微电子先进封装要求微凸点的尺寸不断缩小以满足高密度互连的需求。而微凸点小型化使其微观组织和力学行为都会发生重要变化，进而影响到封装可靠性。通过剪切实验，研究了基体中仅包含一个Sn晶粒微凸点的剪切力学行为及其断裂模式。研究发现在应力和应变速率关系式σ=.εm中，Sn单晶粒微凸点的应变速率敏感度指数m约为0.1，常数值K约为29。Sn单晶粒微凸点的剪切断口表面光滑平整，滑移带分布清晰，属于单晶滑移断裂。研究结果有助于评估Sn单晶粒微凸点的封装可靠性。%With the rapid development of the advanced microelectronic packaging technology, the volume size of microbumps is required continuing to be reduced to meet the high density solder interconnects. The miniaturization of microbumps would lead to a significant change in the microstructure and the mechanical behavior, which would finally influence the reliability of microelectronic packaging. In present research, the mechanical shear property and the fracture mode of the microbumps with only one Sn grain in the bulk have been studied by shearing test. It is found that the strain rate sensitivity exponent m and the constant K is about 0.1 and 29, respectively in the relationship of stress and strain rate (σ=.εm ). The microbumps with one Sn grain have a smooth fracture surface with clear slip bands, indicating that the fracture mode is the slidingfracture of monocrystal. The results are helpful to assess the packaging reliability of the microbumps with one Sn grain.
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