JP2016015563A - Vibration element, electronic device, electronic apparatus and mobile body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibration element which reduces leakage output and has high detection sensitivity, and also to provide an electronic device, an electronic apparatus and a mobile body which have this vibration element.SOLUTION: A vibration gyro element 1 as a vibration element includes: a base part 10; a driving vibration arm 12 extending from the base part 10; and an adjustment vibration arm 14 which extends from the base part 10 and outputs an output signal of a reverse phase to the output signal of leakage vibration of the driving vibration arm 12. When a virtual straight line LL connecting a vibration node part P1 of the driving vibration arm 12 and a vibration node part P2 of the adjustment vibration arm 14 is provided, the virtual straight line LL is overlapped on the base part 10 in a plan view of the base part 10.

Description

  The present invention relates to a vibration element, an electronic device including the vibration element, an electronic apparatus, and a moving body.

  Conventionally, a vibration gyro sensor (hereinafter referred to as a vibration gyro) as an angular velocity sensor has been used in a technology for autonomously controlling the attitude of a ship, an aircraft, a rocket, and the like. It is used for detecting the vehicle position of the system, vibration control correction (so-called camera shake correction) of digital cameras, video cameras and mobile phones. With the downsizing and high performance of these electronic devices, the vibration gyro is also required to be downsized and high performance.

  A vibrating gyro element as a vibrating element used in a vibrating gyroscope includes a base, a pair of driving vibrating arms extending in parallel from one end of the base, and a driving vibration arm on the opposite side of the base. And a pair of vibrating arms for detection extending in parallel from the other end, and the material is widely used quartz that has a high Q value and is easy to obtain high detection sensitivity. ing. The base portion and each arm portion of the vibrating gyro element can be integrally formed by etching a crystal by a photolithography technique. Originally, the cross-sectional shape of the vibrating arm is designed to be rectangular, but due to the etching anisotropy of crystal and variations in processing processes, it does not become rectangular but parallelograms, rhombuses, or more complicated Presents an irregular shape. At this time, if the cross-sectional shape of the vibrating arm greatly deviates from the originally designed rectangular shape, the vibration direction of the vibrating arm deviates from the design value, so that an undesired vibration leakage called so-called leakage output occurs, and the vibration gyro element It becomes a factor which degrades detection sensitivity. As a method for suppressing such leakage output, in Patent Document 1, an adjustment vibrating arm is provided at the base, and in-plane vibrations of the adjustment vibrating arm and the driving vibration arm are combined to create an adjustment current, thereby leak output. It is disclosed that the leakage output is suppressed and the detection sensitivity is improved by offsetting the mechanical vibration leakage current.

Japanese Patent Laid-Open No. 11-304494

  However, the vibration gyro element of Patent Document 1 needs to narrow the frequency interval of the in-plane vibration between the adjustment vibration arm and the drive vibration arm in order to increase the adjustment current when the leakage output is further suppressed. is there. Therefore, if the adjustment current is increased by narrowing the frequency interval between the adjustment vibration arm and the drive vibration arm, the frequency interval between the in-plane vibration of the drive vibration arm and the out-of-plane vibration of the detection vibration arm becomes too close. There was a problem that the detection sensitivity to the angular velocity was deteriorated.

  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 vibration element according to this application example includes a base, a first vibrating arm extending from the base, and an output signal of leakage vibration of the first vibrating arm that extends from the base. A second resonating arm that outputs a phase output signal, and a virtual straight line connecting the resonating node of the first resonating arm and the resonating node of the second resonating arm is provided. The imaginary straight line overlaps the base.

  According to this application example, the vibration node portion of the in-plane vibration of the first vibrating arm and the vibration node portion of the in-plane vibration of the second vibrating arm are arranged close to each other. Since the coupling of the in-plane vibration with the second vibrating arm becomes strong and the adjustment current increases, the frequency interval of the in-plane vibration between the first vibrating arm and the second vibrating arm can be widened. Therefore, if the in-plane vibration of the first vibrating arm is for driving, the out-of-plane vibration is for detection, and the in-plane vibration of the second vibrating arm is for adjustment, the driving in-plane vibration and the detecting out-of-plane vibration Since the adjustment current can be increased while maintaining the frequency interval at the optimum value that maximizes the detection sensitivity, it is possible to obtain a vibration element that suppresses leakage output and has high detection sensitivity with respect to angular velocity.

  Application Example 2 The vibration element according to the application example described above includes a third vibrating arm extending from the base in a direction opposite to the extending direction of the first vibrating arm from the base. And

  According to this application example, when the third vibrating arm is provided, when the in-plane vibration of the first vibrating arm is used for driving, the out-of-plane vibration of the third vibrating arm is used for detection. When the out-of-plane vibration of one vibrating arm is used for detection, the in-plane vibration of the third vibrating arm can be used for driving, so that the driving and detecting vibrating arms can be separated, and electrode formation is performed. And the influence of the mutual noise components can be reduced, so that a vibration element having high detection characteristics (detection accuracy) can be obtained.

  Application Example 3 In the resonator element according to the application example, the second vibrating arm extends along an extending direction of the third vibrating arm, and the first vibrating arm is a driving vibrating arm. When an axis is provided along the main surface of the base, the third vibrating arm vibrates according to the Coriolis force due to the angular velocity around the axis.

