Pressure drop and heat transfer characteristics of square pin fin enhanced microgaps in single phase microfluidic cooling

Three dimensional (3D) stacking of semiconductor chips has the advantages of high electrical performance, including improved bandwidth, reduced wire interconnection lengths, low cost, and heterogeneous integration. However, the power density increases sharply within the stack and the thermal management challenges become major bottlenecks. Inter-tier microfluidic cooling with microgaps with surface area enhancements such as pin fins can potentially achieve superior thermal performance. As such, the hydraulic and thermal characteristics of this configuration over parametric ranges of practical interest are important. A lot of work has been done on circular cross-section pin fins, with only limited work on square pin fins. In this work, a parametric study was conducted for the first time to investigate the effect of all pin fin dimensions, including diameter(D_h), transversal (S_T) and longitudinal (S_L) spacing, height (H_p), and Re on Pressure drop (ΔP) in terms of friction factor (f) and Heat Transfer coefficient (HTC) in terms of Colburn j factor. Correlations of f and Colburn j factor were proposed for Re<;100. The performance of circular and square micro pin fin were compared. The comparison results show that the circular micro pin fin array has better thermal performance under same pumping power.