JP2010117292A - Angular velocity sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an angular velocity sensor which can detect angular velocity, with a vector directed into a plane parallel to a substrate, by a planar constitution. <P>SOLUTION: A first drive mass part 29a and a second drive mass part 29b which are formed of a planar silicon wafer are driven so that they vibrate in a reciprocating manner in phases reverse to each other in the direction of X1-X2. When a vertical axis angular-velocity sensor 1 has an angular velocity around the vertical axis Oz on the occasion, Coriolis forces directed opposite to each other in the direction of Y1-Y2 act on the first drive mass part 29a and the second drive mass part 29b. As the result, a detecting rotary part supporting the first drive mass part 29a and the second drive mass part 29b rotates in directions of (iii) and (iv) and the amount of this rotation is detected as a change in the capacitance of movable electrode parts 28 and a fixed electrode layer opposite to these parts. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an angular velocity sensor having a fine structure formed by processing a silicon layer, and more particularly to an angular velocity sensor capable of detecting an angular velocity at which a vector faces in a plane parallel to a support substrate.

A MEMS (Micro-Electro-Mechanical Systems) element is formed by finely processing an SOI (Silicon on Insulator) layer in which _two silicon (Si) wafers are joined via an insulating layer such as SiO ₂ . In the MEMS element, one silicon wafer of the SOI layer is used as a support substrate, the other silicon wafer is used as a functional layer, and the functional layer is separated by etching so that the mass part can be operated. An elastically deformable portion to be supported, a movable electrode portion that detects the amount of movement of the mass portion, a fixed electrode portion, and the like are formed.

When processing the SOI layer, a part of the insulating layer such as SiO ₂ is left, and a part of the functional layer and the supporting substrate are joined by the insulating layer, and the mass part, the elastically deforming part, and The insulating layer between the movable electrode portion and the support substrate is removed, and the mass portion, the elastic deformation portion, the movable electrode portion, and the like can be operated in the space on the support substrate.

  The following Patent Document 1 and Patent Document 2 disclose MEMS elements that function as angular velocity sensors.

  The angular velocity sensor described in Patent Document 1 is supported by a pair of first vibrating bodies supported movably in a direction parallel to the surface of the substrate (X direction), and the respective first vibrating bodies, A second vibrating body is provided that is movably supported in a direction (Z direction) perpendicular to the surface of the substrate. When the pair of first vibrating bodies are driven so as to be in opposite phases to each other in the direction parallel to the plane (X direction), the direction perpendicular to the plane of the pair of second vibrating bodies (Z direction) ), The Coriolis force component in the Z direction can be detected, so that the angular velocity around the Y axis parallel to the surface of the substrate, that is, the angular velocity at which the vector faces in the plane perpendicular to the Y axis is known. Can do.

A gyroscope that is an angular velocity sensor described in Patent Document 2 is supported inside a ring-shaped base so that the ring-shaped frame can be angularly vibrated, and a vertical direction perpendicular to the angular vibration direction is supported in the frame. Two masses that can vibrate in the (Z direction) are provided. By oscillating the two masses in opposite directions in the Z direction and measuring the angular vibration of the frame excited by the Coriolis force, the angular velocity around the Y axis parallel to the plane including the angular vibration, that is, the Y axis It is possible to know the angular velocity at which the vector faces in an orthogonal plane.
Japanese Patent Laid-Open No. 2001-21360 Special table 2007-509346 gazette

  In the angular velocity sensors described in Patent Document 1 and Patent Document 2, a pair of second vibrating bodies and a pair of mass parts are driven in a direction perpendicular to a substrate formed of a silicon wafer or the like. Therefore, both can detect the angular velocity around the Y axis parallel to the surface of the substrate, but the vector is directed to the angular velocity around the axis perpendicular to the surface of the substrate (around the Z axis), that is, the surface parallel to the substrate. The angular velocity component cannot be detected.

  Therefore, in order to detect the angular velocity component around the Z axis in the space, it is necessary to use the substrate in a vertical direction, and the advantage of using a thin MEMS element cannot be fully utilized.

  In addition, in order to detect an angular velocity in which a vector may be directed in all directions in the three-dimensional space using the angular velocity sensor, two angular velocity sensors are arranged so that their substrates are in the same plane. The angular velocity components around the X axis and the Y axis can be detected by changing the arrangement angle of the two angular velocity sensors in the same plane by 90 degrees, and the other angular velocity sensor is mounted on the substrate. It is necessary to arrange it in a direction perpendicular to the plane so that the angular velocity component around the Z axis can be detected. As described above, the angular velocity sensors that detect the angular velocity components in the three directions must be combined with the substrates facing each other vertically, the structure of the entire sensor becomes complicated, and the thickness cannot be reduced.

  The present invention solves the above-mentioned conventional problems, and arranges each member in parallel with the surface of the supporting substrate, while the angular velocity component around the axis perpendicular to the surface, that is, the vector in the surface parallel to the surface of the substrate. It is an object of the present invention to provide an angular velocity sensor that can detect an angular velocity component to which is directed.

  It is another object of the present invention to provide an angular velocity sensor that can detect vector components of angular velocities in three directions orthogonal to each other by the movement of members arranged in the same plane.

The present invention supports a support substrate, a plurality of fixed support portions provided on the support substrate, and is supported by the fixed support portion via a first elastic deformation portion and rotates in a plane parallel to the support substrate. A detection rotation unit capable of moving, a pair of drive mass units supported by the detection rotation unit via a second elastic deformation unit and movable in the plane, and a pair of drive mass units in the plane In-plane driving members that are driven in opposite directions, a movable electrode portion that is provided integrally with the detection rotation portion, and a fixed electrode portion that is fixed on the support substrate and faces the movable electrode portion. And
A pair of the drive mass units are driven in opposite directions within the plane, and the rotation of the detection rotation unit is detected by a change in the facing state of the movable electrode and the fixed electrode. An angular velocity acting on the driving mass unit with the vector facing is detected.

  The angular velocity sensor of the present invention drives the driving mass unit in directions opposite to each other in a plane parallel to the substrate, and detects the Coriolis force by the rotating operation of the detection rotating unit that supports the driving mass unit. Therefore, it is possible to detect an angular velocity component around an axis perpendicular to the surface of the support substrate, that is, an angular velocity component in which a vector faces in the surface. Therefore, even when detecting an angular velocity acting around a vertical axis in space, the support substrate can be arranged horizontally, and the apparatus can be thinned.

  In addition, since the pair of drive mass units and the detection rotation unit operate in the same plane and there is no portion that operates perpendicular to the surface of the support substrate, the movable units such as the drive mass unit and the detection rotation unit And the support substrate can be minimized. Since it is not necessary to process the escape portion for preventing the movable portion from hitting the support substrate more deeply than necessary, the processing is easy and a thin sensor can be easily configured.

  In the present invention, the in-plane driving member is a piezoelectric element attached to the second elastic deformation portion, and the second elastic deformation portion is bent and deformed in the plane by an electrostrictive effect of the piezoelectric element. Thus, the pair of drive mass units are driven in opposite directions.

  By forming the in-plane driving member with a piezoelectric element, a large voltage is not required during driving and driving control is facilitated compared to driving the driving mass with electrostatic force. However, the in-plane driving member of the present invention may be one that vibrates and drives a pair of driving mass parts using electrostatic force.

