At-cut crystal element, crystal resonator and crystal unit

Patent metadata

Field	Value
Publication number	US-2016294356-A1
Application number	US-201615086064-A
Country	US
Kind code	A1
Filing date	Mar 31, 2016
Priority date	Apr 2, 2015
Publication date	Oct 6, 2016
Grant date	—

Abstract

An AT-cut crystal element is provided. The AT-cut crystal element includes side surfaces intersecting with a Z′-axis of a crystallographic axis of a crystal. At least one side surface of the side surfaces is constituted of three surfaces of a first surface to a third surface. Besides, a crystal resonator including the AT-cut crystal element, and a crystal unit including the crystal resonator are provided.

First claim

What is claimed is:

1 . An AT-cut crystal element, comprising:
side surfaces intersecting with a Z′-axis of a crystallographic axis of a crystal, and at least one side surface of the side surfaces being constituted of three surfaces of a first surface, a second surface and a third surface.

2 . The AT-cut crystal element according to claim 1 , wherein
the first surface is a surface corresponding to a surface where an X-Z′ surface of the AT-cut crystal element is rotated around an X-axis of the crystal by 4°±3.5°, the X-Z′ surface is represented by the crystallographic axes of the crystal, and the X-Z′ surface is a principal surface.

3 . The AT-cut crystal element according to claim 1 , wherein
the first surface, the second surface, and the third surface intersect in this order, and the first surface is a surface corresponding to a surface where a principal surface is rotated around an X-axis of the crystal by 4°±3.5°, wherein the principal surface is an X-Z′ surface of the AT-cut crystal element and the X-Z′ surface is represented by the crystallographic axes of the crystal, the second surface is a surface corresponding to a surface where the principal surface is rotated around the X-axis of the crystal by −57°±5°, and the third surface is a surface corresponding to a surface where the principal surface is rotated around the X-axis of the crystal by −42°±5°.

4 . The AT-cut crystal element according to claim 1 , wherein
the first surface, the second surface, and the third surface intersect in this order, and the first surface is a surface corresponding to a surface where a principal surface is rotated around the X-axis of the crystal by 4°±3°, wherein the principal surface is an X-Z′ surface of the AT-cut crystal element and the X-Z′ surface is represented by the crystallographic axes of the crystal, the second surface is a surface corresponding to a surface where the principal surface is rotated around the X-axis of the crystal by −57°±3°, and the third surface is a surface corresponding to a surface where the principal surface is rotated around the X-axis of the crystal by −42°±3°.

5 . The AT-cut crystal element according to claim 1 , wherein
the AT-cut crystal element has a planar shape in a rectangular shape, and one side of the planar shape is disposed along the Z′-axis.

6 . The AT-cut crystal element according to claim 1 , wherein
each side surface of both of the side surfaces is constituted of the three surfaces of the first surface, the second surface and the third surface.

7 . The AT-cut crystal element according to claim 1 , wherein
both the side surfaces are disposed in a point symmetry one another with a center point of the AT-cut crystal element as a center.

8 . A crystal resonator, comprising:
the AT-cut crystal element according to claim 1 ; excitation electrodes disposed on front and back of the AT-cut crystal element; and extraction electrodes extracted from the excitation electrodes.

9 . A crystal unit, comprising:
the crystal resonator according to claim 8 ; and a container housing the crystal resonator.

Assignees

• Nihon Dempa Kogyo Co

Inventors

• Kuwahara Takayuki
• Shimao Kenji
• Iwata Hirokazu

Classifications

• H03H3/02

  for the manufacture of piezoelectric or electrostrictive resonators or networks (H03H3/08 takes precedence) · CPC title

• H03H9/19 Primary

  consisting of quartz · CPC title

• H03H9/02133

  of stress · CPC title

• H03H9/02023

  consisting of quartz · CPC title

• H03H2003/022

  the resonators or networks being of the cantilever type · CPC title