Investigations of thermal interfaces aging under thermal cycling conditions for power electronics applications

This paper presents new investigations on the aging of Thermal Interface Materials (TIMs) subjected to thermal cycling conditions. The challenge was to design a specific and original set-up in order to not only undergo avionic temperature mission profile (50 C/+150 C) but also to perform standardized thermal characterization at always same conditions. Thermal conductivity is used as aging indicator. Several TIM materials (change phase, graphite and polymer based) have undergone more than 1500 of such cycles. As a result, only the phase change material thermal interface has been affected with a 30% increase of initial thermal resistance.