JPS61268090A - Printed wiring 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 [Industrial Field of Application] The present invention relates to printed wiring boards, and particularly to high-density printed wiring boards with narrow pattern spacing.

[Conventional technology]

Conventionally, high-density printed wiring boards of this type have been produced by closely adhering a copper foil to one surface of an insulator such as Kapton, and then forming a predetermined conductive pattern using well-known patterning and etching techniques.

[Problem that the invention seeks to solve]

In the conventional printed wiring board described above, conductor patterns are formed on the same plane of an insulator, so if the distance between adjacent conductors becomes narrow and an electric field is applied, the conductor will It has the disadvantage that it grows between bodies and shorts the adjacent conductors.

FIG. 2 shows an example of a failure of the prior art. 22 is a Kapton, and 211 and 212 are adjacent conductors formed on the Kapton. If the distance 210 between the conductors 211 and 212 is shortened to about several tens of microns and the conductors 211 and 212 are left in the air with a voltage of several volts applied between them, a migration phenomenon occurs. That is, ionized metal ions are deposited on the negative electrode side by the electric field. As this phenomenon progresses, conductors 211 and 212 become short-circuited. .

[Means for solving problems]

The printed wiring board of the present invention has an insulator having a recess between a conductor and an adjacent conductor.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a sectional view of an embodiment of the present invention. Insulator 12
After laminating pan foils 111 and 112 on top, predetermined patterns 111 and i12 are formed using well-known patterning and etching techniques. Thereafter, a groove or recess 121 is formed in the insulator between the adjacent conductors 111 and 112.

This recess 121 has the following effects. One is conductor 1
11 is applied positively and the conductor 112 is applied negatively, ie
Since no electric field is applied in the vertical direction to the vertical portion 122 of the concave portion 121 of the edge, there is an effect that the above-mentioned migration phenomenon does not occur.

Another reason is that the spatial distance between adjacent conductors 111 and 112 is 110, but due to the presence of the recess 121 in the insulator, the effective migration distance is
The effect is to increase by 2.

〔Effect of the invention〕

As explained above, the present invention prevents the migration phenomenon that occurs between adjacent conductors by providing recesses in the insulator between adjacent conductors, and has the effect of realizing a high-density printed wiring board.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a printed wiring board of the present invention, and FIG. 2 is a sectional view of a conventional wiring board. 111.112, 211.212-°゛...Conductor pattern, 12.22...Insulator, 121...
... recess on the insulator, 122 ... vertical part of the recess on the insulator, 110.210 ... "distance between adjacent conductors. \, -

Claims (1)

[Claims] 1. A printed wiring board in which a predetermined conductor pattern is formed on the same plane of an insulator, characterized in that a recess is provided in the insulator between adjacent conductors.