Modeling and analysis of IGBT performance degradation based on solder layer crack propagation
Under fatigue load,insulated gate bipolar transistor(IGBT)experience structural damage and performance degradation,impacting the reliability of power electronic systems.To address this,the relationship between solder layer fatigue crack length and thermal resistance is derived based on heat transfer theory,firstly.The Darveaux model is used to characterize the evolution law of solder layer cracks in IGBT,and a new IGBT performance degradation model along with a method for estimating its undetermined coefficients is proposed.Then,considering the non-stationary characteristics of actual working conditions,a variable amplitude fatigue load model for IGBT is established using the response surface methodology.The rainflow counting method and linear cumulative damage criterion are then employed to assess the extent of IGBT performance degradation.Finally,using a type of IGBT product as an example,power cycling tests are conducted,and performance degradation modeling and analysis are carried out based on experimental data,verifying the effectiveness of the models and algorithms.