PIEZOELECTRIC RESONATOR, ETCHING AMOUNT DETECTING DEVICE, AND OSCILLATOR

摘要

A piezoelectric resonator includes a plate-shaped crystal element, excitation electrodes, and an unwanted response suppression portion. The excitation electrodes are disposed on both surfaces of the crystal element. The unwanted response suppression portion is formed by inverting a crystallographic axis of the crystal element to suppress an unwanted response that oscillates at a different frequency from a frequency of a main vibration of the crystal element.