JP2016170141A - Vibration piece, gyro sensor, electronic apparatus, and mobile body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibration piece having a high Q-value and excellent shock resistance, and a gyro sensor, an electronic apparatus and a mobile body including the vibration piece.SOLUTION: The vibration piece has a base part 10 and a pair of first vibration arms 12a, 12b extending from the base part 10, in which through-holes 26a1, 26a2, 26b1, 26b2 are formed in the first vibration arms 12a, 12b. The through-holes 26a1, 26a2, 26b1, 26b2 include: first through holes 26a1, 26b1 where a hole width on a side close to an end 10a of the base part 10 from which the first vibration arms 12a, 12b extend, decreases toward the tips of the first vibration arms 12a, 12b; and second through-holes 26a2, 26b2 where a hole width on a side close to the tip of the first vibration arms 12a, 12b decreases toward the end 10a.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a resonator element, a gyro sensor including the resonator element, an electronic device, and a moving object.

  Conventionally, gyro sensors have been used in technologies that autonomously control the attitude of ships, aircraft, rockets, etc., but recently, vehicle body control in vehicles, position detection of car navigation systems, digital cameras, video cameras, It is also used for vibration control correction (so-called camera shake correction) for mobile phones. The gyro sensor uses a gyro element made of a piezoelectric single crystal such as quartz as a highly elastic material to detect an electrical signal generated in a part of the gyro element as an angular velocity due to vibrations such as shaking or rotation of the object as a rotation angle. Is obtained by calculating the displacement of the object.

  As a gyro element used for a gyro sensor, a gyro element formed of a piezoelectric material such as quartz is widely used. A commonly used gyro element called an H-type structure has a base, a pair of drive vibrating arms extending in parallel from one end of the base, and a drive vibration from the other end of the base. A pair of vibrating arms for detection extending in parallel to the direction in which the arms extend. When the drive vibration arm is vibrated in the direction along the main surface by applying a drive signal to the gyro element (in-plane vibration), the drive vibration arm is rotated around the axis in the extending direction. The driving vibrating arm vibrates in the direction orthogonal to the main surface (out-of-plane vibration) by the Coriolis force. This out-of-plane vibration is transmitted through the base and vibrates the detection vibrating arm out of plane, whereby charges are generated in the detection electrodes provided on the detection vibrating arm. Since the generated electric charge is proportional to the rotational speed of the gyro element, it can be detected as an angular speed.

  With recent miniaturization of digital cameras, video cameras, and mobile phones, gyro elements are required to be miniaturized together with gyro sensors used for camera shake correction and the like. However, when the gyro element is downsized, there is a problem that the equivalent series resistance R1 is large and the Q value is small, so that high sensitivity cannot be obtained. Therefore, the gyro element described in Patent Document 1 (referred to as an inertial sensor element in Patent Document 1) includes a through-hole having a shape in which an opening major axis is arranged in the length direction of the vibrating arm portion in the vibrating arm portion. By arranging a plurality of these along the length direction, the equivalent series resistance R1 is small, the Q value is large, and high sensitivity is obtained.

JP 2006-208261 A

  However, in the gyro element described in Patent Document 1, if the wall thickness on both sides of the through hole provided in the vibrating arm portion is made thin in order to further improve the sensitivity, the vibrating arm portion is damaged when an impact is applied. was there.

  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 vibrating piece according to this application example is a vibrating piece having a base portion and a pair of first vibrating arms extending from the base portion, and each of the first vibrating arms has a through hole. The through-hole has a first portion having a hole width that becomes narrower from an end portion side of the base portion where the first vibrating arm extends toward a distal end side of the first vibrating arm. It includes a through hole and a second through hole having a portion whose hole width becomes narrower from the distal end side of the first vibrating arm toward the end portion.

  According to this application example, since the through hole is provided in the first vibrating arm, the sensitivity can be improved. Further, the hole width of the first through hole becomes narrower from the end side of the base portion toward the distal end side of the first vibrating arm, and conversely, the hole width of the second through hole extends from the distal end side of the first vibrating arm to the base portion. Since it is narrowing toward the end, the first through-hole and the second through-hole can be provided with a connecting portion in the first vibrating arm, which increases the rigidity against bending in the hole width direction, and has an impact resistance. Improvements can be made. Therefore, it is possible to obtain a resonator element having high sensitivity and excellent impact resistance.

  Application Example 2 In the resonator element according to the application example described above, it is preferable that the through hole has a right triangle shape or an isosceles triangle shape in plan view.

  According to this application example, since the through hole has a right triangle shape, the wall thickness on the side where the right angle portion of the through hole is arranged can be made substantially constant, so that the electric field efficiency can be improved. , Sensitivity can be improved. In addition, since the through-hole has an isosceles triangle shape, the isosceles portion can form a connecting portion and can be formed so as to be in contact with the end portion of the base portion. Can be further improved in rigidity, and impact resistance can be further improved.

  Application Example 3 In the resonator element according to the application example described above, the resonator element includes a pair of second vibrating arms extending from an end opposite to the base side from which the first vibrating arm extends. It is preferable that the vibrating arm is formed by arranging a plurality of through holes along a direction in which the second vibrating arm extends.

  According to this application example, the detection vibrating arm, the driving vibrating arm, and the driving vibrating arm have the H-shaped structure with the first vibrating arm as the detecting vibrating arm and the second vibrating arm as the driving vibrating arm. Since the through-holes are respectively provided, a vibrating piece for a gyro with low impedance and high sensitivity can be obtained. Moreover, since the connection part is formed in the vibration arm for a detection of the 1st vibration arm by the 1st through-hole and the 2nd through-hole, it is excellent in impact resistance.

  Application Example 4 A gyro sensor according to this application example includes the resonator element according to the above application example, an electronic component including a circuit for driving the resonator element and a circuit for detecting a signal, the resonator element, and the electronic component. And a package for housing the device.

  According to this application example, there is an effect that a gyro sensor including a resonator element having high sensitivity and excellent impact resistance can be configured.