  In the present invention, a plurality of the movable electrode portions are provided such that a distance between the movable electrode portions increases as the distance from the detection rotation portion increases, and each of the movable electrode portions is opposed to each of the movable electrode portions from one side facing the rotation direction. A fixed output portion and a second fixed electrode portion facing from the other, a detection output based on a change in capacitance between the movable electrode portion and the first fixed electrode portion, and the movable electrode It is preferable that a difference between the detection output based on the change in capacitance between the first fixed electrode unit and the second fixed electrode unit is obtained.

  In the present invention, when the drive mass unit is driven and the drive mass unit has an angular velocity, the detection rotation unit is rotated by the Coriolis force. At this time, a change in the interval between the movable electrode portion and the first fixed electrode portion and a change in the interval between the movable electrode portion and the second fixed electrode portion are detected as a change in capacitance. At this time, by obtaining the difference between the detection output obtained at the first fixed electrode portion and the detection output obtained at the second fixed electrode portion, the rotation amount of the detection rotation portion can be detected with a large output.

  Further, the detection rotation unit moves in a direction perpendicular to the surface of the support substrate, which is a direction other than the rotation direction, or in a direction parallel to the surface of the support substrate, and the movable electrode unit and each fixed electrode unit When the opposed area of the first and second counter electrodes fluctuates, the output due to the fluctuation can be canceled by obtaining the difference between the detection output obtained by the first fixed electrode portion and the detection output obtained by the second fixed electrode portion. Therefore, it is possible to prevent the operation noise of disturbances other than the driving direction due to the Coriolis force component from being superimposed.

In the present invention, an SOI layer in which two Si layers are bonded via an insulating layer is used, one Si layer is used as the support substrate, and the other Si layer is used as a functional layer. The fixed support portion, the detection rotation portion and the drive mass portion, the first elastic deformation portion and the second elastic deformation portion, the movable electrode portion and the fixed electrode portion are formed separately. And
The insulating layer is left at a joint portion between the fixed support portion and the support substrate, and a joint portion between the part of the fixed electrode portion and the support substrate, and the detection rotation portion, the driving mass portion, the first The insulating layer is removed between each of the first elastic deformation portion, the second elastic deformation portion, the movable electrode portion, and the support substrate.

  According to the present invention, a closing member that covers the functional layer is provided, and the closing member, the fixed support portion, and the closing member and a part of the fixed electrode portion are joined via a second insulating layer. Is.

  When the support substrate and the functional layer are formed by the SOI layer, a thin and small angular velocity sensor can be obtained.

  In the present invention, it is preferable that a weight layer of a metal material having a specific gravity larger than that of the Si layer is laminated on the driving mass unit.

  Increasing the mass of the drive mass unit by stacking the weight layer on the drive mass unit can increase the inertial force when the drive mass unit is operated, and the inertia when force is applied to the drive mass unit by Coriolis force The force also increases, and the rotation amplitude of the detection rotation unit can be amplified.

In the present invention, the angular velocity sensor having any one of the structures described above is used as a vertical axis angular velocity sensor,
Further, instead of the second elastic deformation portion, a third elastic deformation portion that supports the pair of drive mass portions so as to be movable in a direction perpendicular to the surface is provided, and is changed to the in-plane drive member. A vertical surface drive member that drives the pair of drive mass units in directions opposite to each other in a direction perpendicular to the surface, and in a vertical plane orthogonal to a horizontal axis extending in the direction in which the pair of drive mass units are arranged. Is used as a horizontal axis angular velocity sensor to detect the angular velocity acting on the drive mass unit with the vector facing to
The support substrate of the vertical axis angular velocity sensor and the support substrate of the horizontal axis angular velocity sensor are formed as a single common support substrate, and the vertical axis angular velocity sensor and the horizontal axis angular velocity are provided on the common support substrate. The sensor is arranged side by side.

  Further, in the present invention, two sets of the horizontal axis angular velocity sensors are provided on the common support substrate, and the horizontal axis angular velocity sensors are different from each other in the direction of the horizontal axis by 90 degrees.

  In the above invention, the three angular velocity sensors formed in a plane on the common substrate can detect angular velocity components in all three directions in the space.

  Furthermore, the present invention provides the vertical axis angular velocity sensor and the horizontal axis angular velocity sensor, the fixed support portion, the detection rotation portion, the first elastic deformation portion, the pair of driving mass portions, and the movable electrode portion. It is preferable that the shapes and dimensions of the fixed electrode portions are the same.

  In the above invention, since the parts other than the elastically deforming part and the driving member can be made the same structure, the processing when forming three angular velocity sensors with the same silicon wafer or the like is easy, and there are many common parts. Is also easy.

  The angular velocity sensor of the present invention can detect an angular velocity component in which a vector faces in a plane parallel to the substrate surface. Therefore, it is possible to detect the angular velocity component around the vertical axis by installing the support substrate horizontally in the space. In this case, since it is not necessary to orient the support substrate vertically as in the prior art, the apparatus can be configured thin.

  In addition, the present invention can be formed by arranging both a vertical axis angular velocity sensor and a horizontal axis angular velocity sensor in a plane on a common support substrate, so that the angular velocity component in which the vector is directed in the other direction is detected while being thin. It becomes possible to do.

  FIG. 1 is a plan view showing a structure of a functional layer of a vertical axis angular velocity sensor according to an embodiment of the present invention, and FIG. 2 is a sectional view of the vertical axis angular velocity sensor shown in FIG. FIG. 3A is a plan view partially showing a detection rotating portion and a driving mass portion provided in the functional layer, and FIG. 3B is a cross-sectional view taken along the line BB in FIG. 4 to 6 are partial plan views showing the second elastic deformation portion and the in-plane driving member according to the embodiment. FIGS. 7A and 7B are explanatory diagrams of the operation of the vertical axis angular velocity sensor.

  The vertical axis angular velocity sensor 1 shown in FIGS. 1 and 2 is a MEMS (Micro-Electro-Mechanical Systems) element, and its planar shape is a quadrangle as shown in FIG.

As shown in FIG. 2, in the vertical axis angular velocity sensor 1, a functional layer 20 is laminated on a support substrate 2, and a part of the functional layer 20 and the support substrate 2 are bonded via a first insulating layer 3. The support substrate 2, the functional layer 20, and the first insulating layer 3 are formed by finely processing an SOI (Silicon on Insulator) layer. The SOI layer used here is obtained by integrally bonding two silicon wafers with an SiO ₂ layer as an insulating layer (Insulator) interposed therebetween. One silicon wafer of the SOI layer is used as the support substrate 2, and the other silicon wafer is used as the functional layer 20, and the functional layer 20 is finely processed to separate the respective functional portions. Further, a part of the SiO ₂ layer is left to become the first insulating layer 3.

  As shown in FIG. 2, the functional layer 20 is overlaid with the closing member 4, and the functional layer 20 is sandwiched between the support substrate 2 and the closing member 4. The closing member 4 is a single Si substrate. The closing member 4 has a second insulating layer 5 formed on the surface facing the functional layer 20.

  A conductive layer is embedded in the second insulating layer 5 to form a lead layer. Further, the surface of the second insulating layer 5 and each energization portion of the functional layer 20 are electrically connected through the metal bonding layer, and each metal bonding layer is in the second insulating layer 5. It is electrically connected to the lead layer embedded in.

