JPS63164389A - Printed wiring board - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention comprises at least a conductive metal and an insulating substrate,
The invention relates to a printed wiring board characterized in that the insulating substrate is a crosslinked product of a copolymer of two types of ethylene and a monomer having a polar group, an epoxy resin, and a mixture of a reaction accelerator; The object of the present invention is to provide a printed wiring board which not only has good heat resistance but also has extremely good adhesion to conductive metals.

The latest electronic devices are becoming smaller, lighter, thinner, and more densely packaged. In particular, printed wiring boards began to be commercialized for use in consumer devices such as radios, televisions, washing machines, and compact discs, and are now used in telephones, facsimile machines, word processors, robots, and computers, supported by mass production and high reliability. Applications are expanding to office equipment such as machines and industrial equipment.

Additionally, flexible printed wiring boards were initially used as an alternative to electric wires and cables.

Due to its flexibility, it can not only be mounted three-dimensionally at high density in a narrow space, but also can be repeatedly bent, so it can function as a wiring, cable, or connector for the moving parts of electronic devices. Its uses are being expanded.

Currently, the materials used as three-dimensional wiring materials in devices such as cameras, electric desktop calculators, telephones, and printers are:
A wiring pattern is formed using a flexible copper-clad board in which electrolytic copper foil of 35 microns is adhered to both or one side of a polyimide or polyester film with a thickness of about 25 microns. A wiring pattern in which through-hole plating is applied, and both sides and the outer layer are coated with a coverlay is also used.

Current flexible printed wiring boards generally use polyimide or polyester resin films as base materials, but polyester films not only have poor solder heat resistance, but also are difficult to bond with conductive metal layers such as copper foil. The epoxy adhesives currently available have a high water absorption rate and a large thermal expansion coefficient at 20°C to 250°C, so they lack through-hole connection reliability. In addition, when manufacturing 17
Curing is sometimes carried out by steam press at 0° C., and when multilayered, not only the adhesiveness between resins decreases but also the flexibility tends to decrease.

On the other hand, polyimide film is soldered at the normal soldering temperature (26
Polyimide resin has the advantage of being able to easily perform solder connections at temperatures above 0°C), but in addition to being hygroscopic, polyimide resin has poor surface activity, making it extremely difficult to bond with metal foil. There are drawbacks. To solve this problem of adhesion, the surface of the film is generally treated by chemical treatment using caustic soda, chromic acid mixture, aluminum hydroxide, etc., and then bonded using an adhesive. method is being carried out. However, even if these methods are used for adhesion, it is not possible to obtain a printed wiring board with sufficient adhesion, and the adhesive layer has poor chemical resistance, heat resistance, water resistance, etc., so etching treatment and I. ＼There are drawbacks such as copper foil lifting due to copper flow.

In addition, thermosetting adhesives with excellent heat resistance (for example,
In the method of bonding with metal foil using epoxy resin,
Polyimide film coated with adhesive must be layered with metal foil and cured using heat and pressure in a press for 1 to 20 hours, which poses problems in terms of productivity, mass production, and cost. Furthermore, due to its high hygroscopicity, there are other problems such as the need to dehydrate it under reduced pressure while heating it before the soldering process.

For these reasons, a part of the present invention provides a conductive metal and an insulating substrate, or a metal plate such as aluminum, a ceramic plate, an aramid m-fiber, and a thermosetting resin (for example, epoxy resin, unsaturated polyester resin), and the insulating substrate has a copolymer of ethylene and unsaturated dicarboxylic acid, its anhydride or halfester, and an epoxy group capable of radical copolymerization with ethylene. We have previously proposed printed wiring boards or flexible printed wiring boards that are crosslinked products of mixtures of copolymers with unsaturated monomers (Japanese Patent Applications No. 80-149183, No. 81-24089, No. 81).
-94837, No. 131-104854, etc.), these printed wiring boards and flexible printed wiring boards not only have good heat resistance and chemical resistance, but also have low water absorption and are easy to manufacture. However, these printed wiring boards and flexible printed wiring boards do not always have satisfactory adhesion with other materials such as polyimide and conductive metals at relatively high temperatures.

From the above, the present invention does not have these problems (defects), that is, it not only has excellent heat resistance and chemical resistance, but also has low water absorption and resistance to relatively high temperatures (for example, 100'0) has excellent adhesion to other substances such as polyimide and conductive metals, and moreover, printed wiring boards (including flexible printed wiring boards) can be easily obtained.

, and according to the present invention, these problems are solved by at least a conductive metal and an insulating substrate.

The insulating substrate is derived from (A) at least a unit derived from ethylene and at least one monomer selected from the group consisting of α, β-unsaturated monocarboxylic acid, α, β-unsaturated dicarboxylic acid, anhydride thereof, and halfester; a copolymer (I) consisting of a unit derived from ethylene, (B) a copolymer consisting of at least a unit derived from ethylene and a unit derived from an ethylenically unsaturated monomer containing an epoxy group (■),
(C) A cross-linked product of a mixture consisting of an epoxy resin having at least two epoxy groups in one molecule and a (+) reaction accelerator, including copolymer (1) and copolymer (II).
) and copolymer in the total amount of epoxy resin (
The mixing ratio of I) is 10 to 80% by weight, and the mixing ratio of the epoxy resin in the total amount of the copolymer (II) and epoxy resin is 5.0 to 80% by weight, and the carboxyl group and carboxylic acid anhydride AO, 2/1
to 5/1, and the mixing ratio of the reaction accelerator to 100 parts by weight of these total amounts is 0.005 to 5.0.
A printed wiring board, characterized in that it is a heavy part, can be solved by. The present invention will be explained in detail below.

The copolymer (I) used in the present invention has at least units derived from ethylene and is selected from the group consisting of α, β-unsaturated monocarboxylic acids, α, β-unsaturated dicarboxylic acids, their anhydrides, and halfesters. It is a copolymer consisting of units derived from at least one type of monomer. Examples of the copolymer include the following polymers.

(1) Copolymer of ethylene and α,β-unsaturated monocarboxylic acid (hereinafter referred to as “ethylene copolymer (a)”) (2) Copolymer of ethylene and α,β-unsaturated monocarboxylic acid ester A copolymer obtained by saponifying part or all of the copolymer and performing a neutralization reaction such as demetallization using an acid etc. [hereinafter referred to as "ethylene copolymer (b)"] )] and (3) copolymers of ethylene and α, β-unsaturated dicarboxylic acids, their anhydrides, or their halfesters [hereinafter referred to as “
These copolymers (I) are preferably those that melt at a temperature of 150° C. or lower and have fluidity.

(A) Ethylene copolymer (a) Ethylene copolymer (a) contains at least ethylene and α,
It is a copolymer with β-unsaturated monocarboxylic acid, in order to ensure the above-mentioned fluidity properties.

It is preferable to use a copolymerized comonomer with a radically polymerizable comonomer having a polar group (hereinafter referred to as "third component").

By copolymerizing this third component as a comonomer, a multi-component copolymer having units derived from the monomer corresponding to the third component copolymerized into the ethylene copolymer (a) can be obtained [see below. The same applies to the ethylene copolymers (b) to ethylene copolymers (d)).