According to this application example, when an angular velocity about an axis along the main surface of the base is applied in a state where the first vibrating arm is a driving vibrating arm and in-plane vibration is performed, the first vibrating arm is According to the Coriolis force caused by, out-of-plane vibrations that displace in the direction intersecting the main surface of the base. The out-of-plane vibration of the first vibrating arm is propagated to the third vibrating arm via the base, so that the third vibrating arm also performs out-of-plane vibration. As a result, the third vibrating arm can detect the angular velocity by detecting charges generated due to the out-of-plane vibration for detection.
In addition, since the first vibrating arm for driving and the second vibrating arm for adjustment are arranged close to each other, the coupling of in-plane vibrations for driving and adjustment is strengthened, and the adjustment current is increased. Therefore, it is possible to obtain a vibration element that suppresses leakage output and has high detection sensitivity with respect to angular velocity.

  Application Example 4 In the resonator element according to the application example, the second vibrating arm extends along an extending direction of the third vibrating arm, and the third vibrating arm is a driving vibrating arm. When an axis is provided along the main surface of the base, the first vibrating arm vibrates according to the Coriolis force due to the angular velocity around the axis.

According to this application example, when the third vibrating arm is a driving vibrating arm and in-plane vibration is applied, when an angular velocity about an axis along the main surface of the base is applied, the third vibrating arm is According to the Coriolis force caused by, out-of-plane vibrations that displace in the direction intersecting the main surface of the base. The out-of-plane vibration of the third vibrating arm is propagated to the first vibrating arm via the base, so that the first vibrating arm also vibrates out of plane. As a result, the first vibrating arm can detect the angular velocity by detecting charges generated due to the out-of-plane vibration for detection.
In addition, since the third vibrating arm for driving and the second vibrating arm for adjustment are arranged closer to each other, the coupling of in-plane vibration for driving and for adjusting becomes stronger, and the adjustment current is further increased. Since it can be enlarged, it is possible to obtain a vibrating element that further suppresses leakage output and has high detection sensitivity with respect to angular velocity.

  Application Example 5 In the resonator element according to the application example described above, the first side of the base portion to which the first vibrating arm is connected and the third side of the base portion to which the third vibrating arm is connected. When the distance between the first side and the second side of the base to which the second vibrating arm is connected is L2, L1> L2. And

  According to this application example, the distance L2 between the first side of the base to which the first vibrating arm for driving is connected and the second side of the base to which the second vibrating arm for adjustment is connected is The distance is shorter than the distance L1 between the first side and the third side of the base to which the third vibrating arm for detection is connected. Therefore, the first vibrating arm for driving and the second vibrating arm for adjustment can be arranged close to each other, and the coupling of in-plane vibration between the driving vibrating arm and the adjusting vibrating arm is strengthened, and the adjustment current is increased. Therefore, it is possible to obtain a vibration element that suppresses leakage output and has high detection sensitivity with respect to angular velocity.

  Application Example 6 An electronic device according to this application example includes the vibration element according to any of the application examples, a circuit element electrically connected to the vibration element, the vibration element, and the circuit element. And a package for housing the container.

  According to this application example, an electronic device having this configuration includes the vibration element described in any of the above application examples, and therefore provides an electronic device that exhibits the effect described in any of the above application examples. Can do.

  Application Example 7 An electronic apparatus according to this application example includes the vibration element according to any one of the application examples.

  According to this application example, since the electronic device having this configuration includes the vibration element according to any one of the application examples, an electronic device having the effect according to any of the application examples is provided. Can do.

  Application Example 8 A moving body according to this application example includes the vibration element according to any one of the application examples.

  According to this application example, the moving body of this configuration includes the vibration element described in any of the above application examples, and therefore provides a moving body that exhibits the effect described in any of the above application examples. Can do.

1 is a schematic plan view showing a schematic configuration of a vibrating gyro element according to a first embodiment of the present invention. The schematic plan view explaining the leak output adjustment method of the vibration gyro element which concerns on 1st Embodiment of this invention. FIG. 3 is a schematic plan view showing a driving vibration state of the vibration gyro element according to the first embodiment of the present invention. FIG. 3 is a schematic plan view showing a detected vibration state when an angular velocity ω about the Y axis is applied to the vibration gyro element according to the first embodiment of the present invention. The schematic plan view which shows schematic structure of the vibration gyro element which concerns on 2nd Embodiment of this invention. The schematic plan view which shows schematic structure of the vibration gyro element which concerns on 3rd Embodiment of this invention. 1 is a schematic plan view illustrating a schematic configuration of an electronic device including a vibrating gyro element according to the present invention. The schematic cross section in the AA in FIG. 1 is a schematic perspective view illustrating a configuration of a mobile (or notebook) personal computer as an electronic apparatus including a vibrating gyro element according to the present invention. The model perspective view which shows the structure of the mobile telephone (PHS is also included) as an electronic device provided with the vibration gyro element which concerns on this invention. The perspective view which shows the structure of the digital camera as an electronic device provided with the vibration gyro element which concerns on this invention. The perspective view which shows the structure of the motor vehicle as a moving body provided with the vibration gyro element which concerns on this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each figure shown below, the size and ratio of each component may be described differently from the actual component in order to make each component large enough to be recognized on the drawing. is there.

[Vibration element]
<First Embodiment>
As an example of the vibration element according to the first embodiment of the present invention, a vibration gyro element that detects an angular velocity ω around the Y axis is given, and a schematic configuration thereof will be described with reference to FIG.
FIG. 1 is a schematic plan view showing a schematic configuration of the vibrating gyro element according to the first embodiment of the present invention. For convenience, electrode patterns and wiring patterns are not shown in the following drawings. Further, for convenience of explanation, the X axis, the Y axis, and the Z axis are illustrated as three axes orthogonal to each other, and the distal end side of the illustrated arrow is the “+ side” and the proximal end side is the “− side”. Yes. 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”. Furthermore, for convenience of explanation, an XY plane that is a plane in the Z-axis direction in the plan view when viewed from the Z-axis direction will be described as the main surface F1.

