WO2009107576A1 - Angular velocity sensor - Google Patents

Angular velocity sensor Download PDF

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Publication number
WO2009107576A1
WO2009107576A1 PCT/JP2009/053142 JP2009053142W WO2009107576A1 WO 2009107576 A1 WO2009107576 A1 WO 2009107576A1 JP 2009053142 W JP2009053142 W JP 2009053142W WO 2009107576 A1 WO2009107576 A1 WO 2009107576A1
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WO
WIPO (PCT)
Prior art keywords
axis direction
angular velocity
mass
excitation
velocity sensor
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PCT/JP2009/053142
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French (fr)
Japanese (ja)
Inventor
康男 早川
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アルプス電気株式会社
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Publication of WO2009107576A1 publication Critical patent/WO2009107576A1/en

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01C—MEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY
    • G01C19/00—Gyroscopes; Turn-sensitive devices using vibrating masses; Turn-sensitive devices without moving masses; Measuring angular rate using gyroscopic effects
    • G01C19/56—Turn-sensitive devices using vibrating masses, e.g. vibratory angular rate sensors based on Coriolis forces
    • G01C19/5719—Turn-sensitive devices using vibrating masses, e.g. vibratory angular rate sensors based on Coriolis forces using planar vibrating masses driven in a translation vibration along an axis

Definitions

  • the present invention relates to an angular velocity sensor formed using MEMS (Micro Electro Mechanical System) technology.
  • MEMS Micro Electro Mechanical System
  • An angular velocity sensor (gyro sensor) formed using an SOI substrate includes a mass portion (Mass) located above the support substrate, a support beam that supports the mass portion in a displaceable manner, and an excitation for exciting the mass portion. And a detection unit for detecting the amount of displacement of the mass unit displaced due to the Coriolis force.
  • the angular velocity sensor disclosed in Patent Document 1 has a structure in which a plurality of mass portions (Mass) are provided, and a mass portion located at the center and a mass portion located on both sides thereof are excited in opposite directions.
  • the central mass part is displaced due to the Coriolis force.
  • the movable-side vibrating electrode that constitutes the vibration generating unit is also integrally formed on the central mass portion provided with the detection electrode.
  • the movable side vibration electrode which comprises a vibration generation part is also integrally formed in the mass part provided with a detection electrode.
  • the angular velocity sensor disclosed in Patent Document 3 has a structure in which a circular mass portion is excited by a comb electrode, and a second mass portion provided in the notch portion is displaced by receiving a Coriolis force.
  • the circular mass is centrally supported on the substrate.
  • the angular velocity sensor disclosed by patent document 4 equips an inner side and an outer side with a mass part, respectively.
  • the outer mass portion is vibrated, Coriolis force is transmitted from the outer mass portion to the inner mass portion, and the displacement amount is measured by receiving the Coriolis force in the inner mass portion.
  • the movable side vibration electrode is integrally formed in the mass part provided with the detection electrode.
  • the drive signal supplied to the movable vibration electrode easily leaks to the detection side through the parasitic capacitance of the substrate etc., and vibration in the detection direction (leakage vibration) occurs in the mass even in the state where the angular velocity ⁇ does not act. It was easy to occur. Then, in order to suppress such leaked vibration, it is necessary to devise an electrode for suppressing leaked vibration (a quadrature cancellation (balancing) electrode) as in Patent Document 2, for example, and the structure becomes complicated and large. It was easy to convert.
  • a quadrature cancellation (balancing) electrode as in Patent Document 2
  • the mass portion including the detection electrode is not directly provided with the movable vibration electrode, and the movable vibration electrode is integrated with another mass portion connected to the mass portion including the detection electrode.
  • the structure is complicated, the leakage to the detection side of the drive signal supplied to the vibration generating unit can not be made sufficiently small.
  • rotational vibration is applied as in the angular velocity sensor of Patent Document 3
  • Patent Document 4 although the Coriolis force is transmitted from the outer mass portion to the inner mass portion, the Coriolis force is transmitted, and it is considered that the Coriolis force is largely attenuated and it is difficult to detect with high accuracy.
  • Coriolis force always acts on the vibration generating part together with the mass part.
  • the present invention is intended to solve the above-mentioned conventional problems, and in particular, it is possible to suppress leakage vibration, excite the mass appropriately with a simple configuration, and appropriately improve the detection accuracy of the angular velocity. It is an object of the present invention to provide an angular velocity sensor capable of
  • the angular velocity sensor comprises a support substrate, a mass portion positioned above the support substrate, an excitation portion for exciting the mass portion, and the mass portion and the excitation portion supported so as to be displaceable in a predetermined direction. And a detection unit for detecting a displacement amount of the mass unit which is displaced by receiving a Coriolis force,
  • An outline connecting each support beam is formed in a frame shape, Assuming that two directions orthogonal to each other in the plane of the support substrate are the X-axis direction and the Y-axis direction, the mass portion is supported by the support beams positioned on two sides of the frame shape facing each other in the X-axis direction.
  • each mass portion and each excitation portion is suspended by an elastically deformable spring portion, When the pair of excitation parts vibrate in the opposite phase in the X-axis direction, the pair of mass parts are excited in the opposite phase in the Y-axis direction.
  • the mass portion and the excitation portion are provided separately.
  • a pair of mass parts are respectively provided on the support beams located on two sides of the frame shape facing each other in the Y-axis direction, and the excitation portions are provided for the support beams located on two sides of the frame shape facing each other in the X-axis direction.
  • the support beam located between each mass portion and each excitation portion is suspended by an elastically deformable spring portion, and the pair of excitation portions vibrate in the opposite phase in the X-axis direction, the pair of mass portions It was made to excite in opposite phase in the Y-axis direction.
  • the occurrence of leakage vibration can be appropriately suppressed, and the pair of mass portions can be excited in an opposite phase appropriately with a simple structure. Therefore, according to the present invention, the detection accuracy of the angular velocity can be improved as compared with the prior art.
  • a vibration transmission beam is connected between the support beams located on adjacent sides of the frame shape.
  • the arrangement direction of the pair of mass parts is orthogonal to the arrangement direction of the pair of excitation parts.
  • the outline connecting the support beams is substantially square or substantially rectangular, and the first spring portion is located at a position near each corner of the support beam located between each corner of the frame shape and each mass portion.
  • the second spring portion is preferably connected to a position near each corner of the support beam located between each corner of the frame shape and each excitation portion.
  • the outline connecting the support beams is substantially square or substantially rectangular, and the spring portion is provided at four corners of the frame shape.
  • the spring portion is preferably formed in a meander shape.
  • the excitation unit is a comb-like fixed side drive electrode fixedly supported by the support substrate, and is connected to the support beam so as to be positioned above the support substrate, and the fixed side drive electrode
  • the movable side drive electrodes have a structure in which the movable side drive electrodes are vibrated by the coulomb force generated between the fixed side drive electrodes and the movable side drive electrodes.
  • the present invention when an angular velocity is generated around the X axis, a Coriolis force is generated in the Z axis direction orthogonal to the X axis direction and the Y axis direction, so that the pair of mass parts are reversed in the Z axis direction.
  • the present invention can be effectively applied to a structure that is displaced in phase and the displacement amount at this time is detected as a capacitance change by the detection unit.
  • the vibration direction of the excitation unit and the rotation axis coincide with each other, the excitation unit does not receive the Coriolis force, the excitation vibration efficiency can be more appropriately improved, and the detection accuracy of the angular velocity is improved. Is possible.
  • the detection accuracy of the angular velocity can be improved as compared with the prior art.
  • FIG. 1 is a conceptual view of an angular velocity sensor according to a first embodiment of the present invention
  • FIG. 2 is a partial cross-sectional view at the time of cutting in the height direction along line AA shown in FIG. 4 is a plan view of a spring portion
  • FIG. 5 is a specific configuration diagram (plan view) of the angular velocity sensor shown in FIG. 1
  • FIG. 6 is a view shown in FIG. A specific configuration diagram (plan view) of the angular velocity sensor
  • FIG. 7 is a specific configuration diagram (plan view) of the angular velocity sensor partially different from FIG. 6
  • FIG. 8 is a specific configuration of the angular velocity sensor partially different from FIG.
  • FIG. 9 (plan view) is a specific configuration diagram (plan view) of an angular velocity sensor capable of detecting the angular velocity ⁇ around the Z axis by changing the structure of the mass portion of the angular velocity sensor of FIG.
  • the X-axis direction and the Y-axis direction in each figure refer to two orthogonal directions in the support substrate plane.
  • the Z-axis direction indicates a height direction (film thickness direction) orthogonal to the X-axis direction and the Y-axis direction.
  • the angular velocity sensor 1 is formed using an SOI (Silicon on Insulator) substrate 2.
  • SOI substrate 2 is located between a support substrate 3 formed of a silicon substrate, an SOI layer (active layer) 5 formed of a silicon substrate, and the support substrate 3 and the SOI layer 5.
  • the SOI substrate 2 is located between a support substrate 3 formed of a silicon substrate, an SOI layer (active layer) 5 formed of a silicon substrate, and the support substrate 3 and the SOI layer 5.
  • it is a laminated structure of the oxidation insulating layer (sacrificial layer) 4 formed of SiO 2 .
  • mass parts (Mass) 10 and 11, excitation parts 12 and 13, and support beams 14 to 21 are formed in the SOI layer 5 constituting the SOI substrate 2. None of the oxide insulating layer 2 is located below the mass portions 10 and 11 and the support beams 14 to 21, and the mass portions 10 and 11 and the support beams 14 to 21 are located above the support substrate 3.
  • the structure of the excitation units 12 and 13 will be described in detail later.
  • the contour C connecting the support beams 14 to 21 has a frame shape.
  • the frame shape may be a circular shape, an elliptical shape, or the like.
  • the excitation portions 12 and 13 and the mass portions 10 and 11 can be stably opposed to each other.
  • the shape is a polygonal shape or a square shape, and specifically, it is preferable that the shape is a substantially rectangular shape or a substantially square shape. Alternatively, it may be octagonal in addition to quadrilateral.
  • elastically deformable spring portions 90 to 97 connected to the support beams 14 to 21 are provided near the four corners of the frame shape.
  • the spring portions 90 to 97 have low rigidity compared to the support beams 14 to 21, and can be deformed in any of the X axis direction, the Y axis direction, and the Z axis direction, for example.
  • the spring portions 90, 93, 94, 97 connected to the support beams 14, 15, 18, 19 positioned between the corners of the frame shape and the mass portions 10, 11 are referred to as “first spring portions
  • anchor portions 100 to 107 fixedly supported on the support substrate 3 via the insulating material layer 4 are provided at the end portions of the spring portions 90 to 97 (FIG. 2A). reference).
  • the spring portions 90 to 97 may be connected to the side surfaces of a projecting frame portion formed so as to surround the support substrate 3.
  • the support beams 14 to 21 are suspended by the spring portions 90 to 97.
  • the first mass portion 10 is provided between the support beam 14 and the support beam 15 linearly extending in the X-axis direction, and the second mass portion 11 is formed in the X-axis direction.
  • the first mass portion 10 and the second mass portion 11 face each other in the Y axis direction.
  • the first excitation unit 12 is provided between the support beam 20 and the support beam 21 linearly extending in the Y-axis direction, and the second excitation unit 13 is in the Y-axis direction.
  • the first excitation unit 12 and the second excitation unit 13 face each other in the X axis direction.
  • the arrangement direction of the pair of mass parts 10 and 11 and the arrangement direction of the pair of excitation parts 12 and 13 be orthogonal to each other.
