An overview of heat transfer enhancement methods in microchannel heat sinks

With the high miniaturization and integration of micro-electro-mechanical systems, micro-satellite, lasers, and high-voltage electrical appliances, the heat transfer of electronic equipment is facing severe challenges. The microchannel heat sink is widely used as an effective heat transfer method, which can achieve large heat flux cooling. However, conventional microchannel heat sinks have disadvantages, such as large wall superheat, low boiling critical heat flux, large pressure drop, and poor temperature uniformity. In view of the above problems, people have devoted themselves to designing and improving microchannel heat sinks to improve their comprehensive heat transfer performance, in recent years. In this paper, the latest research achievements and trends of microchannel heat sinks are systematically reviewed and summarized from four aspects: microchannel structure, internal reinforcement structure, surface treatment, and material types, which are beneficial to promote the practical application and commercialization of microchannel heat sinks. To the best of the authors' knowledge, this is the first time to summarize the research progress of enhancing the heat transfer performance of microchannel heat sinks from the perspective of surface treatment and material types. Then, the heat transfer performance and fabrication technology of diamond microchannel heat sink with great heat transfer potential are mainly studied. Based on the reviewed studies, although the combination of various enhanced heat transfer methods can improve heat transfer, the key issue is how to balance the heat transfer efficiency and the pressure drop penalty. Finally, the important research progress of enhanced microchannel heat sinks is objectively expounded, and the rationalized suggestions for the future research direction and research ideas of microchannel heat sinks are presented.