Characterization of an Embedded Heat Pipe Heat Sink for Multiple Heat Sources for Power Electronics Applications

A concentric annular heat pipe heat sink (AHPHS) was proposed and fabricated to investigate its thermal behavior. The present AHPHS consists of two concentric pipes of different diameters, which create vacuumed annular vapor space. The main advantage of the AHPHS as a heat sink is that it can largely increase the heat transfer area for cooling compared to conventional heat pipes. In the current AHPHS, condensation takes place along the whole annular space from the certain heating area as the evaporator section. Therefore, the whole inner space of the AHPHS except the heating area can be considered the condenser. In the present study, AHPHSs of different diameters were fabricated and studied experimentally. Basic studies were carried out with a 50 mm-long stainless steel AHPHS with diameter ratios of 1.1 and 1.3 and the same inner tube diameter of 76 mm. Several experimental parameters such as volume fractions of 10–70%, different air flow velocity, flow configurations, and 10–50 W heat inputs were investigated to find their effects on the thermal performance of an AHPHS. Experimental results show that a 10% filling ratio was found to be the optimum charged amount in terms of temperature profile with a low heater surface temperature and water as the working fluid. For the methanol, a 40% filling ratio shows better temperature behavior. Internal working behavior shows not only circular motion but also 3-D flow characteristics moving in axial and circular directions simultaneously.

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Enabling Thermal Management of High-Powered Server Processors Using Passive Thermosiphon Heat Sink

ASME 2019 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems ◽

10.1115/ipack2019-6530 ◽

2019 ◽

Author(s):

Devdatta P. Kulkarni ◽

Priyanka Tunuguntla ◽

Guixiang Tan ◽

Casey Carte

Keyword(s):

Heat Pipe ◽

High Power ◽

Heat Sink ◽

Capital Investment ◽

Thermal Design ◽

Heat Sinks ◽

Air Cooling ◽

Liquid Cooling ◽

Two Phase ◽

Pipe Heat

Abstract In recent years, rapid growth is seen in computer and server processors in terms of thermal design power (TDP) envelope. This is mainly due to increase in processor core count, increase in package thermal resistance, challenges in multi-chip integration and maintaining generational performance CAGR. At the same time, several other platform level components such as PCIe cards, graphics cards, SSDs and high power DIMMs are being added in the same chassis which increases the server level power density. To mitigate cooling challenges of high TDP processors, mainly two cooling technologies are deployed: Liquid cooling and advanced air cooling. To deploy liquid cooling technology for servers in data centers, huge initial capital investment is needed. Hence advanced air-cooling thermal solutions are being sought that can be used to cool higher TDP processors as well as high power non-CPU components using same server level airflow boundary conditions. Current air-cooling solutions like heat pipe heat sinks, vapor chamber heat sinks are limited by the heat transfer area, heat carrying capacity and would need significantly more area to cool higher TDP than they could handle. Passive two-phase thermosiphon (gravity dependent) heat sinks may provide intermediate level cooling between traditional air-cooled heat pipe heat sinks and liquid cooling with higher reliability, lower weight and lower cost of maintenance. This paper illustrates the experimental results of a 2U thermosiphon heat sink used in Intel reference 2U, 2 node system and compare thermal performance using traditional heat sinks solutions. The objective of this study was to showcase the increased cooling capability of the CPU by at least 20% over traditional heat sinks while maintaining cooling capability of high-power non-CPU components such as Intel’s DIMMs. This paper will also describe the methodology that will be used for DIMMs serviceability without removing CPU thermal solution, which is critical requirement from data center use perspective.

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Thermal analysis of an LED module with a novelly assembled heat pipe heat sink

Journal of Central South University ◽

10.1007/s11771-017-3494-9 ◽

2017 ◽

Vol 24 (4) ◽

pp. 921-928 ◽

Cited By ~ 2

Author(s):

Yong Tang ◽

Qiu Chen ◽

Wo-huan Guan ◽

Zong-tao Li ◽

Bin-hai Yu ◽

...

