Separation measurement of parasitic impedance on a power electronics circuit board using TDR

Accurate identification of parasitic parameters on a printed circuit board (PCB) and establishment of a new design method by considering the parasitic components in a power electronics circuit will become major technological issues to promote power density of the circuit. This study focuses on time domain reflectometry (TDR) which is a high-speed transmission technique for the effective measurement of parasitic parameters on PCBs with complicated wiring arrangements. Identify of some individual parasitic inductances existing on a buck chopper PCB can be realized by utilizing an interaction between a reverse-side ground layer and a printed wiring of the PCB. And then, influence of stray capacitances formed between a heat-sink and power devices are mentioned in this paper. The accuracy of the measured parasitic inductances is verified by a comparison of experimental and simulation results.