JPH03264351A - Copper clad laminate - Google Patents

Abstract

PURPOSE:To obtain copper clad laminate, which is excellent in rigidity, strength, soldering heat resistance and peel strength of copper foil, by a method wherein copper foil is laminated to allyl ester resin laminate through adhesive, which is prepared by mixing epoxy resin and poly(vinyl butyral). CONSTITUTION:The copper clad laminate concerned is produced by laminating allyl ester resin laminate and copper foil to each other through adhesive, which is prepared by mixing 10 - 300 pts. wt. of poly(vinyl butyral) with 100 pts. wt. of epoxy resin. Allyl ester resin is resin consisting of saturated polyester, which is made of saturated polybasic acid and saturated polyhydric alcohol and at the terminal of which allyl ester group is provided. As the adhesive, mixture prepared by melting and mixing epoxy resin, hardener and poly(vinyl butyral) with one another by proper solvent is used. As the copper foil, electrolytic copper foil or rolled copper foil, which is commonly used for copper clad laminate for electric circuit, is employed. The application of the adhesive to the copper foil is performed with roll coater, blade coater, wire bar coater or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a copper-clad laminate used in electrical equipment, electronic equipment, communication equipment, etc.

[Conventional technology]

Conventionally, paper-phenol, glass-epoxy, and the like have been commonly used as copper-clad laminates. Here, the copper-clad laminate refers to a laminate having a wall thickness of 0.15 to 5+ nm, which is used, for example, as a substrate for various electronic components.

[Problem to be solved by the invention]

However, when manufacturing paper-phenol laminates,
As the phenolic resin hardens, reaction by-products such as water are generated, and this reaction by-product has a negative effect on the physical properties of the laminate. It becomes necessary to apply pressure. moreover,
Paper-phenol laminates have the disadvantage of poor electrical properties such as dielectric constant, dielectric loss tangent, and tracking resistance. moreover,
When producing paper-phenolic or glass-epoxy laminates, the resin is usually dissolved in a solvent to form a solution, the solution is impregnated into a substrate, and the solvent is removed from the impregnated substrate to produce an intermediate called prepreg. A laminate was manufactured by forming a prepreg body and laminating the prepregs under high temperature and pressure. However, when a laminate is manufactured using such a prepreg method, there are problems in that raw material costs and equipment costs are high, and the process is complicated. In order to solve these problems, a paper-based laminate made of unsaturated polyester resin was proposed, but since unsaturated polyester resin inherently has poor heat resistance, the laminate also has poor heat resistance. There are problems such as low rigidity and insufficient strength.

In addition, epoxy resin adhesives have traditionally been used to attach copper foil to such unsaturated polyester resin laminates, but the heat resistance of this adhesive is insufficient, and it is difficult to withstand soldering heat. There are problems in that the adhesive strength of the copper foil is low and the adhesive strength of the copper foil is also insufficient.

The present invention was made in view of the above circumstances, and an object of the present invention is to provide a copper-clad laminate that is manufactured without using the prepreg method and has good rigidity, strength, soldering heat resistance, and beer strength of copper foil. That is.

[Means for Solving the Problem] As a result of various studies, the present inventors pasted copper foil together using an adhesive containing 10 to 300 parts by weight of polyvinyl butyral to 100 parts by weight of epoxy resin. It was found that the above object was achieved by an allyl ester resin copper-clad laminate, and the present invention was completed. That is, the problems in manufacturing paper-phenol laminates and glass-epoxy laminates are solved by an allyl ester resin that can manufacture laminates without using the prepreg method, and moreover, the laminates are manufactured using this resin. As a result, it has higher physical properties than laminates manufactured using unsaturated polyester resin, better electrical properties than laminates manufactured using phenolic resin, and is also compatible with allyl ester resin laminates. By using certain adhesives,
A laminate with excellent solder heat resistance and copper foil peel strength can be obtained.

Hereinafter, the content of the present invention will be explained in detail.

First, the allyl ester resin laminate according to the present invention will be explained.

The allyl ester resin as used in the present invention refers to a resin having an allyl ester group at the end of a saturated polyester formed from a saturated polybasic acid and a saturated polyhydric alcohol.

