JP2013186029A - Vibration piece, sensor unit, and electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibration piece capable of suppressing a leakage output without being provided with ultrafine cutting portions, and further to provide a sensor unit and an electronic apparatus provided with the vibration piece.SOLUTION: A vibration piece formed of a base material having a thickness (t) comprises: a pair of detection vibration arms extending from one end of a base portion; a pair of driving vibration arms extending from the other end thereof opposite to the one end; and a pair of adjustment vibration arms that extend from one of the ends and are provided so as to interpose the pair of detection vibration arms or the pair of driving vibration arms therebetween. In the vibration piece, a relation among the thickness (t), a clearance (B) between the pair of detection vibration arms or the pair of driving vibration arms, a clearance (A) between one of the adjustment vibration arms and one of the detection vibration arms or one of the driving vibration arms, and a clearance (C) between the other of the adjustment vibration arms and the other of the detection vibration arms or the other of the driving vibration arms satisfies expressions of B<t, B×0.8<A<B×1.2, and B×0.8<C<B×1.2.

Description

  The present invention relates to a resonator element, a sensor unit, and an electronic device.

  Vibration gyro sensors are widely used as angular velocity sensors that enhance vehicle control in vehicles, vehicle position detection in car navigation systems, and vibration control correction functions (so-called camera shake correction) for digital cameras and digital video cameras. . The vibration gyro sensor detects an electrical signal generated in a part of the gyro vibrating piece as an angular velocity by a vibration such as shaking or rotation of the object by a gyro vibrating piece made of a piezoelectric single crystal such as quartz as a highly elastic material. The displacement of the object is obtained by calculating the rotation angle.

  As a vibrating piece used for a gyro sensor, a piezoelectric vibrating piece (gyro element) formed of a piezoelectric material such as quartz is widely used (see, for example, Patent Document 1). The vibrating piece described in Patent Document 1 is a so-called tuning fork type piezoelectric vibrating piece including a base made of quartz and a pair of vibrating arms extended in parallel from one end of the base. A driving electrode (driving electrode, excitation electrode) for supplying a driving voltage for exciting the vibrating arm is provided on the main surface (first surface) of each vibrating arm, and a detection electrode is provided on the side surface orthogonal to the first surface. It has been. And a vibrating arm can be vibrated by applying a drive signal (excitation signal) to a drive electrode. Here, when a drive signal is applied to the vibrating piece to vibrate the vibrating arm in the direction along the first surface (in-plane vibration), the axis of the vibrating arm in the extending direction (for example, a quartz Z plate In the case of a gyro element as a base material, when the Y axis) is rotated as a detection axis, the vibrating arm vibrates in a direction perpendicular to the first surface (out-of-plane vibration) by Coriolis force. Since the amplitude of the out-of-plane vibration is proportional to the rotational speed of the vibration piece, it can be detected as an angular velocity.

  The base part and the vibrating arm of the gyro element as described above can be integrally formed by etching a piezoelectric material, for example, quartz using photolithography. 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 leak called so-called leakage output occurs, and the gyro element is detected. It becomes a factor which deteriorates sensitivity. As a method for suppressing such leakage output, for example, Patent Document 2 introduces a gyro element in which a cutting portion is provided near the base of a vibrating arm base.

  The gyro element (angular velocity sensor element) of Patent Document 2 includes a base and a vibrating arm extending from the base, and the vibrating arm includes a drive electrode that excites vibration in the width direction of the vibrating arm, and a vibrating arm. And a detection electrode (detection electrode) for detecting charges due to vertical vibration in the thickness direction. In the vicinity of the base of the vibrating arm, a plurality of cutting portions formed by laser processing are provided at at least one end in the width direction of the vibrating arm. It is described that the leakage output (diagonal vibration) can be suppressed by changing the mass distribution by the cutting portion provided near the base of the vibrating arm.

JP-A-5-256723 JP 2008-209215 A

  However, in the gyro element described in Patent Document 2, it is necessary to provide an extremely fine cutting portion in order to perform fine adjustment for suppressing leakage output. With the downsizing, there is a problem that the formation of the cutting part becomes more difficult and the mechanical strength of the gyro element becomes weak due to the formation of the cutting part.

  The present invention can be realized as the following forms or application examples so as to solve at least one of the above-described problems.

Application Example 1 The vibration piece of this application example is a vibration piece formed of a base material having a thickness t, and includes a base, a pair of detection vibrating arms extending from one end of the base, A pair of drive vibrating arms extending from the other end of the base opposite to the one end and the one end or the other end, and the detection vibrating arm or the driving vibrating arm A pair of adjustment vibrating arms provided so as to be sandwiched between the thickness t, the detection vibrating arm, or the distance B between the pair of driving vibration arms, and one of the adjustment vibrating arms. An interval A between the vibrating arm and the one of the detecting vibrating arms or the driving vibrating arm adjacent to the adjusting vibrating arm, the other adjusting vibrating arm, and the other of the adjusting vibrating arm adjacent to the adjusting vibrating arm. The relationship between the detection vibrating arm or the driving vibration arm and the distance C is as follows:
B <t, B × 0.8 <A <B × 1.2, and B × 0.8 <C <B × 1.2,
It is characterized by being.

According to the resonator element of this application example, the thickness t of each vibrating arm (base material), the pair of arms of the detecting vibrating arm or the driving vibrating arm, and the distance B between the arms, and the detecting vibration The relationship between the arm or the distance A between the driving vibration arm and the adjacent adjustment vibration arm and the distance C is B × 0.8 <A <B × 1.2 and B × 0.8 <C <. B × 1.2.
As described above, the distance A between the detection vibrating arm or the driving vibrating arm and the adjustment vibrating arm adjacent to the detecting vibrating arm or the driving vibrating arm based on the distance B between the pair of arms of the detecting vibrating arm or the driving vibrating arm. By configuring the distance C, the outer shape of the connecting portion between the base and each vibrating arm can be stably formed. The outer shape of the connecting portion is a shape of a corner formed to face the inner side of each pair of arms of the detection vibrating arm or the driving vibrating arm. Or it is a shape of a pair of corner | angular part formed inside the vibrating arm for detection or the vibrating arm for a drive, and the vibrating arm for adjustment.
When the relationship between the thickness t of each vibrating arm (base material) and the pair of arms of the vibrating arm for detection or the vibrating arm for driving and the arm spacing B is B <t, It is known that the outer shape of the connecting portion with each vibrating arm tends to be unstable.
However, as in this application example, by configuring the distance A and the distance C between the vibrating arm for detection or the driving vibrating arm and the adjacent vibrating arm based on the distance B, the configuration of B <t Even so, it is possible to stably form the outer shape of the connecting portion between the base and each vibrating arm.
As a result, it is possible to suppress vibration leakage output caused by variations in the outer shape of the connecting portion between the base and each vibrating arm, or to suppress unnecessary mode vibration (Tux mode vibration), and stabilize the vibration characteristics of the resonator element. Therefore, a highly sensitive and highly accurate vibrating piece can be obtained.
Thus, according to the resonator element of this application example, vibration leakage output can be suppressed or unnecessary mode vibration (Tux mode vibration) can be suppressed without providing an extremely fine cutting portion. Thus, it is advantageous for downsizing. Furthermore, since precise adjustment is possible, a resonator element having a small size, high mechanical strength, and high sensitivity can be provided.

Application Example 2 In the application example described above, a pair of balance vibration arms provided so as to sandwich the pair of adjustment vibration arms, and the one adjustment vibration arm and the adjustment vibration arm. The relationship between the distance D between the balance vibrating arm adjacent to the vibrating arm and the distance E between the other adjustment vibrating arm and the other balance vibrating arm adjacent to the adjustment vibrating arm. But,
A × 0.8 <D <A × 1.2, and C × 0.8 <E <C × 1.2,
It is characterized by being.

According to the above application example, in addition to the above application example, the balance vibrating arm is provided. The relationship between the distance D between the adjustment vibration arm and one balance vibration arm and the distance E between the other adjustment vibration arm and the other balance vibration arm is A × 0.8 <D <. A × 1.2 and C × 0.8 <E <C × 1.2.
Thus, by providing the balance vibrating arm, it is possible to further suppress the vibration leakage output or the unnecessary mode vibration (Tux mode vibration). In addition, the above-described application example is achieved by setting the intervals of the vibrating arms to A × 0.8 <D <A × 1.2 and C × 0.8 <E <C × 1.2. The same effect can be obtained.

