Honeywell's experience with screening plastic encapsulated microcircuit

Honeywell's Air Transport Division has historically screened plastic encapsulated microcircuits (PEM's) for 160 h at 125/spl deg/C, followed by a tri-temp screen at 40/spl deg/C, room temperature, and 125/spl deg/C, in accordance with the traditional view that this would increase the reliability of the end product due to reduced infant mortality. Recently, Honeywell has been collecting and evaluating field reliability and screening fallout data to reach a data driven conclusion as to the necessity of doing part screening, particularly burn-in. This used both internally generated data and semiconductor supplier data. This data shows clearly that for parts from a "high quality" semiconductor manufacturer, burn-in not only adds no value, it will actually increase the field failure rate of the devices built with these burned-in parts.