| 摘要 |
PURPOSE:To assemble sensor members easily and to eliminate the contact between the sensor members and an IDT electrode. CONSTITUTION:A piezoelectric substrate 1 is made of a material for propagating leakage surface acoustic wave, and IDT electrode 2 for exciting the surface acoustic wave and an IDT electrode 3 for converting the leakage surface acoustic wave propagated on the substrate 1 are formed on the surface, a recessed part 1A is formed at the center of the inverse side of the substrate 1, and a sensor member 4 is applied to the recessed part 1A, thus constituting a sensor which changes the sound velocity of the leakage surface acoustic wave propagated on the substrate 1 depending on the sensing state of the sensor member 4. The sensor member 4 and the IDT electrode 2 are positioned on mutually separated surfaces for eliminating contact, thus preventing the damage and at the same time facilitating the manufacture. By providing the recessed part 1A, the sensor member 4 is positioned at a shallow location from the substrate surface, thus improving the sensor sensitivity for the leakage surface acoustic wave. |
