Research on advanced packaging and heat management for High Power Gallium Nitride (GaN) High Electron Mobility Transistor (HEMT) devices is critical due to the rising demand for high-power electronics across various sectors. GaN HEMT devices offer significant advantages including high-power density, efficiency, and frequency operation. However, their operation generates substantial heat that can compromise performance and reliability if not managed effectively. Thus, integrating these GaN HEMT devices into multiple subsystems with advanced packaging techniques and efficient heat management strategies is vital. This project aims to develop innovative packaging solutions and thermal management techniques to ensure optimal performance and reliability of high-power GaN HEMT devices in applications such as power electronics, RF amplifiers, and wireless communication systems.