JP2012023429A - Vibrating piece, vibrator, oscillator, and electronic apparatus - Google Patents

Abstract

Provided is a resonator element that suppresses a thermoelastic loss of a vibration part and also suppresses a force in a torsional direction, and has good vibration characteristics and Q value.
A resonating piece (10) having a base (14) and a plurality of resonating arms (16a to 16c) extending from the base (14) and bending-vibrates in a normal direction of a vibration surface. The vibration arm 16 disposed at least on the outermost side of 16 is formed with a protrusion 18 that suppresses vibrations having characteristics different from the main vibration of the vibration arm 16. The resonating arm 16 has a first surface along a direction intersecting the bending direction, and a second surface facing the first surface, and an excitation electrode (first layer excitation electrode 22) is formed on the first surface. And the second layer excitation electrode 40) and the protrusion 18 on the second surface.
[Selection] Figure 1

Description

  The present invention relates to a resonator element, a resonator, an oscillator, and an electronic device, and in particular, a resonator element that excites bending vibration, a resonator including the resonator element, an oscillator, and an electron including these resonator and oscillator Regarding equipment.

  In the resonator element that excites bending vibration, a design that takes into account the thermoelastic loss caused by local compression and tension generated on the front and back surfaces of the vibration part is required. For example, according to the technique disclosed in Patent Document 1, it is understood that the Q value indicating the stability of resonance can be improved by providing a groove in the arm portion of the crystal resonator.

However, as the electronic device becomes smaller and thinner, it becomes very difficult to accurately form the groove in the vibrating portion as the vibrating piece becomes smaller and thinner.
As means for avoiding such problems, it has been devised to make the vibration part thinner and to form a piezoelectric layer on the vibration part (Patent Documents 2-4). In the resonator element having such a configuration, it is possible to excite vibration in a direction (out-of-plane direction) intersecting with the formation surface of the piezoelectric layer by applying electric fields having different potentials to the front and back of the piezoelectric layer.

Japanese Utility Model Publication No. 2-3322 JP 2009-5022 A JP 2009-5023 A JP 2009-5024 A

  If it is a vibration piece of the structure currently disclosed by patent documents 2-4, the thermoelastic loss accompanying the bending of a vibration part can be suppressed certainly. The resonator element disclosed in Patent Literature 2-4 includes a plurality of vibrating arms as a vibrating portion, specifically, an odd number, and a base portion formed at the base ends of the plurality of vibrating arms.

  In the resonator element having such a configuration, vibration is excited using a mode in which the vibrating arm vibrates in the same phase or with a specific phase. However, in such a resonating arm that vibrates while balancing a plurality of resonating arms, the resonating arm is extremely thinned, so that the resonating arm located on the outer edge side bends and twists due to this bending. There is a problem.

  This is mainly due to the fact that the outer vibrating arm is applied with a force in the rotational direction with the vibrating arm located at the center as the base point and the lack of rigidity due to the thinning of the outer vibrating arm. In particular, it tends to occur when the base of the vibrating arm is thinned. When such a torsional motion occurs, vibration leakage occurs in the main vibration, which degrades the vibration characteristics, particularly the Q value indicating the stability of vibration. I will let you.

  Therefore, in the present invention, the above-described problems are solved, the thermoelastic loss of the vibration part is suppressed, and the force in the torsional direction is also suppressed, and the vibration piece, the vibrator, the oscillator, and the electronic apparatus having good vibration characteristics and Q value The purpose is to provide.

SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.
Application Example 1 A base portion provided on a plane including a first direction and a second direction orthogonal to the first direction, and a plurality of vibrations extending from the base portion in the first direction The vibration arm is bent and vibrated in a normal direction of the plane, and is compressed or expanded by the bending vibration; and the first surface is expanded and compressed when the first surface is compressed. And a second surface that compresses when the surface extends, and a vibration arm disposed at least on the outermost side of the plurality of vibration arms has a protrusion formed thereon. Piece.
If it is a vibration piece which has such a characteristic, the twist of the vibration arm arrange | positioned at the outermost side which is the vibration arm which is most likely to produce a twist can be suppressed. In addition, the Q value can be improved, and a highly accurate and highly reliable resonator element can be provided.

[Application Example 2] The resonator element according to Application Example 1, wherein the resonator element includes an excitation electrode on the first surface and the protrusion on the second surface.
With this configuration, it is possible to form the protrusion on the vibrating arm while making the first surface on which the excitation electrode and the piezoelectric layer are formed flat.

