To assure high airtightness and high bonding strength and to attain high frequency precision in a piezoelectric vibrator in which upper and lower piezoelectric substrates are bonded on both surfaces of a piezoelectric substrate formed by integrating a piezoelectric vibration chip and an outer frame.
A crystal oscillator 1 has an intermediate crystal plate 2 to which an AT cut crystal oscillation chip 5 and the outer frame 6 are integrally coupled, upper and lower crystal substrates 3, 4. Conductive films 10, 13 are formed on a lower surface of the outer frame of the intermediate crystal plate, metal thin films 16, 18 are formed on an upper surface of the lower crystal substrate and airtightly joined together by diffused junction after being mutually sanctified and activated by plasm processing. Frequency adjustment of the crystal oscillation chip is performed before joining the intermediate crystal plate and the upper crystal substrate after joining the intermediate crystal plate and the lower crystal substrate. The upper surface of the outer frame of the intermediate crystal plate and the lower surface of the upper crystal substrate consist of crystal element surfaces and airtightly joined by surface activated bonding using the plasma processing.
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| JP3120214 | CRYSTAL OSCILLATOR WITH FREQUENCY-ADJUSTING FUNCTION |
| JP5451266 | Electronic device |
Akihiko Umeda
Fujitsuna Hideyoshi
Osamu Suzawa