ABSTRACT
In this study, we designed, prepared, and characterized Low Temperature Co-fired Ceramic (LTCC) toxic gas sensor devices with nanostructured SnO2 semiconducting thick films. In order to promote the reaction of carbon monoxide (CO) toxic gas molecules on the SnO2 thick films, a RuO2 planar heater was inserted into the LTCC substrate. Using an optimized RuO2 heater, the surface temperature of the LTCC substrate reached 360 °C within 25 seconds at an applied voltage of 5 V. The power consumption for the surface of the LTCC substrate to reach 300 °C was 778 mW. A nanostructured SnO2 thick film as a gas sensing layer was prepared by the ink dropping method on Pt electrodes patterned on the LTCC substrate. The gas sensor device was packaged in a commercial housing to measure the CO gas response. The fabricated gas sensor showed a gas response (Rair/Rgas) of 5.26 at a CO gas concentration of 500 ppm and a temperature of 300 °C. Additionally, a mild plasma post-treatment using Ar discharge gas improved the gas response up to 6.35 at the equivalent measurement conditions.
