JP4543816B2 - Piezoelectric vibrator, vibratory gyroscope - Google Patents

Description

  The present invention relates to a piezoelectric vibrating piece and a vibrating gyroscope equipped with the piezoelectric vibrating piece.

  2. Description of the Related Art Conventionally, in a vibrating gyroscope for measuring a rotational angular velocity in a predetermined plane, a piezoelectric vibrating piece extending in a predetermined plane is provided. The piezoelectric vibrating piece includes a base where the center of gravity of the piezoelectric vibrating piece is located, and a peripheral edge of the base A plurality of drive vibration arms and detection vibration arms protruding from the portion, each of which is formed with respect to each vibration arm, a drive signal electrode, a detection signal electrode, an electrode pattern connecting them, and a power supply pad (electrode land) However, there is known an electrode wiring configuration of a vibration gyroscope that is independently formed on the base (see, for example, Patent Document 1).

JP 2001-41749 A (5th page, FIG. 1)

  In such Patent Document 1, since the electrode pattern and electrode land of the drive signal electrode and the detection signal electrode formed at the base of the piezoelectric vibrating piece are provided close to each other, the drive signal electrode and the detection signal electrode It is expected that stray capacitance will occur between them. Since the piezoelectric vibrating piece used in the vibration gyroscope is a minute charge detection element, even if this stray capacitance is minute, it affects the output detection signal and an accurate detection signal cannot be obtained. There is a problem like this.

  An object of the present invention is to reduce a stray capacitance between a drive signal electrode and a detection signal electrode and obtain an accurate detection signal, and a highly reliable vibration type gyro mounted with the piezoelectric vibration piece. Is to provide a scope.

The piezoelectric vibrating piece of the present invention includes a drive signal electrode and a detection signal electrode provided on a predetermined surface, a drive signal electrode pattern continuous to the drive signal electrode, a detection signal electrode pattern continuous to the detection signal electrode, and at least the A drive signal electrode and the detection signal electrode, or a plurality of constant potential electrode patterns formed between the drive signal electrode pattern and the detection signal electrode pattern are provided.
Here, the constant potential electrode pattern indicates, for example, a GND (ground) electrode pattern having the same potential.

  In the piezoelectric vibrating piece of the present invention, a plurality of constant potential electrode patterns are formed between a drive signal electrode and a detection signal electrode formed on a predetermined surface or between a drive signal electrode pattern and a detection signal electrode pattern. Therefore, a minute stray capacitance is generated between the detection signal electrode pattern and the adjacent constant potential electrode pattern. However, a constant potential electrode is further provided between the constant potential electrode pattern and the detection signal electrode pattern. Since the pattern is formed, the stray capacitance between the adjacent constant potential electrode patterns is so small as to be negligible, and the influence on the detection signal is so small that an accurate detection signal can be obtained.

  The piezoelectric vibrating piece described above is formed on a rectangular base portion formed on a predetermined surface, a driving vibration arm and a detection vibration arm extending from respective opposing end surfaces of the base portion, and the driving vibration arm. A drive signal electrode; a detection signal electrode formed on the detection vibrating arm; a drive signal electrode pattern continuous to the drive signal electrode formed continuously on at least one main surface of the base; and the detection signal electrode It is preferable that a continuous detection signal electrode pattern and a plurality of constant potential electrode patterns formed between the drive signal electrode pattern and the detection signal electrode pattern are provided.

Here, for example, when the piezoelectric vibrating piece is formed of quartz, the predetermined surface indicates a plane constituted by an X axis called an electric axis and a Y axis called a mechanical axis. The thickness direction is a Z axis called an optical axis.
Furthermore, the center-of-gravity position of the base is also the center-of-gravity position of the piezoelectric vibrating piece.

  According to such a structure, since a plurality of constant potential electrode patterns are formed between the drive signal electrode pattern and the detection signal electrode pattern formed at the base of the piezoelectric vibrating piece, there are two GND electrodes. A small stray capacitance is generated between the drive signal electrode pattern and the GND electrode pattern adjacent to the drive signal electrode pattern, and another one is provided between the GND electrode pattern and the detection signal electrode pattern. Since the GND electrode pattern is formed, the stray capacitance between adjacent GND electrode patterns is negligibly small, and the influence of this stray capacitance on the detection signal is so small that it can be ignored, so that an accurate detection signal is obtained. be able to.

  The same can be explained when this is seen from the detection signal electrode pattern side. That is, it is possible to reduce the stray capacitance generated between the detection signal electrode pattern and the adjacent GND electrode pattern from affecting the drive signal.

For example, when three GND electrodes are formed between the drive electrode pattern and the detection electrode pattern, the stray capacitance generated between the drive electrode pattern and the adjacent GND electrode pattern is further reduced to the center GND electrode pattern. Between the GND electrode pattern and the GND electrode pattern adjacent to the detection signal electrode pattern, and an accurate detection signal can be obtained.
The number of the GND electrode patterns is not limited to two or three, but can be increased. However, it is appropriate to provide three GND electrode patterns in a limited area of the base.

  In the piezoelectric vibrating piece having the above-described structure, the drive signal electrode pattern, the detection signal electrode pattern, and the constant potential electrode pattern are symmetrical with respect to a line parallel to the X axis passing through the center of gravity of the base portion. Is preferred.

  As will be described in detail later, for example, when the detection vibrating arm is extended in parallel to the Y axis from each of the opposing end surfaces of the base, the aforementioned electrode pattern formed with respect to the X axis passing through the center of gravity is symmetrical. Therefore, even if the stray capacitance as described above occurs, the detection signal electrode has the same stray capacitance, so that the detection signal of one detection vibration arm and the detection vibration arm of the other detection vibration arm are the same. Since the influence on the detection signal is also the same, the value of the output detection signal is also the same, and in addition to the effect obtained by providing the GND electrode pattern, a more accurate detection signal can be obtained.

  Further, in the configuration of each electrode pattern described above, among the drive signal electrode pattern, the drive signal electrode pattern, and the constant potential electrode pattern, the electrode patterns adjacent to each other have substantially the same gap. Is preferred.

  The stray capacitance generated between adjacent electrode patterns can be calculated from the dielectric constant of the substance between the electrode patterns, the area of the opposing electrode pattern, and the distance between the electrode patterns. Here, as described above, each electrode pattern is formed symmetrically with respect to the X axis passing through the center of gravity, and the distance between the electrode patterns is set to be substantially the same. The influence of the generated micro stray capacitance has the same influence on the detection signals of the detection vibrating arms extending from the opposite end faces of the base, so that this influence can be offset and a stable detection signal can be obtained. Can do. This can further reduce the influence of the stray capacitance in combination with the provision of the GND electrode pattern between the drive signal electrode pattern and the detection signal electrode pattern as described above.

  In the piezoelectric vibrating piece of the present invention, the drive signal electrode pattern, the detection signal electrode pattern, and the constant potential electrode pattern each include an electrode land portion, and the electrode land portion passes through the center of gravity. And it is preferable to be provided in a symmetrical position with respect to a line parallel to the Y axis.

  As will be described in detail later, the piezoelectric vibrating piece is connected to and supported by each electrode pattern by a lead member. Each electrode pattern is provided with an electrode land portion for connection at a connection portion with the lead member. Since the electrode land portion is provided symmetrically with respect to the X axis and the Y axis with the center of gravity as the center, the piezoelectric vibrating piece is stably supported, so that stable performance can be maintained over a long period of time. it can.

Furthermore, it is preferable that the constant potential electrode pattern is formed independently in the piezoelectric vibrating piece.
As will be described in detail later, the drive signal electrode and the detection signal electrode described above are provided with corresponding GND electrodes. The potential of the GND electrode is controlled to a constant potential. The electrode pattern of the constant potential is configured independently in the piezoelectric vibrating piece, and is preferably connected to the GND electrode in a semiconductor device that performs drive and detection control of the piezoelectric vibrating piece, for example. In the resonator element, the above-described effect of eliminating the influence of the stray capacitance generated between the electrode patterns described above can be obtained, and the circuit configuration of the semiconductor device can be simplified.

  A rectangular base provided on the predetermined surface; two vibrating arms extending in parallel from one end face of the base; a detection signal electrode formed on a main surface of the vibrating arm; and the vibrating arm A drive signal electrode formed on a side surface of the base, a drive signal electrode pattern continuous with the drive signal electrode formed continuously on at least one main surface of the base, and a detection signal electrode pattern continuous with the detection signal electrode Preferably, the detection signal electrode and the drive signal electrode pattern, or a plurality of constant potential electrode patterns formed between the drive signal electrode pattern and the detection signal electrode pattern are provided.

