计及焊料老化效应的IGBT热网络模型

IGBT模块热行为建模过程中通常忽略焊料老化对内部传热路径的影响,导致结温估计偏差。针对此问题,该文提出一种计及焊料老化效应的自适应热网络模型。首先,利用壳温不均匀性的动态响应实时监测焊料老化状态,建立两者间的对应关系近似估计内部传热路径的恶化程度,对热网络参数进行更新。考虑封装层物理特性不同导致的时间常数差异,完善老化进程中的瞬态热行为。通过有限元分析和Simulink仿真实验验证该模型的有效性,相较于传统的热网络模型,该模型结温估计结果更为精确。因此,修正后的热网络模型能良好地表征焊料老化状态下的瞬时热行为。

The influence of solder aging on the internal heat transfer path is usually ignored in the thermal behavior modeling process of IGBT module,which leads to the deviation of junction temperature estimation.In order to solve this problem,an adaptive thermal network model considering the aging effect of solder is proposed in this paper.First of all,the aging state of solder is monitored in real time by using the dynamic response of shell temperature non-uniformity,the corresponding relationship between them is established to approximately estimate the deterioration of internal heat transfer path,and the parameters of thermal network are updated.Considering the difference of time constant caused by different physical properties of the packaging layer,the transient thermal behavior in the aging process is improved.The validity of the model is verified by finite element analysis and Simulink simulation experiments.Compared with the traditional thermal network model,the junction temperature estimation result of this model is more accurate.Therefore,the modified thermal network model can well characterize the instantaneous thermal behavior of solder in aging state.