Assembly-level reliability of flex-substrate BGA, elastomer-on-flex packages and 0.5 mm pitch partial array packages

The assembly-level reliability of the 0.8 mm pitch flex-substrate EGA, 0.65 mm pitch elastomer-on-flex package, and 0.5 mm pitch partial array EGA has been characterized in thermal fatigue, out-of-plane deformation, low frequ ency repeated bending, and thermal aging. Non-linear finite element models have been used to identify and predict the dominant failure mechanisms and identify the assembly parameters which have a dominant impact on reliabilit y. The model predictions have been verified with accelerated test data. The results have been bench marked against other technologies including 1.5 mm pitch OMPAC(TM) and 1 mm pitch, 196 I/O Glob-top EGA. (C) 2000 Published b y Elsevier Science Ltd.