Simulation And Analysis Of High-Power IGBT Solder Layer Aging Based On Multiphysics Coupling

With the rapid development of urban rail transit,subway trains have gradually become an important means of transportation for people to travel.The traction converter is the core device of the subway train traction system,and the IGBT power device is the core component of the traction converter.Therefore,the reliability of the IGBT is closely related to the safety of the train.This paper takes the IGBT module used in the rail transit line as the research object.The aging process of the IGBT module is studied by the ANSYS finite element method under the different degrees of aging of the solder layer.First of all,in terms of IGBT aging stress inducement analysis and reproduction,based on Matlab/Simulink,this paper conducts the equivalent simulation of dual-machine pair-to-traction electric heat,reproduces the load curve of the traction converter in the actual subway application scenario,and studies it under a specific load curve.The variation law of junction temperature and heating power under different rotational speeds and torques is obtained.The data space of IGBT module loss under different working conditions is established to provide reference data for multi-physics coupling simulation.Secondly,a detailed modeling and finite element multi-physics coupling simulation are carried out for the temperature,stress distribution and change trend of the IGBT module during the aging process of the solder layer.Because the IGBT bonding wire usually starts to age when the solder layer is nearly half of the age,and it is very difficult to measure the failure parameters of the solder layer online.In this paper,four different nodes of aging 0%,25%,37.5%,and 50% are selected,and the IGBT loss under the speed limit of 80km/h is used as the input condition,and the change of thermal stress of the solder layer is analyzed emphatically.The results show that the thermal stress is jointly affected by the temperature amplitude and the temperature gradient,and with the aging,the thermal stress of the solder layer increases gradually and the growth rate accelerates.In addition,considering that vibration inevitably occurs during the traveling of subway trains,and vibration is an important factor affecting the failure of electronic equipment,modal analysis and random vibration analysis are carried out on the IGBT module.Observing the vibration stress distribution,it can be seen that the conventional vibration during the train operation has a great influence on the bonding wire,but compared with the aging effect caused by temperature,the vibration does not significantly accelerate the aging of the bonding wire and the solder layer.Finally,the strain generated by the fatigue failure of the solder layer is analyzed from the perspective of material failure principle,and combined with the Conffin-Manson model and the Basquin formula,the life prediction is carried out for IGBT modules with different aging degrees.When the stress is continuously greater than 185 MPa,the IGBT module has basically completely failed.Figures: 109,Tables:26,References:73.