JP2011097499A - Tuning-fork type vibrating element, tuning-fork type vibrator and oscillator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an inexpensive tuning-fork type piezoelectric vibrator which is easily made compact and manufactured in simple steps. <P>SOLUTION: A tuning-fork type vibrating element comprises: a substrate 9 having two principal surfaces; a first beam 11 and a second beam 12 which are cantilevered by the substrate 9; and a third beam 13 cantilevered by a portion of the substrate 9 between the first beam 11 and the second beam 12. In at least a part of front surfaces of the first and the second beams 11 and 12, first driving electrodes 11a and 12a are formed and in at least a part of their rear surfaces, second driving electrodes 11b and 12b are formed. In at least a part of a front surface of the third beam 13, a third driving electrode 13a is formed and in at least a part of its rear surface, a fourth driving electrode 13b is formed. Between the first driving electrode and the second driving electrode, a signal is applied, which has a potential opposite to a potential to be applied between the third driving electrode and the fourth driving electrode. The first and the second beams 11 and 12 and the third beam 13 are piezoelectric materials that cause thickness-shear distortion by an electric field generated in a thickness direction. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to a tuning fork type vibration element, a tuning fork type vibrator, and an oscillator, and more particularly to a tuning fork type vibration element using a bending vibration that generates a thickness-slip distortion on a piezoelectric substrate and is excited by the distortion, and the tuning fork type vibration. The present invention relates to a tuning fork type vibrator using an element and an oscillator.

Piezoelectric vibrators are widely used from communication equipment to electronic equipment because they have advantages such as small size, small secular change, and easy acquisition of highly stable frequencies. Above all, tuning fork type (
Piezoelectric vibrators are widely used as clock sources for various ICs including watches.
Patent Document 1 discloses a tuning fork vibrator having three vibrating arms. FIG. 9A is a plan view of the tuning fork type vibration element, and FIG. 9B is a cross-sectional view taken along the line Q-Q. The tuning fork type vibration element 70 includes arm parts 71, 72, 73, a base part 74 that connects one end of each of these three arm parts, and piezoelectric body elements 75, 76, 77. .
The base 74 is connected to one end of each of the three arm portions 71, 72, 73, and connects these arm portions 71, 72, 73. The piezoelectric element 75 is provided on the upper surface 71 a of the arm portion 71. Similarly, the piezoelectric elements 76 and 77 are the upper surfaces 72a and 73 of the arm portions 72 and 73, respectively.
a is provided.

The piezoelectric element 75 includes a lower electrode film 75a disposed on the upper surface 71a of the arm 71, a piezoelectric film 75b disposed on the lower electrode film 75a, and an upper electrode film disposed on the piezoelectric film 75b. 75c. The piezoelectric film 75b is made of, for example, ZnO, AlN, PZT, LiNbO _3.
Etc. The configuration of the piezoelectric elements 76 and 77 is the same as that of the piezoelectric element 75.
The lower electrode film 75a (76a, 77a) and the upper electrode film 75c (76c, 77c) are conductor films such as a chromium film and a gold film, respectively. Each of the lower electrode films 75a and 77a provided on the two arm portions 71 and 73 disposed on the outer side of the tuning fork type vibration element 70, and the upper electrode film 76c provided on the arm portion 72 disposed on the inner side. They are connected to each other. In addition, the upper electrode films 75c and 77c provided on the two arm portions 71 and 73 disposed on the outer side and the lower electrode film 76a provided on the arm portion 72 disposed on the inner side are electrically connected to each other. ing.
When an electric signal is supplied through the electrode pads 84 and 86 of the tuning fork type vibration element 70, the arm portion 71 is provided.
73 and arm part 72 can be alternately vibrated up and down. Thus, it is disclosed that the Q value can be increased even in a vibration mode using vertical vibration by adopting a tripod structure.

JP 2009-5022 A

However, in the tuning fork type vibration element disclosed in Patent Document 1, a lower electrode film is formed on the upper surface of each arm, a piezoelectric film is formed on the lower electrode film, an upper electrode film is formed on the piezoelectric film, and a vapor deposition apparatus. Alternatively, it is necessary to repeat the film forming process several times using a sputtering apparatus, which causes a problem that the film forming process becomes complicated. Further, when the multilayer film is formed over the entire width of the arm portion, there is a problem that a short circuit or the like occurs. In addition, the manufacturing process is complicated and the tuning fork vibrator is expensive.
The present invention has been made to solve the above-described problems, and it is an object of the present invention to provide an inexpensive tuning fork type piezoelectric vibrator that is easy to downsize, has a simple manufacturing process, and is inexpensive.