  Application Example 3 In the application example described above, the detection vibrating arm is provided with a detection electrode, the adjustment vibrating arm is provided with a metal film, and the metal film and the detection electrode are electrically connected. It is connected to.

  According to the application example described above, a part of the metal film provided in the adjustment part of the adjustment vibrating arm is removed by, for example, laser irradiation, or the metal film is added by vapor deposition or sputtering. By controlling the charge (current) of the vibrating arm for use, it is possible to perform more precise adjustment of the leakage output.

  Application Example 4 In the application example described above, a wide portion is provided at a distal end portion of the adjustment vibrating arm opposite to the base portion side.

  According to the application example described above, it is possible to improve the effect of suppressing the leakage vibration while suppressing an increase in the length of the adjusting vibration arm, and it is possible to increase the adjustment range for suppressing the leakage vibration. A resonator element having a highly sensitive characteristic can be provided.

  Application Example 5 In the application example described above, the length of the adjustment vibration arm is shorter than the length of the drive vibration arm and the detection vibration arm.

  According to the application example described above, the vibration of the vibration arm for adjustment for adjusting the leakage output does not hinder the main vibration of the vibration piece by the vibration arm for driving and the vibration arm for detection. The vibration characteristics are stabilized, and it is advantageous for downsizing the resonator element.

  Application Example 6 A sensor unit according to this application example detects the resonator element according to any one of the application examples described above, a drive circuit that excites the drive vibration arm, and a detection signal generated in the detection vibration arm. An electronic component including a detection circuit, a package that accommodates the vibration piece, and the electronic component.

  According to the sensor unit of this application example, the sensor unit can obtain a sensor unit including the resonator element having the effects described in any one of the application examples. In addition, the package type sensor unit having the above-described configuration is advantageous for downsizing and thinning, and can have high impact resistance.

  Application Example 7 An electronic apparatus according to this application example includes the above-described vibrating element.

  According to the electronic device of this application example, since the high-sensitivity vibration piece that has been adjusted to suppress the leakage output according to any of the above application examples is provided, an electronic device having a high-function and stable characteristic is provided. Can be provided.

The outline of the gyro element concerning a 1st embodiment is shown, (a) is a perspective view and (b) is a top view. The outline of electrode arrangement | positioning of the gyro element which concerns on 1st Embodiment is shown, (a) is a top view of one surface, (b) is a top view of the other surface, (c) is AA shown to (a). Sectional drawing of 'part, (c) is sectional drawing of BB' part shown to (a). The schematic plan view which shows the form of another gyro element. The schematic plan view which shows the form of another gyro element. The top view which shows the outline of the gyro element which concerns on 2nd Embodiment. The outline of the gyro sensor which concerns on 3rd Embodiment is shown, (a) is a top view, (b) is sectional drawing of CC 'part shown to (a). (A)-(c) is explanatory drawing which shows the relationship of the phase of the vibrating arm for a detection of a gyro element, and the vibrating arm for adjustment. (A)-(c) is explanatory drawing which shows the relationship of the phase of the vibrating arm for a detection of a gyro element, and the vibrating arm for adjustment. (A), (b) is a schematic plan view which shows the vibration direction of the gyro element for demonstrating the vibration of "TuX" mode. (A), (b) is a schematic plan view which shows the vibration direction of the gyro element for demonstrating the vibration of "TuX" mode. The graph which shows the relationship between the space | interval between each vibrating arm, and the electric charge acquired from the vibrating arm for adjustment. The other gyro sensor is shown, (a) is a top view, (b) is sectional drawing of the D-O-D 'part shown to (a). The external view which shows the electronic device which concerns on 4th Embodiment.

  Embodiments according to the present invention will be described below with reference to the drawings.

(Gyro element according to the first embodiment)
First, an embodiment in which the resonator element of the invention is embodied as a vibrating gyro element will be described. 1A and 1B show an embodiment of a vibrating gyro element as a vibrating piece, in which FIG. 1A is a schematic perspective view and FIG. 1B is a plan view schematically shown. As shown in FIG. 1 (a), a vibrating gyro element 10 (hereinafter referred to as a gyro element 10) as a vibrating piece is a base 1 formed integrally by processing a base material (material constituting a main part). Drive vibration arms 2a and 2b, detection vibration arms 3a and 3b, and adjustment vibration arms 4a and 4b. Furthermore, a first support portion 5 is formed by a first connecting portion 5a extending from the base portion 1 and a first fixing portion 5b connected to the first connecting portion 5a and fixed to a substrate such as a package (not shown). A second support portion 6 is formed by the second connecting portion 6a extending from the base portion 1 and the second fixing portion 6b connected to the second connecting portion 6a and fixed to a substrate such as a package (not shown).

  In the gyro element 10 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 so-called plate having a predetermined thickness t in the Z-axis direction perpendicular to the plane is cut out along a plane defined by the X-axis and the Y-axis orthogonal to the quartz crystal axis and processed into a flat plate shape. An example in which a quartz Z plate is used as a base material will be described. Here, the predetermined thickness t is appropriately set depending on the oscillation frequency (resonance frequency), the outer size, the workability and the like. Further, the flat plate forming the gyro element 10 can tolerate errors in the angle of cut-out from the quartz crystal in a certain range for each of the X axis, Y axis, and Z axis. For example, it is possible to use what is cut out by rotating in the range of 0 to 2 degrees around the X axis. The same applies to the Y axis and the Z axis.

  The gyro element 10 is arranged so as to be parallel to the substantially rectangular base portion 1 located in the central portion and one end portion (the end portion in the (−) Y direction in the figure) of the end portions of the base portion 1 in the Y-axis direction. A pair of drive vibrating arms 2a and 2b extended along the Y axis and a distance B along the Y axis from the other end (the end in the (+) Y direction in the figure) of the base 1 And a pair of vibrating arms for detection 3a and 3b extended in parallel. In this way, the pair of driving vibrating arms 2a and 2b and the pair of detecting vibrating arms 3a and 3b are respectively extended in the coaxial direction from both ends of the base 1. Due to such a shape, the gyro element 10 according to the present embodiment may be referred to as an H-type vibrating piece (H-type gyro element). In the H-type gyro element 10, the driving vibration arms 2a and 2b and the detection vibration arms 3a and 3b are extended from both ends of the base 1 in the same axial direction, so that the driving system and the detection system are separated. Therefore, the 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 vibrating arms for driving and two vibrating arms for detection are provided, taking an H-shaped vibrating piece as an example, but the number of vibrating arms may be one or three or more. good. Further, the driving electrode and the detection electrode may be formed on one vibrating arm.

In addition, the gyro element 10 is paired from the base 1 so as to be parallel to the detection vibrating arms 3a and 3b and sandwich the detection vibrating arms 3a and 3b in a direction intersecting the crystal X axis (electrical axis) of quartz. The adjustment vibrating arms 4a and 4b are extended. That is, the adjustment vibrating arms 4a and 4b are extended in the (+) Y direction along the Y axis. Further, one adjustment vibrating arm 4a has an interval A between the adjacent detection vibrating arms 3a, and the other adjustment vibrating arm 4b has an interval C between the adjacent detection vibrating arms 3b. doing. The relationship between the distance A and the distance C, the distance B between the pair of detection vibrating arms 3a and 3b, and the thickness t of the base material is as follows.
B <t, B × 0.8 <A <B × 1.2, and B × 0.8 <C <B × 1.2,
Thus, the adjustment vibrating arms 4a and 4b and the detection vibrating arms 3a and 3b are formed. The adjusting vibrating arms 4a and 4b are formed to have a shorter overall length than the driving vibrating arms 2a and 2b and the detecting vibrating arms 3a and 3b. Thereby, the vibration of the adjustment vibrating arms 4a and 4b for adjusting the leakage output does not hinder the main vibration of the gyro element 10 by the drive vibrating arms 2a and 2b and the detection vibrating arms 3a and 3b. Therefore, the vibration characteristics of the gyro element 10 are stabilized, and it is advantageous for downsizing the gyro element 10.

  The center of the base 1 can be the center of gravity of the gyro element 10. The X axis, the Y axis, and the Z axis are orthogonal to each other and pass through the center of gravity. The outer shape of the gyro element 10 can be symmetric with respect to a virtual center line in the Y-axis direction passing through the center of gravity. Thereby, the outer shape of the gyro element 10 is well balanced, which is preferable because the characteristics of the gyro element 10 are stabilized and the detection sensitivity is improved. Such an outer shape of the gyro element 10 can be formed by etching (wet etching or dry etching) using a photolithography technique. A plurality of gyro elements 10 can be taken from one crystal wafer.

