Method for manufacturing an ultra-thin metal layer printed circuit board

Abstract

The present invention discloses a method for manufacturing a printed circuit board having an ultra-thin metal layer. The method discharges alkaline aliphatic amine gas and the nitrogen bubbled in the cupric sulfate solution via capacitive coupling in a vacuum, to generate low temperature plasma. The polyimide film and the epoxy resin board coated with fiberglass cloth are etched and the surface is treated to graft active groups, so as to increase the surface roughness and chemical activity. Subsequently, sputtering copper plating or chemical copper plating is directly conducted. The electroplating is conducted to thicken the copper film to a required thickness. The method of the invention not only does not need adhesive (adhesive free), but also has a high peeling strength. It can be used for the preparation of the flexible PCB, the rigid PCB, the multi-layer PCB, and rigid-flex PCB, having an ultra-thin metal layer.

Dependencies are inferred from the claim text.