| 摘要 |
PURPOSE:To acquire an echo waveform that has the satisfactory damping performance by setting the thickness of the electrodes provided on the ultrasonic wave transmitting/receiving surface and its opposite surface of a piezoelectric substance at a specific radio or less against the wavelength of the working ultrasonic wave. CONSTITUTION:A piezoelectric substance 1 is an array of sets of piezoelectric pieces consisting of the solid solution single crystal including zinc niobate and titanate of 91:9. Then the substance 1 oscillates in an arrow direction A. A 1st electrode 3 and a 2nd electrode 4 are formed in a sputtering process of Ti/Au on the ultrasonic wave transmitting/receiving surface and its opposite surface of each piezoelectric piece respectively. An acoustic matching layer 5 is formed on each electrode 3, and an acoustic lens 6 is formed on the ultrasonic wave transmitting/receiving surface of a whole array of piezoelectric pieces including the layer 5. Then the thickness of both electrodes 3 and 4 are set at 1% or less against the waveform of the working ultrasonic wave. Thus the satisfactory acoustic matching is secured. |