  Further, as described above, the relationship between the distance A and the distance C, the distance B between the pair of detection vibrating arms 3a and 3b, and the thickness t of the base material is B <t, B × 0.8 < The adjustment vibrating arms 4a and 4b and the detection vibrating arms 3a and 3b are provided so that A <B × 1.2 and B × 0.8 <C <B × 1.2. The following effects can be obtained. In this way, with reference to the distance B between the pair of arms of the detection vibrating arms 3a and 3b, the distance A between the detection vibration arms 3a and 3b and the adjacent adjustment vibration arms 4a and 4b and the distance C are set as follows. By configuring, it is possible to stably form the outer shape of the connecting portion between the base 1, the detection vibrating arms 3a and 3b, and the adjustment vibrating arms 4a and 4b.

  Here, the relationship between the formation of the outer shape of the gyro element 10 and the vibration characteristics will be described in detail. When the outer shape of the gyro element 10 is formed by etching using a photolithography technique, a connecting portion between the base 1, the detection vibrating arms 3a and 3b, and the adjustment vibrating arms 4a and 4b (due to etching anisotropy of quartz) Etching residues (also referred to as fins) 3c, 3d, 3e, 3f, 4c, and 4d are generated at the corners.

  The etching remainders 3c, 3d, 3e, 3f, 4c, and 4d have different sizes depending on the root positions of the respective vibrating arms due to the etching anisotropy of the crystal. For example, in the detection vibrating arm 3a, the etching residue 3c generated at the root on the left side (the side facing the adjustment vibrating arm 4a) is the etching residue generated at the root on the right side (the side facing the detection vibrating arm 3b). It becomes larger than 3e. Similarly, in the detection vibrating arm 3b, the remaining etching 3d that occurs at the left base (the side facing the detection vibrating arm 3a) in the drawing is the etching that occurs at the right base (the side facing the adjustment vibrating arm 4b) in the drawing. It becomes larger than the remaining 3f. Similarly, the adjustment vibrating arm 4a has an etching residue 4d at the root of the right side of the drawing (the side facing the detection vibrating arm 3a), but it faces the adjustment vibrating arm 4a of the adjacent detection vibrating arm 3a. It becomes smaller than the etching residue 3c generated at the base of the side to be processed. Similarly, the adjustment vibrating arm 4b has an etching residue 4c at the base of the left side of the figure (the side facing the detection vibrating arm 3b), but faces the adjustment vibrating arm 4b of the adjacent detection vibrating arm 3b. This is larger than the remaining etching 3f generated at the base of the side to be processed.

  Such a phenomenon requires a particularly long etching time. When the base material thickness t is large (thick), that is, the base material thickness t is a pair of arms and arms of the detection vibrating arms 3a and 3b. It appears remarkably when the distance B is larger (thick) than when the distance between the adjacent vibrating arms or the distance between the vibrating arms (the above-mentioned distances A, B, C) is narrow. It is also effective when the thickness t of the base material is smaller (thin) than the distance B between the pair of arms of the vibrating arms for detection 3a, 3b, but in this case, the etching processing time is short, Since the etching residues 3c, 3d, 3e, 3f, 4c, and 4d are relatively small, they are hardly affected by vibration characteristics. Further, when the size of the etching residue generated at the base of the adjacent (facing) vibrating arms is different (the outer shape varies), the frequency or the vibration mode of each vibrating arm is slightly shifted. Due to this deviation, the vibration balance of the respective vibrating arms is lost, and vibration leakage output or unnecessary mode vibration (TuX mode vibration) is likely to occur.

  In the gyro element 10 of the present embodiment, when the relationship between the distance B between the pair of detection vibrating arms 3a and 3b and the thickness t of the base material is B <t, detection adjacent to one adjustment vibrating arm 4a is performed. The relationship between the distance A between the vibrating arm 3a, the distance C between the other vibrating arm 4b for adjustment and the adjacent vibrating arm 3b, and the distance B between the pair of vibrating arms 3a, 3b is B × 0. 8 <A <B × 1.2 and B × 0.8 <C <B × 1.2. This makes it possible to form a stable shape for the etching residues 3c, 3d, 3e, 3f, 4c, and 4d formed at the bases of the respective vibrating arms. Therefore, it is possible to suppress vibration leakage output or unnecessary mode vibration (TuX mode vibration) caused by large etching residue formed at the base of each vibration arm or variation in the shape of the etching residue, and stable vibration characteristics of the resonator element. Therefore, a highly sensitive and highly accurate vibration piece can be obtained.

  Although the distances A and C can be set to 1.2 times or more the distance B, the outer shape of the gyro element 10 becomes large, and it becomes impossible to meet the demand for miniaturization, which is not practical.

  Next, an embodiment of the electrode arrangement of the gyro element 10 will be described. 2A and 2B show the electrode arrangement of the gyro element 10 according to the first embodiment, wherein FIG. 2A is a plan view showing the electrode arrangement on one main surface side, and FIG. 2B shows the electrode arrangement on the other main surface side. FIG. 4C is a cross-sectional view taken along the line AA ′ of the driving vibrating arms 2a and 2b shown in FIG. 4A. FIG. 4D is a detecting vibrating arms 3a and 3b and an adjusting vibrating arm shown in FIG. It is sectional drawing in the BB 'part of 4a, 4b.

  As shown in FIG. 2A, electrodes 11 and 12 are formed to drive the driving vibrating arms 2a and 2b. As shown in FIG. 2C, the electrodes 11 and 12 are formed with a driving electrode 11a on one main surface 2c of the driving vibrating arm 2a and a driving electrode 11b on the other main surface 2d. ing. Further, a driving electrode 12c is formed on one side surface 2e and the other side surface 2f of the driving vibrating arm 2a including the tip of the driving vibrating arm 2a. Similarly, a driving electrode 12a is formed on one main surface 2g of the driving vibrating arm 2b, and a driving electrode 12b is formed on the other main surface 2h. Further, a driving electrode 11c is formed on one side surface 2j and the other side surface 2k of the driving vibration arm 2b including the tip of the driving vibration arm 2b.

  The driving electrodes 11a, 11b, 11c, 12a, 12b, and 12c formed on the driving vibrating arms 2a and 2b have the same potential between the driving electrodes that are disposed to face each other via the driving vibrating arms 2a and 2b. Are arranged as follows. As shown in FIGS. 2A and 2B, the electrode 11 is connected to the connection pad 11f formed on the first fixing portion 5b connected by the wirings 11d and 11e, and the electrode 12 is connected to the wirings 12d and 12e. By alternately applying a potential difference between the electrode 11 and the electrode 12 through the connection pad 12f formed in the second fixing portion 6b, the so-called tuning fork vibration is excited in the driving vibrating arms 2a and 2b.

  Next, the detection electrodes that are formed on the detection vibrating arms 3a and 3b and detect distortion generated in the quartz crystal that is the base material when the detection vibrating arms 3a and 3b vibrate will be described. As shown in FIGS. 2A and 2B, in the detection vibrating arm 3a, detection electrodes 21a and 22a are formed on one main surface 3c along the extending direction of the detection vibrating arm 3a. ing. Also, detection electrodes 21b and 22b are formed on the other main surface 3d opposite to the main surface 3c along the extending direction of the detection vibrating arm 3a. The detection electrode 22a and the detection electrode 22b are electrically connected via the tip of the detection vibrating arm 3a, and the detection electrodes 21a and 21b extend to the vicinity of the tip of the detection vibrating arm 3a. Has been. The detection electrodes 21a and 21b are electrically connected to connection pads 21h formed on the first fixing portion 5b by wirings 21d, 21e, 21f, and 21g, respectively. The detection electrodes 22a and 22b are electrically connected to the wiring 22d, the adjustment electrode 22c formed on the adjustment vibrating arm 4a described later, and the connection pad 22f formed on the first fixing portion 5b by the wiring 22e. It is connected to the.

  The detection electrode 21a and the detection electrode 21b are connected to have the same potential, and the detection electrode 22a and the detection electrode 22b are connected to have the same potential. Thereby, the distortion caused by the vibration of the detection vibrating arm 3a is detected by detecting the potential difference between the detection electrodes 21a and 21b and the detection electrodes 22a and 22b. That is, the potential difference between the electrode 21 and the electrode 22 is detected from the connection pads 21h and 22f.

