JP2015175810A - Gyro sensor element, gyro device, electronic equipment, and traveling object - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact gyro sensor element.SOLUTION: A gyro sensor element includes: a base part 10; and vibration arms 20 and 30 extending from the base part 10. One surfaces of the vibration arms 20 and 30 are respectively formed with a first laminate 40 and a second laminate 50 following an extension direction, and the first laminate 40 and the second laminate 50 respectively include: drive parts 47 and 57 including first electrode layers 41 and 51, second electrode layers 43 and 53 and first piezoelectric layers 42 and 52 disposed between the first electrode layers 41 and 51 and the second electrode layers 43 and 53; and detection parts 48 and 58 including the second electrode layers 43 and 53, third electrode layers 45 and 55 and second piezoelectric layers 44 and 54 disposed between the second electrode layers 43 and 53 and the third electrode layers 45 and 55. The piezoelectric strain constants of the first piezoelectric layers 42 and 52 are larger than the piezoelectric strain constants of the second piezoelectric layers 44 and 54, and the dielectric constants of the second piezoelectric layers 44 and 54 are smaller than the dielectric constants of the first piezoelectric layers 42 and 52.

Description

  The present invention relates to a gyro sensor element, a gyro device, an electronic apparatus, and a moving body.

  Conventionally, gyro sensors have been used in technologies for autonomously controlling the attitude of ships, aircraft, rockets, and the like. Recently, it is used for vehicle body control in vehicles, vehicle position detection of a car navigation system, vibration control correction (so-called camera shake correction) for digital cameras, video cameras, and mobile phones. Along with the downsizing of these electronic devices, for example, as described in Patent Document 1, a driving unit that excites a vibrating part on the arm of a tuning fork vibrator made of a silicon substrate and a deflection of the vibrating part are detected. There is known a gyro sensor provided with a detecting unit to perform.

JP 2005-249395 A

  A tuning fork type gyro sensor described in Patent Literature 1 includes a vibrating arm (arm) extending from a base, a pair of driving units provided on one surface of the vibrating arm along the extending direction of the vibrating arm, and a pair of And a detection unit (detection unit) provided between the drive units. The drive unit and the detection unit are formed of a laminate having an upper electrode layer, a lower electrode layer, and a piezoelectric layer sandwiched between the upper electrode layer and the lower electrode layer. In other words, the vibrating arm needs to have a size (arm width) for providing three stacked bodies including two stacked bodies having a drive unit and one stacked body having a detection unit. In order to reduce the size of the gyro sensor having this configuration, it is necessary to reduce the width of the stacked body. However, when the width of the stacked body is narrowed, the driving efficiency and the detection sensitivity may be lowered, and it is difficult to reduce the size.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

  Application Example 1 A gyro sensor element according to this application example includes a base portion and a vibrating arm extending from the base portion, and a first laminated layer is formed on one surface of the vibrating arm along the extending direction. And a second laminated body, and the first laminated body and the second laminated body are provided between the first electrode layer, the second electrode layer, and the first electrode layer and the second electrode layer. A driving unit including the first piezoelectric layer, the second electrode layer, the third electrode layer, and a second piezoelectric layer provided between the second electrode layer and the third electrode layer. And a piezoelectric strain constant of the first piezoelectric layer is greater than a piezoelectric strain constant of the second piezoelectric layer, and a dielectric constant of the second piezoelectric layer is greater than a dielectric constant of the first piezoelectric layer. It is small.

According to this application example, in the gyro sensor element, the driving unit and the detection unit are formed in one stacked body, and the gyro sensor element is formed of two stacked bodies of the first stacked body and the second stacked body. Can be configured. As a result, the width of the vibrating arm can be reduced, and a small gyro sensor element can be provided.
In addition, the drive unit of the gyro sensor element of this application example uses the inverse piezoelectric effect to apply a voltage to the first piezoelectric layer, thereby causing distortion in the first piezoelectric layer and driving the vibrating arm. By using a piezoelectric material having a piezoelectric strain constant larger than that of the second piezoelectric layer (inverse piezoelectric effect) for the first piezoelectric layer, the conversion efficiency from electrical energy (voltage) to mechanical energy (strain) is improved. The driving efficiency of the vibrating arm is improved.

  Further, the detection unit of the gyro sensor element detects the electric charge appearing in the second piezoelectric layer according to the amount of strain by the piezoelectric effect due to the Coriolis force generated by the angular velocity applied to the vibrating arm adds strain to the second piezoelectric layer. By using a piezoelectric material having a dielectric constant smaller than the dielectric constant of the first piezoelectric layer for the second piezoelectric layer, the amount of charge staying in the detection unit can be reduced. improves. In other words, the width of the first stacked body, the second stacked body, and the width of the vibrating arm can be reduced without sacrificing the driving efficiency and detection sensitivity of the gyro sensor element. Thereby, a further smaller gyro sensor element can be provided.

  Application Example 2 In the gyro sensor element according to the application example described above, the first stacked body and the second stacked body may be configured such that the first electrode layer, the first piezoelectric layer, and the first stacked body are formed on one surface of the vibrating arm. It is preferable that two electrode layers, the second piezoelectric layer, and the third electrode layer are laminated in this order.

According to this application example, the drive unit of the gyro sensor element includes the first electrode layer that is in contact with the vibrating arm, the first piezoelectric layer that is stacked on the first electrode layer, and the first piezoelectric layer that is stacked on the first piezoelectric layer. And a second electrode layer. The detection unit is formed of a second electrode layer, a second piezoelectric layer stacked on the second electrode layer, and a third electrode layer stacked on the second piezoelectric layer. Usually, when layers are stacked in multiple layers, the layers stacked later are affected by the surface shape of the underlying layer formed earlier, and the unevenness in the thickness direction generated on the surface of the layer becomes large. In other words, the closer the piezoelectric layer is to the vibrating arm, the better the surface shape is, the better the film quality is, and the larger the piezoelectric strain constant is, so the piezoelectric layer having the larger piezoelectric strain constant is formed. As a result, the driving efficiency of the vibrating arm is improved.
In addition, since the detection unit is formed at a position away from the one surface of the vibrating arm via the first electrode layer and the first piezoelectric layer in the thickness direction, when a force in the thickness direction is applied to the vibrating arm, Since the amount of strain applied to the second piezoelectric layer is increased and the amount of charge appearing in the second piezoelectric layer is increased, the detection accuracy of the charge generated when the angular velocity is applied is improved. Accordingly, the width of the first stacked body, the second stacked body, and the width of the vibrating arm can be reduced without sacrificing the driving efficiency and detection sensitivity of the gyro sensor element. Can be provided.

  Application Example 3 A gyro sensor element according to this application example includes a base and a vibrating arm extending from the base, and a first laminated layer is formed on one surface of the vibrating arm in parallel with the extending direction. And a second laminated body, and the first laminated body and the second laminated body are provided between the first electrode layer, the second electrode layer, and the first electrode layer and the second electrode layer. A driving unit including the first piezoelectric layer, the second electrode layer, the third electrode layer, and a second piezoelectric layer provided between the second electrode layer and the third electrode layer. And at least the first piezoelectric layer is separated into the first stacked body and the second stacked body, and the vibrating arm bends and vibrates in a direction along an in-plane direction. To do.

