Stress behavior during thermal cycling in metal-polyimide layered films

Abstract

A comparative study has been carried out on the stress behavior of metal/polymer/quartz structures during thermal cycling for two polyimides, PMDA-ODA and BPDA-PDA. Using Cu as the metal layer to minimize the effect of the interfacial chemistry, this study focuses on the effect of the polyimide properties. The polymer layer was found to serve as an effective buffer layer to reduce the overall thermal stress of the layered structure. The effect was found to depend on the viscoelastic properties and the thickness of the polymer. BPDA-PDA was more effective than PMDA-ODA because of its viscoelastic characteristics at high temperature as well as a better matching in thermal expansion with Cu.