JP2010193331A - Vibrating piece and vibrator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce occurrence of vibration leakage and common mode vibration and to make a vibrating piece compact with a simple structure. <P>SOLUTION: The vibrating piece 1 comprises a base part 15, odd-number of three or more vibrating arms 11, 12, 13 and a connecting part 14 positioned between the base part 15 and the vibrating arms 11, 12, 13 for connecting them, respectively. In the vibrating piece 1, the respective vibrating arms 11, 12, 13 are vibrated in a thickness direction and neighboring vibrating arms are vibrated in opposite directions to each other. When the thickness of the vibrating arms 11, 12, 13 is defined as t<SB>1</SB>, the thickness of the connecting part 14 is defined as t<SB>2</SB>and the thickness of the base part 15 is defined as t<SB>3</SB>, t<SB>1</SB>≤t<SB>2</SB><t<SB>3</SB>is established. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vibrating piece having a vibrating arm and a vibrator containing the vibrating piece.

In a vibrator having a vibrating arm, a vibrating piece is known that vibrates in the thickness direction of the vibrating arm, instead of vibrating in-plane like a bending vibration. This resonator element is a resonator element that has a plurality of vibrating arms and performs walk mode vibration in which adjacent vibrating arms repeat vibrations in opposite directions alternately.
In particular, in a vibrating piece using an odd number of vibrating arms, there is a problem in that vibration leaks to the base connected to the vibrating arms because the shape of vibration is not symmetrical.
As a countermeasure against this, in Patent Literature 1, a vibrating piece having three arms (legs) is provided with a rod-like support portion between the mounting portion and the arm, and the support portion functions as a torsion bar. A vibrator element that reduces leakage is disclosed.

JP 2001-196891 A

However, in the structure of Patent Document 1, since the support portion is provided, the size of the vibrating piece is increased, and it is difficult to reduce the size of the vibrating piece.
Further, in the resonator element using the walk mode vibration, there may be a common-mode vibration in which all the vibrating arms vibrate in the same direction. This occurs because the resonance frequencies of the main mode walk mode vibration and the common mode vibration are close to each other, and a resonator element that suppresses the common mode vibration is desired.

  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 resonator element according to this application example includes a base, an odd number of three or more vibrating arms, and a connecting portion that is positioned between the base and the vibrating arms and connects each of them. Each of the vibrating arms vibrates in the thickness direction, and the adjacent vibrating arms vibrate in directions opposite to each other, wherein the thickness of the vibrating arm is t ₁ , the thickness of the connecting portion is t ₂ , when the thickness of the base t _3, and characterized in that _{t 1 ≦ t 2 <t 3} , a.

In the vibration piece having this configuration, the thickness t _{2 of the} connecting portion is formed to be equal to or thicker than the thickness t _{1 of the} vibrating arm, and the thickness t ₃ of the base portion is formed to be thicker than the thickness t _{2 of the} connecting portion.
In this way, by forming the connecting part and the base part thicker than the vibrating arm thickness, the vibration energy of the vibrating arm is reflected by these thickened parts, and the vibration energy is confined in the vibrating arm. It is possible to prevent leakage to the base.
In addition, by providing a connecting portion formed to be equal to the thickness of the vibrating arm, the resonance frequency of the common mode, which is the spurious mode of the vibrating piece, can be separated from the frequency of the main vibration. By separating the resonance frequency of the common mode from the resonance frequency of the main vibration, the vibration of the common mode is less likely to occur.
As described above, the resonator element according to this application example can reduce the occurrence of vibration leakage and common-mode vibration, and can reduce the size of the resonator element with a simple structure.

  Application Example 2 In the resonator element according to the application example described above, the connecting portion is divided using a center line that bisects the distance between the vibrating arms adjacent to each other in the extending direction of the vibrating arm as a dividing line. For example, the sum of the volumes of the odd-numbered vibrating arms and the divided connecting portions connected to the odd-numbered vibrating arms and the even-numbered vibrating arms and the divided connecting portions connected thereto are counted from the vibrating arms at one end. It is desirable that the total volume of

According to the resonator element having this configuration, the sum of the volumes of the odd-numbered vibrating arms and the divided connecting portions connected thereto is equal to the sum of the volumes of the even-numbered vibrating arms and the divided connecting portions connected thereto.
In the resonator element having this configuration, since the connecting portion is distorted with the vibration of the vibrating arm, the volume of each vibrating arm and the connecting portion that vibrates in one direction, and the vibrating arm and the connecting portion that vibrates in the other direction. By equalizing the volume, the state of vibration becomes symmetric and vibration leakage can be reduced.

  Application Example 3 In the resonator element according to the application example described above, it is preferable that shoulder portions projecting in a direction in which the vibrating arms are arranged are formed at both ends of the connecting portion.