  According to this application example, the gyro sensor element includes the first electrode layer, the second electrode layer, the first electrode layer, and the first electrode layer on each of the first stacked body and the second stacked body formed on one surface of the vibrating arm. A drive unit including a first piezoelectric layer provided between the two electrode layers, a second electrode layer, a third electrode layer, and a second electrode provided between the second electrode layer and the third electrode layer. And a detection unit including a piezoelectric layer. Since the first piezoelectric layer and the second piezoelectric layer are separated into the first stacked body and the second stacked body, the drive unit of the first stacked body and the drive unit of the second stacked body have different polarities. When a voltage is applied, the vibrating arm bends and vibrates in a direction along the plane. Further, the Coriolis force generated by the angular velocity applied to the vibrating arm adds distortion to the second piezoelectric layer, and at least the amount of charge appearing in the detection unit of the first stacked body and the detection unit of the second stacked body according to the amount of distortion due to the piezoelectric effect. The angular velocity is obtained by detecting one of them.

  In the gyro sensor element of this application example, the driving unit and the detection unit are formed in one laminated body, and the gyro sensor element is configured by two laminated bodies of the first laminated body and the second laminated body. Therefore, the width of the vibrating arm can be reduced, and a small gyro sensor element can be provided.

  Application Example 4 In the gyro sensor element according to the application example described above, the displacement applied to the vibrating arm is detected by the detection unit of the first stacked body and the detection unit of the second stacked body. It is preferable to obtain the sum of the charge amounts.

  According to this application example, the detection unit of the gyro sensor element is provided in the first stacked body and the second stacked body. The Coriolis force generated by the angular velocity applied to the vibrating arm adds strain to the second piezoelectric layer, and electric charges appear in the detection unit of the first stacked body and the detection unit of the second stacked body according to the amount of strain due to the piezoelectric effect. The detection sensitivity of the angular velocity can be improved by detecting the sum of the charge amounts appearing in the detection unit of the first stacked body and the detection unit of the second stacked body. Thereby, the small gyro sensor element which improved the detection sensitivity of angular velocity can be provided.

  Application Example 5 The gyro sensor element according to the application example preferably includes two vibrating arms extending in parallel from the base portion.

  According to this application example, in the gyro sensor element, the two vibrating arms extending in parallel from the base portion bend and vibrate in opposite directions along the in-plane direction. Leakage vibration caused by bending vibration is canceled through the base portion, so that the Q (Quality factor) value of the gyro sensor element can be improved. Thereby, a small and high Q value gyro sensor element can be provided.

  Application Example 6 In the gyro sensor element according to the application example described above, the first stacked body and the second stacked body may be configured such that the first electrode layer, the first piezoelectric layer, and the second stacked body are formed from the one surface of the vibrating arm. The second electrode layer, the second piezoelectric layer, and the third electrode layer are stacked in this order, provided in line symmetry with respect to the center line in the extending direction of the vibrating arm, and the in-plane of the second piezoelectric layer The width in the direction is narrower than the width in the in-plane direction of the first piezoelectric layer, and the second laminated body has the center line of the second piezoelectric layer that the first laminated body has. The center-to-center distance from the center line of the second piezoelectric layer is the center line of the first piezoelectric layer that the first stacked body has and the first piezoelectric layer that the second stacked body has. It is preferably narrower than the center-to-center distance.

According to this application example, the drive unit of the gyro sensor element includes the first electrode layer in contact with one surface of the vibrating arm, the first piezoelectric layer stacked on the first electrode layer, and the first piezoelectric layer. And the second electrode layer. The detection unit is formed of a second electrode layer, a second piezoelectric layer stacked on the second electrode layer, and a third electrode layer stacked on the second piezoelectric layer. Usually, when electrode layers and piezoelectric layers are laminated in multiple layers, the later laminated layers are affected by the surface shape of the layer that is formed first, and the unevenness in the thickness direction generated on the surface becomes large. In other words, the closer the piezoelectric layer is to the vibrating arm, the better the surface shape and the better film quality, and the larger the piezoelectric strain constant is formed. Therefore, by using the first piezoelectric layer as the drive unit, the vibrating arm Driving efficiency is improved.
Further, since the detection unit is formed at a position away from the vibrating arm in the thickness direction via the first electrode layer and the first piezoelectric layer, when a force in the thickness direction is applied to the vibrating arm, the detection unit is applied to the second piezoelectric layer. Since the applied strain increases and the amount of charge appearing in the second piezoelectric layer also increases, the detection accuracy of the charge generated when the angular velocity is applied is improved.

The first piezoelectric layer included in the driving unit of the first stacked body and the second stacked body preferably has a width as wide as possible with respect to the width of the vibrating arm in order to improve the driving efficiency of the vibrating arm. For this reason, the width of the first piezoelectric layer included in the first stacked body and the second stacked body is wider than the width of the second piezoelectric layer, and is symmetrical with respect to the center line in the extending direction of the vibrating arm. Is provided.
The second piezoelectric layer included in the detection unit of the first stacked body and the second stacked body can reduce detection noise (charge generated by bending vibration along the in-plane direction) caused by stacking deviation during manufacturing. It is preferable to provide only inside the vibrating arm. For this reason, the width of the second piezoelectric layer included in the first stacked body and the second stacked body is narrower than the width of the first piezoelectric layer, and the center line of the second piezoelectric layer included in the first stacked body; The center-to-center distance representing the distance from the center line of the second piezoelectric layer included in the second stacked body is greater than the center-to-center distance between the first piezoelectric layer of the first stacked body and the first piezoelectric layer of the second stacked body. The second piezoelectric layer is narrow and symmetrical with respect to the center line of the vibrating arm. Thereby, a small gyro sensor element with improved driving efficiency and detection accuracy can be provided.

  Application Example 7 A gyro apparatus according to this application example includes the gyro sensor element described in the application example.

  According to this application example, it is possible to provide a small gyro device including a small gyro sensor element.

  Application Example 8 An electronic apparatus according to this application example includes the gyro sensor element described in the application example.

  According to this application example, it is possible to provide a small electronic device including a small gyro sensor element.

  Application Example 9 A moving object according to this application example includes the gyro sensor element described in the application example.

  According to this application example, it is possible to provide a moving body including a small gyro sensor element.

