JP2010286468A - Double tuning fork type vibrator element, vibratory sensor element and vibratory sensor - Google Patents

Abstract

A double tuning fork type resonator element having a small size and high sensitivity is provided.
In a double tuning fork type resonator element, a first vibrating arm portion is arranged in order along a direction from a first base end portion to a second base end portion. 14 and the third region 16, and the second vibrating arm portion 20 is arranged in order along the direction from the first base end portion 30 toward the second base end portion 40, the fourth region 22, the fifth region 24, and The sixth region 26 has front and back surfaces of the first region 12, both side surfaces of the second region 14, front and back surfaces of the third region 16, both side surfaces of the fourth region 22, front and back surfaces of the fifth region 24, and First excitation electrodes 110 electrically connected to each other are formed on both side surfaces of the sixth region 26. Both side surfaces of the first region 12, front and back surfaces of the second region 14, both side surfaces of the third region 16, The front and back surfaces of the fourth region 22, both side surfaces of the fifth region 24, and the front and back surfaces of the sixth region 26 are electrically connected to each other. The second excitation electrode 120 is formed.
[Selection] Figure 1

Description

  The present invention relates to a double tuning fork resonator element, a vibration sensor element, and a vibration sensor.

  Conventionally, vibration sensors have been widely used from automobiles, airplanes, rockets to abnormal vibration inspection devices for various plants. In particular, the vibration type sensor using a double tuning fork type piezoelectric vibrating piece changes the frequency of the double tuning fork type vibrating piece in proportion to the magnitude of applied stress. Excellent reproducibility and temperature characteristics.

  In general, a double tuning fork type resonator element can obtain a higher element sensitivity (detection sensitivity) as the length of a vibrating arm portion that vibrates and increases the S / N ratio (Signal to Noise ratio). be able to. Here, in the double tuning fork type vibration piece disclosed in Patent Document 1, the support part of the double tuning fork type vibration piece is disposed between the two vibrating arm parts. Such a double tuning fork type resonator element can increase the length of the vibrating arm portion by the amount of the support portion when the size is restricted by the area of the package, for example. Therefore, element sensitivity can be improved.

Japanese Patent Laid-Open No. 9-5176

  By the way, the vibration type sensor is required to be further downsized and highly sensitive. Along with this, in addition to the arrangement of the support portions disclosed in Patent Document 1, for example, a structure that can further increase the sensitivity is required for the double tuning fork type resonator element.

  One of the objects according to some aspects of the present invention is to provide a double tuning fork type resonator element that is small and has high sensitivity. Another object of some aspects of the present invention is to provide a vibration type sensor element and a vibration type sensor having the above-mentioned double tuning fork type vibration piece.

  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 aspects or application examples.

[Application Example 1]
A double tuning fork type resonator element having a front surface and a back surface in a front / back relationship, and a side surface connected to the front surface and the back surface,
A first vibrating arm portion and a second vibrating arm portion extending in parallel;
A first base end connected to one end of the first vibrating arm and the second vibrating arm;
A second base end connected to the other end of the first vibrating arm and the second vibrating arm;
A first support portion connected to the first base end portion and disposed between the first vibrating arm portion and the second vibrating arm portion;
A second support portion connected to the second base end portion and disposed between the first vibrating arm portion and the second vibrating arm portion;
Including
The first vibrating arm portion includes a first region, a second region, and a third region, which are sequentially arranged along a direction from the first base end portion to the second base end portion,
The second vibrating arm portion includes a fourth region, a fifth region, and a sixth region, which are sequentially arranged along a direction from the first base end portion to the second base end portion.
Front and back surfaces of the first region, both side surfaces of the second region, front and back surfaces of the third region, both side surfaces of the fourth region, front and back surfaces of the fifth region, and both side surfaces of the sixth region A first excitation electrode electrically connected to each other is formed;
On both side surfaces of the first region, front and back surfaces of the second region, both side surfaces of the third region, front and back surfaces of the fourth region, both side surfaces of the fifth region, and front and back surfaces of the sixth region A double tuning fork type resonator element in which second excitation electrodes electrically connected to each other are formed.

  According to such a double tuning fork type resonator element, it is small and has high sensitivity due to the arrangement of the first support part and the second support part and the arrangement of the first excitation electrode and the second excitation electrode. A double tuning fork type resonator element can be provided.

  In the description according to the present invention, the term “electrically connected” is used, for example, as another specific member (hereinafter “electrically connected” to “specific member (hereinafter referred to as“ A member ”)”. B member "))" and the like. In the description according to the present invention, in the case of this example, the case where the A member and the B member are in direct contact and electrically connected, and the A member and the B member are the other members. The term “electrically connected” is used as a case where the case where the terminals are electrically connected to each other is included.

[Application Example 2]
In application example 1,
A first extraction electrode and a second extraction electrode are formed between the adjacent areas of the first vibrating arm portion and the second vibrating arm portion,
The first extraction electrode is
One of the adjacent regions is extended from the first excitation electrode formed on the front surface or the back surface of one of the regions, branched at least bifurcated, and one of the branched electrodes is one of the other regions. Connected to the first excitation electrode formed on the side surface, the other branched electrode is connected to the first excitation electrode formed on the other side surface of the other region,
The second extraction electrode is
One of the adjacent regions is extended from the second excitation electrode formed on the front or back surface of one of the regions, branched at least bifurcated, and one branched electrode is one of the other regions. A double tuning fork type resonator element that is connected to the second excitation electrode formed on a side surface, and the other branched electrode is connected to the second excitation electrode formed on the other side surface of the other region.

  According to such a double tuning fork type vibrating piece, even if the double tuning fork type vibrating piece is miniaturized, there is a concern that the first extraction electrode and the second extraction electrode may be short-circuited on the front and back surfaces between the adjacent regions. Absent. In addition, it is not necessary to extremely reduce the width of the first extraction electrode and the second extraction electrode, and increase in electrical resistance and disconnection of the first extraction electrode and the second extraction electrode can be suppressed. In addition, in the excitation electrodes formed on both side surfaces of the region, even if one of the side electrodes is disconnected, it is possible to maintain energization with the other electrode. Such a problem becomes a serious problem because the influence of misalignment of the photomask becomes relatively large when further miniaturization is performed by a photolithography technique or the like.

