ULTRASONIC THICKNESS SENSOR AND METHOD OF MANUFACTURING THE SAME

PROBLEM TO BE SOLVED: To provide: an ultrasonic thickness sensor which is slim and flexible, and is capable of following even a curved target face to be measured; and a method of manufacturing the ultrasonic thickness sensor.SOLUTION: An ultrasonic thickness sensor comprises: a substrate made of a zirconia-based ceramic, e.g. yttria partially stabilized zirconia and having an average thickness of 30-100 μm; a metallization layer formed as a first electrode on a surface of the substrate, made of a high-temperature oxidation resistant metal with good conductivity, and having an average thickness of 5-20 μm; a sintered compact layer formed on the metallization layer, made of an oxide-based piezoelectric material, and having a density of 70-80% and an average thickness of 30-150 μm; and a second electrode formed on the sintered compact layer, and having an average thickness of 10-100 μm. A method of manufacturing the ultrasonic thickness sensor comprises the steps of: metallizing the surface of the substrate (i.e. forming the first electrode); and coating the resultant substrate with a viscous liquid material including the oxide-based piezoelectric material; sintering the substrate; forming the second electrode; and performing polarization treatment.