JPH0989572A - Piezoelectric vibrator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a piezoelectric vibrator improved in mechanical joint reliability and electrical connecting reliability through the improvement of mechanical resonance acuteness by effectively suppressing the distortion of the piezoelectric vibrator caused by thrashing vibration generated at a detecting side vibrating part. SOLUTION: A driving side vibrating part 1A composed of vibrating branches 3, 4 with driving electrodes 31-34, 41-44, and an intermediate holding branch 5 with driving input electrodes 51, 52; and a detecting side vibrating part 1B composed of vibrating branches 6, 7 with detecting electrodes 61-64, 71-74, and an intermediate holding branch 8 with detecting output electrodes 81, 82 are integrally disposed with a connecting base part 2 placed in between to form a piezoelectric vibrator 1, and the width direction of the connecting base part 2 is protruded more than the width of the driving side vibrating part 1A and/or detecting side vibrating part 1B.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric vibrator used for an angular velocity sensor.

[0002]

2. Description of the Related Art Various angular velocity sensors used for camera shake correction, automobile navigation, and attitude control of a moving body have been proposed.

For example, US Pat. No. 4,524,619.
JP-A-3-291517 and the like utilize a tuning fork vibration mode in which a driving side tuning fork-shaped vibrating section and a tuning fork shaped sensing side vibrating section are integrated, and the piezoelectric substrate is H-shaped as a whole. An angular velocity sensor having a vibrating body has been proposed.

As shown in FIG. 5, this piezoelectric vibrating body 91 is basically an H-shaped piezoelectric substrate, that is, a driving side vibrating portion 91A and a detecting side vibrating portion 91B in the direction of both end faces with a coupling base portion 92 sandwiched therebetween. Are arranged.

Further, the drive electrodes 93a to 93 are provided on the four side surfaces of each of the two vibrating branches 93 and 94 of the drive side vibrating portion 91A.
d, 94a to 94d (93b, 93d, 94b, 94c
Does not appear in the figure) is formed.

Further, a pair of detection electrodes 95a to 95d, 96a to 96d (95a, 95) parallel to each other are provided on the opposite side surfaces of the two vibrating branches 95, 96 of the detection side vibrating section 91B.
b, 96a, 96b are not shown in the figure) are formed.

In the drive side vibrating portion 91A, the drive electrode 9
3a and the drive electrode 93c (not shown) facing the drive electrode 93a, and between the drive electrode 94d and the electrode 94b (not shown) opposed to the drive electrode 94d, The potential on one side of the alternating voltage signal is applied,
At the same time, between the driving electrode 93d and the electrode 93b (not shown) facing the driving electrode 93d, and between the driving electrode 94a and the electrode 94c (not shown) facing the driving electrode 94a. To the other side of the alternating voltage signal. As a result, the drive electrodes 93a to 93d, 94a of the vibrating branches 93, 94 of the drive-side vibrating section 91A.
When an alternating voltage for driving is applied to ~ 94d, the driving-side vibrating unit 9
In 1A, tuning fork vibration occurs in one plane.

Further, in the detection side vibrating portion 91B, two detection electrodes 95 are provided on the side surface of the vibrating branch 95 in the depth direction in the figure.
a and 95b (neither of which appear in the figure) are formed, and two detection electrodes 95 are formed on the inner side surface of the tuning fork that is paired with this side surface.
c and 95d are arranged side by side, and similarly, two detection electrodes 96c and 96d are formed on the side surface of the vibrating branch 96 in the front direction in the figure, and the detection electrode 96a is formed on the side surface on the inner side of the tuning fork that is paired with this side surface. , 96b are arranged in parallel.

Therefore, when a rotational motion (angular velocity) is applied to the piezoelectric vibrating body 91 while the drive-side vibrating portion 91A is vibrating a predetermined tuning fork, the two vibrating branches 93 and 94 of the drive-side vibrating portion 91B are generated. Due to the Coriolis force, vertical vibrations are alternately generated with an amplitude proportional to the angular velocity of the rotary motion in a direction perpendicular to the plane of the piezoelectric substrate. This vibration is hereinafter referred to as flap vibration. This vibration of the flap will be transmitted to the entire piezoelectric substrate, and the detection electrode 95a of the detection-side vibrating portion 91B will be transmitted.
And 95b, 95c and 95d, 96a and 96b, 96c and 96d, an electric field determined by the flap vibration direction and the polarization direction of the piezoelectric substrate (crystal axis direction in the quartz substrate) is generated, An electrical signal (detection signal) corresponding to a predetermined angular velocity can be extracted.