  • “orthogonal relationship” means a line connecting the centers of a pair of mass parts 10 and 11 (parallel to the Y-axis direction) and a line connecting the centers of a pair of excitation parts 12 and 13 (X-axis direction Parallel) means that they are orthogonal to each other.
  • the frame shape connecting the support beams 14 to 21 shown in FIG. 1 is substantially square, and the centers O2 and O3 of the mass portions 10 and 11 and the centers O4 and O5 of the excitation portions 12 and 13 have four sides of the frame shape. Match each center. Therefore, the distances from the center O1 of the frame shape to the centers O2 and O3 of the respective mass parts 10 and 11 and the centers O4 and O5 of the respective excitation parts 12 and 13 are substantially equal.
  • the support beams 16, 17, 20, 21 may be configured to be easily displaced only in the X-axis direction.
  • the support beams 14, 15, 18, 19 extending in the X-axis direction for supporting the mass units 10, 11 are displaceable in the Y-axis direction and the Z-axis direction, but hardly displaceable in the X-axis direction. Adjustment of the displacement direction of each support beam can be controlled by the thickness dimension, width dimension, length dimension, etc. of the support beam.
  • the driving force is generated by the drive signal applied to the pair of excitation parts 12 and 13.
  • the pair of excitation portions 12, 13 linearly reverse phase in the X axis direction. Vibration (solid arrows D and E or dotted arrows F and G). At this time, the excitation units 12 and 13 vibrate at the natural frequency.
  • an electrode portion 49 is provided on the support substrate 3 located below the mass portions 10 and 11.
  • the angular velocity ⁇ is detected based on the change in electrostatic capacitance caused by the change in the distance between the electrode unit 49 and the mass units 10 and 11 which occurs when the mass units 10 and 11 are displaced in the Z-axis direction.
  • the electrode unit 49 is provided only below the mass units 10 and 11, but the electrode unit is provided only above the mass units 10 and 11 or both above and below the mass units 10 and 11. May be
  • the mass units 10 and 11 and the excitation units 12 and 13 are separately provided. Further, a pair of mass parts 10 and 11 are provided on the support beams 14, 15, 18 and 19 located on two sides of the frame shape facing each other in the Y axis direction, and the excitation parts 12 and 13 face each other in the X axis direction
  • the support beams 16, 17, 20, 21 located on two sides of the frame shape are respectively provided.
  • support beams 14 to 21 positioned between mass portions 10 and 11 and respective excitation portions 12 and 13 are suspended by elastically deformable spring portions 90 to 97, and a pair of excitation portions 12 and 13 extend in the X axis direction.
  • the pair of mass portions 10 and 11 When vibrating in the opposite phase, the pair of mass portions 10 and 11 are excited in the opposite phase in the Y-axis direction.
  • the leakage of the drive signals supplied to the excitation units 12 and 13 to the mass units 10 and 11 can be sufficiently reduced, and the leakage vibration can be appropriately suppressed.
  • the detection accuracy of the angular velocity can be improved as compared with the prior art.
  • the arrangement direction of the mass units 10 and 11 and the arrangement direction of the excitation units 12 and 13 are orthogonal to each other. Although not limited to the orthogonal relationship, the orthogonal relationship more appropriately vibrates the pair of excitation units 12 and 13 in the reverse phase in the X-axis direction, and reverses the pair of mass units 10 and 11 in the Y-axis direction. Can be excited by
  • the excitation vibration efficiency can be improved as compared with the conventional case, and the detection accuracy of the angular velocity can be more effectively improved.
  • the structure of the angular velocity sensor 30 shown in FIG. 3 is different from the angular velocity sensor 1 shown in FIG. 1 in that vibration transfer beams 31 to 34 are provided.
  • the same parts as those of the angular velocity sensor 1 of FIG. 1 are denoted by the same reference numerals as those of FIG.
  • the vibration transfer beam 31 is connected to the support beam 15 and the support beam 16
  • the vibration transfer beam 32 is connected to the support beam 17 and the support beam 18, and the vibration transfer beam 33 is connected to the support beam 19 and the support beam 20.
  • the vibration transmission beam 34 is connected to the support beam 14 and the support beam 21.
  • FIG. 3 (b) note that the spring parts 90 to 97 are omitted from the drawing in FIG. 3 (b)).
  • the vibration can be effectively transmitted to the mass units 10 and 11 via the vibration transfer beams 31 to 34.
  • the pair of mass portions 10 and 11 can be excited with an opposite phase and a large amplitude in the Y-axis direction.
  • the first spring portions 90, 93, 94, 97 connected to the support beams 14, 15, 18, 19 supporting the mass portions 10, 11 and the excitation portions 12, 13 are supported.
  • Second spring portions 91, 92, 95, 96 connected to the support beams 16, 17, 20, 21 are provided, and two spring portions are provided in the vicinity of four corners of the frame shape composed of the support beams 14-21.
  • FIG. 4 shows a spring portion 110 connected to the corner formed by the support beam 15 and the support beam 16.
  • the shape of the spring portion is not particularly limited.
  • the spring portions 90 to 97 are formed in a meander shape.
  • the rigidity can be reduced by forming the spring portion in a meander shape.
  • the spring portion 110 may have a shape in which it is alternately folded back in the X direction and the Y direction at the position of the diagonal line in the XY plane. With the form of the spring portion 110 of FIG. 4, substantially the same elastic deformation can be exerted in both the X-axis direction and the Y-axis direction, and the excitation vibration efficiency can be improved.
  • the excitation units 12 and 13 have a comb-like fixed side drive electrode 35 fixedly supported on the support substrate 3 and Y positioned above the support substrate 3.
  • a comb-like movable side drive electrode 36 connected to the support beams 16, 17, 20, 21 linearly extending in the axial direction and alternately arranged with the fixed side drive electrodes 35 is provided.
  • the movable side drive electrode 36 is connected to the support beams 16, 17, 20, 21 and extends linearly on the support portion 37 in the X axis direction. And a comb-like electrode 38 disposed at a predetermined interval in the Y-axis direction. Further, two fixed side drive electrodes 35 are provided for each of the excitation portions 12 and 13, and the fixed side drive electrodes 35 are fixedly supported on the support substrate 3 via the oxide insulating layer 4, and A comb-like electrode 40 extending between the comb-like electrodes 38 of the movable drive electrode 36 from the fixed portion 39 is formed. Although not limited, there is no oxidation insulating layer 4 below the comb-like electrode 40 of the fixed drive electrode 35, and the comb-like electrode 40 floats above the support substrate 3.
  • the pair of mass units 10 and 11 support the mass units 10 and 11 by the excitation units 12 and 13 vibrating in opposite phase in the X-axis direction.
  • excitation is performed in the opposite phase in the Y axis direction.
  • the present embodiment shown in FIG. 5 is configured to be capable of detecting an angular velocity when an angular velocity ⁇ is applied to the angular velocity sensor with the X axis direction as a rotation axis. That is, as described above, in the present embodiment, the mass units 10 and 11 receive the Coriolis force in the Z-axis direction when the angular velocity ⁇ is applied to the angular velocity sensor with the X-axis direction as the rotation axis, but the excitation units 12 and 13 I do not receive power. Therefore, in the present embodiment shown in FIG. 4, when the angular velocity ⁇ is applied with the X axis direction as the rotation axis, the angular velocity can be detected with excellent excitation vibration efficiency.
  • both of the mass units 10 and 11 are displaced in the same direction under the force (inertial force) accompanying the acceleration. Etc. can prevent false detection.
  • FIG. 6 shows a specific configuration provided with the vibration transfer beams 31 to 34 described in FIG.
  • the form of the excitation parts 12 and 13 is the same as that of FIG.
  • the vibration transmitting beams 31 to 34 have a substantially L shape in FIG. 6, for example, as shown in FIG. 6, the vibration transmitting beams 41 to 44 may be formed in a linear shape. As shown in FIG. 5, the vibration transfer beams 45 to 48 may be formed in a curved shape.
  • the form of the vibration transmission beam is not particularly limited.
  • FIGS. 5 to 8 detects the angular velocity ⁇ with the X axis direction as the rotation axis.
  • the angular velocity sensor shown in FIGS. 5 to 8 by 90 degrees in the XY plane, it becomes possible to detect the angular velocity ⁇ with the Y axis direction as the rotation axis.
  • the displacement amount of the mass units 10 and 11 in the Z-axis direction may be detected by a structure other than the electrode structure described with reference to FIG.
  • FIG. 10 shows the movable electrode 70 and the fixed electrode 72 in a cross-sectional shape cut in the thickness direction. Note that only the movable electrode 70 is hatched so that the movable electrode and the fixed electrode can be easily distinguished.
  • the movable electrode 70 and the fixed electrode 72 are formed to have the same thickness, and in the initial state (state in which Coriolis force is not applied), the upper surface of the movable electrode 70 is from the upper surface of the fixed electrode 72 Is also in a high position.
  • the comb-like electrode structure for detecting the displacement in the Z-axis direction shown in FIG. 10 is an example.
  • the structure of the electrode is not particularly limited as long as the change in electrostatic capacitance tends to be reversed between when the movable electrode moves upward and when it moves downward.
  • the structure shown in FIG. 9 can be considered.
  • the angular velocity sensor 50 shown in FIG. 9 has a comb-like electrode formed on the side surfaces of the mass portions 10 and 11 of the angular velocity sensor shown in FIG. Therefore, the angular velocity sensor 50 of FIG. 9 is the same as that of FIG. 5 except for the portions of the comb-like electrodes provided on the side surfaces of the mass portions 10 and 11 (the same reference numerals as in FIG. 5 denote the same portions).
  • comb-shaped movable electrodes 63, 64, 65 and 66 arranged at intervals in the X-axis direction on both side surfaces of each of the mass portions 10 and 11 are mass portions 10 and 11, respectively. It is provided integrally. Further, comb-like fixed electrodes 67, 68, 69, 71 fixedly supported on the support substrate 3 via the oxide insulating layer 4 are alternately arranged with the movable electrodes 63, 64, 65, 66.
  • the pair of excitation units 12 and 13 vibrate in antiphase in the X-axis direction, and the pair of mass units 10 and 11 are excited in antiphase in the Y-axis direction.
  • FIG. 11 shows a method of manufacturing the angular velocity sensor in the present embodiment.
  • FIG. 11 shows a manufacturing method in a cross-sectional shape along the line AA shown in FIG.
  • the support substrate 3 made of silicon is prepared, and as shown in FIG. 11B, the electrode portion 49 is formed on the surface 3a of the support substrate 3.
  • an oxide insulating layer (SiO 2 layer, sacrificial layer) 4 is formed.
  • the surface of the oxide insulating layer 4 is planarized using, for example, a CMP technique.
  • the SOI layer (silicon layer) 5 is formed on the oxide insulating layer 4.
  • the SOI layer 5 for example, the mass portions 10 and 11 shown in FIG. 5, the excitation portions 12 and 13, the support beams 14 to 21, the spring portions 90 to 97, and the anchor portions 100 to 107 are defined.
  • the SOI layer 5 is removed using, for example, deep RIE. At this time, a large number of fine through holes 80 are formed in the mass portions 10 and 11.
  • the oxide insulating layer 4 is wet except for the oxide insulating layer 4 under the anchor portions 22 to 25 and under the fixing portion 39 constituting the excitation portions 12 and 13. It is removed by an isotropic etching process by etching or dry etching. At this time, the oxide insulating layer 4 under the mass parts 10 and 11 is also removed through the above-mentioned through holes.
  • an angular velocity sensor module can be configured that can detect each angular velocity when a plurality of angular velocity sensors with at least two of the X-axis direction, the Y-axis direction, and the Z-axis direction are generated.
