JP2018105809A - Sensor element, physical quantity sensor, electronic apparatus and mobile entity - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sensor element with which it is possible to sufficiently improve detection sensitivity, and provide a physical quantity sensor, an electronic apparatus and a mobile entity equipped with such a sensor element.SOLUTION: Provided is a sensor element characterized by comprising a base, a vibration arm extending in a first direction from the base and provided with at least one first open hole penetrating the base through the thickness direction, and further characterized in that when assuming that HL represents the length of the first open hole along the first direction and HW represents the length of the first open hole along a direction orthogonal to the first direction in a plan view seen from the thickness direction, HL/HW is 1.3 to 3.0 inclusive.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a sensor element, a physical quantity sensor, an electronic device, and a moving object.

  A physical quantity sensor that detects physical quantities such as angular velocity and acceleration is used for, for example, vehicle body control in a vehicle, vehicle position detection of a car navigation system, vibration control correction (so-called camera shake correction) of a digital camera, a video camera, or the like.

  Such a physical quantity sensor includes, for example, a vibration element as disclosed in Patent Document 1. The vibration element described in Patent Literature 1 includes a base, and a drive arm and a detection arm that extend from the base. In such a vibration element, when the driving arm is flexibly vibrated and the driving arm receives an angular velocity in a predetermined direction in this state, Coriolis force acts on the driving arm, and accordingly, the detection arm is flexed and vibrated. By detecting such bending vibration of the detection arm, the angular velocity can be detected. Further, in the vibration element described in Patent Document 1, through holes are provided in each of the drive arm and the detection arm for the purpose of reducing the impedance of the vibration element and improving the detection sensitivity.

JP, 2006-61710, A

  However, conventionally, for example, in a vibration element as described in Patent Document 1, depending on the size of the through hole provided in the drive arm, the Q value of the drive vibration of the drive arm may be excessively low. There is a problem that it is difficult to sufficiently improve the detection sensitivity.

  An object of the present invention is to provide a sensor element that can sufficiently improve the detection sensitivity, and to provide a physical quantity sensor, an electronic apparatus, and a moving body including the sensor element.

The above object is achieved by the present invention described below.
The sensor element of the present invention comprises a base,
A drive vibrating arm provided with a first through hole extending in a first direction from the base and penetrating in a thickness direction of the base;
In a plan view as viewed from the thickness direction, the length of the first through hole along the first direction is HL, and the length of the first through hole along the direction orthogonal to the first direction is When it is HW
HL / HW is 1.3 or more and 3.0 or less.

  According to such a sensor element, the driving vibration arm is provided with a through hole (first through hole), so that the driving vibration arm is not provided with a through hole or a bottomed groove is provided. It is possible to reduce the thermoelastic loss in the driving vibration of the vibrating arm, increase the electric field efficiency of the excitation in the driving vibrating arm, and improve the Q value of the driving vibration of the driving vibrating arm. In particular, by setting HL / HW to 1.3 or more and 3.0 or less, the above-described effects (reduction in thermoelastic loss and improvement in electric field efficiency) can be sufficiently exerted, and the resonance of the drive vibration of the drive vibration arm can be improved. A decrease in Q value due to a decrease in sharpness can be suppressed. Therefore, noise due to unnecessary vibration of the drive vibrating arm can be reduced, and detection sensitivity can be sufficiently improved.

In the sensor element according to the aspect of the invention, it is preferable that the driving vibration arm includes a plurality of the first through holes.
Thereby, the electric field efficiency of excitation in the drive vibrating arm can be further increased.

  In the sensor element according to the aspect of the invention, in the plan view, the width along the direction perpendicular to the first direction of the drive vibrating arm at a position between the two first through holes adjacent to each other may be the first penetration. It is preferable that the width of the drive vibrating arm at the position of the hole is larger than the width along the direction orthogonal to the first direction.

  Thereby, it is possible to improve the shock resistance of the drive vibrating arm while improving the electric field efficiency of excitation in the drive vibrating arm.

  In the sensor element according to the aspect of the invention, it is preferable that the first through hole has any shape of an octagon or more polygon, a streamline, and an ellipse in the plan view.

  Thereby, the thermoelastic loss in the drive vibration of a drive vibration arm can be reduced more. Therefore, the Q value of the drive vibration of the drive vibration arm can be further improved.

  In the sensor element of the present invention, the driving vibration arm is divided into two by the first through hole when viewed in a cross section perpendicular to the first direction, and from one side to the other in the through direction of the first through hole. It is preferable to have two walls with decreasing thickness towards the side.

  Thereby, the wall part which has a narrow part in a drive vibration arm can be formed comparatively easily. Therefore, the electric field efficiency of excitation in the drive vibrating arm can be further increased.

The sensor element of the present invention includes a detection vibrating arm provided with a second through hole extending in the second direction from the base and penetrating in the thickness direction,
In the plan view, when the length of the second through hole along the second direction is HL2, and the length of the second through hole along the direction orthogonal to the second direction is HW2,
It is preferable that HL2 / HW2 is larger than HL / HW.

  As a result, the electric field efficiency of detection in the detection vibration arm is increased and the Q value of the detection vibration of the detection vibration arm is reduced (the unnecessary vibration that causes the detection vibration arm to vibrate with the drive vibration of the drive vibration arm). And the detection vibration of the detection vibration arm can be easily excited accurately). Therefore, the detection sensitivity can be further improved.

In the sensor element of the present invention, it is preferable that the detection vibrating arm includes a plurality of the second through holes.
Thereby, the electric field efficiency of detection in the detection vibrating arm can be further increased.

  In the sensor element according to the aspect of the invention, in the plan view, the width along the direction orthogonal to the second direction of the detection vibrating arm at the position between the two adjacent second through holes may be the second penetration. It is preferable that the width of the detection vibrating arm at the position of the hole is larger than a width along a direction orthogonal to the second direction.

  Thereby, it is possible to improve the shock resistance of the detection vibrating arm while improving the electric field efficiency of detection in the detection vibrating arm.

  In the sensor element of the present invention, it is preferable that the first direction and the second direction are opposite to each other.

  As a result, a so-called H-type sensor element having excellent detection sensitivity can be realized.

In the sensor element of the present invention, the second through hole has a shape having two sides along the second direction and two sides along a direction orthogonal to the second direction in the plan view. Preferably there is.
Thereby, the electric field efficiency of detection in the detection vibrating arm can be further increased.

  In the sensor element of the present invention, the detection vibrating arm is divided into two by the second through hole when viewed in a cross section perpendicular to the second direction, and from one side to the other in the through direction of the second through hole. It is preferable to have two walls with decreasing thickness towards the side.

  Thereby, the wall part which has a narrow part in a detection vibration arm can be formed comparatively easily. Therefore, the electric field efficiency of detection in the detection vibrating arm can be further increased.

  In the sensor element of the present invention, the driving vibration arm is divided into two by the first through hole when viewed in a cross section perpendicular to the first direction, and from one side to the other in the through direction of the first through hole. It is preferable to have two wall portions whose thicknesses are constant toward the side or that are decreasing at a reduction rate smaller than the reduction rate of the wall thickness of the detection vibrating arm.

  Thereby, the unnecessary vibration of the drive vibration arm can be reduced, and as a result, the detection sensitivity can be further improved.

In the sensor element of the present invention, the base includes a support arm provided with a third through hole extending in the third direction and penetrating in the thickness direction,
In the plan view, when the length of the third through hole along the third direction is HL3 and the length of the third through hole along the direction orthogonal to the third direction is HW3,
It is preferable that HL3 / HW3 is larger than HL / HW.

  Thereby, the Q value of the vibration of the support arm can be reduced (this can reduce the unnecessary vibration of the support arm). Therefore, the detection sensitivity can be further improved.

  In the sensor element according to the aspect of the invention, it is preferable that the first direction and the second direction are parallel to each other and orthogonal to the third direction.

  As a result, a so-called double T-type sensor element having excellent detection sensitivity can be realized.

The physical quantity sensor of the present invention includes the sensor element of the present invention.
According to such a physical quantity sensor, the sensor element of the physical quantity sensor can be improved by enjoying the excellent effect of the sensor element.

The electronic device of the present invention includes the sensor element of the present invention.
According to such an electronic device, it is possible to enjoy the excellent effect of the sensor element and improve the characteristics of the electronic device.

The moving body of the present invention includes the sensor element of the present invention.
According to such a moving body, it is possible to enjoy the excellent effect of the sensor element and improve the characteristics of the moving body.

It is a top view which shows the sensor element which concerns on 1st Embodiment of this invention. It is the sectional view on the AA line in FIG. It is the BB sectional view taken on the line in FIG. It is CC sectional view taken on the line in FIG. FIG. 2 is an enlarged plan view of a drive vibration arm included in the sensor element shown in FIG. 1. It is a figure for demonstrating the other shape of the 1st through-hole shown in FIG. It is a figure for demonstrating the other shape of the 1st through-hole shown in FIG. FIG. 2 is an enlarged plan view of a detection vibrating arm included in the sensor element shown in FIG. 1. It is a top view which shows the sensor element which concerns on 2nd Embodiment of this invention. It is a top view which shows the sensor element which concerns on 3rd Embodiment of this invention. It is the DD sectional view taken on the line in FIG. It is the EE sectional view taken on the line in FIG. FIG. 11 is an enlarged plan view of a drive vibration arm included in the sensor element shown in FIG. 10. FIG. 11 is an enlarged plan view of a detection vibrating arm included in the sensor element shown in FIG. 10. It is a perspective view which shows an example of the physical quantity sensor of this invention. It is sectional drawing of the physical quantity sensor shown in FIG. 1 is a perspective view illustrating a configuration of a mobile (or notebook) personal computer that is an example of an electronic apparatus of the present invention. It is a perspective view which shows the structure of the mobile telephone (PHS is also included) which is an example of the electronic device of this invention. 1 is a perspective view illustrating a configuration of a digital still camera that is an example of an electronic apparatus of the present invention. It is a perspective view which shows the structure of the motor vehicle which is an example of the mobile body of this invention.

