Title :
Characteristics of improved thin-film multijunction thermal converters
Author :
Lee, Y.H. ; Kwon, S.W. ; Kim, K.J. ; Lee, K.C. ; Park, S.I. ; Ihm, Y.E.
Author_Institution :
Dept. of Material Eng., Chung Nam Nat. Univ., Taejon, South Korea
Abstract :
We fabricated thin-film MJTCs which consisted of a heater and thermocouple hot junctions on a dielectric membrane and cold junctions supported by a silicon frame. The sensitivity of the converter is higher in vacuum, 21.41 V/W, than in air, 5.82 V/W. The AC-DC transfer differences taken at 1 V and 40 Hz were 42.1 ppm in air and 11.8 ppm in vacuum. The AC-DC transfer differences were stabilized below 1 ppm in the frequency range from 1 kHz to 500 kHz. Studies to develop advanced converters with a thermal island structure under the heater to decrease the AC-DC transfer difference at low frequencies are under way. At the same time, new processes to optimize the skin effect and capacitive loss at high frequencies are being developed.
Keywords :
micromachining; microsensors; thermoelectricity; thermopiles; transfer standards; 1 V; 1 to 500 kHz; 40 Hz; AC-DC converters; AC-DC transfer difference; capacitive loss optimization; devices fabrication; dielectric membrane; heater; improved thin-film multijunction thermal converters; primary standard; sensitivity; silicon frame; skin effect optimization; thermal island structure; thermocouple cold junctions; thermocouple hot junctions; thermoelectric effect; AC-DC power converters; Analog-digital conversion; Dielectric thin films; Frequency conversion; Heat transfer; Power measurement; Skin effect; Temperature sensors; Thermal conductivity; Transistors;
Conference_Titel :
Solid-State Sensors, Actuators and Microsystems, 2005. Digest of Technical Papers. TRANSDUCERS '05. The 13th International Conference on
Print_ISBN :
0-7803-8994-8
DOI :
10.1109/SENSOR.2005.1496480
