JP2017156353A - Physical quantity sensor, electronic device, and mobile unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a physical quantity sensor capable of preventing a movable body from sticking to a circuit board.SOLUTION: A physical quantity sensor according to the present invention includes: a circuit board 10; a movable unit 20 provided with movable electrode parts 21 and 22; support parts 30 and 32 for supporting the movable body 20 around a first axis Q so as to be displaceable; a first fixed electrode part 50 which, when the movable body 20 is divided at the first axis Q between a first portion 20a and a second portion 20b, is disposed on the circuit board 10 facing the first portion 20a; and a second fixed electrode part 52 disposed on the circuit board 10 facing the second portion 20b. On the circuit board 10 is provided a guard part 60 for suppressing electrostatic force occurring between the movable body 20 and the circuit board 10 in an inter-electrode area 14a between the first fixed electrode part 50 and the second fixed electrode part 52.SELECTED DRAWING: Figure 1

Description

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

In recent years, for example, silicon MEMS (Micro Electro Mechanical)
A physical quantity sensor that detects a physical quantity such as an acceleration using a (Systems) technology has been developed.

  The physical quantity sensor includes, for example, a substrate, a fixed electrode portion fixed to the substrate, and a movable body including a movable electrode portion arranged to face the fixed electrode portion. The fixed electrode portion and the movable electrode portion The physical quantity such as acceleration is detected based on the capacitance between the two.

  In such a physical quantity sensor, for example, when manufacturing the physical quantity sensor, a potential difference is generated between the movable body and the substrate, and the movable body is pulled to the substrate side by electrostatic force, and the movable body sticks to the substrate. There is. In particular, when the lid (cap) for sealing the movable body and the substrate are anodically bonded, a large potential difference is generated between the movable body and the substrate, which is a problem.

  In order to prevent the movable body from sticking to the substrate, for example, Patent Document 1 discloses a physical quantity sensor that contacts the shield before the fixed electrode contacts the movable body (test mass). .

US Pat. No. 7,121,141

  However, in the technique disclosed in Patent Document 1, since the substrate is exposed in the region between the two fixed electrodes, the movable member is stretched on the substrate by the electrostatic force between the exposed region and the movable member. It may be attached. In particular, the physical quantity sensor disclosed in Patent Document 1 has a problem that the movable body tends to stick to the substrate because the exposed region of the substrate faces the torsion bar having low rigidity.

  One of the objects according to some aspects of the present invention is to provide a physical quantity sensor that can prevent a movable body from sticking to a substrate. Another object of some aspects of the present invention is to provide an electronic apparatus and a moving body including the physical quantity sensor.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following aspects or application examples.

[Application Example 1]
The physical quantity sensor according to this application example is
A substrate,
A movable body having a movable electrode portion;
A support part for supporting the movable body so as to be displaceable about a first axis;
When the movable body is divided into a first part and a second part with the first axis as a boundary,
A first fixed electrode portion disposed on the substrate facing the first portion;
A second fixed electrode portion disposed on the substrate so as to face the second portion,
A guard portion is provided on the substrate to suppress an electrostatic force generated between the movable body and the substrate in an interelectrode region between the first fixed electrode portion and the second fixed electrode portion. .

  According to such a physical quantity sensor, the electrostatic force acting between the movable body and the substrate can be suppressed, and the movable body can be prevented from sticking to the substrate.

[Application Example 2]
In the physical quantity sensor according to this application example,
The guard part may be provided at a position overlapping the support part in plan view on the substrate.

  According to such a physical quantity sensor, the electrostatic force acting between the support portion and the substrate can be suppressed, and the movable body can be prevented from sticking to the substrate.

[Application Example 3]
In the physical quantity sensor according to this application example,
The guard portion may be provided at a position overlapping the movable body in a plan view and outside the first fixed electrode portion, the second fixed electrode portion, and the inter-electrode region.

  According to such a physical quantity sensor, the electrostatic force acting between the movable body and the substrate can be suppressed, and the movable body can be prevented from sticking to the substrate.

[Application Example 4]
In the physical quantity sensor according to this application example,
The guard part may be an electrode electrically connected to the movable body.

  According to such a physical quantity sensor, the electrostatic force acting between the movable body and the substrate can be suppressed, and the movable body can be prevented from sticking to the substrate.

  In the description according to the present invention, the term “electrically connected” is used, for example, as another specific member (hereinafter “electrically connected” to “specific member (hereinafter referred to as“ A member ”)”. B member "))" and the like. In the description according to the present invention, in the case of this example, the case where the A member and the B member are in direct contact and electrically connected, and the A member and the B member are the other members. The term “electrically connected” is used as a case where the case where the terminals are electrically connected to each other is included.

[Application Example 5]
In the physical quantity sensor according to this application example,
The electrode of the guard part may be provided on an inner bottom surface of a groove part provided on the substrate.

  According to such a physical quantity sensor, the electrostatic force acting between the movable body and the substrate can be suppressed, and the movable body can be prevented from sticking to the substrate.

[Application Example 6]
In the physical quantity sensor according to this application example,
A groove portion may be provided in a region between the electrode of the substrate and the first fixed electrode portion and a region between the electrode of the substrate and the second fixed electrode portion.

  According to such a physical quantity sensor, the electrostatic force acting between the movable body and the substrate can be suppressed, and the movable body can be prevented from sticking to the substrate.

[Application Example 7]
In the physical quantity sensor according to this application example,
The number of the electrodes adjacent to the first fixed electrode portion may be equal to the number of the electrodes adjacent to the second fixed electrode portion.

  According to such a physical quantity sensor, it is possible to easily equalize the parasitic capacitance generated between the first fixed electrode portion and the electrode and the parasitic capacitance generated between the second fixed electrode portion and the electrode. it can. Therefore, it is possible to cancel the influence of the parasitic capacitance in the first fixed electrode portion and the influence of the parasitic capacitance in the second fixed electrode portion by using the differential detection method.

[Application Example 8]
In the physical quantity sensor according to this application example,
At least one of the electrode, the first fixed electrode portion, and the second fixed electrode portion may be provided with a protruding portion that protrudes toward the movable body.

  According to such a physical quantity sensor, the movable body can be prevented from sticking to the substrate.

[Application Example 9]
In the physical quantity sensor according to this application example,
The guard part may be a groove part.

  According to such a physical quantity sensor, the electrostatic force acting between the movable body and the substrate can be suppressed, and the movable body can be prevented from sticking to the substrate.

[Application Example 10]
The physical quantity sensor according to this application example is
A substrate,
A movable body having a movable electrode portion;
A support part for supporting the movable body so as to be displaceable about a first axis;
A fixed electrode portion disposed on the substrate facing the movable electrode portion,
On the substrate, a guard portion that suppresses an electrostatic force generated between the support portion and the substrate is provided in a region overlapping the support portion in plan view.

