JPH01223799A - Manufacture of board for multi-layer printed wiring board - Google Patents

Abstract

PURPOSE:To improve haloing and heat-resistance, by forming a circuit on a laminated plate coated with adhesive including plating catalyzer and then reducing the copper surface of it after chemically roughing the surface and by laminating a prepreg with plating catalyzer and an adhesive sheet with plating catalyzer by heat and pressure. CONSTITUTION:After forming a circuit by the additive process on a laminated plate coated with adhesive including plating catalyzer, the copper surface is made rough by chemicals and then is reduced. On top of it, prepreg with plating catalyzer and an adhesive sheet with plating catalyzer are piled up and are formed into one body by applying heat and pressure. Since the materials are adhered to each other after internal layer copper is previously made rough by chemicals and the surface is reduced, a good layer-to-layer adhesion is gained. Both the prepreg resin and the adhesive include plating catalyzer, so inner surfaces, including even very minute recesses, of through-holes are well coated with plating in cooperation with the effect of activation treatment. Therefore, plating can be conducted effectively with only a small penetration of activation fluids.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention is directed to a manufacturing method for a printed circuit board using the Adi-9-tip method, and a reliable flat multilayer printed circuit board with less haloing. Relating to a manufacturing method.

(Prior Art) Conventionally, multilayer printed wiring boards for industrial equipment, electronic parts, and electrical equipment are manufactured by bonding a copper-clad horizontal board in multiple layers with prepreg after circuit formation.

There are two methods for this, the pin lamination method and the mass lamination method, each of which has advantages and disadvantages, and should be used depending on the purpose. However, nine cases rely on the mass lamination method for laminated boards with inner layer circuits.

(Problems to be Solved by the Invention) In order to form these through holes in wiring boards, it is necessary to perform an activation treatment as a pretreatment in order to apply plating to the inner wall surface of the opened hole. The activation treatment solution is generally acidic with hydrochloric acid,
This hydrochloric acid erodes the inner layer steel and prepreg...
There is a problem called rowing, which reduces reliability.

(Means for solving problems) The present inventor conducted studies in order to solve the above problems.

Haloing can be seen as a phenomenon in which defects deep in the inner wall surface of the through hole are eaten away by the activation treatment liquid. The defect is due to poor adhesion between the steel and the aluminum resin, and this is the result of the activation treatment penetrating and corroding the copper and resin, so it is necessary to improve the contact between the steel and the prepreg resin. There is a need to. As a countermeasure, the surface of the inner layer steel foil is roughened and further treated with a reducing agent.

Furthermore, when viewed as a fine structure, the inner wall surface of the through hole has a very uneven cross section, and there are severe depressions between each layer.

It is determined that conventional activation treatment alone is insufficient to plate this surface, and deep plating becomes insufficient, promoting the haloing dust phenomenon.

As a countermeasure to this problem, we decided to add a plating catalyst to the resin and adhesive of the prepreg.

The present inventor has completed a method for manufacturing a multilayer printed wiring board substrate based on the above knowledge.

The present invention involves forming a circuit using an additive method on a bevel plate containing a plating catalyst, and then roughening the steel surface with chemicals, treating it with a reducing agent, and then applying a prepreg containing a plating catalyst and a plating catalyst. Heat the input N7-1 together 〃Ω
There is a manufacturing method in which it is pressed and molded into one piece.

The outermost layer of the laminate according to the invention is provided with a copper foil or an adhesive layer, and generally the steel foil is used in an etching process and the adhesive layer in an additive process. In addition, both the copper foil and the adhesive layer can be used to form a thin plate.
You may also apply VC hydration.

(Function) Since the inner layer copper has been roughened with a chemical or the like in advance, and the surface has been subjected to reduction treatment, it is then attached to a multilayer 1i# layer, so the interlayer layer is good. In addition, since both the prepreg resin and the adhesive contain a plating catalyst, the plating on the inner wall of the cross section of the through hole adheres well to the minute recesses in conjunction with the activation treatment.

Therefore, the penetration of the activation treatment liquid is small and the plating effect is good.

(Example) Regarding the examples of the present invention, comparative examples, and conventional methods, the main manufacturing conditions and test results of the products are shown in Table 1 and compared.

Table 1 (Effects of the invention) As is clear from Table 1, the effects of the surface treatment of the inner layer copper foil and the addition of a plating catalyst are extremely noticeable in improving haloing and force resistance. sex has improved.

Claims (1)

[Claims] After forming a circuit using an additive method on a laminate with a plating catalyst-containing adhesive, the copper surface is chemically roughened and then treated with a reducing agent, and then a prepreg with a plating catalyst and an adhesive sheet with a plating catalyst are overlaid and heated. A method for manufacturing a substrate for a multilayer printed wiring board, characterized by integral molding by pressing.