JP2006233231A - Resin sheet manufacturing method, resin sheet for insulated substrate, insulated substrate, and multi-layered substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a resin sheet capable of enhancing the adhesiveness of a conductive film when the conductive film is deposited by plating on a surface of the resin sheet with a large number of holes formed therein, to provide a resin sheet for an insulated substrate, the insulated substrate, and a multi-layered substrate. <P>SOLUTION: In the resin sheet manufacturing method, after the surface of a resin sheet consisting of a thermosetting resin composition is treated with inorganic acid, the surface of the resin sheet treated with inorganic acid is roughened by using roughened aqueous solution containing permanganate salt to obtain the resin sheet with a large number of holes formed in the surface of the resin sheet. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for producing a resin sheet, a resin sheet for an insulating substrate, an insulating substrate, and a multilayer substrate, and more specifically, a resin sheet that can exhibit high adhesion when a conductive film is formed on the surface by plating. The present invention relates to a manufacturing method, a resin sheet for an insulating substrate, an insulating substrate, and a multilayer substrate.

  A multilayer printed board used in an electronic device has a plurality of layers of insulating substrates and a circuit pattern disposed between the plurality of layers of insulating substrates. Conventionally, as this type of insulating substrate, that is, an interlayer insulating substrate, for example, a resin sheet made of a thermosetting resin composition or a photocurable resin is used.

  Metal wiring may be formed on a resin sheet made of a thermosetting resin composition or the like by electroless plating, sputtering, or vacuum deposition. When the metal wiring is formed, it is required that the adhesiveness between the resin sheet and the metal wiring is high and the connection reliability is excellent. In order to exhibit high adhesiveness and excellent connection reliability, various attempts have been made to form a large number of holes on the surface of the resin sheet.

  In order to form a large number of holes on the surface of the resin sheet, conventionally, a pretreatment for swelling the surface of the resin sheet using a swelling agent or the like and then roughening the surface of the resin sheet using an oxidizing agent Has been done.

  The following Patent Document 1 discloses a method for manufacturing a multilayer wiring board including a resin swelling process using an organic solvent and an alkali, and a resin roughening process using an oxidizing agent.

  In Patent Document 1, in order to swell the surface of an insulating layer made of a curable resin, for example, a treatment using an organic solvent such as dimethylformamide (DMF) and an alkali such as sodium hydroxide or potassium hydroxide is performed. It is. Next, the insulating layer is roughened using an oxidizing agent such as potassium permanganate to form many holes. By performing a plating process on the insulating layer in which many holes are formed, the plating solution is likely to penetrate into the insulating layer, and the adhesiveness is improved.

  On the other hand, in the following Patent Document 2, the surface of a resin sheet containing a resin composed of a thermosetting resin, a photocurable resin, a resin cured product, a thermoplastic resin, and the like and a layered silicate is obtained using a swelling agent. A method for roughening a resin sheet is disclosed in which after swelling, a roughening treatment liquid containing methanesulfonic acid is used for roughening.

  In Patent Document 2, an aqueous solution containing an amine, or an aqueous solution containing methanephosphonic acid in an aqueous solution containing an amine is used as a swelling agent to swell the surface of the resin sheet. Next, the surface of the resin sheet is roughened using methanephosphonic acid.

Methanephosphonic acid used for the swelling treatment and roughening treatment of the resin sheet can dissolve the thermosetting resin, thermoplastic resin and layered silicate constituting the resin sheet. Therefore, it is said that the surface of the resin sheet can be dissolved to form fine irregularities on the surface. Therefore, if metal wiring is formed on the surface of the roughened resin sheet by electroless plating, electroplating, sputtering, or vacuum deposition, the adhesive strength between the resin sheet and the metal wiring is drastically improved.
JP 2001-7528 A JP 2004-51973 A

  However, in the swelling treatment / roughening treatment described in Patent Documents 1 and 2, a large number of holes may not be sufficiently formed on the resin surface. Therefore, when the metal wiring is formed on the surface of the resin sheet by electroless plating, electroplating, sputtering, or vacuum deposition, the adhesion of the metal wiring is not sufficient, and high connection reliability may not be obtained. In particular, in the case of a resin sheet composed of a resin having an unsaturated double bond such as a flexible epoxy resin having a butadiene skeleton or a resin sheet containing a layered silicate, the above-mentioned Patent Documents 1 and 2 In the described swelling treatment / roughening treatment, it may be difficult to form a large number of holes on the resin surface.

  An object of the present invention is to provide a resin sheet in which a large number of holes are formed on the surface of the resin sheet, and the adhesion of the conductive film can be improved when the conductive film is formed on the surface by plating in view of the current state of the prior art described above. It is in providing the manufacturing method of this, the resin sheet for insulating substrates, an insulating substrate, and a multilayer substrate.

  The method for producing a resin sheet according to the present invention is a resin treated with an inorganic acid using a roughened aqueous solution containing a permanganate after treating the surface of the resin sheet made of a thermosetting resin composition with an inorganic acid. By roughening the surface of the sheet, a resin sheet having a large number of holes formed on the surface of the resin sheet is obtained.

  In a specific aspect of the method for producing a resin sheet according to the present invention, sulfuric acid is used as an inorganic acid.

  In a limited aspect of the method for producing a resin sheet according to the present invention, the concentration of sulfuric acid is 5 to 50%.

  On the other specific situation with the manufacturing method of the resin sheet which concerns on this invention, a thermosetting resin composition is an epoxy-type thermosetting resin composition containing an epoxy-type resin and an epoxy-type resin hardening | curing agent.

  In still another specific aspect of the method for producing a resin sheet according to the present invention, the epoxy resin is a flexible epoxy resin having a butadiene skeleton.

  On the limited situation with the manufacturing method of the resin sheet which concerns on this invention, an epoxy resin hardening | curing agent consists of a compound which has a phenol group, It is characterized by the above-mentioned.

  In still another specific aspect of the method for producing a resin sheet according to the present invention, the thermosetting resin composition includes a layered silicate.

  The resin sheet for an insulating substrate according to the present invention comprises a resin sheet obtained by the method for producing a resin sheet of the present invention.

  An insulating substrate according to the present invention includes a resin sheet obtained by the method for producing a resin sheet of the present invention, and a conductive film formed by plating on at least one surface of the resin sheet.

  The multilayer board | substrate which concerns on this invention contains the resin sheet obtained by the manufacturing method of the resin sheet of this invention as an interlayer insulation layer.

  After the surface of the resin sheet made of the thermosetting resin composition is treated with an inorganic acid, the surface of the resin sheet treated with the inorganic acid is roughened using a roughening aqueous solution containing a permanganate. A large number of holes are uniformly formed on the surface. Furthermore, as shown in the experimental examples described later, even when a resin having a carbon-carbon double bond such as a flexible epoxy resin having a butadiene skeleton is used, a large number of holes are formed on the surface of the resin sheet. can do.

  When sulfuric acid is used as the inorganic acid, a large number of pores are more uniformly formed on the surface of the resin sheet. When the sulfuric acid concentration is in the range of 5 to 50%, more pores are uniformly formed on the surface of the resin sheet. Therefore, when the conductive film is formed on the surface of the resin sheet by plating, the adhesion between the resin sheet and the conductive film is enhanced.

  When the thermosetting resin composition is an epoxy thermosetting resin composition containing an epoxy resin and an epoxy resin curing agent, the resin sheet obtained by the production method according to the present invention has excellent mechanics. Characteristics. When the epoxy resin is a flexible epoxy resin having a butadiene skeleton, the cured product has high elongation over a wide temperature range from a low temperature range to a high temperature range, and exhibits even better mechanical properties. obtain.