  According to this configuration, the shoulder portions that protrude in the direction in which the vibrating arms are arranged are formed at both ends of the connecting portion. With such a structure, assuming that the resonator element is divided with the center line that bisects the distance between adjacent vibrating arms as a dividing line, the shape of the vibrating arm and the connecting portion connected to the vibrating arm are similar. Thus, the symmetry of vibration is increased, and vibration leakage can be reduced.

  Application Example 4 In the resonator element according to the application example described above, it is preferable that a piezoelectric element is provided at a position near the coupling portion of the vibrating arm.

According to this configuration, the piezoelectric element having the piezoelectric material sandwiched between the electrodes is provided at a position close to the connecting portion of the vibrating arm.
By applying an alternating voltage to the electrodes of the piezoelectric element, the piezoelectric element expands and contracts, and the vibrating arm vibrates. Thus, the vibrating arm can be easily driven by providing the vibrating arm with the piezoelectric element.

  Application Example 5 In the resonator element according to the application example described above, an inclined surface portion is formed on at least one of the vibration arm and the connection portion and the connection portion and the base portion where a difference in thickness occurs. It is desirable that

  According to this configuration, the inclined surface portion is formed at least one of the vibration arm and the connection portion and the connection portion and the base portion where the difference in thickness occurs. For this reason, the step part which arises by the difference in thickness is not formed, but the wiring connected to the electrode provided in the vibrating arm can be arranged through this slope part, and the wiring can be arranged reliably without disconnection.

  Application Example 6 A vibrator according to this application example includes the above-described vibration piece and a container that stores the vibration piece, and the vibration piece is housed in the container in an airtight manner. It is characterized by.

  According to this configuration, since the resonator element with reduced vibration leakage is accommodated in the container, it is possible to provide a vibrator having excellent characteristics and a reduced size.

FIG. 3 is a schematic plan view illustrating a configuration of a resonator element according to the first embodiment. The schematic plan view of the back surface of FIG. 1 which shows the structure of the vibration piece in 1st Embodiment. 1 is a schematic cross-sectional view illustrating a configuration of a piezoelectric element according to a first embodiment. The schematic sectional drawing which shows the structure of the vibration piece in 1st Embodiment, and follows the BB disconnection of FIG. Explanatory drawing which shows the structure of the vibration piece blank in 1st Embodiment. The schematic plan view of the wiring connected to the lower electrode in 1st Embodiment. The schematic plan view of the wiring of the back surface connected to the lower electrode in 1st Embodiment. The schematic plan view of the wiring connected to the upper electrode in 1st Embodiment. The schematic plan view of the wiring of the back surface connected to the upper electrode in 1st Embodiment. FIG. 6 is a schematic diagram for explaining the operation of the resonator element according to the first embodiment. FIG. 9 is an explanatory diagram illustrating a configuration of a resonator element blank according to Modification 1. FIG. 10 is an explanatory diagram illustrating a configuration of a resonator element blank according to Modification 2. Explanatory drawing which shows the structure of the vibration piece blank in the modification 3. FIG. The structure of the vibrator | oscillator in 2nd Embodiment is shown, (a) is a schematic plan view, (b) is a schematic sectional drawing.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described with reference to the drawings. In the drawings used for the following description, the ratio of dimensions of each member is appropriately changed so that each member has a recognizable size.
(First embodiment)

FIG. 1 is a schematic plan view showing the configuration of the resonator element according to this embodiment. FIG. 2 is a schematic plan view of the back surface of FIG. 1 showing the configuration of the resonator element according to the present embodiment. FIG. 3 is a schematic cross-sectional view showing the configuration of the piezoelectric element and taken along the line AA in FIG. 4 is a schematic cross-sectional view taken along the line BB in FIG.
As shown in FIGS. 1 and 2, the resonator element 1 is formed by providing the resonator element blank 1 a with piezoelectric elements 61, 62, and 63. The vibrating reed blank 1a is formed using a base material such as quartz or silicon. The resonator element 1 is configured to have a thickness in the Z direction when deployed on the XY plane in an orthogonal coordinate system. The resonator element 1 includes three vibrating arms 11, 12, and 13. The vibrating arms 11, 12, and 13 are arranged in parallel in the X direction and extend in parallel to each other in the Y direction.
The vibrating arms 11, 12, and 13 are connected to the connecting portion 14, and the connecting portion 14 is further connected to the base portion 15. Further, the first surface 16a and the second surface 16b, which are surfaces perpendicular to the Z direction, of the vibrating arms 11, 12, and 13 are opposed to each other, and the dimension between the first surface 16a and the second surface 16b is the vibrating arm 11. , 12 and 13 are defined.

