Design, Fabrication and Characterization of Silicon based Microfluidic Structures for High Heat-flux Cooling Application

With the rapid development of integrated circuits (ICs), especially for RF and microwave field, three-dimensional (3-D) high performance ICs, such as GaN power amplifiers, have been widely used in many microsystem products. Resulting from this, the power consumption and heat flux have sharply risen in electronic systems. Increasing demand for removing heat from 3-D ICs has become the major challenge in this field and has constrained their applications. Due to the limitations of conventional cooling methods, a systematic study of silicon based microfluidic cooling technology had been carried out in this paper. A three dimensional computational fluid dynamic (CFD) models were developed to understand the flow resistance status, heat dissipation capacity of different kind microfluidic structures. To verify the numerical analysis results, straight-through and serpentine microfluidic coolers had been manufactured by using deep silicon etching and anodic bonding. Also, Aluminum Nitride (AlN) based thermal test chips were realized by Tantalum Nitride (TaN) thin-film process, from which a certain joule heat could be generated as real devices. In addition, thermal characteristic test fixture had been designed to assembly test chips and microfluidic coolers together. Furthermore, the liquid cooling experimental setup had been built to characterize different kinds of microfluidic structures. Test results fully proved the rationality of our simulations, drawing a conclusion that a high heat flux about 440W/cm
²
could be reached using serpentine microfluidic structures.