  According to such a physical quantity sensor, the electrostatic force acting between the support portion and the substrate can be suppressed, and the movable body can be prevented from sticking to the substrate.

[Application Example 11]
The electronic device according to this application example is
A physical quantity sensor according to any of the application examples is included.

  According to such an electronic device, since the physical quantity sensor according to any one of the application examples is included, high reliability can be obtained.

[Application Example 12]
The mobile object according to this application example is
A physical quantity sensor according to any of the application examples is included.

  According to such a moving body, since the physical quantity sensor according to any one of the application examples is included, it is possible to have high reliability.

The top view which shows typically the physical quantity sensor which concerns on 1st Embodiment. Sectional drawing which shows typically the physical quantity sensor which concerns on 1st Embodiment. Sectional drawing which shows typically the manufacturing process of the physical quantity sensor which concerns on 1st Embodiment. Sectional drawing which shows typically the manufacturing process of the physical quantity sensor which concerns on 1st Embodiment. Sectional drawing which shows typically the manufacturing process of the physical quantity sensor which concerns on 1st Embodiment. The top view which shows typically the physical quantity sensor which concerns on the 1st modification of 1st Embodiment. Sectional drawing which shows typically the physical quantity sensor which concerns on the 1st modification of 1st Embodiment. The top view which shows typically the physical quantity sensor which concerns on the 2nd modification of 1st Embodiment. Sectional drawing which shows typically the physical quantity sensor which concerns on the 2nd modification of 1st Embodiment. The top view which shows typically the physical quantity sensor which concerns on the 3rd modification of 1st Embodiment. Sectional drawing which shows typically the physical quantity sensor which concerns on the 3rd modification of 1st Embodiment. The top view which shows typically the physical quantity sensor which concerns on 2nd Embodiment. Sectional drawing which shows typically the physical quantity sensor which concerns on 2nd Embodiment. The top view which shows typically the physical quantity sensor which concerns on the modification of 2nd Embodiment. Sectional drawing which shows typically the physical quantity sensor which concerns on the modification of 2nd Embodiment. The perspective view which shows typically the electronic device which concerns on 3rd Embodiment. The perspective view which shows typically the electronic device which concerns on 3rd Embodiment. The perspective view which shows typically the electronic device which concerns on 3rd Embodiment. The perspective view which shows typically the mobile body which concerns on 4th Embodiment.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. The embodiments described below do not unduly limit the contents of the present invention described in the claims. In addition, not all of the configurations described below are essential constituent requirements of the present invention.

1. 1. First embodiment 1.1. Physical Quantity Sensor First, the physical quantity sensor according to the first embodiment will be described with reference to the drawings. FIG. 1 is a plan view schematically showing a physical quantity sensor 100 according to the first embodiment. 2 is a cross-sectional view taken along the line II-II of FIG. 1 schematically showing the physical quantity sensor 100 according to the first embodiment. For convenience, illustration of the lid 70 is omitted in FIG. 1 and 2 show the X axis, the Y axis, and the Z axis as three axes orthogonal to each other, and the X axis, the Y axis, and the Z axis are the same in the following drawings. An axis is illustrated.

  As shown in FIGS. 1 and 2, the physical quantity sensor 100 includes a substrate 10, a movable body 20, a support unit 30, a fixed unit 40, fixed electrode units 50 and 52, guard units 60 and 62, and electrodes. 64 and a lid 70. Hereinafter, an example in which the physical quantity sensor 100 is an acceleration sensor (capacitive MEMS acceleration sensor) that detects acceleration in the vertical direction (Z-axis direction) will be described.

The material of the substrate 10 is, for example, an insulating material such as glass. For example, when the substrate 10 is made of an insulating material such as glass and the movable body 20 is made of a semiconductor material such as silicon, the two can be easily electrically insulated, and the sensor structure can be simplified.

  A recess 12 is formed in the substrate 10. Above the recess 12, the movable body 20 and the support portions 30 and 32 are provided via a gap. In the example illustrated in FIG. 1, the planar shape of the recess 12 (the shape viewed from the Z-axis direction) is a rectangle.

  The substrate 10 has a post portion 16 provided on the bottom surface (surface of the substrate 10 defining the recess 12) 14 of the recess 12. The post portion 16 protrudes upward (+ Z-axis direction) from the bottom surface 14. For example, the height of the post portion 16 and the depth of the concave portion 12 are equal. The post portion 16 is provided with wiring (not shown) for applying a predetermined potential to the movable body 20.

  The movable body 20 can be displaced around a support shaft (first axis) Q. Specifically, when the acceleration in the vertical direction (Z-axis direction) is applied, the movable body 20 swings the seesaw using the support shaft Q determined by the support portions 30 and 32 as the rotation shaft (swing shaft). The support axis Q is, for example, parallel to the Y axis. The planar shape of the movable body 20 is, for example, a rectangle. The thickness (size in the Z-axis direction) of the movable body 20 is, for example, constant.

  The movable body 20 includes a first seesaw piece (first part) 20a and a second seesaw piece (second part) 20b. The first seesaw piece 20a is one of the two parts of the movable body 20 defined by the support shaft Q (a part located on the left side in FIG. 1) in plan view. The second seesaw piece 20b is the other of the two parts of the movable body 20 defined by the support shaft Q (a part located on the right side in FIG. 1) in plan view. That is, the movable body 20 is divided into a first seesaw piece 20a and a second seesaw piece 20b with the support shaft Q as a boundary.

  For example, when vertical acceleration (for example, gravitational acceleration) is applied to the movable body 20, a rotational moment (moment of force) is generated in each of the first seesaw piece 20a and the second seesaw piece 20b. Here, when the rotational moment of the first seesaw piece 20a (for example, counterclockwise rotational moment) and the rotational moment of the second seesaw piece 20b (for example, clockwise rotational moment) are balanced, the inclination of the movable body 20 is increased. No change occurs and acceleration cannot be detected. Accordingly, when the acceleration in the vertical direction is applied, the rotational moment of the first seesaw piece 20a and the rotational moment of the second seesaw piece 20b are not balanced, and the movable body 20 has a predetermined inclination. 20 is designed.

  In the physical quantity sensor 100, the support shaft Q is disposed at a position deviated from the center (center of gravity) of the movable body 20 (by making the distance from the support shaft Q to the tips of the seesaw pieces 20a and 20b different). The seesaw pieces 20a and 20b have different masses. That is, the mass of the movable body 20 is different on one side (first seesaw piece 20a) and the other side (second seesaw piece 20b) with the support shaft Q as a boundary. In the illustrated example, the distance from the support shaft Q to the end surface 24 of the first seesaw piece 20a is larger than the distance from the support shaft Q to the end surface 25 of the second seesaw piece 20b. Further, the thickness of the first seesaw piece 20a is equal to the thickness of the second seesaw piece 20b. Therefore, the mass of the first seesaw piece 20a is larger than the mass of the second seesaw piece 20b. Thus, the seesaw pieces 20a and 20b have different masses, so that when the acceleration in the vertical direction is applied, the rotational moment of the first seesaw piece 20a and the rotational moment of the second seesaw piece 20b are not balanced. be able to. Therefore, when vertical acceleration is applied, the movable body 20 can be caused to have a predetermined inclination.