FIG. 2 is a schematic plan view illustrating a schematic configuration of a gyro sensor element according to the first embodiment. Sectional drawing in the AA in FIG. FIG. 4 is a schematic plan view showing a schematic configuration of a gyro sensor element according to a second embodiment. Sectional drawing in the BB line in FIG. The schematic plan view which shows schematic structure of the gyro sensor element which concerns on a modification. Sectional drawing in CC in FIG. Sectional drawing which shows the outline of a gyro apparatus provided with a gyro sensor element. The perspective view which shows the structure of the mobile type (or notebook type) personal computer as an electronic device provided with a gyro sensor element. The perspective view which shows the mobile telephone as an electronic device provided with a gyro sensor element. The perspective view which shows the digital still camera as an electronic device provided with a gyro sensor element. The perspective view which shows the motor vehicle as a moving body provided with a gyro sensor element. The schematic plan view which shows schematic structure of the gyro sensor element by a prior art. Sectional drawing in the DD line | wire in FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following drawings, the scale of each layer and each member is different from the actual scale so that each layer and each member can be recognized.

<Gyro sensor element>
(Embodiment 1)
FIG. 1 is a schematic plan view showing a schematic configuration of a gyro sensor element 1 according to the first embodiment. FIG. 2 is a cross-sectional view taken along line AA in FIG. Here, in FIG. 1, FIG. 2, and FIG. 3 to FIG. 6, FIG. 12, and FIG. 13 described later, for convenience of explanation, the X axis, the Y axis, and the Z axis are illustrated as three axes orthogonal to each other. The tip end side of the arrow illustrating the axial direction is the “+ side”, and the base end side is the “− side”. Hereinafter, a direction parallel to the X axis is referred to as an “X axis direction”, a direction parallel to the Y axis is referred to as a “Y axis direction”, and a direction parallel to the Z axis is referred to as a “Z axis direction”.
First, a schematic configuration of the gyro sensor element 1 according to the first embodiment will be described with reference to FIGS. 1 and 2.

  As shown in FIG. 1, the gyro sensor element 1 includes a base 10 and a pair of vibrating arms 20 and 30 extending from the base 10. Specifically, the gyro sensor element 1 includes a pair of prismatic vibrating arms 20 and 30 that extend in parallel to each other in the Y-axis direction from one side of the substantially rectangular flat plate-like base 10 on the + Y-axis side. The base 10 and the vibrating arms 20 and 30 constituting the gyro sensor element 1 are integrally formed, and for example, a material mainly composed of silicon (Si) is used. The gyro sensor element 1 of the present embodiment is also called a tuning fork type gyro because of its planar shape.

The gyro sensor element 1 has a main surface 11 on the + Z-axis side of the base 10 and the vibrating arms 20 and 30, and a back surface 12 on the −Z-axis side opposite to the main surface 11.
The main surface 11 of the vibrating arm 20 that is one surface of the vibrating arm is provided with a rectangular first stacked body 40 having a long side in the Y-axis direction on the + X-axis side, and in the Y-axis direction on the −X-axis side. A rectangular second laminated body 50 having a long side is provided.
The main surface 11 of the vibrating arm 30 that is one surface of the vibrating arm is provided with a rectangular first stacked body 40 having a long side in the Y-axis direction on the −X-axis side, and a Y-axis on the + X-axis side. A rectangular second stacked body 50 having a long side in the axial direction is provided.
The first stacked body 40 and the second stacked body 50 are provided in a substantially line-symmetric shape with respect to the center line CL2 of the main surface 11 of the vibrating arm 20 and the center line CL3 of the main surface 11 of the vibrating arm 30. Yes.

The first stacked body 40 includes a first electrode layer 41, a first piezoelectric layer 42, a second electrode layer 43, a second piezoelectric layer 44, and a third electrode layer 45 from the main surface 11 of the vibrating arm 20 and the vibrating arm 30. A drive unit 47 that is sequentially stacked and includes a first electrode layer 41, a first piezoelectric layer 42, and a second electrode layer 43, and a second electrode layer 43, a second piezoelectric layer 44, and a third electrode layer 45. And a detecting unit 48.
The second stacked body 50 includes a first electrode layer 51, a first piezoelectric layer 52, a second electrode layer 53, a second piezoelectric layer 54, and a third electrode layer 55 from the main surface 11 of the vibrating arm 20 and the vibrating arm 30. A drive unit 57 that is sequentially stacked and includes a first electrode layer 51, a first piezoelectric layer 52, and a second electrode layer 53, and a second electrode layer 53, a second piezoelectric layer 54, and a third electrode layer 55. And a detecting unit 58.

The electrode materials of the first electrode layers 41 and 51, the second electrode layers 43 and 53, and the third electrode layers 45 and 55 are not particularly limited. For example, platinum (Pt), aluminum (Al), molybdenum (Mo), Chromium (Cr), titanium (Ti), nickel (Ni), copper (Cu), silver (Ag), gold (Au), or the like can be used.
The first piezoelectric layers 42 and 52 and the second piezoelectric layers 44 and 54 include barium titanate (BaTiO ₃ ), lead titanate (PbTiO ₃ ), lead zirconate titanate (PZT), and lead metaniobate (PbNb ₂ O). ₆ ) A piezoelectric material (piezoelectric material) such as zinc oxide (ZnO) can be used.

First electrode layers 41 and 51, first piezoelectric layers 42 and 52, second electrode layers 43 and 53, second piezoelectric layers 44 and 54, and third electrode layers constituting the first stacked body 40 and the second stacked body 50. For example, a sputtering method or the like is used for forming the films 45 and 55, and for example, a photolithography method or an etching method is used for patterning (outer shape formation).
In the present embodiment, the first stacked body 40 and the second stacked body 50 are provided on the main surface 11 of the vibrating arms 20 and 30 and are not provided on the back surface 12 corresponding to the opposite side of the main surface 11. As a result, batch processing such as sputtering, photolithography, and etching can be efficiently performed.

Next, bending vibration of the gyro sensor element 1 will be described.
The piezoelectric bodies of the first piezoelectric layer 42 of the drive unit 47 and the first piezoelectric layer 52 of the drive unit 57 that are configured in the resonating arms 20 and 30, respectively, are polarized in the −Z-axis direction, and the second electrode layer 43 and 53 are connected to the ground.

First, the displacement of the vibrating arm 20 will be described. When a + (plus) potential is applied to the first electrode layer 41 of the drive unit 47 constituting the first stacked body 40, a rectangular first piezoelectric layer 42 having a long side in the Y-axis direction due to the inverse piezoelectric effect. Extends in the ± Z-axis direction and contracts in the ± Y-axis direction.
At the same time, when a-(minus) potential is applied to the first electrode layer 51 of the drive unit 57 constituting the second stacked body 50, the rectangular first piezoelectric layer 52 having the long side in the Y-axis direction becomes ± Shrinks in the Z-axis direction and extends in the ± Y-axis direction.
The vibrating arm 20 is provided with a first stacked body 40 in the + X-axis direction and a second stacked body 50 in the −X-axis direction in a substantially line-symmetric shape with respect to the center line CL2 of the main surface 11. Therefore, the vibrating arm 20 is displaced in the + X axis direction along the XY plane.

