KR102546390B1 - Process for producing resin sheet - Google Patents

Abstract

[Problem] To provide a method for producing a resin sheet capable of controlling the film thickness and the coating width by suppressing the formation of the resin layer and suppressing the occurrence of tearing and spattering of the resin layer.
[Solution] (A) a step of applying a resin varnish containing a resin composition and a solvent onto a support; (B) a step of drying the resin varnish to form a resin layer; A method for producing a resin sheet, wherein the contact angle of the resin varnish 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).
[Selectivity] None

Description

Method for manufacturing a resin sheet {PROCESS FOR PRODUCING RESIN SHEET}

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

As a manufacturing technology of a printed wiring board, a build-up method in which a circuit formed conductor layer and an insulating layer are alternately stacked is widely used. In the build-up method, the insulating layer is generally formed by laminating a resin sheet containing a resin layer to an inner layer substrate and curing the resin layer.

On the other hand, with the miniaturization and thinning of electronic devices in recent years, thinning of the resin layer is progressing. For example, Patent Document 1 describes an insulated resin sheet in which a first layer (resin layer) having a thickness of 2 to 18 μm is formed on a support.

Japanese Unexamined Patent Publication No. 2014-17301

When forming a thin resin layer on a support, generally, coating stability is secured by using a resin varnish having a low concentration of non-volatile components obtained by diluting a resin composition with a large amount of solvent, and increasing the thickness of the coating film. In recent years, from the viewpoint of surface smoothness of the insulating layer and reduction of the risk of foreign matter adhesion during curing, there are cases where the resin layer is thermally cured with the support attached thereto. Supports are often used. In such a situation, when the resin varnish is applied to the surface of the support, the thickness of the resin layer becomes larger in the region closer to the end than the center due to the difference in polarity between the surface of the support and the resin varnish or the change in polarity due to volatilization of the solvent. There were cases in which "swelling" and frying 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 is a risk of change in plating characteristics or bleeding out during storage. Further, in the case where the difference in polarity between the surface of the support and the coating liquid is small (when the wettability is high), the coating may be wetted wider than the set coating width, making it difficult to control the coating width or film thickness.

An object of the present invention is to provide a method for producing a resin sheet with good control of film thickness and coating width, suppressing the occurrence of tearing and spattering of the resin layer when forming the resin layer.

As a result of earnestly examining the above problems, the present inventors have found that the above problems can be solved by including a step of applying a resin varnish on a support so that the contact angle of the resin varnish with respect to the support in the droplet method is 0.1 to 20°. and came to complete the present invention.

That is, the present invention includes the following contents.

[1] (A) a step of applying a resin varnish containing a resin composition and a solvent onto a support; (B) a step of drying the resin varnish to form a resin layer; A method for producing a resin sheet, wherein the contact angle of the resin varnish for the liquid drop method is 0.1 to 20°, and the thickness of the resin layer is 5 μm or less in step (B).

[2] The method for producing a resin sheet according to [1], wherein the content of the non-volatile 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 is provided with 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 contains a polar solvent having a dielectric constant of 12 or more and a non-polar solvent having a dielectric constant of 9 or less.

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

[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 tearing and splashing of a resin layer can be suppressed, and the manufacturing method of the resin sheet with good control of film thickness and coating width can be provided.

[Method for Manufacturing 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 onto a support, and (B) a step of drying the resin varnish to form a resin layer, In A), the contact angle of the resin varnish with respect to the support in the droplet method is 0.1 to 20°, and in step (B), the thickness of the resin layer is 5 μm or less.

<Process (A)>

In step (A), a resin varnish containing a resin composition and a solvent is applied onto a support. A resin varnish is prepared by dissolving or dispersing a 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, conventionally well-known curable resin used when forming the insulating layer of a printed wiring board can be used, and among these, an epoxy resin is preferable. Thus, in one embodiment, the resin composition contains an epoxy resin and a curing agent. The resin composition may further contain additives, such as an inorganic filler, a thermoplastic resin, a hardening accelerator, a flame retardant, and rubber particle, as needed.

-Epoxy Resin-

Examples of the epoxy resin include bisphenol type epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, and bisphenol AF type epoxy resin, dicyclopentadiene type epoxy resin, and trisphenol type epoxy resin. Resin, naphthol novolak type epoxy resin, phenol novolak type epoxy resin, tert-butyl-catechol type epoxy resin, naphthalene type epoxy resin, naphthol type epoxy resin, anthracene type epoxy resin, glycidylamine type epoxy resin, glycerin Cydyl ester type epoxy resin, cresol novolac type epoxy resin, biphenyl type epoxy resin, linear aliphatic epoxy resin, epoxy resin having a butadiene structure, alicyclic epoxy resin, heterocyclic epoxy resin, spiro ring containing epoxy resin, cyclohexane A dimethanol type epoxy resin, a naphthylene ether type epoxy resin, a trimethylol type epoxy resin, a tetraphenylethane type epoxy resin, etc. are mentioned. An epoxy resin may be used individually by 1 type, and may be used in combination of 2 or more type.

As the epoxy resin, a group consisting of bisphenol-type epoxy resins, fluorine-type epoxy resins (eg, bisphenol AF-type epoxy resins), dicyclopentadiene-type epoxy resins, naphthalene-type epoxy resins, biphenyl-type epoxy resins, and mixtures of these epoxy resins It is preferable to use one or two or more epoxy resins selected from

It is preferable that an epoxy resin contains the epoxy resin which has 2 or more epoxy groups in 1 molecule. When the non-volatile component of the epoxy resin is 100% by mass, it is preferable that at least 50% by mass or more is an epoxy resin having two or more epoxy groups in one molecule. Among these, an epoxy resin that has two or more epoxy groups in one molecule and is liquid at a temperature of 20°C (hereinafter referred to as "liquid epoxy resin"), and an epoxy resin that has three or more epoxy groups in one molecule and is solid at a temperature of 20°C. It is preferable to contain resin (henceforth "solid-state epoxy resin"). As the epoxy resin, a resin composition having excellent flexibility is obtained by using a liquid epoxy resin and a solid epoxy resin together. Moreover, the breaking strength of the cured product of the resin composition is also improved.

As the 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 novolak type epoxy resin, alicyclic epoxy having an ester skeleton Resins and epoxy resins having a butadiene structure are preferable, and bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol AF type epoxy resins and naphthalene type epoxy resins are more preferable. As a specific example of the liquid epoxy resin, "HP4032", "HP4032D", "HP4032SS" (naphthalene type epoxy resin) manufactured by DIC Corporation, "828US" manufactured by Mitsubishi Chemical Corporation, "jER828EL" (bisphenol A type) Epoxy resin), "jER807" (bisphenol F-type epoxy resin), "jER152" (phenol novolak-type epoxy resin), "YL7760" (bisphenol AF-type epoxy resin), "ZX1059" manufactured by Nippon Steel Sumikin Chemicals Co., Ltd. " (Mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin), "EX-721" (glycidyl ester type epoxy resin) manufactured by Nagase Chemtex Co., Ltd., "Serok" manufactured by Daicel Co., Ltd. Side 2021P” (an alicyclic epoxy resin having an ester skeleton) and “PB-3600” (an epoxy resin having a butadiene structure). These may be used individually by 1 type, and may be used in combination of 2 or more type.

