JP2018132492A - Physical quantity sensor, physical quantity sensor device, electronic device and mobile object - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a physical quantity sensor that can reduce drift of output, and a physical quantity sensor device including the physical quantity sensor, an electronic apparatus and a movable body.SOLUTION: A physical quantity sensor comprises a base, a movable part that can swing around a swinging shaft with respect to the base, and an electrode that is arranged on the base. The movable part includes a first movable part that is located at one side of the swinging shaft, and a second movable part that is located at the other side and has a smaller moment of rotation around the swinging shaft than that of the first movable part. The electrode includes a first detection electrode that is arranged opposite to the first movable part, and a second detection electrode that is arranged opposite to the second movable part. The electrode includes a first exposed part in which a surface of the base is exposed on a periphery of the first detection electrode, and the first exposed part is arranged opposite to the first movable part; the electrode includes a second exposed part in which the surface of the base is exposed on a periphery of the second detection electrode, and the second exposed part is arranged opposite to the second movable part.SELECTED DRAWING: Figure 2

Description

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

  For example, a physical quantity sensor (acceleration sensor) described in Patent Literature 1 includes a base substrate, a movable portion that can swing a seesaw with respect to the base substrate, an electrode that is provided on the base substrate and is disposed to face the movable portion, have. The movable portion has a first movable portion located on one side of the swing shaft and a second movable portion located on the other side. In addition, the electrode includes a first detection electrode disposed to face the first movable portion, and a second detection electrode and a dummy electrode disposed to face the second movable portion. In such a physical quantity sensor, when the acceleration is applied, the movable part swings the seesaw, and thereby, the capacitance between the first movable part and the first detection electrode, the second movable part and the second detection electrode, Since the capacitance changes during the period, the applied acceleration is detected based on the change in the capacitance.

Special table 2003-519384 gazette

  However, in such a configuration, the electrostatic attraction between the first movable portion and the exposed portion of the base substrate (the surface exposed from the first detection electrode) generated by charging the base substrate, the second movable portion, The electrostatic attraction between the exposed portion of the base substrate (the surface exposed from the second detection electrode and the dummy electrode) is deviated. For this reason, the electrostatic attraction force causes the movable part to oscillate in spite of the absence of acceleration, resulting in output drift.

  The objective of this invention is providing the physical quantity sensor which can reduce the drift of an output, the physical quantity sensor device provided with this physical quantity sensor, an electronic device, and a moving body.

  Such an object is achieved by the present invention described below.

The physical quantity sensor of the present invention includes a base,
A movable part swingable about a swing axis with respect to the base part;
An electrode disposed on the base and disposed opposite to the movable portion;
The movable part is
A first movable part located on one side of the swing shaft;
A second movable portion located on the other side of the swing shaft and having a rotational moment around the swing shaft smaller than the first movable portion;
The electrode is
A first detection electrode disposed opposite to the first movable part;
A second detection electrode disposed opposite to the second movable part,
Around the first detection electrode, there is a first exposed portion where the surface of the base is exposed,
The first exposed portion is disposed opposite to the first movable portion,
Around the second detection electrode, there is a second exposed portion where the surface of the base is exposed,
The second exposed portion is disposed opposite to the second movable portion.
As a result, the electrostatic attractive force (second electrostatic attractive force) generated between the first exposed portion and the first movable portion by the electrostatic attractive force (second electrostatic attractive force) generated between the second exposed portion and the second movable portion. 1 electrostatic attraction) can be offset. Therefore, the swinging of the movable part due to the electrostatic attractive force can be suppressed, and the output drift can be reduced.

In the physical quantity sensor of the present invention, the electrode is
A first dummy electrode having the same potential as the movable portion;
The first movable part is
A tip portion disposed opposite to the first dummy electrode;
A proximal end portion that is located closer to the swing shaft than the distal end portion and is disposed opposite to the first detection electrode;
A connecting portion that connects the distal end portion and the proximal end portion,
The first exposed portion is formed between the first dummy electrode and the first detection electrode;
It is preferable that the first exposed portion is disposed to face at least a part of the connecting portion.
As described above, by providing the first dummy electrode, the first electrostatic attraction generated between the base and the first movable portion can be reduced, and the swing of the movable portion due to the first electrostatic attraction can be further reduced. It can be effectively reduced.

In the physical quantity sensor of the present invention, the second movable portion is
A main body disposed opposite to the second detection electrode;
It is preferable to have a protruding portion that protrudes from the main body portion and at least a part of the protruding portion is disposed to face the second exposed portion.
Thereby, a 2nd electrostatic attraction can be generated between the protrusion part and the 2nd exposure part, and at least a part of the 1st electrostatic attraction can be canceled by this 2nd electrostatic attraction. Thus, the swing of the movable part due to the first electrostatic attraction can be suppressed with a relatively simple configuration in which only the protrusion is provided.

In the physical quantity sensor of the present invention, the electrode is
A second dummy electrode disposed opposite to a part of the protruding portion and having the same potential as the movable portion;
The second exposed portion is formed between the second dummy electrode and the second detection electrode;
It is preferable that the second exposed portion is disposed to face a part of the protruding portion.
Thereby, the magnitude | size of 2nd electrostatic attraction can be adjusted by adjusting the separation distance of a 2nd dummy electrode and a 2nd detection electrode. Therefore, it is easy to adjust the magnitude of the second electrostatic attraction.

In the physical quantity sensor according to the aspect of the invention, the portion of the connecting portion that faces the first exposed portion and the portion of the protruding portion that faces the second exposed portion are arranged symmetrically with respect to the swing axis. It is preferable.
As a result, the rotational moment generated in the movable part by the first electrostatic attraction and the rotational moment generated in the movable part by the second electrostatic attraction become substantially equal, and the swing of the movable part by the first electrostatic attraction is further increased. It can be effectively reduced. Moreover, the physical quantity sensor can be easily designed by using such a symmetrical shape.

The physical quantity sensor device of the present invention includes the physical quantity sensor of the present invention,
And an electronic component electrically connected to the physical quantity sensor.
Thereby, the physical quantity sensor device which can enjoy the effect of the physical quantity sensor mentioned above and has high reliability is obtained.

The electronic device of the present invention includes the physical quantity sensor of the present invention.
Thereby, the electronic device which can enjoy the effect of the physical quantity sensor mentioned above and has high reliability is obtained.

The moving body of the present invention has the physical quantity sensor of the present invention.
Thereby, the moving body which can enjoy the effect of the physical quantity sensor mentioned above and has high reliability is obtained.