  When the epoxy resin curing agent is made of a compound having a phenol group, the heat resistance, low water absorption and dimensional stability of the resin sheet can be improved.

  When the thermosetting resin composition contains a layered silicate, the resin sheet obtained by the production method according to the present invention has excellent mechanical properties, transparency, moisture resistance, etc., and restrains molecular chains. Dimension based on improvement in heat resistance, reduction in thermal linear expansion coefficient, nucleation effect of layered silicate in crystal formation and improvement in moisture resistance, etc. The stability is improved.

  The resin sheet obtained by the production method according to the present invention is obtained by treating the surface of the resin sheet with an inorganic acid and then roughening the surface of the resin sheet treated with the inorganic acid using a roughening aqueous solution containing permanganate. Therefore, a large number of holes are formed on the surface of the resin sheet. Therefore, when a conductive film is formed on the surface of the resin sheet obtained by the present invention, the adhesion between the resin sheet and the conductive film is effectively enhanced. Therefore, the resin sheet according to the present invention can be preferably used as a resin sheet for an insulating substrate, and an insulating substrate having a conductive film formed by plating on at least one surface of the resin sheet has excellent connection reliability.

  The multilayer substrate using the resin sheet with metal foil in which the conductive film is formed on the surface of the resin sheet according to the present invention is excellent in mechanical properties, dimensional stability, heat resistance, and flame retardancy. Even when the multi-layer substrate is used in a harsh environment, the conductive film is detached from the resin and hardly causes a short circuit or disconnection, and has high reliability.

  In the present invention, after the surface of a resin sheet comprising a thermosetting resin composition is treated with an inorganic acid, the surface of the resin sheet treated with an inorganic acid is roughened using a roughening aqueous solution containing a permanganate. By this, it is related with the manufacturing method of the resin sheet which obtains the resin sheet in which many holes are formed in the surface of the resin sheet.

  The thermosetting resin composition includes a thermosetting resin and a curing agent for the thermosetting resin.

(Thermosetting resin)
The thermosetting resin is a liquid, semi-solid or solid at room temperature, and is made of a relatively low molecular weight substance that exhibits fluidity at room temperature or under heating. This substance is a resin that can be insoluble and infusible by forming a three-dimensional network structure while increasing the molecular weight by causing a chemical reaction such as a curing reaction or a crosslinking reaction by the action of a curing agent, catalyst, or heat. To do.

  Examples of the thermosetting resin include epoxy resins, thermosetting modified polyphenylene ether resins, thermosetting polyimide resins, silicon resins, benzoxazine resins, melamine resins, urea resins, and allyl resins. Phenolic resins, unsaturated polyester resins, bismaleimide triazine resins, alkyd resins, furan resins, polyurethane resins, aniline resins, and the like. Among these, epoxy resins, thermosetting modified polyphenylene ether resins, thermosetting modified polyphenylene ether resins, thermosetting polyimide resins, silicon resins, benzoxazine resins, melamine resins, and the like are suitable. These thermosetting resins may be used alone or in combination of two or more.

  In the present invention, an epoxy resin is preferably used as the thermosetting resin. When an epoxy resin is used, the cured product of the thermosetting resin composition has excellent mechanical properties. More specifically, it has a high elongation.

  The epoxy resin refers to an organic compound having at least one epoxy group (oxirane ring). The number of epoxy groups in the epoxy resin is preferably 1 or more per molecule, and more preferably 2 or more per molecule. Here, the number of epoxy groups per molecule is obtained by dividing the total number of epoxy groups in the epoxy resin by the total number of molecules in the epoxy resin.

  A conventionally well-known epoxy resin can be used as said epoxy resin, For example, the epoxy resin (1)-epoxy resin (11) shown below etc. are mentioned. These epoxy resins may be used alone or in combination of two or more. Moreover, derivatives or hydrogenated products of these epoxy resins may be used as the epoxy resins.

  Examples of the epoxy resin (1) which is an aromatic epoxy resin include bisphenol type epoxy resins and novolac type epoxy resins. Examples of the bisphenol type epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, and bisphenol S type epoxy resin. Examples of the novolac type epoxy resin include phenol novolac type epoxy resins and cresol novolac type epoxy resins. In addition to these, epoxy resins made of aromatic compounds such as trisphenol methane triglycidyl ether, biphenyl type epoxy resin, dicyclopentadiene type epoxy resin, and naphthalene type epoxy resin are also included.

Examples of the epoxy resin (2) that is an alicyclic epoxy resin include 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 3,4-epoxy-2-methylcyclohexylmethyl-3, for example. , 4-epoxy-2-methylcyclohexanecarboxylate, bis (3,4-epoxycyclohexyl) adipate, bis (3,4-epoxycyclohexylmethyl) adipate, bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate 2- (3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy) cyclohexanone-meta-dioxane, bis (2,3-epoxycyclopentyl) ether, and the like. As what is marketed among such an epoxy resin (2), the brand name "EHPE" by Daicel Chemical Industries, Ltd., for example.
-3150 "(softening temperature 71 ° C).

  Examples of the epoxy resin (3) which is an aliphatic epoxy resin include diglycidyl ether of neopentyl glycol, diglycidyl ether of 1,4-butanediol, diglycidyl ether of 1,6-hexanediol, and glycerin. Triglycidyl ether, trimethylolpropane triglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, polyoxyalkylene glycol containing an alkylene group having 2 to 9 carbon atoms (preferably 2 to 4 carbon atoms) And polyglycidyl ether of a long-chain polyol containing polytetramethylene ether glycol and the like.

  Examples of the epoxy resin (4) that is a glycidyl ester type epoxy resin include phthalic acid diglycidyl ester, tetrahydrophthalic acid diglycidyl ester, hexahydrophthalic acid diglycidyl ester, diglycidyl-p-oxybenzoic acid, and salicylic acid. Glycidyl ether-glycidyl ester, dimer acid glycidyl ester and the like.

  Examples of the epoxy resin (5) which is a glycidylamine type epoxy resin include, for example, triglycidyl isocyanurate, N, N′-diglycidyl derivatives of cyclic alkylene urea, and N, N, O-triglycidyl of p-aminophenol. Derivatives, N, N, O-triglycidyl derivatives of m-aminophenol, and the like.

  Examples of the epoxy resin (6) that is a glycidyl acrylic epoxy resin include a copolymer of glycidyl (meth) acrylate and a radical polymerizable monomer such as ethylene, vinyl acetate, (meth) acrylic acid ester, and the like. Is mentioned.

  Examples of the epoxy resin (7) which is a polyester type epoxy resin include a polyester resin having one or more, preferably two or more epoxy groups per molecule.

  Examples of the epoxy resin (8) include a compound mainly composed of a conjugated diene compound such as epoxidized polybutadiene or a compound obtained by epoxidizing an unsaturated carbon double bond in a polymer of partially hydrogenated product. Can be mentioned.

  The epoxy resin (9) has a polymer block mainly composed of a vinyl aromatic compound and a polymer block mainly composed of a conjugated diene compound or a partially hydrogenated polymer block in the same molecule. Examples of the block copolymer include a compound obtained by epoxidizing a double bond portion of unsaturated carbon contained in a conjugated diene compound. Examples of such a compound include epoxidized SBS.

  Examples of the epoxy resin (10) include urethane-modified epoxy resins and polycaprolactone-modified epoxy resins in which urethane bonds and polycaprolactone bonds are introduced into the structures of the epoxy resins (1) to (9). It is done.