  As shown in FIG. 1, a vibration gyro element 1 as a vibration element includes a base 10 formed integrally by processing a base material (material constituting a main part), and a first extending from the base 10. A pair of driving vibrating arms 12 as a vibrating arm, a pair of adjusting vibrating arms 14 as a second vibrating arm extending from the base 10, and a pair of third vibrating arms extending from the base 10 And a vibrating arm 16 for detection.

In the vibrating gyro element 1 of the present embodiment, an example in which quartz that is a piezoelectric material is used as a base material will be described. The crystal has an X axis called an electric axis, a Y axis called a mechanical axis, and a Z axis called an optical axis. In the present embodiment, a so-called quartz crystal Z that is cut out along a plane defined by the X-axis and the Y-axis orthogonal to the quartz crystal axis, is processed into a flat plate shape, and has a predetermined thickness in the Z-axis direction orthogonal to the plane. The example which used the board as a base material is demonstrated. Here, the predetermined thickness is appropriately set depending on the oscillation frequency (resonance frequency), the outer size, the workability, and the like.
Further, the flat plate forming the vibrating gyro element 1 can tolerate errors in the angle of cut-out from the quartz crystal in a certain range for each of the X axis, the Y axis, and the Z axis. For example, it is possible to use what is cut out by rotating in the range of 0 to 7 degrees around the X axis. The same applies to the Y axis and the Z axis.

  The vibration gyro element 1 is connected to the convex base 10 located in the center portion and the first side 20 of the base 10 in a plan view, and a pair of driving gyro elements 1 extending in parallel along the Y axis. Connected to the vibrating arm 12 and the second side 22 of the base 10, connected to the pair of vibrating arms 14 for adjustment extending in parallel along the Y axis, and the third side 24 of the base 10, And a pair of detection vibrating arms 16 extending in parallel along the direction opposite to the extending direction of the driving vibrating arm 12 (+ Y-axis direction in the drawing).

  The vibrating gyro element 1 extends the adjusting vibrating arm 14 along the extending direction (+ Y axis direction) of the detecting vibrating arm 16, and the angular velocity ω around the Y axis in the Y axis direction along the main surface F1 of the base portion 10. The detection vibrating arm 16 vibrates in accordance with the Coriolis force generated by. Therefore, the vibrating gyro element 1 of the present embodiment can detect the angular velocity ω around the Y axis.

  An adjustment vibration that outputs an output signal having an opposite phase to the vibration node P1 of the driving vibration arm 12 (position where vibration displacement is minimized) and the output signal of the leakage vibration in the in-plane vibration of the driving vibration arm 12 A virtual straightness LL connecting the vibration node P <b> 2 of the arm 14 overlaps the base 10 in a plan view of the main surface F <b> 1 of the base 10. By bringing the vibration node P1 of the drive vibration arm 12 and the vibration node P2 of the adjustment vibration arm 14 close to each other, the coupling of in-plane vibrations between the drive vibration arm 12 and the adjustment vibration arm 14 is strengthened. Therefore, the adjustment current for reducing the leakage output accompanying the leakage vibration of the driving vibrating arm 12 can be increased. Therefore, the frequency interval of the in-plane vibration between the driving vibrating arm 12 and the adjusting vibrating arm 14 can be widened.

  In the convex base 10, a distance L2 between the first side 20 of the base 10 to which the driving vibration arm 12 is connected and the second side 22 of the base 10 to which the adjustment vibration arm 14 is connected is It is shorter than the distance L1 between the first side 20 and the third side 24 of the base to which the detection vibrating arm 16 is connected. With such a configuration, the driving vibrating arm 12 and the adjusting vibrating arm 14 can be brought closer to each other, and the in-plane vibration coupling between the driving vibrating arm 12 and the adjusting vibrating arm 14 is strengthened. be able to.

  Thus, the vibration gyro element 1 has the shape in which the pair of drive vibration arms 12 and the pair of detection vibration arms 16 extend in the same direction from both ends of the base 10 in the Y-axis direction. , Sometimes referred to as an H-type vibration element (H-type vibration gyro element). In the H-type vibrating gyro element 1, the driving vibrating arm 12 and the detecting vibrating arm 16 extend from both ends of the base 10 in the same axial direction, so that the driving system and the detection system are separated. Therefore, electrostatic coupling between the electrodes of the drive system and the detection system or between the wirings is reduced, and the detection sensitivity is stabilized. In the present embodiment, two drive vibration arms 12 and two detection vibration arms 16 are provided for each of the H-type vibration elements as an example. However, even if the number of vibration arms is one, the number is three or more. May be. Further, the drive electrode and the detection electrode may be formed on one vibrating arm.

  The adjustment vibrating arm 14 is formed to have a smaller overall length than the driving vibrating arm 12 and the detection vibrating arm 16. Accordingly, the vibration of the adjustment vibrating arm 14 for adjusting the leakage output does not hinder the main vibration of the vibration gyro element 1 by the driving vibration arm 12 and the detection vibration arm 16. 1 is stable, and the vibration gyro element 1 is advantageously reduced in size.

  Such an outer shape of the vibrating gyro element 1 can be formed by etching (wet etching or dry etching) using a photolithography technique. Note that a plurality of vibrating gyro elements 1 can be obtained from one quartz wafer.

