Compact 3D-Printed Jet-Impingement Nozzle for Top-Side-Cooled GaN Power Devices

The stringent performance requirements for power-electronic converters in electric vehicles necessitate advanced cooling techniques and device structures. This paper presents a thermal-management solution for automotive power-electronic converters that leverages top-side-cooled GaN devices and liquid-based jet-impingement cooling for enhanced thermal performance. Stereolithographic 3D printing allows the nozzle structure to be customized according to PCB geometry, minimizing volume overhead. Deposited boron nitride is used to create a thermal interface material (TIM) with high thermal conductivity and electrical isolation to separate the GaN devices from the coolant, minimizing the impact of the TIM. Experimental results using 1 L/min fluid flow show average thermal resistances as low as 1ºC/W with a heat flux of approximately 250W/cm
²
, demonstrating the effectiveness of the proposed solution.