Piezoelektrischer Vibrator, der auf eine zuverlässige Weise einen dielektrischen Durchbruch verhindert und Verfahren zu seiner Herstellung

摘要

On a first piezoelectric sheet (28) of a piezoelectric vibrator, a second piezoelectric sheet (29) is stacked with interposition, between the sheets, of first-set electrodes (24(1), 24(2)) formed on an upper surface of the first piezoelectric sheet. Second-set electrodes (25(1), 25(2)) are formed on an upper surface of the second piezoelectric sheet with each placed halfway between two adjacent ones of the first-set electrodes. The second piezoelectric sheet is poled in directions from each second-set electrode to the two adjacent ones of the first-set electrodes. Preferably, third-set electrodes (30(1), 30(2)) are formed on a lower surface of the first piezoelectric sheet with each arranged halfway between two adjacent ones of the first-set electrodes. In this event, the first piezoelectric sheet is poled in directions from each third-set electrodes to two adjacent ones of the first-set electrodes. Each first-set electrode has a first end along a side surface of the first piezoelectric sheet with each second-set and each third-set electrode possessed of a second and a third end along opposite side surfaces of the first and the second piezoelectric sheets. First and second common outside electrodes are formed on such side surfaces in contact with the first end of each first-set electrode either directly or through a first common electrode and in contact with the second and the third ends of the second-set and the third-set electrodes either directly or through second and third common electrodes.