10 - Electromigration in flip-chip solder joints

Abstract

This review is devoted to four types of physical failure mechanisms in microelectronic devices for high-current density applications; those failures are electromigration (EM), Joule heating-induced failures, stress-related damage, and thermomigration (TM). In practice, some of these failure mechanisms occur together so that the real root cause cannot easily be detected and understood. Reliability designers need to be well informed to evaluate the electrical characteristics, thermal characteristics and mechanical strength for solder interconnects in advance. Recent progress in failure mechanism evaluation is summarized and a critical overview of the basis of atomic transport, diffusion kinetics, morphological evolution, and numerical simulation is presented. Special emphasis is on the understanding of EM interactions with other failure mechanisms. In addition to this review of the current knowledge, the remaining challenges as well as future directions are also discussed.