Microfluidic two-phase cooling of a high power microprocessor part B: Test and characterization

Abstract

The effective use of embedded radial expanding micro-channels with micro-pin fields for two phase cooling of semiconductor dies has been demonstrated [1, 2]. In this second part of a two part paper, the functional results of integrating this approach into a high performance server are presented. First, a number of microprocessor modules were fully characterized within a high performance server utilizing both an idle state and a workload designed to drive maximum processor power. These characterizations were done across a wide operating frequency range of 2.2 to 4.3 GHz. After modification to incorporate embedded radial expanding micro-channels for two phase flow, the microprocessor modules were reinstalled in the server supported by a two phase liquid cooling pump and condenser system with flow, temperature and pressure drop measuring capabilities. The modules were then characterized again over the same operating frequency range for a range of coolant flow rates and resulting average vapor qualities. The results show full processor function and excellent thermal behavior across a wide range of coolant flow rates, directly demonstrating the feasibility of this technology for cooling actual high power electronic devices.