Power Mosfet's Thermal Resistance Measures Different Value between Body-Diode and Saturate Test Conditions

摘要

The distribution of heat flux in power MOSFET package is significantly affected by the effective heat- ing area of MOSFET chip. Under different operation conditions, power consumption distribution changes due to MOSFET's different temperature sensitive parameter. As the result, in cases when MOSFET works in saturation mode (V_(th) < V_(gs) < V_(th)+V_(ds)) and Body-Diode mode, different transient thermal response is usually measured. This article studies thermal resistance change and gives numerical result based on thermal transient test on a popular commercial MOSFET packages. CFD simulation model calibration is also used to visualize heat flux distribution inside package and discuss how it affects package's thermal characteristics.