基于细观力学均匀化等效材料参数的复合泡沫热致应力预测方法

环氧复合泡沫采用空心玻璃微珠改性环氧树脂，对于降低电子封装材料的热致应力非常有效．为提高环氧复合泡沫的设计效率，本文提出了一种宏细观结合的环氧复合泡沫热致应力分析方法．首先通过细观力学建立不同微珠粒径、壁厚、微珠体积分数等微观结构参数下环氧复合泡沫的等效性能预测模型，然后结合宏观线弹性热应力分析模型，进行环氧复合泡沫电子封装的热致应力分析，最终获得了一种电子封装热致应力与环氧复合泡沫微观结构之间的关联模型．基于模型探讨了微珠壁厚、微珠体积分数、微珠配比等微观结构参数对封装热致应力的影响规律，并基于两种典型封装结构证明了方法的可行性，研究成果对于开发低应力封装技术、提高电子封装的可靠性及环境适应性具有重要的意义．

A New Method to Predict the Thermal-Induced Stress of Syntactic Foams Based on Mesomechanics Homogenized Material Properties

Epoxy resin syntactic foams are a class of composite materials that are synthesized by dispersing hollow particle fillers in the matrix materials, which is an efficient way to decrease the thermal-induced stress in electronic packaging and insulating encapsulation. In order to improve the design efficiency, an approach combining macro-mechanics and micro-mechanics methods was proposed to analyze thermal-induced stress in this paper. First, the equivalent properties of syntactic foams were predicted using micro-mechanics in which the effects of the hollow glass micro-balloon diameters, wall thicknesses and volume fractions were included. The macro thermal-induced stresses in electronic packaging were predicted using the linear-elastic method. Lastly, the relationship between the micro parameters of the hollow glass micro-balloon and the thermal-induced stresses in the electronic packaging was obtained. The thermal-induced stresses were predicted for two typical electronic packaging structures. This work is of great importance to develop the low-stress technique, increase reliability and environment adaptability of the electronic package.