Screen printing process and apparatus and electrical printed circuits obtained therewith

摘要

A process for providing through plated holes in a substrate by screen printing provides uniformly thick plating of the holes. One side of the substrate is screen plated while being subjected to an underpressure between 10 and 200 gr/cm2 from a chamber fed by a large volume vacuum vat. When treating the other side of the substrate, vacuum may be increased up to 2.5 times the first underpressure.