Tuning fork type piezoelectic oscillatory sheet, its mfg. method and piezoelectric device

Abstract

The tuning fork type crystal vibrating piece (14) is constituted like this, by wet etching the Y axis of its crystal axis, the X axis and the Z axis correspond to the length direction, the width direction and the thickness direction of the vibrating arms (16a), (16b) For the oriented crystal substrate, grooves (18a) and (18b) in the longitudinal direction are arranged on the main plane of the vibrating arm. , the left and right stiffnesses in the width direction of the vibrating arm are balanced, and the bending motion of the vibrating arm is stabilized. In the manufacturing process of the tuning fork type piezoelectric vibrating plate, the dislocation of the position in the width direction of the upper and lower main planes (17a) and (17b) of the vibrating arm caused by the misalignment of the photomask, on the cross section in the width direction of the vibrating arm, in the thickness direction The centers of gravity M1 and M2 of the upper and lower parts divided into two equal parts are adjusted on the same straight line perpendicular to the main plane. By adjusting the relative positions of the grooves (18a) and (18b) in the width direction, vibration due to vibration Displacement in the thickness direction of the arm is eliminated and suppressed, and distortion energy loss due to vibration leakage is prevented. High stability is achieved by suppressing the CI value to improve its performance.

Description

technical field [0001] The present invention relates to piezoelectric devices such as piezoelectric vibrators and piezoelectric oscillators used in various electronic devices, piezoelectric vibrating gyroscopes used in angular velocity sensors, and more specifically, to tuning fork-type piezoelectric devices used in this regard. Oscillating plate and its manufacturing method. Background technique [0002] For a long time, in ordinary clocks and household appliances, various information, communication instruments and OA instruments and other civil and industrial electronic instruments, piezoelectric vibrators, piezoelectric oscillators and Piezoelectric devices such as oscillators and real-time clock modules in which IC chips are packaged in the same package. In addition, piezoelectric vibrating gyroscopes are widely used as rotation angular velocity sensors for attitude control and navigation control of ships, aircraft, and automobiles, and for preventing and detecting hand...

AI Technical Summary

Problems solved by technology

As a result, there is a risk of unstable vibration characteristics due to distortion energy loss due to vibration leakage

In addition, if this distortion energy loss increases, there is a problem that the natural frequency of the piezoelectric vibrating piece, that is, the number of resonant frequencies decreases, and the fluctuation value of the natural frequency increases.

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