JPS6344821B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for manufacturing an adhesive-coated insulating board used to form a printed wiring board by using chemical plating or a combination of chemical plating and electric plating to form a required circuit. Methods for manufacturing printed wiring boards by forming the required circuits using chemical plating or a combination of chemical plating and electroplating include: (1) Forming a plating resist on areas other than the portions of the insulating substrate where the circuits are to be formed; A method of manufacturing printed wiring boards by forming circuits using chemical plating. (2) Apply chemical plating to the entire surface of the insulating substrate, form an electroplating resist on areas other than the areas where the circuit will be formed, form the circuit by electroplating, remove the electroplating resist, and apply chemical plating to the area where the circuit is not formed. A method of manufacturing a printed wiring board by removing the plating layer by quick quetting. is being carried out. Conventionally, when chemically plating the surface of an insulating substrate, an adhesive is applied to the surface of the insulating substrate, and after drying and curing, the surface is treated with an oxidizing roughening liquid or the like to maintain good adhesion to the plating metal. Adhesives for this purpose usually have acrylonitrile-butadiene copolymer as the main component, to which thermosetting resin components such as phenol resin and epoxy resin are added, and if necessary, curing accelerators, gourd vulcanizing agents, etc. Vulcanization accelerator, filler,
Pigments, Metzki catalysts, etc. are added and used, but the common thing is that acrylonitrile-butadiene copolymer accounts for 30% or more by weight of the organic material components excluding the solvent. Acrylonitrile-butadiene copolymer has the following properties: (1) When treated with an oxidizing roughening solution, the double bond is broken, and the amount dissolved increases due to lower molecular weight and generation of functional groups, causing unevenness on the adhesive surface. , the anchoring effect of the plated metal increases, and the adhesive strength increases. (2) Adhesive strength increases with the content of the highly polar acrylonitrile group in the molecule and the functional group generated in (1). In order to stably obtain a wiring board that has the following effects and has an adhesion strength of 1.2 kg/cm or more, which is the standard, it is necessary to use acrylonitrile-butadiene rubber in an amount of 30% by weight or more. On the other hand, wiring boards are required to have higher density, and because of their uses, adhesives are also desired to have improved electrical properties such as high frequency properties such as electrical insulation resistance, dielectric constant, and dielectric loss tangent. The acrylonitrile-butadiene copolymer in the adhesive composition is one of the materials with the worst electrical properties even after vulcanization among various polymers, and should be improved by changing to styrene-butadiene rubber, polybutadiene, etc. Cannot be put into practical use due to low adhesive strength. Therefore, we investigated lowering the acrylonitrile-butadiene copolymer content. (1) When the copolymer content is lowered and the epoxy resin content is increased, phase separation occurs in the organic solvent solution. (2) A liquid acrylonitrile-butadiene copolymer containing functional groups (carboxyl groups, amine groups, etc.) that is used as an impact resistance improver for cured epoxy resins.
