JP2019066294A - Physical quantity sensor, inertial measurement device, mobile object positioning device, portable electronic device, electronic device and mobile object - Google Patents

Abstract

A physical quantity sensor capable of reducing a drift of an output signal, an inertial measurement device provided with the physical quantity sensor, a mobile positioning device, a portable electronic device, an electronic device, and a mobile. A physical quantity sensor includes a substrate, a first mass part, and a second mass part having a mass larger than the first mass part, and between the first mass part and the second mass part in a plan view. A movable portion capable of swinging about a swinging axis located on the first substrate; a first fixed electrode disposed on the substrate facing the first mass; and disposed on the substrate; An opposing second fixed electrode, an adjusting electrode disposed on the substrate, facing the second mass, and generating an electrostatic attraction between the second mass and the substrate of the movable part And a lid disposed opposite to the side of the cover. [Selected figure] Figure 1

Description

  The present invention relates to a physical quantity sensor, an inertial measurement device, a mobile object positioning device, a portable electronic device, an electronic device, and a mobile object.

  For example, the acceleration sensor described in Patent Document 1 includes a movable electrode portion capable of seesaw rocking about a rocking axis, and a substrate disposed opposite to each other via the movable electrode portion. Further, the movable electrode portion has a first movable electrode portion located on one side of the rocking shaft and a second movable electrode portion located on the other side. Further, the first and second movable electrode portions have rotational moments about the swinging axis different from each other. Further, the substrate is provided with a first fixed electrode arranged to face the first movable electrode part and a second fixed electrode arranged to face the second movable electrode part. .

  In the acceleration sensor having such a configuration, when acceleration is applied, the movable electrode portion seesaws rocking around the rocking axis based on the direction and the size. Then, the capacitance between the first movable electrode portion and the first fixed electrode and the capacitance between the second movable electrode portion and the second fixed electrode change. Therefore, the applied acceleration can be detected based on the change in capacitance.

US Patent Publication No. 2005/0109109

  However, in such a configuration, the first torque acting on the movable electrode portion due to the electrostatic attractive force generated between the one side of the substrate and the movable electrode portion, the other side of the substrate and the movable electrode portion And the second torque (a torque in the direction opposite to the first torque) acting on the movable electrode portion due to the electrostatic attraction generated between the first and second torques. As a result, the movable electrode portion is rocked by the seesaw, causing a drift (variation in zero point bias output) to occur in the output signal.

  An object of the present invention is to provide a physical quantity sensor capable of reducing the drift of an output signal, an inertial measurement device provided with the physical quantity sensor, a mobile positioning device, a portable electronic device, an electronic device and a mobile. .

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

The physical quantity sensor of the present invention comprises a substrate,
A first mass portion and a second mass portion having a mass larger than the first mass portion, and swinging around a swing axis located between the first mass portion and the second mass portion in plan view Possible moving parts,
A first fixed electrode disposed on the substrate and facing the first mass portion;
A second fixed electrode disposed on the substrate and facing the second mass portion;
An adjustment electrode disposed on the substrate, facing the second mass, and generating an electrostatic attractive force with the second mass;
A lid disposed on the opposite side of the movable portion to the substrate side;
It is characterized by including.
This provides a physical quantity sensor capable of reducing the drift of the output signal.

In the physical quantity sensor of the present invention, in a plan view from the direction in which the substrate and the movable portion overlap,
The second mass part is
A first portion that is in line symmetry with the first mass portion with respect to the swing axis;
A second portion located on the opposite side to the swing shaft side of the first portion;
Including
The second fixed electrode portion is disposed to face the first portion,
It is preferable that the adjustment electrode is disposed to face the second portion.
Thereby, since the first fixed electrode and the second fixed electrode can be arranged symmetrically with respect to the swing axis, it is possible to detect the acceleration more accurately.

In the physical quantity sensor of the present invention, the torque about the swinging axis due to the electrostatic attractive force generated between the second portion and the lid is T1,
Assuming that the torque about the swinging axis resulting from the electrostatic attraction generated between the second portion and the adjustment electrode is T2,
0 <T2 <2 × T1
It is preferable to satisfy
As a result, compared to the conventional configuration in which the torque T2 is not generated, it is possible to suppress the unintentional swinging of the movable portion in the natural state.

In the physical quantity sensor of the present invention,
0.5T1 <T2 <1.5 × T1
It is preferable to satisfy
Thereby, the unintentional swinging in the natural state of the movable portion can be effectively suppressed.

In the physical quantity sensor of the present invention,
0.7T1 <T2 <1.3 × T1
It is preferable to satisfy
Thereby, it is possible to more effectively suppress the unintentional swinging of the movable portion in the natural state.

In the physical quantity sensor of the present invention,
0.9T1 <T2 <1.1 × T1
It is preferable to satisfy
This makes it possible to more effectively suppress the unintentional swinging of the movable portion in the natural state.

In the physical quantity sensor of the present invention,
T1 = T2
It is preferable to satisfy
As a result, it is possible to more effectively suppress unintentional swinging in the natural state of the movable portion.

In the physical quantity sensor of the present invention, the distance between the second portion and the lid is d1,
When a separation distance between the second portion and the adjustment electrode is d2,
1/3 <d1 / d2 <3
It is preferable to satisfy
As a result, it is possible to suppress that one of d1 and d2 becomes too small, and it is possible to suppress the contact of the movable portion with the substrate or the lid during the seesaw rocking. Moreover, it is suppressed that the other of d1 and d2 becomes large too much, and it can suppress the excessive enlargement to the height direction of a physical quantity sensor.

In the physical quantity sensor of the present invention,
1/2 <d1 / d2 <2
It is preferable to satisfy
As a result, it is possible to effectively suppress contact of the movable portion with the substrate or the lid during the seesaw rocking. Moreover, the excessive enlargement to the height direction of a physical quantity sensor can be suppressed effectively.

In the physical quantity sensor of the present invention,
d1 = d2
It is preferable to satisfy
This makes it easy to satisfy the relationship of T1 = T2.

In the physical quantity sensor of the present invention, in the plan view,
The area of the second portion is S1,
When an area of a region where the second portion and the adjustment electrode overlap is S2,
S1 = S2
It is preferable to satisfy
This makes it easy to satisfy the relationship of T1 = T2.

In the physical quantity sensor of the present invention, the distance between the second portion and the adjustment electrode is d2,
When a separation distance between the first portion and the second fixed electrode and a separation distance between the first mass portion and the first fixed electrode are d3
d2> d3
It is preferable to satisfy
Thus, the electrostatic capacitance formed between the first mass portion and the first fixed electrode and the second mass portion formed between the second fixed electrode and the second fixed electrode while suppressing the contact between the substrate and the movable portion. Capacitance can be increased. Therefore, while being able to detect acceleration more accurately, acceleration can be detected in a wider range.

In the physical quantity sensor of the present invention, preferably, the adjustment electrode is connected to a ground.
As a result, there is no need to provide a power supply for the adjustment electrode, and the apparatus configuration is simplified.

In the physical quantity sensor of the present invention, the lid is preferably connected to a ground.
As a result, disturbance is blocked by the lid, and acceleration can be detected more accurately.

An inertial measurement device of the present invention is a physical quantity sensor of the present invention,
A control circuit that controls driving of the physical quantity sensor;
It is characterized by including.
Thereby, the effect of the physical quantity sensor of the present invention can be obtained, and a highly reliable inertial measurement device can be obtained.

A mobile positioning device according to the present invention comprises the inertial measurement device according to the present invention;
A receiver for receiving a satellite signal on which position information is superimposed from a positioning satellite;
An acquisition unit that acquires position information of the reception unit based on the received satellite signal;
An arithmetic unit that calculates the attitude of the moving object based on the inertial data output from the inertial measurement device;
Calculating the position of the moving body by correcting the position information based on the calculated attitude;
It is characterized by including.
Thereby, the effect of the inertial measurement device of the present invention can be enjoyed, and a highly reliable mobile positioning device can be obtained.

