JP2002249606A - Prepreg - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminate suitable for a circuit board, in which a relative dielectric constant and a dielectric loss do not increase due to blistering of the board or occurrence of corrosion or migration of a part electrode, even if subjected to an elevated temperature of around 260 deg.C, for example, at a soldering reflow process, and to provide a prepreg and a method for producing the same. SOLUTION: A curable resin composition is obtained by solving or dispersing 100 pts.wt. of an alicylic olefin polymer and 10-100 pts.wt. of a thermosetting resin to a mixed solvent containing a polar solvent and a nonpolar solvent. The prepreg is obtained by leaving to stand a fiber base material in an atmosphere of 100-450 deg.C, then impregnating the fiber base material with the curable resin composition, followed by drying to remove the mixed solvent. The prepreg has a dielectric loss tangent (1 MHz) of 0.05 or less, a water absorption of 1.5% or less, and a delamination strength of 200 gf/cm or more.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a prepreg, a method for producing the prepreg, and a laminate using the prepreg. More specifically, the present invention relates to a prepreg, which is exposed to a high temperature of about 260.degree. The present invention relates to a laminate suitable for a circuit board which does not increase in relative dielectric constant and dielectric loss due to corrosion or migration, a prepreg for obtaining the same, and a method for producing the same.

[0002]

2. Description of the Related Art In order to reduce the size, weight, and density of electronic devices, a method of surface mounting electronic components (leadless chip components) on a printed circuit board has been adopted. Also,
In order to increase the circuit density of a printed circuit board, a multilayer printed circuit board in which an insulating layer of the printed circuit board is formed into multiple layers and a circuit is arranged in the inner layer has been increasingly used. In addition, in order to effectively use the area of the circuit board, electrical connection between inner-layer circuits arranged via an insulating layer has been made through non-through holes. As a material for forming the insulating layer of such a high-density multilayer printed circuit board, a prepreg constituted by impregnating a resin into a heat-resistant synthetic fiber base material such as a glass fiber nonwoven fabric or an aromatic polyamide fiber (aramid fiber) nonwoven fabric is used. Has been proposed. Examples of the resin to be impregnated include a bisphenol-based epoxy resin, an epoxy resin having a cycloalkane structure (Japanese Patent Application Laid-Open No. H11-261239), a naphthol-modified epoxy resin, and an epoxy resin containing a biphenyl group.
-35659). However, in a multilayer circuit board using these prepregs, in the process of exposing the board to a high temperature such as in a reflow furnace, the board swells, corrosion and migration of component electrodes occur, and the relative permittivity and dielectric constant are increased. Losses may increase. Further, when an external force was applied, the metal foil sometimes peeled off from the insulating layer. The present applicant has proposed a resin varnish obtained by dissolving a thermoplastic norbornene-based polymer and a curable resin with a non-polar solvent such as toluene as a material for obtaining a prepreg by impregnating organic fibers or glass fibers. (International Publication WO / 98/15595). It discloses that a prepreg obtained by impregnating a glass nonwoven fabric with this curable composition can provide a laminate having a low dielectric constant and a low water absorption, and having high solder resistance and copper foil peel strength. However, according to the study of the present inventor, the curable resin composition may not be uniformly impregnated into the fiber base material, and after storing the laminate obtained by laminating the prepreg in a high humidity atmosphere, Exposure to an atmosphere may cause swelling of the laminate, corrosion or migration of component electrodes, and an increase in relative dielectric constant and dielectric loss.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a semiconductor device which is exposed to a high temperature of about 260.degree. C. as in a solder reflow process. It is an object of the present invention to provide a laminate suitable for a circuit board in which the dielectric constant and the dielectric loss do not increase, a prepreg for obtaining the laminate, and a method for producing the same. The present inventors have conducted intensive studies to achieve the above object, and as a result, impregnated a fiber base with a curable resin composition containing 100 parts by weight of an alicyclic olefin polymer and 10 to 100 parts by weight of a thermosetting resin. By using a prepreg having a dielectric loss tangent, water absorption and delamination strength after curing within a specific range, even if the substrate is exposed to a high temperature of about 260 ° C. as in a solder reflow process, the substrate swells, and the mounted components become It was found that a laminate suitable for a circuit board that does not fall off can be easily obtained, and that a cycloaliphatic olefin polymer and a thermosetting resin are dissolved in a mixed solvent composed of a polar solvent and a non-polar solvent to be curable. A resin composition was obtained, a fiber substrate treated in a specific temperature range was impregnated with the composition, and then the prepreg was obtained by removing the mixed solvent. And Zui, which resulted in the completion of the present invention.

[0004]

Thus, according to the present invention, a fibrous base material is impregnated with a curable resin composition containing 100 parts by weight of an alicyclic olefin polymer and 10 to 100 parts by weight of a thermosetting resin. The dielectric loss tangent after curing (1 MH
The present invention provides a prepreg having z) of 0.05 or less, a water absorption of 1.5% or less, and a delamination strength of 200 gf / cm or more, and a laminate in which a layer obtained by curing the prepreg is laminated. Further, according to the present invention, an alicyclic olefin polymer 1 is added to a mixed solvent containing a polar solvent and a non-polar solvent.
And 100 to 100 parts by weight of the thermosetting resin are dissolved or dispersed to obtain a curable resin composition.
A method for producing a prepreg, comprising impregnating the fibrous base material with the curable resin composition after leaving the fiber base material to stand at a temperature of about 450 ° C. and then drying and removing the mixed solvent.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The prepreg of the present invention comprises 100 parts by weight of an alicyclic olefin polymer and 10 to 1 thermosetting resin.
A fiber base material is impregnated with a curable resin composition containing 00 parts by weight, and has a dielectric loss tangent (1 MHz) of 0.05 after curing.
Below, the water absorption is 1.5% or less and the delamination strength is 200
gf / cm or more.

The curable resin composition used in the present invention contains an alicyclic olefin polymer and a thermosetting resin. The alicyclic olefin polymer usually contains a repeating unit derived from an olefin having an alicyclic structure (hereinafter, sometimes referred to as an alicyclic olefin). Examples of the alicyclic structure include a cycloalkane structure and a cycloalkene structure, and a cycloalkane structure is preferable from the viewpoint of mechanical strength, heat resistance, and the like. In addition, examples of the alicyclic structure include a monocyclic ring and a polycyclic ring (such as a condensed polycyclic ring, a bridged ring, and a polycyclic ring obtained by combining them). The number of carbon atoms constituting the alicyclic structure is not particularly limited, but is usually 4 to 30.
When the number is in the range of 5 to 20, more preferably 5 to 15, the mechanical strength, heat resistance, and various properties of the moldability are highly balanced and suitable. The proportion of the repeating unit derived from the alicyclic olefin in the alicyclic olefin polymer is appropriately selected depending on the purpose of use,
It is usually from 30 to 100% by weight, preferably from 50 to 100% by weight, more preferably from 70 to 100% by weight. If the proportion of the repeating unit derived from an alicyclic olefin is too small, heat resistance, dielectric properties, and low water absorption are unfavorably poor.

