Sensing Head for Ultrasonic Transducer made by Direct Bonding

抄録

A sensing head for a high frequency ultrasonic transducer was created by direct bonding between Al and Pb(Zr, Ti) O₃ (PZT). The forming of hydrogen bridges at the interface was used as the bonding method in this study. After the surface was treated hydrophilically by bombardment of positive ions formed by introducing water into an ion source, the hydrophilictreated surfaces were placed in contact with each other and heated at above 250°C in the air. It was determined that the bonded device had sufficient bonding strength. In respect to characteristics of acoustic wave propagation, the signal is not distorted by the multiple reflections in the direct bonding interface. The frequency of the ultrasonic transducer was 17MHz. Thus, the high frequency sonar has ahigh resolution. The present bonding method may be successful for assembling the ultrasonic transducer of a micromachine.