Surface characteristics of a polyimide film treated with a dielectric barrier discharge plasma

Polyimide (PI) has many outstanding properties, such as good thermal stability, low dielectric constant, low dissipation factor and inherent surface inertness. The surface characteristics of PI were modified by using a dielectric barrier discharge (DBD) plasma treatment in ambient helium, air and oxygen gas at atmospheric pressure. The surface energy of the PI films was evaluated using a contact angle analysis according to the sessile-drop method. The plasma-treated surface of the PI films became hydrophilic. A change in the surface morphology was observed using scanning electron microscopy (SEM). The surface roughness of the plasma-treated PI films increased compared with that of the untreated film. In addition, the effects of plasma treatment on the surface chemical characteristics of the PI films were observed by using X-ray photoelectron spectroscopy (XPS).