Prediction of the electrochemical migration induced failure on power PCBs under humidity condition — A case study

The goal of this paper is to demonstrate a case study on prediction of the electrochemical migration (ECM) induced failures which occur on the printed circuit boards (PCBs). At first, a brief introduction on a gate driver PCB utilized in this study is provided. Under condensing conditions, the electrochemical reactions which occur on a PCB board contaminated by weak organic acids (WOAs) are investigated. Based on COMSOL, an approach is thereby proposed to simulate the electrochemical reactions. To calibrate the parameters utilized in the simulation, the leakage current (LC) on the surface insulation resistance (SIR) is measured. A parameter optimization procedure is thereby performed to make sure the simulated LC matches the measured data. To validate the proposed method, the humidity test is performed on the gate driver PCB. The failure observed in the test is compared with the simulated LC density, which is used as an indicator for the formation of ECM. Finally, the simulation is performed when the PCB operates under real operation conditions. The simulation identifies the possible ECM path which can occur on the PCB.