The alicyclic olefin polymer preferably has a polar group. As the polar group, a hydroxyl group, a carboxyl group, an alkoxyl group, an epoxy group,
Examples thereof include a glycidyl group, an oxycarbonyl group, a carbonyl group, an amino group, an ester group, and a carboxylic anhydride group, and a carboxyl group or a carboxylic anhydride group is particularly preferable. These polar groups can be used alone or in combination of two or more. The content of the polar group in the alicyclic olefin polymer is appropriately selected depending on the purpose of use, but is usually 3 to 150 mol%, preferably 6 to 100 mol%, based on the total number of monomer units in the polymer.
Mol%, more preferably in the range of 10 to 80 mol%. When the content of the polar group of the alicyclic olefin polymer is in this range, the impregnating property with the organic fiber base material is excellent, and the properties of adhesion, heat resistance, and low water absorption are highly balanced and suitable. .

The alicyclic olefin polymer is usually obtained by addition polymerization or ring-opening polymerization of an alicyclic olefin and, if necessary, hydrogenation of an unsaturated bond portion or addition polymerization of an aromatic olefin. And hydrogenation of the aromatic ring portion of the polymer. Further, the alicyclic olefin polymer having a polar group includes, for example, 1) a monomer having a polar group by introducing a compound having a polar group into the alicyclic olefin polymer by a modification reaction. Or (3) by (co) polymerizing a monomer containing a polar group such as an ester group as a polymerization component and then hydrolyzing the ester group. Of these,
The polar group-containing alicyclic olefin polymer obtained by the method 1) is preferred.

The alicyclic olefin used to obtain the alicyclic olefin polymer includes, for example, bicyclo [2.2.1] hepta-2-ene (common name norbornene), 5-methyl-bicyclo [ 2.2.1] Hepta-2
-Ene, 5,5-dimethyl-bicyclo [2.2.1] hept-2-ene, 5-ethyl-bicyclo [2.2.1]
Hept-2-ene, 5-butyl-bicyclo [2.2.
1] Hept-2-ene, 5-ethylidene-bicyclo [2.2.1] -hepta-2-ene, 5-hexyl-bicyclo [2.2.1] hepta-2-ene, 5-octyl-bicyclo [2.2.1] hepta-2-ene, 5-octadecyl-bicyclo [2.2.1] hepta-2-ene,
5-ethylidene-bicyclo [2.2.1] hepta-2-
Ene, 5-methylidene-bicyclo [2.2.1] hepta-2-ene, 5-vinyl-bicyclo [2.2.1] hepta-2-ene, 5-propenyl-bicyclo [2.2.
1] Hept-2-ene, tricyclo [4.3.0.1
^2,5 ] deca-3,7-diene (commonly used dicyclopentadiene), tricyclo [4.4.0.1 ^2,5 ] undeca-3,8-diene, tricyclo [4.4.0.1]
^2,5 ] undec-3-ene, 5-cyclopentyl-bicyclo [2.2.1] hept-2-ene, 5-cyclohexyl-bicyclo [2.2.1] hept-2-ene, 5
-Cyclohexenylbicyclo [2.2.1] hept-2
-Ene, 5-phenyl-bicyclo [2.2.1] hept-2-ene, tetracyclo [4.4.0.1 ^2,5 . 1
^7,10 ] -dodec-3-ene (also simply referred to as tetracyclododecene),

8-methyltetracyclo [4.4.0.1]
^2,5. 1^7,10] -Dodeca-3-ene, 8-ethyl
Tetracyclo [4.4.0.1^2,5. 1^7,10]-
Dodeca-3-ene, 8-methylidenetetracyclo [4.
4.0.1.^2,5. 1^{7,1 0}] -Dodeka-3-ene,
8-ethylidenetetracyclo [4.4.0.1^2,5.
1^7,10] -Dodeca-3-ene, 8-vinyltetracy
Black [4.4.0.1 ^2,5. 1^7,10]-Dodeca-
3-ene, 8-propenyl-tetracyclo [4.4.
0.1^2,5. 1^7,10] -Dodeca-3-ene, 8-
Cyclopentyl-tetracyclo [4.4.0.
1^2,5. 1^7,10] -Dodeca-3-ene, 8-sic
Rohexyl-tetracyclo [4.4.0.1^2,5. 1
^7,10] -Dodeca-3-ene, 8-cyclohexenyl
-Tetracyclo [4.4.0.1^2,5. 1 ^7,10]
-Dodeca-3-ene, 8-phenyl-cyclopentyl-
Tetracyclo [4.4.0.1^2,5. 1^7,10]-
Dodeca-3-ene; tetracyclo [7.4.0.1
^10,13. 0^2,7] Trideca-2,4,6,11-
Tetraene (1,4-methano-1,4,4a, 9a-te
Tetrahydrofluorene), tetracyclo [8.
4.0.1.^11,14. 0^3,8] Tetradeca-3,
5,7,12-tetraene (1,4-methano-1,4,4)
4a, 5,10,10a-hexahydroanthracene and
Pentacyclo [6.5.1]^3,6.
0^2,7. 0^9,13] Pentadeca-3,10-die
Pentacyclo [7.4.0.1 ^3,6. 1
^10,13. 0^2,7] Pentadeca-4,11-die
Adduct of tetramer or cyclopentadiene,
Enenylbicyclo [2.2.1] hept-2-ene, tet
Lacyclo [6.5.0.1^2,5. 0^8,13] Tride
C-3,8,10,12-tetraene (1,4-methano
Also called -1,4,4a, 9a-tetrahydrofluorene
), Tetracyclo [6.6.0.1^2,5. 0
^8,13] Tetradeca-3,8,10,12-tetraet
(1,4-methano-1,4,4a, 5,10,10a
-Also called hexahydroanthracene),

