hardener , Is the value obtained by dividing the solid content mass of each curing agent by the equivalent of the reactive group for all curing agents. By setting the ratio of the amount of the epoxy resin to the curing agent within the above range, the heat resistance of the cured product of the resin composition can be further improved.

The resin composition may contain additives such as inorganic fillers, thermoplastic resins, curing accelerators, flame retardants, and rubber particles in addition to the epoxy resins and curing agents described above.

-Inorganic filler-

The material of the inorganic filler is not particularly limited, and examples include silica, alumina, glass, cordierite, silica, barium sulfate, barium carbonate, talc, clay, mica powder, zinc oxide, hydrotalcite, and aluminum Minerals, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum nitride, manganese nitride, aluminum borate, strontium carbonate, strontium titanate, calcium titanate, magnesium titanate, titanium Bismuth oxide, titanium oxide, zirconium oxide, barium titanate, barium zirconate titanate, barium zirconate, calcium zirconate, zirconium phosphate, and zirconium tungstate phosphate, etc. Among these, silicon dioxide is particularly suitable. Spherical Dioxide Silicon is preferred. The inorganic filler system may be used alone or in combination of two or more kinds. Examples of commercially available inorganic fillers include "SO-C2", "SO-C1", and "SO-C4" manufactured by Admatechs.

The average particle size of the inorganic filler is not particularly limited, but from the viewpoint of obtaining an insulating layer with a small surface roughness or the viewpoint of improving the formation of fine wiring, 5μm or less is preferred, and 4μm or less is more preferred It is more preferably 3 μm or less, and more preferably 1 μm or less, 0.7 μm or less, 0.5 μm or less, or 0.3 μm or less. On the other hand, when a resin composition is used to form a resin varnish, it is possible to obtain a resin varnish with a moderate viscosity and good workability. From the viewpoint of preventing the melt viscosity of the resin sheet from increasing, the average inorganic filler The particle size is preferably 0.01 μm or more, more preferably 0.03 μm or more, and more preferably 0.05 μm or more, 0.07 μm or more, or 0.1 μm or more.

The average particle size of the inorganic filler can be measured by the laser diffraction and scattering method based on the Mie scattering theory. Specifically, the particle size distribution of the inorganic filler can be created on a volume basis by a laser diffraction scattering particle size distribution measuring device, and the average particle size can be measured as the average particle size. The measurement sample system can preferably be used as an inorganic filler dispersed in water by ultrasonic waves. As a laser diffraction scattering type particle size distribution measuring device, "LA-500" manufactured by Horiba Manufacturing Co., Ltd. etc. can be used.

Inorganic fillers, from the viewpoint of improving moisture resistance and dispersibility, use aminosilane coupling agents, siloxane oxide coupling agents, mercaptosilane coupling agents, silane coupling agents, organosilazane compounds, titanium One or more surface treatment agents such as an acid ester coupling agent are preferably treated. Make Commercial products of surface treatment agents include "KBM403" (3-glycidoxypropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., and "KBM803" manufactured by Shin-Etsu Chemical Co., Ltd. (3- Mercaptopropyl trimethoxysilane), "KBE903" (3-aminopropyltriethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., and "KBM573" (N-phenyl-3) manufactured by Shin-Etsu Chemical Co., Ltd. -Aminopropyltrimethoxysilane), "SZ-31" (hexamethyldisilazane) manufactured by Shin-Etsu Chemical Co., Ltd., and "KBM103" (phenyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd. ), "KBM-4803" (long-chain epoxy silane coupling agent) manufactured by Shin-Etsu Chemical Co., Ltd., etc.

The degree of surface treatment by the surface treatment agent can be evaluated based on the amount of carbon per unit surface area of the inorganic filler. The amount of carbon per unit surface area of the inorganic filler, from the viewpoint of improving the dispersibility of the inorganic filler, is preferably 0.02 mg/m ² or more, more preferably 0.1 mg/m ² or more, and 0.2 mg /m ² or more is more preferable. On the other hand, from the viewpoint of the melting viscosity of the resin varnish or the prevention of the increase of the melting 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 The mg/m ² or less is more preferable.

The amount of carbon per unit surface area of the inorganic filler can be measured after washing the surface-treated inorganic filler with a solvent (for example, methyl ethyl ketone (MEK)). Specifically, a sufficient amount of MEK as a solvent can be added to the inorganic filler surface-treated with a surface treatment agent, and ultrasonic cleaning can be performed at 25°C for 5 minutes. After removing the supernatant and drying the solid content, use a carbon analyzer to The amount of carbon per unit surface area of the inorganic filler is measured. As a carbon analyzer system, "EMIA-320V" manufactured by Horiba Manufacturing Co., 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 50% by mass from the viewpoint of obtaining an insulating layer on which fine wiring can be formed. % Or less, or 40% by mass or less. The lower limit of the content of the inorganic filler in the resin composition is not particularly limited, and it may be 0% by mass, but it can usually be set to 5% by mass or more, 10% by mass or more, or 20% by mass or more.

-Thermoplastic resin-

Examples of thermoplastic resins include phenoxy resins, polyvinyl acetal resins, polyolefin resins, polybutadiene resins, polyimide resins, polyimide resins, polyetherimide resins, Thermoplastic resins such as polyether resin, polyether resin, polyphenylene ether resin, polycarbonate resin, polyether ether ketone resin, and polyester resin. A thermoplastic resin system may be used individually by 1 type, or may be used in combination of 2 or more types.

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

Examples of phenoxy resins include bisphenol A skeletons, bisphenol F skeletons, bisphenol S skeletons, bisphenol acetophenone skeletons, phenolic skeletons, biphenyl skeletons, pyrene skeletons, dicyclopentadiene skeletons, A phenoxy resin with one or more skeletons selected from the group of bornene skeleton, naphthalene skeleton, anthracene skeleton, adamantane skeleton, terpene skeleton, and trimethylcyclohexane skeleton. The terminal of the phenoxy resin may be any functional group such as a phenolic hydroxyl group and an epoxy group. A phenoxy resin system may be used individually by 1 type, or may be used in combination of 2 or more types. Specific examples of phenoxy resins include "1256" and "4250" manufactured by Mitsubishi Chemical Corporation (both are phenoxy resins containing bisphenol A skeleton), and "YX8100" (containing bisphenol S skeleton) Phenoxy resin), and "YX6954" (phenoxy resin containing bisphenol acetophenone skeleton). In addition to these, Nippon Steel & Sumikin Chemical Co., Ltd.’s "FX280" and "FX293" , "YL6954BH30", "YX7553", "YL7769BH30", "YL6794", "YL7213", "YL7290" and "YL7482" manufactured by Mitsubishi Chemical Corporation.

