Predicting the Positive Effects of Combined Metallurgical and Thermo-Mechanical Impacts on the Reliability of Solder Joint Interconnections

摘要

Generally speaking, solder joints fail due to both fatigue and creep. Therefore both mechanisms are strongly considered by designers and manufacturers as an important design criteria. However, since most designers take parameters individually, their designs are considered as an over design. The parameters considered in this study, which have a direct influence on fatigue life and creep individually, are grain direction, grain size, temperature, and yield strength. Obviously, most of these parameters have opposite dual effects on both the fatigue and creep mechanism. In other words, each parameter might have a positive effect on fatigue but also a negative effect on creep and vice versa. For this purpose, this study uses the metallurgical assumptions, and stress analysis theories, on the data present in literatures in order to characterise and determine the significance degree of each parameter, and also determine the overall effect on the solder life. This study recommends focusing on the combinability of the parameters that have significant effects on solder joints reliability in electronic interconnection, recognising the positive effects, and using them on the overall solder life. Such potential approach may assist in reducing the size and cost.