LEAD-FREE ELECTRONICS USE AND REPAIR DYNAMIC SIMULATION

Abstract

The conversion from tin-lead to lead-free electronics has increased concern amongst engineers about the reliability of electronic assemblies. In order to communicate the impact of the conversion in terms of cost and availability, a simulation of electronic systems at the LRU level to and through a repair facility was created. The model includes the effects of repair prioritization, multiple possible failure mechanisms, no-fault-founds, and un-repairable units. Example analyses were performed on electronic assemblies that use SAC and SnPb solder using a repair process modeled after a NSWC Crane Aviation Repair Process.

The case studies revealed that LRUs exposed to usage profiles characteristic of aerospace and high performance applications, high thermal cycling temperatures with short dwell times, SAC exhibited significantly increased repair costs when compared to tin-lead. Prioritizing LRUs and increasing the rate of deployment had no significant impact on the cost or availability metrics for the cases considered.