Experimental Characterization of Two-Phase Cooling of Power Electronics in Thermosiphon and Forced Convection Modes

2021 ◽  
Vol 143 (3) ◽  
Author(s):  
Fabio Battaglia ◽  
Farah Singer ◽  
David C. Deisenroth ◽  
Michael M. Ohadi
Keyword(s):  
Heat Flux ◽  
Thermal Resistance ◽  
Power Electronics ◽  
Forced Convection ◽  
Heat Removal ◽  
High Heat ◽  
Heat Fluxes ◽  
High Heat Flux ◽  
Two Phase ◽  
Total Thermal Resistance

Abstract In this paper, we present the results of an experimental study involving low thermal resistance cooling of high heat flux power electronics in a forced convection mode, as well as in a thermosiphon (buoyancy-driven) mode. The force-fed manifold microchannel cooling concept was utilized to substantially improve the cooling performance. In our design, the heat sink was integrated with the simulated heat source, through a single solder layer and substrate, thus reducing the total thermal resistance. The system was characterized and tested experimentally in two different configurations: the passive (buoyancy-driven) loop and the forced convection loop. Parametric studies were conducted to examine the role of different controlling parameters. It was demonstrated that the thermosiphon loop can handle heat fluxes in excess of 200 W/cm2 with a cooling thermal resistance of 0.225 (K cm2)/W for the novel cooling concept and moderate fluctuations in temperature. In the forced convection mode, a more uniform temperature distribution was achieved, while the heat removal performance was also substantially enhanced, with a corresponding heat flux capacity of up to 500 W/cm2 and a thermal resistance of 0.125 (K cm2)/W. A detailed characterization leading to these significant results, a comparison between the performance between the two configurations, and a flow visualization in both configurations are discussed in this paper.

Integrated Vapor Chamber Heat Spreader for Power Module Applications

2017 ◽  
Author(s):  
Clayton L. Hose ◽  
Dimeji Ibitayo ◽  
Lauren M. Boteler ◽  
Jens Weyant ◽  
Bradley Richard
Keyword(s):  
Heat Flux ◽  
Thermal Resistance ◽  
Power Electronics ◽  
Coefficient Of Thermal Expansion ◽  
High Heat ◽  
Heat Fluxes ◽  
High Heat Flux ◽  
Vapor Chamber ◽  
Power Module ◽  
Heat Spreader

This work presents a demonstration of a coefficient of thermal expansion (CTE) matched, high heat flux vapor chamber directly integrated onto the backside of a direct bond copper (DBC) substrate to improve heat spreading and reduce thermal resistance of power electronics modules. Typical vapor chambers are designed to operate at heat fluxes > 25 W/cm2 with overall thermal resistances < 0.20 °C/W. Due to the rising demands for increased thermal performance in high power electronics modules, this vapor chamber has been designed as a passive, drop-in replacement for a standard heat spreader. In order to operate with device heat fluxes >500 W/cm2 while maintaining low thermal resistance, a planar vapor chamber is positioned onto the backside of the power substrate, which incorporates a specially designed wick directly beneath the active heat dissipating components to balance liquid return and vapor mass flow. In addition to the high heat flux capability, the vapor chamber is designed to be CTE matched to reduce thermally induced stresses. Modeling results showed effective thermal conductivities of up to 950 W/m-K, which is 5 times better than standard copper-molybdenum (CuMo) heat spreaders. Experimental results show a 43°C reduction in device temperature compared to a standard solid CuMo heat spreader at a heat flux of 520 W/cm2.