As the solid epoxy resin, a naphthalene type tetrafunctional epoxy resin, a cresol novolak type epoxy resin, a dicyclopentadiene type epoxy resin, a trisphenol type epoxy resin, a naphthol type epoxy resin, a biphenyl type epoxy resin, a naphthylene ether type epoxy resin , Anthracene-type epoxy resins, bisphenol A-type epoxy resins, and tetraphenylethane-type epoxy resins are preferred, and naphthalene-type tetrafunctional epoxy resins, naphthol-type epoxy resins, and biphenyl-type epoxy resins are more preferred. As specific examples of the solid epoxy resin, "HP4032H" (naphthalene type epoxy resin), "HP-4700", "HP-4710" (naphthalene type tetrafunctional epoxy resin), "N-690" (cresol) manufactured by DIC Co., Ltd. novolak 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 Nihon Kayaku Co., Ltd., "NC7000L" (naphthol novolak type epoxy resin), "NC3000H", "NC3000", "NC3000L", "NC3100" (biphenyl type epoxy resin), "ESN475V" (naphthol type epoxy resin) manufactured by Nippon Steel & Chemical Co., Ltd. ), "ESN485" (naphthol novolak type epoxy resin), "YX4000H", "YL6121" (biphenyl type epoxy resin), "YX4000HK" (bike silenol type epoxy resin), "YX8800" manufactured by Mitsubishi Chemical Corporation "(anthracene type epoxy resin), "PG-100" and "CG-500" manufactured by Osaka Gas Chemical Co., Ltd., "YL7800" (fluorene type epoxy resin) manufactured by Mitsubishi Chemical Corporation, Mitsubishi Chemical Co., Ltd. manufacture "jER1010" (solid bisphenol A type epoxy resin), "jER1031S" (tetraphenylethane type epoxy resin), etc. are mentioned.

When the epoxy resin contains a solid epoxy resin and a liquid epoxy resin, the ratio of the mass ( _{MS ) of the solid epoxy resin to the mass (M L )} of the liquid epoxy resin ( _MS /M _L ) is 1 to 1 A range of 10 is preferred. By setting M _S /M _L within this range, i) when used in the form of a resin sheet, adequate tackiness is brought about, ii) when used in the form of a resin sheet, sufficient flexibility is obtained, and handling properties are improved. and iii) effects such as being able to obtain a cured product having sufficient breaking strength.

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, still more preferably 10% by mass or more, from the viewpoint of obtaining an insulating layer exhibiting good mechanical strength and insulation reliability. . The upper limit of the content of the epoxy resin is not particularly limited as long as the effect of the present invention is exhibited, but is preferably 50% by mass or less, more preferably 45% by mass or less, still more preferably 40% by 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 otherwise specified.

The epoxy equivalent of the epoxy resin is preferably 50 to 5000, more preferably 50 to 3000, still more preferably 80 to 2000, still more preferably 110 to 1000. By being in this range, the crosslinking density of hardened|cured material becomes sufficient, and an insulating layer with small surface roughness can be produced. In addition, epoxy equivalent can be measured according to JIS K7236, and is the mass of resin containing an epoxy group of 1 equivalent.

The weight average molecular weight of the epoxy resin is preferably 100 to 5000, more preferably 250 to 3000, still more preferably 400 to 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.

-hardener-

The curing agent is not particularly limited as long as it has a function of curing the epoxy resin, and examples thereof include phenol-based curing agents, naphthol-based curing agents, active ester-based curing agents, benzoxazine-based curing agents, cyanate ester-based curing agents, and carbodiimide-based curing agents. can be heard A 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 novolac structure or a naphthol-based curing agent having a novolac 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-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, it is preferable to use a triazine structure-containing phenol novolac curing agent from the viewpoint of highly satisfying heat resistance, water resistance, and adhesion to the conductor layer (peel strength).

Specific examples of the phenol-based curing agent and the naphthol-based curing agent include, for example, "MEH-7700", "MEH-7810", and "MEH-7851" manufactured by Showa Kasei Co., Ltd., manufactured by Nihon Kayaku Co., Ltd. "NHN", "CBN", "GPH", "SN170", "SN180", "SN190", "SN475", "SN485", "SN495", "SN375" manufactured by Nippon-Steel Sumiking Chemicals Co., Ltd. "SN395", DIC Corporation "LA7052", "LA7054", "LA3018", etc. are mentioned.

The active ester-based curing agent is not particularly limited, but in general, phenol esters, thiophenol esters, N-hydroxyamine esters, esters with high reaction activity, such as esters of heterocyclic hydroxy compounds, are used in one molecule. A compound having two or more is preferably used. The active ester curing agent is preferably obtained by a condensation reaction of a carboxylic acid compound and/or a thiocarboxylic acid compound with a hydroxy compound and/or a thiol compound. In particular, from the viewpoint of improving heat resistance, an active ester-based curing agent obtained from a carboxylic acid compound and a hydroxy compound is preferable, and an active ester-based curing agent obtained from a carboxylic acid compound, 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, phenolphthalin, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m- Cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, Trihydroxy benzophenone, tetrahydroxy benzophenone, fluoroglucine, benzene triol, dicyclopentadienyl diphenol, phenol novolak, etc. are mentioned.

Specifically, an active ester compound containing a dicyclopentadienyldiphenol structure, an active ester compound containing a naphthalene structure, an active ester compound containing an acetylate of a phenol novolac, and an active ester compound containing a benzoyl compound of a phenol novolac. An ester compound is preferable, and among these, an active ester compound containing a naphthalene structure and an active ester compound containing a dicyclopentadienyldiphenol structure are more preferable.

As a commercially available active ester curing agent, as an active ester compound containing a dicyclopentadienyldiphenol structure, "EXB9451", "EXB9460", "EXB9460S", "HPC-8000-65T" (manufactured by DIC Co., Ltd.), "EXB9416-70BK" (manufactured by DIC Co., Ltd.) as an active ester compound containing a naphthalene structure, "DC808" (manufactured by Mitsubishi Chemical Corporation) as an active ester compound containing an acetylated phenol novolac, phenol novolac "YLH1026" (Mitsubishi Chemical Co., Ltd.) etc. are mentioned as an active ester compound containing the benzoylide of rockfish.

As a specific example of a benzoxazine type hardening|curing agent, "HFB2006M" by Showa Kofunshi Co., Ltd., "P-d" by Shikoku Chemical Industry Co., Ltd., and "F-a" are mentioned.

Examples of the cyanate ester curing agent include bisphenol A dicyanate, polyphenol cyanate (oligo(3-methylene-1,5-phenylencyanate)), and 4,4'-methylenebis(2,6). -Dimethylphenylcyanate), 4,4'-ethylidenediphenyldicyanate, hexafluorobisphenol A dicyanate, 2,2-bis(4-cyanate)phenylpropane, 1,1-bis(4 -Cyanate phenylmethane), bis(4-cyanate-3,5-dimethylphenyl)methane, 1,3-bis(4-cyanatephenyl-1-(methylethylidene))benzene, bis(4- Bifunctional cyanate resins such as cyanatephenyl)thioether and bis(4-cyanatephenyl)ether, polyfunctional cyanate resins derived from phenol novolacs and cresol novolacs, etc., these cyanate resins are partially triazinated prepolymers and the like. As specific examples of the cyanate ester curing agent, "PT30" and "PT60" (both phenol novolak type polyfunctional cyanate ester resins) manufactured by Lonza Japan Co., Ltd., "BA230" (part or all of bisphenol A dicyanate) a prepolymer obtained by triazation to form a trimer); and the like.

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

In the present invention, the curing agent preferably contains at least one selected from a phenol-based curing agent, a cyanate ester-based curing agent, and an active ester-based curing agent, and a triazine structure-containing phenol-based curing agent, a cyanate ester-based curing agent, and an active It is more preferable to contain at least one type selected from ester type curing agents.

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, still 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 is exhibited, but is preferably 30% by mass or less, more preferably 25% by mass or less, still more preferably 20% by mass or less.