  Examples of the epoxy resin (11) include acrylonitrile-butadiene copolymer rubber (NBR), terminal carboxyl group-modified butadiene-acrylonitrile copolymer rubber (CTBN), polybutadiene, epoxy resins (1) to (10), and the like. Examples thereof include rubber-modified epoxy resins containing rubber components such as acrylic rubber. In addition to the epoxy resin, a resin having at least one oxirane ring or an oligomer may be added.

  When the low elastic component is designed with a resin structure, a flexible epoxy resin is preferably used as the epoxy resin. As the flexible epoxy resin, one that can exhibit flexibility even after being cured with a thermosetting resin curing agent can be suitably used.

  Examples of the flexible epoxy resin include diglycidyl ether of polyethylene glycol, diglycidyl ether of polypropylene glycol, polyoxyalkylene glycol and polytetramethylene ether glycol containing an alkylene group having 2 to 9 carbon atoms (preferably 2 to 4 carbon atoms), etc. Copolymers of polyglycidyl ethers and glycidyl (meth) acrylates of long-chain polyols containing ethylene and radical polymerizable monomers such as ethylene, vinyl acetate or (meth) acrylic acid esters, mainly conjugated diene compounds (co) Epoxidized unsaturated carbon double bond in polymer or partially hydrogenated (co) polymer, polyester resin having 1 or more, preferably 2 or more epoxy groups per molecule, urethane bond And introduced polycaprolactone bond Urethane-modified epoxy resin, polycaprolactone-modified epoxy resin, dimer acid-modified epoxy resin in which epoxy group is introduced into the molecule, NBR, CTBN, polybutadiene, acrylic rubber, etc. Examples thereof include a rubber-modified epoxy resin introduced.

  Examples of the flexible epoxy resin preferably used include compounds having an epoxy group and a butadiene skeleton in the molecule. When a flexible epoxy resin having a butadiene skeleton is used, the flexibility of the thermosetting resin composition and its cured product can be further enhanced, and the cured product is high over a wide temperature range from a low temperature range to a high temperature range. It has elongation and can exhibit even better mechanical properties.

  More preferably, the flexible epoxy resin is a dimer acid-modified epoxy resin in which an epoxy group is introduced in the molecule of dimer acid or a derivative thereof, or in the molecule of a rubber component such as NBR, CTBN, polybutadiene, or acrylic rubber. A rubber-modified epoxy resin into which an epoxy group is introduced is used.

  In the present invention, more preferably, a flexible epoxy resin represented by the following chemical formula (A) is used.

In the formula (A), R is —CH ₂ —CH═CH—CH ₂ — or —CH ₂ —CH (CH═CH ₂ ) —,
A _{is, -φ-C (CH 3)} 2 -φ-O-CH 2 -CH (OH) -CH 2 -O- (C = 0) -
(Φ is a benzene ring),
B represents — (C═O) —O—CH ₂ —CH (OH) —CH ₂ —O—φ—C (CH ₃ ) ₂ —φ—.
(Φ is a benzene ring), m is 0 or 1, and n is a positive positive number.

  When the polybutadiene component in the formula (A) is small, the electrical characteristics are good. Specifically, the dielectric constant and dielectric loss tangent can be lowered. The preferred number n of polybutadiene units is 100 or less, more preferably 40 or less.

  As thermosetting modified polyphenylene ether resin which is one of thermosetting resins, for example, some functional groups of monomers constituting polyphenylene ether resin have thermosetting properties such as amino group, glycidyl group and isocyanate group. Examples thereof include resins substituted with one or more of the functional groups possessed. As a result of the functional group substitution, this thermosetting modified polyphenylene ether resin exhibits thermosetting properties, and when the functional group of this resin is thermoset, it increases irreversibly while increasing the molecular weight. The resin exhibits thermosetting properties by forming a three-dimensional network structure.

  The thermosetting modified polyphenylene ether resin has properties different from those of the polyphenylene ether resin used as the thermoplastic resin. These thermosetting modified polyphenylene ether resins may be used alone or in combination of two or more.

  The thermosetting polyimide resin that is one of the thermosetting resins is not particularly limited as long as the resin has an imide bond in the molecular main chain, and specifically, for example, aromatic diamine and aromatic tetracarboxylic acid. Condensation polymer with acid, bismaleimide resin which is addition polymer of aromatic diamine and bismaleimide, polyamino bismaleimide resin which is addition polymer of aminobenzoic acid hydrazide and bismaleimide, dicyanate compound and bismaleimide resin And bismaleimide triazine resin. Of these, bismaleimide triazine resin is preferably used. These thermosetting polyimide resins may be used alone or in combination of two or more.

  The urea-based resin that is one of thermosetting resins is not particularly limited as long as it is a thermosetting resin obtained by addition condensation reaction of urea and formaldehyde.

  In addition, as a hardening | curing agent used for the curing reaction of a urea-type resin, an obvious hardening agent, a latent hardening agent, etc. are mentioned, for example. Examples of the apparent curing agent include acidic salts such as inorganic acids, organic acids, and acidic sodium sulfate. Examples of the latent curing agent include salts such as carboxylic acid esters, acid anhydrides, ammonium chloride, and ammonium phosphate. Of these, latent curing agents are preferably used because of their long shelf life.

  The allyl resin that is one of thermosetting resins is not particularly limited as long as it is obtained by polymerization and curing reaction of diallyl phthalate monomer. Examples of the diallyl phthalate monomer include an ortho isomer, an iso isomer, and a tele isomer. In addition, although it does not specifically limit as a catalyst of hardening reaction, For example, combined use of t-butyl perbenzoate and di-t-butyl peroxide is suitable.

  The silicon-based resin that is one of thermosetting resins is not particularly limited as long as it includes at least one of a silicon-silicon bond, a silicon-carbon bond, a siloxane bond, and a silicon-nitrogen bond in the molecular chain. Examples of such a silicon-based resin include polysiloxane, polycarbosilane, polysilazane, and the like.

  The benzoxazine-based resin that is one of thermosetting resins is not particularly limited as long as it is a monomer capable of ring-opening polymerization of the oxazine ring of the benzoxazine monomer and can be obtained by ring-opening polymerization. Examples of such a benzoxazine monomer include those in which a functional group such as a phenyl group, a methyl group, or a cyclohexyl group is bonded to nitrogen of the oxazine ring, or a phenyl group or a methyl group between two oxazine ring nitrogens. And those having a substituent such as a cyclohexyl group bonded thereto.

(Curing agent for thermosetting resin)
The curing agent cures the thermosetting resin.

  The curing agent is not particularly limited, and conventionally known curing agents for thermosetting resins can be used. For example, amine compounds, compounds synthesized from amine compounds, tertiary amine compounds, imidazole compounds, hydrazide compounds. , Melamine compounds, acid anhydrides, phenol compounds, thermal latent cationic polymerization catalysts, photolatent cationic polymerization initiators, dicyandiamide and derivatives thereof. These hardening | curing agents may be used independently and 2 or more types may be used together. In addition to the curing agent, derivatives of these curing agents may be used as a resin curing catalyst such as acetylacetone iron.

  Examples of the amine compound include a chain aliphatic amine compound, a cyclic aliphatic amine, and an aromatic amine.

  Examples of the chain aliphatic amine compound include ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, polyoxypropylenediamine, polyoxypropylenetriamine, and the like.

  Examples of the cycloaliphatic amine compound include mensendiamine, isophoronediamine, bis (4-amino-3-methylcyclohexyl) methane, diaminodicyclohexylmethane, bis (aminomethyl) cyclohexane, N-aminoethylpiperazine, 3, Examples include 9-bis (3-aminopropyl) -2,4,8,10-tetraoxaspiro (5,5) undecane.