  As shown in FIG. 4, the vibrating reed blank 1 a is formed so that the thickness of the vibrating arms 11, 12, 13 is equal to the thickness of the connecting portion 14, and the base portion 15 is formed thicker than the connecting portion 14. The base portion 15 on the second surface 16b side of the vibrating arm is formed with a slope portion 17 that gradually increases in thickness from the connecting portion 14 side without forming a step portion due to a difference in thickness with the connecting portion 14. Yes.

Piezoelectric elements 61, 62, and 63 are formed at positions close to the connecting portion 14 of the vibrating arms 11, 12, and 13, respectively.
As shown in FIG. 3, the piezoelectric element 61 formed on the vibrating arm 11 is formed by laminating the lower electrode 21, the piezoelectric film 31, and the upper electrode 51.
The lower electrode 21 is provided on the first surface 16 a of the opposing surfaces that define the thickness of the vibrating arm 11. Further, the lower electrode 21 is formed with a width equal to the width of the vibrating arm 11. On the lower electrode 21, a piezoelectric film 31 is formed over the side surface and the second surface 16 b so as to cover the lower electrode 21 and surround the periphery of the vibrating arm 11. An upper electrode 51 that covers the piezoelectric film 31 is formed on the piezoelectric film 31. Further, the wiring 58 connected to the upper electrode 51 is drawn out to the second surface 16 b through the side surface of the vibrating arm 11 so as to surround the vibrating arm 11.

In this manner, the piezoelectric element 61 is formed by the lower electrode 21 and the upper electrode 51 facing each other with the piezoelectric film 31 interposed therebetween, and the piezoelectric film 31 is compressed or expanded by applying a positive or negative voltage between the electrodes. It is possible. The piezoelectric arm 31 can be compressed or expanded to displace the vibrating arm 11 in the Z direction. In this way, the vibration arm 11 can be easily driven by providing the piezoelectric element 61 on the vibration arm 11.
Similarly, the piezoelectric elements 62 and 63 formed on the vibrating arms 12 and 13 are formed by stacking the lower electrodes 22 and 23, the piezoelectric films 32 and 33, and the upper electrodes 52 and 53. Further, the wiring 58 connected to the upper electrodes 52 and 53 is drawn out to the second surface 16 b through the side surfaces of the vibrating arms 12 and 13 so as to surround the vibrating arms 12 and 13.

Since the lower electrodes 21, 22, 23, the upper electrodes 51, 52, 53 and the wirings 28, 58 connected to these electrodes are formed continuously, the lower electrodes 21, 22 are described in the description of this embodiment. , 23 and the upper electrodes 51, 52, 53 are portions where these electrodes overlap each other with the piezoelectric films 31, 32, 33 interposed therebetween, and the other portions are referred to as wirings 28, 58 connected to the respective electrodes.
Further, an insulating film such as SiO ₂ or Si ₂ N ₃ is provided between the lower electrodes 21, 22, 23 and the upper electrodes 51, 52, 53, and the lower electrodes 21, 22, 23 and the upper electrodes 51, 52, 53 are provided. An electrical short circuit between the two may be reliably prevented.

  Next, as shown in FIGS. 1, 2, and 4, the wiring 28 connected to the lower electrodes 21, 22, and 23 and the wiring 58 connected to the upper electrodes 51, 52, and 53 are connected to the base portion 15 of the resonator element 1. And is connected to mount electrodes 65 and 66 that are fixed to a base such as a package to achieve electrical conduction. At this time, the wiring 58 is disposed through the slope portion 17 on the second surface 16b side of the resonator element. Further, a connecting portion 57 is provided so as to connect the lower electrode 22 and the upper electrodes 51 and 53 so that the polarities of the piezoelectric elements 61 and 63 and the piezoelectric element 62 are reversed.

The lower electrode and the upper electrode can use metal materials such as Au, Al, and Ti. The lower electrode and the upper electrode may be provided with a Cr film between the lower electrode and the upper electrode in order to improve the adhesion strength with the lower electrode. As the piezoelectric film, materials such as ZnO, AlN, PZT, LiNbO ₃ , and KNbO ₃ can be used. In particular, ZnO and AlN are preferable because better characteristics are obtained.
Moreover, when using a crystal | crystallization as a base material of the vibration piece blank 1a, an X cut board, an AT cut board, a Z cut board, etc. can be utilized.