The α,β-unsaturated monocarboxylic acid that can be used to produce the ethylene copolymer (a) generally has 3 to 20 carbon atoms, with 3 to 104H being particularly preferred. Examples include acrylic ugliness, methacrylic acid, crotonic acid, heptanoalkyl maleate, and monoalkyl fumarate.

Further, the third component is a radically polymerizable vinyl compound containing a polar group, and representative examples include unsaturated carboxylic acid esters, vinyl esters, and alkoxyalkyl (meth)acrylates.

The unsaturated carboxylic acid ester usually has 4 to 40 carbon atoms, preferably 4 to 20 carbon atoms! /X0 Typical examples include methyl (meth)acrylate, ethyl (meth)
Those having thermal stability such as acrylate are preferable, and those having poor thermal stability such as t-butyl (meth)acrylate are not preferable because they cause foaming.

Furthermore, the alkoxyalkyl (meth)acrylate usually has at most 20 carbon atoms. Moreover, those in which the alkyl group has 1 to 8 carbon atoms (suitably, 1 to 4 carbon atoms) are preferable, and those in which the alkoxy group has 1 to 8 carbon atoms (suitably, 1 to 4 carbon atoms) are preferable. Representative examples of preferable alkoxy(meth)alkyl acrylates include methoxyethyl acrylate, ethoxyethyl acrylate, and butoxyethyl acrylate. In addition, the number of carbon atoms in vinyl ester is generally at most 20 (
Typical examples thereof include vinyl acetate, vinyl propionate, vinyl butyrate,
Examples include vinyl vivarate.

In the ethylene copolymer (a), the amount of the third component is 2
It is preferably 5 mol% or less, and particularly preferably 2 to 20 mol%. Even if it exceeds 25 mol%, the characteristics of the present invention are expressed, but it is not necessary to exceed 25 mol%, and from the viewpoint of production and economy. Undesirable.

Ethylene copolymer of α,β-unsaturated monocarboxylic acid (
The amount of bonding in a) is preferably 0.5 mol% or more and 25 mol% or less, particularly preferably 1.0 mol% to 15 mol%. Although block or random copolymers are available, random copolymers are particularly preferred.

The α,β-unsaturated monocarboxylic acid is used as a crosslinking reaction point with the ethylene copolymer (d) described later and the epoxy resin, and to provide adhesiveness with a wide variety of base materials. There is no need to be excessive in terms of
If the amount increases, water absorption increases, which not only has negative effects such as foaming during molding and deterioration of electrical properties due to water absorption after molding, but also production problems such as safety, separation, and recovery, and economic problems. is also disadvantageous and undesirable; on the other hand, 0
．． If it is less than 5 mol %, there will be no problem in terms of adhesiveness, but it will be undesirable because it will be insufficient in terms of heat resistance.

The ethylene copolymer (a) is a mixture of ethylene and an unsaturated carboxylic acid, or a mixture of these and a third component.
~2500Kg/crn' ultra-high pressure, 120~
Radical polymerization at a temperature of 280°C, optionally with a chain transfer agent, in a stirred autoclave or tubular reactor, using a free radical generator such as peroxide, or optionally followed by a free radical generator. It can be obtained by graft copolymerizing an unsaturated carboxylic acid in the coexistence of an unsaturated carboxylic acid.

(B) Ethylene copolymer (b) Furthermore, the ethylene copolymer (ti) used in the present invention is one of the ester groups in the ethylene copolymer consisting of ethylene and an unsaturated carboxylic acid ester. It is a copolymer obtained by saponifying part or all of it and performing a neutralization reaction such as demetalization treatment.

The number of carbon atoms in the unsaturated carboxylic acid ester is usually 4 to 40, and 4 to 20 carbon atoms are particularly preferred. Typical examples include methyl (meth)acrylate, ethyl (meth)acrylate, and isopropyl (meth)acrylate. , n-
Examples include butyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, diethyl fumarate, and the like.

The content of unsaturated carboxylic acid ester in the ethylene copolymer (b) is preferably 1 to 25 mol%. The conversion rate, calculated as carboxylic acid-containing units in the copolymer after neutralization, is preferably 0.5 to 20 mol%, and particularly preferably 13 mol%.

The saponification reaction can be carried out using a widely known method, for example, using a mixed solvent of toluene and isobutyl alcohol (mixing ratio: 50:
50) by adding a copolymer containing NaOH and ester groups and refluxing for 3 hours.
It can be arbitrarily adjusted by adjusting the amount of OH. Furthermore, this saponified product is precipitated with water or alcohol, and after filtering the solvent, it is vacuum-dried at 50° C. day and night. Ethylene copolymer (b) is obtained by dispersing this polymer in water, adding sulfur to it, and stirring at 70° C. for 1 hour to perform a metal removal treatment (=neutralization reaction).

(C) Ethylene copolymer (C) Also, the ethylene copolymer (C) used in the present invention
) may result in a copolymer of ethylene and an α,β-unsaturated dicarboxylic acid, its anhydride, or its monoester (which may also contain the third component),
That is, it is a direct copolymerization of ethylene, α,β-unsaturated dicarboxylic acid, its anhydride or its halfester, or these and the third component.

Examples of the third component include the same type of compound as the ethylene copolymer (a).

When the ethylene copolymer (C) is produced by a direct copolymerization method, α,β-unsaturated dicarboxylic acid, its anhydride, or its halfester is selected as the comonomer.

The α,β-unsaturated dicarboxylic acid usually has at most 20 carbon atoms, preferably 4 to 16 carbon atoms. Typical examples of the dicarboxylic acid include maleic acid,
Examples include fumaric acid, itaconic acid, citraconic acid, and 3,6-endomethylene-1,2,3,6-titrahydrosis-phthalic acid (nadic acid@).

α,β-unsaturated unsaturated dicarboxylic acid ni-7 ester is
The number of carbon atoms is generally at most 40, especially 5 to 20.
I can give you individual things. A typical example thereof is one in which one of the carboxyl groups of the dicarboxylic acid is halfesterified with a representative example of an alcohol described below. Typical examples of the alcohol include primary alcohols having at most 20 carbon atoms, such as methanol, ethanol, propatool, and butanol. Representative examples of Hafestel include maleic acid monomethyl ester,
Examples include monoethyl maleate, monoisopropyl maleate, monobutyl maleate, and monoethyl itaconate.

The bond amount of "α,β-unsaturated dicarboxylic acid or its halfester" (hereinafter referred to as "unsaturated dicarboxylic acid component") in the copolymer (C) is 0.5 mol% or more and 20 mol% or less. It is preferable that there is, more preferably 1.0
~15 mol%.

The copolymer (II) used in the present invention is an ethylene copolymer [hereinafter referred to as "ethylene copolymer"] consisting of at least units derived from ethylene and units derived from an ethylenically unsaturated monomer containing an epoxy group. d).

CD) Ethylene copolymer (d) The ethylene copolymer (d) contains at least ethylene and "
It is a copolymer with an "unsaturated monomer having an epoxy group capable of radical copolymerization" (hereinafter referred to as "epoxy compound"). Furthermore, a multicomponent copolymer obtained by copolymerizing ethylene and an epoxy compound with the third component can also be used for the same reason as above.

