Abstract
Flexible Printed Circuits (FPCs) have been commonly utilized for electric gadgets such as Liquid Crystal Displays (LCDs). Direct-Metallization is a promising method for plating highly conductive copper onto the polyimide films when fabricating the FPCs. In this paper, we suggest a two-step reduction process to improve the adhesion between the polyimide film and the precipitated copper metal with an enhanced mechanical interlocking effect. The peel strength of the metalized polyimide-based film is improved from 0.3 to 0.8 kN/m by adopting this process. Observation of the boundary structure between the copper metal and polyimide film reveals that the precipitating small and uniformly-sized copper particles are distributed just below the surface of the polyimide.
