JPH0428017B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field of the Invention] The present invention relates to a method for manufacturing a laminate for chemical plating of unsaturated polyester resin used in an additive method. [Technical background of the invention and its problems] Printed wiring boards range from paper phenol-based single-sided printed wiring boards for consumer use to glass epoxy-based multilayer printed wiring boards for industrial use, and are used to improve the performance of electrical and electronic equipment. , their role is becoming increasingly important in conjunction with the demand for high-density packaging.
The general method for manufacturing printed wiring boards is the subtractive method, in which a copper-clad laminate is used as a material and unnecessary copper foil parts are etched away to form a desired conductive pattern part, and the manufacturing process has not been established. There is. However, in recent years, the subtractive method has begun to be reconsidered in terms of improving quality, saving resources, saving energy, reducing pollution, and reducing costs.
Although development is progressing, the additive method of manufacturing printed wiring boards using chemical plating technology has been attracting attention. Unlike the subtractive method, this method uses a laminate as the material, especially a laminate with a surface adhesive layer, and selectively forms only the desired conductive pattern with an arbitrary thickness using chemical plating.
Its features are as follows. (1) Less loss of materials and chemicals. (2) Low pollution factors. (3) Through-hole portions can also be formed at the same time. In particular, the manufacturing process for double-sided through-hole printed boards is simplified and reliability is improved. (4) It is also possible to manufacture high-precision, high-density patterns. Since there are fewer etching steps, there are fewer defects associated with etching such as undercuts, etching residues, and overhangs. (5) Excellent mass production and economy. However, the laminates for which the additive method is currently being attempted are phenolic resin and epoxy resin laminates, and unsaturated polyester resin laminates have not been attempted. This is because the affinity between the cellulose base material and the unsaturated polyester resin is poor, and due to moisture absorption, etc., peeling occurs at the interface between the cellulose and the unsaturated polyester resin, resulting in an increase in the amount of moisture absorbed, which in turn leads to poor electrical properties and heat resistance. This is because it has the disadvantage of deteriorating mechanical properties and the like. Therefore, although there is a demand for an additive-use unsaturated polyester laminate with excellent electrical insulation, soldering heat resistance, and moisture resistance, no satisfactory product has yet been developed. [Object of the Invention] The object of the present invention has been made in view of the above-mentioned drawbacks, and it is an object of the present invention to provide a material suitable for additive use, which has excellent electrical insulation properties, soldering heat resistance, and moisture resistance, and is also excellent in print wiring processability. It is an object of the present invention to provide a method for producing a chemically plated laminate made of saturated polyester resin. [Summary of the Invention] As a result of extensive research to achieve the above object, the present invention has discovered a method for producing a chemical plating laminate made of an unsaturated polyester resin suitable for additive use. That is, the present invention
After pre-impregnating a paper base material with a compound that has an affinity for the paper base material, a plurality of prepregs made by impregnating an unsaturated polyester resin are stacked together and laminated under heat and pressure to form a laminate. An adhesive made of butadiene nitrile rubber, xylene resin or phenolic resin, epoxy resin, sulfur, dicyandiamide, and finely powdered silicon oxide is applied to at least one surface of the laminate and cured to form an adhesive layer on the surface of the laminate. This is a method of manufacturing a laminate for chemical plating, which is characterized by the following. The paper base material used in the present invention is mainly composed of cellulose fibers and has a basis weight of 50 g/m2 to 250 g/ ^m2 .
Examples include kraft paper, linter paper, cotton paper, mixed paper, etc. with a size of about ² m2. Since unsaturated polyester resin has poor affinity with paper base materials, it is pretreated with a compound that has an affinity for it. Compounds that are compatible with the paper base material used in the present invention include phenol resins, resorcinol resins,
In addition to resins such as urea resin, melanin resin, and guanamine resin, vinyl polymers containing polar monomers such as acetic acid, acrylic acid, acrylic ester, N-methylol acrylamide, and acrylamide-maleic anhydride as copolymerization components are mentioned. These may be used alone or in a mixture of two or more. When impregnating these compounds, the following solvents are used. Examples of this solvent include alcohols such as methanol, ethanol, n-propanol, and isopropanol, acetone, methylacetone,
Ketones such as methyl ethyl ketone, dioxane,
Ethers such as tetrahydrofuran, methyl formate,
These are esters such as methyl acetate, and nitrogen-containing solvents such as N,N-dimethylformamide.
Use seeds or a mixture of two or more. The unsaturated polyester resin used in the present invention is a resin synthesized from an unsaturated polybasic acid, a saturated polybasic acid, and a polyol, and is a resin synthesized from an unsaturated polybasic acid, a saturated polybasic acid, and a polyol.