  In FIG. 1, the lead layer wired inside the second insulating layer 5 is shown by a solid line. When the piezoelectric element of the in-plane driving member provided in the second elastically deforming portions 30a, 30b, 30c, 30d, 30e, 30f, 30g, and 30h is one-phase driving, it is applied to one electrode layer of the piezoelectric element. One drive lead layer 11 to be energized is provided, and the drive lead layer 11 is connected to the drive electrode pad 11a. When the piezoelectric element is driven in two phases, the electrode layer of the piezoelectric element is energized by another driving lead layer 12 in addition to the driving lead layer 11, and the driving lead layer 12 is connected to the driving electrode pad 12a. . The other electrode layer of the piezoelectric element is electrically connected to the ground electrode pad 13 a through the ground lead layer 13.

  The detection output of the Coriolis force is a change in capacitance between the movable electrode portion 28 and the first fixed electrode portion 23, and a change in capacitance between the movable electrode portion 28 and the second fixed electrode portion 24. Detected by. An energization lead layer 14 for intermittently supplying a predetermined potential is electrically connected to the movable electrode portion 28, and this energization lead layer 14 is connected to the energization electrode pad 14a. Each of the plurality of first fixed electrode portions 23 provided in conduction is connected to the first detection lead layer 15, and the first detection lead layer 15 is connected to the first detection electrode pad 15a. Similarly, a plurality of second fixed electrode portions 24 are electrically connected to the second detection lead layer 16, and the second detection lead layer 16 is connected to the second detection electrode pad 16a.

  On both sides in the Y direction shown in FIG. 1, the closing member 4 protrudes from the support substrate 2, and the electrode pads 11 a, 12 a, 13 a are formed on the surface of the second insulating layer 5 at the protruding portion of the closing member 4. , 14a, 15a, 16a are formed and can be connected to an external circuit.

  The closing member 4 is not limited to a single Si substrate, and may be a glass substrate or the like. Alternatively, the surface of the IC package in which various circuits such as a drive circuit and a detection circuit are accommodated is used as the closing member 4, and the insulating layer on the surface of the IC package is used instead of the second insulating layer 5. The functional layer 20 and the support substrate 2 may be laminated and bonded in order. In this case, each of the lead layers 11, 12, 13, 14, 15, 16 is connected to an electrode bump or the like provided on the upper surface of the IC package and connected to an internal circuit of the IC package.

As shown in FIGS. 1 and 2, in the functional layer 20, a frame body layer 21 is formed by separating a part of the silicon wafer. In FIG. 1, a region where the frame body layer 21 is formed is shown with hatching. The rectangular frame-shaped frame body layer 21 is formed in a frame shape around the vertical axis angular velocity sensor 1. The frame layer 21 and the support substrate 2 are bonded via the first insulating layer 3 in which a part of the SiO ₂ layer of the SOI layer is left, and the frame layer 21 and the second insulating layer 5 are bonded to the metal bonding layer. The operation space 7 surrounded by the frame layer 21 is shielded from the outside air.

  In the operation space 7, the fixed support portions 22a, 22b, 22c and 22d separated from the silicon wafer of the functional layer 20, the detection rotation portion 26, the first elastic deformation portions 25a, 25b, 25c and 25d, the driving mass The portions 29a and 29b, the second elastic deformation portions 30a, 30b, 30c, 30d, 30e, 30f, 30g, and 30h, the movable electrode portion 28, the first fixed electrode portion 23, and the second fixed electrode portion 24 are formed. ing. As shown in FIG. 2, these parts are formed separately from the same silicon wafer, and therefore the thickness dimension in the Z direction is the same.

The four fixed support portions 22 a, 22 b, 22 c, and 22 d are provided at each of the four corners inside the frame body layer 21. One surface of each of the fixed support portions 22a, 22b, 22c, and 22d is joined to the support substrate 2 via the first insulating layer 3 in which a part of the SiO ₂ layer of the SOI layer is left. The other surfaces of 22a, 22b, 22c, and 22d are fixed to the second insulating layer 5 through the bonding metal layer. The joining metal layers joining the fixed support portions 22a, 22b, 22c, and 22d are electrically connected to the respective lead layers 11, 12, 13, and 14.

  The first electrode fixing portions 23a and the second electrode fixing portions 24a are alternately arranged inside the inner sides of the frame body layer 21. The first electrode fixing portion 23 a and the second electrode fixing portion 24 a are arranged in a line along the inner side of each inner side of the frame body layer 21. On the inner side of each inner side, the second electrode fixing portions 24a are alternately arranged next to the first electrode fixing portions 23a in the counterclockwise direction.

Each of the first electrode fixing portions 23a is bonded to the support substrate 2 via the first insulating layer 3 in which one surface of the SiO ₂ layer of the SOI layer is left. The other surface of each first electrode fixing portion 23a is bonded to the second insulating layer 5 via a metal bonding layer, and each metal bonding layer is electrically connected to the first detection lead layer 15. ing. Each of the second electrode fixing portions 24a is bonded to the support substrate 2 via the first insulating layer 3 in which one surface of the second electrode fixing portion 24a is left with a part of the SiO ₂ layer of the SOI layer. The other surface of each second electrode fixing portion 24a is bonded to the second insulating layer 5 via a metal bonding layer, and each metal bonding layer is electrically connected to the second detection lead layer 16. ing.

  Among the functional parts formed separately from the functional layer 20 in the operation space 7, the fixed support parts 22a, 22b, 22c, 22d, other than the first electrode fixing part 23a and the second electrode fixing part 24a. The portion is not fixed to both the support substrate 2 and the closing member 4. As shown in FIG. 2, in the operation space 7, recesses 2 a facing the respective portions of the functional layer 20 are formed on the inner surface of the support substrate 2. Similarly, a recess 4 a is formed on the inner surface of the closing member 4 at a portion facing each of the above portions.

  In the functional layer 20, a first elastic deformation portion 25a extends from the fixed support portion 22a, and similarly, the first elastic deformation portions 25b, 25c, and 25d extend from the fixed support portions 22b, 22c, and 22d, respectively. Yes. The first elastic deformation portions 25 a, 25 b, 25 c, 25 d extend radially toward the center of the operation space 7. A square frame-shaped detection rotation unit 26 is provided at the center of the operation space 7. The first elastic deformation portion 25a is connected to the upper right corner of the detection rotation portion 26 via a link fulcrum portion 27a. Similarly, the first elastic deformation portions 25b, 25c, and 25d are connected to corner portions of the detection rotation portion 26 through link fulcrum portions 27b, 27c, and 27d, respectively.

  When the first elastic deformation portions 25a, 25b, 25c, and 25d are bent and deformed, and the link fulcrum portions 27a, 27b, 27c, and 27d are deformed, the detection rotation portion 26 is parallel to the surface of the support substrate 2. It is possible to rotate clockwise and counterclockwise in the plane.

  A plurality of movable electrode portions 28 extending outward are integrally formed on the four outer sides of the detection rotating portion 26. Each of the movable electrode portions 28 is formed in a radial pattern so that the interval increases as the distance from the center of the detection rotation portion 26 (centroid in the plan view of FIG. 11) increases.

  The plurality of first electrode fixing portions 23a are integrally formed with a first fixed electrode portion 23 extending radially toward the center of the detection rotating portion 26, and the plurality of second electrode fixing portions 23a. The second fixed electrode portion 24 that extends radially toward the center of the detection rotating portion 26 is integrally formed with the 24 a. Each movable electrode portion 28 is sandwiched between the first fixed electrode portion 23 and the second fixed electrode portion 24. All the first fixed electrode portions 23 are opposed to the movable electrode portion 28 in the clockwise direction, and all the second fixed electrode portions 24 are opposed to the movable electrode portion 28 in the counterclockwise direction. ing.