A portable electronic device of the present invention is the physical quantity sensor of the present invention,
A case containing the physical quantity sensor;
A processing unit housed in the case and processing output data from the physical quantity sensor;
A display unit housed in the case;
A translucent cover closing the opening of the case;
It is characterized by including.
Thereby, the effect of the physical quantity sensor of the present invention can be obtained, and a highly reliable inertial measurement device can be obtained.

An electronic device of the present invention includes the physical quantity sensor of the present invention,
Control circuit,
A correction circuit,
It is characterized by including.
Thereby, the effect of the physical quantity sensor of the present invention can be obtained, and a highly reliable electronic device can be obtained.

A mobile according to the present invention is a physical quantity sensor according to the present invention,
A posture control unit,
It is characterized by including.
Thereby, the effect of the physical quantity sensor of the present invention can be enjoyed, and a highly reliable mobile object can be obtained.

It is a top view of a physical quantity sensor concerning a 1st embodiment of the present invention. It is the sectional view on the AA line in FIG. It is a top view which shows the electrode of the physical quantity sensor shown in FIG. It is the BB sectional drawing in FIG. It is a perspective view of the element part which the physical quantity sensor shown in FIG. 1 has. 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 function of the adjustment electrode which the physical quantity sensor shown in FIG. 1 has. It is sectional drawing explaining the function of the adjustment electrode which the physical quantity sensor shown in FIG. 1 has. It is a sectional view of a physical quantity sensor concerning a 2nd embodiment of the present invention. It is a top view of the physical quantity sensor concerning a 3rd embodiment of the present invention. It is an exploded perspective view of an inertial measurement device concerning a 4th embodiment of the present invention. It is a perspective view of the board | substrate which the inertial measurement device shown in FIG. 13 has. It is a block diagram showing the whole system of the mobile positioning device concerning a 5th embodiment of the present invention. It is a figure which shows an effect | action of the mobile positioning device shown in FIG. It is a perspective view showing the electronic equipment concerning a 6th embodiment of the present invention. It is a perspective view showing the electronic equipment concerning a 7th embodiment of the present invention. It is a perspective view which shows the electronic device which concerns on 8th Embodiment of this invention. It is a top view which shows the portable electronic device which concerns on 9th Embodiment of this invention. It is a functional block diagram which shows schematic structure of the portable electronic device shown in FIG. It is a perspective view showing the mobile concerning a 10th embodiment of the present invention.

  Hereinafter, a physical quantity sensor, an inertial measurement device, a mobile positioning device, a portable electronic device, an electronic device and a mobile according to the present invention will be described in detail based on embodiments shown in the attached drawings.

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

  FIG. 1 is a plan view of a physical quantity sensor according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view taken along line AA in FIG. FIG. 3 is a plan view showing an electrode of the physical quantity sensor shown in FIG. FIG. 4 is a cross-sectional view taken along the line B-B in FIG. FIG. 5 is a perspective view of an element portion of the physical quantity sensor shown in FIG. FIG. 6 is a graph showing the drive voltage. 7 and 8 are cross-sectional views for explaining the operation of the physical quantity sensor shown in FIG. 9 and 10 are cross-sectional views for explaining the function of the adjustment electrode of the physical quantity sensor shown in FIG.

  In the following, for convenience of explanation, the front side of the paper surface in FIG. 1 and the upper side in FIG. 2 are also referred to as “upper”, and the back side in FIG. 1 and the lower side in FIG. Further, in each drawing, an X axis, a Y axis and a Z axis are illustrated as three axes orthogonal to each other.

  The physical quantity sensor 1 shown in FIG. 1 is an acceleration sensor capable of measuring an acceleration Az in the Z-axis direction (vertical direction). Such a physical quantity sensor 1 includes a substrate 2, an element unit 3 disposed on the substrate 2, and a lid 4 joined to the substrate 2 so as to cover the element unit 3. Hereinafter, these units will be described in detail in order.

(substrate)
As shown in FIG. 1, the substrate 2 is in the form of a plate having a rectangular plan view shape. Further, the substrate 2 has a recess 21 opened on the upper surface side. Further, in plan view from the Z-axis direction, the concave portion 21 is formed larger than the element portion 3 so as to enclose the element portion 3 inside. Such a concave portion 21 functions as a relief portion for preventing (suppressing) the contact between the element portion 3 and the substrate 2.

  Further, as shown in FIG. 2, the substrate 2 has a projecting mount portion 22 provided on the bottom surface of the recess 21. The element section 3 is joined to the mount section 22. Thereby, the element portion 3 can be fixed to the substrate 2 in a state of being separated from the bottom surface of the recess 21.

  Further, as shown in FIG. 1, the substrate 2 has groove portions 25, 26, 27, 28 opened to the upper surface side. Further, one end portions of the groove portions 25, 26, 27, 28 are respectively located outside the lid 4, and the other end portions are respectively connected to the recess 21.

Such a substrate 2 is made of, for example, a glass material containing alkali metal ions (mobile ions such as Na ⁺ ) (eg, Tempax glass (registered trademark), borosilicate glass such as Pyrex glass (registered trademark)) A configured glass substrate can be used. Thereby, depending on the constituent material of the lid 4, for example, the substrate 2 and the lid 4 can be joined by anodic bonding, and these can be firmly joined. In addition, since the substrate 2 having light transparency can be obtained, the state of the element unit 3 (for example, the element unit 3 adheres to the bottom surface of the recess 21) from the outside of the physical quantity sensor 1 via the substrate 2. It is possible to visually recognize “sticking”.

  However, the substrate 2 is not particularly limited, and for example, a silicon substrate or a ceramic substrate may be used. When 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 on which a silicon oxide film (insulating oxide) is formed by thermal oxidation or the like is used. Is preferred.

  Further, as shown in FIG. 1 and FIG. 2, the first fixed electrode 81, the second fixed electrode 82, and the adjustment electrode 83 are disposed apart from each other as the electrode 8 on the bottom surface of the recess 21. The first fixed electrode 81, the second fixed electrode 82, and the adjustment electrode 83 will be described in detail later.

  Further, as shown in FIG. 3, in the grooves 25, 26, 27, 28, wirings 75, 76, 77, 78 are provided. The wiring 75 is routed through the bottom of the recess 21 to the mount 22 and is electrically connected to the element 3 on the mount 22 (see FIG. 4). Also, the wiring 76 is electrically connected to the first fixed electrode 81. The wiring 77 is also electrically connected to the second fixed electrode 82. Further, the wiring 78 is electrically connected to the adjustment electrode 83. Further, one end portions of the wires 75, 76, 77, 78 are exposed to the outside of the lid 4, respectively, and form electrode pads P for electrically connecting to an external device.

  It does not specifically limit as a constituent material of electrode 8 and each wiring 75, 76, 77, 78, For example, gold (Au), silver (Ag), platinum (Pt), palladium (Pd), iridium (Ir) ), Metal materials such as copper (Cu), aluminum (Al), nickel (Ni), Ti (titanium), tungsten (W), alloys containing these metal materials, ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide) And transparent conductive materials of oxides such as ZnO and IGZO, and one or more of them may be used in combination (for example, as a laminate of two or more layers).