5-methoxy-carbonyl-bicyclo [2.2.1] hept-2-ene, 5-cyano-bicyclo [2.2.1] hept-2-ene, 5-methyl-5
Methoxycarbonyl-bicyclo [2.2.1] hepta
2-ene; 5-methoxycarbonylbicyclo [2.
2.1] Hept-2-ene, 5-ethoxycarbonylbicyclo [2.2.1] hept-2-ene, 5-methyl-
5-methoxycarbonylbicyclo [2.2.1] hept-2-ene, 5-methyl-5-ethoxycarbonylbicyclo [2.2.1] hept-2-ene, bicyclo [2.
2.1] Hept-5-enyl-2-methylpropionate, bicyclo [2.2.1] hept-5-enyl-2-
Methyl octanate, bicyclo [2.2.1] hept-
2-ene-5,6-dicarboxylic anhydride, 5-hydroxymethylbicyclo [2.2.1] hept-2-ene,
5,6-di (hydroxymethyl) bicyclo [2.2.
1] Hept-2-ene, 5-hydroxy-i-propylbicyclo [2.2.1] hept-2-ene, 5,6-dicarboxybicyclo [2.2.1] hept-2-ene;
5-Cyanobicyclo [2.2.1] hept-2-ene, bicyclo [2.2.1] hept-2-ene-5,6
-Dicarboxylic acid imide, 8-methoxycarbonyltetracyclo [4.4.0.1 ^2,5 . 17, ¹⁰ ] -Dodeca-3-ene, 8-methyl-8-methoxycarbonyltetracyclo [4.4.0.1 ^2,5 . 17, ¹⁰ ] -dodec-3-ene, 8-hydroxymethyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -dodeca-3-
Ene, 8-carboxytetracyclo [4.4.0.1
^2,5 . Norbornene monomers such as [ ^17,10 ] -dodec-3-ene;

Cyclobutene, cyclopentene, cyclohexene, 3,4-dimethylcyclopentene, 3-methylcyclohexene, 2- (2-methylbutyl) -1-cyclohexene, cyclooctene, 3a, 5,6,7a-tetrahydro-4,7- Monocyclic cycloalkene monomers such as methano-1H-indene and cycloheptene; vinyl alicyclic hydrocarbon monomers such as vinylcyclohexene and vinylcyclohexane; alicyclic conjugated dienes such as cyclopentadiene and cyclohexadiene System monomer;
And the like. Examples of the aromatic olefin include styrene, α-methylstyrene, divinylbenzene, and the like. The alicyclic olefin and / or the aromatic olefin can be used alone or in combination of two or more. The method of polymerizing the alicyclic olefin and / or the aromatic olefin and the method of hydrogenation performed as necessary are not particularly limited, and can be performed according to a known method.

[0013] The alicyclic olefin polymer is not particularly limited by its molecular weight. The molecular weight of the alicyclic olefin polymer is a weight average molecular weight (Mw) in terms of polystyrene (or polyisoprene) measured by gel permeation chromatography (GPC) using cyclohexane or toluene as a solvent, and is usually 5,000 to 1,00
000, preferably 5,000 to 500,000,
More preferably, it is in the range of 5,000 to 250,000. Weight average molecular weight (Mw) of alicyclic olefin polymer
Is within this range, heat resistance and smoothness after prepreg lamination are well balanced. The molecular weight distribution of the alicyclic olefin polymer is determined by the ratio (Mw / Mn) between the weight average molecular weight (Mw) and the number average molecular weight (Mn) measured by GPC using cyclohexane or toluene as a solvent.
And usually 5.0 or less, preferably 4.0 or less, and more preferably 3.5 or less. The glass transition temperature of the alicyclic olefin polymer may be appropriately selected according to the purpose of use, but is usually 50 ° C. or higher, preferably 70 ° C. or higher, more preferably 100 ° C. or higher, and most preferably 120 ° C. or higher. is there.

The thermosetting resin used in the present invention is not particularly limited in its kind, but is usually 2 per molecule.
It is composed of a compound having two or more reactive groups and a curing agent and / or a curing accelerator. Examples of the compound having two or more reactive groups in one molecule include a compound having two or more epoxy groups in one molecule, a compound having two or more vinyl groups or internal olefin groups in one molecule, and Those having two or more (meth) acryloyl groups in the molecule, those having at least two or more reactive groups selected from the epoxy group, vinyl group, and (meth) acryloyl group in one molecule; Among them, those having two or more epoxy groups in one molecule or those having at least two or more reactive groups selected from epoxy group, vinyl group and (meth) acryloyl group in one molecule are preferable. .
Further, among those having at least two or more reactive groups selected from an epoxy group, a vinyl group and a (meth) acryloyl group in one molecule, those having at least one of the reactive groups being an epoxy group are particularly preferred. As those having two or more epoxy groups in one molecule, for example, epoxy resins such as bisphenol type, novolak type, alicyclic type, heterocyclic type, fused ring type, glycerin type, and dicyclopentadiene type No. Specifically, a bisphenol type epoxy resin represented by the formula (E1),

[0015]

Embedded image (Wherein, R is a hydrocarbon group, n = 0 or an integer of 1 or more. However, R may be linear or branched,
Preferably, it is an isopropylidene group. Further, n may be a mixture of 0 or an integer of 1 or more. Further, the aromatic ring may be substituted with a halogen group. A) a hydrogenated bisphenol type epoxy resin obtained by hydrogenating a bisphenol type epoxy resin represented by the formula (E1), a naphthalene type epoxy resin represented by the formula (E2) or (E3), and the like.

[0016]

Embedded image (Where n is an integer of 0 to 5)

[0017]

Embedded image

Among those having at least two reactive groups selected from an epoxy group, a vinyl group and a (meth) acryloyl group in one molecule, those having at least one epoxy group include, for example, a glycidyl group. And vinyl compounds and (meth) acrylate compounds having a cyclohexene oxide structure. Specifically, 4
-Vinyl-1-cyclohexene-1,2-epoxide,
3,4-epoxycyclohexylmethyl (meth) acrylate, 3,4-epoxy-1-butene, 1,2-epoxy-5-hexene, 1-allieu 3,5-diglycidyl isocyanurate, 1,3-diallyl-5-glycidyl And isocyanurate.

The compound having two or more reactive groups in one molecule may be a polymer such as polyimide having a reactive group in addition to the above. For example, addition-type aromatic polyimides such as nadic acid-terminated polyimides and acetylene-terminated polyimides; polyaminobismaleimide (PI) resins, modified imide resins obtained by adding epoxy compounds, allyl compounds, acrylic compounds, vinyl compounds, and the like to PI, bismaleimides Bismaleimide type polyimide such as triazine (BT) resin; and the like. These compounds having two or more reactive groups in one molecule can be used alone or in combination of two or more.