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 tuning fork type vibration element according to the present invention has two main surfaces that are front and back in order to realize a tuning fork type piezoelectric vibration element that is easy to downsize, has a simple manufacturing process, and is inexpensive. Substrate,
Cantilever is supported by the base and cantilevered by the first and second beams that protrude in parallel to the surface direction of the main surfaces, and the base portion between the first and second beams A tuning fork-type vibrating piece provided with a third beam supported and projecting in the same direction as each of the beams; a first driving electrode formed on at least a part of the surface of the first and second beams; A second drive electrode formed on a portion of the back surface of each of the first and second beams facing at least a portion of the first drive electrode; and a second drive electrode formed on at least a portion of the surface of the third beam. 3 drive electrodes, and a fourth drive electrode formed on a back surface portion of the third beam facing at least a part of the third drive electrode, the first drive electrode and the second drive A potential applied between the third drive electrode and the fourth drive electrode; A signal having a reverse potential is applied, and the first beam, the second beam, and the third beam are piezoelectric materials that cause thickness-slip distortion due to an electric field generated in a thickness direction that is the front-back direction. This is a characteristic tuning fork type vibration element.

For example, a partial region of the piezoelectric substrate is etched from one side, the region is processed to a desired thickness, and the thinned region is etched again to form the tuning fork type vibrating piece. A driving electrode is formed on a piece in a vacuum to obtain a tuning fork type vibration element. Thus, if the tuning fork type resonator element is formed by etching, there is an effect that it is easy to downsize and mass production is possible. In addition, if a piezoelectric substrate is used, the film forming process can be completed in one time, so that the manufacturing process is facilitated. The first and second beams on both sides;
By driving the third beam in the center in the opposite phase, vibration leakage from the base can be reduced, and the Q value of the tuning fork type vibration element can be improved.

Application Example 2 In the tuning fork type vibration element, the first drive electrode, the second drive electrode, the third drive electrode, and the fourth drive electrode have a full width in the width direction of the beam on which each is formed. The tuning-fork type vibration element according to application example 1, wherein the tuning-fork type vibration element extends over a range.

Since the first to fourth drive electrodes are formed in one film formation process, the drive electrodes are formed on the first, second and third beams over the entire width in the width direction. Is possible,
There is an effect that the slip distortion can be excited efficiently.

Application Example 3 In addition, the tuning fork type vibration element is configured such that the thickness gradually increases as the base moves away from the connection portion between the first beam, the second beam, and the third beam. The tuning fork type vibration element according to Application Example 1 to be described.

Since the first beam, the second beam, and the third beam are processed to be extremely thin, it becomes easy to excite bending vibration by the slip strain generated between the drive electrodes. In addition, since the thickness of the base body gradually increases as the distance from the connecting portion increases, it is easy to support the tuning fork type vibration element, and the vibration leakage of the bending vibration is reduced and the Q value is improved. There is an effect of doing.

Application Example 4 Further, the tuning fork type vibration element according to any one of Application Examples 1 to 3, wherein the tuning fork type vibration piece is made of quartz.

Since the tuning fork type resonator element is formed using quartz, there is an effect that processing accuracy is good and miniaturization is facilitated. Further, since the material has a high Q value, there is an effect that a tuning fork type vibration element having a high Q and good temperature characteristics can be obtained.

Application Example 5 A tuning fork vibrator according to the present invention includes the tuning fork vibration element according to any one of Application Examples 1 to 4 and a package that accommodates the tuning fork vibration element. It is a characteristic tuning fork type vibrator.

Since the tuning fork vibrator is configured using the tuning fork vibrator according to any one of Application Examples 1 to 4, a tuning fork vibrator that is small in size, has a large Q value, has good temperature characteristics, and is inexpensive. There is an effect that it is obtained.

Application Example 6 An oscillator according to the invention includes a tuning fork type vibration element according to any one of Application Examples 1 to 4, an IC circuit for exciting the tuning fork type vibration element, the tuning fork type vibration element, and the tuning fork type vibration element. An oscillator comprising an IC circuit package.

Since the oscillator is configured using the tuning fork type vibration element according to any one of Application Examples 1 to 4 and an IC circuit, there is an effect that a small and inexpensive oscillator can be obtained.

