SAE Publishes Revision to Electronic Microcircuit Wearout Standard

March 06, 2019 by Paul Shepard

SAE International has published Revision A of Aerospace Recommended Practice ARP6338: "Process for Assessment and Mitigation of Early Wearout of Life-limited Microcircuits." This revision addresses a complex technical issue that has been of concern to the aerospace industry for almost 20 years because aerospace electronics are typically required to last for decades compared to other types of electronics such as cellphones and computers.

As a result of that concern, a consortium of aerospace companies including Boeing, Honeywell, GE, Collins Aerospace and government agencies DoD, FAA and NASA sponsored a project at the Aerospace Vehicle Systems Institute (AVSI), along with the University of Maryland and DfR Solutions, to conduct research into aging and early wearout of semiconductor devices used in the aerospace industry.

The project recommended that industry standards should be developed to address life-limited semi-conductor devices. SAE International's Avionics Process Management Committee (APMC) thus developed the original SAE ARP6338 published in 2015. It is now considered the most effective, and acceptable, means to address microcircuit aging/wearout in aerospace electronics system design and certification.

Recently, other high reliability electronics industries, such as automotive and servers, have also observed aging and early wearout of microcircuits in their electronic systems, and concern over the issue is growing widespread as microcircuit technology continues to progress.

The new revision (SAE ARP6338A) includes updates to the physics-based mathematical models used to assess the likelihood of failure of microcircuits in aerospace, automotive, defense, and other high performance (AADHP) industries and provides new information regarding software tools used in the assessment process.

It also addresses the major microcircuit aging/wearout mechanisms: electromigration, hot carrier injection, time-dependent dielectric breakdown, and negative bias temperature instability. The revision effort was again conducted by the SAE Avionics Process Management Committee (APMC) and led by Lloyd Condra of DfR Solutions.