It is a top view of the physical quantity sensor which concerns on 1st Embodiment of this invention. It is the sectional view on the AA line in FIG. It is a graph which shows a drive voltage. It is sectional drawing explaining the action | operation of the physical quantity sensor shown in FIG. It is sectional drawing explaining the action | operation of the physical quantity sensor shown in FIG. It is sectional drawing explaining the action | operation of the physical quantity sensor shown in FIG. It is a partial expanded sectional view of the physical quantity sensor shown in FIG. It is a partial expanded sectional view of the physical quantity sensor shown in FIG. It is a partial expanded sectional view of the physical quantity sensor shown in FIG. It is a top view of the physical quantity sensor which concerns on 2nd Embodiment of this invention. It is the BB sectional view taken on the line in FIG. It is a top view of the physical quantity sensor which concerns on 3rd Embodiment of this invention. It is sectional drawing which shows the physical quantity sensor device which concerns on 4th Embodiment of this invention. It is a perspective view which shows the electronic device which concerns on 5th Embodiment of this invention. It is a perspective view which shows the electronic device which concerns on 6th Embodiment of this invention. It is a perspective view which shows the electronic device which concerns on 7th Embodiment of this invention. It is a perspective view which shows the mobile body which concerns on 8th Embodiment of this invention.

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

<First Embodiment>
First, the physical quantity sensor according to the first embodiment of the invention will be described.

  FIG. 1 is a plan view of a physical quantity sensor according to the first embodiment of the present invention. 2 is a cross-sectional view taken along line AA in FIG. FIG. 3 is a graph showing the drive voltage. 4 to 6 are sectional views for explaining the operation of the physical quantity sensor shown in FIG. 7 to 9 are partial enlarged sectional views of the physical quantity sensor shown in FIG.

  In the following, for convenience of explanation, the front side of the sheet in FIG. 1 and the upper side in FIG. 2 are also referred to as “up”, and the back side in FIG. 1 and the lower side in FIG. In each figure, an X axis, a Y axis, and a Z axis are shown as three axes orthogonal to each other. Hereinafter, a direction parallel to the X axis is also referred to as an “X axis direction”, a direction parallel to the Y axis is referred to as a “Y axis direction”, and a direction parallel to the Z axis is referred to as a “Z axis direction”. Further, the arrow tip side of each axis is also referred to as “plus side”, and the opposite side is also referred to as “minus side”.

  A physical quantity sensor 1 shown in FIG. 1 is an acceleration sensor that can measure an acceleration Az in the Z-axis direction (vertical direction). Such a physical quantity sensor 1 has a substrate 2, an element portion 3 disposed on the substrate 2, and a lid portion 4 joined to the substrate 2 so as to cover the element portion 3. Hereinafter, each of these units will be described in detail in order.

(substrate)
As shown in FIG. 1, the board | substrate 2 has comprised the plate shape which has a rectangular planar view shape. The substrate 2 also has a recess 21 that opens to the upper surface side. Further, the concave portion 21 is formed larger than the element portion 3 so as to enclose the element portion 3 inside in a plan view from the Z-axis direction. Such a recess 21 functions as an escape portion for preventing (suppressing) contact between the element portion 3 and the substrate 2.

  Further, as shown in FIG. 2, the substrate 2 has a protruding mount portion 22 provided on the bottom surface of the recess 21. The element unit 3 is joined to the mount unit 22. Thereby, the element part 3 can be fixed to the board | substrate 2 in the state spaced apart from the bottom face of the recessed part 21. FIG.

  Moreover, as shown in FIG. 1, the board | substrate 2 has the groove parts 25, 26, and 27 opened to the upper surface side. In addition, one end portions of the groove portions 25, 26, and 27 are respectively positioned outside the lid portion 4, and the other end portions are respectively connected to the recessed portions 21.

As such a substrate 2, for example, a glass substrate made of a glass material containing alkali metal ions (movable ions such as Na ⁺ ) (for example, borosilicate glass such as Pyrex glass (registered trademark)) is used. Can do. Thereby, for example, depending on the constituent material of the lid part 4, the substrate 2 and the lid part 4 can be joined by anodic bonding, and these can be firmly joined. In addition, since the light-transmitting substrate 2 is obtained, the state of the element unit 3 (for example, the element unit 3 sticks to the bottom surface of the recess 21 from the outside of the physical quantity sensor 1 through the substrate 2 is a phenomenon. The presence or absence of “sticking” can be visually recognized.

  However, the substrate 2 is not particularly limited, and for example, a silicon substrate or a ceramic substrate may be used. In the case where a silicon substrate is used as the substrate 2, from the viewpoint of preventing a short circuit, a high resistance silicon substrate is used, or a silicon substrate having a silicon oxide film (insulating oxide) formed on the surface by thermal oxidation or the like is used. It is preferable.

  As shown in FIGS. 1 and 2, a first detection electrode 81, a second detection electrode 82, and a dummy electrode 83 are arranged as electrodes 8 on the bottom surface of the recess 21 so as to be separated from each other. The first detection electrode 81, the second detection electrode 82, and the dummy electrode 83 will be described in detail later.

  Further, as shown in FIG. 1, wirings 71, 72, and 73 are provided in the groove portions 25, 26, and 27. Further, one end portions of the wirings 71, 72, 73 are exposed to the outside of the lid portion 4, and function as electrode pads P that are electrically connected to an external device. The other end portion of the wiring 71 is routed to the mount portion 22 through the bottom surface of the recess 21, and is electrically connected to the element portion 3 via the conductive bump B on the mount portion 22. . In addition, the wiring 71 branches off in the middle and is electrically connected to the dummy electrode 83. The other end of the wiring 72 is electrically connected to the first detection electrode 81, and the other end of the wiring 73 is electrically connected to the second detection electrode 82.

  The constituent materials of the first detection electrode 81, the second detection electrode 82, the dummy electrode 83, and the wirings 71, 72, and 73 are not particularly limited. For example, gold (Au), silver (Ag), platinum ( Pt), palladium (Pd), iridium (Ir), copper (Cu), aluminum (Al), nickel (Ni), Ti (titanium), tungsten (W) and other metal materials, alloys containing these metal materials, ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), oxide-based transparent conductive materials such as ZnO, IGZO, and the like can be given, and one of these or a combination of two or more thereof (for example, lamination of two or more layers) As body).

  Among these materials, it is preferable to use a transparent conductive material for at least the first detection electrode 81, the second detection electrode 82, and the dummy electrode 83. Thereby, the state of the element unit 3 can be visually recognized from the outside of the physical quantity sensor 1 through the substrate 2 and the electrodes 81, 82, 83.

