Influence of environment on the fatigue of Pb-Sn solder joints

摘要

The effect of a vacuum ( approximately 10/sup -6/ torr) on the low cycle fatigue life (25, 50, 75, and 95% drop in load) of 10Sn90Pb and 63Sn37Pb solder joints tested in shear was investigated in total strain control ( Delta gamma /sub t/=0.006 to 0.5, upsilon =0.1 Hz ramp cycling) at 300 K. The influence of a grease coating was determined for the 63Sn37Pb alloy for Delta gamma /sub t/=0.07=0.80. No clear effect of vacuum occurred for the strain range considered. The grease coating improved fatigue life for a constant total strain range. Possible explanations for the observed effects are given.