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.