Temperature and humidity effects on adhesion of polyimide film to a silicon substrate

A 90° peel tester with substrate heating capability was built to evaluate the adhesion strength of polyimide films to a silicon substrate. The effects of polyimide film thickness and peel rate on polyimide adhesion to a silicon substrate under high or low humidity, and at elevated temperatures, have been evaluated. In a high humidity environment, a low peel strength was measured. The influence of moisture on the peel strength increases with decreasing peel rate. Peeling at elevated temperature reduces the moisture effect even under high humidity conditions. Using a low peel rate in a high humidity environment, the measured peel strength showed a maximum as the polyimide film thickness increased. No striations in peeled polyimide films were observed for peeling in a high humidity environment.