Base material for high packing density circuit boards, esp. SMD boards

摘要

Base material for the mfr. of circuit boards (2),consisting of a plastic substrate (4) and a metal layer (3) on at least one side of the plastic substrate, is novel in that the plastic substrate is made of a light-sensitive plastic material. Also claimed is a process for mfg. circuit boards (2) using the above base material comprising: (a) coating the metal layer (3) with a light- or photo-sensitive layer; (b) applying light to the photosensitive layer using a perforated mask having holes of dia. /- 150-mm; (c) developing etching away the exposed metal layer areas down to the plastic substrate (4); (e) applying light to the exposed hole image of the plastic substrate (4); and (f) developing the exposed hole image of the plastic substrate (4) using a developer such that a through-hole (9) or a blind hole is produced.