US-12620956-B2 - Method for manufacturing resonator element and resonator element assembly

Abstract

A method for manufacturing a resonator element includes: a substrate preparation step of preparing a substrate; an etching step of performing an etching process on the substrate to form a resonator element, a frame portion, and a holding portion that couples the resonator element and the frame portion; and a break-off step of breaking off the resonator element from the frame portion. The holding portion includes a narrow portion in which a part of a width is narrow. The width of the narrow portion is minimum at a position closer to a resonator element side than at a center of the holding portion. In a cross-sectional view, an angle formed by a side surface of the narrow portion with respect to a flat surface of the holding portion is in a range of 85° or more and 95° or less. The etching process is dry etching.

Inventors

• Atsushi Matsuo
• Kensaku ISOHATA
• Masaya Kanno

Assignees

• SEIKO EPSON CORPORATION

Dates

Publication Date

20260505

Application Date

20221215

Priority Date

20211217

Claims (14)

1. 1 . A method for manufacturing a resonator element comprising: a substrate preparation step of preparing a substrate; an etching step of performing an etching process on the substrate to form a resonator element, a frame portion, and a holding portion that couples the resonator element and the frame portion; and a break-off step of breaking off the resonator element from the frame portion, wherein the holding portion includes a narrow portion in which a part of a width is narrow, the width of the narrow portion is minimum at a position closer to a resonator element side than at a center of the holding portion, in a cross-sectional view, an angle formed by a side surface of the narrow portion with respect to a flat surface of the holding portion is in a range of 85° or more and 95° or less, and the etching process is dry etching.
2. 2 . The method for manufacturing the resonator element according to claim 1 , wherein the substrate is formed of an SC cut quartz crystal substrate.
3. 3 . The method for manufacturing the resonator element according to claim 1 , wherein the substrate is formed of an AT cut quartz crystal substrate.
4. 4 . The method for manufacturing the resonator element according to claim 1 , wherein the position at which the width of the narrow portion is minimum is an end portion of the resonator element.
5. 5 . The method for manufacturing the resonator element according to claim 1 , wherein an outer shape of the holding portion has a concave curve line in a plan view, and the width of the narrow portion gradually decreases from the frame portion toward the resonator element.
6. 6 . The method for manufacturing the resonator element according to claim 1 , wherein an outer shape of the holding portion has a convex curve line in a plan view, and the width of the narrow portion gradually decreases from the frame portion toward the resonator element.
7. 7 . The method for manufacturing the resonator element according to claim 1 , wherein an outer shape of the holding portion has a linear portion between the resonator element and a position having a minimum width in a plan view.
8. 8 . The method for manufacturing the resonator element according to claim 1 , wherein an outer shape of the holding portion has a linear portion between the frame portion and a position having a minimum width in a plan view.
9. 9 . The method for manufacturing the resonator element according to claim 1 , wherein the resonator element and the frame portion are coupled to each other by one or more coupling portions including the holding portion.
10. 10 . A resonator element assembly comprising: a resonator element; a frame portion; and a holding portion that couples the resonator element and the frame portion, wherein the holding portion includes a narrow portion in which a part of a width is narrow, the width of the narrow portion is minimum at a position closer to a resonator element side than at a center of the holding portion, and in a cross-sectional view, an angle formed by a side surface of the narrow portion with respect to a flat surface of the holding portion is in a range of 85° or more and 95° or less.
11. 11 . The resonator element assembly according to claim 10 , wherein the resonator element, the frame portion, and the holding portion are formed by dry etching.
12. 12 . The resonator element assembly according to claim 10 , wherein the resonator element, the frame portion, and the holding portion are formed of an SC cut quartz crystal substrate.
13. 13 . The resonator element assembly according to claim 10 , wherein the resonator element, the frame portion, and the holding portion are formed of an AT cut quartz crystal substrate.
14. 14 . The resonator element assembly according to claim 10 , wherein the position at which the width of the holding portion is minimum is an end portion of the resonator element.

