A Universal Scaling Formulation of the Generalized Peck’s Equation for Corrosion Limited Lifetime in Self-Heated ICs

Abstract

Since the early 1980s, the highly accelerated stress test in conjunction with conventional Temperature-Humidity-Bias testing has been the industry-standard method for interpreting relative humidity (RH) and temperature (T) dependent failure modes in non-hermetically packaged ICs, solar modules, and other electronic components. In recent years, however, testing requirements based on JEDEC standards and the corresponding lifetime extrapolation to end-use conditions using Peck’s equation have been criticized as overly conservative for modern self-heated logic/power ICs. In practice, the self-heated ICs correlate RH, and T in a way that is not explicitly accounted for by Peck’s equation. In this study, we investigate the IC lifetime due to electrochemical failures – Cu-Al bond wire corrosion – by considering the effects of ambient RH, T, duty cycle, and self-heating temperature rise using an integrated self-consistent finite element-based Multiphysics model and propose a generalized Peck’s equation for self-heated ICs. Our study reveals how the asymmetry between On and Off-state heating leads to dramatic suppression of the effective RH experienced by an integrated circuit and, most importantly, identifies that the corrosion of Cu-Al bond wire occurs in spikes during the on-off transition when both RH and T are high. The generalized Peck’s equation also predicts an elegant scaling relationship among the fundamental variables associated with a self-heated IC lifetime. The prediction is validated by experimental lifetime data from self-heated IC published in the literature. The experimental validation of the physics-informed generalized Peck’s equation suggests the possibility of more accurate (and optimistic) lifetime predictions of modern ICs and solar modules.