Cooling of High-Performance Server Modules Using Direct Immersion

2012 ◽  
Author(s):  
Aravind Sridhar ◽  
Sarah Styslinger ◽  
Christopher Duron ◽  
Sushil H. Bhavnani ◽  
Roy W. Knight ◽  
...  
Keyword(s):  
Heat Flux ◽  
High Speed ◽  
High Performance ◽  
Heat Dissipation ◽  
Heat Removal ◽  
Liquid Pool ◽  
Circuit Board ◽  
Air Cooling ◽  
High Speed Imaging ◽  
Close Proximity

An alternative to air-cooling of high performance computing equipment is presented. Heat removal via pool boiling in FC-72 was tested. Tests were conducted on a multichip module using 1.8 cm × 1.8 cm test die with multiple thermal test cells with temperature sensing capability. Measurements with the bare silicon die in direct contact with the fluid are reported. Additional testing included the test die directly indium-attached to copper heat spreaders having surface treatments. A screen-printed sintered boiling-enhanced surface (4 cm × 4 cm) was evaluated. Tests were conducted on an array of five die. Parameters tested include heat flux levels, dielectric liquid pool conditions (saturated or subcooled), and effect of neighboring die. Information was gathered on surface temperatures for a range of heat flux values up to 12 W/cm2. The highest heat dissipated from a circuit board with five bare die was 195 W (39 W per die). Addition of the heat spreader allowed heat dissipation of up to 740 W (from a five-die array). High-speed imaging was also acquired to help examine detailed information on the boiling process. Numerical modeling indicated that placing multiple boards in close proximity to each other did not degrade performance until board spacing was reduced to 3 mm.

Critical Aspects of High-Performance Microprocessor Packaging

MRS Bulletin ◽  
2003 ◽  
Vol 28 (1) ◽  
pp. 21-34 ◽  
Author(s):  
Vasudeva P. Atluri ◽  
Ravi V. Mahajan ◽  
Priyavadan R. Patel ◽  
Debendra Mallik ◽  
John Tang ◽  
...  
Keyword(s):  
High Speed ◽  
High Performance ◽  
Heat Dissipation ◽  
Printed Circuit Board ◽  
Power Input ◽  
Power Delivery ◽  
Circuit Board ◽  
Perspective View ◽  
Broad Perspective ◽  
Future Evolution

AbstractHistorically, the primary function of microprocessor packaging has been to facilitate electrical connectivity of the complex and intricate silicon microprocessor chips to the printed circuit board while providing protection to the chips from the external environment. However, as microprocessor performance continues to follow Moore's law, the package has evolved from a simple protective enclosure to a key enabler of performance. The art and science of semiconductor packaging has advanced radically over the past few decades as faster and more powerful microprocessors with tens of millions of transistors continue to be available, which require more signal and power input/output connections as well as greater power-dissipation capabilities. Key drivers for the development of packaging technologies include power delivery, thermal management, and interconnect scaling, in which the space transformation from fine-featured silicon interconnects to the relatively coarse features seen on motherboards has to be enabled by the package. These drivers, under constant market-driven cost pressure, have led to increased demands on new materials and new package architectures to enable silicon performance. Significant advances have already been made in the areas of heat dissipation, power delivery, high-speed signaling, and high-density interconnects. It is expected that the future evolution of microprocessors will be increasingly challenging in these areas. This article focuses on providing a broad perspective view of the evolution of microprocessor packaging and discusses future challenges.

