Chillin'

A dynamic system for component cooling

Heat is the killer. Circuits fail, adhesives weaken, insulation softens and burns away. The heat is not just exothermic, from sources outside of the package, but also from within the package itself, particularly as miniaturization crowds circuit elements closer together.

As an alternative to real estate-robbing heat sinks and fluid analysis of fan-cooling schemes, Ferrotec, Nashua, NH, offers an array of thermoelectric modules that act as heat pumps to remove (or add, if necessary) heat from virtually any environment. In combination with a heat exchanger, the modules can be used to cool liquids, gasses or solid materials, maintaining temperatures to within 0.1°C. The solid-state devices operate as an application of the Peltier effect, in which a low voltage DC source is applied to a thermoelectric module to produce the movement of heat from one side to another. This results in one face of the module cooling while the other face heats, a phenomenon that can be reversed by the simple switching of the DC polarity. Thus, one module can be used where processes require alternating cooling and heating cycles.

Ferrotec's product lines include their standard modules, offered with a choice of two maximum temperature ratings of 150° and 200°C; customized modules that can be developed to fit unique requirements, as in the case of an optical application where the module may be part of the detector or the diode; and the Arctic line of cold plates and heat exchangers. The latter units are used in industrial applications and apply cooling through exchanges of either air-air, air-liquid, or liquid-liquid.

Applications already using thermoelectric modules cover a wide range of industries. They are found in medical instruments and telecommunication systems, and are used to cool infrared detectors and laser diodes. As a part of a weapons system, the modules operate with little power, are electrically quiet, and can function in any orientation. In aerospace applications, the modules readily operate in zero to high-G levels, keeping all systems go.

--RM