  Similarly, in the detection vibrating arm 3b, detection electrodes 31a and 32a are formed on one main surface 3e along the extending direction of the detection vibrating arm 3b. Also, detection electrodes 31b and 32b are formed on the other main surface 3f opposite to the main surface 3e along the extending direction of the detection vibrating arm 3b. The detection electrode 32a and the detection electrode 32b are electrically connected via the tip of the detection vibrating arm 3b, and the detection electrodes 31a and 31b extend to the vicinity of the tip of the detection vibrating arm 3b. Has been. The detection electrodes 31a and 31b are electrically connected to connection pads 31h formed on the second fixing portion 6b by wirings 31e, 31f and 31g, respectively. The detection electrodes 32a and 32b are electrically connected to a wiring 32d, an adjustment electrode 32c formed on the adjustment vibrating arm 4b described later, and a connection pad 32f formed on the second fixing portion 6b by the wiring 32e. It is connected to the. The detection electrode 31a and the detection electrode 31b are connected to have the same potential, and the detection electrode 32a and the detection electrode 32b are connected to have the same potential. Thereby, the distortion caused by the vibration of the detection vibrating arm 3b becomes a potential difference between the detection electrodes 31a and 31b and the detection electrodes 32a and 32b, and this potential difference is detected. That is, the potential difference between the electrode 31 and the electrode 32 is detected from the connection pads 31h and 32f.

  Next, an electrode as an adjustment portion provided on the adjustment vibrating arms 4a and 4b will be described. As shown in FIGS. 2A, 2B, and 2D, the adjustment vibrating arm 4a has an adjustment electrode 21c on one main surface 4c and the other main surface opposite to the main surface 4c. 4d is formed with an adjustment electrode 21d as an adjustment electrode having the same potential. Further, the adjustment electrode 22c is provided on one side surface 4e of the adjustment vibration arm 4a, and the adjustment electrode 22c on the side surface 4e and the tip of the adjustment vibration arm 4a are provided on the other side surface 4f opposite to the side surface 4e. A continuous adjustment electrode 22c. The adjustment electrodes 21c and 21d are connected to the connection pad 21h by wirings 21f and 21g. The adjustment electrode 22c is electrically connected to the connection pad 22f by the wiring 22e. Similarly, the adjustment vibrating arm 4b has an adjustment electrode 31c on one main surface 4g and an adjustment electrode 31d on the other main surface 4h opposite to the main surface 4g. It is formed as an electrode. The adjustment electrode 32c is provided on one side surface 4j of the adjustment vibrating arm 4b, and the adjustment electrode 32c on the side surface 4j and the tip of the adjustment vibration arm 4b are provided on the other side surface 4k opposite to the side surface 4j. A continuous adjustment electrode 32c. The adjustment electrodes 31c and 31d are connected to the connection pad 31h by wirings 31f and 31g. The adjustment electrode 32c is electrically connected to the connection pad 32f by the wiring 32e.

  As described above, according to the gyro element 10 according to the present embodiment, the angular vibration velocity is applied to the gyro element 10 in a state where the driving vibrating arms 2a and 2b are vibrated by applying a predetermined excitation drive signal. The detection vibrating arms 3a and 3b are vibrated by Coriolis force. The adjustment vibrating arms 4a and 4b are excited by the vibration of the detection vibrating arms 3a and 3b. Therefore, the weights of the adjustment electrodes 21c, 21d, 22c, 31c, 31d, 32c, which are metal films provided on the adjustment vibration arms 4a, 4b, are increased or decreased, or the adjustment electrodes 21c, 21d, 22c, 31c, By changing the charge amount by increasing or decreasing the volumes of 31d and 32c, it is possible to suppress unwanted leakage output of the vibrating arms for detection 3a and 3b.

  Therefore, the leakage output that may occur due to the variation in the cross-sectional shape of the driving vibration arms 2a and 2b and the detection vibration arms 3a and 3b due to the etching anisotropy of the crystal that is the base material of the gyro element 10 and the manufacturing variation. It is possible to suppress a decrease in detection sensitivity that is a cause, and it is possible to provide the gyro element 10 as a vibration piece with high sensitivity.

In the description of the gyro element according to the above-described embodiment, the pair of vibrating vibrating arms 3a and 3b and the pair of vibrating vibrating arms 4a and 4b sandwiching the vibrating vibrating arms 3a and 3b at one end of the base 1 are provided. Is used, and a pair of drive vibrating arms 2a and 2b is provided at the other end. However, the present invention is not limited to this configuration. For example, the driving vibration arm and the adjustment vibration arm may be extended from the same end of the base portion in the same direction. More specifically, the gyro element is provided with a pair of drive vibration arms and a pair of adjustment vibration arms sandwiching the drive vibration arms at one end of the base, and a pair of detection vibrations at the other end of the base. Arms are provided (see FIG. 10).
Such a form can be applied to gyro elements according to embodiments and modifications described below.

  FIG. 3 is a plan view showing another form of the gyro element 10 according to the first embodiment. In the gyro element 1A shown in FIG. 3A, the fixing portion 7 connected to the base 1 by the first connecting portion 5a and the second connecting portion 6a has a frame shape. In other words, in this example, the fixing portion 7 is formed in which the first fixing portion 5b and the second fixing portion 6b in the gyro element 10 according to the first embodiment are integrally connected on the driving vibrating arms 2a and 2b. ing. Also in the gyro element 1A, one adjustment vibrating arm 4a has an interval A between the adjacent detection vibrating arms 3a, and the other adjustment vibrating arm 4b is adjacent to the detection vibrating arms 3b. And an interval C. The relationship between the distance A and the distance C, the distance B between the pair of vibrating arms for detection 3a and 3b, and the thickness t of the substrate is B <t, B × 0.8 <A <B ×. The adjustment vibrating arms 4a and 4b and the detection vibrating arms 3a and 3b are formed so that 1.2 and B × 0.8 <C <B × 1.2.

  3B, the gyro element 1B includes a base 1, driving vibration arms 2a and 2b, detection vibration arms 3a and 3b, and adjustment vibration arms 4a and 4b inside a frame-shaped fixing portion 8. The gyro element 1B shown in FIG. Is arranged, and the base 1 and the fixed part 8 are connected by the first connecting part 5a and the second connecting part 6a. Also in the gyro element 1B, one adjustment vibrating arm 4a has an interval A between the adjacent detection vibrating arms 3a, and the other adjustment vibrating arm 4b is adjacent to the detection vibrating arms 3b. And an interval C. The relationship between the distance A and the distance C, the distance B between the pair of vibrating arms for detection 3a and 3b, and the thickness t of the substrate is B <t, B × 0.8 <A <B ×. The adjustment vibrating arms 4a and 4b and the detection vibrating arms 3a and 3b are formed so that 1.2 and B × 0.8 <C <B × 1.2.

  As described above, according to the gyro elements 1A and 1B as shown in FIGS. 3A and 3B, in addition to the effects described in the gyro element 10, the gyro elements 1A and 1B are accommodated in a package described later. When the gyro unit is formed, the fixing force is increased by increasing the fixing area of the fixing portion 7 or the fixing portion 8 fixed to the package, so that vibration leakage to the package can be suppressed. Further, since the fixing portion 7 or 8 has a frame shape, the strength of the gyro elements 1A and 1B can be increased and vibration leakage to the fixing portion 7 or the fixing portion 8 can be suppressed.

(Modification 1)
In the gyro element 10 of the first embodiment described above, the adjustment vibrating arms 4a and 4b contribute to high sensitivity of the gyro element 10 by adding a shape change that allows mass to be added to the tip portion. The effect can be further improved. FIG. 4 is a schematic plan view showing a modification of the gyro element as a vibrating piece provided with a wide portion at the tip of the adjustment vibrating arm. In FIG. 4, the same components as those of the gyro element 10 according to the first embodiment are denoted by the same reference numerals, description thereof is omitted, and illustration is also omitted.

