North America

Red Room - Session 1

9:10 to 10:10 a.m. Tuesday, June 3, 2014

Improving Product Reliability with Advanced ESS Techniques

As companies strive to reduce warranty costs, it is becoming clear that an Environmental Stress Screening (ESS) program limited to simple run-in or burn-in is inadequate. A combination of aggressive thermal and vibration stressing is required to achieve the higher reliability levels required. Burn-in is only a fraction of what is needed to significantly change field failure rates. An enhanced ESS that includes a combination of thermal cycling, at high rates of change, with 6-DOF (degrees of freedom) RS (repetitive shock) vibration will capture many more defective or marginal products. The results of this enhanced ESS will not only identify and remove more products with potential early life failures, but will also expose weaknesses that can result in later life warranty failures. This ESS can be completed in a much shorter time than a conventional burn-in.

This presentation uses calculations and experimental data to demonstrate the effectiveness of a combined stress environment for ESS. It will review case studies describing reliability improvements experienced by using this approach and the results of a direct comparison study between Highly Accelerated Stress Audits (HASA) versus burn-in in a high volume power supply manufacturer. This enhanced ESS program is a much more effective mechanism for exposing weak or defective components.

Key Words: ESS, Combined Stress, 6DOF, Repetitive Shock Vibration, Burn-in, Reliability Improvement, HALT, HASS, HASA, Reliability, Reliability Testing, Reduce Test Time

Tom Peters and Neill Doertenbach


Denver, Colorado