  As aromatic amine compounds, m-xylenediamine, α- (m / p-aminophenyl) ethylamine, m-phenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, α, α-bis (4-aminophenyl) -p- Examples include diisopropylbenzene.

  As a compound synthesize | combined from the said amine compound, a polyaminoamide compound, a polyaminoimide compound, a ketimine compound etc. are mentioned, for example.

  Examples of the polyaminoamide compound include compounds synthesized from the above amine compounds and carboxylic acids. Examples of the carboxylic acid include succinic acid, adipic acid, azelaic acid, sebacic acid, dodecadioic acid, isophthalic acid, terephthalic acid, dihydroisophthalic acid, tetrahydroisophthalic acid, hexahydroisophthalic acid and the like.

  Examples of the polyaminoimide compound include compounds synthesized from the above amine compounds and maleimide compounds. Examples of the maleimide compound include diaminodiphenylmethane bismaleimide.

  As said ketimine compound, the compound etc. which are synthesize | combined from said amine compound and a ketone compound are mentioned, for example.

  In addition, the compound synthesized from the amine compound is synthesized from, for example, the above amine compound and a compound such as an epoxy compound, a urea compound, a thiourea compound, an aldehyde compound, a phenol compound, or an acrylic compound. Compounds.

Examples of the tertiary amine compound include N, N-dimethylpiperazine, pyridine, picoline, benzyldimethylamine, 2- (dimethylaminomethyl) phenol, 2,4,
Examples include 6-tris (dimethylaminomethyl) phenol and 1,8-diazabiscyclo (5,4,0) undecene-1.

  Examples of the imidazole compound include 2-ethyl-4-methylimidazole, 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, and 2-phenylimidazole.

  Examples of the hydrazide compound include 1,3-bis (hydrazinocarboethyl) -5-isopropylhydantoin, 7,11-octadecadien-1,18-dicarbohydrazide, eicosane diacid dihydrazide, adipic acid dihydrazide, and the like. Is mentioned.

  Examples of the melamine compound include 2,4-diamino-6-vinyl-1,3,5-triazine.

  Examples of the acid anhydride include phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic anhydride, ethylene glycol bisanhydro trimellitate, glycerol tris anhydro trimellitate, Methyltetrahydrophthalic anhydride, tetrahydrophthalic anhydride, nadic anhydride, methyl nadic anhydride, trialkyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, 5- (2,5-dioxo Tetrahydrofuryl) -3-methyl-3-cyclohexene-1,2-dicarboxylic acid anhydride, trialkyltetrahydrophthalic anhydride-maleic anhydride adduct, dodecenyl succinic anhydride, polyazelinic anhydride, polydodecanedioic anhydride No chlorendic acid Thing, and the like.

  The heat-latent cationic polymerization catalyst is not particularly limited. For example, benzylsulfonium salt, benzylammonium salt, benzylpyridinium salt, zen, with antimony hexafluoride, phosphorus hexafluoride, boron tetrafluoride and the like as a counter anion. Examples include ionic thermal latent cationic polymerization catalysts such as disulfonium salts; nonionic thermal latent cationic polymerization catalysts such as N-benzylphthalimide and aromatic sulfonic acid esters.

  The photolatent cationic polymerization catalyst is not particularly limited, and examples thereof include aromatic diazonium salts, aromatic halonium salts, and aromatic sulfoniums using antimony hexafluoride, phosphorus hexafluoride, boron tetrafluoride and the like as counter anions. Onium salts such as salts, and ionic photolatent cationic polymerization initiators such as organometallic complexes such as iron-allene complexes, titanocene complexes, and arylsilanol-aluminum complexes; nitrobenzyl esters, sulfonic acid derivatives, phosphate esters, Nonionic photolatent cationic polymerization initiators such as phenolsulfonic acid ester, diazonaphthoquinone, N-hydroxyimide sulfonate and the like can be mentioned.

  When the curing agent has a phenol group, heat resistance, low water absorption and dimensional stability can be improved.

  Examples of the phenol compound having a phenol group include phenol novolak, o-cresol novolak, p-cresol novolak, t-butylphenol novolak, and dicyclopentadiene cresol. These derivatives can also be used, and the phenol compound may be used alone or in combination of two or more.

  When the curing agent is a hydrophobic phenol compound represented by the following chemical formula (B) or (C), in addition to dimensional stability when given heat resistance, low water absorption, and heat history, dielectric A resin sheet having a low rate and dielectric loss tangent can be obtained, and electrical characteristics can be improved.

  Any of the above-described thermosetting resin curing agents can be used as an epoxy resin curing agent.

  A suitable equivalent ratio of the thermosetting resin (epoxy resin) and the curing agent is in the range of 1: 0.5 to 1: 1.5. If the curing agent is less than an equivalent ratio of 0.5, the thermosetting resin may not be sufficiently cured, and the mechanical properties of the cured product may be inferior. When there are more hardening ratios than 1.5, it may become excess in hardening a thermosetting resin, and the mechanical characteristic of hardened | cured material may become low with an excess hardening agent.

(Layered silicate)
In this specification, the layered silicate means a layered silicate mineral having an exchangeable metal cation between layers, and may be a natural product or a synthetic product.

  The exchangeable metal cation existing between the layers of the layered silicate means metal ions such as sodium and calcium existing on the surface of the lamellar crystal of the layered silicate. Since these metal ions have a cation exchange property with a cationic substance, various substances having a cationic property can be inserted (intercalated) between crystal layers of the layered silicate.

  Although it does not specifically limit as a cation exchange capacity | capacitance of a layered silicate, It is preferable that it is 50-200 milliequivalent / 100g.

When the cation exchange capacity is less than 50 milliequivalents / 100 g, the amount of the cationic substance intercalated between the crystal layers of the layered silicate by the cation exchange decreases, so that the crystal layers are sufficiently depolarized ( May not be hydrophobized). When the cation exchange capacity exceeds 200 milliequivalents / 100 g, the bonding force between the crystal layers of the layered silicate becomes too strong,
It becomes difficult to exfoliate the lamellar crystals of the layered silicate.

  The layered silicate preferably has a large shape anisotropy effect defined by the following formula (1). By using a layered silicate having a large shape anisotropy effect, the thermosetting resin cured product can have excellent mechanical properties.

Shape anisotropy effect = surface area of laminated surface of flaky crystals / cross-sectional area of laminated side surfaces of flaky crystals (1)
Examples of the layered silicate having a large shape anisotropy effect include smectite clay minerals, swellable mica, vermiculite, and halloysite. Examples of smectite clay minerals include montmorillonite, hectorite, saponite, beidellite, stevensite, and nontronite.

  Among these, at least one selected from the group consisting of montmorillonite, hectorite, and swellable mica is preferably used as the layered silicate. These layered silicates may be used alone or in combination of two or more.

  The layered silicate is preferably uniformly dispersed in the thermosetting resin, and more preferably dispersed in a fine state in the thermosetting resin. When the layered silicate is uniformly dispersed in the thermosetting resin or dispersed in a fine state in the thermosetting resin, the interface area between the thermosetting resin and the layered silicate may be increased. it can.

  Further, since the layered silicate is dispersed as flaky crystals having a predetermined number of layers, the physical strength of the obtained thermosetting resin cured product can be increased, and the thermosetting resin cured product can be formed into a thin sheet. Even when processed, high physical strength can be obtained. Furthermore, it is preferable that the distance between the dispersed layered silicates is an appropriate distance.