[Application Example 3]
In application example 1,
A first extraction electrode and a second extraction electrode are formed between the adjacent areas of the first vibrating arm portion and the second vibrating arm portion,
The first extraction electrode is
The adjacent one of the regions extends from the first excitation electrode formed on the front surface or the back surface of one of the regions, and is connected to the first excitation electrode formed on one side surface of the other region. ,
The second extraction electrode is
Out of the adjacent regions, the second excitation electrode formed on the front surface or the back surface of one of the regions is connected to the second excitation electrode formed on one side surface of the other region. The double tuning fork type vibration piece.

  According to such a double tuning fork type resonator element, the degree of freedom in design in the arrangement and shape of the first extraction electrode and the second extraction electrode can be increased.

[Application Example 4]
In any of Application Examples 1 to 3,
On the front and back surfaces of the first support portion, a first terminal electrically connected to the first excitation electrode and a second terminal electrically connected to the second excitation electrode are formed,
A double tuning fork type vibrating piece in which an annular opening is formed between the first terminal and the second terminal of the first support portion.

  According to such a double tuning fork type resonator element, the distance between the first terminal and the second terminal can be reduced, and the area of the first support portion can be reduced accordingly. As a result, the distance between the first vibrating arm portion and the second vibrating arm portion can be reduced, and the double tuning fork type vibrating piece can be miniaturized. Further, a high Q value and a small CI (crystal impedance) value can be realized.

[Application Example 5]
In any of Application Examples 1 to 3,
The first support part is formed with a first terminal electrically connected to the first excitation electrode and a second terminal electrically connected to the second excitation electrode,
One of the first terminal and the second terminal is formed on one of the front surface of the first support part and the back surface of the front surface.
The double tuning fork type resonator element, wherein the other of the first terminal and the second terminal is formed on the other of the front surface and the back surface of the first support portion.

  According to such a double tuning fork type resonator element, since two terminals are not formed on one surface of the first support portion, the area of the first support portion can be reduced accordingly. As a result, the distance between the first vibrating arm portion and the second vibrating arm portion can be reduced, and the double tuning fork type vibrating piece can be miniaturized. Also, a high Q value and a small CI value can be realized.

[Application Example 6]
In any of Application Examples 1 to 5,
The first vibrating arm portion and the second vibrating arm portion have grooves formed on the front and back surfaces of the region,
The first tuning electrode and the second excitation electrode formed on the front and back surfaces of the region are a double tuning fork type resonator element provided on the inner wall of the groove.

  According to such a double tuning fork type resonator element, an electric field generated when a voltage is applied can be efficiently converted into vibration, so that an increase in CI value can be suppressed.

[Application Example 7]
The base,
An elastic part continuous to the base part;
Another base that is continuous with the elastic portion and supported by the elastic portion;
The double tuning fork type resonator element according to any one of claims 1 to 6, which is fixed to the base portion and the other base portion,
Including a vibration type sensor element.

  According to such a vibration type sensor element, a vibration type sensor element having a small size and high sensitivity can be provided.

[Application Example 8]
The vibration-type sensor element according to Application Example 7,
A package containing the vibration-type sensor element;
Including vibration sensor.

  According to such a vibration type sensor, it is possible to provide a vibration type sensor having a small size and high sensitivity.

The figure for demonstrating the structure of the double tuning fork type vibration piece which concerns on this embodiment. Sectional drawing which shows typically the vibration arm part of the double tuning fork type vibration piece which concerns on this embodiment. The figure for demonstrating the structure of the double tuning fork type vibration piece which concerns on the 1st modification of this embodiment. The figure for demonstrating the structure of the double tuning fork type vibration piece which concerns on the 2nd modification of this embodiment. The figure for demonstrating the structure of the double tuning fork type vibration piece which concerns on the 3rd modification of this embodiment. The perspective view which shows typically the vibration type sensor element which concerns on this embodiment. Sectional drawing which shows typically the vibration type sensor which concerns on this embodiment.

  Preferred embodiments of the present invention will be described below with reference to the drawings.

1. First, a double tuning fork type vibrating piece 100 according to this embodiment will be described with reference to the drawings. The double tuning fork type resonator element 100 is connected to the first main surface (one main surface) and the second main surface (the other main surface), and the first main surface and the second main surface which are in a front-back relationship. And a side surface. FIG. 1A is a plan view of the double tuning fork vibrating piece 100 as viewed from one main surface (hereinafter also referred to as “surface”), and one main surface ( It is a figure for demonstrating the structure of the surface side. FIG. 1B is a perspective view of the double tuning fork vibrating piece 100 as viewed from one main surface (front surface) side, and the other main surface of the double tuning fork vibrating piece 100 (hereinafter also referred to as “back surface”). .) Is a diagram for explaining the configuration on the side. Hereinafter, the shape and the like of the double tuning fork type vibrating piece 100 will be described first, and then the arrangement of excitation electrodes, extraction electrodes, terminals, etc. formed on the double tuning fork type vibrating piece 100 will be described.

1.1. Shape of Twin Tuning Fork Type Vibrating Piece, etc. The double tuning fork type vibrating piece 100 has an outer surface having a front surface (see FIG. 1A), a back surface (see FIG. 1B), and side surfaces connected to the front and back surfaces. Shape. The back surface is a surface fixed to a base portion 502 and a mass portion 506 as another base portion, as shown in FIG. Note that the surface illustrated in FIG. 1A can be a back surface, that is, a surface fixed to the base portion 502 and the mass portion 506, and the surface illustrated in FIG. Examples of the material of the double tuning fork type resonator element 100 include piezoelectric materials such as quartz, lithium tantalate, and lithium niobate.

  As shown in FIG. 1, the double tuning fork type vibrating piece 100 includes a first vibrating arm portion 10, a second vibrating arm portion 20, a first base end portion 30, a second base end portion 40, and a first support. Part 50 and second support part 60.

(1) 1st vibrating arm part and 2nd vibrating arm part The 1st vibrating arm part 10 and the 2nd vibrating arm part 20 are quadrangular prism shapes, and are parallel from the 1st base end part 30 to the 2nd base end. It extends to part 40. The vibrating arm portions 10 and 20 have inner side surfaces (side surfaces on the support portions 50 and 60 side) which are side surfaces facing each other, and outer side surfaces which are side surfaces opposite to the inner side surfaces. The vibrating arm portions 10 and 20 are spaced apart from each other, and a central axis extending in a direction from the first base end portion 30 to the second base end portion 40 (Y-axis direction) of the double tuning fork vibrating piece 100, (Not shown).