(Cover)
As shown in FIG. 1, the cover part 4 has comprised the plate shape which has a rectangular planar view shape. Moreover, as shown in FIG. 2, the cover part 4 has the recessed part 41 open | released in the lower surface side (board | substrate 2 side). Such a lid portion 4 is bonded to the upper surface of the substrate 2 so as to house the element portion 3 in the recess 41. A storage space S for storing the element portion 3 is formed inside the lid portion 4 and the substrate 2.

  As shown in FIG. 2, the lid 4 has a communication hole 42 that communicates the inside and outside of the storage space S. The storage space S can be replaced with a desired atmosphere through the communication hole 42. A sealing member 43 is disposed in the communication hole 42, and the communication hole 42 is hermetically sealed by the sealing member 43.

  The sealing member 43 is not particularly limited as long as the communication hole 42 can be sealed. For example, gold (Au) / tin (Sn) alloy, gold (Au) / germanium (Ge) alloy, gold (Au) / Various alloys such as aluminum (Al) alloys, glass materials such as low melting point glass, and the like can be used.

  The storage space S is an airtight space. The storage space S is preferably filled with an inert gas such as nitrogen, helium, or argon and is at atmospheric pressure at the operating temperature (about −40 ° C. to 80 ° C.). By setting the storage space S to atmospheric pressure, the viscous resistance is increased and the damping effect is exhibited, so that the vibration of the element unit 3 can be quickly converged. Therefore, the accuracy of detecting the acceleration of the physical quantity sensor 1 is improved.

  As such a cover part 4, a silicon substrate can be used, for example. However, the lid 4 is not particularly limited, and for example, a glass substrate or a ceramic substrate may be used. Moreover, it does not specifically limit as a joining method of the board | substrate 2 and the cover part 4, What is necessary is just to select suitably according to the material of the board | substrate 2 and the cover part 4, For example, the joining surface activated by anodic bonding and plasma irradiation Examples include activation bonding for bonding together, bonding with a bonding material such as glass frit, diffusion bonding for bonding metal films formed on the upper surface of the substrate 2 and the lower surface of the lid 4, and the like.

In the present embodiment, as shown in FIG. 2, the substrate 2 and the lid 4 are bonded via a glass frit 49 (low melting point glass) which is an example of a bonding material. In the state where the substrate 2 and the lid portion 4 are overlapped, the inside and outside of the storage space S communicate with each other through the groove portions 25, 26, and 27, but by using the glass frit 49, the substrate 2 and the lid portion 4 And the grooves 25, 26, and 27 can be sealed. Therefore, the storage space S can be hermetically sealed more easily. When the substrate 2 and the lid 4 are bonded by anodic bonding or the like (a bonding method in which the grooves 25, 26, and 27 cannot be sealed), for example, formed by a CVD method using TEOS (tetraethoxysilane) or the like. The groove portions 25, 26, and 27 can be closed by the formed SiO ₂ film.

(Element part)
The element unit 3 is provided above the substrate 2. As shown in FIG. 1, the element portion 3 includes a fixed portion 31 having a joint portion 311 joined to the mount portion 22, a movable portion 32 that can be displaced with respect to the fixed portion 31, and the fixed portion 31 and the movable portion 32. And a beam portion 33 that connects the two. The movable portion 32 can swing the seesaw with respect to the fixed portion 31 while twisting and deforming the beam portion 33 about the beam portion 33 as the swing axis J.

  Such an element part 3 can be formed, for example, by patterning a silicon substrate doped with impurities such as phosphorus (P) and boron (B). The element unit 3 is bonded to the substrate 2 (mount unit 22) by, for example, anodic bonding. However, the material of the element part 3 and the bonding method of the element part 3 to the substrate 2 are not particularly limited.

  The movable portion 32 has a longitudinal shape extending in the X direction, and a portion on the plus side (one side) in the X axis direction with respect to the swing axis J is a first movable portion 321, A portion on the negative side (the other side) in the X-axis direction is the second movable portion 322. Further, the first movable portion 321 is longer in the X-axis direction than the second movable portion 322, and the rotational moment (torque) when the acceleration Az is applied is larger than that of the second movable portion 322. When the acceleration Az is applied due to the difference in rotational moment, the movable portion 32 swings the seesaw around the swing axis J.

  The first movable portion 321 is located between the proximal end portion 321a located on the proximal end side, the distal end portion 321b located on the distal end side, and the proximal end portion 321a and the distal end portion 321b, and a connecting portion 321c that connects them. And have.

  A pair of connection portions 321c are provided, and are provided at both ends of the first movable portion 321 in the width direction (Y-axis direction). Each connecting portion 321c extends in the X-axis direction, and the width (the length in the Y-axis direction) is substantially constant along the extending direction. However, the configuration of the connecting portion 321c is not particularly limited as long as the base end portion 321a and the distal end portion 321b can be connected. For example, one or three or more connecting portions 321c are provided. Also good.

  The second movable portion 322 includes a main body portion 322a and a protruding portion 322c that protrudes from the main body portion 322a toward the minus side in the X-axis direction.

  A pair of projecting portions 322c are provided, and are provided at both ends of the second movable portion 322 in the width direction (Y-axis direction). Each protrusion 322c extends in the X-axis direction, and has a substantially constant width (length in the Y-axis direction) along the extending direction. However, the configuration of the protruding portion 322c is not particularly limited, and for example, one or three or more protruding portions 322c may be provided.

  In such an element part 3, the base end part 321a of the first movable part 321 and the main body part 322a of the second movable part 322 are in relation to the swing axis J in a plan view seen from the Z-axis direction. It is provided symmetrically. Also, the connecting portion 321c of the first movable portion 321 and the protruding portion 322c of the second movable portion 322 are provided symmetrically with respect to the swing axis J in a plan view as viewed from the Z-axis direction.

  Further, in order to reduce the resistance of the movable portion 32 when the seesaw is swung, a plurality of through holes 320 are formed in each of the first movable portion 321 and the second movable portion 322. However, the through-hole 320 may be formed as necessary and may be omitted.

  As shown in FIG. 2, the above-described electrodes 8 (first detection electrode 81, second detection electrode 82, and dummy electrode 83) are provided so as to face the element portion 3 as described above. The first detection electrode 81 is disposed to face the base end portion 321a of the first movable portion 321. Thereby, a capacitance C1 is formed between the first detection electrode 81 and the base end portion 321a. The In addition, the second detection electrode 82 is disposed to face the main body 322a of the second movable portion 322, thereby forming a capacitance C2 between the second detection electrode 82 and the main body 322a. The The first and second detection electrodes 81 and 82 are provided symmetrically with respect to the swing axis J in a plan view as viewed from the Z-axis direction, and are static in a state where no acceleration Az is applied. It is preferable that the capacitances C1 and C2 are substantially equal to each other.

