JPWO2008114674A1 - Insulating composite, method for producing the same, and use of insulating composite - Google Patents

Abstract

The present invention has a varnish (1) having a composition for forming a cured product excellent in fine wiring pattern formability, and a composition for forming a cured product excellent in properties such as flame retardancy, Insulation obtained by applying a varnish (2) having a polymer of a specific molecular weight to a fiber base material on each side, then removing the organic solvent to form a thermosetting composition supported by the fiber base material. A sex complex is provided. The insulating composite of the present invention is excellent in flame retardancy, electrical insulation, and crack resistance, and is suitable for the production of a multilayer circuit board having a fine wiring pattern.

Description

  The present invention relates to an insulating composite that is excellent in flame retardancy, electrical insulation and crack resistance, and suitable for manufacturing a multilayer circuit board having a fine wiring pattern, and a method for manufacturing the same. Furthermore, the present invention provides a cured product obtained by curing the insulating composite, a laminate obtained by laminating a substrate and an electrical insulating layer comprising the cured product, a method for producing the same, and an electrical insulation layer of the laminate. Furthermore, the present invention relates to a multilayer circuit board formed by further forming a conductor layer, a method for manufacturing the same, and an electronic device having the multilayer circuit board.

  With recent miniaturization, multifunctionalization, high-speed communication, and the like of electronic devices, circuit boards used in electronic devices are required to have higher density and higher accuracy. In order to satisfy these requirements, the use of multilayer circuit boards is rapidly increasing.

  In a multilayer circuit board, an electric insulating layer obtained by curing an insulating composite or an insulating film is usually laminated on an inner layer board composed of an electric insulating layer and a conductor layer formed on the surface thereof. It is obtained by forming a conductor layer on the insulating layer. The electrical insulating layer and the conductor layer can be laminated in several stages as required.

  By the way, when the conductor layer of such a multilayer circuit board is a high-density pattern, since heat_generation | fever of a conductor layer or a board | substrate becomes large, the flame retardance improvement of an electrically insulating layer is calculated | required.

  Conventionally, as a means for improving the flame retardancy of an electrical insulation layer, a method of blending a flame retardant such as a halogen-based flame retardant into the electrical insulation layer is known (Patent Document 1).

  However, when the used multilayer circuit board is incinerated, there is a problem that the halogen-based flame retardant mixed in the electrical insulating layer is thermally decomposed to generate a halogen-based harmful substance. In addition, the electrical insulating layer containing the flame retardant has problems that the strength is insufficient and the impact and heat history are received, so that cracks occur and electrical characteristics are deteriorated. As a method of increasing the strength of the electrical insulating layer, a method of reinforcing with a glass cloth is known, but this method further deteriorates the electrical characteristics, and the flame retardant is difficult to spread uniformly throughout the electrical insulating layer. In some cases, the flammability was insufficient.

  On the other hand, as a method for forming an electrical insulating layer, a method using an adhesive sheet for multilayer wiring boards is known. For example, in Patent Document 2, a resin composition containing biphenyl and a novolak structure epoxy resin, acrylonitrile butadiene rubber and a thermosetting agent as essential components is impregnated into a nonwoven fabric made of liquid crystal polyester, and then dried. A method for achieving a semi-cured state has been proposed.

  However, the electrical insulation layer formed using the adhesive sheet for multilayer wiring boards obtained by this method has insufficient electrical properties such as dielectric constant and dielectric loss tangent, and the electrical insulation layer formed on the formed electrical insulation layer is dense and fine. It was difficult to form a simple wiring.

JP-A-2-255848 JP 2005-175265 A

  The present invention has been made in view of such a state of the art, and has excellent flame retardancy, electrical insulation and crack resistance, and is suitable for manufacturing a multilayer circuit board having a fine wiring pattern. It is an object to provide a sex composite and a method for producing the same. Furthermore, the present invention provides a cured product obtained by curing the insulating composite, a laminate obtained by laminating a substrate and an electrical insulation layer comprising the cured product, a method for producing the laminate, and an electrical insulation layer of the laminate. It is another object of the present invention to provide a multilayer circuit board formed with a conductor layer, a method for manufacturing the same, and an electronic apparatus having the multilayer circuit board.

  As a result of intensive studies to solve the above problems, the present inventors have formed a cured product excellent in fine wiring pattern formability in producing an insulating composite comprising a fiber base material and a thermosetting composition. The varnish (1) having the composition of (1) and the varnish (2) having a composition for forming a cured product excellent in properties such as flame retardancy and having a polymer having a specific molecular weight are used as the fiber substrate. It has been found that an insulating composite that is excellent in flame retardancy, electrical insulation and crack resistance and suitable for the production of a multilayer circuit board having a fine wiring pattern can be obtained by coating one surface on each side. The present invention has been completed based on the findings.

Thus, according to the first aspect of the present invention, there is provided an insulating composite comprising a fiber base material and a thermosetting composition obtained by the following steps.
(Step 1) Containing a polymer (1) having a carboxyl group or an acid anhydride group, a polyvalent epoxy compound (1), rubber and an organic solvent (1) on one side of the fiber substrate, and substantially Step of applying varnish (1) not containing filler (Step 2) The fiber base has a carboxyl group or an acid anhydride group on the surface opposite to the surface to be applied in Step 1, and has a weight average molecular weight. Step of applying a varnish (2) containing a polymer (2) having a molecular weight of 15,000 to 100,000, a polyvalent epoxy compound (2), a filler and an organic solvent (2) (step 3) an organic solvent ( Steps for removing 1) and (2) to form a thermosetting composition supported by a fiber substrate

  In the insulating composite of the present invention, the polymer (1) is an alicyclic olefin polymer having a carboxyl group or an acid anhydride group, and the polymer (2) is a carboxyl group or an acid anhydride. It is preferably an alicyclic olefin polymer having a group, the filler contained in the varnish (2) is a flame retardant, and the fiber base material is a cloth made of long fibers of a liquid crystal polymer. .

According to a second aspect of the present invention, there is provided a method for producing an insulating composite comprising a fiber substrate and a thermosetting composition, the method comprising the following steps: Is done.
(Step 1) Containing a polymer (1) having a carboxyl group or an acid anhydride group, a polyvalent epoxy compound (1), rubber and an organic solvent (1) on one side of the fiber substrate, and substantially Step of applying varnish (1) not containing filler (Step 2) The fiber base has a carboxyl group or an acid anhydride group on the surface opposite to the surface to be applied in Step 1, and has a weight average molecular weight. Step of applying a varnish (2) containing a polymer (2) having a molecular weight of 15,000 to 100,000, a polyvalent epoxy compound (2), a filler and an organic solvent (2) (step 3) an organic solvent ( Steps for removing 1) and (2) to form a thermosetting composition supported by a fiber substrate

According to the third aspect of the present invention, there is provided a cured product obtained by curing the insulating composite of the present invention.
According to the 4th of this invention, the laminated body formed by laminating | stacking the board | substrate which has a conductor layer (1) on the surface, and the electrically insulating layer which consists of hardened | cured material of this invention is provided.

According to the fifth aspect of the present invention, on the substrate having the conductor layer (1) on the surface, the insulating composite of the present invention is heated so that the surface coated in the step 2 is in contact with the conductor layer (1). A method for producing a laminate according to the present invention is provided, wherein the electrical insulating layer is formed by pressure bonding and curing.
According to the sixth aspect of the present invention, there is provided a multilayer circuit board in which a conductor layer (2) is further formed on the electrical insulating layer of the laminate of the present invention.
According to the seventh aspect of the present invention, there is provided a method for producing a multilayer circuit board according to the present invention, which comprises a step of forming a conductor layer (2) on the electrical insulating layer of the laminate according to the present invention by plating.
According to an eighth aspect of the present invention, there is provided an electronic apparatus including the multilayer circuit board according to the present invention.

ADVANTAGE OF THE INVENTION According to this invention, the insulating composite_body | complex excellent in a flame retardance, electrical insulation, and crack resistance, and suitable for manufacture of the multilayer circuit board which has a fine wiring pattern, and its manufacturing method are provided.
According to the present invention, a cured product obtained by curing the insulating composite of the present invention, a laminate obtained by laminating a substrate and an electrical insulating layer made of the cured product, a method for producing the same, and electrical insulation of the laminate. Provided are a multilayer circuit board in which a conductor layer is further formed on the layer and a method for producing the same.
The multilayer circuit board provided by the present invention can be suitably used as a semiconductor element such as a CPU or a memory or other mounting component board in an electronic device such as a computer or a mobile phone.

Hereinafter, the present invention will be described in detail.
1) Insulating composite The first of the present invention is an insulating composite comprising a fiber base material and a thermosetting composition, which is obtained by the following steps.

(Step 1) Containing a polymer (1) having a carboxyl group or an acid anhydride group, a polyvalent epoxy compound (1), rubber and an organic solvent (1) on one side of the fiber substrate, and substantially Step of applying varnish (1) not containing filler (Step 2) The fiber base has a carboxyl group or an acid anhydride group on the surface opposite to the surface to be applied in Step 1, and has a weight average molecular weight. Step of applying a varnish (2) containing a polymer (2) having a molecular weight of 15,000 to 100,000, a polyvalent epoxy compound (2), a filler and an organic solvent (2) (step 3) an organic solvent ( Steps for removing 1) and (2) to form a thermosetting composition supported by a fiber substrate

Process 1
Step 1 contains a polymer (1) having a carboxyl group or an acid anhydride group on one side of a fiber base, a polyvalent epoxy compound (1), rubber and an organic solvent (1), and substantially It is a step of applying a varnish (1) containing no filler.

