Effect of Al trace dimension on electromigration failure time of flip-chip solder joints

Abstract

The effect of Al-trace dimension on electromigration of flip-chip solder joints was investigated. The Al trace dimension was found to have a significant influence on the electromigration failure time. When joints with Al traces 100 µm wide were stressed by 1.0 A at 100°C, failure times were 35 h, 1,700 h, and >3,000 h for joints with Al traces that were 2,550 µm, 1,700 µm, and 850 µm long, respectively. Solder joints with Al traces 40 µm wide and 2,550 µm long failed instantly at 0.6 A. The Joule heating effect was found to be responsible for the huge difference in failure time.