Examples of polyvinyl acetal resins include polyvinyl formaldehyde resins and polyvinyl butyral resins, and polyvinyl butyral resins are preferred. Specific examples of polyvinyl acetal resins include "Denkabutyral 4000-2", "Denkabutyral 5000-A", "Denkabutyral 6000-C", and "Denkabutyral 6000-" manufactured by Denka Chemical Industry Co., Ltd. EP", S-LEC BH series manufactured by Sekisui Chemical Co., Ltd., BX series, KS series, BL series, BM series, etc.

Specific examples of polyimide resins include "RIKACOAT SN20" and "RIKACOAT PN20" manufactured by Nippon Rika Co., Ltd. As a specific example of the polyimide resin, a linear polyimide obtained by reacting a bifunctional hydroxyl-terminated polybutadiene, a diisocyanate compound, and a tetrabasic acid anhydride (Japanese Patent Application Publication No. 2006-37083) The polyimide described in the publication), the polyimide containing a polysiloxane skeleton (the polyimide described in the Japanese Patent Laid-Open No. 2002-12667 and the Japanese Patent Laid-Open No. 2000-319386), etc. Quality polyimide.

Specific examples of polyimide resins include "VYLOMAX HR11NN" and "VYLOMAX HR16NN" manufactured by Toyobo Co., Ltd. As specific examples of polyimide resins, modification of "KS9100" and "KS9300" (polysiloxane skeleton-containing polyimide imide) manufactured by Hitachi Chemical Co., Ltd. can also be cited. Polyamide imine.

As a specific example of the polyether sulfite resin, "PES5003P" manufactured by Sumitomo Chemical Co., Ltd. and the like can be cited.

As a specific example of the polymer resin, the polymer "P1700" and "P3500" manufactured by Solvay Advanced Polymers (stocks) can be mentioned.

Among them, when combined with other components, from the viewpoint that the surface roughness can be lower and an insulating layer with excellent adhesion to the conductor layer can be obtained, as the thermoplastic resin, phenoxy resin or polyethylene shrinkage is used. Aldehyde resin is preferred. Therefore, in a suitable embodiment, the thermoplastic resin is The sub-system includes one or more selected from the group consisting of phenoxy resin and polyvinyl acetal resin.

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

-Hardening accelerator-

Examples of hardening accelerators include phosphorus hardening accelerators, amine hardening accelerators, imidazole hardening accelerators, guanidine hardening accelerators, etc., such as phosphorus hardening accelerators, amine hardening accelerators, and imidazole hardening accelerators. The agent is preferable, and an amine-based hardening accelerator and an imidazole-based hardening accelerator are more preferable. The hardening accelerator system may be used individually by 1 type, and may be used in combination of 2 or more types.

Examples of phosphorus-based hardening accelerators include triphenylphosphine, phosphonium borate compounds, tetraphenylphosphonium tetraphenylborate, n-butylphosphonium tetraphenylborate, tetrabutylphosphonium decanoate, (4- (Methyl phenyl) triphenyl phosphonium thiocyanate, tetraphenyl phosphonium thiocyanate, butyl triphenyl phosphonium thiocyanate, etc., preferably triphenyl phosphine, tetrabutyl phosphonium decanoate .

Examples of amine-based hardening accelerators include trialkylamines such as triethylamine and tributylamine, 4-dimethylaminopyridine, benzylmethylamine, 2,4,6,-reference ( Dimethylaminomethyl)phenol, 1,8-diazabicyclo(5,4,0)-undecene, etc., with 4-dimethylaminopyridine, 1,8-diazabicyclo( 5,4,0)-Undecene is preferred.

Examples of imidazole-based hardening accelerators include 2-methylimid Azole, 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-cyano 2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl- 2-Phenylimidazole, 1-cyanoethyl-2-alkylimidazole trimellitate, 1-cyanoethyl-2-phenylimidazole 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 Compounds, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo[1,2-a ] Benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2-methylimidazoline, 2-phenylimidazoline and other imidazoline compounds and imidazoline compounds and rings The adduct of oxygen resin is preferably 2-ethyl-4-methylimidazole and 1-benzyl-2-phenylimidazole.

As the imidazole-based hardening accelerator, a commercially available product can be used, for example, "P200-H50" manufactured by Mitsubishi Chemical Corporation.

As the guanidine hardening accelerator, for example, dicyandiamide, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, 1-(o-tolyl)guanidine, metformin Guanidine, diphenylguanidine, trimethylguanidine, tetramethylguanidine, pentamethylguanidine, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7-methyl-1 ,5,7-Triazabicyclo[4.4.0]dec-5-ene, 1-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-benzene Dicyandiamide, 1,5,7-triazabicyclo[4.4.0]dec-5-ene and the like are preferred.

The content of the hardening accelerator in the resin composition is not particularly limited, but it is preferably used within the range of 0.05% by mass to 3% by mass.

-Flame Resistant Agent-

The resin composition system may also contain a flame retardant. Examples of flame retardants include organic phosphorus flame retardants, organic nitrogen-containing phosphorus compounds, nitrogen compounds, silicone flame retardants, and metal hydroxides. The flame retardant system may be used individually by 1 type, or may use 2 or more types together.

As the flame retardant, commercially available products may also be used, and examples 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 more preferably 1.5% by mass to 10% by mass Better.

-Organic filler-

The resin composition system may further include an organic filler. As the organic filler, any organic filler that can be used for forming the insulating layer of a printed wiring board can be used, and examples thereof include rubber particles, polyamide particles, polysiloxane particles, etc., and rubber particles are preferred.

As the rubber particles, commercially available products may also be used, and examples include "AC3816N" manufactured by Aica Industries Co., Ltd. and the like.

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

The resin composition system may further contain other additives in addition to flame retardants and organic fillers as required. Examples of the above-mentioned other additives include organic copper compounds, organic zinc compounds, and organic cobalt compounds, and other organic metal compounds, and Resin additives such as thickeners, defoamers, leveling agents, adhesion imparting agents, and coloring agents.

(Solvent)

As the solvent contained in the resin varnish, as long as the resin varnish exhibiting a desired contact angle can be obtained for the support, a known solvent can be used without particular limitation. Examples of solvents include ketones such as acetone, methyl ethyl ketone (MEK) and cyclohexanone, ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, and carbitol Acetates such as acetates, cellosolves and carbitols such as butyl carbitol, aromatic hydrocarbons such as toluene, xylene, and ethylbenzene, dimethylformamide, dimethyl ethyl Amide-based solvents such as amide (DMAc) and N-methylpyrrolidone. An organic solvent system may be used individually by 1 type, and may be used in combination of 2 or more types, and you may use what contains 2 or more types of solvents, such as a solvent naphtha.

