Stress Analysis In Pulse Power Integration Module Based On RSD

The reversely switched dynistor(RSD)is a special kind of devices applied in the pulsed power area.Based on the controllable plasma layer turn-on principle,RSD has low dissipation and high di/dt capability.Due to the advantages of small volume,low parasitic parameters and high reliability for the integrated modules,similar to the power electronic area,the integration trend has also appeared in the pulsed power area in recent years.Because the pulse power technology has the characteristics of high voltage,high current and high repetition frequency,the reliability of the integrated module in the special working condition is a key problem.Therefore,the stress on the integrated module based on RSD was analyzed in this paper,including the electromagnetic force and thermal stress.In this paper,by establishing the electrical-thermal-mechanical multi-physical fields coupling finite element models,the electromagnetic field and temperature field distribution of the module are analyzed,and the distributions of the electromagnetic and thermal stress in the module are discussed on the secondary packaging integrated module of PCB level based on RSD.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 of the amplitude of the current.The thermal stress increases with the increase of 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: For the RSD-based integration module used in this paper,the peak value of the current with a pulse width of 1μs at 100 Hz is 3 kA;the peak of the current with a pulse width of 1 μs at 10 Hz is 13 kA;the peak of the current with a pulse width of 1 μs at 5 Hz is 19 kA.In the turn-on experiments of the module,the surface temperature of the module was measured using an infrared thermal imager.The maximum temperature of the module was observed on RSD,the temperature of the pad at the capacitor pin was higher than that of other pads,which was consistent with the simulation results.The magnetic field on the module is measured by the near field probe,the magnetic field near the magnetic field is stronger than the magnetic field at the magnetic field.The experimental results verify the contents of the model analysis.