(Lid)
As shown in FIG. 1, the lid 4 is in the form of a plate having a rectangular plan view shape. Moreover, as shown in FIG. 2, the cover 4 has the recessed part 41 opened to the lower surface side. The lid 4 is joined to the top surface of the substrate 2 so as to accommodate the element portion 3 in the recess 41. The lid 4 and the substrate 2 form an internal space S for housing the element unit 3. A portion overlapping with the recess 41 of the lid 4 (a portion thinned by the recess 41) is a ceiling portion 48 and is opposed to the element portion 3. Further, the inner surface 481 of the ceiling portion 48 is substantially parallel to the element portion 3. Such a lid 4 has a constant potential, and is connected to the ground (0 V) in the present embodiment. Thereby, the disturbance can be cut off, and the detection accuracy of the acceleration Az is improved.

  Further, as shown in FIG. 2, the lid 4 has a communication hole 42 that communicates the inside and the outside of the internal space S. The internal space S can be replaced with a desired atmosphere via the communication hole 42. Further, 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 it can seal the communication hole 42. For example, a gold (Au) / tin (Sn) alloy, a gold (Au) / germanium (Ge) alloy, a gold (Au) / Various alloys such as aluminum (Al) based alloy, glass materials such as low melting point glass, etc. can be used.

  The internal space S is an airtight space. In addition, it is preferable that the internal space S be filled with an inert gas such as nitrogen, helium, argon or the like, and be at substantially atmospheric pressure at a use temperature (about -40 ° C to about 80 ° C). By setting the internal space S to the atmospheric pressure, the viscosity resistance is increased, the damping effect is exhibited, and the oscillation of the element unit 3 can be rapidly converged. Therefore, the detection accuracy of the acceleration Az of the physical quantity sensor 1 is improved.

  For example, a silicon substrate can be used as such a lid 4. However, the lid 4 is not particularly limited, and, for example, a glass substrate or a ceramic substrate may be used. The method of bonding the substrate 2 and the lid 4 is not particularly limited and may be appropriately selected depending on the materials of the substrate 2 and the lid 4, but for example, bonding surfaces activated by anodic bonding or plasma irradiation Examples include activation bonding for bonding together, bonding using a bonding material such as glass frit, and diffusion bonding for bonding metal films formed on the upper surface of the substrate 2 and the lower surface of the lid 4.

  Further, a glass substrate or a ceramic substrate may be used as the material of the lid 4, and the inner side 481 of the lid 4 is coated with a metal film or the like, and electrically connected to the ground to bring the lid 4 to the GND potential. Preferably, the internal space S is shielded electrostatically.

In the present embodiment, as shown in FIG. 2, the substrate 2 and the lid 4 are joined via a glass frit 49 (low melting point glass) which is an example of a joining material. In the state where the substrate 2 and the lid 4 are superimposed, the inside and the outside of the internal space S communicate with each other through the groove portions 25, 26, 27 and 28. However, by using the glass frit 49, the substrate 2 and the lid 4 and the grooves 25, 26, 27, 28 can be sealed. Therefore, the internal space S can be hermetically sealed more easily. When the substrate 2 and the lid 4 are joined by anodic bonding or the like (joining method in which the grooves 25, 26, 27, 28 can not be sealed), for example, the CVD method using TEOS (tetraethoxysilane) The grooves 25, 26, 27, 28 can be closed by the SiO ₂ film formed in the above.

(Element part)
The element unit 3 is provided above the substrate 2. As shown in FIGS. 1 and 5, the element unit 3 includes a fixed portion 31 joined to the mount portion 22, a movable electrode portion 32 as a movable portion displaceable with respect to the fixed portion 31, and a fixed portion 31. And a pair of beam portions 33 (33a, 33b) connecting the movable electrode portion 32 and the movable electrode portion 32. The movable electrode portion 32 can be rocked seesaw with respect to the fixed portion 31 while torsionally deforming the beam portions 33 a and 33 b with the beam portions 33 a and 33 b as the swing axis J.

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

  The movable electrode portion 32 has a longitudinal shape extending in the X-axis direction, and a portion on one side with respect to the rocking axis J is a first movable electrode portion 321 as a first mass portion. A portion on the other side with respect to the other is a second movable electrode portion 322 as a second mass portion. Further, the second movable electrode portion 322 is longer in the X-axis direction than the first movable electrode portion 321, and the rotational moment (torque) when the acceleration Az is applied is larger than that of the first movable electrode portion 321. Due to the difference in the rotational moment, when acceleration Az is applied, the movable electrode portion 32 seesaws rocking around the rocking axis J.

  The second movable electrode portion 322 is symmetrical as a first portion disposed at a position in line symmetry with the first movable electrode portion 321 with respect to the swing axis J in plan view from the Z-axis direction. It has a portion 322A and an asymmetric portion 322B as a second portion which is disposed asymmetrically with the first movable electrode portion 321 with respect to the swing axis J. That is, the asymmetric portion 322B as the second portion is disposed at a position opposite to the swing axis J of the symmetrical portion 322A as the first portion.

  In the present embodiment, the symmetrical portion 322A as the first portion is located on the proximal end side (the side closer to the swing axis J) of the second movable electrode portion 322, and on the distal end side (the side farther from the swing axis J). The asymmetric portion 322B as the second portion is located. That is, the asymmetrical portion 322B is formed to extend further in the direction away from the swing axis J from the tip of the symmetrical portion 322A. As described above, the second movable electrode portion 322 has the asymmetric portion 322B, so that the rotational moment (torque) when the acceleration Az is applied is larger than that of the first movable electrode portion 321.

  As shown in FIG. 2, the first fixed electrode 81, the second fixed electrode 82, and the adjustment electrode 83 are provided to face the element portion 3 as described above. The first fixed electrode 81 is disposed to face the first movable electrode portion 321. The second fixed electrode 82 is disposed to face the symmetrical portion 322A of the second movable electrode portion 322. The adjustment electrode 83 is disposed to face the asymmetric portion 322 </ b> B of the second movable electrode portion 322. The first and second fixed electrodes 81 and 82 are provided symmetrically with respect to the swing axis J in a plan view from the Z-axis direction.

  At the time of operation of the physical quantity sensor 1, for example, the voltage Vd1 in FIG. 6 is applied to the movable electrode portion 32, and the voltage Vd2 in FIG. 6 is applied to the first fixed electrode 81 and the second fixed electrode 82, respectively. The voltage Vd1 is a voltage at which the potential changes periodically between VDD and GND (0 V) with reference to the reference potential VDD / 2. Therefore, the voltage Vd1 is a voltage which is VDD / 2 when averaged over time. On the other hand, the voltage Vd2 is a fixed voltage whose potential is VDD / 2 (that is, the reference potential of the voltage Vd1). Thereby, the electrostatic capacitance C1 is formed between the first fixed electrode 81 and the first movable electrode portion 321, and the electrostatic capacitance is generated between the second fixed electrode 82 and the second movable electrode portion 322 (the symmetrical portion 322A). A capacitance C2 is formed. Note that VDD / 2 is not particularly limited, but can be, for example, about 0.5 V or more and 5 V or less.

  As shown in FIG. 7, when acceleration −Az to the negative side in the Z-axis direction is applied to the physical quantity sensor 1, the movable electrode portion 32 shakes due to the difference in rotational moment of the first and second movable electrode portions 321 and 322. The seesaw swings counterclockwise around the motion axis J. Further, as shown in FIG. 8, when the acceleration + Az in the positive Z-axis direction is applied to the physical quantity sensor 1, the movable electrode portion 32 seesaws rocking clockwise about the rocking axis J.

  Due to such seesaw rocking of the movable electrode portion 32, the gap between the first movable electrode portion 321 and the first fixed electrode 81 and the gap between the second movable electrode portion 322 and the second fixed electrode 82 change in opposite phases, In response to this, the electrostatic capacitances C1 and C2 change in opposite phase. Therefore, the acceleration Az can be detected based on the changes in the capacitances C1 and C2. Note that a first detection signal (a detection signal based on a capacitance C1) obtained from the first fixed electrode 81 and a second detection signal (a detection signal based on a capacitance C2) obtained from the second fixed electrode 82; By differentially computing, it is possible to cancel the noise and to detect the acceleration Az more accurately.

