Micro-bulk fatigue testing was developed to investigate the fatigue lives and damage mechanisms of Sn-3.0Ag-0.5Cu and Sn-37Pb solder alloys. The fatigue lives of micro-bulk solder obeyed Manson-Coffin’s empirical law, and the fatigue ductility exponents were about 0.55 for both Sn-Ag-Cu and Sn-Pb alloys. The fatigue life of Sn-3.0Ag-0.5Cu alloy was 10 times longer than that of Sn-37Pb alloy under symmetrical wave profile, although fatigue resistance of Sn-3.0Ag-0.5Cu alloy was not so superior under asymmetrical wave condition. The fatigue crack was developed from extrusion and intrusion of slip band in Sn-3.0Ag-0.5Cu alloy, while the crack was observed at colony boundary in Sn-37Pb alloy. The difference in damage mechanism may affect the sensitivity of fatigue life to reversibility of loading profile.

This content is only available via PDF.
You do not currently have access to this content.