Fiber substrate The fiber substrate used in the present invention is in the form of a cloth, for example, a paper substrate such as linter paper or kraft paper; a glass substrate such as glass cloth, glass mat, or glass paper quartz fiber; and polyester Synthetic resin fiber base materials such as fibers and aramid fibers can be used, and a cloth made of liquid crystal polymer long fibers is preferable.

  The cloth made of long fibers of liquid crystal polymer is a woven fabric or a non-woven fabric using liquid crystalline polyester long fibers. Further, the liquid crystalline polyester continuous fiber referred to here is a continuous filament obtained by spinning a polymer having an ester bond and showing a liquid crystal state (hereinafter sometimes referred to as “liquid crystal polymer”) by melt extrusion or the like.

  Examples of such a liquid crystal polymer include the compounds (a) to (d) exemplified below, and known liquid crystal polyesters and liquid crystal polyester amides obtained by copolymerizing these compounds in an appropriate combination.

(A) Aromatic or aliphatic dihydroxy compounds (b) Aromatic or aliphatic dicarboxylic acids (c) Aromatic hydroxycarboxylic acids (d) Aromatic diamines, aromatic hydroxylamines or aromatic aminocarboxylic acids Among these As the liquid crystal polymer, a wholly aromatic polyester having substantially no aliphatic hydrocarbon in the main chain is preferable.

  The wholly aromatic polyester is synthesized by combining monomers such as aromatic diol, aromatic dicarboxylic acid, and aromatic hydroxycarboxylic acid, and changing the composition ratio. Examples thereof include a copolymer of p-hydroxybenzoic acid and 2-hydroxy-6-naphthoic acid, a copolymer of p-hydroxybenzoic acid or terephthalic acid and 4,4'-dihydroxybiphenyl, and the like.

Examples of the form of a cloth made of liquid crystal polymer long fibers include woven or non-woven cloth such as roving cloth, chopped mat, and surfacing mat. Among these forms, a woven fabric is preferable from the viewpoint of dimensional stability, and a nonwoven fabric is preferable from the viewpoint of workability.
Moreover, what compressed these woven fabrics or nonwoven fabrics with the hot roll etc. is preferable.

  In the present invention, a woven fabric and a non-woven fabric may be laminated and used in order to combine the features of both. Further, glass, aramid, polybenzoxazole and natural cellulosic fiber cloth or microfibrils may be mixed with cloth made of long fibers of liquid crystal polymer.

The thickness of the insulating composite obtained by the cloth made of long fibers of the liquid crystal polymer used in the present invention can be arbitrarily changed depending on the mass per unit area. The mass per unit area of the cloth composed of long fibers of the liquid crystal polymer is preferably 3 to 55 g / m ² , more preferably 6 to 45 g / m ² .
When the mass per unit area is in this range, coating is easy, and the thickness and strength of the electrical insulating layer of the resulting multilayer circuit board are also preferable.

  Examples of the cloth composed of long fibers of a liquid crystal polymer preferably used in the present invention include a nonwoven fabric composed of fibers obtained by highly orienting a fully aromatic polyester by a melt blow method. Specifically, Vecrus and Vectran (both are trade names of Kuraray Co., Ltd.) can be used.

Varnish (1)
The varnish (1) is a polymer (1) having a carboxyl group or an acid anhydride group (hereinafter, both may be collectively referred to as “carboxyl group etc.”), a polyvalent epoxy compound (1), and rubber. And the organic solvent (1) and substantially free of filler.

  Here, “substantially not containing” means not containing 5 mass% or more in the varnish (1). Moreover, compared with the varnish (2) mentioned later, in order to obtain the hardened | cured material which was excellent in fine wiring pattern formation property, a varnish (1) is characterized by containing rubber | gum, Preferably liquid rubber. The viscosity of the varnish (1) is preferably 200 to 2000 mPa · s, more preferably 400 to 1600 mPa · s. When the viscosity is in this range, the coating property is good and it is preferable that the viscosity is not excessively mixed with the varnish (2).

Polymer (1)
In the polymer (1), a carboxyl group or the like has other divalent linking groups such as a methylene group, an oxy group, an oxycarbonyloxyalkylene group, and a phenylene group directly on the main chain of the electrically insulating polymer forming a skeleton. It is connected through.

  The polymer constituting the skeleton of the polymer (1) is not particularly limited, and specific examples thereof include maleimide resin, acrylic resin, diallyl phthalate resin, triazine resin, alicyclic olefin polymer, and aromatic polyether polymer. Benzocyclobutene polymer, cyanate ester polymer, and polyimide resin. In the present invention, these polymers can be used alone or in combination of two or more. Among these, alicyclic olefin polymer, aromatic polyether polymer, benzocyclobutene polymer, cyanate ester polymer, and polyimide resin are preferable because of excellent electrical properties such as dielectric constant and dielectric loss tangent. Cyclic olefin polymers and aromatic polyether polymers are more preferred, and alicyclic olefin polymers are particularly preferred.

Although content, such as a carboxyl group, in a polymer (1) is not specifically limited, The range of 5-50 mol% is preferable and the range of 10-40 mol% is more preferable. If the content of carboxyl groups, etc. is too small, the plating adhesion and heat resistance of the electrical insulation layer may be reduced. If the content of carboxyl groups, etc. is too large, the insulation properties of the electrical insulation layer may be reduced. There is. The content of the carboxyl group or the like is a ratio of the number of moles of the carboxyl group or the like to the total number of monomer units in the polymer, and can be calculated from the measurement result of ¹ H-NMR spectrum, for example.

Although the weight average molecular weight (Mw) of a polymer (1) is not specifically limited, Preferably it is 15,000-150,000, More preferably, it is 20,000-100,000. When the Mw is within this range, the strength, electrical insulation and surface roughness of the resulting cured product will be good.
In the present invention, Mw is a polystyrene equivalent value determined by gel permeation chromatography (GPC).

  It is preferable that the glass transition temperature (Tg) of a polymer (1) is 120-300 degreeC. If the Tg is too low, the resulting electrical insulation layer cannot maintain sufficient electrical insulation at high temperatures. If the Tg is too high, the multilayer wiring board will crack when subjected to a strong impact, causing damage to the conductor layer. there's a possibility that.

  The alicyclic olefin polymer is a homopolymer or copolymer of an alicyclic compound having a carbon-carbon unsaturated bond (hereinafter sometimes referred to as “alicyclic olefin”) and a derivative thereof (hereinafter referred to as “alicyclic olefin”). It is a general term for “hydrogenated products”. The polymerization mode may be addition polymerization or ring-opening polymerization.

  Specific examples of the alicyclic olefin polymer include a ring-opening polymer of a monomer having a norbornene ring (hereinafter referred to as “norbornene-based monomer”), a hydrogenated product thereof, and attachment of a norbornene-based monomer. Mentioning addition polymers, addition polymers of norbornene monomers and vinyl compounds, monocyclic cycloalkene addition polymers, alicyclic conjugated diene polymers, vinyl alicyclic hydrocarbon polymers and hydrogenated products thereof. Can do. An example is a polymer in which an alicyclic structure is formed by hydrogenation after polymerization, such as an aromatic olefin hydrogenated product of an aromatic olefin polymer, and has a structure equivalent to an alicyclic olefin polymer. It is. Among these, ring-opening polymers of norbornene monomers and hydrogenated products thereof, addition polymers of norbornene monomers, addition polymers of norbornene monomers and vinyl compounds, and aromatic olefin polymers Aromatic hydrogenated products are preferred, and in particular, hydrogenated products of ring-opening polymers of norbornene monomers are preferred.

  The method for setting the content of the carboxyl group or the like of the polymer (1) in the above range is not limited. For example, (i) a method of homopolymerizing a monomer having a carboxyl group or the like, or a method of copolymerizing a monomer having a carboxyl group or the like and a monomer copolymerizable therewith; (ii) a carboxyl group or the like A method of introducing a carboxyl group or the like by graft-bonding a compound having a carboxyl group or the like and a carbon-carbon unsaturated bond, for example, in the presence of a radical initiator to a polymer having no carboxyl group; (iii) a carboxylate group There is a method of polymerizing a monomer having a group that becomes a precursor of a carboxyl group, and then converting the precursor group to a carboxyl group by hydrolysis or the like.

As the carboxyl group-containing alicyclic olefin monomer used in the method (i), 8-hydroxycarbonyltetracyclo [4.4.0.1 ^2,5 . ^{17, 10} ] dodec-3-ene, 5-hydroxycarbonylbicyclo [2.2.1] hept-2-ene, 5-methyl-5-hydroxycarbonylbicyclo [2.2.1] hept-2-ene , 5-carboxymethyl-5-hydroxycarbonylbicyclo [2.2.1] hept-2-ene, 8-methyl-8-hydroxycarbonyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene, 8-carboxymethyl-8-hydroxycarbonyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene, 5-exo-6-endo-dihydroxycarbonylbicyclo [2.2.1] hept-2-ene, and 8-exo-9-endo-dihydroxycarbonyltetracyclo [4]. .4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene;

Examples of the acid anhydride group-containing alicyclic olefin monomer used in the method (i) include bicyclo [2.2.1] hept-2-ene-5,6-dicarboxylic acid anhydride, tetracyclo [ 4.4.0.1 ^2,5 . 1 ^7,10 ] dodec- ³ -ene-8,9-dicarboxylic anhydride, and hexacyclo [6.6.1.1 ^3,6 . 1 ^10,13 . 0 ^2,7 . 0 ^9,14] heptadec-4-ene-11,12-dicarboxylic acid anhydride; and the like.
The monomer copolymerizable with the carboxyl group-containing alicyclic olefin monomer used in the method (i) is not particularly limited, but an alicyclic olefin monomer having no carboxyl group or the like is preferable. .