  • a conceptual view of an angular velocity sensor according to a first embodiment of the present invention A partial sectional view when cut in the height direction along the line AA shown in FIG. 1;
  • a conceptual view of an angular velocity sensor according to a second embodiment of the present invention Plan view of the spring part,
  • the specific block diagram (plan view) of the angular velocity sensor shown in FIG. The specific block diagram (plan view) of the angular velocity sensor shown in FIG. 3;

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Abstract

Provided is an angular velocity sensor by which particularly leakage vibration can be prevented, mass portions can be suitably excited by a simple constitution, and the angular velocity detection accuracy can be properly improved. A contour (C) which connects support beams (14-21) is formed in a frame shape. Mass portions (10, 11) are supported by support beams located on two side of the frame shape which face each other in an X-axis direction, and excitation portions (12, 13) are supported by support beams located on two sides of the frame shape which face each other in a Y-axis direction. Support beams near four corners of the frame shape are suspended by elastically deformable spring portions (90-97). When a pair of excitation portions (12, 13) vibrate in opposite phases in the X-axis direction, a pair of mass portions (10, 11) are excited in opposite phases in the Y-axis direction.

Description

角速度センサAngular velocity sensor
　本発明は、ＭＥＭＳ（微小電気機械システム：Micro ElectroMechanical System）技術を用いて形成された角速度センサに関する。 The present invention relates to an angular velocity sensor formed using MEMS (Micro Electro Mechanical System) technology.
　ＳＯＩ基板を用いて形成された角速度センサ（ジャイロセンサ）は、支持基板の上方に位置する質量部（Ｍａｓｓ）と、質量部を変位可能に支持する支持梁と、質量部を励振させるための励振部と、コリオリ力を受けて変位する質量部の変位量を検知するための検知部等を有して構成される。 An angular velocity sensor (gyro sensor) formed using an SOI substrate includes a mass portion (Mass) located above the support substrate, a support beam that supports the mass portion in a displaceable manner, and an excitation for exciting the mass portion. And a detection unit for detecting the amount of displacement of the mass unit displaced due to the Coriolis force.
　下記特許文献にはＭＥＭＳ技術を用いて形成された角速度センサの構造が開示されている。 The following patent documents disclose the structure of an angular velocity sensor formed using MEMS technology.
　下記特許文献１に開示された角速度センサは、複数の質量部（Ｍａｓｓ）を備え、中心に位置する質量部と、その両側に位置する質量部とを互いに逆方向に励振させる構造である。中心の質量部がコリオリ力を受けて変位する。検出電極を備える中央の質量部には振動発生部を構成する可動側振動電極も一体的に形成される。 The angular velocity sensor disclosed in Patent Document 1 has a structure in which a plurality of mass portions (Mass) are provided, and a mass portion located at the center and a mass portion located on both sides thereof are excited in opposite directions. The central mass part is displaced due to the Coriolis force. The movable-side vibrating electrode that constitutes the vibration generating unit is also integrally formed on the central mass portion provided with the detection electrode.
　また特許文献２に記載された角速度センサでは、２つの質量部を逆位相で励振させている。検出電極を備える質量部に振動発生部を構成する可動側振動電極も一体的に形成されている。 In the angular velocity sensor described in Patent Document 2, two mass parts are excited in opposite phase. The movable side vibration electrode which comprises a vibration generation part is also integrally formed in the mass part provided with a detection electrode.
　また、特許文献３に開示された角速度センサは、円形の質量部を櫛歯状電極で励振し、切欠き部に設けられた第２質量部がコリオリ力を受けて変位する構造である。円形の質量部は中心部で基板上に支持されている。 Further, the angular velocity sensor disclosed in Patent Document 3 has a structure in which a circular mass portion is excited by a comb electrode, and a second mass portion provided in the notch portion is displaced by receiving a Coriolis force. The circular mass is centrally supported on the substrate.
　また、特許文献４に開示された角速度センサは、内側と外側とに夫々質量部を備える。特許文献４では、外側の質量部を振動させ、コリオリ力を外側の質量部から内側の質量部へと伝達し、内側の質量部でコリオリ力を受けて変位した変位量を測定する構造である。
特開２００２－８１９３９号公報 ＷＯ２００６／００９５７８ 特開２００６－１５３７９８号公報 特表２００１－５２０３８５号公報 Moreover, the angular velocity sensor disclosed by patent document 4 equips an inner side and an outer side with a mass part, respectively. In Patent Document 4, the outer mass portion is vibrated, Coriolis force is transmitted from the outer mass portion to the inner mass portion, and the displacement amount is measured by receiving the Coriolis force in the inner mass portion. .
JP 2002-81939 A WO 2006/009578 Unexamined-Japanese-Patent No. 2006-153798 JP 2001-520385 gazette
　上記した特許文献１，２に記載された発明では、検出電極を備える質量部に可動側振動電極が一体的に形成されている。 In the invention described in the patent documents 1 and 2 mentioned above, the movable side vibration electrode is integrally formed in the mass part provided with the detection electrode.
　そのため、可動側振動電極に供給された駆動信号が、基板等の寄生容量を介して検出側に漏れやすく、角速度Ωが作用していない状態でも質量部に検出方向への振動（漏れ振動）が発生しやすかった。そして、このような漏れ振動を抑制するために、例えば特許文献２のように漏れ振動抑制用の電極（quadrature cancellation（balancing）electrode）を設ける等の工夫が必要であり、構造が複雑化・大型化しやすかった。 Therefore, the drive signal supplied to the movable vibration electrode easily leaks to the detection side through the parasitic capacitance of the substrate etc., and vibration in the detection direction (leakage vibration) occurs in the mass even in the state where the angular velocity Ω does not act. It was easy to occur. Then, in order to suppress such leaked vibration, it is necessary to devise an electrode for suppressing leaked vibration (a quadrature cancellation (balancing) electrode) as in Patent Document 2, for example, and the structure becomes complicated and large. It was easy to convert.
　また特許文献３や特許文献４では、検出電極を備える質量部に直接、可動側振動電極を備えておらず、検出電極を備える質量部と連結された別の質量部に可動側振動電極を一体的に形成しているが、構造が複雑化する上に、振動発生部に供給された駆動信号の検出側への漏れを十分に小さくできない。また特許文献３の角速度センサのように回転振動を与える構成では、直線振動を与えるより困難であり実現性が低く、また回転振動させたときの質量部の振動方位と設計上の振動方位との間にずれが生じやすいと考えられ、不要な方向への振動が増大する恐れがあった。 Further, in Patent Document 3 and Patent Document 4, the mass portion including the detection electrode is not directly provided with the movable vibration electrode, and the movable vibration electrode is integrated with another mass portion connected to the mass portion including the detection electrode. Although the structure is complicated, the leakage to the detection side of the drive signal supplied to the vibration generating unit can not be made sufficiently small. Further, in the configuration in which rotational vibration is applied as in the angular velocity sensor of Patent Document 3, it is more difficult and less feasible to apply linear vibration, and the vibration direction of the mass portion and the vibration direction in design when rotational vibration is performed. It is considered that a gap tends to occur, and there is a possibility that vibration in an unnecessary direction may increase.
　また特許文献４では、コリオリ力を外側の質量部から内側の質量部へと伝達させているが、コリオリ力を伝達しているためコリオリ力の減衰が大きく高精度な検出が難しいと思われる。 Further, in Patent Document 4, although the Coriolis force is transmitted from the outer mass portion to the inner mass portion, the Coriolis force is transmitted, and it is considered that the Coriolis force is largely attenuated and it is difficult to detect with high accuracy.
　さらに上記した特許文献では、質量部と共に必ず振動発生部にもコリオリ力が作用する不具合があった。 Furthermore, in the above-mentioned patent documents, Coriolis force always acts on the vibration generating part together with the mass part.
　よって特許文献の角速度センサの構造では、角速度の検出精度を適切に向上させることができなかった。 Therefore, in the structure of the angular velocity sensor of patent document, the detection accuracy of the angular velocity was not able to be improved appropriately.
　そこで本発明は上記従来の課題を解決するためのものであり、特に、漏れ振動を抑制し、簡単な構成で質量部を適切に励振させることができ、角速度の検出精度を適切に向上させることが可能な角速度センサを提供することを目的としている。 Therefore, the present invention is intended to solve the above-mentioned conventional problems, and in particular, it is possible to suppress leakage vibration, excite the mass appropriately with a simple configuration, and appropriately improve the detection accuracy of the angular velocity. It is an object of the present invention to provide an angular velocity sensor capable of
本発明の角速度センサは、支持基板と、前記支持基板の上方に位置する質量部と、前記質量部を励振するための励振部と、前記質量部及び前記励振部を所定方向に変位可能に支持する支持梁と、コリオリ力を受けて変位する前記質量部の変位量を検出するための検知部と、を備え、
　各支持梁を結んだ輪郭が枠形状に形成されており、
　支持基板平面にて直交する２方向をＸ軸方向とＹ軸方向としたとき、前記質量部はＸ軸方向にて向かい合う前記枠形状の２辺に位置する前記支持梁に支持され、前記励振部はＹ軸方向にて向かい合う前記枠形状の２辺に位置する前記支持梁に支持され、
　各質量部と各励振部の間に位置する前記支持梁が、弾性変形可能なばね部により懸架されており、
　前記一対の励振部が前記Ｘ軸方向に逆位相で振動したときに、前記一対の質量部が前記Ｙ軸方向に逆位相で励振することを特徴とするものである。 The angular velocity sensor according to the present invention comprises a support substrate, a mass portion positioned above the support substrate, an excitation portion for exciting the mass portion, and the mass portion and the excitation portion supported so as to be displaceable in a predetermined direction. And a detection unit for detecting a displacement amount of the mass unit which is displaced by receiving a Coriolis force,
An outline connecting each support beam is formed in a frame shape,
Assuming that two directions orthogonal to each other in the plane of the support substrate are the X-axis direction and the Y-axis direction, the mass portion is supported by the support beams positioned on two sides of the frame shape facing each other in the X-axis direction. Is supported by the support beams located on two sides of the frame shape facing each other in the Y-axis direction,
The support beam positioned between each mass portion and each excitation portion is suspended by an elastically deformable spring portion,
When the pair of excitation parts vibrate in the opposite phase in the X-axis direction, the pair of mass parts are excited in the opposite phase in the Y-axis direction.
　本発明では、質量部と、励振部とを別々に設けた。また、一対の質量部を、Ｙ軸方向にて向かい合う枠形状の２辺に位置する支持梁に夫々設け、励振部をＸ軸方向にて向かい合う前記枠形状の２辺に位置する支持梁に夫々設けた。さらに、各質量部と各励振部の間に位置する支持梁を、弾性変形可能なばね部により懸架し、一対の励振部がＸ軸方向に逆位相で振動したときに、一対の質量部がＹ軸方向に逆位相で励振するようにした。本発明によれば、漏れ振動の発生を適切に抑制でき、簡単な構造で、適切に、一対の質量部を逆位相で励振させることが出来る。よって本発明では、従来に比べて、角速度の検出精度を向上させることができる。 In the present invention, the mass portion and the excitation portion are provided separately. In addition, a pair of mass parts are respectively provided on the support beams located on two sides of the frame shape facing each other in the Y-axis direction, and the excitation portions are provided for the support beams located on two sides of the frame shape facing each other in the X-axis direction. Provided. Furthermore, when the support beam located between each mass portion and each excitation portion is suspended by an elastically deformable spring portion, and the pair of excitation portions vibrate in the opposite phase in the X-axis direction, the pair of mass portions It was made to excite in opposite phase in the Y-axis direction. According to the present invention, the occurrence of leakage vibration can be appropriately suppressed, and the pair of mass portions can be excited in an opposite phase appropriately with a simple structure. Therefore, according to the present invention, the detection accuracy of the angular velocity can be improved as compared with the prior art.