Application Example 3 The vibration piece according to Application Example 2, wherein the excitation electrode and the protrusion overlap when the vibration piece is viewed in plan from the normal direction. Vibrating piece.
By setting it as such a structure, a thermoelastic loss can be suppressed compared with the case where a projection part is formed in the root of a vibrating arm. In addition, as in the case where a protrusion is formed at the tip, it is possible to obtain a twist preventing effect without the need to consider the characteristics of the hammerhead type vibrator. Furthermore, by providing it at a position overlapping with the excitation electrode in plan view, it is possible to positively suppress partial bending that contributes to vibration, and to enhance the effect on vibration characteristics and the effect of suppressing vibration leakage.

[Application Example 4] The resonator element according to any one of Application Examples 1 to 3, wherein the protrusion is formed over the entire width of the resonator arm. .
By setting it as such a structure, the effect which suppresses the bending and twist of the width direction in a vibrating arm can be heightened.

[Application Example 5] The vibration piece according to any one of Application Examples 1 to 4, wherein the protrusion is formed on all of the plurality of vibration arms.
By setting it as such a structure, the bending and the twist in all the vibrating arms can be suppressed. Moreover, the stability of the amplitude can be ensured by forming similar protrusions for all the vibrating arms.

Application Example 6 A vibrator having the resonator element according to any one of Application Examples 1 to 5 and a package in which the resonator element is mounted.
With such a configuration, a highly accurate and highly reliable vibrator can be obtained even when the size is reduced.

[Application Example 7] An oscillator comprising the resonator element according to any one of Application Examples 1 to 5, and an electronic component that controls oscillation of the resonator element.
By adopting such a configuration, a highly accurate and reliable oscillator can be obtained even when downsized.

[Application Example 8] An electronic apparatus comprising the resonator element according to any one of Application Examples 1 to 5.
With such a configuration, it is possible to cope with downsizing of electronic devices.

FIG. 3 is a trihedral view illustrating a configuration of a resonator element according to the embodiment. FIG. 6 is a partially exploded perspective view illustrating a configuration of a resonator element according to the embodiment. It is a figure for demonstrating the bending and torsion which arise in the vibration piece which is not provided with a projection part. It is a figure for demonstrating the manufacturing process of the vibration piece which concerns on embodiment. It is a figure which shows the structure of the vibrator | oscillator which mounted the vibration piece which concerns on embodiment. It is a figure which shows the structure of the oscillator which mounted the resonator element which concerns on embodiment, and the electronic component provided with the circuit which oscillates this resonator element. It is a figure which shows the mobile telephone as an example of the electronic device carrying at least one of the vibrator | oscillator which concerns on embodiment, or an oscillator. It is a figure which shows the personal computer as an example of the electronic device carrying at least one of the vibrator | oscillator which concerns on embodiment, or an oscillator.

Hereinafter, embodiments of the resonator element, the vibrator, the oscillator, and the electronic device according to the invention will be described in detail with reference to the drawings.
First, the resonator element according to the first embodiment will be described with reference to FIGS. 1 and 2. 1A is a plan view of the resonator element, FIG. 1B is a view showing an AA arrow in FIG. 1A, and FIG. It is a back view of a piece. FIG. 2 is an exploded perspective view of the resonator element. The resonator element 10 according to this embodiment includes a substrate 12, a piezoelectric layer 28, a first electrode 20, and a second electrode 38.

  The substrate 12 is made of, for example, a single crystal material such as quartz or silicon, and includes a base portion 14 and a plurality (three in the form shown in FIGS. 1 and 2) of vibrating arms 16 extending from the base portion 14 as a base end. (16a-16c). In the case of the example according to the embodiment, the base 14 is provided on a plane including an arbitrarily defined first direction and a second direction orthogonal to the first direction, and is larger than the vibrating arm 16. It is formed to be thick and can maintain the mechanical strength during mounting. On the other hand, the resonating arm 16 extends in the first direction with the base portion 14 as the base end, is formed thinner than the base portion 14, and suppresses thermoelastic loss during vibration. The substrate 12 according to the embodiment configured to have a thickness different between the base portion 14 and the vibrating arm 16 includes a first surface in which the base portion 14 and the vibrating arm 16 are continuously flattened, and the base portion 14 and the vibrating arm 16. And a second surface formed with a step between them. The first surface of the vibrating arm 16 is a surface that is compressed or expanded when the vibrating arm 16 excites bending vibration, and the second surface is expanded when the first surface is compressed, and the first surface is It is the surface that compresses when stretched. The first surface formed in this manner is a surface along a direction intersecting (orthogonal) with the bending direction of the vibrating arm 16, and the second surface is a surface facing the first surface. When the substrate 12 is made of quartz, the cut angle of the base plate 12a (see FIG. 4) when forming the substrate 12 is preferably a Z-cut, but may be an X-cut or an AT-cut. good. Since the substrate 12 according to the embodiment is not a target to which a voltage is directly applied, basically the cut angle does not affect the vibration characteristics. However, when the base plate 12a cut by the Z cut is used, there is an advantage that the processing becomes easy by utilizing the anisotropic etching characteristics of the crystal.

