DESIGN OF CIRCULAR HEAT SPREADERS ON SEMIINFINITE HEAT SINKS IN MICROELECTRONICS DEVICE APPLICATIONS

Using the rigorous analytical solutions, we discuss design aspects in terms of thermal resistance and temperature uniformity for the canonic al heat dissipation configuration consisting of a circular heat spread er on a semi-infinite heat sink, Regarding the optimized size of the h eat spreader, we have found that the minimum temperature thickness of the spreader depends on the thermal conductivity values of the spreade r and the sink, in contrast to the results published previously by oth er researchers, In addition, a new design formula d = 0.44b for the se lection of spreader thickness d from the spreader radius b is proposed to replace the commonly used rule d = b/3, Our results have confirmed the design rule b = 5a for the selection of the spreader radius b fro m a given heat source radius a, To facilitate the complete design of t he heat spreaders, we present two nomographs in the form of contour pl ots for the normalized thermal resistance and the normalized temperatu re uniformity.