Specific examples of the alicyclic olefin monomer having no carboxyl group and the like include bicyclo [2.2.1] hept-2-ene (common name: norbornene), 5-ethyl-bicyclo [2.2. 1] hept-2-ene, 5-butyl-bicyclo [2.2.1] hept-2-ene, 5-ethylidene-bicyclo [2.2.1] hept-2-ene, 5-methylidene-bicyclo [ 2.2.1] Hept-2-ene, 5-vinyl-bicyclo [2.2.1] hept-2-ene, tricyclo [4.3.0.1 ^2,5 ] deca-3,7-diene (common name: dicyclopentadiene), tetracyclo ^{[8.4.0.1 11,14.} 0 ^2,8 ] tetradeca-3,5,7,12,11-tetraene, tetracyclo [4.4.0. ^{12, 5} . 1 ^7,10 ] dec-3-ene (common name: tetracyclododecene), 8-methyl-tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene, 8-ethyl-tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene, 8-methylidene-tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene, 8-ethylidene-tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene, 8-vinyl-tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene, 8-propenyl-tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene, pentacyclo [6.5.1.1 ^3,6 . 0 ^2,7 . 0 ^9,13] pentadeca-3,10-diene, pentacyclo [7.4.0.1 ^3,6. 1 ^10,13 . 0 ^2,7 ] pentadeca-4,11-diene, cyclopentene, cyclopentadiene, 1,4-methano-1,4,4a, 5,10,10a-hexahydroanthracene, and 8-phenyl-tetracyclo [4.4. .0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene;

The alicyclic olefin polymer having no carboxyl group or the like used in the method (ii) is obtained by polymerizing the alicyclic olefin monomer having no carboxyl group or the like.
The mode of polymerization may be addition polymerization, ring-opening polymerization, or a derivative thereof (hydrogenated product or the like).

  Examples of the carbon-carbon unsaturated bond-containing compound having a carboxyl group or the like used in the method (ii) include acrylic acid, methacrylic acid, α-ethylacrylic acid, 2-hydroxyethyl (meth) acrylic acid, maleic acid. Acids, fumaric acid, itaconic acid, endocis-bicyclo [2.2.1] hept-5-ene-2,3-dicarboxylic acid, and methyl-endocis-bicyclo [2.2.1] hept-5-ene- Unsaturated carboxylic acid compounds such as 2,3-dicarboxylic acid; unsaturated carboxylic acid anhydrides such as maleic anhydride, chloromaleic anhydride, butenyl succinic anhydride, tetrahydrophthalic anhydride, and citraconic anhydride; .

As the norbornene-based monomer having a carboxyl group precursor used in the method (iii), 8-methyl-8-methoxycarbonyltetracyclo [4.4.0.1 ^2,5 . ^{17, 10} ] dodec-3-ene, 5-methoxycarbonyl-bicyclo [2.2.1] hept-2-ene, and 5-methyl-5-methoxycarbonyl-bicyclo [2.2.1] hept- 2-ene; and the like.

  The polymer (1) may have a functional group other than a carboxyl group. Examples of the functional group other than the carboxyl group include an alkoxycarbonyl group, a cyano group, a hydroxyl group, an epoxy group, an alkoxyl group, an amino group, an amide group, and an imide group.

[Polyvalent epoxy compound (1)]
The polyvalent epoxy compound (1) is a compound having two or more epoxy groups in the molecule. Examples of the polyvalent epoxy compound (1) include phenol novolac type epoxy compounds, cresol novolac type epoxy compounds, cresol type epoxy compounds, bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, brominated bisphenol A type epoxy compounds, bromine Glycidyl ether type epoxy compounds such as hydrogenated bisphenol F type epoxy compounds, hydrogenated bisphenol A type epoxy compounds, alicyclic epoxy compounds, glycidyl ester type epoxy compounds, glycidyl amine type epoxy compounds, isocyanurate type epoxy compounds, etc. .

Among these, bisphenol A type epoxy compounds such as bisphenol A bis (propylene glycol glycidyl ether) ether, because the compatibility with the polymer (1) is good and the mechanical properties of the resulting insulating composite are good. Is preferred.
These can be used alone or in combination of two or more.
The usage-amount of a polyvalent epoxy compound (1) is 1-100 mass parts normally with respect to 100 mass parts of a polymer (1), Preferably it is 5-80 mass parts, More preferably, it is the range of 10-50 mass parts. It is.

The curing accelerator varnish (1) preferably further contains a curing accelerator from the viewpoint of easily obtaining a cured product having high heat resistance. For example, curing accelerators such as tertiary amine compounds and boron trifluoride complex compounds are preferably used. Of these, the use of a tertiary amine compound is preferred because the insulation resistance, heat resistance, chemical resistance and the like are improved.

  As tertiary amine compounds, chain tertiary amine compounds such as benzylmethylamine, triethanolamine, triethylamine, tributylamine, tribenzylamine, dimethylformamide; pyrazoles, pyridines, pyrazines, pyrimidines, indazoles , Nitrogen-containing heterocyclic compounds such as quinolines, isoquinolines, imidazoles, and triazoles; Among these, imidazoles, particularly substituted imidazole compounds having a substituent are preferable.

  Examples of substituted imidazole compounds include 2-ethylimidazole, 2-ethyl-4-methylimidazole, bis-2-ethyl-4-methylimidazole, 1-methyl-2-ethylimidazole, 2-isopropylimidazole, and 2,4-dimethyl. Alkyl-substituted imidazole compounds such as imidazole and 2-heptadecylimidazole; 2-phenylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-ethylimidazole, benzimidazole, 2-ethyl-4-methyl-1- (2′-cyanoethyl) imidazole, 2-ethyl-4-methyl-1- [2 ′-(3 ″, 5 ″ -diaminotriazinyl) ethyl] imidazole, 1-benzyl-2-phenylimidazole, etc. Carbonization with a ring structure such as aryl or aralkyl groups Imidazole compounds substituted with a containing group; and the like. These curing accelerators can be used alone or in combination of two or more. Among these, an imidazole compound substituted with a hydrocarbon group having a ring structure is preferable, and 1-benzyl-2-phenylimidazole is particularly preferable.

  Although the compounding quantity of a hardening accelerator is suitably set according to a use purpose, it is 0.001-30 mass parts normally with respect to 100 mass parts of the polymer 1, Preferably it is 0.01-10 mass parts, More preferably Is 0.03 to 5 parts by mass.

The curing aid varnish (1) may further contain a curing aid in order to improve heat resistance and thermal shock resistance. Here, the curing aid is a compound that undergoes a curing reaction with the polymer (1) or the polyvalent epoxy compound (1) to modify the physical properties of the cured product. Examples of the curing aid to be used include carboxylic anhydrides having two or more acid anhydride groups in the molecule (hereinafter sometimes referred to as “tetracarboxylic dianhydride”).

  Examples of tetracarboxylic dianhydrides include pyromellitic anhydride, hexahydropyromellitic anhydride, cyclobutanetetracarboxylic anhydride, naphthalenetetracarboxylic anhydride, benzophenonetetracarboxylic anhydride, undecahydrobenzophenonetetracarboxylic anhydride , Tetralin-dianhydride, ethylene glycol bis (anhydro trimellitate), ethylene glycol bis (anhydro trimellitate) monoacetate, glycerin bis (anhydro trimellitate) monoacetate, 4- (2, 5-Dioxotetrahydrofuran-3-yl) -1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic anhydride, 5- (2,5 dioxotetrahydroxyfuryl) -3-methyl-3- Cyclohexene-1,2-dicarboxylic acid Anhydride, 1,2,3,4-butane tetracarboxylic acid dianhydride, 4,4'-sulfonyldibenzoic phthalic anhydride; and the like. Among these, ethylene glycol bis (anhydro trimellitate), ethylene glycol bis (anhydro trimellitate) monoacetate and glycerin from the viewpoint of compatibility with the other components of the curable resin composition (b2). Bis (anhydrotrimellitate) monoacetate is preferred, and ethylene glycol bis (anhydrotrimellitate) monoacetate and glycerin bis (anhydrotrimellitate) monoacetate are particularly preferred.

Rubber The rubber used in the present invention is a polymer compound having a glass transition temperature measured by differential scanning calorimetry of 30 ° C. or less. Among these, liquid rubber (liquid rubber) at normal temperature (25 ° C.) in the absence of a solution is preferable.

  The usage-amount of rubber | gum is 1-100 mass parts normally with respect to 100 mass parts of a polymer (1), Preferably it is 5-70 mass parts, More preferably, it is the range of 10-50 mass parts. The fine wiring pattern formability in which the blending amount of rubber is within this range is excellent.

  Examples of the liquid rubber include liquid polyisoprene, liquid polybutadiene, liquid styrene-butadiene rubber, liquid acrylonitrile-butadiene rubber, liquid polychloroprene, liquid silicone rubber, liquid polysulfide rubber, liquid fluororubber, and liquid polyisobutylene. These liquid rubbers can be used alone or in combination of two or more. The viscosity of the liquid rubber at 25 ° C. is usually in the range of 0.01 to 10,000 Pa · s, preferably 0.05 to 1,000 Pa · s, more preferably 0.1 to 500 Pa · s.

