An efficient cooling system is necessary for the reliability and safety of modern microchips for a longer life. As microchips become smaller and more powerful, the heat flux generated by these chips per unit area also rises sharply. Traditional cooling techniques are inadequate to meet the recent cooling requirements of microchips. To meet the current cooling demand of microelectromechanical systems (MEMS) devices and microchips, microchannel heat sink (MCHS) technology is the latest invention, one that can dissipate a significant amount of heat because of its high surface area to volume ratio. This study provides a concise summary of the design, material selection, and performance parameters of the MCHSs that have been developed over the last few decades. The limitations and challenges associated with the different techniques employed by researchers over time to enhance the thermal efficiency of microchannel heat sinks are discussed. The effects on the thermal enhancement factor, Nusselt number, and pressure drop at different Reynold numbers in passive techniques (flow obstruction) i.e., ribs, grooves, dimples, and cavities change in the curvature of MCHSs, are discussed. This study also discusses the increase in heat transfer using nanofluids and how a change in coolant type also significantly affects the thermal performance of MCHSs by obstructing flow. This study provides trends and useful guidelines for researchers to design more effective MCHSs to keep up with the cooling demands of power electronics.

The microchannel heat sink (MCHS) is a robust cooling technique that ensures the efficiency and reliability of compact electronic devices by dissipating a large amount of heat because of its high surface area-to-volume ratio. This study proposes a novel modification of the pin-fins geometry in MCHS, and geometric optimization using response surface methodology (RSM) to build a low thermal resistant MCHS with enhanced heat transfer efficiency with low-pressure drop. Three dimensional numerical simulations using ANSYS FLUENT 2021 R2 are performed on three pin-fins configurations, i.e., MC-BW (pins mounted transversely to the bottom wall), MC-SW (pins mounted transversely to the side wall), and MC-Mixed (pins mounted transversely to the bottom and side wall). The thermal and flow characteristics are investigated using a laminar conjugate heat transfer model at Reynolds numbers 100–1000. Results show that introducing pin-fins significantly enhances heat dissipation as it continuously breaks the boundary layer and generates flow separation downstream of the pin-fins, which enhances fluid mixing and increases heat transfer augmentation inside MCHS. Among different configurations, the MC-Mixed gives the highest improvement of 50% in the convective heat transfer coefficient at Re = 1000. The highest thermal enhancement factor of η = 1.4 is obtained for the MC-Mixed configuration at Re = 600. For the base wall pin fin configuration RSM yields optimized values of 2.50 mm, 0.25 mm, and 0.045 mm for transverse pitch, longitudinal pitch, and diameter of pin respectively, and for the mixed pin fin configuration it gives 1.0 mm, 0.150 mm, 0.035 mm and 1.250 mm values for transverse pitch, longitudinal pitch, diameter of pin and pitch of side wall pins respectively for the maximum heat transfer and minimum pressure drop.

An efficient cooling system is necessary for the reliability and safety of the modern microchips for longer life. As microchips become smaller and more powerful, the heat flux generated by these chips per unit area also rises sharply. Traditional cooling techniques are inadequate to meet the recent cooling requirements of microchips. To meet the current cooling demand of Microelectromechanical devices (MEMS) devices and microchips, microchannel heat sinks (MCHS) technology is the latest invention that can dissipate a significant amount of heat because of its high surface area to volume ratio. This study provides a concise summary of design, material selection, and performance parameters of MCHS that are developed over the last few decades. The limitations and challenges associated with different techniques employed by researchers over time to enhance the thermal efficiency of microchannel heat sinks are discussed. The effects on the thermal enhancement factor, Nusselt number, and pressure drop at different Reynold numbers, in passive techniques (flow obstruction) i.e. ribs, grooves, dimples, and cavities change in curvature of MCHS are discussed. This study also discusses the increase in heat transfer using nanofluids and how change in coolant type also significantly affects the thermal performance of MCHS by obstructing flow. This study provides trends and useful guidelines for researchers to design more effective MCHS to keep up with the cooling demands of power electronics.