Cooling of circuit boards using natural convection

Abstract

In this paper, we study the air cooling of circuit boards populated with multiple integrated circuits using natural convection. The simulation and the modeling results of the model are obtained by digital software Comsol Multiphysics. The results then accurately describe the heat transport and temperature changes. From such simulations, it is also possible to derive accurate estimations of the film coefficients. The objective is to determine the evolution of the temperature and the flow of the velocity of the fluid. The results show that the temperature of the ICs (the heat sources) increases considerably under a constant heating load from the components. The temperature increase of the sources varies from 30 K for the lowest IC up to 90 K at the top IC. For the velocity of the fluid, the circuit board contributes a large amount of cooling power on its backside, although the thermal conductivity is quite small.