Solder life prediction for leadless chip carriers

Abstract

An approach is described which incorporates the results of energy-based studies and solder-to-package mismatch into a single solder life model of comparable complexity to the Manson-Coffin approach. This model is verified by detailed analytical models and test data. Hazard rate analysis is used to properly account for the failed and unfailed items, and to determine the reliability distribution. The reliability distribution is incorporated into the solder joint model to analytically provide cycles to failure at various reliability levels. This method predicts the solder joint life in long-term thermal cycling, leading to reduced field failure rates. Applications for this approach include life prediction for the the US Air Force Avionic Integrity Program (AVIP) and life prediction for various military and commercial avionic programs.< >