中文摘要：

为研究焊锡接点金属间化合物微结构对其微观一宏观力学行为的影响，采用Voronoi图算法构造了金属间化合物的晶粒尺度几何模型，通过在晶粒界面配置内聚力界面单元，提出了模拟金属间化合物晶粒界面裂纹起裂、扩展与连通的有限元数值模拟方法．基于该方法，研究了晶粒形状和晶粒界面缺陷对晶界微开裂模式和整体响应的影响，研究了金属间化合物微结构对焊锡接点强度和破坏模式的影响．结果表明，晶粒形状对整体强度影响不大，但对微裂纹开裂模式有影响．当考虑晶界随机缺陷时，强度较低的晶粒界面对整体强度影响较大．金属间化合物层的厚度对焊锡接点强度和破坏模式均有影响，而金属间化合物与焊料界面的粗糙度主要影响焊锡接点的破坏模式．

英文摘要：

In order to investigate the effect of the microstructure of intermetaUic compound （IMC） on the micro and macro mechanical behaviors of solder joints, a finite element based numerical approach is developed to simulate initiation, propagation and coalescence of microcracks along the grain boundaries in the IMC layer. In the approach, the topological microstructure of IMC grains is generated by Voronoi tessellations, and the proposed cohesive interface elements are embedded between the grain boundaries. By the proposed approach, the effect of grain shape and randomly distributed grain interracial defects on the microcrack pattern and the overall response, and the effect of IMC microstructure on the strength and the failure mode of solder joints, are investigated. The results indicate that the grain shape has little effect on the overall mechanical response, but affects the cracking path. In the model with Weibull distributed grain interfacial strength, the weak grain interface plays a key role in the overall strength. The thickness of the IMC layer has a significant influence on the strength and failure mode of solder joints, while the roughness of the solderflMC interface has an influence on the failure mode only.