  The dummy electrode 83 includes a first dummy electrode 831 disposed on the X axis direction plus side of the first detection electrode 81, and a second dummy electrode 832 disposed on the X axis direction minus side of the second detection electrode 82. ,have. The first dummy electrode 831 is disposed so as to face the distal end portion 321b of the first movable portion 321. The second dummy electrode 832 is disposed to face the protruding portion 322c of the second movable portion 322. As described above, the dummy electrode 83 is electrically connected to the movable portion 32 via the wiring 71 and has the same potential as the movable portion 32. Therefore, no electrostatic capacitance is substantially formed between the first movable part 321 and the first dummy electrode 831 and between the second movable part 322 and the second dummy electrode 832.

Such a dummy electrode 83 has the following functions, for example. For example, when the bottom surface 211 of the concave portion 21 is charged due to the movement of movable ions (Na ⁺ ) in the substrate 2 and the surface potential of the bottom surface 211 changes, an electrostatic attractive force is generated between the bottom surface 211 and the movable portion 32. Then, the first movable portion 321 is attracted to the substrate 2 by this electrostatic attraction, and the movable portion 32 swings (inclines) even though the acceleration Az is not applied. As a result, output drift occurs. In addition, the “sticking” in which the movable portion 32 attracted to the substrate 2 by the electrostatic attraction force sticks to the bottom surface 211 may occur, and the sensor may not function. Therefore, by arranging a dummy electrode 83 having the same potential as that of the movable portion 32 on the bottom surface 211, the influence of charging of the bottom surface 211 is reduced, and the above-described problems are hardly caused.

  Next, the operation of the physical quantity sensor 1 will be described. When the physical quantity sensor 1 is operated, for example, the voltage V1 in FIG. 3 is applied to the movable portion 32, and the voltage V2 in FIG. 3 is applied to the first detection electrode 81 and the second detection electrode 82, respectively. . As shown in FIG. 4, when the acceleration Az is not applied to the physical quantity sensor 1, the movable unit 32 maintains a state parallel to the substrate 2, and both the capacitances C <b> 1 and C <b> 2 do not change. On the other hand, as illustrated in FIG. 5, when acceleration −Az in the Z-axis direction minus side is applied to the physical quantity sensor 1, the movable part 32 is caused by a difference in rotational moment between the first and second movable parts 321 and 322. Swings the seesaw counterclockwise about the swing axis J. On the contrary, as shown in FIG. 6, when the acceleration + Az in the positive direction of the Z axis is applied to the physical quantity sensor 1, the movable portion 32 swings the seesaw clockwise about the swing axis J. By such seesaw swinging of the movable portion 32, the gap between the first movable portion 321 and the first detection electrode 81 and the gap between the second movable portion 322 and the second detection electrode 82 change, and the capacitance is accordingly changed. C1 and C2 change. Therefore, the acceleration Az can be detected based on the amount of change in the capacitances C1 and C2 (differential signals of the capacitances C1 and C2).

  Here, the first dummy electrode 831 described above must be physically separated from the first detection electrode 81 in order to be insulated from the first detection electrode 81. Therefore, between these, as shown in FIG. 7, the 1st exposed part 211a which the bottom face 211 exposes is formed. Since the first exposed portion 211a faces the connecting portion 321c of the first movable portion 321, if the bottom surface 211 is charged, a first electrostatic attractive force F1 is generated between the first exposed portion 211a and the connecting portion 321c. . Then, the first movable portion 321 is attracted to the substrate 2 by the first electrostatic attractive force F1, and the movable portion 32 swings (inclines) even though the acceleration Az is not applied as shown in FIG. As a result, output drift occurs.

  Therefore, in the present embodiment, in order to reduce (preferably prevent) the swing of the movable portion 32 due to the first electrostatic attraction force F1, a second electrostatic attraction force F2 for generating a reverse rotational moment is generated. ing. Thereby, at least a part of the first electrostatic attraction F1 is canceled by the second electrostatic attraction F2, and the swinging of the movable portion 32 as described above can be reduced (preferably prevented). This will be described below.

  The second dummy electrode 832 is physically separated from the second detection electrode 82 in order to insulate from the second detection electrode 82. Therefore, as shown in FIG. 9, a second exposed portion 211 b where the bottom surface 211 is exposed is formed between the second dummy electrode 832 and the second detection electrode 82. The second exposed portion 211b faces the protruding portion 322c. If the bottom surface 211 is charged, a second electrostatic attractive force F2 is generated between the second exposed portion 211b and the protruding portion 322c. By this second electrostatic attraction force F2, at least a part of the first electrostatic attraction force F1 can be canceled, and the swing of the movable portion 32 in a state where the acceleration Az is not applied can be reduced. As a result, output drift can be reduced.

  In particular, in the present embodiment, as shown in FIG. 1, a portion 321c ′ of the connecting portion 321c facing the first exposed portion 211a and a portion 322c ′ of the protruding portion 322c facing the second exposed portion 211b are Z They are arranged symmetrically with respect to the swing axis J in a plan view seen from the axial direction. Thereby, the distance L1 (see FIG. 7) from the swing axis J to the position where the first electrostatic attraction force F1 is applied, and the distance L2 from the swing axis J to the position where the second electrostatic attraction force F2 is applied (see FIG. 9). ) Are substantially equal, and the first electrostatic attractive force F1 and the second electrostatic attractive force F2 are substantially equal. Therefore, the rotational moment generated in the movable part 32 by the first electrostatic attractive force F1 and the rotational moment generated in the movable part 32 by the second electrostatic attractive force F2 are substantially equal, and the movable part 32 by the first electrostatic attractive force F1. Can be more effectively reduced. Moreover, there exists an advantage that the design of the physical quantity sensor 1 becomes easy by setting it as such a symmetrical shape.

  The rotational moment N2 generated in the movable part 32 by the second electrostatic attractive force F2 is preferably as small as the difference from the rotational moment N1 generated in the movable part 32 by the first electrostatic attractive force F1. Specifically, (N2 / N1) is preferably 0.8 or more and 1.2 or less, more preferably 0.9 or more and 1.1 or less, and 0.95 or more and 1.05. The following is more preferable, and 1 is most preferable. Thereby, the swinging of the movable part 32 due to the first electrostatic attractive force F1 can be reduced more effectively.