  Next, the function of the adjustment electrode 83 will be described. As described above, the voltage Vd1 in FIG. 6 is applied to the movable electrode portion 32, and the lid 4 is connected to the ground. Therefore, a potential difference is generated between the movable electrode portion 32 and the lid 4, and an electrostatic attractive force F acts between them. As shown in FIG. 9, in the electrostatic attractive force F, the first electrostatic attractive force Fa generated between the first movable electrode portion 321 and the lid 4 and the symmetrical portion 322A of the second movable electrode portion 322 and the lid A second electrostatic attractive force Fb generated between itself and the body 4 and a third electrostatic attractive force Fc generated between the asymmetrical portion 322B of the second movable electrode portion 322 and the lid 4 are included.

  As described above, the voltage Vd1 in FIG. 6 is applied to the movable electrode portion 32, and the voltage Vd2 in FIG. 6 is applied to the first and second fixed electrodes 81 and 82. The voltage Vd1 is a voltage which is VDD / 2 when averaged over time, and the voltage Vd2 is a fixed voltage whose potential is VDD / 2.

  As described above, the first movable electrode portion 321 and the symmetrical portion 322A of the second movable electrode portion 322 are arranged symmetrically with respect to the swing axis J in plan view from the Z-axis direction. Further, the separation distance between the first movable electrode portion 321 and the ceiling portion 48 and the separation distance between the symmetrical portion 322A and the ceiling portion 48 are substantially equal. Therefore, the torque Ta acting on the movable electrode portion 32 due to the first electrostatic attractive force Fa and the torque Tb acting on the movable electrode portion 32 due to the second electrostatic attractive force Fb are substantially equal to each other and are offset each other. Since the torque Tc (unbalanced torque) caused by the third electrostatic attractive force Fc further acts on the movable electrode portion 32, the movable electrode portion 32 has a state shown in FIG. 9 regardless of the natural state where the acceleration Az is not applied. As shown in, it is inclined (rocked). As a result, output drift (variation in zero point bias output) occurs, and the detection characteristic of the acceleration Az deteriorates.

  Therefore, in the physical quantity sensor 1, the adjustment electrode 83 is provided, and a fourth electrostatic attractive force Fd is generated between the adjustment electrode 83 and the asymmetrical portion 322B to cancel at least a part of the torque Tc. By generating the torque of the direction, as shown in FIG. 10, the unintentional inclination (rocking) of the movable electrode portion 32 is suppressed. That is, the adjustment electrode 83 functions as an electrode for controlling the posture of the movable electrode portion 32 in the natural state.

  The torques Tc and Td satisfy the relationship of 0 <Td <2 × Tc (| Td−Tc | <Tc). Thereby, compared with the structure which torque Td does not generate | occur | produce, the unwilling inclination of the movable electrode part 32 as shown in FIG. 9 can be reduced. The torques Tc and Td may be 0 <Td <2 × Tc, among which 0.5Tc <Td <1.5 × Tc is preferable, and 0.7Tc <Td <1.3 × Tc. Is more preferable, 0.9 Tc <Td <1.1 × Tc is more preferable, and Tc = Td is particularly preferable. As a result, the balance between the torques Tc and Td is improved, and the above-described effect becomes more remarkable. The torques Tc and Td can be calculated, for example, as follows.

  The third electrostatic attractive force Fc is such that the area (area in plan view) of the asymmetric portion 322B is S1, the separation distance between the asymmetric portion 322B and the ceiling portion 48 is d1, and the potential difference between the asymmetric portion 322B and the ceiling portion 48 is When V1 is set, the following formula (1) is obtained. In equation (1), ε is the dielectric constant of the gas in the internal space S. Furthermore, the torque Tc generated in the movable electrode portion 32 by the third electrostatic attractive force Fc is expressed by the following equation (2), where L1 is the distance from the swing axis J to the asymmetrical portion 322B. The distance L1 can be a distance to the center of the asymmetric portion 322B (that is, an average distance).

  In the fourth electrostatic attractive force Fd, the area of the portion where the asymmetric portion 322B and the adjustment electrode 83 are opposed is S2, the separation distance between the asymmetric portion 322B and the adjustment electrode 83 is d2, and the asymmetric portion 322B and the adjustment electrode 83 When the potential difference with is V2, the following equation (3) is obtained. In the equation (3), ε is the dielectric constant of the gas in the internal space S. Further, when the distance from the rocking axis J to the position to which the fourth electrostatic attractive force Fd is applied is L2, the torque Td generated in the movable electrode portion 32 by the fourth electrostatic attractive force Fd is expressed by the following equation (4) Become. The distance L2 can be a distance to the center of the facing portion (that is, an average distance).

The dielectric constant ε is represented by the product of the vacuum dielectric constant ε0 (= 8.854187817 × 10 ⁻¹² [F / m]) and the relative dielectric constant εr. As a specific example of the relative dielectric constant に お け る r at 1 atmospheric pressure, 1.000536 for air, 1.000574 for nitrogen, 1.000517 for hydrogen, 1.000272 for helium, 1.000070 for helium, and some examples for air pressure It is 1.002900 (Reference: Science chronology 2005).

  As shown in FIG. 1, in the present embodiment, the adjustment electrode 83 faces the entire area of the asymmetrical portion 322B, and thus the relationship of S1 = S2 and L1 = L2 is satisfied. Thus, by equalizing at least one of the parameters affecting the torques Tc and Td, the relationship of Tc = Td can be easily satisfied.

  The relationship between d1 and d2 is preferably 1/3 <d1 / d2 <3 and more preferably 1/2 <d1 / d2 <2. As a result, it is possible to suppress that one of d1 and d2 becomes too small, and it is possible to suppress the contact of the movable electrode portion 32 with the substrate 2 or the lid 4 at the time of seesaw rocking. Moreover, it is suppressed that the other of d1 and d2 becomes large too much, and the excessive enlargement to the height direction (Z-axis direction) of the physical quantity sensor 1 can be suppressed.

  In particular, in the present embodiment, the relationship of d1 = d2 is satisfied. Therefore, the above-mentioned effect becomes more remarkable. Further, since S1 = S2, L1 = L2 and d1 = d2, the relationship of Tc = Td can be easily satisfied simply by setting V1 = V2. As described above, the movable electrode portion 32 has a potential of VDD / 2 in time average, and the lid 4 is connected to the ground (0 V). Therefore, V1 is VDD / 2. Therefore, by connecting the adjustment electrode 83 to the ground or by applying the voltage VDD to the adjustment electrode 83, V1 = V2, and the relationship of Tc = Td can be satisfied. Note that by connecting the adjustment electrode 83 to the ground, there is no need to provide a power supply for the adjustment electrode 83, so the device configuration is simplified.

  In the physical quantity sensor 1, the relationship between the torques Tc and Td does not change even if the voltage VDD changes, so that it is possible to exhibit ratiometric characteristics. The ratiometric characteristic is a characteristic in which the zero point bias output is proportional to the voltage VDD.

  The relationship between S1 and S2, the relationship between L1 and L2, the relationship between d1 and d2, and the relationship between V1 and V2 is not limited to the above relationship, and any relationship as long as 0 <Td <2Tc is satisfied. It may be

  The physical quantity sensor 1 has been described above. As described above, such a physical quantity sensor 1 has the substrate 2, the first movable electrode portion 321 (the first mass portion), and the second movable electrode portion 322 (the second movable electrode portion 321 having a larger mass than the first movable electrode portion 321). A movable electrode portion 32 (movable portion) swingable around a swing axis J, which includes a mass portion) and is located between the first movable electrode portion 321 and the second movable electrode portion 322 in plan view; And the second fixed electrode 82 disposed on the substrate 2 and opposed to the second movable electrode portion 322 and disposed on the substrate 2 And the adjustment electrode 83 that generates an electrostatic attractive force between the second movable electrode portion 322 and the second movable electrode portion 322, and the movable electrode portion 32 is disposed on the opposite side to the substrate 2 side And the cover 4. As described above, by generating an electrostatic attractive force between the second movable electrode portion 322 and the adjustment electrode 83, the attitude of the movable electrode portion 32 in the natural state is controlled (unwanted oscillation is suppressed). Can. Therefore, the drift of the output signal (the fluctuation of the zero point bias output) is reduced, and the detection characteristic of the acceleration Az is improved.

