基于有限元法的IGBT模块封装散热性能及热应力的仿真研究

发布时间：2018-01-05 00:34

本文关键词：基于有限元法的IGBT模块封装散热性能及热应力的仿真研究　出处：《重庆大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着IGBT模块电流密度的不断增大、功率不断提升、体积不断缩小,IGBT模块内部发热量成倍增加,热量在内部堆积不易散发,温度引起的热学、力学载荷愈加严重,进而导致温度升高及热应力形变加重。若器件在此条件下长期运行,容易导致材料疲劳、可靠性降低、甚至影响使用寿命。因此,对IGBT模块封装的热可靠性相关问题的进一步探索和研究,揭示影响IGBT模块封装可靠性的主要因素,对IGBT模块结构优化设计、改善散热性能有非常重要的指导意义及工程实用价值。本文以改善IGBT模块散热性能为目的,以ANSYS有限元分析软件为平台,分别研究了复合材料导热性能、IGBT模块的散热性能以及热应力,并根据计算得到的IGBT模块封装的最高结温和最大热应力的结果,并对散热设计及结构优化提出建议。首先,参考复合材料实际的性能参数,模拟复合材料的微观结构,建立三维有限元模型,计算复合材料的等效导热率,其计算值与理论值、试验值能很好吻合,说明有限元方法计算复合材料导热率的可行性。在此基础上对复合材料导热性能的影响因素进行分析:基体导热率、填料导热率、填料体积百分数、填料分布、填料形状、填料取向及椭球填料颗粒长径比,并对改善复合材料导热性能的措施提出建议。其次,研究了IGBT模块封装的散热性能,建立切合实际的IGBT模块封装三维有限元模型,对温度场进行仿真。通过计算得到的IGBT模块封装的最高结温,研究基板、焊层、衬板的材料及其厚度对IGBT模块封装散热性能的影响,并对IGBT模块的散热设计进行分析,为其结构优化提供参考。最后,对IGBT模块进行热-结构耦合分析,用间接法分析IGBT模块封装的热应力分布,通过计算得到的IGBT模块封装的最大热应力,研究基板、焊层、衬板的材料及其厚度对IGBT模块封装最大热应力的影响,并提出IGBT模块结构优化的措施。
[Abstract]:With the increasing of current density and power of IGBT module, the volume is reduced and the internal heat is multiplied, the heat is not easy to be emitted, and the heat is caused by temperature. The mechanical load becomes more and more serious, which leads to temperature rise and thermal stress deformation aggravation. If the device runs under this condition for a long time, it will easily lead to material fatigue, reliability decline, and even affect the service life. Further research on the thermal reliability of IGBT module packaging, reveal the main factors that affect the reliability of IGBT module packaging, and optimize the structure of IGBT module. In order to improve the heat dissipation performance of IGBT module, ANSYS finite element analysis software is used as the platform. The heat dissipation and thermal stress of the IGBT module were studied, and the results of the highest junction and maximum thermal stress of the IGBT module were calculated. First of all, referring to the actual performance parameters of the composite material, the microstructure of the composite is simulated, the three-dimensional finite element model is established, and the equivalent thermal conductivity of the composite is calculated. The calculated value is in good agreement with the theoretical value and the experimental value, which shows that the finite element method is feasible to calculate the thermal conductivity of composite material. On this basis, the factors affecting the thermal conductivity of composite material are analyzed: the thermal conductivity of matrix. The thermal conductivity, volume percentage, packing distribution, packing shape, packing orientation and the ratio of length to diameter of ellipsoidal packing particles are also discussed, and some suggestions for improving the thermal conductivity of composites are put forward. The heat dissipation performance of IGBT module package is studied. The 3D finite element model of IGBT module package is established and the temperature field is simulated. The maximum junction temperature of IGBT module package is calculated. The influence of the material and thickness of substrate, welding layer and liner on the heat dissipation performance of IGBT module packaging is studied, and the heat dissipation design of IGBT module is analyzed to provide a reference for its structure optimization. The thermo-structural coupling analysis of IGBT module is carried out, and the thermal stress distribution of IGBT module package is analyzed by indirect method. The maximum thermal stress of IGBT module package is calculated, and the substrate and welding layer are studied. The influence of liner material and its thickness on the maximum thermal stress of IGBT module packaging is discussed. The measures for optimizing the structure of IGBT module are put forward.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN322.8

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