It may also be a polyester or vinyl ester type resin. Unsaturated polybasic acids include maleic anhydride and fumaric anhydride; saturated polybasic acids include phthalic anhydride, isophthalic acid, terephthalic acid, adipic acid, and sebacic acid; and polyols include ethylene glycol, propylene glycol, and diethylene glycol. , 1,4-butanediol, 1,
Examples include 5-pentanediol. A crosslinking monomer is used in the unsaturated polyester resin synthesized from these components. Styrene is commonly used as a monomer, but other monomers include α-methylstyrene, vinyltoluene, chlorostyrene,
Divinylbenzene, alkyl acrylate, diallyl phthalate, etc. are used. As the curing catalyst, a general-purpose organic peroxide, a photo-curing catalyst, a radiation/electron beam curing catalyst, etc. can be used together with or alone with an organic peroxide. Depending on the purpose, flame retardants, polymerization inhibitors, ultraviolet absorbers, fillers,
Coloring agents and the like can be added. The adhesive used in the present invention consists of an adhesive resin component consisting of butadiene nitrile rubber, xylene resin or phenol resin, epoxy resin, sulfur and dicyandiamide, and finely powdered silicon oxide. Butadiene nitrile rubber, which is the resin component of the adhesive, is made by copolymerizing acrylonitrile and butadiene, or by adding a third component such as acrylic acid to the two-component system and copolymerizing it. 1042 (trade name, manufactured by Nippon Zeon Co., Ltd.), Hiker 1072 (trade name, manufactured by Gutsudoritsuchi Co., Ltd.), etc., and these may be used alone or in combination of two or more. The amount of butadiene nitrile rubber used is 30 to 60% by weight based on the adhesive resin content. If it is less than 30% by weight or more than 60% by weight, it will have no effect on the adhesion, heat resistance and electrical properties of the plating metal layer. Xylene resin, which is the resin component of the adhesive, is a phenol-modified resin obtained by reacting xylene and formaldehyde in the presence of a catalyst, such as Nicanol (trade name, manufactured by Mitsubishi Gas Chemical Co., Ltd.). Phenol resin is a resin obtained by reacting phenol and formaldehyde in the presence of a catalyst, and examples include BKPA5904 (trade name, manufactured by Union Carbide).
The amount of xylene resin or phenol resin to be blended is preferably 10 to 60% by weight based on the adhesive resin content, taking into consideration the adhesive strength and electrical properties of the plating layer when heated. Examples of the epoxy resin that is the resin component of the adhesive include bisphenol type epoxy resins, alicyclic epoxy resins, novolac type epoxy resins, and the like, and one type or a mixture of two or more of these can be used. The content of the epoxy resin is preferably 10 to 30% by weight based on the adhesive resin content. If the amount is less than 10% by weight or more than 30% by weight, it will have no effect on the adhesion and heat resistance of the plating layer. Furthermore, sulfur and dicyandiamide are used as crosslinking agents for the adhesive, and heat resistance is improved by using these crosslinking agents. As components of the adhesive used in the present invention, a composition consisting of butadiene nitrile rubber, xylene resin or phenol resin, epoxy resin, sulfur, and dicyandiamide may be sufficient to achieve the purpose.
Furthermore, it has been found that the soldering heat resistance can be significantly improved by adding finely powdered silicon oxide to this. The amount of the finely divided oxygen silicon powder is preferably 5 to 20 parts by weight based on 100 parts by weight of the total amount of the butadiene nitrile rubber, xylene resin or phenol resin, epoxy resin, sulfur and dicyandiamide. If the amount is less than 5 parts by weight, it has no effect on soldering heat resistance, and if it exceeds 20 weight %, it becomes difficult to form an adhesive film suitable for chemical plating, and various properties are adversely affected, which is not preferable.
The adhesive can be applied to the laminate by dipping, roll coating, curtain coating, or the like, followed by drying and curing by heating at a temperature of 100° C. for 10 minutes or more. The thickness of the adhesive is preferably as thin as possible, but 20 to 80 μm is appropriate since it is necessary to make it compatible for plating. As a method for manufacturing a laminate for chemical plating according to the present invention, a paper base material is first impregnated with a compound having an affinity for the paper base material, and then an unsaturated polyester resin is impregnated to obtain a prepreg. Next, a plurality of sheets of the prepreg were laminated and heated and pressurized to form an integral laminate to obtain an unsaturated polyester laminate. Next, an adhesive is applied to at least one surface of this laminate and cured to obtain a laminate for chemical plating. [Examples of the Invention] Next, the present invention will be described with reference to Examples. In Examples and Comparative Examples, "parts" means "parts by weight." Example 1 A phenolic resin was applied to kraft paper with a basis weight of 140 g/m ² and dried, and then 50 parts of Polycol 6304 (trade name of unsaturated polyester resin manufactured by Takeda Pharmaceutical Company Limited),
A prepreg was obtained by impregnating it with an unsaturated polyester resin consisting of 0.5 part of cumene hydroperoxide and 0.1 part of cobalt naphthenate. Four sheets of this prepreg were stacked together and cured at 130° C. for 2 hours to produce a laminate with a thickness of 1.6 mm. Next, 45 parts of acrylonitrile rubber (product name: Hiker 1072, manufactured by Gutudoritsu), 25 parts of xylene resin (product name: Nicanol, manufactured by Mitsubishi Gas Chemical Co., Ltd.), 30 parts of epoxy resin,
2 parts sulfur, 2 parts dicyandiamide, imidazole
An adhesive consisting of 0.2 parts and 10 parts of finely powdered silicon oxide was applied to the surface of the laminate to a thickness of 50 μm.
