Motivated by the dramatic increase of renewable energy and electric vehicle, a variety of customized power modules are rapidly designed and developed. However, it is necessary to expend a long time to examine the new power modules to ensure the reliability concerns via massive experiments, such as power cycling. The deformation characterization of the bare die has a grave impact on the failure of the power module. Therefore, to observe the weak point and presume the cycling lifetime of the power module package, the online characterization of deformation under the field application is significant. Besides, the outcomes can provide confident evidence for the finite element simulation model to conduct research on electrothermal-mechanical stress. In this letter, the mathematical model is created to understand the mechanical deformation induced by electrothermal coupling. To characterize the deformation of the power module in real-time for field application, a noninvasive confocal methodology is proposed. In addition, to confirm the feasibility of the proposed routine, an experimental setup is set up by using the front-to-front converter. The experiment results show that the maximal overall deformation occurs on the middle surface of the die while the edge of the bare die suffers minimal deformation, which corresponds to the simulation results. Besides, the overall and partial deformation errors between experimental and simulation results are within 5% and 7%, respectively.

中文翻译：

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通过共焦方法在线表征功率模块的电热机械效应


在可再生能源和电动汽车急剧增长的推动下，各种定制电源模块迅速设计和开发。然而，需要花费很长时间来检验新的电源模块，通过大量的实验（例如功率循环）来确保可靠性问题。裸芯片的变形特性对功率模块的失效有严重影响。因此，为了观察功率模块封装的弱点并推测其循环寿命，现场应用下变形的在线表征具有重要意义。此外，研究结果可为有限元仿真模型开展电热机械应力研究提供可靠的证据。在这封信中，创建了数学模型来理解电热耦合引起的机械变形。为了实时表征电源模块的变形以供现场应用，提出了一种非侵入性共焦方法。此外，为了确认所提出的程序的可行性，使用前至前转换器建立了实验装置。实验结果表明，最大的整体变形发生在模具的中间表面，而裸模边缘的变形最小，这与仿真结果相对应。此外，实验结果与模拟结果之间的整体和局部变形误差分别在5%和7%以内。