As the above-mentioned piezoelectric substrate, for example, a quartz substrate cut in the crystal axis direction in consideration of the above-mentioned electric field generation direction is used, and the piezoelectric substrate is etched so that the whole becomes H-shaped. In addition, the drive electrodes 93a to 93d, 94a to 9
4d, 95a to 95d, 96a to 96d are deposited by a thin film technique such as vapor deposition.

When such a piezoelectric vibrating body 91 is used as an angular velocity sensor, it is necessary to mount it on a printed wiring board or store it in a case in order to connect it to an external processing circuit. In this case, it is desirable that the fixing structure to the wiring board, the case, etc. does not adversely affect each vibration mode and can be performed stably and easily. At the same time, the drive electrode 9
3a to 93d, 94a to 94d and detection electrodes 95a to 95
It is important that the electrical connection with the d and 96a to 96d be simple and stable.

In the example shown in FIG. 5, in order to stabilize the fixing structure, in the above-described piezoelectric vibrating body 91, the vibrating branches 93 and 94 are provided on the coupling base 92 that couples the two vibrating portions 91A and 91B. , 95, 96 are provided with holding branches 97, 98 projecting in a direction orthogonal to the extending direction.

However, in terms of electrical connection, no specific and practical structure is shown, and each electrode 93a is assumed.
.About.93d, 94a to 94d and a predetermined circuit are electrically connected by wire bonding thin wires, drive electrodes 93b, 93d, 94b, 94d formed on the side surfaces of the vibrating branches 93, 94, 95, 96. And detection electrodes 95a-9
The connection with 5d and 96a to 96d becomes complicated and difficult.

Therefore, the applicant of the present invention has previously proposed that the mechanical holding of the piezoelectric vibrating body and the electrical connection with the external processing circuit be such that the vibrating branches (intermediate holding branches) not related to the vibration are connected to the vibrating parts. We proposed a piezoelectric vibrating body placed between the vibrating branches. The specific structure will be described with reference to the front side perspective view of FIG. 6 and the back side perspective view of FIG.

This piezoelectric vibrating body uses a piezoelectric substrate whose overall shape is a "king" shape. The drive-side vibrating portion 1A and the detection-side vibrating portion 1B are arranged at both ends of the coupling base portion 20 of the piezoelectric vibrating body. This drive side vibrating section 1A
Is composed of two drive vibration branches 3 and 4 and a drive intermediate holding branch 5, and the detection side vibrating section 1B is composed of two detection vibration branches 6 and 7 and a drive intermediate holding branch 8. There is.

Further, drive electrodes 31 to 34, 41 to 44 are formed on four side surfaces of the drive vibrating branches 3 and 4,
Detection electrodes 61 to 63 are provided on both main surfaces of the vibrating branches 6 and 7 for detection.
71 to 74 are formed.

Further, one drive input electrode 51 is formed on one main surface (front surface side) of the piezoelectric substrate of the driving intermediate holding branch 5, and the other drive surface is formed on the other main surface (back surface side). The input electrode 52 is formed. In addition, the intermediate holding branch 8 for detection
The first detection output electrode 81 is formed on one main surface of the piezoelectric substrate, and the second detection output electrode 8 is formed on the other main surface.
2 is formed.

Here, the coupling base 20, the driving vibrating branch 3,
4 includes drive input electrode 51 and drive electrodes 31, 33, 4
In order to electrically connect 2, 44, the lead conductor 2
1, 35, 46 are formed, and similarly, the drive input electrode 52 is formed.
The lead-out conductors 22, 36, 45 are formed to electrically connect the drive electrodes 32, 34, 41, 43 with each other.