  The first vibrating arm unit 10 includes a first region 12, a second region 14, and a third region 16 that are arranged in order along the direction from the first base end 30 toward the second base end 40. The second vibrating arm portion 20 has a fourth region 22, a fifth region 24, and a sixth region 26 that are arranged in order along the direction from the first base end portion 30 toward the second base end portion 40. In the illustrated example, the first region 12 and the fourth region 22 are adjacent to the first base end 30. Further, the third region 16 and the sixth region 26 are adjacent to the second base end portion 40. The first region 12, the third region 16, the fourth region 22, and the sixth region 26 are also regions provided at the ends of the vibrating arm portions 10 and 20. It can be said that the second region 14 and the fifth region 24 are regions provided in the central portion of the vibrating arm portions 10 and 20. In the illustrated example, the lengths of the second region 14 and the fifth region 24 (the length in the Y-axis direction) are larger than the lengths of the first region 12, the third region 16, the fourth region 22, and the sixth region 26. . Excitation electrodes 110 and 120 are formed in the respective regions 12, 14, 16, 22, 24 and 26. The vibrating arm portions 10 and 20 can be flexibly vibrated by the voltage applied to the excitation electrodes 110 and 120.

  Here, FIG. 2 is a cross-sectional view taken along the line II-II of FIG. 1 schematically showing the vibrating arm portions 10 and 20. As shown in FIG. 2, the vibrating arm portions 10 and 20 may have a groove 15. The groove 15 can be formed on the front and back surfaces of the regions 12, 14, 16, 22, 24, 26. The cross-sectional shape of the groove 15 is rectangular in the illustrated example, but is not particularly limited thereto. By the groove 15, the vibrating arm portions 10 and 20 can have an H-shaped cross-sectional shape. A first excitation electrode 110 or a second excitation electrode 120 is formed on the inner wall of the groove 15. Thereby, since the vibration loss at the time of a voltage application is reduced, the double tuning fork type vibrating piece 100 can suppress the increase in CI value. In FIG. 1, the grooves 15 are not shown for convenience.

(2) 1st base end part and 2nd base end part The 1st base end part 30 is connected to the edge part of the one side of the 1st vibration arm part 10 and the 2nd vibration arm part 20, as shown in FIG. Has been. The second base end portion 40 is connected to the other ends of the first vibrating arm portion 10 and the second vibrating arm portion 20. That is, it can be said that the base end portions 30 and 40 sandwich the vibrating arm portions 10 and 20.

  As shown in FIG. 1, two protrusions 32 may be connected to the first base end 30, and two protrusions 42 may be connected to the second base end 40. The protruding portion 32 extends from the first base end portion 30 toward the second base end portion 40 and is disposed with the vibrating arm portions 10 and 20 interposed therebetween. The protruding portion 42 extends from the second base end portion 40 toward the first base end portion 30 and is disposed with the vibrating arm portions 10 and 20 interposed therebetween. By the protrusions 32 and 42, the double tuning fork type vibrating piece 100 can prevent unnecessary vibration and can suppress an increase in CI value.

(3) First support portion and second support portion The first support portion 50 is connected to the first base end portion 30 and is disposed between the first vibrating arm portion 10 and the second vibrating arm portion 20. . The second support portion 60 is connected to the second base end portion 40 and is disposed between the first vibrating arm portion 10 and the second vibrating arm portion 20. That is, the first support portion 50 extends from the first base end portion 30 toward the second base end portion 40 (in the −Y axis direction), and the second support portion 60 extends from the second base end portion 40 to the second base end portion 40. It extends toward the one base end portion 30 (in the + Y-axis direction). Thereby, for example, the first support portion extends from the first base end portion in the + Y axis direction, and the second support portion extends from the second base end portion in the −Y axis direction. Thus, the length of the double tuning fork resonator element 100 in the Y-axis direction can be reduced. That is, the size of the double tuning fork type vibrating piece 100 can be reduced.

  The back surfaces of the support portions 50 and 60 can be fixed to the base portion 502 and the mass portion 506 as shown in FIG. That is, the double tuning fork type vibrating piece 100 is supported by two places, the first support part 50 and the second support part 60. For this reason, for example, the variation in the support state (for example, the amount of adhesive, the adhering state, etc.) can be reduced because the number of support portions is smaller than that of a double tuning fork type vibrating piece supported at three or more locations. If the variation in the support state is large, for example, when applied to a vibration type sensor, it is likely to be affected by a disturbance (such as a change in temperature due to temperature or adhesive material change). That is, N of the S / N ratio becomes large and high-precision measurement cannot be performed. Therefore, it is necessary to strictly manage the support state, which may increase the cost. In the double tuning fork type vibrating piece 100, since it is supported by two places, it is possible to prevent performance degradation due to variations in the support state. Further, the cost does not increase more than necessary.

1.2. Excitation Electrode, Extraction Electrode, Terminal Arrangement, etc. As shown in FIG. 1, the double tuning fork resonator element 100 includes a first excitation electrode 110, a second excitation electrode 120, a first extraction electrode 112, and a second extraction electrode. An electrode 122, a first terminal 114, and a second terminal 124 are formed. For convenience, in FIG. 1, the first excitation electrode 110, the first extraction electrode 112, and the first terminal 114 are indicated by a lower right oblique line, and the second example oscillation electrode 120, the second extraction electrode 122, and the second terminal 124 are crossed. Shown with diagonal lines. The same applies to FIGS. 3 to 5 described later.

