Research On The Thermal Effect Of Electromagnetic Damage And The Thermal Reliability In IGBT

With the development of integrated circuits,the degree of integration of Insulated Gate Bipolar Transistor(IGBT)has gradually increased,the sensitivity of IGBT to electromagnetic pulse has increased,and the fatigue and aging of IGBT are caused by the power of electromagnetic pulse,which increases the internal temperature of IGBT.High temperature will lead to abnormal function of equipment,instability of equipment,even burnout of equipment,damage the whole system.In practical engineering,equipment failure caused by overheating accounts for a large proportion.In order to improve the stability of power converter and ensure the normal operation of electronic equipment,it is necessary to study the influence of electromagnetic pulse on IGBT.At the same time,the accumulated heat in IGBT module is not easy to dissipate,and the thermal stress and deformation are aggravated by temperature.If the equipment operates under these conditions for a long time,it will easily lead to material fatigue,reliability reduction,and even affect the service life.Therefore,further exploring and studying the thermal reliability of IGBT module packaging,revealing the main factors affecting the heat dissipation performance of IGBT module,has important guiding significance and engineering practical value for optimizing the structure of IGBT module and improving its heat dissipation performance.Firstly,based on the cell-level three-dimensional thermal model of IGBT established by finite element software COMSOL,the variation of junction temperature of IGBT under steady and transient conditions is analyzed.The thermal accumulation effect of IGBT under monopulse and periodic pulse is studied.The transient thermal response and peak temperature of IGBT are captured and compared.The results show that the maximum temperature occurs in the center of the chip,and the factors such as pulse power amplitude,pulse width,waveform and frequency will affect the junction temperature to varying degrees,which will lead to module failure in serious cases.Secondly,the thermal model of IGBT module is established,and the temperature field characteristics of solder layer on substrate and solder layer onchip are simulated and analyzed from the macroscopic point of view.The results show that the aging of solder layer increases the solder layer temperature.Under the same conditions,the aging of substrate solder layer has little effect on the temperature fluctuation,and the aging of chip solder layer has greater effect on the solder layer temperature.Finally,the heat dissipation performance of IGBT packaging module is analyzed.The maximum junction temperature of IGBT module is calculated by simulation.The effects of substrate,solder layer,liner material and thickness on the heat dissipation performance of IGBT module are studied.The appropriate material and material thickness are found,which can provide some reference for the optimization design of IGBT module.