  Hereinafter, a sensor element, a physical quantity sensor, an electronic device, and a moving body of the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.

1. Sensor Element <First Embodiment>
FIG. 1 is a plan view showing a sensor element according to the first embodiment of the present invention. 2 is a cross-sectional view taken along line AA in FIG. 3 is a cross-sectional view taken along line BB in FIG. 4 is a cross-sectional view taken along the line CC in FIG.

  In each figure, for convenience of explanation, the x axis, the y axis, and the z axis are shown as three axes orthogonal to each other. Hereinafter, a direction parallel to the x-axis is referred to as an “x-axis direction”, a direction parallel to the y-axis is referred to as a “y-axis direction”, and a direction parallel to the z-axis is referred to as a “z-axis direction”. Further, the tip side of the arrow indicating each axis is “+”, and the base end side is “−”. The + z-axis direction side is referred to as “upper”, and the −z-axis direction side is referred to as “lower”. Moreover, in FIG. 1, illustration of each electrode is abbreviate | omitted for convenience of explanation.

  A sensor element 1 shown in FIG. 1 is an angular velocity detection element (gyro element) capable of detecting an angular velocity ωz around an axis az parallel to the z axis. The sensor element 1 includes a piezoelectric substrate 2 (vibrating piece) and electrodes (see FIGS. 2 to 4) provided on the surface of the piezoelectric substrate 2. Hereinafter, first, a schematic configuration of the sensor element 1 will be described.

-Piezoelectric substrate-
Examples of the constituent material of the piezoelectric substrate 2 include piezoelectric materials such as quartz, lithium tantalate, and lithium niobate. Among these, it is preferable to use quartz as a constituent material of the piezoelectric substrate 2. By using quartz, the sensor element 1 having excellent frequency temperature characteristics as compared with other materials can be obtained. Hereinafter, a case where the piezoelectric substrate 2 is made of quartz will be described.

  The piezoelectric substrate 2 has a plate shape that extends in the XY plane defined by the Y axis (mechanical axis) and the X axis (electric axis), which are crystal axes of the quartz substrate, and has a thickness in the Z axis (optical axis) direction. I am doing. That is, the piezoelectric substrate 2 is composed of a Z-cut quartz plate. Note that the Z-axis does not necessarily coincide with the thickness direction of the piezoelectric substrate 2, and may be slightly inclined with respect to the thickness direction from the viewpoint of reducing the change due to the temperature of the frequency near room temperature. Specifically, the Z-cut quartz plate is such that a surface obtained by rotating a surface orthogonal to the Z-axis within a range of 0 degrees to 10 degrees around at least one of the X-axis and the Y-axis is the main surface. Includes crystal plate with cut angle. Moreover, the thickness of the piezoelectric substrate 2 is not particularly limited, but is, for example, about 40.0 to 300.0 μm.

  The piezoelectric substrate 2 has a so-called double T type configuration. More specifically, the piezoelectric substrate 2 includes a base portion 21, driving vibration arms 221 to 224 and detection vibration arms 231 and 232 extending from the base portion 21, fixing portions 241 and 242, a fixing portion 241 and a base portion 21. Support beams 251 and 252, and support beams 253 and 254 that connect the fixed portion 242 and the base portion 21. The piezoelectric substrate 2 is formed symmetrically as shown in FIG.

  The base 21 includes a main body 211 located at the center, a connecting arm 212 extending from the main body 211 in the −x-axis direction, and a connecting arm 213 extending from the main body 211 in the + x-axis direction. Have.

  The drive vibrating arm 221 extends in the + y-axis direction from the distal end portion of the connecting arm 212 of the base portion 21. The drive vibrating arm 222 extends in the −y-axis direction from the distal end portion of the connecting arm 212. Similarly, the drive vibrating arm 223 extends in the + y-axis direction from the distal end portion of the connecting arm 213. Further, the drive vibrating arm 224 extends in the −y axis direction from the distal end portion of the connecting arm 213.

  The drive vibrating arm 221 is provided on the arm portion 2211 extending from the base portion 21, the wide portion 2212 provided on the distal end side of the arm portion 2211 and wider than the arm portion 2211, and the arm portion 2211. A plurality of through holes 2213. Similarly, the drive vibration arms 222, 223, and 224 are provided on the distal ends of the arm portions 2221, 2231, and 2241 extending from the base portion 21 and the arm portions 2221, 2231, and 2241, respectively. Wide portions 2222, 2232, 2242 having a width wider than 2231, 2241, and a plurality of through holes 2223, 2233, 2243 provided in the arm portions 2221, 2231, 2241 are provided.

  In such driving vibration arms 221, 222, 223, and 224, wide portions 2212, 2222, 2232, and 2242 (hammer heads) are provided to improve the angular velocity detection sensitivity, and the driving vibration arms 221, 222, and 223. 224 can be shortened. Further, by providing the through holes 2213, 2223, 2233, and 2243, the thermoelastic loss and the CI value can be reduced, and the drive vibrating arms 221, 222, 223, and 224 can be driven and vibrated efficiently. Note that the wide portions 2212, 2222, 2232, and 2242 may be provided as necessary and may be omitted. The drive vibrating arms 221, 222, 223, and 224 will be described in detail later.

  The detection vibrating arm 231 extends in the + y-axis direction from the main body 211 of the base 21. The detection vibrating arm 232 extends from the main body 211 in the −y axis direction.

  The detection vibrating arms 231 and 232 are respectively provided with arm portions 2311 and 2321 extending from the base portion 21, and wide portions that are provided on the distal end sides of the arm portions 2311 and 2321 and are wider than the arm portions 2311 and 2321. 2312 and 2322 and a plurality of through holes 2313 and 2323 provided in the arm portions 2311 and 2321.

  In such detection vibration arms 231 and 232, by providing the wide portions 2312 and 2322, the resonance frequency (natural frequency) of the detection vibration arms 231 and 232 can be lowered, or the length of the detection vibration arms 231 and 232 can be reduced. It can be shortened. Further, by providing the through holes 2313 and 2323, the detection vibration can be detected efficiently. Note that the wide portions 2312 and 2322 may be provided as necessary and may be omitted. The detection vibrating arms 231 and 232 will be described in detail later together with the driving vibrating arms 221 to 224.

  The fixed portion 241 is located on the + y axis direction side with respect to the base portion 21 and extends in the x axis direction. On the other hand, the fixing portion 242 is located on the −y axis direction side with respect to the base portion 21 and extends in the x axis direction.

  The support beam 251 passes between the drive vibration arm 221 and the detection vibration arm 231 and connects the main body portion 211 and the fixed portion 241 of the base 21. Further, the support beam 252 passes between the drive vibration arm 223 and the detection vibration arm 231 and connects the main body portion 211 of the base portion 21 and the fixed portion 241. Similarly, the support beam 253 passes between the drive vibration arm 222 and the detection vibration arm 232 and connects the main body portion 211 and the fixed portion 242 of the base portion 21. Further, the support beam 254 passes between the drive vibration arm 224 and the detection vibration arm 232 and connects the main body portion 211 and the fixed portion 242 of the base portion 21. In the drawing, each of the support beams 251 to 254 has a long shape, and has a plurality of portions bent or curved in the middle thereof.

-Electrode-
As shown in FIGS. 1, 2, 3 and 4, the electrodes provided on the surface of the piezoelectric substrate 2 described above include a drive signal electrode 311, a drive ground electrode 312, a detection signal electrode 321, and a detection signal electrode 321. It has a ground electrode 322, a drive signal terminal 313, a drive ground terminal 314, a detection signal terminal 323, and a detection ground terminal 324.

  As shown in FIGS. 2 and 3, the drive signal electrode 311 is provided on the wall surface of the through hole 2213 of the drive vibration arm 221 and on both side surfaces of the arm portion 2231 of the drive vibration arm 223. Although not shown, the drive signal electrodes 311 are also provided on the wall surface of the through hole 2223 of the arm portion 2221 of the drive vibration arm 222 and on both side surfaces of the arm portion 2241 of the drive vibration arm 224, respectively. The drive signal electrode 311 is an electrode for exciting the drive vibration of the drive vibration arms 221 to 224.

  The drive ground electrode 312 is provided on both side surfaces of the arm portion 2211 of the drive vibration arm 221 and the wall surface of the through hole 2233 of the drive vibration arm 223. Although not shown, the drive ground electrode 312 is also provided on both side surfaces of the arm portion 2221 of the drive vibration arm 222 and on the wall surface of the through hole 2243 of the drive vibration arm 224. The drive ground electrode 312 has a potential that serves as a ground with respect to the drive signal electrode 311.

  As shown in FIG. 1, the drive signal terminal 313 is disposed at the left end portion of the fixed portion 242, and is electrically connected to the drive signal electrode 311 via a drive signal wiring (not shown) formed on the support beam 253. Connected. Similarly, the drive ground terminal 314 is disposed at the left end portion of the fixed portion 241 and is electrically connected to the drive ground electrode 312 via a drive ground wiring (not shown) formed on the support beam 251. Has been.

  As shown in FIG. 4, the detection signal electrode 321 is provided on the wall surface of the through hole 2313 of the detection vibrating arm 231. Although not shown, the detection signal electrode 321 is also provided on the wall surface of the through hole 2323 of the detection vibrating arm 232. The detection signal electrode 321 is an electrode for detecting charges generated by the detection vibration when the detection vibration of the detection vibration arms 231 and 232 is excited.

  The detection ground electrode 322 is provided on both side surfaces of the arm portion 2311 of the detection vibrating arm 231. Although not shown, the detection ground electrode 322 is also provided on both side surfaces of the arm portion 2321 of the detection vibrating arm 232. The detection ground electrode 322 has a potential that becomes a ground with respect to the detection signal electrode 321.

  As shown in FIG. 1, the detection signal terminal 323 is formed on the right end of each of the fixing portions 241 and 242, and via detection signal wiring (not shown) formed on the support beams 252 and 254, The detection signal electrode 321 is electrically connected.