The displacement of the vibrating arm 30 will be described. When a + (plus) potential is applied to the first electrode layer 41 of the drive unit 47 constituting the first stacked body 40, a rectangular first piezoelectric layer 42 having a long side in the Y-axis direction due to the inverse piezoelectric effect. Extends in the ± Z-axis direction and contracts in the ± Y-axis direction.
At the same time, when a-(minus) potential is applied to the first electrode layer 51 of the drive unit 57 constituting the second stacked body 50, the rectangular first piezoelectric layer 52 having the long side in the Y-axis direction becomes ± Shrinks in the Z-axis direction and extends in the ± Y-axis direction.
The vibrating arm 30 is provided with a first stacked body 40 in the −X axis direction and a second stacked body 50 in the + X axis direction in a substantially line-symmetric shape with respect to the center line CL3 of the main surface 11. Therefore, the vibrating arm 20 is displaced in the −X axis direction along the XY plane.

  Therefore, when an alternating voltage having a phase difference of 180 degrees is applied to the driving unit 47 of the first stacked body 40 and the driving unit 57 of the second stacked body 50, the vibrating arm 20 and the vibrating arm 30 are moved to the XY plane. Bending vibrations that are displaced in opposite directions along (in-plane direction) are repeated. This is called vibration in the direction along the surface. Thereby, the gyro sensor element 1 becomes easy to receive the Coriolis force which arises with angular velocity.

  As described above, the drive units 47 and 57 of the gyro sensor element 1 of the present embodiment are provided in contact with the main surface 11 of the vibrating arms 20 and 30, and the detection units 48 and 58 are located above the drive units 47 and 57. (+ Z axis side). Usually, when layers are stacked in multiple layers, the layers stacked later are affected by the surface shape of the previously formed base layer, and the unevenness in the thickness direction generated on the surface becomes large. In other words, a piezoelectric layer closer to the main surface 11 of the vibrating arms 20 and 30 has a flat surface shape and better film quality, and a piezoelectric layer having a large piezoelectric strain constant is formed. Therefore, drive efficiency can be improved by providing the drive parts 47 and 57 in contact with the main surface 11 of the vibrating arms 20 and 30.

  Next, detection of the angular velocity applied to the gyro sensor element 1 will be described. When an angular velocity ω is applied around the Y axis in a state where the vibrating arms 20 and 30 are vibrating in the above-described plane, a Coriolis force is generated in the vibrating arms 20 and 30, and the vibrating arms 20 and 30 are It is displaced in the + Z-axis direction and the -Z-axis direction. The vibration generated by this is called vibration in a direction along the out-of-plane direction.

The piezoelectric bodies of the second piezoelectric layer 44 of the detection unit 48 and the second piezoelectric layer 54 of the detection unit 58 that are configured in the vibrating arms 20 and 30 are polarized in the −Z-axis direction.
First, the case where the vibrating arm 20 is displaced in the + Z-axis direction will be described. When the vibrating arm 20 is displaced in the + Z-axis direction, the rectangular second piezoelectric layers 44 and 54 having the long side in the Y-axis direction contract in the ± Y-axis direction and extend in the ± Z-axis direction. Then, due to the piezoelectric effect, −charge is generated in the third electrode layer 45 of the detection unit 48 and the third electrode layer 55 of the detection unit 58 according to the displacement amount of the vibrating arm 20.

  A case where the vibrating arm 30 is displaced in the −Z-axis direction will be described. When the vibrating arm 30 is displaced in the −Z axis direction, the rectangular second piezoelectric layers 44 and 54 having the long side in the Y axis direction extend in the ± Y axis direction and contract in the ± Z axis direction. Then, due to the piezoelectric effect, −charge is generated in the third electrode layer 45 of the detection unit 48 and the third electrode layer 55 of the detection unit 58 according to the displacement amount of the vibrating arm 30.

The gyro sensor element 1 detects the amount of charge generated in at least one of the third electrode layer 45 of the detection unit 48 and the third electrode layer 55 of the detection unit 58 provided in the vibrating arms 20 and 30, The angular velocity ω applied around the Y axis of the gyro sensor element 1 can be detected.
In the gyro sensor element 1 of the present embodiment, the first stacked body 40 including the detection unit 48 and the second stacked body 50 including the detection unit 58 are in relation to the center line CL2 or the center line CL3 of the main surface 11. The third electrode layer 45 of the detection unit 48 and the third electrode layer 55 of the detection unit 58 are electrically connected to each other. For this reason, the charges generated by the vibration in the direction along the in-plane are canceled out, and the charges generated by the vibration in the direction along the out-of-plane are detected as a sum (integration). Thereby, the detection sensitivity of the angular velocity ω can be improved.

  As described above, the detection units 48 and 58 of the gyro sensor element 1 of the present embodiment are provided on the + Z axis side via the drive units 47 and 57 provided on the main surface 11 of the vibrating arms 20 and 30. . Since the detectors 48 and 58 are formed at positions away from the main surface 11 of the vibrating arms 20 and 30 toward the + Z-axis side, when a force in the ± Z-axis direction is applied to the vibrating arms 20 and 30, The amount of strain applied to the layers 44 and 54 increases, and the amount of charge appearing in the detection units 48 and 58 also increases. Therefore, the detection accuracy of the angular velocity ω can be improved by providing the detection units 48 and 58 on the main surface 11 of the vibrating arms 20 and 30 via the drive units 47 and 57.

  In addition, although the gyro sensor element 1 of this embodiment demonstrated that the 1st laminated body 40 and the 2nd laminated body 50 were isolate | separated completely, it is not limited to this. If at least the first piezoelectric layer 42 of the driving unit 47 and the first piezoelectric layer 52 of the driving unit 57 are separated, and any one of the first electrode layers 41 and 51 and the second electrode layers 43 and 53 is separated. The vibrating arms 20 and 30 can be vibrated in a direction along the plane. Further, even when the second piezoelectric layer 44 of the detection unit 48 and the second piezoelectric layer 54 of the detection unit 58 are coupled by the same piezoelectric layer, the angular velocity ω can be detected.

  In the gyro sensor element 1 of the present embodiment, a base material such as silicon is formed in a tuning fork shape, and a laminated body (first laminated body 40, second laminated body 50) is formed on the main surface 11 of the vibrating arms 20 and 30. The tuning fork type gyro provided. Since the two vibrating arms 20 and 30 of the gyro sensor element 1 which is a tuning fork type gyroscope bend and vibrate in opposite directions, the leakage vibration caused by the bending vibration is canceled through the base 10. Therefore, the gyro sensor element 1 which is a tuning fork type gyro can obtain a higher Q value than a gyro having another shape.

  FIG. 12 is a schematic plan view showing a schematic configuration of a gyro sensor element 300 according to the prior art. 13 is a cross-sectional view taken along line DD in FIG. A conventional gyro sensor element 300 will be described with reference to FIGS. 12 and 13.

