A mechanical and microstructural study was performed of 434314 tinleadbismuth solder. This alloy melts lower than the commonly used tinlead solders and therefore holds promise as a useful material in twostep soldering processes or in processes with thermally sensitive components. Mechanical testing of 434314 tinleadbismuth showed a strength comparable to that of tinlead solders but increased creep rate. Microstructural analysis scanning electron microscopyenergy dispersive Xray exhibited the same mechanism of fatigue as for tinlead solders, viz., heterogeneous coarsening. Thermocyclic fatigue demonstrated that the longterm reliability of 434314 tinleadbismuth is comparable to that of tinlead solders.
Soldering & Surface Mount Technology – Emerald Publishing
Published: Mar 1, 1991