  When the detection rotation unit 26 rotates in the clockwise direction, the interval between the movable electrode unit 28 and the first fixed electrode unit 23 becomes narrower, and the movable electrode unit 28 and the first fixed electrode unit 23 are separated from each other. The capacitance between them increases. Conversely, the gap between the movable electrode portion 28 and the second fixed electrode portion 24 is widened, and the capacitance is reduced. When the detection rotation unit 26 rotates counterclockwise, the capacitance between the movable electrode unit 28 and the first fixed electrode unit 23 decreases, and the movable electrode unit 28 and the second fixed electrode unit 24 The capacitance between the two increases. By obtaining the difference between the detection output due to the change in capacitance obtained from the first fixed electrode portion 23 and the detection output due to the change in capacitance obtained from the second fixed electrode portion 24, the detection rotation portion It is possible to detect the amount of rotation of 26 in the clockwise direction and the counterclockwise direction.

  Further, when the detection rotation unit 26 linearly moves in the X direction and the Y direction which are directions other than the rotation direction, or moves in the Z direction which is a direction perpendicular to the surface of the support substrate 2, 1 The change in the facing area between the two movable electrode portions 28 and the first fixed electrode portion 23 is the same as the change in the facing area between the movable electrode portion 28 and the second fixed electrode portion 24, so that the first fixed By obtaining the difference between the detection output from the electrode unit 23 and the detection output from the second fixed electrode unit 24, the detection output is canceled out. Therefore, disturbance noise due to an operation other than the rotation direction that is the original detection direction of the detection rotation unit 26 is not superimposed on the detection output.

  The detection rotation unit 26 includes a right support 26a extending in the Y direction on the right side in the figure, a left support part 26b extending in the Y direction on the left side in the figure, and an intermediate support extending in the Y direction between the left and right support parts 26a and 26b. Part 26c.

  A first drive mass unit 29a is provided between the right support part 26a and the intermediate support part 26c, and a second drive mass part 29b is provided between the left support part 26b and the intermediate support part 26c. Yes.

  As shown also in FIG. 7, the right side portion of the first drive mass portion 29a is supported by the right side support portion 26a via two second elastic deformation portions 30a and 30b provided at intervals in the Y direction. In addition, the left side portion is supported by the intermediate support portion 26c via two second elastically deformable portions 30c and 30d provided at an interval in the Y direction. The right side portion of the second drive mass portion 29b is supported by the intermediate support portion 26c via two second elastic deformation portions 30e and 30f provided at intervals in the Y direction, and the left side portion is Y It is supported by the left support part 26b via two second elastically deforming parts 30g, 30h provided with a gap in the direction.

  The first drive mass unit 29a supported by the second elastic deformation portions 30a, 30b, 30c, and 30d at a total of four locations on the left and right sides is parallel to the surface of the support substrate 2 inside the detection rotation unit 26. Reciprocating in the direction. Similarly, the second drive mass unit 29b supported by the second elastically deforming portions 30e, 30f, 30g, and 30h at a total of four locations on the left and right sides is also connected to the surface of the support substrate 2 inside the detection rotating unit 26. Reciprocating in the parallel X direction is possible.

  FIG. 3 is a partially enlarged view showing a state in which the first driving mass portion 29a is supported by the four second elastic deformation portions 30a, 30b, 30c, and 30d.

  As shown in FIG. 3A, the first drive mass unit 29a has a rectangular shape whose long side is oriented in the Y direction. A long hole 36a that penetrates in the Z direction and is long in the Y direction is formed in the right side portion of the first drive mass portion 29a, and a connecting elastic deformation portion 35a is integrally formed on the right side of the long hole 36a. Yes. The connecting elastic deformation portion 35a has both Y-side end portions 35c and 35d integrated with the first drive mass portion 29a, and can be bent and deformed in the X direction with the both end portions 35c and 35d as fulcrums. A connecting elastic deformation portion 35b is integrally formed on the left side portion of the first drive mass portion 29a through a long hole 36b. The connected elastic deformation portion 35b is integrally connected to the first drive mass portion 29a via both end portions 35e and 35f in the Y direction, and can be bent and deformed in the X direction using the both end portions 35e and 35f as fulcrums. .

  The second elastic deformation portions 30a and 30b connect the right support portion 26a of the detection rotation portion 26 and the connection elastic deformation portion 35a. The 2nd elastic deformation part 30a and the 2nd elastic deformation part 30b are line symmetrical shapes on both sides of the line extended in a X direction. The second elastic deformation portions 30c and 30d connect the intermediate support portion 26c of the detection rotation portion 26 and the connection elastic deformation portion 35a. The second elastic deformation portion 30c and the second elastic deformation portion 30d have a line-symmetric shape across a line extending in the X direction. Further, the second elastic deformation portion 30a and the second elastic deformation portion 30c are line symmetrical with respect to a line extending in the Y direction, and the second elastic deformation portion 30b and the second elastic deformation portion 30d are also Y It has a line-symmetric shape across a line extending in the direction.

  FIG. 4A shows the second elastic deformation portion 30a in an enlarged manner. The base end connecting portion 31 of the second elastic deformation portion 30a is integrally connected to the right support portion 26a of the detection rotating portion 26, and the base end connecting portion 31 has a hole 31a for reducing the mass Z. It is formed to penetrate in the direction. The distal end coupling portion 32 of the second elastic deformation portion 30a is integrally coupled to the coupling elastic deformation portion 35a, and a hole 32a for reducing mass is formed in the distal end coupling portion 32 so as to penetrate in the Z direction. Yes.

  A first beam 33 and a second beam 34 are provided between the proximal end coupling portion 31 and the distal end coupling portion 32. An end portion 33 a on the Y1 side of the first beam 33 is integrally connected to the proximal end connection portion 31, and an end portion 33 b on the Y2 side is integrally connected to the distal end connection portion 32. Similarly, the end portion 34a on the Y1 side of the second beam 34 is integrally connected to the base end connecting portion 31, and the end portion 34b on the Y2 side is integrally connected to the distal end connecting portion 32.

  The first beam 33 and the second beam 34 are formed in parallel with each other with a space portion 38 penetrating in the Z direction. A connecting beam 37 that connects the first beam 33 and the second beam 34 is integrally formed at a central portion that bisects the space 38 in the Y direction. The first beam 33 has a uniform width dimension and cross-sectional area from the end portion 33a to the end portion 33b, and the second beam 34 also has a uniform width size and cross-sectional area from the end portion 34a to the end portion 34b.

  The first beam 33 and the second beam 34 may have the same width dimension and cross-sectional area, or may be different. As shown in FIG. 4A, since the in-plane driving member 41 is attached to the first beam 33 and a deformation force is applied to the first beam 33, the width dimension and cross-sectional area of the first beam 33 are increased. Is preferably larger than the second beam 34.

  The in-plane driving member 41 is a piezoelectric element, and is provided on both the upper surface and the lower surface of the first beam 33 facing the Z direction. The first beam 33 is separated from the silicon wafer and is conductive. Therefore, an insulating layer is formed on the upper surface and the lower surface of the first beam 33, and the lower electrode layer, the piezoelectric element layer, and the upper electrode layer are sequentially stacked on the insulating layer to form the in-plane driving member 41. ing.

