US-12620965-B2 - Resonance device

US12620965B2US 12620965 B2US12620965 B2US 12620965B2US-12620965-B2

Abstract

A resonance device is provided that includes a lower lid that has a recessed portion, and a resonator that is mounted on the lower lid and has a vibration arm that performs out-of-plane bending vibration in a space including the recessed portion and a frame provided around the vibration arm and having a facing portion facing a tip of the vibration arm. The facing portion of the frame is located in an outer-side portion of the resonator with respect to a straight line connecting an intersection point of a perpendicular extending from the tip of the vibration arm toward the recessed portion of the lower lid and the recessed portion of the lower lid, to a cavity edge of the recessed portion facing the tip of the vibration arm.

Inventors

Masakazu FUKUMITSU
Takehiko Kishi

Assignees

MURATA MANUFACTURING CO., LTD.

Dates

Publication Date: 20260505
Application Date: 20220907
Priority Date: 20200424

Claims (20)

1 . A resonance device comprising: a first lid that has a first recessed portion; a resonator mounted on the first lid and having at least one vibration arm configured to vibrate in a space including the first recessed portion; a second lid that has a second recessed portion that faces the first recessed portion of the first lid; and a frame that is disposed between the first lid and the second lid and is further disposed around the at least one vibration arm and that has a facing portion that faces a tip of the at least one vibration arm, wherein a cavity edge of the first recessed portion faces the tip of the at least one vibration arm in a horizontal direction in which the at least one vibration arm extends, wherein a perpendicular that extends from the tip of the at least one vibration arm towards the first recessed portion intersects an inner surface of the first lid at an intersection point, and wherein the second lid has a smaller thickness in the horizontal direction than a thickness of the first lid in the horizontal direction, such that the facing portion of the frame is located in an outer-side of a straight line that connects the intersection point and the cavity edge and extends to a side surface of the second lid.
2 . The resonance device according to claim 1 , wherein the at least one vibration arm is configured to vibrate by performing an out-of-plane bending vibration in the space.
3 . The resonance device according to claim 1 , wherein the second recessed portion of the second lid is disposed in a direction in which the second recessed portion faces the first recessed portion of the first lid, such that the resonator is disposed between the second lid and the first lid.
4 . The resonance device according to claim 3 , wherein the at least one vibration arm is configured to perform an out-of-plane bending vibration in a space that includes the second recessed portion of the second lid and the first recessed portion of the first lid.
5 . The resonance device according to claim 3 , wherein a cavity edge of the second recessed portion facing the tip of the at least one vibration arm is located in an outer-side portion of the resonator with respect to the cavity edge of the first recessed portion facing the tip of the at least one vibration arm.
6 . The resonance device according to claim 3 , wherein a cavity edge of the second recessed portion facing the tip of the at least one vibration arm is located in the outer-side portion of the resonator with respect to the straight line.
7 . The resonance device according to claim 1 , wherein the perpendicular extends in a thickness direction of the resonance device and the cavity edge of the first recessed portion faces the tip of the at least one vibration arm in the horizontal direction that is orthogonal to the thickness direction.
8 . The resonance device according to claim 3 , wherein 0.1≤X/Y≤2.0 is satisfied, and wherein X represents a horizontal distance between the intersection point of the perpendicular extending from the tip of the at least one vibration arm toward the first recessed portion of the first lid and the first recessed portion of the first lid, and the cavity edge of the first recessed portion facing the tip of the vibration arm, and Y represents a difference in height between the intersection point of the perpendicular extending from the tip of the at least one vibration arm towards the first recessed portion of the first lid and the first recessed portion of the first lid, and the cavity edge of the first recessed portion facing the tip of the at least one vibration arm.
9 . The resonance device according to claim 8 , wherein 0.3≤X/Y≤0.7 is satisfied.