　本発明では、前記枠形状の隣接する各辺に位置する前記支持梁間に振動伝達梁が連結されていることが好ましい。これにより、一対の励振部をＸ軸方向に逆位相で振動させたときに、効果的に一対の質量部をＹ軸方向に逆位相で励振させることが出来る。 In the present invention, it is preferable that a vibration transmission beam is connected between the support beams located on adjacent sides of the frame shape. Thus, when the pair of excitation parts are vibrated in the opposite phase in the X-axis direction, the pair of mass parts can be excited effectively in the opposite phase in the Y-axis direction.
　また本発明では、前記一対の質量部の並び方向と、前記一対の励振部の並び方向とが直交していることが好ましい。また、各支持梁を結んだ輪郭が略正方形あるいは略長方形であり、前記枠形状の各隅と各質量部の間に位置する前記支持梁の前記各隅に近い位置に第１の前記ばね部が連結され、前記枠形状の各隅と各励振部の間に位置する前記支持梁の前記各隅に近い位置に第２の前記ばね部が連結されていることが好ましい。あるいは、本発明では、各支持梁を結んだ輪郭が略正方形あるいは略長方形であり、前記ばね部は、前記枠形状の四隅に設けられる構造であることが好ましい。
　また限定しないが、例えば、前記ばね部は、ミアンダ状で形成されることが好ましい。 Further, in the present invention, it is preferable that the arrangement direction of the pair of mass parts is orthogonal to the arrangement direction of the pair of excitation parts. Further, the outline connecting the support beams is substantially square or substantially rectangular, and the first spring portion is located at a position near each corner of the support beam located between each corner of the frame shape and each mass portion. The second spring portion is preferably connected to a position near each corner of the support beam located between each corner of the frame shape and each excitation portion. Alternatively, in the present invention, it is preferable that the outline connecting the support beams is substantially square or substantially rectangular, and the spring portion is provided at four corners of the frame shape.
Although not limited, for example, the spring portion is preferably formed in a meander shape.
　また本発明では、前記励振部は、前記支持基板に固定支持される櫛歯状の固定側駆動電極と、前記支持基板の上方に位置して前記支持梁に連結され、前記固定側駆動電極と交互に配置される櫛歯状の可動側駆動電極とを備え、前記固定側駆動電極と前記可動側駆動電極間に発生するクーロン力により前記可動側駆動電極が振動する構造であることが好ましい。これにより、簡単な構成により適切に、一対の励振部をＸ方向に逆位相で振動させることが出来る。 Further, in the present invention, the excitation unit is a comb-like fixed side drive electrode fixedly supported by the support substrate, and is connected to the support beam so as to be positioned above the support substrate, and the fixed side drive electrode It is preferable that the movable side drive electrodes have a structure in which the movable side drive electrodes are vibrated by the coulomb force generated between the fixed side drive electrodes and the movable side drive electrodes. As a result, the pair of excitation parts can be vibrated in antiphase in the X direction appropriately by a simple configuration.
　また本発明では、Ｘ軸周りに角速度が発生したとき、前記Ｘ軸方向及び前記Ｙ軸方向と直交するＺ軸方向にコリオリ力が生じることで、前記一対の質量部が前記Ｚ軸方向に逆位相で変位し、このときの変位量が前記検知部にて静電容量変化として検知される構造に効果的に適用出来る。この構成では、励振部の振動方向と回転軸とが一致しているため、励振部がコリオリ力を受けず、励振振動効率をより適切に向上させることができ、角速度の検出精度を向上させることが可能である。 In the present invention, when an angular velocity is generated around the X axis, a Coriolis force is generated in the Z axis direction orthogonal to the X axis direction and the Y axis direction, so that the pair of mass parts are reversed in the Z axis direction. The present invention can be effectively applied to a structure that is displaced in phase and the displacement amount at this time is detected as a capacitance change by the detection unit. In this configuration, since the vibration direction of the excitation unit and the rotation axis coincide with each other, the excitation unit does not receive the Coriolis force, the excitation vibration efficiency can be more appropriately improved, and the detection accuracy of the angular velocity is improved. Is possible.
　本発明の角速度センサの構成によれば、従来に比べて、角速度の検出精度を向上させることができる。 According to the configuration of the angular velocity sensor of the present invention, the detection accuracy of the angular velocity can be improved as compared with the prior art.
　図１は、本発明の第１実施形態の角速度センサの概念図、図２は図１に示すＡ－Ａ線に沿って高さ方向に切断した際の部分断面図、図３は、本発明の第２実施形態の角速度センサの概念図、図４は、ばね部の平面図、図５は、図１に示す角速度センサの具体的構成図（平面図）、図６は、図３に示す角速度センサの具体的構成図（平面図）、図７は、図６と一部異なる角速度センサの具体的構成図（平面図）、図８は、図６と一部異なる角速度センサの具体的構成図（平面図）、図９は、図５の角速度センサの質量部の構造を変えて、Ｚ軸回りの角速度Ωを検知可能とした角速度センサの具体的構成図（平面図）、である。 FIG. 1 is a conceptual view of an angular velocity sensor according to a first embodiment of the present invention, FIG. 2 is a partial cross-sectional view at the time of cutting in the height direction along line AA shown in FIG. 4 is a plan view of a spring portion, FIG. 5 is a specific configuration diagram (plan view) of the angular velocity sensor shown in FIG. 1, and FIG. 6 is a view shown in FIG. A specific configuration diagram (plan view) of the angular velocity sensor, FIG. 7 is a specific configuration diagram (plan view) of the angular velocity sensor partially different from FIG. 6, and FIG. 8 is a specific configuration of the angular velocity sensor partially different from FIG. FIG. 9 (plan view) is a specific configuration diagram (plan view) of an angular velocity sensor capable of detecting the angular velocity Ω around the Z axis by changing the structure of the mass portion of the angular velocity sensor of FIG.
　各図におけるＸ軸方向及びＹ軸方向は支持基板平面内での直交する２方向を指す。Ｚ軸方向はＸ軸方向及びＹ軸方向に対して直交する高さ方向（膜厚方向）を指す。 The X-axis direction and the Y-axis direction in each figure refer to two orthogonal directions in the support substrate plane. The Z-axis direction indicates a height direction (film thickness direction) orthogonal to the X-axis direction and the Y-axis direction.
　角速度センサ１は、ＳＯＩ（Silicon on Insulator）基板２を用いて形成される。図２に示すように、ＳＯＩ基板２は、シリコン基板で形成された支持基板３と、シリコン基板で形成されたＳＯＩ層（活性層）５と、支持基板３とＳＯＩ層５の間に位置する例えばＳｉＯ2で形成された酸化絶縁層（犠牲層）４の積層構造である。 The angular velocity sensor 1 is formed using an SOI (Silicon on Insulator) substrate 2. As shown in FIG. 2, the SOI substrate 2 is located between a support substrate 3 formed of a silicon substrate, an SOI layer (active layer) 5 formed of a silicon substrate, and the support substrate 3 and the SOI layer 5. For example, it is a laminated structure of the oxidation insulating layer (sacrificial layer) 4 formed of SiO 2 .
　図１（ａ）に示すように、ＳＯＩ基板２を構成するＳＯＩ層５には、質量部（Ｍａｓｓ）１０，１１、励振部１２，１３、及び支持梁１４～２１が形成される。質量部１０，１１及び支持梁１４～２１の下側にはいずれも酸化絶縁層２はなく、質量部１０，１１及び支持梁１４～２１は支持基板３の上方に位置している。励振部１２、１３の構造については後で詳述する。 As shown in FIG. 1A, in the SOI layer 5 constituting the SOI substrate 2, mass parts (Mass) 10 and 11, excitation parts 12 and 13, and support beams 14 to 21 are formed. None of the oxide insulating layer 2 is located below the mass portions 10 and 11 and the support beams 14 to 21, and the mass portions 10 and 11 and the support beams 14 to 21 are located above the support substrate 3. The structure of the excitation units 12 and 13 will be described in detail later.
　図１（ａ）に示すように、各支持梁１４～２１を結んだ輪郭Ｃは枠形状となっている。枠形状は、円形状や楕円形状等でもよいが、多角形のほうが励振部１２、１３同士、質量部１０，１１同士が安定して対向できる。また、多角形でも四角状であることが好ましく、具体的には略長方形あるいは略正方形であることが好適である。あるいは四角形以外に八角形等でもよい。 As shown in FIG. 1A, the contour C connecting the support beams 14 to 21 has a frame shape. The frame shape may be a circular shape, an elliptical shape, or the like. However, in the polygon, the excitation portions 12 and 13 and the mass portions 10 and 11 can be stably opposed to each other. In addition, it is preferable that the shape is a polygonal shape or a square shape, and specifically, it is preferable that the shape is a substantially rectangular shape or a substantially square shape. Alternatively, it may be octagonal in addition to quadrilateral.
　図１（ａ）に示すように、枠形状の四隅付近には、各支持梁１４～２１に連結された弾性変形可能なばね部９０～９７が設けられる。ばね部９０～９７は、支持梁１４～２１に比べて低剛性であり、例えばＸ軸方向、Ｙ軸方向及びＺ軸方向のいずれの方向にも変形可能である。なお以下では、枠形状の各隅と各質量部１０，１１との間に位置する支持梁１４，１５，１８，１９に連結されたばね部９０，９３，９４，９７を「第１のばね部」と称し、枠形状の各隅と各励振部１２，１３との間に位置する支持梁１６，１７，２０，２１に連結されたばね部９１，９２，９５，９６を「第２のばね部」と称する。 As shown in FIG. 1A, elastically deformable spring portions 90 to 97 connected to the support beams 14 to 21 are provided near the four corners of the frame shape. The spring portions 90 to 97 have low rigidity compared to the support beams 14 to 21, and can be deformed in any of the X axis direction, the Y axis direction, and the Z axis direction, for example. In the following, the spring portions 90, 93, 94, 97 connected to the support beams 14, 15, 18, 19 positioned between the corners of the frame shape and the mass portions 10, 11 are referred to as “first spring portions Spring portions 91, 92, 95, 96 connected to the support beams 16, 17, 20, 21 positioned between the corners of the frame shape and the respective excitation portions 12, 13 ".
　図１（ａ）に示すように、各ばね部９０～９７の端部には支持基板３上に絶縁材料層４を介して固定支持されたアンカ部１００～１０７が設けられている（図２参照）。また個々にアンカ部１００～１０７を設けるのでなく、例えば支持基板３上を囲むように形成された突出形状の枠体部分の側面に各ばね部９０～９７が連結される構成でもよい。 As shown in FIG. 1A, anchor portions 100 to 107 fixedly supported on the support substrate 3 via the insulating material layer 4 are provided at the end portions of the spring portions 90 to 97 (FIG. 2A). reference). Further, instead of providing the anchor portions 100 to 107 individually, for example, the spring portions 90 to 97 may be connected to the side surfaces of a projecting frame portion formed so as to surround the support substrate 3.
　本実施形態では、支持梁１４～２１がばね部９０～９７により懸架された構造となっている。 In the present embodiment, the support beams 14 to 21 are suspended by the spring portions 90 to 97.