Although not shown, the support shaft Q is arranged at the center of the movable body 20 and the seesaw pieces 20a and 20b have different thicknesses so that the seesaw pieces 20a and 20b have different masses. May be. Even in such a case, when vertical acceleration is applied, the movable body 20 can be caused to have a predetermined inclination.

  The movable body 20 is provided apart from the substrate 10. The movable body 20 is provided on the recess 12. In the illustrated example, a gap is provided between the movable body 20 and the substrate 10. In addition, the movable body 20 is connected to the fixed portion 40 so as to be separated by the support portions 30 and 32. As a result, the movable body 20 can swing on the seesaw.

  The movable body 20 includes a first movable electrode portion 21 and a second movable electrode portion 22 that are provided with the support axis Q as a boundary. The first movable electrode portion 21 is provided on the first seesaw piece 20a. The second movable electrode portion 22 is provided on the second seesaw piece 20b.

  The first movable electrode portion 21 is a portion of the movable body 20 that overlaps the first fixed electrode portion 50 in plan view. The first movable electrode portion 21 forms a capacitance C <b> 1 with the first fixed electrode portion 50. That is, the first movable electrode portion 21 and the first fixed electrode portion 50 form a capacitance C1.

  The second movable electrode portion 22 is a portion of the movable body 20 that overlaps the second fixed electrode portion 52 in plan view. The second movable electrode portion 22 forms a capacitance C <b> 2 with the second fixed electrode portion 52. That is, the second movable electrode part 22 and the second fixed electrode part 52 form a capacitance C2. In the physical quantity sensor 100, the movable body 20 is made of a conductive material (silicon doped with impurities), so that the movable electrode portions 21 and 22 are provided. That is, the first seesaw piece 20 a functions as the first movable electrode portion 21, and the second seesaw piece 20 b functions as the second movable electrode portion 22.

  For example, the electrostatic capacitance C1 and the electrostatic capacitance C2 are configured to be equal to each other in a state where the movable body 20 illustrated in FIG. 2 is horizontal. The positions of the movable electrode portions 21 and 22 change according to the movement of the movable body 20. The capacitances C1 and C2 change according to the positions of the movable electrode portions 21 and 22. A predetermined potential is applied to the movable body 20 via the support portions 30 and 32.

  The movable body 20 is provided with a slit portion 26 that penetrates the movable body 20. Thereby, the influence (air resistance) of the air when the movable body 20 swings can be reduced. In the illustrated example, a plurality of slit portions 26 are provided.

  The movable body 20 is provided with an opening 28. The opening 28 is provided with support portions 30 and 32 and a fixing portion 40. The movable body 20 is connected to the fixed portion 40 via the support portions 30 and 32.

  The support portions 30 and 32 support the movable body 20 so as to be displaceable about the support axis Q. The support parts 30 and 32 function as torsion springs (torsion springs). Thereby, it can have a strong restoring force with respect to the torsional deformation which arises in the support parts 30 and 32 when the movable body 20 rocks a seesaw.

  The support portions 30 and 32 are disposed on the support shaft Q in plan view. The support portions 30 and 32 connect the fixed portion 40 and the movable body 20. The support portions 30 and 32 extend along the support axis Q. The support part 30 extends from the fixed part 40 in the + Y axis direction. The support portion 32 extends from the fixed portion 40 in the −Y axis direction.

The fixing part 40 is provided in the opening part 28. The fixed portion 40 is provided on the support shaft Q in plan view. The fixing part 40 is joined to the post part 16 of the substrate 10. In the illustrated example, the central portion of the fixing portion 40 is joined to the post portion 16.

  A through hole 46 is provided in a portion of the fixing portion 40 that is separated from the substrate 10. The through hole 46 is disposed on the support shaft Q in plan view. By providing the through hole 46 in the fixing portion 40, stress generated by a difference between the thermal expansion coefficient of the substrate 10 and the thermal expansion coefficient of the structure 2, stress applied to the apparatus during mounting, and the like are given to the support portions 30 and 32. The influence can be reduced.

  The movable body 20, the support parts 30 and 32, and the fixed part 40 are provided integrally. The movable body 20, the support portions 30, 32, and the fixed portion 40 are integrally provided by patterning, for example, one substrate (silicon substrate). In the illustrated example, the movable body 20, the support portions 30 and 32, and the fixed portion 40 constitute one structure (silicon structure) 2. The material of the structure 2 is, for example, silicon imparted with conductivity by doping impurities such as phosphorus and boron. When the material of the substrate 10 is glass and the material of the structure 2 is silicon, the substrate 10 and the fixing portion 40 are bonded by, for example, anodic bonding.

  In the physical quantity sensor 100, the structure 2 is fixed to the substrate 10 by one fixing portion 40. That is, the structure 2 is fixed to the substrate 10 at one point (one fixed portion 40). Therefore, for example, compared with the case where the structure 2 is fixed to the substrate 10 at two points (two fixing portions 40) (see, for example, FIGS. 12 and 13), the thermal expansion coefficient of the substrate 10 and the structure 2 It is possible to reduce the influence of the stress generated by the difference from the thermal expansion coefficient, the stress applied to the apparatus during mounting, and the like on the support portions 30 and 32.

  The first fixed electrode portion 50 is provided on the substrate 10. The first fixed electrode portion 50 is disposed to face the first movable electrode portion 21. Above the first fixed electrode portion 50, the first movable electrode portion 21 is located via a gap. When the movable body 20 is divided into the first seesaw piece 20a and the second seesaw piece 20b with the support axis Q as a boundary, the first fixed electrode portion 50 is disposed on the substrate 10 so as to face the first seesaw piece 20a. Has been.

  The second fixed electrode portion 52 is provided on the substrate 10. The second fixed electrode portion 52 is disposed so as to face the second movable electrode portion 22. Above the second fixed electrode portion 52, the second movable electrode portion 22 is located via a gap. When the movable body 20 is divided into the first seesaw piece 20a and the second seesaw piece 20b with the support axis Q as a boundary, the second fixed electrode portion 52 is disposed on the substrate 10 so as to face the second seesaw piece 20b. Has been.

  The area of the portion of the first fixed electrode portion 50 facing the movable body 20 is equal to the area of the portion of the second fixed electrode portion 52 facing the movable body 20. The planar shape of the first fixed electrode portion 50 and the planar shape of the second fixed electrode portion 52 are symmetric with respect to the support axis Q, for example.

