| 摘要 |
<P>PROBLEM TO BE SOLVED: To resolve such a problem that etching a thin Z plate crystal with a mask having a conventional shape results in leaking the oscillation energy of a tuning fork type oscillating piece to a tuning fork support part of a crystal oscillating piece at a high rate since the crystal oscillating piece having left shoulders of tuning fork arm parts notched at an angle of about 30° is formed by this etching and is asymmetrical to the center line. <P>SOLUTION: Right shoulder parts in front ends of tuning fork arm parts 12a and 12b of an etching mask 10 are notched at an angle θ2 (preferably θ2=θ1≈30° and 25°<2θ<35°), and a crystal oscillating piece 11 which has left and right shoulders in front ends of tuning fork arm parts 12a and 12b cut at angles θ12 and θ2 (θ1=θ2) is formed by etching with this mask 10 and has a shape symmetrical to the center line, so that oscillation is kept balanced to reduce the leakage rate of the oscillation energy to a tuning fork support part 12. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