Examples of the curing agent include aliphatic polyamine compounds, alicyclic polyamine compounds, aromatic polyamine compounds, bisazide compounds, acid anhydrides, dicarboxylic acid compounds, diol compounds, triol compounds, polyphenol compounds, polyamides, and diisocyanate compounds. And the like, and preferably include polyhydric phenol compounds and aromatic polyamine compounds, specifically, phenol novolak, cresol novolak, diaminodiphenylmethane, dicyandiamide, and the like. These curing agents can be used alone or in combination of two or more. The amount of the curing agent is usually 0.01 to 20 parts by weight based on 100 parts by weight of the reactive compound.

Examples of the curing accelerator include amine compounds, imidazole compounds, nitrogen-containing heterocyclic compounds such as diazabicycloundecene, organic phosphines, organic boron complexes, quaternary ammonium compounds, and quaternary compounds. Known materials such as phosphonium can be used. Of these, imidazole compounds are preferred because they have a high curing promoting effect, and organic phosphorus compounds and diazabicycloundecene have the effect of reducing the amount of ionic impurities extracted. Examples of the imidazole compound include 2-methylimidazole, 2-ethylimidazole, and 2-ethyl-4.
-Methylimidazole, bis-2-ethyl-4-methylimidazole, 1-methyl-2-ethylimidazole,
Alkyl-substituted imidazole compounds such as 2-isopropylimidazole, 2,4-dimethylimidazole, 2-heptadecylimidazole; 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl -2-ethylimidazole, 1-benzyl-2-phenylimidazole, benzimidazole, 2-ethyl-4-methyl-1- (2'-cyanoethyl) imidazole, 2-ethyl-4-methyl-1- [2'- (3 ", 5" -diaminotriazinyl) ethyl] imidazole compounds substituted with a hydrocarbon group having a ring structure such as an aryl group such as imidazole or an aralkyl group, 2,4'-diamino-6
— [2′-ethyl-4′-methylimidazolyl (1 ′)] ethyl-s-triazine, 2-methylimidazole / isocyanuric acid adduct, 2-methylimidazole / trimellitic acid adduct, 2-undecylimidazole, 1-cyanoethyl-2-undecylimidazole,
2,4-diamino-6- [2′-undecylimidazolyl (1 ′)] ethyl-s-triazine and the like. Examples of the organic phosphorus compound include triphenylphosphine and triphenylphosphine phenol salt. Among these, imidazole having a substituent having a ring structure is preferable from the viewpoint of compatibility with the alicyclic olefin polymer, and 1-benzyl-2-phenylimidazole is particularly preferable. Each of these curing accelerators, alone,
Alternatively, two or more kinds are used in combination. The amount of the curing accelerator can be appropriately selected according to the type of the compound having a reactive group. Usually, the compound 1 having the reactive group
It is usually 0.001 to 1 part by weight based on 00 parts by weight.

These thermosetting resins are used alone or in combination of two or more. The amount of the thermosetting resin is 10 to 100 parts by weight, preferably 10 to 90 parts by weight, based on 100 parts by weight of the alicyclic olefin polymer.
Parts by weight, more preferably 20 to 70 parts by weight. When it is in this range, it is excellent in low water absorption, delamination strength, etc., and is preferable.

In addition to the above, the curable resin composition used in the present invention contains a flame retardant, a radical crosslinking agent, another resin, a filler, a heat stabilizer, an antioxidant, a weather stabilizer, an ultraviolet absorber, a leveling agent. Agents, antistatic agents, slip agents, anti-blocking agents, anti-fogging agents, lubricants, dyes, pigments, natural oils, synthetic oils, waxes, emulsifiers, etc. It is appropriately selected within a range that does not impair.

Examples of the radical crosslinking agent include methyl ethyl ketone peroxide, cyclohexanone peroxide, 1,1-bis (t-butylperoxy) 3,3,3
5-trimethylcyclohexane, 2,2-bis (t-butylperoxy) butane, t-butyl hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide, dicumyl peroxide, 2,5-dimethyl-2 , 5-di (t-butylperoxy) hexyne-
3, organic peroxides such as α, α'-bis (t-butylperoxy-m-isopropyl) benzene, octanoyl peroxide, isobutyryl peroxide, and peroxydicarbonate; These crosslinking agents can be used alone or in combination of two or more, and the amount thereof is usually 0.001 to 20 parts by weight, based on 100 parts by weight of the alicyclic olefin polymer,
Preferably it is in the range of 0.01 to 10 parts by weight.

As the flame retardant, a flame retardant generally used for making plastics flame retardant can be used, and a reactive flame retardant can also be used. Specifically, phosphates such as tris (tribromoneopentyl) phosphate, decabromodiphenyl ether,
Examples include antimony trioxide, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and quinone adducts thereof, polyphosphoramide, melamine polyphosphate, and tetrabromobisphenol A. The amount of the flame retardant is appropriately selected according to the purpose of use, but is usually 0.1 to 50 parts by weight, preferably 1 to 20 parts by weight, based on 100 parts by weight of the alicyclic olefin polymer. You.

Examples of the polymer other than the alicyclic olefin polymer and the thermosetting resin include a rubbery polymer and other resins. The rubbery polymer is usually 30
It is a polymer having a Tg of not more than ℃, as a specific example,
Natural rubber, polyisobutylene rubber, butyl rubber, polybutadiene rubber, polyisoprene rubber, acrylonitrile / butadiene copolymer rubber, styrene / butadiene copolymer rubber, styrene / isoprene copolymer rubber, styrene / butadiene / isoprene terpolymer Diene rubbers such as rubbers and hydrogenated products of these diene rubbers; saturated polyolefin rubbers such as ethylene / α-olefin copolymers such as ethylene / propylene copolymers and propylene / other α-olefin copolymers; Α-olefin-diene polymer rubbers such as propylene-diene copolymer, α-olefin-diene copolymer, isobutylene-isoprene copolymer, isobutylene-diene copolymer; urethane rubber, polyether rubber, acrylic Rubber, propylene oxide Special rubbers such as side rubber and ethylene acrylic rubber; styrene thermoplastic elastomers such as styrene / butadiene / styrene block copolymer rubber, styrene / isoprene / styrene block copolymer rubber and their hydrogenated products; urethane thermoplastic elastomer A polyamide thermoplastic elastomer;
2-polybutadiene-based thermoplastic elastomer;

Other resins include, for example, polyolefins such as low density polyethylene, high density polyethylene, linear low density polyethylene, ultra low density polyethylene, polypropylene, syndiotactic polypropylene, polybutene and polypentene; polyamides such as nylon 66 Ethylene-ethyl acrylate copolymer, ethylene-vinyl acetate copolymer; polyester; polycarbonate; acrylic resin; These polymers can be used alone or in combination of two or more. The mixing ratio of the other polymer is usually 100 parts by weight or less, preferably 70 parts by weight or less, more preferably 50 parts by weight or less, based on 100 parts by weight of the alicyclic olefin polymer, and the lower limit is 0 part by weight. Department.