<Configuration of vibrator blank>
Next, the configuration of the resonator element blank will be described in detail.
FIG. 5 is an explanatory diagram showing the configuration of the resonator element blank. In this figure, the positional relationship is displayed correspondingly using a plan view and a cross-sectional view.
The resonator element blank 1 a includes vibrating arms 11, 12, and 13, a connecting portion 14, and a base portion 15. When the thickness of the vibrating arms 11, 12, 13 is t ₁ , the thickness of the connecting portion 14 is t ₂ , and the thickness of the base portion 15 is t ₃ , t ₁ = t ₂ , t ₂ <t ₃ . is there.
Further, the arm width W ₁ of the vibrating arm 11, the arm width W ₂ of the vibrating arm 12, when the arm width of the vibration arm 13 W _3, and is, W ₂ = W ₁ + W _3, are set to satisfy the relationship of .

Further, let D _{1 be} the distance between the vibrating arm 11 and the vibrating arm 12, and D _{2 be} the distance between the vibrating arm 12 and the vibrating arm 13. distance D _1, D ₂ and assume that the center line C _1, C ₂ each bisecting divides the connecting part 14 as a dividing line.
The volume of the connecting portion 14 divided by the center line C ₁ connected to the vibrating arm 11 is Vb ₁ , and the volume of the connecting portion 14 connected to the vibrating arm 12 and divided by the center lines C ₁ and C ₂ is Vb ₂ . Let Vb _{3 be} the volume of the connecting portion 14 connected to the arm 13 and divided by the center line C ₂ . The volume of the vibrating arm 11 is Va ₁ , the volume of the vibrating arm 12 is Va ₂ , and the volume of the vibrating arm 13 is Va ₃ . At this time, a relationship of (Va ₁ + Vb ₁ ) + (Va ₃ + Vb ₃ ) = Va ₂ + Vb ₂ is set. That is, the sum of the volumes of the odd-numbered (first and third) vibrating arms 11 and 13 counted from the vibrating arm 11 and the divided connecting portion connected thereto, and the even-numbered (second) vibrating arm 12 and the same. There is an equal relationship with the sum of the volumes of the divided connecting portions.

<Configuration of wiring connected to lower electrode and upper electrode>
Next, the wiring connected to the lower electrode and the upper electrode of the resonator element 1 will be described in detail.
6 is a schematic plan view of the wiring connected to the lower electrode, and FIG. 7 is a schematic plan view of the back surface of FIG. 8 is a schematic plan view of wiring connected to the upper electrode, and FIG. 9 is a schematic plan view of the back surface of FIG.

First, as shown in FIG. 6, the lower electrodes 21, 22, and 23 are provided on the first surface 16 a of the opposing surfaces that define the thickness of the vibrating arms 11, 12, and 13.
From the lower electrode 22 formed on the vibrating arm 12 located in the center, the wiring 28 is drawn out to the connecting portion 14 on the same surface and connected to the connecting portion 27. From the lower electrodes 21 and 23 formed on the vibrating arms 11 and 13 located on both sides of the vibrating arm 12, wirings 28 are drawn out and connected to the connecting portion 14 and the base portion 15 on the same surface. It is connected to the mount electrode 66. Moreover, as shown in FIG. 7, it is not necessary to form wiring on the other surface (back surface).

Next, as shown in FIGS. 8 and 9, the upper electrodes 51, 52, 53 are formed at positions covering the lower electrode. A wiring 58 connected to the upper electrodes 51, 52, 53 is drawn out to the second surface 16 b through the side surfaces of the vibrating arms 11, 12, 13 so as to surround the vibrating arms 11, 12, 13.
On the surface of the resonator element, as shown in FIG. 8, the wiring 58 is drawn out to the connecting portion 14 from the upper electrodes 51, 53 formed on the vibrating arms 11, 13 located on both sides of the vibrating arm 12. Connected to the unit 57.

On the other hand, on the back surface of the resonator element, as shown in FIG. 9, the upper electrode 52 formed on the vibrating arm 12 located at the center leads the wiring 58 to the connecting portion 14 and the base portion 15, and the slope portion 17 is formed. It is connected to the mount electrode 66 through. The mount electrode 66 is routed around the surface of the resonator element by the wiring formed on the side surface of the base portion 15, and the mount electrode 66 is provided on the front and back sides.
Further, from the upper electrode 51 formed on the vibrating arm 11, the wiring 58 is drawn out to the connecting portion 14 and the base portion 15, and is connected to the mount electrode 65 through the slope portion 17. The mount electrode 65 is routed around the surface of the resonator element by the wiring formed on the side surface of the base portion 15, and the mount electrode 65 is provided on the front and back sides.
Thus, the wiring 58 can be arranged through the slope portion 17 and there is no stepped portion, so that the wiring 58 is not disconnected.

