Tuning fork-type piezoelectric vibration piece

The tuning-fork type piezoelectric vibrating piece addresses the issue of joint weakness by incorporating a thick support arm portion and metal bump joining, resulting in a more robust and impact-resistant design.

JP2025079991APending Publication Date: 2025-05-23DAISHINKU CORP
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Patent Information

Application Number
JP2023192928
Authority / Receiving Office
JP · JP
Patent Type
Applications
Current Assignee / Owner
Filing Date
2023-11-13
Publication Date
2025-05-23

AI Technical Summary

Technical Problem

Existing tuning-fork type piezoelectric vibrating pieces with support arms extending from a base between the vibrating arms are prone to breaking at the joint due to stress concentration from impacts.

Method used

A tuning-fork type piezoelectric vibrating piece with a support arm extending from between the vibrating arms, featuring a thick portion at the joint area for increased strength and a metal bump joining mechanism for enhanced bonding with the container.

Benefits of technology

The configuration enhances the physical strength near the joint, improving the impact resistance and preventing damage to the vibrating piece during external impacts.

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Abstract

To provide a tuning fork-type piezoelectric vibration piece with a larger strength.SOLUTION: A tuning fork-type piezoelectric vibration piece 2 is in the shape of a tuning fork in plan view, and includes: a base part 20; a pair of vibration arm parts 21, 22 extending from one end side of the base part 20; and a supporting arm part 23 extending in the same direction as the direction in which the vibration arm parts 21, 22 extend, from between the pair of vibration arm parts 21, 22 in the base part 20. The supporting arm part 23 includes: metal bumps 7a, 7b joined to the container 3; and a thick part 24 in the region in which the metal bumps 7a, 7b are provided, the thick part being thicker in the thickness direction than the other regions of the supporting art part 23. The tuning fork-type piezoelectric vibration piece is mounted in the container 3 and serves as a turning fork-type piezoelectric vibrator 1.SELECTED DRAWING: Figure 3
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Description

[Technical field]

[0001] The present invention relates to a tuning-fork type piezoelectric vibrating piece in which a pair of vibrating arms vibrates in a flexural vibration mode. [Background technology]

[0002] Tuning-fork type piezoelectric vibrating pieces have been widely used as frequency generating sources for reference signals for clocks, etc. Such tuning-fork type piezoelectric vibrating pieces are bonded and mounted inside the concave shape of an insulating base (container), and are used as surface-mount tuning-fork type piezoelectric vibrators in which the concave portion is hermetically sealed with a lid.

[0003] As such a tuning fork type piezoelectric vibrator, a tuning fork type crystal vibrator has been disclosed that incorporates a three-arm tuning fork type crystal piece having first and second vibrating arms extending parallel to each other from a base and a support arm extending from the base between the vibrating arms (see Patent Document 1). Such a three-arm tuning fork type crystal piece can be made smaller than a tuning fork type crystal piece that has support arms on the left and right of the vibrating arms. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication 2019-165348 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in a configuration having support arms extending from a base between the vibrating arms as described in Patent Document 1, when an impact is applied to a tuning fork-type quartz crystal vibrator (tuning fork-type piezoelectric vibrator), stress due to the impact is concentrated at the joint between the support arms of the tuning fork-type quartz crystal vibrating piece (tuning fork-type piezoelectric vibrating piece) and the container, and there is a risk that the tuning fork-type piezoelectric vibrating piece will break at the joint. In other words, there has been a demand for a tuning fork-type piezoelectric vibrating piece with a stronger structure having support arms extending from a base between the vibrating arms.

[0006] The present invention has been made in consideration of the above problems, and an object of the present invention is to provide a tuning-fork-type piezoelectric vibrating piece having higher strength. [Means for solving the problem]

[0007] The present invention is characterized in that it is a tuning-fork-type piezoelectric vibrating piece that has a tuning fork shape when viewed in a plane and is mounted inside a container to become a piezoelectric vibrator, and that it comprises a base, a pair of vibrating arms extending from one end side of the base, and a support arm extending from between the pair of vibrating arms in the same direction as the vibrating arms, the support arm having a joint that is joined to the container, and a thick portion in the area where the joint is provided that is thicker in the thickness direction than other areas of the support arm.

