Performances Of Silicon Micro-Flow-Passage Cold Plates From Single-Phase To Two-Phase With Water And Hfe-7100 As Working Fluids

Two-phase (phase-change) microchamel (MC) system is a promising technology for achieving enhanced heat removal for high-density electronics. Yet phase-change studies in MCs with hydraulic diameters on the order of several hundred micrometers or smaller have been inconclusive. Most of earlier studies involved one specific channel design and one type of working fluid. It is thus difficult to make fair comparisons across various experimental works toward recommending the best design option for real applications under specific operating conditions. In the current work, flow boiling experiments were conducted for MC cold plates with channel widths ranging from 61,mu m to 330 mu m and channel height - 300,mu m (hydraulic diameters from - 100 pin to - 337 pin) and a pin-fin array cold plate with fin size and inter-spacing similar to 150 mu m. Two working fluids, deionized water at sub-atmospheric pressure (similar to 25 kPa to 45 kPa) and HFE-7100 at ambient pressure, were tested respectively. High-speed visualization facilities were employed to help understand the rapid phase-change processes inside the flow passages. Pressure drop and heat transfer characteristics of the microchannel cold plates under various heat flux and flow rate conditions were recorded and analyzed as well as boiling fluctuations. Detailed visualization results will be presented in a separate paper [Tong et al., IMECE2007-420281.