Modular Heat Sinks for Enhanced Thermal Management of Electronics

Author(s):  
Muhammad Jahidul Hoque ◽  
Alperen Günay ◽  
Andrew Stillwell ◽  
Yashraj Gurumukhi ◽  
Robert Pilawa-Podgurski ◽  
...  

Abstract Power electronics are vital for the generation, conversion, transmission, and distribution of electrical energy. Improving the efficiency, power density, and reliability of power electronics is an important challenge that can be addressed with electro-thermal co-design and optimization. Current thermal management approaches utilize metallic heat sinks, resulting in parasitic load generation due to different potentials between electronic components on the printed circuit board (PCB). To enable electrical isolation, a thermal interface material (TIM) or gap pad is placed between the PCB and heat sink, resulting in poor heat transfer. Here, we develop an approach to eliminate TIMs and gap pads through modularization of metallic heat sinks. The use of smaller modular heat sinks (MHSs) strategically placed on high power dissipation areas of the PCB enables elimination of electrical potential difference, and removal of electrical isolation materials, resulting in better cooling performance due to direct contact between devices and the heat sink. By studying a gallium nitride (GaN) 2kW DC-DC power converter as a test platform for electro-thermal co-design using the modular approach, and benchmarking performance with a commercial off-the-shelf heat sink design, we showed identical power dissipation rates with a 54% reduction in heat sink volume and a 8°C reduction in maximum GaN device temperature. In addition to thermal performance improvement, the MHS design showed a 73% increase in specific power density with a 22% increase in volumetric power density.

2021 ◽  
Vol 163 ◽  
pp. 106796
Author(s):  
Yongtong Li ◽  
Liang Gong ◽  
Bin Ding ◽  
Minghai Xu ◽  
Yogendra Joshi

Author(s):  
Tunc Icoz ◽  
Mehmet Arik ◽  
John T. Dardis

Thermal management of electronics is a critical part of maintaining high efficiency and reliability. Adequate cooling must be balanced with weight and volumetric requirements, especially for passive air-cooling solutions in electronics applications where space and weight are at a premium. It should be noted that there are systems where thermal solution takes more than 95% of the total weight of the system. Therefore, it is necessary to investigate and utilize advanced materials to design low weight and compact systems. Many of the advanced materials have anisotropic thermal properties and their performances depend strongly on taking advantage of superior properties in the desired directions. Therefore, control of thermal conductivity plays an important role in utilization of such materials for cooling applications. Because of the complexity introduced by anisotropic properties, thermal performances of advanced materials are yet to be fully understood. Present study is an experimental and computational study on characterization of thermal performances of advanced materials for heat sink applications. Numerical simulations and experiments are performed to characterize thermal performances of four different materials. An estimated weight savings in excess of 75% with lightweight materials are observed compared to the traditionally used heat sinks.


Author(s):  
V. Shanmugasundaram ◽  
M. L. Ramalingam ◽  
Brian Donovan ◽  
T. Mahefkey ◽  
B. Hager

A general thermodynamic analytical evaluation tool was developed to investigate the impact of technological improvements on mission effectiveness and weapon power generation in an aircraft based pulsed power system. The power system investigated consists of six major components, the prime power source, the power generator, the power conditioner, the pulsed power source, the pulsed power processor and the thermal management with a total estimated payload restriction of 4600 kgs. based on a USAF cargo aircraft. The analysis was based on a 2.5 MW pulsed power source output and a notional mission profile with an engagement period of 60 minutes during which several duty cycle scenarios were considered. Six power system architectures were evaluated with a baseline power system model that incorporated current off-the-shelf technologies for each component. A helicopter engine was used as the primary power source because of its high power density but the engine performance is very sensitive to increasing altitude where the output power diminishes rapidly. As a result of this and the necessity to accommodate load-following during engagement, the investigations were extended to a hybrid power system architecture with turboalternator-battery and turboalternator-flywheel combinations. Preliminary analysis based on prorated values of specific power and power density for all the components revealed that the overall mass of the power system could be brought down from 13,330 kgs. for the baseline architecture to 4075 kgs. for the conceptual load-following turboalternator-battery hybrid power system. Coolant requirements for an open thermal management system ranged from 2007 kgs. of Ammonia or 1127 kgs. of water for a heat load of 2.9 Mwt corresponding to a 30% duty cycle pulsed power source operation.


