Assessing electronic parts for use outside manufacturer-specified temperature limits

The availability of electronic parts rated for operating temperature ranges wider than -40 to 85°C is decreasing as semiconductor manufacturers are driven by commercial applications such as computers and communications. The need for parts rated for wider temperature range is growing for applications such as avionics, military, and automotive electronics, although their market share is insignificant.; This dissertation examines how the performance assessment of electronic parts can be integrated into the part selection and management process. It provides for the methods of assessment of part to determine if they are capable of operating in an application when the operating temperature range is wider than the manufacturer-specified operating temperature ranges. Three methods of assessment are developed: namely parameter conformance assessment, stress balancing, and parameter re-characterization.; Stress balancing method of thermal uprating is analogous to power derating of active and passive electronic parts where power consumption is limited at higher temperatures. In stress balancing method, this concept is extended above the manufacturer-specified temperature range. The electrical parameters of the part or the system, which affect the power dissipation of the part, are limited to reduce the power dissipation.; Parameter re-characterization method of thermal derating mimics the electrical characterization process of the semiconductor manufacturers. Semiconductor manufacturers use characterization process to establish data sheet specification limits and to determine variations of electrical parameters with respect to various electrical and environmental factors. The re-characterization method works on a limited scope to determine effects of change in temperature using the manufacturers' electrical specifications as baseline.