JPS60250035A - Production of laminate - Google Patents

Abstract

PURPOSE:To produce a laminate for printed circuits, which has good quality and little gives marks made by striking on the laminated surface, by using a specified surface layer and an inner layer composed of a prepreg of a substrate which has a width and a length shorter than those of the surface layer and of which the single fiber is easily floating, laminating the surface layer on the inner layer and molding the laminate by heating under pressure. CONSTITUTION:A prepreg 2 of a substrate whose single fiber is hardly floating, such as woven glass fabric, as a surface layer is laminated on a prepreg 1 of a substrate whose single fiber is easily floating, such as nonwoven glass fabric, as an inner layer. Optionally, a metallic foil 3 such as copper foil serving as a circuit is put upon the outer side of the surface layer to form a laminating material which is then molded by heating under pressure to obtain a laminated sheet. The peripheral part thereof is removed to obtain the finished laminated sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for producing a printed circuit laminate in which the occurrence of dents on the surface of the laminate due to single fibers floating from a base material is reduced.

[Prior art]

Conventionally, printed circuit laminates have been manufactured using a thermosetting resin face made of various substrates (e.g., kraft paper, linter paper, woven glass cloth,
It is manufactured by laminating a plurality of prepregs that have been impregnated and dried in glass nonwoven fabric, adding copper foil to one or both sides depending on the purpose, and then heating and press-molding them. Laminated boards are usually made of one type of base material and those made of two or more types of base materials (
Recently, the number of composite materials (hereinafter referred to as composite materials) has been increasing.

In this base material, the single fibers in the base material separate from the base material, float in the air, adhere to the prepreg surface laminated during manufacturing, and cause dents (fine dents) on the surface of the formed laminate. There are some materials that are susceptible to unevenness or scratches (for example, glass nonwoven fabric).

In recent years, printed circuit wiring boards have become denser and circuit conductors have become thinner. Under such circumstances, dents on the laminated board cause circuit breakage and damage, and become a major hindrance in the processing of printed circuit wiring boards.

[Purpose of the invention]

An object of the present invention is to reduce the occurrence of the above-mentioned dents and to stably manufacture high-quality laminates.

[Structure of the invention]

In order to achieve the above object, the inner layer is prepreg, which is a base material in which single fibers tend to float, and the prepreg, which is a base material in which single fibers are difficult to float, is layered on the surface layer.

This can significantly suppress the floating of single fibers. An example of this is one in which the inner layer is made of glass nonwoven fabric and the surface layer is made of glass woven fabric.

Furthermore, in order to make the single fibers float a little more, the width and length of the inner layer prepreg are made smaller than the width and length of the surface layer prepreg. The length to be reduced is preferably 2 to 20 cm. When the size is reduced by more than 20 degrees, it often has an adverse effect on product dimensions, etc., and when it is less than 2 fran, the effect of preventing dents is reduced.

Note that, if necessary, a metal foil such as copper foil for circuits is superimposed on the outside of the surface layer. The laminated material constructed in this manner is molded under heat and pressure, and after the laminated plate is manufactured, the peripheral portion is removed to form a finished product.

FIG. 1 is a cross-sectional view showing the structure of the present invention, in which (1) is a base material such as a glass nonwoven fabric on which single fibers easily float, and (2) is a base material such as a glass woven fabric on which single fibers are difficult to float. ,(
3) is a metal foil, and (4) is a mirror plate.

〔Effect of the invention〕

According to the method of the present invention, the floating of single fibers is extremely small, and therefore the number of dents on the surface of the laminate is reduced, so that the method is of extremely high industrial value.

[Example] - Next, examples and comparative examples will be described.

EXAMPLE In manufacturing an epoxy resin laminate, a glass nonwoven fabric prepreg was used as the inner layer and a glass woven fabric prepreg was used as the surface layer. The length of one side of the base material is glass nonwoven fabric 1045
wn, glass woven fabric 1050w+m. An epoxy resin laminate was produced by heating and press-molding the prepreg having such a configuration in a conventional manner. The occurrence rate of dents at this time is 0.2
It was 3%.

Comparative Example In manufacturing an epoxy resin laminate having the same structure as the example,
The length of one side of the base material is 10 for both glass nonwoven fabric and glass woven fabric.
When the distance was the same as that of 50 m++, the occurrence rate of dents was 4.38 inches.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the structure of the present invention. (1): Base material where single fibers easily float, (2): Base material where single fibers do not easily float, (3): Metal foil, (4): Mirror plate patent applicant Sumitomo Bakelite Co., Ltd.

Claims (1)

[Claims] In a method for producing a laminate in which two or more types of base materials are used, and one of the base materials is a base material in which single fibers easily float, a prepreg of the base material in which single fibers easily float is used as an inner layer. , and the width and length of the prepreg are smaller than the width and length of the surface prepreg.