  Application Example 5 An electronic apparatus according to this application example includes the resonator element according to the application example.

  According to this application example, there is an effect that it is possible to configure an electronic device including a resonator element having high sensitivity and excellent impact resistance.

  Application Example 6 A moving object according to this application example includes the resonator element according to the application example.

  According to this application example, there is an effect that it is possible to configure a moving body that includes a resonator element having high sensitivity and excellent impact resistance.

FIG. 3 is a schematic plan view showing a structure of a gyro element as an example of a resonator element according to the first embodiment of the invention. The graph which shows the correlation with wall thickness t and impedance of the gyro element as an example of the resonator element which concerns on embodiment of this invention. The graph which shows the correlation with the wall thickness t of a gyro element as an example of the vibrating element which concerns on embodiment of this invention, and a sensitivity. FIG. 3 is a schematic plan view for explaining the operating principle of a gyro element as an example of a resonator element according to the first embodiment of the invention. The schematic plan view which shows the structure of the gyro element as an example of the vibration piece which concerns on 2nd Embodiment of this invention. The schematic plan view which shows the structure of the gyro element as an example of the vibration piece which concerns on 3rd Embodiment of this invention. The schematic plan view which shows the structure of the gyro element as an example of the vibration piece which concerns on 4th Embodiment of this invention. It is the schematic which shows the structure of a gyro sensor provided with the gyro element as an example of the vibration piece which concerns on embodiment of this invention, (a) is a schematic plan view, (b) is the AA line in (a). FIG. The perspective view which shows the structure of the mobile type (or notebook type) personal computer which shows an electronic device provided with the gyro element as an example of the vibration piece which concerns on embodiment of this invention. The perspective view which shows the structure of the mobile telephone (PHS is also included) which shows an electronic device provided with the gyro element which concerns on embodiment of this invention. The perspective view which shows the structure of the digital camera as an electronic device provided with the gyro element as an example of the vibration piece which concerns on embodiment of this invention. The perspective view which shows the structure of the motor vehicle as a moving body provided with the gyro element as an example of the vibration piece which concerns on embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following drawings, the scale of each layer and each member is different from the actual scale so that each layer and each member can be recognized. 1 and 4 to 8, 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 tip side of the illustrated arrow is the “+ side”, The base end side is defined as “− side”. In the following description, 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”. say. Furthermore, for convenience of explanation, the surface in the Z-axis direction will be described as a main surface in a plan view when viewed from the Z-axis direction.

<First Embodiment>
[Gyro element]
As an example of the resonator element according to the first embodiment of the invention, a gyro element having a structure called an H-type is cited and described with reference to FIGS.
FIG. 1 is a schematic plan view showing the structure of a gyro element as an example of a resonator element according to the first embodiment of the invention. Note that the driving electrode and the detection electrode are not shown for convenience of explanation.
FIG. 2 is a graph showing the correlation between the wall thickness t and the impedance of the gyro element as an example of the resonator element according to the embodiment of the invention. FIG. 3 is a graph showing the correlation between the wall thickness t and the sensitivity of the gyro element as an example of the resonator element according to the embodiment of the invention.

(Gyro element structure)
As shown in FIG. 1, the gyro element 100 includes a rectangular base 10 integrally formed by processing a base material (material constituting a main part), and a direction intersecting with the long side direction of the base 10 (Y A pair of detection vibrating arms 12a and 12b as a pair of first vibrating arms extending from one end 10a of the ends 10a and 10b in the axial direction in parallel along the + Y-axis direction; A pair of drive vibrating arms 14a, 14b as a pair of second vibrating arms extended from the other end 10b opposite to the one end 10a of the 10 in parallel along the -Y-axis direction; And a pair of adjustment vibrating arms 16a and 16b extending in parallel along the + Y-axis direction from one end portion 10a.

  The detection vibrating arms 12a and 12b are formed with first through holes 26a1 and 26b1 and second through holes 26a2 and 26b2 arranged along the extending direction of the detection vibrating arms 12a and 12b. Also, a plurality of through holes 28a1, 28a2, 28b1, 28b2 are arranged and formed in the driving vibrating arms 14a, 14b along the extending direction of the driving vibrating arms 14a, 14b.

  Moreover, the 1st connection part 20a extended from the base 10 and the 1st support part 22a connected to the 1st connection part 20a, and the 2nd connection part 20b extended in the opposite direction to the 1st connection part 20a from the base 10 And a second support portion 22b connected to the second connection portion 20b. Further, the first support portion 22a and the second support portion 22b are integrally connected on the drive vibrating arms 14a and 14b side to form a fixed frame portion 24. The gyro element 100 is fixed to a substrate such as a package (not shown) at a predetermined position of the fixed frame portion 24.

  The detection vibrating arms 12a and 12b as the first vibrating arms extend along the + Y-axis direction from one end portion 10a of the base 10, and the arm width (length in the X-axis direction) of the detection vibrating arms 12a and 12b. ) Is the arm width (length in the X-axis direction) at one end portion 10a joined to the base 10, and the arm width (length in the X-axis direction) at the tip end portion in the + Y-axis direction of the detection vibrating arms 12a and 12b. ) And are substantially the same.

  In the detection vibrating arm 12a, a first through hole 26a1 and a second through hole 26a2 are arranged along the extending direction (+ Y-axis direction) of the detection vibrating arm 12a and formed with the connecting portion 34a interposed therebetween. Similarly to the detection vibrating arm 12a, the first through hole 26b1 and the second through hole 26b2 are arranged in the detection vibrating arm 12b along the extending direction (+ Y-axis direction) of the detection vibrating arm 12b. It is formed with the connecting portion 34b interposed therebetween.

