Hydrolysis of Polyimide Films: Information from IR Spectroscopy

Hydrolysis of polyimides used as dielectrics is of concern because the formation of polar, hydrophillic products could significantly increase the dielectric losses. IR spectroscopy has been used to measure the changes occuring in films of polyimides during exposure to 100 C and 100% RH. This technique may be used to quantitate the hydrolysis of both the imide linkages and the trace of anhydride remaining in cured films. The decrease in anhydride is followed by observing the absorption at ~ 1850 cm sup - 1. The imide hydrolysis is quantitated using the imide band located near 1370 cm sup -1.