Electrical Characterization of Modular 3D Packaging Assembled with Compressed Metal Foams

This paper proposes a novel modular packaging concept based on the 3D integration of 1.2kV SiC MOSFET with metal foams for electrical contacts with pressure assembly. These foams could allow improving the disassembly of switching cells by keeping low electrical resistance and inductance inside the package. Thus, static and dynamic experimental characterizations are carried out to evaluate their impact compared to a massive interconnection represented by copper interposers. Static measurements show that the electrical resistance of the package is 2.3mΩ which represents 7% of the total resistance. Dynamic characterizations demonstrate that the stray inductance of the switching cell is equal to 2.7nH. With results of the massive interconnection close to the ones of foams, the material used for the electrical interconnection have no impact on the electrical performances of the power module. The modification of pressure assembly of the power module shows however a global increase of the packaging resistance and stray inductance of the power module for both solutions. This increase is more important for the massive interconnection due the non-deformable mechanicals properties.