Evaporative Wicking Phenomena on Nanotextured Surfaces for Heat Pipe Applications

2018 ◽  
Author(s):  
Duong Vy Le ◽  
Shiwei Zhang ◽  
Jonggyu Lee ◽  
Yoonjin Won
Keyword(s):  
Thin Film ◽  
High Speed ◽  
High Performance ◽  
Heat Dissipation ◽  
Thermal Conditions ◽  
Temperature Profiles ◽  
Textured Surfaces ◽  
High Speed Imaging ◽  
Thin Film Evaporation ◽  
Film Evaporation

Thermal management has become more important as high-performance electronics have concentrated heat loads with current cooling technologies. This motivates the implementation of new cooling solutions to dissipate high heat levels from high-performance electronics. Evaporative cooling is one of the most promising approaches for meeting these future thermal demands. Thin-film evaporation promotes heat dissipation through the phase change process with minimal conduction resistance. In this process, it is important to design surface properties and structures that can minimize meniscus thickness, increase liquid-vapor interface area, and enhance evaporation performances. In this study, we thereby investigate thin-film evaporation by employing nanotextured copper substrates for varying thermal conditions. Specifically, we visualize the liquid spreading on the nanotextured surfaces using a high-speed imaging technique to quantify evaporative heat transfer for various designs. The permeability is calculated using an enhanced wicking model to account for the evaporation effect. The mass balance measurements allow us to calculate evaporation rates. Then, we employ infrared thermography to examine two-dimensional temporal temperature profiles of the samples during the evaporative wicking with a given heat flux. The combination of time-lapse images, evaporation rate measurements, and temperature profiles will provide a comprehensive understanding of evaporation performances of textured surfaces.

Revolution in Fan Heat Sink Cooling Technology to Extend and Maximize Air Cooling for High Performance Processors in Laptop / Desktop / Server Application

2005 ◽  
Author(s):  
Masataka Mochizuki ◽  
Yuji Saito ◽  
Thang Nguyen ◽  
Vijit Wuttijumnong ◽  
Xiaoping Wu ◽  
...  
Keyword(s):  
Heat Flux ◽  
High Performance ◽  
Heat Dissipation ◽  
Air Cooling ◽  
Confined Space ◽  
Design Data ◽  
Clock Speed ◽  
Processor Performance ◽  
Design Changes ◽  
Year 2000

The trend of the processor performance and heat dissipation have been increased significantly every year. In the year 2000, the clock speed of processors used in Personal Computers (PC) was approximately 1GHz and heat dissipation approximately 20 W, but in the year 2004 the processor’s clock speed is higher than 3 GHz and the heat dissipation is approaching 100 W. Heat dissipation has increased but in contrast the size of die on the processor has reduced or remained the same size and thus the heat flux is critically high. The heat flux is about 10–15 W/cm2 in the year 2000 and could reach 100 W/cm2 in 2005. The purpose of this paper is to provide an overview of practical various cooling solutions including the use of heat pipes and vapor chambers for cooling high power processors in a confined space of PCs. This paper discusses how to extend the air cooling capability and maximize its performance. Included in this paper are the design, data, photos and discussion of various fan sink air cooling designs showing how the design changes can push the limit of the air cooling capability.

Evaporative Wicking Phenomena on Nanotextured Surfaces

2019 ◽  
Vol 141 (3) ◽  
Author(s):  
Duong Vy Le ◽  
Quang N. Pham ◽  
Jonggyu Lee ◽  
Shiwei Zhang ◽  
Yoonjin Won
Keyword(s):  
Thin Film ◽  
High Speed ◽  
High Performance ◽  
Heat Dissipation ◽  
Thermal Conditions ◽  
Temperature Profiles ◽  
Textured Surfaces ◽  
High Speed Imaging ◽  
Thin Film Evaporation ◽  
Film Evaporation

AbstractAs modern electronics become miniaturized with high power, thermal management for electronics devices has become significant. This motivates the implementation of new cooling solutions to dissipate high-heat levels from high-performance electronics. Evaporative cooling is one of the most promising approaches for meeting these future thermal demands. Thin-film evaporation promotes heat dissipation through the phase change process with minimal conduction resistance. In this process, it is important to design surface structures and corresponding surface properties that can minimize meniscus thickness, increase liquid–vapor interfacial area, and enhance evaporation performances. In this study, we investigate thin-film evaporation by employing nanotextured copper substrates for varying thermal conditions. The liquid spreading on the nanotextured surfaces is visualized using a high-speed imaging technique to quantify evaporative heat transfer for various surfaces. The permeability is calculated using an enhanced wicking model to estimate the evaporation effect combined with the mass measurements. Then, infrared (IR) thermography is employed to examine two-dimensional temporal temperature profiles of the samples during the evaporative wicking with a given heat flux. The combination of optical time-lapse images, evaporation rate measurements, and temperature profiles will provide a comprehensive understanding of evaporation performances using textured surfaces.