It was heat cured at ℃ for 10 minutes. This laminate was immersed in a chromic acid solution (chromic anhydride 75 g/, concentrated sulfuric acid 300 ml/) at 50°C for 12 minutes, then activated and chemically plated to form a chemical copper plate with a thickness of 0.5 μm only on the pattern area. A plating layer was provided, and then electrolytic copper plating was applied to build up to a thickness of 35 μm. Regarding the obtained laminate having a copper plating layer,
The peel strength, soldering heat resistance, electrical properties, and water absorption were tested in accordance with JIS-C-6481, and the results are shown in Table 1. Examples 2 to 8 Laminated plates were manufactured in the same manner as in Example 1 using the adhesive composition and thickness shown in Table 1, and properties were tested in the same manner.The results are shown in Table 1. Comparative Example 1 A prepreg was made by impregnating and drying phenol resin on kraft paper with a basis weight of 135/ ^m2 , and this was
The sheets were piled up and heated and pressed at 180°C and 150 kg/cm ² for 90 minutes to produce a phenolic resin laminate with a thickness of 1.6 mm. 45 parts of Hiker 1072 (trade name of acrylonitrile rubber manufactured by Gutsudoritsu),
An adhesive consisting of 25 parts of Nicanol (trade name of xylene resin manufactured by Mitsubishi Gas Chemical Co., Ltd.), 30 parts of epoxy resin, 2 parts of sulfur, 2 parts of dicyandiamide, 0.2 parts of imidazole, and 10 parts of finely powdered silicon oxide was applied to a thickness of 20 μm. , heat-cured at 100°C for 10 minutes. After immersing the adhesive-coated laminate in a chromic acid solution (chromic anhydride 75 g/, concentrated sulfuric acid 300 ml/) at 50°C for 12 minutes, activation and chemical plating treatment were performed, and the patterned area was coated with a 0.5 μm thick chemical plating. A copper plating layer was provided, and electrolytic copper plating was further applied to a thickness of about 35 μm. Regarding this, as in Example 1, JIS-
Characteristic tests were conducted in accordance with C-6481, and the results are shown in Table 1. Comparative Example 2 An adhesive-coated laminate was prepared according to Table 1, then plated, and subjected to characteristic tests according to JIS-C-6481, and the results are shown in Table 1. Comparative Example 3 A copper-clad laminate was made by overlapping copper foil on the surface of a phenol resin-impregnated paper base material according to Table 1, and JIS-C
-6481, and the results are shown in Table 1.

【table】

[Table] *: Comprehensive evaluation of circuit formation, regeneration of defective products, drilling workability, punching performance, number of manufacturing steps, difficulty in processing high-density patterns, and advantages. ○ mark: Good, × mark: Poor.
[Effects of the Invention] The laminate manufactured by the above method has excellent soldering heat resistance, moisture resistance, and electrical properties compared to additive-use phenolic resin laminates, and is also suitable for circuit formation, defective product regeneration, drilling processing, It is practical in terms of punching performance, number of manufacturing steps, and pattern density.

Claims (1)

[Scope of Claims] 1. A paper base material is pre-impregnated with a compound that has an affinity for the paper base material, and then a plurality of prepregs are impregnated with an unsaturated polyester resin, and a plurality of prepregs are stacked together and molded under heat and pressure. Then, an adhesive consisting of butadiene nitrile rubber, xylene resin or phenol resin, epoxy resin, sulfur, dicyandiamide, and finely powdered silicon oxide is applied to at least one side of the laminate and cured to form a laminate surface. A method for producing a laminate for chemical plating, comprising forming an adhesive layer on the laminate. 2 The adhesive is butadiene nitrile rubber 30~60
Weight%, xylene resin or phenolic resin 10-60
% by weight, and the method for manufacturing a laminate for chemical plating according to claim 1, characterized in that the epoxy resin is contained in an amount of 10 to 30% by weight. 3. The adhesive comprises a total of 100 parts by weight of butadiene nitrile rubber, xylene resin or phenolic resin, epoxy resin, sulfur, and dicyandiamide, and 5 to 20 parts by weight of finely powdered silicon oxide. A method for manufacturing a laminate for chemical plating according to scope 1 or 2. 4. Claim 1, characterized in that the thickness of the cured adhesive layer is in the range of 20 to 80 μm.
A method for manufacturing a laminate for chemical plating according to any one of items 1 to 3.