  The first fixed electrode part 50 is provided between the guard part 60 and the guard part 62. That is, the number of electrodes 61 adjacent to the first fixed electrode portion 50 is two. In addition, the second fixed electrode portion 52 is provided between the guard portion 60 and the electrode 64. That is, the number of electrodes 61 and 64 adjacent to the second fixed electrode portion 52 is two. As described above, in the physical quantity sensor 100, the number of the electrodes 61 adjacent to the first fixed electrode portion 50 and the number of the electrodes 61 and 64 adjacent to the second fixed electrode portion 52 are equal.

  Although not shown, the first fixed electrode portion 50 is provided at a position of the lid body 70 facing the first movable electrode portion 21, and the first position of the lid body 70 is opposed to the second movable electrode portion 22. Two fixed electrode portions 52 may be provided.

The guard portions 60 and 62 are electrostatic force and support portions 30 that act between the movable body 20 and the substrate 10.
It is a member for suppressing the electrostatic force acting between 32 and the substrate 10. The guard parts 60 and 62 are electrodes 61 electrically connected to the movable body 20 in the illustrated example.

  The guard portion 60 is provided in a region (first region, interelectrode region) 14a between the first fixed electrode unit 50 and the second fixed electrode unit 52 of the substrate 10 in plan view. In the illustrated example, the region 14a of the substrate 10 has a region that overlaps the movable body 20 (first seesaw piece 20a and second seesaw piece 20b) and a region that overlaps the support portions 30 and 32 (second region) in plan view. including.

  The electrode 61 constituting the guard part 60 is disposed to face the movable body 20 and the support parts 30 and 32. That is, the electrode 61 constituting the guard portion 60 overlaps the movable body 20 (the first seesaw piece 20a and the second seesaw piece 20b) and the support portions 30 and 32 in plan view. On the electrode 61 which comprises the guard part 60, the movable body 20 (the 1st seesaw piece 20a and the 2nd seesaw piece 20b) and the support parts 30 and 32 are located through the gap.

  The guard part 62 is provided in the area 14b in the −X-axis direction of the first fixed electrode part 50, which is an area overlapping the first seesaw piece 20a of the substrate 10 in plan view. The guard part 62 is provided at the position overlapping the movable body 20 in plan view on the substrate 10 and outside the first fixed electrode part 50, the second fixed electrode part 52, and the first region 14a. . The guard part 62 is a position overlapping the movable body 20 in plan view on the substrate 10 and is provided to avoid the first fixed electrode part 50, the second fixed electrode part 52, and the first region 14a. The electrode 61 which comprises the guard part 62 is arrange | positioned facing the 1st seesaw piece 20a. That is, the electrode 61 constituting the guard portion 62 overlaps the first seesaw piece 20a in plan view. On the electrode 61 which comprises the guard part 62, the 1st seesaw piece 20a is located through the gap | interval.

  The electrode 64 is provided in the region 14c in the + X-axis direction of the second fixed electrode portion 52. In the illustrated example, the electrode 64 is provided in a region that does not overlap the movable body 20. The regions 14a, 14b, and 14c of the substrate 10 are part of the bottom surface 14 of the recess 12 in the illustrated example.

  The electrode 61 constituting the guard part 60 is electrically connected to the movable body 20 via, for example, wiring (not shown) provided on the surface of the post part 16, the fixed part 40, and the support parts 30 and 32. ing. Moreover, the electrode 61 and the electrode 64 which comprise the guard part 62 are electrically connected to the electrode 61 of the guard part 60 by the wiring which is not shown in figure. Note that the movable body 20 and the electrodes 61 and 64 may be electrically connected by a bonding wire (not shown) or the like. In the physical quantity sensor 100, since each electrode 61 is electrically connected to the movable body 20, each electrode 61 and the movable body 20 can be equipotential. Thereby, the electrostatic force which acts between the structure 2 (movable body 20) and the board | substrate 10 can be suppressed.

  The materials of the fixed electrode portions 50 and 52, the electrodes 61 constituting the guard portions 60 and 62, and the electrode 64 are, for example, aluminum, gold, ITO (Indium Tin Oxide), or the like. The material of the fixed electrode portions 50 and 52, the electrodes 61 constituting the guard portions 60 and 62, and the electrode 64 is preferably a transparent electrode material such as ITO. When the substrate 10 is a transparent substrate (glass substrate) by using a transparent electrode material as the material of the fixed electrode portions 50 and 52, the electrode 61 constituting the guard portions 60 and 62, and the electrode 64, the fixed electrode portion 50 , 52, the electrodes 61 constituting the guard portions 60, 62, and foreign matters existing on the electrode 64 can be easily visually recognized.

The lid body 70 is provided on the substrate 10. The lid 70 is bonded to the substrate 10. The lid 70 and the substrate 10 form a cavity 72 that accommodates the movable body 20. The cavity 72 is, for example, an inert gas (for example, nitrogen gas) atmosphere. The material of the lid 70 is, for example, silicon. When the material of the lid 70 is silicon and the material of the substrate 10 is glass, the substrate 10 and the fixing portion 40 are bonded by, for example, anodic bonding.

  Next, the operation of the physical quantity sensor 100 will be described.

  In the physical quantity sensor 100, the movable body 20 swings around the support axis Q according to physical quantities such as acceleration and angular velocity. As the movable body 20 moves, the distance between the first movable electrode portion 21 and the first fixed electrode portion 50 and the distance between the second movable electrode portion 22 and the second fixed electrode portion 52 change. To do.

  Specifically, for example, when vertical upward (+ Z-axis direction) acceleration is applied to the physical quantity sensor 100, the movable body 20 rotates counterclockwise, and between the first movable electrode portion 21 and the first fixed electrode portion 50. , And the distance between the second movable electrode portion 22 and the second fixed electrode portion 52 is increased. As a result, the capacitance C1 increases and the capacitance C2 decreases.

  For example, when vertical downward acceleration (−Z axis direction) is applied to the physical quantity sensor 100, the movable body 20 rotates clockwise, and the distance between the first movable electrode portion 21 and the first fixed electrode portion 50 is increased. The distance between the second movable electrode portion 22 and the second fixed electrode portion 52 becomes smaller. As a result, the capacitance C1 is reduced and the capacitance C2 is increased. Therefore, based on the difference between the capacitance C1 and the capacitance C2 (by a so-called differential detection method), it is possible to detect a physical quantity such as the direction and size of acceleration, angular velocity, and the like.

  As described above, the physical quantity sensor 100 can be used as an inertial sensor such as an acceleration sensor or a gyro sensor. Specifically, for example, a capacitance for measuring acceleration in the vertical direction (Z-axis direction). It can be used as a type acceleration sensor.

  The physical quantity sensor 100 has the following features, for example.