The drive vibration arm 12, the adjustment vibration arm 14, and the detection vibration arm 16 (hereinafter, also referred to as arm portions 12, 14, 16) of the vibration gyro element 1 are formed in a substantially prismatic shape. In addition, the weight part may be provided in the front-end | tip.
Specifically, the weight portion is wider than the arm width of each arm portion 12, 14, 16 (the length in the X-axis direction orthogonal to the extending direction of each arm portion 12, 14, 16 when viewed from the Z-axis direction). It is shaped like a hammer. Note that the size (thickness) of the weight portion in the Z-axis direction is the same as that of each of the arm portions 12, 14, and 16. Thereby, the frequency of the bending vibration of each arm part 12, 14, 16 can be lowered and the length in the extending direction of each arm part 12, 14, 16 can be shortened, so that the vibration gyro element 1 can be miniaturized.

In addition, each of the arms 12, 14, and 16 is provided with a groove extending along the Y-axis direction that is the extending direction of each of the arms 12, 14, and 16 on at least one or both of the upper surface and the lower surface of the main surface F1. It may be done.
More specifically, the groove is formed so that the cross-sectional shape of each of the arms 12, 14, and 16 is H-shaped. In addition, it is preferable that the groove part is provided from the base of each arm part 12,14,16 to the root of a weight part. As a result, the thermoelastic loss due to the diffusion (heat conduction) of heat generated by the bending vibration of each of the arms 12, 14, 16 can be reduced, so that the Q value of the vibrating gyro element 1 can be increased and high. The vibrating gyro element 1 having detection sensitivity can be obtained.

(Leakage output adjustment of vibration gyro element)
Here, a method for adjusting the leakage output of the vibration gyro element 1 will be described.
FIG. 2 is a schematic plan view for explaining a leakage output adjusting method of the vibrating gyro element.

  As shown in FIG. 2, the vibration gyro element 1 is configured such that the drive vibration arm 12 is driven by an external drive signal (alternating voltage) being input to a drive electrode (not shown) of the drive vibration arm 12. By the inverse piezoelectric effect, bending vibration (in-plane bending vibration) is alternately performed at a predetermined frequency in the black arrow direction and the white arrow direction along the main surface F1. When a driving signal (alternating voltage) having a phase opposite to that of the driving signal (alternating voltage) to the driving vibrating arm 12 is input to a driving electrode (not shown) of the adjusting vibrating arm 14, the adjusting vibrating arm 14. However, due to the inverse piezoelectric effect, bending vibration (in-plane bending vibration) that vibrates in the opposite phase to the driving vibrating arm 12 at a predetermined frequency in the black arrow direction and the white arrow direction along the main surface F1.

  Here, the cross-sectional shape of each of the arms 12, 14, and 16 changes in the finished shape due to processing variations. For example, even when a vibrating arm having a rectangular cross-section is designed, the cross-sectional shape becomes a parallelogram shape, a trapezoidal shape, or a rhombus shape due to the etching anisotropy of quartz as a base material. Therefore, a vibration leak called a leak output occurs in the pair of vibrating arms, which is a factor that deteriorates the detection sensitivity of the vibration gyro element 1.

  Therefore, a part of a film body (not shown) provided on the adjustment vibrating arm 14 is removed or added, and the substrate of the adjustment vibrating arm 14 is shaved, so that the mass of the adjustment vibrating arm 14 is reduced. Is decreased or increased, the resonance frequency is changed, and the relationship between the resonance frequency f1 of the drive vibrating arm 12 and the resonance frequency f2 of the adjustment vibrating arm 14 is adjusted to an appropriate relationship. Specifically, the film body of the vibrating arm 14 for adjustment is trimmed by, for example, irradiating a laser, or a film body of the same or different kind as the film body is added by vapor deposition or sputtering to reduce the mass or By increasing the resonance frequency, the resonance frequency is changed and the phases of f1 and f2 are adjusted.

  After the phase adjustment, the leakage output suppression adjustment is performed. Specifically, a part of an adjustment electrode (not shown) provided on the adjustment vibrating arm 14 is removed by, for example, laser irradiation, or an electrode metal is added by vapor deposition or sputtering. By reducing or increasing the amount of adjustment current (charge), the influence of leakage output is minimized.

  In the present embodiment, as shown in FIG. 1, the vibration node P <b> 1 of the drive vibration arm 12 and the vibration node P <b> 2 of the adjustment vibration arm 14 are close to each other. The distance L2 between the first side 20 of the base 10 to which the driving vibration arm 12 is connected and the second side 22 of the base 10 to which the adjustment vibrating arm 14 is connected is the first side 20. And the distance L1 from the third side 24 of the base to which the detection vibrating arm 16 is connected. Therefore, the driving vibrating arm 12 and the adjusting vibrating arm 14 can be brought closer to each other, and the coupling of in-plane vibrations between the driving vibrating arm 12 and the adjusting vibrating arm 14 can be strengthened. Therefore, the adjustment current for reducing the leakage output accompanying the leakage vibration of the driving vibration arm 12 can be increased, and the frequency interval of the in-plane vibration between the driving vibration arm 12 and the adjustment vibration arm 14 is widened. be able to. Therefore, the adjustment current can be increased while the frequency interval between the in-plane vibration of the drive vibrating arm 12 and the out-of-plane vibration of the detection vibrating arm 16 is maintained at the optimum value at which the detection sensitivity is maximized. It is possible to obtain the vibrating gyro element 1 that suppresses the leakage output and has high detection sensitivity with respect to the angular velocity ω.

(Operation for angular velocity ω of vibrating gyro element)
Next, the operation of the vibrating gyro element 1 with respect to the angular velocity ω around the Y axis will be described.
3 and 4 are schematic plan views for explaining the operation of the vibrating gyro element with respect to the angular velocity ω. FIG. 3 is a schematic plan view showing a driving vibration state of the vibrating gyro element. FIG. 4 is a schematic plan view showing a detection vibration state in which an angular velocity ω around the Y axis of the vibration gyro element is detected. In FIG. 4, a black dot symbol surrounded by a circle indicates a displacement in the + Z-axis direction, and a cross symbol surrounded by a circle indicates a displacement in the −Z-axis direction.