Further, the coupling base 20, the vibrating branch 6 for detection,
7 includes a detection output electrode 81 and detection electrodes 61, 71, 6
The routing conductor 2 for electrically connecting 4, 74 to each other.
3, 26, 65 are formed, and similarly, the detection output electrode 82 is formed.
The lead-out conductors 24, 25, 75 are formed in order to electrically connect with the detection electrodes 62, 72, 63, 73.

With this structure, when the piezoelectric vibrating body 1 is fixed to a printed wiring board or a housing case, a conductive spacer is provided between the back surface of the two intermediate holding branches 5 and 8 and the board or case. It can be easily fixed by interposing a member. At the same time, electrical connection with an external processing circuit can also be made via the conductive spacer member in the drive input electrode 52 and the detection output electrode 82 formed on the back surfaces of the two intermediate holding branches 5 and 8. Further, the drive input electrode 51 and the first detection output electrode 81 formed on the one main surface of the intermediate holding branches 5 and 8 can be connected via a wire bonding thin wire or the like.

Therefore, according to the piezoelectric vibrating body shown in FIGS. 6 and 7, the mechanical connection between the piezoelectric vibrating body and the printed wiring board, the case or the like and the electrical connection between the external processing circuit and the intermediate holding branch are made. 5 and 8 can be achieved, and since the drive input electrodes 51 and 52 and the drive output electrodes 81 and 82 are formed on both main surfaces thereof, stable and easy mechanical connection and electrical connection can be achieved. It can be carried out.

[0022]

However, as a result of various experiments and examinations conducted by the present inventors, the twisting phenomenon occurs in the coupling base portion 20 especially when the foot vibrations or the like occur in the driving side vibration portion 1B. I found out that. This twist also affects the two intermediate holding branches 5 and 8 extending from the coupling base 20, and, for example, the drive input electrode 52, the detection output electrode 82, and the conductive spacer formed on the back main surface of the coupling base 20. It also has a great influence on the bonding state (electrical connection). This is because a large strain or internal stress occurs at the joint between the intermediate holding branches 5 and 8 and the conductive spacer.

At the same time, the foot vibration generated in the detection vibration branches 6 and 7 appears as a twist in the coupling base portion 20, so that the mechanical resonance sharpness Q of the detection side vibration portion 1B is particularly low. As a result, the sensitivity of the detection signal is reduced.

The present invention has been devised on the basis of the above-mentioned findings, and an object thereof is to generate twist (internal stress) in the coupling base portion even if a predetermined vibration is generated in the detection side vibration portion. , Which reduces connection reliability,
Further, the present invention provides a piezoelectric vibrating body that does not deteriorate in characteristics (detection sensitivity).

[0025]

SUMMARY OF THE INVENTION According to the present invention, two vibrating branches forming a vibrating portion on one end side surface driving side of opposing coupling base portions having a rectangular shape and an intermediate holding between the two vibrating branches. A branch, a piezoelectric substrate having two vibrating branches forming the detecting side vibrating section on the other side and an intermediate holding branch disposed between the two vibrating branches, and for generating driving vibration in the driving side vibrating section. In a piezoelectric vibrating body having a drive electrode and a drive input electrode formed on the, and a detection electrode and a detection output electrode formed to detect the vibration generated in the detection side vibration part, the coupling base is The piezoelectric vibrating body projects outward from each vibrating branch in a direction orthogonal to the direction in which the branch and the intermediate holding branch extend.

[0026]

According to the present invention, the coupling base portion for coupling the driving side vibration portion and the detection side vibration portion is projected in the width direction of the coupling base portion (direction orthogonal to the extending direction of each vibration branch). Therefore, the mechanical rigidity of the coupling base is increased, and even if the detection-side vibrating section has a fluttering vibration, the twist generated in the coupling base can be effectively suppressed.

This makes it possible to effectively suppress the influence of twisting in the two intermediate holding branches extending from the connecting base.
It is possible to prevent the joint state between the intermediate holding branch and the printed wiring board or the case from being deteriorated and the connection to the external processing circuit from becoming unstable.

Further, it is possible to effectively prevent the mechanical resonance sharpness Q from being lowered due to the twist, and to improve the sensitivity of the detection signal.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION A piezoelectric vibrating body of the present invention will be described below with reference to the drawings.