The filler can be added for the purpose of improving the mechanical strength, reducing the coefficient of thermal expansion, and achieving an arbitrary relative dielectric constant. Specifically, crystalline silica, fused silica, alumina, zircon, calcium silicate, calcium carbide, silicon carbide, boron nitride, beryllia, magnesia, zirconia, forsterite, steatite, spinel, mullite, titania, calcium titanate, barium titanate, strontium titanate, barium strontium _titanate, Bi ₄ Ti ₃ O 12 -PbTi
O ₃ system, Bi ₂ WO ₆ —Bi ₂ MoO ₆ system, Pb (Fe
_{2/3 W 1/3) O 3 -Pb (} Fe 1/2 Nb 1/2)
O _{3 type, Pb (Mg 1/3 Nb 2/3)} O 3 -PbTi
Known inorganic fillers such as an O ₃ -MgO-based filler are exemplified. The shape is selected from powder, granule, needle, or fiber depending on the purpose. Among these fillers, titanates are preferable because the relative dielectric constant can be adjusted to a desired value while keeping the dielectric loss tangent low. The amount of the filler is 0.1 to 200 parts by weight based on 100 parts by weight of the alicyclic olefin polymer, and the amount is determined depending on the purpose.

The curable composition contains a solvent for dissolving an alicyclic olefin polymer or the like in order to impregnate the fiber base material. In order to easily obtain the prepreg of the present invention, it is preferable to use a mixed solvent composed of a nonpolar solvent and a polar solvent. Suitable mixed solvents have a solubility parameter of 7.0.
～9.4 and (cal / cm) ^1/2 non-polar solvent, a solubility parameter 9.8~12.0 (cal / cm) ^1/2 mixed solvent containing a polar solvent. By using a mixed solvent consisting of a non-polar solvent and a polar solvent as an organic solvent for dissolving the alicyclic olefin polymer, etc., excellent impregnation into the fiber base material, low dielectric property, low dielectric loss tangent property, low water absorption Properties, interlayer adhesion and high heat resistance are highly balanced. When the organic solvent is a non-polar solvent alone or a polar solvent alone, the thermosetting composition may not be uniformly dispersed in the fiber base material and may not cover the fiber interface. As a result, in particular, it is inferior in water absorption and low dielectric loss tangent. Examples of the non-polar solvent (the solubility parameter [(cal / cm) ^1/2 ] in parentheses) include, for example, toluene (8.9) and xylene (8.
8), aromatic hydrocarbons such as ethylbenzene (8.2); n-pentane (7.0), n-hexane (7.
3), aliphatic hydrocarbons such as n-heptane (7.4); cyclopentane (8.7), cyclohexane (8.
Alicyclic hydrocarbons such as 2); and among them, aromatic hydrocarbons and alicyclic hydrocarbons are specific from the viewpoint of excellent compatibility with the alicyclic olefin polymer. Is preferably xylene or toluene.

Examples of polar solvents (in parentheses, solubility parameters [(cal / cm) ^1/2 ]) include, for example, chlorobenzene (9.5), dichlorobenzene (10.0),
Halogenated hydrocarbons such as acetone (9.9), methyl ethyl ketone (9.3), methyl isobutyl ketone (8.4), cyclopentanone (10.4), cyclohexanone (9.9), benzophenone, acetophenone Ketones such as (10.6); ethers such as tetrahydrofuran (9.1), tetrahydropyran and anisole; methyl formate, ethyl formate, methyl acetate (9.
6), ethyl acetate (9.1), propyl acetate (8.
8), butyl acetate (8.5), amyl acetate (8.5),
Methyl propionate (8.9), ethyl propionate,
Esters such as propyl propionate, methyl butyrate, ethyl butyrate, butyl butyrate, amyl butyrate, ethyl lactate, dimethyl carbonate, dimethyl phthalate, diethyl phthalate, and γ-butyl lactone; ethylene carbonate (14.
7), carbonate compounds such as propylene carbonate; N-methylpyrrolidone (11.3), N-ethylpyrrolidone, N-phenylpyrrolidone, N-benzylpyrrolidone, N, N-dimethylformamide (12.1);
Amide compounds such as N, N-diethylformamide and N, N-dimethylacetamide; acetonitrile (11.
9), nitrile compounds such as propionitrile (10.8), butyronitrile, benzonitrile, and capronitrile; sulfoxide compounds such as dimethylsulfoxide (14.5); Among these, ketones, esters, carbonate compounds, amide compounds, and the like are preferable from the viewpoint of compatibility with the alicyclic olefin polymer, and ketones are particularly preferable, and specifically, cyclopentanone and cyclohexanone are preferable. . The mixing ratio of the non-polar solvent and the polar solvent can be appropriately selected, but is usually from 5:95 to 95: 5, preferably from 10:90 by weight.
90:10, more preferably in the range of 20:80 to 80:20. The amount of the solvent to be used is appropriately selected according to the type of the fiber base material.
0 wt%, preferably 10 to 65 wt%, more preferably 20 to 60 wt%.

The method of dissolving the alicyclic olefin polymer, the thermosetting resin and other optional components in a solvent may be in accordance with a conventional method, for example, using a stirrer and a magnetic stirrer. Stirring, a high-speed homogenizer, a dispersion, a planetary stirrer, a twin-screw stirrer, a ball mill, a three-roll method, or the like.

The fiber base material used in the present invention includes those conventionally known for prepregs. As the fibers constituting the fiber base material, polyester fibers, nylon 66 fibers, m-phenylene isophthalamide fibers (meta-aramid fibers), p-phenylene terephthalamide fibers, p-diphenyl ether terephthalamide fibers (para-aramid fibers) Fiber), organic synthetic fiber such as polyacrylate fiber; natural fiber such as cellulose, cotton, hemp, wool, silk; glass fiber (E glass, C glass, D glass, S glass)
Glass, NE glass, H glass, etc.), asbestos, and inorganic fibers such as carbon fibers. These fibers are individually formed or mixed to form a nonwoven or woven fabric.
Among these fibers, aramid fibers, polyester fibers, and glass fibers are preferable, and particularly, meta-aramid fibers, para-aramid fibers, wholly aromatic polyester fibers, E glass fibers, and H glass fibers are preferable.

