Shear performance and failure fracture analysis data of Sn-Pb-Ag solder joints at different low temperatures

The commonly used connecting materials for spacecraft electronic products are mainly tin-lead-based solder, and with the deep space exploration, the extremely low temperature and large temperature change environment have put forward higher requirements for spacecraft materials. At present, domestic research on the performance of the solder is mainly concentrated in -55℃ and above, and the research on the evolution of the performance under very low temperature conditions is still relatively small. In this paper, an experimental study was carried out on Sn62Pb36Ag2 solder joints commonly used in spacecrafts, and their shear strengths were tested at room temperature, -50°C, -100°C, -150°C, and -196°C, and their mechanical property changes and failure modes were analyzed at different temperatures. The results show that the shear strength of Sn62Pb36Ag2 solder joints increases gradually as the temperature decreases. At temperatures of -100℃ and above, the fracture morphology is dominated by ductile fracture characterized by shear bands. -150 ℃ and liquid nitrogen temperature, fracture morphology to crack cut through the tip of the intermetallic compound leaving a small plane, the corresponding fracture path from the solder matrix to the Cu interface transfer, low temperature brittleness increased significantly.