Piezoelectric vibrating piece and piezoelectric vibrator

Abstract

A piezoelectric resonator element includes a piezoelectric substrate formed of an AT-cut quartz crystal substrate in which the thickness direction thereof is a direction parallel to the Y' axis; and excitation electrodes disposed so as to face vibrating regions on both front and rear principal surfaces of the piezoelectric substrate. The piezoelectric substrate includes a rectangular excitation portion in which sides parallel to the X axis are long sides thereof, and sides parallel to the Z' axis are short sides thereof; and a peripheral portion having a smaller thickness than the excitation portion and formed around the excitation portion. Each of side surfaces of the excitation portion extending in a direction parallel to the X axis is present in one plane, and each of side surfaces of the excitation portion extending in a direction parallel to the Z' axis has a step.

Description

technical field [0001] The invention relates to a piezoelectric vibrating piece and a piezoelectric vibrator. Background technique [0002] AT-cut piezoelectric vibrating reeds use the thickness-shear vibration mode with excellent temperature characteristics as the main resonance. This AT-cut piezoelectric vibrating piece is processed by machining or photolithography. [0003] Patent Document 1 discloses a piezoelectric vibrator that exhibits the same energy confinement effect as the slope structure and the convex structure, and implements so-called mesa-type thickness-shear vibration. [0004] In recent years, the trend toward miniaturization of the size of the vibrating element has increased, and the necessity of vibrators with a relatively small side-to-side ratio has increased. In general, a vibrator with a relatively small side length ratio is easily affected by a mode (contour vibration) caused by the profile of the vibrator, and the thickness shear mode is suppresse...

AI Technical Summary

Problems solved by technology

[0017] But obviously, in the thickness-shear piezoelectric vibrating piece of the multi-stage mesa structure in which the extending direction of the long side is parallel to the X-axis, especially in the piezoelectric vibrating piece with a relatively small X-side length ratio, there will be thickness shearing. When the CI (Crystal Impedance: Crystal Impedance) value is increased due to the combination of unnecessary modes such as vibration and contour vibration

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