Acceleration factor study of lead-free solder joints under wide range thermal cycling conditions

In this study, a comprehensive set of tests were performed on test vehicles with different package types, sizes, pitches, and solder joints metallurgies. Accelerated Thermal Cycling (ATC) testing was performed using four different thermal cycling profiles: 0–100 °C, −40–125 °C, −55–125 °C, and −60–150 °C. Data from the tests were analyzed for failure mode and failure rate using Weibull statistics, and the characterized life for each test condition was determined and analyzed. The impact of solder alloy metallurgies, package types, sizes, and pitches on acceleration factors was also analyzed. The data will help quantify discrepancies due to test condition variations, and will also provide valuable guidance on effects of package types, size, pitches, and solder joints metallurgies. In addition, failure analysis was performed at different stages of the tests for each thermal cycling condition. The failure modes and failure mechanism were compared and discussed across all the thermal cycling profiles.