  When an AC voltage is applied between the upper electrode layer and the lower electrode layer, the in-plane driving members 41 provided on the upper and lower surfaces of the first beam 33 extend and contract together, and as a result, FIG. As shown in B), the first beam 33 generates bending deformation vibration so that the proximal end coupling portion 31 serves as a support end and the distal end coupling portion 32 moves in the X1-X2 direction.

  The other second elastic deformation portions 30b, 30c, and 30d supporting the first drive mass portion 29a have different directions or are symmetric with respect to the second elastic deformation portion 30a shown in FIG. Although it is a shape, its structure is substantially the same. That is, the second elastic deformation portions 30b, 30c, and 30d are also provided with the first beam 33 on the side away from the first drive mass portion 29a, and on the side closer to the first drive mass portion 29a. A beam 34 is provided. In-plane drive members 41 are provided on the upper and lower surfaces of the first beam 33.

  The in-plane driving member 41 may be provided only on one of the upper surface and the lower surface of the first beam 33. The same applies to other embodiments described below.

  As shown in FIG. 7A, a connecting elastic deformation part 35g is formed on the right side of the left second driving mass part 29b, and a connecting elastic deformation part 35h is formed on the left side. The structure of the connection elastic deformation portions 35g and 35h is the same as that of the connection elastic deformation portions 35a and 35b provided in the first drive mass portion 29a. The second elastic deformation portions 30e and 30f connect the intermediate support portion 26c and the connection elastic deformation portion 35g, and the second elastic deformation portions 30g and 30h include the left support portion 26b and the connection elastic deformation portion 35h. Are connected.

  The second elastic deformation portions 30e, 30f, 30g, and 30h that support the second drive mass portion 29b at four locations are the second elastic deformation portions 30a, 30b, 30c, and 30d shown in FIG. Are substantially the same in structure, and each has a first beam 33 on the side away from the second driving mass unit 29b and a second beam 34 on the side approaching the second driving mass unit 29b. And in-plane drive members 41 are provided on both upper and lower surfaces of the first beam 33.

  A lead pattern is formed on the lower surface of each of the frame-shaped detection rotation portion 26, the first elastic deformation portion 25a, and the fixed support portion 22a via an insulating layer. One electrode layer of the in-plane driving means 41 provided on the first beam 33 of the second elastically deforming portions 30a to 30h provided at a total of eight locations is connected to the lead pattern. Further, the lead pattern is bonded to the drive electrode pad 11 a via the drive lead layer 11.

  Still another lead pattern is formed on the lower surface of each of the frame-shaped detection rotation portion 26, the first elastic deformation portion 25a, and the fixed support portion 22a via an insulating layer. The other electrode layer of the in-plane driving means 41 provided in a total of eight locations is connected to the lead pattern. Further, the lead pattern is electrically connected to the ground electrode pad 13 a through the ground lead layer 13.

  When the in-plane driving member 41 provided in the second elastically deforming portions 30a, 30b, 30g, and 30h extends and deforms in the Y direction, the in-plane driving member provided in the elastically deforming portions 30c, 30d, 30e, and 30f. When the in-plane driving member 41 provided in the second elastically deforming portions 30a, 30b, 30g, and 30h contracts and deforms in the Y direction, the elastically deforming portions 30c and 30d are changed. , 30e and 30f, the polarization direction of each in-plane drive member 41 is set so that the in-plane drive member 41 extends in the Y direction and deforms, or the drive lead layer 11 and the ground lead of the upper and lower electrode layers The connection state to the layer 13 is selected. Therefore, when the right first driving mass unit 29a is driven in the X1 direction, the second driving mass unit 29b is driven in the X2 direction, and the right first driving mass unit 29a is driven in the X2 direction. Sometimes the first drive mass unit 29a and the second drive mass unit 29b are driven to vibrate in opposite directions in the X direction so that the second drive mass unit 29b is driven in the X1 direction. .

  5 and 6 show another example of the in-plane driving member attached to the first beam 33. FIG.

  In the embodiment shown in FIG. 5A, the in-plane drive members 41 are provided on the upper and lower surfaces of the first beam 33 of the first elastic deformation portion, and the in-plane drive members 42 are provided on the upper and lower surfaces of the second beam 34. Is provided. Each of these in-plane driving members 41 and 42 forms an insulating layer on the upper and lower surfaces of the first beam 33 and the second beam 34, and a lower electrode layer, a piezoelectric element layer, and an upper electrode layer are sequentially stacked on the surface. And are laminated.

  When the in-plane drive member 41 provided on the first beam 33 extends in the Y direction, the in-plane drive members 41 and 42 are arranged such that the in-plane drive member 42 provided on the second beam 34 contracts in the Y direction. The polarization direction of the piezoelectric element layer that constitutes and the connection state of the upper and lower electrode layers to the drive lead layer 11 and the ground lead layer 13 are selected. As a result, as shown in FIG. 5 (B), the base end coupling portion 31 is used as a support end, and bending deformation is vibrated so that the front end coupling portion 32 touches in the X1-X2 direction.

  In the embodiment shown in FIG. 6A, the upper and lower surfaces of the first beam 33 on the Y2 side of the connecting beam 37 and the upper and lower surfaces of the second beam 34 on the Y1 side of the connecting beam 37 are the same surface. The inner drive member 43 is provided, and the same in-plane drive is provided on the upper and lower surfaces of the second beam 34 on the Y1 side of the connecting beam 37 and on the upper and lower surfaces of the second beam 34 on the Y2 side of the connecting beam 37. A member 44 is provided. Each of the in-plane driving members 43 and 44 has an insulating layer formed on the upper and lower surfaces of the first beam 33 and the second beam 34, and a lower electrode layer, a piezoelectric element layer, and an upper electrode layer are sequentially stacked on the surface. It is formed by stacking.

  When the two in-plane drive members 43, 43 extend in the Y direction, the two in-plane drive members 44, 44 contract in the Y direction, and when the in-plane drive members 43, 43 contract in the Y direction, two surfaces The polarization direction of the piezoelectric element layers constituting the in-plane driving members 43 and 44 and the connection state of the upper and lower electrode layers to the driving lead layer 11 and the ground lead layer 13 are set so that the inner driving members 44 and 44 extend in the Y direction. Is selected. As a result, as shown in FIG. 6B, both the first beam 33 and the second beam 34 are used so that the distal end coupling portion 32 touches in the X1-X2 direction with the proximal end coupling portion 31 as a support end. Bends and vibrates in an S-shape. At this time, since the tip connecting portion 32 vibrates in the X1-X2 direction without much rotation in the XY plane, the second elastic deformation portions 30a to 30h and the connection elastic deformation portions 35a, 35b, 35g , 35h, torsional stress is less likely to act.

  As shown in FIG. 5 or FIG. 6, when two types of in-plane driving members are provided in one second elastically deformable portion and the two types of in-plane driving members need to be driven separately, the respective surfaces One electrode layer of the inner drive member is connected to the ground lead layer 13, while the other electrode layer is separately connected to the drive lead layer 11 and the drive lead layer 12.

  As shown in FIGS. 4 to 6, the second elastically deformable portions 30 a to 30 h are so-called two beams 33 and 34 provided in parallel with each other between the proximal end connecting portion 31 and the distal end connecting portion 32. Since it has a ramen structure, when the two beams 33 and 34 are bent in the X1 direction and the X2 direction in the XY plane, the two beams 33 and 34 are easy to move in parallel with the XY plane. Difficult to deform in a twisted direction with respect to a plane. Further, since the distal end coupling portion 32 moves in the X1-X2 direction while the proximal end coupling portion 31 and the distal end coupling portion 32 maintain the parallel state before the deformation shown in FIG. Twist in the XY plane is unlikely to occur at the connecting portion with the connecting elastic deformation portion 35a. Even if a slight twist occurs in the connecting portion, the twist is absorbed by the bending deformation of the connecting elastic deformation portion 35a.