Keyword(s):

Thermal Analysis ◽

Heat Pipe ◽

Heat Sink ◽

Pipe Heat

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Experimental Study on Applied Thin Vapor Chamber and Embedded Heat Pipe Heat Sinks

ASME 2009 InterPACK Conference, Volume 2 ◽

10.1115/interpack2009-89191 ◽

2009 ◽

Author(s):

Garrett A. Glover ◽

Yongguo Chen ◽

Annie Luo ◽

Herman Chu

Keyword(s):

Heat Pipe ◽

Heat Sink ◽

High Performance ◽

Structural Integrity ◽

Heat Pipes ◽

Electronic Cooling ◽

Working Fluid ◽

Vapor Chamber ◽

Trade Offs ◽

Pipe Heat

The current work is a survey of applied applications of passive 2-phase technologies, such as heat pipe and vapor chamber, in heat sink designs with thin base for electronic cooling. The latest improvements of the technologies and manufacturing processes allow achievable heat sink base thickness of 3 mm as compared to around 5 mm previously. The key technical challenge has been on maintaining structural integrity for adequate hollow space for the working fluid vapor in order to retain high performance while reducing the thickness of the overall vapor chamber or flattened heat pipe. Several designs of thin vapor chamber base heat sink and embedded heat pipe heat sink from different vendors are presented for a moderate power density application of a 60 W, 13.2 mm square heat source. Numerous works have been published by both academia and commercial applications in studying the fundamental science of passive 2-phase flow technologies; their performance has been compared to solid materials, like aluminum and copper. These works have established the merits of using heat pipes and vapor chambers in electronic cooling. The intent of this paper is to provide a methodical approach to help to accelerate the process in evaluating the arrays of different commercial designs of these devices in our product design cycle. In this paper, the trade-offs between the different types of technologies are discussed for parameters such as performance advantages, physical attributes, and some cost considerations. This is a bake-off evaluation of the complete heat sink solutions from the various vendors and not a fundamental research of vapor chambers and heat pipes — for that, it is best left to the vendors and universities.

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EXPERIMENTAL CHARACTERIZATION OF A DOUBLE BACK TO BACK PULSATING HEAT PIPE FOR POWER ELECTRONICS

Heat Pipe Science and Technology An International Journal ◽

10.1615/heatpipescietech.2016016212 ◽

2015 ◽

Vol 6 (3-4) ◽

pp. 123-134

Author(s):

Bruno Agostini ◽

Mathieu Habert

Keyword(s):

Heat Pipe ◽

Power Electronics ◽

Experimental Characterization ◽

Pulsating Heat Pipe

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Thermal management solution for enclosed controller used in inverter air conditioner based on heat pipe heat sink

International Journal of Refrigeration ◽

10.1016/j.ijrefrig.2018.12.020 ◽

2019 ◽

Vol 99 ◽

pp. 69-79 ◽

Cited By ~ 4

Author(s):

Guanghui Xia ◽

Dawei Zhuang ◽

Guoliang Ding

Keyword(s):

Heat Pipe ◽

Thermal Management ◽

Heat Sink ◽

Air Conditioner ◽

Pipe Heat

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Heat Pipe Heat Sinks With Matched Coefficient of Thermal Expansion Surfaces for Direct Silicon Attach

Heat Transfer: Volume 4 ◽

10.1115/ht2005-72207 ◽

2005 ◽

Author(s):

John R. Hartenstine ◽

Jerome E. Toth

Keyword(s):

Thermal Expansion ◽

Heat Pipe ◽

Heat Sink ◽

Coefficient Of Thermal Expansion ◽

Heat Sinks ◽

Design Concepts ◽

Input Surface ◽

Prototype Test ◽

Thermal Improvement ◽

Pipe Heat

Die level power densities are hitting unprecedented fluxes of over 200W/cm2, in turn driving the junction-to-case and case-to-sink resistances higher than the sink to ambient resistance. The biggest potential for thermal improvement now lies within the heat sink to device interface. Reduction in this critical interface resistance can be realized through direct attach of the heat sink base to the silicon. Challenges to this approach include the near matching of the coefficient of thermal expansion (CTE) of these two surfaces. Design concepts for a heat pipe heat sink with a CTE similar to that of silicon are investigated. Design concepts take into account materials, heat sink design configurations, and material compatibility with heat pipe working fluids. Prototype test articles were designed and fabricated using a copper/molybdenum/copper laminate as the heat input surface. Test data indicating an evaporator thermal resistance of 0.080 cm2·°C/W at 290W/cm2 are presented.

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