A New Hybrid Heat Sink with Impinging Micro-Jet Arrays and Microchannels Fabricated Using High Volume Additive Manufacturing

This work describes the design of a high-performance water cooled micro heat sink for thermal management of high heat flux microelectronics. The design process leverages advances in additive manufacturing to produce flow channels and composite material structures that are not possible with traditional machining processes. The micro heat sink was designed with microchannels and an array of fins with integrated microjets (FINJET™ architecture). Simulation Driven Design (SDD), using ANSYS Fluent CFD software, was used to design the micro heat exchanger with overall outer dimensions of 4.1mm (length) × 3.2mm (width) × 1mm (thickness). Based on the SDD results, a prototype was fabricated and tested with heat fluxes up to and exceeding 1000 W/cm2. The results show that the numerical and experimental results are in reasonable agreement considering the complexity of the flow and associated conjugate heat transfer within the device. Importantly, experimental performance achieved an estimated overall thermal conductance of ~300 kW/m2K with an associated pressure drop of 160 kPa (23 psi) for a flow rate of 0.5 L/min. For 20°C water at the inlet, this corresponded to a measured base temperature of 54°C for an applied heat flux of 1000 W/cm2.