Temperature Profile Inside Microscale Thermoelectric Module Acquired Using Near-Infrared Thermoreflectance

We present high-resolution thermal images of the electrical contacts inside an active thermoelectric micromodule that are acquired through the silicon substrate using near-infrared thermoreflectance. The temperature distribution of the contacts induced by the Peltier and Joule effects are separated. This technique can be utilized as a nondestructive means to evaluate metallization and contact resistance of micrometer-scale thermoelectric modules. By determining localized sources of Joule heating, one can identify manufacturing errors and generate design rules that can improve the cooling performance of the thermoelectric device.