scholarly journals Experimental study of the dynamic behaviour of High Performance Concrete (HPC) under tensile loading

2018 ◽  
Vol 183 ◽  
pp. 02043 ◽  
Author(s):  
Bratislav Lukić ◽  
Dominique Saletti ◽  
Pascal Forquin
Keyword(s):  
High Speed ◽  
High Performance ◽  
High Performance Concrete ◽  
Imaging System ◽  
Spall Strength ◽  
High Speed Imaging ◽  
Dynamic Tensile Strength ◽  
Full Field ◽  
Local Point ◽  
Measurement Results

This paper presents the measurement results of the dynamic tensile strength of a High Performance Concrete (HPC) obtained using full-field identification method. An ultra-high speed imaging system and the virtual fields method were used to obtain this information. Furthermore the measurement results were compared with the local point-wise measurement to validate the data pressing. The obtained spall strength was found to be consistently 20% lower than the one obtained when the Novikov formula is used.

scholarly journals A portable smartphone-based laryngoscope system for high-speed vocal cord imaging of patients with throat disorders (Preprint)

2020 ◽  
Author(s):  
Jun Ki Kim ◽  
Youngkyu Kim ◽  
Jungmin Oh ◽  
Seung-Ho Choi ◽  
Ahra Jung ◽  
...  
Keyword(s):  
Image Processing ◽  
Vocal Cord ◽  
High Speed ◽  
High Performance ◽  
Vocal Folds ◽  
Frame Rate ◽  
Endoscopic Imaging ◽  
High Speed Imaging ◽  
Underdeveloped Countries ◽  
Longitudinal Edge

BACKGROUND Recently, high-speed digital imaging (HSDI), especially HSD endoscopic imaging is being routinely used for the diagnosis of vocal fold disorders. However, high-speed digital endoscopic imaging devices are usually large and costly, which limits access by patients in underdeveloped countries and in regions with inadequate medical infrastructure. Modern smartphones have sufficient functionality to process the complex calculations that are required for processing high-resolution images and videos with a high frame rate. Recently, several attempts have been made to integrate medical endoscopes with smartphones to make them more accessible to underdeveloped countries. OBJECTIVE To develop a smartphone adaptor for endoscopes to reduce the cost of devices, and to demonstrate the possibility of high-speed vocal cord imaging using the high-speed imaging functions of a high-performance smartphone camera. METHODS A customized smartphone adaptor was designed for clinical endoscopy using selective laser melting (SLM)-based 3D printing. Existing laryngoscope was attached to the smartphone adaptor to acquire high-speed vocal cord endoscopic images. Only existing basic functions of the smartphone camera were used for HSDI of the vocal folds. For image processing, segmented glottal areas were calculated from whole HSDI frames, and characteristics such as volume, shape and longitudinal edge length were analyzed. RESULTS High-speed digital smartphone imaging with the smartphone-endoscope adaptor could achieve 940 frames per second, and was used to image the vocal folds of five volunteers. The image processing and analytics demonstrated successful calculation of relevant diagnostic variables from the acquired images. CONCLUSIONS A smartphone-based HSDI endoscope system can function as a point-of-care clinical diagnostic device. Furthermore, this system is suitable for use as an accessible diagnostic method in underdeveloped areas with inadequate medical service infrastructure.

