| 摘要 |
PROBLEM TO BE SOLVED: To realize high frequency precision while facilitating countermeasures to the miniaturization of a tuning fork type crystal oscillating bar, and to exclude worry such as electrode short-circuiting due to the re-attachment of weight materials to be removed by frequency adjustment after package sealing. SOLUTION: The outer shape of a tuning fork type crystal oscillating bar 2 is machined in a crystal wafer 1, and an electrode 5 and a weight 6 are formed on the surface by adhering weight materials for frequency adjustment to an oscillating arm 2a, the top end side of the weight part is irradiated with a laser beam, and the weight materials are trimmed so that the frequency can be roughly adjusted. The tuning fork type crystal oscillating bar isolated from the crystal wafer is air-tightly sealed in a package 10, the base edge side of the weight is irradiated with the laser beam 16 from the outer side through a transparent cover 12 of the package compared with the case of the rough adjustment of the frequency, and the weight materials of the oscillating arm are trimmed so that the frequency can be finely adjusted. The laser beam is emitted while being shifted by prescribed pitches, so that adjacent irradiation spots 7 and 17 can be partially overlapped with each other, and the spot diameter of the laser beam in the case of the fine adjustment of the frequency is made smaller than that in the case of the rough adjustment of the frequency.
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