Cooling Performance of Heat Sinks Used in Electronic Devices

International Journal of Mechanical Engineering and Technology, 2017

The development of the digital computer and its usage day by day is rapidly increasing. But the reliability of electronic components is getting affected critically by the temperature at which the junction operates. As operating power and speed increases, and as the designers are forced to reduce overall systems dimensions, the problems of extracting heat and controlling temperature becomes crucial. A heat sink is a passive heat exchanger that transfers the heat generated by an electronic or a mechanical device to a fluid medium, often air or a liquid coolant. Modern electronic devices are becoming more compact in size so the heat sink must be developed for such device. The study of heat sink is an important field for the last decade. The reason is mainly the possibilities of reducing the size, weight and cost as compared to current designs. The continual development of faster desktop computers being sold at lower prices into the market place has demanded that thermal management engineers develop and optimize thermal management devices that not only perform better, but are at the same or lower cost than previous generations. An overview of different types of heat sinks is provided. Modelling of heat sink and the development of overall model is described.

IIUM Engineering Journal, 1970

Cooling of electronic components continues to attract many research and development activities towards achieving an effective way of cooling. Computational fluid dynamics (CFD) tools may be considered as a cheap substitute for expensive experimental testing methods. In this work the cooling of a simulated electronic board was modeled using FLUENT TM CFD software, and experimental procedures were followed to validate the estimated results, and to understand the factors that would affect the software capability to predict the actual measured values. Results showed good agreement between the simulation and experimental results. The software was found to be capable to predict the exact values at the locations where the temperature values were similar to the board mean temperature. The maximum percentage error was found to be limited to 4.7%, and the capability of the software to estimate the exact measured values was found to be affected by the function of thermal wake generation.

Journal of Electronics Cooling and Thermal Control, 2013

Heat transfer experiments were conducted to investigate the thermal performance of air cooling through mini-channel heat sink with various configurations. Two types of channels have been used, one has a rectangular cross section area of 5  18 mm 2 and the other is triangular with dimension of 5  9 mm 2. Four channels of each configuration have been etched on copper block of 40 mm width, 30 mm height, and 200 mm length. The measurements were performed in steady state with air flow rates of 0.002-0.005 m 3 /s, heating powers of 80-200 W and channel base temperatures of 48˚C, 51˚C, 55˚C and 60˚C. The results showed that the heat transfer to air stream is increased with increasing both of air mass flow rate and channel base temperature. The rectangular channels have better thermal performance than triangular ones at the same conditions. Analytical fin approach of 1-D and 2-D model were used to predict the heat transfer rate and outlet air temperature from channels heat sink. Theoretical results have been compared with experimental data. The predicted values for outlet air temperatures using the two models agree well with a deviation less than ±10%. But for the heat transfer data, the deviation is about +30% to-60% for 1-D model, and-5% to-80% for 2-D model. The global Nusselt number of the present experimental data is empirically correlated as 0.6 0.3 0.052 Re Pr Nu H w  with accuracy of ±20% for and compared with other literature correlations. 3 3 10 Re 5 10     4 channel heat sink. The results showed that significant

2014 International Conference on Computational Science and Computational Intelligence, 2014

Heat sinks were invented to absorb heat from an electronic circuit conduct, and then to dissipate or radiate this heat to the surrounding supposedly, ventilated space, at a rate equal to or faster than that of its buildup. Ventilation was not initially recognized as an essential factor to thermal dispersion. However, as electronic circuit-boards continued to heat up, circuit failure became a problem, forcing the inclusion of miniaturized high speed fans. Later, heat sinks with fins and quiet fans were incorporated in most manufactured circuits. Now heat sinks come in the form of a fan with fans made to function as fins to disperse heat. Heat sinks absorb and radiate excess heat from circuit-boards in order to prolong the circuit's life span. The higher the thermal conductivity of the material used the more efficient and effective the heat sink is. This paper is an attempt to theoretically design a heat sink with a temperature gradient lower than that of the circuit board's excess heat.