FIG. 1 is an external perspective view of the surface side of the piezoelectric vibrating body of the present invention, and FIG. 2 is a perspective view of the back surface side thereof.
[Fig. 4] is a schematic diagram for explaining an electrical connection state of a drive-side vibrating portion of the piezoelectric vibrating body, and Fig. 4 is a schematic diagram for explaining an electrical connection state of a detecting-side vibrating portion of the piezoelectric vibrating body. 6 and 7
The same parts as in FIG.

The piezoelectric vibrating body 1 of the present invention comprises a driving side vibrating portion 1
A, a detection side vibrating section 1B, and a coupling base section 2 are included.

The piezoelectric vibrating body 1 may be, for example, a quartz substrate or the like that is predeterminedly cut, for example, Z-cut according to the crystal polarization axis of quartz. Other examples include a piezoelectric ceramic substrate that is polarized in a predetermined direction.

The driving side vibrating portion 1A is integrally arranged on one side of a pair of end faces (hereinafter, referred to as longitudinal end faces) of the coupling base portion 2, and the detecting side vibrating portion 1B is integrally arranged on the other side. Has been done.

The drive-side vibrating section 1A is mainly composed of two drive vibrating branches 3 and 4 and a drive intermediate holding branch 5. The intermediate holding branch 5 is sandwiched between the vibrating branches 3 and 4, and The drive vibration branches 3 and 4 and the intermediate holding branch 5 extend in the same direction.

Further, the detecting side vibrating section 1B is mainly composed of two detecting vibrating branches 6 and 7 and a detecting intermediate holding branch 8, and the intermediate holding branch 8 is sandwiched between the detecting vibrating branches 6 and 7. All the vibrating branches 6 and 7 and the intermediate holding branch 8 extend in the direction opposite to the direction in which the vibrating branches 3 and 4 and the intermediate holding branch 5 of the drive vibrating section 1A extend.

Here, it is important to note that the coupling base portion 2 has its width direction outside the width direction of the driving side vibrating portion 1A outside the width direction of the vibrating branches 3 and 4 and the detecting side vibrating portion 1B. It is formed so as to project more than some of the vibrating branches 6 and 7.

The vibrating branches 3A, 1B have different lengths and widths of the vibrating branches 3, 4 and 6, 7 so that the resonance frequencies are different.

With the above-described structure, the substrate forming the piezoelectric vibrating body 1 has a substantially "king" shape.
In particular, only the connecting base portion 2 has a shape protruding in the width direction.

Further, the vibrating branch 3 serving as the driving side vibrating section 1A,
4, an intermediate holding branch 5, a vibrating branch 6 serving as the detection side vibrating section 1B,
Various kinds of predetermined electrodes and conductor films are formed on the main surface and / or the side surface of the intermediate holding branch 8 and the bonding base 2, respectively. still,
The predetermined electrode and the conductor film are formed by a thin film technique such as vapor deposition of chromium or Au or spattering.

First, in the drive side vibrating portion 1A, drive electrodes 31 to 34, 41 to 44 for converting a predetermined drive signal into vibration are formed on each of four surfaces of the two vibrating branches 3 and 4. . A drive input electrode 51 and a drive input electrode 52 to which a drive signal is input are formed on both main surfaces of the intermediate holding branch 5.

Next, in the detection side vibrating portion 1B, the two vibrating branches 6 and 7 and the intermediate holding branch 8 are provided with a detection electrode 61 for converting a foot vibration corresponding to an angular velocity into a detection signal.
˜64 and 71 to 74 are formed with detection output electrodes 81 and 82 on both main surfaces of the intermediate holding branch 8 for outputting the converted detection signals to an external circuit, respectively. Specifically, two detection electrodes 61 and 62 are formed on one main surface of the vibrating branch 6 in parallel in the longitudinal direction of the vibrating branch 6 at a predetermined interval. Two detection electrodes 7 on the surface
1 and 72 are formed side by side in parallel in the length direction of the vibrating branch 7 at a predetermined interval, and similarly, the two detection electrodes 63 and 73 and the detecting electrodes 63 and 73 are also detected on the other main surface of the vibrating branch 6 and 7. Electrode 64,
74 are formed side by side in parallel.

