Abstract : Micromodule thermoelectric cooling devices suit able for direct incorporation into Army micro modules a special microelements having the purpose of protecting heat-sensitive circuit elements were fabricated. These devices, called Thermoelectric Thermal Barrier Microelements (TEB's) would be located between microelement wafers supporting heat-sensitive and heat-generating circuit elements. Selective temperature control, as a new circuit design parameter, holds the promise of increasing the reliability and performance of electronic packaging of the high density required to reduce the space and weight requirements associated with defense electronic systems. The design theory related to Thermo electric Thermal Barrier (TEB) microelements is developed and all equations used in the design are derived and discussed. The results are presented for Th 125C and thermal loads of 50, 100, and 200 mw. These results were obtained by measuring Tc as a function of current. The test data under type I to IV conditions is presented on each of the four batches of 25 units designed to meet type I to IV conditions. Data are presented from more complete tests on six single-junction and six double-junction devices. These include delta T and Tc vs. I curves for various heat loads, maximum temperature difference under zero applied heat load, and temperature difference vs. heat load for various constant currents