Embedded Cooling of High Heat Flux Electronics Utilizing Distributed Microfluidic Impingement Jets

Abstract

Embedded cooling techniques, utilizing microfluidic channels directly within a die substrate or in a miniature heat sink attached to the base of the die, have been known for decades [1] [2] [3]. Despite their demonstrated thermal benefits, such techniques and devices have not been successfully transitioned from the laboratory to either the commercial or military arena. Some of the hurdles preventing implementation to date have been the inability to miniaturize the supporting hardware, the high unit cost of fabricating individual microfluidic coolers, and the unknown reliability of the new technologies introduced. Recent advances in micro manufacturing and co-design/simulation capabilities have enabled significant progress to be made, aided by a significant new focus on embedded cooling technologies was recently initiated by DARPA [4]. This paper will present a recently fabricated embedded cooling system consisting of a state of the art, micro-miniature, 3D microfluidic manifold suitable for near term integration into existing systems. Computational fluid dynamics (CFD) and conjugate heat transfer (CHT) simulations demonstrate the ground breaking thermal performance achieved by the device, and coupled-field flow, thermal, structural and erosion simulations are also presented to address some of the reliability concerns. Finally, measured thermal performance is presented, validating the predicted thermal performance.