Through hole metallization method of fine ceramic circuit board

Abstract

The invention discloses a through hole metallization method of a fine ceramic circuit board. The method comprises the following steps: plating a metal seed layer on the upper surface and the lower surface of the circuit board and the inner wall of a through hole in vacuum, forming anti-plating films on the upper surface and the lower surface of the circuit board by adopting photoresist, and exposing and developing twice in different directions so as to realize through hole filling without thickening the metal layer on the surface and expose the through hole to achieve the self-alignment mask effect. Compared with a dry film mask method, method avoids the problem of inaccurate alignment. The upper surface and the lower surface are not thickened during electroplating and hole filling, so that on one hand, the use of expensive electroplating liquid medicine is greatly reduced, and the cost is saved; and on the other hand, the thinner the surface metal layer is, the narrower the wire width and the finer the circuit of the wire prepared by adopting the pattern transfer method are, so that the higher the integration level of the circuit board is, the preparation of the refined circuit is facilitated, the subsequent thickening can be carried out as required, and the application requirements of more complex and higher integration level circuit design can be met.

Description

technical field [0001] The invention relates to the technical field of circuit board manufacturing, in particular to a through-hole metallization method of a fine ceramic circuit board. Background technique [0002] For a circuit board with circuits on the upper and lower sides, it is usually necessary to drill a through hole for the circuit board and fill the through hole with metal to realize the conduction between the upper and lower sides of the circuit. [0003] The existing circuit board through-hole metallization technology is to firstly vacuum-plate a thin metal seed layer on the upper and lower sides of the circuit board and the inner wall of the through-hole, and then use electroplating to fill the through-hole with metal. The disadvantage of this prior art is that when the through holes are filled by electroplating, the metal layers on the upper and lower sides will also be thickened, and it is difficult to prepare a fine circuit layer when the circuit layer is pr...

AI Technical Summary

Problems solved by technology

The disadvantage is that if the film thickness is too high, it will be difficult to refine the circuit pattern, and if the film is too thin, the copper plating will partially cover the dry film, making it difficult to fade the film

However, it does not explain how to realize that the photosensitive material completely blocks the metal layers on the upper and lower surfaces to expose the through holes.

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