That is, the detection electrodes 61, 6 of the vibrating branches 6, 7 are
2, 71 and 72 are formed on the same main surface as the detection output electrode 81 of the intermediate holding branch 8, and the detection electrodes 63, 64, 73 and 74.
Are formed on the same main surface as the detection output electrode 82 of the intermediate holding branch 8.

The drive input electrode 5 of the drive side vibrating section 1A
In order to connect 1 to the drive electrodes 31, 33, 42, 44 of the vibrating branches 3, 4, lead-out conductor films 21, 36, 45 are formed at the tips or bases of the coupling base 2, the vibrating branches 3, 4, respectively. Drive input electrode 52 and drive electrodes 32, 34,
In order to connect with 41 and 43, the routing conductor films 22 and 4 are provided at the tips or bases of the coupling base 2, the vibrating branches 3 and 4, respectively.
6, 35 are formed.

Further, the detection output electrode 8 of the detection side vibrating portion 1B
In order to connect 1 to the detection electrodes 61, 71, 64, 74 of the vibrating branches 6, 7, lead-out conductor films 23, 26, 65 are formed at the tips of the coupling base 2, the vibrating branches 3, 4, respectively. In order to connect the detection output electrode 82 and the detection electrodes 62, 72, 63, 73, at the tips of the coupling base 2, the vibrating branches 3, 4,
The leading conductor films 24, 25, 75 are formed.

As a result, the drive input electrodes 51, 52 and the drive electrodes 31-34, 41-44 of the drive-side vibrating section 1A.
Is in the connected state as shown in FIG.
B detection output electrodes 81 and 82, and detection electrodes 61 to 64 and 7
1 to 74 are in the connected state as shown in FIG.

In the piezoelectric vibrating body 1 having the above-described structure, by applying a driving AC voltage between the driving input electrodes 51 and 52, the driving side vibrating portion 1A is indicated by the solid line arrow in the figure, and at the next moment, A tuning fork vibration mode is generated as indicated by the dotted arrow. The tuning fork vibration is not transmitted to the detection side vibrating section 1B having a different natural resonance frequency.

When a rotary motion is applied to the entire piezoelectric vibrating body 1 in this state, Coriolis force acts, and the detecting side vibrating portion 1B shown in FIG. At the moment of, the flap vibration occurs as shown by the dotted arrow in the figure.

Further, as described above, the detection side vibrating section 1B
Between the detection electrodes 61 and 62, 63 and 64, which are arranged in parallel so as to face each other on the main surfaces of the vibrating branches 6 and 7.
A predetermined electric field is generated between 1 and 72 and between 73 and 74 due to the relationship between the flap vibration and the polarization direction (orientation) of the piezoelectric substrate, and a potential difference is generated.

This potential is formed on the one main surface side of the intermediate holding branch 8 and the detection output electrode 81 and the detection output electrode 82.
Will be extracted (detection signal) from and.

The detection signals obtained from the detection output electrodes 81 and 82 are processed by an external circuit including an amplifier (op amp).

In the piezoelectric vibrating body 1 having such a structure, two conductive spacer (holder) members are arranged at a predetermined interval on a part of a case that houses the piezoelectric vibrating body 1, for example, a substrate (not shown). Then, it is arranged on the two holder members with a conductive adhesive so as to come into contact with the drive input electrode 52 and the detection output electrode 82 of the intermediate holding branches 5 and 8. Thereby, the mechanical holding of the piezoelectric vibrating body 1 is achieved, and at the same time, the predetermined circuit wiring on the surface of the substrate is connected to the drive input electrode 52 and the detection output electrode 82. The drive input electrode 51 and the detection output electrode 81 on the one main surface side of the piezoelectric vibrating body 1
The connection with is made by, for example, a wire bonding thin wire.

A feature of the present invention is that the end face in the width direction of the coupling portion 2 which constitutes the piezoelectric vibrating body 1 is the drive vibrating portion 1A,
That is, it protrudes to the outside as compared with the width of the detection vibration part 1B.