The first electrode 20, the piezoelectric layer 28, and the second electrode 38 are stacked on the first surface of the substrate 12. Here, the first electrode 20 is an electrode formed before the piezoelectric layer 28 is formed, and the second electrode 38 is an electrode formed after the piezoelectric layer 28 is formed. Therefore, the expressions such as the first electrode 20 and the second electrode 38 are not related to the potential at each electrode. Further, the potential of each electrode depends on the direction of hatching in the first electrode 20 and the second electrode 38 shown in the exploded perspective view of FIG. As a material for forming the first electrode 20 and the second electrode 38, it is preferable that the first electrode 20 and the second electrode 38 have good adhesion to the crystal serving as the substrate 12 and facilitate the orientation of the piezoelectric layer 28. Examples of materials that are versatile as electrode members include Au, Pt, Al, Ag, Cu, Mo, Cr, Nb, W, Ni, Fe, Ti, Co, Zn, and Zr. In the present embodiment, both the first electrode 20 and the second electrode 38 are formed of a metal layer having a two-layer structure in which the lower layer is Cr and the upper layer is Au. Further, examples of the piezoelectric layer 28 include ZnO, AlN, PZT, LiNbO ₃ , KNbO _3, etc., and in this embodiment, AlN is mainly adopted.

  The first electrode 20 includes, for example, first layer excitation electrodes 22a, 22b, and 22c and first layer extraction electrodes 24 and 26. Here, the first layer excitation electrode 22 a and the first layer excitation electrode 22 c have the same potential and are connected by the first layer extraction electrode 24. On the other hand, the first layer excitation electrode 22b is in an electrically floating state and is connected to an extraction electrode 26 for connection to a second electrode 38, which will be described in detail later.

  The piezoelectric layer 28 is formed so as to cover the first electrode 20 described above. Specifically, it includes excitation electrode covering portions 30 a, 30 b, 30 c formed on the vibrating arms 16 a, 16 b, 16 c and an extraction electrode covering portion 32 formed on the base portion 14. The lead electrode covering portion 32 is provided with openings 34 and 36 for electrically connecting the above-described first electrode 20 and a second electrode 38 to be described in detail later. Note that the piezoelectric layer 28 is applied with voltages having different potentials on the front and back surfaces thereof, so that it is in the out-of-plane direction (direction intersecting the piezoelectric layer 28 forming surface: normal direction of the piezoelectric layer forming surface). It has the property of bending to the side.

  The second electrode 38 includes, for example, second layer excitation electrodes 40a, 40b, and 40c, second layer extraction electrodes 46 and 48, and input / output electrodes 42 and 44. Here, the second layer excitation electrode 40 b and the input / output electrode 42 have the same potential and are connected by the second layer extraction electrode 46. Further, the second layer extraction electrode 46 is electrically connected to the first layer extraction electrode 24 through the opening 34 formed in the piezoelectric layer 28 described above. Therefore, the same potential voltage is applied to the first layer excitation electrodes 22a and 22c and the second layer excitation electrode 40b. On the other hand, the second layer excitation electrodes 40a and 40c and the input / output electrode 44 are at the same potential, but the second layer extraction electrode 48 is cut off via the second layer extraction electrode 46 and is directly connected. It has not been. However, the second layer extraction electrode 48 is electrically connected to the first layer extraction electrode 26 via the opening 36 formed in the piezoelectric layer 28 described above, and the first layer extraction electrode 26 and the second layer The second layer excitation electrodes 40a and 40c, the first layer excitation electrode 22b, and the input / output electrode 44 are electrically connected via the extraction electrode 48. In FIGS. 1 and 2, a part of the first layer extraction electrodes 24 and 26 and a part of the second layer extraction electrodes 46 and 48, which have different potentials, are shown as being overlapped. Actually, the extraction electrodes having different potentials are designed so as not to overlap on the front and back surfaces of the piezoelectric layer 28. This is to suppress excitation at locations other than the vibrating arm 16.