  Note that the area of the portion 321c ′ of the connecting portion 321c facing the first exposed portion 211a is S1, the distance between the connecting portion 321c and the first exposed portion 211a is d1, and the connecting portion 321c and the first exposed portion 211a. When the voltage (potential difference) applied during the period is V1, the first electrostatic attraction F1 is expressed by the following formula (1). Further, the rotational moment N1 generated in the movable portion 32 by the first electrostatic attraction force F1 is expressed by the following equation (2) when the distance from the swing axis J to the position where the first electrostatic attraction force F1 is applied is L1. .

  In addition, the area of the portion 322c ′ of the protruding portion 322c facing the second exposed portion 211b is S2, the distance between the protruding portion 322c and the second exposed portion 211b is d2, and the protruding portion 322c and the second exposed portion 211b. When the voltage (potential difference) applied during the period is V2, the second electrostatic attractive force F2 is expressed by the following formula (3). Further, the rotational moment N2 generated in the movable portion 32 by the second electrostatic attraction force F2 is expressed by the following formula (4) when the distance from the swing axis J to the position where the second electrostatic attraction force F2 is applied is L2. .

  In the physical quantity sensor 1, since the separation distances d1 and d2 and the voltages V1 and V2 are designed to be equal, the areas S1 and S2 are equalized and the distances L1 and L2 are equalized as in the present embodiment. N2 / N1) can be easily set to 1 (closer to 1).

  The physical quantity sensor 1 has been described above. As described above, the physical quantity sensor 1 has the substrate 2 as the base, the movable portion 32 that can swing around the swing axis J with respect to the substrate 2, and the movable portion 32 that is disposed on the substrate 2. And an electrode 8 disposed to face each other. The movable part 32 is located on one side of the swing axis J and the other side of the swing axis J, and the rotational moment around the swing axis J is greater than that of the first movable part 321. And a small second movable portion 322. In addition, the electrode 8 includes a first detection electrode 81 disposed to face the first movable portion 321 and a second detection electrode 82 disposed to face the second movable portion 322. Further, there is a first exposed portion 211a around the first detection electrode 81 where the surface (bottom surface 211) of the substrate 2 is exposed, and the first exposed portion 211a is disposed opposite to the first movable portion 321. Around the second detection electrode 82, there is a second exposed portion 211 b where the surface (bottom surface 211) of the substrate 2 is exposed, and the second exposed portion 211 b is disposed opposite to the second movable portion 322. Accordingly, the first electrostatic attraction generated between the first exposed portion 211a and the first movable portion 321 due to the second electrostatic attractive force F2 generated between the second exposed portion 211b and the second movable portion 322. At least a portion of F1 can be offset. Therefore, the swing of the movable part 32 caused by a force other than the acceleration Az (that is, a force other than the force to be detected) can be suppressed, and output drift can be reduced.

  Further, as described above, the electrode 8 has the first dummy electrode 831 that has the same potential as the movable portion 32. The first movable portion 321 is positioned opposite to the first dummy electrode 831, is positioned closer to the swing axis J than the tip portion 321 b, and is positioned opposite to the first detection electrode 81. It has the base end part 321a and the connection part 321c which connects the front-end | tip part 321b and the base end part 321a. A first exposed portion 211a is formed between the first dummy electrode 831 and the first detection electrode 81, and the first exposed portion 211a is disposed to face at least a part of the connecting portion 321c. As described above, by providing the first dummy electrode 831, the first electrostatic attractive force F <b> 1 generated between the substrate 2 and the first movable portion 321 can be reduced, and the movable portion due to the first electrostatic attractive force F <b> 1. The swing of 32 can be reduced more effectively.

  Note that the first dummy electrode 831 may be omitted. In this case, the rotational moment due to the first electrostatic attractive force F1 becomes larger than that in the present embodiment, but the rotational moment due to the second electrostatic attractive force F2 may be designed correspondingly.

  Further, as described above, the second movable portion 322 protrudes from the main body portion 322a facing the second detection electrode 82 and the main body portion 322a, and at least a part thereof is disposed facing the second exposed portion 211b. And a protruding portion 322c. Thereby, the second electrostatic attractive force F2 can be generated between the protruding portion 322c and the second exposed portion 211b, and at least a part of the first electrostatic attractive force F1 is canceled by the second electrostatic attractive force F2. can do. Thereby, the swinging of the movable part 32 due to the first electrostatic attractive force F1 can be suppressed with a relatively simple configuration in which only the protruding part 322c is provided.

  In addition, as described above, the electrode 8 includes the second dummy electrode 832 that is disposed to face a part of the protruding portion 322c and has the same potential as the movable portion 32, and the second dummy electrode 832 and the second detection electrode. A second exposed portion 211b is formed between the second exposed portion 211b and the second exposed portion 211b. The second exposed portion 211b is disposed to face a part of the protruding portion 322c. According to such a configuration, for example, the magnitude of the second electrostatic attractive force F2 can be adjusted by adjusting the separation distance between the second dummy electrode 832 and the second detection electrode 82. Therefore, it is easy to adjust the magnitude of the second electrostatic attractive force F2. Note that the second dummy electrode 832 may be omitted. In this case, the magnitude of the second electrostatic attraction can be adjusted by adjusting the shape (planar shape) of the protruding portion 322c.

  Further, as described above, the portion 321c ′ facing the first exposed portion 211a of the connecting portion 321c and the portion 322c ′ facing the second exposed portion 211b of the protruding portion 322c are seen in a plan view as viewed from the Z-axis direction. Thus, they are arranged symmetrically with respect to the swing axis J. Thereby, the rotational moment generated in the movable part 32 by the first electrostatic attractive force F1 and the rotational moment generated in the movable part 32 by the second electrostatic attractive force F2 are substantially equal, and the movable part by the first electrostatic attractive force F1. The swing of 32 can be reduced more effectively. Moreover, there exists an advantage that the design of the physical quantity sensor 1 becomes easy by setting it as such a symmetrical shape.

  The portion 321c ′ facing the first exposed portion 211a of the connecting portion 321c and the portion 322c ′ facing the second exposed portion 211b of the protruding portion 322c are arranged symmetrically with respect to the swing axis J. It does not have to be. For example, when the portion 322c ′ is closer to the swing axis J than the portion 321c ′, for example, the area S2 of the portion 322c ′ is made larger than the area S1 of the portion 321c ′ and the second electrostatic attractive force F2 is increased. By increasing the one electrostatic attraction force F1, the swing of the movable portion 32 due to the first electrostatic attraction force F1 can be effectively reduced. On the other hand, when the portion 322c ′ is farther from the swing axis J than the portion 321c ′, for example, the area S2 of the portion 322c ′ is made smaller than the area S1 of the portion 321c ′ and the second electrostatic attractive force F2 is set. By also reducing the first electrostatic attractive force F1, the swing of the movable portion 32 due to the first electrostatic attractive force F1 can be effectively reduced. That is, it is sufficient to design so that S1 · L1 and S2 · L2 are equal.

