Performance assessment of thermoelectric coolers for use in high temperature electronics applications

Thermoelectric cooling (TEC) modules which are rated for operation up to 200/spl deg/C are now widely available commercially, making them potential candidates for use in the thermal management of high temperature electronics applications. Through the use of these TECs, traditional electronic devices could be employed at much higher temperatures than they might otherwise tolerate, by creating a low temperature "micro-environment" around the specific components of interest, To gauge the feasibility of using TECs for high temperature thermal management, a single stage TEC was operated at constant current, near its maximum temperature limit for up to 1500 hours to assess the long term effect of elevated temperature on the module's performance. Results of the test showed a gradual decline in the overall temperature differential generated by the TEC during powered operation. Analysis of the exposed module by E-SEM suggests diffusion of Te from the thermoelements into the Bi solder region and a degradation of the Ni diffusion barrier between the copper tabs and the bismuth solder layer.