Here, as the piezoelectric vibrating piece having two vibrating arms extending in parallel from one end face of the base, for example, a tuning fork type piezoelectric vibrating piece may be employed. The main surface of the vibrating arm means a surface that is in the same plane as the predetermined surface on which the base is formed.
According to such a structure, between the detection signal electrode formed on the main surface of the vibrating arm and the driving signal electrode formed on the side surface of the vibrating arm, or between the driving signal electrode pattern and the driving signal electrode pattern. Since the constant potential electrode pattern is provided, even the tuning-fork type piezoelectric vibrating piece can minimize the influence of the stray capacitance on the detection signal as described above.

In the piezoelectric vibrating piece according to the present invention, the vibrating body having at least three predetermined surfaces, the drive signal electrode formed on a predetermined surface that is not parallel to each of the predetermined surfaces of the vibrating body, and the Preferably, a plurality of constant potential electrode patterns formed between the detection signal electrode, the drive signal electrode, and the detection signal electrode are provided.
Thus, as the vibrating body having a plurality of predetermined surfaces, for example, a vibrating body having a polygonal cross section such as a triangular prism or a quadrangular prism is shown, and the predetermined surface means a side surface such as a triangular prism.

  As described above, even in the case of the vibrating body such as the triangular prism or the quadrangular prism, the stray capacitance is converted into the detection signal by providing a plurality of constant potential electrode patterns between the adjacent detection signal electrode and the drive signal electrode. The effect on this can be minimized.

  Further, the vibrating gyroscope of the present invention has one end connected to a container composed of a side body and a lid for storing the piezoelectric vibrating piece, and to each electrode land of the base of the piezoelectric vibrating piece. A lead member having the other end connected to the side body or the lid, and the lead member is symmetrical with respect to a line parallel to the X axis and the Y axis passing through the center of gravity of the base It is equipped to become.

According to such a structure, since the piezoelectric vibrating piece is supported in the container in a balanced manner in the X-axis direction and the Y-axis direction by the lead members, the piezoelectric vibrating piece is supported with a stable posture and a well-balanced supporting force. Stable vibration can be obtained.
Further, when the lead member is formed of an elastic material, it can have a buffering function against external impacts and vibrations.

  In addition, such a vibration type gyroscope includes an electrode land portion to which the other end of the lead member is connected to an inner surface of the side body or the lid body, and a drive signal electrode that is continuous with the electrode land portion, respectively. It is preferable that a pattern, a detection signal electrode pattern, and a plurality of constant potential electrode patterns formed between the drive signal electrode pattern and the detection signal electrode pattern are provided.

  The piezoelectric vibrating piece described above is connected to a side body or a lid by a lead member, and is further connected to a semiconductor device described later by an electrode pattern formed on the side body or the lid. Among these electrode patterns, a plurality of constant potential electrode patterns are formed between the drive signal electrode pattern and the detection signal electrode pattern. Therefore, the stray capacitance generated between the electrode pattern in the process leading to the piezoelectric vibrating piece and the semiconductor device is reduced. In combination with the above-described decrease in the stray capacitance of the piezoelectric vibrating piece, the influence of the stray capacitance on the detection signal can be further reduced, and a high-performance vibrating gyroscope can be provided.

  The vibrating gyroscope further includes a shield electrode pattern connected to at least one of the constant potential electrode patterns on an inner surface of the side body or the lid.

  According to such a structure, most of the inner surface of the container is covered with the constant potential electrode pattern, that is, the GND electrode pattern, so that electromagnetic noise from the outside can be shielded. Further, it is possible to prevent electromagnetic noise from being emitted from the vibrating gyroscope to the outside. Accordingly, it is possible to provide a vibration gyroscope with high reliability that can be used even in an environment with electromagnetic noise and that does not affect other electronic devices.

  Further, in the vibratory gyroscope according to the present invention, the above-described tuning fork-type piezoelectric vibrating piece, a container including the side body and the lid body in which the piezoelectric vibrating piece is stored, and the side body or the lid body. A pedestal provided on either side, and the base of the piezoelectric vibrating piece is fixed to the pedestal.

  In this way, the above-described piezoelectric vibrating piece has a plurality of constant potential electrode patterns between the detection signal electrode and the drive signal electrode, so that it is not easily affected by stray capacitance, and the vibrating arm Since the base that does not receive the vibration is fixed to the pedestal, the piezoelectric vibrating piece is supported in a stable posture, can obtain a stable vibration, and can obtain an accurate detection signal over a long period of time.

  Furthermore, in the vibratory gyroscope according to the present invention, the above-described piezoelectric vibrating piece having at least three predetermined surfaces, a container including a side body and a lid for storing the piezoelectric vibrating piece, and the piezoelectric The support member that supports the resonator element and a ridge line portion constituted by an adjacent predetermined surface among the plurality of predetermined surfaces are supported by the support member.

  According to such a structure, the above-described piezoelectric vibrating piece has a plurality of constant potential electrode patterns between the detection signal electrode and the drive signal electrode formed on each predetermined surface. In addition, the ridge line portion such as a triangular prism or a quadrangular prism has a node point that does not affect the vibration of the vibrating body, and the node point of the ridge line portion is supported by a support member. Can obtain a stable vibration and an accurate detection signal.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 7 show a piezoelectric vibrating piece and a vibrating gyroscope according to a first embodiment of the present invention. FIG. 8 shows a piezoelectric vibrating piece according to the second embodiment, and FIG. 9 shows a vibration according to the third embodiment. 10 shows a piezoelectric vibrating piece according to the fourth embodiment, FIG. 11 shows a vibrating gyroscope according to the fourth embodiment, and FIGS. 12 and 13 show piezoelectric vibration according to the fifth embodiment. FIG. 14 shows a vibrating gyroscope according to the fifth embodiment.
(Embodiment 1)

1 to 7 show a piezoelectric vibrating piece and a vibrating gyroscope according to the first embodiment.
FIG. 1 is a plan view showing a vibrating gyroscope according to the first embodiment, and FIG. 2 is a schematic sectional view. FIG. 1 shows a state in which the lid 30 shown in FIG. 2 is removed for easy understanding of the internal structure of the vibration gyroscope. 1 and 2, the vibration gyroscope 100 according to the first embodiment stores the piezoelectric vibrating piece 10 as a vibration source, lead members 41 to 52 that support the piezoelectric vibrating piece 10, and the piezoelectric vibrating piece 10. It is comprised from the side body 20 and the cover body 30 (refer FIG. 2) which comprise a container, and the support substrate 60 which supports the lead members 41-52.

  The piezoelectric vibrating piece 10 is formed in the XY plane as a predetermined surface. In the first embodiment, the piezoelectric vibrating piece 10 is made of quartz and cut in the plane direction of the X axis and the Y axis of the X axis called the electric axis, the Y axis called the mechanical axis, and the Z axis called the optical axis. This is a Z-cut quartz substrate. The piezoelectric vibrating piece 10 is formed of a quartz substrate having a predetermined thickness. The planar shape of the piezoelectric vibrating piece 10 is developed on the XY plane in accordance with the crystal axis of the crystal, and has a 180 ° point-symmetric shape with respect to the center point G. The center point G is the position of the center of gravity of the piezoelectric vibrating piece 10. Although not shown in FIG. 1, predetermined electrodes are formed on the surface of the piezoelectric vibrating piece 10 (see FIG. 3).

  The piezoelectric vibrating piece 10 is formed with a rectangular base portion 12 having end faces parallel to the X-axis direction and the Y-axis direction, respectively, and extends in the direction parallel to the X-axis from the center of the two end faces parallel to the Y-axis of the base portion 12. Two extending connecting arms 13 and 14 and a detection vibrating arm system 16 extending in the direction parallel to the Y axis from the center of the two end faces parallel to the X axis of the base 12 are formed. A detection vibrating arm 16A extends in the Y-axis plus direction and 16B extends in the Y-axis minus direction. A pair of drive vibration arm systems 15 are formed at the tips of the connection arms 13 and 14, and the drive vibration arms 15 </ b> A and 15 </ b> B extend in the direction perpendicular to the tip of the connection arm 13. Driving vibration arms 15C and 15D are extended from the tip of the arm 14 in a right angle direction.

  The driving vibration arms 15A, 15B, 15C, and 15D have dimensions such as width and length so that driving vibration of a predetermined frequency is generated. In addition, the detection vibrating arms 16A and 16B and the connecting arms 13 and 14 have dimensions such as width and length so that predetermined detection vibration is generated.