It is a figure which shows the structure of the tuning fork type vibration element which concerns on this invention, (a) is a top view, (b) is sectional drawing, (c) is a back view. (A), (b) is explanatory drawing which shows the voltage applied to the drive electrode of the beams 11-13. Sectional drawing explaining that a sliding distortion produces a bending vibration. (A), (b) is sectional drawing of the bending vibration mode of the beams 11-13. It is a figure which shows the structure of the tuning fork type vibration element of 2nd Example, (a) is a top view, (b) is sectional drawing, (c) is a back view. The top view of the tuning fork type vibration element of a 3rd Example. Sectional drawing of the tuning fork type vibrator of the present invention. Sectional drawing of the oscillator of this invention. It is a figure which shows the structure of the conventional tuning fork type vibration element, (a) is a top view, (b) is sectional drawing of each arm part.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic view showing a configuration of a tuning fork type vibration element 1 according to an embodiment of the present invention. FIG. 1 (a) is a plan view, and FIG.
) Is a cross-sectional view taken along the line Q-Q, and FIG.
The tuning fork type vibration element 1 is a rectangular plate made of a piezoelectric material and has a frame 5 and a frame 5 from one side of the frame 5.
Three beams that are parallel to the principal plane (XZ plane of the coordinate axis) and project parallel to each other in the Z-axis direction, and the driving electrodes formed on the front and back surfaces of the three beams, respectively, A lead electrode extending from the electrode for use and connected to a pad electrode formed at an end of the frame 5.
The rectangular plate-shaped frame 5 is composed of four members 6, 7, 8, and 9 having the same thickness (Y-axis direction), and joins one end of the member 6 and one end of the member 7. Then, the other end of the member 7 and one end of the member 8 are joined, the other end of the member 8 and one end of the member 9 are joined, and the other end of the member 9 A rectangular plate-shaped frame 5 is configured by joining the other end of the member 6. Here, the member 9 of the frame 5 is wider in the Z-axis direction than the other members 6, 7, 8, and is referred to as a base body 9.
Note that the coordinate axes (X, Y, Z) shown in FIG. 1 are coordinate axes indicating the direction of the tuning fork type vibration element 1 and not the crystal axes of the piezoelectric crystal. Further, although the frame 5 has been described as having a rectangular shape, the frame 5 does not necessarily have to have a rectangular shape and may have another shape.

The tuning fork type vibration element 1 includes a base body (member) 9 having two main surfaces (XZ plane) in a front / back relationship.
A first beam 11, a second beam 12, and a first beam 11, each of which is cantilevered by a base 9 and protrudes parallel to the surface direction of each main surface and parallel to the Z-axis direction; It includes a tuning fork-type vibrating piece including a third beam 13 that is cantilevered by a base 9 portion between the second beam 12 and protrudes in the same direction as each of the beams 11 and 12.
At least a part of the surface of the first and second beams 11 and 12 is provided with a first driving electrode 11a,
12a is formed. Second drive electrodes 11b and 12b are formed on the back surfaces of the first and second beams 11 and 12 that face at least a part of the first drive electrodes 11a and 12a, respectively. A third driving electrode 13a is formed on at least a part of the surface of the third beam 13, and the fourth driving electrode 13b is formed on the back surface of the third beam 13 facing at least a part of the third driving electrode 13a. Is formed.
The first drive electrodes 11a, 12a, the second drive electrodes 11b, 12b, the third drive electrode 13a, and the fourth drive electrode 13b have full widths in the width direction (X-axis direction) of the beams 11, 12, 13 on which they are formed. It is formed over.
A lead electrode 21a extends from the first driving electrode 11a formed on the surface of the first beam 11 to a pad electrode 25a formed on the end of the surface of the base 9, and is connected to the pad electrode 25a. Similarly, the lead electrode 23a extends from the third driving electrode 13a formed on the surface of the third beam 13 to the pad electrode 26a formed on the end of the surface of the base 9, and is connected to the pad electrode 26a. The first driving electrode 12a formed on the surface of the second beam 12 is connected to the pad electrode 25a formed on the end portion of the base body 9 by the lead electrode 22a formed on the surface of the base body 9 and the members 8, 7 and 6. It is connected.

A lead electrode 22b extends from the second driving electrode 12b formed on the back surface of the second beam 12 to a pad electrode 26b formed on the end of the back surface of the base 9, and is connected to the pad electrode 26b. Similarly, a lead electrode 23b extends from the fourth driving electrode 13b formed on the back surface of the third beam 13 to a pad electrode 25b formed on the end of the back surface of the substrate 9, and is connected to the pad electrode 25b. . The second driving electrode 11b formed on the back surface of the first beam 11 is connected to the pad electrode 26 at the end of the substrate 9 by the lead electrode 21b formed on the back surface of the substrate 9 and the members 6, 7, and 8.
connected to b.
The pad electrode 25a formed on the surface of the substrate 9 and the pad electrode 25 formed on the back surface of the substrate 9
The pad electrode 26a formed on the surface of the base body 9 and the pad electrode 26b formed on the back surface of the base body 9 are used in a conductive state.