(1) First Excitation Electrode and Second Excitation Electrode The first excitation electrode 110 and the second example excitation electrode 120 are formed on the first vibrating arm portion 10 and the second vibrating arm portion 20. More specifically, the first excitation electrode 110 includes a front surface and a back surface (hereinafter, also referred to as “front and back surfaces”) of the first region 12, an inner surface and an outer surface (hereinafter, “both side surfaces”) of the second region 14. It is also formed on the front and back surfaces of the third region 16, both side surfaces of the fourth region 22, front and back surfaces of the fifth region 24, and both side surfaces of the sixth region 26. The first excitation electrodes 110 formed in the regions 12, 14, 16, 22, 24 and 26 are electrically connected to each other by the first extraction electrode 112. The second excitation electrode 120 includes both side surfaces of the first region 12, front and back surfaces of the second region 14, both side surfaces of the third region 16, front and back surfaces of the fourth region 22, both side surfaces of the fifth region 24, and It is formed on the front and back surfaces of the sixth region 26. The second excitation electrodes 120 formed in the regions 12, 14, 16, 22, 24, and 26 are electrically connected by the second extraction electrode 122.

  The first excitation electrode 110 and the second excitation electrode 120 may have different potentials. That is, in each of the regions 12, 14, 16, 22, 24, and 26, excitation electrodes having different potentials are formed on the front and back surfaces and both side surfaces. Excitation electrodes 110 and 120 having different potentials are alternately formed on the front and back surfaces of the vibrating arm portions 10 and 20. In addition, excitation electrodes 110 and 120 having different potentials are alternately formed on both side surfaces of the vibrating arm portion. In the illustrated example, the excitation electrodes 110 and 120 are disposed so as to be symmetric with respect to a center line (not shown) along the Y-axis direction of the double tuning fork resonator element 100. With the arrangement of the excitation electrodes 110 and 120, the vibrating arm portions 10 and 20 can efficiently bend and vibrate so as to be symmetric with respect to the center line along the Y-axis direction of the double tuning fork vibrating piece 100.

  As shown in FIG. 2, when the vibrating arm portions 10 and 20 have the grooves 15, the excitation electrodes 110 and 120 formed on the front and back surfaces of the regions 12, 14, 16, 22, 24, and 26 It is formed on the inner wall. Moreover, as shown in FIG. 2, the excitation electrodes 110 and 120 formed on both side surfaces of the regions 12, 14, 16, 22, 24 and 26 may partially extend to the front and back surfaces.

  As the material for the excitation electrodes 110 and 120, for example, a material in which chromium and gold are laminated in this order from the double tuning fork type vibrating piece 100 side can be used. The excitation electrodes 110 and 120 can be formed by, for example, a sputtering method or a vacuum deposition method.

(2) First Extraction Electrode and Second Extraction Electrode As shown in FIG. 1, the first extraction electrode 112 and the second extraction electrode 122 are formed in adjacent regions of the first vibrating arm portion 10 and the second vibrating arm portion 20. It is formed between. More specifically, the first extraction electrode 112 extends from the first excitation electrode 110 formed on the front surface or the back surface of one of the adjacent regions, branches into two, and the other region Are connected to first excitation electrodes 110 formed on both side surfaces of the first excitation electrode 110. The second extraction electrode 122 extends from the second excitation electrode 120 formed on the front surface or the back surface of one of the adjacent regions, branches into two, and is formed on both side surfaces of the other region. It is connected to the formed second excitation electrode 120. Hereinafter, the arrangement of the extraction electrodes 112 and 122 will be described in more detail.

  As shown in FIG. 1A, a first extraction electrode 112 is formed on the surface of the first vibrating arm portion 10 located between the first region 12 and the second region 14. The first extraction electrode 112 extends from the first excitation electrode 110 formed on the surface of the first region 12 toward the second region 14 and bifurcates into both side surfaces of the first vibrating arm unit 10. Has reached. Then, the first excitation electrode 110 formed on both side surfaces of the second region 14 is connected.

  Similarly, a second extraction electrode 122 is formed between the second region 14 and the third region 16, and the second excitation electrode 120 formed on the surface of the second region 14 and both side surfaces of the third region 16. Are connected to the second excitation electrode 120. A second extraction electrode 122 is formed between the fourth region 22 and the fifth region 24, and the second excitation electrode 120 formed on the surface of the fourth region 22 is formed on both side surfaces of the fifth region 24. The formed second excitation electrode 120 is connected. In addition, a first extraction electrode 112 is formed between the fifth region 24 and the sixth region 26, and the first excitation electrode 110 formed on the surface of the fifth region 24 and both side surfaces of the sixth region 26. The formed first excitation electrode 110 is connected.

  As shown in FIG. 1B, a second extraction electrode 122 is formed on the back surface of the first vibrating arm portion 10 located between the first region 12 and the second region 14. The second extraction electrode 122 extends from the second excitation electrode 120 formed on the back surface of the second region 14 toward the first region 12 and bifurcates to both side surfaces of the first vibrating arm unit 10. Has reached. And it connects to the 2nd excitation electrode 120 formed in the both sides | surfaces of the 1st area | region 12.

  Similarly, a first extraction electrode 112 is formed between the second region 14 and the third region 16, and the first excitation electrode 110 formed on both side surfaces of the second region 14 and the back surface of the third region 16. Are connected to the first excitation electrode 110 formed. A first extraction electrode 112 is formed between the fourth region 22 and the fifth region 24, and the first excitation electrode 110 formed on both side surfaces of the fourth region 22 and the back surface of the fifth region 24. The formed first excitation electrode 110 is connected. In addition, a second extraction electrode 122 is formed between the fifth region 24 and the sixth region 26, and the second excitation electrode 120 formed on both side surfaces of the fifth region 24 and the back surface of the sixth region 26. The formed second excitation electrode 120 is connected.

  As described above, only one of the first extraction electrode 112 and the second extraction electrode 122 is formed on the surface between the adjacent regions of the vibrating arm portions 10 and 20. Similarly, only one of the first extraction electrode 112 and the second extraction electrode 122 is formed on the back surface between the adjacent regions of the vibrating arm portions 10 and 20.

  In addition, as a material and manufacturing method of the extraction electrodes 112 and 122, the material and manufacturing method enumerated by description of the excitation electrodes 110 and 120 are applicable, for example.

(3) First Terminal and Second Terminal As shown in FIG. 1, the first terminal 114 and the second terminal 124 are formed on the front and back surfaces and side surfaces of the first support portion 50. Although not shown, the terminals 114 and 124 may be formed on the second support portion 60. The terminals 114 and 124 are formed apart from each other, and the shape thereof is not particularly limited. In the illustrated example, the first terminal 114 and the second terminal 124 formed on the surface of the first support portion 50 have the same (substantially the same) area. Similarly, the first terminal 114 and the second terminal 124 formed on the back surface of the first support portion 50 have the same (substantially the same) area.

