3D Packaging for vertical power devices

Abstract:
This paper presents recent advances and breakthroughs of a commutation cell true 3D packaging solution with vertical power devices. This hybrid approach combines both wafer level and module level interconnection and assembly leading to an efficient 3D package. It can be used for regular inverters or to simplify the implementation of interleaved power converters. Direct copper bonding technology is used for the active power devices interconnection; vertical power devices are bonded at wafer level to a metallic substrate. The 3D assembly is carried out at module level based on the interconnection of matrices of low side and high side vertical power devices. As a result, the 3D integration of the active parts for power converters is optimized to the highest possible level regarding EMI levels and increased switching speed capabilities. Key challenges on design, fabrication and implementation are presented, and the first prototypes based on four switching cells of vertical 500V power diodes and MOSFETs are introduced.