Author(s):  
Jimil M. Shah ◽  
Ravya Dandamudi ◽  
Chinmay Bhatt ◽  
Pranavi Rachamreddy ◽  
Pratik Bansode ◽  
...  

Abstract In today’s networking world, utilization of servers and data centers has been increasing significantly. Increasing demand of processing and storage of data causes a corresponding increase in power density of servers. The data center energy efficiency largely depends on thermal management of servers. Currently, air cooling is the most widely used thermal management technology in data centers. However, air cooling has started to reach its limits due to high-powered processors. To overcome these limitations of air cooling in data centers, liquid immersion cooling methods using different dielectric fluids can be a viable option. Thermal shadowing is an effect in which temperature of a cooling medium increases by carrying heat from one source and results in decreasing its heat carrying capacity due to reduction in the temperature difference between the maximum junction temperature of successive heat sink and incoming fluid. Thermal Shadowing is a challenge for both air and low velocity oil flow cooling. In this study, the impact of thermal shadowing in a third-generation open compute server using different dielectric fluids is compared. The heat sink is a critical part for cooling effectiveness at server level. This work also provides an efficient range of heat sinks with computational modelling of third generation open compute server. Optimization of heat sink can allow to cool high-power density servers effectively for single-phase immersion cooling applications. A parametric study is conducted, and significant savings in the volume of a heat sink have been reported.


Author(s):  
Saeed Ghalambor ◽  
John Edward Fernandes ◽  
Dereje Agonafer ◽  
Veerendra Mulay

Forced convection air cooling using heat sinks is one of the most prevalent methods in thermal management of microelectronic devices. Improving the performance of such a solution may involve minimizing the external thermal resistance (Rext) of the package. For a given heat sink design, this can be achieved by reducing the thermal interface material (TIM) thickness through promotion of a uniform interfacial pressure distribution between the device and heat sink. In this study, a dual-CPU rackmount server is considered and modifications to the heat sink assembly such as backplate thickness and bolting configuration are investigated to achieve the aforementioned improvements. A full-scale, simplified model of the motherboard is deployed in ANSYS Mechanical, with emphasis on non-linear contact analysis and torque analysis of spring screws, to determine the optimal design of the heat sink assembly. It is observed that improved interfacial contact and pressure distribution is achieved by increasing the number of screws (loading points) and positioning them as close to the contact area as possible. The numerical model is validated by comparison with experimental measurements within reasonable accuracy. Based on the results of numerical analysis, the heat sink assembly is modified and improvement over the base configuration is experimentally quantified through interfacial pressure measurement. The effect of improved interfacial contact on thermal performance of the solution is discussed.


Author(s):  
Anjali Chauhan ◽  
Bahgat Sammakia ◽  
Kanad Ghose ◽  
Gamal Refai-Ahmed ◽  
Dereje Agonafer

The stacking of processing and memory components in a three-dimensional (3D) configuration enables the implementation of processing systems with small form factors. Such stacking shortens the interconnection length between processing and memory components to dramatically lower the memory access latencies, and contributes to significant improvements in the memory access bandwidth. Both of these factors elevate overall system performance to levels that are not realizable with prevailing and other proposed solutions. The shorter interconnection lengths in stacked architectures also enable the use of smaller drivers for the interconnections, which in turn reduces interconnection-level energy dissipations. On the down side, stacking of processing and memory components introduces a significant thermal management challenge that is rooted in the high thermal resistance of stacked designs. This paper examines and evaluates three distinct solutions that address thermal management challenges in a system that stacks DRAM components onto a processing core. We primarily focus on three different configurations of a microchannel-based single-phase liquid cooling system with a traditional air-cooled heat sink. Our evaluations, which are intended to study the limits of each solution, assume a uniform power dissipation model for the processor and accounts for the thermal resistance offered by the thermal interface material (TIM), the interconnect layer, and through-silicon vias (TSVs). The liquid-cooled microchannel heat sink shows more promising results when integrated into the package than when added to the microprocessor package from outside.


Author(s):  
Gilberto Moreno ◽  
Sreekant Narumanchi ◽  
Xuhui Feng ◽  
Paul Anschel ◽  
Steve Myers ◽  
...  