As a result, the mechanical rigidity of the coupling portion 2 is improved, and the tuning fork vibration generated in the driving side vibrating portion 1A of the piezoelectric vibrating body 1 and the vibration and the Coriolis force cause a flapping in the detecting side vibrating portion 1B. Even if vibration of the foot or the like occurs, the joint base 2 is not twisted, and as a result, the piezoelectric vibrating body 1
The overall mechanical resonance sharpness Q can be maintained stably, and the characteristics are improved. Further, a portion (driving input electrode 52, detection output electrode 82) joined to the wiring board via the intermediate holding branches 5 and 8.
The stress is not concentrated on the joint portion between the conductive holder member and the conductive holder member, and stable joint can be maintained.

[0054]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present inventors have made the shapes of the driving side vibrating section 1A, that is, the driving vibrating branches 3 and 4, the intermediate holding branch 5 and the detecting side vibrating section 1B, that is, the detecting vibrating branches 6 and 7, the intermediate holding branch 8. The size of the coupling base portion 2 is changed to various values, and the detection side vibrating portion 1 is made constant.
The mechanical resonance sharpness Q of B was measured.

In Table 1, ls is the length of the detection vibrating branches 6 and 7 of the detection side vibrating section 1B, and ld is the driving side vibrating section 1.
A is the length of the drive vibration branches 3 and 4, and li is the coupling base 2
In the longitudinal direction, Wm is the width of the intermediate holding branches 5 and 8 of the drive-side vibrating section 1A and the detection-side vibrating section 1B, and Ws is the width of the detection-vibrating branches 6 and 7 of the detection-side vibrating section 1B. And Wd
Is the width of the drive vibrating branches 3 and 4 of the drive side vibrating portion 1A, and W
ps is the interval width between the detection vibrating branches 6 and 7 of the detection side vibrating section 1B and the intermediate holding branch 8, and Wpd is the driving vibrating branches 3 and 4 and the intermediate holding branch 5 of the driving side vibrating section 1A. Is the interval width between.

The unit of length and width is mm, the thickness t of the substrate is the same (0.53 mm), and the drive side vibrating section 1A is used.
The structure and size of each electrode and the structure and size of each electrode of the detection-side vibrating portion 1B are the same.

[0057]

[Table 1]

In Table 1, Sample No. 1 is a conventional piezoelectric vibrating body having the structure shown in FIGS. 6 and 7, Sample No. 2 is a comparative example, and Sample Nos. 3 to 5 are piezoelectric vibrations of the present invention. It is the body.

In the sample No. 1, when the length of the coupling base portion 20 was 1.50 mm and the width thereof was 2.10 mm, the mechanical resonance sharpness Q in the detection side vibrating portion was 9000.

With respect to the sample No. 1, the width of the binding base 2 was 5.10 mm (protruded by 1.5 mm on both sides).
In Sample No. 3 of the present invention described above, the mechanical resonance sharpness Q in the detection-side vibrating portion 1B is as large as 23000.

Further, the length direction of the bonding base 2 is made longer than that of the sample No. 1, and the width of the bonding base 2 is 5.10 mm.
In the sample No. 4 of the present invention in which (protruded by 1.5 mm on both sides), the mechanical resonance sharpness Q at the detection-side vibrating portion is Q.
Becomes 32500, which is even larger.

For this sample number 4, the detection vibration branch 6,
In Sample No. 5 in which the width Ws of 7 is narrowed, the mechanical resonance sharpness Q is further increased to 33000.

Generally, it is important that the mechanical resonance sharpness Q is sufficiently large in order to extract the fluttering vibration or the like generated in the detection side vibrating section 1B as a sufficiently stable electric signal. The mechanical resonance sharpness Q can be reliably improved by projecting the width of the.

The mechanical rigidity of the intermediate joint portion 2 can be increased by increasing the length l i of the intermediate joint base portion 2, but by comparing with sample numbers 1, 2, and 3. As will be clear, from the viewpoint of the mechanical resonance sharpness Q, actually, the protrusion in the width direction is more effective than simply increasing the length of the intermediate coupling base 2. Further, it is conceivable to increase the thickness of the intermediate coupling base portion 2, but it is effective to simply project the intermediate coupling base portion 2 in the width direction in consideration of the manufacturing process of the piezoelectric substrate.