American Journal of Applied Sciences, 2012

Problem statement: The performance of electronic devices has been improving along with the rapid technology development. Cooling of electronic systems is consequently essential in controlling the component temperature and avoiding any hot spot. The study aims to review the present electronic cooling methods which are widely used in electronic devices. Approach: There are several methods to cool down the electronics components such as the pin-fin heat sink, confined jet impingement, heat pipe, micro heat sink and so on. Results: The cooling techniques can obviously increase heat transfer rate. Nonetheless, for active and passive cooling methods the pressure drop could extremely rise, when the heat transfer rate is increased. Conclusion: When the cooling techniques are used, it is clearly seen that the heat transfer increases with pressure drop. To avoid excessive expense due to high pressure drop, optimization method is required to obtain optimum cost and cooling rate.

International Journal of High Speed Electronics and Systems, 2006

Recent trends in processor power for the next generation devices point clearly to significant increase in processor heat dissipation over the coming years. In the desktop system design space, the tendency has been to minimize system enclosure size while maximizing performance, which in turn leads to high power densities in future generation systems. The current thermal solutions used today consist of advanced heat sink designs and heat pipe designs with forced air cooling to cool high power processors. However, these techniques are already reaching their limits to handle high heat flux, and there is a strong need for development of more efficient cooling systems which are scalable to handle the high heat flux generated by the future products. To meet this challenge, there has been research in academia and in industry to explore alternative methods for extracting heat from high-density power sources in electronic systems. This talk will discuss the issues surrounding device cooling, from the transistor level to the system level, and describe system-level solutions being developed for desktop computer applications developed in our group at Stanford University.

STM Journals, Journal of Energy, Enviornment and Carbon Credits, 2018

Electronic equipment plays an important role in day-to-day life. Almost every object or equipment or machine uses electronic components to complete its task. For electronic component to work it needs electric current to flow through the circuits. And hence they become main reason of excessive heating. Continued shrinking of electronic systems has resulted in a histrionic increase in the amount of heat generated per unit volume. Air cooling with the help of heat sinks is the most economical & efficient method of electronics cooling. In this study, thermal analysis of a server system is proposed, and an effort is made to lower the maximum temperature in the CPUs by changing CPU heat sink design. The server computer of form factor SSI EEB is modelled in detail and is analyzed by using commercial computational fluid dynamics (CFD) software packages Icepak and Fluent. To optimize parameters of heat, sink parameters the CFD simulations will be performed for maximum dissipation of heat. Few iterations will be performed by changing geometry and material of heat sinks number of fins of heat sinks and changing the fan positions on computer chassis. The optimum grouping of parameters and results will be compared with the commercially available heat sink.

The ever rising transistor densities and switching speeds in microprocessors have been accompanied a dramatic increase in the system heat flux and power dissipation. In this context the rising IC densities combined with even more stringent performance and reliability requirement have made thermal management issues ever more prominent in the design of sophisticated microelectronic systems. So in order to achieve a high degree power dissipation extruded heat sinks, a number of research works have been done in last two decades. It is observed that components of modern portable electronic devices with increasing heat loads with decrease in the space available for heat dissipation. The increasing heat load of the device needs to be removed for maintaining the efficient performance of the device. The exponential increase in thermal load in air cooling devices requires the thermal management system to be optimized to attain the highest performance in the given space. In the present paper a review report on comprehensive description for thermal conditions for cooling purpose within the heat sink for electronic devices has been summarized.

Volume 7: Fluid Flow, Heat Transfer and Thermal Systems, Parts A and B, 2010

ABSTRACT Novel flow channel configurations in heat sinks for electronics cooling were proposed in this paper. Computational analyses were carried out to better understand the heat transfer performance, the uniformity of temperature fields of the heat sinking surface, as well as the pressure losses and pumping power in the operation of heat sinks. Comparison of the overall performance regarding to temperature uniformity on the heat sink surface and pumping power consumption was made for heat sinks having novel flow channel configurations and having traditional flow channel configurations. It has been found that the novel flow channel configuration dramatically reduces the pressure loss in the flow field. Giving the same pumping power consumption of an electronics cooling process, the temperature difference on surface of the heat sink which has novel flow channel configuration can be much lower than that of the heat sinks which have traditional flow channel configurations.