  Examples of the rubber other than the liquid rubber include a solid rubbery polymer at normal temperature (25 ° C.). Examples of rubber polymers that are solid at room temperature include natural rubber, polybutadiene rubber, polyisoprene rubber, acrylonitrile / butadiene copolymer rubber, styrene / butadiene copolymer rubber, styrene / isoprene copolymer rubber, and styrene / butadiene.・ Diene rubbers such as isoprene terpolymer rubbers; hydrogenated products of these diene rubbers; ethylene / α-olefin copolymers such as ethylene / propylene copolymers, propylene / other α-olefin copolymers Saturated polyolefin rubber such as ethylene / propylene / diene copolymer, α-olefin / diene copolymer, isobutylene / isoprene copolymer, isobutylene / diene copolymer, etc. α-olefin / diene polymer rubber; urethane Rubber, polyether rubber, acrylic rubber, propylene resin Special rubbers such as side rubber and ethylene acrylic rubber; Thermoplastic elastomers such as styrene / butadiene / styrene block copolymer rubber, hydrogenated styrene / isoprene / styrene block copolymer rubber; Urethane thermoplastic elastomer; Polyamide heat Plastic elastomer; 1,2-polybutadiene thermoplastic elastomer; and the like.

Organic solvent (1)
As the organic solvent (1), those capable of dissolving the polymer 1, the polyvalent epoxy compound (1), rubber and the like contained in the varnish (1) are preferable. The boiling point is preferably 30 to 250 ° C, more preferably 50 to 200 ° C. When an organic solvent having a boiling point in such a range is used, it is suitable for heating and volatilizing and drying later.

  Specific examples of such organic solvents include aromatic hydrocarbon solvents such as toluene, xylene, ethylbenzene and trimethylbenzene; aliphatic hydrocarbon solvents such as n-pentane, n-hexane and n-heptane; cyclopentane and cyclohexane And alicyclic hydrocarbon solvents such as chlorobenzene, dichlorobenzene and trichlorobenzene; ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone and cyclohexanone;

  The amount of the organic solvent (1) used is appropriately selected according to the viscosity of the varnish (1) and the thickness of the resulting thermosetting composition, but the solid content concentration of the varnish (1) (other than the organic solvent in the varnish) Is usually in the range of 5 to 70% by mass, preferably 10 to 65% by mass, more preferably 20 to 60% by mass.

  In addition to the above, the varnish (1) includes a laser processability improver, a thermal stabilizer, a weathering stabilizer, an anti-aging agent, a leveling agent, an antistatic agent, a slip agent, an antiblocking agent, Clouding agents, lubricants, dyes, pigments, natural oils, synthetic oils, waxes, emulsions and the like can be included. The blending amounts thereof are appropriately selected within a range that does not impair the object of the present invention.

  Examples of the method for coating the varnish (1) on one side of the fiber base include known coating methods such as a roll coating method, a curtain coating method, a die coating method, a slit coating method, and a gravure coating method.

  In general, the thickness of the varnish (1) applied in step 1 is 0.1 to 30 μm, preferably 1 to 20 μm, more preferably 3 on the fiber substrate of the composition formed in step 3. What is necessary is just to design so that it may become 10 micrometers. When in this range, the cured product obtained has good flame retardancy and mechanical properties.

Process 2
Step 2 is a step of coating the varnish (2) on the surface of the fiber base opposite to the surface to be coated in Step 1.

Varnish (2)
The varnish (2) has a carboxyl group or an acid anhydride group and has a weight average molecular weight of 15,000 to 100,000, a polymer (2), a polyvalent epoxy compound (2), a filler and an organic solvent (2 ). Moreover, compared with varnish (1), varnish (2) contains a filler in order to form hardened | cured material excellent in characteristics, such as a flame retardance, and has a polymer with a specific molecular weight. It is characterized by that.

  The viscosity of the varnish (2) is preferably 200 to 2000 mPa · s, more preferably 400 to 1600 mPa · s. When the viscosity is within this range, the coating property is good and it is preferable that the viscosity is not excessively mixed with the varnish (1).

  If the polymer (2) has a carboxyl group or an acid anhydride group and has a weight average molecular weight of 15,000 to 100,000, it is the same as the polymer (1) contained in the varnish (1). May be the same as or different from the polymer (1).

  The weight average molecular weight (Mw) of the polymer (2) is 15,000 to 100,000, preferably 25,000 to 70,000. When the Mw is within this range, the laminate property of the obtained insulating composite is good, and the strength and electrical properties of the resulting cured product are good.

  The polyvalent epoxy compound (2) may be the same as the polyvalent epoxy compound (1) contained in the varnish (1), and may be the same as or different from the polyvalent epoxy compound (1). good. The amount used may be the same as the amount used in varnish (1).

The filler contained in the filler varnish (2) is preferably a flame retardant. From the viewpoint of environmental protection, a halogen-free compound that does not generate halogen-containing harmful substances during incineration (hereinafter referred to as a non-halogen flame retardant) Is more preferable.

  Non-halogen flame retardants include, for example, metal hydroxides such as aluminum hydroxide and magnesium hydroxide; ammonium orthophosphate, orthophosphoric acid, condensed phosphoric acid, phosphoric anhydride, urea phosphate, phosphoric acid serving as a phosphoric acid source Ammonium monohydrogen and a mixture thereof, and melamine, dicyancyanamide, guanidine, guanylurea and a mixture thereof as nitrogen sources, urea as a condensing agent, urea phosphate (which also serves as a phosphate source) and In the presence of these mixtures, a phosphate of a basic nitrogen-containing compound obtained by subjecting it to a heat condensation reaction and then calcining; As the phosphate of the basic nitrogen-containing compound, preferred compounds are melamine polyphosphate compounds such as melamine polyphosphate, melam salt of polyphosphate, melem salt of polyphosphate, melamine / melam / melem double salt of polyphosphate.

  Other flame retardants include antimony compounds such as antimony trioxide, antimony pentoxide, and sodium antimonate; inorganic flame retardants such as zinc borate, guanidine sulfamate, zirconium compounds, molybdenum compounds, tin compounds; triphenyl phosphate, tri Cresyl phosphate, trixylenyl phosphate, trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, tributoxyethyl phosphate, octyl diphenyl phosphate, cresyl diphenyl phosphate, xylenyl diphenyl phosphate, resorcinol bis (diphenyl) phosphate, 2 -Ethylhexyl diphenyl phosphate, dimethyl methyl phosphate, triallyl phosphate, diethyl bis Hydroxyethyl) aminomethyl phosphate, triallyl phosphate, tris (3-hydroxypropyl) phosphine oxide, glycidyl-α-methyl-β-di (butoxy) phosphinyl propionate, dibutylhydroxymethyl phosphonate, dimethylmethyl phosphonate Condensed aromatic phosphates, di (ethoxy-bis- (2-hydroxyethyl) -aminomethyl phosphate, di (polyoxyethylene) -hydroxymethyl phosphonate, ammonium polyphosphate, butyl pyrophosphate, butyl acid phosphate, Butoxyethyl acid phosphate, 2-ethylhexyl acid phosphate, diethyl phenyl phosphonate, dimethyl phenyl phosphonate, di (isopropyl) N, N-bi (2-hydroxyethyl) aminomethyl phosphonate, dibutylbis (2-hydroxypropyl) pyro phosphonate, and the like phenyl phosphinic acid.

  As fillers other than flame retardants, carbonates such as calcium carbonate, magnesium carbonate, barium carbonate; silicates such as magnesium silicate, calcium silicate, zirconium silicate, talc, and clay; zinc oxide, titanium oxide, oxidation Examples thereof include oxides such as magnesium, alumina, and silica; sulfates such as barium sulfate and calcium sulfate; crosslinked fine particles of polymer compounds such as epoxy, rubber, urethane, polyimide, and polyamide;

  These fillers can be used alone or in combination of two or more. The content of the filler is preferably 1 to 100% by mass, more preferably 5 to 80% by mass, and particularly preferably 10 to 60% by mass with respect to the varnish (2). When the amount of the filler used is within this range, the resulting cured insulating composite has good mechanical properties. When the filler is a flame retardant, the flame retardancy is good.

  The shape and size of the filler are not limited. When the filler is particulate, the volume average particle diameter of the primary particles is preferably 0.1 to 5.0 μm, and more preferably 0.5 to 2.0 μm. When the particle size is within this range, the laminate property to the inner layer substrate is good.

Organic solvent (2)
As the organic solvent (2), those having excellent filler dispersibility and dissolving the polymer (2), the polyvalent epoxy compound (2) and the like are preferable. The boiling point is preferably 30 to 250 ° C, more preferably 50 to 200 ° C. When an organic solvent having a boiling point in such a range is used, it is suitable for heating and volatilizing and drying later.

Specific examples of the organic solvent (2) include those similar to the organic solvent (1).
Although the usage-amount of an organic solvent (2) is suitably selected according to the viscosity of a varnish (2) and the thickness of the thermosetting composition obtained, the solid content density | concentration of a varnish (2) is 5-70 normally. It is the range which becomes mass%, Preferably it is 10-65 mass%, More preferably, it is 20-60 mass%.

  The varnish (2) is preferably prepared such that the melt viscosity at 110 ° C. of the composition formed in Step 3 is 100 to 100,000 Pa · s. The melt viscosity of the composition is more preferably from 500 to 75,000 Pa · s, and even more preferably from 1,000 to 50,000 Pa · s. When the melt viscosity of the composition is within this range, the embedding property and fluidity at the time of lamination are good.