  The detection ground terminal 324 is formed at the center in the longitudinal direction of each of the fixing portions 241 and 242, and is electrically connected to the detection ground electrode 322 via detection ground wiring (not shown) formed on the support beams 251 to 254. Connected.

  The configuration of the electrode as described above is not particularly limited as long as it has conductivity. For example, Ni (nickel), Au (metal) layer such as Cr (chromium), W (tungsten), etc. (Gold), Ag (silver), Cu (copper), etc. can be comprised by the metal film which laminated | stacked each film.

The schematic configuration of the sensor element 1 has been described above.
In the sensor element 1 configured as described above, an electric field is generated between the drive signal electrode 311 and the drive ground electrode 312 by inputting a drive signal to the drive signal terminal 313 in a state where no angular velocity is applied to the sensor element 1. When this occurs, each of the drive vibration arms 221 to 224 performs bending vibration (drive vibration) in the direction indicated by the arrow a in FIG. At this time, since the drive vibration arms 221 and 222 and the drive vibration arms 223 and 224 perform bilaterally symmetric vibration in FIG. 1, the base 21 and the detection vibration arms 231 and 232 hardly vibrate.

  When the angular velocity ωz around the axis az (center of gravity) along the z-axis is applied to the sensor element 1 in the state where the driving vibration is performed, the detection vibration (vibration in the detection mode) is excited. Specifically, Coriolis force in the direction indicated by the arrow b in FIG. 1 acts on the drive vibrating arms 221 to 224 and the connecting arms 212 and 213 of the base portion 21 to excite new vibrations. As a result, detection vibrations in the direction indicated by the arrow c in FIG. 1 are excited in the detection vibration arms 231 and 232 so as to cancel the vibrations of the connecting arms 212 and 213. Then, the electric charge generated between the detection signal electrode 321 and the detection ground electrode 322 by this detection vibration is taken out from the detection signal terminal 323 as a detection signal, and the angular velocity is obtained based on this detection signal.

(Detailed description of the drive vibration arm and detection vibration arm)
Hereinafter, the drive vibration arms 221 to 224 and the detection vibration arms 231 and 232 will be described in detail.

  FIG. 5 is an enlarged plan view of a drive vibration arm included in the sensor element shown in FIG. FIG. 6 is a view for explaining another shape of the first through hole shown in FIG. 5. FIG. 7 is a view for explaining another shape of the first through hole shown in FIG. 5. FIG. 8 is an enlarged plan view of a detection vibrating arm included in the sensor element shown in FIG. In each figure, for convenience of explanation, the same x-axis, y-axis, and z-axis as those in the above-described figures are shown, and the illustration of electrodes is omitted.

  First, the drive vibrating arm 221 will be described in detail. In the following, the drive vibration arm 221 will be described as a representative, but the drive vibration arms 222 to 224 are the same as the drive vibration arm 221.

  As described above, the sensor element 1 includes the base 21 (including the connecting arm 212) and the drive vibrating arm 221 extending from the base 21 (in the middle of the connecting arm 212) in the y-axis direction that is the “first direction”. And comprising. Here, as shown in FIG. 5, the drive vibrating arm 221 has at least one (first through hole in the figure) “first through hole” penetrating in the thickness direction (z-axis direction) of the base portion 21. A certain through hole 2213 is provided. As a result, the thermoelastic loss in the drive vibration of the drive vibration arm 221 is reduced and the excitation (drive) in the drive vibration arm 221 is reduced as compared with the case where the drive vibration arm 221 is not provided with a through hole or a bottomed groove. Vibration) and the Q value of the drive vibration of the drive vibration arm 221 can be improved.

  In particular, in the sensor element 1, the length along the y-axis direction (first direction) of the through-hole 2213 in the plan view (hereinafter also simply referred to as “plan view”) viewed from the thickness direction of the base 21 is HL. When the length (width) along the direction (x-axis direction) perpendicular to the y-axis direction of the through hole 2213 is HW, HL / HW is 1.3 or more and 3.0 or less. Thus, it is possible to suppress the decrease in the Q value due to the decrease in the sharpness of the resonance of the drive vibration of the drive vibration arm 221 while fully exhibiting the above-described effects (reduction in thermoelastic loss and improvement in electric field efficiency). it can. Therefore, noise due to unnecessary vibration of the drive vibrating arm 221 can be reduced and detection sensitivity can be sufficiently improved.

  On the other hand, when HL / HW is smaller than 1.3, the length HL is shortened, so that the length in the y-axis direction of the drive signal electrode 311 or the drive ground electrode 312 provided in the through hole 2213 is shortened. Since the length in the y-axis direction of the portion where the through-hole 2213 of the drive vibrating arm 221 is not provided becomes long, it is difficult to sufficiently exhibit the above-described effects (reduction in thermoelastic loss and improvement in electric field efficiency). . On the other hand, when HL / HW is greater than 3.0, the rigidity of the drive vibration arm 221 becomes extremely low, so that vibration modes other than the drive vibration mode of the drive vibration arm 221 are likely to occur, and the drive vibration arm 221 When the sharpness of the resonance of the drive vibration is lowered, the Q value is lowered, noise due to unnecessary vibration of the drive vibration arm 221 is increased, and as a result, the detection sensitivity is extremely lowered.

  In the sensor element 1, as described above, one drive vibrating arm 221 includes a plurality of through holes 2213 (first through holes). Thus, the area where the drive signal electrode 311 and the drive ground electrode 312 face each other can be increased according to the number of the through holes 2213, and the electric field efficiency of excitation (drive vibration) in the drive vibration arm 221 can be further increased. it can. Here, the plurality of through holes 2213 are arranged in the extending direction of the drive vibrating arm 221, and the length L1 between two adjacent through holes 2213 is not particularly limited, but with respect to the length HW It is preferably 0.3 times or more and 1.5 times or less, and more preferably 0.5 times or more and 1.0 times or less. Thereby, in the case where a plurality of through holes 2213 are provided, unnecessary vibrations of the drive vibrating arm 221 can be accurately reduced. The shapes and dimensions of the plurality of through holes 2213 are preferably equal to each other, but may be different.

  In the present embodiment, the width (length HW) of the through hole 2213 in the x-axis direction becomes smaller toward the both end sides of the through hole 2213 in the y-axis direction. In the drawing, each through hole 2213 (first through hole) has a dodecagonal shape in plan view. Here, the outline of each through-hole 2213 in a plan view includes two first sides along the y-axis direction, two second sides along the x-axis direction, and two first sides. There are four third sides that are connected, and four fourth sides that connect the two second sides and the four third sides. The length of each second side is longer than the length of each first side. In addition, the length of each third side is longer than the length of each fourth side.

  Thus, the through-hole 2213 is an octagon or more polygon (in the figure, a dodecagon) in a plan view, so that the opposing area between the drive signal electrode 311 and the drive ground electrode 312 is increased, and the drive vibrating arm 221 is increased. The heat (elastic heat) generated in the peripheral portion of the through-hole 2213 due to the drive vibration can be reduced, and the thermoelastic loss in the drive vibration of the drive vibration arm 221 can be further reduced. Therefore, the Q value of the drive vibration of the drive vibration arm 221 can be further improved. In addition, such a through-hole 2213 having a plan view has an advantage that it can be easily formed by etching.

  On the other hand, for example, when the width (HW) is constant as in the through hole 2213X1 shown in FIG. 6, the area where the drive signal electrode 311 and the drive ground electrode 312 substantially face each other (the electric field contributing to the drive force). However, the thermoelastic loss in the driving vibration of the arm portion 2211 is larger than that in the case where the through hole 2213 is provided as described above. This is because the stress generated by the drive vibration of the drive vibration arm 221 is large at the corner portion of the through-hole 2213 in plan view, so that the temperature difference between one side and the other side in the width direction of the arm portion 2211 is large. It is to become.

  Further, if the shape of the through hole 2213X1 described above is simply cut out as in the through hole 2213X2 shown in FIG. 7, even if the thermoelastic loss in the driving vibration of the arm portion 2211 can be reduced, The opposing area between the drive signal electrode 311 and the drive ground electrode 312 is reduced.

  For this reason, the through-hole 2213 (first through-hole) may be in the shape of an octagon or more (more preferably a dodecagon or more) polygon, streamline, or ellipse in plan view. preferable. That is, the shape of the through hole 2213 in plan view is not limited to a dodecagon, and may be any other shape such as an octagon or other polygon, streamline, or ellipse. However, the same effect as described above can be obtained. In the drawing, the shape of the through hole 2213 in plan view is symmetric in the y-axis direction, but may be asymmetric. In addition, the plan view shape of the through hole 2213 is preferably symmetric in the x-axis direction from the viewpoint of reducing unnecessary vibration of the drive vibrating arm 221.

  Further, as shown in FIG. 2, the drive vibrating arm 221 has two walls divided by a through hole 2213 (first through hole) when viewed in a cross section perpendicular to the y-axis direction (first direction). Parts 2211a and 2211b. The two wall portions 2211a and 2211b are respectively directed from one side (upper side in the figure) to the other side (lower side in the figure) in the penetration direction (z-axis direction) of the through hole 2213 (first through hole). The thickness (width W1) is decreasing. In other words, the length HW of the through hole 2213 changes (decreases or increases) along the z-axis direction. As a result, the wall portions 2211a and 2211b having narrow portions of the width W1 can be formed on the drive vibrating arm 221 relatively easily (for example, using side etching when the through hole 2213 is formed by etching). Therefore, the electric field efficiency of excitation in the drive vibrating arm 221 can be further increased.

  Here, in the figure, the thicknesses W1 of the wall portions 2211a and 2211b monotonously decrease from one side to the other side in the z-axis direction (continuously and at a constant reduction rate). The rate may change from one side to the other side in the z-axis direction, and the thickness of each wall portion 2211a, 2211b changes stepwise from one side to the other side in the z-axis direction. You may do it. Also, in the drawing, both side surfaces of the wall portions 2211a and 2211b are inclined with respect to the z-axis direction, but one side surface (that is, the wall surface of the through-hole 2213 or the side surface of the arm portion 2211). May be parallel to the z-axis. Moreover, the inclination angle of the side surfaces of the wall portions 2211a and 2211b with respect to the z-axis direction is not particularly limited, but is preferably 10 ° or less.

