Investigation of the locus and mechanism of adhesion failure during peel tests on copper-chromium coated polyimide systems

Auger depth profiling and X-ray photoelectron spectroscopy (XPS) techniques were used to elucidate the adhesion process in copper-chromium coated polyimide. Metal layers were sputter-deposited on polyimide, which was modified by glow discharge under various conditions. The results showed that glow discharge could increase the chromium coverage on polyimide, improve or deteriorate adhesion at various interfaces, and change the locus of adhesion failure. Auger depth profiles could explain the various failure modes by revealing the chemistry at each interface. Additional information was provided by XPS results obtained from surfaces generated by failure. The effects of accelerated aging on this metal-polymer system were also studied.