From the viewpoint of suppressing cratering and high edges, it is preferable that the solvent contains a polar solvent. In the present invention, the specific permittivity (20~25℃) of the polar solvent is preferably 10 or more, more preferably 12 or more, 14 or more Above, above 16, 18 or above 20. Preferably it is 50 or less. As such a polar solvent, for example, ethanol (25.3), methyl ethyl ketone (18.6), cyclohexanone (16.1), DMAc (38.85), etc. (the value in parentheses indicates the specific permittivity).

From the viewpoint of suppressing cratering and high edges for a wide variety of supports, the solvent preferably contains a polar solvent and a non-polar solvent. The polar solvent system is as described above. In the present invention, the specific permittivity (20-25°C) of the non-polar solvent is preferably less than 10, and more preferably less than 9, 8, 7, 7, 6, or 5. Preferably it is 1 or more or 1.5 or more. Examples of such non-polar solvents include toluene (2.38), xylene (the bonding position of the methyl group, that is, 2.27~2.56 corresponding to the ortho, meta, and para positions), ethylbenzene (2.45), solvent petroleum Brain (a mixed solvent of aromatic hydrocarbons with toluene, xylene, and ethylbenzene as main components). Among them, the solvent is preferably a polar solvent with a specific permittivity of 12 or more and a non-polar solvent with a permittivity of 9 or less; a polar solvent with a permittivity of 14 or more and a non-polar solvent with a permittivity of 8 or less are preferred. Polar solvents are more preferred; polar solvents with a specific permittivity of 16 or higher and non-polar solvents with a permittivity of 6 or less are more preferred; to include one or two selected from ethanol and methyl ethyl ketone. More than one kind of polar solvents, and one or more kinds of non-polar solvents selected from toluene and solvent naphtha are more preferable. The mass ratio of the polar solvent to the non-polar solvent in the solvent [polar solvent/non-polar solvent] is based on the specific permittivity of these solvents or the type of support, but it is preferably 2/8~8/2, and more The best is 3/7~7/3.

From the viewpoint of suppressing shrinkage and high sides of the support In other words, the solvent contains a solvent with 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 less than 100°C (preferably 95°C) Below, 90°C or less, 85°C or less, or 80°C or less) solvents are suitable. The mass ratio of a solvent with a boiling point above 100°C and a solvent with a boiling point below 100°C [(a solvent with a boiling point above 100°C)/(a solvent with a boiling point below 100°C)] is preferably 2/8 to 8/2, and Preferably it is 3/7~7/3.

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

The support has only to exhibit a desired contact angle, and the viscosity of the resin varnish is not particularly limited. From the viewpoint of easy control of the coating width, it is preferably 2 mPa·s or more, and 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. In order to further enjoy the effects of the present invention, the so-called good film thickness control when forming a thinner resin layer is preferably 15mPa‧s or less, more preferably 14mPa‧s or less, 13mPa ‧S or less, 12mPa‧s or less, 11mPa‧s or less, or 10mPa‧s or less.

The viscosity of the resin varnish can be measured at a temperature of 25°C using, for example, a rotary vibration viscometer (viscometer VM-10A manufactured by Tech-jam).

As the support used in the step (A), for example, a film made of a plastic material, metal foil, and release paper, and a film made of a plastic material or a metal foil is preferred.

When a film made of a plastic material is used as the support, examples of the plastic material include polyethylene terephthalate (hereinafter sometimes referred to as "PET"), polyethylene naphthalate (hereinafter sometimes referred to as (“PEN”) and other polyester, polycarbonate (hereinafter sometimes referred to as “PC”), polymethylmethacrylate (PMMA) and other acrylic, cyclic polyolefin, triacetyl cellulose (TAC), Polyether sulfide (PES), polyether ketone, polyimide, etc. Among them, polyethylene terephthalate and polyethylene naphthalate are preferred, and inexpensive polyethylene terephthalate is particularly preferred.

When metal foil is used as a support, copper foil, aluminum foil, etc. are mentioned as a metal foil, Copper foil is preferable. As the copper foil system, a foil made of a single metal of copper can be used, and a foil made of an alloy of copper and other metals (for example, tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.) can also be used.

As mentioned above, in the manufacture of printed wiring boards, in recent years, in order to achieve the surface smoothness of the insulating layer or to reduce the risk of foreign matter adhesion during hardening, the resin layer may be thermo-hardened while the support is attached. In such a case, a support body with a release layer or a support body of a material with low adhesion is often used. However, when the support body is formed with a thin resin layer, it may become difficult to control the film thickness. In the present invention, even if it is a support with a release layer or a support with a material with low adhesion When a thinner resin layer is formed on it, good film thickness control can be achieved.

Therefore, in an embodiment that can further enjoy the effects of the present invention, the support system includes a mold release layer, that is, a support body with a mold release layer attached to the support system. Examples of the mold release agent used in the mold release layer of the support with the mold release layer include alkyd resins, polyolefin resins, urethane resins, acrylic resins, and silicone resins. One or more mold release agents selected from the group. The support system with a release layer can also use commercially available products. Examples include PET film with a release layer based on an alkyd resin-based release agent, "SK-1" manufactured by Lintec (Stock), "AL-5", "AL-7", etc.

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

In the step (A), the coating of the resin varnish may be carried out by any conventionally known method as long as it can form a coating film having a uniform thickness. The resin varnish can be coated on the support using methods such as a die coating method, a comma coating method, a gravure coating method, and a bar coating method. Among these methods, the gravure coating method is preferable from the viewpoint of being suitable for forming a resin layer with a small film thickness.

In step (A), the contact angle when the resin varnish is dropped on the support by the dropping method is 0.1°-20°. With such a structure, shrinkage and high sides can be suppressed. The contact angle is preferably 0.2° or more, and more preferably It is 0.4° or more. Moreover, the upper limit of the contact angle is preferably 18° or less, and more preferably 16° or less, 14° or less, 12° or less, 11° or less, or 10° or less.

The contact angle when the resin varnish is dropped on the support by the dropping method can be measured using an automatic contact angle meter (DropMaster DMs-401 manufactured by Kyowa Interface Science Co., Ltd.). Specifically, the measurement can be performed according to the method described in the following (Method of Measuring Contact Angle by the Dropping Method).

<Step (B)>

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

In the present invention, there is no problem of high sides or shrinkage holes, and a thin resin layer with a thickness of 5 μm or less can be formed with a desired coating width. The thickness of the resin layer is 4 μm or less, and may be 3 μm or less. The lower limit of the thickness of the resin layer is not particularly limited, but it is usually 1 μm or more.