Representative examples of this epoxy compound include those whose general formulas are represented by the following formulas [formula (1) and formula (I())].

Typical examples of epoxy compounds represented by formulas (I) and (II) include glycidyl methacrylate, glycidyl acrylate, α-methylglycidyl acrylate, α-methylglycidyl methacrylate, vinyl glycidyl ether, allyl glycidyl ether, and methacrylate. Examples include lyl glycidyl ether.

The melt index (JIS K-
7210, temperature is 180℃ and load is 2.1
(measured at 8Kg, hereinafter referred to as "Ni, 1.") is usually 0.5g710 minutes or more, and 5.0g / 10
The heating time is preferably 50 g for 710 minutes or more, particularly 50 g for 710 minutes or more.

(E) Epoxy resin The epoxy resin used in the present invention has at least two epoxy groups in one molecule. Generally, the softening temperature indicated by the Durand method is 170°C or lower, preferably 180°C or lower. If an epoxy resin whose softening temperature exceeds 170° C. is used, a reaction occurs during mixing in a molten state, making it impossible to obtain a homogeneous mixture.

For more information on this epoxy resin, please refer to 'Encyclopedia Off Polymer Science and Technology (
Ene7elopedia of Po17s+erS
science and Technology)” [
Interscience Publishers (Division)
Off John Wiley & Sons Ltd.) (r
nterscie-nce Publisher di
Vision of John Wiley & 5o
nsInc, ), published in 1987], Volume 8, No. 2
Pages 08 to 271, edited by Shunsuke Murahashi, Ryohei Oda, and Minoru Iki, “Plastic Handbook” (Breakfast Shoten, published February 1988) Pages 272 to 281, edited by Hiroshi Kakiuchi, “Epoxy Resin” (Shokodo) (Published in August 1978) From pages 89 to 105, the manufacturing method, softening,
It describes the purpose etc.

Examples of this epoxy resin include a reaction product between an active hydrogen compound (e.g., bisphenol A) and epichlorohydrin, a reaction product between a novolac resin and epichlorohydrin, a reaction product between an oxycarboxylic acid (e.g., oxybenzoic acid) and epichlorohydrin, and a reaction product between a polyphenol and epichlorohydrin. Reaction products with epichlorohydrin, resorcinol-acetone resins with epichlorohydrin, polyhydric phenols with epichlorohydrin, aromatic carboxylic acids with epichlorohydrin, alicyclic hydrocarbons (e.g. cyclohexene, dicyclopenta Examples include epoxy resins obtained by oxidizing gen, cyclopentene).

(F) Reaction accelerator The reaction accelerator used in the present invention is widely known as a curing agent for epoxy resins. 5
4), pages 26 to 28, pages 32 to 35, pages 108 to 128, pages 185 to 188, pages 330 and 331. can be given.

Typical examples of this reaction accelerator include primary, secondary or tertiary amines represented by formula (III), acids,
Examples include alkaline compounds and ammonium salts represented by formula (IV).

In addition, as the copolymer (I), an ethylene-based 4-copolymer (a
), when using a copolymer of units derived from ethylene and units derived from an unsaturated dicarboxylic acid anhydride (i.e., a copolymer having no carboxyl group), it is necessary to use a tertiary amine. There is.

In formula (m) and formula (■), Rj R7, R8 and R8 may be the same or different, and each may be a hydrogen atom,
A hydrocarbon group selected from an alkyl group, an aryl group, an alkaryl group, and an aralkyl group having 1 to 32 carbon atoms, but not all hydrogen atoms, and X is a halogen atom. In these formulas, R8 to R9
is preferably a hydrocarbon group having 12 or less carbon atoms, and
X is preferably a chlorine atom or a bromine atom.

Typical examples of the reaction accelerator include ethanolamine, jetanolamine, triethanolamine, dimethylamine, diethylamine, n-propylamine, isopropylamine, n-butylamine, M,N-dimethylaminoethanol, N,N- Diethylaminoethanol, morpholine, piperidine, pyridine, N,N-dimethylaminoethyl acrylate, N,N-dimethylaminomethacrylate, N,N-diethylaminoethyl acrylate, trimethylamine, triethylamine,
Tertiary amines such as tri-n-butylamine, N,N-dimethylbenzylamine, hexamethylenetetramine, triethylenediamine, N,N-dimethylpiperazine and N-methylmorpholine, p-toluenesulfonic acid and potassium hydroxide. Mention may be made of acidic or alkaline compounds and halogen salts of ammonium such as trimethylbenzylammonium chloride, tetraethylammonium bromide, tetrabutylammonium chloride and cetyltrimethylammonium chloride, as well as zinc chloride. Particularly preferred are N,N-dimethylbenzyl 7mine and p-toluenesulfonic acid.

In producing the mixture of the present invention, the copolymer (I) is a copolymer consisting of units derived from ethylene and units derived from α,β-unsaturated dicarboxylic acid anhydride, that is, ethylene and α,β- When using an unsaturated dicarboxylic acid anhydride or an ethylene-based multicomponent copolymer consisting of these and the third component, it is an organic compound or polymer with a boiling point of 150°C or higher, and a hydroxyl group (-0H
The above copolymer (I) or carboxyl group (-C0OH group) is blended (mixed) with
) and the copolymer (■).

The polymer includes the ethylene copolymer (a),
Ethylene copolymer (b), ethylene copolymer (C)
Among them, units derived from ethylene and α,β-unsaturated molybdenum/
Copolymers with units derived from monomers selected from the group consisting of carboxylic acids, α, β-unsaturated dicarboxylic acids, and halfesters thereof (these copolymers are ethylene-based multicomponent copolymers containing a third component) ), saponified copolymers of ethylene and vinyl acetate, copolymers of ethylene and hydroxyalkyl (meth)acrylates, and polymers mainly composed of ethylene or propylene (
(including homopolymers), α, β-unsaturated monocarboxylic acids, α, β-unsaturated dicarboxylic acids used in producing the ethylene copolymer (a) and ethylene copolymer (C). Alternatively, modified olefin polymers obtained by graft polymerization of anhydrides thereof can be mentioned. Furthermore, examples of organic compounds include ethylene glycol, polyethylene glycol, propylene glycol, glycerin, and polypropylene glycol.

(C) Mixing ratio Mixing ratio of ethylene copolymer (a) to ethylene copolymer (c) in the total amount of copolymer (1) of the present invention, copolymer (■), and epoxy resin is 10 to 80% by weight as their total amount, and 15 to 80% by weight
is preferred, particularly 20 to 85% by weight. Even if the mixing ratio of ethylene copolymer (a) to ethylene copolymer (C) in the total amount is less than 10% by weight, and even if the total amount exceeds 80% by weight, 1
Depending on the composition ratio, the crosslinking properties of the mixture may be insufficient, and the resulting crosslinked product may have poor heat resistance.Also, the mixing ratio of the epoxy resin in the total amount of the ethylene copolymer (d) and the epoxy resin may be insufficient. is 5.0 to 80% by weight, and 5.
0 to 70% by weight is preferred, especially 10 to 70% by weight
is suitable. The mixing ratio of the epoxy resin in the total amount of the ethylene copolymer (d) and the epoxy resin is 5.
If it is less than 0% by weight, the adhesion to metals at high temperatures is poor, while if it exceeds 80% by weight, the resulting crosslinked product will have poor flexibility.