  In the resonator element 10 according to this embodiment having such a basic configuration, the protrusions 18 (18 a to 18 c) are formed on the vibrating arm 16 of the substrate 12. The protrusion 18 is formed on the second surface of the vibrating arm 16. The protrusions 18 are formed on all of the plurality (three) of the vibrating arms 16 and are formed at the same position in the longitudinal direction of the vibrating arms 16. With this configuration, the resonance characteristics of the vibrating arm 16 can be matched. When the positions of the protrusions 18 are made different or the protrusions 18 are selectively formed, the protrusions 18 are preferably formed as a unit for each vibrating arm 16 that vibrates in the same phase as a pair or a set. This is because if the resonance characteristics of the vibrating arms 16 that vibrate in the same phase as a pair or a pair are different, the vibration is not canceled out and a moment in the rotational direction is generated. Further, it is desirable that the protrusion 18 is formed over the entire width of each vibrating arm 16. This is because by adopting such a configuration, it is possible to enhance the effect of suppressing the bending and twisting in the width direction generated in the vibrating arm 16.

  The formation position of the protrusion 18 is not particularly limited, but preferably when the vibrating arm 16 is viewed in plan, the excitation electrodes (first layer excitation electrodes 22a to 22c, second layer excitation electrodes 40a to 40c). It is good to form in either of the site | parts which overlap with the formation position. This is because the bending in the width direction at the portion contributing to vibration can be positively suppressed.

  By setting it as such a structure, the bending (refer FIG. 3) of the width direction of the vibrating arm 16 is suppressed, and the twist at the time of the vibrating arm 16 swinging can be prevented. In FIG. 3, FIG. 3A shows the state of the vibrating piece before excitation, and FIG. 3B shows the state of the vibrating piece that has been twisted and bent by the excitation.

  Next, with reference to FIG. 4, the manufacturing process of the resonator element 10 according to the present embodiment will be described. First, a base plate 12a that serves as a basis for the resonator element 10 is prepared. In the present embodiment, quartz is adopted as the base plate 12a. When the base plate 12a is made of quartz, the thickness is preferably about 50 to 100 μm (see FIG. 4A).

  Next, a part of the base plate 12a is thinned. The thinning may be performed by etching using buffered hydrofluoric acid (BHF) or the like. At this time, when the base plate 12a is made of quartz, the thickness of the thin portion 12b may be about 2 to 5 μm (see FIG. 4B).

  After thinning, the protrusion 18 and the outer shape of the substrate 12 are formed. The formation of the protrusion 18 and the outer shape of the substrate 12 may be performed in advance, but when the protrusion 18 is formed, from the second surface side, when the outer shape is formed, the first surface. It is desirable to perform etching from the side. Note that when processing is performed, a spray-type resist coating that can form a resist film along a three-dimensional surface may be employed, and BHF may be used for etching (see FIG. 4C).

  After finishing the outer shape of the protrusion 18 and the substrate 12, the first electrode 20 (see FIG. 2) is formed on the first surface. First, the first electrode 20 is formed by forming a metal layer on the entire first surface. The metal layer may be formed using a technique such as magnetron sputtering. After forming the metal layer, a resist is applied to the entire surface. Thereafter, the metal layer is etched by a photolithography method to obtain a metal pattern along the shape of the first electrode 20.

  After the first electrode 20 is formed, the piezoelectric layer 28 is formed at a desired location. First, a piezoelectric layer is formed on the entire first surface of the substrate including the first electrode 20. The formation of the piezoelectric layer is performed using a reactive RF magnetron sputtering method. In the case where the piezoelectric layer is made of AlN, the thickness of the piezoelectric layer is preferably in the range of about 2000 mm to 10,000 mm (see FIG. 4D).

  Next, the piezoelectric layer is formed into a desired pattern by patterning the resist by photolithography and wet etching. When the piezoelectric layer is made of AlN, a strong alkaline aqueous solution is used as an etchant for wet etching. Examples of strong alkaline aqueous solutions include tetramethylammonium hydroxide aqueous solutions. In addition, in an acid system, it is possible to etch even phosphoric acid heated.

