Benefits and Costs of Overstress Testing

摘要

Overstress test, tests using stresses beyond the design limit of the product, is successful at uncovering faults in both product design and the manufacturing process and ensures the overall robustness of the product. The benefits of overstress test include the following: 1. Early detection of latent faults. 2. Reduced total engineering time and cost. 3. Reduced production and warranty costs. 4. Earlier and mature product introduction with yields stabilized. 5. Higher reliability. 6. Greatly reduced manufacturing screening costs. Overstress tests traditionally have been divided into highly accelerated life test (HALT) and highly accelerated stress screen (HASS). In this article, the test results and the conclusions drawn from them are based on my experience at Tandem Computers, Compaq, and Cisco Systems. Products from these companies can be characterized as high-complexity, high-bandwidth electronic products primarily for enterprise customers.