With rapid increase in miniaturization of electronic devices, there is a need of heat transfer augmentation in microchannel. In this paper, a comparative experimental study of square pin fin microchannel configurations having different tip clearance has been presented using single phase coolant flow. Fabrication of microchannels, development of experimental setup and detailed methodologies adopted during experiments are thoroughly discussed. Single phase deionized liquid water is used as working medium at a fixed inlet temperature of 30°C. Heat transfer potential with tip clearance of 1.0 mm i.e., TC = 50% in not worthy as it leads to considerably lower convective surface area. Whereas, tip clearance of 25% has shown superior performance compared to completely closed heat sink i.e. H_f = 2.0 mm (TC = 0) although having ~7% lesser convective surface area. It may be concluded that open space above the fin's top surface provides a connecting link between primary and secondary flow passages hence; optimum value of tip clearance is desirable to propagate enhanced fluid mixing and heat transfer rate.