  After the formation of the shape of the piezoelectric layer 28 is completed, the second electrode 38 (see FIG. 2) is formed. As with the formation of the first electrode 20, the second electrode 38 may be formed by forming a metal layer on the entire first surface, patterning a resist by photolithography, and forming a shape by wet etching (FIG. 4 (E)).

  In the said embodiment, it described that the board | substrate 12 was comprised with quartz. However, the resonator element 10 according to the present embodiment excites vibrations in the out-of-plane direction by the piezoelectric layer 28. For this reason, the material of the substrate 12 may be a member other than quartz. Specifically, a piezoelectric material other than quartz may be used, or a semiconductor material such as silicon may be used.

In the above embodiment, the second electrode 38 is directly formed on the upper surface of the piezoelectric layer 28. However, in the resonator element 10 according to the present embodiment, an insulating layer (insulating film) may be formed between the piezoelectric layer 28 and the second electrode 38 (not shown). By adopting such a configuration, it is possible to prevent a short circuit between the first electrode 20 and the second electrode 38 even when the through hole is formed in the piezoelectric layer 28. In addition, as a film thickness of an insulator layer, it is desirable to set it as 50 nm or more from a viewpoint of short circuit prevention. On the other hand, from the viewpoint of suppressing the deterioration of the characteristics of the piezoelectric layer 28, the thickness is desirably 500 nm or less. Here, the insulator layer may be made of silicon dioxide SiO ₂ or silicon nitride SiN _X.

Furthermore, you may make it form an inorganic body layer (inorganic film | membrane) with respect to the 2nd surface of the vibrating arm 16 in the vibration piece 10 which concerns on the said embodiment (not shown). By providing an insulator layer made of SiO ₂ or SiN _X , the frequency temperature characteristic can be corrected. In particular, silicon dioxide by thermal oxidation is known to have negative temperature characteristics, and is suitable for adjusting the frequency temperature characteristics.
Furthermore, a plurality of protrusions may be provided for one vibrating arm 16. This is because it is possible to improve the effect of suppressing twisting.

  Next, an embodiment according to the vibrator of the present invention will be described with reference to FIG. The vibrator 50 according to the present embodiment includes the vibrating piece 10 and a package 52 in which the vibrating piece 10 is mounted.

  The vibrating piece 10 employs the vibrating piece 10 according to the above embodiment. The package 52 is configured based on a package base 54 and a lid 56. The package base 54 has a box shape and includes the resonator element mounting terminal 60 inside. On the other hand, an external mounting terminal 62 electrically connected to the resonator element mounting terminal 60 is provided on the outer bottom surface of the package base 54.

  The package base 54 having such a configuration may be formed of an insulating member. For example, the package base 54 can be formed by laminating a flat plate and a frame-shaped ceramic green sheet and firing them. The resonator element mounting terminal 60 and the external mounting terminal 62 can be formed by screen printing on a ceramic green sheet.

  The lid 56 may be a flat plate made of metal or glass. As a constituent material of the lid 56, a material whose linear expansion coefficient approximates that of the constituent material of the package base 54 is desirable. This is to suppress the occurrence of cracks and peeling due to temperature changes. When the package base 54 is made of ceramic, it is preferable to use kovar (alloy) or soda glass.

  For joining the package base 54 and the lid 56, welding using a brazing material 58 is performed. When the lid 56 is made of metal, the brazing material 58 may be a low melting point metal, and when the lid 56 is glass, the brazing material 58 may be low melting point glass.

  In the manufacture of the vibrator 50 according to this embodiment composed of such constituent members, first, the resonator element 10 is mounted inside the package base 54. The vibration piece 10 may be mounted using the adhesive 64. After mounting the resonator element 10 on the package base 54, wire bonding is performed using a gold wire 66 or the like to electrically connect the resonator element mounting terminal 60 and the input / output terminals 42 and 44 (see FIG. 1) of the resonator element 10. Connecting. After the mounting of the resonator element 10 is thus completed, the lid 56 is joined to the package base 54, and the opening is sealed.

  According to the vibrator 50 having such a configuration, the torsion of the vibrating arm 16 in the vibrating piece 10 is eliminated, so that vibration stability is improved and a high Q value can be obtained. In the vibrator 50 according to this embodiment, the package base 54 is box-shaped and the lid 56 is flat. However, the package base may be flat and the lid may be cap-shaped.

