FPCB via hole selective plating process

Abstract

The invention relates to an FPCB via hole selective plating process. The process comprises the working procedures of circuit formation, covering film pasting, drilling, copper plating, selective plating exposure and development, copper removal and the like. According to the FPCB via hole selective plating process of the invention, the process of drilling, then plating copper and then forming a circuit in the traditional process is changed into the mode of firstly forming the circuit, attaching a cover film and then drilling and plating copper, so that the yield of the circuit is ensured; the copper plating uniformity is ensured by replacing selective plating with whole-surface copper plating; and therefore, the etching stability of a circuit board is ensured, and the yield is improved.

Description

Technical field: [0001] The invention relates to the technical field of circuit board processing, in particular to a selective plating process for via holes of an FPCB board. Background technique: [0002] In the PCB manufacturing process, in order to meet the ultra-thin characteristics and good bendability of the flexible circuit board at the same time, and ensure the copper thickness of the hole, the hole selective plating scheme is generally adopted. [0003] The basic process of the traditional selective plating scheme is as follows: [0004] S1, Drilling: processing via holes on double-sided copper foil substrates by laser or mechanical means; [0005] S2, metallization of the inner wall of the hole: a layer of conductive graphite is deposited on the inner wall of the hole; [0006] S3, selective plating exposure and development: paste a dry film on the surface of the copper foil substrate processed with through holes, and selectively expose and develop around the hol...

AI Technical Summary

Problems solved by technology

[0012] In the traditional selective plating process, because copper is only electroplated around the corresponding holes, the area of ​​the holes is small and the distribution is irregular. During electroplating, the uniformity of copper plating on the entire plate will be poor due to uneven current density; moreover, only around the holes and on the inner wall. Copper plating inevitably forms a level difference with the non-copper-plated area. When the line is etched, there is a risk of air bubbles remaining in these step differences. These two factors will make it difficult to etch the line, resulting in a high scrap rate

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