  As shown in FIG. 3, the vibration gyro element 1 has an external drive signal (alternating voltage) input to a drive electrode (not shown) of the drive vibration arm 12 as shown in FIG. The driving vibrating arm 12 bends and vibrates at a predetermined frequency (in-plane bending vibration) alternately in the black arrow direction and the white arrow direction along the main surface F1 due to the inverse piezoelectric effect.

  When an angular velocity ω about the Y-axis is applied in the driving vibration state as shown in FIG. 3, as shown in FIG. 4, the Coriolis force acts on the driving vibration arm 12, and the pair of driving vibration arms 12 are In the direction crossing the main surface F1 (Z-axis direction), bending vibrations are performed in opposite directions (bending vibrations in opposite phases). More specifically, each of the pair of drive vibrating arms 12 alternately bends and vibrates in the −Z axis direction and the + Z axis direction.

  In conjunction with this, the vibrating arm 16 for detection bends and vibrates in the direction (Z-axis direction) intersecting the main surface F1. More specifically, when one detection vibrating arm 16 of the pair of detection vibrating arms 16 vibrates in the −Z-axis direction, the other detection vibrating arm 16 vibrates in the + Z-axis direction, and one of the detection vibrating arms 16 is detected. When the vibrating arm 16 vibrates in the + Z-axis direction, the other detecting vibrating arm 16 vibrates in the −Z-axis direction.

  In other words, when one drive vibrating arm 12 vibrates in the −Z axis direction, one detection vibrating arm 16 vibrates in the + Z axis direction. When the other drive vibrating arm 12 vibrates in the + Z-axis direction, the other detection vibrating arm 16 vibrates in the −Z-axis direction. Conversely, when one drive vibrating arm 12 vibrates in the + Z-axis direction, one detection vibrating arm 16 vibrates in the −Z-axis direction. When the other drive vibrating arm 12 vibrates in the −Z-axis direction, the other detection vibrating arm 16 vibrates in the + Z-axis direction.

  In the vibrating gyro element 1, the pair of detection vibrating arms 16 bend and vibrate in opposite phases, so that the detection electrodes provided on the detection vibrating arms 16 are accompanied by the piezoelectric effect caused by the vibration of the detection vibrating arms 16. By detecting the charge generated in (not shown), the angular velocity ω around the Y axis can be derived.

  As described above, the vibrating gyro element 1 of the first embodiment includes the base 10, the driving vibrating arm 12 as the first vibrating arm extending from the base 10, and the driving vibrating arm 12 extending from the base 10. A vibration arm for adjustment 14 as a second vibration arm that outputs an output signal having a phase opposite to that of the output signal of the leakage vibration of the vibration, and the vibration node P1 of the drive vibration arm 12 and the vibration arm 14 for adjustment When the virtual straight line LL that connects the vibration node P <b> 2 is provided, the virtual straight line LL overlaps the base 10 in a plan view of the base 10.

  As a result, the vibration node P1 of the in-plane vibration of the driving vibration arm 12 and the vibration node P2 of the in-plane vibration of the adjustment vibration arm 14 are arranged close to each other. Since the coupling of in-plane vibrations with the adjusting vibration arm 14 becomes stronger and the adjustment current increases, the frequency interval of the in-plane vibration between the driving vibrating arm 12 and the adjusting vibrating arm 14 can be widened. Therefore, the adjustment current can be increased while the frequency interval between the in-plane vibration of the driving vibrating arm 12 and the out-of-plane vibration of the detecting vibrating arm 16 is maintained at an optimum value that maximizes the detection sensitivity. It is possible to obtain the vibration gyro element 1 that suppresses the leak output and has high detection sensitivity for the angular velocity ω.

  In addition, a detection vibrating arm 16 extending from the base 10 is provided in a direction opposite to the extending direction of the driving vibrating arm 12 from the base 10.

  As a result, by including the detection vibrating arm 16, the out-of-plane vibration displaced in the direction intersecting the main surface F <b> 1 according to the Coriolis force due to the angular velocity ω around the Y axis of the driving vibrating arm 12 causes the base 10 to move. Therefore, the detection vibration arm 16 can detect charges that propagate to the detection vibration arm 16 and generate due to the out-of-plane vibration, and can detect the angular velocity ω around the Y axis.

  The adjusting vibrating arm 14 extends along the extending direction of the detecting vibrating arm 16, and the driving vibrating arm 12 is used for driving and extends in the Y-axis direction along the main surface F <b> 1 of the base 10. The detection vibrating arm 16 vibrates according to the Coriolis force caused by the angular velocity ω around the Y axis.

  As a result, when the angular velocity ω about the Y axis is applied in a state where the driving vibrating arm 12 is in-plane vibration, the driving vibrating arm 12 causes the main surface F1 of the base portion 10 according to the Coriolis force due to the angular velocity ω. Vibrating out of plane in a direction that intersects The out-of-plane vibration of the drive vibration arm 12 is propagated to the detection vibration arm 16 via the base 10, so that the detection vibration arm 16 also performs out-of-plane vibration. For this reason, the angular velocity ω about the Y axis can be detected by detecting the charge generated due to the out-of-plane vibration of the detection vibrating arm 16.

  Further, the distance between the first side 20 of the base 10 to which the driving vibration arm 12 is connected and the third side 24 of the base 10 to which the detection vibrating arm 16 is connected is L1, and the first When the distance between the side 20 and the second side 22 of the base 10 to which the adjustment vibrating arm 14 is connected is L2, L1> L2.

