Site-Specific and On-Demand High Heat-Flux Cooling Using Superlattice Based Thin-Film Thermoelectrics

Author(s):  
Ihtesham Chowdhury ◽  
Ravi Prasher ◽  
Kelly Lofgreen ◽  
Sridhar Narasimhan ◽  
Ravi Mahajan ◽  
...  

We have recently reported the first ever demonstration of active cooling of hot-spots of >1 kW/cm2 in a packaged electronic chip using thin-film superlattice thermoelectric cooler (TEC) cooling technology [1]. In this paper, we provide a detailed account of both experimental and theoretical aspects of this technological demonstration and progress. We have achieved cooling of as much as 15°C at a location on the chip where the heat-flux is as high as ∼1300 W/cm2, with the help of a thin-film TEC integrated into the package. To our knowledge, this is the first demonstration of high heat-flux cooling with a thin-film thermoelectric device made from superlattices when it is fully integrated into a usable electronic package. Our results, which validate the concept of site-specific micro-scale cooling of electronics in general, will have significant potential for thermal management of future generations of microprocessors. Similar active thermal management could also be relevant for high-performance solid-state lasers and power electronic chips.

Micromachines ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 89 ◽  
Author(s):  
Zhibin Yan ◽  
Mingliang Jin ◽  
Zhengguang Li ◽  
Guofu Zhou ◽  
Lingling Shui

Advanced thermal management methods have been the key issues for the rapid development of the electronic industry following Moore’s law. Droplet-based microfluidic cooling technologies are considered as promising solutions to conquer the major challenges of high heat flux removal and nonuniform temperature distribution in confined spaces for high performance electronic devices. In this paper, we review the state-of-the-art droplet-based microfluidic cooling methods in the literature, including the basic theory of electrocapillarity, cooling applications of continuous electrowetting (CEW), electrowetting (EW) and electrowetting-on-dielectric (EWOD), and jumping droplet microfluidic liquid handling methods. The droplet-based microfluidic cooling methods have shown an attractive capability of microscale liquid manipulation and a relatively high heat flux removal for hot spots. Recommendations are made for further research to develop advanced liquid coolant materials and the optimization of system operation parameters.


Author(s):  
Akira Matsui ◽  
Kazuhisa Yuki ◽  
Hidetoshi Hashizume

Detailed heat transfer characteristics of particle-sintered porous media and metal foams are evaluated to specify the important structural parameters suitable for high heat removal. The porous media used in this experiment are particle-sintered porous media made of bronze and SUS316L, and metal foams made of copper and nickel. Cooling water flows into the porous medium opposite to heat flux input loaded by a plasma arcjet. The result indicates that the bronze-particle porous medium of 100μm in pore size shows the highest performance and achieves heat transfer coefficient of 0.035MW/m2K at inlet heat flux 4.6MW/m2. Compared with the heat transfer performance of copper fiber-sintered porous media, the bronze particlesintered ones give lower heat transfer coefficient. However, the stable cooling conditions that the heat transfer coefficient does not depend on the flow velocity, were confirmed even at heat flux of 4.6MW/m2 in case of the bronze particle-sintered media, while not in the case of the copper-fiber sintered media. This signifies the possibility that the bronze-particle sintered media enable much higher heat flux removal of over 10MW/m2, which could be caused by higher permeability of the particle-sintered pore structures. Porous media with high permeability provide high performance of vapor evacuation, which leads to more stable heat removal even under extremely high heat flux. On the other hand, the heat transfer coefficient of the metal foams becomes lower because of the lower capillary and fin effects caused by too high porosity and low effective thermal conductivity. It is concluded that the pore structure having high performance of vapor evacuation as well as the high capillary and high fin effects is appropriate for extremely high heat flux removal of over 10MW/m2.


Author(s):  
Hani H. Sait ◽  
Steve M. Demsky ◽  
HongBin Ma

An analytical model describing thin film evaporation is developed that includes the effects of surface tension, frictional shear stress, wetting characteristics and disjoining pressure. The effects of thermal conductivity of working fluids and operating temperature on the evaporating thin film region are also studied. The results indicate that when the thermal conductivity of the working fluid increases, a high heat flux can be removed from the evaporating thin film region. The operating temperature affects the thin film evaporation. The higher the operating temperature, the more heat flux can be removed from the region. The information of thin film evaporation presented in the paper results in a better understanding of heat transfer mechanism occurring in micro heat pipes.


2001 ◽  
Vol 25 (5) ◽  
pp. 231-242 ◽  
Author(s):  
Cristina H. Amon ◽  
Jayathi Murthy ◽  
S.C. Yao ◽  
Sreekant Narumanchi ◽  
Chi-Fu Wu ◽  
...  

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