[0008] In other words, the tuning-fork type piezoelectric vibrating piece of the present invention has a supporting arm portion that extends from between a pair of vibrating arms in the same direction as the vibrating arms, and has a thick portion that is thicker in the thickness direction than other regions of the supporting arm portion in the region where the joint that is joined to the container is provided. With this configuration, the physical strength of the tuning-fork type piezoelectric vibrating piece near the joint can be increased, resulting in a tuning-fork type piezoelectric vibrating piece with higher strength.

[0009] The thick portion may be formed so as to be convex toward at least the joint portion in the thickness direction. With this configuration, when the tuning-fork type piezoelectric vibrator is mounted in a container to form a tuning-fork type piezoelectric vibrator, a sufficient distance can be secured between the container and the portion of the supporting arm other than the thick portion. In other words, even if the tuning-fork type piezoelectric vibrator receives an external impact, the tuning-fork type piezoelectric vibrator can be prevented from coming into contact with the container.

[0010] The joining member constituting the joining portion may be formed of a bump made of metal. In such a configuration, the tuning-fork type piezoelectric vibrating piece and the container can be joined by metal bump joining. Furthermore, if the joining is by metal bump joining, the joining strength between the container and the tuning-fork type piezoelectric vibrating piece can be improved compared to joining by adhesive. Furthermore, by improving the joining strength, an impact from the outside can be more easily transmitted to the tuning-fork type piezoelectric vibrating piece, but since the tuning-fork type piezoelectric vibrating piece of the present invention has improved physical strength, it is possible to prevent damage to the tuning-fork type piezoelectric vibrating piece near the joining portion where stress due to an impact is concentrated. Effect of the Invention

[0011] According to the present invention, it is possible to provide a tuning-fork type piezoelectric vibrating piece having higher strength. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a top view of a tuning-fork type piezoelectric vibrator according to a first embodiment. [Diagram 2] 2 is a cross-sectional view taken along the line AA of the tuning-fork-type piezoelectric vibrator in the state where it is hermetically sealed with a lid in FIG. 1. [Diagram 3] 1 is a schematic plan view of one main surface of a tuning-fork type piezoelectric vibrating piece according to a first embodiment. [Figure 4] 4 is a cross-sectional view of the tuning-fork type piezoelectric vibrating piece shown in FIG. [Diagram 5] FIG. 11 is a cross-sectional view of a tuning-fork type piezoelectric vibrating piece according to another embodiment of the present invention; [Figure 6] FIG. 11 is a BB cross-sectional view of a tuning-fork type piezoelectric vibrating piece according to still another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In this specification, the description of various electrodes formed on the piezoelectric vibrating piece (tuning fork type piezoelectric vibrating piece) is omitted. Also, the X-axis direction (X-direction) described in each drawing and this specification is the same as the X-axis direction of the crystal axis of the quartz crystal, the Y-axis direction (Y-direction) is the same as the Y-axis direction of the crystal axis of the quartz crystal (or the Y' direction tilted from the Y-axis by several degrees), and the Z-axis direction (Z-direction) is the same as the Z-axis direction of the crystal axis of the quartz crystal (or the Z' direction tilted from the Z-axis by several degrees).

[0014] FIG. 1 is a top view of a tuning-fork type piezoelectric vibrator 1 according to the first embodiment, and FIG. 2 is a cross-sectional view taken along line AA of the tuning-fork type piezoelectric vibrator 1 in FIG. 1 in a state where it is hermetically sealed with a lid 4. As shown in FIG. In this specification, the depth direction in FIG. 1 is the bottom side of tuning fork type piezoelectric vibrator 1, and the front direction is the top side of tuning fork type piezoelectric vibrator 1, and the bottom and top are described.

[0015] The tuning fork type piezoelectric vibrator 1 (quartz crystal vibrator 1) in the first embodiment (present embodiment) is a surface mount type quartz crystal vibrator having a package structure of a substantially rectangular parallelepiped shape. The external dimensions of the quartz crystal vibrator 1 are not particularly limited, and may be any of various known dimensions depending on the application.

