Experimental study of ultralow flow resistance fractal microchannel heat sinks for electronics cooling

Silicon-based fractal tree-shaped microchannel heat sinks with different bifurcation angles were designed and manufactured. The heat transfer and pressure drop characteristics of the fractal microchannel network were experimentally studied under an inlet Reynolds number of Re₀ = 500–1700. The results showed that compared with the traditional linear microchannel heat sink, the fractal microchannel heat sinks could achieve considerable flow drag reduction and heat transfer enhancement. Maintaining the chip temperature below 85 °C, the pressure drop can be reduced by up to 92%, and the heat transfer coefficient can be enhanced by 1.5 times of the fractal microchannel network at the same flow rate. The optimized bifurcation angle of the fractal network was recommended to be 30°. The COP of fractal microchannel heat sinks with a bifurcation angle of 30° can reach 12–13 times that of the linear microchannel.