Saturated polybasic acids include, for example, dibasic acids such as orthophthalic acid, orthophthalic anhydride, isophthalic acid, phthalic acids such as terephthalic acid, tetrahydrophthalic acid, methyltetrahydrophthalic acid, endomethylenetetrahydrophthalic acid, methylendomethylenetetrahydrophthalate. acid,
Hexahydrophthalic acid, methyl hexahydrophthalic acid,
and hydrophthalic acids such as their acid anhydrides, aliphatic dibasic acids such as malonic acid, succinic acid, glutaric acid, adipic acid, tetrabromophthalic acid, tetrachlorophthalic acid, chlorendic acid, and acid anhydrides thereof, etc. Examples include halogenated dibasic acids. Examples of trifunctional or higher-functional polybasic acids include trimellitic acid, pyromellitic acid, and acid anhydrides thereof. These can be used alone or in combination.

Saturated polyhydric alcohols include ethylene glycol, 1
．． Aliphatic, alicyclic or aromatic compounds such as 2-propylene glycol, 1,4-butanediol, 1,6-hesanodiol, neopentyl glycol, 1,4-cyclohesanodiol, paraxylene glycol, etc. In addition to dihydric alcohols containing the general formula Ho(CHRCHt○)□
H (R is H or CsHtm*++m is an integer from I to 5,
n is an integer of 2 to 10) dihydric alcohols obtained by addition reaction of alkylene oxides such as ethylene oxide and propylene oxide. Examples of trihydric or higher polyhydric alcohols include aliphatic trihydric alcohols such as glycerin and trimethylolpropane, and tetrahydric or higher alcohols such as pentaerythritol and sorbitol. Further examples include aliphatic, alicyclic or aromatic halogenated polyhydric alcohols containing a halogen atom, such as dibromoneopentyl glycol and tetrabromobisphenol A ethylene oxide adduct. These can be used alone or in combination.

The method for producing allyl ester resins is already known and is described, for example, in Japanese Patent Application No. 63-262217. For example, an allyl ester resin is produced by charging a diallyl ester of a saturated dibasic acid such as diallyl terephthalate and a saturated polyhydric alcohol together with a transesterification catalyst into a reactor and reacting the allyl alcohol while distilling off the allyl alcohol. A more industrially effective method is to charge a dialkyl ester of a saturated dibasic acid, such as dimethyl terephthalate, in place of diallyl terephthalate, together with allyl alcohol, polyhydric alcohol, and a transesterification catalyst, to remove by-produced alcohols such as methanol. It can be obtained by reacting while distilling off.

Further, depending on the reaction temperature, a polymerization inhibitor such as hydroquinone may be allowed to coexist in the reaction solution. In this way, an allyl ester resin having an allyl ester group at the end of a saturated polyester can be produced.

The types of allyl ester resins that can be used in the present invention may be one type or a mixture of two or more types. By selecting various types of saturated polybasic acid and saturated polyhydric alcohol, a laminate with a good balance of heat resistance, electrical properties, etc. can be obtained.

In producing the laminate in the present invention, a radically polymerizable crosslinking monomer can be used together with the allyl ester resin, and any known ones can be used, but for example, diallyl orthophthalate, diallyl isophthalate, etc. , diallyl terephthalates such as diallyl terephthalate, substituted styrenes such as styrene, α-methylstyrene, p-methylstyrene, p-chlorostyrene, bromustyrene, divinylbenzene,
Methyl (meth)acrylate, Ethyl (meth)acrylate, Butyl (meth)acrylate, 2-(meth)acrylate
Acrylic acid or methacrylic acid esters such as ethyl silyl, lauryl (meth)acrylate, benzyl (meth)acrylate, brominated phenyl (meth)acrylate, ethylene glyfur di(meth)acrylate, 1 .4-Butanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, diacrylated incyanurate, pentae IJ thritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, glycerin di(meth)acrylate, )
Vinyl polyfunctional acrylic acid or methacrylic acid esters such as acrylate, inopentyl glycol di(meth)acrylate, bisphenol A di(meth)acrylate, polyurethane(meth)acrylate, polyether(meth)acrylate, epichlorohydrin-modified bisphenol A Vinyl polyfunctional oligoesters such as di(meth)acrylate, polyethylene glycol di(meth)acrylate, and polypropylene glycol di(meth)acrylate are included.

There is no problem in using two or more types of crosslinking monomers in combination depending on the purpose. In the present invention, by blending a crosslinking monomer, the viscosity of the allyl ester resin, which is originally a solid or viscous liquid, can be lowered, and the manufacturing process of the laminate can be simplified without going through the prepreg state using a solvent etc. can be converted into

The allyl ester resin in the present invention can be cured using a general-purpose organic peroxide, and may be used together with the organic peroxide or alone, such as a polymerization initiator that is sensitive to light, a polymerization initiator that is sensitive to radiation, or an electron beam. Known polymerization initiators can also be used.

