Design and performance study of a hydrophilic surface-treated jet microchannel liquid cooling system for chip heat dissipation

Jet cooling is one of the most promising solutions for high-performance chip thermal management. However, traditional jet cooling primarily focuses on the influence of macrostructures on its performance, with an emphasis on flow characteristics or heat transfer coefficients, while studies on the effects of microstructures remain relatively limited. This paper proposes a hydrophilic surface-treated jet microchannel liquid cooling system for chip heat dissipation, which introduces hydrophilic surface to enhance the jet microchannel cooling for heat transfer under single-phase flow. The microstructure of the hydrophilic surface is studied using microscopic surface characterization techniques (SEM, EDS, and contact angle measurements) to analyze the influence of the hydrophilic surface on heat transfer behavior. Additionally, experimental investigations are conducted to examine the effect of different jet parameters on the system's performance. The results show that the hydrophilic copper surface forms the micro-/nano-structures dominated by copper oxide (CuO), significantly improving surface roughness and wettability. The heat transfer performance of hydrophilic surface-treated jet microchannel liquid cooling system is enhanced, particularly under lower flow rate. At a heat source power of 1000W and a flow rate of 1.0 L/min, the average temperature of the heat source decreases by 11.23 °C, resulting in a 14.09 % improvement in heat transfer performance. The pump power consumption increases by 4.89 %, while the comprehensive performance is enhanced by 28.44 %. As the flow rate increases from 1.0L/min to 3.0L/min, the heat source temperature reduction decreases from 23.36 % to 4.09 %, and the increase in Nusselt number (${Nu}_j$) decreases from 25.57 % to 3.16 %. Additionally, the heat source temperature initially decreases and then increases with the increase in orifice spacing, while it decreases as the jet height decreases. At a flow rate of 1.5 L/min and a heat source power of 1000W, the hydrophilic surface-treated jet microchannel liquid cooling system achieves optimal comprehensive performance when orifice spacing is 6 mm and jet height is 1 mm, with a comprehensive performance evaluation criteria of 1.96.