  Further, as shown in FIGS. 4 to 6, the second elastic deformation portions 30 a to 30 h are connected to each other at the midpoint between the first beam 33 and the second beam 34 by the connecting beam 37. The second beam 34 and the second beam 34 can be deformed while maintaining an interval in the X direction. Therefore, the driving force generated by the in-plane driving members 41 to 44 is transmitted to the first driving mass unit 29a and the second driving mass unit 29b with little loss.

  The first driving mass unit 29 a and the second driving mass unit 29 b are formed separately from the silicon wafer that is the functional layer 20. Therefore, as shown in FIG. 3B, a weight layer 39 having a specific gravity larger than that of silicon is formed on the first drive mass unit 29a and the second drive mass unit 29b. The weight layer 39 is formed of any one of Mo, Hf, Ta, W, Ru, Rh, Pd, Ag, Re, Os, Ir, Pt, Au, or an alloy thereof.

Next, the operation of the vertical axis angular velocity sensor 1 will be described.
When the ground electrode pad 13a shown in FIG. 1 is set to the ground potential, an alternating drive voltage is applied to the drive electrode pad 11a, or an alternating drive voltage is applied to the drive electrode pad 11a and the drive electrode pad 12a, each second elasticity The in-plane driving member 41 (see FIG. 4), the in-plane driving members 41 and 42 (see FIG. 5) or the in-plane driving members 43 and 44 (see FIG. 6) provided in the deformable portions 30a to 30h are driven. . With this driving force, the first driving mass unit 29a and the second driving mass unit 29b are driven in the X1-X2 direction in the XY plane parallel to the surface of the support substrate 2. As shown by arrows (i) and (ii) in FIG. 7B, when the first driving mass unit 29a is driven in the X1 direction, the second driving mass unit 29b is driven in the X2 direction, and the first driving mass unit 29a is driven in the X2 direction. When the driving mass unit 29a is driven in the X2 direction, the second driving mass unit 29b is driven in the X1 direction. Thus, the first drive mass unit 29a and the second drive mass unit 29b are driven to vibrate so that the phases are reversed.

  When the driven vertical axis angular velocity sensor 1 moves with an angular velocity and the vector of the angular velocity is located in the XY plane, that is, the vertical axis angular velocity sensor 1 is perpendicular to the XY plane. When moving at an angular velocity around the Oz axis, the first drive mass unit 29a and the second drive mass unit 29b are oriented in the direction perpendicular to the velocity vector at the time of driving (Y1-Y2 direction). The power of Coriolis acts. Since the first driving mass unit 29a and the second driving mass unit 29b move with velocity vectors opposite to each other, they are Y1- with respect to the first driving mass unit 29a and the second driving mass unit 29b. Coriolis forces opposite to each other in the Y2 direction act.

  The Coriolis force acting on the first drive mass unit 29a and the second drive mass unit 29b acts on the detection rotation unit 26 via the second elastic deformation units 30a to 30h. The Coriolis force acting on the first drive mass unit 29a and the Coriolis force acting on the second drive mass unit 29b are opposite to each other in the Y direction. Therefore, a couple of forces acts on the detection rotation unit 26, and the detection rotation unit 26 generates a rotation vibration about the vertical axis Oz as shown by (iii) and (iv) in FIG. 7B. Due to this rotational vibration, the opposing distance and electrostatic capacity of each movable electrode portion 28 and the first fixed electrode portion 23 change, and the opposing distance and static electricity between the movable electrode portion 28 and the second fixed electrode portion 24 change. The capacitance changes.

  A pulse voltage is applied to the energizing electrode pad 14a shown in FIG. 1, and this voltage is applied from the energizing seed layer 14 to the silicon fixed support portion 22c. The pulse voltage is applied to the silicon detection rotation unit 26 through the first elastic deformation unit 25 c and further to the movable electrode unit 28. The current value of the current that flows in the first fixed electrode portion 23 in a short time at the rising edge of the voltage pulse fluctuates in accordance with the change in the capacitance between the movable electrode portion 28 and the first fixed electrode portion 23. This also applies to the current flowing through the second fixed electrode portion 24. By obtaining the difference between the detection output of the first fixed electrode portion 23 and the detection output of the second fixed electrode portion 24, the amplitude at the time of rotation of the detection rotation portion 26 can be detected, thereby converting the angular velocity. It becomes possible.

  The second elastic deformation portions 30a to 30h have a so-called ramen structure shown in FIGS. 4 to 6 and have high Y-direction rigidity. Therefore, when Coriolis force in the Y1-Y2 direction is applied to the first driving mass unit 29a and the second driving mass unit 29b, the second elastic deformation units 30a to 30h are detected without buckling. The rotation unit 26 is given. Therefore, the first drive mass unit 29a, the second drive mass unit 29b, and the detection rotation unit 26 can be integrally rotated in the (iii) and (iv) directions.

  8 to 11 show the horizontal axis angular velocity sensor 1A. 8 and 9 are partial plan views showing a third elastic deformation part supporting the driving mass unit, FIG. 10 is an explanatory view showing the operation of the driving mass unit, and FIGS. 11A and 11B are horizontal views. It is operation | movement explanatory drawing of an axial angular velocity sensor.

  In the horizontal axis angular velocity sensor 1A, the shape and structure of the third elastic deformation portion and the surface vertical driving member supporting the first driving mass portion 29a and the second driving mass portion 29b are the same as those of the vertical axis angular velocity sensor 1. Only the second elastic deformation portions 30a to 30h and the in-plane driving members 41 to 44 are different from each other, and other configurations are substantially the same as those of the vertical axis angular velocity sensor 1.

  FIG. 8 shows a third elastic deformation portion 50 a that supports the right side portion of the first drive mass portion 29 a on the right support portion 26 a of the detection rotation portion 26. The third elastic deformation part 50a is cut out from the silicon wafer together with the first drive mass part 29a and the detection rotation part 26, and the thickness dimension of the third elastic deformation part 50a in the Z direction is as follows. The first driving mass unit 29a and the detection rotating unit 26 are the same.

  The third elastic deformation portion 50a includes a first outer link portion 52a in which a fixed end 51a on the Y1 side is integrally fixed to the right support portion 26a of the detection rotating portion 26, and a fixed end 51b on the Y2 side supported on the right side. It has the 2nd outer side link part 52b fixed to the part 26a integrally. A first inner link portion 53a is provided inside the first outer link portion 52a, and an end portion on the Y1 side of the first inner link portion 53a is connected to the first inner link portion 53a via the torsional deformation portion 54a. Is integrally connected to the right side portion of the drive mass portion 29a. A second inner link portion 53b is provided on the inner side of the second outer link portion 52b, and an end portion on the Y2 side of the second inner link portion 53b is connected to the first inner via a torsional deformation portion 54b. Is connected to the right side of the drive mass portion 29a.