  Examples of the method for dispersing the layered silicate in the thermosetting resin include a method using an organic layered silicate, a method using a foaming agent, and a method using a dispersant. By using these methods, the layered silicate can be more uniformly and finely dispersed in the resin.

  When the layered silicate is dispersed in the thermosetting resin, the layered silicate can be uniformly and finely dispersed, and the thermosetting resin cured product has sufficient strength and excellent mechanical and electrical characteristics. In addition, since a fired body is formed by the organically modified layered silicate during combustion, the shape of the combustion residue is maintained, the shape does not easily collapse even after combustion, and it is possible to prevent the spread of flame, and excellent flame retardancy Is expressed.

  As a method of using the organically modified layered silicate, which is one of the methods for dispersing the layered silicate, the organically modified layered silicic acid obtained by chemical modification by the following chemical modification (1) method to chemical modification (6) method The method using a salt is mentioned. These chemical modification methods may be used alone or in combination of two or more.

  The organically modified layered silicate refers to a compound whose dispersibility in the resin is improved by chemically modifying the layered silicate.

  The chemical modification (1) method is also called a cation exchange method using a cationic surfactant. Specifically, the cation exchange is performed between the layers of the layered silicate using the cationic surfactant, and In this method, the interlayer is hydrophobized in advance. Since the interlayer of the layered silicate is hydrophobized in advance, the affinity between the layered silicate and the low-polarity resin is increased, so that the layered silicate can be dispersed in a more uniform and fine state.

  Such a cationic surfactant is not particularly limited, and examples thereof include quaternary ammonium salts and quaternary phosphonium salts. Among these, the quaternary ammonium salt having an alkyl chain having 6 or more carbon atoms and containing an alkylammonium ion having 6 or more carbon atoms is preferably used since the crystal layer of the layered silicate can be sufficiently hydrophobized.

  Examples of the quaternary ammonium salt having an alkyl group having 6 or more carbon atoms include, for example, trimethylalkylammonium salt, triethylalkylammonium salt, tributylalkylammonium salt, dimethyldialkylammonium salt, dibutyldialkylammonium salt, methylbenzyldialkylammonium salt, Dibenzyldialkylammonium salt, trialkylmethylammonium salt, trialkylethylammonium salt, trialkylbutylammonium salt, quaternary ammonium salt having an aromatic ring, quaternary ammonium salt derived from aromatic amines such as trimethylphenylammonium, polyethylene glycol Dialkyl quaternary ammonium salt having two chains, dialkyl quaternary ammonium salt having two polypropylene glycol chains, polyester Trialkyl quaternary ammonium salt having one alkylene glycol chain, a trialkyl quaternary ammonium salt having one polypropylene glycol chain. Among these, lauryl trimethyl ammonium salt, stearyl trimethyl ammonium salt, methyl trioctyl ammonium salt, distearyl dimethyl ammonium salt, di-cured tallow dimethyl ammonium salt, distearyl dibenzyl ammonium salt, N-polyoxyethylene-N-lauryl- N, N-dimethylammonium salt and the like are preferably used. These quaternary ammonium salts may be used alone or in combination of two or more.

  Examples of the quaternary phosphonium salt include dodecyltriphenylphosphonium salt, methyltriphenylphosphonium salt, lauryltrimethylphosphonium salt, stearyltrimethylphosphonium salt, methyltrioctylphosphonium salt, distearyldimethylphosphonium salt, distearyldibenzylphosphonium. Examples include salts. These quaternary phosphonium salts may be used alone or in combination of two or more.

  In the chemical modification (2) method, a functional group capable of chemically bonding to this hydroxyl group or a hydroxyl group present on the crystal surface of the organically modified layered silicate chemically modified by the chemical modification (1) method is used. In this method, chemical modification is performed using a compound having at least one functional group with high chemical affinity at the molecular end.

  Examples of the functional group capable of chemically bonding to a hydroxyl group or a functional group having a large chemical affinity with a hydroxyl group include an alkoxy group, a glycidyl group, a carboxyl group (including a dibasic acid anhydride), a hydroxyl group, an isocyanate group, Examples include an aldehyde group.

  Moreover, as a compound which has these functional groups, the silane compound, titanate compound, glycidyl compound, carboxylic acid, alcohols, etc. which have these functional groups are mentioned, for example. These compounds may be used independently and 2 or more types may be used together.

The silane compound having these functional groups is not particularly limited, and examples thereof include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, γ-aminopropyltrimethoxysilane, and γ-aminopropylmethyldimethoxy. Silane, γ-aminopropyldimethylmethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldiethoxysilane, γ-aminopropyldimethylethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, trimethylmethoxysilane, hexyltri Methoxysilane, hexyltriethoxysilane, N-β- (aminoethyl) γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) γ-aminopropyltriethoxysilane, N-β- ( Minoethyl) γ-aminopropylmethyldimethoxysilane, octadecyltrimethoxysilane, octadecyltriethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ- And methacryloxypropyltriethoxysilane. These silane compounds may be used independently and 2 or more types may be used together.

  In the chemical modification (3) method, a functional group capable of chemically bonding to the hydroxyl group or a chemical group with the hydroxyl group is chemically bonded to the hydroxyl group present on the crystal surface of the organically modified layered silicate chemically modified by the chemical modification (1) method. This is a method of chemical modification using a functional group having a large affinity and a compound having at least one reactive functional group at the molecular end.

  In the chemical modification (4) method, the crystal surface of the organically modified layered silicate chemically modified by the chemical modification (1) method is chemically modified using a compound having an anionic surface activity.

  The compound having such anionic surface activity is not particularly limited as long as it can chemically modify the layered silicate by ionic interaction. For example, sodium laurate, sodium stearate, sodium oleate, higher alcohol sulfate Examples thereof include ester salts, secondary higher alcohol sulfates, and unsaturated alcohol sulfates. These compounds may be used independently and 2 or more types may be used together.

  The chemical modification (5) method is a method of chemical modification using a compound having one or more reactive functional groups in addition to the anionic site in the molecular chain among the compounds having anionic surface activity.

  The above chemical modification (6) method is a functional group capable of reacting with a layered silicate with respect to an organically modified layered silicate chemically modified by any one of the chemical modification (1) method to the chemical modification (5) method. In this method, a resin having a group is added and used as a resin composed of at least one of a thermoplastic resin and a thermosetting resin.

  The layered silicate before being dispersed in the thermosetting resin preferably has a diameter of 0.5 μm or less. When the diameter of the layered silicate is 0.5 μm or less, the interface area between the resin and the layered silicate can be further increased.

  In addition, the diameter of layered silicate is measured by observing the cross section of a thermosetting hardened | cured material with an electron microscope etc.

The number of laminated layers of the layered silicate dispersed in the thermosetting resin is preferably 5 layers or less, more preferably 3 layers or less, and even more preferably 1 layer.
The interfacial area between the thermosetting resin and the layered silicate can be increased by dispersing the layered silicate in the thermosetting resin in 5 layers or less. In addition, the laminated body of 5 layers or less specifically means that the flaky crystals are 5 layers or less because the interaction between the flaky crystals of the layered silicate is weakened.

  Further, the proportion of the layered silicate having 5 layers or less dispersed in the thermosetting resin is preferably 10% or more, and more preferably 20% or more.

  When the ratio of the layered silicate in the thermosetting resin is less than 10%, the strength of the thermosetting resin cured product may be lowered.

  By the way, in order to reduce the number of stacked layers, for example, it is necessary to increase the amount of chemical treatment such as the amount of the cationic surfactant to be cation-exchanged so that the dispersibility of the layered silicate is improved. However, physical properties may be deteriorated by a large amount of the cationic surfactant, and the dispersion conditions at the time of dispersion may have to be made more severe. For example, when dispersing with an extruder, it may be necessary to increase the number of rotations of the rotating blades when increasing the shearing force during extrusion or when stirring with a mixer.