  The first terminal 114 is connected to the first excitation electrode 110 formed on the front and back surfaces of the first region 12 and the inner surface of the fourth region 22 via the first wiring 116 formed on the first base end portion 30. It is connected to the formed first excitation electrode 110. The second terminal 124 is connected to the second excitation electrode 120 formed on the inner surface of the first region 12 and the front and rear surfaces of the fourth region 22 via the second wiring 126 formed on the first base end portion 30. It is connected to the formed second excitation electrode 120.

  In the double tuning fork resonator element 100, the first excitation electrode formed in each of the regions 12, 14, 16, 22, 24, and 26 by applying a drive signal between the first terminal 114 and the second terminal 124. An electric field is generated between 110 and the second excitation electrode 120, and the first vibrating arm 10 and the second vibrating arm 20 can be flexibly vibrated.

  As materials and manufacturing methods of the terminals 114 and 124, for example, the materials and manufacturing methods listed in the description of the excitation electrodes 110 and 120 can be applied.

  The double tuning fork type vibrating piece 100 according to the present embodiment has, for example, the following characteristics.

  According to the double tuning fork type resonator element 100, the first support part 50 and the second support part 60 are disposed between the first vibrating arm part 10 and the second vibrating arm part 20. Therefore, for example, when the size is restricted by the area of the package, the length of the vibrating arm portions 50 and 60 can be increased by the amount of the support portions 50 and 60. Therefore, the double tuning fork vibrating piece 100 can have high sensitivity. Further, the length of the vibrating arms 10 and 20 in the extending direction (Y-axis direction) can be reduced, and the double tuning fork type vibrating piece 100 can be downsized. Further, according to the double tuning fork type resonator element 100, excitation electrodes 110 and 120 are formed on the front and back surfaces and both side surfaces in each of the regions 12, 14, 16, 22, 24 and 26. With such an arrangement of the excitation electrodes 110 and 120, the double tuning fork type vibrating piece 100 can be used, for example, when excitation electrodes are provided only in the regions at both ends of the vibrating arm portion, or only in the central region of the vibrating arm portion. Compared with the case where the excitation electrode is provided, a high Q value and a small CI value can be realized. That is, the vibration characteristics are improved and the resonance frequency is stabilized. When applied to a vibration-type sensor that detects a change in resonance frequency due to an external force, since the S / N ratio N can be reduced, high-accuracy measurement is possible. As described above, the double tuning fork type vibrating piece 100 can be small and have high sensitivity depending on the arrangement of the support portions 50 and 60 and the arrangement of the excitation electrodes 110 and 120, and a highly accurate sensor can be realized.

  According to the double tuning fork resonator element 100, the first extraction electrode 112 extends from the first excitation electrode 110 formed on the front surface or the back surface of one of the adjacent regions, and is bifurcated. The first excitation electrode 110 formed on both side surfaces of the other region is connected. The same contents as those described for the first extraction electrode 112 can be applied to the second extraction electrode 122. That is, only one of the first extraction electrode 112 and the second extraction electrode 122 is formed on the front and back surfaces between adjacent regions of the vibrating arm portions 10 and 20. Therefore, even when the width (the length in the Y-axis direction) of the vibrating arm portions 10 and 20 is reduced with the miniaturization of the double tuning fork resonator element, the first extraction electrode 112 is formed on the front and back surfaces between adjacent regions. There is no concern that the second extraction electrode 122 will short-circuit. Further, it is not necessary to extremely reduce the width of the extraction electrodes 112 and 122, and an increase in electrical resistance and disconnection of the extraction electrodes 112 and 122 can be suppressed.

  According to the double tuning fork resonator element 100, the excitation electrodes 110 and 120 can be formed on the inner wall of the groove 15. Thereby, since the electric field generated at the time of voltage application can be efficiently converted into vibration, the double tuning fork vibrating piece 100 can suppress an increase in CI value.

2. First Modification of Double Tuning Fork Type Vibrating Piece Next, a double tuning fork type vibrating piece 200 according to a first modification of the present embodiment will be described with reference to the drawings. FIG. 3A is a plan view of the double tuning fork vibrating piece 200 as viewed from one main surface (front surface) side, and illustrates the configuration of one main surface (front surface) side of the double tuning fork vibrating piece 200. It is a figure for doing. FIG. 3B is a perspective view of the double tuning fork vibrating piece 200 viewed from one main surface (front surface) side, and the configuration of the other main surface (back surface) side of the double tuning fork vibrating piece 200 is described. It is a figure for doing. Hereinafter, in the double tuning fork vibrating piece 200 according to the first modification of the present embodiment, members having the same functions as the constituent members of the double tuning fork vibrating piece 100 according to the present embodiment are denoted by the same reference numerals, Detailed description thereof is omitted.

  In the example of the double tuning fork type resonator element 100, the first extraction electrode 112 extends from the first excitation electrode 110 formed on the front surface or the back surface of one of the adjacent regions, and is bifurcated. The first excitation electrode 110 formed on both side surfaces of the other region was connected. The same contents as those described for the first extraction electrode 112 can be applied to the second extraction electrode 122.

  In the double tuning fork type resonator element 200, as shown in FIG. 3, the first extraction electrode 112 extends from the first excitation electrode 110 formed on the front surface or the back surface of one of the adjacent regions, and the other Is connected to the first excitation electrode 110 formed on one side surface of the region. The second extraction electrode 122 extends from the second excitation electrode 120 formed on the front surface or the back surface of one of the adjacent regions, and the second excitation electrode is formed on one side surface of the other region. It is connected to the electrode 120.

  More specifically, as shown in FIG. 3A, the first extraction electrode 112 and the second electrode are formed on the surface of the first vibrating arm portion 10 located between the first region 12 and the second region 14. An extraction electrode 122 is formed. The first extraction electrode 112 extends from the first excitation electrode 110 formed on the surface of the first region 12 toward the second region 14 and reaches the outer surface of the first vibrating arm portion 10. And it is connected to the first excitation electrode 110 formed on the outer surface of the second region 14. The second extraction electrode 122 extends from the second excitation electrode 120 formed on the surface of the second region 14 toward the first region 12 and reaches the inner surface of the first vibrating arm unit 10. Then, it is connected to the second excitation electrode 120 formed on the inner surface of the first region 12.

