Double-Sided Cooling Half-Bridge Power Module of 650V/150A Gallium Nitride High-Electron-Mobility Transistor

The efficiency and power density of power conversion systems can be greatly improved by utilizing gallium nitride high-electron-mobility transistors (GaN HEMTs) due to their ultra-low on-resistances and switching energy losses. However, the wide adoption of these transistors is hindered by the challenges of packaging them within power modules to minimize parasitic inductances and maximize heat extraction. To address these challenges, in this article a packaging concept is proposed and experimentally validated for a 650 V/150 A commercial GaN HEMT in a half-bridge module with double-sided cooling (DSC). The module contains two devices sandwiched between two direct-bond copper substrates and connected face-to-face through a third direct-bond-copper interposer. Compared to a traditional wire-bond package layout, this design results in a module footprint that is at least two times smaller. Additionally, decoupling capacitors are included between the two substrates to reduce the power loop inductance to 2.087 nH. The implementation of DSC in this package reduces the junction-to-case thermal resistance of the module to 0.079°C/W. This packaging technique is a significant step toward overcoming the packaging challenges associated with GaN HEMTs and increasing their widespread use in power conversion systems.