  In the present embodiment, as shown in FIG. 7, the distance D1 between the first detection electrode 81 and the first dummy electrode 831 (that is, the length of the first exposed portion 211a) is the length of the connecting portion 321c. The first exposed portion 211a is shorter than L ′ (the length in the X-axis direction) and faces the central portion excluding both ends of the connecting portion 321c. Similarly, as shown in FIG. 9, the separation distance D2 between the second detection electrode 82 and the second dummy electrode 832 (that is, the length of the second exposed portion 211b) is the length L ″ (X The second exposed portion 211b is opposed to the central portion excluding both end portions of the projecting portion 322c, so that the element portion 3 is located on the substrate 2 due to a manufacturing error or the like. Even if the first and second electrostatic attractive forces F1 and F2 are displaced from each other in the X-axis direction, it is possible to suppress the deviation from the design value, although the distances D1 and D2 are not particularly limited. For example, the length can be about 3 μm or more and 5 μm or less, and the lengths L ′ and L ″ can be about 20 μm or more and 30 μm or less, for example. Thereby, it is possible to sufficiently tolerate manufacturing errors that may occur.

Second Embodiment
Next, a physical quantity sensor according to a second embodiment of the invention will be described.

  FIG. 10 is a plan view of a physical quantity sensor according to the second embodiment of the present invention. 11 is a cross-sectional view taken along the line BB in FIG.

  The physical quantity sensor according to the present embodiment is the same as the physical quantity sensor according to the first embodiment described above except that the shape of the substrate is mainly different.

  In the following description, the physical quantity sensor according to the second embodiment will be described with a focus on the differences from the first embodiment described above, and description of similar matters will be omitted. In FIGS. 10 and 11, the same reference numerals are given to the same configurations as those of the above-described embodiment.

  As shown in FIG. 10, in this embodiment, compared with 1st Embodiment mentioned above, the connection part 321c and the protrusion part 322c are designed longer. Moreover, in the 1st movable part 321, the front-end | tip part 321b protrudes between a pair of connection parts 321c.

  As shown in FIG. 11, the bottom surface 211 of the substrate 2 has a first bottom surface 211 ′ and a second bottom surface 211 ″ protruding from the first bottom surface 211 ′. The first bottom surface 211 ′ and the second bottom surface 211 ″ having a smaller distance from the movable portion 32 than the first bottom surface 211 ′. Note that the second bottom surface 211 ″ is provided symmetrically with respect to the swing axis J in a plan view viewed from the Z-axis direction.

  The first and second detection electrodes 81 and 82 are mainly disposed on the second bottom surface 211 ″. Thereby, the first detection electrode 81 and the first movable portion 321 (base end portion 321a) are arranged. And the gap between the second detection electrode 82 and the second movable portion 322 (main body portion 322a) can be reduced, respectively, so that the static electricity formed between the first detection electrode 81 and the first movable portion 321 can be reduced. Capacitance C1 and the capacitance C2 formed between the second detection electrode 82 and the second movable portion 322 can be increased, and the acceleration Az can be detected with higher accuracy.

  Further, the portion of the first detection electrode 81 facing the connecting portion 321c extends to the first bottom surface 211 '. The first dummy electrode 831 is mainly disposed on the first bottom surface 211 '. Therefore, the first exposed portion 211a is located on the first bottom surface 211 '. That is, the portion 321c 'of the connecting portion 321c facing the first exposed portion 211a is located on the first bottom surface 211'. Thereby, the separation distance between the portion 321c 'and the bottom surface 211 can be increased. Therefore, the first electrostatic attractive force F1 can be reduced, and the swing of the movable portion 32 due to the first electrostatic attractive force F1 can be reduced more effectively.

  Further, the portion of the second detection electrode 82 facing the protruding portion 322c extends to the first bottom surface 211 '. The second dummy electrode 832 is mainly disposed on the first bottom surface 211 '. Therefore, the second exposed portion 211b is located on the first bottom surface 211 '. That is, the portion 322c 'of the protruding portion 322c facing the second exposed portion 211b is located on the first bottom surface 211'. Thereby, the separation distance between the portion 322c ′ and the bottom surface 211 can be made equal to the separation distance between the portion 321c ′ and the bottom surface 211, and the second electrostatic attraction force F2 having the same magnitude as the first electrostatic attraction force F1 is formed. It becomes easy.

  Also according to the second embodiment, the same effects as those of the first embodiment described above can be exhibited.

<Third Embodiment>
Next, a physical quantity sensor according to a third embodiment of the invention will be described.

FIG. 12 is a plan view of a physical quantity sensor according to the third embodiment of the present invention.
The physical quantity sensor according to the present embodiment is the same as the physical quantity sensor according to the first embodiment described above except that the shapes of the element part and the dummy electrode are mainly different.

  As shown in FIG. 12, a pair of connecting portions 321c are provided extending from the distal end portion of the base end portion 321a to both sides in the Y-axis direction. Similarly, a pair of protrusions 322c are provided to extend from the tip of the main body 322a to both sides in the Y-axis direction. As in the first embodiment described above, the connecting portion 321c and the protruding portion 322c are provided symmetrically with respect to the swing axis J.

  The dummy electrode 83 is composed of a first dummy electrode 831. That is, the second dummy electrode 832 that was present in the first embodiment described above is omitted. The first dummy electrode 831 is located on the Y axis direction plus side of the first and second detection electrodes 81 and 82, and extends in the X axis direction, and on the Y axis direction minus side. And a second extending portion 831b extending in the X-axis direction.

  Further, the first extending portion 831a faces the distal end portions of the connecting portion 321c and the protruding portion 322c that are located on the Y axis direction plus side. Further, the second extending portion 831b faces the distal end portions of the connecting portion 321c and the protruding portion 322c located on the Y axis direction negative side. A first exposed portion 211a is formed between the first and second extending portions 831a and 831b and the first detection electrode 81, and the first exposed portion 211a faces the connecting portion 321c. Similarly, a second exposed portion 211b is formed between the first and second extending portions 831a and 831b and the second detection electrode 82, and the second exposed portion 211b faces the protruding portion 322c.

  Also according to the third embodiment, the same effects as those of the first embodiment described above can be exhibited.

<Fourth embodiment>
Next, a physical quantity sensor device according to a fourth embodiment of the invention will be described.