  Further, as shown in FIG. 3B, the first extraction electrode 112 and the second extraction electrode 122 are formed on the back surface of the first vibrating arm portion 10 located between the first region 12 and the second region 14. Is formed. The first extraction electrode 112 extends from the first excitation electrode 110 formed on the back surface of the first region 12 toward the second region 14 and reaches the inner surface of the first vibrating arm unit 10. And it is connected to the first excitation electrode 110 formed on the inner side surface of the second region 14. The second extraction electrode 122 extends from the second excitation electrode 120 formed on the back surface of the second region 14 toward the first region 12 and reaches the outer surface of the first vibrating arm unit 10. And it is connected to the second excitation electrode 120 formed on the outer surface of the first region 12.

  The above description of the extraction electrode between the first region 12 and the second region 14 can be applied to the extraction electrode between other regions.

  According to the double tuning fork type vibrating piece 200, regardless of the arrangement and shape of the extraction electrodes 112 and 122 shown in the example of the double tuning fork type vibrating piece 100, the first example vibrating electrodes 110 are connected to each other, and the second excitation electrode is used. 120 can be connected. That is, the degree of freedom of design in the arrangement and shape of the extraction electrodes 112 and 122 can be increased.

3. Second Modified Example of Twin Tuning Fork Type Vibrating Piece Next, a double tuning fork type vibrating piece 300 according to a second modified example of the present embodiment will be described with reference to the drawings. FIG. 4A is a plan view of the double tuning fork vibrating piece 300 as viewed from one main surface (surface) side, and illustrates the configuration of one main surface (front surface) side of the double tuning fork vibrating piece 300. It is a figure for doing. FIG. 4B is a perspective view of the double tuning fork vibrating piece 300 viewed from one main surface (front surface) side, and the configuration of the other main surface (back surface) side of the double tuning fork vibrating piece 300 is described. It is a figure for doing. Hereinafter, in the double tuning fork type vibrating piece 300 according to the second modification of the present embodiment, members having the same functions as those of the components of the double tuning fork type vibrating piece 100 according to the present embodiment are denoted by the same reference numerals. Detailed description thereof is omitted.

  In the double tuning fork resonator element 300, as shown in FIG. 4, an opening 350 is formed between the first terminal 114 and the second terminal 124 of the first support portion 50. Although not shown, for example, when the first terminal 114 and the second terminal 124 are formed on the second support part 60, between the first terminal 114 and the second terminal 124 of the second support part 60, An opening 350 may be formed. The opening 350 is formed to be separated from the outer periphery of the first support portion 50 in plan view. The planar shape of the opening 350 can be said to be annular, but is rectangular in the illustrated example. The opening 350 may be a through-hole penetrating from the front surface to the back surface, or may have a groove shape having a bottom surface without penetrating. When the opening 350 is formed as a through hole, the opening 350 can be formed at the same time when the outer shape of the double tuning fork type vibrating piece 300 is formed by etching or the like. That is, the opening 350 can be formed without increasing the number of manufacturing steps.

  According to the double tuning fork type resonator element 300, the opening 350 can be formed in the first support portion 50 as described above. In the opening 350, for example, air (or vacuum) having a dielectric constant smaller than that of the crystal constituting the first support portion 50 is provided. Therefore, the coupling capacitance between the first terminal 114 and the second terminal 124 can be reduced. Thereby, the distance between the 1st terminal 114 and the 2nd terminal 124 can be made small, and the area of the 1st support part 50 can be made small by that much. As a result, the distance between the first vibrating arm portion 10 and the second vibrating arm portion 20 can be reduced, and the size of the double tuning fork type vibrating piece 300 can be reduced. In general, it is known that in a double tuning fork type vibrating piece, the coupling of vibration energy increases as the distance between two vibrating arms decreases. Therefore, according to the double tuning fork type resonator element 300, a high Q value and a small CI value can be realized.

  Further, according to the double tuning fork type resonator element 300, for example, as shown in FIG. 6 to be described later, when an adhesive is used to join the first support portion 50 to the base portion 502, excess adhesive is put into the opening 350. Can escape. Thereby, it can suppress that an adhesive agent flows out from the outer periphery of the 1st support part 50, and can improve reliability.

  Further, according to the double tuning fork type resonator element 300, the opening 350 is separated from the outer periphery of the first support part 50 in plan view. For example, if the opening is provided so as to be connected to the outer periphery of the first support part and to divide the first support part, the number of places for supporting the double tuning fork type vibration piece is substantially increased. As described above, when there are many support portions, the variation in the support state increases, and the sensitivity of the double tuning fork type resonator element may decrease. In the double tuning fork type vibrating piece 300, the opening 350 can be provided without increasing the number of supporting portions more than necessary.

4). Third Modification of Double Tuning Fork Type Vibrating Piece Next, a double tuning fork type vibrating piece 400 according to a third modification of the present embodiment will be described with reference to the drawings. FIG. 5A is a plan view of the double tuning fork vibrating piece 400 viewed from one main surface (surface) side, and illustrates the configuration of one main surface (front surface) side of the double tuning fork vibrating piece 400. It is a figure for doing. FIG. 5B is a perspective view of the double tuning fork vibrating piece 400 as viewed from one main surface (front surface) side, and illustrates the configuration of the other main surface (back surface) side of the double tuning fork vibrating piece 400. It is a figure for doing. Hereinafter, in the double tuning fork type vibrating piece 400 according to the third modification of the present embodiment, the members having the same functions as the constituent members of the double tuning fork type vibrating piece 100 according to the present embodiment are denoted by the same reference numerals, Detailed description thereof is omitted.

  In the example of the double tuning fork resonator element 100, the first terminal 114 and the second terminal 124 are formed on the surface of the first support portion 50. Similarly, the first terminal 114 and the second terminal 124 are formed on the back surface of the first support portion 50.