  The first through holes 26a1 and 26b1 are arranged on the end 10a side of the detection vibrating arms 12a and 12b, and the hole width (X-axis direction) on the end 10a side of the base 10 from which the detection vibrating arms 12a and 12b extend. Has a portion that becomes narrower from the end portion 10a side of the base portion 10 toward the tips in the + Y-axis direction of the detection vibrating arms 12a and 12b. The second through holes 26a2 and 26b2 are disposed on the front end side in the + Y-axis direction of the detection vibrating arms 12a and 12b, and the hole width (the length in the X-axis direction) on the front end side in the + Y-axis direction of the detection vibrating arms 12a and 12b. ) Has a portion that becomes narrower from the tip in the + Y-axis direction of the detection vibrating arms 12a and 12b toward the end 10a of the detection vibrating arms 12a and 12b. The so-called first through holes 26a1 and 26b1 have a right-angled triangle shape with the right-angled portion on the end 10a side in plan view. The shape of the second through-holes 26a2 and 26b2 is a right-angled triangle with the right-angled portion being the tip side of the detection vibrating arms 12a and 12b in plan view.

  The detection vibrating arm 12 a is provided so that one end of the connecting portion 34 a that forms the first through hole 26 a 1 and the second through hole 26 a 2 is in contact with one end portion 10 a of the base portion 10. The detection vibrating arm 12 b is provided so that one end of the connecting portion 34 b forming the first through hole 26 b 1 and the second through hole 26 b 2 is in contact with one end portion 10 a of the base portion 10. Therefore, since the detection vibrating arms 12a and 12b can increase the rigidity against bending in the hole width direction (X-axis direction), the shock resistance can be improved.

  The detection vibrating arm 12a has a substantially constant wall thickness (length in the X-axis direction) t due to the side walls 30a1 and 30a2 of the detection vibrating arm 12a and the first through hole 26a1 and the second through hole 26a2. It is formed to become. The detection vibrating arm 12b has a substantially constant wall thickness (length in the X-axis direction) t due to the side walls 30b1 and 30b2 of the detection vibrating arm 12b and the first through hole 26b1 and the second through hole 26b2. It is formed to become.

  Therefore, the electric field efficiency of the detection vibrating arms 12a and 12b can be increased, and the sensitivity can be improved. In addition, in the in-plane mode bending vibration that vibrates in the X-axis direction and the out-of-plane mode bending vibration that vibrates in the Z-axis direction, which will be described later, the amount of displacement in the ± X-axis direction or ± Z-axis direction is uniform, and stable bending Vibration can be excited.

  In the present embodiment, the shapes of the first through holes 26a1, 26b1 and the second through holes 26a2, 26b2 are right-angled triangles. However, the present invention is not limited to this. A trapezoidal shape having two right angle portions along the extending direction (+ Y-axis direction) of 12a and 12b may be used.

Here, the thicknesses of the side walls 32a1, 32a2, 32b1, 32b2 of the driving vibrating arms 14a, 14b, the inner walls of the first through holes 28a1, 28b1, and the inner walls of the second through holes 28a2, 28b2 are used. The relationship between the wall thickness t and the impedance of the gyro element 100 will be described with reference to FIG.
FIG. 2 shows the structure of the driving vibrating arms 14a and 14b of the present embodiment. The impedances of the driving vibrating arms 14a and 14b when the wall thickness t of the driving vibrating arms 14a and 14b is changed from 12 μm to 21 μm. It is the graph which showed the result analyzed by the finite element method (FEM), a horizontal axis shows wall thickness t of drive vibration arms 14a and 14b, and a vertical axis shows impedance of drive vibration arms 14a and 14b. ing.

  From FIG. 2, the impedance of the drive vibrating arms 14a and 14b tends to decrease as the wall thickness t increases and tends to be excited, and becomes substantially constant at about 30 kΩ when the wall thickness t exceeds about 20 μm. Therefore, it can be seen that when the wall thickness t is less than about 20 μm, the impedance increases, which is not suitable for the design of the driving vibrating arms 14a and 14b.

  Next, FIG. 3 shows the structure of the gyro element 100 of the present embodiment, and the sensitivity to the angular velocity around the Y axis of the gyro element 100 when the wall thickness t of the detection vibrating arms 12a and 12b is changed from 10 μm to 14 μm. Is a graph showing the results of analysis by a finite element method (FEM), the horizontal axis indicates the wall thickness t of the detection vibrating arms 12a and 12b, and the vertical axis indicates the gyro when the wall thickness t is 10 μm. The sensitivity based on the sensitivity of the element 100 is shown.

  As shown in FIG. 3, the sensitivity of the gyro element 100 tends to decrease as the wall thickness t increases, and is about 88.9% of the sensitivity when the wall thickness t is 12 μm and the wall thickness t is 10 μm. At 14 μm, the wall thickness t is about 74.7% of the sensitivity at 10 μm. Therefore, it can be seen that the sensitivity decreases to about 75% when the wall thickness t becomes 1.4 times thicker.

  Next, returning to FIG. 1, the driving vibrating arms 14a and 14b as the second vibrating arms are -Y from the other end 10b opposite to the base 10 side from which the detecting vibrating arms 12a and 12b extend. The arm width (length in the X-axis direction) of the driving vibrating arms 14a and 14b extends substantially along the axial direction and is substantially constant toward the tip in the -Y-axis direction. That is, the arm width (length in the X-axis direction) at the other end portion 10b joined to the base portion 10 of the drive vibrating arms 14a, 14b and the arm width (X-axis direction) at the tip portions of the drive vibrating arms 14a, 14b. The length is substantially the same.

Two through-holes 28a1 and 28a2 are arranged in the driving vibrating arms 14a and 14b along the extending direction (−Y-axis direction) of the driving vibrating arm 14a so as to sandwich the connecting portion 36a. Similarly to the driving vibration arm 14a, two through holes 28b1 and 28b2 are arranged in the driving vibration arm 14b along the extending direction (−Y-axis direction) of the driving vibration arm 14b. 36b is interposed therebetween.
The shape of the through holes 28a1, 28a2, 28b1, and 28b2 is a rectangular shape having a long side in the extending direction (Y-axis direction) of the driving vibrating arms 14a and 14b in plan view.

