BGA单板结构与板级结构焊点剪切力学行为分析

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力学性能. 结果表明, 单板结构中焊点的抗剪强度高于板级结构中焊点的抗剪强度. 在单板结构中，高银焊点的抗剪强度最大，加入稀土元素的低银焊点只是得到了一定程度上的改善，然而对于板级结构，加入稀土元素的低银焊点剪切力学性能基本与高银焊点相当. 在同等拘束条件下，低银焊点的延展性优于高银焊点. 此外，对于同一种钎料而言，单板结构中的焊点断裂在体钎料上，而板级结构则断裂在IMC/体钎料界面处.

Analysis of shear mechanical behavior of solder joints in BGA in veneer structure and board-level structure

The shear behavior of solder joints in BGA package structure is studied by shear experiments. The mechanical properties of four solder joints with Sn-3Ag-0.5Cu, Sn-0.3Ag-0.7Cu, Sn-0.3Ag-0.7Cu-0.07La and Sn-0.3Ag-0.7Cu-0.07La-0.05Ce in the veneer and board-level structure were compared and analyzed. The results show that the shear strength of the solder joints in veneer structure is higher than that of the solder joints in board-level structure. The shear strength of the high-silver solder joints is the largest and the low-silver solder joint with rare earth element has been improved to a certain extent in veneer structure. However, the shear mechanical properties of low-silver solder joints with rare earth elements are basically equivalent to those of high-silver solder joints in board-level structure. The ductility of the low-silver solder joints is better than that of the high-silver solder joints under the same constraint conditions. In addition, for the same solder, the joints in veneer structure fracture in the bulk solder, and the joints in board-level structure fracture at the interface of the IMC and bulk solder.