　図１（ａ）に示すように、第１質量部１０は、Ｘ軸方向に直線状に延びる支持梁１４と支持梁１５との間に設けられ、第２質量部１１は、Ｘ軸方向に直線状に延びる支持梁１８と支持梁１９との間に設けられ、第１質量部１０と第２質量部１１は、Ｙ軸方向に向かい合っている。 As shown in FIG. 1A, the first mass portion 10 is provided between the support beam 14 and the support beam 15 linearly extending in the X-axis direction, and the second mass portion 11 is formed in the X-axis direction. The first mass portion 10 and the second mass portion 11 face each other in the Y axis direction.
　また図１（ａ）に示すように、第１励振部１２は、Ｙ軸方向に直線状に延びる支持梁２０と支持梁２１との間に設けられ、第２励振部１３は、Ｙ軸方向に直線状に延びる支持梁１６と支持梁１７の間に設けられ、第１励振部１２と第２励振部１３は、Ｘ軸方向に向かい合っている。 Further, as shown in FIG. 1A, the first excitation unit 12 is provided between the support beam 20 and the support beam 21 linearly extending in the Y-axis direction, and the second excitation unit 13 is in the Y-axis direction. The first excitation unit 12 and the second excitation unit 13 face each other in the X axis direction.
　図１（ａ）に示すように、一対の質量部１０，１１の並び方向と、一対の励振部１２，１３の並び方向とは直交した関係であることが好ましい。ここで「直交関係」とは、一対の質量部１０，１１の各中心を結んだ線（Ｙ軸方向に平行）と、一対の励振部１２，１３の中心を結んだ線（Ｘ軸方向に平行）とが直交していることを指す。 As shown in FIG. 1A, it is preferable that the arrangement direction of the pair of mass parts 10 and 11 and the arrangement direction of the pair of excitation parts 12 and 13 be orthogonal to each other. Here, “orthogonal relationship” means a line connecting the centers of a pair of mass parts 10 and 11 (parallel to the Y-axis direction) and a line connecting the centers of a pair of excitation parts 12 and 13 (X-axis direction Parallel) means that they are orthogonal to each other.
　図１に示す各支持梁１４～２１を結んだ枠形状は略正方形であり、各質量部１０，１１の中心Ｏ２，Ｏ３及び各励振部１２，１３の中心Ｏ４，Ｏ５は枠形状の四辺の各中心に一致している。よって枠形状の中心Ｏ１から、各質量部１０，１１の中心Ｏ２，Ｏ３の距離と各励振部１２，１３の中心Ｏ４，Ｏ５の距離はほぼ等しい。 The frame shape connecting the support beams 14 to 21 shown in FIG. 1 is substantially square, and the centers O2 and O3 of the mass portions 10 and 11 and the centers O4 and O5 of the excitation portions 12 and 13 have four sides of the frame shape. Match each center. Therefore, the distances from the center O1 of the frame shape to the centers O2 and O3 of the respective mass parts 10 and 11 and the centers O4 and O5 of the respective excitation parts 12 and 13 are substantially equal.
　励振部１２，１３を支持するＹ軸方向に延びる支持梁１６，１７，２０，２１は、Ｘ軸方向及びＺ軸方向に変位可能であるがＹ軸方向には変位しにくい。なお、支持梁１６，１７，２０，２１はＸ軸方向のみに変位しやすい構造としてもよい。一方、質量部１０，１１を支持するＸ軸方向に延びる支持梁１４，１５，１８，１９は、Ｙ軸方向及びＺ軸方向に変位可能であるがＸ軸方向には変位しにくい。各支持梁の変位方向の調整は、支持梁の厚さ寸法、幅寸法、及び長さ寸法等にて制御できる。 The support beams 16, 17, 20, 21 extending in the Y-axis direction, which support the excitation units 12 and 13, are displaceable in the X-axis direction and the Z-axis direction, but hardly displaceable in the Y-axis direction. The support beams 16, 17, 20, 21 may be configured to be easily displaced only in the X-axis direction. On the other hand, the support beams 14, 15, 18, 19 extending in the X-axis direction for supporting the mass units 10, 11 are displaceable in the Y-axis direction and the Z-axis direction, but hardly displaceable in the X-axis direction. Adjustment of the displacement direction of each support beam can be controlled by the thickness dimension, width dimension, length dimension, etc. of the support beam.
　図１（ｂ）（なお図１（ｂ）にはばね部９０～９７を図面から省略している）に示すように、一対の励振部１２，１３に印加した駆動信号により駆動力が発生して一対の励振部１２，１３が、支持梁１６，１７，２０，２１及び第２のばね部９１，９２，９５，９６のＸ方向への変位に伴い、Ｘ軸方向に直線的に逆位相で振動する（実線の矢印Ｄ，Ｅ、あるいは点線の矢印Ｆ，Ｇ）。このとき励振部１２，１３は固有振動数で振動する。すると、質量部１０，１１を支持する支持梁１４，１５，１８，１９及び第１のばね部９０，９３，９４，９７がＹ方向へ変位し、一対の質量部１０，１１は、Ｙ軸方向に直線的に逆位相で励振する（実線の矢印Ｈ，Ｉ、あるいは点線の矢印Ｊ，Ｋ）。図１（ｂ）は、励振部１２，１３がＸ軸方向にて近づく方向（実線の矢印Ｄ，Ｅ）に振動し、質量部１０，１１がＹ軸方向に離れる方向（実線の矢印Ｈ，Ｉ）に励振した一状態を示している。 As shown in FIG. 1 (b) (note that the spring parts 90 to 97 are omitted from the drawing in FIG. 1 (b)), the driving force is generated by the drive signal applied to the pair of excitation parts 12 and 13. Thus, with the displacement of the support beams 16, 17, 20, 21 and the second spring portions 91, 92, 95, 96 in the X direction, the pair of excitation portions 12, 13 linearly reverse phase in the X axis direction. Vibration (solid arrows D and E or dotted arrows F and G). At this time, the excitation units 12 and 13 vibrate at the natural frequency. Then, the support beams 14, 15, 18, 19 supporting the mass portions 10, 11 and the first spring portions 90, 93, 94, 97 are displaced in the Y direction, and the pair of mass portions 10, 11 It excites in the opposite phase linearly in the direction (solid arrows H, I or dotted arrows J, K). In FIG. 1B, the excitation units 12 and 13 vibrate in a direction (solid arrows D and E) approaching in the X-axis direction, and the mass units 10 and 11 move away in the Y-axis direction (solid arrows H and H) An excited state is shown in I).
　図１（ｂ）の状態で、角速度センサ１にＸ軸方向を回転軸として角速度Ωが加わると、質量部１０，１１はコリオリ力を受けてＺ軸方向と平行な方向に変位する。このとき第１質量部１０が図示上方向（あるいは図示下方向）に変位したとき、第２質量部１１は図示下方向（あるいは図示上方向）に変位するように質量部１０、１１はＺ軸方向に逆位相で変位する。 In the state of FIG. 1B, when an angular velocity Ω is applied to the angular velocity sensor 1 with the X axis direction as a rotation axis, the mass portions 10 and 11 receive Coriolis force and are displaced in a direction parallel to the Z axis direction. At this time, when the first mass portion 10 is displaced upward in the drawing (or downward in the drawing), the mass portions 10 and 11 are Z-axis such that the second mass portion 11 is displaced downward in the drawing (or upward in the drawing) Displace in the opposite phase in the direction.
　例えば図２に示すように、質量部１０，１１の下方に位置する支持基板３上には電極部４９が設けられている。そして質量部１０，１１がＺ軸方向に変位したときに生じる電極部４９と質量部１０，１１間の距離が変化することで生じる静電容量変化に基づき角速度Ωを検出する。なお図２では、質量部１０，１１の下方にのみ電極部４９が設けられているが、電極部は、質量部１０，１１の上方にのみ、あるいは質量部１０，１１の上下両方に設けられてもよい。 For example, as shown in FIG. 2, an electrode portion 49 is provided on the support substrate 3 located below the mass portions 10 and 11. The angular velocity Ω is detected based on the change in electrostatic capacitance caused by the change in the distance between the electrode unit 49 and the mass units 10 and 11 which occurs when the mass units 10 and 11 are displaced in the Z-axis direction. In FIG. 2, the electrode unit 49 is provided only below the mass units 10 and 11, but the electrode unit is provided only above the mass units 10 and 11 or both above and below the mass units 10 and 11. May be
　以上のように本実施形態では、質量部１０，１１と、励振部１２，１３とを別々に設けた。また、一対の質量部１０，１１を、Ｙ軸方向にて向かい合う枠形状の２辺に位置する支持梁１４，１５，１８，１９に夫々設け、励振部１２，１３をＸ軸方向にて向かい合う枠形状の２辺に位置する支持梁１６，１７，２０，２１に夫々設けた。さらに質量部１０，１１と各励振部１２，１３の間に位置する支持梁１４～２１を、弾性変形可能なばね部９０～９７により懸架し、一対の励振部１２，１３がＸ軸方向に逆位相で振動したときに、一対の質量部１０，１１がＹ軸方向に逆位相で励振するようにした。本実施形態の構成によれば、励振部１２，１３に供給される駆動信号の質量部１０，１１への漏れを十分小さくでき、漏れ振動を適切に抑制できる。しかも本実施形態では、簡単な構造で、適切に、一対の質量部１０，１１を逆位相で大きい振幅にて励振させることが出来る。よって従来に比べて、角速度の検出精度を向上させることができる。 As described above, in the present embodiment, the mass units 10 and 11 and the excitation units 12 and 13 are separately provided. Further, a pair of mass parts 10 and 11 are provided on the support beams 14, 15, 18 and 19 located on two sides of the frame shape facing each other in the Y axis direction, and the excitation parts 12 and 13 face each other in the X axis direction The support beams 16, 17, 20, 21 located on two sides of the frame shape are respectively provided. Furthermore, support beams 14 to 21 positioned between mass portions 10 and 11 and respective excitation portions 12 and 13 are suspended by elastically deformable spring portions 90 to 97, and a pair of excitation portions 12 and 13 extend in the X axis direction. When vibrating in the opposite phase, the pair of mass portions 10 and 11 are excited in the opposite phase in the Y-axis direction. According to the configuration of the present embodiment, the leakage of the drive signals supplied to the excitation units 12 and 13 to the mass units 10 and 11 can be sufficiently reduced, and the leakage vibration can be appropriately suppressed. Moreover, in the present embodiment, with a simple structure, it is possible to excite the pair of mass portions 10 and 11 with large amplitude and in opposite phase. Therefore, the detection accuracy of the angular velocity can be improved as compared with the prior art.
　図１に示す構造では、質量部１０，１１の並び方向と励振部１２，１３の並び方向とが直交した関係となっている。直交関係に限定しないが、直交関係とすることで、より適切に、一対の励振部１２，１３をＸ軸方向に逆位相で振動させ、一対の質量部１０，１１をＹ軸方向に逆位相で励振させることが出来る。 In the structure shown in FIG. 1, the arrangement direction of the mass units 10 and 11 and the arrangement direction of the excitation units 12 and 13 are orthogonal to each other. Although not limited to the orthogonal relationship, the orthogonal relationship more appropriately vibrates the pair of excitation units 12 and 13 in the reverse phase in the X-axis direction, and reverses the pair of mass units 10 and 11 in the Y-axis direction. Can be excited by
　そして、上記構成により、Ｘ軸方向を回転軸として角速度Ωが生じると、回転軸と、励振部１２，１３の振動方向とが一致しているので、励振部１２、１３はコリオリ力を受けない。よって本実施形態では、従来に比べて、励振振動効率を向上させることができ、角速度の検出精度をより効果的に向上させることができる。 With the above configuration, when the angular velocity Ω occurs with the X axis direction as the axis of rotation, the axes of rotation and the directions of vibration of the excitation units 12 and 13 coincide with each other, so the excitation units 12 and 13 do not receive Coriolis force. . Therefore, in the present embodiment, the excitation vibration efficiency can be improved as compared with the conventional case, and the detection accuracy of the angular velocity can be more effectively improved.