  As shown in FIG. 4, the gyro element 1 </ b> C according to this modification includes a base 1 having the same configuration as that of the gyro element 10 according to the first embodiment and a pair of drives extending from both ends of the base 1 in the Y-axis direction. For vibration arms 2a, 2b and a pair of vibration arms for detection 3a, 3b. Further, an adjustment vibrating arm 15a adjacent to the detection vibrating arm 3a in the X (−) direction and extending from the base 1 in the Y direction, and a detection vibrating arm 3b adjacent to the X (+) direction in the Y direction. 1 and an adjustment vibrating arm 15b extending from 1. Also in the gyro element 1C, one adjustment vibrating arm 15a has a distance A from the adjacent detection vibrating arm 3a, and the other adjustment vibrating arm 15b is adjacent to the detection vibrating arm 3b. And an interval C. The relationship between the distance A and the distance C, the distance B between the pair of vibrating arms for detection 3a and 3b, and the thickness t of the substrate is B <t, B × 0.8 <A <B ×. The adjustment vibrating arms 15a and 15b and the detection vibrating arms 3a and 3b are formed so that 1.2 and B × 0.8 <C <B × 1.2. Adjustment electrodes 21c and 31c as film bodies for adjusting the leakage output of the gyro element 1C are provided on the main surfaces of the adjustment vibration arms 15a and 15b, and adjustment electrodes 21c and 31b are provided on the side surfaces of the adjustment vibration arms 15a and 15b. Electrodes 22c and 32c are provided, respectively.

  Weight portions 16a and 16b are provided on the distal end sides of the adjustment vibrating arms 15a and 15b as wide portions of a substantially rectangular shape that are wider (longer in the X-axis direction) than the adjustment vibration arms 15a and 15b. ing. Film bodies 40a and 40b are provided on the surfaces of the weight portions 16a and 16b. The film body can be provided on both main surfaces of the weight portions 16a and 16b and on both side surfaces although not shown. Moreover, the film bodies 40a and 40b may be formed of the same metal material as other electrodes, or may be formed of a non-conductive material. By forming the film bodies 40a and 40b from the same metal material as the other electrodes, it can be manufactured simultaneously with the other electrodes, so that productivity can be increased. In addition, forming the film bodies 40a and 40b from a non-conductive material is advantageous in that the choices of the film body forming material are widened. In addition, as a film body forming material, it is preferable to use a material having a density as high as possible (a high specific gravity).

  According to the gyro element 1C according to the first modification, the leakage vibration is suppressed by providing the adjustment vibrating arms 15a and 15b in the same manner as the adjustment vibrating arms 4a and 4b described in the gyro element 10 according to the first embodiment. A gyro element 1C thus obtained can be obtained. Further, by having the weight portions 16a and 16b as the wide portions on the tip side of the adjustment vibrating arms 15a and 15b, it is possible to suppress leakage vibration while suppressing an increase in the length of the adjustment vibrating arms 15a and 15b. The effect can be improved. Further, since the adjustment range of the weight of the film bodies (electrodes) provided in the adjustment vibrating arms 15a and 15b for suppressing the leakage vibration can be widened, it is possible to perform fine adjustment for suppressing the leakage vibration, and the gyro with higher sensitivity. Element 1C can be provided.

(Gyro element according to the second embodiment)
A gyro element according to the second embodiment will be described with reference to FIG. FIG. 5 is a plan view schematically showing the gyro element according to the second embodiment. In the present description, the same components as those of the gyro element 10 of the first embodiment described above may be denoted by the same reference numerals and the description thereof may be omitted or simplified.

  As shown in FIG. 5, the gyro element 10a includes a base 1 formed integrally by processing a base material (material constituting a main part), driving vibration arms 2a and 2b, and detection vibration arms 3a, 3b, adjustment vibrating arms 4a and 4b, and balance vibrating arms 9a and 9b. Further, a first support portion 5 is formed by a first connecting portion 5a extending from the base portion 1 and a first fixing portion 5b connected to the first connecting portion 5a and fixed to a substrate such as a package (not shown). The second support portion 6 is formed by the second connecting portion 6a extending from the base portion 1 and the second fixing portion 6b connected to the second connecting portion 6a and fixed to a substrate such as a package (not shown). Yes.

  The gyro element 10a of the present embodiment uses quartz having a thickness t as a base material, but the description thereof is omitted.

  The gyro element 10a has a pair of driving elements extending along the Y-axis so as to be parallel from one end of the substantially rectangular base 1 located in the central portion and the end of the base 1 in the Y-axis direction. And a pair of vibration arms for detection 3a and 3b extending in parallel with a distance B from the other end of the base 1 along the Y axis. Further, the gyro element 10a is paired from the base 1 so as to be parallel to the detection vibrating arms 3a and 3b and sandwich the detection vibrating arms 3a and 3b in a direction intersecting the crystal X axis (electrical axis) of the crystal. The adjustment vibrating arms 4a and 4b are extended. That is, the adjustment vibrating arms 4a and 4b are extended in the (+) Y direction along the Y axis. Further, one adjustment vibrating arm 4a has an interval A between the adjacent detection vibrating arms 3a, and the other adjustment vibrating arm 4b has an interval C between the adjacent detection vibrating arms 3b. doing.

  Further, the gyro element 10a is paired from the base 1 so as to be parallel to the adjustment vibrating arms 4a and 4b and sandwich the adjustment vibrating arms 4a and 4b in a direction intersecting the crystal X-axis (electric axis) of the crystal. The balance vibrating arms 9a and 9b are extended. That is, the balance vibrating arms 9a and 9b are extended in the (+) Y direction along the Y axis. Further, one balance vibrating arm 9a has a distance D between adjacent adjustment vibrating arms 4a, and the other balance vibrating arm 9b has a distance E between adjacent adjustment vibrating arms 4b. doing.

And the relationship between this space | interval A, space | interval C, space | interval D, space | interval E, space | interval B of a pair of vibrating arms 3a and 3b for a detection, and the thickness t of a base material is the following.
B <t, B × 0.8 <A <B × 1.2, and B × 0.8 <C <B × 1.2, and A × 0.8 <D <A × 1.2, and C × 0.8 <E <C × 1.2,
The adjustment vibrating arms 4a and 4b, the detection vibrating arms 3a and 3b, and the balance vibrating arms 9a and 9b are formed.

  The adjusting vibrating arms 4a and 4b are formed to have a shorter overall length than the driving vibrating arms 2a and 2b and the detecting vibrating arms 3a and 3b. Further, the balance vibrating arms 9a and 9b are formed to have a shorter overall length than the adjustment vibrating arms 4a and 4b. As a result, the vibration of the adjustment vibrating arms 4a and 4b for adjusting the leakage output and the vibration of the balance vibrating arms 9a and 9b are caused by the gyro element by the driving vibrating arms 2a and 2b and the detecting vibrating arms 3a and 3b. Since the main vibration of 10a is not hindered, the vibration characteristics of the gyro element 10a are stabilized, and it is advantageous for downsizing the gyro element 10a.

  According to the gyro element 10a of the second embodiment, in addition to the configuration of the gyro element 10 of the first embodiment described above, the balance vibration arm has the distance D and the distance E from the adjustment vibration arms 4a and 4b. Since 9a and 9b are provided, the etching residue (fin) generated at the base can be reduced and the shape can be stabilized. Further, the balance vibrating arms 9a and 9b function as a balancer, and further suppression of vibration leakage output or unnecessary mode vibration (Tux mode vibration) is possible.

(Gyro sensor according to the third embodiment)
As a third embodiment, a gyro sensor as a sensor unit including the gyro element 10 according to the first embodiment will be described. 6A and 6B show the gyro sensor 100 according to the third embodiment, in which FIG. 6A is a schematic plan view drawn with the lid omitted, and FIG. 6B is a cross-sectional view taken along the line CC ′ shown in FIG. is there.

  As shown in FIG. 6B, the gyro sensor 100 accommodates the gyro element 10 and the semiconductor device 120 as an electronic component in the recess of the package 110, and the opening of the package 110 is sealed with a lid 130. And the inside is kept airtight. As shown in FIG. 6B, the package 110 includes a first substrate 111 on a flat plate, a frame-shaped second substrate 112, a third substrate 113, and a fourth substrate 114 on the first substrate 111 in order. A concave portion that is formed by stacking and fixing and accommodating the semiconductor device 120 and the gyro element 10 is formed. The substrates 111, 112, 113, and 114 are made of, for example, ceramics.

  In the first substrate 111, a die pad 115 on which the semiconductor device 120 is placed and fixed is provided on the electronic component mounting surface 111 a on which the semiconductor device 120 on the concave side is mounted. The semiconductor device 120 is bonded and fixed on the die pad 115 by, for example, a brazing material (die attach material) 140.