[0016] 2, in the quartz crystal resonator 1 according to this embodiment, a tuning-fork type piezoelectric vibrating piece 2 (quartz crystal vibrating piece 2) is accommodated in a recess 5 of a container 3 made of an insulating material, and then a flat lid 4 is bonded to the open end of the container 3 so as to cover the recess 5, thereby hermetically sealing the quartz crystal vibrating piece 2 in the internal space. The container 3 and the lid 4 are bonded together via a sealing material (not shown).

[0017] The container 3 is a box-shaped body made of an insulating material mainly composed of ceramic such as alumina, and is formed by, for example, stacking three ceramic green sheets and sintering them together to form a bottom layer 3a, a middle layer 3b, and an upper layer 3c. In this embodiment, of the bottom layer 3a, the middle layer 3b, and the upper layer 3c, the rectangular frame-shaped middle layer 3b is stacked on the bottommost layer 3a, and the rectangular frame-shaped upper layer 3c is stacked on the middle layer 3b. Therefore, the container 3 has a rectangular recess 5 in plan view, with the upper surface of the bottom layer 3a as the bottom surface and the middle layer 3b and the upper layer 3c as the frame-shaped bank portion 30. The middle layer 3b protrudes toward the recess 5 on the upper surface of the bottom layer 3a, and a part of it forms a step portion 31 on which the quartz crystal vibrating piece 2 is mounted. A sealing material (not shown) is formed in a frame shape in a plan view on the upper surface 300 of the bank portion 30 (upper layer portion 3c).

[0018] The step 31 forms an edge 32 as an end face in a direction protruding toward the recess 5 in a plan view. The step 31 in this embodiment is formed from near the center of the short side of the container 3 in a plan view and protrudes toward the recess 5, and has a substantially rectangular shape with a uniform width with the protruding direction as the longitudinal direction in a plan view. The step 31 also has two mounting pads 6a, 6b on the upper surface thereof that are conductively bonded to the crystal vibrating piece 2. The mounting pads 6a, 6b are formed in parallel with a gap between them, and are connected to the metal bumps 7a, 7b of the tuning fork type piezoelectric vibrating piece 2 by bump bonding, respectively. That is, the mounting pads 6a, 6b correspond to the mounting portion in the present invention. In this embodiment, the mounting pads 6a, 6b are arranged in parallel in the long side direction of the container 3 in a plan view (the longitudinal direction of the step 31), but the width of the step 31 may be formed to be sufficiently large and arranged in parallel in the short side direction of the container 3 in a plan view. The two mounting pads 6a, 6b have opposite polarities and are electrically connected to a plurality of external connection terminals 8 provided on the outer bottom surface of the container 3 through internal wiring and vias (not shown).

[0019] In this embodiment, the two mounting pads 6a and 6b are formed by laminating nickel and gold in this order on the upper surface of a tungsten metallization layer using a method such as plating. Note that molybdenum may be used as the metallization layer instead of tungsten.

[0020] The lid 4 may be, for example, a metal lid body having a rectangular shape in plan view and made of Kovar as a base. Also, for example, the lid 4 may be configured such that a brazing material made of metal is formed in a circumferential shape on a nickel-plated layer on the outer periphery of the joint surface side with the container 3. Furthermore, the joint between the lid 4 and the container 3 may be made by brazing or seam welding.

[0021] FIG. 3 is a schematic plan view of one main surface side of the tuning-fork type piezoelectric vibrating piece 2 according to the embodiment of the present invention. For ease of explanation, of the two opposing main surfaces of the quartz crystal vibrating piece 2, the main surface that faces the mounting pads 6a, 6b when mounted on the container 3 will be referred to as the back surface, and the main surface opposite the back surface will be referred to as the front surface. That is, Fig. 3 is a plan view of the quartz crystal vibrating piece 2 as seen from the front surface side.

