Thermal Performance Comparisons of Different Spacer Structures in Double-Sided Cooling Power Modules

The thermal performance of double-sided cooling (DSC) power module is influenced by different spacer structures. In this paper, thermal performance improvement principles of different kinds of spacer structures are described qualitatively and thermal performance of these structures are analyzed by finite element method (FEM) quantitatively. Both Expanding spacer area and connecting low temperature areas to high-temperature areas by thermal conductor are effective methods to improve overall thermal performance. Structure with spacer under the bare die have the best thermal performance among these structures due to larger heat conduction area. Furtherly, transient dual interface method is utilized to measure the thermal resistance of different structures. The body diode electrical characteristic is chosen as the temperature sensitive electrical parameter.