Thermal Characters of the Air-Cooled High Speed Motorized Spindle for Wood-Working Machine

2013 ◽  
Vol 579-580 ◽  
pp. 568-572
Author(s):  
Da Guo Ma ◽  
Xin Bo Jiang
Keyword(s):  
High Speed ◽  
Metal Cutting ◽  
Heat Dissipation ◽  
Element Model ◽  
Structure Design ◽  
Air Cooling ◽  
Heat Sources ◽  
Motorized Spindle ◽  
Dissipation Structure ◽  
Motorized Spindles

The structure and composition of the air-cooled high speed motorized spindle for wood-working machine and some features relative to the metal cutting motorized spindle are introduced briefly. Then the main heat sources and heat dissipation mechanism of the air-cooled motorized spindle are thoroughly analyzed, finite element model of the air-cooled motorized spindle is built, the motorized spindles temperature distribution under thermal steady state and the influence of speed are analyzed. The results show that air cooling relative to the water or oil cooling has many advantages and reasonable heat dissipation structure design of air-cooled motorized spindle could meet the requirements of the high-speed motorized spindle for wood-working machine.

Optimized High Power GaN Transistors

2015 ◽  
Vol 2015 (HiTEN) ◽  
pp. 000195-000199
Author(s):  
J. Roberts ◽  
A. Mizan ◽  
L. Yushyna
Keyword(s):  
High Speed ◽  
Figure Of Merit ◽  
Printed Circuit Board ◽  
Heat Removal ◽  
Vital Role ◽  
Circuit Board ◽  
Die Structure ◽  
Power Switches ◽  
On Chip ◽  
Very High

GaN transistors intended for use at 600–900 V and that are capable of providing of 30–100 A are being introduced this year. These devices have a substantially better switching Figure-of-Merit (FOM) than silicon power switches. Rapid market acceptance is expected leading to compound annual growth rates of 85 %. However these devices present new packaging challenges. Their high speed combined with the very high current being switched demands that very low inductance packaging must be combined with highly controlled drive circuitry. While convention, and the usually vertical power device die structure, has largely determined power transistor package formats in the past, the lateral nature of the today GaN devices requires the use of new package types. The new packages have to operate at high temperatures while providing effective heat removal, low inductance, and low series resistance. Because GaN devices are lateral they require the package metal tracks to be integrated within the on-chip tracks to carry the current away from the thin on-chip metal tracks. The new GaN devices are available in two formats: one for use in embedded modular assemblies and the other for use mounted upon conventional circuit board systems. The package intended for discrete printed circuit board (PCB) assemblies has a top side cooling option that simplifies the thermal interface to the heat sink. The paper describes the die layout including the added copper tracks. The corresponding package elements that interface directly with the surface of the die play a vital role in terms of the current handling. They also provide the interface to the external busbars that allow the package to be mounted within, or on PCB. The assembly has been subject to extensive thermal analysis and the performance of a 30 A, 650 V transistor is described.

Dependence of Heat Transfer Coefficient on Porous Structure in Porous Media

2008 ◽  
Author(s):  
Akira Matsui ◽  
Kazuhisa Yuki ◽  
Hidetoshi Hashizume
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Porous Media ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
High Performance ◽  
Heat Removal ◽  
High Heat ◽  
Metal Foams ◽  
High Heat Flux

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.

Flow Boiling of Sub-Cooled Pentane on a Micro-Porous Coating

2012 ◽  
Author(s):  
Paul J. Laca ◽  
Richard A. Wirtz
Keyword(s):  
Heat Flux ◽  
High Speed ◽  
High Performance ◽  
Flow Boiling ◽  
High Heat ◽  
Surface Coatings ◽  
Porous Coating ◽  
High Heat Flux ◽  
Characteristic Curves ◽  
High Speed Video

Flow boiling experiments with sub-cooled Isopentane and n-Pentane at 3.0bar pressure assess the utility of compressed copper- and steel-filament screen laminate surface coatings as high performance boiling surfaces. High-speed video show that at high heat flux ebullition is unsteady. Isopentane and n-Pentane are found to produce nearly identical boiling characteristic curves. At the same applied heat flux, the superheat of copper filament coatings are much smaller than the steel filament coating superheats.

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