  Further, as described above, in the physical quantity sensor 1, the second movable electrode portion 322 is the first movable electrode portion 321 with respect to the swing axis J in plan view from the direction in which the substrate 2 and the movable electrode portion 32 overlap. And a nonsymmetrical portion 322B (second portion) located on the opposite side to the side of the swing axis J of the symmetrical portion 322A (the first portion). . The second fixed electrode portion 82 is disposed to face the symmetrical portion 322A, and the adjustment electrode 83 is disposed to face the asymmetrical portion 322B. As a result, since the first fixed electrode 81 and the second fixed electrode 82 can be arranged symmetrically with respect to the swing axis J, detection of the acceleration Az can be detected more accurately.

  Further, as described above, in the physical quantity sensor 1, the torque around the swing axis J due to the third electrostatic attractive force Fc generated between the asymmetric portion 322 B and the lid 4 is Tc (T 1), the asymmetric portion 322 B and When Td (T2) is a torque around the swing axis J due to the fourth electrostatic attractive force Fd generated between the adjusting electrode 83, 0 <Td <2 × Tc is satisfied. As a result, compared to the conventional configuration in which the torque Td is not generated, it is possible to suppress the unintentional swinging of the movable electrode portion 32 in the natural state. In addition, it is preferable to satisfy 0.5Tc <Td <1.5 × Tc, and it is more preferable to satisfy 0.7Tc <Td <1.3 × Tc, and 0.9Tc <Td <1.1 × Tc. It is further preferable to satisfy the following condition, and it is particularly preferable to satisfy Tc = Td. This makes the above-mentioned effects more remarkable.

  Further, as described above, in the physical quantity sensor 1, when the separation distance between the asymmetric part 322B and the ceiling part 48 is d1 and the separation distance between the asymmetric part 322B and the adjustment electrode 83 is d2, 1/3 <d1 / d2 It is preferable to satisfy <3. As a result, it is possible to suppress that one of d1 and d2 becomes too small, and it is possible to suppress the contact of the movable electrode portion 32 with the substrate 2 or the lid 4 at the time of seesaw rocking. Moreover, it is suppressed that the other of d1 and d2 becomes large too much, and the excessive enlargement to the height direction (Z-axis direction) of the physical quantity sensor 1 can be suppressed. In addition, it is preferable to satisfy 1/2 <d1 / d2 <2. This makes the above-mentioned effects remarkable. In particular, in the present embodiment, d1 = d2 is satisfied. As a result, the above-mentioned effect becomes more remarkable, and it becomes easy to satisfy the relationship of Tc = Td.

  Further, as described above, in the physical quantity sensor 1, when the area of the asymmetrical portion 322B is S1 and the area of the region where the asymmetrical portion 322B and the adjustment electrode 83 overlap in a plan view is S2, S1 = S2 is satisfied. There is. This makes it easier to satisfy the relationship of Tc = Td.

  Further, as described above, in the physical quantity sensor 1, the adjustment electrode 83 is connected to the ground. As a result, there is no need to provide a power supply for the adjustment electrode 83, and the apparatus configuration is simplified.

  Further, as described above, in the physical quantity sensor 1, the lid 4 is connected to the ground. As a result, the disturbance is blocked by the lid 4 and the acceleration Az can be detected more accurately.

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

  FIG. 11 is a cross-sectional view of a physical quantity sensor according to a second 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 shape of the substrate is mainly different.

  In the following description, the physical quantity sensor according to the second embodiment will be described focusing on differences from the first embodiment described above, and the description of the same matters will be omitted. Further, in FIG. 11, the same components as those in the above-described embodiment are denoted by the same reference numerals.

  As shown in FIG. 11, the recess 21 of the substrate 2 has a first recess 21A opened in the upper surface of the substrate 2 and a second recess 21B opened in the bottom of the first recess 21A. The second concave portion 21B is arranged to overlap the asymmetric portion 322B (the tip of the second movable electrode portion 322) in a plan view from the Z-axis direction.

  The first and second fixed electrodes 81 and 82 are disposed on the bottom surface of the first recess 21A, and the adjustment electrode 83 is disposed on the bottom surface of the second recess 21B. Therefore, the separation distance between the asymmetric portion 322B and the adjustment electrode 83 is d2, the separation distance between the symmetrical portion 322A and the second fixed electrode 82, and the separation distance between the first movable electrode portion 321 and the first fixed electrode 81 is d3. When, d2> d3 is satisfied. With such a configuration, the electrostatic capacitance and the second movable formed between the first movable electrode portion 321 and the first fixed electrode 81 are suppressed while the contact between the substrate 2 and the movable electrode portion 32 is suppressed. The capacitance formed between the electrode portion 322 and the second fixed electrode 82 can be increased. Therefore, the acceleration Az can be detected more accurately, and the acceleration Az can be detected in a wider range.

  Also by such a second embodiment, the same effect as that of the first embodiment described above can be exhibited.

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

  FIG. 12 is a plan view of a physical quantity sensor according to a 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 portion and the dummy electrode are mainly different.

  As shown in FIG. 12, the physical quantity sensor 1 of the present embodiment has a dummy electrode 84 as the electrode 8 in addition to the first fixed electrode 81, the second fixed electrode 82, and the adjustment electrode 83. The dummy electrode 84 is disposed between the second fixed electrode 82 and the adjustment electrode 83, and faces the asymmetric portion 322B. Further, the voltage Vd1 is applied to the dummy electrode 84, and the dummy electrode 84 and the movable electrode portion 32 have the same potential.

  In such a configuration, S1 ≠ S2, L1 ≠ L2, d1 = d2 and V1 = V2, so design S1, S2, L1, L2 so that S1 · L1 = S2 · L2 Then, the relationship of Tc = Td can be satisfied.

  Also by such a third embodiment, the same effect as that of the first embodiment described above can be exhibited.

Fourth Embodiment
Next, an inertial measurement device according to a fourth embodiment of the present invention will be described.

  FIG. 13 is an exploded perspective view of an inertial measurement device according to a fourth embodiment of the present invention. FIG. 14 is a perspective view of a substrate of the inertial measurement device shown in FIG.

  A sensor unit 2000 shown in FIG. 13 is an inertial measurement unit (IMU) that detects the posture or behavior (inertial movement amount) of a moving body (mounted device) such as a car or a robot. The sensor unit 2000 functions as a so-called six-axis motion sensor provided with a three-axis acceleration sensor and a three-axis angular velocity sensor.

  The sensor unit 2000 is a rectangular solid having a substantially square planar shape. Further, screw holes 2110 as fixing portions are formed in the vicinity of two apexes located in the diagonal direction of the square. The sensor unit 2000 can be fixed to the mounting surface of a mounting object such as a car by passing two screws through the two screw holes 2110. In addition, it is also possible to miniaturize to a size that can be mounted on, for example, a smartphone or a digital camera, by selecting parts or changing the design.

  The sensor unit 2000 has an outer case 2100, a joining member 2200, and a sensor module 2300. The sensor module 2300 is inserted into the outer case 2100 with the joining member 2200 interposed. . The sensor module 2300 also includes an inner case 2310 and a substrate 2320.