The wiring 28 connected to the lower electrodes 21, 22, and 23 and the wiring 58 connected to the upper electrodes 51, 52, and 53 are configured, and the connecting portion 27 on the lower electrode side and the connecting portion 57 on the upper electrode side are configured. Are connected, and the lower electrode 22 and the upper electrodes 51 and 53 are connected. Further, it is connected to the mount electrode 65 on the upper electrode side through the upper electrode 51. In this way, the lower electrode 22 and the upper electrodes 51 and 53 become wirings connected to the mount electrode 65.
The lower electrode side mount electrode 66 and the upper electrode side mount electrode 66 are connected, and the lower electrodes 21 and 23 and the upper electrode 52 are connected. In this way, the lower electrodes 21 and 23 and the upper electrode 52 are connected to the mount electrode 66.

FIG. 10 is a schematic diagram for explaining the operation of the resonator element according to the first embodiment.
In the resonator element 1 configured as described above, the vibrating arm is displaced in the Z direction by applying a voltage to each piezoelectric element (not shown). Since the vibrating arm 11 and the vibrating arm 13 are provided with piezoelectric elements having the same polarity, the vibrating arm 12 at the center and the vibrating arms 11 and 13 on both sides vibrate in opposite directions to apply an alternating voltage. The adjacent vibrating arms perform vibration (walk mode vibration) in which vibrations in opposite directions are repeated alternately.

Above, the vibrating element 1 of this embodiment, the connecting portion 14 and the thickness t ₂ equally formed with the thickness t ₁ of the vibrating arms 11, 12, 13, the thickness of the thickness t ₃ of the base portion 15 coupling portion 14 t ₂ It is made thicker.
In this way, by forming the thickness t _{3 of the} base 15 thicker than the thickness t ₁ of the vibrating arms 11, 12, 13, the vibration energy is reflected by these thickened portions, and the vibration energy is thereby reduced. 12 and 13 can prevent the vibration from leaking to the base 15.
Further, by providing the connecting portion 14 formed to be equal to the thickness t ₁ of the vibrating arms 11, 12, 13, the resonance frequency of the common mode, which is the spurious mode, of the vibrating piece 1 is lowered and separated from the resonance frequency of the main vibration. It is possible. By separating the resonance frequency of the common mode from the resonance frequency of the main vibration, the vibration of the common mode is less likely to occur.
As described above, the resonator element 1 of the present embodiment can reduce the size of the resonator element 1 with a simple structure by reducing the occurrence of vibration leakage and common-mode vibration.

In addition, the resonator element 1 of the present embodiment includes the sum of the volumes of the odd-numbered vibrating arms 11 and 13 and the divided connecting portions connected thereto, and the volume of the even-numbered vibrating arms 12 and the divided connecting portions connected thereto. The sum is equal.
In the resonator element 1 having this configuration, the connecting portion 14 is distorted with the vibration of the vibrating arms 11, 12, and 13. Therefore, the vibrating arms that vibrate in one direction and the volume of the connecting portion and the other direction vibrate. By making the volume of the vibrating arm to be connected and the volume of the connecting portion equal, the vibration form becomes symmetric and vibration leakage can be reduced.
(Modification 1)

Next, a modification of the first embodiment will be described. In the following modifications, the shape of the resonator element blank is different from that of the first embodiment.
FIG. 11 is an explanatory diagram illustrating a configuration of the resonator element blank according to the first modification. In this figure, the positional relationship is displayed correspondingly using a plan view and a cross-sectional view.
The resonator element blank 2 a includes vibrating arms 111, 112, 113, a connecting portion 114, and a base portion 115. Then, the thickness of the vibrating arms 111, 112, 113 t _1, the thickness of the connecting portion 114 t _2, the thickness t ₃ of the base portion 115, when set to _{t 1 = t 2, t 2} <t 3, the relationship is there. The base 115 is provided with a slope portion 117 whose thickness increases from the connecting portion 114 to eliminate a step due to a difference in thickness.
Further, assuming that the arm width of the vibrating arm 111 is W ₁₁ , the arm width of the vibrating arm 112 is W ₁₂ , and the arm width of the vibrating arm 113 is W ₁₃ , W ₁₂ > W ₁₁ + W ₁₃ is set. .
At both ends of the connecting portion 114, shoulder portions 118 are provided to project in the direction in which the vibrating arms 111, 112, 113 are arranged.

