Mechanical Reliability Evaluation of Sn-37Pb Solder/Cu and Sn-37Pb Solder/ENIG Joints Using a High Speed Lap-shear Test

고속 전단시험법을 이용한 Sn-37Pb/Cu 와 Sn-37Pb/ENIG 솔더 접합의 기계적신뢰성 평가

This study utilized a high speed lap-shear test to evaluate the mechanical behavior of Sn-37Pb/Cu and Sn-37Pb/Electroless Nickel immersion Gold under bump metallization solder joints under high speed loading and hence the drop reliability. The samples were aged for 120 h at different temperatures ($120^{\circ}C,\;150^{\circ}C,\;170^{\circ}C$) and afterward tested at different displacement rates (0.01 mm/s to 500 mm/s) to examine the effects of aging on the drop life reliability. The combination of the stress-strain graphs captured from the shear tests and identifying a fracture mode dominant in the samples for different strain rates leads us to conclude that the drop reliability of solder joints degrades as the aging temperature increases, possibly due to the role of the IMC layer. This study successfully demonstrates that the analysis based on a high speed lap-shear test could be critically used to evaluate the drop reliability of solder joints.