  However, if the layered silicate is dispersed in about three layers, the above-described effects can be sufficiently exhibited. Therefore, it is preferred that 30% or more of the layered silicate laminate is dispersed in three or more layers. In addition, if the proportion of three or more layers is excessively increased, the above-described physical properties are difficult to obtain. Therefore, the proportion of the layered silicate laminate dispersed in three or more layers is 70% or less. preferable.

  Here, the ratio of the layered silicate dispersed as a laminate of 5 layers or less, and the ratio of the layered silicate dispersed in 3 or more layers are the transmission type of the thermosetting resin cured product of the present invention. It is obtained by magnifying it 100,000 times with an electron microscope and confirming the dispersion state of the layered silicate. The total number of layered silicate laminates (X) that can be observed in a certain area, the number of layered silicate layers (Y) dispersed as a laminate of 5 layers or less, and a laminate of 3 or more layers The number of layered silicate layers (Z) is measured. The ratio (%) of the layered silicate dispersed as a laminate of 5 layers or less and 3 or more layers is calculated by the following formula, and the dispersion state of the layered silicate is evaluated according to the following criteria.

Ratio of layered silicate dispersed as a laminate of 5 layers or less (%) = (Y / X) × 100
Ratio of layered silicate dispersed as a laminate of three or more layers (%) = (Z / X) × 100
The layered silicate dispersed in the resin preferably has an average interlayer distance of (001) plane of 3 to 5 nm as measured by a wide angle X-ray diffraction measurement method. The average interlayer distance of the layered silicate means the average distance between the layers when the lamellar crystal of the layered silicate is regarded as a layer, and a wide-angle X-ray such as an X-ray diffraction peak and transmission electron microscope photography. It is a distance calculated by a diffraction measurement method.

  Also, when the average interlayer distance exceeds 5 nm, the lamellar crystals of the layered silicate are separated for each layer and the interaction of the layered silicate becomes so weak that it can be ignored. May not be sufficiently improved.

  Further, the average interlayer distance of the layered silicate is 3 to 5 nm, and a part or all of the layered silicate is dispersed as a laminate of 5 layers or less, whereby the interface between the thermosetting resin and the layered silicate. The area is sufficiently large, and the distance between the flaky crystals of the layered silicate is appropriate. For this reason, in the thermosetting resin hardened | cured material, the mechanical characteristic and flame retardance superior to the time of using a well-known inorganic filler can be acquired.

  The mixing ratio of the layered silicate in the thermosetting resin composition is preferably 0.5 to 50 parts by weight with respect to 100 parts by weight of the thermosetting resin. More preferably, it is 1 to 30 parts by weight. If the amount of layered silicate is less than 0.5 parts by weight, mechanical properties and electrical properties may not be sufficient. When there is more layered silicate than 50 weight part, the dispersibility of layered silicate may worsen.

(Other ingredients)
In the thermosetting resin composition, as long as the object of the present invention is not inhibited, thermoplastic elastomers, cross-linked rubbers, oligomers, inorganic compounds, nucleating agents, antioxidants (anti-aging agents) are used as necessary. , Additives such as heat stabilizers, light stabilizers, ultraviolet absorbers, lubricants, flame retardant aids, antistatic agents, antifogging agents, fillers, softeners, plasticizers, and colorants may be blended. . These may be used alone or in combination of two or more.

(Production method of resin sheet)
In this invention, after kneading the said thermosetting resin composition by a suitable method, a resin sheet is manufactured. The method of kneading the resin composition is not particularly limited, and for example, a method of kneading using a kneader such as a planetary stirrer, an extruder, a homogenizer, a mechanical chemical stirrer, two rolls, a Banbury mixer, or the like. Can be mentioned. By applying a shearing force, the average length of the layered silicate may be shortened. The resin sheet molding method is not particularly limited. For example, the resin sheet is melt-kneaded in an extruder and then extruded, and formed on a film using a T die or a circular die, or dissolved or dispersed in a solvent such as an organic solvent. After casting, a casting molding method of casting and molding on a film can be used.

  As described above, a resin sheet is obtained by molding the thermosetting resin composition prepared in the present invention.

  Next, in the method for producing a resin sheet according to the present invention, the surface of the resin sheet is treated with an inorganic acid. As the inorganic acid, for example, hydrochloric acid, hydrofluoric acid, nitric acid, phosphoric acid, sulfuric acid and the like can be used. Among these, sulfuric acid is preferable because a large number of holes are easily formed uniformly on the surface of the resin sheet.

The concentration of the sulfuric acid is preferably 5 to 50%. If the concentration of sulfuric acid is higher than 50%, the resin may be damaged by acid. If the concentration is lower than 5%, the effect of sulfuric acid treatment may not be sufficient.
The condition for treating the surface of the resin sheet with an inorganic acid is, for example, immersing the surface of the resin sheet in sulfuric acid at room temperature (25 ° C.) for 2 to 20 minutes, preferably 5 to 10 minutes. If the immersion time is shorter than 2 minutes, the effect of sulfuric acid treatment may not be sufficient. If it is longer than 20 minutes, the entire resin may be damaged by the acid.

  In addition, you may perform the said immersion under heating, and when it heats, an effect can be improved more. For example, when 30% sulfuric acid is treated at 45 ° C. for about 3 minutes, the same effect as when treated with 30% sulfuric acid at room temperature (25 ° C.) for 10 minutes is obtained. In particular, when the thermosetting resin composition contains a layered silicate, it is an effective technique because it is difficult to form holes on the surface of the resin sheet.

  By roughening the surface of the resin sheet treated with an inorganic acid as described above using a roughening aqueous solution containing a permanganate, a large number of holes are formed on the surface of the resin sheet.

  Examples of the permanganate contained in the roughened aqueous solution include potassium permanganate, sodium permanganate, and ammonium permanganate. Among these, potassium permanganate is preferable. Permanganate may be used alone or in combination of two or more. In addition to the permanganate, alkali (sodium hydroxide) etc. may be mix | blended with the aqueous solution for roughening, for example.

  The conditions for roughening the surface of the resin sheet treated with the inorganic acid using a roughened aqueous solution containing a permanganate are, for example, 45 ° C. for 3 to 20 minutes, preferably 5 to 7 minutes. Is immersed in a roughening aqueous solution. When the immersion time is longer than 20 minutes, excessive roughening may occur, and when the immersion time is shorter than 3 minutes, the effect of the permanganate roughening treatment may not be sufficient.

In addition, when the said immersion is performed under a heating, the roughening effect can be heightened more. In particular, when the thermosetting resin composition contains a layered silicate, it is an effective technique because it is difficult to form holes on the surface of the resin sheet.

  By roughening the surface of the resin sheet treated with an inorganic acid as described above using a roughening aqueous solution containing a permanganate, a large number of holes can be efficiently formed on the surface of the resin sheet. .

  As a method of providing a conductive film on a resin sheet having a roughened surface, for example, copper plating is provided on the roughened thermosetting resin composition, and then 0.5 to 2 at 150 to 180 ° C. The method of heating for a time is mentioned.

  In the manufacturing method according to the present invention, after the surface of the resin sheet described above is treated with an inorganic acid, the surface of the resin sheet treated with the inorganic acid is roughened, so that a large number of fine holes are formed on the surface of the resin sheet. The Therefore, when a conductive film is formed on the surface of the resin sheet obtained by the present invention, the adhesion between the resin sheet and the conductive film is effectively enhanced.