  As a result, when L2 is shorter than L1, the driving vibrating arm 12 and the adjusting vibrating arm 14 can be disposed close to each other, so that the in-plane of the driving vibrating arm 12 and the adjusting vibrating arm 14 is in-plane. Since the coupling of vibration can be strengthened and the adjustment current can be increased, it is possible to obtain the vibration gyro element 1 that suppresses the leak output and has high detection sensitivity with respect to the angular velocity ω.

  As described above, the vibrating gyro element 1 of the present embodiment has a configuration in which the first vibrating arm is the driving vibrating arm 12, the second vibrating arm is the adjusting vibrating arm 14, and the third vibrating arm is the detecting vibrating arm 16. However, the detection vibrating arm 16 that is the third vibrating arm is used for driving and the driving vibrating arm 12 that is the first vibrating arm is used for detection. Alternatively, the detection may be performed by the driving vibrating arm 12 that is the first vibrating arm that vibrates according to the Coriolis force due to the angular velocity ω.

  With this configuration, the detection vibrating arm 16 that is the third driving vibration arm and the adjustment vibrating arm 14 that is the second adjustment vibrating arm can be arranged closer to each other. In addition, since the coupling of in-plane vibrations for driving and adjustment becomes stronger and the adjustment current can be increased, the vibration gyro element 1 having a high detection sensitivity for the angular velocity ω can be obtained because the leakage output is further suppressed. Can do.

In the above embodiment, an example in which quartz is used as a material for forming the vibrating gyro element 1 as a vibrating element has been described. However, a piezoelectric material other than quartz can be used. For example, aluminum nitride (AlN), lithium niobate (LiNbO ₃ ), lithium tantalate (LiTaO ₃ ), lead zirconate titanate (PZT), lithium tetraborate (Li ₂ B ₄ O ₇ ), langasite (La ₃ Ga ₅ SiO ₁₄ ), etc., laminated piezoelectric substrates constructed by laminating piezoelectric materials such as aluminum nitride and tantalum pentoxide (Ta ₂ O ₅ ) on glass substrates, or piezoelectric ceramics Can be used.
In addition, the resonator element can be formed using a material other than the piezoelectric material. For example, the vibration element can be formed using a silicon semiconductor material such as polysilicon (polycrystalline silicon) or amorphous silicon (amorphous silicon).
Further, the vibration (drive) method of the vibration gyro element 1 as the vibration element is not limited to piezoelectric drive. In addition to the piezoelectric drive type using a piezoelectric substrate, the vibration gyro element 1 such as an electrostatic drive type using electrostatic force or a Lorentz drive type using magnetic force also exhibits the configuration and effects of the present invention. be able to.

Second Embodiment
Next, a vibrating gyro element 1a according to a second embodiment of the present invention will be described with reference to FIG.
FIG. 5 is a schematic plan view showing a schematic configuration of the vibrating gyro element according to the second embodiment of the present invention.

The vibrating gyro element 1a according to the second embodiment is different from the vibrating gyro element 1 described in the first embodiment in that the base portion 10 and the adjusting vibrating arm 14a are connected by a support portion 18.
Since other configurations are substantially the same as those of the vibration gyro element 1 described in the first embodiment, the same reference numerals and reference numerals are given to the same configurations, and a part of the description is omitted and the vibration gyro element 1a is omitted. explain.

In the vibrating gyro element 1a of the present embodiment, the adjustment vibrating arm 14a is respectively along the X axis from both ends in the direction (X axis direction) orthogonal to the driving vibrating arm 12 and the detecting vibrating arm 16 of the base portion 10. A pair of extending support portions 18 are provided in parallel with the detection vibrating arm 16 from the distal end portions thereof. In other words, the adjustment vibrating arm 14 a extends from the tip of the support portion 18 along the Y axis (in the + Y axis direction).
A virtual straightness LLa connecting the vibration node P1a of the drive vibration arm 12 and the vibration node P2a of the adjustment vibration arm 14a overlaps the base 10 in a plan view of the main surface F1 of the base 10.

  By adopting such a configuration, the same effects as those of the first embodiment can be obtained. Further, since the length of the adjustment vibrating arm 14a in the extending direction can be increased, the frequency can be further reduced, and the resonance frequency f1 of the driving vibration arm 12 and the resonance frequency of the adjustment vibration arm 14a. The frequency interval with f2 can be set to an optimum frequency interval that provides high detection sensitivity.

<Third Embodiment>
Next, a vibrating gyro element 1b according to a third embodiment of the present invention will be described with reference to FIG.
FIG. 6 is a schematic plan view showing a schematic configuration of the vibrating gyro element according to the third embodiment of the present invention.

The vibrating gyro element 1b according to the third embodiment is different from the vibrating gyro element 1 described in the first embodiment in that the third vibrating arm 16b serves both for driving and for detecting.
Since other configurations are substantially the same as those of the vibration gyro element 1 described in the first embodiment, the same reference numerals and numerals are assigned to the same configurations, and a part of the description is omitted, and the vibration gyro element 1b is omitted. explain.

The vibrating gyro element 1b of the present embodiment is connected to the third side 24 of the base 10 and has a driving electrode (not shown) and a detection electrode (not shown) on the third vibrating arm 16b extending in the + Y-axis direction. ) For driving and detecting.
A virtual straightness LLb connecting the vibration node P1b of the third vibration arm 16b for driving and detection and the vibration node P2b of the adjustment vibration arm 14 is a plan view of the main surface F1 of the base 10, It overlaps with the base 10.
By adopting such a configuration, the same effects as those of the first embodiment can be obtained. Further, since the base portion 10, the pair of third vibrating arms 16b, and the pair of adjusting vibrating arms 14 are configured, the size of the vibrating gyro element 1b in the Y-axis direction can be significantly reduced.

