The objective of this review article is to provide a comprehensive analysis of the latest research on microchannel heat sinks, with a particular focus on single-phase flow, flow boiling, and coating microchannels. The review aims to highlight the progress made in this field and identify the challenges that need to be addressed to promote the widespread adoption of microchannel heat sinks. The review article examines the research on microchannel heat sinks and analyzes the findings related to single-phase flow, flow boiling, and coating microchannels. The analysis of single-phase flow in microchannels covers the impact of various parameters, including channel size, fluid properties, and flow conditions, on the heat transfer rate. The analysis of flow boiling in microchannels includes the identification of the potential advantages and challenges associated with this technique, as well as the strategies developed to mitigate these issues. The analysis of coating microchannels examines the effects of surface coatings on flow behavior and heat transfer performance. The review finds that microchannel heat sinks have gained significant attention due to their potential for high heat transfer rates in a compact size. The analysis of single-phase flow reveals that the heat transfer rate is proportional to the channel diameter and inversely proportional to the fluid viscosity. Increasing the flow rate results in higher heat transfer rates and pressure drops. The analysis of flow boiling reveals that this technique can significantly increase the heat transfer rate compared to single-phase flow. However, it can also lead to flow instability, wall superheat, and premature drying. The review identifies strategies to mitigate these issues, including using different surface coatings, enhancing nucleation, and optimizing channel geometry. The analysis of coating microchannels shows that coatings can alter the surface energy, wettability, and roughness of the channel walls, affecting the flow behavior and heat transfer performance. Coatings made from materials such as metals, polymers, and self-assembled monolayers have been investigated, and their effects on the flow of boiling heat transfer have been analyzed. The review highlights the need for further research to address the challenges associated with microchannel heat sinks, including flow instability and premature drying. Additionally, the review suggests that there is a need for more comprehensive studies on the effects of different surface coatings on flow behavior and heat transfer performance. Future research can also explore the potential of other materials for coating microchannels and investigate new strategies to optimize channel geometry and enhance nucleation. The review article concludes that the progress made in understanding microchannel heat transfer is significant, but further research is necessary to realize the full potential of microchannel heat sinks.