  In the physical quantity sensor 100, the substrate 10, the movable body 20 including the movable electrode portions 21 and 22, the support portion 30 that supports the movable body 20 so as to be displaceable around the support axis Q, and the movable body 20 with the support axis Q. When divided into a first seesaw piece 20a and a second seesaw piece 20b at the boundary, the first fixed electrode portion 50 disposed on the substrate 10 facing the first seesaw piece 20a and the second seesaw piece 20b A second fixed electrode portion 52 disposed on the substrate 10, and the movable body is disposed on the substrate 10 in the inter-electrode region 14 a between the first fixed electrode portion 50 and the second fixed electrode portion 52. A guard portion 60 that suppresses the electrostatic force generated between the substrate 20 and the substrate 10 is provided. Thereby, the electrostatic force acting between the movable body 20 and the substrate 10 can be suppressed, and the movable body 20 can be prevented from sticking to the substrate 10. Therefore, for example, when the physical quantity sensor 100 is manufactured, a potential difference is generated between the movable body 20 and the substrate 10, the movable body 20 is pulled toward the substrate 10 by electrostatic force, and the movable body 20 sticks to the substrate 10. The problem does not occur.

  In the physical quantity sensor 100, the guard unit 60 is provided at a position overlapping the support units 30 and 32 in plan view on the substrate 10. Therefore, the electrostatic force acting between the support portions 30 and 32 and the substrate 10 can be suppressed, and the movable body 20 can be prevented from sticking to the substrate 10.

  In the physical quantity sensor 100, the guard part 62 is positioned so as to overlap the movable body 20 in a plan view, and the first fixed electrode part 50, the second fixed electrode part 52, and the area 14b outside the interelectrode area 14a. Is provided. Therefore, the electrostatic force acting between the movable body 20 and the substrate 10 can be suppressed, and the movable body can be prevented from sticking to the substrate.

  In the physical quantity sensor 100, the guard parts 60 and 62 are electrodes 61 that are electrically connected to the movable body 20. Therefore, the potential difference between the movable body 20 and the support portions 30 and 32 and the electrode 61 can be reduced (or no potential difference is generated). Therefore, the electrostatic force acting between the movable body 20 and the support portions 30 and 32 and the substrate 10 can be suppressed, and the movable body 20 can be prevented from sticking to the substrate 10.

  In the physical quantity sensor 100, the number of electrodes 61 adjacent to the first fixed electrode portion 50 and the number of electrodes 61 and 64 adjacent to the second fixed electrode portion 52 are equal. Therefore, the parasitic capacitance generated between the first fixed electrode portion 50 and the electrode 61 and the parasitic capacitance generated between the second fixed electrode portion 52 and the electrodes 61 and 64 can be easily equalized. . Therefore, it is possible to cancel the influence of the parasitic capacitance in the first fixed electrode portion 50 and the influence of the parasitic capacitance in the second fixed electrode portion 52 by using the differential detection method.

1.2. Manufacturing Method of Physical Quantity Sensor Next, a manufacturing method of the physical quantity sensor according to the first embodiment will be described with reference to the drawings. 3-5 is sectional drawing which shows typically the manufacturing process of the physical quantity sensor 100 which concerns on 1st Embodiment.

  As shown in FIG. 3, for example, a glass substrate is patterned to form a substrate 10 having recesses 12 and post portions 16. The patterning of the glass substrate is performed, for example, by photolithography and etching.

  Next, the fixed electrode portions 50 and 52, the electrodes 61 constituting the guard portions 60 and 62, and the electrodes 64 are formed on the bottom surface 14 of the recess 12. For the fixed electrode portions 50 and 52, the electrodes 61 and the electrodes 64 constituting the guard portions 60 and 62, a conductive layer is formed on the bottom surface 14 by sputtering or the like, and then the conductive layer is patterned by photolithography and etching. Is formed.

  As shown in FIG. 4, a silicon substrate 102 is bonded to the substrate 10. The bonding between the substrate 10 and the silicon substrate 102 is performed by, for example, anodic bonding.

  As shown in FIG. 5, the silicon substrate 102 is ground and thinned by, for example, a grinding machine, and then patterned to integrally form the movable body 20, the support portions 30 and 32, and the fixed portion 40. The patterning is performed by photolithography and etching (dry etching), and a Bosch method can be used as a more specific etching technique.

  As shown in FIG. 2, the lid 70 is bonded to the substrate 10, and the movable body 20 and the like are accommodated in the cavity 72 formed by the substrate 10 and the lid 70. The bonding between the substrate 10 and the lid 70 is performed by, for example, anodic bonding. By performing this step in an inert gas atmosphere, the cavity 72 can be filled with an inert gas.

  In this step, when the lid 70 is bonded to the substrate 10, a large potential difference is generated between the structure 2 including the movable body 20, the support portions 30 and 32, and the fixed portion 40 and the substrate 10. However, the electrostatic force acting between the movable body 20 and the support portions 30 and 32 and the substrate 10 can be suppressed by the guard portions 60 and 62. Therefore, the movable body 20 can be prevented from sticking to the substrate 10.

  Through the above steps, the physical quantity sensor 100 can be manufactured.

1.3. Modified Example Next, a modified example of the physical quantity sensor according to the first embodiment will be described with reference to the drawings. In the physical quantity sensors 200, 300, and 400 according to the following modifications, members having the same functions as those of the constituent members of the physical quantity sensor 100 described above are denoted by the same reference numerals and description thereof is omitted.

(1) First Modification First, a first modification will be described. FIG. 6 is a plan view schematically showing the physical quantity sensor 200 according to the first modification. FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. 6 schematically illustrating the physical quantity sensor 200 according to the first modification. For convenience, illustration of the lid 70 is omitted in FIG. 6.

  In the example of the physical quantity sensor 100 described above, as shown in FIGS. 1 and 2, the guard portions 60 and 62 are configured by the electrodes 61 that are electrically connected to the movable body 20.

  On the other hand, in the physical quantity sensor 200, as shown in FIGS. 6 and 7, the guard portions 60 and 62 include the electrode 61 electrically connected to the movable body 20, and the groove portion 18 provided on the substrate 10. ,including.

  In the example shown in the figure, the guard portion 60 is composed of one electrode 61 and two groove portions 18. In the guard portion 60, the groove portion 18 includes, in plan view, a region between the first fixed electrode portion 50 of the substrate 10 and the electrode 61 constituting the guard portion 60, and the second fixed electrode portion 52 and the guard portion of the substrate 10. It is provided in a region between the electrodes 61 constituting 60.

  The groove 18 is provided on the bottom surface 14 of the recess 12. The groove portion 18 has a bottom surface (a surface facing the movable body 20, an inner bottom surface) having a larger distance from the movable body 20 than the bottom surface 14 of the recess 12. By providing the groove 18, the distance between the substrate 10 and the movable body 20 can be increased.

  Here, the magnitude of the electrostatic force is inversely proportional to the square of the distance. Therefore, by providing the groove portion 18, the electrostatic force acting between the substrate 10 and the movable body 20 can be suppressed. In addition, the depth of the groove part 18 will not be specifically limited if it is the depth which the board | substrate 10 and the movable body 20 do not stick with an electrostatic force.