[Electronic device]
Next, the electronic device 2 including the vibrating gyro element 1 (1a, 1b) according to an embodiment of the present invention will be described.
FIG. 7 is a schematic plan view showing a schematic structure of an electronic device including the vibrating gyro element according to the embodiment of the present invention. FIG. 8 is a schematic cross-sectional view taken along line AA in FIG. In FIG. 7, for convenience of explanation of the internal configuration of the vibration gyro element 1, a state in which the lid member 170 is removed is illustrated. For convenience of explanation, an X axis, a Y axis, and a Z axis are illustrated as three axes orthogonal to each other. Further, for convenience of explanation, in the plan view when viewed from the Z-axis direction, the surface in the + Z-axis direction is described as the upper surface, and the surface in the −Z-axis direction is described as the lower surface.

  7 and 8, the electronic device 2 includes a vibration gyro element 1, a circuit element 200 for driving the vibration gyro element 1 and processing a detection signal, the vibration gyro element 1, the circuit element 200, and the like. The package main body 100 in which the recessed part for accommodating this is formed, and the cover member 170 which consists of glass, a ceramic, a metal, etc. are comprised. Note that the inside of the cavity 190 that houses the vibrating gyro element 1 is hermetically sealed in a substantially vacuum reduced pressure atmosphere.

  As shown in FIG. 8, the package body 100 is formed by stacking a first substrate 110, a second substrate 120, a third substrate 130, an external terminal 140, and a sealing member 160. A plurality of external terminals 140 are formed on the lower surface of the first substrate 110. A plurality of internal terminals 150 that are electrically connected to the external terminals 140 are formed on the upper surface of the first substrate 110 through through electrodes (not shown) and wiring patterns (not shown). The second substrate 120 and the third substrate 130 are annular bodies from which the central portion is removed, and constitute a cavity 190 that accommodates the vibrating gyro element 1 and the circuit element 200. A sealing member 160 such as low melting point glass is formed on the upper peripheral edge of the third substrate 130.

  In the cavity 190 of the package body 100, the circuit element 200 that drives the vibrating gyro element 1 and outputs a detection signal generated by the angular velocity ω is placed via the bonding member 230. The connection terminals 220 formed on the first substrate 110 and the internal terminals 150 of the first substrate 110 are electrically connected by bonding wires 240.

  In the vibrating gyro element 1 accommodated in the cavity 190 of the package body 100, the connection terminal 210 formed on the base 10 and the connection terminal 30 formed on the circuit element 200 are aligned to form a metal bump or the like. It is joined on the circuit element 200 via the joining member 180. Therefore, the vibration arm 12 for driving, the vibration arm 14 for adjustment, and the vibration arm 16 for detection of the vibration gyro element 1 can be vibrated without coming into contact with the circuit element 200. Therefore, the vibration gyro element having a high Q value. The electronic device 2 having 1 can be provided.

  As described above, the first substrate 110, the second substrate 120, and the third substrate 130 of the package main body 100 described above are made of an insulating material. Such a material is not particularly limited, and various ceramics such as oxide ceramics, nitride ceramics, and carbide ceramics can be used. In addition, each electrode and terminal provided in the package body 100, or a wiring pattern or an in-layer wiring pattern for electrically connecting them is generally a metal wiring such as tungsten (W) or molybdenum (Mo). The material is provided by screen printing on an insulating material and baking, and then plating such as nickel (Ni) or gold (Au).

  The lid member 170 is preferably made of a light transmitting material, such as borosilicate glass, and is hermetically sealed in the cavity 190 of the package body 100 by being joined by the sealing member 160. ing. Thereby, after sealing the lid of the package body 100, laser light is transmitted from the outside through the lid member 170, and the driving vibration arm 12, the adjustment vibration arm 14, and the detection vibration arm 16 tip of the vibration gyro element 1. The frequency can be adjusted by a mass reduction method by irradiating a metal coating (not shown) provided on the portion or the weight and partially evaporating the metal coating. When the frequency is not adjusted after being mounted on such a package body 100, the lid member 170 can be formed of a metal material such as a Kovar alloy.

[Electronics]
Next, an electronic device including the vibrating gyro element 1 (1a, 1b) according to an embodiment of the present invention will be described in detail with reference to FIGS.

FIG. 9 is a perspective view illustrating a schematic configuration of a mobile type (or notebook type) personal computer as an example of an electronic apparatus including the vibration gyro element according to the embodiment of the present invention.
In FIG. 9, a personal computer 1100 includes a main body portion 1104 provided with a keyboard 1102 and a display unit 1106 provided with a display portion 1000. The display unit 1106 rotates with respect to the main body portion 1104 via a hinge structure portion. It is supported movably. Such a personal computer 1100 incorporates a vibrating gyro element 1 having a function of detecting an angle when the personal computer 1100 is rotated.

FIG. 10 is a perspective view showing a schematic configuration of a mobile phone 1200 (including PHS) as an example of an electronic apparatus including the vibrating gyro element according to the embodiment of the present invention.
In FIG. 10, 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 the vibration gyro element 1 having a function of detecting an angle when the cellular phone 1200 is rotated.

  FIG. 11 is a perspective view illustrating a schematic configuration of a digital camera 1300 as an example of an electronic apparatus including the vibrating gyro element according to the embodiment of the present invention. Note that FIG. 11 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 camera 1300 photoelectrically converts the light image of the subject with an image sensor such as a CCD (Charge Coupled Device). An imaging signal (image signal) is generated.