Examples of organic peroxides include ketone peroxides such as methyl ethyl ketone peroxide and acetylacetone peroxide; 1. 1bis(t-butylperoxy)3,3.5-)limethylcyclohexane, n-
Peroxy ketals such as butyl-4,4-bis(t-butylperoxy)valerate, hydroperoxides such as t-butyl hydroperoxide, cumene hydroperoxide, p-menthane hydroperoxide, di-t- - dialkyl peroxides such as butyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5 di(1-butylperoxy)hexane, diacyl peroxides such as lauroyl peroxide, benzoyl peroxide, etc. Peroxydicarbonates such as 1so-propylbyroxydicarbonate, dimyristilveroxydicarbonate, bis(4-t-butylcyclohexyl)peroxydicarbonate, t-butylperoxybibarate, t Examples include peroxy esters such as -butylperoxy-2-ethylhexanoate and t-butylperoxybenzoate. These can be used in one type or in a mixture of two or more types depending on the type of resin and curing conditions.

In the present invention, fillers, reinforcing materials, mold release agents, coloring agents, curing accelerators, stabilizers, etc. may be used in combination with the allyl ester resin to further enhance the performance of the laminate.

Allyl ester resins or resin compositions based on them can be used to manufacture copper-clad laminates according to known methods. That is, a base material is impregnated with the above-mentioned resin composition, a plurality of impregnated base materials are laminated, a copper foil coated with an adhesive as described below is layered on one or both sides, and heated and cured without pressure or under pressure. A copper-clad laminate can be manufactured by molding. Of course, it is possible to first form a laminate and then stack copper foil coated with adhesive on it.

The above base material can be the same as the base materials used for conventional laminates, such as glass base materials such as glass fiber cloth and glass nonwoven fabric, cellulose such as kraft paper, linter paper, cotton paper, etc. Refers to paper base materials, inorganic fiber-based belt-like or band-like base materials, etc.

When paper is used as the base material, from the viewpoint of impregnability and quality, it is preferable to use paper mainly composed of cellulose fibers, such as kraft paper, which has a density of 0.3 to 0.7 g/cm 3 when dried in air.

Before impregnating these base materials with the impregnating resin composition, N
- It is also possible to improve the electrical properties by impregnating and drying with a methylol compound, phenol resin, silane coupling agent, etc.

Next, the adhesive used in the present invention will be explained.

Evoquin resin here is a compound that has two or more oxirane rings in one molecule and becomes three-dimensional by using a curing agent. Although there are many types and various types can be used, glycidyl type epoxy resin is preferred among them. Further, among the glycidyl type epoxy resins, it is particularly preferable in the present invention to use a mixture of bisphenol A diglycidyl ether and novolac polyglycidyl ether in an appropriate ratio, but the invention is of course not limited thereto. In this case, the mixing ratio of bisphenol A diglycidyl ether and novolak polyglycidyl ether is preferably 40 to 90% by weight for the former and 10 to 60% by weight for the latter.

There are many types of curing agents used. The types of polyamines include diethylenetriamine,
triethylenetetramine, tetraethylenepentamine,
Linear aliphatic polyamines such as diethylaminopropylamine, menthene diamine, isophorone diamine, N-
Aminoethylbiperacin, 3.9-bis(3-aminopropyl)2.4,8.10-tetraoxinbiro(55
) undecane adduct, alicyclic polyamines such as bis(4-amino-3-methylcyclohexyl)methane, bis(4-aminocyclohexyl)methane, m-xylene diamine, diaminodiphenylmethane, m-phenylenediamine, diaminodiphenyl Aromatic polyamines such as sulfone, various polyamides, modified polyamines, etc.
Examples of acid anhydrides include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnadic anhydride, dodecylsuccinic anhydride, chlorenedisocic anhydride, and anhydride. Pyromellitic acid, benzophenonetetracarboxylic anhydride, ethylene glycol bis(anhydrotrimate), methylchlorohexenetetracarboxylic anhydride, trimellitic anhydride, polyazelaic anhydride, etc. Phenol novolak,
There are polymercaptans and polysulfides. The above are classified as polyaddition type, but as those classified as catalyst type, anionic polymerization type is 2,4.6-)
Lis(dimethylaminomethyl)phenol, various imidazoles, and cationic polymerization types include BF3 monoethylamine complex.

In addition, dicyandiamide may be mentioned as a latent curing agent. The present invention is not limited to these, and appropriate selection can be made depending on the purpose.

