Highly reliable DC/DC power module for demanding applications-from design to field tracking

Abstract

This paper describes the design, design qualification, manufacturing inspections, burn-in and field tracking of DC/DC power converter modules for telecommunication and other demanding applications to achieve high reliability. In a highly reliable DC/DC power converter module, components are substantially temperature- and voltage-derated. Case temperature is kept low by having sufficient surface area for efficient heat dissipation. Rugged mechanical design protects the module against damages in handling and application. Conformal coating, potting or transfer molding are used to protect the power module against harsh environmental conditions. Stress testing in design qualification will uncover potential design and manufacturing defects. Manufacturing inspections and 100% burn-in and final test will screen out manufacturing defects and control outgoing quality. A quality and reliability process is set up to establish the reliability performance of power converter modules by means of reliability prediction, reliability testing and systematic field tracking of failures. Common causes of power converter modules failure can also be identified for continuous design improvement.