The drying system of the resin varnish can be performed by a well-known drying method such as heating and blowing hot air. The drying conditions can be determined in accordance with the boiling point of the solvent contained in the resin varnish. The drying conditions are not particularly limited, but the content of the organic solvent in the resin layer is 10% by mass or less, and it is preferable to dry it so that it is 5% by mass or less.

The drying treatment system may be implemented only once or multiple times. When the drying treatment is performed multiple times, the respective drying conditions may be the same or different.

If only the drying process is performed once, for example, 50 ℃~200℃ (preferably 80℃~200℃, and more preferably 90℃~200℃) for 1 minute to 30 minutes (preferably 1 minute to 20 minutes, more preferably 1 minute to 15 minutes) ) To dry the resin varnish to form a resin layer.

If the drying treatment is performed multiple times, for example, the second and subsequent drying treatments can be performed at a higher temperature than the first drying treatment. For example, the first drying can be performed at a temperature above 50°C but less than 150°C (preferably 70°C or more and 140°C or less, and more preferably 80°C or more and 130°C or less, or 90°C or more and 120°C or less) The treatment can be carried out at a temperature of 150°C or higher and 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) for the second and subsequent drying treatments. If the drying treatment is performed multiple times, the time for each drying treatment can be, for example, 1 minute to 30 minutes (preferably 1 minute to 20 minutes, and more preferably 1 minute to 15 minutes, or 1 minute to 10 minutes).

The resin sheet may further be provided with a protective film based on the support on the surface that is not bonded to the support of the resin layer (that is, the surface on the opposite side to the support). Therefore, in one embodiment, the manufacturing method of the branched resin sheet of the present invention is after step (B), and further includes a step of providing a protective film by bonding with the resin layer (hereinafter also referred to as "step (C)" ).

In step (C), the protective film is preferably laminated with the resin layer by a roll or a press. The lamination process can be implemented using a commercially available vacuum laminator. As a commercially available vacuum laminating machine, you can include For example, a vacuum pressure laminator manufactured by Meiji Seisakusho Co., Ltd., a vacuum laminator manufactured by Nichigo-Morton (stock), etc.

The thickness of the protective film is not particularly limited, and is, for example, 1 μm to 40 μm. By laminating the protective film, it is possible to prevent adhesion and scratches of dust and the like on the surface of the resin layer. The resin sheet can be rolled into a roll and stored later. If the resin sheet has a protective film, it can be used by peeling off the protective film.

The resin sheet produced in the method of the present invention can be used as a resin sheet for forming an insulating layer of a printed wiring board (resin sheet for an insulating layer of a printed wiring board). Among them, in the manufacture of printed wiring boards by the build-up method, it can be suitably used as a resin sheet for forming an insulating layer (resin sheet for build-up insulating layers of printed wiring boards), and more suitable for use as A resin sheet on which an insulating layer of a circuit is formed by a plating process (resin sheet for a build-up insulating layer of a printed wiring board on which a circuit is formed by a plating process) is formed.

[Laminated sheet and its manufacturing method]

In one embodiment, it is possible to bond the resin layer of the resin sheet obtained according to the present invention and various films represented by the insulating resin layer to form a laminated sheet.

When forming an insulating layer of a printed wiring board as an insulating resin layer, a conventionally well-known insulating resin layer can be used. The thickness of the insulating resin layer is preferably 70 μm or less, and more preferably 60 μm or less, 50 μm or less, 40 μm or less, and 30 μm or less from the viewpoint of making the insulating layer thinner. μm or less, or 20 μm or less. The lower limit of the thickness of the insulating resin layer is not particularly limited, but it can usually be 1 μm or more, 5 μm or more, 10 μm or more.

From the viewpoint of obtaining a thin insulating layer with excellent mechanical strength, a prepreg is preferred as the insulating resin layer, but a thermosetting resin composition layer that does not contain a sheet-like fiber substrate (below Abbreviated as "thermosetting resin composition layer"). The thermosetting resin composition layer is not particularly limited as long as it can exhibit sufficient hardness and insulation after curing, but generally contains an epoxy resin and a curing agent. The types or content of the epoxy resin and the hardener are described respectively as the epoxy resin and the hardener in the above (resin composition).

From the viewpoint of reducing the thermal expansion coefficient of the obtained insulating layer and preventing the generation of cracks or circuit deformation due to the difference in thermal expansion between the insulating layer and the conductor layer, the thermosetting resin composition layer system further contains an inorganic filler The material is better. As an inorganic filler system, the inorganic filler in the above-mentioned (resin composition) can be used. In terms of the content of the inorganic filler in the thermosetting resin composition layer, from the viewpoint of reducing the thermal expansion coefficient of the resulting insulating layer, if the non-volatile content in the thermosetting resin composition layer is set to 100 mass %, preferably 50% by mass or more, more preferably 55% by mass or more, more preferably 60% by mass or more, 65% by mass or more, 70% by mass or more, or 75% by mass or more. The upper limit of the content of the inorganic filler is preferably 95% by mass or less, and more preferably 90% by mass or less or 85% by mass from the viewpoint of the mechanical strength of the insulating layer to be obtained. As other components that can be contained in the thermosetting resin composition layer, For example, additives such as thermoplastic resins, hardening accelerators, flame retardants, rubber particles, etc., described in the above (resin composition) can be mentioned.

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

In the prepreg system, a thermosetting resin composition is impregnated in a sheet-like fiber base material.

The thermosetting resin composition used in the prepreg is not particularly limited as long as the cured product has sufficient hardness and insulating properties, and conventionally known ones used in the formation of insulating layers of printed wiring boards can be used. The thermosetting resin composition. For example, the resin composition used in the formation of the above-mentioned thermosetting resin composition layer can be used. In addition, the thermosetting resin composition used in the prepreg may be the same as the resin composition used in the formation of the resin layer in the resin sheet of the present invention.

The sheet-like fibrous substrate used in the prepreg is not particularly limited, and the substrates for prepregs such as glass cloth, aromatic polyamide nonwoven fabric, liquid crystal polymer nonwoven fabric, etc. can be used as common ones. From the viewpoint of reducing the thickness of the insulating layer, the thickness of the flaky fibrous substrate is preferably 50 μm or less, more preferably 40 μm or less, and more preferably 30 μm or less, 25 μm or less, or 20 μm or less. The lower limit of the thickness of the sheet-like fibrous base material is not particularly limited, but it can usually be 5 μm or more, 10 μm or more.

The prepreg system can be produced by a well-known method such as a hot melt method and a solvent method.