  In addition to the above, the varnish (2) in the present invention includes a flame retardant aid, a laser processability improver, a heat stabilizer, a weathering stabilizer, an anti-aging agent, a leveling agent, an antistatic agent, and a slip agent as necessary. , Antiblocking agents, antifogging agents, lubricants, dyes, pigments, natural oils, synthetic oils, waxes, emulsions, and the like. The blending amounts thereof are appropriately selected within a range that does not impair the object of the present invention.

  As a method of applying the varnish (2) to the surface opposite to the surface to be coated in step 1 of the fiber base, the same method as the method of coating the varnish 1 can be mentioned.

  Usually, the thickness which applies a varnish (2) in the process 2 is adjusted so that the thickness on the fiber base material of the composition formed in the process 3 may be 10-50 micrometers. The thickness is preferably 15 to 40 μm, and more preferably 20 to 30 μm. Within this range, the resulting insulating composite has good wiring embedding properties.

Process 3
Step 3 is a step of removing the organic solvents (1) and (2) to form a thermosetting composition supported by the fiber substrate.

  A method for removing the organic solvent, that is, a drying method is appropriately selected depending on the type of the organic solvent, and a hot-air drying method or a far-infrared drying method is usually employed. A drying temperature is 20-300 degreeC normally, Preferably it is 30-200 degreeC. If the drying temperature is too high, the curing reaction proceeds and the resulting composite resin molded article may not be in an uncured or semi-cured state. The drying time is usually 30 seconds to 1 hour, preferably 1 minute to 30 minutes.

  Here, “uncured” is a state in which substantially the entire polymer is dissolved in a solvent capable of dissolving the polymer (1) or (2). Further, “semi-cured” is a state in which the polymer (1) or (2) is dissolved in a solvent capable of dissolving the polymer (1) or (2). Specifically, it means a state in which 7% by mass or more) is dissolved, or a swelling rate when the insulating composite obtained in a solvent is immersed for 24 hours is 200% or more of the volume before immersion. .

Thermosetting composition The thermosetting composition in the present invention is a varnish (1) having a composition for forming a cured product excellent in fine wiring pattern formability, and a cured product excellent in properties such as flame retardancy. The varnish (2) having a composition for forming the film is applied to the fiber base material one side at a time, and the organic solvent is removed to form a varnish supported on the fiber base material.

(Process order)
Either step 1 or step 2 may be performed first or simultaneously. Step 3 is after step 1 and step 2, but may be performed twice after step 1 and after step 2. From the viewpoint of productivity and production cost, it is preferable to perform Step 1 and Step 2 simultaneously or continuously, and then perform Step 3. Examples of the coating apparatus in this case include a double-sided simultaneous die coater and a double-sided simultaneous roll coater.

2) Cured product The cured product of the present invention is obtained by curing the above-described insulating composite of the present invention.
Curing of the insulating composite is usually performed by heating the insulating composite. Curing conditions are appropriately selected according to the type of curing agent. The curing temperature is usually 30 to 400 ° C, preferably 70 to 300 ° C, more preferably 100 to 200 ° C. The curing time is usually 0.1 to 5 hours, preferably 0.5 to 3 hours. The heating method is not particularly limited, and may be performed using, for example, an electric oven.

  Prior to curing, it is preferable to provide a step of bringing a compound having metal coordination ability into contact with the insulating composite and then washing with a good solvent for these compounds such as water. By this step, the surface of the insulating composite can be smoothed, and the adhesion with the metal thin film coated thereon in the subsequent step can be improved. Examples of the compound having metal coordination ability include imidazoles such as 1- (2-aminoethyl) -2-methylimidazole; pyrazoles; triazoles; triazines;

  The cured product of the present invention is excellent in flame retardancy, electrical insulation and crack resistance, and excellent in fine wiring pattern formability. Therefore, it is suitable as an electrical insulating layer of the laminate and the multilayer circuit board of the present invention.

3) Laminate The laminate of the present invention is formed by laminating a substrate having a conductor layer (1) on the surface and an electrically insulating layer made of the cured product of the present invention.

Substrate The substrate used in the present invention has a conductor layer (1) on the surface of an electrically insulating substrate.
The electrically insulating substrate contains a known electrically insulating material (for example, alicyclic olefin polymer, epoxy resin, maleimide resin, acrylic resin, methacrylic resin, diallyl phthalate resin, triazine resin, polyphenyl ether, glass, etc.). It is formed by curing a curable resin composition.

Conductor layer (1)
The conductor layer (1) is not particularly limited, but is usually a layer including wiring formed of a conductor such as a conductive metal, and may further include various circuits. Further, the configuration and thickness of the wiring and circuit are not particularly limited.

  Specific examples of the substrate having the conductor layer (1) on the surface include a printed wiring board and a silicon wafer substrate. The thickness of the substrate having the conductor layer (1) on the surface is usually 10 μm to 10 mm, preferably 20 μm to 5 mm, more preferably 30 μm to 2 mm.

  The substrate having the conductor layer (1) on the surface used in the present invention is preferably pretreated on the surface of the conductor layer (1) in order to improve adhesion to the electrical insulating layer.

  As a pretreatment method, a known technique is not particularly limited and can be used. For example, if the conductor layer (1) is made of copper, a strong alkali oxidizing solution is brought into contact with the surface of the conductor layer (1) to form a copper oxide layer on the surface of the conductor layer (1) and roughened. An oxidation treatment method, a method in which the surface of the conductor layer (1) is oxidized by the previous method and then reduced with sodium borohydride, formalin, etc., a method in which the conductor layer (1) is plated and roughened, a conductor layer ( Examples thereof include a method in which an organic acid is brought into contact with 1) to elute and roughen the grain boundaries of copper, and a method in which a primer layer is formed on the conductor layer (1) with a thiol compound or a silane compound.

  Among these, from the viewpoint of easy maintenance of the shape of the fine wiring pattern, a method of bringing the conductor layer (1) into contact with an organic acid to elute and roughen the copper grain boundary, and a thiol compound or a silane compound A method of forming the primer layer by, for example, is preferable.

Method for Producing Laminate The laminate of the present invention is such that the surface on which the insulating composite of the present invention is applied in step 2 is in contact with the conductor layer (1) on the substrate having the conductor layer (1) on the surface. It can be manufactured by thermocompression-bonding and curing to form an electrically insulating layer. It can manufacture by carrying out thermocompression bonding so that the surface coated at the process 2 may contact the conductor layer (1).
Thus, the surface coated in step 1 becomes the surface, and a laminate excellent in fine wiring pattern formability can be produced efficiently.

  As a method of thermocompression bonding, an insulating composite is overlaid so as to be in contact with the conductor layer (1) of the substrate, and a release film is overlaid thereon, followed by a pressure laminator, press, vacuum laminator, vacuum Examples thereof include a method of forming an insulating composite layer on the conductor layer (1) by thermocompression bonding (lamination) using a press such as a press or a roll laminator. By heating and pressurizing, bonding can be performed so that voids do not substantially exist at the interface between the conductor layer (1) and the insulating composite layer on the substrate surface.

Examples of the release film include resin films such as polyethylene terephthalate film, polypropylene film, polyethylene film, polycarbonate film, polyethylene naphthalate film, polyarylate film, and nylon film.
Among these films, a polyethylene terephthalate film and a polyethylene naphthalate film are preferable from the viewpoints of heat resistance, chemical resistance, peelability, and the like.

The temperature of the thermocompression bonding operation is usually 30 to 250 ° C., preferably 70 to 200 ° C., and the applied pressure is usually 10 kPa to 20 MPa, preferably 100 kPa to 10 MPa.
The thermocompression bonding time is usually 30 seconds to 5 hours, preferably 1 minute to 3 hours.
The thermocompression bonding is preferably performed under reduced pressure in order to improve the embedding property of the wiring pattern and suppress the generation of bubbles. The pressure of the atmosphere in which thermocompression bonding is performed is usually 100 kPa to 1 Pa, preferably 40 kPa to 10 Pa.

The insulating composite is usually cured by heating the entire substrate on which the insulating composite is formed on the conductor layer (1) after peeling the release film. Curing can be performed simultaneously with the thermocompression bonding operation. Alternatively, the thermocompression may be performed after the thermocompression operation is performed under conditions that do not cause curing, that is, at a relatively low temperature for a short time.
Further, for the purpose of improving the flatness of the electrical insulating layer or increasing the thickness of the electrical insulating layer, two or more insulating composites may be bonded and laminated on the conductor layer (1) of the substrate. Good.

4) Multilayer circuit board and its manufacturing method The multilayer circuit board of this invention forms a conductor layer (2) on the electric insulation layer of the laminated body of this invention mentioned above.

  The multilayer circuit board of the present invention is preferably manufactured by forming the conductor layer (2) on the electrical insulating layer by plating or the like in the manufacture of the laminate. Moreover, it can also manufacture by replacing with a peeling film and using a metal foil, etching this metal foil in a pattern shape by a well-known etching method, and forming a conductor layer (2).

  Examples of the metal foil used include copper foil, aluminum foil, nickel foil, chrome foil, gold foil, and silver foil. Among these, a copper foil, particularly an electrolytic copper foil or a rolled copper foil is preferable from the viewpoint of good conductivity.

  Hereinafter, a method for producing the multilayer circuit board of the present invention by forming the conductor layer (2) on the electrically insulating layer by plating will be specifically described.