Abstract Effective thermal management of traction-drive power electronics is critical to the advancement of electric-drive vehicles and is necessary for increasing power density and improving reliability. Replacing traditional silicon devices with more efficient, higher temperature, higher voltage, and higher frequency wide-bandgap (WBG) devices will enable increased power density but will result in higher device heat fluxes. Compact packaging of high-temperature WBG devices near low-temperature-rated components creates thermal management challenges that need to be addressed for future power-dense systems. This paper summarizes the thermal performance of on-road automotive power electronics thermal management systems and provides thermal performance and pumping-power metrics for select vehicles. Thermal analyses reveal that the package/conduction resistance dominates the total thermal resistance (for existing automotive systems). We model advanced packaging concepts and compare the results with existing packaging designs to quantify their thermal performance enhancements. Double-side-cooled configurations that do not use thermal interface materials are package concepts predicted to provide a low junction-to-fluid thermal resistance (compared to current packages). Dielectric-fluid-cooled concepts enable a redesign of the package to reduce the package resistance, can be implemented in single- and two-phase cooling approaches, and allow for cooling of passive components (e.g., capacitors) and bus bars.


Author(s):  
Ed Walsh ◽  
Ronan Grimes

The increasing heat flux densities from portable electronics are leading to new methodologies being implemented to provide thermal management within such devices. Many technologies are under development to transport heat within electronic equipment to allow it to be transported into the surroundings via conduction, natural convection and radiation. Few have considered the approach of implementing a forced convection cooling solution in such devices. This work addresses the potential of a low profile integrated fan and heat sink solution to electronics thermal management issues of the future, particularly focusing upon possible solutions in low profile portable electronics. We investigate two heat sink designs with mini channel features, applicable to low profile applications. The thermal performance of the heat sinks is seen to differ by approximately 40% and highlights the importance of efficient heat sink design at this scale.


2015 ◽  
Vol 1120-1121 ◽  
pp. 1368-1372 ◽  
Author(s):  
Daniel Henrique de Souza Obata ◽  
Thiago Antonini Alves ◽  
Márcio Antonio Bazani ◽  
Amarildo Tabone Paschoalini

In this research, a vapor chamber embedded in the base of a heat sink was experimentally analyzed for the application in thermal management of microelectronics. The vapor chamber was produced by a copper and molybdenum alloy with length of 240 mm, width of 54 mm, thickness of 3 mm, and capillary structures composed by copper screen meshes. The working fluid used was de-ionized water. The pure aluminum heat sink was cooled by air forced convection and the evaporator vapor chamber was heated using an electrical resistor simulating integrated circuit power dissipation. The experimental tests were done in a suction type wind tunnel with open return for a heat load varying from 20 to 80 W and for an airflow velocity varying from 1 to 4 m/s. The experimental results showed that the considered vapor chamber worked successfully, maintaining low operating temperature.


Author(s):  
Ying Feng Pang ◽  
Elaine P. Scott ◽  
Zhenxian Liang ◽  
J. D. van Wyk

The objective of this work is to quantify the advantages of using double-sided cooling as the thermal management approach for the integrated power electronics modules. To study the potential advantage of the Embedded Power packaging method for the double-sided cooling, experiments were conducted. Three different cases were studied. To eliminate the effect of the heat sink on either side of the module, no heat sink was used in all three cases. The thermal tests were conducted such that the integrated power electronics modules were placed in the middle of flowing air in an insulated wind tunnel. Modules without additional top DBC, with additional top DBC, and with additional top DBC as well as heat spreaders on both sides were tested under the same condition. A common parameter, junction-to-ambient thermal resistance, was used to compare the thermal performance of these three cases. Despite the shortcoming of this parameter in describing the three-dimensional heat flow within the integrated power electronics modules, the concept of the thermal resistance is still worthwhile for evaluating various cooling methods for the module. The results show that increasing the top surface area can help in transferring the heat from the heat source to the ambient through the top side of the module. Consequently, the ability to handle higher power loss can also be increased. In summary, the Embedded Power technology provides an opportunity for implementing double-sided cooling as thermal management approach compared to modules with wire-bonded interconnects for the multichips.


Sign in / Sign up

Export Citation Format

Share Document