　図３に示す角速度センサ３０の構造は、図１に示す角速度センサ１と異なって振動伝達梁３１～３４が設けられている。なお図１の角速度センサ１と同じ部位には図１と同じ符号が付されている。 The structure of the angular velocity sensor 30 shown in FIG. 3 is different from the angular velocity sensor 1 shown in FIG. 1 in that vibration transfer beams 31 to 34 are provided. The same parts as those of the angular velocity sensor 1 of FIG. 1 are denoted by the same reference numerals as those of FIG.
　振動伝達梁３１は、支持梁１５と支持梁１６とに連結し、振動伝達梁３２は、支持梁１７と支持梁１８とに連結し、振動伝達梁３３は支持梁１９と支持梁２０とに連結し、振動伝達梁３４は、支持梁１４と支持梁２１とに連結して設けられている。 The vibration transfer beam 31 is connected to the support beam 15 and the support beam 16, the vibration transfer beam 32 is connected to the support beam 17 and the support beam 18, and the vibration transfer beam 33 is connected to the support beam 19 and the support beam 20. The vibration transmission beam 34 is connected to the support beam 14 and the support beam 21.
　このように、振動伝達梁３１～３４を設けることで、図１の構造に比べて、図３（ｂ）（なお図３（ｂ）にはばね部９０～９７を図面から省略している）に示すように、一対の励振部１２、３をＸ軸方向に逆位相で振動させたときに、その振動を振動伝達梁３１～３４を介して効果的に質量部１０，１１にまで伝達でき、効果的に、一対の質量部１０，１１をＹ軸方向に逆位相で大きい振幅で励振させることが出来る。 Thus, by providing the vibration transmission beams 31 to 34, as compared with the structure of FIG. 1, FIG. 3 (b) (note that the spring parts 90 to 97 are omitted from the drawing in FIG. 3 (b)). As shown in the figure, when the pair of excitation units 12 and 3 vibrate in the opposite phase in the X-axis direction, the vibration can be effectively transmitted to the mass units 10 and 11 via the vibration transfer beams 31 to 34. Effectively, the pair of mass portions 10 and 11 can be excited with an opposite phase and a large amplitude in the Y-axis direction.
　図１，図３では、質量部１０，１１を支持する支持梁１４，１５，１８，１９に連結される第１のばね部９０，９３，９４，９７と、励振部１２，１３を支持する支持梁１６，１７，２０，２１に連結される第２のばね部９１，９２，９５，９６を設け、各支持梁１４～２１より成る枠形状の４隅近傍に２つずつばね部が設けられる形態であった。 In FIG. 1 and FIG. 3, the first spring portions 90, 93, 94, 97 connected to the support beams 14, 15, 18, 19 supporting the mass portions 10, 11 and the excitation portions 12, 13 are supported. Second spring portions 91, 92, 95, 96 connected to the support beams 16, 17, 20, 21 are provided, and two spring portions are provided in the vicinity of four corners of the frame shape composed of the support beams 14-21. Form.
　ただし図４に示すようにばね部１１０は、枠形状の各隅に１つずつ設けられてもよい。図４は支持梁１５と支持梁１６との成す隅に連結されたばね部１１０である。 However, as shown in FIG. 4, one spring portion 110 may be provided at each corner of the frame shape. FIG. 4 shows a spring portion 110 connected to the corner formed by the support beam 15 and the support beam 16.
　また本実施形態では、ばね部の形状を特に限定するものではない。例えば図１等に示すように、ばね部９０～９７はミアンダ形状で形成される。ばね部をミアンダ形状にすることで低剛性に出来る。またミアンダ形状でも例えば図４のように、Ｘ－Ｙ平面での対角線の位置でＸ方向とＹ方向とに交互に折り返した形状のばね部１１０であってもよい。図４のばね部１１０の形態とすると、Ｘ軸方向及びＹ軸方向の双方にほぼ同じ弾性変形力を発揮でき、励振振動効率を向上させることができる。 Further, in the present embodiment, the shape of the spring portion is not particularly limited. For example, as shown in FIG. 1 etc., the spring portions 90 to 97 are formed in a meander shape. The rigidity can be reduced by forming the spring portion in a meander shape. Further, even in the meander shape, for example, as shown in FIG. 4, the spring portion 110 may have a shape in which it is alternately folded back in the X direction and the Y direction at the position of the diagonal line in the XY plane. With the form of the spring portion 110 of FIG. 4, substantially the same elastic deformation can be exerted in both the X-axis direction and the Y-axis direction, and the excitation vibration efficiency can be improved.
　次に、図５の具体的形態に示すように、励振部１２，１３は、支持基板３に固定支持される櫛歯状の固定側駆動電極３５と、支持基板３の上方に位置してＹ軸方向に直線状に延びる支持梁１６，１７，２０，２１に連結され固定側駆動電極３５と交互に配置される櫛歯状の可動側駆動電極３６とを備える。 Next, as shown in the specific form of FIG. 5, the excitation units 12 and 13 have a comb-like fixed side drive electrode 35 fixedly supported on the support substrate 3 and Y positioned above the support substrate 3. A comb-like movable side drive electrode 36 connected to the support beams 16, 17, 20, 21 linearly extending in the axial direction and alternately arranged with the fixed side drive electrodes 35 is provided.
　図５に示すように可動側駆動電極３６は、支持梁１６，１７，２０，２１に連結されＹ軸方向に直線状に延びる支持部３７と、支持部３７のＸ軸方向の両側に延びると共に、Ｙ軸方向に所定間隔を空けて配置された櫛歯状電極３８を備える。また固定側駆動電極３５は、励振部１２，１３の夫々に２個ずつ設けられ、固定側駆動電極３５は、支持基板３上に酸化絶縁層４を介して固定支持される固定部３９と、この固定部３９から可動側駆動電極３６の櫛歯状電極３８間に延びる櫛歯状電極４０とで構成される。限定されないが、固定側駆動電極３５の櫛歯状電極４０下には酸化絶縁層４が無く、櫛歯状電極４０は支持基板３の上方に浮いている。 As shown in FIG. 5, the movable side drive electrode 36 is connected to the support beams 16, 17, 20, 21 and extends linearly on the support portion 37 in the X axis direction. And a comb-like electrode 38 disposed at a predetermined interval in the Y-axis direction. Further, two fixed side drive electrodes 35 are provided for each of the excitation portions 12 and 13, and the fixed side drive electrodes 35 are fixedly supported on the support substrate 3 via the oxide insulating layer 4, and A comb-like electrode 40 extending between the comb-like electrodes 38 of the movable drive electrode 36 from the fixed portion 39 is formed. Although not limited, there is no oxidation insulating layer 4 below the comb-like electrode 40 of the fixed drive electrode 35, and the comb-like electrode 40 floats above the support substrate 3.
　励振部１２、１３に対して互いに逆位相となる交流の駆動信号を印加すると、各励振部１２，１３の可動側駆動電極３６と固定側駆動電極３５との間にはクーロン力が作用し駆動力が発揮される。そして一対の励振部１２、１３は、支持梁１６，１７，２０，２１及び第２のばね部９１，９２，９５，９６のＸ方向への変位に伴い、Ｘ軸方向に逆位相で振動する。 When AC drive signals having opposite phases to each other are applied to the excitation units 12 and 13, a Coulomb force acts between the movable drive electrodes 36 and the fixed drive electrodes 35 of the excitation units 12 and 13 to drive them. Power is exerted. And a pair of excitation parts 12 and 13 vibrate in antiphase to the X-axis direction with displacement of support beams 16, 17, 20, 21 and second spring parts 91, 92, 95, 96 in the X direction. .
　図１（ｂ）で説明したように、励振部１２，１３がＸ軸方向に逆位相で振動することで、一対の質量部１０，１１は、質量部１０，１１を支持する支持梁１４，１５，１８，１９及び第１のばね部９０，９３，９４，９７のＹ方向への変位に伴い、Ｙ軸方向に逆位相で励振する。 As described with reference to FIG. 1B, the pair of mass units 10 and 11 support the mass units 10 and 11 by the excitation units 12 and 13 vibrating in opposite phase in the X-axis direction. With the displacement of the first and second spring portions 90, 93, 94, 97 in the Y direction, excitation is performed in the opposite phase in the Y axis direction.
　そして図１で説明したように、Ｘ軸方向を回転軸として角速度Ωが角速度センサに加わると、コリオリ力を受けて質量部１０，１１がＺ軸方向に変位する。このとき第１質量部１０と第２質量部１１とが逆位相で変位する。質量部１０，１１と支持基板３の距離が変動することで、図２に示す支持基板３上に設けられた電極部４９と質量部１０，１１間の静電容量変化をとらえ、この静電容量変化に基づき角速度Ωを検出する。 Then, as described with reference to FIG. 1, when an angular velocity Ω is applied to the angular velocity sensor with the X axis direction as a rotation axis, the mass portions 10 and 11 are displaced in the Z axis direction under Coriolis force. At this time, the first mass unit 10 and the second mass unit 11 are displaced in the opposite phase. By changing the distance between the mass portions 10 and 11 and the support substrate 3, the capacitance change between the electrode portions 49 and the mass portions 10 and 11 provided on the support substrate 3 shown in FIG. The angular velocity Ω is detected based on the change in capacitance.
　図５に示す本実施形態は、角速度センサにＸ軸方向を回転軸として角速度Ωが加わったときに角速度を検知できる構成である。すなわち既に述べたように本実施形態では角速度センサにＸ軸方向を回転軸として角速度Ωが加わると、質量部１０，１１はＺ軸方向へのコリオリ力を受けるが、励振部１２、１３はコリオリ力を受けない。よって図４に示す本実施形態では、Ｘ軸方向を回転軸として角速度Ωが加わったときに、優れた励振振動効率にて角速度を検知できる。 The present embodiment shown in FIG. 5 is configured to be capable of detecting an angular velocity when an angular velocity Ω is applied to the angular velocity sensor with the X axis direction as a rotation axis. That is, as described above, in the present embodiment, the mass units 10 and 11 receive the Coriolis force in the Z-axis direction when the angular velocity Ω is applied to the angular velocity sensor with the X-axis direction as the rotation axis, but the excitation units 12 and 13 I do not receive power. Therefore, in the present embodiment shown in FIG. 4, when the angular velocity Ω is applied with the X axis direction as the rotation axis, the angular velocity can be detected with excellent excitation vibration efficiency.
　また、本実施形態では、コリオリ力を受けて質量部１０，１１が逆位相で変位するため、加速度に伴う力（慣性力）を受けて質量部１０，１１の双方が同じ方向に変位した場合等に誤検知を防止できる。 Further, in the present embodiment, when the mass units 10 and 11 are displaced in opposite phase due to the Coriolis force, both of the mass units 10 and 11 are displaced in the same direction under the force (inertial force) accompanying the acceleration. Etc. can prevent false detection.
　図６は図３にて説明した振動伝達梁３１～３４を備える具体的構成である。励振部１２，１３の形態は図５と同様である。図６では、振動伝達梁３１～３４の形態は略Ｌ字状であるが、例えば、図６に示すように、振動伝達梁４１～４４は、直線状で形成されてもよいし、図７に示すように、振動伝達梁４５～４８は、湾曲状で形成されてもよい。本実施形態では、振動伝達梁の形態を特に限定しない。 FIG. 6 shows a specific configuration provided with the vibration transfer beams 31 to 34 described in FIG. The form of the excitation parts 12 and 13 is the same as that of FIG. Although the vibration transmitting beams 31 to 34 have a substantially L shape in FIG. 6, for example, as shown in FIG. 6, the vibration transmitting beams 41 to 44 may be formed in a linear shape. As shown in FIG. 5, the vibration transfer beams 45 to 48 may be formed in a curved shape. In the present embodiment, the form of the vibration transmission beam is not particularly limited.