The fiber substrate can be used as it is,
It is preferable to use one that has been surface-treated for the purpose of improving the adhesion to the curable composition. As the surface treatment method, for example, heat treatment with hot air, infrared rays, near infrared rays, etc .;
Immersion treatment with a solvent such as an acid, alkali, or alcohol; plasma treatment; corona treatment; ozone treatment; and pre-impregnation treatment with a polyimide siloxane, an aramid elastomer, a biphenyl-type epoxy resin, a naphthalene-based epoxy resin, a coupling agent, or the like. These surface treatments can be used alone or in combination of two or more. Among these surface treatments, a heat treatment or a pre-impregnation treatment with a coupling agent, particularly a heat treatment, is effective for preventing swelling of the substrate. In the heat treatment, the fiber substrate is heated to 100 to 450 ° C, preferably 140 to 400 ° C.
Heat in a high-temperature atmosphere of ℃. The heating time can be appropriately selected and is usually 5 to 120 minutes. By performing the heat treatment under reduced pressure, the heating temperature can be reduced and the heating time can be shortened.

Examples of the coupling agent used in the pre-impregnation treatment include epoxy silane, amino silane, acryl silane, vinyl silane, γ-mercaptopropyl trimethoxy silane, and the like. Specifically, vinyl trimethoxy silane, vinyl phenyl Trimethoxysilane, 3-
Methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 4-glycidylbutyltrimethoxysilane, 3-aminopropyltrimethoxysilane, N-2- (aminoethyl) 3-aminopropyltrimethoxysilane, N Silane coupling agents such as-[beta] (N-vinylbenzylaminoethyl) [gamma] -aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, imidazole silane, triazine silane, etc .; isopropyl trisisostearoyl titanate, isopropyl tris-i- Dodecylbenzenesulfonyl titanate, isopropyltris-n-dodecylbenzenesulfonyl titanate, isopropyl-tris (dioctylpyrophosphate) titanate, tetraisopropyl-bis ( Dioctyl phosphite) titanate, tetraoctyl-bis (ditridecyl phosphite) titanate, tetra (2,2, -diallyloxymethyl-1-butyl) -bis (ditridecyl phosphite) titanate, bis (dioctyl pyrophosphate)
Oxyacetate titanate, bis (dioctyl pyrophosphate) ethylene titanate, isopropyl trioctanoyl titanate, isopropyl dimethacryl isostearyl titanate, isopropyl isostearyl titanate, isopropyl tri (dioctyl phosphate) titanate, isopropyl tricumyl phenyl titanate, isopropyl tri (N- Aminoethyl) titanate, dicklephenyloxyacetate titanate,
Titanate-based coupling agents such as diisostearoylethylene titanate; zirconate-based coupling agents such as acetoalkoxyaluminum diisopropylate; zirconia-aluminate-based coupling agents; organopolysilanes, titanium-based adhesion promoters, surfactant-based couplings Agents and the like.

The amount of the curable composition impregnated into the fiber base material is appropriately selected according to the purpose of use, and is usually 10/10 by weight ratio of [curable composition solids] / [fiber base material]. 90-90
/ 10, preferably 20/80 to 80/20, more preferably 30/70 to 70/30. When in this range, low dielectric properties, low water absorption and delamination strength are highly balanced and suitable. The method of impregnating the fiber base with the curable composition is not particularly limited, for example,
The method can be carried out by a method of immersing the fiber base material in the composition, a method of flowing the composition into the fiber base material under reduced pressure, or a method of spraying the composition on the fiber base material.

After impregnating the organic fiber base material with the curable composition, the solvent is removed. The method for removing the solvent is appropriately selected depending on the solvent type of the mixed solvent used, but the drying temperature is usually in the range of 50 to 200 ° C, preferably 70 to 150 ° C. After the solvent is removed, the curable composition impregnated in the fiber base material is preferably in an uncured state. In order to cure the prepreg, it is heated to a temperature at which the curable composition undergoes a curing reaction. (Hereinafter, in the present specification, the prepreg in an uncured state may be referred to as “A-stage prepreg” or simply “prepreg”, and the prepreg after curing may be referred to as “C-stage prepreg” or “post-cured prepreg”. The prepreg of the present invention has a low dielectric loss tangent and a low water absorption and a high delamination strength in the C-stage prepreg. The C-stage prepreg has a dielectric loss tangent at a value of 1 MHz of 0.05 or less, preferably 0.01 or less. The water absorption is 1.5% or less, preferably 0.7% or less, more preferably 0.5% or less. The delamination strength is 200 gf / cm or more, preferably 300 gf / cm or more, more preferably 400 gf / cm.
cm or more. The thickness of the prepreg is appropriately selected according to the purpose of use, but is usually 10 to 1000 μm, preferably 20 to 500 μm, and more preferably 50 to 250 μm.
m. When the thickness of the prepreg is in this range, the mechanical strength and the workability are balanced, which is preferable.

The prepreg of the present invention is obtained by laminating a plurality of sheets, performing heat compression molding, and curing and heat fusing.
A laminate having a required thickness can be obtained. When a prepreg is used for a circuit board, for example, a conductor layer made of a metal foil or the like is laminated on the prepreg, and then a circuit is formed by surface etching treatment or the like, so that the prepreg can be used as a circuit board. Also, after forming the circuit board, the metal foil and prepreg are further stacked and heated and compression molded,
By performing the surface etching treatment, a multilayer circuit board having a conductor layer not only on the outer surface of the laminate but also on the inside can be obtained. The method of laminating the conductor layer is not particularly limited. In addition to the method of performing the etching treatment after laminating the metal foil shown above, dry plating such as vapor deposition and sputtering; and wet plating such as electrolytic plating and electroless plating There is a method such as plating. Metals generally used for conductor layers are:
Examples include copper, nickel, tin, silver, gold, aluminum, platinum, titanium, zinc, and chromium. Of these,
Copper is preferred. In order to prevent warpage during high-temperature treatment and to efficiently cure the curable composition, the heating temperature at the time of heating and pressing is set to 100 to 300 ° C., particularly 150 to 2 ° C.
The temperature is preferably in the range of 60 ° C. Further, it is preferable that the pressurizing force at the time of heating and pressurizing is in the range of 10 to 80 kgf / cm ² , preferably 20 to 60 kgf / cm ² . By applying heat and pressure at a temperature and pressure in this range, the adhesive force between the metal foil and the resin layer and between the metal foil and the conductive resin composition can be increased, thereby substantially eliminating air holes in the fiber base material. , Thereby improving the substrate characteristics.