First, a schematic configuration of the gyro sensor element 300 will be described.
As shown in FIG. 12, the gyro sensor element 300 according to the prior art includes a base 310 and a pair of vibrating arms 320 and 330 extending in the + Y-axis direction from one side of the base 310 on the + Y-axis side. Yes. The main surface 11 of each of the vibrating arm 320 and the vibrating arm 330 is between a pair of rectangular driving laminates 340 and 350 having a long side in the Y-axis direction and a pair of driving laminates 340 and 350. And a provided laminated body 360 for detection.
The driving laminate 340 and the driving laminate 350 are substantially line-symmetric with respect to the center line CL32 of the main surface 11 of the vibrating arm 320 and the center line CL33 of the main surface 11 of the vibrating arm 330. It was arranged and provided. The detection laminate 360 was provided such that the shapes of the + X axis side and the −X axis side were substantially line symmetric with respect to the center lines CL32 and CL33.

The driving laminate 340 includes a driving unit 347 including a lower electrode layer 341, an upper electrode layer 343, and a driving piezoelectric layer 342 provided between the lower electrode layer 341 and the upper electrode layer 343. It was.
The driving laminate 350 includes a driving unit 357 including a lower electrode layer 351, an upper electrode layer 353, and a driving piezoelectric layer 352 provided between the lower electrode layer 351 and the upper electrode layer 353. It was.
The detection laminate 360 includes a detection unit 368 including a lower electrode layer 361, an upper electrode layer 363, and a driving piezoelectric layer 362 provided between the lower electrode layer 361 and the upper electrode layer 363. It was.

Next, detection of vibration and angular velocity in the direction along the surface of the gyro sensor element 300 will be described.
When an AC voltage having a phase difference of 180 degrees is applied to the driving unit 347 and the driving unit 357, the vibrating arm 320 and the vibrating arm 330 vibrate in a direction along the plane due to the inverse piezoelectric effect.
When the angular velocity ω is applied around the Y axis in a state where the vibrating arms 320 and 330 are vibrating in the in-plane direction, the vibrating arm 320 and the vibrating arm 330 vibrate in the direction along the out-of-plane direction. Then, electric charges are generated in the detection unit 368 due to the piezoelectric effect. By detecting this amount of charge, the angular velocity ω applied to the gyro sensor element 300 has been detected.

The gyro sensor element 300 according to the prior art includes three laminated bodies (driving laminated bodies 340 and 350, a detecting laminated body 360) in parallel with the Y-axis direction on each of the vibrating arms (vibrating arms 320 and 330). Was provided. For this reason, in order to reduce the size of the gyro sensor element 300, it is necessary to narrow the width in the X-axis direction of the laminated body (driving laminated bodies 340 and 350, the detecting laminated body 360). However, if the width in the X-axis direction is narrowed, the driving efficiency and the detection sensitivity may be lowered, and it is difficult to reduce the size.
Therefore, in the gyro sensor element 1 of the present embodiment, the drive unit 47, the detection unit 48, the drive unit 57, and the detection unit 58 are arranged in five layers (the first stack 40 and the second stack 50). ), And the number of stacked bodies provided on one vibrating arm (vibrating arms 20 and 30) is reduced to two, that is, the first stacked body 40 and the second stacked body 50, thereby achieving downsizing.

As described above, according to the gyro sensor element 1 according to the present embodiment, the following effects can be obtained.
In the gyro sensor element 1, the first stacked body 40 and the second stacked body 50 are formed on the main surfaces 11 of the vibrating arms 20 and 30 in parallel with the Y-axis direction. The first stacked body 40 includes a drive unit 47 and a detection unit 48, and the second stacked body 50 includes a drive unit 57 and a detection unit 58. Since the first piezoelectric layer 42 constituting the drive unit 47 and the first piezoelectric layer 52 constituting the drive unit 57 are separated by the first stacked body 40 and the second stacked body 50, The vibration arms 20 and 30 can be vibrated in a direction along the plane by applying voltages having different polarities to the drive unit 57. Further, when the angular velocity ω is applied to the vibrating arms 20 and 30, the vibrating arms 20 and 30 vibrate in a direction along the out-of-plane, and distortion is applied to the second piezoelectric layers 44 and 54. The angular velocity ω is obtained by detecting the amount of charge appearing in the detection units 48 and 58 in accordance with the amount of distortion. Therefore, the angular velocity ω can be obtained with the configuration in which the two laminated bodies (the first laminated body 40 and the second laminated body 50) are provided in each of the vibrating arms (the vibrating arm 20 and the vibrating arm 30). Without sacrificing the driving efficiency and detection sensitivity of the element 1, the width of the first stacked body 40, the second stacked body 50, and the width of the vibrating arms 20 and 30 can be reduced. Can be provided.

(Embodiment 2)
FIG. 3 is a schematic plan view showing a schematic configuration of the gyro sensor element 100 according to the second embodiment. 4 is a cross-sectional view taken along line BB in FIG.
First, a schematic configuration of the gyro sensor element 100 according to the second embodiment will be described with reference to FIGS. 3 and 4. In addition, about the same component as the gyro sensor element 1, the same code | symbol is attached | subjected and the overlapping description is abbreviate | omitted.

A rectangular first laminated body 140 having a long side in the Y-axis direction is provided on the + X-axis side of the main surface 11 of the vibrating arm 20 that is one surface of the vibrating arm, and a Y-axis direction is provided on the −X-axis side. A rectangular second laminated body 150 having a long side is provided.
A rectangular second stacked body 150 having a long side in the Y-axis direction is provided on the + X-axis side of the main surface 11 of the vibrating arm 30 that is one surface of the vibrating arm, and the Y-axis direction is provided on the −X-axis side. A rectangular first laminated body 140 having a long side is provided.
The first stacked body 140 and the second stacked body 150 are provided in a substantially line-symmetric shape with respect to the center line CL2 of the main surface 11 of the vibrating arm 20 and the center line CL3 of the main surface 11 of the vibrating arm 30. Yes.

The first stacked body 140 includes a first electrode layer 41, a first piezoelectric layer 142, a second electrode layer 43, a second piezoelectric layer 144, and a third electrode layer 45 from the main surface 11 of the vibrating arm 20 and the vibrating arm 30. A drive unit 147 that is sequentially stacked and includes a first electrode layer 41, a first piezoelectric layer 142, and a second electrode layer 43, and a second electrode layer 43, a second piezoelectric layer 144, and a third electrode layer 45. And a detecting unit 148.
The second stacked body 150 includes the first electrode layer 51, the first piezoelectric layer 152, the second electrode layer 53, the second piezoelectric layer 154, and the third electrode layer 55 from the main surface 11 of the vibrating arm 20 and the vibrating arm 30. A drive unit 157 that is sequentially stacked and includes the first electrode layer 51, the first piezoelectric layer 152, and the second electrode layer 53, and the second electrode layer 53, the second piezoelectric layer 154, and the third electrode layer 55. And a detecting unit 158.

PZT, which is known as a piezoelectric material having a large piezoelectric strain constant (absolute value), is used for the first piezoelectric layers 142 and 152, and ZnO (zinc oxide) is used for the second piezoelectric layers 144 and 154. Yes.
The absolute value (d) of the piezoelectric strain constant of PZT is about 130 × 10 ⁻¹² m / V, and the absolute value (d) of the piezoelectric strain coefficient of ZnO is about 6 × 10 ⁻¹² m / V. The relative dielectric constant (εr) of PZT is 800 to 3000, and the relative dielectric constant (εr) of ZnO is 8 to 10. Here, the relative dielectric constant (εr) represents the ratio (εr = ε / ε _O ) between the dielectric constant (ε) of the substance and the dielectric constant (ε _O ) of the vacuum.