  In the double tuning fork type resonator element 400, as shown in FIG. 5A, only the first terminal 114 is formed on the surface of the first support portion 50, and the second terminal 124 is not formed. In the example of FIG. 5A, the second terminal 124 is formed on the side surface of the first support portion 50. Further, as shown in FIG. 5B, only the second terminal 124 is formed on the back surface of the first support portion 50, and the first terminal 114 is not formed. In the example of FIG. 5B, the first terminal 114 is formed on the side surface of the first support portion 50. Although not shown, only the second terminal 124 may be formed on the front surface of the first support portion 50, and only the first terminal 114 may be formed on the back surface of the first support portion 50.

  According to the double tuning fork type resonator element 400, as described above, one terminal can be formed on one of the front and back surfaces of the first support portion 50. That is, two terminals are not formed on one surface of the first support portion 50, for example, like the double tuning fork type vibrating piece 100. Therefore, the area of the first support portion 50 can be reduced accordingly. As a result, the distance between the first vibrating arm unit 10 and the second vibrating arm unit 20 can be reduced, and the size of the double tuning fork type vibrating piece 400 can be reduced. Further, according to the double tuning fork type resonator element 400, a high Q value and a small CI value can be realized.

5). Next, the vibration type sensor element 500 according to the present embodiment will be described with reference to the drawings. FIG. 6 is a perspective view schematically showing the vibration type sensor element 500. The vibration type sensor element 500 includes a double tuning fork type vibration piece according to the present invention. In the present embodiment, an example in which a double tuning fork type vibrating piece 100 is used as a double tuning fork type vibrating piece according to the present invention will be described. Hereinafter, in the vibration type sensor element 500 according to the present embodiment, members having the same functions as those of the components of the double tuning fork type vibrating piece 100 according to the present embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. To do. For convenience, the excitation electrodes 110 and 120, the extraction electrodes 112 and 122, the terminals 114 and 124, and the wirings 116 and 126 are not shown in FIG.

  As shown in FIG. 6, the vibration sensor element 500 includes a base portion 502, an elastic portion 504 continuous with the base portion 502, and a mass portion 506 as another base portion that is continuous with the elastic portion 504 and supported by the elastic portion 504. And a double tuning fork type vibrating piece 500 fixed to the base portion 502 and the mass portion 506. Examples of the material of the base portion 502, the elastic portion 504, and the mass portion 506 include piezoelectric materials such as crystal, lithium tantalate, and lithium niobate, and metal materials such as brass, aluminum, and phosphor bronze.

  The base 502 is a portion that is mechanically fixed to the vibration sensor element 500 when the vibration sensor element 500 is mounted on a device such as an automobile, an aircraft, or a rocket. The shape of the base 502 is not limited. The functions of the base portion 502 are to support the mass portion 506 via the elastic portion 504 and to be a reference for the displacement of the elastic portion 504 that occurs when a physical quantity such as acceleration is input to the vibration type sensor element 500. , Etc.

  The elastic portion 504 is a portion that connects the base portion 502 and the mass portion 506 so that the base portion 502 supports the mass portion 506. Although not shown, a plurality of elastic portions 504 may be provided. Examples of the shape of the elastic portion 504 include a leaf spring shape, a string spring (coil) shape, and a bent shape. In the illustrated example, the elastic portion 504 corresponds to a portion having a smaller thickness than the base portion 502 and the mass portion 506 (a portion having a narrowed thickness in a sectional view). The elastic part 504 has elasticity. In other words, the elastic portion 504 has a restoring force that attempts to return the mass portion 506 to a position before being displaced when the mass portion 506 is a force receiving portion and receives a force and is displaced with respect to the base portion 502.

  The mass part 506 is a part that is continuous with the elastic part 504 and supported by the elastic part 504. The shape of the mass part 506 is not particularly limited. Examples of the form in which the mass part 506 is supported include a cantilever form, a doubly-supported form, and a form suspended by the elastic part 504. The mass unit 506 becomes an inertial resistance (mass) when acceleration or the like is applied to the vibration sensor element 500. Therefore, when an inertial force is generated in the spring / cone vibration system, the elastic portion 504 can be distorted by the action of the mass portion 506. Further, when an acceleration or the like is applied to the vibration type sensor element 500, the relative position of the mass unit 506 with respect to the base 502 changes due to the inertia of the mass unit 506. Therefore, the vibration type sensor element 500 can measure applied acceleration or the like by detecting a change in the position of the mass portion 506 relative to the base portion 502. In the illustrated example, the mass portion 506 is continuous with the elastic portion 504 and is held in a cantilever shape. In the illustrated example, when the acceleration in the Y-axis direction is applied to the vibration sensor element 500, the elastic portion 504 is distorted, and the position of the mass portion 506 relative to the base 502 changes.

  The double tuning fork type vibrating piece 100 is fixed to the base portion 502 and the mass portion 506. In the illustrated example, the first support portion 50 is fixed to the base portion 502, and the second support portion 60 is fixed to the mass portion 506. Although not shown, the second support portion 60 may be fixed to the base portion 502, and the first support portion 50 may be fixed to the mass portion 506. The support portions 50 and 60 can be fixed to the base portion 502 and the mass portion 506 by, for example, a conductive adhesive. Thereby, for example, the terminals 114 and 124 formed on the back surface of the first support portion 50 and the wiring (not shown) formed on the base portion 502 can be electrically connected. In addition, it is also possible to electrically connect the terminals 114 and 124 formed on the surface of the first support part 50 to the outside by, for example, wires (not shown).

  According to the vibration type sensor element 500, as described above, the small and highly sensitive double tuning fork type vibration piece 100 is fixed to the base portion 502 and the mass portion 506. Therefore, the vibration type sensor element 500 having a small size and high sensitivity can be provided.

6). Next, the vibration type sensor 600 according to the present embodiment will be described with reference to the drawings. FIG. 7 is a cross-sectional view schematically showing the vibration type sensor 600. The vibration type sensor 600 includes the vibration type sensor element according to the present invention. In the present embodiment, an example in which a vibration sensor element 500 is used as a vibration sensor element according to the present invention will be described. Hereinafter, in the vibration sensor 600 according to the present embodiment, members having the same functions as those of the constituent members of the vibration sensor element 500 according to the present embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 7, the vibration type sensor 600 includes a package 602, an IC chip 602 accommodated in the package 602, and a vibration type sensor element 500.