  In the example shown in the figure, the guard portion 62 includes one electrode 61 and one groove portion 18. In the guard part 62, the groove part 18 is provided in a region between the first fixed electrode part 50 of the substrate 10 and the electrode 61 constituting the guard part 62 in plan view.

  In the physical quantity sensor 200, the guard part 60 is provided in the first region 14a and is electrically connected to the movable body 20, and the first electrode 61 and the first electrode 61 constituting the guard part 60 of the substrate 10 in plan view. A region between the fixed electrode portion 50 and the groove portion 18 provided between the electrode 61 constituting the guard portion 60 of the substrate 10 and the second fixed electrode portion 52 are included. Thus, the electrostatic force acting between the movable body 20 and the support portions 30 and 32 and the substrate 10 can be suppressed by the electrode 61 and the groove portion 18, and the movable body 20 can be prevented from sticking to the substrate 10.

  The manufacturing method of the physical quantity sensor 200 is the same as the manufacturing method of the physical quantity sensor 100 described above except that a step of forming the groove 18 by etching on the bottom surface 14 of the recess 12 is added, and the description thereof is omitted.

Although not shown, the guard part 60 may be constituted by only the groove part 18. That is, in FIG. 6 and FIG. 7, the electrode 61 constituting the guard part 60 may be the groove part 18. Specifically, the entire first region 14 a (excluding the post portion 16) may be used as the groove portion 18. Even in such a case, the electrostatic force acting between the movable body 20 and the support portions 30 and 32 and the substrate 10 can be suppressed, and the movable body 20 can be prevented from sticking to the substrate 10. Similarly, the guard part 62 may be constituted by only the groove part 18.

  Although not shown, the electrode 61 may be provided on the bottom surface (inner bottom surface) of the groove 18. Further, the groove portion 18 may be provided in the entire first region 14 a (excluding the post portion 16), and the electrode 61 may be provided on the inner bottom surface of the groove portion 18 to form the guard portion 60. Similarly, the guard portion 62 may be formed by providing the groove portion 18 in the entire second region 14 b and providing the electrode 61 on the inner bottom surface of the groove portion 18. Even in such a case, the electrostatic force acting between the movable body 20 and the support portions 30 and 32 and the substrate 10 can be suppressed, and the movable body 20 can be prevented from sticking to the substrate 10.

(2) Second Modification Next, a second modification will be described. FIG. 8 is a plan view schematically showing a physical quantity sensor 300 according to the second modification. FIG. 9 is a cross-sectional view taken along the line IX-IX of FIG. 8 schematically showing the physical quantity sensor 300 according to the second modification. For convenience, the lid 70 is not shown in FIG.

  In the physical quantity sensor 300, as shown in FIGS. 8 and 9, the fixed electrode portions 50 and 52 and the electrode 61 are provided with protrusions 65, respectively.

  The protrusion 65 protrudes from the electrodes 50, 52, 61 toward the movable body 20. The shape of the protrusion 65 is, for example, a weight. The protrusion 65 is provided in a region overlapping the movable body 20 in plan view. The number and position of the protrusions 65 are not particularly limited. In the example shown in the figure, the protrusions 65 are provided on both sides of the exposed region of the bottom surface 14 of the substrate 10 (the region where the electrodes 50, 52, 61 are not formed).

  Specifically, in the illustrated example, the protrusions 65 are the four corners of the first fixed electrode portion 50 and the second fixed electrode portion 52, the four corners of the electrode 61 constituting the guard portion 60, and the electrode 61 constituting the guard portion 62. Of the first fixed electrode portion 50 side.

  In the physical quantity sensor 300, at least one of the electrode 61, the first fixed electrode unit 50, and the second fixed electrode unit 52 is provided with a protrusion 65 that protrudes toward the movable body 20. Thereby, it is possible to prevent the movable body 20 from sticking to the substrate 10.

  In the manufacturing method of the physical quantity sensor 300, when the recess 12 is formed, etching is performed so that a protrusion is formed on the bottom surface 14, and a conductive layer to be the electrodes 50, 52, 61 is formed on the protrusion and the protrusion is formed. Except for forming the portion 65, the method is the same as the method for manufacturing the physical quantity sensor 100 described above, and the description thereof is omitted.

(3) Third Modification Next, a third modification will be described. FIG. 10 is a plan view schematically showing a physical quantity sensor 400 according to the third modification. FIG. 11 is a cross-sectional view taken along the line XI-XI of FIG. 10 schematically showing a physical quantity sensor 400 according to a third modification. For convenience, the lid 70 is not shown in FIG.

In the physical quantity sensor 400, as shown in FIGS. 10 and 11, the movable body 20 is opposed to the region 14d of the substrate 10 between the electrode 61 constituting the guard part 60 and the first fixed electrode part 50. A slit portion 26 is provided. In addition, the movable body 20 is provided with a slit portion 26 facing the region 14 e between the electrode 61 constituting the guard portion 60 and the second fixed electrode portion 52 of the substrate 10.

  The movable body 20 is further provided with a slit portion 26 facing the region 14 f between the electrode 61 constituting the guard portion 62 and the first fixed electrode portion 50 of the substrate 10.

  In the physical quantity sensor 400, the movable body 20 is provided with a slit portion 26 facing the regions 14d, 14e, and 14f where the substrate 10 is exposed. Thereby, the electrostatic force acting between the movable body 20 and the substrate 10 can be suppressed, and the movable body 20 can be prevented from sticking to the substrate 10.

(4) Fourth Modification Next, a fourth modification will be described. Although not shown, the physical quantity sensor according to the fourth modified example includes the groove 18 shown in FIGS. 6 and 7, the protrusion 65 shown in FIGS. 8 and 9, and the slit 26 shown in FIGS. 10 and 11. It is configured to include. Thereby, it can prevent more reliably that the movable body 20 sticks to the board | substrate 10. FIG.

2. Second Embodiment 2.1. Physical Quantity Sensor Next, a physical quantity sensor according to the second embodiment will be described with reference to the drawings. FIG. 12 is a plan view schematically showing a physical quantity sensor 500 according to the second embodiment. FIG. 13 is a cross-sectional view taken along line XIII-XIII in FIG. 12 schematically showing a physical quantity sensor 500 according to the second embodiment. For convenience, illustration of the lid 70 is omitted in FIG.

  Hereinafter, in the physical quantity sensor 500 according to the second embodiment, members having the same functions as those of the constituent members of the physical quantity sensor 100 according to the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  In the physical quantity sensor 500, as shown in FIGS. 12 and 13, the support portions 30 and 32 connect the fixed portions 40a and 40b provided around the movable body 20 to the movable body 20, and the guard portion 60 A region (first region, interelectrode region) 14a between the first fixed electrode portion 50 and the second fixed electrode portion 52 of the substrate 10 and a region (second region) overlapping the support portion 30 of the substrate 10 in plan view. The electrode 61 provided in 14h and 14i is included.