The thickness of the prepreg can be 70μm or less, 60μm or less Lower, 50 μm or less, 40 μm or less, or 30 μm or less. The lower limit of the thickness of the prepreg is not particularly limited, but it can usually be 10 μm or more, 12 μm or more. Still, the thickness of the prepreg can be easily changed by adjusting the impregnation amount of the thermosetting resin composition.

The laminated sheet can be produced by lamination by bonding the resin layer of the resin sheet and the insulating resin layer (preferably a prepreg). For example, the resin layer of the resin sheet and the insulating resin layer can be joined, and the resin sheet obtained according to the present invention can be laminated on the insulating resin layer to produce a laminated sheet.

The lamination process can be implemented using a commercially available vacuum laminator. Commercially available vacuum laminating machines are as described above.

In the manufacture of the laminated sheet, the insulating resin layer can be used in the form of an adhesive sheet including a support and an insulating resin layer bonded to the support. As the support system, the same ones as those described for the above-mentioned resin sheet can be used.

In another embodiment, the resin layer of the resin sheet obtained according to the present invention may be formed by coating an insulating resin composition and then drying the coating film to form an insulating resin layer to produce a laminated sheet.

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

As the insulating resin composition, a composition containing an epoxy resin and a hardener is preferable. Type or content of epoxy resin and hardener The amounts are described separately as the epoxy resin and hardener in the above (resin composition). As the organic solvent, the same solvent as that contained in the above-mentioned resin varnish can be used.

The drying system of the insulating resin varnish can be performed by a well-known drying method such as heating and blowing hot air.

As the laminated sheet system, 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) can be used. Among them, in the manufacture 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 can be more suitably used as A laminate sheet used to form an insulating layer on which a circuit is formed by a plating process (a laminate sheet for a build-up insulating layer of a printed wiring board where a circuit is formed by a plating process).

Furthermore, when the insulating resin layer is used in the form of the above-mentioned adhesive sheet during the manufacture of the laminated sheet, the resulting laminated sheet will have a surface of the insulating resin layer that is not bonded to the resin sheet of the present invention (that is, with The resin sheet of the present invention has a support derived from the adhesive sheet on the surface on the opposite side). When manufacturing laminates or printed wiring boards, it can be used by peeling off the support derived from the above-mentioned adhesive sheet.

[Laminate and its manufacturing method]

The resin sheet obtained by the manufacturing method of the present invention can be used in the manufacture of laminates such as printed wiring boards. In one embodiment, the laminate can use the resin sheet and insulation obtained by the manufacturing method of the present invention. The edge resin layer is manufactured by a method including the following step (I-1) (hereinafter also referred to as "first embodiment").

(I-1) One or more insulating resin layers are arranged between two resin sheets arranged in such a way that the resin layers are opposed to each other, and the insulating resin layer is heated and pressurized at 200°C or higher under reduced pressure. One-piece molding steps

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 carried out by a procedure such as using a vacuum heat press device and the following procedure.

First, in a vacuum heat press device, a laminated structure is arranged such that one or more insulating resin layers are arranged between two resin sheets arranged so that the resin layers face each other.

Then, under reduced pressure, the laminated structure is heated and pressed by a vacuum hot press. The vacuum heat press process can be implemented by a conventionally known vacuum heat press device that presses a metal plate such as a heated SUS plate from the two facing laminated structures. As a commercially available vacuum heat press device, for example, "MNPC-V-750-5-200" manufactured by Meike Manufacturing Co., Ltd., "VH1-1603" manufactured by Kitagawa Seiki Co., Ltd., and the like can be cited.

The conditions of the vacuum heat press processing are not particularly limited, and it can be used for well-known conditions used in the manufacture of laminates.

Step (I-1) is implemented by using two or more insulating resin layers, and placing an inner substrate between the insulating resin layers. Two or more insulating resin layers may be the same or different.

In the present invention, the so-called "inner substrate" mainly refers to substrates such as glass epoxy substrates, metal substrates, polyester substrates, polyimide substrates, BT resin substrates, thermosetting polyphenylene ether substrates, etc., or on the substrates A circuit board with a pattern-processed conductor layer (circuit) formed on one or both sides. In the production of printed wiring boards, furthermore, the inner layer circuit board on which the insulating layer and/or the conductor layer should be formed as an intermediate product is also included in the so-called "inner layer substrate" in the present invention.

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

In other embodiments, the laminate may use the above-mentioned laminate sheet and be manufactured by a method including the following steps (II-1) and (II-2) (hereinafter also referred to as "the second embodiment ").

(II-1) The step of laminating the laminated sheet on the inner substrate with the insulating resin layer in contact with the inner substrate

(II-2) The step of thermally hardening the laminated sheet to form an insulating layer

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

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

The lamination system of the laminate sheet and the inner substrate in step (II-1) can be performed by, for example, heating and pressing the laminate sheet on the inner substrate from the support side. As a member for heating and pressing the laminated sheet to the inner substrate (hereinafter also referred to as "heating and pressing member"), for example, a heated metal plate (SUS mirror plate, etc.) or metal roller (SUS roller), etc. can be mentioned. Still not The heating and pressing member is directly pressed on the laminated sheet, but in order to make the laminated sheet fully follow the surface irregularities of the inner substrate, it is preferable to press with an elastic material such as heat-resistant rubber.

The lamination system of the laminated sheet and the inner substrate can be implemented by a vacuum lamination method. In the vacuum lamination method, the heating temperature is preferably 60°C~160°C, and more preferably within the range of 80°C~140°C, and the pressure bonding pressure is preferably 1kgf/cm ² ~18kgf/cm ² (0.098MPa~1.77 MPa), and preferably within the range of 3kgf/cm ² ~15kgf/cm ² (0.29MPa~1.47MPa), the pressure bonding time is preferably 20 seconds to 400 seconds, and more preferably 30 seconds to 300 Within seconds. The lamination system is preferably carried out under reduced pressure of 26.7 hPa or less.

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

The lamination system of the laminated sheet and the inner substrate can be performed by a commercially available vacuum laminator. Commercially available vacuum laminating machines are as described above.

In step (II-2), the laminated sheet is thermally cured to form an insulating layer. The thermal curing conditions are not particularly limited, and the conditions generally used when forming the insulating layer of a printed wiring board can be used.

In 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 the difference between the first embodiment and the second embodiment, (III) the step of making holes on the insulating layer, (IV) the step of roughening the insulating layer, and (V) on the surface of the insulating layer Steps to form a circuit. Therefore, in one embodiment, the laminate is included in the insulating The circuit formed on the surface of the layer.

