An Experimental Approach to Identify Source and Cause of Radiation Noise of Inverter Systems and Bare Si Power Chips

Dynamic characteristics of IGBTs (Insulated Gate Bipolar Transistors) and FWDs (Free Wheeling Diodes) for power modules have been modified continually in order to improve energy efficiency of inverter systems. However, this implies radiation noise has been increasing due to modification of power chip characteristics. Identification of exact source and cause of radiation noise is essential for taking measures to improve power module design to keep within EMI standards. This paper describes an experimental approach to identify source and cause of radiation noise by scanning near field magnetic field over an inverter system and a half bridge with bare Si power chips suitable for identifying underlying noise sources in IGBT and FWD chips.