  Further, as shown in FIG. 5, wall portions 2211 a and 2211 b are respectively provided on both side surfaces of the arm portion 2211 of the drive vibrating arm 221 at positions corresponding to portions between two adjacent through holes 2213. Protruding portions 2216 are formed so as to protrude in the direction (−x axis direction and + x axis direction). Therefore, in plan view, along the direction (x-axis direction) orthogonal to the y-axis direction (first direction) of the drive vibrating arm 221 at a position between two adjacent through-holes 2213 (first through-hole). The width W3 is larger than the width W4 along the direction (x-axis direction) orthogonal to the y-axis direction (first direction) of the drive vibrating arm 221 at the position of the through-hole 2213 (first through-hole). Thereby, it is possible to improve the shock resistance of the drive vibrating arm 221 while improving the electric field efficiency of excitation in the drive vibrating arm 221. The width W3 is an average value of width values along a direction orthogonal to the y-axis direction of the drive vibrating arm 221 at a position between two adjacent through holes 2213 in plan view.

  Here, the length L2 of the protruding portion 2216 in the y-axis direction is larger than the length L1 between two adjacent through holes 2213. Thereby, the impact resistance of the drive vibrating arm 221 can be improved accurately. Even when the length L2 is shorter than the length L1, the impact resistance of the drive vibrating arm 221 can be improved as compared with the case where the protrusion 2216 is not provided.

  Further, the length L3 of the protruding portion 2216 in the x-axis direction is not particularly limited, but is preferably 0.05 times or more and 0.3 times or less with respect to the width W1, and is 0.1 times or more and 0.00. More preferably, it is 2 times or less. Thereby, the impact resistance of the drive vibration arm 221 can be enhanced while suppressing an increase in the rigidity of the drive vibration arm 221 more than necessary.

  Further, the protrusion 2216 has a length in the x-axis direction that continuously decreases toward one side and the other side in the y-axis direction. As a result, it is possible to reduce the occurrence of unintentional stress on the drive vibration arm 221 when the drive vibration arm 221 vibrates. In addition, the planar view shape of the protrusion part 2216 is not limited to the shape of illustration, For example, you may comprise the rectangle.

  Further, the drive vibration arm 221 is provided at the proximal end portion of the arm portion 2211 and has a tapered portion 2214 whose width increases from the distal end side toward the proximal end side, and is provided at the distal end portion of the arm portion 2211 and is proximal to the proximal end portion. And a tapered portion 2215 whose width increases from the side toward the tip side. The taper portion 2214 can reduce the stress between the arm portion 2211 and the base portion 21, and can improve the impact resistance of the drive vibration arm 221. Further, the taper portion 2215 can reduce the stress between the arm portion 2211 and the wide portion 2212, and the impact resistance of the drive vibrating arm 221 can also be improved in this respect.

  Next, the detection vibrating arm 231 will be described in detail. In the following, the detection vibrating arm 231 will be representatively described, but the detection vibrating arm 232 is the same as the detection vibrating arm 231.

  As described above, the sensor element 1 includes the detection vibrating arm 231 extending in the y-axis direction that is the “second direction” from the base portion 21 (main body portion 211). Here, as shown in FIG. 8, the detection vibrating arm 231 has at least one (second through hole) “second through-hole” penetrating in the thickness direction (z-axis direction) of the base portion 21. A certain through hole 2313 is provided. Thereby, the electric field efficiency of detection in the detection vibrating arm 231 can be increased as compared with the case where the detection vibrating arm 231 is not provided with a through hole or a bottomed groove is provided.

  In particular, in the sensor element 1, in plan view, the length along the y-axis direction (second direction) of the through hole 2313 (second through hole) is HL2, and the y axis of the through hole 2313 (second through hole) is When the length along the direction (x-axis direction) orthogonal to the direction (second direction) is HW2, HL2 / HW2 is larger than HL / HW. As a result, the electric field efficiency of detection in the detection vibration arm 231 is increased and the Q value of the detection vibration of the detection vibration arm 231 is decreased (the detection vibration arm 231 vibrates with the drive vibration of the drive vibration arm 221). Unnecessary vibrations can be reduced, and the detection vibration of the detection vibration arm 231 can be easily excited accurately). Therefore, the detection sensitivity can be further improved.

  In the sensor element 1, one detection vibrating arm 231 includes a plurality of through holes 2313 (second through holes). Thereby, the area where the detection signal electrode 321 and the detection ground electrode 322 face each other can be increased according to the number of the through holes 2313, and the electric field efficiency of detection in the detection vibrating arm can be further increased. Here, the plurality of through holes 2313 are arranged in the extending direction of the detection vibrating arm 231, and the length between the two adjacent through holes 2313 is not particularly limited, but with respect to the length HW2 It is preferably 0.3 times or more and 1.5 times or less, and more preferably 0.5 times or more and 1.0 times or less. Thereby, in the case where a plurality of through holes 2313 are provided, the unnecessary vibration of the detection vibrating arm 231 can be accurately reduced. The shapes and dimensions of the plurality of through holes 2313 are preferably equal to each other, but may be different.

  In this embodiment, the number of through holes 2313 provided in one detection vibrating arm 231 is smaller than the number of through holes 2213 provided in one driving vibrating arm 221. Thereby, even when a plurality of through holes 2313 are provided in the detection vibrating arm 231, the length HL2 of the through hole 2313 in the y-axis direction can be made longer than the length of the through-hole 2213 in the y-axis direction. Therefore, the electric field efficiency of detection in the detection vibrating arm 231 can be further increased. Further, as the length HL2 of the through-hole 2313 in the y-axis direction becomes longer, the Q value of the detection vibration of the detection vibration arm 231 can be reduced, so that the detection sensitivity can be further improved.

  In the present embodiment, the through hole 2313 (second through hole) has a shape in which a rectangular corner is rounded in a plan view. Accordingly, the through hole 2313 (second through hole) has two sides along the y-axis direction (second direction) and a direction (x-axis direction) orthogonal to the y-axis direction (second direction) in plan view. And has two sides along the line. Thereby, the opposing area of the detection signal electrode 321 and the detection ground electrode 322 can be increased, and the electric field efficiency of detection in the detection vibrating arm 231 can be further increased. Although the through hole 2313 may have a rectangular shape in plan view, the mechanical strength of the detection vibrating arm 231 can be improved by rounding (or inclining) the corners of the rectangle. In addition, there is an advantage that the through hole 2313 can be easily formed by etching.

  Further, as shown in FIG. 4, the detection vibrating arm 231 has two walls divided by a through hole 2313 (second through hole) when viewed in a cross section perpendicular to the y-axis direction (second direction). Parts 2311a and 2311b. The two wall portions 2311a and 2311b are respectively directed from one side (upper side in the figure) to the other side (lower side in the figure) in the penetration direction (z-axis direction) of the through hole 2313 (second through hole). The thickness is decreasing. In other words, the length HW2 of the through hole 2313 changes (decreases or increases) along the z-axis direction. As a result, the wall portions 2311a and 2311b having narrow portions of the width W2 can be formed on the detection vibrating arm 231 relatively easily (for example, by using side etching when the through hole 2313 is formed by etching). Therefore, the electric field efficiency of detection in the detection vibrating arm 231 can be further increased.

  Here, as described above, the drive vibrating arm 221 has two wall portions divided into two by the through hole 2213 (first through hole) when viewed in a cross section perpendicular to the y-axis direction (first direction). Although there are 2211a and 2211b, the reduction rate of the thickness of the two wall portions 2311a and 2311b of the detection vibration arm 231 is the reduction rate of the thickness of the wall portions 2211a and 2211b of the drive vibration arm 221. Is preferably larger. That is, the two wall portions 2211a and 2211b included in the drive vibrating arm 221 are each from one side (upper side in FIG. 2) to the other side (upper side in FIG. 2) of the through hole 2213 (first through hole) in the penetrating direction (z-axis direction). The thickness W1 is constant toward the lower side in FIG. 2 or is decreasing at a reduction rate smaller than the reduction rate of the thickness W2 of the wall portions 2311a and 2311b of the detection vibrating arm 231. Is preferred. Thereby, the unnecessary vibration of the drive vibration arm 221 can be reduced, and as a result, the detection sensitivity can be further improved.

  In the figure, the thickness W2 of each wall portion 2311a, 2311b monotonously decreases from one side to the other side in the z-axis direction (continuously and at a constant reduction rate). May change from one side to the other side in the z-axis direction, and the thickness of each wall portion 2311a, 2311b changes stepwise from one side to the other side in the z-axis direction. It may be. Further, in the drawing, both side surfaces of the wall portions 2311a and 2311b are inclined with respect to the z-axis direction, but one side surface of the both side surfaces (that is, the wall surface of the through hole 2313 or the side surface of the arm portion 2311). May be parallel to the z-axis. Moreover, the inclination angle of the side surfaces of the wall portions 2311a and 2311b with respect to the z-axis direction is not particularly limited, but is preferably 10 ° or less.

  Further, as shown in FIG. 8, on both side surfaces of the arm portion 2311 of the detection vibrating arm 231, wall portions 2311a and 2311b are respectively provided at positions corresponding to portions between two adjacent through holes 2313. Protruding portions 2316 are formed so as to protrude in the direction (−x axis direction and + x axis direction). Therefore, in plan view, along the direction (x-axis direction) orthogonal to the y-axis direction (second direction) of the detection vibrating arm 231 at a position between two adjacent through-holes 2313 (second through-hole). The width is larger than the width along the direction (x-axis direction) orthogonal to the y-axis direction (second direction) of the detection vibrating arm 231 at the position of the through-hole 2313 (second through-hole). Thereby, it is possible to improve the impact resistance of the detection vibrating arm 231 while improving the electric field efficiency of detection in the detection vibrating arm 231. The configuration of the protruding portion 2316 in the detection vibrating arm 231 is the same as the configuration of the protruding portion 2216 in the drive vibrating arm 221 described above. In plan view, the width along the direction orthogonal to the y-axis direction of the detection vibrating arm 231 at a position between two adjacent through holes 2313 is an average value of the width values.