Regardless of the difference between the first embodiment and the second embodiment, as long as the support is removed before forming a circuit on the surface of the insulating layer, the surface smoothness of the obtained insulating layer and the risk of foreign matter adhesion during curing are reduced. From a standpoint, it is better to remove the resin layer after thermal hardening. In detail, in the first embodiment, the support only needs to be between step (I-1) and step (III), between step (III) and step (IV), or between step (IV) and step (V). ). In the second embodiment, as long as the support is between step (II-2) and step (III), between step (III) and step (IV), or between step (IV) and step (V) Just remove it.

Step (III) is a step of opening a hole on the insulating layer, whereby holes such as through holes and through holes can be formed on the insulating layer. Step (III) can be implemented using, for example, drilling, laser, plasma, etc., depending on the resin layer used for the formation of the insulating layer and the composition of the insulating resin layer. The size or shape of the hole can be appropriately determined according to the design of the printed circuit board.

Step (IV) is a step of roughening the insulating layer. The procedures and conditions of the roughening treatment are not particularly limited, and well-known procedures and conditions generally used when forming the insulating layer of a printed wiring board can be adopted. In this order, for example, a swelling treatment by a swelling liquid, a roughening treatment by an oxidizing agent, and a neutralization treatment by a neutralization liquid can be performed to roughen the insulating layer. The swelling liquid is not particularly limited, and an alkali solution, a surfactant solution, etc. are mentioned, and an alkali solution is preferred. As the alkali solution, a sodium hydroxide solution or a potassium hydroxide solution is more preferred. As a commercially available swelling fluid, there are For example, "Swelling Dip Securiganth P" and "Swelling Dip Securiganth SBU" manufactured by Atotech Japan (stock). The swelling treatment by the swelling liquid is not particularly limited, and can be performed by, for example, immersing the insulating layer in the swelling liquid at 30 to 90° C. for 1 to 20 minutes. The oxidizing agent is not particularly limited, and, for example, an alkaline permanganic acid solution in which potassium permanganate or sodium permanganate is dissolved in an aqueous solution of sodium hydroxide is mentioned. The roughening treatment by an oxidizing agent such as an alkaline permanganic acid solution is preferably performed by immersing the insulating layer in an oxidizing agent solution heated to 60°C to 80°C for 10 minutes to 30 minutes. In addition, the concentration of permanganate in the alkaline permanganic acid solution is preferably 5 to 10% by mass. Examples of commercially available oxidants include alkaline permanganic acid solutions such as "Concentrate Compact CP" manufactured by Atotech Japan Co., Ltd. and "Dosing solution Securiganth P". In addition, an acidic aqueous solution is preferable as the neutralizing liquid, and as a commercially available product, for example, "Reduction solution Securiganth P" manufactured by Atotech Japan (Stock) can be mentioned. The treatment by the neutralization liquid can be performed by immersing the treated surface roughened by the oxidizing agent in the neutralization liquid 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 suitable embodiment, the conductor layer includes one selected from the group consisting of gold, platinum, palladium, silver, copper, aluminum, cobalt, chromium, zinc, nickel, titanium, tungsten, iron, tin, and indium. More than species of metals. The conductor layer may be a single metal layer or an alloy layer. Examples of the alloy layer include 2 selected from the above group A layer formed by an alloy of more than one metal (for example, nickel‧chromium alloy, copper‧nickel alloy and copper‧titanium alloy). Among them, in terms of the versatility, cost, and ease of patterning of the conductor layer, a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper, or nickel? The alloy layer of chromium alloy, copper‧nickel alloy, 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 To be more preferable, a single metal layer of copper is more preferable.

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

The thickness of the conductor layer depends on the design of the desired printed circuit board, but it is usually 3 μm-50 μm, preferably 5 μm-30 μm.

The conductor layer can be formed by a plating process. For example, by plating on the surface of the insulating layer by a conventionally known technique such as a semi-additive method and a full-additive method, a conductor layer having a desired wiring pattern can be formed.

The laminate can be used for various applications depending on its manufacturing method and structure (for example, the presence or absence of the inner substrate in the first embodiment, the presence or absence of circuits in the first and second embodiments, etc.). For example, it is also possible to use as an inner layer substrate such as an insulating core substrate and an inner layer circuit board used in the manufacture of a printed wiring board, or as a printed wiring board.

[Semiconductor Device]

The semiconductor device can be manufactured using a printed wiring board composed of the above-mentioned laminate or a printed wiring board manufactured using the above-mentioned laminate.

Examples of semiconductor devices include various semiconductor devices provided in electrical products (for example, computers, mobile phones, digital cameras, and televisions, etc.) and vehicles (for example, motorcycles, automobiles, trams, ships, and aircrafts).

[Example]

Hereinafter, the present invention will be described in more detail through examples, but the present invention is not limited to these examples. However, in the following description, unless otherwise specified, "parts" and "%" refer to "parts by mass" and "% by mass" respectively.

[Preparation of resin varnish] (Preparation of standard resin varnish)

10 parts of naphthyl ether type epoxy resin (DIC Corporation "EXA-7311-G4S", epoxy equivalent 186), dixylenol type epoxy resin (Mitsubishi Chemical Corporation "YX4000HK", Epoxy equivalent approximately 185) 10 parts, biphenyl type epoxy resin (Nippon Kayaku Co., Ltd. "NC3000H", epoxy equivalent 288) 20 parts, and phenoxy resin (Mitsubishi Chemical Co., Ltd. "YX7553BH30" , Cyclohexanone with a solid content of 30% by mass: 25 parts of a 1:1 solution of methyl ethyl ketone (MEK), in a mixed solvent of 15 parts of naphtha and 5 parts of cyclohexanone, while stirring It is heated to dissolve. After cooling to room temperature, mix 10 parts of phenolic hardener containing triazine skeleton (hydroxy equivalent 125, "LA-7054" made by DIC (stock), 60% solid content MEK solution), naphthol Hardener (Nippon Steel & Sumikin Chemical Co., Ltd. "SN485", hydroxyl equivalent 215, solid content 60% MEK solution) 19 parts, polyvinyl butyral resin (glass transition temperature 105°C, Sekisui Chemical Industry ( (Stock) made "KS-1") 10 parts of a 1:1 mixed solution of 15% ethanol and toluene, amine hardening accelerator (4-dimethylaminopyridine (DMAP), solid content 5 mass% MEK solution) 1 part, imidazole-based hardening accelerator (Mitsubishi Chemical Co., Ltd. "P200-H50", 50 mass% propylene glycol monomethyl ether solution), 2 parts, aminosilane-based Coupling agent (Shin-Etsu Chemical Co., Ltd. "KBM573") surface-treated spherical silica ((Stock) Admatechs "SOC2", average particle size 0.5μm, carbon content per unit surface area 0.38mg/m ² ) 50 parts, uniformly dispersed by a high-speed rotary mixer, filtered with a filter cartridge ("SHP050" manufactured by ROKITECHNO) to prepare a standard resin varnish.

