| 摘要 |
PROBLEM TO BE SOLVED: To provide an air gap system piezoelectric device ensuring energy confinement effect more suitably.SOLUTION: A crystal oscillator 1 includes a piezoelectric substrate 17 having a vibration part 11, a lid substrate 21 having an opposite surface 21b facing one principal surface of the vibration part 11 via a gap, a base substrate 13 having an opposite surface 13b facing the other principal surface of the vibration part 11 via a gap, a laminar excitation electrode 25B provided on the opposite surface 21b, and a laminar excitation electrode 25A provided on the opposite surface 13b. In the opposite surfaces 13b and 21b, the distance of the regions facing the central portion of the vibration part 11 is shorter than the distance of the regions facing the outer peripheral portion of the vibration part 11.SELECTED DRAWING: Figure 3 |
