# US 7,608,987 B2 · AT cut quartz crystal resonator element and method for manufacturing the same

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- Number: US 7,608,987 B2
- Document ID: US7608987B2
- Status: Granted
- Kind: B2
- Application number: 11/882,019
- Filed: 2007-07-30
- Published: 2008-02-14
- Granted: 2009-10-27
- Earliest claimed: 2006-08-09
- Assignees: Epson Toyocom Corporation
- Inventors: Matsutaro Naito; Yoshiyuki Aoshima; Kenji Komine
- Web page: https://patentgrep.com/patent/US7608987B2

## CPC

- H03H 9/177: {of the energy-trap type}
- H03H 3/04: for obtaining desired frequency or temperature coefficient
- H03H 9/02007: {of bulk acoustic wave devices}
- H03H 9/02102: {of temperature influence (cutting angles H03H9/02015)}
- H03H 9/0595: {the holder support and resonator being formed in one body}
- H03H 9/19: consisting of quartz
- Y10T 29/42: Piezoelectric device making
- H03H: IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS (waveguides, resonators, lines or other devices of the waveguide type H01P)
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

An AT cut quartz crystal resonator element includes a quartz crystal element piece having an exciting part formed from an AT cut quartz crystal plate in a rectangular shape having an X-axis direction of a quartz crystal set to a long side, and an exciting electrode formed on each of front and back main surfaces of the exciting part, in which each side surface in the longitudinal direction of the exciting part is composed of two faces, an m-face of a quartz crystal and a crystal face other than the m-face.

## Claims

### Claim 1

An AT cut quartz crystal resonator element comprising:
a quartz crystal element piece having an exciting part formed from an AT cut quartz crystal plate in a rectangular shape, the rectangular shape having four sides, each side including a side surface, having an X-axis direction of a quartz crystal set to a long side of the four sides having two ends; and
an exciting electrode formed on each of front and back main surfaces of the exciting part, wherein:
each side surface at the two ends of the long side of the exciting part is composed of two faces, an m-face of a quartz crystal and a crystal face other than the m-face.

### Claim 2 (depends on 1)

The AT cut quartz crystal resonator element according to claim 1, wherein: the crystal face other than the m-face is tilted at an angle of 3 degrees ±30 minutes with respect to a normal direction of the main surface of the exciting part.

### Claim 3 (depends on 1)

The AT cut quartz crystal resonator element according to claim 1, wherein: the quartz crystal element piece includes a thick center portion and a thin surrounding portion both composing the exciting electrode; and each side surface in a longitudinal direction of a step between the thick center portion and the thin surrounding portion is composed of the in-face of the quartz crystal or the crystal face other than the m-face.

### Claim 4 (depends on 3)

The AT cut quartz crystal resonator element according to claim 3, wherein: a difference in a thickness between the thick center portion and the thin surrounding portion is set to smaller than or equal to 10% of a thickness of the thick center portion.