A study of adhesive improvement of a Cr-Ni alloy layer on a polyimide surface by low pressure gas plasma modification

The influence of low pressure oxygen (O-2) and argon (Ar) gas plasma modification of polyimide film on the adhesion to an alloy plating layer made from chromium (Cr) and nickel (Ni) was investigated. X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) were employed, respectively, to estimate the chemical and morphological status of the modified polyimide surface. Attenuated total reflectance-Fourier transform infrared (ATR-IR) spectroscopy and scanning electron microscopy (SEM) were also employed to determine the fracture mode during an adhesion durability test. The results indicated that O-2 plasma treatments generated carboxyl groups, but an excess of carboxyl groups could oxidize the Cr at the interface at elevated temperatures, which led to a loss of adhesion. (C) 2013 Elsevier B.V. All rights reserved.