The Investigation of the Silicon Fabricated Balanced Shunt Micro Pin Fins Cold Plate for High Heat Flux Devices

As an appropriate cooling solution for high heat flux device, the micro pin fin architecture can significantly enhance the fluidic uniformity and the nucleate boiling occurring inside the flow boiling cold plate. In this paper, three types balanced shunt micro pin fins (triangular, hexagonal, and circular) cold plates were fabricated by silicon processes. The fluidic spreading and the boiling states (bubble flow, slug flow, and annular flow) inside the Si-Glass cold plates could be distinguishably observed through the high-speed camera. The relationship between the local two-phase heat transfer coefficient inside the cold plate and the phenomenon of bubble states was investigated. As the results, the cusp regions of the triangular micro pin fins could promote the flow and mixing of the coolant to eliminate the slug flow. The triangular micro pin fins cold plate therefore had the best heat transfer characteristics and pressure drop performance. In addition, the Si-Si cold plate (40 mm  40 mm  1.3 mm) could satisfy 500 W total heat dissipation under 1000 W/cm2 local (4  25 mm2) heat flux density. The heat transfer coefficient of Si-Si cold plate was approximately 1.3 times higher than Si-Glass one.