  First, in manufacturing a multilayer circuit board, before forming the conductor layer (2), via holes penetrating the laminate are formed to connect the conductor layers in the multilayer circuit board.

  The via hole can be formed by chemical processing such as photolithography, or physical processing such as drilling, laser, or plasma etching. Among these, a method using a laser (a carbon dioxide laser, an excimer laser, a UV-YAG laser, or the like) is preferable because a finer via hole can be formed without degrading the characteristics of the electrical insulating layer.

Next, in order to improve the adhesiveness with the conductor layer (2), the surface of the electrical insulating layer is oxidized and roughened, and adjusted to a desired average surface roughness.
In the present invention, the surface average roughness Ra of the electrical insulating layer is usually 0.05 μm or more and less than 0.3 μm, preferably 0.06 μm or more and 0.2 μm or less, and the surface ten-point average roughness Rzjis is 0.3 μm or more. It is less than 4 μm, preferably 0.5 μm or more and 2 μm or less.

  Here, Ra is the centerline average roughness shown in JIS B0601: 2001 (ISO 4207: 1997), and the surface ten-point average roughness Rzjis is in JIS B0601: 2001 (ISO 4207: 1997) Annex 1. The ten-point average roughness shown.

  The electrical insulating layer surface can be oxidized by bringing the electrical insulating layer surface into contact with the oxidizing compound.

  Examples of the oxidizing compound to be used include known compounds having an oxidizing ability such as inorganic peroxides and organic peroxides; gas; In view of easy control of the average surface roughness of the electrical insulating layer, it is particularly preferable to use an inorganic peroxide or an organic peroxide.

Specific examples of inorganic peroxides include permanganate, chromic anhydride, dichromate, chromate, persulfate, activated manganese dioxide, osmium tetroxide, hydrogen peroxide, periodate, Examples include ozone.
Specific examples of the organic peroxide include dicumyl peroxide, octanoyl peroxide, m-chloroperbenzoic acid, peracetic acid and the like.

  There is no particular limitation on the method of oxidizing the surface of the electrical insulating layer using an inorganic peroxide or an organic peroxide. For example, there is a method in which an oxidizing compound solution prepared by dissolving the oxidizing compound in a soluble solvent is brought into contact with the surface of the electrical insulating layer.

  There is no particular limitation on the method of bringing the inorganic peroxide or organic peroxide or these solutions into contact with the surface of the electrical insulating layer. For example, a dipping method in which the electrical insulating layer is immersed in an oxidizing compound solution, an oxidizing compound solution Any method may be used, such as a liquid filling method in which a surface tension is applied to an electric insulating layer, or a spray method in which a solution of an oxidizing compound is sprayed onto a substrate.

  The temperature and time for bringing these inorganic peroxides and organic peroxides into contact with the surface of the electrical insulating layer may be arbitrarily set in consideration of the concentration and type of peroxide, the contact method, and the like. The said temperature is 10-250 degreeC normally, Preferably it is 20-180 degreeC, and the said time is 0.5-60 minutes normally, Preferably it is 1-30 minutes.

  Examples of the method for oxidizing using gas include plasma treatment for radical or ionization of gas such as reverse sputtering and corona discharge. Examples of the gas include air, oxygen, nitrogen, argon, water, carbon disulfide, and carbon tetrachloride.

When the gas for oxidation treatment is liquid at the treatment temperature but becomes gas under reduced pressure, the oxidation treatment is performed under reduced pressure.
Further, when the gas for oxidation treatment is a gas at the treatment temperature and pressure, the oxidation treatment is performed after pressurizing to a pressure capable of radicalization or ionization.

  The temperature and time for bringing the plasma into contact with the surface of the electrical insulating layer may be set in consideration of the type and flow rate of the gas. The contacting temperature is usually 10 to 250 ° C., preferably 20 to 180 ° C., and the contacting time is usually 0.5 to 60 minutes, preferably 1 to 30 minutes.

  After the oxidation treatment of the electrical insulating layer, the surface of the electrical insulating layer is usually washed with water in order to remove the oxidizing compound. If a substance that cannot be cleaned with water alone is attached, wash the substance further with a cleaning solution that can be dissolved, or make it a water-soluble substance by bringing it into contact with other compounds, and then wash with water. To do. For example, when an alkaline aqueous solution such as an aqueous potassium permanganate solution or an aqueous sodium permanganate solution is brought into contact with the electrical insulating layer, a mixed solution of hydroxyamine sulfate and sulfuric acid for the purpose of removing the generated manganese dioxide film, etc. It can wash | clean with water, after neutralizing-reducing process with the acidic aqueous solution of this.

  After the electrical insulation layer is oxidized to adjust the surface average roughness, a conductor layer (2) is formed on the electrical insulation layer surface and the inner wall surface of the via hole. As a method for forming the conductor layer (2), a plating method is preferable from the viewpoint of forming the conductor layer (2) having excellent adhesion.

  Examples of the method for forming the conductor layer (2) by plating include a method in which a metal thin film is formed on the electrical insulating layer by plating or the like, and then the metal layer is grown by thick plating.

  When forming a metal thin film by electroless plating, it is common to deposit catalyst nuclei such as silver, palladium, zinc and cobalt on the electrical insulation layer before forming the metal thin film on the surface of the electrical insulation layer. It is.

  The method for attaching the catalyst nucleus to the electrical insulating layer is not particularly limited. For example, a metal compound such as silver, palladium, zinc, or cobalt, or a salt or complex thereof is added to water or an organic solvent such as alcohol or chloroform to 0.001. Examples include a method of reducing a metal after dipping in a solution (which may contain an acid, an alkali, a complexing agent, a reducing agent, etc., if necessary) dissolved at a concentration of 10 to 10% by mass.

  As the electroless plating solution used in the electroless plating method, a known autocatalytic electroless plating solution may be used, and the metal species, reducing agent species, complexing agent species, hydrogen ion concentration, The dissolved oxygen concentration and the like are not particularly limited.

  For example, electroless copper plating solution using ammonium hypophosphite, hypophosphorous acid, ammonium borohydride, hydrazine, formalin, etc. as a reducing agent; electroless nickel-phosphorous plating solution using sodium hypophosphite as a reducing agent Electroless nickel-boron plating solution using dimethylamine borane as a reducing agent; electroless palladium plating solution; electroless palladium-phosphorous plating solution using sodium hypophosphite as a reducing agent; electroless gold plating solution; electroless silver Plating solution: An electroless plating solution such as an electroless nickel-cobalt-phosphorous plating solution using sodium hypophosphite as a reducing agent can be used.

After the metal thin film is formed, the substrate surface can be brought into contact with a rust preventive agent to carry out a rust prevention treatment.
Moreover, after forming a metal thin film, a metal thin film can also be heated for the adhesive improvement etc.
The heating temperature is usually 50 to 350 ° C, preferably 80 to 250 ° C.
Heating may be performed under pressurized conditions. Examples of the pressing method at this time include a method using physical pressing means such as a hot press machine and a pressurizing and heating roll machine. The applied pressure is usually 0.1 to 20 MPa, preferably 0.5 to 10 MPa. If it is this range, the high adhesiveness of a metal thin film and an electrically insulating layer is securable.

  A resist pattern for plating is formed on the metal thin film thus formed, and further, plating is grown thereon by wet plating such as electrolytic plating (thick plating), then the resist is removed, and the metal thin film is formed by etching. The conductor layer (2) is formed by etching in a pattern. Therefore, the conductor layer (2) formed by this method is usually composed of a patterned metal thin film and plating grown thereon.

  By using the multilayer circuit board obtained as described above as a new laminate, the above-described steps of forming the electrical insulating layer and the conductor layer (2) can be repeated to achieve further multilayering.

Thereby, a desired multilayer circuit board can be obtained.
The multilayer circuit board of the present invention is excellent in adhesion between the electrical insulating layer and the conductor layer (2). The peel strength measured in accordance with JIS C6481: 1996 between the conductor layer (2) and the electrical insulating layer in the multilayer circuit board of the present invention is usually 6 N / cm or more, preferably 8 N / cm or more. is there.

  The multilayer circuit board of the present invention is excellent in crack resistance. When the multilayer circuit board of the present invention was tested according to JIS Z2247: 2006, the distance (Erichsen value) that the punch tip moved from the wrinkle holding surface when the surface of the board was cracked was: Usually, it is 4 mm or more, preferably 5 mm or more.

  Since the multilayer circuit board of the present invention has excellent electrical characteristics, as will be described later, it is suitable as a substrate for semiconductor elements such as CPU and memory and other mounting parts in electronic devices such as computers and mobile phones. Can be used.

5) Electronic device The electronic device of the present invention has the multilayer circuit board of the present invention described above.
The electronic device of the present invention includes a mobile phone, PHS, notebook computer, PDA (personal digital assistant), mobile video phone, personal computer, super computer, server, router, liquid crystal projector, engineering workstation (EWS), pager. , A word processor, a television, a viewfinder type or a monitor direct-view type video tape recorder, an electronic notebook, an electronic desk calculator, a car navigation device, a POS terminal, a device equipped with a touch panel, and the like.
Since the electronic device of the present invention includes the multilayer circuit board of the present invention, it is a high-performance and high-quality electronic device.