  Further, the detection vibrating arm 231 is provided at the proximal end portion of the arm portion 2311 and has a taper portion 2314 whose width increases from the distal end side toward the proximal end side, and a proximal end portion provided at the distal end portion of the arm portion 2311. And a tapered portion 2315 whose width increases from the side toward the tip side. The taper portion 2314 can reduce the stress between the arm portion 2311 and the base portion 21, and can improve the shock resistance of the detection vibrating arm 231. In addition, the taper portion 2315 can reduce the stress between the arm portion 2311 and the wide portion 2312, and the impact resistance of the detection vibrating arm 231 can also be improved in this respect.

Second Embodiment
FIG. 9 is a plan view showing a sensor element according to the second embodiment of the present invention. In FIG. 9, for convenience of explanation, the same x-axis, y-axis, and z-axis as those in the above-described figure are shown. Moreover, in FIG. 9, illustration of each electrode is abbreviate | omitted for convenience of explanation.

  A sensor element 1A shown in FIG. 9 includes a piezoelectric substrate 2A. The piezoelectric substrate 2A includes the base 21A instead of the base 21 of the first embodiment described above, and includes the piezoelectric substrate of the first embodiment. Same as 2.

  21 A of base parts are the main-body part 211 located in a center part, the connection arm 212A (support arm) extended from the main-body part 211 to the -x-axis direction, and the connection arm extended from the main-body part 211 to the + x-axis direction. 213A (supporting arm). The connecting arm 212A is provided with a through hole 2121 penetrating in the z-axis direction. Similarly, the connecting arm 213A is provided with a through hole 2131 penetrating in the z-axis direction.

  Thus, the base portion 21A is at least one (third through hole) extending in the x-axis direction (third direction) and penetrating in the thickness direction of the base portion 21A. The connecting arms 212A and 213A, which are “supporting arms” provided with through holes 2121 and 2131, are provided. In the through holes 2121 and 2131 provided in the connecting arms 212A and 213A, the length along the x-axis direction (third direction) of the through holes 2121 and 2131 (third through hole) in plan view. Is HL3, and the length along the direction (y-axis direction) perpendicular to the x-axis direction (third direction) of the through holes 2121, 2131 (third through-hole) is HW3, HL3 / HW3 is HL / It is preferable that it is larger than HW. Thereby, the Q value of the vibration of the connecting arms 212A and 213A can be reduced (thereby reducing unnecessary vibration of the connecting arms 212A and 213A). Therefore, the detection sensitivity can be further improved.

  Here, the “first direction” that is the extending direction of the drive vibrating arm 221 and the “second direction” that is the extending direction of the detection vibrating arm 231 are parallel to each other, and the connecting arms 212A and 213A are extended. It is orthogonal to the “third direction” that is the current direction. As a result, a so-called double T-type sensor element 1A having excellent detection sensitivity can be realized.

<Third Embodiment>
FIG. 10 is a plan view showing a sensor element according to the third embodiment of the present invention. 11 is a cross-sectional view taken along the line DD in FIG. 12 is a cross-sectional view taken along line EE in FIG.

  In these drawings, for convenience of explanation, the same x-axis, y-axis, and z-axis as those in the above-described drawings are shown. In FIG. 10, illustration of each electrode is omitted for convenience of explanation.

  A sensor element 1B shown in FIG. 10 is an angular velocity detection element (gyro element) capable of detecting an angular velocity around an axis ay parallel to the y axis. The sensor element 1B includes a piezoelectric substrate 4 and electrodes (see FIGS. 11 and 12) formed on the piezoelectric substrate 4.

-Piezoelectric substrate-
The piezoelectric substrate 4 is composed of a Z-cut quartz plate, like the piezoelectric substrate 2 of the first embodiment described above. The piezoelectric substrate 4 includes a base 41, drive vibration arms 421 and 422, detection vibration arms 431 and 432, adjustment vibration arms 441 and 442, a support portion (frame body) 45, and four connection portions 461 and 462. , 463, 464, which are integrally formed.

  The drive vibrating arms 421 and 422 respectively extend from the base 41 in the −y axis direction. The drive vibrating arms 421 and 422 are arranged side by side along the x-axis direction.

  The drive vibration arm 421 includes an arm part 4211 extending from the base part 41, a wide part 4212 provided on the distal end side of the arm part 4211 and wider than the arm part 4211, and an extension extending to the arm part 4211. And a plurality (six in the drawing) of through holes 4213 provided side by side in the direction. Similarly, the drive vibration arm 422 includes an arm portion 4221 extending from the base portion 41, a wide portion 4222 provided on the distal end side of the arm portion 4221 and wider than the arm portion 4221, and the arm portion 4221. And a plurality (six in the drawing) of through holes 4223 provided side by side in the extending direction.

  In such driving vibration arms 421 and 422, by providing wide portions 4212 and 4222 (hammer heads), the detection sensitivity of the angular velocity can be improved, or the length of the driving vibration arms 421 and 422 can be shortened. it can. Further, by providing the through holes 4213 and 4223, the thermoelastic loss and the CI value can be reduced, and the drive vibrating arms 421 and 422 can be driven and vibrated efficiently. The wide portions 4212 and 4222 may be provided as necessary and may be omitted. The configuration of the drive vibrating arms 421 and 422 will be described in detail later.

  The detection vibrating arm 431 and the detection vibrating arm 432 extend from the base 41 in the + y axis direction, respectively. The detection vibrating arm 431 and the detection vibrating arm 432 are arranged side by side along the x-axis direction.

  The detection vibrating arm 431 includes an arm portion 4311 extending from the base portion 41, a wide portion 4312 that is provided on the distal end side of the arm portion 4311 and wider than the arm portion 4311, and extends to the arm portion 4311. A plurality of (two in the drawing) through-holes 4313 provided side by side in the direction. Similarly, the detection vibrating arm 432 includes an arm portion 4321 extending from the base portion 41, a wide portion 4322 provided on the distal end side of the arm portion 4321 and wider than the arm portion 4321, and the arm portion 4321. A plurality of (two in the drawing) through-holes 4323 provided side by side in the extending direction.

  In such detection vibration arms 431 and 432, by providing the wide portions 4312 and 4322, the resonance frequency (natural frequency) of the detection vibration arms 431 and 432 can be lowered, or the length of the detection vibration arms 431 and 432 can be reduced. It can be shortened. Further, by providing the through holes 4313 and 4323, the detection vibration can be detected efficiently. The wide portions 4312 and 4322 may be provided as necessary and may be omitted. The detection vibrating arms 431 and 432 will be described in detail later together with the drive vibrating arms 421 and 422.

  The adjustment vibration arm 441 and the adjustment vibration arm 442 respectively extend from the base portion 41 in the + y axis direction. The adjustment vibration arm 441 and the adjustment vibration arm 442 are arranged side by side along the x-axis direction with the detection vibration arms 431 and 432 described above interposed therebetween.

  The adjustment vibrating arm 441 includes an arm portion 4411 extending from the base portion 41, and a wide portion 4412 provided on the distal end side of the arm portion 4411 and wider than the arm portion 4411. Similarly, the adjustment vibration arm 442 includes an arm portion 4421 extending from the base portion 41, and a wide portion 4422 provided on the distal end side of the arm portion 4421 and wider than the arm portion 4421.

  In such adjustment vibration arms 441 and 442, by providing wide portions 4412 and 4422, the resonance frequency (natural frequency) of the adjustment vibration arms 441 and 442 can be lowered, or the length of the adjustment vibration arms 441 and 442 can be reduced. It can be shortened. The wide portions 4312 and 4322 may be provided as necessary and may be omitted. Further, grooves may be provided on the main surfaces of the adjustment vibrating arms 441 and 442. Further, the adjustment vibrating arms 441 and 442 may be omitted.

  The support portion 45 has a function of supporting the base portion 41 via the connecting portions 461, 462, 463, and 464. The support portion 45 is disposed on the −y-axis direction side with respect to the base portion 41 and has a long portion 451 extending along the x-axis direction, and from the both ends of the portion 451 along the + y-axis direction. Two portions 452 and 453 extending in the direction.

  The connecting portion 461 has an elongated shape, one end is connected to the + y-axis direction end of the portion 452, and the other end is connected to the −x-axis side end of the base 41. 41 and the support part 45 are connected. Similarly, the connecting portion 462 has an elongated shape, one end is connected to the end of the portion 453 on the + y axis direction side, and the other end is connected to the end of the base portion 41 on the + x axis direction side. The base part 41 and the support part 45 are connected.

  The connecting portion 463 has a long shape, one end is connected to the center of the portion 451, and the other end is connected to the end of the base 41 on the −x-axis direction side, and supports the base 41. The part 45 is connected. Similarly, the connecting portion 464 has an elongated shape, one end is connected to the central portion of the portion 451, and the other end is connected to the end on the + x-axis direction side of the base 41, and supports the base 41. The part 45 is connected.

  Such connecting portions 461, 462, 463, and 464 each have a plurality of portions bent or curved in the middle. Specifically, each of the connecting portions 461, 462, 463, and 464 is configured by alternately connecting a plurality of portions extending along the x-axis direction and portions extending along the y-axis direction. ing. By providing a plurality of such bent or curved portions, the flexibility of the connecting portions 461, 462, 463, and 464 in various directions can be increased. For this reason, the shock resistance of the sensor element 1B is increased, or the frequency of unnecessary vibrations of the base 41 accompanied by bending deformation of the connecting portions 461, 462, 463, and 464 is increased away from the frequency of driving vibration and detection vibration to improve detection characteristics. Can be. Further, the sensor element 1B can be downsized.