The ratio of the amount of the epoxy resin to the curing agent is preferably in the range of 1:0.2 to 1:2, preferably 1:0.3 to 1:1.5, in the ratio of [the total number of epoxy groups in the epoxy resin]:[the total number of reactive groups in the curing agent]. is more preferred, and 1:0.4 to 1:1 is still more preferred. Here, the reactive group of the curing agent is an active hydroxyl group, an active ester group, or the like, and differs depending on the type of the curing agent. In addition, the total number of epoxy groups of an epoxy resin is the value obtained by dividing the solid content mass of each epoxy resin by the epoxy equivalent with respect to the epoxy resin, and the total number of reactive groups of the curing agent refers to the solid content mass of each curing agent by the reactive group equivalent. It is the sum of the divided values for all curing agents. By making the quantity ratio of an epoxy resin and a hardening|curing agent into this range, the heat resistance of the hardened|cured material of a resin composition improves more.

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 above epoxy resin and curing agent.

-Inorganic filler-

The material of the inorganic filler is not particularly limited, and examples thereof include silica, alumina, glass, cordierite, silicon oxide, barium sulfate, barium carbonate, talc, clay, mica powder, zinc oxide, hydrotalcite, boehmite, 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, bismuth titanate, titanium oxide, zirconium oxide, barium titanate , barium zirconate titanate, barium zirconate, calcium zirconate, zirconium phosphate, zirconium tungstate phosphate, and the like. Among these, silica is particularly suitable. Moreover, as silica, spherical silica is preferable. An inorganic filler may be used individually by 1 type, and may be used in combination of 2 or more types. As a commercial item of an inorganic filler, "SO-C2", "SO-C1", and "SO-C4" by Adomatex Co., Ltd. are mentioned, for example.

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 more preferably 3 µm or less, from the viewpoint of obtaining an insulating layer with small surface roughness or improving fine wiring formability. More preferably, 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, when forming a resin varnish using a resin composition, the average particle diameter of the inorganic filler is 0.01 µm or more from the viewpoint of obtaining a resin varnish having an appropriate viscosity and good handling properties and preventing an increase in the melt viscosity of the resin sheet. is preferably 0.03 μm or more, more preferably 0.05 μm or more, 0.07 μm or more, or even more preferably 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, it can be measured by creating the particle size distribution of the inorganic filler on a volume basis with a laser diffraction scattering type particle size distribution analyzer and taking the median diameter as the average particle diameter. As the measurement sample, a material obtained by dispersing an inorganic filler in water by ultrasonic waves can be preferably used. As a laser diffraction scattering type particle size distribution analyzer, &quot;LA-500&quot; manufactured by Horiba Sesakusho Co., Ltd. or the like can be used.

From the viewpoint of improving moisture resistance and dispersibility, inorganic fillers include aminosilane-based coupling agents, epoxysilane-based coupling agents, mercaptosilane-based coupling agents, silane-based coupling agents, organosilazane compounds, titanate-based coupling agents, and the like. It is preferable to be treated with one or more kinds of surface treatment agents. As a commercial item of a surface treatment agent, for example, "KBM403" (3-glycidoxypropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Industry Co., Ltd., "KBM803" (3-mercapto propyltrimethoxysilane), Shin-Etsu Chemical Co., Ltd. "KBE903" (3-aminopropyltriethoxysilane), Shin-Etsu Chemical Industry "KBM573" (N-phenyl-3-aminopropyl trimethoxysilane) methoxysilane), Shin-Etsu Chemical Industry Co., Ltd. "SZ-31" (hexamethyldisilazane), Shin-Etsu Chemical Industry Co., Ltd. "KBM103" (phenyltrimethoxysilane), Shin-Etsu Chemical Industry Co., Ltd. ( Note) Manufacture "KBM-4803" (long chain epoxy type silane coupling agent) etc. are mentioned.

The degree of surface treatment by the surface treatment agent can be evaluated by the amount of carbon per unit surface area of the inorganic filler. The amount of carbon per unit surface area of the inorganic filler is preferably 0.02 mg/m 2 or more, more preferably 0.1 mg/m 2 or more, and still more preferably 0.2 mg/m 2 or more, from the viewpoint of improving the dispersibility of the inorganic filler. On the other hand, from the viewpoint of preventing an increase in the melt viscosity of the resin varnish or the melt viscosity in the sheet form, 1 mg/m or less is preferable, 0.8 mg/m or less is more preferable, and 0.5 mg/m or less is still more preferable. .

The amount of carbon per unit surface area of the inorganic filler can be measured after washing the inorganic filler after surface treatment with a solvent (for example, methyl ethyl ketone (MEK)). Specifically, a sufficient amount of MEK as a solvent is added to the surface-treated inorganic filler with a surface treatment agent, followed by ultrasonic cleaning at 25°C for 5 minutes. After removing the supernatant and drying the solid content, the amount of carbon per unit surface area of the inorganic filler can be measured using a carbon analyzer. As a carbon analyzer, &quot;EMIA-320V&quot; manufactured by Horiba Sesakusho Co., Ltd., etc. 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, 50% by mass or less, or 40% by mass, from the viewpoint of obtaining an insulating layer on which fine wiring can be formed. less than % 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, and the like.

-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, and polyphenylene. and thermoplastic resins such as ether resins, polycarbonate resins, polyether ether ketone resins, and polyester resins. A thermoplastic resin 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 still 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 a gel permeation chromatography (GPC) method. Specifically, the weight average molecular weight of the thermoplastic resin in terms of polystyrene was measured using LC-9A/RID-6A manufactured by Shimadzu Corporation as a measuring device and Shodex K-800P/K manufactured by Showa Denko Co., Ltd. as a column. -804L/K-804L can be calculated using chloroform or the like as a mobile phase, measuring the column temperature at 40°C, and using a standard polystyrene calibration curve.

Examples of the phenoxy resin include bisphenol A skeleton, bisphenol F skeleton, bisphenol S skeleton, bisphenolacetphenone skeleton, novolak skeleton, biphenyl skeleton, fluorene skeleton, dicyclopentadiene skeleton, norbornene skeleton, and naphthalene. and phenoxy resins having at least one skeleton selected from the group consisting of a skeleton, anthracene skeleton, adamantane skeleton, terpene skeleton, and trimethylcyclohexane skeleton. Any functional group, such as a phenolic hydroxyl group and an epoxy group, may be sufficient as the terminal of a phenoxy resin. A phenoxy resin may be used individually by 1 type, and may be used in combination of 2 or more types. Specific examples of the phenoxy resin include "1256" and "4250" (both bisphenol A skeleton-containing phenoxy resins), "YX8100" (bisphenol S skeleton-containing phenoxy resin), and "YX6954" manufactured by Mitsubishi Chemical Corporation. (bisphenol acetphenone skeleton-containing phenoxy resin), in addition, “FX280” and “FX293” manufactured by Nippon Steel & Chemical Co., Ltd., “YL6954BH30” and “YX7553” manufactured by Mitsubishi Chemical Corporation ”, “YL7769BH30”, “YL6794”, “YL7213”, “YL7290” and “YL7482”.

As polyvinyl acetal resin, polyvinyl formal resin and polyvinyl butyral resin are mentioned, for example, and polyvinyl butyral resin is preferable. Specific examples of the polyvinyl acetal resin include "Denka Butyral 4000-2", "Denka Butyral 5000-A", "Denka Butyral 6000-C", and "Denka Butyral 6000-C" manufactured by Denki Kagaku Kogyo Co., Ltd. Butyral 6000-EP", Sekisui Chemical Industry Co., Ltd.'s Srec BH series, BX series, KS series, BL series, BM series, etc. are mentioned.

As a specific example of the polyimide resin, "Ricacoat SN20" and "Ricacoat PN20" manufactured by New Japan Rica Co., Ltd. can be mentioned. Specific examples of the polyimide resin include a linear polyimide obtained by reacting a bifunctional hydroxyl group-terminated polybutadiene, a diisocyanate compound and a tetrabasic acid anhydride (polyimide described in Japanese Unexamined Patent Publication No. 2006-37083), and polysiloxane. and modified polyimides such as skeleton-containing polyimide (polyimides described in Japanese Unexamined Patent Publication Nos. 2002-12667 and 2000-319386, etc.).