Description

The present application is based on, and claims priority from JP Application Serial Number 2021-204880, filed Dec. 17, 2021, the disclosure of which is hereby incorporated by reference herein in its entirety. BACKGROUND 1. Technical Field The present disclosure relates to a method for manufacturing a resonator element and a resonator element assembly. 2. Related Art As a method for manufacturing a piezoelectric resonator element used in a piezoelectric device, for example, JP-A-2007-142995 discloses a method for manufacturing a piezoelectric resonator element by wet etching a quartz crystal wafer by a photolithography method to form an element piece assembly and then breaking off element pieces to be individual resonator elements from a quartz crystal frame. However, in the element piece broken off from the quartz crystal frame disclosed in JP-A-2007-142995, a progress rate of etching by a crystal axis orientation is different due to etching anisotropy of the quartz crystal accompanying the wet etching. Therefore, a crack which is a portion that becomes an inclined surface in a cross-sectional view is generated on one side of a support portion, and no crack is generated on the other side. In this case, stress is concentrated on both ends of the crack at the time of breaking off on the side where the crack can be generated. Therefore, it is not possible to control on which side of the crack the breaking off is performed, and a shape of the support portion after the breaking off may vary. SUMMARY A method for manufacturing a resonator element includes: a substrate preparation step of preparing a substrate; an etching step of performing an etching process on the substrate to form a resonator element, a frame portion, and a holding portion that couples the resonator element and the frame portion; and a break-off step of breaking off the resonator element from the frame portion. The holding portion includes a narrow portion in which a part of a width is narrow. The width of the narrow portion is minimum at a position closer to a resonator element side than at a center of the holding portion. In a cross-sectional view, an angle formed by a side surface of the narrow portion with respect to a flat surface of the holding portion is in a range of 85° or more and 95° or less. The etching process is dry etching. A resonator element assembly includes: a resonator element; a frame portion; and a holding portion that couples the resonator element and the frame portion. The holding portion includes a narrow portion in which a part of a width is narrow. The width of the narrow portion is minimum at a position closer to a resonator element side than at a center of the holding portion. In a cross-sectional view, an angle formed by a side surface of the narrow portion with respect to a flat surface of the holding portion is in a range of 85° or more and 95° or less. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view showing a schematic configuration of a resonator element assembly according to a first embodiment. FIG. 2 is an enlarged view of a portion A in FIG. 1. FIG. 3 is a cross-sectional view taken along a line B-B in FIG. 2. FIG. 4 is a flowchart showing a method for manufacturing a resonator element. FIG. 5 is a plan view showing a schematic configuration of a resonator element assembly according to a second embodiment. FIG. 6 is a plan view showing a schematic configuration of a resonator element assembly according to a third embodiment. FIG. 7 is a plan view showing a schematic configuration of a resonator element assembly according to a fourth embodiment. FIG. 8 is a plan view showing a schematic configuration of a resonator element assembly according to a fifth embodiment. FIG. 9 is a plan view showing a schematic configuration of a resonator element assembly according to a sixth embodiment. FIG. 10 is a plan view showing a schematic configuration of a resonator element assembly according to a seventh embodiment. DESCRIPTION OF EXEMPLARY EMBODIMENTS 1. First Embodiment 1.1. Resonator Element Assembly First, a resonator element assembly 1 according to a first embodiment will be described with reference to FIGS. 1, 2, and 3. For convenience of description, in the following drawings except for FIG. 4, an X axis, a Y axis, and a Z axis are shown as three axes orthogonal to one another. A direction along the X axis is referred to as an “X direction”. A direction along the Y axis is referred to as a “Y direction”. A direction along the Z axis is referred to as a “Z direction”. An arrow side of each axis is also referred to as a “plus side”. A side opposite to the arrow side is referred to as a “minus side”. The resonator element assembly 1 according to the present embodiment is capable of thickness-shear resonation, and includes various piezoelectric substrates such as quartz crystal. Typically, the crystal substrate is an AT cut quartz crystal substrate or an SC cut quartz crystal substrate. In the present embodime