A Review of Two-Phase Forced Cooling in Three-Dimensional Stacked Electronics: Technology Integration

2015 ◽  
Vol 137 (4) ◽  
Author(s):  
Craig Green ◽  
Peter Kottke ◽  
Xuefei Han ◽  
Casey Woodrum ◽  
Thomas Sarvey ◽  
...  
Keyword(s):  
Heat Flux ◽  
Heat Sink ◽  
Three Dimensional ◽  
High Heat ◽  
Heat Fluxes ◽  
Thermal Design ◽  
High Heat Flux ◽  
Two Phase ◽  
Forced Cooling ◽  
Fluidic Routing

Three-dimensional (3D) stacked electronics present significant advantages from an electrical design perspective, ranging from shorter interconnect lengths to enabling heterogeneous integration. However, multitier stacking exacerbates an already difficult thermal problem. Localized hotspots within individual tiers can provide an additional challenge when the high heat flux region is buried within the stack. Numerous investigations have been launched in the previous decade seeking to develop cooling solutions that can be integrated within the 3D stack, allowing the cooling to scale with the number of tiers in the system. Two-phase cooling is of particular interest, because the associated reduced flow rates may allow reduction in pumping power, and the saturated temperature condition of the coolant may offer enhanced device temperature uniformity. This paper presents a review of the advances in two-phase forced cooling in the past decade, with a focus on the challenges of integrating the technology in high heat flux 3D systems. A holistic approach is applied, considering not only the thermal performance of standalone cooling strategies but also coolant selection, fluidic routing, packaging, and system reliability. Finally, a cohesive approach to thermal design of an evaporative cooling based heat sink developed by the authors is presented, taking into account all of the integration considerations discussed previously. The thermal design seeks to achieve the dissipation of very large (in excess of 500 W/cm2) background heat fluxes over a large 1 cm × 1 cm chip area, as well as extreme (in excess of 2 kW/cm2) hotspot heat fluxes over small 200 μm × 200 μm areas, employing a hybrid design strategy that combines a micropin–fin heat sink for background cooling as well as localized, ultrathin microgaps for hotspot cooling.

Geometry Effects on Two-Phase Flow Regimes in a Diabatic Manifolded Microgap Channel

2017 ◽  
Author(s):  
David C. Deisenroth ◽  
Avram Bar-Cohen ◽  
Michael Ohadi
Keyword(s):  
Heat Flux ◽  
Mass Flux ◽  
Electronics Cooling ◽  
Flow Regimes ◽  
High Heat ◽  
Heat Fluxes ◽  
High Heat Flux ◽  
Two Phase ◽  
Channel Geometry ◽  
Cooling Channels

Two-phase cooling has become an increasingly attractive option for thermal management of high-heat flux electronics. Cooling channels embedded directly on the back of the heat source (chip) facilitate two-phase boiling/evaporation effectiveness, eliminating many thermal resistances generated by more traditional, remote chip-cooling approaches. Accordingly, manifold-microchannel flow paths in embedded cooling systems can allow very high heat fluxes with low junction temperatures. But, the effect of the feeding manifold design, channel geometry, and the associated shear, stagnation zones, and centripetal accelerations with varying heat flux and mass flux are not well understood. This study builds upon our previous work and elucidates effects of channel geometry, mass flux, and outlet quality on the boiling/evaporation flow regimes in a manifolded microgap channel.

Development of Miniature Loop Heat Pipes for the Thermal Control of Laptops

2008 ◽  
Author(s):  
Masataka Mochizuki ◽  
Yuji Saito ◽  
Thang Nguyen ◽  
Tien Nguyen ◽  
Vijit Wuttijumnong ◽  
...  
Keyword(s):  
Heat Flux ◽  
Electronic Devices ◽  
Thermal Control ◽  
High Heat ◽  
Control Device ◽  
Heat Fluxes ◽  
High Heat Flux ◽  
Total Thermal Resistance ◽  
Evaporation Zone ◽  
Loop Heat Pipes

Thermal management of laptops is becoming increasingly challenging task due to the high heat flux associated with the microprocessors and limited available space for the integration of the thermal control device inside the cabinet. In this paper, results from the investigation of two different designs of miniature Loop Heat Pipe (mLHP) for thermal control of compact electronic devices including notebooks have been discussed. Two prototypes of mLHP, one with a disk shaped evaporator of 30 mm in diameter and 10 mm thick, and the other with a rectangular shaped evaporator of 45×35 mm2 planar area and 5 mm thick, were designed to handle heat fluxes of up to 50 W/cm2. Total thermal resistance of these mLHPs lies in the range of 1 to 5 °C/W. In addition to this, two new designs of the mLHP pertaining to enhance the heat transfer inside the evaporation zone and to develop the loop evaporator with thickness as small as 3 mm are discussed. In conclusions, the designed mLHPs were able to satisfy the thermal and design requirements of the current laptop equipments and can be classified as potential candidates for cooling of the compact electronic devices with restricted space and high heat flux chipsets.

