Drop Shock Test of PCB at Elevated Temperature

The electronics industry has faced an ongoing reliability challenge with lead-free solder materials since the implementation of the restriction of hazardous substances (RoHS) Directive. Among the various lead-free solder options, SAC-based solders have gained substantial popularity as replacements for the traditional SnPb (Tin-Lead) solder. Board-level drop shock testing of these solder materials is an essential criterion for evaluating reliability. The conventional approach in drop shock testing has primarily involved room temperature conditions. However, a substantial knowledge gap exists concerning solder joint behavior in real-world operating temperatures. Therefore, this study aims to conduct drop shock tests at elevated temperatures to effectively bridge the critical gap and ensure the reliability of solder joints in real-world practical conditions. In this study, drop shock performance testing of the SAC305 alloy has been performed at both room temperature and an elevated temperature of 75°C. The experiments followed the joint electron device engineering council (JEDEC) drop test standards, featuring a peak acceleration of 1500G and a 0.5 ms duration. After the drop tests, Weibull analysis was employed to assess the drop shock reliability under each test condition. Additionally, microstructure analysis was conducted to accurately identify the failure location and the failure modes. The results revealed a substantial reduction in the reliability of solder joint when subjected to elevated temperatures. Furthermore, microstructure analysis identified a change in the failure mode at elevated temperatures.