In addition, the carboxyl group (-C00H) of the ethylene copolymer (a) to ethylene copolymer (C) in the mixture
and the sum of carboxylic acid anhydride groups, 0.3/1
Preferably from 0.5/1 to 3/1, especially from 0.5/1 to 2/1
is suitable. Even when the ratio exceeds 5:1 in a mixture, the adhesion to metals at high temperatures is poor.

Furthermore, the mixing ratio of 1 reaction accelerator is 0.005 to 5.0 parts by weight, and 0.01 to 5.0 parts by weight based on 100 parts by weight of the total amount of copolymer (1), copolymer (II), and epoxy resin.
It is preferably 5.0 parts by weight, and particularly preferably 0.01 to 2.0 parts by weight. Even if the reaction accelerator is blended in an amount exceeding 5.0 parts by weight with respect to the total amount of 100 parts by weight,
Although the low-temperature crosslinking promoting effect appears, the reaction accelerator itself may not only inhibit crosslinking adhesion, but also cause the reaction accelerator to bleed onto the surface of the molded product, making it difficult to obtain a good molded product. It is undesirable because it cannot be used.

When producing the mixture of the present invention, when blending the above-mentioned organic compound and/or polymer having a hydroxyl group or carboxyl group, the mixing ratio thereof should be the above-mentioned copolymer (I), copolymer (II) and epoxy Usually at most 20 parts by weight, preferably from 0.1 to 20 parts by weight, based on 100 parts by weight of the total amount with the resin, and 0.5 parts by weight.
-20 parts by weight are preferred, especially 1.0-15 parts by weight.

(H) Mixing method To produce the mixture of the present invention, two or more copolymers (1
) [i.e., selected from ethylene copolymer (a), ethylene copolymer (b) and ethylene copolymer (C)], copolymer (II) (i.e., ethylene copolymer ( d) ).

In this case, the epoxy resin and the reaction accelerator, or an organic compound or polymer having hydroxyl or carboxyl groups (hereinafter referred to as the "mixing component") may be uniformly mixed.

When the thin-walled material obtained by blending an inorganic filler with a thermal conductivity of 1×1 O-3 Cal/℃・CII・sec or more and an electrical resistance value of 10 Ω・cm or more is relatively thin. Thermal conductivity can be improved.

Representative examples of such inorganic fillers include beryllium oxide, boron nitrogen, magnesium oxide (magnesia), aminium oxide (alumina), silicon carbide, and glass beads. In addition, the particle size of the inorganic filler powder is preferably 100 JLII or less, particularly 0.1 to 20 IJ, and 11 is preferable. Difficult to uniformly disperse in compositions. On the other hand, if it exceeds 100JL11, the thickness of the resin layer will increase and the adhesive strength will further decrease, which is not desirable.

The blending ratio of this inorganic filler is at most 70% by volume. The thickness of this insulating layer is small (e.g.

20 hiro or less), fill (compound) with an inorganic filler.
Even if it is not used, the thermal conductivity improves, so there is no need to specifically incorporate it, but since the insulation property decreases, it is limited to applications with low voltage resistance. Generally, the thicker the insulating layer, the better the insulation, but the lower the thermal conductivity, so inorganic fillers are more effective. from these things.

When the thickness of the insulating layer (resin layer) is in the range of 10 to 30 IL, the blending ratio of the inorganic filler is preferably 50% by volume or less.
Also, the thickness is 30gm to 4. (In the range of lss,
The ratio of the inorganic filler in the resin layer is preferably 20 to 70% by volume, and if it exceeds 70% by volume, the thermal conductivity of the resin layer will improve, but it will not interact with the other substances and conductive metals described later. This is not preferable because not only the adhesiveness of the resin layer decreases, but also the resin layer (insulating layer) may break during bending or drawing, resulting in cracking.

The mixing method may be tri-blending using a mixer such as a Henschel mixer, which is commonly used in the field of olefin polymers, or melt-kneading using a mixer such as a Banbury, extruder, or roll mill. can give. At this time, a more uniform mixture can be obtained by triblending in advance and melt-kneading the resulting mixture. When melt-crosslinking, it is necessary that the mixed components do not undergo a substantial crosslinking reaction (if crosslinking occurs, not only will the moldability deteriorate when the resulting mixture is molded as described later), but also the desired molded product will not be formed properly. (This is undesirable because it may cause a decrease in heat resistance when crosslinking the shape or molded product.)
From this.

The melt-kneading temperature depends on the type and viscosity of the ethylene polymer and epoxy resin used, but it ranges from room temperature (20
℃) to 150℃, preferably 140℃ or less.

As a guideline for this "substantially no crosslinking", the total amount of copolymer (I), copolymer (II) and epoxy resin is extracted in boiling toluene for 3 hours, and then the diameter is 0. It is generally preferable that the afterflame of 1 gm or more (hereinafter referred to as "extracted afterglow") is 15% by weight or less,
It is preferably 10% by weight or less, optimally 5% by weight or less.

In producing this mixture, in order to further improve heat dissipation (thermal conductivity) and insulation,
Moreover, by filling the inorganic filler with high thermal conductivity, the effects of the present invention can be further exhibited.

(J) Production of thin-walled products To produce thin-walled products from the mixture obtained as described above, films should be produced using the T-Guy film method or the inflated film method, which are commonly used in the field of thermoplastic resins. It can be obtained by extruding it into a film or sheet using an extruder that is widely used in Japan. At this time, if extrusion is carried out at a high temperature, part or all of the mixed components will be crosslinked and small gel-like particles will be generated, making it impossible to obtain a uniformly thin product. The extrusion temperature is usually 250°C or lower. In particular, it is preferable to carry out the process in the same temperature range as in the case of the above-mentioned melt crosstalk.

In any of the above cases, after producing the thin-walled article, a good thin-walled article can be obtained by rapidly cooling it in a water-cooling roll or a water bath to prevent adhesion between the thin-walled articles or between the thin-walled articles and a take-up roll or the like. The thickness of the thin-walled product thus obtained is 5 gm to 4.0 gm. It is Omri! 0IL
11 to 3.0 ms is preferred, particularly 20 to 50 G 4 ts.

It is preferable that the thin-walled product obtained in this way is not crosslinked, that is, the extracted afterflame is preferably 15% by weight or less, as described above, preferably 10% by weight or less, and particularly preferably 5% by weight or less. .

(K) Conductive metal Methods for obtaining the conductive metal of the present invention include a method using a foil of a metal or alloy described below, a method of vapor depositing a metal, a method of electroless plating, and a method of electroless plating. An example of this method is to use a combination of the method and the electrolytic plating method.

(1) Metals and alloys for foil include aluminum, gold, silver,
Metals such as iron, copper, nickel and platinum, and alloys containing these as main components (50% by weight or more) (e.g.
stainless steel).

