Research on nondestructive measurement of power VDMOS thermal contact resistance

A nondestructive measurement method of VDMOS thermal contact resistance has been researched in this paper. The result shows that the transient heating response curves of the chip in VDMOS device are different, which are measured under different contact pressures between device and heat sink. Based on the curves, structure function method is used to analyze the thermal resistance constitution of chip-to-heat sink. A mathematical model has been presented to extract the function relationship between thermal contact resistances and contact pressures. The research solves the problem of nondestructive measurement of thermal contact resistance. Moreover, a simulation model of thermal contact resistance is established, and the results are consistent with the experiments.