  The semiconductor device 120 has a drive circuit as an excitation unit for driving and vibrating the gyro element 10 and a detection circuit as a detection unit for detecting a detection vibration generated in the gyro element 10 when an angular velocity is applied. Specifically, the drive circuit included in the semiconductor device 120 includes drive electrodes 11a, 11b, and 12c and drive electrodes 11c formed on the pair of drive vibrating arms 2a and 2b (see FIG. 2) of the gyro element 10, respectively. , 12a, 12b (see FIG. 2). In addition, the detection circuit included in the semiconductor device 120 includes detection electrodes 21a, 21b, 22a, 22b and detection electrodes 31a, 31b, 32a formed on the pair of detection vibrating arms 3a, 3b of the vibration gyro element 10, respectively. The detection signal generated in 32b (see FIG. 2) is amplified to generate an amplified signal, and the rotational angular velocity applied to the gyro sensor 100 is detected based on the amplified signal.

  The second substrate 112 is formed in a frame shape having an opening large enough to accommodate the semiconductor device 120 mounted on the die pad 115. The third substrate 113 is formed in a frame shape having an opening wider than the opening of the second substrate 112, and is laminated and fixed on the second substrate 112. A bonding wire BW that is electrically connected to an electrode pad (not shown) of the semiconductor device 120 is formed on the second substrate surface 112a that is formed on the second substrate 112 and is laminated inside the opening of the third substrate 113. A plurality of IC connection terminals 112b to be connected are formed. An electrode pad (not shown) of the semiconductor device 120 and an IC connection terminal 112b provided in the package 110 are electrically connected using a wire bonding method. That is, the plurality of electrode pads provided on the semiconductor device 120 and the corresponding IC connection terminal 112b of the package 110 are connected by the bonding wire BW. Any one of the IC connection terminals 112b is electrically connected to a plurality of external connection terminals 111c provided on the external bottom surface 111b of the first substrate 111 by an internal wiring (not shown) of the package 110.

  On the third substrate 113, a fourth substrate 114 having an opening wider than the opening of the third substrate 113 is laminated and fixed. Then, the fourth substrate 114 is laminated on the third substrate 113, and the third substrate surface 113a appearing inside the opening of the fourth substrate 114 has connection pads 11f and 12f formed in the gyro element 10 shown in FIG. , 21h, 22f, 31h, and 32f are formed with a plurality of gyro element connection terminals 113b. The gyro element connection terminal 113b is electrically connected to one of the IC connection terminals 112b by an internal wiring (not shown) of the package 110. In the gyro element 10, the first fixing part 5b and the second fixing part 6b of the gyro element 10 are positioned on the third substrate surface 113a at the connection pads 11f, 12f, 21h, 22f, 31h, and 32f and the gyro element connection terminal 113b. And are fixedly bonded by the conductive adhesive 150.

  Further, a lid 130 is disposed on the upper surface of the opening of the fourth substrate 114, the opening of the package 110 is sealed, and the inside of the package 110 is hermetically sealed, whereby the gyro sensor 100 is obtained. The lid 130 can be formed using, for example, a metal such as 42 alloy (an alloy containing 42% nickel in iron) or Kovar (an alloy of iron, nickel, and cobalt), ceramics, glass, or the like. For example, when the lid 130 is formed of metal, it is joined to the package 110 by seam welding via a seal ring 160 formed by punching a Kovar alloy or the like into a rectangular ring shape. Since the recessed space formed by the package 110 and the lid 130 serves as a space for the gyro element 10 to operate, it is preferably sealed and sealed in a reduced pressure space or an inert gas atmosphere.

(Explanation of leakage output of gyro element)
In the gyro sensor 100, the leakage output of the gyro element 10 is suppressed and adjusted before the lid 130 is hermetically sealed. First, the principle of the leakage output suppression adjustment method of the gyro element 10 will be described. As shown in the gyro element 10 (see FIG. 1), the base is attached to an H-shaped vibrating piece having driving vibration arms 2a and 2b and detection vibration arms 3a and 3b extending from both ends of the base 1 in the Y-axis direction. In the configuration including the adjusting vibrating arms 4a and 4b extending in the same direction from the extending end portions of the one detecting vibrating arms 3a and 3b, the vibration direction of the leak output is a finished shape due to variations in etching processing of the vibrating arms. It is effective to make an adjustment that suppresses leakage output accordingly.

  Specifically, when the gyro element 10 is driven, when the driving vibrating arms 2a and 2b are moving in the direction of the arrow P as shown in FIG. 7A, the outputs of the driving vibrating arms 2a and 2b are output. The output waveforms S1 more and S2 more of the leak outputs of the detection arms 3a and 3b that move in the direction of the waveform DS and the arrow Q show waveforms as shown in FIG. In order to cancel such a leak output, the phases of the adjustment vibrating arms 4a and 4b need to be the phases T1 and T2 shown in FIG. 7C. For this purpose, the driving vibrating arms 2a and 2b and the adjusting vibrating arms 4a and 4b need to be in opposite phases. Further, when the gyro element 10 is driven, as shown in FIG. 8A, when the driving vibrating arms 2a and 2b are moving in the direction indicated by the arrow P, the output waveforms DS of the driving vibrating arms 2a and 2b, The output waveforms S1 more and S2 more of the leak outputs of the detection vibrating arms 3a and 3b that move in the direction of the arrow Q show waveforms as shown in FIG. In order to cancel such a leak output, the phases of the adjustment vibrating arms 4a and 4b need to be the phases T1 and T2 shown in FIG. 8C. For this purpose, the driving vibrating arms 2a and 2b and the adjusting vibrating arms 4a and 4b need to be in phase.

As described above, the vibration direction of such a leak output varies depending on the finished shape due to processing variations of each vibrating arm. For example, even when a vibrating arm with a rectangular cross section is designed, the cross section becomes a parallelogram shape, a trapezoidal shape, or a rhombus shape due to the etching anisotropy of the quartz crystal that is the base material, It affects the vibration direction of the leak output. Here, when the resonance frequency of the drive vibrating arms 2a and 2b is fd and the resonance frequency of the adjustment vibrating arms 4a and 4b is ft, the drive vibration arms 2a and 2b are set according to the relationship between fd and ft. The relationship in which the phase of 2b and the phases of the adjustment vibrating arms 4a and 4b are in phase or out of phase holds as follows. That is,
fd <ft
In this case, the phase of the driving vibrating arms 2a and 2b and the phase of the adjusting vibrating arms 4a and 4b are opposite to each other,
fd> ft
In this case, the phase of the driving vibrating arms 2a and 2b and the phase of the adjusting vibrating arms 4a and 4b are in phase.

  Next, an example of a leakage output suppression adjustment method for the gyro element 10 based on the relationship between the various vibrating arms described above will be described. First, a part of the film provided on the adjustment vibrating arms 4a, 4b is removed or added, or the substrate of the adjustment vibrating arms 4a, 4b is shaved, etc., to adjust the adjustment vibrating arms 4a, 4b. The resonance frequency is changed by reducing or increasing the mass of the actuator to adjust the relationship between the resonance frequency fd of the drive vibrating arms 2a and 2b and the resonance frequency ft of the adjustment vibrating arms 4a and 4b to an appropriate relationship. At the same time, the leakage output is suppressed and adjusted. Specifically, the adjustment electrodes 21c, 21d, 22c, 31c, 31d, and 32c as film bodies provided on the adjustment vibrating arms 4a and 4b are trimmed by, for example, laser irradiation, or A film body of the same or different type as the adjustment electrodes 21c, 21d, 22c, 31c, 31d, and 32c is added by vapor deposition or sputtering to reduce or increase the mass of the adjustment vibrating arms 4a and 4b. From this increase / decrease in mass, the resonance frequency is changed to adjust the phase relationship between fd and ft to the desired relationship (fd <ft or fd> ft), and the charge amount is decreased or increased. The effect of leakage output is minimized. In this case, the adjustment electrodes 21c, 21d, 22c, 31c, 31d, and 32c of the adjustment vibration arms 4a and 4b, and the detection electrodes 21a, 21b, 22a, 22b, and 31a of the detection vibration arms 3a and 3b, 31b, 32a, and 32b are electrically connected.

  As described above, the leakage output suppression adjustment method of the present embodiment removes or adds a part of the adjustment electrodes 21c, 21d, 22c, 31c, 31d, and 32c of the adjustment vibrating arms 4a and 4b. Thus, by adjusting the resonance frequency fd of the driving vibrating arms 2a and 2b and the resonance frequency ft of the adjusting vibrating arms 4a and 4b to an appropriate relationship and changing the amount of charge, the leakage output can be reduced. Adjustments can be made. For example, in the case of the gyro element 1C shown in the modified example in which the adjustment vibrating arms 4a and 4b have the weight portions as the wide portions, first, the wide portions provided at the tip portions of the adjustment vibrating arms 15a and 15b. The film bodies 40a and 40b of the weight portions 16a and 16b are trimmed by, for example, laser irradiation, or a film body of the same or different type as the film bodies 40a and 40b is added by vapor deposition or sputtering. The mass of the parts 16a and 16b is reduced or increased. Due to the increase / decrease of the mass, the resonance frequency is changed to adjust the phase relationship between fd and ft to a desired relationship (fd <ft or fd> ft).

