Parametric study on relevant design and material parameters for reliable hard encapsulation of automotive power modules
Parametric study on relevant design and material parameters for reliable hard encapsulation of automotive power modules
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汽车电源模块可靠硬封装相关设计和材料参数的参数化研究
DOI：
10.1109/eptc56328.2022.10013218
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
J. Franke
中科院分区：
文献类型：
--
作者：
M. Sprenger;Niklas Noll;Christoph Hecht;Malte de Greiff;Lars Müller;J. Franke
在功率模块封装中，标准的封装方法是用低可见度和杨氏模数的软硅胶灌封。在过去的十年里，由于潜在的成本降低和可靠性提高，通过大面积传递模塑实现的硬封装已经成为一种替代方案。液体硬胶囊材料的大面积灌装是实现硬胶囊的另一种选择。无论采用哪种工艺技术，基板、散热器和模块尺寸一般较大，多材料堆积，工作过程中循环热负荷大，高温高压工作都对硬封装的材料选择提出了挑战。在材料选择过程中，密封剂的分层和脆性断裂以及通过密封剂对被封结构的破坏是主要关注的问题。热机械模拟可以在这种材料选择过程中提供支持和指导。因此，在这项研究中进行了对比参数模拟，以估计几何参数(如基板金属化厚度和散热器厚度)和工艺参数(如灌封材料的固化温度)对封装封装的热机械行为的影响。本研究引入“有效包装热膨胀系数”的概念，作为有效选择封装剂的工具。所得结果可用于指导不同组件堆叠封装材料的选择。
In power module packaging, the standard approach for encapsulation is potting by soft silicone gels with low vis-cosity and youngs modulus. Within the last decade, hard encapsulation realized by large area transfer-molding of epoxy mold compounds has established itself as an alternative due to potential cost reduction and reliability enhancement. Large-area potting of liquid hard encapsulant material is another option for realization of a hard encapsulation. Regardless of the used process technology the large substrate, heatsink and module size in general, multi-material stack-up, heavy cyclic thermal loads during operation, high temperature and high voltage operation possess challenges to the material choice for hard encapsulation. Delamination and brittle fracture of the encapsulant and damage of the encapsulated structure through the encapsulant are the main concerns within the material selection process. Thermo-mechanical simulations can support and provide guidance within this material selection process. Therefore comparative parametric simulations have been performed within this study in order to estimate the influences of geometric parameters, such as substrate metallization thickness and heatsink thickness, and process parameters, such as curing temperature of the potting material, onto the thermo-mechanical behavior of the encapsulated packages. The concept of calculating an “effective package coefficient of thermal expansion” is introduced in this study as a tool for effective selection of encapsulants. The obtained results can be used as a guideline for the selection of encapsulation materials for different module stack ups.