[0022] The quartz crystal vibrating piece 2 is a thin-plate-shaped quartz crystal Z plate having a thickness in the Z direction. The quartz crystal vibrating piece 2 includes a base 20, a pair of vibrating arms 21, 22 formed side by side from one end side of the base 20 and protruding (extending) in the Y direction (first direction), and a support arm 23 formed protruding in the Y direction (the same direction as the vibrating arms 21, 22) from between the pair of vibrating arms 21, 22 at one end side of the base 20. Therefore, the quartz crystal vibrating piece 2 is a tuning fork-shaped piezoelectric vibrating piece having a tuning fork shape in a plan view, and is formed into a three-arm shape by the support arm 23 extending in the same direction as the longitudinal vibrating arms 21, 22 and the pair of vibrating arms 21, 22. In this embodiment, the vibrating arms 21, 22 and the support arm 23 are formed to extend in the +Y direction, but may be formed to extend in the -Y direction.

[0023] The shape of the quartz crystal vibrating piece 2 of this embodiment (the vibrating arms 21, 22, base 20, and support arms 23 that constitute the quartz crystal vibrating piece 2) is formed, for example, by wet etching a quartz crystal blank (not shown), which is a quartz crystal piece made of anisotropic material.

[0024] In this embodiment, the base 20 has a shape that is symmetrical (symmetrical in the X direction) in a plan view. The base 20 is formed to be wider (longer in the X direction) than the vibrating arms 21, 22 and the supporting arm 23. The side of the base 20 is formed to be gradually narrower from the vibrating arms 21, 22 side to the other end side. The base 20 may have one or more through holes penetrating in the Z direction. Such a configuration having through holes can ensure the conduction of the extraction electrodes described later. In addition, the mechanical vibration of the tuning fork vibrating arm part during operation can be efficiently attenuated and the propagation of the vibration to the supporting arm 23 can be suppressed, thereby reducing acoustic leakage and lowering the series resonance resistance (equivalent series resistance value, crystal impedance, CI value).

[0025] The pair of vibrating arms 21, 22 are formed continuously from the base 20. The pair of vibrating arms 21, 22 are formed with narrow parts 214, 224 that are gradually narrower from the base 20, long parts 215, 225 that are formed continuously from the narrow parts 214, 224 and have a uniform width, wide parts 212, 222 that are further formed continuously from the long parts 215, 225 and gradually widen toward the tip side, and wide parts 211, 221 (weight parts) that are further formed continuously from the wide parts 212, 222 and are wider than the width of the long parts 215, 225 (the arm dimension in the second direction of the long parts 215, 225). That is, the wide parts 211, 221 form the tip parts of the vibrating arms 21, 22 in the second direction (X direction). The corners on the tip side of each of the wide portions 211, 221 are chamfered. The vibrating arms 21, 22 have a pair of main surfaces facing each other in the Z direction and a pair of side surfaces facing each other in the X direction.

[0026] A long groove is formed on the main surface of the pair of vibrating arms 21 and 22 in order to further reduce the equivalent series resistance value (Crystal Impedance, CI value). More specifically, a long groove 213 is formed on the front main surface (front surface) of the vibrating arm 21, and a long groove (not shown) is formed on the back main surface (back surface) of the vibrating arm 21, so that the long grooves are formed to face each other. In addition, a long groove 223 is formed on the front main surface (front surface) of the vibrating arm 22, and a long groove (not shown) is formed on the back main surface (back surface) of the vibrating arm 22, so that the long grooves are formed to face each other. The long grooves 213 and 223 formed on the front surface of each of the vibrating arms 21 and 22 and the long groove (not shown) formed on the back surface are formed with a predetermined depth (length in the Z direction) and width (length in the X direction) on the front and back main surfaces of each of the vibrating arms 21 and 22. Moreover, one end of each long groove in the Y direction is formed up to the region of the base 20, and the other end is formed at the boundary between the long portions 215, 225 and the widened portions 212, 222. That is, all the long grooves have a longitudinal direction along the direction in which the vibrating arms 21, 22 protrude (first direction, Y direction) and a width direction along the direction in which the vibrating arms 21, 22 are arranged side by side (second direction, X direction). Moreover, an excitation electrode (not shown) described later is formed inside each long groove. Moreover, each long groove is formed by wet etching.