[0038]

The present invention will be specifically described below with reference to examples and comparative examples. In the examples, “parts” means “parts by weight” unless otherwise specified. (Evaluation Method) (1) The molecular weight was measured as a polystyrene equivalent value by gel permeation chromatography (GPC) using toluene as a solvent unless otherwise specified. (2) Hydrogenation rate (ratio of moles of hydrogenated hydrogen to moles of unsaturated bond in polymer before hydrogenation) and carboxyl group content (carboxyl group to total number of monomer units in polymer) Is the ratio of ¹ H-N
It was determined from the measurement results by MR. (3) The glass transition temperature (Tg) was determined by dynamic viscoelasticity analysis (D
MA method) was determined from the peak temperature of the loss tangent. (4) The relative dielectric constant and dielectric loss tangent at 1 MHz were measured by laminating four prepregs and using an automatic balance bridge method according to JIS C6481.

(5) The water absorption was measured according to JIS C6481 for a sample in which four prepregs were laminated. (6) The test for delamination strength was performed according to the copper foil peel strength test of JIS C6481. When an aramid nonwoven fabric is used as the base material, one prepreg is heated and pressurized to obtain a C-stage prepreg, and a cut of about 2 cm is inserted between two layers from an end of the C-stage prepreg, and both sides are formed on an aluminum plate. An adhesive tape was applied, and the edge of the cut portion of one layer was gripped by a jig of a peel strength tester, and pulled in a direction perpendicular to the aluminum plate surface to measure the peel strength. When glass is used as the base material, two prepregs are stacked and heated and pressed to obtain a laminate, and 2 cm from an end of the laminate.
Make a notch between the two layers, stick the laminated body to the aluminum plate with double-sided adhesive tape, grasp the edge of the cut part of one layer with the jig of the peel strength tester, and make a direction perpendicular to the aluminum plate surface And the peel strength was measured.

Production Example 8-Ethylidene-tetracyclo [4.4.0.
^12,5 . [ ^7,10 ] Dodeca-3-ene homopolymer (ETD) was subjected to ring-opening polymerization, followed by a hydrogenation reaction to obtain a hydrogenated ETD ring-opened polymer. The hydrogenation rate of the obtained polymer was 99% or more. 28 parts of this hydrogenated ring-opening polymer, 10 parts of maleic anhydride and 3 parts of dicumyl peroxide were dissolved in 130 parts of t-butylbenzene and reacted at 140 ° C. for 6 hours. The reaction product solution was poured into methanol to coagulate the reaction product. The coagulated product was vacuum-dried at 100 ° C. for 20 hours to obtain a hydrogenated maleic acid-modified ring-opening polymer (Polymer A). Polymer A has a weight average molecular weight (Mw) of 77,000, a molecular weight distribution (Mw / Mn) of 3.2, and a glass transition temperature (T
g) was 170 ° C., and the maleic acid group content was 22 mol%.

Example 1 100 parts of polymer A, 40 parts of brominated bisphenol A type epoxy resin (trade name: EPICLON 152: manufactured by Dainippon Ink Co., Ltd.), hydrogenated bisphenol A type epoxy resin (trade name: EPICLON EXA7015: Dainippon Ink) 40 parts and 1-benzyl-2-
0.1 part of phenylimidazole was dissolved in a mixed solvent of 114 parts of xylene and 76 parts of cyclopentanone to obtain a thermosetting resin composition having a solid concentration of 30%. The above composition was impregnated into an aramid nonwoven fabric substrate heat-treated at 200 ° C. and dried at 120 ° C. for 10 minutes to obtain a prepreg having a resin amount of 60%. The aramid nonwoven fabric substrate is obtained by laminating two aramid nonwoven fabrics. The prepreg was thermocompression-bonded with a vacuum press machine at 50 kgf / cm ^{2 at} a temperature of 200 ° C. for 60 minutes to cure the prepreg and obtain a C-stage prepreg. This C-stage prepreg had a water absorption of 0.47%, a relative dielectric constant of 3.82, a dielectric loss tangent of 0.015, and a delamination strength of 480 gf / cm. The two prepregs were overlapped and thermocompressed under the same conditions as above to obtain a laminate. In addition, wiring interval 150μ
The prepreg was superimposed on a substrate on which a comb-shaped electrode having a width of 150 μm and a wiring width of 150 μm was formed, and thermocompression-bonded under the same conditions as above to obtain a circuit board. The laminate and the circuit board obtained from the prepreg were evaluated by the following methods. Table 1 shows the results.

(1) Moisture and heat resistance: The laminate was heated at 121 ° C.
After leaving it for 4 hours under the condition of 00% RH, it was floated in a 260 ° C. solder bath for 20 seconds. The surface of the laminated body was observed, and evaluation was made as “A” when there was no swelling and “B” when there was swelling. (2) Insulation: The circuit board was left for 100 hours at 85 ° C. and 85% RH with a DC voltage of 30 V applied. The interlaminar insulation resistance is measured after standing, resistance more than 10 ⁹ Ω "A", less than 10 ⁸ or more ^{10 9 Ω "B", 10} 8 Ω
A sample having a short circuit and no short circuit was evaluated as “C”, and a short circuit was evaluated as “D”.

