Miniaturization of microelectronic components comes at a price of high heat flux density. By adopting liquid cooling, the rising demand of high heat flux devices can be met while the reliability of the microelectronic devices can also be improved to a greater extent. Liquid cooled cold plates are largely replacing air based heat sinks for electronics in data center applications, thanks to its large heat carrying capacity. A bench level study was carried out to characterize the thermohydraulic performance of two microchannel cold plates which uses warm DI water for cooling Multi Chip Server Modules (MCM). A laboratory built mock package housing mock dies and a heat spreader was employed while assessing the thermal performance of two different cold plate designs at varying coolant flow rate and temperature. The case temperature measured at the heat spreader for varying flow rates and input power were essential in identifying the convective resistance. The flow performance was evaluated by measuring the pressure drop across cold plate module at varying flow rates. Cold plate with the enhanced microchannel design yielded better results compared to a traditional parallel microchannel design. The study conducted at higher coolant temperatures yielded lower pressure drop values with no apparent change in the thermal behavior using different cold plates. The tests conducted after reversing the flow direction in microchannels provide an insight at the effect of neighboring dies on each other and reveal the importance of package specific cold plate designs for top performance. The experimental results were validated using a numerical model which are further optimized for improved geometric designs.
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Numerical modeling and optimization of a V-groove warm water cold-plate
In electronics cooling, water is increasingly replacing air for applications requiring high heat flux. Water is the ideal substitute due to its high specific heat capacity and density. Indeed, high values of heat capacity (high density and specific heat capacity) enable water to receive, store and carry higher amounts of energy compared to air. Water's incompressibility and very low specific volume also requires smaller amounts of mechanical work for fluid circulation. Using warm water instead of chilled water makes the cooling process more economical, but requires more efficiently designed cold-plates. Our current work focuses on modeling and optimization of a V-groove mini-channel cold-plate using warm water as the coolant. Our results show that the performance of an impinging channel heat sink is significantly different compared to parallel channel designs. Dividing the flow into two branches cuts the fluid velocity and flow path in half for the impinging design. This reduction in the fluid velocity and flow length affects the developing thermal boundary layer and is an important consideration for a shorter length heat exchanger (where the channel length is comparable to the thermal entrance length). Distributing the coolant uniformly to every channel is a challenge for impinging cold-plates where there are strict limitations on size.
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- Award ID(s):
- 1738793
- NSF-PAR ID:
- 10057999
- Date Published:
- Journal Name:
- Thermal Measurement, Modeling & Management Symposium (SEMI-THERM), 2017 33rd
- Page Range / eLocation ID:
- 314 to 319
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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The present research investigates the thermal enhancement of the performance of de-ionized water-based dielectric coolant with Copper nanoparticles for a higher heat transfer from the server cold plates. Detailed 3-D modeling of a commercial cold plate is completed and the CFD analysis is done in a commercially available CFD code ANSYS CFX. The obtained results compare the improvement in heat transfer due to improvement in coolant properties with data available in the literature.
- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Conference Paper:
- https://doi.org/10.1109/SEMI-THERM.2017.7896948
