Miniaturization of the energy systems and high powered electronic devices necessitates the high capacity compact heat exchangers to dissipate the heat generated. Microchannel heatsinks (MCHS) are modern heat exchangers with the fluid flowing channels of size in microscale. These are very compact heat exchangers with higher ratios of heat transfer area to the volume. Huge research work has been going on to improve the hydraulic and thermal performance of the MCHS. This article provides the information about experimental and numerical studies that has been done on the heat transfer and its enhancement in micro-scale cooling devices. This review mainly concentrate on the heat transfer enhancement techniques in microchannel, numerical methods that has been implemented for the study of micro-channels and the parameters which effects the heat transfer rate. The recent studies on microchannel heat sink to improve its performance by geometry modifications, jet impingement, using Nano fluids, flow boiling and Magneto-hydrodynamics are thoroughly discussed in this article.

能量系统和高功率电子设备的小型化需要高容量的紧凑型热交换器来散发产生的热量。微通道散热器（MCHS）是现代热交换器，其流体流动通道的尺寸为微米级。这些是非常紧凑的热交换器，其传热面积与体积之比更高。为了改善MCHS的水力和热力性能，正在进行大量的研究工作。本文提供有关热传递及其在微型冷却装置中的增强作用的实验和数值研究的信息。这篇评论主要集中在微通道中的传热增强技术上，用于研究微通道和影响传热速率的参数的数值方法。本文对微通道散热器的最新研究进行了详尽的讨论，该微通道散热器通过几何形状修改，射流撞击，使用纳米流体，流动沸腾和磁流体动力学来改善其性能。