The thickness of this foil is usually 5 to 500mm thick, and 10 to 30mm thick.
0 ILm is desirable, especially 15 to 1100
p is preferred. Among the metals and alloys mentioned above, electrolytic copper foil with a thickness of 15 to 50 JL11 is preferably used.

(2) Vapor deposition As a method for vapor depositing the metal, commonly used vacuum heating vapor deposition such as resistance heating, electron beam heating, induction heating, or thermal radiation heating, or sputtering can be applied. Particularly for fine circuits, platinum and gold are often used, and when forming a circuit by etching after forming a thin film, copper, aluminum, and alloys containing these as main components are preferably used.

The thickness of the deposited conductive thin film can be freely selected depending on the conditions of the equipment used, but it is usually about 100 mm (
Angstroms (10nm) to 100m, especially 1000s (100n+s) to 20J
L11 is desirable.

Furthermore, copper, nickel,
It is also possible to electroplate or solder plate a metal such as gold to protect the surface and prevent corrosion, or to apply solder on the conductive path through a solder bath.

A so-called full additive method is also possible in which a circuit is formed by vapor deposition on the inner surface of the through-hole of the metal or alloy plate described above by the vapor deposition carried out in the present invention.

In addition, the conductive metal layer can be manufactured by using an electroless plating method or a combination of an electroless plating method and an electrolytic plating method, which are described in detail in Japanese Patent Application No. 80-8HI3.

In manufacturing the printed wiring board of the present invention, a crosslinked product obtained by crosslinking a thin product of the above-mentioned mixture as described below can be obtained by providing a conductive metal on at least one side of the crosslinked product. It is common to provide a layer of other material on the substrate.

Other materials include metal plates, metal foils, heat-resistant resins, heat-resistant fiber moldings, ceramics, and thermosetting resins. These other substances are not special and are widely used in the field of printed wiring boards (including flexible printed wiring boards).

(L) Metal plate and metal foil Examples of the metal types of the metal plate and metal foil include plates of metals such as aluminum, copper, and iron, and alloys containing these metals as main components (for example, stainless steel). The thickness of the metal plate is generally 0.5 to 5.0 mm, particularly preferably 1.0 to 5.0 am, and the metal foil usually has a thickness of 5 to 500 mm (preferably, 3
0 to 500 gta, preferably 50 to 5 oogm), and the heat dissipation can be improved by providing unevenness on the surface (outer surface) of the metal plate. At this time, the specific surface of the metal plate is 1.1 or more, preferably 1.8 or more.

Examples of methods for increasing the specific surface include methods using mechanical processing (for example, cutting processing and scorching processing) and methods using chemical processing (for example, alumite processing).

(M) Heat-resistant resin Examples of the heat-resistant resin include polyimide, saturated polyester, and other heat-resistant polymer substances.

Polyimide is generally obtained by casting a polyimide acid solution obtained by a low-temperature solution polymerization method, drying it, and then subjecting it to a dehydration ring-closing reaction. Furthermore, in the present invention, polyamide-imide having an amide group in the polymer main chain of the above-mentioned polyimide can also be preferably used. The general formula of the polyimide is shown in formula (V), and the general formula of polyamide-imide is shown in formula (1).These polymers are used as heat-resistant resins used in printed circuit boards in "Electronic Materials" June 1979 issue, No. 251. As described on page 1, the polymer has an aromatic ring in its chain unit.

Aromatic dicarboxylic acids or their ester-forming derivatives (
may be substituted with at most 40 mol% aliphatic dicarboxylic acid or alicyclic dicarboxylic acid) and aliphatic diol having 2 to 20 carbon atoms or its ester-forming derivative (at most 50 mol% molecular weight). It is a polymer or copolymer obtained by a condensation reaction containing as a main component a long chain glycol of 400 to s, ooo.

The intrinsic viscosity of this polyester is usually 0.4 to 165 (preferably 0.4
0 to 1.3) Typical polyesters are polyalkylene terephthalate resins, which are widely used as polyethylene terephthalate, polypropylene terephthalate and polybutylene terephthalate.

Other heat-resistant polymer substances include glass transition temperature (
Examples of heat-resistant polymers having a temperature (hereinafter referred to as rTgJ) of 200 to 400°C include those having the following polymer skeletons. For those with an amide bond as the backbone,
For example, poly-m-xy p-benzamide (Tg 230°C or higher) which is a polycondensate of xylene diamine and adipic acid + NH+ Go+ n, poly-p-phenylene terephthalamide (Tg 345°C), -E-NH+NH-Co -Yu Xco] -n, Polly m-
Examples include phenylene isophthalamide (7g23゜Co-)n, and those with an ester bond as a skeleton include polyarylate P-hydroxybenzoic acid obtained by polycondensing bisphenol A with isophthalic acid chloride or terephthalic acid chloride. polyoxymethylene [CH
2-Ol n, polyphenitersulfone compound S
02-◇XO machine, polysulfone polyether ether ketone polyphenylene sulfide +→[phase]XS÷. Others include polytriazine (Tg24o~
330°C), polyparabanic acid, polyazomethine, and polydistyrylpyrazine.

These thin heat-resistant resins are generally used as films or sheets. The thickness of the thin material is usually 107
It is preferably between 2 Gpm and 2.0 layers, and particularly preferably between 5 Gpm and 1.8 layers.

(N) Heat-resistant fibrous material Examples of the heat-resistant resin used in the present invention include aramid fiber sheets, glass Ia#I cloth, and nonwoven fabric.

Aramid fibers are generally polyamide fibers whose molecular skeleton is aromatic (hereinafter referred to as "aromatic polyamides"), and 1 normal aliphatic polyamide fibers (nylon).
It is distinguished from

This aromatic polyamide has a para-bond type with a linear molecular skeleton represented by the general formula (■) [hereinafter referred to as "aromatic polyamide (1)"], and a zigzag-shaped meta-bond type represented by the formula (VIN). Bond type [hereinafter r aromatic polyamide (2
)" and the zigzag meta-bond type represented by formula (IX) (hereinafter referred to as "aromatic polyamide (3)").

(■) The fiber shape is multifilament (usually 1 to 3
It is possible to have a circular cross section with a denier length of 10 to 20 ILm diameter), and it can be made into a single non-woven fabric or cut into 3 to 15 m5 pieces. Examples include In and those manufactured by centrifugal spinning into surface fibrils having a thickness of 17 zm or less and a length of 2 to 5 m.

Regarding this aramid fiber, see "Plastics" by Sakai, Kamiyoshi, and Tada, Vol. 36, No. 3, pp. 20 to 45.
(1985).

The size of the ms is preferably as small as possible in order to reduce unevenness on the surface of the printed circuit board, generally 10 gm or less, and particularly preferably 1 gm or less.

In addition, this sheet-like material generally has a
0g or more, 10g/rn' to 500g
7 m2 is preferable, especially 20 g/m to 5
00 g/rn' is preferred.

Furthermore, regarding the glass am and its sheet-like products and fabrics (eg, glass cloth, glass mat), those used in the glass fiber industry can be preferably used. In addition, it is desirable to use a material that has been subjected to a general sealing treatment, as well as a cleaning treatment or a silane treatment to improve compatibility with the synthetic resin used.