  In the present embodiment, in each of the pair of driving vibrating arms 14a and 14b, two through holes are formed in each vibrating arm, but the present invention is not limited to this, and the vibrating arms extend. Two or more plural pieces may be formed on the vibrating arm along the direction. By forming two or more through holes in the vibrating arm, it is possible to provide a plurality of connecting portions on the vibrating arm, and to increase the strength of the vibrating arm against impact while reducing the impedance due to the through hole. Can do.

  Next, weight portions 42a and 42b are provided at the distal ends of the detection vibrating arms 12a and 12b, and weight portions 44a and 44b are provided at the distal ends of the drive vibrating arms 14a and 14b. By providing the weight portions 42a, 42b, 44a, 44b, the length in the extending direction of the detection vibrating arms 12a, 12b and the driving vibrating arms 14a, 14b with the same resonance frequency (length in the Y-axis direction). Therefore, the gyro element 100 can be downsized. Further, the resonance frequencies of the detection vibrating arms 12a and 12b and the driving vibrating arms 14a and 14b can be lowered. Furthermore, the weight portions 42a, 42b, 44a, 44b may have a plurality of widths (lengths in the X-axis direction) as necessary, or may be omitted. The mass portions (not shown) formed of a metal film or the like are provided on the weight portions 42a, 42b, 44a, 44b, and a part of the mass portion is removed with a laser beam or the like, thereby detecting the vibrating arms 12a, The resonance frequency of 12b and drive vibrating arms 14a and 14b can be adjusted.

  In the gyro element 100 of the present embodiment, an example in which quartz that is a piezoelectric material is used as a base material will be described. The base material forming the gyro element 100 is cut out along a plane defined by the X-axis and the Y-axis orthogonal to the crystal crystal axis, processed into a flat plate shape, and has a predetermined thickness in the Z-axis direction orthogonal to the plane. doing. What is cut out by rotating in the range of 0 to 2 degrees around the X axis can be used. The same applies to the Y axis and the Z axis. In this embodiment, the gyro element 100 uses quartz, but other piezoelectric materials such as lithium tantalate and lead zirconate titanate may be used as a base material. The predetermined thickness (the length in the Z-axis direction) is appropriately set depending on the vibration frequency, the outer size, workability, and the like.

  Further, as shown in FIG. 1, the gyro element 100 includes the detection vibrating arms 12a and 12b in parallel with the detection vibrating arms 12a and 12b in a direction intersecting the crystal X axis (electrical axis) of the crystal. A pair of adjustment vibrating arms 16 a and 16 b extending from one end portion 10 a of the base portion 10 are provided so as to be sandwiched between them. That is, the adjustment vibrating arms 16a and 16b extend in the + Y-axis direction along the Y axis, and are positioned so as to be sandwiched inside and spaced apart from the detection vibrating arms 12a and 12b by a predetermined distance. Is provided.

  The adjustment vibrating arms 16a and 16b are sometimes called tuning arms. By providing the adjustment vibrating arms 16a and 16b, the cross-sectional shape of the driving vibrating arms 14a and 14b is not rectangular due to the etching anisotropy of quartz and the variation in the processing process. It is possible to adjust the deviation from the design value of the vibration direction of the drive vibrating arms 14a and 14b due to the parallelogram or rhombus, that is, the leak output due to so-called vibration leakage. In other words, the drive vibration leaks (propagates), and the charges of the detection vibrating arms 12a and 12b generated by so-called vibration leakage can be offset by the charges generated in the adjustment vibrating arms 16a and 16b.

  The adjustment vibrating arms 16a and 16b are formed to have a shorter overall length than the detection vibrating arms 12a and 12b and the driving vibrating arms 14a and 14b. Thereby, the vibration of the adjustment vibrating arms 16a and 16b for adjusting the leakage output does not hinder the main vibration of the gyro element 100 by the detection vibrating arms 12a and 12b and the driving vibrating arms 14a and 14b. Therefore, the vibration characteristics of the gyro element 100 are stabilized, and the gyro element 100 is advantageously reduced in size.

  Further, the tip of the other end side opposite to the one end connected to the base portion 10 of the adjustment vibrating arms 16a, 16b is wider than the adjustment vibration arms 16a, 16b (the dimension in the X-axis direction is large). Rectangular weight portions 46a and 46b are provided. As described above, by providing the weight portions 46a and 46b at the tip portions of the adjustment vibrating arms 16a and 16b, mass change in the adjustment vibrating arms 16a and 16b can be made remarkable, and the sensitivity of the gyro element 100 can be increased. The effect which contributes to can be further improved.

  The center of the base 10 can be the center of gravity of the gyro element 100. 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 100 can be symmetric with respect to a virtual center line in the Y-axis direction passing through the center of gravity. Accordingly, the outer shape of the gyro element 100 is well balanced, which is preferable because the characteristics of the gyro element 100 are stabilized and the detection sensitivity is improved. Such an outer shape of the gyro element 100 can be formed by etching (wet etching or dry etching) using a photolithography technique. A plurality of gyro elements 100 can be obtained from one crystal wafer.

(Gyro element operating principle)
Next, the principle of operation of the gyro element 100 will be described with reference to FIG.
FIG. 4 is a schematic diagram for explaining the operation principle of the gyro element according to the first embodiment of the present invention, FIG. 4 (a) is a schematic plan view showing a driving state, and FIG. 4 (b) is a Y-axis. It is a schematic plan view which shows the detection state to which angular velocity (omega) rotated around is applied. For convenience of explanation, only the periphery of the base 10 is shown. In FIG. 4B, 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.

  When a predetermined AC voltage is applied to the drive electrode in the drive mode, the drive vibrating arms 14a and 14b are reversed in the XY in-plane direction, that is, close to and away from each other, as shown in FIG. Bending vibration (in-plane mode vibration). Further, the adjustment vibrating arms 16a and 16b resonate with the bending vibration (in-plane mode vibration) of the driving vibrating arms 14a and 14b via the base 10, and in the XY plane similarly to the driving vibrating arms 14a and 14b. Bending vibration (in-plane mode vibration) occurs in the direction opposite to the direction, that is, in the direction approaching or separating from each other.

