Assessing High-Voltage PWM-Induced Degradation of FR4 PCBs in Aircraft Applications

With the substantial increase in transportation electrification, operating voltages have risen with the use of high-voltage and high-power electronic switches. The need for high-density power converters necessitates integrating low-voltage circuits (modulation, sensing, and control circuits) as well as high-voltage switches onto the same PCB. To achieve compactness, integrating magnetics into the PCB is also a design methodology adopted, which poses additional stresses between PCB layers. Additionally, PCB material stresses become significant when a PCB-based bus bar design is used. This work aims to develop a methodology to understand the degradation of FR4-PCBs subjected to high-voltage PWM pulses, as repetitive high-voltage pulses may impact the aging rate of the PCB.