The polyvinyl butyral used preferably has a composition ratio of vinyl butyral groups in the molecular chain of 75% by weight or more and an average degree of polymerization of 500 to 5,000. If the composition ratio is less than 75% by weight or the average degree of polymerization is less than 500, problems will occur in the heat resistance of the adhesive, and if the average degree of polymerization is less than 500, problems will occur.
．． If it exceeds 000, the solubility in solvents will deteriorate.

The blending ratio of polyvinyl butyral to 1001 parts of epoxy resin is preferably 10 to 300 parts by weight, and 20 parts by weight.
~200 parts by weight is preferred. If it is less than 10 parts by weight, the beer strength of the copper foil will be low, and if it exceeds 300 parts by weight, the solder heat resistance will be poor.

The epoxy resin, curing agent, and polyvinyl butyral are mixed and dissolved using a suitable solvent to form an adhesive formulation. Depending on the type of curing agent, for example, dicyandiamide may be used in a dispersed state. Therefore, the type of solvent is not limited, and may be appropriately selected depending on the purpose, coating process, etc.

It is also possible to add fillers, reinforcing materials, coloring agents, hardening accelerators, anti-aging agents, stabilizers, etc. to this adhesive formulation as required.

Furthermore, the copper foil used in the present invention refers to copper foil generally used for copper-clad laminates for electric circuits, that is, electrolytic copper foil and rolled copper foil. The coating may be carried out using a blade coater or a wire bar coater as appropriate. The copper foil coated with the adhesive is preferably heat-treated to remove the solvent and to be used in a partially cured state.

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples unless it departs from the gist of the present invention. Throughout this specification, all temperatures are in degrees Celsius, and parts and percentages are by weight unless otherwise specified.

〔Example〕

Production Example 1 Production of allyl ester resin (1) Diallyl terephthalate 60 was added to 11 reactors equipped with a distillation apparatus.
0 g (2,44 mof2), 95.9 g (1,26 mof2) of propylene glycol, and 0.1 g of dibutyltin oxide were charged and heated at 180'C under a nitrogen stream.
The allyl alcohol produced was distilled off.

When 140 g (2.41 moff) of allyl alcohol had been distilled off, the pressure inside the reactor was reduced to 50 mmHg to accelerate the distillation rate. After allyl alcohol equivalent to propylene glycol was distilled off, unreacted diallyl terephthalate was distilled off at 1 mmHg while maintaining the reaction solution at 200'C using a thin film distiller. The reaction solution was poured into a hat, cooled and pulverized to obtain powdery allyl ester resin (1).

Production Example 2 Production of allyl ester resin (2) containing bromine Except for the conditions shown in Table 1, allyl ester resin (1
) to obtain a bromine-containing allyl ester resin (2).

Examples 1 to 5 and Comparative Examples 1 to 3 Kraft paper with a basis weight of 155 g/m'' and a thickness of 300 μm was soaked in a water-methanol solution of melamine resin (S-305 manufactured by Nippon Carbide Co., Ltd.) and air-dried at 120'C. The amount of melamine resin adhered to 100 parts by weight of kraft paper was 18 parts by weight. This paper base material was immersed in a blended solution of the resin composition shown in Table 2 to remove the resin acid. After impregnating and stacking seven sheets, one side was layered with adhesive-coated copper foil shown in Table 2, and both sides were layered with a 50 μm polyester film, followed by heating and pressure molding with a press. The conditions are 140°C - 10 minutes - 20kg/
It was Cm'. After pressing, heat in hot air drying oven at 150℃
Heating was performed for -5 hours to obtain a copper-clad laminate with a thickness of 1.6 mm. Table 3 shows the results of measuring the physical properties of the copper-clad laminate.

As is clear from the results in Table 3, the copper uneven laminate of the present invention has excellent solder heat resistance and also has high copper foil peel strength.

〔Effect of the invention〕

The copper-clad laminate of the present invention can be manufactured without using the prepreg method, and has advantages such as good rigidity, strength, soldering heat resistance, and copper foil peel strength.

Claims (2)

[Claims] (1) The allyl ester resin laminate and the copper foil contain 10 to 3 parts by weight of polyvinyl butyral per 100 parts by weight of the epoxy resin.
A copper-clad laminate that is laminated using an adhesive containing 0.00 parts by weight. (2) The above epoxy resin contains 40 to 90% by weight of bisphenol A type epoxy resin and 1 part of novolak type epoxy resin.
The copper-clad laminate according to claim 1, comprising 0 to 60% by weight.