Further, the distance between the vibrating arm 111 and the vibrating arm 112 is D ₁ , the distance between the vibrating arm 112 and the vibrating arm 113 is D ₂ , and along the extending direction of the vibrating arms 111, 112, 113, It is assumed that the connecting portion 114 is divided with the center lines C ₁ and C ₂ dividing the distances D ₁ and D ₂ into two equal parts, respectively.
The volume of the connecting portion 114 connected to the vibrating arm 111 and divided by the center line C ₁ is Vb ₁ , and the volume of the connecting portion 114 connected to the vibrating arm 112 and divided by the center lines C ₁ and C ₂ is Vb ₂ . Let Vb _{3 be} the volume of the connecting portion 114 connected to the arm 113 and divided by the center line C ₂ . The volume of the vibrating arm 111 is Va ₁ , the volume of the vibrating arm 112 is Va ₂ , and the volume of the vibrating arm 113 is Va ₃ . At this time, a relationship of (Va ₁ + Vb ₁ ) + (Va ₃ + Vb ₃ ) = Va ₂ + Vb ₂ is set. That is, the sum of the volumes of the odd-numbered (first and third) vibrating arms 111 and 113 counted from the vibrating arm 111 and the divided connecting portions connected thereto, and the even-numbered (second) vibrating arm 112 and the same. There is an equal relationship with the sum of the volumes of the divided connecting portions.

Then, the resonator element can be obtained by providing the piezoelectric elements 161, 162, and 163 at positions close to the connecting portion 114 of the vibrating arms 111, 112, and 113 and arranging necessary wiring (not shown).
As in the first modification, shoulder portions 118 that protrude in the direction in which the vibrating arms 111, 112, 113 are arranged may be provided at both ends of the connecting portion 114 in the vibrating reed blank 2 a.
According to this configuration, when it is assumed that the resonator element is divided using the center lines C ₁ and C ₂ that divide the distance between adjacent vibrating arms into two equal parts, the shape of the vibrating arm and the connecting portion connected thereto is It becomes a similar shape, the symmetry of vibration is increased, and vibration leakage can be reduced.
(Modification 2)

FIG. 12 is an explanatory diagram illustrating a configuration of the resonator element blank according to the second modification. In this figure, the positional relationship is displayed correspondingly using a plan view and a cross-sectional view.
The resonator element blank 3 a includes vibrating arms 121, 122, 123, a connecting portion 124, and a base portion 125. Then, t ₁ <t ₂ <t ₃ , where t _{1 is} the thickness of the vibrating arms 121, 122, and 123, t _{2 is} the thickness of the connecting portion 124, and t _{3 is} the thickness of the base portion 125.
The connecting portion 124 is provided with a slope portion 128 whose thickness is increased from the vibrating arms 121, 122, and 123 to eliminate a step due to a difference in thickness. Similarly, the base portion 125 is provided with an inclined surface portion 127 whose thickness increases from the connecting portion 124 to eliminate a step due to a difference in thickness.
Further, assuming that the arm width of the vibrating arm 121 is W ₂₁ , the arm width of the vibrating arm 122 is W ₂₂ , and the arm width of the vibrating arm 123 is W ₂₃ , W ₂₂ = W ₂₁ + W ₂₃ is set. .

Furthermore, the distance between the vibrating arm 121 and the vibrating arm 122 is D ₁ , the distance between the vibrating arm 122 and the vibrating arm 123 is D ₂ , and along the extending direction of the vibrating arms 121, 122, 123, It is assumed that the connecting portion 124 is divided with the center lines C ₁ and C ₂ dividing the distances D ₁ and D ₂ into two equal parts, respectively.
The volume of the connecting portion 124 divided by the center line C ₁ connected to the vibrating arm 121 is Vb ₁ , and the volume of the connecting portion 124 divided by the center lines C ₁ and C ₂ connected to the vibrating arm 122 is Vb ₂ . Let Vb _{3 be} the volume of the connecting portion 124 divided by the center line C ₂ and continuing to the arm 123. The volume of the vibrating arm 121 is Va ₁ , the volume of the vibrating arm 122 is Va ₂ , and the volume of the vibrating arm 123 is Va ₃ . At this time, a relationship of (Va ₁ + Vb ₁ ) + (Va ₃ + Vb ₃ ) = Va ₂ + Vb ₂ is set. That is, the sum of the volumes of the odd-numbered (first and third) vibrating arms 121 and 123 and the divided connecting portions connected to the odd-numbered (first and third) vibrating arms 121 and the even-numbered (second) vibrating arms 122 and the same. There is an equal relationship with the sum of the volumes of the divided connecting portions.

