Development of a New Fabrication Method of Thermoelectric Microgenerators

Hybrid thermoelectric microgenerators, which are based on magnetron sputtered constantan (alloy of copper and nickel) and screen-printed silver, deposited on alumina substrate, were manufactured and characterized in previous research [1]. This paper describes new fabrication method of mixed microgenerators on LTCC substrates. Thermopiles consist of sixteen thermocouples, in which one arms were made from magnetron sputtered constantan and the remaining arms - as screen-printed Ag-based film. Single thermocouple arm was 27 mm long, and 0.3 mm wide. The distance between arms was equal to 0.3 mm. Microgenerators were performed on 34×28×0.2 mm
³
substrates. Firstly, the substrates were prepared, then the constantan layer was deposited by magnetron sputtering on the whole substrates in a vacuum. Next, the photolithography was carried out using the previously prepared photomask. The etching process in the appropriate solution exposed the first thermocouples arms. The low-temperature silver ink was screen-printed onto the LTCC substrate and then fired in a nitrogen atmosphere in order to create the second arms of the thermopile. Thermoelectric and electric parameters of such structures were characterized in detail.