Comprehensive Model for Humidity Testing Correlation

This paper reviews all published life in humidity conditions vs life at 85C/85% RH for epoxy packages; 61 data points are used. An acceleration formula is described which provides direct extrapolation from test results in autoclave tests at up to at least 140C to low-humidity down to below 30XRH. This formula compares favorably with previously-published formulae. The possible effect of the Tg of the epoxy is recognized, and other high-temperature and low-humidity effects are disclosed. Recommendat ions are made for future tests, replacing 1000 hours at 85C/85%RH with a 20-hour test at 140C/100%RH, to reduce test time and increase test usefulness.