What is Burn-in?

Burn-in is the application of thermal and electrical stresses for the purpose of inducing the failure of "marginal (microelectronic) devices, those with inherent defects or defects resulting from manufacturing aberrations which cause time and stress dependent failures."
Who Uses Burn-in?

Burn-in is normally performed by semiconductor manufacturers or independent test labs (ITL's); however it is not unusual for end users or contract manufacturers to use burn-in. Sample units of new devices or new lots are burned in to provide reliability data for the remaining devices. Integrated circuits for military and aerospace applications are burned in to ensure the highest level of quality.