  A connecting portion 55 is provided at the center of the third elastic deformation portion 50a. The connecting portion 55 itself is not deformed. The end portion on the Y2 side of the first outer link portion 52a is connected to the connecting portion 55 via a twist deformation portion 56a, and the end portion on the Y1 side of the second outer link portion 52b is twisted. It connects with the connection part 55 via the deformation | transformation part 56b. The Y2 side end of the first inner link portion 53a is connected to the connecting portion 55 via a torsional deformation portion 57a, and the Y1 side end portion of the second inner link portion 53b is torsionally deformed. It is connected to the connecting part 55 via the part 57a.

  Surface vertical drive members 61 and 61 are provided on the upper surface of the first outer link portion 52a facing the Z1 direction and the upper surface of the second outer link portion 52b. The surface vertical drive members 61, 61 form insulating layers on the surfaces of the first outer link portion 52a and the second outer link portion 52b formed of a silicon wafer, and a lower electrode layer, a piezoelectric element layer, and The upper electrode layer is laminated. For example, the lower electrode layer is connected to the ground lead layer 13 equivalent to that shown in FIG. 1, the upper electrode layer is connected to the drive lead layer 11 equivalent to that shown in FIG. At the same time, an alternating drive voltage is applied.

  As shown in FIG. 11A, the first driving mass unit 29a is supported by the right support portion 26a of the detection rotating portion 26 at the side portion on the X1 side via the third elastic deformation portion 50a. The left side portion is supported by the intermediate support portion 26c of the detection rotation portion 26 via the third elastic deformation portion 50b symmetrical to the third elastic deformation portion 50a. The right side of the second drive mass unit 29b is fixed to the intermediate support 26c via the third elastic deformation unit 50c having the same shape as the third elastic deformation unit 50a, and the left side of the second drive mass unit 29b. The part is supported by the left support part 26b via a third elastic deformation part 50d having the same structure as the third elastic deformation part 50b.

  The two surface vertical drive members 61, 61 provided in one elastically deforming portion extend and deform in the Y direction at the same time, contract and deform at the same time, and this is repeated. FIG. 10A shows the surface vertical drive members 61 and 61 of the third elastic deformation portion 50a and the surface vertical drive members 61 and 61 of the third elastic deformation portion 50b supporting the first drive mass portion 29a. This shows the moment when is extended in the Y direction. Since both the first outer link portion 52a and the second outer link portion 52b are curved and deformed so that the Z1 side is convex, the torsional deformable portions 56a and 56b are twisted and the connecting portion 55 moves in the Z2 direction. Further, the torsional deforming parts 54a and 54b and the torsional deforming parts 57a and 57b are torsionally deformed, and the first driving mass part 29a moves in the Z2 direction. Further, when the surface vertical drive members 61, 61 contract and deform, the first drive mass unit 29a moves in the Z1 direction.

  Here, the surface vertical drive members 61 and 61 of the third elastic deformation portions 50a and 50b supporting the first drive mass portion 29a and the third elasticity supporting the second drive mass portion 29b. The plane vertical drive members 61 and 61 of the deformable portions 50c and 50d are supplied with drive voltages from different energization paths. When the first drive mass unit 29a moves in the Z1 direction, the second drive mass unit 29b moves in the Z2 direction, and when the first drive mass unit 29a moves in the Z2 direction, the second drive mass unit The first driving mass unit 29a and the second driving mass unit 29b are driven to vibrate so as to have opposite phases in the Z direction so that 29b moves in the Z1 direction.

  FIG. 9 is an enlarged plan view showing another embodiment of the surface vertical drive member attached to the third elastic deformation portion 50a.

  In the example shown in FIG. 9, a first surface vertical drive member 62 is provided on the Y1 side of the first outer link portion 52a, and a second surface vertical drive member 63 is provided on the Y2 side. In the second outer link portion 52b, a first surface vertical drive member 62 is provided on the Y2 side, and a second surface vertical drive member 63 is provided on the Y1 side. The first surface vertical driving member 62 and the second surface vertical driving member 63 are driven at different phases, and when the first surface vertical driving member 62 extends, the second surface vertical driving member 63 contracts and deforms.

  As a result, as shown in FIG. 10B, the first outer link portion 52a and the second outer link portion 52b are deformed in an S shape, and as a result, the torsion deformed portion connected to the connecting portion 55. It is possible to prevent an excessively large torsional deformation force from acting on 56a, 56b and the like.

  In FIG. 11B, as shown by arrows (v) and (vi), the first drive mass unit 29a and the second drive mass unit 29b are driven to vibrate in opposite phases in the Z direction. Sometimes the angular velocity is applied to the horizontal axis angular velocity sensor 1A. When the vector of the angular velocity is directed in a plane perpendicular to the axis Ox extending in the X direction, which is the direction in which the first driving mass unit 29a and the second driving mass unit 29b are arranged, that is, the horizontal axis angular velocity sensor 1A. When an angular velocity around the axis Oz acts on the surface, a Coriolis force in the Y1-Y2 direction, which is a direction orthogonal to the driving directions of the first driving mass unit 29a and the second driving mass unit 29b, acts in the plane.

  Since the first driving mass unit 29a and the second driving mass unit 29b vibrate in opposite phases to each other in the Z direction, Coriolis acting on the first driving mass unit 29a and the second driving mass unit 29b. The directions of the forces are opposite to each other in the Y direction. Since the Coriolis force acts as a couple on the detection rotation unit 26, the detection rotation unit 26 reciprocates as shown by arrows (vii) and (Viii) in FIG. At this time, a change in electrostatic capacitance between the movable electrode portion 28 and the first fixed electrode portion 23 and a change in electrostatic capacitance between the movable electrode portion 28 and the second fixed electrode portion 24 are detected. Thus, the angular velocity around the axis Ox can be detected.

  The vertical axis angular velocity sensor 1 and the horizontal axis angular velocity sensor 1A include second elastic deformation portions 30a to 30h for supporting the first driving mass unit 29a and the second driving mass unit 29b on the detection rotation unit 26. The third elastic deformation portions 50a to 50d are different in shape and structure, and the other portions are almost the same in shape and size. Therefore, the vertical axis angular velocity sensor 1 and the horizontal axis angular velocity sensor 1A are formed by substantially the same etching process only by changing the shapes of the second elastic deformation portions 30a to 30h and the third elastic deformation portions 50a to 50d. Can do.

  In addition, the vertical axis angular velocity sensor 1 and the horizontal axis angular velocity sensor 1A have the same thickness and a planar configuration, but can detect an angular velocity at which a vector faces in a plane orthogonal to each other.

  FIG. 12 shows an angular velocity sensor 100 in which one vertical axis angular velocity sensor 1 and two horizontal axis angular velocity sensors 1A are two-dimensionally configured in a common substrate.

  In this angular velocity sensor 100, a common function layer 120 having a rectangular shape is sandwiched between a common support substrate 102 having a rectangular shape and a common closing member 104 (not shown) having a rectangular shape. The common support substrate 102 and the common functional layer 120 are formed of two silicon wafers of SOI layers.

  The silicon wafer of the common functional layer 120 is separated by etching to form one vertical axis angular velocity sensor 1 and two horizontal axis angular velocity sensors 1A. However, in one of the two horizontal axis angular velocity sensors 1A, the arrangement direction of the first drive mass unit 29a and the second drive mass unit 29b is the Y direction, and the other is the X direction. The common functional layer 120 is integrally formed with a partition layer 121 for distinguishing one vertical axis angular velocity sensor 1 and two horizontal axis angular velocity sensors 1A.