scholarly journals Two-phase cooling system with controlled pulsations

2019 ◽  
Vol 196 ◽  
pp. 00021
Author(s):  
Karapet Eloyan ◽  
Alexey Kreta ◽  
Egor Tkachenko
Keyword(s):  
Heat Flux ◽  
Gas Flow ◽  
Cooling System ◽  
High Heat ◽  
Heat Fluxes ◽  
High Heat Flux ◽  
Two Phase ◽  
Forced Circulation ◽  
Evaporative Cooling System ◽  
Large Heat

One of the promising ways of removing large heat fluxes from the surface of heat-stressed elements of electronic devices is the use of evaporating thin layer of liquid film, moving under the action of the gas flow in a flat channel. In this work, a prototype of evaporative cooling system for high heat flux removal with forced circulation of liquid and gas coolants with controlled pulsation, capable to remove heat flux of up to 1,5 kW/cm2 and higher was presented. For the first time the regime with controlled pulsation is used. Due to pulsations, it is possible to achieve high values of critical heat flux due to a brief increase in the flow rate of the liquid, which allows to "wash off" large dry spots and prevent the occurrence of zones of flow and drying.

Reliability Challenges in Design and Operation of High Heat Powered Processors

2005 ◽  
Author(s):  
Ali Heydari ◽  
Vadim Gektin
Keyword(s):  
Heat Flux ◽  
Closed Loop ◽  
Heat Removal ◽  
High Heat ◽  
Electrical Signal ◽  
Open Loop ◽  
Heat Fluxes ◽  
High Heat Flux ◽  
Air Cooling ◽  
Interconnect Design

Advances in processor design have been made possible in part by increases in the packaging density of electronics. At the same time, combination of increased power dissipation and packaging density has led to substantial growth in the chip and system heat fluxes and amplified complexity in electrical signal integrity and mechanical stack-up design in the recent years, particularly, in the high-end computers. With the trend towards miniaturization, heat removal, along with increased reliability requirements, has become a major bottleneck in product development, especially, in low profile systems, telecom servers and blades. Cooling of high heat flux components may require consideration of innovative open-loop, as well as plausible closed-loop, cooling designs for data centers. This paper addresses reliability aspects of thermal, electrical, mechanical, and interconnect design and long-life operation of high-end air-cooling, as well as feasible active open and closed-loop cooling technologies of high heat flux processors.

A Review of High-Heat-Flux Heat Removal Technologies

2011 ◽  
Vol 133 (11) ◽  
Author(s):  
M. A. Ebadian ◽  
C. X. Lin
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Flow Boiling ◽  
Heat Removal ◽  
High Heat ◽  
High Heat Flux ◽  
Phase Flow ◽  
Two Phase ◽  
Recent Developments ◽  
Removal Technologies

In recent years, high-heat-flux cooling techniques have received great attention from researchers around the world due to its importance in thermal management of both commercial and defense high-power electronic devices. Although impressive progress has been made during the last few decades, high-heat-flux removal still largely remains as a challenging subject that needs further exploration and study. In this paper, we have reviewed recent developments in several high-heat-flux heat removal techniques, including microchannels, jet impingements, sprays, wettability effects, and piezoelectrically driven droplets. High-heat-flux removal can be achieved effectively by either single-phase flow or two-phase flow boiling heat transfer. Better understandings of the underlying heat transfer mechanisms for performance improvement are discussed.

STABLE, CALM, AND HIGH-HEAT-FLUX HEAT REMOVAL USING A POROUS-MICRO-CHANNEL

2017 ◽  
Author(s):  
Tomio Okawa ◽  
Junki Ohashi ◽  
Ryo Hirata ◽  
Koji Enoki
Keyword(s):  
Heat Flux ◽  
Heat Removal ◽  
High Heat ◽  
High Heat Flux ◽  
Micro Channel
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