【摘要】 采用试验方法研究BGA封装结构中焊点的剪切力学行为.分析并比较了Sn-3Ag-0.5Cu,Sn-0.3Ag-0.7Cu,Sn-0.3Ag-0.7Cu-0.07La和Sn-0.3Ag-0.7Cu-0.07La-0.05Ce四种钎料焊点在单板结构与板级结构中的尺寸效应.结果表明,单板结构与板级结构中焊点的抗剪强度均随焊点尺寸的减小而增加,板级结构焊点表现的更加明显.低银焊点与高银焊点的剪切力学性能差距随着焊点尺寸的减小逐渐降低.随着焊点尺寸的减小,单板结构中焊点的剪切应变逐渐增加;板级结构则遵循先增加后减小的变化规律.此外,高银焊点随焊点尺寸的减小断裂模式由韧脆混合型向韧性断裂形式转变,另外三种低银焊点断裂模式不变,仅是断裂位置向体钎料侧偏移.更多还原

【Abstract】 The shear behavior of solder joints in BGA package structure was studied by test method. The size effect of Sn-3 Ag-0.5 Cu,Sn-0.3 Ag-0.7 Cu,Sn-0.3 Ag-0.7 Cu-0.07 La and Sn-0.3 Ag-0.7 Cu-0.07 La-0.05 Ce four solder joints were analyzed and compared under the veneer and board-level structure.Results showed: The shear strength of solder joints in the veneer and board-level structure increased with the decrease of the solder joints size,this phenomenon in the solder joints under boardlevel structure was more obvious. With the decrease of the size of the solder joints,the gap of shear mechanical properties of the low silver solder joints and the high silver solder joints were gradually decreased. The shear strain of the solder joints in the veneer structure increased gradually with the decrease of solder joints size,while the shear strain of the solder joints in the board-level structure was followed by the change law of the first increase and then decrease. In addition,the fracture mode of the high silver solder joints was changed from the mixed-mode of ductile and brittle to the ductile fracture with the size of the solder joint. The fracture mode was unchanged for the other three kinds of low silver solder joints,only the fracture location shifted to the bulk solder.更多还原