Thermal stress analysis for polyimide thin film and a substrate layer system

We propose an analytical model based on Timoshenko's theory which describes chemical and physical properties of a polymer and a substrate layer system. This temperature dependent model is developed to account for the thermal stress caused by a mismatch of isobaric expansivity, due to the solvent evaporation and imidization. The stress-temperature profiles calculated from the proposed model are compared with experimental data for the given systems. The model gives a qualitative information for the stress development during the heating-cooling process.