FIG. 13 is a cross-sectional view showing a physical quantity sensor device according to the fourth embodiment of the present invention.
As shown in FIG. 13, a physical quantity sensor device 1000 includes a base substrate 1010, a physical quantity sensor 1 provided on the base substrate 1010, a circuit element 1020 (electronic component) provided on the physical quantity sensor 1, and a physical quantity sensor. 1 and a bonding wire BW1 that electrically connects the circuit element 1020; a bonding wire BW2 that electrically connects the base substrate 1010 and the circuit element 1020; and a molding unit 1030 that molds the physical quantity sensor 1 and the circuit element 1020. ,have. Here, as the physical quantity sensor 1, for example, any of the first to third embodiments described above can be used.

  The base substrate 1010 is a substrate that supports the physical quantity sensor 1, and is, for example, an interposer substrate. A plurality of connection terminals 1011 are arranged on the upper surface of the base substrate 1010 and a plurality of mounting terminals 1012 are arranged on the lower surface. In addition, internal wiring (not shown) is arranged in the base substrate 1010, and each connection terminal 1011 is electrically connected to the corresponding mounting terminal 1012 through this internal wiring. Such a base substrate 1010 is not particularly limited, and for example, a silicon substrate, a ceramic substrate, a resin substrate, a glass substrate, a glass epoxy substrate, or the like can be used.

  Further, the physical quantity sensor 1 is disposed on the base substrate 1010 with the substrate 2 facing downward (base substrate 1010 side). The physical quantity sensor 1 is bonded to the base substrate 1010 via a bonding member.

  The circuit element 1020 is disposed on the physical quantity sensor 1. The circuit element 1020 is joined to the lid 4 of the physical quantity sensor 1 via a joining member. The circuit element 1020 is electrically connected to each electrode pad P of the physical quantity sensor 1 through the bonding wire BW1, and is electrically connected to the connection terminal 1011 of the base substrate 1010 through the bonding wire BW2. Such a circuit element 1020 includes a drive circuit that drives the physical quantity sensor 1, a detection circuit that detects acceleration based on an output signal from the physical quantity sensor 1, and a signal from the detection circuit that is converted into a predetermined signal. An output circuit or the like for output is included as necessary.

  The mold unit 1030 molds the physical quantity sensor 1 and the circuit element 1020. Thereby, the physical quantity sensor 1 and the circuit element 1020 can be protected from moisture, dust, impact, and the like. Although it does not specifically limit as the mold part 1030, For example, a thermosetting epoxy resin can be used, For example, it can mold by the transfer mold method.

  The physical quantity sensor device 1000 as described above includes the physical quantity sensor 1 and a circuit element 1020 as an electronic component that is electrically connected to the physical quantity sensor 1. Therefore, the effect of the physical quantity sensor 1 can be enjoyed, and a highly reliable physical quantity sensor device 1000 can be obtained.

  Note that the configuration of the physical quantity sensor device 1000 is not limited to the above configuration, and for example, the physical quantity sensor 1 may be configured to be housed in a ceramic package.

<Fifth Embodiment>
Next, an electronic apparatus according to a fifth embodiment of the invention will be described.

FIG. 14 is a perspective view showing an electronic apparatus according to the fifth embodiment of the present invention.
A mobile (or notebook) personal computer 1100 shown in FIG. 14 is an application of an electronic device including the physical quantity sensor of the present invention. In this figure, a personal computer 1100 includes a main body portion 1104 provided with a keyboard 1102 and a display unit 1106 provided with a display portion 1108. The display unit 1106 is rotated with respect to the main body portion 1104 via a hinge structure portion. It is supported movably. Such a personal computer 1100 incorporates a physical quantity sensor 1 that functions as an acceleration sensor. Here, as the physical quantity sensor 1, for example, any of the first to third embodiments described above can be used.

  Such a personal computer 1100 (electronic device) has a physical quantity sensor 1. Therefore, the effect of the physical quantity sensor 1 described above can be enjoyed and high reliability can be exhibited.

<Sixth Embodiment>
Next, an electronic apparatus according to a sixth embodiment of the invention will be described.

FIG. 15 is a perspective view showing an electronic apparatus according to the sixth embodiment of the present invention.
A cellular phone 1200 (including PHS) illustrated in FIG. 15 is an application of an electronic device including the physical quantity sensor of the present invention. In this figure, a cellular phone 1200 includes an antenna (not shown), a plurality of operation buttons 1202, an earpiece 1204, and a mouthpiece 1206, and a display unit 1208 is provided between the operation buttons 1202 and the earpiece 1204. Has been placed. Such a cellular phone 1200 incorporates a physical quantity sensor 1 that functions as an acceleration sensor. Here, as the physical quantity sensor 1, for example, any of the first to third embodiments described above can be used.

  Such a cellular phone 1200 (electronic device) has a physical quantity sensor 1. Therefore, the effect of the physical quantity sensor 1 described above can be enjoyed and high reliability can be exhibited.

<Seventh embodiment>
Next, an electronic apparatus according to a seventh embodiment of the invention will be described.

FIG. 16 is a perspective view showing an electronic apparatus according to the seventh embodiment of the present invention.
A digital still camera 1300 shown in FIG. 16 is an application of an electronic device including the physical quantity sensor of the present invention. In this figure, a display unit 1310 is provided on the back of a case (body) 1302, and is configured to display based on an image pickup signal by a CCD. The display unit 1310 is a finder that displays an object as an electronic image. Function. 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. Such a digital still camera 1300 incorporates a physical quantity sensor 1 that functions as an acceleration sensor. Here, as the physical quantity sensor 1, for example, any of the first to third embodiments described above can be used.

  Such a digital still camera 1300 (electronic device) has a physical quantity sensor 1. Therefore, the effect of the physical quantity sensor 1 described above can be enjoyed and high reliability can be exhibited.

  The electronic device of the present invention includes, for example, a smart phone, a tablet terminal, a watch (including a smart watch), an ink jet discharge, in addition to the personal computer and mobile phone of the above-described embodiment and the digital still camera of the present embodiment. Wearable terminals such as devices (for example, inkjet printers), laptop personal computers, televisions, HMDs (head-mounted displays), video cameras, video tape recorders, car navigation devices, pagers, electronic notebooks (including those with communication functions), electronic Dictionary, calculator, electronic game device, word processor, workstation, video phone, security TV monitor, electronic binoculars, POS terminal, medical device (eg electronic thermometer, blood pressure monitor, blood glucose meter, electrocardiogram measuring device, ultrasound diagnosis Device, electronic endoscope), fish finder, various measuring equipment, mobile terminal base station equipment, instruments (eg, vehicles, aircraft, ship instruments), flight simulator, network server, etc. it can.

<Eighth Embodiment>
Next, a moving object according to an eighth embodiment of the invention will be described.