  Of both surfaces of the base portion 12 of the piezoelectric vibrating piece 10, the electrode pattern described later (see FIG. 3) is formed on the bottom surface 21 side (hereinafter referred to as the main surface 10 </ b> A) of the side body 20. Electrode land portions are provided, and one end portions of the lead members 41 to 52 are connected. The other ends of the lead members 41 to 52 are connected to electrode land portions provided on the bottom surface of the side body 20.

In FIG. 1, lead members 41, 42, and 43 are provided downward in the figure, and the lead members 47, 48, and 49 are lead members 41 to 43 with respect to a line parallel to the X axis that passes through the gravity center position G. It is line symmetric. The lead members 44, 45, 46 are provided in the left direction in the figure, and the lead members 50, 51, 52 are line symmetric with respect to a line passing through the center of gravity G and parallel to the Y axis.
That is, the lead members 41 to 52 facing the center of gravity G are arranged symmetrically with respect to the X-axis and Y-axis directions, respectively, and the shape is also symmetric.

  FIG. 2 shows a schematic cross-sectional view (cross-section AA in FIG. 1) of the piezoelectric vibrator 1 according to the first embodiment. This will be described with reference to FIG. Since the shape of each lead member and the connection structure between each lead member and the piezoelectric vibrating piece and the bottom surface of the side body are the same, lead members 41 and 52 (hereinafter referred to as lead member 41 etc.) are representative examples. Is described and explained. In FIG. 2, the side body 20 is a base of a container having a bottom surface formed of ceramics or the like, and a semiconductor device 90 that performs drive signal control and detection signal control of the piezoelectric vibrating piece 10 is placed and fixed on the bottom surface 21. 5 are connected to the electrode lands 214B, 215B, 216B, 317B, 212B, 318B, 220B, 219B, 213B, 218B, 211B, and 217B shown in FIG.

  A metal layer is formed on the peripheral end surface 20A of the side body 20, and a metal lid 30 is closely fixed by means such as seam welding to form a container. This container is in a vacuum state.

  Next, the support structure of the piezoelectric vibrating piece 10 will be described. Lead members 44 to 46 and 50 to 52 extending in the X-axis direction, and lead members 41 to 43 and 47 to 49 extending in the Y direction (in FIG. 2, the lead members 41 and 52 are described as representative examples) Is a strip-shaped member in which the lead members at the respective opposing positions have the same shape. The lead members 41 and 52 have one end connected to an electrode land portion (described in detail in FIG. 3) formed on the base 12 of the piezoelectric vibrating piece 10, and the other end connected to the bottom surface 21 of the side body 20. It is connected to the electrode land to be formed (described in detail in FIG. 5). Further, portions of the lead members 41 and 52 connected to the bottom surface 21 of the side body 20 are supported by the support substrate 60.

The support substrate 60 is a substrate in which an insulating layer 75 such as a polyimide resin is provided on a stainless steel plate (see FIGS. 1 and 2). The support substrate 60 is a plate-like member having a quadrangular outer shape. 43, an opening 62 through which the connecting portion between the bottom surface 21 and the lead member 44-46 and an opening 63 through which the connecting portion between the bottom surface 21 and an opening through which the connecting portion between the lead members 47-49 and the bottom surface 21 can be viewed. 64 and an opening 65 through which a connecting portion between the lead members 50 to 52 and the bottom surface 21 is viewed is formed. In addition, a rectangular window opening 66 through which the rising portions of the lead members 41 to 52 are inserted is formed at the center of the support substrate 60. Although the openings 62 to 65 and the window opening 66 are rectangular in the first embodiment, the shapes are not limited as long as the shapes do not hinder the connection of the lead member.
In addition, the material of the support substrate 60 can employ ceramics in addition to the stainless steel plate. In the case of ceramics, the insulating layer can be omitted.

  Next, the cross-sectional shape of the lead member will be described in detail with reference to FIG. Since the basic shape of each lead member is the same, the lead members 41 and 52 will be described as a representative example. The lead members 41 and 52 shown in FIG. 2 are formed so that the piezoelectric vibrating reed 10 does not come into contact with the place other than the lead member connecting portion, the side body 20 and the support substrate 60. More specifically, the lead members 41 and 52 having one ends connected to electrode lands 215A and 217A (hereinafter sometimes referred to as electrode lands 215A and the like) formed on the bottom surface 21 of the side body 20 are windows of the support substrate 60. After being bent once in the direction from the peripheral edge of the support substrate 60 toward the center upward at the position of the opening 66, the portion including the end is further bent so as to be substantially parallel to the bottom surface 21 of the side body 20. Are connected to electrode land portions 115A and 117A (hereinafter, referred to as electrode land portions 115A and the like) of the piezoelectric vibrating piece 10.

  Next, a connection structure between the lead member and the piezoelectric vibrating piece and the lead member and the side body will be described in detail. This will be described with reference to FIG. The lead members 41 and 52 will be described as the lead member 41 and the like. First, the lead member 41 or the like is fixed to the support substrate 60 with an adhesive at the upper end, and a means such as heat bonding of a conductive adhesive or Au bump to the electrode land 215A or the like formed on the bottom surface 21 of the side body 20. Connected and fixed with.

  In such a state, the piezoelectric vibrating piece 10 is placed on one end of the lead member 41 and the like, and the conductive adhesive 80 is applied to the electrode land portion 115A and the like formed on the main surface 10A of the base 12 and dried. Then, the lead member 41 and the piezoelectric vibrating piece 10 are connected and fixed.

The lid 30 is tightly fixed to the peripheral edge 20A of the side body 20 by means such as seam welding. Since this operation is performed in a vacuum environment, the inside of the piezoelectric vibrator 1 is in a vacuum state.
In addition, it is preferable that the lid body 30 and the side body 20 have such a degree of rigidity that they do not deform within a range of external force that is expected to be encountered in a normal environment.

Next, the electrode configuration of the piezoelectric vibrating piece 10 according to the first embodiment will be described with reference to the drawings.
FIG. 3 is a plan view illustrating an electrode configuration of the piezoelectric vibrating piece according to the first embodiment. FIG. 3 shows the main surface 10A (in FIG. 2, the lower surface side of the piezoelectric vibrating piece) to which the lead member of the piezoelectric vibrating piece 10 is connected. This will be described with reference to FIG. In FIG. 3, drive signal electrodes 111 are formed on the surfaces of the drive vibration arms 15 </ b> A and 15 </ b> B and continue to the surface of the base 12 through the surface of the connecting arm 13. The electrode pattern formed on the base 12 is a drive signal electrode pattern 111A. The drive signal electrode pattern 111A has an electrode land portion 111B connected to the lead member 45 (indicated by a circle in the figure. Note that the circle indicates the position of the electrode land portion and does not indicate the size). Have The drive signal electrode pattern 111 </ b> A continues to the end on the opposite side of the base 12. The drive signal electrode pattern 111A is continuous from the end 111C of the connecting arm 13 to the main surface 10B, and passes through the connecting arms 13 and 14 (not shown) to the other main surface 10B of the drive vibrating arms 15C and 15D (in FIG. 2). The upper surface of the piezoelectric vibrating piece is symmetrical to the drive signal electrode 112.

  A drive signal electrode 112 is formed on the main surface 10A of the drive vibrating arms 15C and 15D and reaches the surface of the base 12 through the surface of the connecting arm 14. The electrode pattern formed on the base 12 is a drive signal electrode pattern 112A. This drive signal electrode pattern has an electrode land portion 112 </ b> B (marked in the drawing) connected to the lead member 51. The drive signal electrode pattern 112A passes through the main surface 10B (not shown) and the side surfaces of the connection arms 14 and 13 (not shown) from the end 112C of the connection arm 14, and the other main surface 10B of the drive vibration arms 15A and 15B. (In FIG. 2, the upper surface of the piezoelectric vibrating piece is formed so as to be symmetrical with the drive signal electrode 111.)

  Further, the detection signal electrode 113 is formed on the main surface 10A of the detection vibrating arm 16A and reaches the base portion 12, and the detection signal electrode pattern 113A is formed and connected to the lead member 47 in the electrode land portion 113B (in the drawing). , ○). Although not shown, the detection signal electrode 113 is continuous with the surface on the main surface 10B side through the side surface of the detection vibrating arm 16A, and a detection signal electrode symmetrical to the detection signal electrode 113 is formed.

  The detection signal electrode 114 is formed on the main surface 10A of the detection vibrating arm 16B and reaches the base 12, the detection signal electrode pattern 114A is formed, and the electrode land portion 114B connected to the lead member 43 (in FIG. Mark). Although not shown, the detection signal electrode 114 continues to the surface on the main surface 10B side through the side surface of the detection vibrating arm 16B, and a detection signal electrode that is plane-symmetric with the detection signal electrode 114 is formed. ing.

