JPS58175222A - Method of producing smooth circuit board - 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 method of manufacturing a smooth circuit board having a smooth surface, which is used as a channel selection circuit of various receivers and a contact circuit board of other rotary switches, slide switches, and the like.

Conventionally, this type of smooth circuit board was usually produced by a lamination press method as shown in FIG. That is, in this case, a semi-cured copper-clad laminate 1 made by laminating copper foil 1b on A base material 1a, which is relatively easy to process, is used (see FIG. 1(a)), and a predetermined circuit is first applied to this laminate 1. A pattern etching process is performed to remove the copper foil other than the contact circuit copper foil part 1b' (Fig. 1(b)), and then a plating process is performed to cover the copper foil part 1b'. A metal plating layer 2 is formed (FIG. 1(C)). After that, this laminate 1 is, for example, 120
? 40 with strong skin of /cd and temperature of 160° to 180°C
By performing smoothing press for ~50 minutes, Fig. 1 (d
), the copper foil portion 1b' and the plating layer 2 are buried inside the base material 1a, thus obtaining a smooth circuit board with a smooth surface. After this, the substrate is punched or punched, if necessary.

However, with the conventional manufacturing method for smooth circuit boards as described above, it is difficult to obtain high smoothness accuracy of ±10μ or less, which is the general specification for contact circuit boards, or ±5μ or less, which is a special specification, and it is also disadvantageous in terms of productivity and cost. There were many points.

The present invention has been made in view of these points, and it is an object of the present invention to provide a manufacturing method capable of obtaining a smooth circuit board with high smoothness accuracy.

The present invention will be described below with reference to embodiments shown in the drawings. Second
The figure shows a process diagram of one embodiment of the manufacturing method of the present invention, and here, as shown in FIG. Using the stretched laminate 1, first half-punch the laminate 1 as shown in Figure 2 (
As shown in b), the IC is recessed at a predetermined location. Next, a predetermined circuit pattern is etched on the laminated board 1 having such unevenness, and a part of the copper foil part 1 is left as a contact circuit.
The copper foil other than b' is removed by etching as shown in FIG. 2(C), and then plating is performed to form a metal plating layer 2 on this copper foil portion 1b' as shown in FIG. 2(d). Form.

After that, the recess IC depressed by the half-punching process described above is pressed from the bottom surface to form the shape shown in Fig. 2(e).
), lift it up to the height of the surface of the plating layer 20. The final circuit surface of the circuit board thus produced is flush. After that, if necessary, the second substrate may be punched and pressed.

According to the manufacturing method of the present invention, since a smooth circuit board is created through the steps described above, it is possible to obtain a smooth circuit board with higher smoothing accuracy, for example, ±3μ or less, compared to conventional methods. . Therefore, the present invention is extremely effective when used as a method for manufacturing contact circuit boards such as switches.

Furthermore, according to the manufacturing method of the present invention, other through holes such as id holes can be punched at the same time when performing the first nozzle punching process, as required, compared to conventional methods. The process can also be simplified and costs can be reduced.

[Brief explanation of the drawing]

FIG. 1' is a process sectional view showing a conventional method of manufacturing a smooth circuit board, and FIG. 2 is a process sectional view of an embodiment of the manufacturing method of the present invention. 1... Copper-clad laminate, 1a... Base material, 1b... Copper foil, 2... Plated layer

Claims (1)

[Claims] 1. A copper-clad laminate made by laminating copper foil on the surface of an insulating base material is first half-punched to create recesses in predetermined places, then etched and plated with a predetermined circuit pattern, and then A method for producing a smooth circuit board, which comprises pressing the concave portions of the base material at the half-punched locations to the final circuit surface height to create a board with a smooth surface.