10 . A resonance device comprising: a lower lid that has a first recessed portion; an upper lid that has a second recessed portion and is disposed such that the second recessed portion faces the first recessed portion of the lower lid; and a resonator disposed between the upper lid and the lower lid and that has at least one vibration arm configured to vibrate in a space defined by the first and second recessed portions, and a frame disposed around the at least one vibration arm and having a facing portion that faces a tip of the at least one vibration arm, wherein a first cavity edge of the first recessed portion faces the tip of the at least one vibration arm in a horizontal direction in which the at least one vibration arm extends, wherein a perpendicular that extends from the tip of the at least one vibration arm towards the first recessed portion intersects an inner surface of the lower lid at an intersection point, and wherein the upper lid has a smaller thickness in the horizontal direction than a thickness of the lower lid in the horizontal direction, such that a second cavity edge of the second recessed portion that faces the tip of the at least one vibration arm is located in an outer-side portion of a straight line that connects the intersection point and the first cavity edge of the first recessed portion and extends to a side surface of the upper lid.
11 . The resonance device according to claim 10 , wherein the at least one vibration arm is configured to vibrate by performing an out-of-plane bending vibration in the space defined by the first and second recessed portions.
12 . The resonance device according to claim 10 , wherein the second cavity edge of the second recessed portion is located in an outer-side portion of the resonator with respect to the first cavity edge of the first recessed portion that faces the tip of the at least one vibration arm.
13 . The resonance device according to claim 10 , wherein the second cavity edge of the second recessed portion is located in the outer-side portion of the resonator with respect to the straight line.
14 . The resonance device according to claim 10 , wherein the perpendicular extends in a thickness direction of the resonance device and the first cavity edge of the first recessed portion faces the tip of the at least one vibration arm in the horizontal direction that is orthogonal to the thickness direction.
15 . The resonance device according to claim 10 , wherein 0.1≤X/Y≤2.0 is satisfied, and wherein X represents a horizontal distance between the intersection point of the perpendicular extending from the tip of the at least one vibration arm toward the first recessed portion of the first lid and the first recessed portion of the first lid, and the first cavity edge of the first recessed portion facing the tip of the vibration arm, and Y represents a difference in height between the intersection point of the perpendicular extending from the tip of the at least one vibration arm towards the first recessed portion of the first lid and the first recessed portion of the first lid, and the first cavity edge of the first recessed portion facing the tip of the at least one vibration arm.
16 . The resonance device according to claim 15 , wherein 0.3≤X/Y≤0.7 is satisfied.
17 . A resonance device comprising: a first lid that has a first recessed portion; a second lid that has a second recessed portion that faces the first recessed portion of the first lid; and a resonator disposed between the first lid and the second lid and having at least one vibration arm that extends in a space that includes at least the first recessed portion, and a frame that is disposed around the at least one vibration arm and that has a facing portion that faces a tip of the at least one vibration arm, wherein a cavity edge of the first recessed portion faces the tip of the at least one vibration arm in a horizontal direction in which the at least one vibration arm extends, wherein a perpendicular that extends from the tip of the at least one vibration arm towards the first recessed portion intersects an inner surface of the first lid at an intersection point, and wherein the second lid has a smaller thickness in the horizontal direction than a thickness of the first lid in the horizontal direction, such that the facing portion of the frame is located in an outer-side of a straight line that connects the intersection point and the cavity edge of the first recessed portion and extends to a side surface of the second lid.
18 . The resonance device according to claim 17 , wherein the perpendicular extends in a thickness direction of the resonance device and the cavity edge of the first recessed portion faces the tip of the at least one vibration arm in the horizontal direction that is orthogonal to the thickness direction.
19 . The resonance device according to claim 17 , wherein 0.1≤X/Y≤2.0 is satisfied, and wherein X represents a horizontal distance in the horizontal direction between the intersection point and the cavity edge of the first recessed portion, and Y represents a difference in height between the intersection point and the cavity edge of the first recessed portion facing the tip of the at least one vibration arm in the horizontal direction.
