Surface plasma characterization of polyimide films for flexible electronics

Flexible electronics have drawn much attention due to vast application possibilities. Polyimide was the substrate of choice as a flexible substrate owing to its properties such as good mechanical strength, high temperature resistance, good dimensional stability, and low dielectric constant. The adhesion between metal and polymer substrate plays a crucial role for reliability of these applications and low adhesion was the cause for most failures. In this study, plasma surface treatments were applied on polyimide surface by inductively coupled plasma (ICP) treatment system. The results of contact angle measurements and atomic force microscopy (AFM) show a large increase in surface roughness with increasing treatment time. Complete wetting was found for both argon and oxygen plasma treatment. Analysis of chemical composition by FTIR reveals an increase in carbon-oxygen functional groups and the concentration of oxygen on the surfaces.