  The outer shape of the outer case 2100 is a rectangular solid having a substantially square planar shape, similar to the overall shape of the sensor unit 2000 described above, and screw holes 2110 are formed in the vicinity of two apexes located in the diagonal direction of the square. There is. The outer case 2100 is box-shaped, and the sensor module 2300 is housed inside.

  The inner case 2310 is a member that supports the substrate 2320 and has a shape that fits inside the outer case 2100. Further, in the inner case 2310, a recess 2311 for preventing contact with the substrate 2320 and an opening 2312 for exposing a connector 2330 described later are formed. Such an inner case 2310 is joined to the outer case 2100 via a joining member 2200 (for example, a packing impregnated with an adhesive). A substrate 2320 is bonded to the lower surface of the inner case 2310 via an adhesive.

  As shown in FIG. 14, on the upper surface of the substrate 2320, a connector 2330, an angular velocity sensor 2340z for detecting an angular velocity around the Z axis, an acceleration sensor 2350 for detecting acceleration in each axial direction of X, Y and Z axes, etc. Has been implemented. Further, on the side surface of the substrate 2320, an angular velocity sensor 2340x for detecting an angular velocity around the X axis and an angular velocity sensor 2340y for detecting an angular velocity around the Y axis are mounted. The angular velocity sensors 2340z, 2340x, and 2340y are not particularly limited, and, for example, vibration gyro sensors using Coriolis force can be used. The acceleration sensor 2350 is not particularly limited. For example, an electrostatic capacitance type acceleration sensor can be used, and in particular, the above-described first to third embodiments for detecting the acceleration in the Z-axis direction are used. Any of the following configurations can be used.

  Further, a control IC 2360 is mounted on the lower surface of the substrate 2320. The control IC 2360 is an MCU (Micro Controller Unit), and includes a storage unit including a non-volatile memory, an A / D converter, and the like, and controls each unit of the sensor unit 2000. The storage unit stores a program that defines the order and content for detecting acceleration and angular velocity, a program that digitizes detection data and incorporates it into packet data, and accompanying data. A plurality of other electronic components are mounted on the substrate 2320.

  The sensor unit 2000 (inertial measurement device) has been described above. Such a sensor unit 2000 includes angular velocity sensors 2340z, 2340x, 2340y and an acceleration sensor 2350 as physical quantity sensors, and a control IC 2360 (control circuit) for controlling driving of the respective sensors 2340z, 2340x, 2340y, 2350. It is. Thereby, the effect of the physical quantity sensor of the present invention can be enjoyed, and a highly reliable sensor unit 2000 can be obtained.

Fifth Embodiment
Next, a mobile positioning device according to a fifth embodiment of the present invention will be described.

  FIG. 15 is a block diagram showing an entire system of a mobile positioning device according to a fifth embodiment of the present invention. FIG. 16 is a diagram showing an operation of the mobile positioning device shown in FIG.

  A mobile body positioning device 3000 shown in FIG. 15 is a device mounted on a mobile body and used to perform positioning of the mobile body. The moving body is not particularly limited, and may be a bicycle, a car (including a four-wheeled car and a motorcycle), a train, an airplane, a ship, etc., but in the present embodiment, it will be described as a four-wheeled car. The mobile positioning device 3000 includes an inertial measurement device 3100 (IMU), an arithmetic processing unit 3200, a GPS receiving unit 3300, a receiving antenna 3400, a position information obtaining unit 3500, a position combining unit 3600, and a processing unit 3700. , A communication unit 3800, and a display unit 3900. Note that, as the inertial measurement device 3100, for example, the sensor unit 2000 of the fourth embodiment described above can be used.

  Further, the inertial measurement device 3100 has a 3-axis acceleration sensor 3110 and a 3-axis angular velocity sensor 3120. Arithmetic processing unit 3200 receives acceleration data from acceleration sensor 3110 and angular velocity data from angular velocity sensor 3120, performs inertial navigation arithmetic processing on these data, and performs inertial navigation positioning data (data including acceleration and attitude of moving body) Output).

  Also, the GPS reception unit 3300 receives a signal from a GPS satellite (GPS carrier wave, satellite signal on which position information is superimposed) via the reception antenna 3400. The position information acquisition unit 3500 also outputs GPS positioning data representing the position (latitude, longitude, altitude), velocity, and direction of the mobile positioning device 3000 (mobile) based on the signal received by the GPS reception unit 3300. Do. The GPS positioning data also includes status data indicating a reception state, a reception time, and the like.

  The position synthesis unit 3600 determines the position of the moving object, specifically, the moving object on the ground, based on the inertial navigation positioning data output from the arithmetic processing unit 3200 and the GPS positioning data output from the position information acquisition unit 3500. Calculate if you are traveling in position. For example, even if the position of the moving object included in the GPS positioning data is the same, as shown in FIG. The moving body is traveling. Therefore, it is not possible to calculate the accurate position of the mobile using GPS positioning data alone. Therefore, the position synthesis unit 3600 calculates which position on the ground the moving body is traveling using the inertial navigation positioning data (in particular, data on the attitude of the moving body). Note that the determination can be made relatively easily by calculation using a trigonometric function (slope θ with respect to the vertical direction).

  The position data output from the position combining unit 3600 is subjected to predetermined processing by the processing unit 3700, and is displayed on the display unit 3900 as a positioning result. The position data may be transmitted to the external device by the communication unit 3800.

  The mobile positioning device 3000 has been described above. As described above, such a mobile positioning device 3000 includes the inertial measurement device 3100, the GPS receiving unit 3300 (receiving unit) for receiving the satellite signal on which the position information is superimposed from the positioning satellite, and the received satellite signal Based on the position information acquisition unit 3500 (acquisition unit) that acquires position information of the GPS reception unit 3300 and the inertial navigation positioning data (inertial data) output from the inertial measurement device 3100, It includes an arithmetic processing unit 3200 (arithmetic unit) to calculate, and a position synthesis unit 3600 (calculator) that calculates the position of the moving body by correcting the position information based on the calculated attitude. As a result, the effect of the inertial measurement device of the present invention can be enjoyed, and a highly reliable mobile positioning device 3000 can be obtained.

Sixth Embodiment
Next, an electronic device according to a sixth embodiment of the present invention will be described.

  FIG. 17 is a perspective view showing an electronic device according to a sixth embodiment of the present invention.

  The mobile (or notebook) personal computer 1100 shown in FIG. 17 is an application of the electronic device of the present invention. In this figure, the personal computer 1100 comprises a main unit 1104 having a keyboard 1102 and a display unit 1106 having a display unit 1108. The display unit 1106 is connected to the main unit 1104 via a hinge structure. It is rotatably supported.

  Such a personal computer 1100 includes a physical quantity sensor 1, a control circuit 1110 that controls driving of the physical quantity sensor 1, and a correction circuit 1120 that corrects the physical quantity detected by the physical quantity sensor 1 based on, for example, the environmental temperature. Is built-in. The physical quantity sensor 1 is not particularly limited, but, for example, any one of the above-described embodiments can be used.

  Such a personal computer 1100 (electronic device) includes the physical quantity sensor 1, a control circuit 1110, and a correction circuit 1120. Therefore, the effects of the physical quantity sensor 1 described above can be obtained, and high reliability can be exhibited.

Seventh Embodiment
Next, an electronic device according to a seventh embodiment of the present invention will be described.

  FIG. 18 is a perspective view showing an electronic device according to a seventh embodiment of the present invention.

  A mobile phone 1200 (including a PHS) shown in FIG. 18 is an application of the electronic device of the present invention. In this figure, the mobile 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 button 1202 and the earpiece 1204. It is arranged.