(Preparation of resin varnish 1)

Mix the solvent of methyl ethyl ketone (MEK) and solvent naphtha at 50:50 (mass ratio) into the standard resin varnish, and adjust the content of non-volatile components to 25% Thus, the resin varnish 1 was prepared.

(Preparation of resin varnish 2)

A solvent mixture made by mixing ethanol and toluene at a ratio of 50:50 (mass ratio) Incorporate into a standard resin varnish, and adjust the non-volatile content to 25% to prepare resin varnish 2.

(Preparation of resin varnish 3)

A solvent prepared by mixing MEK and cyclohexanone at 50:50 (mass ratio) was mixed into a standard resin varnish, and the content of non-volatile components was adjusted to 25% to prepare resin varnish 3.

(Preparation of resin varnish 4)

The standard resin varnish is mixed with cyclohexanone, and the content of the non-volatile components is adjusted to 25% to prepare the resin varnish 4.

(Preparation of resin varnish 5)

A solvent prepared by mixing MEK and solvent naphtha at a 50:50 (mass ratio) was mixed into a standard resin varnish, and the content of non-volatile components was adjusted to 35% to prepare resin varnish 5.

(Preparation of resin varnish 6)

A solvent prepared by mixing ethanol and toluene at 50:50 (mass ratio) was mixed into a standard resin varnish, and the content of non-volatile components was adjusted to 35% to prepare a resin varnish 6.

(Preparation of resin varnish 7)

A solvent made by mixing MEK and cyclohexanone at 50:50 (mass ratio) It is mixed into a standard resin varnish, and the content of the non-volatile components is adjusted to 35% to prepare a resin varnish 7.

(Preparation of resin varnish 8)

The standard resin varnish was mixed with cyclohexanone, and the content of the non-volatile components was adjusted to 35% to prepare resin varnish 8.

(Preparation of resin varnish 9)

A solvent prepared by mixing MEK and solvent naphtha at a 50:50 (mass ratio) was mixed into a standard resin varnish, and the content of non-volatile components was adjusted to 15% to prepare a resin varnish 9.

(Preparation of resin varnish 10)

The standard resin varnish is mixed with dimethylacetamide (DMAc), and the content of non-volatile components is adjusted so as to be 25% to prepare the resin varnish 10.

(Preparation of resin varnish 11)

The standard resin varnish was mixed with DMAc, and the content of the non-volatile components was adjusted to 35% to prepare the resin varnish 11.

(Determination of viscosity of resin varnish)

Using a rotary vibration viscometer (viscometer VM-10A manufactured by Tech-jam), the resin is measured at a temperature of 25°C Viscosity of varnish 1~11. The value from the start of the measurement to 2 minutes later was used 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 coating the resin varnish 1 to 11 on the support 1 to 3, and measuring the contact angle according to the method described later, the resin varnish applied on the support is dried according to the following method to form a resin layer. Hole, high side, and coating width are used for evaluation test.

The supporting bodies 1 to 3 used are as follows.

Support 1: A PET film ("Lumirror T60" manufactured by Toray Co., Ltd.) is prepared by setting a mold release layer composed of an alkyd-based mold release agent (surface roughness 22nm, by dripping method). (The measured water contact angle is 90°)

Support 2: A PET film (“Lumirror T60” manufactured by Toray Co., Ltd.) is prepared by setting a mold release layer composed of an olefin-based mold release agent (surface roughness is 22nm, and is prepared by the dropping method). The measured water contact angle is 110°)

Support 3: PET film (“Lumirror T60” manufactured by Toray Co., Ltd.) is directly used (surface roughness is 22nm, water contact angle measured by drip method is 75°)

(Example 1)

With a gravure coater, the resin varnish 1 is uniformly coated on the support 1 so that the thickness of the dried resin layer becomes 2 μm, and The resin layer is formed on the support 1 by drying from 100° C. to 120° C. for 3 minutes to produce a resin sheet.

(Example 2)

Except that the resin varnish 2 was used instead of the resin varnish 1, a resin layer was formed on the support 1 in the same manner as in Example 1, thereby producing a resin sheet.

(Example 3)

Except that the resin varnish 3 was used instead of the resin varnish 1, a resin layer was formed on the support 1 in the same manner as in Example 1 to produce a resin sheet.

(Example 4)

Except that the resin varnish 4 was used instead of the resin varnish 1, a resin layer was formed on the support 1 in the same manner as in Example 1, thereby producing a resin sheet.

(Example 5)

Except that the resin varnish 5 was used instead of the resin varnish 1, a resin layer was formed on the support 1 in the same manner as in Example 1 to produce a resin sheet.

(Example 6)

Except that the resin varnish 6 was used instead of the resin varnish 1, a resin layer was formed on the support 1 in the same manner as in Example 1, thereby producing a resin sheet.

(Example 7)

Except that the resin varnish 7 was used instead of the resin varnish 1, a resin layer was formed on the support 1 in the same manner as in Example 1, thereby producing a resin sheet.

(Example 8)

Except that the resin varnish 8 was used instead of the resin varnish 1, a resin layer was formed on the support 1 in the same manner as in Example 1, thereby producing a resin sheet.

(Example 9)

Except that the support 2 was used instead of the support 1, a resin layer was formed on the support 2 in the same manner as in Example 1, thereby fabricating a resin sheet.

(Example 10)

Except that the resin varnish 2 was used instead of the resin varnish 1, a resin layer was formed on the support 2 in the same manner as in Example 9 to produce a resin sheet.

(Example 11)

Except that the resin varnish 3 was used instead of the resin varnish 1, a resin layer was formed on the support 2 in the same manner as in Example 9 to produce a resin sheet.

(Example 12)

Except that the resin varnish 5 was used instead of the resin varnish 1, a resin layer was formed on the support 2 in the same manner as in Example 9 to produce a resin sheet.

(Example 13)

Except that the resin varnish 6 was used instead of the resin varnish 1, a resin layer was formed on the support 2 in the same manner as in Example 9 to produce a resin sheet.

(Example 14)

Except that the resin varnish 7 was used instead of the resin varnish 1, a resin layer was formed on the support 2 in the same manner as in Example 9 to produce a resin sheet.

(Example 15)

Except that the resin varnish 9 was used instead of the resin varnish 1, a resin layer was formed on the support 2 in the same manner as in Example 9 to produce a resin sheet.

(Example 16)

Except that the support 3 was used instead of the support 1, a resin layer was formed on the support 3 in the same manner as in Example 1, thereby producing a resin sheet.