  In this state, when the gyro element 100 applies an angular velocity ω that rotates around the Y axis that is the extending direction of each vibrating arm, the action of the Coriolis force generated according to the angular velocity ω causes an action as shown in FIG. In addition, the driving vibrating arms 14a and 14b undergo bending vibration (out-of-plane mode vibration) in directions opposite to each other in the out-of-plane direction perpendicular to the main surface, that is, the Z-axis direction. Resonating with the vibration in the Z-axis direction, the detection vibrating arms 12a and 12b perform bending vibrations (out-of-plane mode vibrations) in the opposite directions in the Z-axis direction in the detection mode. At this time, the vibration direction of the detection vibrating arms 12a and 12b is opposite in phase to the vibration direction of the driving vibration arms 14a and 14b.

  That is, when the driving vibrating arm 14a vibrates in the + Z-axis direction, the driving vibrating arm 14b becomes an out-of-plane mode bending vibration that vibrates in the −Z-axis direction. The bending vibrations in the out-of-plane mode of the driving vibrating arms 14a and 14b are transmitted to the detecting vibrating arms 12a and 12b via the base 10, thereby resonating the detecting vibrating arms 12a and 12b. When vibrating in the −Z-axis direction, the detection vibrating arm 12b becomes an out-of-plane mode bending vibration that vibrates in the + Z-axis direction.

  In this detection mode, the angular velocity ω applied to the gyro element 100 is obtained by taking out the amount of charge generated between the detection electrodes (not shown) of the detection vibrating arms 12a and 12b.

Second Embodiment
Next, a gyro element 100a as a resonator element according to a second embodiment of the invention will be described with reference to FIG.
FIG. 5 is a schematic plan view showing the structure of a gyro element as an example of a resonator element according to the second embodiment of the invention.
Hereinafter, the gyro element 100a according to the second embodiment will be described focusing on differences from the gyro element 100 of the first embodiment described above. Moreover, the same code | symbol is attached | subjected to the same structure and the description is abbreviate | omitted about the same matter.

  In the gyro element 100a according to the second embodiment, the shapes of the detection vibrating arms 121a and 121b are different, and three through holes are provided in each of the pair of detection vibrating arms 121a and 121b. In the detection vibrating arm 121a, a first through hole 261a1, a third through hole 261a3, and a second through hole 261a2 are arranged along the extending direction (+ Y-axis direction) of the detection vibrating arm 121a to connect the connecting portions 341a1, 341a2 is interposed therebetween. Similarly to the detection vibrating arm 121a, the detection vibrating arm 121b also includes the first through hole 261b1, the third through hole 261b3, and the first through hole 261b3 along the extending direction (+ Y-axis direction) of the detection vibrating arm 121b. Two through holes 261b2 are arranged and formed so as to sandwich the connecting portions 341b1 and 341b2.

  The shape of the first through holes 261a1, 261b1 is the same as that of the first embodiment, and is a right triangle having a right angle portion on the end 10a side. The shape of the second through holes 261a2 and 261b2 is the same as that of the first embodiment, is a right triangle shape, and the right angle portion is the front end side in the + Y-axis direction, and the right angle portions of the first through holes 261a1 and 261b1 are arranged. Is placed on the side that is. The shape of the third through-hole 261a3 is an isosceles triangular shape in which the connecting portions 341a1 and 341a2 forming the first through-hole 261a1 and the second through-hole 261a2 are isosceles sides and both base angles are the adjustment vibrating arm 16a side. It is. Further, the shape of the third through hole 261b3 is an isosceles side in which the connecting portions 341b1 and 341b2 forming the first through hole 261b1 and the second through hole 261b2 are isosceles sides and both base angles are the adjustment vibrating arm 16b side. It is triangular.

  In addition, the detection vibrating arm 121a includes a wall thickness (length in the X-axis direction) t formed by the side wall 301a2 of the detection vibrating arm 121a, the first through hole 261a1, and the second through hole 261a2, and the detection vibrating arm 121a. The wall thickness (length in the X-axis direction) t by the side wall 301a1 and the third through hole 261a3 is formed to be substantially constant. Further, the detection vibrating arm 121b includes a wall thickness (length in the X-axis direction) t formed by the side wall 301b1 of the detection vibrating arm 121b, the first through hole 261b1, and the second through hole 261b2, and the detection vibrating arm 121b. The wall thickness (length in the X-axis direction) t by the side wall 301b2 and the third through hole 261b3 is formed to be substantially constant.

  With such a configuration, in addition to the effects in the first embodiment, the connecting portions 341a1, 341a2, 341b1, and 341b2 are formed on the vibrating arms whose strength is reduced by providing the through holes. The rigidity against bending in the (X-axis direction) is further increased, and the impact resistance in the arm width direction (X-axis direction) of the detection vibrating arms 121a and 121b can be further improved. Therefore, it is possible to obtain the gyro element 100a including the detection vibrating arms 121a and 121b having high sensitivity and excellent impact resistance.

<Third Embodiment>
Next, a gyro element 100b as a resonator element according to a third embodiment of the invention will be described with reference to FIG.
FIG. 6 is a schematic plan view showing the structure of a gyro element as an example of a resonator element according to the third embodiment of the invention.
Hereinafter, the gyro element 100b according to the third embodiment will be described focusing on differences from the gyro element 100 of the first embodiment described above. Moreover, the same code | symbol is attached | subjected to the same structure and the description is abbreviate | omitted about the same matter.

  In the gyro element 100b according to the third embodiment, the shapes of the detection vibrating arms 122a and 122b are different, and four through holes are provided in each of the pair of detection vibrating arms 122a and 122b. The detection vibrating arm 122a includes a first through hole 262a1, a second through hole 262a2, a third through hole 262a3, and a fourth through hole 262a4 along the extending direction (+ Y-axis direction) of the detection vibrating arm 122a. They are arranged and connected with the connecting portions 342a1 and 342a2 interposed therebetween. Similarly to the detection vibrating arm 122a, the detection vibrating arm 122b also includes the first through hole 262b1, the second through hole 262b2, and the third through the extending direction (+ Y-axis direction) of the detection vibrating arm 122b. A through hole 262b3 and a fourth through hole 262b4 are arranged and formed with the connecting portions 342b1 and 342b2 interposed therebetween.

