Quartz crystal unit and its manufacturing method
AssigneePiedek Technical Laboratory
InventorHirofumi Kawashima
Life of this patent
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Abstract
A quartz crystal unit has a quartz crystal tuning fork resonator capable of vibrating in a flexural mode, a case for housing the quartz crystal tuning fork resonator, and a lid for covering an open end of the case. The quartz crystal tuning fork resonator has a tuning fork base, a pair of tuning fork tines connected to the tuning fork base, a series of grooves each formed on opposite main surfaces of each of the tuning fork tines, and a series of electrodes each disposed in a respective one of the grooves. When W and W2 represent a width of each tuning fork tine and a width of at least one of the grooves formed in the tuning fork tines, respectively, W2 is within a range of 0.03 mm to 0.12 mm, and a ratio (W2/W) is greater than 0.35 and less than 1.
Claims24
A quartz crystal unit comprising:
- a quartz crystal tuning fork resonator capable of vibrating in a flexural mode, the quartz crystal tuning fork resonator having a tuning fork base, a plurality of tuning fork tines connected to the tuning fork base, a groove having a stepped portion formed in at least one of opposite main surfaces of each of the tuning fork tines, a plurality of first electrodes each disposed on the stepped portion of the groove of a respective one of the tuning fork tines, and a plurality of second electrodes each disposed on at least one side surface of a respective one of the tuning fork tines, the second electrodes having an electrical polarity opposite to an electrical polarity of the first electrodes;
- a case for housing the quartz crystal tuning fork resonator;
- and a lid for covering an open end of the case;
- wherein a width W2 of the groove in each of the tuning fork tines is within a range of 0.03 mm to 0.12 mm, and a ratio (W2/W) is greater than 0.35 and less than 1, where W represents a width of each of the tuning fork tines.
A quartz crystal unit comprising:
- a quartz crystal tuning fork resonator capable of vibrating in a flexural mode, the quartz crystal tuning fork resonator having a tuning fork base, a pair of tuning fork tines connected to the tuning fork base, a plurality of grooves each formed on opposite main surfaces of each of the tuning fork tines, and a plurality of electrodes each disposed in a respective one of the grooves;
- a case for housing the quartz crystal tuning fork resonator;
- and a lid for covering an open end of the case;
- wherein a distance W4 between the tuning fork tines is within a range of 0.05 to 0.35 mm and is greater than or equal to a width W2 of at least one of the grooves formed in each of the fork tines.
A quartz crystal oscillator comprising:
- a quartz crystal unit having a quartz crystal tuning fork resonator capable of vibrating in a flexural mode and a CMOS inverter and a plurality of capacitors and resistors connected to the quartz crystal tuning fork resonator, the quartz crystal tuning fork resonator having a tuning fork base, a plurality of tuning fork tines connected to the tuning fork base, a plurality of grooves each formed on opposite main surfaces of each of the tuning fork tines, and a plurality of electrodes each disposed in a respective one of the grooves;
- wherein a width W2 of at least one of the grooves formed in each of the tuning fork tines is within a range of 0.03 mm to 0.12 mm, and a ratio (W2/w) is greater than 0.35 and less than 1, where W represents a width of each of the tuning forks.
Dependencies are inferred from the claim text.