Heat pipes: The silent way to manage desktop thermal problems

The continuous increase of system power and the decrease of available volume present interesting challenges in the thermal management of desktop computers. Traditional desktop computer design has relied on natural convection ft om a heat sink placed directly on the processor. With the increasing power of today's processors, it has been necessary to add a processor fan to these local heat sinks, Mechanical components with moving parts are the most unreliable components in desktop computers. The use of heat pipes may eliminate the use of the processor fans and their inherent reliability concerns. A heat pipe heat sink is a passive cooling device that requires no moving parts, and operates silently, and more importantly, reliably. Additionally, heat pipe technology is emerging as a cost-effective thermal design solution for the desktop industry. This paper explains the basic operation of heat pipes and provides a method to determine the feasibility of a heat pipe heat sink design. Issues regarding the manufacturability and reliability of heat pipe heat sinks are also addressed. Fan sinks placed directly over the processor occupy the most valuable real estate in a computer and can interfere with the placement of add-on boards and other system components. Heat pipe sinks provide the system designer with a powerful tool. The heat pipes transport heat away from the obstructions and constraints of neighboring boards to where it can be conveniently dissipated. The ability of the heat pipe to be formed to meet location and space availability and its characteristic low Delta T as a function of length permit the heat pipe heat sink system to provide the maximum effective heat sink surface area with the minimum volume demand. The heat load can be conducted to open areas within the system.