JPH0126332B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for manufacturing a laminate for chemical plating, and more specifically, a laminate with excellent metal adhesion and soldering heat resistance, which is integrally molded using a special adhesive.
The present invention relates to a method of manufacturing a laminate for chemical plating. Conventionally, when chemically plating the surface of a laminate,
After applying an adhesion improver, such as a diluted solution of butadiene resin in a solvent, to the surface of the laminate by dipping, roll coating, or brush coating, and drying,
Chemical plating treatment is performed. However, with this method, wrinkles and mottling occur due to uneven evaporation of the solvent and aggregation of the resin during the evaporation process, making it difficult to obtain a smooth surface. Another method is to place a release film on top of a desired number of laminated thermosetting resin prepregs, mold the resulting laminate, and then chemically plate the resulting laminate. The surface became mirror-like, and it was necessary to perform a swelling treatment with a solvent before chemical plating treatment, resulting in a significant decrease in the adhesion strength of the metal. Another method is to form an adhesive layer of a general adhesive on a release film and integrate the adhesive layer by laminating prepreg, but conventional adhesives are not integrated. When a laminate with a metal layer obtained by chemical plating is used as a printed circuit board, it has the disadvantage of being unreliable in terms of adhesion strength and soldering heat resistance. In order to improve the above-mentioned drawbacks of chemically plated laminates, the inventors of the present invention have conducted intensive studies on the plating adhesive film on the surface of the laminate and its formation method. By using a prepreg with an adhesive layer coated and dried, a laminate with sufficient reliability in terms of adhesion strength, soldering heat resistance, and electrical properties can be obtained when the laminate is made into a printed circuit board by chemical plating. We have discovered that it is possible to do this and that it can be manufactured at low cost. That is, in the present invention, (a) 30 to 60% by weight of the adhesive resin component is added to at least one surface of the thermosetting resin prepreg.
Butadiene nitrile rubber, adhesive resin component
60-10% by weight xylene resin, in adhesive resin component
An adhesive consisting of 10 to 30% by weight of epoxy resin, sulfur and dicyandiamide is applied and dried to form a semi-cured adhesive layer, and (b) at least one side of the separately prepared and superimposed thermosetting resin prepreg is coated and dried. To,
(a) Layer the prepreg with adhesive layer so that the adhesive layer is on the surface, heat and pressurize and integrally mold using a release film, and remove the release film from the obtained molded product. This is a method for manufacturing a laminate for chemical plating, characterized by the following. The thermosetting resin prepreg (b), which is the basis of the laminate of the present invention, is obtained by impregnating and drying the base material for the laminate, such as paper or glass cloth, with epoxy resin, phenol resin, melamine resin, polyimide resin, etc. It is a pre-preg. The thermosetting resin prepreg (a) used to form the adhesive layer may be the same or the same type as the thermosetting resin prepreg (b), but a different or different type may also be used. The special adhesive (a) used in the present invention uses putadiene nitrile rubber as the first component. This is a copolymerization of acrylonitrile and butadiene, or a copolymerization of this two-component system with the addition of a third component, such as acrylic acid. Commercial products of such butadiene nitrile rubber include, for example, Nipole 1042 (trade name, manufactured by Nippon Zeon Co., Ltd.) and Hiker 1072 (trade name, manufactured by Gutsudoritsu Co., Ltd.). The amount of butadiene nitrile rubber used is 30 to 60% by weight of the adhesive resin (total amount of the first to third components), taking into account the adhesion, heat resistance, and electrical properties of the plated metal layer. You can select as appropriate. The xylene resin, which is the second component of the adhesive, is a phenol-modified resin obtained by reacting xylene and formaldehyde in the presence of a catalyst, and is commercially available as Nicanol (trade name, manufactured by Mitsubishi Gas Chemical Co., Ltd.). Considering the adhesion and electrical insulation properties of the plated metal layer when heated, it is preferable to use 60 to 10% by weight of the adhesive resin. Examples of the epoxy resin as the third component include bisphenol type epoxy resin, epoxy-modified phenol resin, and alicyclic epoxy resin. The content is preferably 10 to 30% by weight based on the resin content. Further, by adding sulfur and dicyandiamide as crosslinking agents, heat resistance is improved. In the present invention, the composition consisting of the above-mentioned butadiene nitrile rubber, xylene resin, epoxy resin, sulfur and dicyandiamide as adhesive components is sufficient to achieve the purpose, but if finely powdered silicon oxide is further added to this, the laminated layer can be It has been found that when the board is used as a printed circuit board with a metal layer formed by chemical plating, the solder heat resistance is significantly improved. The mixing ratio of silicon oxide is based on the adhesive resin content.
A range of 5 to 20 parts by weight per 100 parts by weight is preferred.
If the amount is less than 5 parts by weight, the effect of the addition cannot be obtained.
On the other hand, if it exceeds 20 parts by weight, it becomes difficult to form an adhesive film suitable for chemical plating, and various properties are adversely affected. A solution prepared by diluting the adhesive as described above with an appropriate solvent is applied to the prepreg on the surface and dried to form a semi-cured adhesive layer with a thickness of about 30 to 60 μm.