  Next, an embodiment according to the oscillator of the present invention will be described with reference to FIG. The oscillator 70 according to the present embodiment is basically configured of the resonator element 10, an electronic component 82 for causing the resonator element 10 to oscillate, and a package 72 in which the resonator element 10 and the electronic component 82 are mounted.

  The vibrating piece 10 employs the vibrating piece 10 according to the above embodiment. The package 72 is configured based on a package base 74 and a lid 76. The package base 74 according to the present embodiment includes a center substrate 74a for mounting as a base point and includes cavities on the upper and lower sides thereof. The upper cavity is a resonator element mounting region 75a and the lower cavity is an electronic component mounting region 75b.

  A vibration piece mounting terminal 60 is provided on the center board 74 on the vibration piece mounting region 75a side, and an electronic component mounting terminal 80 is provided on the electronic component mounting region 75b side. In addition, an external mounting terminal 86 that is electrically connected to the electronic component mounting terminal 80 is provided at a portion corresponding to the bottom surface of the package base 74. The constituent members and the manufacturing method are the same as those of the package base 54 in the vibrator 50 described above. In the present embodiment, the lid 76 may be a flat plate made of metal or glass, and the vibration piece mounting region 75 in the package base 74 is sealed using the brazing material 78.

The electronic component 82 may be an IC provided with an integrated circuit, for example, and may be mounted on the electronic component mounting terminal 80 by flip chip bonding using bumps 84 or the like.
Since the oscillator 70 having such a configuration also eliminates the twist of the vibrating arm 16 in the resonator element 10 like the vibrator 50, the vibration stability is improved and a high Q value can be obtained. And can be highly reliable.

  As an example of the electronic apparatus according to the present invention, a mobile phone 100 shown in FIG. 7, a personal computer 200 shown in FIG. In any case, at least one of the vibrator 50 and the oscillator 70 shown in the above embodiment is mounted as a local oscillator used for clock source or signal modulation or demodulation. By having such a feature, it is possible to cope with downsizing and thinning of electronic devices. Further, even when downsizing is performed, it is possible to improve the accuracy of communication or the like according to the function of the electronic device.

DESCRIPTION OF SYMBOLS 10 ......... Vibrating piece, 12 ...... Board | substrate, 14 ......... Base part, 16 (16a-16c) ...... Vibrating arm, 18 (18a-18c) ...... Protrusion part, 20 ......... 1st electrode , 22 (22a to 22c) ......... first layer excitation electrode, 24 ......... first layer extraction electrode, 26 ......... first layer extraction electrode, 28 ......... piezoelectric layer, 30 (30a-30c) ......... Excitation electrode covering part, 32 ......... Extraction electrode covering part, 34 ......... Opening part, 36 ......... Opening part, 38 ......... Second electrode, 40 (40a to 40b) ......... Second Layer excitation electrode 42... Input / output electrode 44... Input / output electrode 46... Second layer extraction electrode 48 48 Second layer extraction electrode 50. ... oscillator.

Claims (8)

A base provided on a plane including a first direction and a second direction orthogonal to the first direction;
A plurality of vibrating arms extending from the base in the first direction;
The vibrating arm bends and vibrates in a normal direction of the plane, and is compressed when the first surface is compressed, and is compressed when the first surface is expanded. A second surface to be
A vibration piece, wherein a protrusion is formed on a vibration arm arranged at least on the outermost side of the plurality of vibration arms. The resonator element according to claim 1,
An excitation electrode on the first surface;
A vibrating piece comprising the protrusion on the second surface. The resonator element according to claim 2,
The resonator element, wherein the excitation electrode and the protrusion overlap when the resonator element is viewed in plan from the normal direction. The vibration piece according to any one of claims 1 to 3,
The vibrating piece according to claim 1, wherein the protrusion is formed over the entire width of the vibrating arm. 5. The resonator element according to claim 1, wherein:
The projecting portion is formed on all of the plurality of vibrating arms. A vibrating piece according to any one of claims 1 to 5,
A vibrator having a package for mounting the resonator element therein. A vibrating piece according to any one of claims 1 to 5,
And an electronic component that controls oscillation of the resonator element.   An electronic apparatus comprising the resonator element according to any one of claims 1 to 5.

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