Seiko Epson Corporation

Eiji Karaki

Masako Tanaka

Osamu Kawauchi

Hideaki Nakamura

Tatsuo Ikeda

Takuo Kuwahara

Yukihiro Unno

Guoqing Zhang

Hiroshi Arahari

Setsuhiro Hama

The invention provides a stabilized frequency characteristic over a wide temperature range. A quartz resonating piece is provided such that an electrical axis of quartz corresponds to an X axis, a mechanical axis of the quartz corresponds to a Y axis, and an optical axis of the quartz corresponds to a Z axis. The quartz resonating piece includes a quartz plate having a side that is parallel to an X'axis set by clockwise rotation of the X axis around the Z axis by an angle equal to or greater than &#x2212;5.0&#xb0; and less than &#x2212;1.0&#xb0; or by an angle greater than +1.0&#xb0; and equal to or less than 15.9&#xb0;, and another side that is parallel to a Z&#x2032; axis set by clockwise rotation of the Z axis around the X&#x2032; axis by an angle in a range from 34.6&#xb0; to 35.1&#xb0; inclusive; or a quartz plate having a side that is parallel to the X&#x2032; axis set by clockwise rotation of the X axis around the Z axis by an angle in a range from &#x2212;15.9&#xb0; to &#x2212;5.0&#xb0; inclusive, and another side that is parallel to the Z&#x2032; axis set by clockwise rotation of the Z axis around the X&#x2032; axis by an angle in a range from 34.2&#xb0; to 35.3&#xb0; inclusive.

Quartz resonating piece, quartz resonator, and quartz device

In a piezoelectric resonator container having a cylindrical case, one end of which is an open end, and a stem for sealing the open end of the case, an outer peripheral face of the stem and an inner peripheral face of the case have a nearly elliptical shape or an elliptical shape, respectively. A pressure allowance when pressing the stem into the open end of the case monotonically increases from a major axis portion of the case toward a minor axis portion. Therefore, since the pressure allowance is large at minor axis portions where vertical stress tends to decrease and the pressure allowance is small at major axis portions where tensile stress tends to increase, incomplete gas-tightness due to inadequate sealing or breaking of the case does not occur. This provides a piezoelectric resonator container in which incomplete gas-tightness is not caused, even if an elliptical or a nearly elliptical case is used, and a piezoelectric resonator piece does not come into contact with the inner periphery of the case.

Piezoelectric resonator container, piezoelectric resonator using the same, circuit board mounting piezoelectric resonator thereon, and method for manufacturing piezoelectric resonator

The case of a piezoelectric resonator in which a piezoelectric vibrator having a piezoelectric body and an electrode is flattened and a guard is provided protruding by the amount about the same as the thickness of the case on the hermetic terminal so that the open edge is received by insertion. Then the hermetic terminal in which one end of the piezoelectric vibrator is supported by the inner lead is inserted in the open edge of the case and the case is sealed by laser welding the welding area extending to the guard and to the open edge. By so doing, a thin piezoelectric resonator is provided which is desirable for surface mounting and being capable of maintaining the inside of the case in a stable vacuum state or sealed with nitrogen and the like for a long time. Moreover, by supporting the piezoelectric vibrator by the flattened inner lead inside the air tight case, a piezoelectric resonator is provided which has excellent frequency characteristics and long term aging characteristics.

Method and apparatus for sealing piezoelectric resonator via laser

The case of a piezoelectric resonator in which a piezoelectric oscillator piece having a piezoelectric body and an electrode is flattened and a guard is provided protruding by the amount about the same as the thickness of the case on the hermetic terminal so that the open edge is received by insertion. Then the hermetic terminal in which one end of the piezoelectric oscillator piece is supported by the inner lead is inserted in the open edge of the case and the case is sealed by laser welding the welding area extending to the guard and to the open edge. By so doing, a thin piezoelectric resonator is provided which is ideal for surface mounting and being capable of maintaining the inside of the case in a stable vacuum state or sealed with nitrogen and the like for a long time.

An AT-cut crystal oscillating reed formed by etching an AT-cut crystal wafer is provided. The wafer has a rotational parallel cut obtained by rotating a parallel cut by an angular degree of .theta..degree. relative to the X-axis of the wafer. The etching cross-section of the AT-cut crystal oscillating reed has a surface at an angle about 90.degree. from the front or back surface of the AT-cut crystal oscillating reed. This AT-cut crystal oscillating reed exhibits uniform characteristics and excellent reliability. Also provided is an AT-cut crystal oscillating reed with a low CI value. Finally, a method of etching an AT-cut crystal oscillating reed from an AT-cut crystal wafer is provided. A corrosion resisting film with gaps coats the wafer and is used in the etching process. In a preferred embodiment, the thickness of the wafer is designated t, the width of the gaps in the corrosion resisting films is designated l, and l.gtoreq.t/tan .theta.. The corrosion resisting film may be metal and may be formed into electrodes after the crystal oscillating reed is etched. In this manner, crystal oscillating reeds may be mass produced at a relatively low cost.

At-cut crystal oscillating reed and method of etching the same

An AT-cut crystal oscillating reed formed by etching an AT-cut crystal wafer is provided. The wafer has a rotational parallel cut obtained by rotating a parallel cut by an angular degree of .theta..degree. relative to the X-axis of the wafer. The etching cross-section of the AT-cut crystal oscillating reed has a surface at an angle about 90.degree. from the front or back surface of the AT-cut crystal oscillating reed. This AT-cut crystal oscillating reed exhibits uniform characteristics and excellent reliability. Also provided is an AT-cut crystal oscillating reed with a low CI value. Finally, a method of etching an AT-cut crystal oscillating reed from an AT-cut crystal wafer is provided. A corrosion resisting film with gaps coats the wafer and is used in the etching process. In a preferred embodiment, the thickness of the wafer is designated t, the width of the gaps in the corrosion resisting films is designated l, and l.ltoreq.t/tan .theta.. The corrosion resisting film may be metal and may be formed into electrodes after the crystal oscillating reed is etched. In this manner, crystal oscillating reeds may be mass produced at a relatively low cost.

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Ina, Japan

Eiji Karaki