Regarding the glass cloth and glass mat, from the viewpoint of flexibility and prevention of peeling from conductive metal and occurrence of cracks when the molded product (printed wiring board) is bent, it is recommended that the weight of the glass cloth and glass mat be 300 g or less per square meter. Common, 30~
250g is preferable.

A weight of 50 to 200 g is suitable.

Regarding the shapes, manufacturing methods, types, etc. of the aramid fiber and glass fiber sheets and fibers, see Japanese Patent Application No. Sho Go-149193 and Japanese Unexamined Patent Publication No. Sho 80-17, respectively.
It is described in each specification of No. 6280.

These heat-resistant m-fibrous materials may be partially or completely impregnated into the crosslinked thin material of the mixture described later when producing a printed wiring board.

(0) Thermosetting resin Thermosetting resins include phenolic resins, epoxy resins, and unsaturated polyester resins. The thickness of this substrate is 0.6 to 4.0 m+s (preferably 0.8 to 3 m+s)
．． 2 layers @), also glass fiber.

It is made of glass fibers such as stable short fibers and has a weight of 20 to 200 g/g/kg and a thickness of 30 to 200 microns. A material impregnated with a curable resin and laminated can also be used. Moreover, these ta
It is also possible to use the fibrous material by mixing it with the pulp. Furthermore, in order to improve the electrical properties of glass paper, epoxy resins, alkyd resins, ethylene-vinyl acetate copolymers, or thermosetting resins treated with so-called silane treatment to improve immersion may also be used. The 6 representative ones that can be used are JIS
Glass cloth base epoxy resin copper clad laminate JI specified in standards such as C-6484, NEMA, NIL, etc.
S designation: GE2, GE2F, GE4, GE4F, paper-based phenolic resin copper-clad laminate (JISC-f148
5) Paper-based epoxy resin copper-clad laminate (JIS
C-8482), etc.

(P) Ceramics The types of ceramics are aluminum → (A sentence 203)
, silicon nitride (Si3Na), strength (Si02), titanium nitride (TiN), titanium (TIC), zirconium oxide (zirconia, Zr02), AJ120
3-3i02 series (mullite porcelain) Zr02/5i02,
Beryl oxide (Bed), magnesium oxide (magnesia, Mg0), BaTiO3, S f T f O3,
Examples include boron nitride (BN) and boron carbide (84C). Among these ceramics, alumina and silicon nitride are preferable. In particular, alumina is relatively inexpensive, and has good heat resistance, thermal conductivity, and mechanical properties. It is preferred for use because it not only has excellent strength, impact resistance, electrical insulation, and chemical durability, but also is easy to process.

In the present invention, these ceramics can be manufactured by firing these ceramics to form a plate shape, or by forming a thin film on the surface of a metal plate.

Chemical vapor deposition (CVD) is a method for forming thin films.
, vacuum evaporation method, sputtering method, thermal spraying method, etc.

The sintering method also depends on the particle size, particle size distribution, agglomeration state, impurities, etc. of the starting material ceramic, as well as the forming method and sintering temperature for 1 hour.

Various sintered products can be obtained depending on the sintering conditions such as the atmosphere. These sintering methods include one-reaction sintering method, pressure sintering method, (H
P method, HIP method), pressureless sintering method, gas pressure sintering method, etc. Furthermore, recently, injection molding methods have become popular for mass production. In this method, ceramic powder and an organic binder are generally mixed in advance, the resulting mixture is used to make a primary molded product using an injection molding machine, and the product is made into a product through a degreasing process and a main sintering process.

The methods for forming and sintering the thin film are industrially practiced and widely known.

The method for forming these thin films and the sintering method are described in detail in Japanese Patent Application No. 59-288312.

The thickness of the ceramic substrate thus obtained varies depending on the method of forming the thin film and the method of firing. In the method of forming a thin film, generally 100
layer m) to 0.1■, especially! Shuho or 10G
, Feng is preferred, and in the firing method, it is usually 50 or more! O intestine ■, 0.11 layer to 1.51
is desirable.

(Q) Crosslinking method In order to manufacture the printed wiring board of the present invention, when using metal foil among the conductive metals described above, a thin-walled product of the metal foil and the mixture manufactured as described above is used. Alternatively, the metal foil and other substances may be cross-linked as described below with a thin layer of the mixture interposed.Also, when depositing or plating a conductive metal, the thin layer of the mixture and other materials may be cross-linked. What is necessary is to crosslink the substance and vapor-deposit or plate the resulting crosslinked product.

The crosslinking method is selected depending on the thickness of other materials, ease of manufacture, productivity, etc., but generally, the crosslinking method is a hot press method using a press molding machine, and a hot roll method is used to manufacture a multilayered product. A typical example is a method using a commonly practiced thermocompression bonding method.

With the heat press method, products with sufficient adhesive properties can be obtained even at heating temperatures of 30°C or higher; however, in cases where thermal properties are required, the temperature is as high as possible (usually 200 to 300°C).
It is preferable to carry out the pressure bonding at a temperature of 10°C to 20°C higher than the required heat resistance temperature, whereby a laminate with good heat resistance and adhesiveness can be obtained. At this time, the heating temperature is 100~
10-20 minutes in the 180'0 range, 180-2
By heating and pressurizing for 0.5 to 10 minutes at 40℃ and 1 to 5 minutes at 240 to 400℃, a crosslinking reaction (condensation reaction) occurs within the resin, improving adhesiveness and heat resistance. performance is significantly improved. The pressurizing conditions are generally 0.1 Kg/cm'' (gauge pressure) or higher, and 1 to 1
00Kg/Cm' is desirable, especially 2 to 20Kg/Cm'.
cm'' is preferable. Furthermore, in order to obtain uniform adhesion, a method of applying pressure with a slight load under vacuum and reduced pressure is also used.

Further, in the thermocompression bonding method, the laminated components may be laminated and thermocompression bonded at a temperature of 250° C. or higher.

In any of the above methods, each laminated component may be temporarily bonded in advance (usually at 120 to 250° C.), and then crosslinked while being heated and bonded as described above.

The extraction afterflame of the thin-walled material crosslinked in this manner is at least 60%, preferably 70% or more, and particularly preferably 75% or more.

(R) Printed wiring board and method for manufacturing the same The printed wiring board of the present invention is composed of at least a conductive metal and an insulating substrate (resin layer, cross-linked mixture), but as described above, it may contain layers of other substances ( It is common to provide a molded article). The mixture in the obtained printed wiring board needs to be crosslinked as described above. In the printed wiring board of the present invention, a layer of a crosslinked product of the mixture is provided between the conductive metal layer and the other material layer. It is necessary to intervene. Further, as shown in FIG. 2-c below, the same applies to the case of having a multi-layered structure or the case of a conductive metal layer and a layer of another substance.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A typical example of a printed wiring board according to the present invention will be explained below with reference to the drawings. The following drawings are partially enlarged sectional views of representative examples of the printed wiring board of the present invention.

The printed wiring board shown in Figure 1-a has a conductive metal layer l.
It is obtained by sequentially laminating a resin layer (thin material) 2 and a thick layer 3 of another material (for example, metal, ceramics, thermosetting resin, heat-resistant resin). 1st
What is shown in Fig. 1-b is a printed wiring board in which an inorganic filler 5 is blended into the resin layer 2 of the printed wiring board shown in Fig. 1-a.