  As illustrated in FIG. 12, the physical quantity sensor 500 includes a first fixed portion 40 a and a second fixed portion 40 b provided around the movable body 20. The fixing portions 40a and 40b are provided on the frame portion 19 of the substrate 10 in the illustrated example. The fixing portions 40a and 40b and the frame portion 19 are joined by, for example, anodic bonding. The first fixed portion 40 a is provided in the + Y axis direction of the movable body 20, and the second fixed portion 40 b is provided in the −Y axis direction of the movable body 20. That is, the movable body 20 is disposed between the first fixed portion 40a and the second fixed portion 40b.

  The frame portion 19 of the substrate 10 is provided so as to surround the recess 12. The side surface of the frame portion 19 is a surface that defines the side surface of the recess 12. The frame portion 19 and the fixing portions 40a and 40b are joined by, for example, anodic bonding.

  The support part 30 connects the first fixed part 40 a and the movable body 20. The support unit 30 is connected to the side surface of the movable body 20 on the + Y axis direction side. The support part 32 connects the second fixed part 40 b and the movable body 20. The support portion 32 is connected to the side surface of the movable body 20 on the −Y axis direction side.

  In the physical quantity sensor 500, the structure 2 is fixed to the substrate 10 by the two fixing portions 40. That is, the structure 2 is fixed to the substrate 10 at two points (two fixing portions 40).

  The guard unit 60 is configured by an electrode 61 provided in the region 14 a of the substrate 10 and the regions 14 h and 14 i of the substrate 10. The region 14h of the substrate 10 is a region that overlaps the support part 30 in plan view. The region 14 i of the substrate 10 is a region that overlaps with the support portion 32 in plan view. Regions 14 h and 14 i of the substrate 10 are part of the bottom surface 14 of the recess 12. In the illustrated example, one electrode 61 is provided over the regions 14a, 14h, and 14i of the substrate 10, but the electrodes 61 may be provided in the regions 14a, 14h, and 14i of the substrate 10, respectively.

  The electrode 61 constituting the guard part 60 may extend to the side surface of the recess 12 and the upper surface of the frame part 19 and be electrically connected to the fixing parts 40a and 40b, for example. Accordingly, the electrode 61 is electrically connected to the movable body 20 via the first fixed portion 40a and the support portion 30 (or the second fixed portion 40b and the support portion 32). Each electrode 61 and the movable body 20 may be electrically connected by a bonding wire (not shown) or the like.

  In the physical quantity sensor 500, the guard unit 60 includes a region 14h that overlaps the region 14a between the first fixed electrode unit 50 and the second fixed electrode unit 52 of the substrate 10 and the support units 30 and 32 of the substrate 10 in plan view. , 14i are included. Thereby, the electrostatic force acting between the movable body 20 and the support portions 30 and 32 and the substrate 10 can be suppressed, and the movable body 20 can be prevented from sticking to the substrate 10.

  The manufacturing method of the physical quantity sensor 500 is the same as the manufacturing method of the physical quantity sensor 100 described above except that the electrodes 61 are formed in the regions 14h and 14i of the substrate 10 and the two fixing portions 40a and 40b are formed. Yes, the description is omitted.

2.2. Modified Example Next, a modified example of the physical quantity sensor according to the second embodiment will be described with reference to the drawings. FIG. 14 is a plan view schematically showing a physical quantity sensor 600 according to a modification of the second embodiment. FIG. 15 is a cross-sectional view taken along the line XV-XV in FIG. 14 schematically showing a physical quantity sensor 600 according to a modification of the second embodiment. For convenience, illustration of the lid 70 is omitted in FIG.

  Hereinafter, in the physical quantity sensor 600 according to this modification, members having the same functions as the constituent members of the physical quantity sensor 500 described above are denoted by the same reference numerals, and description thereof is omitted.

  In the example of the physical quantity sensor 500 described above, as shown in FIGS. 12 and 13, the guard unit 60 is a region between the first fixed electrode unit 50 and the second fixed electrode unit 52 of the substrate 10 in plan view ( The first region 14a and the electrodes 61 provided in the regions (second regions) 14h and 14i overlapping the support portion 30 of the substrate 10 were included.

  On the other hand, in the physical quantity sensor 600, as shown in FIGS. 14 and 15, the guard unit 60 is an area between the first fixed electrode unit 50 and the second fixed electrode unit 52 of the substrate 10 in plan view. (First region, inter-electrode region) 14 includes a groove portion 18 and electrodes 61 provided in regions (second regions) 14 h and 14 i overlapping the support portions 30 and 32 of the substrate 10. The electrode 61 is electrically connected to the movable body 20.

  In the physical quantity sensor 600, the electrostatic force acting between the support portions 30 and 32 and the substrate 10 is suppressed by the electrode 61, and the electrostatic force acting between the movable body 20 and the substrate 10 is suppressed by the groove portion 18 to be movable. It is possible to prevent the body 20 from sticking to the substrate 10. Although not shown, the electrode 61 may be provided on the inner bottom surface of the groove 18.

3. Third Embodiment Next, an electronic apparatus according to a third embodiment will be described with reference to the drawings. The electronic device according to the third embodiment includes a physical quantity sensor according to the present invention. Hereinafter, an electronic apparatus including the physical quantity sensor 100 will be described as the physical quantity sensor according to the present invention.

  FIG. 16 is a perspective view schematically showing a mobile (or notebook) personal computer 1100 as an electronic apparatus according to the third embodiment.

  As shown in FIG. 16, the personal computer 1100 includes a main body portion 1104 having a keyboard 1102 and a display unit 1106 having a display portion 1108. The display unit 1106 has a hinge structure portion with respect to the main body portion 1104. It is supported so that rotation is possible.

  Such a personal computer 1100 incorporates a physical quantity sensor 100.

  FIG. 17 is a perspective view schematically showing a mobile phone (including PHS) 1200 as an electronic apparatus according to the third embodiment.

  As shown in FIG. 17, the mobile phone 1200 includes a plurality of operation buttons 1202, an earpiece 1204, and a mouthpiece 1206, and a display unit 1208 is disposed between the operation buttons 1202 and the earpiece 1204. .

  Such a cellular phone 1200 incorporates a physical quantity sensor 100.

  FIG. 18 is a perspective view schematically showing a digital still camera 1300 as an electronic apparatus according to the third embodiment. Note that FIG. 13 simply shows connection with an external device.

  Here, an ordinary camera sensitizes a silver halide photographic film with a light image of a subject, whereas a digital still camera 1300 photoelectrically converts a light image of a subject with an image sensor such as a CCD (Charge Coupled Device). An imaging signal (image signal) is generated.