[0027] The supporting arm 23 is formed so as to protrude in the Y direction from one end side of the base 20 (the side from which the vibrating arms 21 and 22 protrude). That is, the supporting arm 23 is formed so as to protrude in the first direction from one end side of the base 20. It is preferable that the supporting arm 23 is disposed at equal intervals with respect to each of the vibrating arms 21 and 22. That is, it is preferable that the supporting arm 23 is formed so as to protrude from the exact center of the protruding positions of the two vibrating arms 21 and 22 on the base 20. Moreover, the supporting arm 23 in this embodiment has a substantially rectangular shape having a uniform width with the first direction as the longitudinal direction.

[0028] The support arm 23 has a metal bump 7b on the back side near the tip end extending in the longitudinal direction (first direction), and a metal bump 7a on the back side on the base 20 side as viewed from the metal bump 7b. The metal bumps 7a and 7b are plated bumps formed by electrolytic plating. The metal bump 7a is bonded to the mounting pad 6a of the container 3 when the quartz crystal vibrating piece 2 is mounted on the container 3, and the metal bump 7b is bonded to the mounting pad 6b. That is, the metal bumps 7a and 7b correspond to the bonding portion in the present invention, and the bonding portion is composed of the metal bump. In this embodiment, the metal bump 7b is provided at the tip end of the support arm 23, but is not limited thereto. For example, the metal bump 7b may be provided near the center of the support arm 23 in the first direction, or may be provided at a position further toward the base 20 side from the center. Also, as long as the multiple metal bumps are bonded to both of the mounting pads 6a, 6b (mounting portions) of the container 3, the positions, shapes, and number of the metal bumps on the support arm 23 are not particularly limited. That is, the metal bumps 7a, 7b in this embodiment are elliptical and of the same size, but the shapes of the metal bumps 7a, 7b are not particularly limited and may be of various shapes, and the metal bumps 7a and 7b may be different in size or shape from each other. Also, in this embodiment, the support arm 23 is configured to have two metal bumps 7a, 7b, but it is sufficient that the support arm 23 has multiple (two different polarity) metal bumps, and may have three or more metal bumps.

[0029] Figure 4 is a BB cross-sectional view of the tuning-fork-type piezoelectric vibrating piece 2 in Figure 3, Figure 5 is a BB cross-sectional view of the tuning-fork-type piezoelectric vibrating piece 2 according to another embodiment, and Figure 6 is a BB cross-sectional view of the tuning-fork-type piezoelectric vibrating piece 2 according to yet another embodiment. Further, the supporting arm 23 has a thick portion 24 formed in a region having the metal bumps 7a and 7b, which is thicker in the thickness direction than other regions of the supporting arm 23. That is, the supporting arm 23 has a shape in which the region having the metal bumps 7a and 7b protrudes in the thickness direction. The metal bumps 7a and 7b are provided on the back surface of the thick portion 24 in the supporting arm 23. The thick portion 24 is the portion formed to be the thickest in the crystal vibrating piece 2. Further, the height of the thick portion 24 protruding in the thickness direction is not particularly limited, but is preferably 30% or more, more preferably 50% or more, of the thickness of the portion of the supporting arm 23 excluding the thick portion 24. Furthermore, as shown in FIG. 3, the thick portion 24 in this embodiment protrudes from the side of the metal bumps 7a and 7b (back surface side), but the protruding direction in the thickness direction is not particularly limited as long as it is formed in the region having the metal bumps 7a and 7b. For example, as shown in Fig. 5, the thick portion 24 may have a shape that protrudes from the front side (the side on which the metal bumps 7a, 7b are not provided), or as shown in Fig. 6, the thick portion 24 may have a shape that protrudes from both the back side and the front side. It is preferable that the thick portion 24 has a shape that protrudes from the surface that faces the step portion 31 when mounted on the container 3 (the surface on which the metal bumps 7a, 7b are provided).

[0030] In this embodiment, the thick portion 24 is formed integrally with the support arm 23. Such a thick portion 24 can be formed at the same time as forming the shape of the quartz crystal vibrating piece 2 by wet etching, for example. The thick portion 24 may also be formed by adding it to the main surface of the quartz crystal vibrating piece 2 that has already been formed by wet etching or the like. In this case, the addition added as the thick portion 24 is made of an insulating material. Examples of such insulating materials that can be used include quartz crystal, silicate compounds other than quartz crystal, and resin compositions such as epoxy resin.