A piezoelectric material having a piezoelectric strain constant (absolute value) larger than that of the second piezoelectric layers 144 and 154 constituting the detection units 148 and 158 is formed on the first piezoelectric layers 142 and 152 constituting the driving units 147 and 157. It is used. A piezoelectric material having a dielectric constant smaller than that of the first piezoelectric layers 142 and 152 constituting the driving units 147 and 157 is used for the second piezoelectric layers 144 and 154 constituting the detection units 148 and 158.
In the present embodiment, PZT is used for the first piezoelectric layers 142 and 152, and ZnO is used for the second piezoelectric layers 144 and 154. However, these piezoelectric materials are examples, and the above-described piezoelectric strain constants and dielectrics are used. Piezoelectric materials having a relationship with the rate can be used.

Next, the vibration in the direction along the surface of the gyro sensor element 100 will be described.
When an alternating voltage having a phase difference of 180 degrees is applied to the first electrode layer 41 of the drive unit 147 and the first electrode layer 51 of the drive unit 157, the vibrating arm 20 and the vibrating arm 30 are brought into contact with each other by the inverse piezoelectric effect. It vibrates in the direction along the inside.
In the gyro sensor element 100, PZT, which is a material having a large piezoelectric strain constant, is used for the first piezoelectric layers 142 and 152 constituting the driving units 147 and 157. Therefore, the electricity applied to the first piezoelectric layers 142 and 152 is used. Energy (AC voltage) can be efficiently converted into mechanical energy (shrinkage and expansion). Thereby, the gyro sensor element 100 can cause the vibrating arms 20 and 30 to bend and vibrate with a large amplitude.

Next, detection of the angular velocity ω of the gyro sensor element 100 will be described.
When an angular velocity ω is applied around the Y axis in a state where the vibrating arms 20 and 30 are vibrating in the in-plane direction, the vibrating arm 20 and the vibrating arm 30 vibrate in a direction along the out-of-plane direction. Then, electric charges are generated in the third electrode layer 45 of the detection unit 148 and the third electrode layer 55 of the detection unit 158 due to the piezoelectric effect. By detecting this charge amount, the angular velocity ω applied to the gyro sensor element 100 can be detected.
When the same PZT as the first piezoelectric layers 142 and 152 constituting the drive units 147 and 157 is used for the second piezoelectric layers 144 and 154 constituting the detection units 148 and 158 of the gyro sensor element 100, the PZT is another piezoelectric layer. It has a large dielectric constant compared to the material, and a large amount of charge (capacitance) is charged in the detection units 148 and 158, so that it is difficult to detect a slight change in charge. Therefore, in this embodiment, ZnO having a dielectric constant smaller than that of PZT is used as the piezoelectric material for the second piezoelectric layers 144 and 154. Thereby, since the electrostatic capacitances of the detection units 148 and 158 can be reduced, it is possible to accurately detect a minute change in electric charge that occurs when the angular velocity ω is applied.

As described above, according to the gyro sensor element 100 according to the present embodiment, the following effects can be obtained.
The gyro sensor element 100 of the present embodiment is a tuning fork type gyro having a pair of vibrating arms 20 and 30. Since the angular velocity ω can be obtained by the configuration in which each of the vibrating arms (the vibrating arm 20 and the vibrating arm 30) is provided with two stacked bodies (the first stacked body 40 and the second stacked body 50), the gyro sensor element of the gyro sensor element can be obtained. Miniaturization can be achieved.
In addition, PZT is used for the first piezoelectric layers 142 and 152 constituting the driving units 147 and 157, and ZnO is used for the second piezoelectric layers 144 and 154 constituting the detecting units 148 and 158. Since PZT has a piezoelectric strain constant larger than that of ZnO and ZnO has a dielectric constant smaller than that of PZT, it is possible to improve the driving efficiency of the gyro sensor element 100 and the detection sensitivity of the angular velocity ω. Accordingly, the width of the first stacked body 140, the width of the second stacked body 150, and the width of the vibrating arms 20 and 30 can be reduced without sacrificing driving efficiency and detection sensitivity. The element can be downsized. Therefore, a small gyro sensor element can be provided.

  In addition, this invention is not limited to embodiment mentioned above, A various change, improvement, etc. can be added to embodiment. A modification will be described below.

(Modification)
In the gyro sensor element according to the modification, the width in the X-axis direction of the first piezoelectric layer that constitutes the drive unit is different from the width in the X-axis direction of the second piezoelectric layer that constitutes the detection unit.
FIG. 5 is a schematic plan view showing a schematic configuration of a gyro sensor element 200 according to a modification. 6 is a cross-sectional view taken along line CC in FIG.
First, a schematic configuration of the gyro sensor element 200 according to the modification will be described with reference to FIGS. 5 and 6. In addition, about the same component as the gyro sensor element 1, the same code | symbol is attached | subjected and the overlapping description is abbreviate | omitted.

The main surface 11 of the vibrating arm 20 that is one surface of the vibrating arm is provided with a rectangular first laminated body 240 having a long side in the Y-axis direction on the + X-axis side, and in the Y-axis direction on the −X-axis side. A rectangular second laminated body 250 having a long side is provided.
The main surface 11 of the vibrating arm 30 that is one surface of the vibrating arm is provided with a rectangular second laminated body 250 having a long side in the Y-axis direction on the + X-axis side, and in the Y-axis direction on the −X-axis side. A rectangular first laminated body 240 having a long side is provided.
The first stacked body 240 and the second stacked body 250 are provided in a substantially line-symmetric shape with respect to the center line CL2 of the main surface 11 of the vibrating arm 20 and the center line CL3 of the main surface 11 of the vibrating arm 30. Yes.

The first laminated body 240 includes a first electrode layer 241, a first piezoelectric layer 242, a second electrode layer 243, a second piezoelectric layer 244, and a third electrode layer 245 from the main surface 11 of the vibrating arm 20 and the vibrating arm 30. A driving unit 247 configured by sequentially stacking the first electrode layer 241, the first piezoelectric layer 242, and the second electrode layer 243, and the second electrode layer 243, the second piezoelectric layer 244, and the third electrode layer 245. And a detecting unit 248.
The second stacked body 250 includes the first electrode layer 251, the first piezoelectric layer 252, the second electrode layer 253, the second piezoelectric layer 254, and the third electrode layer 255 from the main surface 11 of the vibrating arm 20 and the vibrating arm 30. A driving unit 257 that is sequentially stacked and includes a first electrode layer 251, a first piezoelectric layer 252, and a second electrode layer 253, and a second electrode layer 253, a second piezoelectric layer 254, and a third electrode layer 255. And a detecting unit 258.