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

As a specific example of polyether sulfone resin, Sumitomo Chemical Co., Ltd. product "PES5003P" etc. are mentioned.

As a specific example of polysulfone resin, Solvay Advanced Polymers Co., Ltd. product polysulfone "P1700", "P3500", etc. are mentioned.

Among these, as a thermoplastic resin, a phenoxy resin and a polyvinyl acetal resin are preferable from the viewpoint of obtaining an insulating layer having a lower surface roughness and better adhesion to the conductor layer in combination with other components. Therefore, in one preferred embodiment, the thermoplastic resin component contains at least one selected from the group consisting of phenoxy resins and polyvinyl acetal resins.

The content of the thermoplastic resin in the resin composition is preferably 0 to 20% by mass, more preferably 0.5 to 10% by mass, still more preferably 1 to 8% by mass, from the viewpoint of suitably adjusting the melt viscosity of the resin sheet. am.

-Curing accelerator-

Examples of the curing accelerator include phosphorus curing accelerators, amine curing accelerators, imidazole curing accelerators, and guanidine curing accelerators. Phosphorus curing accelerators, amine curing accelerators, and imidazole curing accelerators are preferred. , An amine-based hardening accelerator and an imidazole-based hardening 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 the phosphorus curing accelerator include triphenylphosphine, phosphonium borate compounds, tetraphenylphosphonium tetraphenylborate, n-butylphosphonium tetraphenylborate, tetrabutylphosphonium decanoate, and (4-methylphenyl)triphenyl. Phosphonium thiocyanate, tetraphenylphosphonium thiocyanate, butyl triphenylphosphonium thiocyanate, etc. are mentioned, and triphenylphosphine and tetrabutylphosphonium decanoate are preferable.

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

Examples of the imidazole-based curing accelerator include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, and 2-ethyl-4-methyl. Imidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methyl Midazole, 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 trimerytate, 1-cyanoethyl-2-phenylimidazolium Trimeritate, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-undecyl Imidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s- Triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo[1,2-a ] Imidazole compounds such as benzimidazole, 1-dodecyl-2-methyl-3-benzimidazolium chloride, 2-methylimidazoline, and 2-phenylimidazolin, and adducts of imidazole compounds and epoxy resins A sieve is used, and 2-ethyl-4-methylimidazole and 1-benzyl-2-phenylimidazole are preferable.

As an imidazole type hardening accelerator, you may use a commercial item, for example, Mitsubishi Chemical Corporation product "P200-H50" etc. are mentioned.

Examples of the guanidine curing accelerator include dicyandiamide, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, 1-(o-tolyl)guanidine, dimethylguanidine, and diphenylguanidine. , trimethylguanidine, tetramethylguanidine, pentamethylguanidine, 1,5,7-triazabicyclo[4.4.0]deca-5-ene, 7-methyl-1,5,7-triazabicyclo[4.4.0] Deca-5-ene, 1-methylbiguanide, 1-ethylbiguanide, 1-n-butylbiguanide, 1-n-octadecylbiguanide, 1,1-dimethylbiguanide, 1, 1-diethylbiguanide, 1-cyclohexylbiguanide, 1-allylbiguanide, 1-phenylbiguanide, 1-(o-tolyl)biguanide and the like, dicyandiamide, 1,5,7-triazabicyclo[4.4.0]deca-5-ene is preferred.

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

-Flame retardant-

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

As a flame retardant, you may use a commercial item, For example, Sanko Co., Ltd. product "HCA-HQ" etc. are mentioned.

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

-Organic filler-

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

As a rubber particle, you may use a commercial item, and "AC3816N" by Aika Kogyo Co., Ltd. product etc. are mentioned, for example.

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

The resin composition may further contain a flame retardant and other additives other than organic fillers as needed, and examples of these other additives include organometallic compounds such as organocopper compounds, organozinc compounds and organocobalt compounds; and resin additives such as thickeners, antifoaming agents, leveling agents, adhesion imparting agents, and colorants.

(solvent)

The solvent contained in the resin varnish is not particularly limited as long as a resin varnish exhibiting a desired contact angle with respect to the support is obtained, and a known solvent may be used. As the solvent, for example, ketones such as acetone, methyl ethyl ketone (MEK) and cyclohexanone, ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate and carbitol acetate, etc. Acetate esters, cello carbitols such as sorb and butyl carbitol; aromatic hydrocarbons such as toluene, xylene and ethylbenzene; amide solvents such as dimethylformamide, dimethylacetamide (DMAc) and N-methylpyrrolidone; and the like. The organic solvent may be used individually by 1 type, may be used in combination of 2 or more types, or what contains 2 or more types of solvents like solvent naphtha may be used.

From the viewpoint of suppressing splashing and burning, 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 a polar solvent include ethanol (25.3), methyl ethyl ketone (18.6), cyclohexanone (16.1), DMAc (38.85) and the like (values in parentheses indicate relative permittivity).

It is preferable that the solvent contains a polar solvent and a non-polar solvent from the viewpoint of suppressing splashing and burning on a wide variety of supports. The polar solvent is as described above. In the present invention, the relative permittivity (20 to 25°C) of the non-polar 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 (toluene, xylene , a mixed solvent of aromatic hydrocarbons containing ethylbenzene as a main component). Among these, it is preferable that the solvent contains a polar solvent having a dielectric constant of 12 or more and a non-polar solvent having a dielectric constant of 9 or less. It is more preferable to contain a polar solvent with a dielectric constant of 14 or more and a non-polar solvent with a dielectric constant of 8 or less, and it is more preferable to contain a polar solvent with a dielectric constant of 16 or more and a non-polar solvent with a dielectric constant of 6 or less. From ethanol and methyl ethyl ketone It is more preferable to contain one or two or more selected polar solvents together with one or two or more non-polar solvents selected from toluene and solvent naphtha. The mass ratio of the polar solvent to the non-polar solvent [polar solvent/non-polar solvent] in the solvent varies depending on the dielectric constant of these solvents and the type of support, but is preferably 2/8 to 8/2, more preferably 3/7. to 7/3.

From the viewpoint of suppressing splashing and burning on the support, the solvent is a solvent having 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. It is suitable to contain a solvent of 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 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 control of the coating width. more than % The upper limit of the content of the non-volatile component in the resin varnish is preferably 40% by mass or less, more preferably 35% by mass or less.

The viscosity of the resin varnish is not particularly limited as long as it exhibits a desired contact angle with respect to the support. From the viewpoint of easy application 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 a support. From the viewpoint of being able to enjoy the effect of the present invention of bringing about good film thickness control when forming a thin resin layer, preferably 15 mPa s or less, more preferably 14 mPa s or less, 13 mPa s or less, 12 mPa·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., for example, using a rotational vibration viscometer (Viscomate VM-10A manufactured by Techjam Co., Ltd.).

Examples of the support used in step (A) include a film made of plastic material, metal foil, and release paper, and a film made of plastic material and metal foil are preferable.

In the case of using a film made of a plastic material as the support, examples of the plastic material include polyethylene terephthalate (hereinafter sometimes abbreviated as “PET”) and polyethylene naphthalate (hereinafter sometimes abbreviated as “PEN”). ), such as polyester, polycarbonate (hereinafter sometimes abbreviated as "PC"), acrylic such as polymethyl methacrylate (PMMA), cyclic polyolefin, triacetylcellulose (TAC), polyether sulfide (PES), Polyether ketone, polyimide, etc. are mentioned. Among these, polyethylene terephthalate and polyethylene naphthalate are preferable, and inexpensive polyethylene terephthalate is particularly preferable.