Then, the resonator element can be obtained by providing the piezoelectric elements 161, 162, and 163 at positions close to the connecting portion 124 of the vibrating arms 121, 122, and 123 and arranging necessary wiring (not shown).
As in the second modification, the thickness t ₂ of the connecting portion 124 is formed thicker than the thickness t ₁ of the vibrating arms 121, 122, 123, and the thickness t _{3 of the} base portion 125 is thicker than the thickness t ₂ of the connecting portion 124. It may be formed.
In this way, the vibration energy is reflected by the connecting portion 124 and the base portion 125 that are thicker than the vibration arms 121, 122, and 123 to confine the vibration energy in the vibration arms 121, 122, and 123, and vibration leaks to the base portion 125. Can be prevented.
(Modification 3)

FIG. 13 is an explanatory diagram illustrating a configuration of the resonator element blank according to the third modification. In this figure, the positional relationship is displayed correspondingly using a plan view and a cross-sectional view.
The vibrating reed blank 4 a includes five vibrating arms 131 to 135, a connecting portion 144, and a base portion 145. When the thickness of the vibrating arms 131 to 135 is t ₁ , the thickness of the connecting portion 144 is t ₂ , and the thickness of the base portion 145 is t ₃ , t ₁ = t ₂ and t ₂ <t ₃ . The base portion 145 is provided with an inclined surface portion 137 whose thickness increases from the connecting portion 144 to eliminate a step due to a difference in thickness.
The arm width of the vibrating arm 131 is W ₃₁ , the arm width of the vibrating arm 132 is W ₃₂ , the arm width of the vibrating arm 133 is W ₃₃ , the arm width of the vibrating arm 134 is W ₃₄ , and the arm width of the vibrating arm 135 is W ₃₅ , the relationship is set as W ₃₁ + W ₃₃ + W ₃₅ = W ₃₂ + W ₃₄ .

Further, the distance between the vibrating arm 131 and the vibrating arm 132 is D ₁ , the distance between the vibrating arm 132 and the vibrating arm 133 is D ₂ , and the distance between the vibrating arm 133 and the vibrating arm 134 is D ₃ , The distance between the vibrating arm 134 and the vibrating arm 135 is D ₄ , and center lines C ₁ to C that divide these distances D _{1 to} D ₄ into two along the extending direction of the vibrating arms 131 to 135, respectively. _It is assumed that the connecting portion 144 is divided using ₄ as a dividing line.
The volume of the connecting portion 144 divided by the center line C ₁ connected to the vibrating arm 131 is Vb _1. The volume of the connecting portion 144 divided by the center lines C ₁ and C ₂ connected to the vibrating arm 132 is Vb ₂ . The volume of the connecting portion 144 divided by the center lines C ₂ and C ₃ connected to the arm 133 is Vb ₃ , and the volume of the connecting portion 144 divided by the center lines C ₃ and C ₄ connected to the vibrating arm 134 is Vb _4. Let Vb _{5 be} the volume of the connecting portion 144 connected to the vibrating arm 135 and divided by the center line C ₄ .
The volume of the vibrating arm 131 is Va ₁ , the volume of the vibrating arm 132 is Va ₂ , the volume of the vibrating arm 133 is Va ₃ , the volume of the vibrating arm 134 is Va ₄ , and the volume of the vibrating arm 135 is Va ₅ . At this time, a relationship of (Va ₁ + Vb ₁ ) + (Va ₃ + Vb ₃ ) + (Va ₅ + Vb ₅ ) = (Va ₂ + Vb ₂ ) + (Va ₄ + Vb ₄ ) is set. That is, the sum of the volumes of the odd-numbered (first, third, and fifth) vibrating arms 131, 133, and 135 and the divided connecting portions connected to the vibrating arms 131 and the even-numbered (second and fourth). ) And the total sum of the volumes of the divided connecting portions connected to the vibrating arms 132 and 134 are equal to each other.

And a vibration piece can be obtained by providing the piezoelectric elements 161-165 in the position near the connection part 144 of the vibration arms 131-135, and arrange | positioning required wiring (not shown).
Thus, the number of vibrating arms may be an odd number of 3 or more, and the same effect as in the first embodiment can be obtained.

In the above-described embodiment and modification, the total sum of the volumes of the odd-numbered vibrating arms and the divided connecting portions connected to the odd-numbered vibrating arms is equal to the sum of the volumes of the even-numbered vibrating arms and the divided connecting portions connected thereto. However, it is the same even if each volume is referred to as mass.
Furthermore, taking into account the mass of the piezoelectric elements and wiring formed on the vibrating arms and the connecting portion, the sum of the masses of the odd-numbered vibrating arms and the divided connecting portions connected thereto, and the even-numbered vibrating arms and the divided portions connected thereto. If the total sum of the masses of the connected portions is equal, it is possible to obtain a resonator element having a good characteristic in which the form of vibration is further symmetric.
(Second Embodiment)

Next, as a second embodiment, a vibrator provided with the above-described vibrator element will be described.
14A and 14B show a configuration of the vibrator, FIG. 14A is a schematic plan view, and FIG. 14B is a schematic cross-sectional view taken along the line GG in FIG.
The vibrator 5 includes the resonator element 1, a ceramic package 81 as a container, and a lid 85.
The ceramic package 81 is formed with a recess so that the resonator element 1 can be accommodated, and a connection pad 88 connected to the mount electrode of the resonator element 1 is provided in the recess. The connection pad 88 is connected to the wiring in the ceramic package 81 and is configured to be electrically connected to the external connection terminal 83 provided on the outer periphery of the ceramic package 81.
A seam ring 82 is provided around the recess of the ceramic package 81. Further, a through hole 86 is provided at the bottom of the ceramic package 81.