  Three electrode patterns 118, 120, and 119 are provided between the drive signal electrode patterns 111A and 112A formed on the main surface 10A of the base 12 and the detection signal electrode pattern 113A. The electrode patterns 118, 120, and 119 are electrode patterns having the same potential and constant potential, respectively, and in the first embodiment, are GND electrode patterns connected to the GND (ground) electrode of the semiconductor device 90 (see FIG. 2). These GND electrode patterns 118, 120, and 119 include an electrode land portion 118A connected to the lead member 46, an electrode land portion 118B connected to the lead member 50, and an electrode land connected to the lead member 49, respectively. 120 A and electrode land part 119 A connected to lead member 48.

  Further, three electrode patterns 117, 115, and 116 are provided between the drive signal electrodes 111 and 112 and the detection signal electrode pattern 114A formed on the main surface 10A of the base 12 described above. These electrode patterns 117, 115, and 116 are electrode patterns having the same potential and constant potential, respectively, and in the first embodiment, are GND electrode patterns connected to the GND (ground) electrode of the semiconductor device 90 (see FIG. 2). These GND electrode patterns 117, 115, and 116 include an electrode land portion 117 A connected to the lead member 44, an electrode land portion 117 B connected to the lead member 52, and an electrode land connected to the lead member 43, respectively. 115A and electrode land portion 116A connected to lead member 42.

Each electrode pattern formed on the surface of the base 12 described above is set so as to be symmetrical with respect to a straight line passing through the center of gravity position G and parallel to the X axis. Is set to a symmetrical position with respect to a straight line parallel to the X axis and the Y axis.
Further, among the electrode patterns described above formed on the main surface 10A of the base 12 described above, the distances between adjacent electrode patterns are set to be substantially the same.

FIG. 4 shows a cross section of the main part of each electrode pattern. A part of the electrode pattern formed on the base 12 will be exemplified and described. A detection signal electrode pattern 113A, a GND electrode pattern 119, 120, 118, and a drive signal electrode pattern 111A are formed adjacent to each other on the main surface 10A of the base portion 12, and the distance from each adjacent electrode pattern is L1. , L2, L3, L4, and L1 = L2 = L3 = L4.
In the lead members 41 to 52 whose one end is connected to the electrode land described above, the other end is connected to the electrode pattern formed on the bottom surface of the side body 20.

FIG. 5 is a plan view showing an electrode pattern formed on the bottom surface 21 of the side body 20. This will be described with reference to FIGS. In FIG. 5, a semiconductor device 90 that performs drive signal control and detection signal control of the piezoelectric vibrating piece 10 is fixed to the approximate center of the bottom surface 21 of the side body 20 by die attach or the like.
Next, the configuration of each electrode pattern will be described. The GND electrode pattern 215 is formed with electrode lands 215B connected to the semiconductor device at both ends, an electrode land 215A connected to the lead member 41, and an electrode pattern portion 215C extending to the vicinity of the GND electrode pattern 217. The

  The GND electrode pattern 216 includes an electrode land 216 </ b> B connected to the semiconductor device 90, an electrode land 216 </ b> A connected to the lead member 42, and an electrode having a wide area so as to surround the side adjacent to the detection signal electrode pattern 214. The pattern portion 216C is formed.

  In the detection signal electrode pattern 214, an electrode land 214B connected to the semiconductor device 90 and an electrode land 214A connected to the lead member 43 are formed.

  In the GND electrode pattern 217, an electrode land 217B connected to the semiconductor device 90, an electrode land 217A connected to the lead member 44, and an electrode pattern portion 217C extending to a position close to the GND electrode pattern portion 213C are formed. Is done.

  In the drive signal electrode pattern 211, an electrode land 211B connected to the semiconductor device 90 and an electrode land 211A connected to the lead member 45 are formed.

  The GND electrode pattern 218 extends to a position close to a part of the electrode land 218B connected to the semiconductor device 90, the electrode land 218A connected to the lead member 46, and the electrode land 211A of the drive signal electrode pattern 211. The electrode pattern portion 218C to be formed is formed.

  In the detection signal electrode pattern 213, an electrode land 213B connected to the semiconductor device 90 and an electrode land 213A connected to the lead member 47 are formed.

  The GND electrode pattern 219 includes an electrode land 219 </ b> B connected to the semiconductor device 90, an electrode land 219 </ b> A connected to the lead member 48, and an electrode pattern portion 219 </ b> C extending in a wide area until it comes close to the detection signal electrode pattern 213. Is formed.

  The GND electrode pattern 220 includes an electrode land 220B connected to the semiconductor device 90, an electrode land 220A connected to the lead member 49, and an electrode pattern portion extending between the GND electrode pattern 220 and the GND electrode pattern 318. 220C.

  In the GND electrode pattern 318, an electrode land 318B connected to the semiconductor device 90, an electrode land 318A connected to the lead member 50, and an electrode pattern portion 318C close to the electrode land 212A of the drive signal electrode pattern 212 are formed. The

  In the drive signal electrode pattern 212, an electrode land 212B connected to the semiconductor device 90 and an electrode land 212A connected to the lead member 51 are formed.

  The GND electrode pattern 317 includes an electrode land 317B connected to the semiconductor device 90, an electrode land 317A connected to the lead member 52, and an electrode pattern portion 317C extending in a wide area until the GND electrode pattern 215 comes close. It is formed.

  In the electrode pattern configured as described above, three GND electrode patterns 216C, 215C, and 217 are formed between the detection signal electrode pattern 214 and the drive signal electrode pattern 211. Similarly, the drive signal electrode pattern 211 and the detection signal GND electrode patterns 218, 217C, and 219C are formed between the electrode patterns 213, and GND electrodes 219, 220 (220C), and 318 are formed between the detection signal electrode pattern 213 and the drive signal electrode pattern 212. The GND electrode patterns 317 (317C), 215, and 216 are formed between the drive signal electrode pattern 212 and the detection signal electrode pattern 214, and have the same configuration as the electrode pattern of the piezoelectric vibrating piece 10 described above.

In FIG. 3, three GND electrodes are formed between the detection signal electrode pattern and the drive signal electrode pattern on the bottom surface 21 of the side body 20 as described above. These GND electrode patterns are not necessarily required when the distance is so far as not to affect the stray capacitance.
Further, if the distance between the GND electrode patterns can be set sufficiently large as described above, the number of GND electrode patterns may be two.

Next, the vibration operation of the piezoelectric vibrator 1 according to the first embodiment will be described.
6 and 7 are plan views for schematically explaining the operation of the piezoelectric vibrating piece 10 according to the first embodiment. In FIG. 6 and FIG. 7, each vibrating arm is simplified and represented by a line in order to easily express the vibration form. The same components as those in FIG. 1 are denoted by the same reference numerals, and description thereof is omitted.

  FIG. 6 is a diagram for explaining drive vibration. In FIG. 6, the drive vibration is a bending vibration in which the drive vibration arms 15A, 15B, 15C, and 15D vibrate in the direction of arrow A, and the vibration state indicated by the solid line and the vibration state indicated by the two-dot chain line are at a predetermined frequency. It is repeating. At this time, the drive vibration arms 15A and 15B and the drive vibration arms 15C and 15D perform line-symmetric vibration on the Y axis passing through the center of gravity position G. Therefore, the base 12, the connection arms 13 and 14, and the detection vibration arm 16A. , 16B hardly vibrate.

  FIG. 7 is a diagram for explaining the detected vibration. In FIG. 7, the detected vibration repeats a vibration state indicated by a solid line and a vibration state indicated by a two-dot chain line at the frequency of the drive vibration. When the piezoelectric vibrating piece 10 performs the driving vibration shown in FIG. 3 and the rotational angular velocity ω around the Z axis is applied to the piezoelectric vibrating piece 10, the detected vibrations are driven vibrating arms 15 A, 15 B and 15 C, 15 D. This is caused by the Coriolis force in the direction indicated by the arrow B.

  Thus, the drive vibrating arms 15A, 15B, 15C, and 15D perform the vibration indicated by the arrow B. The vibration indicated by the arrow B is a vibration in the circumferential direction with respect to the gravity center position G. At the same time, the detection vibrating arms 16A and 16B vibrate in the direction opposite to the circumferential direction of the arrow B in response to the vibration of the arrow B as indicated by the arrow C.