[0031] In addition, the quartz crystal vibrating piece 2 is formed with a first excitation electrode and a second excitation electrode configured with different potentials, and an extraction electrode drawn from each of the first excitation electrode and the second excitation electrode via a wiring electrode. The first excitation electrode is formed on the front and back main surfaces including the inner circumferential surface of the long groove of one vibrating arm 21, and on the outer and inner surfaces of the other vibrating arm 22 via the wiring electrode. Similarly, the second excitation electrode is formed on the front and back main surfaces including the inner circumferential surface of the long groove of the other vibrating arm 22, and on the outer and inner surfaces of one vibrating arm 21 via the wiring electrode. The extraction electrode drawn from the first excitation electrode is connected to the metal bump 7b via the surface of the base 20 and the support arm 23, and the extraction electrode drawn from the second excitation electrode is connected to the metal bump 7a via the surface of the base 20 and the support arm 23. Note that illustration of each electrode pattern is omitted in each drawing.

[0032] The quartz crystal vibrating piece 2 is mounted on the container 3 by bonding the metal bumps 7a, 7b of the quartz crystal vibrating piece 2 to the mounting pads 6a, 6b. The metal bumps 7a, 7b and the mounting pads 6a, 6b are conductively bonded to each other by FCB (Flip Chip Bonding). That is, the quartz crystal vibrating piece 2 is bonded and mounted on the container 3 by bumps made of metal plating (plated bumps). Note that in this embodiment, bump bonding is performed using plated bumps, but bump bonding using stud bumps may also be used.

[0033] With the above-described configuration, a tuning-fork type piezoelectric vibrating piece having higher strength can be provided. The tuning-fork type piezoelectric vibrating piece 2 (quartz crystal vibrating piece 2) of the present invention has a support arm 23 extending from between a pair of vibrating arms 21, 22 in the same direction as the vibrating arms 21, 22, and has a thick portion 24 that is thicker in the thickness direction than other regions of the support arm 23 in a region where the metal bumps 7a, 7b bonded to the container are provided. With this configuration, the physical strength of the crystal vibrating piece 2 near the metal bumps 7a, 7b can be increased, resulting in a crystal vibrating piece 2 with higher strength. Furthermore, when the crystal vibrating piece 2 is mounted on the container 3 to form a tuning-fork type piezoelectric vibrator 1, the physical strength of the vicinity of the metal bumps 7a, 7b bonded to the container 3 can be improved, resulting in a tuning-fork type piezoelectric vibrator 1 with improved impact resistance.

[0034] In addition, the quartz crystal vibrating piece 2 of the present invention is formed so that the thick portion 24 protrudes (is convex) from at least the metal bumps 7a and 7b in the thickness direction. With this configuration, when the quartz crystal vibrating piece 2 is mounted on the container 3 to form the tuning fork type piezoelectric vibrator 1, the distance between the part of the supporting arm 23 other than the thick portion 24 and the step portion 31 of the container 3, and the distance between the vibrating arms 21, 22 and the inner bottom surface of the container 3 can be made larger by the protruding height of the thick portion 24 than the quartz crystal vibrating piece 2 not provided with the thick portion 24. That is, the distance between the part of the supporting arm 23 other than the thick portion 24 and the step portion 31 of the container 3, and the distance between the vibrating arms 21, 22 and the inner bottom surface of the container 3 can be sufficiently secured. Therefore, even if the tuning fork type piezoelectric vibrator 1 receives an impact from the outside, the quartz crystal vibrating piece 2 inside can be prevented from vibrating and coming into contact with the container 3.

[0035] Furthermore, in the quartz crystal vibrating piece 2 of the present invention, the thick portion 24 protrudes in the thickness direction by 30% or more of the thickness of the portion of the supporting arm 23 excluding the thick portion 24. With this configuration, it is possible to more sufficiently secure the distance between the portion of the supporting arm 23 other than the thick portion 24 and the step portion 31 of the container 3, and the distance between the vibrating arms 21, 22 and the inner bottom surface of the container 3.