The one shown in Fig. 1-c has a conductive resin layer 1 laminated on both sides, and the one shown in Fig. 1-d has a through hole 8 provided in the printed wiring board shown in Fig. 1-0. FIG. 3 is a partially enlarged sectional view of a representative example.

Figure 2-a shows a conductive metal layer 1, a resin layer 2. It is a partially enlarged sectional view of a printed wiring board obtained by sequentially laminating film-like materials (thin materials) 4 such as flexible metal foil, heat-resistant resin, or thermosetting resin. Fig. 2-b is a partially enlarged sectional view of the structure shown in Fig. 2-a with conductive metal layers l provided on both sides, and Fig. 2-c is a partially enlarged sectional view of the same as shown in Fig. 2-a. FIG. 2 is a partially enlarged cross-sectional view of a typical example of a multi-layer board in which the components shown in FIGS.

What is shown in FIG. 3-a is one in which the inside of the resin layer 2 is filled with a heat-resistant fibrous material (for example, aramid cloth, glass cloth) 7. Fig. 3-b shows a case where a nonwoven fabric 6 is filled instead of the fibrous material shown in Fig. 3-a. What is shown in Figure 3-c is Figure 3-a or Figure 3-
The one shown in Figure b is a typical example when a thick layer 3 (or film-like material 4) of another material is laminated.
Figure d is a partially enlarged sectional view when a film-like material 4 made of a heat-resistant resin is laminated on the intermediate layer of the resin layer 2, and the thick layer 3 (or the film-like material 4) is further laminated thereon.

These drawings are typical partially enlarged cross-sectional views of a laminate in which a resin layer (thin material) is used in the printed wiring board of the present invention, but in addition to this, the adhesion of the thin material, It is possible to combine them to take advantage of their insulation performance.

Moreover, as shown in FIG. 2-c, it is also possible to use it as a multilayer printed wiring board.

The present invention will now be explained in more detail with reference to Examples.

In addition, in the examples and comparative examples, the peel strength is JIS
Conductive metal layer (such as copper foil) in accordance with C-6481
The conductive metal layer was removed by etching and the peel strength was measured when the conductive metal layer was peeled off at an 80 degree angle (pulling speed: 50 cm/min). In addition, the heat resistance test was 30
Evaluations were made by floating in a solder bath with lead/tin = 80710 (weight ratio) held at 0°C for 10 seconds, 20 seconds, and 180 seconds. The evaluation is shown in Table 1 as follows.

O: Remains unchanged in its original form ×: Peeling between layers with base insulating material and between copper circuits.

Deformations such as cracks and separation were observed.

In addition, molded products of various other substances, inorganic fillers, copolymer (I) and copolymer (I) used in Examples and Comparative Examples
A mixture with I) is shown below.

[(A) Mixture of copolymer (I) and copolymer (II)]

M,! is 300 g/10 minutes (density: 0.954 g/c, copolymerization ratio of acrylic acid: 20% by weight, hereinafter referred to as REAAJ), 120 g 710 ethylene-methyl methacrylate glycidyl methacrylate terpolymer [copolymerization ratio of methyl methacrylate 18.8
Weight%, copolymerization ratio of glycidyl methacrylate 12
．． 7% by weight, hereinafter referred to as rGMA (1) J) and epoxy resin (manufactured by Nippon Ciba Geigy, trade name Araldite ECN-1219111, epoxy equivalent: 235
g/eq, Duran melting point 98℃, below r ECH (a
)'', a total of 100 parts by weight of these copolymers and epoxy resin, and an additional 2.0 parts by weight of p-)luenesulfonic acid (as a reaction accelerator).
Mixing ratio EAA/GMA(1)/ECH(a)
ethylene-maleic anhydride-ethyl acrylate terpolymer (maleic anhydride copolymerization ratio of 2.8 mol%, copolymerization ratio of ethyl 7 acrylate 9.5 mol%,
(hereinafter referred to as r ETPJ) and the above GMA (1) and ECM (a), these EXA, GNA (1)
A mixture of 0.5 parts by weight of N,N-dimethylbenzylamine (as a reaction accelerator) mixed with 100 parts by weight of ECH (a) [mixing ratio ETP/GMA (
1) / ECH(a) / EAA=40150/1
An ethylene-glycidyl methacrylate-vinyl acetate copolymer [glycidyl methacrylate copolymer] having a weight ratio of 0/10 (referred to as "mixture (II) J" hereinafter) and the above-mentioned ETP is 7.2 g 710 min. Polymerization rate
2.3 mol%, copolymerization ratio of vinyl acetate 2.0 mol%
, hereinafter referred to as rGMA(2) J] and E(:H
(a) and HMA, GMA (2) and ECM
Total amount of (a) 100 layers and 3.0 parts by weight of p
-Mixture containing toluenesulfonic acid (as a crosslinking accelerator) [Mixing ratio ETP/GMA (2)/
ECH (a) = 130/30/10 (weight ratio), hereinafter referred to as "mixture (m)"] was used. In addition, for comparison, a mixture consisting of EAA and GMA (1) [mixing ratio EAA/GNA (1) -50150 (weight ratio), hereinafter referred to as "mixture (a)]" and ETP and GM
Mixture with A(2) [Mixing ratio ETP/GMA(2)
= 70/30 (weight ratio), hereinafter referred to as "mixture (b)"
I also prepared the following.

Note that these mixtures were manufactured by tri-blending the respective mixing components at each mixing ratio for 5 minutes using a Henschel mixer.

[(B) Molded product of other substances]

In addition, as molded products of other materials, commercially available epoxy resin glass cloth substrates (equivalent to JIS C-8484, GE 4, hereinafter referred to as "thermosetting substrates (A)"), commercially available paper phenolic resin laminates ( JIS C-6485, PP
7F equivalent product, hereinafter referred to as "thermosetting substrate (B)"), an aluminum plate with a thickness of 11 m (hereinafter referred to as "aluminum plate"), a silica steel plate with a thickness of 0.5 mm, and a low soda substrate (described later).
An alumina plate (thickness: 1 mm) obtained by sintering alumina (A1203), and an aluminum foil (hereinafter referred to as "aluminum foil") having a thickness of 100 mm.

A polyimide film with a thickness of 25 ps+ [manufactured by Toshisha Co., Ltd., trade name: Kapton, thickness 25 JLm, hereinafter referred to as "Film (1)"], a polyether sulfone film [thickness 50 ILm, hereinafter referred to as "Film (2)"] ]
, Plain weave glass cloth (Weight 400g/d, hereinafter "Ga9")
Non-woven fabric made from 13yo, 1.5 denier aramid fibers using a dry method (fabric weight: 250 g)
/m', hereinafter referred to as "nonwoven fabric").

((C) Inorganic filler) Furthermore, as an inorganic filler, low soda alumina (A1
203) content 88.8% by weight, true density 3.91
g/rn", average particle size 2pm, hereinafter "Al2o3"
) was used.