  Examples of the package 602 include a ceramic package base (container) provided with a lid (lid). The vibration type sensor element 500 can be sealed in the reduced pressure space by the package 602. Thereby, the Q value of the double tuning fork type resonator element 100 can be increased, and thermal noise and member deterioration can be suppressed.

  The IC chip 604 is bonded to the inner bottom surface of the package 602 by, for example, a brazing material (not shown). The IC chip 604 includes a drive circuit for vibrating the drive arm portions 10 and 20 of the double tuning fork vibrating piece 100 and a detection circuit for detecting a physical quantity generated in the double tuning fork vibrating piece 100. The IC chip 604 is electrically connected to the sensor element 500 (double tuning fork type vibrating piece 100) by, for example, a wire (not shown).

  The vibration type sensor element 500 has a base portion 502 bonded to the inner bottom surface of the package 602 by, for example, a brazing material. The mass portion 506 is separated from the inner bottom surface of the package 602. That is, the vibration type sensor element 500 is accommodated in the package 602 in a cantilever state.

  According to the vibration type sensor 600, the small size and high sensitivity vibration type sensor element 500 is housed in the package 602 as described above. Therefore, it is possible to provide a vibration type sensor 600 that is small and has high sensitivity.

  In addition, embodiment mentioned above and a modification are examples, Comprising: It is not necessarily limited to these. For example, it is possible to appropriately combine each embodiment and each modification.

  Although the embodiments of the present invention have been described in detail as described above, those skilled in the art will readily understand that many modifications are possible without substantially departing from the novel matters and effects of the present invention. Accordingly, all such modifications are intended to be included in the scope of the present invention.

10 first vibrating arm part, 15 groove, 20 second vibrating arm part, 30 first base end part,
32 protrusions, 40 second base end, 42 protrusions, 50 first support,
60 second support part, 100 double tuning fork type resonator element, 110 first excitation electrode,
112 first extraction electrode, 114 first terminal, 116 first wiring, 120 second excitation electrode,
122 second extraction electrode, 124 second terminal, 126 second wiring,
200 double tuning fork type vibrating piece, 300 double tuning fork type vibrating piece, 350 opening,
400 double tuning fork type resonator element, 500 vibration type sensor element, 502 base,
504 elastic part, 506 mass part, 600 vibration type sensor, 602 package,
604 IC chip

Claims (8)

A double tuning fork type resonator element having a front surface and a back surface in a front / back relationship, and a side surface connected to the front surface and the back surface,
A first vibrating arm portion and a second vibrating arm portion extending in parallel;
A first base end connected to one end of the first vibrating arm and the second vibrating arm;
A second base end connected to the other end of the first vibrating arm and the second vibrating arm;
A first support portion connected to the first base end portion and disposed between the first vibrating arm portion and the second vibrating arm portion;
A second support portion connected to the second base end portion and disposed between the first vibrating arm portion and the second vibrating arm portion;
Including
The first vibrating arm portion includes a first region, a second region, and a third region, which are sequentially arranged along a direction from the first base end portion to the second base end portion,
The second vibrating arm portion includes a fourth region, a fifth region, and a sixth region, which are sequentially arranged along a direction from the first base end portion to the second base end portion.
Front and back surfaces of the first region, both side surfaces of the second region, front and back surfaces of the third region, both side surfaces of the fourth region, front and back surfaces of the fifth region, and both side surfaces of the sixth region A first excitation electrode electrically connected to each other is formed;
On both side surfaces of the first region, front and back surfaces of the second region, both side surfaces of the third region, front and back surfaces of the fourth region, both side surfaces of the fifth region, and front and back surfaces of the sixth region A double tuning fork type resonator element in which second excitation electrodes electrically connected to each other are formed. In claim 1,
A first extraction electrode and a second extraction electrode are formed between the adjacent areas of the first vibrating arm portion and the second vibrating arm portion,
The first extraction electrode is
One of the adjacent regions is extended from the first excitation electrode formed on the front surface or the back surface of one of the regions, branched at least bifurcated, and one of the branched electrodes is one of the other regions. Connected to the first excitation electrode formed on the side surface, the other branched electrode is connected to the first excitation electrode formed on the other side surface of the other region,
The second extraction electrode is
One of the adjacent regions is extended from the second excitation electrode formed on the front or back surface of one of the regions, branched at least bifurcated, and one branched electrode is one of the other regions. A double tuning fork type resonator element that is connected to the second excitation electrode formed on a side surface, and the other branched electrode is connected to the second excitation electrode formed on the other side surface of the other region. In claim 1,
A first extraction electrode and a second extraction electrode are formed between the adjacent areas of the first vibrating arm portion and the second vibrating arm portion,
The first extraction electrode is
The adjacent one of the regions extends from the first excitation electrode formed on the front surface or the back surface of one of the regions, and is connected to the first excitation electrode formed on one side surface of the other region. ,
The second extraction electrode is
Out of the adjacent regions, the second excitation electrode formed on the front surface or the back surface of one of the regions is connected to the second excitation electrode formed on one side surface of the other region. The double tuning fork type vibration piece. In any of claims 1 to 3,
On the front and back surfaces of the first support portion, a first terminal electrically connected to the first excitation electrode and a second terminal electrically connected to the second excitation electrode are formed,
A double tuning fork type vibrating piece in which an annular opening is formed between the first terminal and the second terminal of the first support portion. In any of claims 1 to 3,
The first support part is formed with a first terminal electrically connected to the first excitation electrode and a second terminal electrically connected to the second excitation electrode,
One of the first terminal and the second terminal is formed on one of the front surface of the first support part and the back surface of the front surface.
The double tuning fork type resonator element, wherein the other of the first terminal and the second terminal is formed on the other of the front surface and the back surface of the first support portion. In any of claims 1 to 5,
The first vibrating arm portion and the second vibrating arm portion have grooves formed on the front and back surfaces of the region,
The first tuning electrode and the second excitation electrode formed on the front and back surfaces of the region are a double tuning fork type resonator element provided on the inner wall of the groove. The base,
An elastic part continuous to the base part;
Another base that is continuous with the elastic portion and supported by the elastic portion;
The double tuning fork type resonator element according to any one of claims 1 to 6, which is fixed to the base portion and the other base portion,
Including a vibration type sensor element. The vibration type sensor element according to claim 7,
A package containing the vibration-type sensor element;
Including vibration sensor.

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