The present invention will be specifically described below with reference to production examples, examples and comparative examples. In the following, “part” is based on mass unless otherwise specified. The test and evaluation were as follows.
(1) Weight average molecular weight (Mw), number average molecular weight (Mn)
It was measured as a polystyrene conversion value by gel permeation chromatography (GPC) using toluene or tetrahydrofuran as a solvent.
(2) Hydrogenation rate and maleic anhydride residue content Hydrogenation rate relative to the number of moles of unsaturated bonds in the polymer before hydrogenation (hydrogenation rate), and the total number of monomer units in the polymer The ratio of the number of moles of maleic anhydride residue (maleic anhydride group content) was measured by ¹ H-NMR spectrum.
(3) Glass transition temperature (Tg) of the polymer
According to JIS K7121: 1987, the temperature was increased by a differential scanning calorimetry (DSC method) at a heating rate of 5 ° C./min.

(4) Flame retardance A portion of the multilayer circuit board for evaluation without a conductor was cut into a strip having a width of 13 mm and a length of 130 mm to prepare a test piece. Methane gas was burned with a Bunsen burner having a tube diameter of 9.5 mm and a tube length of 100 mm, adjusted to a flame with a height of 19 mm, and approached until the obtained specimen was ignited. The flame was removed immediately after ignition and the time during which the test piece was burning was measured. Immediately after the test piece was extinguished, the flame was brought closer until it ignited again. The flame was immediately removed after the second ignition, and the time during which the test piece was burning was measured. When the total of the first burning time and the second burning time of the test piece was within 5 seconds, the test piece was evaluated as “◯”, the case where it exceeded 5 seconds and within 10 seconds, and the case where it exceeded 10 seconds were evaluated as “X”.

(5) Patterning property The patterning property when forming a wiring pattern on an electrically insulating layer was evaluated as follows.
On the electrical insulating layer, 100 wiring patterns having a wiring width of 20 μm, a wiring distance of 20 μm, and a wiring length of 10 cm were formed as patterns for patterning evaluation. The formed pattern was observed with an optical microscope, and all of the 100 patterns were evaluated as ◯ when the shape was not disturbed, Δ when the shape was disordered but not defective, and × when the defect was defective.

(6) Embedding property The embedding property when an insulating composite was laminated on a substrate having a pattern was evaluated as follows.
As a pattern for evaluating embedding, a double-sided copper-clad laminate having 100 wiring patterns with a wiring width of 20 μm, a wiring distance of 20 μm, a wiring length of 10 cm, and a wiring height of 15 μm was used to produce a multilayer circuit board for evaluation. The multilayer circuit board for evaluation was cut perpendicularly to the longitudinal direction of the wiring using a precision cutting machine (manufactured by Struers), and the cut surface was polished by a polishing machine (manufactured by Struers). The polished cross section was observed with an optical microscope, and the embedding property of the resin between the wirings was confirmed. 100 wiring patterns were evaluated as ○ when there was no embedding failure location, ○ when embedding failure location was 1 or more and 5 or less, and × when embedding failure location was 6 or more. .

(7) Flatness Flatness when an insulating composite was laminated and cured on a substrate having a pattern was evaluated as follows.
A multilayer circuit board for evaluation similar to the evaluation of embedding was produced. The surface irregularities were measured with a stylus type film thickness meter (trade name: P-10, manufactured by Tencor) in the direction perpendicular to the longitudinal direction of the wiring, and the step between the portion with the pattern and the portion without the pattern was 0 μm. Those having a particle size of less than 1 μm were evaluated as ◯, those having a particle size of 1 μm or more but less than 2 μm were evaluated as Δ, and those having a particle size of 2 μm or more as x.

(Production Example 1) Preparation of Varnish (1) 8-Ethyl-tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene is subjected to ring-opening polymerization by adding 1-butene as a molecular weight modifier, followed by hydrogenation reaction, and hydrogenated polymer of Mn 31,200, Mw 55,800, Tg 140 ° C. Got. The hydrogenation rate of the obtained hydrogenated polymer was 99% or more.
100 parts of this hydrogenated polymer and 55 parts of maleic anhydride were dissolved in 233 parts of cyclohexane. After raising the temperature to 135 ° C., a solution prepared by dissolving 5.5 parts of dicumyl peroxide in 105 parts of cyclohexanone was added dropwise over 2 hours, and the reaction was further performed at that temperature for 3 hours. The resulting reaction product solution was diluted with 42 parts of cyclohexanone and 362 parts of toluene and then poured into 2768 parts of isopropyl alcohol to solidify the reaction product, and the resulting solid was vacuum dried at 100 ° C. for 20 hours. Thus, a maleic acid-modified hydrogenated polymer a was obtained. The molecular weight of this maleic acid-modified hydrogenated polymer a was Mn = 29,000 and Mw = 76,000. Moreover, Tg was 170 degreeC and maleic acid group content rate was 29 mol%.

  100 parts of maleic acid-modified hydrogenated polymer a as polymer (1), 26.5 parts of bisphenol F type epoxy resin (trade name: EPICLON 830S, manufactured by Dainippon Ink and Chemicals) as polyvalent epoxy compound (1), rubber 30 parts of liquid polybutadiene (trade name: Ricon 156, manufactured by Sartomer), 0.1 part of 1-benzyl-2-phenylimidazole as a curing accelerator, curing aid (trade name: Ricacid TMTA-C, Shin Nippon Rika Co., Ltd.) 2 parts), 1 part of 2- [2-hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl] benzotriazole as a laser processability improver, and Tris (3,5-di -T-butyl-4-hydroxybenzyl) -isocyanurate is replaced with 337 parts of xylene and 145 parts of cyclopentanone. It was dissolved in a mixed solvent of, to give a varnish (1) mixing with a planetary stirrer.

(Production Example 2) Preparation of Varnish (2) 8-Ethyl-tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene was subjected to ring-opening polymerization by adding 1-butene as a molecular weight modifier, and then subjected to hydrogenation reaction to obtain a hydrogenation weight of Mn 25,000, Mw 45,000, Tg 140 ° C. Coalescence was obtained. The hydrogenation rate of the obtained hydrogenated polymer was 99% or more.
100 parts of this hydrogenated polymer and 55 parts of maleic anhydride were dissolved in 233 parts of cyclohexane. After raising the temperature to 135 ° C., a solution prepared by dissolving 5.5 parts of dicumyl peroxide in 105 parts of cyclohexanone was added dropwise over 2 hours, and the reaction was further performed at that temperature for 3 hours. The resulting reaction product solution was diluted with a mixed solvent consisting of 42 parts of cyclohexanone and 362 parts of toluene, and then poured into 2768 parts of isopropyl alcohol to coagulate the reaction product. The obtained solid content was vacuum-dried at 100 ° C. for 20 hours to obtain a maleic acid-modified hydrogenated polymer b. The molecular weight of this maleic acid-modified hydrogenated polymer b was Mn = 21,000 and Mw = 55,000. Moreover, Tg was 160 degreeC and maleic acid group content rate was 29 mol%.

  As polymer (2), maleic acid-modified hydrogenated polymer b 100 parts, as polyvalent epoxy compound 2, bisphenol A bis (propylene glycol glycidyl ether) ether (trade name: Adeka Resin EP4000S, manufactured by Asahi Denka Kogyo Co., Ltd.), filler 20 parts of melamine polyphosphate flame retardant (trade name: PMP200, manufactured by Nissan Chemical Industries) as (flame retardant), and condensed phosphate ester flame retardant (trade name: PX200, manufactured by Daihachi Chemical Industry Co., Ltd.) as a flame retardant aid 20 parts, 1 part 2- [2-hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl] benzotriazole as a laser processability improver, and tris (3,5- 1 part of di-t-butyl-4-hydroxybenzyl) -isocyanurate, 1-benzyl-2-phenylimid as curing accelerator A resin solution is obtained by dissolving 0.1 part of dazole and 5 parts of a curing aid (trade name: Ricacid TMTA-C, manufactured by Shin Nippon Chemical Co., Ltd.) in a mixed solvent consisting of 196 parts of xylene and 84 parts of cyclopentanone. It was.

(Production Example 3) Preparation of Varnish (2 ') Varnish (2 containing maleic acid-modified hydrogenated polymer c) in the same manner as in Production Example 2 except that the amount of 1-butene used as the molecular weight modifier was changed. ') Got. The molecular weight of the maleic acid-modified hydrogenated polymer c was Mn = 65,000 and Mw = 170,000. Moreover, Tg was 160 degreeC and maleic acid group content rate was 29 mol%.

(Example)
Using a double-sided gravure coater on a liquid crystal polymer nonwoven fabric (trade name: Vecrus MBBK14FXSP, manufactured by Kuraray Co., Ltd.) of a wholly aromatic polyester having a width of 250 mm, a thickness of 20 μm, and a mass per unit area of 14 g / m ^2. The varnish (1) was applied at a thickness of 5 μm, and the varnish (2) was applied at a thickness of 25 μm from the opposite side. Subsequently, it was dried at 80 ° C. for 10 minutes in a nitrogen atmosphere to obtain a composite resin molded body having a thickness of 50 μm and a liquid crystal polymer content of 40%.

  Double-sided copper-clad laminate having a thickness of 1.6 mm and a pattern for evaluation of embedding on both sides (trade name: CCL-HL830, manufactured by Mitsubishi Gas Chemical Company, glass cloth and varnish containing epoxy resin are impregnated into glass cloth A copper foil having a thickness of 15 μm was pasted on both surfaces of the obtained core substrate to form a wiring). This double-sided copper-clad substrate is immersed in a 5% sulfuric acid aqueous solution at 25 ° C. for 1 minute, and then washed with pure water to provide an inner layer substrate (corresponding to “a substrate having a conductor layer (1) on the surface” in the present invention). Obtained. Next, a 0.1% isopropyl alcohol solution of 2,4,6-trimercapto-s-triazine was prepared, and the above core substrate was immersed in this solution at 25 ° C. for 1 minute, and then at 90 ° C. for 15 minutes. The primer layer was formed on the inner layer substrate by drying in the replaced oven.