Examples 1 to 15, Comparative Examples 1 to 5 The above mixtures (I) to (m), and mixture (a)
and mixture (b) and FAA and GMA used in producing these mixtures (1) respectively.
- Extrusion v1 with die (diameter 40 layers m, die width 3
0 cm, rotation speed 85 revolutions/min), the cylinder temperature and die temperature are shown in Table 1, and the thickness is 501Lm, 100μm, and 200ILII.
A film was formed and wound around a roll cooled with water at 20°C. Table 1 shows the properties of each film thus obtained.

(Left below) Each film thus obtained was heated to 280°C for 10 minutes using a heat press machine to produce 50kg/cm each.
Conductive metal layers, resin layers and other materials listed in Table 2 in m' (gauge pressure), ie.

A printed wiring board was manufactured by laminating the base substrate).

The structure of each laminate is shown in the columns of Examples and Comparative Examples with the corresponding drawing numbers attached.

The results of the heat resistance test of each printed wiring board obtained in this way and the extraction residual of the crosslinked product of the resin layer mixture were evaluated in a second test.
The heat resistance test shown in the table is based on solder heat resistance and room temperature (2
Peeling tests of the conductive metal layer were conducted at temperatures of 3°C) and 100°C. In this peel test, the conductive metal layer was etched to a width of 10 an, and the tensile speed was 5.
180 degree peel strength measurements were performed at 0 layers per minute.

Note that the copper foil used as the conductive metal layer is electrolytic copper foil (thickness 3
5gm) was used. In addition, "plated copper" refers to a laminate obtained by laminating a resin layer and a molded product of other materials.
Plating was carried out at 72° C. using a chemical plating solution containing the following compound in an aqueous solution of U to obtain a copper plating film of about 30 microns on both sides of the sheet.

CuS0415H2010g EDTA ・2Na ・2820 3GgHC
HO (38%) 3sJLNaOH12
g After plating, the masking was washed off, washed with water, and dried (see "Conductive Metals" in Table 2).

(Write “plated” in the column.)

In Example 2, 100 parts by weight of mixture (1) was mixed with 300 parts by weight of Al2O3.

(Left below) The film obtained by removing the entire copper foil by etching from the laminates obtained in Examples 7 and 12 was JIS K
-Volume resistivity, dielectric constant (IM speed) according to 8911
, dielectric loss tangent and withstand voltage were measured.

The volume resistivity is 1015Ω・cm and the dielectric constant is 2.5
Met. Further, the dielectric loss tangent was 0.02, and the withstand voltage was 20 KV/am.

As is clear from Table 2, the crosslinked product of the mixture of the present invention has good adhesion to metal plates such as aluminum and silica steel plates, and molded products of other materials such as foils, thermosetting resins, and heat-resistant resin films. Excellent sex.

Moreover, it can be seen that the heat resistance is excellent. However, Example 5
and 6, because the heat resistance of the thermosetting resin substrate is poor,
The solder test was conducted at 260°C.

As is clear by comparing Comparative Examples 4 and 5 with Examples, by adding epoxy resin 1
It can be seen that the adhesive strength at 00°C is improved. This effect is effective for mounting a single component after circuit formation, wire bonding, etc. at high temperatures.

Furthermore, since the crosslinking reaction is accelerated by adding a reaction accelerator, it is necessary to set the film forming temperature to a low temperature. Although the peel strength at room temperature slightly decreases due to the high crosslinking rate, the adhesive strength at 100°C is improved.

From the results of the above examples and comparative examples, it is clear that when the crosslinked resin mixture of the present invention is used in the insulating layer and adhesive layer of printed wiring boards, it not only has excellent heat resistance but also has excellent adhesive strength with conductive circuit parts. Because of its large size, it is possible to increase density, attach various chip parts, and wire bonding.
It is clear that it can be widely used in the future as a substrate for Surf Ace mounts and the like.

1. The printed wiring board obtained by the present invention not only has good heat resistance as described above, but also has significantly improved reliability of electrical insulation, and also has crosslinking ability and adhesive properties when pressurized at high temperatures. It is a thing.

It was invented based on an idea completely different from that of conventional heat-resistant polymer chemistry.

(1) Since no thermosetting resin adhesive such as epoxy resin is used, not only the adhesion process is omitted, but also the complicated drying process associated with that process is eliminated.

(2) Excellent electrical properties (for example, insulation, withstand voltage, and dielectric loss tangent performance).

(3) # Good thermal properties, not only can it withstand temperatures of 250°C or higher, but can also be applied to metal layers such as copper foil without using the adhesive by applying pressure at temperatures of 100°C or higher. It can be bonded well.

(4) In particular, one feature of the printed wiring board obtained by the present invention is that, compared to the conventionally used adhesives made of heat-effect resin, the printed wiring board has a large size because it is crosslinked at a relatively high temperature (200°C or higher) as described below. It not only has excellent stability, but also has good adhesion even at high temperatures, has good adhesion, and has extremely few residual voids.

[Brief explanation of the drawing]

Figure 1-a, Figure 1-b, Figure 2-a, Figure 3-a, Figure 3-b, Figure 3-c, and Figure 3-d have a conductive metal layer laminated on one side. 1 is a partially enlarged cross-sectional view of a typical example of a printed wiring board having a structure in which one side is molded of another material; FIG. Moreover, FIG. 1-c and FIG. 2-b are partially enlarged sectional views of representative examples of a double-sided printed wiring board having a structure in which conductive metal layers are laminated on both sides. FIG. 2-c is a partially enlarged sectional view of a wiring board having a multilayer laminated structure, which is a combination of FIGS. 1-a to 1-c and FIGS. 2-a and 2-b. 1...Metal layer 2...Thin wall material crosslinked with mixture 3...
Other materials such as metal plates, ceramics, thermosetting resin substrates 4 Other materials such as thin metal foils and heat-resistant resins 5 Inorganic fillers 6 ...Heat-resistant fiber formed non-woven fabric 7...
・・Heat-resistant 1am formed product in the form of a woven fabric 8・・・・・
・Through hole

Claims (1)

[Claims] It consists of at least a conductive metal and an insulating substrate, and the insulating substrate includes (A) at least units derived from ethylene and α, β-
unsaturated monocarboxylic acids, α,β-unsaturated dicarboxylic acids,
Copolymer (I) consisting of a unit derived from at least one monomer selected from the group consisting of its anhydride and half ester, (B) ethylenically unsaturated containing at least a unit derived from ethylene and an epoxy group. Copolymers (II) and (C) consisting of units derived from monomers
It is a crosslinked product of a mixture consisting of an epoxy resin having at least two epoxy groups in one molecule and (D) a reaction accelerator, and is based on the total amount of copolymer (I), copolymer (II), and epoxy resin. The mixing ratio of the copolymer (I) is 10 to 80% by weight, and the copolymer (II)
The mixing ratio of the epoxy resin in the total amount of the epoxy resin and the epoxy resin is 5.0 to 80% by weight, and the molar ratio of the sum of carboxyl groups and carboxylic acid anhydride groups to the sum of epoxy groups is 0. 2/1 to 5/1, and the mixing ratio of the reaction accelerator to 100 parts by weight of the total amount thereof is 0.005 to 5.0 parts by weight.