  The angular velocity sensor 100 shown in FIG. 12 is formed by separating one vertical axis angular velocity sensor 1 and two horizontal axis angular velocity sensors 1A from the same rectangular silicon wafer. The angular velocity components in all directions in the three-dimensional space acting on the angular velocity sensor 100 can be detected.

  In addition, the vertical axis angular velocity sensor 1 and the horizontal axis angular velocity sensor 1A are the same except for the structures of the second elastic deformation portions 30a to 30h and the third elastic deformation portions 50a to 50d. Since the dimensions are the same, each part shown in FIG. 12 can be easily formed by etching from a silicon wafer.

The top view which shows the whole structure of the vertical-axis angular velocity sensor of embodiment of this invention, Sectional drawing which cut | disconnected the vertical-axis angular velocity sensor shown in FIG. 1 by the II-II line | wire, (A) is a plan view showing an enlarged support structure of the drive mass unit in the detection rotation unit, (B) is a cross-sectional view taken along line BB of (A), (A) is a plan view showing the second elastic deformation portion and the in-plane driving means in an enlarged manner, (B) is an explanatory view showing the deformation operation of the second elastic deformation portion, (A) is an enlarged plan view showing a second elastic deformation part and in-plane driving means of another embodiment, (B) is an explanatory view showing the deformation operation of the second elastic deformation part, (A) is an enlarged plan view showing a second elastic deformation portion and in-plane driving means of still another embodiment, (B) is an explanatory view showing the deformation operation of the second elastic deformation portion, (A) is a plan view showing a drive mass unit, a detection rotation unit, and a movable electrode unit, (B) is an operation explanatory diagram, The top view which shows the structure of the 3rd elastic deformation part and surface vertical drive member of the horizontal-axis angular velocity sensor of embodiment of this invention, The top view which shows other embodiment of the 3rd elastic deformation part of a horizontal-axis angular velocity sensor, and a surface vertical drive member, (A) (B) is explanatory drawing which shows operation | movement of the 3rd elastic deformation part and drive mass part in a horizontal-axis angular velocity sensor, (A) is a plan view showing a driving mass part, a detection rotating part and a movable electrode part of a horizontal axis angular velocity sensor, (B) is an operation explanatory diagram, A plan view of an angular velocity sensor in which one vertical axis angular velocity sensor and two horizontal axis angular velocity sensors are formed as a common support substrate and a common functional layer;

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vertical axis | shaft angular velocity sensor 1A Horizontal axis | shaft angular velocity sensor 2 Support substrate 3 1st insulating layer 4 Closing member 5 2nd insulating layer 7 Operation | movement space 11, 12, 13, 14, 15, 16 Lead layer 11a, 12a, 13a, 14a, 15a, 16a Electrode pad 20 Functional layers 22a, 22b, 22c, 22d Fixed support portion 23 First fixed electrode portion 24 Second fixed electrode portions 25a, 25b, 25c, 25d First elastic deformation portion 26 Detection times Moving part 28 Movable electrode part 29a 1st drive mass part 29b 2nd drive mass part 30a, 30b, 30c, 30d, 30e, 30f, 30g, 30h 2nd elastic deformation part 31 Base end connection part 32 Tip connection part 33 First beam 34 Second beam 41, 42, 43, 44 In-plane drive member 50 Third elastic deformation portion 52a First outer link portion 52b Second outer link portion 53a First Inner link portion 53b Second inner link portions 61, 62, 63 Surface vertical drive member

Claims (9)

A support substrate, a plurality of fixed support portions provided on the support substrate, and a detection circuit which is supported by the fixed support portion via a first elastic deformation portion and is rotatable in a plane parallel to the support substrate. A moving portion, a pair of drive mass portions supported by the detection rotation portion via the second elastic deformation portion and movable in the plane, and a pair of the drive mass portions in opposite directions in the plane An in-plane driving member that is driven on, a movable electrode unit provided integrally with the detection rotation unit, and a fixed electrode unit fixed on the support substrate and facing the movable electrode unit,
A pair of the drive mass units are driven in opposite directions within the plane, and the rotation of the detection rotation unit is detected by a change in the facing state of the movable electrode and the fixed electrode. An angular velocity sensor, wherein an angular velocity acting on the driving mass unit with a vector facing is detected.   The in-plane driving member is a piezoelectric element attached to the second elastic deformation portion, and the second elastic deformation portion is bent and deformed in the plane by the electrostrictive effect of the piezoelectric element, The angular velocity sensor according to claim 1, wherein the pair of driving mass units are driven in directions opposite to each other.   A plurality of the movable electrode portions are provided such that the distance between the movable electrode portions increases as the distance from the detection rotation portion increases, and the first fixed electrode portions face each other from one side facing the rotation direction. And a second fixed electrode portion facing from the other, a detection output based on a change in capacitance between the movable electrode portion and the first fixed electrode portion, the movable electrode portion and the first The angular velocity sensor according to claim 1, wherein a difference from a detection output based on a change in capacitance with the two fixed electrode portions is obtained. An SOI layer in which two Si layers are joined via an insulating layer is used, one Si layer is used as the support substrate, and the other Si layer is used as a functional layer, from the functional layer, the fixed layer The support part, the detection rotation part and the driving mass part, the first elastic deformation part and the second elastic deformation part, the movable electrode part and the fixed electrode part are formed separately,
The insulating layer is left at a joint portion between the fixed support portion and the support substrate, and a joint portion between the part of the fixed electrode portion and the support substrate, and the detection rotation portion, the driving mass portion, the first 4. The angular velocity sensor according to claim 1, wherein the insulating layer is removed between each of the first elastic deformation portion, the second elastic deformation portion, the movable electrode portion, and the support substrate. .   The closure member which covers the said functional layer is provided, The said closure member, the said fixed support part, the said closure member, and a part of said fixed electrode part are joined via the 2nd insulating layer. Angular velocity sensor.   The angular velocity sensor according to claim 4 or 5, wherein a weight layer made of a metal material having a specific gravity larger than that of the Si layer is laminated on the driving mass unit. The angular velocity sensor according to any one of claims 1 to 6 is used as a vertical axis angular velocity sensor,
7. The angular velocity sensor according to claim 1, wherein a third elastic deformation is supported in place of the second elastic deformation portion, wherein the pair of driving mass portions are movably supported in a direction perpendicular to the surface. In addition to the in-plane drive member, a surface vertical drive member for driving the pair of drive mass units in directions opposite to each other in a direction perpendicular to the surface is provided, and the pair of drive mass units In the vertical axis perpendicular to the horizontal axis extending in the direction of the alignment, the vector is oriented and the angular velocity acting on the drive mass unit is detected is used as the horizontal axis angular velocity sensor,
The support substrate of the vertical axis angular velocity sensor and the support substrate of the horizontal axis angular velocity sensor are a single common support substrate, and the vertical axis angular velocity sensor and the horizontal axis angular velocity are provided on the common support substrate. An angular velocity sensor, wherein the sensor is arranged side by side.   The angular velocity sensor according to claim 7, wherein two sets of the horizontal axis angular velocity sensors are provided on the common support substrate, and the horizontal axis angular velocity sensors are different from each other in a direction of the horizontal axis by 90 degrees.   The vertical axis angular velocity sensor and the horizontal axis angular velocity sensor include the fixed support portion, the detection rotation portion, the first elastic deformation portion, the pair of driving mass portions, the movable electrode portion, and the fixed electrode portion. The angular velocity sensor according to claim 7 or 8, wherein each has the same shape and dimensions.

Images