03. Electronics Packaging and Thermal Management

In recent years, the integration of semiconductor integrated circuits has been increasing, leading to higher heat densities in electronic devices. Consequently, advanced cooling techniques for high heat fluxes are demanded. Flow boiling is a promising method for cooling high-heat-density devices. However, shear-driven liquid film flow is proposed as an effective cooling technique due to its superior heat transfer performance. Shear-driven liquid film flow involves a liquid film that is accelerated by increased interfacial shear stress caused by co-current gas flow. The thickness of the liquid film, which is a key factor for determining heat transfer performance utilizing phase change phenomena, can be controlled by adjusting the gas flow rate. This control mechanism can allow for improved heat transfer performance compared to flow boiling. Our study focuses on a larger heating surface of approximately 100 × 100 mm², suitable for next-generation power devices. The experimental setup includes a heating surface 100 mm in length, with a channel 10 mm wide and 2 mm high. Water and nitrogen are used as the test liquid and gas, respectively. The results indicate that for a liquid mass flux of 75 kg/m²s or more, the critical heat flux increases with the gas Reynolds number. This increase of the critical heat flux is attributed to the enhanced interfacial shear stress due to the gas flow, which improves the supply of the evaporating liquid film to the heating surface. At mass flux of 200 kg/m²s and gas Reynolds number of 2712, we achieved a maximum critical heat flux of 1254 kW/m².