Effect of Vibration on Lead-Free Solder Joint Reliability Under Temperature Changes for Automotive Electronics

The reliability of lead-free solder balls of Sn-3.5Ag, Sn-0.7Cu and Sn5.0Sb was evaluated by vibration tests under temperature changes. The materials were used to fabricate BGA test chips, and those are assembled with

daisy chain circuit board to prepare the test module. Random vibration was applied under temperature cycle, and the resistance of the solder ball was monitored during the test. Shear strength and microstructure with respect to IMCs morphologies and thickness were also analyzed. A numerical simulation to obtain the natural frequency and corresponding modes were performed to estimate the frequency range effect of the random vibration on the test module. It was found that Sn-0.7Cu exhibited superior mechanical properties among the investigated solder materials in the present test method.