Quartzdyne Electronics has invested millions of device test hours in life testing of circuits in both powered and un-powered tests. In addition to time at temperature, these tests include thermal cycling and high impact drop testing. Recent projects have required the use of larger packages and components as we have expanded the variety of circuits that we build. It is desirable to predict the effects of these changes on long-term reliability before investing in tooling. In this study we will compare a new design which contains these larger components to the simpler, smaller designs for which we have extensive life-test data. Using a physics-of-failure approach, component mounting stresses will be analyzed using finite element modeling. These results will be compared to pre and post-aging shear strengths of actual components of varying sizes. Aging models will then be developed to predict the reliability of the new design based on the comparative stress margins of the individual components coupled with circuit complexity. Once validated, the aging models will enable reliability prediction and trade-off analysis for future designs.