As shown in FIG. 6, the width of the second piezoelectric layer 244 constituting the detection unit 248 of the first stacked body 240 in the X-axis direction (in-plane direction) is narrower than the width of the first piezoelectric layer 242 in the X-axis direction. The width of the second piezoelectric layer 254 constituting the detection unit 258 of the second stacked body 250 is narrower than the width of the first piezoelectric layer 252 in the X-axis direction.
The center between the centers of the widths in the X-axis direction of the second piezoelectric layer 244 of the first stacked body 240 and the centers of the widths of the second piezoelectric layer 254 of the second stacked body 250 in the X-axis direction. The distance W202 indicates the distance between the center of the width in the X-axis direction of the first piezoelectric layer 242 of the first stacked body 240 and the center of the width of the first piezoelectric layer 252 of the second stacked body 250 in the X-axis direction. Narrower than the center distance W204.
The width in the X-axis direction of the first electrode layer 241 and the second electrode layer 243 sandwiching the first piezoelectric layer 242 of the first laminate 240 is substantially the same as the width of the first piezoelectric layer 242 in the X-axis direction. In addition, the width of the third electrode layer 245 in the X-axis direction is substantially the same as the width of the second piezoelectric layer 244 in the X-axis direction.
The width in the X-axis direction between the first electrode layer 251 and the second electrode layer 253 sandwiching the first piezoelectric layer 252 of the second stacked body 250 is substantially the same as the width in the X-axis direction of the first piezoelectric layer 252. The width of the third electrode layer 255 in the X-axis direction is substantially the same as the width of the second piezoelectric layer 254 in the X-axis direction.

In other words, the width of the first piezoelectric layers 242 and 252 constituting the driving units 247 and 257 in the X-axis direction is as wide as possible with respect to the width of the vibrating arms 20 and 30 in the X-axis direction. The second piezoelectric layers 244 and 254 are wider than the width in the X-axis direction.
The width of the second piezoelectric layers 244 and 254 constituting the detection units 248 and 258 in the X-axis direction is narrower than the width of the first piezoelectric layers 242 and 252 in the X-axis direction, and the main surface 11 of the vibrating arm 20 is as small as possible. The center line CL2 of the vibrating arm 30 or the center line CL3 of the main surface 11 of the vibrating arm 30 is disposed.

As described above, according to the gyro sensor element 200 according to this modification, the following effects can be obtained in addition to the effects in the above-described embodiment.
In the gyro sensor element 200, the width of the first piezoelectric layers 242 and 252 in the X-axis direction is wider than the width of the second piezoelectric layers 244 and 254 in the X-axis direction, and the width of the vibrating arms 20 and 30 in the X-axis direction. On the other hand, it is as wide as possible. Thereby, the drive efficiency of the vibrating arms 20 and 30 can be improved.
The width of the second piezoelectric layers 244 and 254 in the X-axis direction is narrower than the width of the first piezoelectric layers 242 and 252 in the X-axis direction, and the center distance W202 between the second piezoelectric layers 244 and 254 is the first stacked body. 240 and the center distance W204 between the first piezoelectric layers 242 and 252 provided in the second stacked body 250. As a result, detection noise (charge generated by vibration in a direction along the surface) caused by stacking deviation during manufacturing can be reduced, and detection accuracy can be improved. Therefore, a small gyro sensor element with improved driving efficiency and detection accuracy can be provided.

<Electronic device>
Next, a gyro apparatus to which the gyro sensor element according to the embodiment of the present invention is applied will be described. FIG. 7 is a cross-sectional view schematically showing a gyro device 500 including the gyro sensor element 1 of the present embodiment.

The gyro device 500 includes a gyro sensor element 1, an IC chip 530, a package main body 510 formed in a rectangular box shape having a cavity 560 for accommodating the gyro sensor element 1 and the IC chip 530, and a lid. 520.
The package body 510 formed of ceramic or the like has a concave cavity 560, and an IC chip 530 is disposed on the bottom surface of the package body 510, and is formed on the package body 510 with a wire 550 such as gold (Au). Electrical connection is made with wiring (not shown). The IC chip 530 includes a drive circuit that drives the gyro sensor element 1 and a detection circuit that outputs an angular velocity applied to the gyro sensor element 1.

In the gyro sensor element 1, the base 10 of the gyro sensor element 1 is bonded and supported on a support base 512 formed in a recess of the package body 510 via a fixing member 540 such as an adhesive. The fixing member 540 is preferably made of an elastic material. As the fixing member 540 having elasticity, an adhesive based on silicone is known.
In addition, wiring (not shown) is formed on the surface of the support base 512, and the electrode of the gyro sensor element 1 and the wiring are electrically connected by a wire 550 such as Au. The opening of the package body 510 is sealed with a lid 520. Note that the inside of the cavity 560 of the package body 510 that houses the gyro sensor element 1 and the IC chip 530 is an inert gas atmosphere such as nitrogen or a reduced pressure atmosphere.

  As described above, according to the gyro device 500, a gyro device including the small gyro sensor element 1 can be provided.

<Electronic equipment>
Next, an electronic device including a gyro sensor element or a gyro device according to an embodiment of the present invention will be described with reference to FIGS. In this description, an example using the gyro sensor element 1 is shown.

  FIG. 8 is a perspective view schematically illustrating a configuration of a mobile (or notebook) personal computer 1100 as an example of an electronic apparatus including the gyro sensor element 1 according to an embodiment of the present invention. As shown in FIG. 8, the personal computer 1100 includes a main body portion 1104 having a keyboard 1102 and a display unit 1106 having a display portion 1000, and the display unit 1106 has a hinge structure portion with respect to the main body portion 1104. It is supported so that rotation is possible. Such a personal computer 1100 incorporates a gyro sensor element 1 having a function of detecting angular velocity.

  FIG. 9 is a perspective view schematically illustrating a configuration of a mobile phone 1200 (including PHS) as an example of an electronic apparatus including the gyro sensor element 1 according to an embodiment of the present invention. As shown in FIG. 9, the mobile phone 1200 includes a plurality of operation buttons 1202, an earpiece 1204, and a mouthpiece 1206, and a display unit 1000 is disposed between the operation buttons 1202 and the earpiece 1204. . Such a cellular phone 1200 incorporates a gyro sensor element 1 that functions as an angular velocity sensor or the like.

FIG. 10 is a perspective view illustrating a schematic configuration of a digital still camera 1300 as an example of an electronic apparatus including the gyro sensor element 1 according to an embodiment of the present invention. Note that FIG. 10 simply shows connection with an external device. Here, the conventional film camera sensitizes the silver halide photographic film with the light image of the subject, whereas the digital still camera 1300 photoelectrically converts the light image of the subject with an imaging device such as a CCD (Charge Coupled Device). To generate an imaging signal (image signal).
A display unit 1000 is provided on the back surface of a case (body) 1302 in the digital still camera 1300, and is configured to display based on an imaging signal from the CCD. The display unit 1000 displays a subject as an electronic image. Functions as a viewfinder. A light receiving unit 1304 including an optical lens (imaging optical system), a CCD, and the like is provided on the front side (the back side in the drawing) of the case 1302.