  After performing the above phase adjustment, next, leakage output suppression adjustment is performed. Specifically, a part of the adjustment electrodes 21c, 21d, 22c, 31c, 31d, and 32c provided on the adjustment vibration arms 15a and 15b is removed by, for example, laser irradiation, vapor deposition, sputtering, or the like. By adding an electrode metal, the amount of charge is reduced or increased, thereby minimizing the influence of leakage output.

(Explanation of gyro element leakage output and unnecessary mode vibration)
Here, an etching residue generated at the base of the adjacent (facing) vibrating arms (adjusting vibrating arms 4a and 4b, detecting vibrating arms 3a and 3b, balancing vibrating arms 9a and 9b, and driving vibrating arms 2a and 2b). The vibration leakage output or unnecessary mode vibration (TuX mode vibration) caused by the difference in size (the outer shape varies) will be described with reference to FIGS. 9 and 10. FIG. FIGS. 9A and 9B are gyros for explaining the vibration in the “TuX” mode in a form in which the driving vibrating arm and the adjusting vibrating arm extend from the base 1 in opposite directions. It is a schematic plan view which shows the vibration direction of an element. FIGS. 10A and 10B illustrate the vibration in the “TuX” mode in a form in which the driving vibrating arm and the adjusting vibrating arm extend from the same end of the base 1 in the same direction. It is a schematic plan view which shows the vibration direction of the gyro element for this.

  First, the vibration in the “TuX” mode in the form in which the driving vibrating arm and the adjusting vibrating arm extend in the opposite directions from the base 1 will be described with reference to FIG. 9.

  The gyro element 10 according to the embodiment of the present invention includes a pair of detection vibrating arms 3a and 3b and a pair of adjustment vibrating arms 4a and 4b sandwiching the detection vibrating arms 3a and 3b at one end of the base 1. A pair of drive vibration arms 2a and 2b are provided at the other end. Furthermore, the 1st support part 5 and the 2nd support part 6 are provided in the both ends of the base 1 of the direction which cross | intersects the above-mentioned one end and the other end.

  As shown in FIG. 9A, the normal vibration mode of the gyro element 10 is such that the vibration direction f5 of the drive vibration arm 2a and the vibration direction f6 of the drive vibration arm 2b move in opposite directions (reverse phase). The vibration direction e5 of the adjustment vibrating arm 4a and the vibration direction e6 of the adjustment vibration arm 4b move in opposite directions (reverse phase). In addition, each also vibrates in the same phase direction in the vibration in the direction opposite to the above. Even in the case where the driving vibrating arms 2a and 2b and the adjusting vibrating arms 4a and 4b are provided on the opposite side of the base 1 as in the case of this example, such a vibration mode (Tu mode vibration, so-called tuning fork) is provided. The vibration vectors (motion vectors) in the drive vibration arms 2a and 2b and the adjustment vibration arms 4a and 4b are balanced, and stable vibration is performed.

  As described above, stable vibration as described above is caused by variations in the shape of each vibrating arm and the extending portion (base) of the vibrating arm from the base 1 due to manufacturing variations in the formation process of the gyro element 10. A vibration mode deviating from the mode (vibration in the “TuX” mode) also appears in this example. This “TuX” mode vibration will be described with reference to FIG. The configuration of the gyro element 10 is the same as that shown in FIG.

  As shown in FIG. 9B, in the vibration in the “TuX” mode, the respective vibrating arms of the pair of adjusting vibrating arms 4a and 4b move in the same direction (in phase). Specifically, the adjustment vibrating arm 4a moves in the vibration direction e7, and the other adjustment vibration arm 4b moves in the vibration direction e8. That is, the pair of adjustment vibrating arms 4a and 4b move in the same direction (in phase). When such a “TuX” mode vibration occurs, the rotation vector (motion vector) of the driving vibrating arms 2 a and 2 b and the adjusting vibrating arms 4 a and 4 b causes a rotation around the center of the base 1. The balance of vibration (vibration balance) is lost, such as generation of force, and as a result, the vibration leakage output is increased or the vibration characteristics are deteriorated.

  Next, the vibration in the “TuX” mode in the form in which the driving vibrating arm and the adjusting vibrating arm extend in the same direction from the same end of the base 1 will be described with reference to FIG. The gyro element 1010 having such a configuration is provided with a pair of drive vibration arms 1002a and 1002b and a pair of adjustment vibration arms 1004a and 1004b sandwiching the drive vibration arms 1002a and 1002b at one end of the base 1001. A pair of vibrating arms for detection 1003a and 1003b are provided at the other end of the base 1001. Furthermore, the 1st support part 1005 and the 2nd support part 1006 are provided in the both ends of the base 1001 of the direction which cross | intersects the above-mentioned one end and the other end.

  As shown in FIG. 10A, the normal vibration mode of the gyro element 1010 is such that the vibration direction f1 of the drive vibration arm 1002a and the vibration direction f2 of the drive vibration arm 1002b move in opposite directions (reverse phase). The vibration direction e1 of the adjustment vibrating arm 1004a and the vibration direction e2 of the adjustment vibration arm 1004b move in opposite directions (reverse phase). At this time, the vibration direction f1 of the adjacent drive vibration arm 1002a and the vibration direction e1 of the adjustment vibration arm 1004a move in the same direction. Similarly, the vibration direction f2 of the adjacent drive vibration arm 1002b and the vibration direction e2 of the adjustment vibration arm 1004b move in the same direction. In addition, each also vibrates in the same phase direction in the vibration in the direction opposite to the above. By vibrating in such a vibration mode (Tu-mode vibration, so-called tuning fork vibration), the vibration vectors (motion vectors) in the drive vibration arms 1002a and 1002b and the adjustment vibration arms 1004a and 1004b can be balanced and stable. Vibration is performed.

  However, the shape of each vibrating arm or the extended portion (base) of the vibrating arm from the base 1001 varies due to manufacturing variations in the formation process of the gyro element 1010, thereby deviating from the stable vibration mode as described above. Vibration mode (vibration in “TuX” mode) appears. This “TuX” mode vibration will be described with reference to FIG. Note that the configuration of the gyro element 1010 is the same as that shown in FIG.

  In the vibration in the “TuX” mode, each of the vibrating arms 1004a and 1004b for adjustment moves in the same direction (in phase). 10B, the adjustment vibrating arm 1004a moves in the vibration direction e3, and the other adjustment vibration arm 1004b moves in the vibration direction e4. That is, the pair of adjustment vibrating arms 1004a and 1004b move in the same direction (in phase). When such “TuX” mode vibration occurs, the balance of the vibration vectors (motion vectors) between the driving vibration arms 1002a and 1002b and the adjustment vibration arms 1004a and 1004b is lost, resulting in the occurrence of leakage vibration. Will increase.

  However, the gyro element 10 of the present example is formed at a portion (root) extending from the base portion 1,1001 of each vibrating arm because the interval between the vibrating arms is configured as in the above-described embodiment. It becomes possible to form a stable shape of the etching residue. As a result, it is possible to suppress the vibration leakage output caused by these, or the unnecessary mode vibration (TuX mode vibration), and to stabilize the vibration characteristics of the vibration piece. Can be obtained.

  FIG. 11 is a graph showing the relationship between the distance between the vibrating arms of the gyro element 10 according to the above-described embodiment and the amount of charge acquired from the adjusting vibrating arm. When the relationship between the horizontal axis and the substrate thickness t is B <t, the distance B between the pair of detection vibrating arms 3a and 3b, and the detection vibrating arm 3a adjacent to one adjustment vibrating arm 4a , And the distance C between the other adjustment vibration arm 4b and the adjacent detection vibration arm 3b. The vertical axis represents the amount of charge acquired from the adjustment vibrating arm.

  As shown in the graph of FIG. 11, when the ratio of the interval B to the interval A or the interval C exceeds 0.8, the amount of charge acquired from the adjustment vibrating arm becomes positive and a normal vibration mode is obtained. I understand that. Thus, when the relationship between the distance B and the thickness t of the base material is B <t, the distance B, the distance A, and the distance C are B × 0.8 <A <B × 1. In the configuration of 2 and B × 0.8 <C <B × 1.2, suppression of vibration leakage output or suppression of unnecessary mode vibration (TuX mode vibration) can be realized.

