Influence of Coating Thickness on Adhesion Strength of Aluminum Coatings on Aluminum Nitride Substrates by Low Pressure Cold Spraying

Abstract

Cold splay is considered for use in semiconductor devices because it can produce coatings with minimal thermal degradation. However, the adhesion strength between the ceramic substrate and the copper coating used in this application is not sufficient. Therefore, a method to improve adhesion strength by using an aluminum coating as a bond coating has been reported. In particular, aluminum nitride substrates and aluminum coatings show high adhesion strength, which is thought to be due to scientific bonding via Y₂O₃-derived oxide film on the substrate surface. Since the coating thickness was limited to 80 μm only in these previous studies, we varied the coating thickness in this study to investigate the influence of coating thickness on adhesion strength. As a result, the adhesion strength increased as the coating became thicker.