JPS5930554Y2 - printed wiring board - Google Patents

Description

[Detailed description of the invention] This invention relates to a double-sided printed wiring board in which conductor layers are provided on both sides of an insulating substrate, and these conductor layers are electrically connected to each other, and can be easily and reliably achieved without using through holes. The present invention provides an excellent printed wiring board in which conductor layers on both sides are electromechanically bonded to each other.

Generally, when the conductor layers formed on both sides of a double-sided printed wiring board are electrically connected to each other, a through hole 2 is formed in the insulating substrate 1 as shown in Fig. 1, and a conductive material such as silver paint is formed in this hole. 3, the conductive layers 4.5 formed on both surfaces of the insulating substrate 1 are electrically connected to each other.

However, in this case, the material of the conductive material 3, the viscosity,
It is extremely difficult to always uniformly apply the conductive material 3 due to the size of the through hole 2, the processing condition of the inner surface, etc.
In some cases, the remaining air in the through-holes 2 causes large air holes 6 to be formed in the applied conductive material 3, resulting in poor conductivity between the conductor layers 4 and 5 on both surfaces.

In addition, even if the conductive material 3 can be completely applied, cracks may occur inside the conductive material 3 depending on the drying conditions after application, and overall reliability is extremely low. Ta.

This proposal eliminates the above-mentioned conventional drawbacks,
The structure is such that the conductor layers on both sides are easily and reliably connected electrically without using through holes.

Hereinafter, the printed wiring board of the present invention will be explained with reference to drawings of one embodiment.

In FIGS. 2 and 3, 6 is an insulating substrate made of paper phenol, paper epoxy, glass epoxy, etc., 7 and 8 are conductor layers formed on both sides of the insulating substrate 6, 9 is a mounting hole, and 10 is an insulating substrate made of paper phenol, paper epoxy, glass epoxy, etc. This is an arc-shaped notch formed on the end surface of the insulating substrate 6.

Note that one conductor layer 8 is joined to the other conductor layer 7 along the end surface of the insulating substrate 6.

As is clear from the above-mentioned embodiment, the present invention is structured so that one conductor layer 8 is extended and joined to the other conductor layer 7 along the end surface of the insulating substrate 6, unlike the conventional method. The conductor layers on both sides can be easily and easily electrically connected to each other without any air pockets or cracks occurring in the conductor layer, which is extremely advantageous in practical terms.

Although various methods can be considered for manufacturing the printed wiring board of the present invention, it is extremely advantageous to manufacture it by the process shown in FIG. 4.

That is, first, conductor layers 7 are formed on both sides of the insulating substrate 6.
, 8, and as shown in FIG.
Cut the end of.

In this way, only one conductor layer 8 is made to protrude, and a conductive adhesive 1 is applied to this protruding part as shown in the opening of FIG.
2 and adhered to the cut surface and the end of the other conductor layer 7 along the cut surface as shown in FIG. 4C.

Thereafter, as shown in FIG. 42, a predetermined pattern is formed by etching or the like, and mounting holes 9 and notches 10 are formed as necessary to complete the double-sided printed wiring board.

When constructed in this way, it is easy to manufacture as a whole and is extremely advantageous in practice.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional side view of a conventional printed wiring board, Figure 2 is a front view of an embodiment of the printed wiring board of the present invention, Figure 3 is a cross-sectional side view of the same embodiment, and Figure 4 is the same embodiment. FIG. 3 is a process diagram showing an example of manufacturing a printed wiring board. 6... Insulating substrate, 7, 8... Conductor layer,
9...Mounting hole, 10...Notch, 11.
... Processing machine, 12 ... Conductive adhesive.

Claims (1)

[Scope of utility model registration request] One of the conductor layers formed on both surfaces of the insulating substrate is made to protrude from the end surface of the insulating substrate, and this protruding portion is joined to the other conductor layer along the end surface of the insulating substrate. Printed wiring board.