When using metal foil as a support body, examples of the metal foil include copper foil and aluminum foil, and copper foil is preferable. As the copper foil, foil made of a single metal of copper may be used, or foil made of an alloy of copper and other metals (eg, tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.) is used. also good

As described above, in the production of a printed wiring board, in recent years, the resin layer may be thermally cured with a support attached thereto in order to improve surface smoothness of the insulating layer and to reduce the risk of foreign matter adhesion during curing. In such a case, a support with a release layer or a support made of a material with low adhesion is often used, but in forming a thin resin layer on such a support, it may be difficult to control the film thickness. From these points, 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, good film thickness control can be realized.

Therefore, in one embodiment which can enjoy the effect of this invention more, a support body is equipped with a release layer, ie, a support body is a support body with a release layer. As a release agent used for the release layer of the support body with a release layer, one or more types of release agents selected from the group consisting of alkyd resins, polyolefin resins, urethane resins, acrylic resins and silicone resins are exemplified. A support with a release layer may use a commercially available product, for example, "SK-1", "AL-5", "AL -7” and the like.

The thickness of the support is not particularly limited, but is preferably in the range of 5 to 75 μm, and more preferably in the range of 10 to 60 μm. Moreover, 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), the 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 on the support using a method such as a die coating method, a comma coating method, a gravure coating method, or a bar coating method. Among 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 step (A), the contact angle of the resin varnish to the support in the droplet method is 0.1 to 20°. By setting it as such a structure, splashing and tearing 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 in the droplet method can be measured using an automatic contact angle meter (Drop Master DMs-401 manufactured by Kyowa Kaimen Chemical Co., Ltd.). Specifically, it can be measured according to the method described in (Measuring method of contact angle by the droplet method) described later.

<Process (B)>

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

In the present invention, it is possible to form a thin resin layer with a thickness of 5 μm or less with a desired coating width without problems of tearing or splashing. The thickness of the resin layer may be 4 μm or less and 3 μm or less. Although the lower limit 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 spraying. What is necessary is just to determine drying conditions according to the boiling point of the solvent contained in a resin varnish, etc. Drying conditions are not particularly limited, but it is dried 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 treatment may be performed only once or may be performed a plurality of times. In the case of performing the drying treatment a plurality of times, the respective drying conditions may be the same or different.

When the drying treatment is performed only once, for example, at 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 A resin layer may be formed by drying the resin varnish (preferably for 1 to 15 minutes).

When performing a drying process in multiple times, what is necessary is just to perform a drying process from the 2nd time onwards at a higher temperature than the drying process of the 1st time, for example. For example, the first drying treatment is performed at a temperature of 50 ° C or more and less than 150 ° C (preferably 70 ° C or more and 140 ° C or less, more preferably 80 ° C or more and 130 ° C or less, or 90 ° C or more and 120 ° C or less), The second and subsequent drying may be performed at a temperature of 150°C or more and 200°C or less (preferably 160°C or more and 200°C or less, 170°C or more and 200°C or less, or 180°C or more and 200°C or less). When the drying treatment is performed a plurality of times, the time of each drying treatment is, for example, 1 to 30 minutes (preferably 1 to 20 minutes, more preferably 1 to 15 minutes, or 1 to 10 minutes). good to do

In the resin sheet, a protective film conforming to the support may be further provided on the surface of the resin layer not bonded to the support (ie, the surface on the opposite side to the support). Therefore, in one embodiment, the method for manufacturing a resin sheet of the present invention includes a step (hereinafter also referred to as "step (C)") of providing a protective film so as to be bonded to the resin layer again after the step (B). do.

In step (C), the protective film is preferably laminated to the resin layer by roll or press bonding. The lamination process can be performed using a commercially available vacuum laminator. As a commercially available vacuum laminator, a vacuum pressure type laminator manufactured by Meiki Sesakusho Co., Ltd., a vacuum applicator manufactured by Nichigo Morton Co., Ltd., and the like are exemplified.

The thickness of the protective film is not particularly limited, but is, for example, 1 to 40 µm. By laminating the protective film, adhesion of dust and the like to the surface of the resin layer and scratches can be prevented. The resin sheet can be wound into a roll shape and stored. When a resin sheet has a protective film, it becomes usable by peeling a protective film.

The resin sheet manufactured by the method of this invention can be used as a resin sheet (resin sheet for insulating layers of a printed wiring board) for forming the insulating layer of a printed wiring board. Among these, it can be suitably used as a resin sheet (resin sheet for a build-up insulating layer of a printed wiring board) for forming an insulating layer in the manufacture of a printed wiring board by a build-up method, and a circuit is formed thereon by a plating process. It can be used more suitably as a resin sheet (resin sheet for a build-up insulating layer of a printed wiring board in which a circuit is formed by a plating processor) for forming an insulating layer to be formed.

[Laminate sheet and manufacturing method thereof]

In one embodiment, it is possible to form a laminated sheet by bonding various films including an insulating resin layer to the resin layer of the resin sheet obtained by the present invention.

As an insulating resin layer, when forming the insulating layer of a printed wiring board, a conventionally well-known insulating resin layer can be used. 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. The lower limit of the thickness of the insulating resin layer is not particularly limited, but is usually 1 μm or more, 5 μm or more, or 10 μm or more.

From the viewpoint of obtaining a thin insulating layer with excellent mechanical strength, a prepreg is preferable as the insulating resin layer, but a thermosetting resin composition layer not containing a sheet-like fiber base material (hereinafter simply referred to as a "thermosetting resin composition layer") is used. You may use it. The thermosetting resin composition layer is not particularly limited as long as it exhibits sufficient hardness and insulating properties 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), respectively.

It is preferable that the thermosetting resin composition layer further contains an inorganic filler from the viewpoint of reducing the thermal expansion coefficient of the obtained insulating layer and preventing cracks or circuit deformation due to the difference in thermal expansion between the insulating layer and the conductor layer. 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 preferably 50% by mass or more, more preferably 50% by mass or more, when the non-volatile component in the thermosetting resin composition layer is 100% by mass, from the viewpoint of reducing the thermal expansion coefficient of the insulating layer obtained. is 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, 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 incorporated into the thermosetting resin composition layer include additives such as thermoplastic resins, curing accelerators, flame retardants, and rubber particles described above (resin composition).

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

A prepreg is formed by impregnating a thermosetting resin composition into a sheet-like fiber substrate.

The thermosetting resin composition used for the prepreg is not particularly limited as long as the cured product thereof has sufficient hardness and insulating properties, but conventionally known thermosetting resin compositions used for forming the insulating layer of printed wiring boards may be used. For example, the resin composition used for formation of the said thermosetting resin composition layer may be used. 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 substrate used for prepreg is not particularly limited, and those commonly used as prepreg substrates such as glass cloth, aramid nonwoven fabric, and 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 base material 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. The lower limit of the thickness of the sheet-like fiber substrate is not particularly limited, but is usually 5 μm or more, 10 μm or more, and the like.

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. The lower limit of the thickness of the prepreg is not particularly limited, but is usually 10 μm or more, 12 μm or more, or the like. In addition, 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 so that the resin layer of the resin sheet and the insulating resin layer (preferably prepreg) are bonded. For example, a laminated sheet can be manufactured by laminating the resin sheet obtained by this invention to an insulating resin layer so that the resin layer of the said resin sheet may bond to an insulating resin layer.

The lamination process can be performed using a commercially available vacuum laminator. Commercially available vacuum laminators are as described above.

In production of the laminated sheet, the insulating resin layer may be used in the form of an adhesive sheet containing 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 manufacture a laminated sheet by applying an insulating resin composition to the resin layer of the resin sheet obtained by the present invention and drying the coated film to form an insulating resin layer.