The tuning fork type vibration element 1 includes a frame 5, a first beam 11 and a second beam 11, 12 projecting from a base body 9 of the frame 5 in parallel to the main surface, and between the first beam 11 and the second beam 12. And a third beam 13 which is cantilevered by the base 9 portion and protrudes in the same direction as each of the beams 11 and 12, and processes a flat piezoelectric substrate using a photolithography technique and an etching technique. It is manufactured by. That is, it is possible to use an integrated processing method in which the frame 5 is left, the beams 11, 12, and 13 are half-etched to form thin plate-like beams, and the other regions are removed by etching. Examples of the piezoelectric substrate include crystal, lithium tantalate, lithium niobate, and langasite. When a quartz substrate is used, there are an AT-cut quartz substrate (AT plate), a BT-cut quartz substrate (BT plate), a Y-cut quartz substrate (Y plate; a substrate perpendicular to the crystal axis Y of quartz), and the like. If an AT plate, a BT plate, or a Y plate is used, a slip strain can be easily generated by applying a voltage in the thickness direction.

The example shown in FIG. 1 is an example in which a flat crystal substrate is processed. Since the etching rate varies depending on the crystal axis direction of the crystal, as shown in FIGS. 1A, 1B, and 1C, the etching cross section is not perpendicular to the main surface of the crystal substrate, and the inclined surfaces 6a, 7a, 8a. 9a are formed. The angle of each inclined surface 6a, 7a, 8a, 9a depends on the direction of the crystal axis.
The tuning fork type vibration element shown in FIG. 1 proceeds with etching from one main surface (surface) of the quartz substrate,
The first beam 11, the second beam 12, and the third beam 13 are formed so as to remain on the other surface (back surface) of the crystal substrate, and between the frame 5 and the beams 11, 12, 13, and the beams 11, Etching is controlled so that an opening is formed between 12 and 13.
As shown in FIG. 1B, one end of the third beam 13 (first and second beams 11 and 12) is
The substrate 9 is coupled to the substrate 9 via a gently inclined surface (inclined portion) 9a. That is, the base 9
The cross section has a shape in which the thickness gradually increases as the distance from the connecting portion with the third beam 13 (the first and second beams 11 and 12) increases in the −Z-axis direction.
The driving electrodes 11a to 13b and the lead electrodes 21a to 23b are formed by depositing a metal such as chromium Cr, gold Au or the like in a multilayer film in a vacuum using a vacuum deposition apparatus, a sputtering apparatus, or the like. At this time, in order to avoid disconnection of the lead electrodes 21a to 23b, the gently inclined surface 9 of the base 9 is provided.
a, It is desirable to form on the front and back of the frame 5.

FIG. 2 shows the first and second beams 11 when an excitation voltage is applied between the pad electrodes 25a and 26a.
, Twelve first and second driving electrodes 11a to 12b, and third and fourth driving electrodes 13a and 13b of the third beam 13, a cross section showing signs (+, −) of voltage generated at a certain moment FIG. In the first and second drive electrodes 11a and 12b and the third and fourth drive electrodes 13a and 13b, the applied voltages are in reverse phase.

FIG. 3 is an enlarged cross-sectional view of a main part for explaining the vibration state of the first beam 11, and an excitation voltage is applied between the upper electrode 11a and the lower electrode 11b. When the excitation voltage is applied, the first beam 11 first
In addition, an electric field due to the excitation voltage is generated between the second driving electrodes 11a and 11b, and slip distortion is excited. That is, the upper part of the thickness of the first beam 11 is displaced to the right in the figure, and the lower part of the thickness is displaced to the left in the figure. That is, a sinusoidal displacement as shown by the wavy line in FIG. 3 occurs.
Due to this displacement, bending vibration in the Y-axis direction indicated by a one-dot chain line is excited in the first beam 11. That is, a bending vibration in the Y-axis direction is excited in the first beam 11 by the voltage applied between the first driving electrode 11a and the second driving electrode 11b formed on the first beam 11. The same applies to the second beam 12 and the third beam 13, and the description thereof will be omitted.