(Example 17)

Except that the resin varnish 2 was used instead of the resin varnish 1, a resin layer was formed on the support 3 in the same manner as in Example 16, thereby producing a resin sheet.

(Example 18)

Except that the resin varnish 3 was used instead of the resin varnish 1, a resin layer was formed on the support 3 in the same manner as in Example 16, thereby producing a resin sheet.

(Example 19)

Except that the resin varnish 4 was used instead of the resin varnish 1, a resin layer was formed on the support 3 in the same manner as in Example 16, thereby producing a resin sheet.

(Example 20)

Except that resin varnish 5 was used instead of resin varnish 1, a resin layer was formed on the support 3 in the same manner as in Example 16, thereby making Resin flakes.

(Example 21)

Except that the resin varnish 6 was used instead of the resin varnish 1, a resin layer was formed on the support 3 in the same manner as in Example 16, thereby producing a resin sheet.

(Example 22)

Except that the resin varnish 7 was used instead of the resin varnish 1, a resin layer was formed on the support 3 in the same manner as in Example 16, thereby producing a resin sheet.

(Example 23)

Except that the resin varnish 8 was used instead of the resin varnish 1, a resin layer was formed on the support 3 in the same manner as in Example 16, thereby producing a resin sheet.

(Example 24)

Except that the resin varnish 10 is used instead of the resin varnish 1, a resin layer is formed on the support 3 in the same manner as in Example 16, thereby producing a resin sheet.

(Example 25)

In addition to the use of resin varnish 11 instead of resin varnish 1, and the actual In Example 16, a resin layer was formed on the support 3 in the same manner to produce a resin sheet.

(Comparative example 1)

Except that the resin varnish 9 was used instead of the resin varnish 1, a resin layer was formed on the support 1 in the same manner as in Example 1, thereby producing a resin sheet.

(Comparative example 2)

Except that the resin varnish 10 was used instead of the resin varnish 1, a resin layer was formed on the support 1 in the same manner as in Example 1, thereby producing a resin sheet.

(Comparative example 3)

Except that the resin varnish 11 was used instead of the resin varnish 1, a resin layer was formed on the support 1 in the same manner as in Example 1, thereby producing a resin sheet.

(Comparative Example 4)

Except that the resin varnish 4 was used instead of the resin varnish 1, a resin layer was formed on the support 2 in the same manner as in Example 9 to produce a resin sheet.

(Comparative Example 5)

Except that the resin varnish 8 was used instead of the resin varnish 1, a resin layer was formed on the support 2 in the same manner as in Example 9 to produce a resin sheet.

(Comparative Example 6)

Except that the resin varnish 10 was used instead of the resin varnish 1, a resin layer was formed on the support 2 in the same manner as in Example 9 to produce a resin sheet.

(Comparative Example 7)

Except for using the resin varnish 11 instead of the resin varnish 1, a resin layer was formed on the support 2 in the same manner as in Example 9 to produce a resin sheet.

(Comparative Example 8)

Except that the resin varnish 9 was used instead of the resin varnish 1, a resin layer was formed on the support 3 in the same manner as in Example 16, thereby producing a resin sheet.

(Measurement method of contact angle by drip method)

An automatic contact angle meter (DropMaster DMs-401 manufactured by Kyowa Interface Science Co., Ltd.) was used to measure the contact angle when each resin varnish was dripped onto the support by the drip method. Specifically, the resin varnish is filled into a syringe to make 0.8 μL drops, and the drops are adhered to On the support, the value from the time of adhesion to 2000 ms was taken as the contact angle when each resin varnish was dropped on the support by the dropping method, and the results are shown in Table 1.

(Assessment of shrinkage)

Count the number of shrinkage defects in the resin layer 10m ² formed in Examples 1-25 and Comparative Examples 1-8. In the resin layer 10m ² , it can be found that there are more than 10 shrinkage holes with a diameter of 0.1mm or more. Set it as "×", if the number of shrinkage holes is 2-9, set it as "△", and the number of shrinkage holes is 0. ~1 is set as "○", and the results are shown in Table 1.

(High-side evaluation)

The resin layers formed in Examples 1 to 25 and Comparative Examples 1 to 8 were used to measure the thickness of the central part and the thickest part (the thickest part) using a micrometer. If the thickness difference between the central part and the largest thickness part is 10μm or more, set "×", if 2μm~10μm is set as "△", if 0~2μm is set as "○", and the results are shown in Table 1.

(Evaluation of coating width control)

The coating width of the resin layer formed in Examples 1-25 and Comparative Examples 1-8 was measured with a stainless steel ruler. Relative to the target coating width of 1000mm, set the actual coating width with a difference of 5mm or more with "×", 2mm~5mm with "△", and 0~2mm with "○", and display the result in Table 1.

Table 1 shows: the viscosity of the resin varnish, the contact angle when the resin varnish is dropped on the support by the drip method, the evaluation result of shrinkage, the evaluation result of the high side, the evaluation result of the coating width control, and It shows the type and amount of solvent used in the preparation of each resin varnish, and the content of non-volatile components.

Claims (8)

A method for manufacturing a resin sheet, which includes the following steps: (A) a step of coating a resin varnish containing a resin composition and a solvent on a support, and (B) drying the resin varnish to form a resin layer Step; wherein in step (A), the contact angle of the resin varnish on the support body is 0.1°-20° by the drip method, and in step (B), the thickness of the resin layer is 5μm or less, the support system Film or release paper made of plastic materials. A method for manufacturing a resin sheet, which includes the following steps: (A) a step of coating a resin varnish containing a resin composition and a solvent on a support, and (B) drying the resin varnish to form a resin layer Step; wherein in step (A), the contact angle of the resin varnish on the support body is 0.1°-20° by the drip method, and in step (B), the thickness of the resin layer is 5μm or less, the support system With release layer. The method for producing a resin sheet according to claim 1 or 2, wherein the content of non-volatile components in the resin varnish is 40% by mass or less. The method for manufacturing a resin sheet according to claim 1, wherein the support system is provided with a release layer. The method for producing a resin sheet according to claim 1 or 2, wherein the solvent includes a polar solvent. The method for producing a resin sheet according to claim 1 or 2, wherein the solvent includes a polar solvent with a specific dielectric rate of 12 or higher and a non-polar solvent with a dielectric rate of 9 or lower. Such as the method of manufacturing the resin sheet of claim 1 or 2, wherein: In step (A), the resin varnish is applied by a gravure coating method. The method for manufacturing a resin sheet according to claim 1 or 2, wherein the resin sheet is used for the insulating layer of a printed wiring board.