JPH0353052B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a technique for punching a printed wiring board using a metal base.

When punching a printed wiring board using a metal base, conventionally, as shown in FIG. I punched it out with a punch 6 toward the back side. Generally speaking, when punching a metal plate, the punching section on the side where the punch enters is rounded, creating a so-called sag (A), and the side where the punch exits has a burr (B). For this reason, in the conventional punching process, sag (a) occurs on the side of the insulating layer 2 when punching, resulting in a peeling phenomenon between the insulating layer 2 on the surface and the metal base 1 as shown in FIG. This had the disadvantage of causing defective products. In other words, surface destruction occurs at the punched portion of the insulating layer due to punching impact and elongation, and because the insulating layer cannot follow the large elongation of the sagging portion of the metal base, a peeling phenomenon of the insulating layer occurs at the sagging portion. It is.

The present invention has been made in view of the drawbacks of the conventional examples described above, and its purpose is to punch a metal base printed wiring board without causing a peeling phenomenon between the metal base and the insulating layer during the punching process. We are here to provide you with a method.

Hereinafter, the present invention will be explained in detail with reference to the accompanying drawings. The printed wiring board 4 is made by coating the surface of a metal base 1 made of iron or aluminum or the like with a thickness of 0.2 mm or more with an insulating layer 2 of about 20 to 200 μm, and then coating the insulating layer 2 with copper foil or a different layer on the copper foil. The wiring pattern 3 is plated with metal. Note that a solder resist may be applied on the wiring pattern 3.
When performing the punching process on this printed wiring board 4, turn the printed wiring board 4 over so that the insulating layer 2 side is facing down, and punch out with a punch 6 from the back side of the metal base 1 toward the insulating layer 2 side. . That is, punch out from top to bottom. When the printed wiring board 4 is punched out in this way, as shown in FIG. There is no punching impact applied to the metal base 1, no elongation, and no dripping on the metal base 1 on the side of the insulating layer 2.
Since the large elongation associated with (a) does not occur, the peeling phenomenon of the insulating layer 2 does not occur. Note that punching includes not only hole punching but also outer shape punching.

Comparative example 1 1.0mm thick aluminum plate [metal base] 1 and
A printed wiring board 4 was integrally molded from an insulating layer 2 of 100 μm glass epoxy resin and a 35 μm electrolytically plated copper foil 7 (FIG. 4). Next, the copper foil 7 on the surface was removed by etching to form a wiring pattern 3 to form a desired circuit (FIG. 5). After this,
Although punching was performed using a punch with the insulating layer 2 side or circuit side as the entry side, peeling occurred between the aluminum plate 1 and the insulating layer 2 as shown in FIG.

Comparative Example 2 0.8mm thick aluminum plated steel plate [metal base] 1, 50μ epoxy resin insulation layer 2,
A printed wiring board 4 was integrally formed from an 85 μm electrolytically plated copper foil 7, etched in the same manner as in Comparative Example 1, and then punched from the insulating layer 2 side. Peeling occurred between the two.

Example 1 A printed wiring board 4 after the same etching as in Comparative Example 1 was placed on the back side of the aluminum plate 1 (the side opposite to the insulating layer).
was used as the entry side of the punch, but as shown in FIG. 7, no separation occurred between the aluminum plate 1 and the insulating layer 2.

Example 2 A printed wiring board 4 that had been etched in the same manner as in Comparative Example 2 was punched out using the back side of the aluminum-plated steel plate as the input side of the punch 6, but no peeling of the insulating layer 2 occurred.

Since the present invention is configured as described above, there is an advantage that when a printed wiring board is punched out with a punch or the like, no peeling occurs between the insulating layer and the metal base, thereby preventing the occurrence of defective products.

[Brief explanation of drawings]

1 and 2 are sectional views of the conventional example, FIG. 3 is a sectional view of the present invention, FIGS. 4 to 6 are sectional views of the first comparative example (conventional example), and FIG. 7 is a sectional view of the conventional example. FIG. 1 is a sectional view showing a first embodiment of the present invention. 1...Metal base, 2...Insulating layer, 3...Wiring pattern, 4...Printed wiring board.

Claims (1)

[Claims] 1. A metal characterized by covering the surface of a metal base with an insulating layer and punching out a printed wiring board with a metal foil wiring pattern formed on the insulating layer from the back side of the metal base toward the insulating layer side. How to punch out base printed wiring boards.