PCB Embedded Power Electronics for Low Voltage Applications

Abstract:
The performance of a novel 3-phase invertor module embedded in a printed circuit board (PCB) is investigated considering packaging, thermal resistance, reliability and insulation. The embedded power electronic module is based on 6 insulated gate bipolar transistors (IGBTs) and 6 diodes rated to 1.2kV/25A each and it is benchmarked with a comparable traditional wire bonded semiconductor module. A detailed outline of the package is discussed including the top and bottom side metallization and the copper interconnect technology. A FEM thermal simulation is presented comparing a standard package with dies bonded to direct bonded copper (DBC) substrates to the PCB integrated modules. This is also validated with experimental measurement. The integrated module demonstrates up to 44 % lower thermal resistance than that of the traditional wire bonded DBC package for an identical applied current and cooling condition, resulting in a lower overall local chip temperature despite higher device losses. Furthermore, both packages are active power cycled to failure with the PCB embedded package demonstrates superior lifetime to that of the traditional DBC module. Finally, the maximum breakdown limit and the onset of partial discharge with the embedded PCB module are also reported for both aged and non-aged conditions.