  When the photographer confirms the subject image displayed on the display unit 1000 and presses the shutter button 1306, the CCD image pickup signal at that time is transferred and stored in the memory 1308. In the digital still camera 1300, a video signal output terminal 1312 and a data communication input / output terminal 1314 are provided on the side surface of the case 1302. As shown in the figure, a television monitor 1430 and a personal computer 1440 are connected to the video signal output terminal 1312 and the data communication input / output terminal 1314 as necessary. Further, the imaging signal stored in the memory 1308 is output to the television monitor 1430 or the personal computer 1440 by a predetermined operation. Such a digital still camera 1300 incorporates a gyro sensor element 1 as an angular velocity sensor or the like.

  In addition to the personal computer 1100 (mobile personal computer) in FIG. 8, the mobile phone 1200 in FIG. 9, and the digital still camera 1300 in FIG. Inkjet ejection device (for example, inkjet printer), laptop personal computer, TV, video camera, video tape recorder, car navigation device, pager, electronic notebook (including communication function), electronic dictionary, calculator, electronic game device, Word processor, workstation, videophone, security TV monitor, electronic binoculars, POS terminal, medical equipment (eg electronic thermometer, blood pressure monitor, blood glucose meter, electrocardiogram measuring device, ultrasonic diagnostic device, electronic endoscope), fish finder Various measurements Vessels, instruments (e.g., gages for vehicles, aircraft, and ships), can be applied to electronic devices such as flight simulators.

<Moving object>
Next, a movable body including a gyro sensor element or a gyro device according to an embodiment of the present invention will be described with reference to FIG. In this description, an example using the gyro sensor element 1 is shown.
FIG. 11 is a perspective view schematically showing an automobile as an example of a moving body including the gyro sensor element 1 according to an embodiment of the present invention.

  The automobile 1500 is equipped with the gyro sensor element 1 according to the above embodiment. As shown in FIG. 11, an automobile 1500 as a moving body has an electronic control unit 1510 that incorporates a gyro sensor element 1 and controls a tire or the like mounted on the vehicle body. In addition, the gyro sensor element 1 includes a keyless entry, an immobilizer, a car navigation system, a car air conditioner, an anti-lock brake system (ABS), an air bag, a tire pressure monitoring system (TPMS: Tire Pressure Monitoring System), The present invention can be widely applied to electronic control units (ECUs) such as engine controls, battery monitors of hybrid vehicles and electric vehicles, and vehicle attitude control systems.

DESCRIPTION OF SYMBOLS 1 ... Gyro sensor element, 10 ... Base part, 11 ... Main surface, 12 ... Back surface, 20, 30 ... Vibrating arm, 40 ... 1st laminated body, 41 ... 1st electrode layer, 42 ... 1st piezoelectric layer, 43 ... 1st Two electrode layers, 44 ... second piezoelectric layer, 45 ... third electrode layer, 47 ... drive unit, 48 ... detection unit, 50 ... second laminated body, 51 ... first electrode layer, 52 ... first piezoelectric layer, 53 ... 2nd electrode layer, 54 ... 2nd piezoelectric layer, 55 ... 3rd electrode layer, 57 ... Drive part, 58 ... Detection part, 100 ... Gyro sensor element, 140 ... 1st laminated body, 142 ... 1st piezoelectric layer, 144: second piezoelectric layer, 147: driving unit, 148: detecting unit, 150: second laminated body, 152: first piezoelectric layer, 154: second piezoelectric layer, 157 ... driving unit, 158: detecting unit, 200 ... Gyro sensor element, 240 ... first laminated body, 241 ... first electrode layer, 242 ... first piezoelectric layer, 243 ... 2 electrode layers, 244... 2nd piezoelectric layer, 245... 3rd electrode layer, 247... Drive unit, 248... Detection unit, 250 ... 2nd laminated body, 251 ... 1st electrode layer, 252. ... 2nd electrode layer, 254 ... 2nd piezoelectric layer, 255 ... 3rd electrode layer, 257 ... drive part, 258 ... detection part, 500 ... gyro device, 1100 ... personal computer, 1200 ... mobile phone, 1300 ... digital still camera , 1440 ... personal computer, 1500 ... car.

Claims (9)

The base,
A vibrating arm extending from the base,
A first laminated body and a second laminated body are provided on one surface of the vibrating arm along the extending direction,
The first laminated body and the second laminated body include a first electrode layer, a second electrode layer, and a drive including a first piezoelectric layer provided between the first electrode layer and the second electrode layer. And a detection unit including the second electrode layer, the third electrode layer, and a second piezoelectric layer provided between the second electrode layer and the third electrode layer,
The piezoelectric strain constant of the first piezoelectric layer is larger than the piezoelectric strain constant of the second piezoelectric layer,
The gyro sensor element according to claim 1, wherein a dielectric constant of the second piezoelectric layer is smaller than a dielectric constant of the first piezoelectric layer.   The first laminated body and the second laminated body are arranged so that, from one surface of the vibrating arm, the first electrode layer, the first piezoelectric layer, the second electrode layer, the second piezoelectric layer, the third electrode layer, The gyro sensor element according to claim 1, wherein the gyro sensor elements are stacked in the order of. The base,
A vibrating arm extending from the base,
On one surface of the vibrating arm, a first stacked body and a second stacked body are provided in parallel with the extending direction,
The first laminated body and the second laminated body include a first electrode layer, a second electrode layer, and a drive including a first piezoelectric layer provided between the first electrode layer and the second electrode layer. And a detection unit including the second electrode layer, the third electrode layer, and a second piezoelectric layer provided between the second electrode layer and the third electrode layer,
At least the first piezoelectric layer is separated into the first stacked body and the second stacked body,
The gyro sensor element according to claim 1, wherein the vibrating arm bends and vibrates in a direction along an in-plane direction.   The displacement applied to the vibrating arm is obtained as a sum of charge amounts detected by the detection unit of the first stacked body and the detection unit of the second stacked body. The gyro sensor element described.   5. The gyro sensor element according to claim 3, further comprising two vibrating arms extending in parallel from the base portion. The first laminated body and the second laminated body are arranged so that the first electrode layer, the first piezoelectric layer, the second electrode layer, the second piezoelectric layer, and the third electrode layer from the one surface of the vibrating arm. Are provided in line symmetry with respect to the center line in the extending direction of the vibrating arm,
The in-plane width of the second piezoelectric layer is narrower than the in-plane width of the first piezoelectric layer,
The center-to-center distance between the center line of the second piezoelectric layer included in the first stacked body and the center line of the second piezoelectric layer included in the second stacked body is the first stacked body. 6. The center line of the first piezoelectric layer included in the first piezoelectric layer and the center line of the first piezoelectric layer included in the second stacked body are narrower than the center-to-center distance. The gyro sensor element according to any one of the above.   A gyro apparatus comprising the gyro sensor element according to claim 1.   An electronic apparatus comprising the gyro sensor element according to claim 1.   A moving body comprising the gyro sensor element according to claim 1.

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