-Electrode-
As shown in FIGS. 10, 11, and 12, the electrodes provided on the surface of the piezoelectric substrate 4 described above include a drive signal electrode 511, a drive ground electrode 512, a first detection signal electrode 521, and a second electrode. A detection signal electrode 522; a detection ground electrode 523; a drive signal terminal 513; a drive ground terminal 514; a first detection signal terminal 525; a second detection signal terminal 526; and a detection ground terminal 527. Yes.

  As shown in FIG. 11, the drive signal electrode 511 is provided on the wall surface of the through hole 4213 of the drive vibration arm 421 and on both side surfaces of the arm portion 4221 of the drive vibration arm 422. The drive signal electrode 511 is an electrode for exciting the drive vibration of the drive vibration arms 421 and 422.

  The drive ground electrode 512 is provided on both side surfaces of the arm portion 4211 of the drive vibration arm 421 and the wall surface of the through hole 4223 of the drive vibration arm 422. The drive ground electrode 512 has a potential that serves as a ground with respect to the drive signal electrode 511.

  As shown in FIG. 10, the drive signal terminal 513 is disposed slightly on the + x axis side from the central portion of the portion 451, and the drive signal terminal 513 is driven via a drive signal wiring (not shown) formed in the connecting portion 464. The electrode 511 is electrically connected. Similarly, the drive ground terminal 514 is disposed slightly on the −x axis side with respect to the central portion of the portion 451, and the drive ground electrode 512 is connected via a drive ground wiring (not shown) formed in the connecting portion 463. And are electrically connected.

  As shown in FIG. 12, the first detection signal electrode 521 includes the upper left portion, the lower right portion, the lower left portion, and the upper right portion of the arm portion 4311 of the detection vibrating arm 431, and the arm of the detection vibrating arm 432. The upper surface right portion, the lower surface left portion, the left surface upper portion and the right surface lower portion of the portion 4321, and the left side surface, the upper surface right portion and the lower surface right portion of the arm portion 4421 of the adjustment vibration arm 442 are provided. Similarly, the second detection signal electrode 522 includes an upper right portion, a lower left portion, a left upper portion, and a lower right portion of the arm portion 4311 of the detection vibrating arm 431, and an upper surface of the arm portion 4321 of the detection vibrating arm 432. Provided on the left side, the lower right side, the lower left side, and the upper right side, and the right side, upper left side, and lower left side of the arm portion 4411 of the adjustment vibrating arm 441, respectively. The first and second detection signal electrodes 521 and 522 are electrodes for detecting charges generated by the detection vibration when the detection vibration of the detection vibration arms 431 and 432 is excited.

  The detection ground electrode 523 is provided on the upper surface right side portion, lower surface right side portion and left side surface of the arm portion 4411 of the adjustment vibration arm 441, and on the upper surface left side portion, lower surface left side portion and right side surface of the arm portion 4421 of the adjustment vibration arm 442, respectively. It has been. The detection ground electrode 523 has a potential serving as a ground with respect to the first detection signal electrode 521 and the second detection signal electrode 522.

  The first detection signal terminal 525 is formed in the portion 453 as shown in FIG. 10 and is electrically connected to the first detection signal electrode 521 via a detection signal wiring (not shown) formed in the connecting portion 462. It is connected to the. Similarly, the second detection signal terminal 526 is formed in the portion 452, and is electrically connected to the second detection signal electrode 522 via a detection signal wiring (not shown) formed in the connecting portion 461. ing.

  The detection ground terminal 527 is formed in each of the portion 452 and the portion 453 and is electrically connected to the detection ground electrode 523 via a detection ground wiring (not shown) formed in the connecting portions 463 and 464. Yes.

The configuration of the electrode as described above is not particularly limited as long as it has conductivity. For example, Ni (nickel), Au (metal) layer such as Cr (chromium), W (tungsten), etc. (Gold), Ag (silver), Cu (copper), etc. can be comprised by the metal film which laminated | stacked each film.
The configuration of the sensor element 1B has been described above.

  In the sensor element 1B configured as described above, an electric field is generated between the drive signal electrode 511 and the drive ground electrode 512 by inputting a drive signal to the drive signal terminal 513 in a state where no angular velocity is applied to the sensor element 1B. When this occurs, the drive vibration arms 421 and 422 perform bending vibration (drive vibration) so as to be opposite to each other in the x-axis direction as indicated by an arrow d in FIG.

  Further, along with this drive vibration, the adjustment vibration arms 441 and 442 also perform bending vibration (adjustment vibration) so as to be opposite to each other in the x-axis direction.

  When an angular velocity ωy around the central axis ay along the y-axis direction is applied to the sensor element 1B in a state where this driving vibration is performed, Coriolis force acts on the driving vibration arms 421 and 422, and driving is performed by this Coriolis force. The vibrating arms 421 and 422 bend and vibrate so as to be opposite to each other in the z-axis direction. Accordingly, the detection vibrating arms 431 and 432 are flexibly vibrated (detected vibration) so as to be opposite to each other in the z-axis direction as indicated by an arrow e in FIG. Due to this detection vibration, electric charges generated between the first detection signal electrode 521 and the second detection signal electrode 522 and the detection ground electrode 523 are taken out from the first detection signal terminal 525 and the second detection signal terminal 526 as detection signals. Based on this detection signal, the angular velocity is obtained.

  At this time, similarly to the drive vibration arms 421 and 422, the adjustment vibration arms 441 and 442 also bend and vibrate so as to be opposite to each other in the z-axis direction, but no charge is output due to this bending vibration. That is, regardless of the presence or absence of the action of the Coriolis force, the charges output from the adjustment vibration arms 441 and 442 are basically only due to the adjustment vibration described above and are constant. Thereby, the leak output resulting from the manufacturing variation of the piezoelectric substrate 2, etc. can be adjusted.

(Detailed description of the drive vibration arm and detection vibration arm)
Hereinafter, the drive vibration arms 421 and 422 and the detection vibration arms 431 and 432 will be described in detail.

  FIG. 13 is an enlarged plan view of a drive vibrating arm included in the sensor element shown in FIG. 14 is an enlarged plan view of a detection vibrating arm included in the sensor element shown in FIG. In each figure, for convenience of explanation, the same x-axis, y-axis, and z-axis as those in the above-described figures are shown, and the illustration of electrodes is omitted.

  First, the drive vibrating arm 421 will be described in detail. Hereinafter, the drive vibration arm 421 will be described as a representative, but the drive vibration arm 422 is the same as the drive vibration arm 421. Descriptions of the same matters as those of the drive vibration arm 221 of the first embodiment described above are omitted as appropriate.

  As described above, the sensor element 1B includes the base 41 and the drive vibrating arm 421 extending from the base 41 in the y-axis direction that is the “first direction”. Here, as shown in FIG. 13, the drive vibration arm 421 has at least one (first through hole in the figure) “first through hole” penetrating in the thickness direction (z-axis direction) of the base 41. A certain through hole 4213 is provided. As a result, the thermoelastic loss in the drive vibration of the drive vibration arm 421 is reduced and the excitation (drive) in the drive vibration arm 421 is reduced as compared with the case where the drive vibration arm 421 is not provided with a through hole or a bottomed groove is provided. Vibration) and the Q value of the drive vibration of the drive vibration arm 421 can be improved.

  In particular, in the sensor element 1B, the length along the y-axis direction of the through hole 4213 in a plan view (hereinafter also simply referred to as “plan view”) viewed from the thickness direction of the base 41 is HL, and the through hole 4213 When the length along the direction perpendicular to the y-axis direction (x-axis direction) is HW, HL / HW is 1.3 or more and 3.0 or less. As a result, like the sensor element 1 of the first embodiment described above, the sharpness of the resonance of the drive vibration of the drive vibration arm 421 is achieved while sufficiently exhibiting the above-described effects (reduction in thermoelastic loss and improvement in electric field efficiency). A decrease in the Q value due to the decrease can be suppressed. Therefore, noise due to unnecessary vibration of the drive vibrating arm 421 can be reduced and detection sensitivity can be sufficiently improved.

  In the present embodiment, the width of the through-hole 4213 in the x-axis direction becomes smaller toward the both end sides of the through-hole 4213 in the y-axis direction. In the drawing, each through hole 4213 (first through hole) has a dodecagonal shape in plan view. Thereby, like the drive vibration arm 221 of the first embodiment described above, the Q value of the drive vibration of the drive vibration arm 421 can be further improved. Note that the shape of the through hole 4213 in plan view is not limited to a dodecagon, and may be, for example, any of an octagon or more polygon, streamline, or ellipse. However, the same effect as described above can be obtained.

  Further, as shown in FIG. 13, a protruding portion 4216 is provided on each side surface of the drive vibrating arm 421 at a position corresponding to a portion between two adjacent through holes 4213. Accordingly, it is possible to improve the shock resistance of the drive vibration arm 421 while improving the electric field efficiency of the excitation in the drive vibration arm 421.

  Further, the drive vibration arm 421 is provided at the proximal end portion of the arm portion 4211 and has a tapered portion 4214 whose width increases from the distal end side toward the proximal end side, and a proximal end portion provided at the distal end portion of the arm portion 4211. And a tapered portion 4215 whose width increases from the side toward the distal end side. The taper portions 4214 and 4215 can improve the impact resistance of the drive vibrating arm 421.

  In the drawing, when the drive vibrating arm 421 is viewed in a cross section perpendicular to the y-axis direction, the thickness of each of the two wall portions divided into two by the through-hole 4213 is equal to one side in the z-axis direction. However, the thickness of each of the two wall portions is from one side to the other side in the z-axis direction, as in the case of the drive vibration arm 221 of the first embodiment described above. It may be decreasing (or increasing).

  Next, the detection vibrating arm 431 will be described in detail. In the following, the detection vibrating arm 431 will be described as a representative example, but the detection vibrating arm 432 is the same as the detection vibrating arm 431.

  As described above, the sensor element 1B includes the detection vibrating arm 431 extending from the base portion 41 in the y-axis direction that is the “second direction”. Here, as shown in FIG. 14, the detection vibrating arm 431 includes at least one (second through hole) “second through hole” penetrating in the thickness direction (z-axis direction) of the base 41. A certain through hole 4313 is provided. Thereby, the electric field efficiency of detection in the detection vibrating arm 431 can be increased as compared with the case where the detection vibrating arm 431 is not provided with a through hole or a bottomed groove is provided.

