New acceleration factors for temperature, humidity, bias testing

New temperature-humidity acceleration factors for surface conductance (
G
) were determined. These can be used to relate device life in a high-stress laboratory environment to device life in a normal-use environment. Analytical expressions for the acceleration factors were derived for both encapsulated and unencapsulated test specimens. Lower acceleration factors were predicted for specimens encapsulated with DC 3-6550 RTV silicone rubber than for unencapsulated specimens. The new acceleration factors were used to predict failure rates due to electrolytic conduction on active devices.