Thermal Management of Microelectronic Equipment
17 Thermoelectric Coolers
The principals of thermoelectricity were first discovered during the first half of the 19th century, but no practical applications of the principles have been applied until in the second half of the twentieth century. Two major classes of application of thermoelectric devices are heat pumps and power generators. In the former, electrical energy is supplied to transport thermal energy from one location to other locations; while in the latter, thermal energy is converted into electrical energy.
The following characteristics of thermoelectric heat pumps are particularly useful in thermal management of electronic packaging:
1. Heating or cooling can be achieved by controlling the direction of the electrical current.
2. The heat transfer capacity depends on the current.
3. The system is very reliable and quiet because it has no moving parts.
4. The device is independent of gravity and system orientation.
On the other hand, thermoelectric heat pumps have the disadvantage of a low coefficient of performance (COP). In other words, it requires a large electrical power input to pump a small amount of heat.