I enjoyed your recent article by Paul Magill on thin-film thermoelectrics (TECs; “Thin-film TECs give new life to CMOS cooling,” August, p. 75; www.laserfocusworld.com/articles/302489). However, the article contains many weakly supported or incorrect statements that continue to be promoted by purveyors of thin-film TECs. For example, the statement that cooling power is inversely proportional to element length is incorrect when one is talking about actual coolers in operation. Cooling power is inversely proportional to length only in the most ideal theoretical analysis. The influence of the heat-sink thermal resistance, electrical interface resistance, and so on, make this statement untrue in actual thermoelectric devices. Second, the statement on faster response times is extremely weak, as the temperature response time for cooled products is governed most often by the thermal mass of the device that is being cooled, not the thermal mass or cooling power of the thermoelectric cooler itself.
This type of article serves to reinforce misconceptions about both thin-film and traditional bulk thermoelectric coolers in the cooling industry.
Andrew Miner
Founder and Chief Technical Officer
Romny Scientific
Berkely, California
[email protected]