JPS5982785A - Printed circuit board with flat surface and method of producing same - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] The present invention relates to a printed wiring board used in electrical equipment, industrial equipment, electronic equipment, computing equipment, etc., and its purpose is to be used for sliding coils, sliders, etc. Alternatively, the objective is to improve the accuracy, reliability, and production efficiency of printed wiring boards used for computerization.

Conventionally, for this type of printed wiring board, a circuit was first created using a semi-hardened copper clad laminate, and then the circuit was pressed into the base +ttm board by heat and pressure in secondary molding to obtain a printed wiring board with a smooth surface. However, when a circuit is created on a semi-cured copper-clad laminate and then subjected to secondary molding, the circuit accuracy is greatly reduced due to changes in the dimensions of the laminate. There was a problem in that circuits were often damaged due to heating and pressurization, and that production efficiency decreased due to secondary molding.

The present invention solves the above-mentioned drawbacks by laminating a dry film on the circuit surface of a printed wiring board on which two circuits are formed, and then exposing only the area between the circuits and then developing, thereby dissolving the dry film on the circuit area. This is a printed wiring board with a smooth surface by burying the parts between the circuits with a dry film and smoothing the circuit surface, so the circuit accuracy is good and there is no damage to one circuit, improving reliability and greatly improving production efficiency. This is what was created.

(2) It is as follows. As shown in Figure 1, phenol resin, epoxy resin, unsaturated polyester resin, melamine resin, polyimide, polybutadiene, polyamide, polyamide, polysulfone, polybutylene terephthalate, polyether ether ketone, fluorinated resin, etc. alone,
A laminate resin liquid consisting of a modified product or a mixture can be used to make woven fabrics, non-woven fabrics, mats, etc. made of inorganic fibers such as glass and asbestos, organic synthetic fibers such as polyester, polyamide, polyvinyl alcohol, and acrylic, and natural fibers such as cotton. The required number of Gripregs are impregnated into a base material for crushed laminates such as paper, and then a laminate is formed by heating and pressurizing the outermost layer with metal foil such as copper foil, aluminum foil, brass foil, or nickel foil. Printed wiring board 2 with circuits 1 such as through-hole processing and printed wiring formed on a metal foil-covered laminate made of metal foil 2. Dry polyester film, highly complex acetate film, acetate film, polystyrene film, vinyl resin film, etc. on the concave road surface. Film 8 (for example, product name Liston 78
0 FR) is laminated, and then only the circuit part is shaded 4
By doing so, only the inter-circuit portion 5 is exposed to ultraviolet light @6, and then developed with methylene chloride or the like to dissolve the dry film 8 on the circuit portion that is shielded from light, thereby embedding the inter-circuit portion 5 with the dry film 8. However, it is possible to obtain a printed wiring board with a smooth circuit surface. The thickness of the dry film needs to be the same as the thickness of the circuit portion, and it is preferable to use a solder resist dry film. Further, the present invention is applicable regardless of whether the circuit board is a single-sided circuit board or a double-sided circuit board.

As described above, according to the present invention, it is possible to provide a printed wiring board with a smooth surface and excellent circuit accuracy, reliability, and production efficiency.

It is a simplified process diagram of the manufacturing method of a board.

1 is a circuit, 2 printed wiring boards, 8 dry films, 4 light shields, 5 is an area between circuits, and 6 is an ultraviolet ray.

patent applicant Matsushita Electric Works Co., Ltd. (1 other person) Representative Patent Attorney Toshimaru Takemoto (2 others) Kaya-guchi

Claims (2)

[Claims] (1) A printed wiring board with a smooth surface, characterized in that the parts between the circuits on the circuit surface of a printed wiring board on which circuits are formed are buried with a dry film to make one circuit surface smooth. (2) On the circuit surface of the printed wiring board on which the circuit is formed. Manufacture of a printed wiring board with a smooth surface, characterized by laminating a dry film, then exposing only the area between the circuits and developing it to dissolve the dry film on one circuit area and then smoothing the circuit surface. Method.