The Design, Application and Production-Testing of High-Power Fast recovery Diodes", "PCIM Europe", Year

Fast recovery diodes, though an integral part of inverter design, traditionally take a “back seat ” both at the device and equipment design levels where attention tends to focus on the controlled switch. (IGBT, IGCT or GTO). As a result, Snubber, Clamp and above all Free-Wheel Diodes (FWD) remain the Achilles Heel of optimal equipment de-sign. In recognition of this fact, together with the growing trend to eliminate voltage snubbers on diodes, semicon-ductor manufactures are developing new generations of diodes with profiled carrier life-times having enhanced Safe Operating Areas (SOA) and controlled (soft) recovery at very high di/dt and dv/dt levels. The growing concern for SOA (ratings) and not just recovery charge or losses (characteristics) imposes new constraints on production test equipment to ensure the cost-effective delivery of robust and reliable components. In contrast to turn-off devices (transistors and GTOs), thyristors and diodes have traditionally been production-tested for their characteristics only and classified accordingly. New generations of high-performance fast diodes must now also be tested for their dy-namic ratings in production. In this paper, the design and application of rugged devices is summarised and new pro-duction test equipment capable of reproducing a wide range of SOA test-conditions is described. 1