Even if the butadiene copolymer is changed, phase separation occurs in the organic solvent solution. (3) Adhesives with low rubber content inevitably have an increased epoxy resin content, and the type of curing agent for the epoxy resin has a large effect on wiring board characteristics, especially soldering heat resistance. There are other problems. The present invention has been made in view of these points, and involves adding acrylonitrile, a reaction product of an acrylonitrile-butadiene copolymer having a functional group and a double bond, and an epoxy resin to an organic solvent solution of a thermosetting resin. - Mix so that the butadiene copolymer component is 2 to 20% by weight of the organic material excluding the solvent, and add 5 to 50 parts by weight of the inorganic filler dissolved in the chemical roughening liquid to 100 parts by weight of the organic material excluding the solvent. This method is characterized in that adhesives mixed in parts by weight are applied to the surface of an insulating substrate. When reacting an acrylonitrile-butadiene copolymer having a functional group and a double bond with an epoxy resin in advance, the blending ratio of the epoxy resin is 40 to 95% of the sum of the acrylonitrile-butadiene copolymer and the epoxy resin. As a curing agent, a novolac type phenol resin or a vinyl phenol resin is added in an amount of 15 to 50% by weight based on the total amount of epoxy resin and curing agent. If the proportion of the acrylonitrile-butadiene copolymer exceeds 20% by weight in the organic material excluding the solvent, the effect of improving electrical properties by reducing the amount of rubber disappears, and if it is less than 2% by weight, the amount of the roughening liquid-soluble inorganic filler must be increased. Even if the degree of unevenness due to roughening of the adhesive surface is increased, the adhesive force will not exceed 1.2 kg/cm. If the blending ratio of the acrylonitrile-butadiene copolymer with functional groups and double bonds and the epoxy resin in the epoxy resin mixture is 40% by weight or more, and the mixture is heated and reacted before use, phase separation will occur even if stored in a solution state for a long time. I won't. If it is less than 40% by weight, it will separate during storage, so it is necessary to constantly stir when applying the adhesive. If the epoxy resin content exceeds 95% by weight, it is necessary to add unreacted acrylonitrile-butadiene copolymer to make an adhesive, which is unsuitable because phase separation occurs. Note that when acrylonitrile-butadiene copolymer and epoxy resin are reacted in advance, it is usually done by heating in a reaction vessel with stirring without adding a solvent, but by adding an appropriate curing agent for epoxy resin, the heating temperature is You may try to lower it. Acrylonitrile-butadiene copolymers with amino groups introduced as functional groups can also be used, but copolymers containing carboxyl groups are preferred because they tend to glue during preliminary reaction with epoxy resins and emit ammonia odor when adhesive is applied and cured. Suitable for practical use. When the amount of acrylonitrile-butadiene copolymer added is reduced, the unevenness of the adhesive surface created by roughening becomes smaller and the adhesive strength decreases, but this can be improved by adding an inorganic filler soluble in the roughening liquid. .
Addition of inorganic filler to 100 parts by weight of organic material
If it is less than 5 parts by weight, it will not be effective in increasing adhesive strength, and if it exceeds 50 parts by weight, the soldering heat resistance will deteriorate. Calcium carbonate and calcium silicate can be used as the inorganic filler soluble in the roughening liquid in terms of solubility and electrical properties, but calcium carbonate is preferred from the viewpoint of particle shape. That is, when calcium silicate has elongated crystals on the adhesive surface, it tends to form elongated depressions after roughening and cause circuit chips during plating. On the other hand, since calcium carbonate does not contain elongated particles, it is possible to select and mix particles with particle sizes depending on the degree of circuit density. Printed wiring boards require soldering for wiring, component attachment, etc., and high-temperature cohesive strength is required due to heat generation during use. In the case of adhesives with a high rubber content, resol type alkylphenol resins are generally used for resin vulcanization of acrylonitrile-butadiene rubber, and in the case of epoxy resins with no rubber content, dicyandiamide is generally used. In the relatively small amount of rubber-containing adhesive of the present invention,
Although the above curing system can be used if the usage conditions are selected,
The use of novolak, phenolic resin, and vinylphenolic resin improves soldering heat resistance. In the case of novolac type phenolic resin, the amount of epoxy resin (acrylonitrile-butadiene copolymer, epoxy resin in the pre-reacted product, and unreacted epoxy resin) plus phenolic resin is
It is preferably 15 to 50% by weight, preferably 25 to 40% by weight.
If it is less than 15% by weight, it will be insufficiently cured and the solder heat resistance will be poor, and if it exceeds 50% by weight, it will be difficult to roughen and will not have adhesive strength. The vinyl phenol resin should also be used in an amount of 15 to 50% by weight, preferably 25 to 40% by weight. If it is less than 15% by weight, the soldering heat resistance will be poor, and if it exceeds 50% by weight, there will be no adhesive strength. Note that methyl ethyl ketone,
After swelling with an organic solvent such as ethyl acetate or dimethylformamide, it is dissolved with an oxidizing roughening solution. Examples of the oxidizing roughening liquid include oxidizing chromium mixed acid, chromic acid, and hydrofluoric acid liquid. Example 1 Epit 1004 (epoxy resin manufactured by Ciel Chemical Co., Ltd.) and carboxyl group-containing acrylonitrile-butadiene copolymer (Hiker CTBN1300 x 13) were placed in a flask at a weight ratio of 3:1, stirred and heated at 180°C for 3 hours. A pre-react copolymer was created. Prereact copolymer 16 parts by weight, Epicoat
1004, 54 parts by weight, Sb-6600 (novolac type phenolic resin manufactured by Schenectaday Chemical Co.) 30
An adhesive was prepared by dissolving and dispersing 15 parts by weight of calcium carbonate, 6 parts by weight of a plating catalyst (PEC-8 manufactured by Hitachi Chemical Co., Ltd.), and 3 parts by weight of silica powder (Erosil) in cellosolve acetate. This adhesive was applied to a paper-based phenol laminate (manufactured by Hitachi Chemical Co., Ltd.).