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, applying the insulating resin varnish on a support using a die coater or a gravure coater, and drying the insulating resin varnish It can be made by doing.

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), respectively. As the organic solvent, the same solvent as the solvent contained in the above resin varnish can be used.

Drying of the insulating resin varnish may be performed by a known drying method such as heating or hot air spraying.

The laminated sheet can be used as a laminated sheet for forming an insulating layer of a printed wiring board (laminated sheet for an insulating layer of a printed wiring board). Among these, it can be suitably used as a laminated sheet (laminated sheet for buildup insulating layer of a printed wiring board) for forming an insulating layer in the manufacture of a printed wiring board by a build-up method, and a circuit is formed thereon by a plating process. It can be used more suitably as a laminated sheet (laminated sheet for build-up insulating layer of a printed wiring board in which a circuit is formed by a plating process) for forming an insulating layer to be used.

In addition, when the insulating resin layer is used in the form of the adhesive sheet at the time of manufacturing the laminated sheet, the obtained laminated sheet is the surface of the insulating resin layer that is not bonded to the resin sheet of the present invention (ie, the resin sheet of the present invention). On the surface opposite to ), it has a support derived from an adhesive sheet. When manufacturing a laminated board or a printed wiring board, it becomes usable by peeling off the support body derived from this adhesive sheet.

[Laminated plate and manufacturing method thereof]

The resin sheet obtained by the manufacturing method of this invention can be used in manufacture of laminated boards, such as a printed wiring board. In one embodiment, the laminated board can be manufactured by a method including the following step (I-1) using the resin sheet and the insulating resin layer obtained by the manufacturing method of the present invention (hereinafter referred to as "First Embodiment"). Also referred to as “form”).

(I-1) Step of arranging one or more insulating resin layers between two resin sheets arranged so that the resin layers face each other, heating and pressurizing at 200° C. or higher under reduced pressure to integrally mold

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 in the following procedure using, for example, a vacuum hot press machine.

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

Then, a vacuum hot press treatment is performed in which the laminated structure is heat-compressed 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 metal plate such as a heated SUS plate. Examples of commercially available vacuum hot press machines include "MNPC-V-750-5-200" manufactured by Meiki Seiki Co., Ltd. and "VH1-1603" manufactured by Kitagawa Seiki Co., Ltd. can

Conditions for the vacuum hot press treatment are not particularly limited, and well-known conditions used when manufacturing a laminated sheet may be used.

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 substrate such as a glass epoxy substrate, a metal substrate, a polyester substrate, a polyimide substrate, a BT resin substrate, a thermosetting polyphenylene ether substrate, or one side or both sides of the substrate. It refers to a circuit board on which a patterned conductor layer (circuit) is formed. In addition, when manufacturing a printed wiring board, an inner layer circuit board of an intermediate product on which an insulating layer and/or a conductor layer must be further formed is also included in the "inner layer board" as used 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 another embodiment, the laminated board can be manufactured by a method including the following steps (II-1) and (II-2) using the above-described laminated sheet (hereinafter also referred to as “second embodiment”). do).

(II-1) 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) Process of forming an insulating layer by thermally curing the laminated sheet

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 so that the insulating resin layer is in contact with the inner layer substrate.

Lamination of the laminated sheet and the inner-layer substrate in step (II-1) can be performed, for example, by heat-pressing the laminated sheet to the inner-layer substrate from the support body side. Examples of the member for heat-pressing the laminated sheet to the inner layer substrate (hereinafter also referred to as "heat-compression member") include a heated metal plate (such as a SUS head plate) or a metal roll (SUS roll). Further, it is preferable to press the heat-compressed member through an elastic material such as heat-resistant rubber so that the laminated sheet can sufficiently follow the irregularities on the surface of the inner layer substrate instead of directly pressing the laminated sheet.

Lamination of the laminate sheet and the inner layer substrate may be performed by a vacuum lamination method. In the vacuum lamination method, the heating temperature is preferably in the range of 60 to 160°C, more preferably in the range of 80 to 140°C, and the compression pressure is preferably in the range of 1 to 18 kgf/cm2 (0.098 to 1.77 MPa), It is preferably in the range of 3 to 15 kgf/cm 2 (0.29 to 1.47 MPa), and the pressing time is preferably in the range of 20 to 400 seconds, more preferably in the range of 30 to 300 seconds. Lamination is preferably carried out under reduced pressure conditions 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.

The lamination sheet and the inner layer substrate can be laminated using a commercially available vacuum laminator. A commercially available vacuum laminator is as described above.

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

In 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 first embodiment and the second embodiment, (III) a step of drilling a hole in the insulating layer, (IV) a step of roughening the insulating layer, and (V) forming a circuit on the surface of the insulating layer. You may additionally perform the process of doing. Thus, in one embodiment, the laminate includes a circuit formed on the surface of the insulating layer.

In addition, regardless of the first embodiment and the second embodiment, the support may be removed before forming a circuit on the surface of the insulating layer, but from the viewpoint of surface smoothness of the obtained insulating layer and reduction of foreign matter adhesion risk during curing. , It is preferable to remove after thermal curing of the resin layer. Specifically, in the first embodiment, the support is between step (I-1) and step (III), between step (III) and step (IV), or between step (IV) and step (V). good to remove In the second embodiment, the support may be removed between the step (II-2) and the step (III), between the step (III) and the step (IV), or between the step (IV) and the step (V).

Step (III) is a step of piercing 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, laser, plasma or the like, depending on the composition of the resin layer used to form the insulating layer and the insulating resin layer. What is necessary is just to determine the size and shape of a hole suitably according to the design of a printed wiring board.

Step (IV) is a step of roughening the insulating layer. The procedures and conditions of the roughening treatment are not particularly limited, and known procedures and conditions normally used when forming the 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 neutralization liquid in this order. Although it does not specifically limit as a swelling liquid, An alkali solution, surfactant solution, etc. are mentioned, Preferably it is an alkali solution, As said alkali solution, a sodium hydroxide solution and a potassium hydroxide solution are more preferable. Examples of commercially available swelling solutions include "Swelling Deep Securiganth P" and "Swelling Deep Securiganth SBU" manufactured by Atotech Japan Co., Ltd. The swelling treatment by the swelling solution is not particularly limited, but can be performed by, for example, immersing the insulating layer in a swelling solution at 30 to 90°C for 1 to 20 minutes. Although it does not specifically limit as an oxidizing agent, For example, the alkaline permanganate solution which melt|dissolved potassium permanganate or sodium permanganate in the 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 to 80°C for 10 to 30 minutes. Moreover, as for the concentration of permanganate in an alkaline permanganic acid solution, 5-10 mass % is preferable. Examples of commercially available oxidizing agents include alkaline permanganic acid solutions such as "Concentrate Compact CP" and "Dosing Solution Securigant P" manufactured by Atotech Japan Co., Ltd. Moreover, as a neutralization liquid, an acidic aqueous solution is preferable, and as a commercial item, "Reduction Solution Securigant P" by Atotech Japan Co., Ltd. is mentioned, for example. The treatment with the neutralization solution can be performed by immersing the treated surface subjected to the roughening treatment with the oxidizing agent in the neutralization 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 suitable embodiment, the conductor layer contains at least one metal selected from the group consisting of gold, platinum, palladium, silver, copper, aluminum, cobalt, chromium, zinc, nickel, titanium, tungsten, iron, tin and indium. do. The conductor layer may be a single metal layer or an alloy layer, and the alloy layer is, for example, an alloy of two or more types of metals selected from the above groups (eg, nickel-chromium alloy, copper-nickel alloy, and copper-titanium). alloy). Among these, from the viewpoint of versatility of formation of a conductor layer, cost, ease of patterning, etc., a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper, or a nickel-chromium alloy or a copper-nickel alloy , An alloy layer of a copper-titanium alloy is preferable, a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper, or an alloy layer of a nickel-chromium alloy is more preferable, and a single metal layer of copper this is more preferable

The conductor layer may have a single-layer structure or a multi-layer 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 a nickel/chromium alloy.