Conventionally, the twist generated in the detection-side vibrating section rolls in the width direction of the piezoelectric vibrating body 1 with the central axis of the intermediate holding branches 5 and 8 as the central axis of the twist, but from this, the coupling Even if the base 2 is extended in the length direction, the central axis of the twist is simply extended.
It is considered that the degree of improvement in the mechanical resonance sharpness Q of B becomes smaller than that when it is projected in the width direction.

As described above, by protruding the coupling base portion in the width direction as in the present invention, not only the mechanical rigidity of the coupling base portion 2 is increased, but also the fluttering foot vibration generated in the detection side vibrating portion 1B is generated. It is possible to improve the mechanical resonance sharpness Q because it can act so as to directly regulate the above.

Incidentally, the detection electrodes of the above-mentioned detection section vibrating section 1B,
The detection output electrodes are mainly formed on both main surfaces of the detection section vibrating section 1B, but only the detection electrodes or only a part of the detection output electrodes are provided on the side surface orthogonal to the main surface of the detection section vibrating section 1B. You may form.

Further, the structure of the electrodes for converting the foot vibration generated in the detecting portion vibrating portion 1B into an electric signal can be variously changed.

[0069]

As described above, the piezoelectric vibrating body in which the driving side vibrating portion and the detecting side vibrating portion are integrally coupled to the end faces in the longitudinal direction via the coupling base portion, respectively, Since the width direction of the projection protrudes to the outside of the driving-side vibrating section and / or the detecting-side vibrating section, it is possible to effectively suppress the twisting of the coupling base portion caused by the vibration of the foot of the detecting-side vibrating section. As a result, the vibration loss of the flap vibration can be reduced, the mechanical resonance sharpness Q can be improved, and a highly sensitive detection signal can be obtained.

Further, since the twist can be effectively suppressed, the reliability of mechanical joining between the intermediate holding branch and the printed wiring board is improved, and the drive input electrode and the detection output electrode formed on the intermediate holding branch are The reliability of electrical connection with the external detection circuit can be improved.

[0071]

[Brief description of drawings]

FIG. 1 is an external perspective view of a surface side of a piezoelectric vibrating body of the present invention.

FIG. 2 is an external perspective view of the back surface side of the piezoelectric vibrating body of the present invention.

FIG. 3 is a schematic diagram illustrating an electrical connection state of a driving-side vibrating portion that forms a piezoelectric vibrator.

FIG. 4 is a schematic diagram illustrating an electrical connection state of a detection-side vibrating portion constituting the piezoelectric vibrator.

FIG. 5 is an external perspective view of a conventional piezoelectric vibrating body.

FIG. 6 is an external perspective view of the surface side of a conventional piezoelectric vibrating body.

FIG. 7 is an external perspective view of the back surface side of a conventional piezoelectric vibrating body.

[Explanation of symbols]

 1 ... Piezoelectric vibrating body 1A ... Driving side vibrating section 1B ... Detection side vibrating section 2 ... Coupling base 3, 4 ... Vibration branch of driving side vibrating section 5 ... Intermediate holding branch of driving side vibrating section 6, 7 ... Vibration branch of detecting side vibrating section 8 ... Intermediate holding branch of detecting side vibrating section 31-34, 41-44 .... Drive electrodes 61, 63, 71, 73 62, 64, 72, 74 ... Detection electrodes

Claims (1)

[Claims] 1. A two-sided vibrating branch forming a drive-side vibrating section on one side surface of a coupling base section having a rectangular shape facing each other, an intermediate holding branch between the two vibrating branches, and a detection-side vibration on the other side surface. And a piezoelectric substrate in which an intermediate holding branch is arranged between the two vibrating branches and a vibrating branch, and a drive electrode and a drive input formed to generate drive vibration in the drive side vibrating section. In a piezoelectric vibrating body having an electrode and a detection electrode and a detection output electrode formed to detect vibration generated in the detection-side vibrating section, the coupling base is a direction orthogonal to a direction in which each branch extends. A piezoelectric vibrating body, characterized in that the end portions of the are projecting outward from each branch.