Degradation mechanisms of siloxane-based thermal interface materials under reliability stress conditions

This paper describes the degradation behavior of siloxanes as thermal interface materials (TIM) in semiconductor packages. It tackles existing literature degradation studies on siloxane materials. It then presents the failure and material analysis findings and explains the degradation behavior of siloxane-based TIM when exposed to different reliability stresses such as: (1) bake at high temperature (2) moisture exposure and (3) temperature plus moisture exposure. A good correlation was established between known chemical reactions and analysis data after stress. With these data, a good understanding of the reliability performance of siloxanes as thermal interface material was established.