The thickness of the conductor layer varies depending on the design of the desired printed wiring board, but is usually 3 to 50 µm, preferably 5 to 30 µm.

A conductor layer can be formed by a plating process. For example, it is possible to form a conductor layer having a desired wiring pattern by plating the surface of the insulating layer by a conventionally known technique such as a semi-additive method or a positive-directive method.

The laminated sheet can be used for various purposes depending on its manufacturing method and structure (eg, whether or not an inner layer substrate is used in the first embodiment, whether or not a circuit is present in the first and second embodiments, etc.). For example, it may be used as an inner layer substrate such as an insulating core substrate used in the manufacture of a printed wiring board or an inner layer circuit 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 laminated board or using a printed wiring board manufactured using the laminated board.

Examples of semiconductor devices include various semiconductor devices provided for electric appliances (eg, computers, mobile phones, digital cameras, televisions, etc.) and vehicles (eg, motorcycles, automobiles, electric cars, ships, aircraft, etc.). there is.

[Example]

Hereinafter, the present invention will be specifically described by examples, but the present invention is not limited to these examples. In addition, in the description below, "part" and "%" mean "part by mass" and "% by mass", respectively, unless otherwise specified.

[Preparation of Resin Varnish]

(Preparation of standard resin varnish)

Naphthylene ether type epoxy resin ("EXA-7311-G4S" manufactured by DIC Co., Ltd., epoxy equivalent 186) 10 parts, motorcycle silenol type epoxy resin ("YX4000HK" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent weight approx. 185) 10 Part, biphenyl type epoxy resin ("NC3000H" manufactured by Nihon Kayaku Co., Ltd., epoxy equivalent 288) 20 parts, and phenoxy resin ("YX7553BH30" manufactured by Mitsubishi Chemical Corporation "YX7553BH30" manufactured by Mitsubishi Chemical Corporation, cyclohexanone having a solid content of 30% by mass) : 1:1 solution of methyl ethyl ketone (MEK)) 25 parts were heated and dissolved in a mixed solvent of solvent naphtha 15 parts and cyclohexanone 5 parts while stirring. After cooling to room temperature, 10 parts of a triazine skeleton-containing phenol novolak curing agent (hydroxyl equivalent 125, "LA-7054" manufactured by DIC Co., Ltd., MEK solution with a solid content of 60%), naphthol curing agent (Shinnit "SN485" manufactured by Tetsu Sumikin Chemical Co., Ltd., 215 hydroxyl equivalents, 60% solid content MEK solution) 19 parts, polyvinyl butyral resin (glass transition temperature 105 ° C., manufactured by Sekisui Chemical Industry Co., Ltd. "KS- 1”) 10 parts of a 1:1 mixed solution of ethanol and toluene with a solid content of 15%, amine curing accelerator (4-dimethylaminopyridine (DMAP), MEK solution with a solid content of 5% by mass) 1 part, imidazole curing Accelerator (“P200-H50” manufactured by Mitsubishi Chemical Corporation, propylene glycol monomethyl ether solution having a solid content of 50% by mass) 2 parts, surface with an aminosilane coupling agent (“KBM573” manufactured by Shin-Etsu Chemical Co., Ltd.) After mixing 50 parts of the treated spherical silica (“SOC2” manufactured by Adomatex Co., Ltd., average particle diameter 0.5 μm, carbon amount per unit surface area 0.38 mg/m 2 ) and uniformly dispersing with a high-speed rotary mixer, a cartridge filter ( It filtered with "SHP050" by ROKITECHNO) to prepare a standard resin varnish.

(Preparation of Resin Varnish 1)

Resin varnish 1 was prepared by mixing a standard resin varnish with a solvent obtained by mixing methyl ethyl ketone (MEK) and solvent naphtha at a ratio of 50:50 (mass ratio), and adjusting the content of non-volatile components to be 25%.

(Preparation of Resin Varnish 2)

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 non-volatile components to be 25%.

(Preparation of Resin Varnish 3)

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 non-volatile component content to 25%.

(Preparation of Resin Varnish 4)

Resin varnish 4 was prepared by mixing cyclohexanone with the standard resin varnish and adjusting the content of the non-volatile component to be 25%.

(Preparation of Resin Varnish 5)

Resin varnish 5 was prepared by mixing a standard resin varnish with a solvent obtained by mixing MEK and solvent naphtha at a ratio of 50:50 (mass ratio), and adjusting the content of non-volatile components to be 35%.

(Preparation of Resin Varnish 6)

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 non-volatile components to be 35%.

(Preparation of Resin Varnish 7)

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 non-volatile components to be 35%.

(Preparation of Resin Varnish 8)

Resin varnish 8 was prepared by mixing cyclohexanone with the standard resin varnish and adjusting the content of the non-volatile component to be 35%.

(Preparation of Resin Varnish 9)

Resin varnish 9 was prepared by mixing a standard resin varnish with a solvent obtained by mixing MEK and solvent naphtha at a ratio of 50:50 (mass ratio), and adjusting the content of non-volatile components to be 15%.

(Preparation of Resin Varnish 10)

Resin varnish 10 was prepared by mixing dimethylacetamide (DMAc) with a standard resin varnish and adjusting the content of the non-volatile component to be 25%.

(Preparation of Resin Varnish 11)

Resin varnish 11 was prepared by mixing DMAc with the standard resin varnish and adjusting the content of the non-volatile component to be 35%.

(Viscosity measurement of resin varnish)

The viscosities of the resin varnishes 1 to 11 were measured under a temperature condition of 25°C using a rotational vibration viscometer (Viscomate VM-10A manufactured by Techjam Co., Ltd.). The value after 2 minutes from the start of the measurement 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]

Resin varnishes 1 to 11 are applied to supports 1 to 3, respectively, and contact angles are measured by the method described later, and then the resin varnish applied to the support is dried by the following method to form a resin layer, frying, An evaluation test was conducted regarding the application width.

Supports 1 to 3 used are as follows.

Support 1: Support prepared by providing a release layer made of an alkyd release agent on a PET film ("Lumira T60" manufactured by Toray Co., Ltd.) (surface roughness is 22 nm, water contact angle measured by the droplet method is 90 °)

Support 2: Support prepared by providing a release layer made of an olefinic release agent on a PET film ("Lumira T60" manufactured by Toray Co., Ltd.) (surface roughness is 22 nm, water contact angle measured by the droplet method is 110 °)

Support 3: PET film ("Lumira T60" manufactured by Toray Co., Ltd.) was used as it was (surface roughness was 22 nm, water contact angle measured by the droplet method was 75 °)

(Example 1)

Resin varnish 1 is uniformly applied 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 ° C to 120 ° C for 3 minutes to form a resin layer on the support 1, and a resin sheet was produced.

(Example 2)

A resin layer was formed on the support 1 and a resin sheet was produced in the same manner as in Example 1, except that Resin Varnish 2 was used instead of Resin Varnish 1.

(Example 3)

A resin layer was formed on the support 1 and a resin sheet was produced in the same manner as in Example 1 except that Resin Varnish 3 was used instead of Resin Varnish 1.

(Example 4)

A resin layer was formed on the support 1 and a resin sheet was produced in the same manner as in Example 1 except that Resin Varnish 4 was used instead of Resin Varnish 1.

(Example 5)

A resin layer was formed on the support 1 and a resin sheet was produced in the same manner as in Example 1 except that Resin Varnish 5 was used instead of Resin Varnish 1.