  In particular, in the sensor element 1B, in plan view, the length along the y-axis direction (second direction) of the through hole 4313 (second through hole) is HL2, and the y axis of the through hole 4313 (second through hole) is When the length along the direction (x-axis direction) orthogonal to the direction (second direction) is HW2, HL2 / HW2 is larger than HL / HW. This increases the electric field efficiency of detection in the detection vibration arm 431 and decreases the Q value of the detection vibration of the detection vibration arm 431 (the detection vibration arm 431 vibrates with the drive vibration of the drive vibration arm 421). Unnecessary vibrations can be reduced, and the detection vibration of the detection vibration arm 431 can be easily excited accurately). Therefore, the detection sensitivity can be further improved.

  Here, the “first direction” that is the extending direction of the drive vibrating arm 421 and the “second direction” that is the extending direction of the detection vibrating arm 431 are opposite to each other (−y axis direction and + y axis direction). is there. As a result, a so-called H-type sensor element 1B having excellent detection sensitivity can be realized.

  In addition, on both side surfaces of the detection vibrating arm 431, a protruding portion 4316 is provided at a position corresponding to a portion between two adjacent through holes 4313. Thereby, it is possible to improve the shock resistance of the detection vibrating arm 431 while improving the electric field efficiency of detection in the detection vibrating arm 431.

  Further, the detection vibrating arm 431 is provided at the proximal end portion of the arm portion 4311 and has a tapered portion 4314 whose width increases from the distal end side toward the proximal end side, and is provided at the distal end portion of the arm portion 4311 and is proximally provided. And a tapered portion 4315 whose width increases from the side toward the tip side. The taper portions 4314 and 4315 can improve the shock resistance of the detection vibrating arm 431.

  In the figure, when the detection vibrating arm 431 is viewed in a cross section perpendicular to the y-axis direction, the thickness of each of the two wall portions divided into two by the through-hole 4313 is equal to one side in the z-axis direction. However, the thickness of each of the two wall portions is from one side to the other side in the z-axis direction, like the detection vibrating arm 231 of the first embodiment described above. It may be decreasing (or increasing).

2. Physical Quantity Sensor Next, the physical quantity sensor of the present invention will be described.

  FIG. 15 is a perspective view showing an example of the physical quantity sensor of the present invention. 16 is a cross-sectional view of the physical quantity sensor shown in FIG. In FIG. 15, the lid 62 is not shown for convenience of explanation.

  As shown in FIGS. 15 and 16, the physical quantity sensor 10 includes three sensor elements 7X, 7Y, and 7Z, a package 6 that accommodates these sensor elements 7X, 7Y, and 7Z, and an IC chip 8. Yes.

  The package 6 includes a box-shaped base 61 having a recess 611 and a plate-shaped lid 62 joined by closing the opening of the recess 611. The sensor elements 7X, 7Y, and 7Z are housed in the housing space S formed by closing the recess 611 with the lid 62. The storage space S may be in a reduced pressure (vacuum) state, or may be filled with an inert gas such as nitrogen, helium, or argon.

  The recess 611 has a first recess 611a that opens to the upper surface of the base 61, and a second recess 611b that opens to the center of the bottom surface of the first recess 611a.

  Although it does not specifically limit as a constituent material of the base 61, Various ceramics, such as aluminum oxide, and various glass materials can be used. Further, the constituent material of the lid 62 is not particularly limited, but a member having a linear expansion coefficient approximate to that of the constituent material of the base 61 is preferable. For example, when the constituent material of the base 61 is ceramic as described above, an alloy such as Kovar is preferable. In addition, the joining method of the base 61 and the lid 62 is not specifically limited, For example, it can join via an adhesive material or a brazing material. In the present embodiment, the lid 62 is joined to the base 61 via a joining member 63 such as a seam ring, low-melting glass, or adhesive.

  A plurality of connection terminals 641 are formed on the bottom surface of the first recess 611a. The connection terminal 641 is electrically connected to a terminal 642 provided on the bottom surface of the base 61 via wiring layers 643 and 644 provided on the base 61. The connection terminal 641 and the like are not particularly limited as long as they have conductivity. For example, Ni (nickel), Au (gold), a metallization layer (underlayer) such as Cr (chrome), W (tungsten), etc. It is comprised by the metal film which laminated | stacked each film, such as Ag (silver) and Cu (copper).

  The IC chip 8 is fixed to the bottom surface of the second recess 611b with an adhesive or the like. The IC chip 8 has a plurality of terminals 81, and each terminal 81 is electrically connected to each connection terminal 641 by the conductive wire 101. The IC chip 8 includes a drive circuit for driving and vibrating the sensor elements 7X, 7Y, and 7Z, and a detection circuit that detects detection vibration generated in the sensor elements 7X, 7Y, and 7Z when an angular velocity is applied.

  Further, a stress relaxation layer 9 made of a resin such as polyimide is provided on the upper surface of the IC chip 8, and the sensor elements 7X, 7Y, and 7Z are electrically connected on the stress relaxation layer 9. A terminal (not shown) is provided to be exposed.

  The sensor elements 7X, 7Y, and 7Z are fixed on the stress relaxation layer 9 via a conductive adhesive. Thereby, each terminal which sensor element 7X, 7Y, and 7Z has is electrically connected to each terminal on stress relaxation layer 9 via a conductive adhesive. The conductive adhesive is not particularly limited as long as it has conductivity and adhesiveness. For example, conductive adhesive such as silicone particles, epoxy-based, acrylic-based, polyimide-based, and bismaleimide-based conductive materials such as silver particles can be used. What disperse | distributed the property filler can be used.

Here, each of the sensor elements 7X and 7Y is the sensor element 1B of the third embodiment described above. The sensor element 7X is arranged so as to detect the angular velocity ω _X around the X axis, and the sensor element 7Y is arranged so as to detect the angular velocity ω _Y around the Y axis. The sensor element 7Z is the sensor element 1 of the first embodiment described above, and is arranged so as to detect the angular velocity ω _Z around the Z axis. The sensor element 7Z may be the sensor element 1A of the second embodiment.

  The physical quantity sensor 10 as described above includes sensor elements 1 and 1B. Thereby, the sensor element 1 and the excellent effect of 1B can be enjoyed and the sensor characteristic of the physical quantity sensor 10 can be improved. Note that the physical quantity sensor 10 only needs to include at least one of the sensor elements 1, 1A, and 1B described above.

  In this embodiment, the IC chip 8 is provided inside the package 6, but the IC chip 8 may be provided outside the package 6. In this case, the sensor elements 7X, 7Y, and 7Z may be directly fixed to the package 6.

3. Electronic Device Next, the electronic device of the present invention will be described in detail with reference to FIGS.

  FIG. 17 is a perspective view illustrating a configuration of a mobile (or notebook) personal computer that is an example of the electronic apparatus of the invention.

  In this figure, a personal computer 1100 includes a main body portion 1104 provided with a keyboard 1102 and a display unit 1106 provided with a display portion 1108. The display unit 1106 is rotated with respect to the main body portion 1104 via a hinge structure portion. It is supported movably. Such a personal computer 1100 incorporates a sensor element 1 that functions as angular velocity detection means (gyro sensor).

  FIG. 18 is a perspective view illustrating a configuration of a mobile phone (including PHS) which is an example of the electronic apparatus of the invention.

  In this figure, a cellular phone 1200 includes a plurality of operation buttons 1202, an earpiece 1204, and a mouthpiece 1206, and a display unit 1208 is disposed between the operation buttons 1202 and the earpiece 1204. Such a cellular phone 1200 incorporates a sensor element 1 that functions as angular velocity detection means (gyro sensor).

  FIG. 19 is a perspective view showing a configuration of a digital still camera which is an example of the electronic apparatus of the present invention. In this figure, connection with an external device is also simply shown. Here, an ordinary camera sensitizes a silver halide photographic film with a light image of a subject, whereas a digital still camera 1300 photoelectrically converts a light image of a subject with an imaging device such as a CCD (Charge Coupled Device). An imaging signal (image signal) is generated.

  A display unit is provided on the back of a case (body) 1302 in the digital still camera 1300, and is configured to perform display based on an imaging signal from the CCD. The display unit 1310 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 and presses the shutter button 1306, the CCD image pickup signal at that time is transferred and stored in the memory 1308.

  In the digital still camera 1300, a video signal output terminal 1312 and an input / output terminal 1314 for data communication are provided on the side surface of the case 1302. As shown in the figure, a television monitor 1430 is connected to the video signal output terminal 1312 and a personal computer 1440 is connected to the input / output terminal 1314 for data communication as necessary. Further, the imaging signal stored in the memory 1308 is output to the television monitor 1430 or the personal computer 1440 by a predetermined operation.

  Such a digital still camera 1300 incorporates a sensor element 1 that functions as angular velocity detection means (gyro sensor).

  The electronic device as described above includes the sensor element 1. Thereby, the effect of the sensor element 1 can be enjoyed and the characteristics of the electronic device can be improved. In place of the sensor element 1, the sensor element 1A or 1B may be used.

  In addition to the personal computer (mobile personal computer) of FIG. 17, the mobile phone of FIG. 18, and the digital still camera of FIG. Device (for example, inkjet printer), laptop personal computer, TV, video camera, video tape recorder, car navigation device, pager, electronic notebook (including communication function), electronic dictionary, calculator, electronic game device, word processor, work Station, 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 endoscope), fish detector, various measurements Equipment, instruments ( In example, vehicle, aircraft, gauges of a ship), can be applied to a flight simulator or the like.

4). Next, the moving body of the present invention will be described in detail with reference to FIG.
FIG. 20 is a perspective view showing a configuration of an automobile which is an example of the moving body of the present invention.