147F) so that the adhesive thickness after drying was 40μ, dried, and cured by heating at 170°C for 60 minutes.
This adhesive-coated laminate was immersed in a 1:1 mixed solvent of dimethylformamide and isopropyl alcohol for 2 minutes to swell, then roughened by etching with an oxidizing chromium mixed acid, and chemically plated to produce a copper-plated laminate with a copper thickness of 30 μm. . The acrylonitrile-butadiene rubber content in the adhesive used is 4% by weight of the organic material excluding solvent. Example 2 In Example 1, the pre-react copolymer was
A printed wiring board was obtained in the same manner as in Example 1 except that the amount of unreacted Epikote 1004 was reduced accordingly. Rubber content is 10% by weight. Example 3 A printed wiring board was prepared in the same manner as in Example 1 except that SP-6600 was replaced with Resin M (vinyl phenol resin manufactured by Maruzen Sekiyu Co., Ltd.) to prepare an adhesive. Example 4 In Example 1, Epicote 1004 was changed to 80.5 parts, Sp-6600 was excluded, and dicyandiamide was added to 1.5 parts.
A printed wiring board was prepared in the same manner as in Example 1 except that 2 parts of benzyldimethylamine was added to prepare an adhesive. Comparative example Acrylonitrile/butadiene rubber (hiker
1032) 45 parts, Sp-6600 10 parts, Sp-126 (resol type phenolic resin manufactured by Schenectaday Chemical Co., Ltd.) 20 parts, Epicote 1004, 25 parts, zirconium silicate 45 parts, silica powder 3 parts, plating catalyst 6 parts, and cellosolve. An adhesive was prepared by dissolving and dispersing it in acetate, and a copper-plated laminate was prepared in the same manner as in Example 1. Note that the solvent immersion treatment during the process was omitted. The characteristics of the printed wiring boards obtained in these Examples and Comparative Examples were measured and were as shown in Table 1.

[Table] δ is the dielectric loss tangent, and ε is the dielectric constant.
As explained above, in the present invention, it is possible to manufacture an adhesive-coated insulating substrate used for manufacturing printed wiring boards that has particularly excellent dielectric constant and dielectric loss tangent at high frequencies, and has good solder heat resistance and adhesive strength. I can do it.

Claims (1)

[Scope of Claims] 1. A reaction product of an acrylonitrile-butadiene copolymer having a functional group and a double bond and an epoxy resin is added to an organic solvent solution of a thermosetting resin, and the acrylonitrile-butadiene copolymer component is added as a solvent. 2 to 20% by weight of the organic material excluding solvent, and 5 to 50 parts by weight of an inorganic filler dissolved in the chemical roughening liquid per 100 parts by weight of the organic material excluding solvent. A method for producing an adhesive-coated insulating substrate, which comprises applying the adhesive to the surface of the insulating substrate. 2 Acrylonitrile-butadiene copolymer is
The method for producing an adhesive-coated insulating substrate according to claim 1, wherein the adhesive-coated insulating substrate is an acrylonitrile-butadiene copolymer having a carboxyl group. 3. Production of an adhesive-coated insulating substrate according to claim 1, in which the acrylonitrile-butadiene copolymer and epoxy resin are reacted in such a manner that the epoxy resin accounts for 40 to 95% by weight based on the sum of the two. Law.