Fabrication of copper-based microchannel devices and analysis of their flow and heat transfer characteristics

Metal-based microchannel heat exchangers (MHEs) offer potential solutions to high heat flux removal applications, such as cooling of high-performance microelectronic and energy-efficient lighting modules. Efficient fabrication of metal-based MHEs and quantitative flow and heat transfer measurements on them are critical for establishing the economic and technical feasibility of such devices. In this paper, all-Cu MHE prototypes were fabricated. Results of flow and heat transfer testing made on these Cu-based MHE prototypes are reported. Efficient fabrication of Cu-based high-aspect-ratio microscale structures (HARMSs) was achieved through direct molding replication using surface-engineered metallic mold inserts. Replicated Cu HARMSs were assembled through solid-state bonding to form all-Cu MHE prototypes. Flow and heat transfer testing of the Cu MHE prototypes was conducted to determine the average rate of heat transfer from the solid Cu body to water flowing within the enclosed microchannel array. Experimentally observed flow and heat transfer data are analyzed and shown to agree with known macroscale correlations once surface roughness and entrance length effects are taken into account.