FIG. 4 shows the first and second beams 11 and 12 when the tuning fork type vibration element 1 is bonded and fixed to the base 40 using the conductive adhesive 35 and an AC voltage is applied between the pad electrodes 25a and 26a. FIG. 6 is a cross-sectional view showing a state of vibration with the third beam 13.
4 is a cross-sectional view showing an instantaneous vibration state of the first and second beams 11 and 12 and the third beam 13, and the first and second beams 11 and 12 and the third beam 13 are Vibrating in reverse phase. That is, when the first and second beams 11 and 12 are bent downward (−Y-axis direction) at a certain moment, the third beam 1
3 vibrates so as to bend upward (in the + Y-axis direction).
By driving the beams on both sides (first and second beams 11 and 12) and the center beam (third beam 13) in opposite phases, vibration leakage from the base 9 can be reduced, and tuning fork vibration There is an effect that the Q value of the element 1 can be improved.
A part of the piezoelectric substrate is etched from one side, the region is processed to a desired thickness, and the thinned region is etched again to form the tuning fork type vibrating piece. A drive electrode is formed therein to form a tuning fork type vibration element. Thus, if the tuning fork type resonator element is formed by etching, there is an effect that it is easy to downsize and mass production is possible. In addition, if a piezoelectric substrate is used, the film forming process can be completed once,
There is an effect that the manufacturing process becomes easy.

First and second drive electrodes 11a, 12a, 11b and 12b, and third and fourth drive electrodes 13a
, 13b are formed in one film formation step, the first to fourth drive electrodes 11a-13b are connected to the first.
The second and third beams 11, 12, and 13 can be formed over the entire width in the width direction, and there is an effect that the slip strain can be excited efficiently.
Since the first beam 11, the second beam 12, and the third beam 13 are processed extremely thinly, bending vibration can be easily excited by the slip strain generated between the drive electrodes. Further, since the thickness of the base 9 is gradually increased as the distance from the connecting portion with the beam is increased, the tuning fork type vibration element 1 can be easily supported, and the vibration leakage of bending vibration can be reduced. It has the effect of improving the value.
Further, when the tuning fork type resonator element is formed using quartz, there are effects that the processing accuracy is good and the miniaturization becomes easy. In addition, since the material has a high Q value, there is an effect that a tuning fork type vibration element 1 having high Q and good temperature characteristics can be obtained.

FIGS. 5A and 5B are diagrams showing the configuration of the tuning fork type vibration element 2 of the second embodiment. FIG. 5A is a plan view, FIG. 5B is a cross-sectional view, and FIG. is there. The tuning fork type vibration element 2 of the second embodiment is different from the tuning fork type vibration element 1 shown in FIG. 1 in the member 7 and the lead electrodes 22a and 21b. When the quartz substrate is processed using a photolithography technique and an etching technique, the member 7
And a step of forming a groove by half etching at the boundary between the member 6 and the member 8 may be added. By folding along the groove, a substrate of the tuning fork type vibration element 2, that is, a tuning fork type vibration piece is formed. The formation method of the drive electrodes 11a to 13b and the lead electrodes 21a to 23a is formed using the above-described method. However, the connection between the lead electrode 22a on the front surface and the pad electrode 25a and the connection between the lead electrode 21b on the back surface and the pad electrode 26b are made by using a bonding wire or by multilayering the lead electrodes with an insulating layer in between. It is necessary to take the technique to do.

FIG. 6 is a plan view showing the configuration of the tuning fork type vibration element 3 of the third embodiment. The tuning fork type vibration element 3 is different from the tuning fork type vibration element 2 of the second embodiment shown in FIG. When the quartz substrate is processed using a photolithography technique and an etching technique, the substrate 9
What is necessary is just to add the process of forming a groove part by a half etching in the boundary part of the boundary of (member 9) and member 6, and the boundary of the base | substrate 9 (member 9) and member 8. If it is broken along the groove, a tuning fork type vibrating piece as a substrate of the tuning fork type vibration element 3 is formed. The method for forming the drive electrode and the lead electrode is as described above.

