Modeling fatigue behavior of electronically conductive adhesive joints under elevated temperature and humidity conditions

This paper describes a novel fatigue-life prediction methodology aimed at providing the design engineer an easy fatigue life predictive tool using experimental data, for both cumulative fatigue damage, as well as constant loading fatigue conditions. This encompasses an integrated approach to joint testing, analysis, and modeling. Utilizing the proposed methodologies, we aim to predict the changes in fatigue life of the adhesive, based on the whole spectrum of test variables including temperature, humidity, stress ratio, preconditioning (variable stress ratios), and frequency. This modeling approach is expected to give the design engineer an initial assessment tool for the effects of detrimental fatigue conditions, eventually leading to a much improved fatigue life, improved fail-safe capability, and reduced manufacturing costs.