  At this time, the peripheral portion of the base 12 does not vibrate because the vibration system is balanced when the drive vibration arm and the detection vibration arm vibrate as shown in FIG. Therefore, even if the lead member described above is connected to the base portion 12, the vibration of the piezoelectric vibrating piece is not affected.

Therefore, according to the first embodiment of the present invention described above, three GND electrodes are provided between the drive signal electrode patterns 111A and 112A and the detection signal electrode patterns 113A and 114A formed on the base 12 of the piezoelectric vibrating piece 10, respectively. Since the patterns 118, 120, 119 and 117, 115, 116 are formed, the stray capacitance between the adjacent GND electrode patterns is so small that it can be ignored, and it can be ignored that this stray capacitance affects the detection signal. Since it is small, an accurate detection signal can be obtained.
The number of these GND electrode patterns is not limited to three, but can be increased. However, it is appropriate to provide three GND electrode patterns in a limited area of the base, and the above-described effects are sufficient in practical use.

  In addition, the detection vibrating arm extends in parallel to the Y axis from each of the opposing end faces of the base, and the above-described electrode pattern formed with respect to the X axis passing through the center of gravity is formed symmetrically. Even if the stray capacitance as described above occurs, the detection signal electrodes 113 and 114 have the same stray capacitance. Therefore, the detection signal of one detection vibration arm 16A and the detection signal of the other detection vibration arm 16B. Therefore, the value of the output detection signal is the same, and in addition to the effect obtained by providing the GND electrode pattern, a more accurate detection signal can be obtained.

  Further, the stray capacitance generated between adjacent electrode patterns can be calculated from the dielectric constant of the substance between the electrode patterns, the area of the opposing electrode pattern, and the distance between the electrode patterns. According to the first embodiment, each electrode pattern formed on the base 12 is formed symmetrically with respect to the X axis passing through the gravity center position G, and the distance between the electrode patterns is set to be substantially the same. Therefore, the influence of the minute stray capacitance generated between the electrode patterns has the same influence on the detection signals of the detection vibrating arms 16A and 16B extending from the opposite end faces of the base portion 12, and this influence is canceled out. And a stable detection signal can be obtained. As described above, this is combined with the provision of the GND electrode patterns 118, 120, 119 and 117, 115, 116 between the drive signal electrode patterns 111A and 112A and the detection signal electrode patterns 113A and 114A. The effect of capacity can be further reduced.

  The piezoelectric vibrating piece 10 is connected to and supported by each electrode pattern by lead members 41 to 52. Each electrode pattern is provided with an electrode land portion for connection corresponding to each connection portion with the lead members 41 to 52. Since the electrode land portion is provided symmetrically with respect to the X axis and the Y axis with the center of gravity as the center, the piezoelectric vibrating piece is stably supported, so that stable performance can be maintained over a long period of time. .

  Further, the potentials of the GND electrode patterns provided between the drive signal electrode patterns 111A and 112A and the detection signal electrode patterns 113A and 114A are controlled to the same potential and constant potential. These GND electrode patterns are configured independently in the piezoelectric vibrating piece 10 and are connected to the GND electrode in the semiconductor device that controls the driving and detection of the piezoelectric vibrating piece. Accordingly, in the piezoelectric vibrating piece, The above-described effect of reducing the influence of the stray capacitance generated between the electrode patterns described above can be obtained, and the circuit configuration of the semiconductor device can be simplified.

Furthermore, among the lead members 41 to 52, the lead member facing the center of gravity position G is provided so as to be symmetric with respect to a line parallel to the X axis and the Y axis passing through the center of gravity position G of the base 12. Therefore, since the piezoelectric vibrating piece 10 is supported in the container in a balanced manner in the X-axis direction and the Y-axis direction by the lead members, the piezoelectric vibrating piece 10 is supported with a stable posture and a well-balanced supporting force, and is stable. Vibration can be obtained.
Further, when the lead members 41 to 52 are formed of a material having elasticity, the lead members 41 to 52 can have a buffering function against external impacts and vibrations.
(Embodiment 2)

Next, a piezoelectric vibrating piece according to Embodiment 2 of the present invention will be described with reference to the drawings.
FIG. 8 is a plan view illustrating an electrode pattern configuration of the piezoelectric vibrating piece 10 according to the second embodiment. In the second embodiment, the outer shape of the piezoelectric vibrating piece 10 is the same as that of the first embodiment (see FIG. 1), but only the configuration of the electrode pattern formed on the main surface 10A of the base 12 is different. It is characterized in that two GND electrode patterns are formed between the patterns 111A and 112A and the detection signal electrode patterns 113A and 114A. In addition, description of a common part is abbreviate | omitted and the same code | symbol is attached | subjected. In FIG. 8, drive signal electrodes 111 are formed on the surfaces of the drive vibration arms 15 </ b> A and 15 </ b> B and continue to the surface of the base 12 through the surface of the connecting arm 13.

  An electrode pattern continuous to the drive signal electrode 111 on the base 12 is a drive signal electrode pattern 111A. The drive signal electrode pattern 111A has an electrode land portion 111B connected to the lead member 45 (indicated by a circle in the figure. Note that the circle indicates the position of the electrode land portion and does not indicate the size). Have The drive signal electrode pattern 111 </ b> A continues to the end on the opposite side of the base 12. The drive signal electrode pattern 111A is continuous from the end 111C of the connecting arm 13 to the main surface 10B, and passes through the connecting arms 14 and 13 (not shown) to the other main surface 10B of the drive vibrating arms 15C and 15D (in FIG. 2). The upper surface of the piezoelectric vibrating piece is symmetrical to the drive signal electrode 112.

  A drive signal electrode 112 is formed on the main surface 10A of the drive vibrating arms 15C and 15D and reaches the surface of the base 12 through the surface of the connecting arm 14. The electrode pattern formed on the base 12 is a drive signal electrode pattern 112A. This drive signal electrode pattern 112 </ b> A has an electrode land portion 112 </ b> B (marked in the drawing) connected to the lead member 51. The drive signal electrode pattern 112A is connected to the other main surface 10B of the drive vibrating arms 15A and 15B via an electrode pattern formed on the side surfaces of the connection arms 14 and 13 (not shown) from the end 112C of the connection arm 14. Then, it is formed on the upper surface of the piezoelectric vibrating piece so as to be plane-symmetric with the drive signal electrode 111.

  Further, the detection signal electrode 113 is formed on the main surface 10A of the detection vibrating arm 16A and reaches the base 12, and the detection signal electrode pattern 113A is formed and is connected to the lead member 48 in the electrode land portion 113B (in the drawing). , ○). Although not shown, the detection signal electrode 113 is continuous with the surface on the main surface 10B side through the side surface of the detection vibrating arm 16A, and a detection signal electrode symmetrical to the detection signal electrode 113 is formed.

  The detection signal electrode 114 is formed on the main surface 10A of the detection vibrating arm 16B and reaches the base 12, the detection signal electrode pattern 114A is formed, and the electrode land portion 114B connected to the lead member 42 ( Mark). Although not shown, the detection signal electrode 114 continues to the surface on the main surface 10B side via the side surface of the detection vibrating arm 16B, and a detection signal electrode that is plane-symmetric with the detection signal electrode 114 is formed.

  Two electrode patterns 118 and 120 are provided between the drive signal electrode patterns 111A and 112A and the detection signal electrode pattern 113A formed on the main surface 10A of the base 12 described above. The electrode patterns 118 and 120 are electrode patterns having the same potential and constant potential, respectively, and in the second embodiment, are GND electrode patterns connected to the GND (ground) electrode of the semiconductor device 90 (see FIG. 2). These GND electrode patterns 118 and 120 include an electrode land portion 118A connected to the lead member 46, an electrode land portion 118B connected to the lead member 50, and an electrode land portion 120B connected to the lead member 49, respectively. And an electrode land portion 120 </ b> A connected to the lead member 47.

  Further, two electrode patterns 117 and 115 are provided between the drive signal electrode patterns 111A and 112A and the detection signal electrode pattern 114A formed on the main surface 10A of the base 12 described above. The electrode patterns 117 and 115 are electrode patterns having the same potential and constant potential, respectively, and in the second embodiment, are GND electrode patterns connected to the GND (ground) electrode of the semiconductor device 90 (see FIG. 2). These GND electrode patterns 117 and 115 include an electrode land portion 117B connected to the lead member 44, an electrode land portion 117A connected to the lead member 52, and an electrode land portion 115B connected to the lead member 43, respectively. And electrode land portions 115 </ b> A connected to the lead members 41.