Since this adhesive is suitable as a laminating resin, it may be applied to both surfaces of the prepreg.
This prepreg with an adhesive layer is made by stacking separately prepared prepregs on at least one side so that the adhesive layer is on the surface, and using a release film, heat and pressurize according to the prepreg lamination molding conditions to integrally mold. Then, the release film is peeled off from the molded product to obtain a chemically plated laminate. In this way, the adhesive layer can be formed simultaneously with lamination molding. According to the method of the present invention, it is easy to process and can be manufactured at low cost, and the manufactured laminate is suitable for chemical plating.
Chemically plated printed circuit boards have excellent adhesion strength, solder heat resistance, and electrical properties. Next, examples will be shown. Parts below mean parts by weight. Example 1 90 parts of butadiene nitrile rubber, epoxy resin
Add 55 parts of xylene resin, 1 part of sulfur, 2.5 parts of dicyandiamide, and 0.09 parts of curing accelerator to a solution of 55 parts of methyl ethyl ketone and 200 parts of toluene.
and 20 parts of finely powdered silicon were added thereto and thoroughly stirred and mixed to prepare an adhesive solution. The adhesive solution was applied and dried by a roll method on both sides of a prepreg made by impregnating and drying an epoxy resin on a paper base material to a coating thickness of 30 to 60 μm to produce a prepreg with an adhesive layer. . Next, eight sheets of prepreg impregnated with epoxy resin using paper as the base material were stacked, one sheet each of the above prepreg with adhesive layer was stacked on the top and bottom surfaces, and a polypropylene film was used as a release mold and stacked on top of the top and bottom at 150°C. - A molded product with a thickness of 1.6 mm was obtained by heating and pressing at 100 kg/cm ² for 90 minutes and integrally molding. After removing the polypropylene film on the surface, the laminate was soaked in a chromium sulfuric acid solution (chromic anhydride 75°C) at 50°C.
g, 300 ml of concentrated sulfuric acid, and 700 ml of water) for 7 minutes, and after making it hydrophilic, it was sequentially subjected to activation treatment and chemical plating treatment to form a copper plating layer with a thickness of about 0.5μ,
Furthermore, electroplating was applied to build up the material to approximately 35μ. Regarding the laminate with the above-mentioned copper plating layer,
Peel strength, solder heat resistance, and electrical properties were tested in accordance with JIS C-6481 Test Method for Copper Clad Laminates for Printed Circuits. The test results are shown in Table 1 along with the compositions of the prepreg and adhesive. Example 2 100 parts of butadiene nitrile rubber and 50 parts of epoxy resin were mixed with 500 parts of methyl ethyl ketone and 200 parts of toluene.
50 parts of xylene resin, 2 parts of dicyandiamide, 1 part of sulfur, 0.01 part of hardening accelerator (BDMA), and 20 parts of finely powdered silicon oxide are added to the swollen and dissolved solution. was prepared. The adhesive solution was applied to both sides of a separately prepared prepreg impregnated with a phenolic resin (resin content of the prepreg: 50% by weight) and dried to a thickness of 30 to 30%.
It was coated to a thickness of 60μ and dried to obtain a phenolic prepreg with an adhesive layer. Next, 8 sheets of prepreg impregnated with phenol resin were stacked on the paper base material, and one sheet each of the prepreg with the adhesive layer was stacked on the top and bottom of the paper base material, and polypropylene film was used as a release film.
cm ² Γ was heated and pressed for 60 minutes to form an integral molding, to obtain a molded product with a thickness of 1.6 mm. A copper plating layer was provided in the same manner as in Example 1 on a laminate from which the polypropylene film on the surface of the molded product had been peeled off, and a test was conducted. Table 1 shows the results. Examples 3 to 6 Adhesive solutions were prepared in which the amount of finely powdered silicon oxide added was changed from the adhesive composition in Example 1,
In the same manner as in Example 1, it was coated on both sides of a paper-based epoxy resin prepreg and dried to obtain a prepreg with an adhesive layer. Using the obtained prepreg with adhesive layer, a laminate was obtained in the same manner as in Example 1, a copper plating layer was provided, and a test was conducted. The results are shown in Table 1.

【table】

[Table] As is clear from the above table, the chemically plated laminate products produced by the method of the present invention exhibit excellent adhesive strength, solder heat resistance, and electrical properties.

Claims (1)

[Scope of Claims] 1 (a) At least one surface of the thermosetting resin prepreg contains 30 to 60% by weight of butadiene nitrile rubber in the adhesive resin component, 60 to 10% by weight of xylene resin in the adhesive resin component, 10-30 in adhesive resin component
% by weight of an adhesive consisting of epoxy resin, sulfur, and dicyandiamide is applied and dried to form a semi-cured adhesive layer; The adhesive layered prepregs of a) are stacked so that the adhesive layer is on the surface, and using a release film, heat and pressure are applied to integrally mold them, and the release film is removed from the resulting molded product. Features: A manufacturing method for chemically plated laminates. 2 The adhesive in (a) is butadiene nitrile rubber,
Claim 1 containing 5 to 20 parts by weight of finely powdered silicon oxide per 100 parts by weight of components consisting of xylene resin, epoxy resin, sulfur and dicyandiamide.
Manufacturing method described in section.