FIG. 7 is a cross-sectional view showing a configuration of a tuning fork vibrator 50 according to the present invention. The tuning fork vibrator 50 includes a tuning fork type vibration element according to any of the first to third embodiments and a package 5 that accommodates the tuning fork type vibration element.
1 is provided. The package 51 includes a package main body 51a and a lid member 51b, and external connection terminals 52 are formed on the outer bottom portion of the package main body 51a. A pedestal 53 for mounting the tuning fork type vibration element via, for example, a conductive adhesive 53 is provided inside the package body 51a. A connection electrode is provided on the surface of the pedestal 53, and the connection electrode is electrically connected to the external connection terminal 52 of the package body 51a. After the tuning fork type vibration element is accommodated in the package body 51a, the package body 51a is vacuum-sealed, and the lid member 51b is hermetically sealed with resistance welding or glass having a low melting point.
Since the tuning fork vibrator is configured using the tuning fork vibrator of any one of the first to third embodiments, there is an effect that a tuning fork vibrator that is small in size, has a large Q value, has good temperature characteristics, and is inexpensive can be obtained. is there.

FIG. 8 is a cross-sectional view showing the configuration of the oscillator 60 according to the present invention. The oscillator 60 includes the tuning fork type vibration element according to any one of the first to third embodiments, an IC circuit 55 that excites the tuning fork type vibration element, and a package 51 that houses the tuning fork type vibration element and the IC circuit 55. ing. Package 5
1 includes a package body 51a and a lid member 51b, and an external connection terminal 52 is formed on the outer bottom of the package body 51a. A pedestal 5 for mounting the IC pad electrode and the tuning-fork type vibration element, for example, via the conductive adhesive 53 inside the package body 51a.
3 is provided. A connection electrode is provided on the surface of the base 53, and the connection electrode and the IC pad electrode are electrically connected to the external connection terminal 52 of the package body 51a. After housing the tuning fork type vibration element and the IC circuit 55 in the package body 51a, the package body 51a
The lid member 51b is hermetically sealed with resistance welding or glass having a low melting point.
Since the oscillator is configured using the tuning fork type vibration element according to any of the first to third embodiments and the IC circuit, there is an effect that a small and inexpensive oscillator can be obtained.

1, 2, 3, ... tuning fork type vibration element, 5 ... frame, 6, 7, 8 ... member, 9 ... base (member), 6a,
7a, 8a, 9a ... inclined surface, 11 ... first beam, 12 ... second beam, 13 ... third beam, 11a, 12
a ... 1st drive electrode, 11b, 12b ... 2nd drive electrode, 13a ... 3rd drive electrode, 13b
... 4th drive electrode, 21a, 22a, 23a, 21b, 22b, 23b ... Lead electrode, 25
a, 25b, 26a, 26b ... pad electrode, 35 ... conductive adhesive, 40 ... base, 50 ... tuning fork vibrator, 51 ... package, 51a ... package body, 51b ... lid member, 52 ... external connection terminal, 53 ... pedestal, 55 ... IC circuit, 60 ... oscillator

Claims (6)

A base having two main surfaces in a front-back relationship, a first beam and a second beam that are cantilevered by the base and project in parallel with the surface direction of each main surface, and the first beam and the first beam A tuning fork-type vibrating piece including a third beam that is cantilevered by the base portion between the two beams and protrudes in the same direction as each of the beams;
A first driving electrode formed on at least a part of the surface of each of the first and second beams; and a back surface of the first and second beams facing at least a part of the first driving electrode. A second driving electrode formed respectively, a third driving electrode formed on at least a part of the surface of the third beam, and a back surface of the third beam facing at least a part of the third driving electrode. A fourth drive electrode formed at the site of
A signal having a potential opposite to that applied between the third drive electrode and the fourth drive electrode is applied between the first drive electrode and the second drive electrode,
The tuning fork type vibration element, wherein the first beam, the second beam, and the third beam are piezoelectric materials that cause a thickness-slip distortion due to an electric field generated in a thickness direction that is a direction of the front and back surfaces. The first drive electrode, the second drive electrode, the third drive electrode, and the fourth drive electrode each extend over the entire width in the width direction of the beam on which the first drive electrode, the second drive electrode, the third drive electrode, and the fourth drive electrode are formed. Item 2. A tuning-fork type vibration element according to Item 1. 2. The tuning fork type vibration element according to claim 1, wherein the thickness of the base body gradually increases as the distance from the connection portion between the first beam, the second beam, and the third beam increases. The tuning fork type vibrating element according to any one of claims 1 to 3, wherein the tuning fork type vibrating piece is made of quartz. A tuning fork vibrator comprising the tuning fork vibrator according to any one of claims 1 to 4 and a package that accommodates the tuning fork vibrator. A tuning fork type vibration element according to any one of claims 1 to 4, an IC circuit that excites the tuning fork type vibration element, and a package that houses the tuning fork type vibration element and the IC circuit. An oscillator characterized by.

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