高精度オシレータ・モジュールの構成 High Accuracy Oscillator Module
This paper describes the design and development of a miniature 4.2 MHz AT-cut plano-convex quartz-crystal oscillator module for use in the high accuracy clock or other various timing devices. The oscillator module is sealed into TO - 5 metal cold welded hermetic package which has proven to provide high reliability and manufacturing simplicity. we mainly discuss the following items: (1) AT-cut quartz resonator can be miniaturized by introducing the novel annular elec trodes for forming depolarization field. The depolarization field induced by the positive and negative charges appearing on the opposite surfaces modifies the strain in its turn. (2) The suppression of the unwanted modes is performed by the novel annular electrodes.The normal field excitation using the conventional annular electrodes resides in the stronger excitation of the unwanted modes as the plating extends to the edge. (3) The frequency adjustment of±0.1 PPM is achieved by introducing the newly developed. "functional trimming ceramic condenser" for abrasive trimming. A sries of experiments indicate that this oscillator module can realize high reliability e. g., an aging rate of of±0.1 PPM or less/year, as well as manufacturing simplicity.
日本時計学会誌 (101), 1-24, 1982-06-25