  A display unit 1000 is provided on the back surface of a case (body) 1302 in the digital camera 1300, and is configured to perform display based on an imaging signal from the CCD. The display unit 1000 displays a subject as an electronic image. Function as. 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 camera 1300, a video signal output terminal 1312 and an input / output terminal 1314 for data communication are provided on the side surface of the case 1302. As shown in the figure, a television monitor 1430 is connected to the video signal output terminal 1312 and a personal computer 1440 is connected to the input / output terminal 1314 for data communication 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 camera 1300 incorporates a vibrating gyro element 1 having a function of detecting an angle when the digital camera 1300 is rotated.

  The vibrating gyro element 1 according to an embodiment of the present invention includes, for example, a smartphone in addition to the personal computer 1100 (mobile personal computer) in FIG. 9, the mobile phone 1200 in FIG. 10, and the digital camera 1300 in FIG. Mobile terminals such as communication devices, ink jet dispensing devices (for example, ink jet printers), laptop personal computers, tablet personal computers, storage area network devices such as routers and switches, local area network devices, mobile terminal base stations Equipment, TV, video camera, video recorder, car navigation device, real-time clock device, pager, electronic notebook (including communication functions), electronic dictionary, calculator, electronic game device, mobile phone 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 school Electronic equipment such as aircraft, various measuring instruments, instruments (eg, vehicles, aircraft, ships), flight simulators, head mounted displays, motion traces, motion tracking, motion controllers, PDR (pedestrian position measurement) Can be applied.

[Moving object]
Next, a moving body including the vibrating gyro element 1 (1a, 1b) according to an embodiment of the present invention will be described with reference to FIG.
FIG. 12 is a perspective view schematically showing an automobile 1500 as an example of a moving object including a vibrating gyro element according to an embodiment of the present invention.

An automobile 1500 is equipped with the vibrating gyro element 1 according to an embodiment of the present invention.
As shown in FIG. 12, an automobile 1500 as a moving body includes an electronic control unit 1502 that controls a tire 1503 and the like by incorporating a vibration gyro element 1 in a vehicle body 1501. In addition, the vibration gyro element 1 includes a keyless entry, immobilizer, car navigation system, car air conditioner, antilock brake system (ABS), airbag, tire pressure monitoring system (TPMS: Tire Pressure). It can be widely applied to electronic control units (ECUs) such as monitoring systems), engine controls, brake systems, battery monitors for hybrid vehicles and electric vehicles, and vehicle body attitude control systems.

  The vibration gyro element 1 (1a, 1b), the electronic device 2, the electronic apparatus, and the moving body according to the embodiment of the present invention have been described based on the illustrated embodiment. However, the present invention is not limited to this. However, the configuration of each part can be replaced with any configuration having a similar function. In addition, any other component may be added to the present invention. Moreover, you may combine each embodiment mentioned above suitably.

  DESCRIPTION OF SYMBOLS 1, 1a, 1b ... Vibration gyro element as a vibration element, 2 ... Electronic device, 10 ... Base part, 12 ... Driving vibration arm as 1st vibration arm, 14 ... Adjustment vibration arm as 2nd vibration arm, 16 ... Detection vibration arm as the third vibration arm 18. Supporting part 20... First side 22. Second side 24. Third side 30. Connection terminal 100. 1st board | substrate, 120 ... 2nd board | substrate, 130 ... 3rd board | substrate, 140 ... external terminal, 160 ... sealing member, 170 ... lid member, 180 ... joining member, 190 ... cavity, 200 ... circuit element, 210 ... Connection terminal, 220 ... Connection terminal, 230 ... Joint member, 240 ... Bonding wire, 1100 ... Personal computer as electronic device, 1200 ... Mobile phone as electronic device, 1300 ... As electronic device Digital cameras, 1500 ... motor vehicle as a mobile body, F1 ... main surface, L1, L2 ... distance, LL ... virtual line, P1, P2 ... vibration node portions, omega ... angular velocity.

Claims (8)

A base and a first vibrating arm extending from the base;
A second vibrating arm extending from the base and outputting an output signal having an opposite phase to the output signal of the leakage vibration of the first vibrating arm,
When a virtual straight line connecting the vibration node of the first vibrating arm and the vibration node of the second vibrating arm is provided, the virtual straight line overlaps the base in a plan view of the base. A characteristic vibration element.   2. The vibration element according to claim 1, further comprising a third vibrating arm extending from the base in a direction opposite to a direction in which the first vibrating arm extends from the base. The second vibrating arm extends along an extending direction of the third vibrating arm,
The first vibrating arm is a driving vibrating arm;
3. The vibration element according to claim 2, wherein when a shaft is provided along the main surface of the base portion, the third vibrating arm vibrates according to a Coriolis force due to an angular velocity around the shaft. The second vibrating arm extends along an extending direction of the third vibrating arm,
The third vibrating arm is a driving vibrating arm;
The vibrating element according to claim 2, wherein the first vibrating arm vibrates according to a Coriolis force due to an angular velocity around the axis when an axis is provided along the main surface of the base. The distance between the first side of the base to which the first vibrating arm is connected and the third side of the base to which the third vibrating arm is connected is L1,
When the distance between the first side and the second side of the base to which the second vibrating arm is connected is L2,
The vibration element according to any one of claims 2 to 4, wherein L1> L2. The vibration element according to any one of claims 1 to 5,
A circuit element electrically connected to the vibration element;
An electronic device comprising: a package for housing the vibration element and the circuit element.   An electronic apparatus comprising the vibration element according to claim 1.   A moving body comprising the vibration element according to claim 1.

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