Cavitational Failure Phenomenon in Pb-Sn Eutectic Solders

This report concerns mechanisms on the formation of r-type crack (or cavitation) associated with grain boundary sliding in Pb-Sn eutectic solders used for microelectronic applications. The experimental works indicate that cavitation takes place in a specimen deformed in a tensile test at a relatively low strain rate of 7×10-6/ s and in specimens fatigued at 0.1% to 0.2% strain range and a frequency of 1.67×10-2/ s. Based on these phenomenological observations, it is discussed that the presence of cavities requires large sliding displacements combined with a high stresses.