Power Module with Additional Low Inductive Current Path

Abstract:
Parasitic inductances are a major problem with power modules, in particular in fast switching applications. The parasitic inductance of the component interconnections causes an overvoltage condition and increases the switch-off losses in the semiconductor. Many initiatives have been investigated to reduce the parasitic inductance in power modules utilizing a complex mechanical construction of overlapping internal bus bars forming the DC path. An alternative to this approach, which is outlined within this writing, is a concept using today’s standard power module construction but providing an additional ultra low inductive path for the transient current.