Thick Film Temperature Compensating Circuit for Semiconductor StrainGauges

[摘要] Thick film circuits were developed for temperature compensating of semiconductor strain gauges and for connectingthe gauges to amplifiers in electronic pressure and differential pressure transmitters. In each circuit, ten Au pads forAl wire bonding and thirteen Ag/Pd pads for soldering must be fabricated on a small substrate. The results of theresearch are shown below.(1) The resistance values and the thermistor constants required for the thermistors are 0.9 ± 0.09 kilo-ohm and2500 ± 40 Kelvin, respectively. Those characteristics are realized by developing a paste composition composed of anew spinel type oxide (Mn1.6Co0.8Ni0.35Ru0.25O4) RuO2and glass.(2) Accelerated life tests of the thick film thermistors reveal that the resistance drift rates of the thermistors are lessthan ±0.02 %/year at 120°C.(3) Life tests clarify that the wire bonding pads fabricated by using ESL 8882 Au paste keep more than 4 grams inpull strength, and that the soldering pads fabricated by using Sumitomo CLP 495A Ag/Pd paste are more than 1kilo-gram in pull strength.(4) The temperature dependence of zero shift and span shift in the pressure transmitter are suppresed within ±0.2%between –40°C and 120°C by using the thick film circuit developed.

[学科分类] 工程和技术（综合）