　図６～図８に示す実施形態では、いずれも振動伝達梁を備えることで、一対の励振部１２、１３をＸ軸方向に逆位相で振動させたときに、その振動を振動伝達梁を介して効果的に質量部１０，１１にまで伝達でき、効果的に、一対の質量部１０，１１をＹ軸方向に逆位相で励振させることが出来る。 In any of the embodiments shown in FIGS. 6 to 8, when the pair of excitation parts 12 and 13 are vibrated in the opposite phase in the X-axis direction by providing the vibration transmitting beam, the vibration is transmitted through the vibration transmitting beam. Thus, the mass portions 10 and 11 can be effectively transmitted, and the pair of mass portions 10 and 11 can be excited in opposite phase in the Y-axis direction effectively.
　図５～図８はいずれもＸ軸方向を回転軸とした角速度Ωを検出するものであった。当然に、図５～図８に示す角速度センサをＸ－Ｙ平面内で９０度反転させれば、Ｙ軸方向を回転軸とした角速度Ωの検知が可能になる。 Each of FIGS. 5 to 8 detects the angular velocity Ω with the X axis direction as the rotation axis. Naturally, by inverting the angular velocity sensor shown in FIGS. 5 to 8 by 90 degrees in the XY plane, it becomes possible to detect the angular velocity Ω with the Y axis direction as the rotation axis.
　なお質量部１０，１１のＺ軸方向への変位量は、図２で説明した電極構造以外の構造で検出してもよい。 The displacement amount of the mass units 10 and 11 in the Z-axis direction may be detected by a structure other than the electrode structure described with reference to FIG.
　例えば図１０に示すように、質量部１０，１１の側面に共に櫛歯状の可動電極７０が設けられている。また可動電極７０と交互に櫛歯状の固定電極７２が設けられ、この固定電極７２は支持基板３上に固定支持されている。図１０は、可動電極７０及び固定電極７２を厚み方向から切断した断面形状で示している。なお可動電極と固定電極を区別しやすいように可動電極７０のみを斜線で示している。 For example, as shown in FIG. 10, comb-like movable electrodes 70 are provided on the side surfaces of the mass portions 10 and 11, respectively. Further, fixed electrodes 72 having a comb-like shape are provided alternately with the movable electrodes 70, and the fixed electrodes 72 are fixed and supported on the support substrate 3. FIG. 10 shows the movable electrode 70 and the fixed electrode 72 in a cross-sectional shape cut in the thickness direction. Note that only the movable electrode 70 is hatched so that the movable electrode and the fixed electrode can be easily distinguished.
　図１０に示すように、例えば可動電極７０と固定電極７２は同じ厚さ寸法で形成され、初期状態（コリオリ力が作用していない状態）では、可動電極７０の上面は固定電極７２の上面よりも高い位置にある。 As shown in FIG. 10, for example, the movable electrode 70 and the fixed electrode 72 are formed to have the same thickness, and in the initial state (state in which Coriolis force is not applied), the upper surface of the movable electrode 70 is from the upper surface of the fixed electrode 72 Is also in a high position.
　図１０（ａ）に示すように、可動電極７０が下方向に移動すると、可動電極７０と固定電極７２との対向面積は増大するため、静電容量は増大する。一方、図１０（ｂ）に示すように、可動電極７０が上方向に移動すると、可動電極７０と固定電極７２との対向面積は減少するため、静電容量は減少する。 As shown in FIG. 10A, when the movable electrode 70 moves downward, the facing area of the movable electrode 70 and the fixed electrode 72 increases, and hence the capacitance increases. On the other hand, as shown in FIG. 10B, when the movable electrode 70 moves upward, the opposing area of the movable electrode 70 and the fixed electrode 72 decreases, and the electrostatic capacitance decreases.
　これにより、Ｚ軸方向にコリオリ力を受けて質量部１０，１１が変位したときの変位量を静電容量変化の差動出力として得ることが出来る。 As a result, it is possible to obtain a displacement amount when the mass parts 10 and 11 are displaced by receiving Coriolis force in the Z-axis direction as a differential output of the capacitance change.
　なお、図１０に示すＺ軸方向の変位を検知する櫛歯状の電極構造は一例である。可動電極が上方向に移動したときと下方向に移動したときとで静電容量変化の増減が逆傾向になれば特に電極の構造を限定しない。 The comb-like electrode structure for detecting the displacement in the Z-axis direction shown in FIG. 10 is an example. The structure of the electrode is not particularly limited as long as the change in electrostatic capacitance tends to be reversed between when the movable electrode moves upward and when it moves downward.
　Ｚ軸方向を回転軸とした角速度Ωを検知するには、例えば図９に示す構造が考えられる。 In order to detect the angular velocity Ω with the Z axis direction as the rotation axis, for example, the structure shown in FIG. 9 can be considered.
　図９に示す角速度センサ５０は、図５に示す角速度センサの質量部１０，１１の側面に櫛歯状電極を形成したものである。よって図９の角速度センサ５０は、質量部１０，１１の側面に設けられた櫛歯状電極の部分以外、図５と同じである（符号も図５と同じ部位は同じとした）。 The angular velocity sensor 50 shown in FIG. 9 has a comb-like electrode formed on the side surfaces of the mass portions 10 and 11 of the angular velocity sensor shown in FIG. Therefore, the angular velocity sensor 50 of FIG. 9 is the same as that of FIG. 5 except for the portions of the comb-like electrodes provided on the side surfaces of the mass portions 10 and 11 (the same reference numerals as in FIG. 5 denote the same portions).
　図９に示すように、各質量部１０，１１の両側面には、Ｘ軸方向に間隔を空けて配置される櫛歯状の可動電極６３，６４，６５，６６が質量部１０，１１と一体的に設けられる。また支持基板３に酸化絶縁層４を介して固定支持される櫛歯状の固定電極６７，６８，６９，７１が可動電極６３，６４，６５，６６と交互に配置されている。 As shown in FIG. 9, comb-shaped movable electrodes 63, 64, 65 and 66 arranged at intervals in the X-axis direction on both side surfaces of each of the mass portions 10 and 11 are mass portions 10 and 11, respectively. It is provided integrally. Further, comb-like fixed electrodes 67, 68, 69, 71 fixedly supported on the support substrate 3 via the oxide insulating layer 4 are alternately arranged with the movable electrodes 63, 64, 65, 66.
　図９に示す実施形態でも図５～図８と同様に、一対の励振部１２、１３がＸ軸方向に逆位相で振動し、一対の質量部１０，１１がＹ軸方向に逆位相で励振する。 Also in the embodiment shown in FIG. 9, as in FIGS. 5 to 8, the pair of excitation units 12 and 13 vibrate in antiphase in the X-axis direction, and the pair of mass units 10 and 11 are excited in antiphase in the Y-axis direction. Do.
　図９に示すように、Ｚ軸方向を回転軸として角速度Ωが角速度センサ５０に加わると、質量部１０、１１にはＸ軸方向に逆位相でコリオリ力が作用する。このときのＸ軸方向への変位量を可動電極６３，６４，６５，６６と固定電極６７，６８，６９，７１の間で生じる静電容量変化として検出することで、Ｚ軸方向を回転軸とした角速度Ωの検出が可能となる。 As shown in FIG. 9, when an angular velocity Ω is applied to the angular velocity sensor 50 with the Z axis direction as a rotation axis, Coriolis force acts on the mass portions 10 and 11 in reverse phase in the X axis direction. The amount of displacement in the X-axis direction at this time is detected as a capacitance change generated between the movable electrodes 63, 64, 65, 66 and the fixed electrodes 67, 68, 69, 71, whereby the Z-axis direction is the rotation axis. The angular velocity Ω can be detected.
　図１１は、本実施形態における角速度センサの製造方法を示す。なお図１１は図１に示すＡ－Ａ線に沿った断面形状部分での製造方法である。 FIG. 11 shows a method of manufacturing the angular velocity sensor in the present embodiment. FIG. 11 shows a manufacturing method in a cross-sectional shape along the line AA shown in FIG.
　図１１（ａ）に示すようにシリコンで形成された支持基板３を用意し、図１１（ｂ）に示すように支持基板３の表面３ａに電極部４９を形成する。 As shown in FIG. 11A, the support substrate 3 made of silicon is prepared, and as shown in FIG. 11B, the electrode portion 49 is formed on the surface 3a of the support substrate 3.
　次に図１１（ｃ）に示す工程では、酸化絶縁層（ＳｉＯ2層、犠牲層）４を形成する。成膜後、酸化絶縁層４の表面を例えばＣＭＰ技術を用いて平坦化処理する。 Next, in a step shown in FIG. 11C, an oxide insulating layer (SiO 2 layer, sacrificial layer) 4 is formed. After the film formation, the surface of the oxide insulating layer 4 is planarized using, for example, a CMP technique.
　次に図１１（ｄ）に示す工程では、酸化絶縁層４上にＳＯＩ層（シリコン層）５を形成する。ＳＯＩ層５には、例えば図５に示す質量部１０，１１、励振部１２，１３、支持梁１４～２１、ばね部９０～９７、アンカ部１００～１０７を区画形成し、それ以外の余分なＳＯＩ層５を例えばディープＲＩＥ（Deep　RIE）を用いて除去する。またこのとき、質量部１０、１１には多数の微細な貫通孔８０を形成しておく。 Next, in the step shown in FIG. 11D, the SOI layer (silicon layer) 5 is formed on the oxide insulating layer 4. In the SOI layer 5, for example, the mass portions 10 and 11 shown in FIG. 5, the excitation portions 12 and 13, the support beams 14 to 21, the spring portions 90 to 97, and the anchor portions 100 to 107 are defined. The SOI layer 5 is removed using, for example, deep RIE. At this time, a large number of fine through holes 80 are formed in the mass portions 10 and 11.
　そして図１１（ｅ）に示す工程では、アンカ部２２～２５の下や励振部１２，１３を構成する固定部３９の下の酸化絶縁層４を除いて、それ以外の酸化絶縁層４をウエットエッチングやドライエッチングによる等方性エッチング工程にて除去する。このとき、質量部１０，１１の下にある酸化絶縁層４も上記した貫通孔を通して除去される。 Then, in the step shown in FIG. 11E, the oxide insulating layer 4 is wet except for the oxide insulating layer 4 under the anchor portions 22 to 25 and under the fixing portion 39 constituting the excitation portions 12 and 13. It is removed by an isotropic etching process by etching or dry etching. At this time, the oxide insulating layer 4 under the mass parts 10 and 11 is also removed through the above-mentioned through holes.
　なお、上記した角速度センサを複数用いて、Ｘ軸方向、Ｙ軸方向、及びＺ軸方向のうち少なくとも２方向を回転軸とした角速度が生じたときに、各角速度を検知できる角速度センサモジュールを構成してもよい。例えば、図５に示す構造の角速度センサを２つ用意し、一方の角速度センサの配置を図５と同様にし、他方の角速度センサの配置を図５の向きからＸ－Ｙ平面に９０度傾ける。これによりＸ軸方向及びＹ軸方向を夫々回転軸とした角速度Ωの検知が可能な角速度センサモジュールを形成できる。 Note that an angular velocity sensor module can be configured that can detect each angular velocity when a plurality of angular velocity sensors with at least two of the X-axis direction, the Y-axis direction, and the Z-axis direction are generated. You may For example, two angular velocity sensors having the structure shown in FIG. 5 are prepared, the arrangement of one angular velocity sensor is the same as that of FIG. 5, and the arrangement of the other angular velocity sensor is inclined 90 degrees from the direction of FIG. As a result, it is possible to form an angular velocity sensor module capable of detecting the angular velocity Ω with the X axis direction and the Y axis direction as rotation axes.