  A display unit 1310 is provided on the back of a case (body) 1302 in the digital still camera 1300, and is configured to display based on an imaging signal from the CCD. The display unit 1310 displays an object as an electronic image. Functions as a viewfinder.

  A light receiving unit 1304 including an optical lens (imaging optical system), a CCD, and the like is provided on the front side (the back side in the drawing) of the case 1302.

  When the photographer confirms the subject image displayed on the display unit 1310 and presses the shutter button 1306, the CCD image pickup signal at that time is transferred and stored in the memory 1308.

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

  Such a digital still camera 1300 incorporates a physical quantity sensor 100.

  Since the electronic devices 1100, 1200, and 1300 as described above include the physical quantity sensor 100 that can prevent the movable body 20 from sticking to the substrate 10, it can have high reliability.

  In addition to the personal computer (mobile personal computer) shown in FIG. 16, the mobile phone shown in FIG. 17, and the digital still camera shown in FIG. (For example, inkjet printers), laptop personal computers, televisions, video cameras, video tape recorders, various navigation devices, pagers, electronic notebooks (including those with communication functions), electronic dictionaries, calculators, electronic game devices, head mounted displays, Word processor, workstation, videophone, security TV monitor, electronic binoculars, POS terminal, medical equipment (eg electronic thermometer, blood pressure monitor, blood glucose meter, electrocardiogram measuring device, ultrasonic diagnostic device, electronic endoscope), fish finder Various measuring instruments, gauges (e.g., vehicles, aircraft, rockets, instruments and a ship), attitude control such as a robot or a human body, can be applied to a flight simulator.

4). Fourth Embodiment Next, a moving body according to a fourth embodiment will be described with reference to the drawings. The moving body according to the fourth embodiment includes a physical quantity sensor according to the present invention. Hereinafter, a moving body including the physical quantity sensor 100 will be described as a physical quantity sensor according to the present invention.

  FIG. 19 is a perspective view schematically showing an automobile 1500 as a moving body according to the fourth embodiment.

  The automobile 1500 has a physical quantity sensor 100 built therein. Specifically, as shown in FIG. 19, an electronic control unit (ECU) that controls the output of the engine by incorporating a physical quantity sensor 100 that detects the acceleration of the automobile 1500 into the body 1502 of the automobile 1500. 1504 is mounted. In addition, the physical quantity sensor 100 can be widely applied to a vehicle body attitude control unit, an anti-lock brake system (ABS), an air bag, and a tire pressure monitoring system (TPMS). .

  Since the automobile 1500 includes the physical quantity sensor 100 that can prevent the movable body 20 from sticking to the substrate 10, the automobile 1500 can have high reliability.

  The above-described embodiments and modifications are merely examples, and the present invention is not limited to these. For example, it is possible to appropriately combine each embodiment and each modification.

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

DESCRIPTION OF SYMBOLS 2 ... Structure, 10 ... Board | substrate, 12 ... Concave, 14 ... Bottom, 14a, 14b, 14c, 14d, 14e, 14f, 14h, 14i ... Area | region, 16 ... Post part, 18 ... Groove part, 19 ... Frame part, 20 ... movable body, 20a ... first seesaw piece, 20b ... second seesaw piece, 21 ... first movable electrode part, 22 ... second movable electrode part, 24, 25 ... end face, 26 ... slit part, 28 ... opening part, DESCRIPTION OF SYMBOLS 30, 32 ... Support part, 40 ... Fixed part, 40a ... 1st fixed part, 40b ... 2nd fixed part, 46 ... Through-hole, 50 ... 1st fixed electrode part, 52 ... 2nd fixed electrode part, 60 ... Guard Part, 61 ... electrode, 62 ... guard part, 64 ... electrode, 65 ... projection, 70 ... lid, 72 ... cavity, 100 ... physical quantity sensor, 102 ... silicon substrate, 200, 300, 400, 500, 600 ... Physical quantity sensor, 1100 ... Electronic machine DESCRIPTION OF SYMBOLS 1100 ... Personal computer, 1102 ... Keyboard, 1104 ... Main part, 1106 ... Display unit, 1108 ... Display unit, 1200 ... Mobile phone, 1202 ... Operation button, 1204 ... Earpiece, 1206 ... Mouthpiece, 1208 ... Display unit DESCRIPTION OF SYMBOLS 1300 ... Digital still camera, 1302 ... Case, 1304 ... Light receiving unit, 1306 ... Shutter button, 1308 ... Memory, 1310 ... Display unit, 1312 ... Video signal output terminal, 1314 ... Input / output terminal, 1430 ... TV monitor, 1440 ... Personal computer, 1500 ... automobile, 1502 ... car body, 1504 ... electronic control unit

Claims (12)

A substrate,
A movable body having a movable electrode portion;
A support part for supporting the movable body so as to be displaceable about a first axis;
When the movable body is divided into a first part and a second part with the first axis as a boundary,
A first fixed electrode portion disposed on the substrate facing the first portion;
A second fixed electrode portion disposed on the substrate so as to face the second portion,
A guard portion is provided on the substrate to suppress an electrostatic force generated between the movable body and the substrate in an interelectrode region between the first fixed electrode portion and the second fixed electrode portion. , Physical quantity sensor. In claim 1,
The guard part is a physical quantity sensor provided at a position overlapping the support part in plan view on the substrate. In claim 1,
The guard unit is a physical quantity sensor that is provided at a position overlapping the movable body in a plan view and outside the first fixed electrode unit, the second fixed electrode unit, and the inter-electrode region. In any one of Claims 1 thru | or 3,
The guard unit is a physical quantity sensor that is an electrode electrically connected to the movable body. In claim 4,
The said sensor of the said guard part is a physical quantity sensor provided in the inner bottom face of the groove part provided on the said board | substrate. In claim 4,
A physical quantity sensor, wherein a groove is provided in a region between the electrode and the first fixed electrode portion of the substrate and a region between the electrode and the second fixed electrode portion of the substrate. In any one of Claims 4 thru | or 6,
The physical quantity sensor in which the number of the electrodes adjacent to the first fixed electrode portion and the number of the electrodes adjacent to the second fixed electrode portion are equal. In any one of Claims 4 thru | or 7,
A physical quantity sensor, wherein at least one of the electrode, the first fixed electrode portion, and the second fixed electrode portion is provided with a protruding portion that protrudes toward the movable body. In any one of Claims 1 thru | or 3,
The guard part is a physical quantity sensor which is a groove part. A substrate,
A movable body having a movable electrode portion;
A support part for supporting the movable body so as to be displaceable about a first axis;
A fixed electrode portion disposed on the substrate facing the movable electrode portion,
A physical quantity sensor provided with a guard part for suppressing an electrostatic force generated between the support part and the substrate in a region overlapping the support part in plan view on the substrate.   An electronic device comprising the physical quantity sensor according to claim 1.   A moving body comprising the physical quantity sensor according to claim 1.