A New Nondestructive Evaluation Method for Surface Acoustic Wave Velocity

A new nondestructive evaluation method for surface acoustic wave (SAW) velocity on a piezoelectric wafer was proposed. Split electrodes were formed on a glass wafer and a nonconductive liquid was interposed between the piezoelectric wafer and the glass wafer. The mode of the SAW excited on the piezoelectric wafer surface was leaky (LSAW) and its velocity was evaluated using the electrical reflection characteristics of the split electrodes. The usefulness of the new method was experimentally proven by showing the high reproducibility of the measured velocity and the agreement between the measured and calculated values indicating the SAW characteristics on a rotated-Y langasite wafer.