  Therefore, the conductive film formed on the surface of the resin sheet obtained by the present invention can be composed of various metals other than copper, and even in such a case, the conductive film resin according to the present invention. The adhesion to the sheet surface is effectively and moderately increased. Further, the method for forming the conductive film is not limited to plating, and an appropriate method such as sputtering or vapor deposition can be used.

(Function and effect of resin sheet)
When the resin sheet obtained by the production method of the present invention comprises a flexible epoxy resin having the butadiene skeleton and a thermosetting resin composition containing an epoxy resin curing agent, the cured product is from a low temperature range. It has high elongation over a wide temperature range up to a high temperature range, and can exhibit even more excellent mechanical properties. Moreover, when an epoxy resin hardening | curing agent consists of a compound which has a phenol group, the heat resistance of a resin sheet, low water absorption, and dimensional stability can be improved.

  Furthermore, as shown in the experimental examples to be described later, even with a resin having a carbon-carbon double bond such as a flexible epoxy resin having a butadiene skeleton, the resin sheet manufacturing method according to the present invention, A large number of holes can be formed on the surface of the resin sheet.

  When the resin sheet obtained by the production method of the present invention is composed of a thermosetting resin composition containing a layered silicate, it has excellent mechanical properties, transparency, moisture resistance, etc., due to molecular chain restraint. Dimensional stability based on improvement of heat resistance, reduction of thermal expansion coefficient, nucleation effect of layered silicate in crystal formation and improvement of moisture resistance, etc. based on increase of glass transition temperature and heat distortion temperature The improvement of the property is achieved. In addition, since a fired body is formed by layered silicate during combustion, the shape of the combustion residue is maintained, flame spread can be prevented, and excellent flame retardancy is exhibited. Furthermore, by combining with a non-halogen flame retardant such as a metal hydroxide, it is possible to achieve both excellent mechanical properties and high flame retardancy while considering the environment.

  In the above resin sheet, the layered silicate can be processed into a thin molded body because it imparts excellent mechanical properties and the like without adding a large amount like a normal inorganic filler, increasing the density of the multilayer printed board, The insulating substrate material composed of the resin sheet that has been thinned in response to the thinning can exhibit various performances such as excellent flame retardancy, mechanical properties, high-temperature physical properties, heat resistance, and dimensional stability.

The method for producing a resin sheet according to the present invention can drastically improve the adhesive strength between the resin sheet and the conductive film when the conductive film is formed on the surface of the resin sheet by electroless plating, sputtering or vacuum deposition. Is.

  Therefore, the resin sheet according to the present invention can be preferably used as a resin sheet for an insulating substrate, and an insulating substrate including a conductive film formed by plating on at least one surface of the resin sheet is also one aspect of the present invention.

  The multilayer substrate using the resin sheet with metal foil in which the conductive film is formed on the surface of the resin sheet according to the present invention is excellent in mechanical properties, dimensional stability, heat resistance, and flame retardancy. Even when the multi-layer substrate is used in a harsh environment, the conductive film is detached from the resin and hardly causes a short circuit or disconnection, and has high reliability.

  The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the following examples.

(Manufacture of resin sheets)
58.3 parts by weight of a flexible epoxy-modified polybutadiene resin (manufactured by Nippon Soda Co., Ltd., product number: “EPB-13”, epoxy equivalent 598), and phenol compound (PP-1000-240, manufactured by Nippon Petrochemical Co., Ltd., hydroxyl group) Equivalent: 420) An epoxy thermosetting resin composition consisting of 41.7 parts by weight was prepared. Synthetic hectorite treated with organic trioctylmethylammonium salt as an inorganic compound (layered silicate; manufactured by Corp Chemical Co., Lucentite STN) with respect to 100 parts by weight of the epoxy thermosetting resin composition 8 parts by weight and 400 parts by weight of dimethylformamide (made by Wako Pure Chemical Industries, Ltd., special grade) as an organic solvent were further added in a beaker. This was stirred for 1 hour with a stirrer and then defoamed to obtain an epoxy-based thermosetting resin composition solution.

The solvent was removed in a state where the obtained epoxy thermosetting resin composition solution was applied on a polyethylene terephthalate sheet, and a film having a thickness of 40 microns was formed. Next, it was laminated on a FR4 substrate (manufactured by Risho Kogyo Co., Ltd., material: glass, epoxy, size: 30 × 60 × 0.6 mm) using a vacuum pressure laminator (Meiki Seisakusho Co., Ltd .: device type MVLP-500). Next, PET on the surface was taken and placed in a gear oven, and precured for 1 hour at a temperature of 170 ° C. to prepare a resin sheet.

  The surface of the resin sheet obtained as described above was subjected to the following sulfuric acid treatment and / or permanganate treatment.

(Sulfuric acid treatment)
The sulfuric acid treatment was performed by placing the resin sheet in a beaker containing each sulfuric acid aqueous solution at 25 ° C. and swinging. The resin sheet after completion of the sulfuric acid treatment was thoroughly washed with pure water.

(Permanganate treatment)
The permanganate treatment was performed by placing a resin sheet in a roughened aqueous solution of potassium permanganate (Concentrate Compact CP, manufactured by Atotech Japan) at 45 ° C. and shaking it. Further, the resin sheet that had been subjected to the permanganate treatment was reduced by treatment with a 25 ° C. cleaning solution (Reduction Securigant P, manufactured by Atotech Japan Co., Ltd.) for 2 minutes, thereby terminating the oxidizing action of Mn.

(Examples and Comparative Examples)
In the following Examples and Comparative Examples, the sulfuric acid treatment and / or the permanganate treatment was performed.

Example 1
The sulfuric acid treatment (sulfuric acid treatment time 10 minutes) was performed once using 10% sulfuric acid. After the sulfuric acid treatment, the permanganate treatment (permanganate treatment time 5 minutes) was performed once.

(Example 2)
The sulfuric acid treatment (sulfuric acid treatment time 10 minutes) was performed once using 30% sulfuric acid. After the sulfuric acid treatment, the permanganate treatment (permanganate treatment time 5 minutes) was performed once.

(Example 3)
The sulfuric acid treatment (sulfuric acid treatment time 10 minutes) was carried out once using 50% sulfuric acid. After the sulfuric acid treatment, the permanganate treatment (permanganate treatment time 5 minutes) was performed once.

Example 4
The sulfuric acid treatment (sulfuric acid treatment time 10 minutes) was carried out once using 70% sulfuric acid. After the sulfuric acid treatment, the permanganate treatment (permanganate treatment time 5 minutes) was performed once.

(Example 5)
The sulfuric acid treatment (sulfuric acid treatment time 10 minutes) was performed once using 30% sulfuric acid. After the sulfuric acid treatment, the permanganate treatment (permanganate treatment time 1 minute) was performed once.

(Example 6)
The sulfuric acid treatment (sulfuric acid treatment time 10 minutes) was performed once using 30% sulfuric acid. After the sulfuric acid treatment, the permanganate treatment (permanganate treatment time 3 minutes) was performed once.

(Example 7)
The sulfuric acid treatment (sulfuric acid treatment time 10 minutes) was performed once using 30% sulfuric acid. After the sulfuric acid treatment, the permanganate treatment (permanganate treatment time 7 minutes) was performed once.

(Example 8)
The sulfuric acid treatment (sulfuric acid treatment time 15 minutes) was performed once using 30% sulfuric acid. After the sulfuric acid treatment, the permanganate treatment (permanganate treatment time 5 minutes) was performed once.

