A Wirebond-Less Package for High Voltage Cascode Gallium Nitride Devices

The rapid development of gallium nitride (GaN)-based wide bandgap power devices has been stirring power electronics industry for almost a decade. Advanced packaging solutions are eagerly needed to exploit the maximum potential of the high performance GaN semiconductors. Especially for devices in the cascode configuration, the design and fabrication of a suitable package are very challenging for high-frequency, high-efficiency applications. In this study a new wirebond-less package has been developed for a 650 V, cascode GaN device to address the parasitics and reliability concerns induced by the bonding wires used in the conventional package. The simulated junction-to-case thermal performance and measured switching characteristics for GaN device packaged in this new format are reported and compared with the device in the previously developed stack-die package. This wirebond-less package demonstrates a lower thermal resistance than most of the packages used for commercial power GaN devices. And its footprint/size is smaller than the state-of-the-art packaging format utilized for silicon-based power devices.