This study investigates cooling performance of microchannel heat sinks under various heat flux conditions for different geometry of the channels and headers Thermal load is applied to the microchannel heat sinks by nine separate heaters in order to provide uniform or non-uniform heat flux Straight or diverging channels have been made with rectangular or trapezoidal headers. so four kinds of microchannel heat sinks have been fabricated by the microfabrication processes. such as deep reactive ion etch (DRIE), anodic bonding techniques. and so oil The temperatures of the heaters have been measured under the uniform and non-uniform heat flux conditions, including local heating at hotspots Moreover, the maximum temperatures for different microchannel heat sink under various heating conditions have been obtained as well as the pressure drops. (C) 2009 Elsevier Ltd. All rights reserved