Each electrode pattern formed on the main surface 10A of the base 12 described above is set to be symmetric with respect to a straight line passing through the center of gravity position G and parallel to the X axis. It is set at a symmetrical position with respect to a straight line passing through the gravity center position G and parallel to the X axis and the Y axis.
In addition, among the electrode patterns formed on the main surface 10A of the base 12 described above, the distances between adjacent electrode patterns are set to be substantially the same.

  Although not shown in the drawings, as described in the first embodiment, the bottom end 21 of the side body 20 is connected to the other end of each lead member, the drive signal electrode pattern, and the detection signal electrode pattern. The two GND electrode patterns can be formed.

Therefore, according to the second embodiment described above, the stray capacitance is reduced as compared with the case where the three GND electrode patterns are provided between the drive signal electrode pattern and the detection signal electrode pattern of the first embodiment. Although the effect on the detection signal is slightly inferior, it is sufficient for practical use. Further, in a narrow area such as the base portion 12, there is an effect that the wiring of the electrode pattern can be afforded and manufacturing management is easy. The same applies to the wiring of the electrode pattern formed on the bottom surface 21 of the side body 20.
(Embodiment 3)

Next, a vibrating gyroscope according to Embodiment 3 of the present invention will be described with reference to the drawings.
FIG. 9 is a schematic cross-sectional view of a vibrating gyroscope according to the third embodiment. The third embodiment is characterized in that a shield electrode pattern is formed on the inner surface of the side body 20 and the inner surface 30A of the lid body 30 based on the technical idea described in the first and second embodiments. ing. In FIG. 9, the shape of the piezoelectric vibrating piece 10, the wiring configuration of the electrode pattern, and the support structure are the same as those in the first embodiment (FIGS. 1 to 3), so the description thereof is omitted and the same reference numerals are given.

When the lid 30 is made of a non-conductive material such as ceramics, the shield electrode pattern 88 having the same potential as the GND electrode pattern formed on the piezoelectric vibrating piece 10 is generally provided on the inner surface 30A of the lid 30. Formed entirely. Note that this shield electrode pattern is not necessary when the lid 30 is made of metal.
The shield electrode pattern 88 is connected to a shield electrode pattern 89 formed on the inner surface of the side body 20.

  The shield electrode pattern 89 is developed to almost the entire inner side surface and the bottom surface 21 of the side body 20, and a part thereof is connected to a GND electrode (not shown) of the semiconductor device 90, or the first embodiment ( It may be connected to any one of the GND electrode pattern portions 219C, 317C, 215C, and 217C shown in FIG. As shown in the first embodiment (see FIG. 5), the bottom surface 21 of the side body 20 occupies a wide range of the area of the bottom surface 21 with the electrode pattern having the same potential. It can be said that the periphery is covered with a GND electrode pattern (shield electrode pattern).

Therefore, according to the third embodiment described above, the inner surface of the container is mostly covered with the constant potential, that is, the GND electrode pattern connected to the shield electrode patterns 88 and 89 and the piezoelectric vibrating piece 10. The electromagnetic wave noise from can be shielded. In addition, it is possible to prevent electromagnetic noise from being emitted from the vibrating gyroscope 100 to the outside. Accordingly, it is possible to provide a vibration gyroscope with high reliability that can be used even in an environment with electromagnetic noise and that does not affect other electronic devices.
(Embodiment 4)

Next, a fourth embodiment according to the present invention will be described. The fourth embodiment is characterized in that a tuning fork type piezoelectric vibrating piece is employed as the piezoelectric vibrating piece, and the technical idea of the above-described embodiment is applied to the tuning fork type piezoelectric vibrating piece.
FIG. 10 is a perspective view showing the piezoelectric vibrating piece 400 according to the fourth embodiment. In FIG. 10, the piezoelectric vibrating piece 400 is made of crystal and has a substantially rectangular base portion 403 formed in a predetermined plane, and two vibrating arms 401 having a rectangular cross section from one end surface of the base portion 403. 402 has a tuning fork shape extending in the Y-axis direction.

A detection signal electrode 411 is formed in parallel with the Y axis at the center of the main surface of the vibrating arm 402 (in the figure, displayed in front and on the same plane as the predetermined surface on which the base 403 is formed), and one end thereof Is continuous to the detection electrode land portion 411A provided in the base portion 403. In addition, a detection signal electrode 410 is formed in parallel to the Y axis at the center of the main surface of the vibrating arm 401 (in the figure, displayed in front and in the same plane as the predetermined surface on which the base 403 is formed). The end portion continues to the detection electrode land portion 410 </ b> A provided in the base portion 403. The periphery of the detection signal electrode 411 is surrounded by a constant potential GND electrode pattern 421 including the detection electrode land portion 411A.
The other periphery of the detection signal electrode 410 and the detection electrode land portion 410A is similarly surrounded by the GND electrode pattern 420. The GND electrode pattern 421 and the GND electrode pattern 420 are at the same potential.

  A drive signal electrode 430 is continuously formed up to the base upper surface 403A at the center of the cross section of the inner side surface 401B of the vibrating arm 401 and the inner side surface 402B of the vibrating arm 402 (the drive signal electrode on the side surface 401B side is not shown). The end portion of the base portion 403 extends to the main surface side of the base portion 403 as a drive signal electrode pattern 430A and reaches the drive signal electrode land portion 430B provided at the center portion of the base portion 403 in the X-axis direction. . A GND electrode pattern 422 is formed from the inner side surfaces 401B and 402B of the vibrating arm to the main surface of the base portion 403 so as to surround the drive signal electrode 430, the drive signal electrode pattern 430A, and the drive signal electrode land portion 430B.

  A driving signal electrode 432 is formed on the outer side surface 401A of the vibrating arm 401 at a position facing the driving signal electrode 430, and is continuous with the driving signal electrode pattern 432A from the outer side surface 401A to the main surface of the base 403. The drive signal electrode land portion 432B is provided at the end portion. The periphery of the drive signal electrode 432, the drive signal electrode pattern 432A, and the drive signal electrode land portion 432B is surrounded by a GND electrode pattern 423.

Further, a driving signal electrode (not shown) is formed on the outer side surface 402A of the vibrating arm 402 at a position facing the driving signal electrode 430, and the driving signal electrode pattern 431A extends from the outer side surface 402A to the main surface of the base 403. The drive signal electrode land portion 431B is provided at the end of the drive signal electrode land portion 431B. These drive signal electrode, drive signal electrode pattern 431A, and drive signal electrode land portion 431B are surrounded by a GND electrode pattern 424.
The GND electrode patterns 423 and 424 are set to the same potential.

  As described above, the detection signal electrode, the detection signal electrode pattern, the detection signal electrode land portion, the drive signal electrode, the drive signal electrode pattern, the drive signal electrode land portion, and the GND electrode pattern described in the fourth embodiment are the X axis of the piezoelectric vibrating piece 400. It is formed on the left and right sides with respect to the central axis 404 in the direction.

  The configuration of each signal electrode and the GND electrode pattern is as described above, and the mutual arrangement relationship thereof will be described. In FIG. 10, GND electrode patterns 423 and 420 are disposed between the detection signal electrode 410 and the drive signal electrode 432, and GND electrode patterns 420 and 422 are disposed between the detection signal electrode 410 and the drive signal electrode 430. Is arranged. In addition, GND electrode patterns 421 and 422 are arranged between the detection signal electrode 411 and the drive signal electrode 430, and the detection signal electrode 411 and a drive signal electrode formed on the outer side surface of the vibrating arm 402 (not shown). The GND electrode patterns 421 and 424 are also arranged therebetween.

  As described above, two independent GNDs are provided between the detection signal electrode system and the drive signal electrode system, including the signal electrodes and the electrode patterns and electrode land portions that are continuous with these signal electrodes. Since electrode patterns are arranged and these GND electrode patterns have the same potential, it is possible to minimize the stray capacitance generated between the electrode patterns of the detection signal electrode system and the drive signal electrode system.

  Next, the vibration state of the piezoelectric vibrating piece 400 will be described. This will be described with reference to FIG. The drive vibration is a bending vibration in which the two vibrating arms 401 and 402 vibrate in the direction of arrow A, and the vibration state in the direction of arrow A is repeated at a predetermined frequency. At this time, since the vibrating arms 401 and 402 are oscillating line-symmetrically around the central axis 404, the base 403 hardly vibrates. Further, there is no vibration in the direction of arrow B.

  Detected vibration is performed with the piezoelectric vibrating reed 400 in the state of driving vibration as described above, with the center of the vibrating arms 401 and 402 in the X direction passing through the thickness direction (Z direction) center and parallel to the Y axis. When the rotational angular velocity ω is applied, the vibration arms 401 and 402 are generated by the Coriolis force acting in the direction indicated by the arrow B. This detection vibration is detected by the detection signal electrode.

