Design-for-reliability and implementation on power converters

Reliability is a complex task that needs an integrated teamwork to accomplish. The reliability work of a power converter starts from topology design, component selection and qualification, design, testing, manufacturing, and does not end with the first customer shipment. Reliability has to be designed in, tested in, and built in. This paper provides a comprehensive study on reliability issues related to DC-DC power converter design and a Design-for-Reliability (DFR) practice. First of all, a reliability sensitivity analysis is conducted for a typical DC-DC converter design using an interactive design-for-reliability tool created by the author and colleagues at HP. The design parameters studied include thermal design, component derating, topology design, mechanical layout, and component quality and selections. Then, some common reliability issues of DC-DC converter design are discussed and the component reliability issues and applications in DC-DC converters are discussed in details. In the last part of the paper, an integrated reliability qualification testing matrix is presented using highly accelerated testing methods.