  The shape of the first through hole 262a1 is such that the connecting portions 342a1 and 342a2 forming the first through hole 262a1, the second through hole 262a2, the third through hole 262a3, and the fourth through hole 262a4 are isosceles sides, Is an isosceles triangle with one end 10a side. The shape of the second through-hole 262a2 is an isosceles triangle having the connecting portions 342a1 and 342a2 as isosceles portions and both base angles at the front end side in the + Y-axis direction. The shape of the third through-hole 262a3 is an isosceles triangle having the connecting portions 342a1 and 342a2 as isosceles portions and both base angles being on the adjustment vibrating arm 16a side. The shape of the fourth through hole 262a4 is an isosceles triangle having the connecting portions 342a1 and 342a2 as isosceles portions and both base angles being on the detection vibrating arm 122b side.

  The shape of the first through hole 262b1 is that the connecting portions 342b1 and 342b2 forming the first through hole 262b1, the second through hole 262b2, the third through hole 262b3, and the fourth through hole 262b4 are isosceles sides, Is an isosceles triangle with one end 10a side. The shape of the second through-hole 262b2 is an isosceles triangle having the connecting portions 342b1 and 342b2 as isosceles portions and both base angles at the front end side in the + Y-axis direction. The shape of the third through hole 262b3 is an isosceles triangle having the connecting portions 342b1 and 342b2 as isosceles portions and both base angles being on the adjustment vibrating arm 16b side. The shape of the fourth through hole 262b4 is an isosceles triangle having the connecting portions 342b1 and 342b2 as isosceles portions and both base angles being on the detection vibrating arm 122a side.

  The detection vibrating arm 122a includes a wall thickness (length in the X-axis direction) t between the side wall 302a1 of the detection vibrating arm 122a and the third through hole 262a3, and a side wall 302a2 of the detection vibrating arm 122a and the fourth penetration. The wall thickness (length in the X-axis direction) t due to the hole 262a4 is formed to be substantially constant. The detection vibrating arm 122b includes a wall thickness (length in the X-axis direction) t between the side wall 302b2 of the detection vibrating arm 122b and the third through hole 262b3, and a side wall 302b1 of the detection vibrating arm 122b and the fourth penetration. The wall thickness (length in the X-axis direction) t due to the hole 262b4 is formed to be substantially constant.

  By adopting such a configuration, in addition to the effects of the first embodiment, since one end of each of the connecting portions 342a1, 342a2, 342b1, 342b2 is in contact with one end portion 10a, the arm width direction (X The rigidity against bending in the axial direction is further increased, and the impact resistance in the arm width direction (X-axis direction) of the detection vibrating arms 122a and 122b can be further improved. Therefore, the gyro element 100b including the detection vibrating arms 122a and 122b having a small impedance and high sensitivity and excellent impact resistance can be obtained.

<Fourth embodiment>
Next, a gyro element 100c as a resonator element according to a fourth embodiment of the invention will be described with reference to FIG.
FIG. 7 is a schematic plan view showing the structure of a gyro element as an example of a resonator element according to the fourth embodiment of the invention.
Hereinafter, the gyro element 100c according to the fourth embodiment will be described focusing on differences from the gyro element 100 according to the first embodiment described above. Moreover, the same code | symbol is attached | subjected to the same structure and the description is abbreviate | omitted about the same matter.

  In the gyro element 100c according to the fourth embodiment, the shapes of the detection vibrating arms 123a and 123b are different, and three through holes are provided in each of the pair of detection vibrating arms 123a and 123b. In the detection vibrating arm 123a, a first through hole 263a1, a second through hole 263a2, and a fifth through hole 263a3 are arranged along the extending direction (+ Y-axis direction) of the detection vibrating arm 123a, and the connecting portions 343a1, 343a2 is formed therebetween. Similarly to the detection vibrating arm 123a, the detection vibrating arm 123b also includes the first through hole 263b1, the second through hole 263b2, and the first through hole 263b2 along the extending direction (+ Y-axis direction) of the detection vibrating arm 123b. Five through holes 263b3 are arranged and formed with the connecting portions 343b1 and 343b2 interposed therebetween. The fifth through holes 263a3 and 263b3 are formed between the connecting portions 343a2 and 343b2 and the weight portions 42a and 42b.

  The shape of the first through holes 261a1, 261b1 is the same as that of the first embodiment, and is a right triangle having a right angle portion on the end 10a side. The shape of the second through holes 261a2 and 261b2 is the same as that of the first embodiment, and is a right triangle having the right angle portion as the tip side in the + Y-axis direction. The shapes of the fifth through holes 263a3 and 263b3 are rectangular shapes having a long side in the extending direction (+ Y-axis direction) of the detection vibrating arms 123a and 123b in plan view.

  In addition, the detection vibrating arm 123a includes a wall thickness (length in the X-axis direction) t of the side wall 303a2 of the detection vibrating arm 123a, the first through hole 263a1, and the fifth through hole 263a3, and the detection vibrating arm 123a. The wall thickness (length in the X-axis direction) t formed by the side wall 303a1, the second through hole 263a2, and the fifth through hole 263a3 is formed to be substantially constant. The detection vibrating arm 123b includes a wall thickness (length in the X-axis direction) t formed by the side wall 303b1 of the detection vibrating arm 123b, the first through hole 263b1, and the fifth through hole 263b3, and the detection vibrating arm 123b. The wall thickness (length in the X-axis direction) t formed by the side wall 303b2, the second through hole 263b2, and the fifth through hole 263b3 is formed to be substantially constant.