　上記したＸ－Ｙ軸検知用の角速度センサでは、例えばＸ軸を回転軸とした角速度Ωが加わったとき、Ｘ軸検知用の角速度センサの質量部にはコリオリ力が生じるが、Ｙ軸検知用の角速度センサの質量部にはコリオリ力が生じない。同様に、Ｙ軸を回転軸とした角速度Ωが加わったとき、Ｙ軸検知用の角速度センサの質量部にはコリオリ力が生じるが、Ｘ軸検知用の角速度センサの質量部にはコリオリ力が生じない。よってＸ軸及びＹ軸を回転軸とした角速度Ωが加わったときに、適切に、夫々の角速度Ωの検知が可能である。 In the above-mentioned angular velocity sensor for XY axis detection, for example, when an angular velocity Ω with the X axis as the rotation axis is applied, Coriolis force is generated in the mass of the angular velocity sensor for X axis detection. Coriolis force does not occur in the mass portion of the angular velocity sensor. Similarly, when an angular velocity Ω with the Y axis as the rotation axis is applied, Coriolis force is generated in the mass of the angular velocity sensor for Y axis detection, but Coriolis force is generated in the mass of the angular velocity sensor for X axis detection. It does not occur. Therefore, when an angular velocity Ω with the X-axis and the Y-axis as rotation axes is applied, detection of each angular velocity Ω can be appropriately performed.
本発明の第１実施形態の角速度センサの概念図、A conceptual view of an angular velocity sensor according to a first embodiment of the present invention; 図１に示すＡ－Ａ線に沿って高さ方向に切断した際の部分断面図、A partial sectional view when cut in the height direction along the line AA shown in FIG. 1; 本発明の第２実施形態の角速度センサの概念図、A conceptual view of an angular velocity sensor according to a second embodiment of the present invention; ばね部の平面図、Plan view of the spring part, 図１に示す角速度センサの具体的構成図（平面図）、The specific block diagram (plan view) of the angular velocity sensor shown in FIG. 図３に示す角速度センサの具体的構成図（平面図）、The specific block diagram (plan view) of the angular velocity sensor shown in FIG. 3; 図６と一部異なる角速度センサの具体的構成図（平面図）、A specific configuration diagram (plan view) of an angular velocity sensor which is partially different from FIG. 図６と一部異なる角速度センサの具体的構成図（平面図）、A specific configuration diagram (plan view) of an angular velocity sensor which is partially different from FIG. 図５の角速度センサの質量部の構造を変えて、Ｚ軸回りの角速度Ωを検知可能とした角速度センサの具体的構成図（平面図）、A specific configuration diagram (plan view) of an angular velocity sensor capable of detecting an angular velocity Ω around the Z axis by changing the structure of the mass portion of the angular velocity sensor of FIG. 5; Ｚ軸方向への変位量を測定するための櫛歯状構造の可動電極と固定電極を高さ方向から切断した断面図であり、（ａ）は初期状態と、初期状態から可動電極が下方向に移動したときの図、（ｂ）は初期状態と、初期状態から可動電極が上方向に移動したときの図、It is sectional drawing which cut | disconnected the movable electrode and fixed electrode of a comb-tooth-shaped structure for measuring the displacement amount to Z-axis direction from the height direction, (a) is an initial state and a movable electrode is downward from the initial state. (B) shows the initial state, and the diagram when the movable electrode moves upward from the initial state, 本実施形態の角速度センサの製造方法を示す断面図、Sectional drawing which shows the manufacturing method of the angular velocity sensor of this embodiment,
符号の説明Explanation of sign
１、３０、５０　角速度センサ
２　ＳＯＩ基板
３　支持基板
４　酸化絶縁層
５　ＳＯＩ層
１０、１１、６０、６１　質量部
１２、１３　励振部
１４～２１、５５　支持梁
３１～３４、４１～４４、４５～４８　振動伝達梁
３５　固定側駆動電極
３６　可動側駆動電極
４９　電極部
６３、６４、６５、６６、７０　可動電極
６７、６８、６９、７１、７２　固定電極
９０～９７　ばね部
１００～１０７　アンカ部 1, 30, 50 Angular velocity sensor 2 SOI substrate 3 Support substrate 4 Oxide insulating layer 5 SOI layer 10, 11, 60, 61 Mass portion 12 13 Excitation portion 14 to 21, 55 Support beam 31 to 34, 41 to 44, 45 To 48 vibration transmitting beam 35 fixed side drive electrode 36 movable side drive electrode 49 electrode portion 63, 64, 65, 66, 70 movable electrode 67, 68, 69, 71, 72 fixed electrode 90 to 97 spring portion 100 to 107 anchor portion

Claims (8)

  1. 　支持基板と、前記支持基板の上方に位置する質量部と、前記質量部を励振するための励振部と、前記質量部及び前記励振部を所定方向に変位可能に支持する支持梁と、コリオリ力を受けて変位する前記質量部の変位量を検出するための検知部と、を備え、
    　各支持梁を結んだ輪郭が枠形状に形成されており、
    　支持基板平面にて直交する２方向をＸ軸方向とＹ軸方向としたとき、前記質量部はＸ軸方向にて向かい合う前記枠形状の２辺に位置する前記支持梁に支持され、前記励振部はＹ軸方向にて向かい合う前記枠形状の２辺に位置する前記支持梁に支持され、
    　各質量部と各励振部の間に位置する前記支持梁が、弾性変形可能なばね部により懸架されており、
    　前記一対の励振部が前記Ｘ軸方向に逆位相で振動したときに、前記一対の質量部が前記Ｙ軸方向に逆位相で励振することを特徴とする角速度センサ。     A support substrate, a mass portion positioned above the support substrate, an excitation portion for exciting the mass portion, a support beam supporting the mass portion and the excitation portion so as to be displaceable in a predetermined direction, Coriolis force A detection unit for detecting a displacement amount of the mass unit that is displaced upon receiving the
    An outline connecting each support beam is formed in a frame shape,
    Assuming that two directions orthogonal to each other in the plane of the support substrate are the X-axis direction and the Y-axis direction, the mass portion is supported by the support beams positioned on two sides of the frame shape facing each other in the X-axis direction. Is supported by the support beams located on two sides of the frame shape facing each other in the Y-axis direction,
    The support beam positioned between each mass portion and each excitation portion is suspended by an elastically deformable spring portion,
    The angular velocity sensor characterized in that when the pair of excitation parts vibrate in the opposite phase in the X-axis direction, the pair of mass parts excite in the opposite phase in the Y-axis direction.
  2. 　前記枠形状の隣接する各辺に位置する前記支持梁間に振動伝達梁が連結されている請求項１記載の角速度センサ。 The angular velocity sensor according to claim 1, wherein a vibration transfer beam is connected between the support beams located on adjacent sides of the frame shape.
  3. 　前記一対の質量部の並び方向と、前記一対の励振部の並び方向とが直交している請求項１又は２に記載の角速度センサ。 3. The angular velocity sensor according to claim 1, wherein a direction in which the pair of mass portions is arranged is orthogonal to a direction in which the pair of excitation portions are arranged.
  4. 　各支持梁を結んだ輪郭が略正方形あるいは略長方形であり、前記枠形状の各隅と各質量部の間に位置する前記支持梁の前記各隅に近い位置に第１の前記ばね部が連結され、前記枠形状の各隅と各励振部の間に位置する前記支持梁の前記各隅に近い位置に第２の前記ばね部が連結されている請求項１ないし３のいずれかに記載の角速度センサ。 The outline connecting the support beams is substantially square or rectangular, and the first spring portion is connected to a position near each corner of the support beam located between each corner of the frame shape and each mass portion. The second spring portion is connected to a position close to each corner of the support beam located between each corner of the frame shape and each excitation portion. Angular velocity sensor.
  5. 　各支持梁を結んだ輪郭が略正方形あるいは略長方形であり、前記ばね部は、前記枠形状の四隅に設けられる請求項１ないし３のいずれかに記載の角速度センサ。 The angular velocity sensor according to any one of claims 1 to 3, wherein an outline connecting each support beam is substantially square or substantially rectangular, and the spring portion is provided at four corners of the frame shape.
  6. 　前記ばね部は、ミアンダ状で形成される請求項１ないし５のいずれかに記載の角速度センサ。 The angular velocity sensor according to any one of claims 1 to 5, wherein the spring portion is formed in a meander shape.
  7. 　前記励振部は、前記支持基板に固定支持される櫛歯状の固定側駆動電極と、前記支持基板の上方に位置して前記支持梁に連結され、前記固定側駆動電極と交互に配置される櫛歯状の可動側駆動電極とを備え、前記固定側駆動電極と前記可動側駆動電極間に発生するクーロン力により前記可動側駆動電極が振動する請求項１ないし６のいずれかに記載の角速度センサ。 The excitation unit is disposed on a comb-like fixed side drive electrode fixedly supported on the support substrate, and connected to the support beam above the support substrate and alternately arranged with the fixed side drive electrode. The angular velocity according to any one of claims 1 to 6, further comprising: a comb-like movable side drive electrode, wherein the movable side drive electrode vibrates by a coulomb force generated between the fixed side drive electrode and the movable side drive electrode. Sensor.
  8. 　Ｘ軸周りに角速度が発生したとき、前記Ｘ軸方向及び前記Ｙ軸方向と直交するＺ軸方向にコリオリ力が生じることで、前記一対の質量部が前記Ｚ軸方向に逆位相で変位し、このときの変位量が前記検知部にて静電容量変化として検知される請求項１ないし７のいずれかに記載の角速度センサ。 When an angular velocity is generated around the X-axis, a Coriolis force is generated in the X-axis direction and the Z-axis direction orthogonal to the Y-axis direction, whereby the pair of mass parts is displaced in the opposite phase in the Z-axis direction, The angular velocity sensor according to any one of claims 1 to 7, wherein the displacement amount at this time is detected as a capacitance change by the detection unit.
PCT/JP2009/053142 2008-02-25 2009-02-23 Angular velocity sensor WO2009107576A1 (en)

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JPH11173854A (en) * 1997-12-10 1999-07-02 Murata Mfg Co Ltd Angular velocity sensor
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JP2000105124A (en) * 1998-09-30 2000-04-11 Aisin Seiki Co Ltd Electrostatic drive, electrostatic detecting type angular velocity sensor

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JPH08159776A (en) * 1994-12-08 1996-06-21 Nissan Motor Co Ltd Angular velocity sensor
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JPH11173854A (en) * 1997-12-10 1999-07-02 Murata Mfg Co Ltd Angular velocity sensor
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Publication number Priority date Publication date Assignee Title
WO2014184225A1 (en) * 2013-05-14 2014-11-20 Robert Bosch Gmbh Rotation rate sensor for detecting a rotation rate, having a substrate which has a main extension plane
US9823073B2 (en) 2013-05-14 2017-11-21 Robert Bosch Gmbh Rotation-rate sensor having a substrate having a main extension plane for detecting a rotation rate
CN105324634B (en) * 2013-05-14 2019-06-07 罗伯特·博世有限公司 The speed probe for being used to detect revolving speed with the substrate with main extension plane

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