  Next, the obtained composite resin molded body was overlaid on the inner layer substrate so that the surface coated with the varnish (2) was inside. Further, a polyethylene naphthalate film having a thickness of 40 μm and a surface average roughness Ra of 0.08 μm was stacked thereon as a release film. This was decompressed to 200 Pa using a vacuum laminator equipped with heat-resistant rubber press plates at the top and bottom, and thermocompression bonded at a temperature of 110 ° C. and a pressure of 1.0 MPa for 60 seconds (primary press). Next, the pressure was reduced to 200 Pa using a heat-resistant rubber press plate covered with a metal press plate at the top and bottom, and thermocompression bonded at a temperature of 140 ° C. and a pressure of 1.0 MPa for 60 seconds (secondary press). Thereafter, only the release film was peeled off to obtain an inner layer substrate having a resin molded body layer on the surface.

  Next, the inner layer substrate having the resin molded body layer on the surface is immersed in a 1.0% aqueous solution of 1- (2-aminoethyl) -2-methylimidazole at 30 ° C. for 10 minutes, and then 1 in 25 ° C. water. After dipping for a minute, the excess solution was removed with an air knife. This was left in a nitrogen oven at 60 ° C. for 30 minutes and at 170 ° C. for 60 minutes to dry and cure the resin molded body layer, thereby obtaining a circuit board in which an electrical insulating layer was laminated on the surface of the inner layer board. The obtained circuit board was evaluated for wiring embedding and flatness. The evaluation results are shown in Table 1.

An interlayer connection via hole having a diameter of 30 μm was formed in the electrically insulating layer portion of the obtained circuit board using a third harmonic of a UV-YAG laser.
The obtained multilayer circuit board with via holes was rock-immersed in an aqueous solution at 70 ° C. adjusted to have a permanganate concentration of 60 g / liter and a sodium hydroxide concentration of 28 g / liter for 10 minutes. Next, this multilayer circuit board was immersed in a water tank for 1 minute and further washed in water by immersion in another water tank for 1 minute. Subsequently, the multilayer circuit board was immersed for 5 minutes in a 25 ° C. aqueous solution adjusted to a hydroxylamine sulfate concentration of 170 g / liter and sulfuric acid 80 g / liter, neutralized and reduced, and then washed with water.

  Next, as pre-plating treatment, Alcup activator MAT-1-A (manufactured by Uemura Kogyo Co., Ltd.) is 200 ml / liter, and Alcup activator MAT-1-B (manufactured by Uemura Kogyo Co., Ltd.) is 30 ml. / L, and immersed in a 60 ° C. Pd salt-containing plating catalyst aqueous solution adjusted to 0.35 g / L of sodium hydroxide for 5 minutes. This multilayer circuit board was rocked and immersed in a water tank for 1 minute, and further rinsed and immersed in another water tank for 1 minute, followed by washing with water, and then Alcapredeusa-MAB-4-A (manufactured by Uemura Kogyo Co., Ltd.) was 20 ml / The plating catalyst was reduced by immersion for 3 minutes at 35 ° C. in a solution prepared so that L and Alcapredeusa-MAB-4-B (manufactured by Uemura Kogyo Co., Ltd.) were 200 ml / liter. In this way, a plating catalyst was adsorbed to obtain a multilayer circuit board subjected to plating pretreatment.

  Next, the multilayer circuit board after the plating pretreatment is Sulcup PSY-1A (manufactured by Uemura Kogyo) 100 ml / liter, Sulcup PSY-1B (manufactured by Uemura Kogyo) 40 ml / liter, and formalin 0.2 mol / liter. While blowing air into the aqueous solution adjusted as described above, the electroless copper plating treatment was performed by dipping at a temperature of 36 ° C. for 5 minutes.

  The multilayer circuit board on which the metal thin film layer is formed by electroless plating is further immersed in a water tank for 1 minute, and further washed in a water tank for 1 minute, and then washed and dried to prevent rust. To obtain a multilayer circuit board on which an electroless plating film was formed.

  A dry film of a commercially available photosensitive resist is attached to the surface of the multilayer circuit board that has been subjected to rust prevention treatment by thermocompression bonding, and a mask corresponding to a pattern for patterning evaluation is adhered to the dry film for exposure. Then, development was performed to obtain a resist pattern. Next, it was immersed in an aqueous solution of 100 g / liter of sulfuric acid at 25 ° C. for 1 minute to remove the rust preventive, and electrolytic copper plating was applied to the resist non-formed portion to form an electrolytic copper plating film having a thickness of 18 μm.

Next, the resist pattern is stripped and removed with a stripping solution, and an etching process is performed with a mixed aqueous solution of cupric chloride and hydrochloric acid to form a wiring pattern composed of the metal thin film and the electrolytic copper plating film. A patterned multilayer circuit board was obtained. Finally, annealing treatment was performed at 170 ° C. for 30 minutes to obtain a multilayer printed wiring board (evaluation multilayer circuit board).
The obtained evaluation multilayer circuit board was evaluated for embeddability, flatness, flame retardancy, and patterning property. The evaluation results are shown in Table 1.

(Comparative Example 1)
A multilayer circuit board for evaluation was obtained in the same manner as in Example 1 except that the varnish (2 ′) was used instead of the varnish (2). The evaluation results are shown in Table 1.

(Comparative Example 2)
A multilayer circuit board for evaluation was obtained in the same manner as in Example 1 except that the varnish (1) was used instead of the varnish (2). The evaluation results are shown in Table 1.

(Comparative Example 3)
A multilayer circuit board for evaluation was obtained in the same manner as in Example 1 except that the varnish (2) was used instead of the varnish (1). The evaluation results are shown in Table 1.

According to the results shown in Table 1, the multilayer circuit board of the present invention (Example) was excellent in flame retardancy, and a fine pattern could be formed. In contrast, Comparative Example 1 using a polymer having a high weight average molecular weight resulted in poor embeddability and flatness.
Moreover, the fine pattern was not able to be formed in the comparative example 2 which did not use the varnish (2) which has a composition for forming the hardened | cured material excellent in characteristics, such as a flame retardance.
Furthermore, the comparative example 3 which did not use the varnish (1) which has a composition for forming the hardened | cured material excellent in fine wiring pattern formation property was inadequate in flame retardance.

Claims (12)

An insulating composite comprising a fiber substrate and a thermosetting composition, obtained by the following steps.
(Step 1) Containing a polymer (1) having a carboxyl group or an acid anhydride group, a polyvalent epoxy compound (1), rubber and an organic solvent (1) on one side of the fiber substrate, and substantially Step of applying varnish (1) not containing filler (Step 2) The fiber base has a carboxyl group or an acid anhydride group on the surface opposite to the surface to be applied in Step 1, and has a weight average molecular weight. Step of applying a varnish (2) containing a polymer (2) having a molecular weight of 15,000 to 100,000, a polyvalent epoxy compound (2), a filler and an organic solvent (2) (step 3) an organic solvent ( Steps for removing 1) and (2) to form a thermosetting composition supported by a fiber substrate   The insulating composite according to claim 1, wherein the polymer (1) is an alicyclic olefin polymer having a carboxyl group or an acid anhydride group.   The insulating composite according to claim 1 or 2, wherein the polymer (2) is an alicyclic olefin polymer having a carboxyl group or an acid anhydride group.   The insulating composite according to any one of claims 1 to 3, wherein the filler contained in the varnish (2) is a flame retardant.   The insulating composite according to any one of claims 1 to 4, wherein the fiber base material is a cloth made of long fibers of a liquid crystal polymer. A method for producing an insulating composite comprising a fiber base material and a thermosetting composition, comprising the following steps.
(Step 1) Containing a polymer (1) having a carboxyl group or an acid anhydride group, a polyvalent epoxy compound (1), rubber and an organic solvent (1) on one side of the fiber substrate, and substantially Step of applying varnish (1) not containing filler (Step 2) The fiber base has a carboxyl group or an acid anhydride group on the surface opposite to the surface to be applied in Step 1, and has a weight average molecular weight. Step of applying a varnish (2) containing a polymer (2) having a molecular weight of 15,000 to 100,000, a polyvalent epoxy compound (2), a filler and an organic solvent (2) (step 3) an organic solvent ( Steps for removing 1) and (2) to form a thermosetting composition supported by a fiber substrate   Hardened | cured material formed by hardening | curing the insulating composite of any one of Claims 1-5.   The laminated body formed by laminating | stacking the board | substrate which has a conductor layer (1) on the surface, and the electrically insulating layer which consists of hardened | cured material of Claim 7.   On the substrate having the conductor layer (1) on the surface, the insulating composite according to claim 1 is thermocompression-bonded so that the surface coated in step 2 of claim 1 is in contact with the conductor layer (1), The method for producing a laminate according to claim 8, wherein the electrically insulating layer is formed by curing.   A multilayer circuit board obtained by further forming a conductor layer (2) on the electrically insulating layer of the laminate according to claim 8.   The method for producing a multilayer circuit board according to claim 10, further comprising a step of forming a conductor layer (2) on the electrical insulating layer of the laminate according to claim 8 by a plating method.   An electronic device comprising the multilayer circuit board according to claim 10.