PCB-Level Stress Analysis of an Integrated Module Based on Reversely Switched Dynistor

Abstract

In this paper, the effects of thermal stress and electromagnetic force on PCBs at different frequencies and different pulse current levels in reversely switched dynistor-based pulse power integration modules are studied. According to the theory of the electromagnetic field and thermodynamics, the electromagnetic field and temperature field of the pulse power integrated module are simulated and analyzed by finite-element method. The electromagnetic force and thermal stress on the PCB pad are obtained and their impacts on the pads are compared at different conditions. The simulation results show that the maximum electromagnetic force and thermal stress appear on the pad connected to the capacitor pin. The electromagnetic stress increases with the increase in the amplitude of the current. The thermal stress increases with the increase in the amplitude and the frequency of the current. According to the general specification of the rigid printed circuit board GJB 362B-2009, taken the pull-out force of pads as a standard, the limiting current is determined by the electromagnetic stress at low frequency and by the thermal stress at high frequency.