Planar and three-dimensional thick-film thermoelectric microgenerators

This paper describes manufacturing process as well as thermoelectric properties and long-term stability of planar and three-dimensional (3-D) thermoelectric structures made in thick-film/LTCC technology. Screen-printed thick-film thermocouples based on PdAg, Ag and Ni inks were manufactured and investigated. Seebeck coefficient and electrical output power were measured with the help of custom built automatic measuring system. Achieved results were compared with literature data and earlier authors' results. Seebeck coefficient greater than 20 mu V/K and about 5-8 mu W/junction output power were measured for temperature difference of about 100 K for Ag-Ni thick-film planar thermocouple made on both used substrates. This combination of materials was chosen to create three-dimensional thick-film thermocouples (reported in the literature for the first time). We received for them Seebeck coefficient greater than 15 mu V/K and the output power on level of 1 mu W/junction for temperature gradient of about 60 K. (c) 2008 Elsevier Ltd. All rights reserved.