Example 9
The sulfuric acid treatment (sulfuric acid treatment time 20 minutes) was performed once using 30% sulfuric acid. After the sulfuric acid treatment, the permanganate treatment (permanganate treatment time 5 minutes) was performed once.

(Example 10)
The sulfuric acid treatment (sulfuric acid treatment time 10 minutes) was performed twice using 30% sulfuric acid. After the sulfuric acid treatment, the permanganate treatment (permanganate treatment time 5 minutes) was performed once.

(Comparative Example 1)
The permanganate treatment (permanganate treatment time 3 minutes) was performed once.

(Comparative Example 2)
The permanganate treatment (permanganate treatment time 5 minutes) was performed once.

(Comparative Example 3)
The permanganate treatment (permanganate treatment time 7 minutes) was performed once.

(Comparative Example 4)
The sulfuric acid treatment (sulfuric acid treatment time 10 minutes) was performed once using 30% sulfuric acid.

(Comparative Example 5)
The sulfuric acid treatment (sulfuric acid treatment time 15 minutes) was performed once using 30% sulfuric acid.

(Comparative Example 6)
The sulfuric acid treatment (sulfuric acid treatment time 20 minutes) was performed once using 30% sulfuric acid.

(Evaluation of Example 3 and Comparative Example 2)
The resin sheet of Example 3 which was subjected to a roughening aqueous solution containing potassium permanganate after 30% sulfuric acid treatment, and the roughened aqueous solution containing potassium permanganate without sulfuric acid treatment The surface state of the resin sheet of Comparative Example 2 in which only the roughening treatment was performed using was evaluated.

(result)
FIG. 1 shows a scanning electron microscope (SEM) image of the resin sheet of Example 3, and FIG. 2 shows a scanning electron microscope (SEM) image of the resin sheet of Comparative Example 2.

  As is clear from FIGS. 1 and 2, the resin sheet of Example 3 clearly had more holes than the resin sheet of Comparative Example 2. Therefore, it is considered that the anchor effect is increased and the peel strength described later is improved.

  In addition, when the reflection IR of the resin sheet of Example 3 and Comparative Example 2 is seen, the absorption peak of the carbon-carbon double bond is reduced in the resin sheet of Example 3 compared to the resin sheet of Comparative Example 2. The peak of the carbonyl group was slightly strong. This indicates that the resin sheet of Example 3 was more roughened, which is consistent with the SEM image results shown in FIGS. Therefore, it is considered that a part of the carbon-carbon double bond existing on the surface of the resin sheet after the curing is modified to form a carbonyl group and the adhesion between the resin and the plating is improved.

  Accordingly, in the case of a resin having a carbon-carbon double bond, such as a flexible epoxy resin having a butadiene skeleton, the surface of the resin sheet is treated with an inorganic acid and then a roughened aqueous solution containing a permanganate. It is considered that roughening is promoted by roughening the surface of the resin sheet treated with an inorganic acid.

(Evaluation of Examples 1 to 10 and Comparative Examples 1 to 6)
Next, the surfaces of the resin sheets of Examples 1 to 10 and Comparative Examples 1 to 6 were subjected to electroless plating treatment, then subjected to electrolytic plating treatment, and the peel strength was measured to evaluate the adhesive strength of the plating film. The resin sheets of Examples 1 to 10 and Comparative Examples 1 to 6 that had been subjected to sulfuric acid treatment and / or permanganate treatment were treated with an alkaline cleaner (cleaner securigant 902) at 60 ° C. for 5 minutes, and the surface was degreased and washed. did. Next, the resin sheet was treated with a 25 ° C. pre-dip solution (Pre-Dip Neogant B) for 2 minutes. Thereafter, the resin sheet was treated with an activator solution (activator Neogant 834) at 40 ° C. for 5 minutes to attach a palladium catalyst. Next, it was treated with a reducing solution (reducer Neogant WA) at 30 ° C. for 5 minutes.

Next, chemical copper solution (Basic Print Gantt MSK-DK, Copper Print Gantt M
SK, Stabilizer Print Gantt MSK) and electroless plating with a plating thickness of 0.
It implemented until it became about 5 micrometers. After electroless plating, annealing was performed at a temperature of 120 ° C. for 60 minutes to remove residual hydrogen gas. In all the steps up to the electroless plating step, the treatment liquid was set to 1 L on a beaker scale, and each step was performed while shaking the resin sheet.

Next, electrolytic plating was performed on the electroless plated resin sheet until the plating thickness became 25 μm. Copper sulfate (reducer Cu) was used as the electrolytic copper plating, and the current was 0.6 A / cm ² . After electrolytic plating, annealing was performed in a gear oven at a temperature of 170 ° C. for 1 hour.

(Evaluation method of peel strength)
The peel strength (JIS C 6481) of the resin sheets of Examples 1 to 10 and Comparative Examples 1 to 6 on which the plating films were formed as described above was measured. The plated surface of the resin sheet was cut with a cutter and the section was fixed on a jig, and then a 90 degree roughening peel was measured at a speed of 50 mm / min using an autograph.

(result)
The measurement results of the peel strength of each resin sheet are shown in Table 1 and FIG. Each peel strength is an average value of two resin sheets.

  As is apparent from Table 1, Examples 1 to 10 in which the surface of a resin sheet treated with sulfuric acid was roughened using a roughened aqueous solution containing potassium permanganate after the surface of the resin sheet was treated with sulfuric acid. In the resin sheet, a high peel strength was obtained.

  Further, as shown in FIG. 3, the resin sheets of Examples 1 to 3 having sulfuric acid concentrations of 10%, 30%, and 50% showed high peel strength. In particular, a very high peel strength was exhibited in resin sheets having sulfuric acid concentrations of 10% and 30%.

The scanning electron microscope (SEM) image of the resin sheet which performed the roughening process using the roughening aqueous solution containing potassium permanganate after performing a 30% sulfuric acid process. The scanning electron microscope (SEM) image of the resin sheet which performed only the roughening process using the roughening aqueous solution containing potassium permanganate, without performing a sulfuric acid process. The figure which shows the evaluation result of the peel strength of the resin sheet which concerns on this invention.

Claims (10)

  After treating the surface of the resin sheet made of the thermosetting resin composition with an inorganic acid, using a roughening aqueous solution containing a permanganate, by roughening the surface of the resin sheet treated with the inorganic acid, A method for producing a resin sheet, comprising: obtaining a resin sheet having a large number of holes formed on the surface of the resin sheet.   The method for producing a resin sheet according to claim 1, wherein sulfuric acid is used as the inorganic acid.   The manufacturing method of the resin sheet of Claim 2 whose density | concentration of the said sulfuric acid is 5 to 50%.   The resin sheet production according to any one of claims 1 to 3, wherein the thermosetting resin composition is an epoxy thermosetting resin composition containing an epoxy resin and an epoxy resin curing agent. Method.   The method for producing a resin sheet according to claim 4, wherein the epoxy resin is a flexible epoxy resin having a butadiene skeleton.   The said epoxy resin hardening | curing agent consists of a compound which has a phenol group, The manufacturing method of the resin sheet of Claim 4 or 5 characterized by the above-mentioned.   The method for producing a resin sheet according to claim 1, wherein the thermosetting resin composition contains a layered silicate.   The resin sheet for insulating substrates which consists of a resin sheet obtained by the manufacturing method of the resin sheet of any one of Claims 1-7.   A resin sheet obtained by the method for producing a resin sheet according to any one of claims 1 to 7, and a conductive film formed by plating on at least one surface of the resin sheet, Insulating substrate. A multilayer substrate comprising a resin sheet obtained by the method for producing a resin sheet according to claim 1 as an interlayer insulating layer.