A case study on the benefits of combining reliability stress tests

Abstract

AbstractThis paper discusses two distinct benefits associated with product reliability qualifications by combining individual reliability stress tests into a single test. First, a combined test will make better use of test equipment, personnel and product samples required for the qualification, implying a cost benefit. Secondly, a combined test allows interaction between the stress sources to occur on all failure causes. These benefits were realized as a result of a power supply application. Each individual test was designed to address specific causes which are assumed to be totally independent of other failures. A combined test can verify or deny independence and therefore provide a stronger practical test. Hence, this paper will demonstrate that a combined reliability test will provide more efficient testing with solid engineering product performance coverage. In addition, an approach is proposed for combining tests which fixes the acceleration rates between stress tests as the same ratio as under the nominal operating product environmental conditions.