Polyimide surface chemistry

Abstract

This study investigates the surface modification of polyimides which are employed as insulating layers in fabrication of chips and chip carriers. Polyimides, such as poly (pyromelliticdianhydride-oxydianiline) (PMDA-ODA), react with KOH or NaOH to give a polyamate (salt of polymaric acid) which is subsequently protonated with acid to give the corresponding polyamic acid. Upon curing at 300°C or higher, the polyamic acid is converted back to polyimide. This reaction can be confined to the film surface by adjusting the reaction conditions and the solvent. This work reports on the polymide surface modification, nondestructive measurements of thickness of the modified layers, and the polymer surface structure-surface property relationship.