Example 2 100 parts of polymer A, 50 parts of brominated bisphenol A type epoxy resin (trade name: Araldite AER8049: manufactured by Asahi Ciba Co., Ltd.), brominated tolyl glycidyl ether (trade name: SHELL BROC: Yuka Shell Epoxy Co., Ltd.) 30 parts, antimony trioxide (trade name: Ti
(Monox Blue Star: manufactured by Anzon) 10
Part and 1-benzyl-2-phenylimidazole 0.1
Was dissolved in a mixed solvent of 114 parts of xylene and 76 parts of cyclopentanone to obtain a thermosetting resin composition having a solid content of 30%. The above composition was impregnated into an aramid nonwoven fabric substrate heat-treated at 200 ° C. and dried at 120 ° C. for 10 minutes to obtain a prepreg having a resin amount of 60%. This prepreg has a water absorption of 0.33%, a relative dielectric constant of 3.5 after curing,
Dielectric loss tangent is 0.0096 and delamination strength is 540 gf /
cm. Using this prepreg, a laminate and a circuit board were obtained in the same manner as in Example 1. The laminate and the circuit board were evaluated in the same manner as in Example 1. Table 1 shows the results.
Shown in

Example 3 100 parts of polymer A, 33 parts of brominated bisphenol A type epoxy resin (trade name: Araldite AER8049: manufactured by Asahi Ciba Co., Ltd.), brominated tolyl glycidyl ether (trade name: SHELL BROC: Yuka Shell Epoxy Co., Ltd.) 40 parts, antimony trioxide (trade name: Ti
(Monox Blue Star: manufactured by Anzon) 6 parts and 1 part of 1-benzyl-2-phenylimidazole are dissolved in a mixed solvent of 114 parts of xylene and 76 parts of cyclopentanone to obtain a thermosetting resin having a solid content of 30%. A resin composition was obtained. The resin composition was impregnated into an E glass fiber substrate heat-treated at 180 ° C. and dried at 120 ° C. for 10 minutes to obtain a prepreg having a resin amount of 60%. The prepreg 2
The sheets are stacked and 30kgf / cm by vacuum press
^{2. The} prepreg was cured by thermocompression bonding at a temperature of 180 ° C. for 60 minutes to obtain a laminate, which was used to determine the peel strength. This prepreg has a water absorption of 0.02% after curing,
The relative dielectric constant was 3.3, the dielectric loss tangent was 0.005, and the delamination strength was 490 gf / cm. A laminate was obtained by thermocompression bonding using the four prepregs under the same conditions as described above. Further, a prepreg was overlaid on a substrate on which a comb-shaped electrode having a wiring interval of 50 μm and a wiring width of 50 μm was formed, and thermocompression-bonded under the same conditions as above to obtain a circuit board. The laminate and the circuit board were evaluated in the same manner as in Example 1. Table 1 shows the results.

Comparative Example 1 A prepreg, a laminate and a circuit board were obtained in the same manner as in Example 1 except that the mixed solvent used in Example 1 was changed to 190 parts of xylene. This prepreg has a water absorption of 1.5%, a relative dielectric constant of 3.65 and a dielectric loss tangent of 0.01 after curing.
2. The delamination strength was 180 gf / cm. The laminate and the circuit board were evaluated in the same manner as in Example 1. Table 1 shows the results. Comparative Example 2 Brominated bisphenol A type epoxy resin (trade name: YD
B-500: 82 parts by Toto Kasei Co., Ltd., 13 parts of cresol novolak type epoxy resin (trade name: YDCN-220: Toto Kasei Co., Ltd.), 2.8 parts of dicyandiamide and 2-
0.1 part of ethyl-4-methylimidazole was dissolved in 35 parts of methyl ethyl ketone to obtain a composition having a solid content of 74%, and the prepreg was prepared in the same manner as in Example 1 except that the resin amount was adjusted to 50%. A laminate and a circuit board were obtained. After curing, the prepreg had a water absorption of 0.7%, a relative dielectric constant of 4.0, a dielectric loss tangent of 0.014, and a delamination strength of 890 gf / cm. The laminate and the circuit board were evaluated in the same manner as in Example 1. Table 1 shows the results.
Shown in

Comparative Example 3 2,2-bis (4-cyanatophenyl) propane 900
And 100 parts of bis (4-maleimidophenyl) methane were preliminarily reacted at 150 ° C. for 100 minutes, dissolved in a mixed solvent of methyl ethyl ketone and N, N′-dimethylformamide, and 0.2 part of zinc octylate was added. Then, the mixture was uniformly mixed and dissolved to obtain a composition. This composition was impregnated into an unheated E-glass fiber substrate and dried to obtain a prepreg. The two prepregs were stacked, and thermocompression-bonded with a vacuum press machine at 20 kgf / cm ^{2 at} a temperature of 250 ° C. for 120 minutes to cure the prepreg, obtain a laminate, and measure the peel strength. This prepreg has a water absorption of 0.15%, a relative dielectric constant of 3.7 and a dielectric loss tangent of 0.1 after curing.
002, the delamination strength was 330 gf / cm. A laminate was obtained by thermocompression bonding using the four prepregs under the same conditions as described above. Further, a prepreg was overlaid on a substrate on which a comb-shaped electrode having a wiring interval of 50 μm and a wiring width of 50 μm was formed, and thermocompression-bonded under the same conditions as above to obtain a circuit board. The laminate and the circuit board were evaluated in the same manner as in Example 1. Table 1 shows the results.

[0047]

[Table 1]

[0048]

The laminate using the prepreg of the present invention is:
Even after being left under high temperature and high humidity, the prepreg of the present invention is suitable as a material for a multilayer circuit board or the like because it has high resistance to solder and maintains interlayer insulation. It is suitable as a material for printed wiring boards for mounting semiconductor elements such as CPUs and memories and other mounting components in electronic devices such as computers and mobile phones.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) C08L 65/00 C08L 65/00 101/00 101/00 F term (reference) 4F072 AA04 AA07 AA08 AB06 AB29 AD04 AD11 AD28 AD29 AG03 AG17 AG19 AH02 AH13 AH21 AJ02 AJ04 AJ37 AK05 AK14 AL13 4F100 AK01A AK47A AK80A AR00B BA02 BA07 DG01A DG15A DH01A EJ82A GB43 JB13A JG01 CD12 J02A012

Claims (5)

[Claims] A fiber base material is impregnated with a curable resin composition containing 100 parts by weight of an alicyclic olefin polymer and 10 to 100 parts by weight of a thermosetting resin, and a dielectric loss tangent (1 MHz) after curing. Prepreg having a water absorption of 1.5% or less and a delamination strength of 200 gf / cm or more. 2. The prepreg according to claim 1, wherein the fiber base is an aramid nonwoven fabric. 3. A curable resin composition is prepared by dissolving or dispersing 100 parts by weight of an alicyclic olefin polymer and 10 to 100 parts by weight of a thermosetting resin in a mixed solvent containing a polar solvent and a non-polar solvent. A method for producing a prepreg, comprising: leaving the fiber base in an atmosphere at 100 to 450 ° C., impregnating the fiber base with the curable resin composition, and then drying and removing the mixed solvent. 4. A laminate comprising a plurality of layers obtained by curing the prepreg according to claim 1. 5. A laminate comprising a layer formed by curing the prepreg according to claim 1 and a conductor layer.