Next, the structure of the vibrating gyroscope on which the piezoelectric vibrating piece 400 according to the fourth embodiment described above is mounted will be described.
FIG. 11 is a cross-sectional view illustrating a vibrating gyroscope according to the fourth embodiment. In FIG. 11, the vibrating gyroscope 450 is configured by storing the above-described tuning-fork-shaped piezoelectric vibrating piece 400 in a container including a side body 451 and a lid body 452.

  The side body 451 is formed in a box shape from a material such as ceramics, and a base 454 and a semiconductor device 460 for controlling the drive and detection of the piezoelectric vibrating piece 400 are fixed to the bottom 456 thereof. Around the base 454 of the bottom portion 456 and the semiconductor device 460, a wiring pattern 453 connected to each of the detection signal electrode, the drive signal electrode, and the GND electrode pattern formed on the piezoelectric vibrating piece 400 is formed. .

The base 403 of the piezoelectric vibrating piece 400 is fixed to the upper surface of the base 454 by fixing means such as adhesion. At this time, the vibrating arms 401 and 402 of the piezoelectric vibrating piece 400 are fixed at positions where they do not contact the base 454. Then, the detection signal electrode land portion, the drive signal electrode land portion, and the GND electrode pattern provided on the main surface of the base portion 403 of the piezoelectric vibrating reed are connected to the electrode pattern formed on the pedestal 454 (not shown) by an Au wire 455. ing. The electrode pattern on the pedestal 454 and the wiring pattern 453 on the bottom 456 are connected by a not-shown Au wire or the like. The semiconductor device 460 is also connected to the wiring pattern 453 and the like with Au wires 461.
Note that the detection signal electrode, the drive signal electrode, and the GND electrode pattern formed on the piezoelectric vibrating piece 400 are independently formed while reaching the semiconductor device 460.

  In the state as described above, the metallic lid 452 is hermetically fixed to the peripheral portion of the side body 451 by fixing means such as welding. A space formed by the side body 451 and the lid body 452 is managed in a vacuum state.

  In Embodiment 4 (see FIG. 11) described above, the piezoelectric vibrating piece 400 is fixed to the pedestal 454 provided on the side body 451 side, but the piezoelectric vibrating piece 400 includes the pedestal on the lid body 452 side. It can also be fixed.

  Therefore, according to the fourth embodiment described above, the detection signal electrode system (including the detection signal electrode, the detection signal electrode pattern, and the detection signal electrode land portion) formed on the vibrating arms 401 and 402 and the base 403 and the drive signal electrode system. Since the two GND electrode patterns are provided between the drive signal electrode, the drive signal electrode pattern, and the drive signal electrode land portion, the above-described embodiment can be applied to the tuning-fork type piezoelectric vibrating piece. As in the case of 1, the influence of the stray capacitance on the detection signal can be minimized.

Further, according to the vibrating gyroscope according to the fourth embodiment, the piezoelectric vibrating piece 400 described above is not easily affected by the stray capacitance, and the base 403 that is not subjected to the vibration of the vibrating arms 401 and 402 is fixed to the pedestal 454. Therefore, the piezoelectric vibrating piece 400 is supported in a stable posture, can obtain a stable vibration, and can obtain an accurate detection signal.
(Embodiment 5)

Next, a fifth embodiment according to the present invention will be described with reference to the drawings. The fifth embodiment is characterized in that the piezoelectric vibrating piece is formed of a triangular prism vibrating body, and is configured based on the technical ideas of the first to fourth embodiments described above.
FIG. 12 is a perspective view of a piezoelectric vibrating piece 500 according to the fifth embodiment, and FIG. 13 is a cross-sectional view thereof. 12 and 13, the piezoelectric vibrating piece 500 includes a vibrating body 501, a detecting piezoelectric element 510, driving piezoelectric elements 520 and 530, and support members 505 and 506 as a basic configuration.

  The vibrating body 501 is made of a constant elastic metal material such as an alloy of Ni, Fe, Cr, and Ti and is formed in a regular triangular prism shape. Piezoelectric elements 510 and 515 for detection are provided at the center of side surfaces 503 and 504 as predetermined surfaces of the vibrating body 501, respectively. Also, on the side surface (upper surface in the figure) 502 as the other predetermined surface, two driving piezoelectric elements 520 and 530 are provided in parallel at the center in the longitudinal direction of the vibrating body 501.

  As shown in FIG. 13, the detection piezoelectric element 510 on the side surface 503 side has detection signal electrodes 511 and 512 formed on both sides. One detection signal electrode 512 is bonded to the side surface 503 of the vibrating body 501. A GND electrode pattern 541 is formed around the detection signal electrode 512. The GND electrode pattern 541 has a size within the range of the plane of the side surface 503 and does not protrude from the line portion.

  Further, detection signal electrodes 513 and 514 are formed on both surfaces of the detection piezoelectric element 515 on the side surface 504 side. One detection signal electrode 514 is bonded to the side surface 504 of the vibrating body 501. A GND electrode pattern 542 is formed around the detection signal electrode 514. The GND electrode pattern 542 has a size within the range of the plane of the side surface 504 and does not protrude from the line portion.

  Driving side piezoelectric elements 520 and 530 are provided on the side surface 502 sandwiched between the side surface 503 and the side surface 504. These driving piezoelectric elements 520 and 530 are formed side by side in the width direction of the vibrating body 501. The drive piezoelectric element 520 has drive signal electrodes 521 and 522 formed on both sides, and one drive signal electrode 522 is bonded to the vibrating body 501.

Similarly, drive signal electrodes 531 and 532 are formed on both sides of the drive piezoelectric element 530, and one drive signal electrode 532 is bonded to the vibrating body 501.
In the fifth embodiment, the drive piezoelectric elements 520 and 530 have the same shape, and the drive signal electrodes 522 and 532 bonded to the vibrating body can be made common. A GND electrode pattern 544 is formed around the drive signal electrodes 522 and 532. The GND electrode pattern 544 has a size within the range of the plane of the side surface 502 and does not protrude from the line portion.

  In the vibrating body 501 described above, the two node points of the line portion where the side surfaces 503 and 504 are joined are supported by the support members 505 and 506.

  In the piezoelectric vibrating piece 500 configured as described above, two GND electrode patterns 541 and 544 are formed between the detection signal electrode 512 and the drive signal electrode 522, and the detection signal electrode 514 and the drive signal electrode 532 are formed. Two GND electrode patterns 544 and 542 are formed therebetween, and GND electrode patterns 541 and 542 are also formed between the detection signal electrodes 512 and 514.

  Subsequently, the vibration state of the piezoelectric vibrating piece 500 of the fifth embodiment will be described. This will be described with reference to FIGS. When a drive signal is applied to the driving piezoelectric elements 520 and 530, the vibrating body 501 bends and vibrates in a direction perpendicular to the side surface 502 on which the driving piezoelectric elements 520 and 530 are formed. Since the detection piezoelectric elements 510 and 515 are arranged on both sides of the surface including the vibration direction of the vibrating body 501, the detection voltages are canceled out and the difference becomes almost zero.

  Therefore, when the vibrating body 501 rotates about the axis of the vibrating body, the vibration direction changes due to the Coriolis force, but the vibrating body 501 has side surfaces 503 and 504 in a direction substantially perpendicular to the vibration direction. By providing the detection piezoelectric elements 510 and 515 on the side surfaces 503 and 504, a large output signal can be obtained by taking a difference between detection voltages generated in the respective detection piezoelectric elements.

Next, the structure of a vibrating gyroscope that houses the above-described piezoelectric vibrating piece 500 will be described with reference to the drawings.
FIG. 14 is a cross-sectional view showing the structure of the vibration gyroscope 550 according to the fifth embodiment. In FIG. 14, the vibrating gyroscope 550 is configured such that the above-described triangular prism-shaped piezoelectric vibrating piece 500 is housed in a container including a side body 551 and a lid body 552.

The side body 551 is formed in a box shape with a material such as ceramics, and the support members 505 and 506 are fixed to and supported by two metal film portions 553 formed on the bottom portion 556 by a fixing means such as adhesion. Yes. Further, a semiconductor device 560 that controls driving and detection of the piezoelectric vibrating piece 500 is fixed to the bottom portion 556. Around the semiconductor device 560 of the bottom portion 556, wiring patterns 554 corresponding to the respective drive signal electrodes, detection signal electrodes, and GND electrode patterns formed on the side surfaces of the piezoelectric vibrating piece 500 described above are formed. Etc., the semiconductor device 560 is connected.
Note that the detection signal electrode, the drive signal electrode, and the GND electrode pattern formed on the piezoelectric vibrating piece 500 are independently formed while reaching the semiconductor device 560.