(Example 6)

A resin layer was formed on the support 1 and a resin sheet was produced in the same manner as in Example 1 except for using the resin varnish 6 instead of the resin varnish 1.

(Example 7)

A resin layer was formed on the support 1 and a resin sheet was produced in the same manner as in Example 1 except that Resin Varnish 7 was used instead of Resin Varnish 1.

(Example 8)

A resin layer was formed on the support 1 and a resin sheet was produced in the same manner as in Example 1 except that Resin Varnish 8 was used instead of Resin Varnish 1.

(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 instead of the support 1 to prepare a resin sheet.

(Example 10)

A resin layer was formed on the support 2 and a resin sheet was produced in the same manner as in Example 9, except that Resin Varnish 2 was used instead of Resin Varnish 1.

(Example 11)

A resin layer was formed on the support body 2 and a resin sheet was produced in the same manner as in Example 9 except for using the resin varnish 3 instead of the resin varnish 1.

(Example 12)

A resin layer was formed on the support 2 and a resin sheet was produced in the same manner as in Example 9, except that Resin Varnish 5 was used instead of Resin Varnish 1.

(Example 13)

A resin layer was formed on the support body 2 and a resin sheet was produced in the same manner as in Example 9 except that resin varnish 6 was used instead of resin varnish 1.

(Example 14)

A resin layer was formed on the support 2 and a resin sheet was produced in the same manner as in Example 9 except that Resin Varnish 7 was used instead of Resin Varnish 1.

(Example 15)

A resin layer was formed on the support body 2 and a resin sheet was produced in the same manner as in Example 9 except that resin varnish 9 was used instead of resin varnish 1.

(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 instead of the support 1 to prepare a resin sheet.

(Example 17)

A resin layer was formed on the support 3 and a resin sheet was produced in the same manner as in Example 16, except that Resin Varnish 2 was used instead of Resin Varnish 1.

(Example 18)

A resin layer was formed on the support 3 and a resin sheet was produced in the same manner as in Example 16, except that Resin Varnish 3 was used instead of Resin Varnish 1.

(Example 19)

A resin layer was formed on the support 3 and a resin sheet was produced in the same manner as in Example 16, except that Resin Varnish 4 was used instead of Resin Varnish 1.

(Example 20)

A resin layer was formed on the support 3 and a resin sheet was produced in the same manner as in Example 16, except that Resin Varnish 5 was used instead of Resin Varnish 1.

(Example 21)

A resin layer was formed on the support 3 and a resin sheet was produced in the same manner as in Example 16, except that Resin Varnish 6 was used instead of Resin Varnish 1.

(Example 22)

A resin layer was formed on the support 3 and a resin sheet was produced in the same manner as in Example 16, except that Resin Varnish 7 was used instead of Resin Varnish 1.

(Example 23)

A resin layer was formed on the support body 3 and a resin sheet was produced in the same manner as in Example 16 except for using the resin varnish 8 instead of the resin varnish 1.

(Example 24)

A resin layer was formed on the support body 3 and a resin sheet was produced in the same manner as in Example 16, except that resin varnish 10 was used instead of resin varnish 1.

(Example 25)

A resin layer was formed on the support 3 and a resin sheet was produced in the same manner as in Example 16, except that Resin Varnish 11 was used instead of Resin Varnish 1.

(Comparative Example 1)

A resin layer was formed on the support 1 and a resin sheet was produced in the same manner as in Example 1, except that Resin Varnish 9 was used instead of Resin Varnish 1.

(Comparative Example 2)

A resin layer was formed on the support 1 and a resin sheet was produced in the same manner as in Example 1 except that Resin Varnish 10 was used instead of Resin Varnish 1.

(Comparative Example 3)

A resin layer was formed on the support 1 and a resin sheet was produced in the same manner as in Example 1 except for using the resin varnish 1 instead of the resin varnish 1.

(Comparative Example 4)

A resin layer was formed on the support body 2 and a resin sheet was produced in the same manner as in Example 9 except that resin varnish 4 was used instead of resin varnish 1.

(Comparative Example 5)

A resin layer was formed on the support 2 and a resin sheet was produced in the same manner as in Example 9 except that Resin Varnish 8 was used instead of Resin Varnish 1.

(Comparative Example 6)

A resin layer was formed on the support body 2 and a resin sheet was produced in the same manner as in Example 9, except that resin varnish 1 was used instead of resin varnish 1.

(Comparative Example 7)

A resin layer was formed on the support body 2 and a resin sheet was produced in the same manner as in Example 9, except that resin varnish 11 was used instead of resin varnish 1.

(Comparative Example 8)

A resin layer was formed on the support 3 and a resin sheet was produced in the same manner as in Example 16, except that Resin Varnish 9 was used instead of Resin Varnish 1.

(Method of measuring contact angle by droplet method)

The contact angle of each resin varnish with respect to the support by the droplet method was measured using an automatic contact angle meter (Drop Master DMs-401 manufactured by Kyowa Kaimen Chemical Co., Ltd.). Specifically, in the droplet method in which a syringe is filled with resin varnish, droplets of 0.8 μL are produced, and adhered to a support, the value after 2000 ms from attachment is used as the contact angle of each resin varnish with respect to the support in the droplet method. , the results are shown in Table 1.

(Evaluation of tempura)

The number of fried defects in 10 m 2 of the resin layer formed in Examples 1 to 25 and Comparative Examples 1 to 8 was counted. In 10 m2 of the resin layer, those with 10 or more tempura with a diameter of 0.1 mm or more were confirmed as "x", those with 2 to 9 tempura were designated as "△", those with 0 to 1 tempura were designated as "○", and the result are listed in Table 1.

(Ego's evaluation)

The thicknesses of the center portion and the thickest portion (maximum thickness portion) of the resin layers formed in Examples 1 to 25 and Comparative Examples 1 to 8 were measured using a micrometer. A thickness difference between the central portion and the maximum thickness portion was designated as "X" when the thickness difference was 10 µm or more, "Δ" when the difference was 2 to 10 µm, and "○" when the difference was 0 to 2 µm, and the results are shown in Table 1.

(Evaluation of application 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 steel ruler. The difference between the yarn coating width with respect to the target coating width of 1000 mm is 5 mm or more as "x", 2 to 5 mm as "Δ", and 0 to 2 mm as "○", and the results are shown in Table 1. .

In Table 1, the viscosity of the resin varnish, the contact angle of the resin varnish on the support in the droplet method, the evaluation results of splashing, the evaluation results of the coating, the evaluation results regarding the control of the coating width, together with the solvents used for preparing each resin varnish The type and amount of , the content of non-volatile components, etc. were described.

Claims (8)

(A) a step of applying a resin varnish containing a resin composition and a solvent onto a support;
(B) Step of drying the resin varnish to form a resin layer
including,
In 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 5 μm or less,
A method for producing a resin sheet wherein the support is a film or release paper made of a plastic material. (A) a step of applying a resin varnish containing a resin composition and a solvent onto a support;
(B) Step of drying the resin varnish to form a resin layer
including,
In 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 5 μm or less,
The manufacturing method of the resin sheet in which a support body is provided with a mold release layer. The manufacturing method of the resin sheet of Claim 1 or 2 whose content of the non-volatile component in a resin varnish is 40 mass % or less. The method for producing a resin sheet according to claim 1, wherein the support is provided with a release layer. The method for producing a resin sheet according to claim 1 or 2, wherein the solvent contains a polar solvent. The method for producing a resin sheet according to claim 1 or 2, wherein the solvent contains a polar solvent having a relative permittivity of 12 or more and a non-polar solvent having a relative permittivity of 9 or less. The method for producing a resin sheet according to claim 1 or 2, wherein in step (A), a resin varnish is applied by a gravure coating method. The method for producing a resin sheet according to claim 1 or 2, wherein the resin sheet is for an insulating layer of a printed wiring board.