Abstract
Three different sizes of BGA (Ball Grid Array) solder joints were subjected to mechanical fatigue testing. It was found that the fatigue life of these joints strongly depends on their size and can be expressed by Coffin-Manson's law. In addition, Sn-3Ag-0.5Cu, Sn-1Ag-0.7Cu, and conventional Sn-37Pb BGA solder joints were also subjected to mechanical fatigue testing. It was found that the Sn-3Ag-0.5Cu joints had a fatigue life close to that of the Sn-37Pb joints. In contrast, the Sn-1Ag-0.7Cu joints had a fatigue life half as long as that of the Sn-37Pb joints.