  By adopting such a configuration, in addition to the effects of the first embodiment, since the connecting portions 343a2 and 343b2 are formed, the rigidity against bending in the arm width direction (X-axis direction) is further increased, and the detection vibrating arm The impact resistance in the arm width direction (X-axis direction) of 123a and 123b can be further improved. Accordingly, it is possible to obtain the gyro element 100c including the detection vibrating arms 123a and 123b having small impedance and high sensitivity and excellent impact resistance.

  In the present embodiment, the shapes of the first through holes 263a1, 263b1 and the second through holes 263a2, 263b2 are right-angled triangles. However, the present invention is not limited to this. A trapezoidal shape having two right-angled portions along the extending direction (+ Y-axis direction) of 123a and 123b may be used.

  As described above, the gyro elements 100, 100a, 100b, and 100c as examples of the resonator element according to the embodiment of the present invention have been described using the piezoelectric material, quartz, as a base material, but are mechanically movable on a silicon substrate or a glass substrate. It may be a MEMS (Micro Electro Mechanical System) element in which the structure is formed by a semiconductor micromachining technique. In the case of a MEMS element, it is easy to manufacture by incorporating a semiconductor circuit, which is advantageous for miniaturization and higher functionality.

[Gyro sensor]
Next, the gyro sensor 200 including the gyro element 100 as an example of the resonator element according to the first embodiment will be described.
FIG. 8 is a schematic diagram illustrating a structure of a gyro sensor including a gyro element as an example of a resonator element according to an embodiment of the present invention. FIG. 8A is a schematic plan view, and FIG. FIG. 9 is a schematic cross-sectional view taken along line AA in FIG. In FIG. 8A, for convenience of explaining the internal configuration of the gyro sensor 200, a state in which the lid 240 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.

  As shown in FIG. 8, the gyro sensor 200 accommodates the gyro element 100 and an electronic component 250 including a circuit for driving the gyro element 100 and a circuit for detecting electric charge in the cavity 218 of the package 210. The opening of 210 is sealed with a lid 240, and the inside is kept airtight. As shown in FIG. 8B, the package 210 has a flat plate-like first substrate 212 and a frame-like second substrate 214 and a third substrate 216 stacked and fixed on the first substrate 212 in this order. A cavity 218 is formed to accommodate the electronic component 250 and the gyro element 100. The substrates 212, 214, and 216 are made of, for example, ceramics.

  A die pad (not shown) on which the electronic component 250 is placed and fixed is provided on the cavity 218 side of the first substrate 212. The electronic component 250 is bonded and fixed on the die pad by a joining member 260 such as a brazing material (die attach material).

  The electronic component 250 includes a drive circuit as an excitation unit for driving and vibrating the gyro element 100 and a detection circuit as a detection unit for detecting a detection vibration generated in the gyro element 100 when an angular velocity is applied. Specifically, the drive circuit included in the electronic component 250 supplies drive signals to drive electrodes (not shown) formed on the pair of drive vibration arms 14a and 14b (see FIG. 1) of the gyro element 100, respectively. To do. Further, the detection circuit included in the electronic component 250 amplifies detection signals generated on detection electrodes (not shown) formed on the pair of detection vibrating arms 12a and 12b (see FIG. 1) of the gyro element 100, respectively. An amplified signal is generated, and a rotational angular velocity applied to the gyro sensor 200 is detected based on the amplified signal.

  The second substrate 214 is formed in a frame shape having an opening large enough to accommodate the electronic component 250. The third substrate 216 is formed in a frame shape having an opening wider than the opening of the second substrate 214, and is laminated and fixed on the second substrate 214. Then, the gyro element 100 is formed on the second substrate 214 which is laminated on the second substrate 214 and appears inside the opening of the third substrate 216. The first support portion 22a and the second support portion 22b (see FIG. 1), and is bonded and fixed by a bonding member 270. Therefore, each vibrating arm can vibrate without coming into contact with the package 210 and the lid 240. Therefore, since the vibrating arm has a high Q value and stable vibration characteristics, the gyro sensor 200 with high detection sensitivity can be obtained. . A plurality of internal terminals 222 are formed on the second substrate 214 that appears inside the opening of the third substrate 216.

  The above-described drive circuit and detection circuit are provided on the cavity 218 side of the electronic component 250 fixed on the first substrate 212, and the internal circuit formed on the second substrate 214 is connected to each circuit. A plurality of connection terminals 252, 252 a, and 252 b for connecting to the terminals 222 and electrode pads (not shown) formed on the gyro element 100 are formed. The connection terminal 252 is electrically connected to the internal terminal 222 on the second substrate 214 via the bonding wire 280. The connection terminal 252a is a detection terminal, and is electrically connected to the electrode pads 18a and 18b that output a detection signal on the gyro element 100 via the bonding wire 280. The connection terminal 252b is a ground terminal and is electrically connected to the electrode pads 19a and 19b on the gyro element 100 via the bonding wire 280.

  Any of the internal terminals 222 formed on the second substrate 214 is electrically connected to a plurality of external connection terminals 220 provided on the external bottom surface of the first substrate 212 by internal wiring (not shown) of the package 210. It is connected to the.

  Furthermore, the lid 240 is disposed on the upper surface of the opening of the third substrate 216, the opening of the package 210 is sealed, and the inside of the package 210 is hermetically sealed, whereby the gyro sensor 200 is obtained. The lid 240 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, or glass. For example, when the lid 240 is formed of metal, it is joined to the package 210 by seam welding via a joining member 230 such as a seal ring formed by punching a Kovar alloy or the like into a rectangular ring shape. Since the cavity 218 (internal space) formed by the package 210 and the lid 240 is a space for the gyro element 100 to operate, it is preferable to hermetically seal in a substantially vacuum or reduced pressure atmosphere.

[Electronics]
Next, with reference to FIGS. 9 to 11, an electronic apparatus including the gyro element 100 according to the first embodiment will be described. In the following description, an example using the gyro element 100 will be described. 9 to 11 are perspective views illustrating an example of an electronic apparatus including the gyro element 100 according to the present embodiment.