  In addition, like the gyro element 1A and the gyro element 1B described with reference to FIGS. 3A and 3B, the frame-shaped fixing part 7 connected to the base 1 by the first connecting part 5a and the second connecting part 6a, Similar effects can be obtained even with a configuration having eight shapes and having the first fixing portion 5b and the second fixing portion 6b.

  After the leakage output suppression adjustment is performed, the frequency of the gyro element 10 bonded to the package 110 is finely adjusted. The frequency adjustment is performed by removing a part of the electrode of the gyro element 10 by laser trimming to reduce the mass, by adding mass to the gyro element 10 by vapor deposition or sputtering, or by the semiconductor device 120. This can be done by a method of rewriting data.

(Other gyro sensors)
FIG. 12 shows a gyro sensor 10A that accommodates the gyro element 1B shown in FIG. 3B in place of the gyro element 10 in the gyro sensor 100 according to the third embodiment, and FIG. (B) is sectional drawing of the DODD section shown to (a). In addition, the same code | symbol is attached | subjected to the same structure as the gyro sensor 100 shown in FIG. 6, and description is abbreviate | omitted.

  As shown in FIG. 12, the gyro element 1 </ b> B is placed on the third substrate surface 113 a of the third substrate 113. In the gyro element 1B, the fixing portion 8 is placed in alignment with the connection pads 11f, 12f, 21h, 22f, 31h, and 32f (see FIG. 2) and the gyro element connection terminal 113b. Bonded and fixed. Further, the portions of the fixing portion 8 where the connection pads 11f, 12f, 21h, 22f, 31h, and 32f are not formed are bonded and fixed by the adhesive 170. As the adhesive 170, the conductive adhesive 150 used for the gyro element connection terminal 113b may be used.

  By configuring the gyro sensor 10A using the gyro element 1B having the frame-shaped fixing portion 8, the gyro element 1B is fixed to the package 110 by being bonded and fixed over a wide area by the adhesive 170. A strong gyro sensor can be obtained. Therefore, it is possible to further suppress the vibrations of the drive vibrating arms 2 a and 2 b and the detection vibrating arms 3 a and 3 b from leaking to the package 110.

(Electronic device according to the fourth embodiment)
FIG. 13 shows an external view of an electronic device including the gyro element 10 or the gyro elements 1A, 1B, and 1C according to the first embodiment as the fourth embodiment. FIG. 13A shows a digital video camera 1000 including the gyro element 10 or the gyro elements 1A, 1B, and 1C. The digital video camera 1000 includes an image receiving unit 1100, an operation unit 1200, an audio input unit 1300, and a display unit 1400. Such a digital video camera 1000 can be provided with a camera shake correction function including the gyro elements 10 and 1A of the above-described embodiment and the gyro sensors 100 and 10A as sensor units.

  FIG. 13B shows a mobile phone as an electronic device, and FIG. 13C shows an application example to a personal digital assistant (PDA). A cellular phone 2000 shown in FIG. 13B includes a plurality of operation buttons 2100, scroll buttons 2200, and a display unit 2300. By operating the scroll button 2200, the screen displayed on the display unit 2300 is scrolled. A PDA 3000 shown in FIG. 13C includes a plurality of operation buttons 3100, a power switch 3200, and a display unit 3300. When the power switch 3200 is operated, various types of information such as an address book and a schedule book are displayed on the display unit 3300.

  Various functions can be provided by mounting the gyro elements 10 and 1A of the above-described embodiment and the gyro sensors 100 and 10A as sensor units on the cellular phone 2000 and the PDA 3000. For example, when a camera function (not shown) is added to the mobile phone 2000 of FIG. 13B, camera shake correction can be performed in the same manner as the digital video camera 1000 described above. In addition, when the cellular phone 2000 of FIG. 13B or the PDA 3000 of FIG. 13C is provided with a global positioning system widely known as GPS (Global Positioning System), the gyro element 10 of the above-described embodiment is used. 1A and the gyro sensor 100, 10A as a sensor unit, the position and orientation of the mobile phone 2000 and the PDA 3000 can be recognized by GPS.

  Note that the present invention is not limited to the electronic device shown in FIG. 13, and an electronic device to which the sensor unit (gyro sensor) including the resonator element according to the invention can be applied includes a mobile computer, a car navigation device, an electronic notebook, a calculator, a workstation, a television A telephone, a POS terminal, a game machine, etc. are mentioned.

Although the embodiment has been specifically described above, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. For example, in the above-described embodiment and modification, an example in which quartz is used as the gyro element forming material as the resonator element has been described, but 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 ( Laminated Gauge substrate such as La ₃ Ga ₅ SiO ₁₄ ), laminated piezoelectric substrate constructed by laminating a piezoelectric material such as aluminum nitride or tantalum pentoxide (Ta ₂ O ₅ ) on a glass substrate, 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 resonator element can be formed using a silicon semiconductor material or the like. Further, the vibration (drive) method of the resonator element is not limited to piezoelectric drive. In addition to the piezoelectric drive type using the piezoelectric substrate, the configuration and the effect of the present invention can be exhibited also in an electrostatic drive type using an electrostatic force or a Lorenz drive type using a magnetic force. it can.

  Further, in the above-described modification, the example in which the weight portions 16a and 16b as the wide portions are provided at the free ends of the adjustment vibrating arms 15a and 15b to increase the adjustment width for suppressing the leakage output has been described. . Not limited to this, by providing a weight portion as a wide portion at the free end of the drive vibration arm or detection vibration arm, the resonance frequency can be lowered while suppressing an increase in the external size of the resonator element (gyro element). It is possible to reduce the size and increase the sensitivity.

  DESCRIPTION OF SYMBOLS 1 ... Base part, 2a, 2b ... Drive vibration arm, 3a, 3b ... Detection vibration arm, 4a, 4b ... Adjustment vibration arm, 5 ... 1st support part, 5a ... 1st connection part, 5b ... 1st fixation Part, 6 ... 2nd support part, 6a ... 2nd connection part, 6b ... 2nd fixing | fixed part, 10, 1A, 1B, 1C ... Gyro element, 100, 10A ... Gyro sensor.

Claims (7)

A vibrating piece formed from a substrate having a thickness of t,
The base,
A pair of vibrating arms for detection extending from one end of the base,
A pair of driving vibrating arms extending from the other end of the base opposite to the one end, and the detecting vibrating arm or the driving vibrating arm extending from either the one end or the other end A pair of adjustment vibrating arms provided so as to sandwich the
The thickness t;
A distance B between a pair of arms of the vibrating arm for detection or the vibrating arm for driving;
An interval A between one of the adjusting vibrating arms and one of the adjusting vibrating arms adjacent to the adjusting vibrating arm or the driving vibrating arm;
The relationship between the other adjustment vibration arm and the distance C between the other detection vibration arm or the drive vibration arm adjacent to the adjustment vibration arm is:
B <t, B × 0.8 <A <B × 1.2, and B × 0.8 <C <B × 1.2,
A vibrating piece characterized by being. The resonator element according to claim 1,
And a pair of balance vibrating arms provided so as to sandwich the pair of adjustment vibrating arms.
An interval D between one of the adjustment vibrating arms and one of the adjustment vibrating arms adjacent to the adjustment vibrating arm;
The relationship between the other vibrating arm for adjustment and the distance E between the other vibrating arm adjacent to the adjusting vibrating arm is:
A × 0.8 <D <A × 1.2, and C × 0.8 <E <C × 1.2,
A vibrating piece characterized by being. In the resonator element according to claim 1 or 2,
The detection vibrating arm is provided with a detection electrode,
The adjustment vibrating arm is provided with a metal film,
The metal film and the detection electrode are electrically connected;
A vibrating piece characterized by that. In the resonator element according to any one of claims 1 to 3,
A wide portion is provided at the tip of the adjustment vibrating arm on the side opposite to the base side.
A vibrating piece characterized by that. In the resonator element according to any one of claims 1 to 4,
The length of the adjustment vibration arm is shorter than the length of the drive vibration arm and the detection vibration arm,
A vibrating piece characterized by that. A vibrating piece according to any one of claims 1 to 5,
An electronic component comprising: a drive circuit for exciting the drive vibration arm; and a detection circuit for detecting a detection signal generated in the detection vibration arm;
A sensor unit comprising: the resonator element; and a package that accommodates the electronic component.   An electronic device comprising the resonator element according to claim 1.

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