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In this paper, a 3D model of a flat circuit board with a heat generating electronic chip mounted on it has been studied numerically. The conjugate heat transfer including the conduction in the chip and convection with the surrounding fluid has been investigated numerically. Computational fluid dynamics using the finite volume method has been used for modeling the conjugate heat transfer through the chip and the circuit board. Conjugate heat transfer has broad applications in engineering and industrial applications in design of cooling off electronic components. Effects of various inlet velocities have been studied on the heat transfer variation and temperature of the circuit board. Numerical results show that the temperature of the chip reduces as the velocity of the inlet fluid flow increases.

Electronic equipment has made its way into practically every aspect of modern life, from toys and appliances to high-power computers. The reliability of the electronics of a system is a major factor in the overall reliability of the system. Electronic components depend on the passage of electric current to perform their duties, and they become potential sites for excessive heating, since the current flow through a resistance is accompanied by heat generation. Continued miniaturization of electronic systems has resulted in a dramatic increase in the amount of heat generated per unit volume, comparable in magnitude to those encountered at nuclear reactors and the surface of the sun. Unless properly designed and controlled, high rates of heat generation result in high operating temperatures for electronic equipment, which jeopardizes its safety and reliability. The failure rate of electronic equipment increases exponentially with temperature. Also, the high thermal stresses in the solder joints of electronic components mounted on circuit boards resulting from temperature variations are major causes of failure. Therefore, thermal control has become increasingly important in the design and operation of electronic equipment. The maximum operating temperature has implications both on the chip and package level reliability and performance. At the chip level, the non-uniformity in temperature leads to a clock skew [

system at 298 K with a velocity of 1 m/s. The Reynolds number of the flow, based on the module height, is about 600. The flow is therefore treated as laminar.

the flow circulates in that region.

for the inlet velocity of 7 m/s where the temperature of the chip decreases to 387 and circuit board to 310 K. As seen the temperature difference for the inlet velocities of 5 and 7 m/s is not much which shows that for a certain value of inlet velocity there is a noticeable reduction in the temperature and for values greater than that the temperature stays the same with negligible difference.

In this study, a 3D model of a flat circuit board with a heat generating electronic chip mounted on it has been studied numerically. The flow over the chip is laminar and involves conjugate heat transfer. Effects of various inlet velocities have been studied on the heat transfer variation and temperature of the circuit board. As the results show, increasing the inlet velocity reduces the circuit board and chip temperatures significantly and increases the maximum velocity over the circuit board and the chip.

The author would like to thank both The Saudi Arabia Cultural Mission and University of North Border, Arar.

Alrashidi, A. (2016) Numerical Study of Conjugate Heat Transfer for Cooling the Circuit Board. Journal of Electronics Cooling and Thermal Control, 6, 120-126. http://dx.doi.org/10.4236/jectc.2016.63011