Accelerated Aging System for Prognostics of Power Semiconductor Devices José R. Celaya SGT Inc., NASA Ames Research Center Intelligent Systems Division, Moffett Field, CA USA Vladislav Vashchenko National Semiconductor Corp. Santa Clara, CA USA Philip Wysocki ASRC Aerospace, NASA Ames Research Center Moffett Field, CA USA Sankalita Saha MCT Inc., NASA Ames Research Center Intelligent Systems Division, Moffett Field, CA USA Kai Goebel NASA Ames Research Center Intelligent Systems Division, Moffett Field, CA USA Abstract— Prognostics is an engineering discipline that focuses on estimation of the health state of a component and the prediction of its remaining useful life (RUL) before failure. Health state estimation is based on actual conditions and it is fundamental for the prediction of RUL under anticipated future usage. Failure of electronic devices is of great concern as future aircraft will see an increase of electronics to drive and control safety-critical equipment throughout the aircraft. Therefore, development of prognostics solutions for electronics is of key importance. This paper presents an accelerated aging system for gate-controlled power transistors. This system allows for the understanding of the effects of failure mechanisms, and the identification of leading indicators of failure which are essential in the development of physics-based degradation models and RUL prediction. In particular, this system isolates electrical overstress from thermal overstress. Also, this system allows for a precise control of internal temperatures, enabling the exploration of intrinsic failure mechanisms not related to the device packaging. By controlling the temperature within safe operation levels of the device, accelerated aging is induced by electrical overstress only, avoiding the generation of thermal cycles. The temperature is controlled by active thermal-electric units. Several electrical and thermal signals are measured in-situ and recorded for further analysis in the identification of leading indicators of failures. This system, therefore, provides a unique capability in the exploration of different failure mechanisms and the identification of precursors of failure that can be used to provide a health management solution for electronic devices. Keywords-prognostics; electronics prognostics; accelerated life testing I. INTRODUCTION Prognostics and health management (PHM) is an engineering discipline that focuses on the estimation of the health state of a system and the prediction of the remaining life before failure. The health state estimation is based on the actual condition of the system and it is fundamental for the prediction of remaining life under anticipated future usage. This information can be vital in increasing the safety of operations and can contribute significantly in improving mission success rate as well as reducing the cost of unscheduled maintenance. Most of today's complex systems contain significant amount of electronics. In the aerospace domain, flight and ground crews require health state awareness and prediction technologies across all systems that can accurately diagnose faults, anticipate failures, and predict the remaining life. This includes those from avionics, where electronic components have an increasingly critical role in on-board, autonomous functions for vehicle controls, communications, navigation and radar systems. Power electronics devices such as power MOSFETs (metal oxide semiconductor field effect transistors) and IGBTs (insulated gate bipolar transistors) are semiconductor devices employed in a variety of switch mode power supplies and electrical motor drivers where high frequency switching of high electrical power is required. These devices are critical components of electronic power systems like switch mode power supplies and electrical motor drivers, where high-speed switching of high currents is standard operation Requirement. Research interest in this area has increased in recent years and the notion that electronic devices fail without any previous indication of damage progression has changed as the research community continues to identify precursors of failure in a variety of electronic components. Current research efforts in prognostics for these power devices focuses on: a) identification of the failure modes and mechanisms [1, 2]; b) identification of precursors of failure which serve as leading indicators of failure and play an essential role in the prediction of RUL [1-3]; c) development of accelerated aging methodologies and systems to accelerate the aging process of test devices by accelerating the aging process while continuously measuring key electrical and thermal parameters