  The mobile body 1500 is an automobile, and the mobile body 1500 has a built-in sensor element 1 that functions as an angular velocity detection means (gyro sensor). The sensor element 1 can detect the posture of the vehicle body 1501. The detection signal of the sensor element 1 is supplied to the vehicle body posture control device 1502, and the vehicle body posture control device 1502 detects the posture of the vehicle body 1501 based on the signal, and controls the stiffness of the suspension according to the detection result. The brakes of the individual wheels 1503 can be controlled. In addition, such posture control can be used by a biped robot or a radio control helicopter. As described above, the sensor element 1 is incorporated in realizing the posture control of various moving bodies.

  As described above, the moving object 1500 includes the sensor element 1. Thereby, the excellent effect of the sensor element 1 can be enjoyed and the characteristics of the moving body 1500 can be improved. In place of the sensor element 1, the sensor element 1A or 1B may be used.

  As mentioned above, although the sensor element, physical quantity sensor, electronic device, and moving body of the present invention have been described based on the illustrated embodiments, the present invention is not limited to these.

  Moreover, in this invention, the structure of each part can be substituted by the thing of the arbitrary structures which exhibit the same function, and arbitrary structures can also be added.

  In the embodiment described above, the sensor element of the present invention has been described by taking the H type and the double T type as an example. However, the sensor element is not limited to this as long as it has a drive vibrating arm having a through hole. Various forms such as a leg tuning fork, a tripod tuning fork, an orthogonal type, and a prismatic type may be used.

  In addition, the number of drive vibration arms, detection vibration arms, and adjustment vibration arms may be one or three or more, respectively. Further, the drive vibration arm may also serve as the detection vibration arm.

  Further, the number, position, shape, size, and the like of the drive electrodes are not limited to the above-described embodiment as long as the drive vibration arm can be vibrated by energization.

  In addition, the number, position, shape, size, etc. of the detection electrodes are limited to the above-described embodiment as long as the vibration of the driving vibration arm due to the addition of the physical quantity can be electrically detected. is not.

DESCRIPTION OF SYMBOLS 1 ... Sensor element, 1A ... Sensor element, 1B ... Sensor element, 2 ... Piezoelectric board, 2A ... Piezoelectric board, 4 ... Piezoelectric board, 6 ... Package, 7X ... Sensor element, 7Y ... Sensor element, 7Z ... Sensor element, 8 DESCRIPTION OF SYMBOLS IC chip, 9 ... Stress relaxation layer, 10 ... Physical quantity sensor, 21 ... Base part, 21A ... Base part, 41 ... Base part, 45 ... Support part, 61 ... Base, 62 ... Lid, 63 ... Joining member, 81 ... Terminal, 101 DESCRIPTION OF SYMBOLS ... Conductive wire 211 ... Body part 212 ... Connection arm (support arm), 212A ... Connection arm (support arm), 213 ... Connection arm (support arm), 213A ... Connection arm (support arm), 221 ... Drive vibration Arm 222, drive vibration arm 223 drive vibration arm 224 drive vibration arm 231 detection vibration arm 232 detection vibration arm 241 fixed portion 242 fixed portion 251 support beam 252 support Beam, 253 ... Support beam, 254 ... Support beam, 311 ... Drive signal electrode, 312 ... Drive ground electrode, 313 ... Drive signal terminal, 314 ... Drive ground terminal, 321 ... Detection signal electrode, 322 ... Detection ground electrode, 323 ... Detection signal terminal, 324 ... detection ground terminal, 421 ... drive vibration arm, 422 ... drive vibration arm, 431 ... detection vibration arm, 432 ... detection vibration arm, 441 ... adjustment vibration arm, 442 ... adjustment vibration arm, 451 ... portion, 452 ... part, 453 ... part, 461 ... connection part, 462 ... connection part, 463 ... connection part, 464 ... connection part, 511 ... drive signal electrode, 512 ... drive ground electrode, 513 ... drive signal terminal, 514 ... drive ground Terminals, 521... First detection signal electrode, 522... Second detection signal electrode, 523... Detection ground electrode, 525... First detection signal terminal, 526. Ground terminal, 611... Recess, 611a... First recess, 611b... Second recess, 641... Connection terminal, 642... Terminal, 643 ... Wiring layer, 644. 1106 ... Display unit 1108 ... Display part 1200 ... Mobile phone 1202 ... Operation buttons 1204 ... Earpiece 1206 ... Mouthpiece 1208 ... Display part 1300 ... Digital still camera 1302 ... Case 1304 ... Light receiving unit, 1306 ... shutter button, 1308 ... memory, 1310 ... display unit, 1312 ... video signal output terminal, 1314 ... input / output terminal, 1430 ... TV monitor, 1440 ... personal computer, 1500 ... moving body, 1501 ... vehicle body, 1502 ... Car body attitude control device, 150 DESCRIPTION OF SYMBOLS 3 ... Wheel, 2121 ... Through-hole (1st through-hole), 2131 ... Through-hole (1st through-hole), 2211 ... Arm part, 2211a ... Wall part, 2211b ... Wall part, 2212 ... Wide part, 2213 ... Through-hole (Second through hole), 2213X1 ... through hole, 2213X2 ... through hole, 2214 ... tapered portion, 2215 ... tapered portion, 2216 ... projecting portion, 2221 ... arm portion, 2222 ... wide portion, 2223 ... through hole (second through hole) Hole), 2231 ... arm part, 2232 ... wide part, 2233 ... through hole (second through hole), 2241 ... arm part, 2242 ... wide part, 2243 ... through hole (second through hole), 2311 ... arm part, 2311a ... wall portion, 2311b ... wall portion, 2312 ... wide portion, 2313 ... through hole (third through hole), 2314 ... taper portion, 2315 ... taper portion, 2316 ... projection portion, 2321 ... arm portion, 232 ... Wide part, 2323 ... Through hole (third through hole), 4211 ... Arm part, 4212 ... Wide part, 4213 ... Through hole (first through hole), 4214 ... Taper part, 4215 ... Taper part, 4216 ... Projection part , 4221 ... arm part, 4222 ... wide part, 4223 ... through hole (first through hole), 4311 ... arm part, 4312 ... wide part, 4313 ... through hole (second through hole), 4314 ... taper part, 4315 ... Tapered portion, 4316 ... projecting portion, 4321 ... arm portion, 4322 ... wide portion, 4323 ... through hole (second through hole), 4411 ... arm portion, 4412 ... wide portion, 4421 ... arm portion, 4422 ... wide portion, S ... accommodation space, a ... arrows, ay ... shaft, az ... axis, b ... arrows, c ... arrows, d ... arrows, omega _X ... angular velocity, omega _Y ... angular velocity, omega _Z ... angular velocity, .omega.y ... angular, .omega.z ... angular velocity , L1 ... length, L2 ... length L3 ... Length, W1 ... thick, W2 ... thickness, W3 ... width, W4 ... width, HL ... length, HW ... length, HL2 ... length, HW2 ... Length

Claims (17)

The base,
A drive vibrating arm provided with a first through hole extending in a first direction from the base and penetrating in a thickness direction of the base;
In a plan view as viewed from the thickness direction, the length of the first through hole along the first direction is HL, and the length of the first through hole along the direction orthogonal to the first direction is When it is HW
HL / HW is 1.3 or more and 3.0 or less, The sensor element characterized by the above-mentioned.   The sensor element according to claim 1, wherein the drive vibrating arm includes a plurality of the first through holes.   In the plan view, the width along the direction orthogonal to the first direction of the drive vibration arm at a position between two adjacent first through holes is the drive vibration at the position of the first through hole. The sensor element according to claim 2, wherein the sensor element is larger than a width along a direction orthogonal to the first direction of the arm.   4. The sensor element according to claim 1, wherein the first through hole has a shape of an octagon or more polygon, a streamline, and an ellipse in the plan view. 5.   When viewed in a cross section perpendicular to the first direction, the drive vibrating arm is divided into two by the first through hole, and the thickness is increased from one side to the other side in the through direction of the first through hole. The sensor element according to claim 1, which has two walls that are reduced. A detection vibrating arm provided with a second through-hole extending in the second direction from the base and penetrating in the thickness direction;
In the plan view, when the length of the second through hole along the second direction is HL2, and the length of the second through hole along the direction orthogonal to the second direction is HW2,
The sensor element according to any one of claims 1 to 5, wherein HL2 / HW2 is larger than HL / HW.   The sensor element according to claim 6, wherein the detection vibrating arm includes a plurality of the second through holes.   In the plan view, the width along the direction perpendicular to the second direction of the detection vibrating arm at a position between two adjacent second through holes is the detected vibration at the position of the second through hole. The sensor element according to claim 7, wherein the sensor element is larger than a width along a direction orthogonal to the second direction of the arm.   The sensor element according to claim 6, wherein the first direction and the second direction are opposite to each other.   The second through-hole has a shape having two sides along the second direction and two sides along a direction orthogonal to the second direction in the plan view. The sensor element according to any one of claims.   The detection vibrating arm is bisected by the second through hole when viewed in a cross section perpendicular to the second direction, and has a thickness from one side to the other side in the through direction of the second through hole. 11. A sensor element according to any one of claims 6 to 10, having two walls that are reduced.   When viewed in a cross section perpendicular to the first direction, the drive vibrating arm is divided into two by the first through hole, and the thickness is increased from one side to the other side in the through direction of the first through hole. The sensor element according to claim 11, wherein the sensor element has two wall portions that are constant or decrease at a reduction rate smaller than a reduction rate of the wall thickness of the detection vibrating arm. The base includes a support arm provided with a third through hole extending in the third direction and penetrating in the thickness direction,
In the plan view, when the length of the third through hole along the third direction is HL3 and the length of the third through hole along the direction orthogonal to the third direction is HW3,
The sensor element according to any one of claims 6 to 12, wherein HL3 / HW3 is larger than HL / HW.   The sensor element according to claim 13, wherein the first direction and the second direction are parallel to each other and orthogonal to the third direction.   A physical quantity sensor comprising the sensor element according to claim 1.   An electronic device comprising the sensor element according to claim 1.   A moving body comprising the sensor element according to claim 1.

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