20 . The resonance device according to claim 19 , wherein 0.3≤X/Y≤0.7 is satisfied.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application is a continuation of PCT Application No. PCT/JP2020/042808, filed Nov. 17, 2020, which claims priority to Japanese Patent Application No. 2020-077316, filed Apr. 24, 2020, the entire contents of each of which are hereby incorporated by reference in their entirety. TECHNICAL FIELD The present invention relates to a resonance device. BACKGROUND Currently, a resonator, such as piezoelectric vibrator, is used as a device that realizes a clock function in an electronic device. Resonators are required to be reduced in size accompanying size reduction of electronic devices, and resonators manufactured using micro electro mechanical systems (MEMS) technology (hereinafter, also referred to as MEMS vibrators) are attracting attention. For example, International Publication No. 2017-212677 (hereinafter “Patent Document 1”) describes a configuration in which, by excessively exciting a vibration arm, an adjustment film in the vibration arm is caused to collide with at least one of the bottom plate of the upper lid and the bottom plate of the lower lid to scrape the adjustment film so as to reduce the weight of the vibration arm and adjust the resonant frequency of the resonator. However, in the related art, when the vibration arm is excessively excited, such that the adjustment film scatters from the vibration arm and enters a gap between the upper lid and the resonator or the inner wall of the resonator, an insulation failure may occur. Moreover, this problem similarly occurs not only when the vibration arm is excessively excided, but also when the resonant frequency of the vibration arm is adjusted for the resonator that is joined to the lower lid by trimming the adjustment film using an ion beam or the like. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a resonance device that suppresses an occurrence of an insulation failure due to a scattering object from the vibration arm when the resonant frequency of the vibration arm is adjusted. In an exemplary aspect, a resonance device is provided that includes a lower lid that has a first recessed portion, and a resonator that is mounted on the lower lid and has a vibration arm configured to perform out-of-plane bending vibration in a space including the first recessed portion and a frame provided around the vibration arm and having a facing portion facing a tip of the vibration arm, in which the facing portion of the frame is located in an outer-side portion of the resonator with respect to a straight line connecting an intersection point of a perpendicular extending from the tip of the vibration arm toward the first recessed portion of the lower lid and the first recessed portion of the lower lid, to a cavity edge of the first recessed portion facing the tip of the vibration arm. According to the exemplary embodiment of the present invention, when the resonant frequency of a vibration arm is adjusted, the occurrence of an insulation failure due to a scattering object from the vibration arm is suppressed. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a perspective view schematically illustrating an appearance of a resonance device according to a first exemplary embodiment. FIG. 2 is an exploded perspective view schematically illustrating a structure of the resonance device according to the first exemplary embodiment. FIG. 3 is a plan view of a resonator according to the first exemplary embodiment from which an upper side substrate is removed. FIG. 4 is a sectional view taken along line A-A′ of FIG. 1. FIG. 5 is a diagram for explaining an example of a frequency adjustment method of a resonator. FIG. 6 is a diagram schematically illustrating a main part of the resonance device according to the first exemplary embodiment. FIG. 7 is a diagram for explaining a function of the resonance device according to the first exemplary embodiment. FIG. 8 is a diagram schematically illustrating a main part of a resonance device according to a second exemplary embodiment. FIG. 9 is a diagram for explaining a function of the resonance device according to the second exemplary embodiment. FIG. 10 is a diagram schematically illustrating a main part of a resonance device according to a third exemplary embodiment. FIG. 11 is a diagram for explaining a function of the resonance device according to the third exemplary embodiment. FIG. 12 is a diagram schematically illustrating a main part of a resonance device according to a fourth exemplary embodiment. FIG. 13 is a diagram for explaining a function of the resonance device according to the fourth exemplary embodiment. FIG. 14 is a diagram schematically illustrating a main part of a resonance device according to a fifth exemplary embodiment. FIG. 15 is a diagram for explaining a function of the resonance device according to the fifth exemplary embodiment. FIG. 16 is a diagram schematically illustrating a main part of a resonance device according to a sixt