In this article, the influence of the insulated gate bipolar transistor (IGBT) chip-near temperature gradient on the failure modes in the power cycling test is investigated with the finite element (FE) simulation and experiment. Two important aspects influencing the temperature gradient are studied: one is the load current pulse duration $t_{\mathrm {on}}$ from the testing aspect; the other is the area ratio between the chip region and direct copper bonding (DCB) top side copper determined by the device package layout. The IGBT chip-near temperature gradient caused by these two factors is first investigated using the FE thermal simulation. It was found that by varying $t_{\mathrm {on}}$ and the area ratio, a significant influence on the temperature gradient of the chip and the average temperature of the solder layer can be achieved, which could lead to different dominating failure modes under the same power cycling test conditions. Furthermore, experiments considering those two factors were designed and performed to verify the inference derived from the simulation. The results show that the failure mode indeed can be shifted because of the changed temperature gradient.

中文翻译：

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功率循环中横向温度梯度对失效模式的影响

在本文中，通过有限元（FE）仿真和实验研究了绝缘栅双极型晶体管（IGBT）芯片附近的温度梯度对功率循环测试中故障模式的影响。研究了影响温度梯度的两个重要方面：一是负载电流脉冲持续时间 $ t _ {\ mathrm {on}} $ 从测试方面来看；另一个是芯片区域与直接铜焊（DCB）顶侧铜之间的面积比，具体取决于器件封装的布局。首先使用有限元热仿真研究由这两个因素引起的IGBT芯片附近的温度梯度。发现通过改变 $ t _ {\ mathrm {on}} $ 面积比对芯片的温度梯度和焊料层的平均温度有很大的影响，在相同的功率循环测试条件下，会导致不同的主要失效模式。此外，设计并执行了考虑这两个因素的实验，以验证从仿真中得出的推论。结果表明，由于温度梯度的变化，故障模式的确可以转移。