Method of forming a quartz oscillator temperature sensor
AssigneeSeiko Epson Corporation
InventorsMichiaki Takagi, Mitsuru Nagai
Life of this patent
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Abstract
A quartz oscillator temperature sensor which measures temperature based on the change in resonance or oscillation frequency of a quartz oscillator with the change in temperature of the oscillator can be constructed by cutting a piece of quartz from a wafer with a thickness of about 80 to 150 .mu.m by rotating the plane of the crystal defined by the electrical and mechanical axes 15 to 25.degree. about the electrical axis and then forming the wafer into a quartz tuning fork. The tuning fork is housed in a case sealed with a stem and coupled to electrical leads with heat resistent solder formed with more than about 90 wt % Pb and less than 10% Sn. The area within the case should be at a substantially high vacuum.
Claims7
A method of forming a quartz oscillator temperature sensor, comprising:
- providing an .alpha.-quartz single crystal having an electrical axis (+X) perpendicular to a mechanical axis (+Y) and defining an XY plane and an optical axis (+Z) perpendicular to the XY plane;
- cutting a substantially flat wafer having a thickness between about 80 and 150 .mu.m from the quartz crystal, the wafer cut in the plane obtained by rotating the XY plane about the (+X) axis in a clockwise (-Z) direction by an angle of about 15 to 25.degree. to yield a plane defined by the +Y axis and a Y' axis defined as the (+Y) axis after rotation of the plane of the wafer about the (+X) axis;
- forming a tuning fork shaped piece of quartz having a base and a pair of parallel arms extending from the base from the wafer, in which the arms are parallel with a Y' axis;
- disposing excitation electrodes on the tuning fork;
- and
- enclosing the tuning fork within a housing.
Dependencies are inferred from the claim text.