JPH0442950Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a double-sided wiring board, and particularly to a double-sided wiring board in which wiring patterns on both sides can be connected without using through holes.

<Prior Art> In a double-sided wiring board, a method of gold plating the through holes has been used to connect the wiring on the front and back sides.

<Problems that the invention aims to solve> Conventional double-sided wiring boards have a structure in which through-holes are plated with gold to connect wiring on both sides, which is expensive and eliminates harmful substances generated in the plating process. This method has problems such as requiring expensive equipment to treat the waste liquid.

<Means for solving the problems> The double-sided wiring board of the present invention is a double-sided wiring board in which wiring patterns are formed on both sides of an insulating substrate, and the double-sided wiring board is cut at two adjacent cutting points, and It is characterized in that it is folded back to one of the wiring pattern surfaces, and the wiring patterns on both surfaces are connected by overlapping the different wiring pattern surfaces of the folded wiring board.

<Function> The different wiring pattern surfaces of the folded wiring board are overlapped, and the wiring patterns on both sides are connected.

<Example> FIG. 1 shows a cross-sectional structure of a double-sided wiring board of this example. In the figure, 2 is a film-like insulating substrate, 3 is wiring on the front surface, 4 is wiring on the back surface, and 5 and 6 are cutting locations. FIG. 2 shows the planar structure of this double-sided wiring board, where 7 is a folded portion at the cutting point 5, and 8 is a folded portion at the cutting point 6.

In this double-sided wiring board, wiring patterns are formed on both sides of a film-like insulating substrate 2. and,
2 folded back at two adjacent cutting points 5 and 6
It has a structure in which two parts 7 and 8 overlap each other. In this state, the wiring 4 of the folded portion 7 and the wiring 3 of the folded portion 8 come into contact, and the wiring 3 on the front surface of the double-sided wiring board 1 and the wiring 4 on the back surface are connected.

FIG. 3 shows a method for connecting wiring on both the front and back sides of this double-sided wiring board, in which a double-sided wiring board formed by two cutting points 5 and 6 consisting of arc-shaped slits is folded back at the cutting point 5, and a portion 7 is folded back. Subsequently, the portion 8 is folded back at the cutting point 6. Then, the folded part 8 is overlapped on the folded part 7, and finally, the wires of the parts 7 and 8 are crimped together using a pressure device (not shown).

4 and 5 show patterns on the front and back sides of a double-sided wiring board to which the present invention is applied, and the wiring pattern 14 on the front side is connected to the wiring pattern 15 on the back side by folded connection parts 12 and 13.

To explain the manufacturing method of this double-sided wiring board, wiring patterns are formed on both sides of a film-like insulating substrate (for example, polyester film) using conductive ink (for example, carbon ink) by screen printing, etc., at the required positions as described above. The pattern of the folded connection part is also formed at the same time. Then, an arc-shaped cut portion is formed at this folded connection portion. Thereafter, the double-sided connection is completed by folding back the folded connection portion using the method described above.

The conductive ink used for the wiring patterns on both the front and back surfaces is mainly carbon ink, but in this case, a material whose main component is a bendable thermoplastic resin is used.

<Effects of the invention> As explained above, in the invention, the wiring patterns on both sides are connected by overlapping the different wiring pattern surfaces of the folded wiring board at two adjacent cut points of the double-sided wiring board. As a result, it is possible to connect double-sided patterns regardless of the thickness of the board, and since the connection is made by contacting the pattern surfaces without the need for connection via other media, reliability is improved. A high quality double-sided wiring board can be obtained. Additionally, conventional through-hole gold plating can significantly reduce costs and does not require expensive equipment. Furthermore, since the manufacturing process of the wiring board can be simplified, it is suitable for mass production.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the cross-sectional structure of the embodiment of the invention, Fig. 2 is a diagram showing the planar structure of the embodiment of the invention, and Fig. 3 explains the method of connecting both sides of the double-sided wiring board of the embodiment of the invention. 4 and 5 are diagrams showing the pattern shape of a double-sided wiring board according to an embodiment of the present invention. 1... Double-sided wiring board, 2... Film-like insulating substrate, 3, 4... Wiring, 5, 6... Cutting location, 7,
8...Folded part.

Claims (1)

[Scope of utility model registration request] In a double-sided wiring board in which a wiring pattern is formed on both sides of an insulating substrate, the double-sided wiring board is folded back at two adjacent cutting points to one of the wiring pattern surfaces, and
A double-sided wiring board characterized in that the wiring patterns on both sides are connected by overlapping the different wiring pattern surfaces of the folded wiring board.