Analysis of Electromagnetic Coupling and Current Distribution Inside a Power Module

Due to high-current commutation speed, it has become necessary to minimize stray inductances to reduce over-voltage. This is a great challenge for the power-converter designer. Integration of converters into ever smaller packages decreases stray inductance considerably but, at the same time, increases other phenomena (thermal issues and electromagnetic-compatibility disturbances) capable of decreasing reliability and efficiency of the system. This paper presents a generic equivalent cabling model and examines the impact of parasitic inductance on current-distribution imbalance. This paper could, therefore, be used in thermal analysis in order to better understand the influence of packaging.