  FIG. 9 is a perspective view schematically showing a mobile (or notebook) personal computer 1100 as the electronic apparatus according to the present embodiment. As shown in FIG. 9, the personal computer 1100 includes a main body portion 1104 having a keyboard 1102 and a display unit 1106 having a display portion 1000, and the display unit 1106 has a hinge structure portion with respect to the main body portion 1104. It is supported so that rotation is possible. Such a personal computer 1100 incorporates a gyro element 100.

  FIG. 10 is a perspective view schematically showing a mobile phone (including PHS) 1200 as the electronic apparatus according to the present embodiment. As shown in FIG. 10, the cellular 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 gyro element 100.

  FIG. 11 is a perspective view schematically showing a digital camera 1300 as an electronic apparatus according to the present embodiment. Note that FIG. 11 also shows a simple connection with an external device. Here, an ordinary camera sensitizes a silver salt photographic film with a light image of a subject, whereas a digital camera 1300 captures a light image of a subject by photoelectrically converting it with an image sensor such as a CCD (Charge Coupled Device). A 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. A television monitor 1330 is connected to the video signal output terminal 1312 and a personal computer 1340 is connected to the input / output terminal 1314 for data communication, if necessary. Furthermore, the imaging signal stored in the memory 1308 is output to the television monitor 1330 or the personal computer 1340 by a predetermined operation. Such a digital camera 1300 incorporates the gyro element 100.

  The electronic device provided with the gyro element 100 includes, for example, an ink jet in addition to the personal computer 1100 (mobile personal computer) shown in FIG. 9, the mobile phone 1200 shown in FIG. 10, and the digital camera 1300 shown in FIG. Dispenser (eg inkjet printer), laptop personal computer, TV, video camera, head mounted display, video tape recorder, various navigation devices, pager, electronic notebook (including communication function), electronic dictionary, calculator, electronic Game equipment, word processor, workstation, video phone, 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 internal Mirror), fish finders, various measurement devices, gauges (e.g., vehicles, aircraft, rockets, instruments and a ship), attitude control such as a robot or a human body, can be given flight simulator and the like.

[Moving object]
Next, a moving body including the gyro element 100 according to the first embodiment will be described with reference to FIG.
FIG. 12 is a perspective view schematically showing an automobile as an example of a moving body according to the present embodiment. An automobile 1400 is equipped with a gyro sensor 200 including the gyro element 100 according to the present embodiment. For example, as shown in the figure, an electronic control unit 1402 that incorporates a gyro sensor 200 and controls a tire 1403 and the like is mounted on a vehicle body 1401 of an automobile 1400 as a moving body. The gyro sensor 200 is also used as a posture detection sensor for navigation devices, posture control devices, and the like. Furthermore, the present invention is not limited to the automobile 1400, and can be suitably used as a posture detection sensor of a moving body including a self-propelled robot, a self-propelled transport device, a train, a ship, an airplane, an artificial satellite, and the like.

  The present invention includes configurations that are substantially the same as the configurations described in the embodiments (for example, configurations that have the same functions, methods, and results, or configurations that have the same objects and effects). In addition, the invention includes a configuration in which a non-essential part of the configuration described in the embodiment is replaced. In addition, the invention includes a configuration that achieves the same effect as the configuration described in the embodiment or a configuration that can achieve the same object. Further, the invention includes a configuration in which a known technique is added to the configuration described in the embodiment.

  DESCRIPTION OF SYMBOLS 10 ... Base part, 10a, 10b ... End part, 12a, 12b ... Detection vibration arm as 1st vibration arm, 14a, 14b ... Drive vibration arm as 2nd vibration arm, 16a, 16b ... Adjustment vibration arm, 18a, 18b, 19a, 19b ... electrode pad, 20a ... first connecting part, 20b ... second connecting part, 22a ... first supporting part, 22b ... second supporting part, 24 ... fixed frame part, 26a1, 26b1 ... first 1 through hole, 26a2, 26b2 ... second through hole, 28a1, 28a2, 28b1, 28b2 ... through hole, 30a1, 30a2, 30b1, 30b2, 32a1, 32a2, 32b1, 32b2 ... sidewall, 34a, 34b, 36a, 36b ... Connecting part, 42a, 42b, 44a, 44b, 46a, 46b ... weight part, 100 ... gyro element as vibrating piece, 200 ... gyro sensor, 210 ... pad 212 ... first substrate, 214 ... second substrate, 216 ... third substrate, 218 ... cavity, 220 ... external connection terminal, 222 ... internal terminal, 230 ... joining member, 240 ... lid, 250 ... electronic component , 252, 252a, 252b ... connection terminals, 260, 270 ... bonding members, 280 ... bonding wires, 1000 ... display unit, 1100 ... personal computer as electronic equipment, 1200 ... mobile phone as electronic equipment, 1300 ... as electronic equipment Digital cameras, 1400 ... automobiles as moving objects.

Claims (6)

The base,
A vibration piece having a pair of first vibrating arms extending from the base portion,
A through hole is formed in each of the first vibrating arms,
The through hole has a first through hole that has a portion whose hole width becomes narrower from the end side of the base portion where the first vibrating arm extends toward the distal end side of the first vibrating arm;
A resonator element, comprising: a second through hole having a portion whose hole width becomes narrower from the distal end side of the first vibrating arm toward the end portion. The resonator element according to claim 1,
The resonator element according to claim 1, wherein the through hole has a right triangle shape or an isosceles triangle shape in plan view. In the resonator element according to claim 1 or 2,
A pair of second vibrating arms extending from an end opposite to the base side from which the first vibrating arms extend;
The vibrating piece, wherein the second vibrating arm is formed by arranging a plurality of through holes along a direction in which the second vibrating arm extends. The resonator element according to any one of claims 1 to 3,
A gyro sensor comprising: an electronic component including a circuit for driving the vibration piece and a circuit for detecting a signal; and a package for housing the vibration piece and the electronic component.   An electronic device comprising the resonator element according to any one of claims 1 to 3.   A moving body comprising the resonator element according to any one of claims 1 to 3.

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