[0036] Furthermore, in the quartz crystal vibrating piece 2 of the present invention, the thick portion 24 is formed to be the thickest in the quartz crystal vibrating piece 2. With this configuration, it is possible to more sufficiently secure the distance between the portion of the supporting arm 23 other than the thick portion 24 and the step portion 31 of the container 3, and the distance between the vibrating arms 21, 22 and the inner bottom surface of the container 3.

[0037] Furthermore, in the quartz crystal vibrating piece 2 of the present invention, the thick portion 24 may be formed so as to protrude (be convex) from both the surface (back surface) on which the metal bumps 7a, 7b are provided and the surface (front surface) on which the metal bumps 7a, 7b are not provided in the thickness direction. With this configuration, the physical strength in the vicinity of the metal bumps 7a, 7b can be further improved.

[0038] In addition, in the crystal vibrating piece 2 of the present invention, the bonding member constituting the bonding portion bonded to the container 3 is formed of the metal bumps 7a and 7b. With this configuration, the support arm 23 and the step portion 31 of the container 3 are bonded (bump bonded) by bumps made of metal plating, and the bonding strength between the container 3 and the crystal vibrating piece 2 can be improved compared to bonding by adhesive. In addition, by improving the bonding strength, external impacts tend to be concentrated and transmitted near the metal bumps 7a and 7b of the crystal vibrating piece 2. However, in the crystal vibrating piece 2 of the present invention, the physical strength near the metal bumps 7a and 7b is improved, so that the crystal vibrating piece 2 can be prevented from breaking (breaking, destroying). More specifically, the bump bonding shown in this embodiment can firmly bond the container and the crystal vibrating piece. That is, it is a configuration that can be bonded electrically and mechanically firmly and stably. On the other hand, there is a concern that the cushioning function of the bonding material is less effective than when an adhesive is used as the bonding material, and impact resistance is reduced. The structure of the present invention can achieve stable and strong bonding electrically and mechanically, and can also improve impact resistance. Note that the adhesive referred to here is, for example, a conductive resin adhesive containing a conductive material such as a metal filler.

[0039] It should be noted that the present invention is not limited to the configurations of the above-described embodiments, and many other embodiments can be obtained. The embodiments disclosed herein are illustrative in all respects and are not intended to be limiting. Therefore, the technical scope of the present invention is not interpreted solely by the above-described embodiments, but is defined by the claims. Also, all modifications within the scope and meaning equivalent to the claims are included. [Industrial Applicability]

[0040] The tuning-fork-type piezoelectric vibrating piece of the present invention can be used in the industry of manufacturing and selling tuning-fork-type piezoelectric vibrators in which the tuning-fork-type piezoelectric vibrating piece of the present invention is mounted inside a container. [Explanation of symbols]

[0041] 1...Tuning fork type piezoelectric vibrator 2...Piezoelectric vibrating piece 20…Base 21, 22... Vibrating arm part 23...Support arm 24...Thick wall part 3…Container 31...Double part 6a, 6b...Mounting pad 7a, 7b...Metal bumps

Claims

1. A tuning-fork type piezoelectric vibrating piece having a tuning fork shape in a plan view and mounted inside a container to become a piezoelectric vibrator, A base and A pair of vibrating arms extending from one end side of the base portion; a support arm portion extending from between the pair of vibrating arms in the same direction as the vibrating arms, The support arm portion is a joint joined to the container; The joint is provided in a region having a thick portion that is thicker in a thickness direction than other regions of the support arm. Tuning fork type piezoelectric vibrating piece.

2. The thick portion is The joint portion is formed so as to be convex toward the joint portion in the thickness direction.

2. The tuning-fork type piezoelectric vibrating piece according to claim 1.

3. The bonding member constituting the bonding portion is formed of a bump made of metal.

3. The tuning-fork type piezoelectric vibrating piece according to claim 1.

Citation Information

Patent Citations

  • Turning fork-type crystal vibrator

    JP2019165348A