Computational Analysis of Thermal Performance of Water-Cooled Cold Plate for Chips With Hotspots

Abstract

Abstract A numerical analysis of the effects of water-cooled cold plate designs and the coolant inlet velocity on the thermal management of computer chips with hotspots is presented. With the increasing demand for computational capabilities of highperformance computing, non-uniform temperature distribution across the chip becomes a significant thermal management problem. Localized high temperature regions on the chip surface, known as hotspots, contribute to this non-uniform temperature distribution and may increase the chip temperatures to dangerous levels. Also, the resulting temperature gradient has detrimental impact on various reliability mechanisms of electronic devices. Available research suggests that conventional methods of thermal management, such as air-cooled heat sinks, have reached their optimal limit. Therefore, novel and more efficient thermal management of the computer chips is needed to improve their reliability and performance. Thanks to the advancement of additive manufacturing, it is possible to investigate the heat-removal efficiency of various cold plate designs that are not achievable using conventional manufacturing. In this study, several water-cooled cold plate designs involving different pin fin and mini channel configurations are analyzed for a typical CPU with a hotspot using COMSOL, commercial finite element analysis program. Conjugate heat transfer physics corresponding to heat transfer in solids and laminar flow was used. Various velocities of inlet water are studied as well, while maintaining a laminar flow inside the cold plate. The inlet temperature of water was chosen to be room temperature. Chip temperature uniformity, thermal resistance of the cold plate, maximum and minimum temperatures at the chip level, pressure drop, and pump power were calculated. These response parameters were used to compare the thermal performance of each of the cold plate designs and the inlet velocities. The results from this study suggest that a cold plate with pin fins located on the hotspot performs better than one with only channels in mitigating the hotspot. It is also observed that a quasi-uniform temperature distribution may be achieved if overcooling of the background region is avoided.