| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a tuning fork piezoelectric vibration chip with a grooved vibration arm structure for eliminating or suppressing a loss of distortion energy due to displacement in the thickness direction caused by bending vibration of vibration arms and leaked vibration in addition to higher performance by suppression of a CI (crystal impedance) value. <P>SOLUTION: In the chip 14, wet etching is applied to a crystal wafer wherein the length, width, thickness directions of the vibration arms 16a, 16b are oriented to the Y, X, and Z axes of the crystal crystalline axis and length direction grooves 18a, 18b are located on the arm main surfaces in a way that the center line C1 of the grooves is shifted in a -X direction with respect to each center line C2 of the arms so as to balance left right stiffness in the width direction of the arms and stabilize the bending motion of the arms. Positional deviations of upper lower main surfaces 17a, 17b of the arms in the width direction caused by a positional deviation or the like of a photo mask in the process of the chip 14 are adjusted by shifting the relative positions of the grooves 18a, 18b in the width direction in a manner of matching gravity centers M1, M2 of upper and lower parts resulting from bisecting the cross section of the vibration arms in the thickness direction with a part on the same straight line L vertical to the main surfaces. It causes elimination or suppression of the displacement of the arms in the thickness direction at excitation resulting in preventing a loss of the distortion energy due to vibration leakage. <P>COPYRIGHT: (C)2004,JPO |
