Corrosion protection and adhesion promotion for polyimide/copper system using silane-modified polymeric materials

Abstract

The copolymers of vinyl imidazole (VI) and vinyl trimethoxy silane (VTS) were applied as corrosion inhibitors and as adhesion promoters for polyimide/copper system at elevated temperatures. The mole ratios of VI to VTS were 100:0, 70:30, 30:70, and 0:100. Peel test was performed to evaluate the adhesion strength of polyimide/primer/copper system after heat treatment at 400°C in nitrogen atmosphere. The effect of the copolymer composition on corrosion protection and adhesion promotion was investigated by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). The adhesion strength of polyimide/primer/copper system depended on the thermal stability of the primer and the chemical interaction between polyimide and the primer. It showed the highest value when the mole ratio of VI to VTS is 30:70. The primer reduced or suppressed copper oxide formation in the polyimide layer. The degree of corrosion protection by the primer was affected by its thermal stability and its reactivity with copper.