Comparison of Failure Rates and Reliability of Power Semiconductors in Power Electronic Devices Using Methodologies MIL-HDBK-217F and FIDES

Reliability prediction of power supplies, which are based on power transistors and diodes is a comprehensive process and depends on type of power elements, type of power circuit, control circuit, cooling system, operating and environmental conditions. The relatively accurate indicator for the reliability of given power supply is its operational reliability, based on reliability parameters of elements, blocks and systems which it consists. For calculation of reliability parameters of single electronic component can be used a various methodology such as: MIL-HDBK-217F, FIDES, RDF2000, 217F and others. That methodologies have a different type of models, correction pi-factors and covers a different operating, manufacturing, and environmental parameters. The choice of a method is based on knowledge of the methodology itself, the type of power semiconductors that have been used, their load and the environmental conditions. All mentioned methodologies provided different values for reliability parameters - failure rates and probability for failure free operation and for a reliability engineer it is a complex task to choose the right methodology. In this paper are compared reliability indicators of two types of power semiconductors (MOSFET transistor and power diode), analyzed by two of the widely used methodologies - MIL-HDBK-217F and FIDES.