Study on the Insulation Reliability Model of Printed Circuit Boards Under Continuous Square Impulse Voltage

Printed circuit board (PCB) is the core component of the spacecraft power supply system, and its insulation reliability level directly affects the safe and stable operation of the spacecraft. Therefore, a reliability and life model for PCB insulation based on improved multi-parameter Weibull failure distributions (WFDs) was proposed. First, the WFDs are used to analyze the failure data of PCB under the action of electric and thermal stress, and the insulation characteristic failure time of PCB are obtained by the maximum likelihood estimation. Then, the exponential function (EF) is used to modify the standard WFDs, and the functional relationship among PCB failure probability, electric field strength, failure time and temperature are established. Besides, the PCB insulation failure surface is also obtained. Finally, the breakdown behavior of PCB is discussed and analyzed. The analysis shows that the heat accumulation caused by temperature and electric field is the main factor to accelerate the deterioration of PCB insulation.