  The resonator element 1 is bonded and fixed to the connection pad 88 of the ceramic package 81 via the conductive adhesive 84, and the lid body 85 and the seam ring 82 that cover the concave portion of the ceramic package 81 are seam-welded. A through hole 86 of the ceramic package 81 is filled with a sealing material 87 made of a metal material. The sealing material 87 is melted in a reduced pressure atmosphere and hermetically sealed so that the ceramic package 81 is in a reduced pressure state.

As described above, the resonator element 5 according to the first embodiment or the second embodiment is housed in the ceramic package 81, and the resonator 5 can be easily reduced in size and excellent in characteristics.
The ceramic package 81 may be configured as an oscillator by accommodating circuit elements such as an IC including an oscillation circuit.

DESCRIPTION OF SYMBOLS 1 ... Vibrating piece, 1a, 2a, 3a, 4a ... Vibrating piece blank, 5 ... Vibrator, 11, 12, 13 ... Vibrating arm, 14 ... Connection part, 15 ... Base part, 16a ... 1st surface of a vibrating arm, 16b ... 2nd surface of vibrating arm, 17 ... Slope, 21, 22, 23 ... Lower electrode, 27 ... Connection part, 31, 32, 33 ... Piezoelectric film, 51, 52, 53 ... Upper electrode, 57 ... Connection part, 61, 62, 63 ... Piezoelectric element, 65, 66 ... Mount electrode, 81 ... Ceramic package, 82 ... Seam ring, 83 ... External connection terminal, 84 ... Conductive adhesive, 85 ... Cover, 86 ... Through hole, 87 ... Sealing material, 88 ... Connection pad, 111, 112, 113 ... Vibration arm, 114 ... Connection part, 115 ... Base part, 117 ... Slope part, 118 ... Shoulder part, 121, 122, 123 ... Vibration arm, 124 ... Connection Part, 125 ... base, 127, 128 ... slope part, 31,132,133,134,135 ... vibrating arms, 137 ... inclined surface, 144 ... connection section, 145 ... base, 161,162,163,164,165 ... piezoelectric _{elements, C 1, C 2, C} 3, C ₄ ... center line, t ₁ ... thickness of vibrating arm, t ₂ ... thickness of connecting part, t ₃ ... thickness of base part, W ₁ , W ₂ , W ₃ ... arm width of vibrating arm, D ₁ , D ₂ , D ₃ , D ₄ ... Distance between adjacent vibrating arms, Va ₁ , Va ₂ , Va ₃ , Va ₄ , Va ₅ ... Volume of vibrating arms, Vb ₁ , Vb ₂ , Vb ₃ , Vb ₄ , Vb ₅ . Volume of the part.

Claims (6)

A base portion, an odd number of three or more vibrating arms, and a connecting portion that is positioned between the base portion and the vibrating arm and connects each of the vibrating arms, and each of the vibrating arms vibrates in the thickness direction and is adjacent to each other. The vibrating arms in which the matching vibrating arms vibrate in opposite directions,
A vibrating piece, wherein t ₁ ≦ t ₂ <t ₃ , where t _{1 is} the thickness of the vibrating arm, t _{2 is} the thickness of the connecting portion, and t _{3 is} the thickness of the base portion. The resonator element according to claim 1,
Assuming that the connecting portion is divided with a center line that bisects the distance between the vibrating arms adjacent along the extending direction of the vibrating arm as a dividing line,
Counting from the vibrating arm at one end, the total volume of the odd-numbered vibrating arms and the divided connecting portions connected to the odd-numbered vibrating arms, and the volume of the even-numbered vibrating arms and the divided connecting portions connected thereto. A vibrating piece characterized in that the sum is equal. The resonator element according to claim 2,
A vibrating piece, wherein shoulder portions are formed at both ends of the connecting portion so as to protrude in a direction in which the vibrating arms are arranged. The resonator element according to any one of claims 1 to 3,
A vibrating element, wherein a piezoelectric element is provided at a position near the connecting portion of the vibrating arm. In the resonator element according to any one of claims 1 to 4,
A vibrating piece, wherein a slope portion is formed between at least one of the vibrating arm and the connecting portion, and between the connecting portion and the base portion where a difference in thickness occurs. A resonating piece according to any one of claims 1 to 5, and a container that houses the resonating piece,
The vibrator, wherein the vibrating piece is housed in the container in an airtight manner.

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