In the state as described above, the metallic lid 552 is hermetically fixed to the peripheral portion of the side body 551 by fixing means such as welding. A space formed by the side body 551 and the lid body 552 is managed in a vacuum state.
In Embodiment 5 (see FIG. 14) described above, the piezoelectric vibrating piece 500 is fixed to the side body 551 side. However, the piezoelectric vibrating piece 500 can be fixed to the lid body 552 side.

Therefore, according to the above-described fifth embodiment, even in the piezoelectric vibrating piece having the above-described triangular prism-shaped vibrating body, two constant potential GND electrode patterns are provided between the adjacent detection signal electrode and the drive signal electrode. By providing this, the influence of stray capacitance on the detection signal can be minimized.
Further, the ridge line portion of the vibrating body 501 has a node point that does not affect the vibration of the vibrating body 501, and the ridge line portion is supported by the support members 505 and 506. And an accurate detection signal can be obtained.

It should be noted that the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.
For example, in the first and third embodiments described above, the piezoelectric vibrating piece 10 is connected to the bottom surface 21 of the side body 20 by the lead member, but the lead member is reversed to the top and bottom to the inner surface 30A of the lid body 30. A connecting structure can be adopted.
In such a structure, the same effect as that of the first embodiment described above can be obtained by forming each electrode pattern shown in FIG. 5 connected to the lead member on the inner surface 30A of the lid 30.

  Further, with such a structure, since the lid 30 is a flat plate, it is easy to perform operations such as the formation of each electrode pattern and the connection of the piezoelectric vibrating piece 10 as described above, thereby increasing the production efficiency. This contributes to cost reduction.

  In the first and second embodiments described above, twelve lead members are used. However, the lead members 46 and 50 and the lead members 44 and 52 shown in FIG. 1 are connected to the same GND electrode pattern. Therefore, for example, the lead members 44 and 50 or the lead members 46 and 52 may be omitted by combining the lead members 46 and 52 or the lead members 44 and 50 with each other. In this case, although not shown, it is possible to obtain substantially the same effect as in the first embodiment by changing the wiring configuration of the GND electrode pattern on the bottom surface 21 of the side body 20 in accordance with the configuration of the lead member described above.

  Further, in the first embodiment, the GND electrode pattern shown in FIG. 3 is configured on the bottom surface 21 of the side body 20, but the wiring configuration of these GND electrode patterns is the same as that of the GND electrode pattern shown in FIG. Not limited to this, if two or three drive signal electrode patterns and three detection signal electrode patterns are provided, the wiring can be freely selected and wired.

In the above-described fifth embodiment (see FIG. 14), the piezoelectric vibrating piece 500 is supported by the support members 505 and 506, but the piezoelectric vibrating piece 500 is turned upside down from the posture shown in FIG. The support members 505 and 506 can be supported with the upper line portion as a gate-type support member.
In this way, the piezoelectric vibrating reed can be supported within the portal shape of the support member, and the vibrating gyroscope 550 can be further downsized.

  Furthermore, in the fifth embodiment described above, the piezoelectric vibrating piece 500 exemplifies the triangular prism vibrating body 501, but the vibrating body is not limited to the triangular prism, and can also be applied to a quadrangular prism or higher polygonal prism. The effects according to the above-described embodiment can be obtained.

  Therefore, in the first to fifth embodiments described above, a piezoelectric vibrating piece that can reduce the stray capacitance between the drive signal electrode and the detection signal electrode and obtain an accurate detection signal, and a highly reliable vibration gyroscope. A scope can be provided.

1 is a plan view showing a vibration gyroscope according to a first embodiment of the present invention. 1 is a schematic cross-sectional view showing a vibration gyroscope according to a first embodiment of the present invention. FIG. 3 is a plan view showing the piezoelectric vibrating piece according to the first embodiment of the invention. 1 is a partial cross-sectional view showing a piezoelectric vibrating piece according to Embodiment 1 of the present invention. The top view which shows the electrode pattern wiring of the cover body bottom face of the vibration type gyroscope which concerns on Embodiment 1 of this invention. FIG. 3 is an explanatory diagram showing drive vibration of the piezoelectric vibrating piece according to the first embodiment of the invention. FIG. 3 is an explanatory diagram illustrating detected vibration of the piezoelectric vibrating piece according to the first embodiment of the invention. FIG. 6 is a plan view showing a piezoelectric vibrating piece according to Embodiment 2 of the present invention. Sectional drawing which shows the vibration-type gyroscope which concerns on Embodiment 3 of this invention. The perspective view which shows the piezoelectric vibrating piece which concerns on Embodiment 4 of this invention. Sectional drawing which shows the vibration-type gyroscope which concerns on Embodiment 4 of this invention. FIG. 9 is a perspective view showing a piezoelectric vibrating piece according to Embodiment 5 of the present invention. Sectional drawing which shows the piezoelectric vibrating piece which concerns on Embodiment 5 of this invention. Sectional drawing which shows the vibration-type gyroscope which concerns on Embodiment 5 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Piezoelectric vibrator, 10 ... Piezoelectric vibration piece, 10A ... Main surface, 10B ... Main surface, 12 ... Base, 13, 14 ... Connection arm, 15A, 15B, 15C, 15D ... Drive vibration arm, 16A, 16B ... Detection Vibration arm, 100... Vibrating gyroscope, 111, 112... Drive signal electrode, 111A, 112A... Drive signal electrode pattern, 113, 114. Detection signal electrode, 113A, 114A .. Detection signal electrode pattern, 115, 116, 117, 118, 119, 120 ... GND electrode pattern.

Claims (6)

A base formed on a predetermined surface and having end faces parallel to the X-axis direction and the Y-axis direction ,
Two connecting arms extending in the direction parallel to the X axis from the center of the two end faces parallel to the Y axis of the base, and parallel to the Y axis from the center of the two end faces of the base parallel to the X axis A detection vibrating arm extending in a specific direction, a driving vibrating arm extending from the two connecting arms ,
A drive signal electrode formed on the drive vibrating arm;
A detection signal electrode formed on the detection vibrating arm;
A drive signal electrode pattern continuous with the drive signal electrode formed continuously on at least one main surface of the base, and a detection signal electrode pattern continuous with the detection signal electrode;
A plurality of constant potential electrode patterns formed between the drive signal electrode pattern and the detection signal electrode pattern,
The drive signal electrode pattern, the detection signal electrode pattern, and the constant potential electrode pattern are symmetric with respect to a line parallel to the X-axis that passes through the center of gravity of the base portion toward the drive vibration arm,
A distance between adjacent electrode patterns among the drive signal electrode pattern, the detection signal electrode pattern, and the constant potential electrode pattern is set to be substantially the same. The piezoelectric vibrating piece according to claim 1,
The drive signal electrode pattern, the detection signal electrode pattern, and the constant potential electrode pattern each include an electrode land portion,
The electrode land portion is symmetrical with respect to a line parallel to the X axis passing through the center of gravity position toward the drive vibrating arm and a line parallel to the Y axis passing through the center of gravity position toward the detection vibrating arm. A piezoelectric vibrating piece characterized by being provided in the above. The piezoelectric vibrating piece according to claim 1 or 2,
The piezoelectric vibrating piece, wherein the constant potential electrode pattern is formed electrically independently in the piezoelectric vibrating piece. The piezoelectric vibrating piece according to any one of claims 1 to 3,
A container composed of a side body and a lid for storing the piezoelectric vibrating piece;
A lead member having one end connected to each electrode land portion of the base of the piezoelectric vibrating piece and the other end connected to the side body or the lid, and
The lead member is symmetrical with respect to a line parallel to the X axis passing through the center of gravity of the base toward the drive vibrating arm and a line parallel to the Y axis passing through the center of gravity toward the detection vibrating arm. The vibratory gyroscope is characterized by being equipped with The vibratory gyroscope according to claim 4, wherein
An electrode land portion to which the other end of the lead member is connected to the inner surface of the side body or the lid;
A drive signal electrode pattern and a detection signal electrode pattern respectively continuous with the electrode land portion;
A plurality of constant potential electrode patterns formed between the drive signal electrode pattern and the detection signal electrode pattern;
A vibratory gyroscope characterized by being equipped with In the vibratory gyroscope according to claim 5,
A vibrating gyroscope, wherein a shield electrode pattern connected to at least one of the constant potential electrode patterns is formed on an inner surface of the side body or the lid.

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