Mechanical design considerations for area array solder joints

Concurrent engineering often requires mechanical reliability to be traded off against a number of other criteria. Rather than simple optimization, mechanical design usually relies, explicitly or implicitly, on the assessment of the relative merits of a number of alternatives. However, the evaluation of a large number of designs by finite element and damage integral methods would, at best, be extremely cumbersome. The present work describes design tools based on elastic stress analysis for rapid assessment of area array assembly designs in terms of mechanical reliability. Examples in the discussion illustrate various means of improving the reliability of such assemblies.>