Modeling of parasitic inductive effects in power modules

Computer-assisted analysis of the dynamic behavior of the electromagnetic fields inside and outside the bus bar under realistic transient switching conditions allows us to study the details of the resulting current distribution in its interior and other related quantities (such as the heat dissipation). Hence, it proves to be an indispensable prerequisite for the systematic shape optimization of the interconnects and other structural components of a power module. Using a two-stage model for the electromagnetic fields, we tackled the switching problem by decomposing it in a Laplace equation for the quasi-stationary electric field and in a parabolic equation for the rapidly varying electromagnetic field contributions causing the eddy currents. Both equations were solved by means of finite-element methods