Solder Joint Ductility Research Articles

Solder Joint Ductility

Solder joint arrays were tested under tensile loading to determine the strain-to-failure (ductility) under a wide range of conditions. The trends in ductility with alloy, joint size, pad metallization, and test conditions were quantified and discussed. 63Sn37Pb solder joints showed a significant increase in ductility as applied stress is reduced below 40MPa. Lead free alloy ductility was much less sensitive to applied stress level. Hence, at low stress levels, eutectic SnPb has greater ductility than the lead free alloys. Larger joints showed greater ductility in a constant crosshead rate test compared to smaller joints. This is believed to be a function of the load train stiffness. Such a discrepancy was not observed in the constant load test method.