  Such a portable telephone 1200 includes a physical quantity sensor 1, a control circuit 1210 that controls driving of the physical quantity sensor 1, and a correction circuit 1220 that corrects the physical quantity detected by the physical quantity sensor 1 based on, for example, the environmental temperature. Is built-in. The physical quantity sensor 1 is not particularly limited, but, for example, any one of the above-described embodiments can be used.

  Such a mobile phone 1200 (electronic device) includes the physical quantity sensor 1, a control circuit 1210, and a correction circuit 1220. Therefore, the effects of the physical quantity sensor 1 described above can be obtained, and high reliability can be exhibited.

Eighth Embodiment
Next, an electronic device according to an eighth embodiment of the present invention will be described.

  FIG. 19 is a perspective view showing an electronic device according to an eighth embodiment of the present invention.

  The digital still camera 1300 shown in FIG. 19 is an application of the electronic device of the present invention. In this figure, a display unit 1310 is provided on the back of the case 1302, and is configured to perform display based on an image pickup signal from a CCD, and the display unit 1310 functions as a finder for displaying an object as an electronic image. A light receiving unit 1304 including an optical lens (imaging optical system), a CCD, and the like is provided on the front side (the rear side in the drawing) of the case 1302. Then, when the photographer confirms the subject image displayed on the display unit 1310 and presses the shutter button 1306, the imaging signal of the CCD at that time is transferred and stored in the memory 1308.

  Such a digital still camera 1300 includes a physical quantity sensor 1, a control circuit 1320 that controls driving of the physical quantity sensor 1, and a correction circuit 1330 that corrects the physical quantity detected by the physical quantity sensor 1 based on, for example, the environmental temperature. , Is built-in. The physical quantity sensor 1 is not particularly limited, but, for example, any one of the above-described embodiments can be used.

  Such a digital still camera 1300 (electronic device) includes the physical quantity sensor 1, a control circuit 1320, and a correction circuit 1330. Therefore, the effects of the physical quantity sensor 1 described above can be obtained, and high reliability can be exhibited.

  The electronic device according to the present invention may be, for example, a smartphone, a tablet terminal, a watch (including a smart watch), an inkjet discharge, in addition to the personal computer and the mobile phone of the above-described embodiment and the digital still camera of the present embodiment. Devices (for example, inkjet printers), laptop personal computers, televisions, wearable terminals such as HMDs (head mounted displays), video cameras, video tape recorders, car navigation devices, pagers, electronic organizers (including communication function included), electronics Dictionaries, calculators, electronic game devices, word processors, workstations, video phones, television monitors for crime prevention, electronic binoculars, POS terminals, medical devices (such as electronic thermometers, sphygmomanometers, blood glucose meters, electrocardiogram measuring devices, ultrasound examinations Devices, electronic endoscopes), fish finders, various measuring devices, devices for mobile terminal base stations, instruments (for example, instruments of vehicles, aircraft, ships), flight simulators, network servers, etc. it can.

The Ninth Embodiment
Next, a portable electronic device according to a ninth embodiment of the present invention will be described.

  FIG. 20 is a plan view showing a portable electronic device according to a ninth embodiment of the present invention. FIG. 21 is a functional block diagram showing a schematic configuration of the portable electronic device shown in FIG.

  The wristwatch-type activity meter 1400 (active tracker) shown in FIG. 20 is a wrist device to which the portable electronic device of the present invention is applied. The activity meter 1400 is attached to a site (subject) such as the user's wrist by a band 1401. Further, the activity meter 1400 is equipped with a display portion 1402 of digital display, and is capable of wireless communication. The physical quantity sensor 1 according to the present invention described above is incorporated in the activity meter 1400 as a sensor that measures acceleration or a sensor that measures angular velocity.

  The activity meter 1400 includes a case 1403 in which the physical quantity sensor 1 is accommodated, a processing unit 1410 which is accommodated in the case 1403 and processes output data from the physical quantity sensor 1, and a display unit 1402 which is accommodated in the case 1403. And a translucent cover 1404 closing the opening of the case 1403. In addition, a bezel 1405 is provided on the outside of the translucent cover 1404. A plurality of operation buttons 1406 and 1407 are provided on the side surface of the case 1403.

  As shown in FIG. 21, an acceleration sensor 1408 as the physical quantity sensor 1 detects accelerations in directions of three axes intersecting (ideally orthogonal) with each other, and detects the magnitudes and directions of the detected three-axis accelerations. Outputs a corresponding signal (acceleration signal). Further, the angular velocity sensor 1409 detects angular velocities in the directions of three axes intersecting (ideally orthogonal) with each other, and outputs a signal (angular velocity signal) according to the magnitude and direction of the detected three axial angular velocity. .

  In the liquid crystal display (LCD) constituting the display unit 1402, for example, position information using the GPS sensor 1411 or the geomagnetic sensor 1412, an acceleration sensor 1408 included in the movement amount or physical quantity sensor 1, an angular velocity according to various detection modes. The exercise information such as the amount of exercise using the sensor 1409 or the like, the biological information such as the pulse rate using the pulse sensor 1413 or the like, or the time information such as the current time is displayed. In addition, the environmental temperature using the temperature sensor 1414 can also be displayed.

  The communication unit 1415 performs various controls for establishing communication between the user terminal and an information terminal (not shown). The communication unit 1415 may be, for example, Bluetooth (registered trademark) (including BTLE: Bluetooth Low Energy), Wi-Fi (registered trademark) (Wireless Fidelity), Zigbee (registered trademark), NFC (Near field communication), ANT + (registered trademark) It is configured to include a transceiver corresponding to a short distance wireless communication standard such as a trademark, and a connector corresponding to a communication bus standard such as USB (Universal Serial Bus).

  The processing unit 1410 (processor) is configured of, for example, a micro processing unit (MPU), a digital signal processor (DSP), an application specific integrated circuit (ASIC), or the like. The processing unit 1410 executes various processes based on the program stored in the storage unit 1416 and the signals input from the operation unit 1417 (for example, operation buttons 1406 and 1407). The processing by the processing unit 1410 includes data processing for each output signal of the GPS sensor 1411, the geomagnetic sensor 1412, the pressure sensor 1418, the acceleration sensor 1408, the angular velocity sensor 1409, the pulse sensor 1413, the temperature sensor 1414, and the clock unit 1419, and display unit 1402 Display processing for displaying an image on the screen, sound output processing for outputting sound to the sound output unit 1420, communication processing for communicating with an information terminal via the communication unit 1415, power control processing for supplying power from the battery 1421 to each unit, etc. Is included.

Such an activity meter 1400 can have at least the following functions.
1. Distance: Measure the total distance from the start of measurement by high precision GPS function.
2. Pace: Displays the current running pace from the pace distance measurement.
3. Average Speed: Average Speed Calculates and displays the average speed from the start of driving to the present.
4. Elevation: Measure and display elevation by GPS function.
5. Stride: Measures and displays stride even in a tunnel where GPS radio waves do not reach.
6. Pitch: Measure and display the number of steps per minute.
7. Heart rate: The heart rate is measured and displayed by the pulse sensor.
8. Slope: Measure and display the slope of the ground during training or trail running in mountainous areas.
9. Auto lap: Automatic lap measurement is performed when running a certain distance or certain time set in advance.
10. Exercise calories burned: Display calories burned.
11. Number of steps: Display the total number of steps from the start of exercise.

  The activity meter 1400 (portable electronic device) includes a physical quantity sensor 1, a case 1403 in which the physical quantity sensor 1 is housed, and a case 1403, and a processing unit 1410 that processes output data from the physical quantity sensor 1. And a light transmitting cover 1404 closing the opening of the case 1403. Therefore, the effects of the physical quantity sensor 1 described above can be obtained, and high reliability can be exhibited.

