HYBRID WICK VAPOR CHAMBER THERMAL PERFORMANCE EVALUATION FOR HIGH HEAT FLUX APPLICATION BY AIR COOLING

2018 ◽  
Author(s):  
Feng Zhou ◽  
Tianzhu Fan ◽  
Yanghe Liu ◽  
Ercan M. Dede
2013 ◽  
Vol 789 ◽  
pp. 423-428 ◽  
Author(s):  
Nandy Putra ◽  
Wayan Nata Septiadi ◽  
Ranggi Sahmura ◽  
Cahya Tri Anggara

The development of electronic devices pushes manufacturers to create smaller microchips with higher performance than ever before. Microchip with higher working load produces more heat. This leads to the need of cooling system that able to dissipate high heat flux. Vapor chamber is one of highly effective heat spreading device. Its ability to dissipate high heat flux density in limited space made it potential for electronic cooling application, like Central Processing Unit (CPU) cooling system. The purpose of this paper is to study the application of Al2O3Nanofluid as working fluid for vapor chamber. Vapor chamber performance was measured in real CPU working condition. Al2O3Nanofluid with concentration of 0.1%, 0.3%, 0.5%, 1%, 2% and 3% as working fluid of the vapor chamber were tested and compared with its base fluid, water. Al2O3nanofluid shows better thermal performance than its base fluid due to the interaction of particle enhancing the thermal conductivity. The result showed that the effect of working fluid is significant to the performance of vapor chamber at high heat load, and the application of Al2O3nanofluid as working fluid would enhance thermal performance of vapor chamber, compared to other conventional working fluid being used before.


Author(s):  
David H. Altman ◽  
Joseph R. Wasniewski ◽  
Mark T. North ◽  
Sungwon S. Kim ◽  
Timothy S. Fisher

Spreading of high-flux electronics heat is a critical part of any packaging design. This need is particularly profound in advanced devices where the dissipated heat fluxes have been driven well over 100W/cm2. To address this challenge, researchers at Raytheon, Thermacore and Purdue are engaged in the development and characterization of a low resistance, coefficient of thermal expansion (CTE)-matched multi-chip vapor chamber heat spreader, which utilizes capillary driven two-phase heat transport. The vapor chamber technology under development overcomes the limitations of state-of-the-art approaches by combining scaled-down sintered Cu powder and nanostructured materials in the vapor chamber wick to achieve low thermal resistance. Cu-coated vertically aligned carbon nanotubes is the nanostructure of choice in this development. Unique design and construction techniques are employed to achieve CTE-matching with a variety of device and packaging materials in a low-profile form-factor. This paper describes the materials, design, construction and characterization of these vapor chambers. Results from experiments conducted using a unique high-heat flux capable 1DSS test facility are presented, exploring the effects of various microscopic wick configurations, CNT-functionalizations and fluid charges on thermal performance. The impacts of evaporator wick patterning, CNT evaporator functionalization and CNT condenser functionalization on performance are assessed and compared to monolithic Cu wick configurations. Thermal performance is explained as a function of applied heat flux and temperature through the identification of dominant component thermal resistances and heat transfer mechanisms. Finally, thermal performance results are compared to an equivalent solid conductor heat spreader, demonstrating a >40% reduction in thermal resistance. These results indicate great promise for the use of such novel vapor chamber technology in thickness-constrained high heat flux device packaging applications.


Energies ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1929 ◽  
Author(s):  
M. Sarafraz ◽  
Mohammad Safaei ◽  
Zhe Tian ◽  
Marjan Goodarzi ◽  
Enio Bandarra Filho ◽  
...  

In the present study, we report the results of the experiments conducted on the convective heat transfer of graphene nano-platelets dispersed in water-ethylene glycol. The graphene nano-suspension was employed as a coolant inside a micro-channel and heat-transfer coefficient (HTC) and pressure drop (PD) values of the system were reported at different operating conditions. The results demonstrated that the use of graphene nano-platelets can potentially augment the thermal conductivity of the working fluid by 32.1% (at wt. % = 0.3 at 60 °C). Likewise, GNP nano-suspension promoted the Brownian motion and thermophoresis effect, such that for the tests conducted within the mass fractions of 0.1%–0.3%, the HTC of the system was improved. However, a trade-off was identified between the PD value and the HTC. By assessing the thermal performance evaluation criteria (TPEC) of the system, it was identified that the thermal performance of the system increased by 21% despite a 12.1% augmentation in the PD value. Furthermore, with an increment in the fluid flow and heat-flux applied to the micro-channel, the HTC was augmented, showing the potential of the nano-suspension to be utilized in high heat-flux thermal applications.


2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Shuangshuang Miao ◽  
Jiajia Sui ◽  
Yulong Zhang ◽  
Feng Yao ◽  
Xiangdong Liu

Vapor-liquid phase change is regarded as an efficient cooling method for high-heat-flux electronic components. The copper-water bent heat pipes are particularly suited to the circumstances of confined space or misplaced heat and cold sources for high-heat-flux electronic components. In this paper, the steady and transient thermal performance of a bent copper-water heat pipe is studied based on a performance test system. The effects of cooling temperature, working conditions on the critical heat flux, and equivalent thermal conductivity have been examined and analyzed. Moreover, the influences of heat input and working conditions on the thermal response of a bent heat pipe have also been discussed. The results indicate that the critical heat flux is enhanced due to the increases in cooling temperature and the lengths of the evaporator and condenser. In addition, the critical heat flux is improved by extending the cooling length only when the operating temperature is higher than 50°C. The improvement on the equivalent thermal by increasing the heating length is more evident than that by increasing cooling length. It is also demonstrated by the experiment that the bent copper-water heat pipe can respond quickly to the variation of heat input and possesses superior transient heat transfer performance.


2007 ◽  
Vol 9 (3) ◽  
pp. 261-264 ◽  
Author(s):  
Chong Fali ◽  
Chen Junling ◽  
Li Jiangang ◽  
Zheng Xuebin ◽  
Ding Chuanxian

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