FIG. 17 is a perspective view showing a moving body according to the eighth embodiment of the present invention.
An automobile 1500 shown in FIG. 17 is an automobile to which a moving body including the physical quantity sensor of the present invention is applied. In this figure, an automobile 1500 has a built-in physical quantity sensor 1 that functions as an acceleration sensor, and the physical quantity sensor 1 can detect the posture of the vehicle body 1501. The detection signal of the physical quantity sensor 1 is supplied to the vehicle body posture control device 1502, and the vehicle body posture control device 1502 detects the posture of the vehicle body 1501 based on the signal, and controls the stiffness of the suspension according to the detection result. The brakes of the individual wheels 1503 can be controlled. Here, as the physical quantity sensor 1, for example, any of the first to third embodiments described above can be used.

  Such an automobile 1500 (moving body) has a physical quantity sensor 1. Therefore, the effect of the physical quantity sensor 1 described above can be enjoyed and high reliability can be exhibited.

  In addition, the physical quantity sensor 1 includes a car navigation system, a car air conditioner, an anti-lock brake system (ABS), an air bag, a tire pressure monitoring system (TPMS), an engine control, and a hybrid vehicle. It can be widely applied to electronic control units (ECU) such as battery monitors for electric vehicles and electric vehicles.

  Further, the moving body is not limited to the automobile 1500, and can be applied to, for example, an unmanned airplane such as an airplane, a rocket, an artificial satellite, a ship, an AGV (automated guided vehicle), a bipedal walking robot, and a drone. .

  As described above, the physical quantity sensor, the physical quantity sensor device, the electronic apparatus, and the moving body of the present invention have been described based on the illustrated embodiment, but the present invention is not limited to this, and the configuration of each part has the same function. It can be replaced with one having any structure. In addition, any other component may be added to the present invention. Moreover, you may combine embodiment mentioned above suitably.

  In the above-described embodiment, the configuration of one element unit has been described. However, a plurality of element units may be provided. At this time, by arranging the plurality of element portions so that the detection axes are different from each other, accelerations in a plurality of axial directions can be detected.

  In the above-described embodiment, the acceleration sensor that detects acceleration is described as the physical quantity sensor. However, the physical quantity detected by the physical quantity sensor is not limited to acceleration, and may be angular velocity, pressure, or the like.

  DESCRIPTION OF SYMBOLS 1 ... Physical quantity sensor, 2 ... Board | substrate, 21 ... Recessed part, 211 ... Bottom face, 211 '... 1st bottom face, 211 "... 2nd bottom face, 211a ... 1st exposed part, 211b ... 2nd exposed part, 22 ... Mount part, 25, 26, 27 ... groove portion, 3 ... element portion, 31 ... fixed portion, 311 ... joint portion, 32 ... movable portion, 320 ... through hole, 321 ... first movable portion, 321a ... proximal end portion, 321b ... distal end portion , 321c ... connecting part, 321c '... part, 322 ... second movable part, 322a ... main body part, 322c ... projection part, 322c' ... part, 33 ... beam part, 4 ... lid part, 41 ... concave part, 42 ... communication Hole 43. Sealing member 49 Glass frit 71 72 72 73 Wiring 8 Electrode 81 First detection electrode 82 Second detection electrode 83 Dummy electrode 831 First dummy electrode 831a ... 1st extension part, 831b ... 2nd extension part, 32 ... 2nd dummy electrode, 1000 ... Physical quantity sensor device, 1010 ... Base substrate, 1011 ... Connection terminal, 1012 ... Mounting terminal, 1020 ... Circuit element, 1030 ... Mold part, 1100 ... Personal computer, 1102 ... Keyboard, 1104 ... Body 1106 ... Display unit 1108 ... Display part 1200 ... Mobile phone 1202 ... Operation buttons 1204 ... Earpiece 1206 ... Mouthpiece 1208 ... Display part 1300 ... Digital still camera 1302 ... Case 1304 ... Light receiving unit, 1306 ... shutter button, 1308 ... memory, 1310 ... display, 1500 ... automobile, 1501 ... car body, 1502 ... car body posture control device, 1503 ... wheel, Az ... acceleration, B ... conductive bump, BW1, BW2 ... Bonding wire C1, C2 ... Capacitance, D1, D2 ... Separation distance, F1 ... First electrostatic attraction, F2 ... Second electrostatic attraction, J ... Oscillating shaft, L ', L "... Length, L1, L2 ... Distance, P ... Electrode pad, S ... Storage space, V1, V2 ... Voltage

Claims (8)

The base,
A movable part swingable about a swing axis with respect to the base part;
An electrode disposed on the base and disposed opposite to the movable portion;
The movable part is
A first movable part located on one side of the swing shaft;
A second movable portion located on the other side of the swing shaft and having a rotational moment around the swing shaft smaller than the first movable portion;
The electrode is
A first detection electrode disposed opposite to the first movable part;
A second detection electrode disposed opposite to the second movable part,
Around the first detection electrode, there is a first exposed portion where the surface of the base is exposed,
The first exposed portion is disposed opposite to the first movable portion,
Around the second detection electrode, there is a second exposed portion where the surface of the base is exposed,
The physical quantity sensor, wherein the second exposed portion is disposed to face the second movable portion. The electrode is
A first dummy electrode having the same potential as the movable portion;
The first movable part is
A tip portion disposed opposite to the first dummy electrode;
A proximal end portion that is located closer to the swing shaft than the distal end portion and is disposed opposite to the first detection electrode;
A connecting portion that connects the distal end portion and the proximal end portion,
The first exposed portion is formed between the first dummy electrode and the first detection electrode;
The physical quantity sensor according to claim 1, wherein the first exposed portion is disposed to face at least a part of the connecting portion. The second movable part is
A main body disposed opposite to the second detection electrode;
The physical quantity sensor according to claim 2, further comprising: a protruding portion that protrudes from the main body portion, and at least a portion of the protruding portion is disposed to face the second exposed portion. The electrode is
A second dummy electrode disposed opposite to a part of the protruding portion and having the same potential as the movable portion;
The second exposed portion is formed between the second dummy electrode and the second detection electrode;
The physical quantity sensor according to claim 3, wherein the second exposed portion is disposed to face a part of the protruding portion.   5. The portion of the connecting portion that faces the first exposed portion and the portion of the protruding portion that faces the second exposed portion are arranged symmetrically with respect to the swing axis. The physical quantity sensor according to any one of the above. The physical quantity sensor according to any one of claims 1 to 5,
A physical quantity sensor device comprising: an electronic component electrically connected to the physical quantity sensor.   An electronic apparatus comprising the physical quantity sensor according to claim 1.   A moving body comprising the physical quantity sensor according to claim 1.

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