Properties of metallic films on polymer substrates coated by Ar⁺ ion-beam-assisted deposition

Abstract

The quality of adhesion of a metallic film coated on a polymer substrate constitutes a serious problem affecting the life of coating products. Generally, means for improving the adhesion of films formed by vapor deposition consist of the application of a heating or corona discharge process to the substrate. Methods involving concurrent energetic particle bombardment during evaporation, however, can strongly modify the adhesive properties of the resulting thin film.

In this study the authors report on the adhesion to polymers of films assisted by 2 keV (0.2 A m^-2) Ar⁺ ion bombardment during the initial evaporation and of ordinary vapor deposition films. The wear property of Ti, Cu and Al films on various polymer substrates is measured by the pin-on-disk test to estimate the adhesion. In many samples the defacement of the ordinary vapor deposition films appears more clearly than that of the films assisted by Ar⁺ ion bombardment after a total wear distance of 10 m. The decrease in adhesion between the polymers and the metallic films coated by Ar⁺ ion-beam-assisted deposition depends on the heat distortion temperature of the polymer.