  The activity meter 1400 can be widely applied to a running watch, a runner's watch, a runner's watch for multi sports such as a duathlon or a triathlon, an outdoor watch, and a satellite positioning system, for example, a GPS watch equipped with GPS.

  Also, although the above description has been made using the GPS (Global Positioning System) as a satellite positioning system, another Global Navigation Satellite System (GNSS) may be used. For example, one or more of satellite positioning systems such as EGNOS (European Geostationary-Satellite Navigation Overlay Service), QZSS (Quasi Zenith Satellite System), GLONASS (GLO Bal NAvigation Satellite System), GALILEO, BeiDou (BeiDou Navigation Satellite System), etc. You may use In addition, using at least one of the satellite positioning systems, the Satellite-based Augmentation System (SBAS) such as Wide Area Augmentation System (WAAS), European Geostationary-Satellite Navigation Overlay Service (EGNOS), etc. It is also good.

Tenth Embodiment
Next, a mobile unit according to a tenth embodiment of the present invention will be described.

  FIG. 22 is a perspective view showing a mobile unit according to the tenth embodiment of the present invention.

  An automobile 1500 shown in FIG. 22 is an automobile to which the mobile unit of the present invention is applied. In this figure, a physical quantity sensor 1 functioning as at least one of an acceleration sensor and an angular velocity sensor (preferably a composite sensor capable of detecting both) is built in a car 1500, and the physical quantity sensor 1 detects the posture of the vehicle body 1501. be able to. A detection signal of the physical quantity sensor 1 is supplied to a vehicle body posture control device 1502 (a posture control unit), and the vehicle body posture control device 1502 detects the posture of the vehicle body 1501 based on the signal, and according to the detection result Control the brakes of the individual wheels 1503. Here, as the physical quantity sensor 1, for example, the same ones as those in the above-described embodiments can be used.

  Such an automobile 1500 (moving body) includes the physical quantity sensor 1 and a vehicle body posture control device 1502 (posture control unit). Therefore, the effects of the physical quantity sensor 1 described above can be obtained, and high reliability can be exhibited.

  In addition, the physical quantity sensor 1 also includes car navigation systems, car air conditioners, antilock brake systems (ABS), airbags, tire pressure monitoring systems (TPMS: Tire Pressure Monitoring System), engine control, hybrid vehicles It can be widely applied to electronic control units (ECUs) such as battery monitors of electric vehicles and electric vehicles.

  Also, the moving body is not limited to the car 1500, and can be applied to, for example, airplanes, rockets, artificial satellites, ships, AGVs (unmanned transport vehicles), biped robots, unmanned airplanes such as drone etc. .

  The physical quantity sensor, inertial measurement device, mobile body positioning device, portable electronic device, electronic device and mobile body according to the present invention have been described above based on the illustrated embodiments, but the present invention is not limited thereto. The configuration of each part can be replaced with any configuration having the same function. In addition, any other component may be added to the present invention. Also, the embodiments described above may be combined as appropriate.

  Further, in the embodiment described above, the physical quantity sensor that detects acceleration has been described. However, the present invention is not limited to this. For example, an angular velocity may be detected. In addition, both acceleration and angular velocity may be detected.

  In the embodiment described above, the X axis, the Y axis, and the Z axis are orthogonal to each other, but the present invention is not limited to this as long as they intersect with each other. For example, the X axis is perpendicular to the YZ plane. The Y axis may be slightly inclined with respect to the normal direction of the XZ plane, or the Z axis may be slightly inclined with respect to the normal direction of the XY plane. Note that “slightly” means a range in which the physical quantity sensor can exhibit the effect, and the specific inclination angle (numerical value) differs depending on the configuration or the like.

  DESCRIPTION OF SYMBOLS 1 ... physical quantity sensor, 2 ... board | substrate, 21 ... recessed part, 21A ... 1st recessed part, 21B ... 2nd recessed part, 22 ... mounting part, 25, 26, 27, 28 ... groove part, 3 ... element part, 31 ... fixing part, 32: movable electrode portion 321: first movable electrode portion 322: second movable electrode portion 322A: symmetrical portion 322B: asymmetric portion 33, 33a, 33b: beam portion 4: lid, 41: concave portion 42 ... communication hole, 43 ... sealing member, 48 ... ceiling portion, 481 ... inner surface, 49 ... glass frit, 75, 76, 77, 78 ... wiring, 8 ... electrode, 81 ... first fixed electrode, 82 ... second Fixed electrode, 83: Adjustment electrode, 84: Dummy electrode, 1100: Personal computer, 1102: Keyboard, 1104: Main body, 1106: Display unit, 1108: Display, 1110: Control circuit, 1120: Correction circuit, 12 DESCRIPTION OF SYMBOLS 0 ... Mobile phone, 1202 ... Operation button, 1204 ... Earpiece, 1206 ... Mouthpiece, 1208 ... Display part, 1210 ... Control circuit, 1220 ... Correction circuit, 1300 ... Digital still camera, 1302 ... Case, 1304 ... Light reception unit , 1306: shutter button, 1308: memory, 1310: display unit, 1320: control circuit, 1330: correction circuit, 1500: automobile, 1501: vehicle body, 1502: vehicle body attitude control device, 1503: wheel, 2000: sensor unit, 2100 ... Outer case, 2110 ... screw hole, 2200 ... joining member, 2300 ... sensor module, 2310 ... inner case, 2311 ... recess, 2320 ... substrate, 2330 ... connector, 2340x, 2340y, 2340z ... angular velocity sensor, 2350 ... acceleration sensor Ser 2360 Control IC 3000 Mobile positioning device 3100 Inertial measurement device 3110 Acceleration sensor 3120 Angular velocity sensor 3200 Arithmetic processing unit 3300 GPS reception unit 3400 Receiving antenna 3500 Location Information acquisition unit, 3600 ... position combining unit, 3700 ... processing unit, 3800 ... communication unit, 3900 ... display unit, Az ... acceleration, C1, C2 ... capacitance, F ... electrostatic attraction, Fa ... first electrostatic attraction , Fb: second electrostatic attractive force, Fc: third electrostatic attractive force, Fd: fourth electrostatic attractive force, J: rocking axis, L1, L2: distance, P: electrode pad, S: internal space, S1, S2 ... area, Ta, Tb, Tc, Td ... torque, Vd1, Vd2 ... voltage, θ ... inclination

Claims (19)

A substrate,
A first mass portion and a second mass portion having a mass larger than the first mass portion, and capable of oscillating around a swing axis located between the first mass portion and the second mass portion in a plan view Moving parts,
A first fixed electrode disposed on the substrate and facing the first mass portion;
A second fixed electrode disposed on the substrate and facing the second mass portion;
An adjustment electrode disposed on the substrate, facing the second mass, and generating an electrostatic attractive force with the second mass;
A lid disposed on the opposite side of the movable portion to the substrate side;
Physical quantity sensor characterized by including. In claim 1,
In a plan view from the direction in which the substrate and the movable portion overlap,
The second mass part is
A first portion that is in line symmetry with the first mass portion with respect to the swing axis;
A second portion located on the opposite side to the swing shaft side of the first portion;
Including
The second fixed electrode portion is disposed to face the first portion,
The physical quantity sensor, wherein the adjustment electrode is disposed to face the second portion. In claim 2,
The torque about the swinging axis due to the electrostatic attractive force generated between the second portion and the lid is T1,
Assuming that the torque about the swinging axis resulting from the electrostatic attraction generated between the second portion and the adjustment electrode is T2,
0 <T2 <2 × T1
A physical quantity sensor that satisfies In claim 3,
0.5Tc <Td <1.5 × Tc
A physical quantity sensor that satisfies In claim 4,
0.7Tc <Td <1.3 × Tc
A physical quantity sensor that satisfies In claim 4,
0.9Tc <Td <1.1 × Tc
A physical quantity sensor that satisfies In any one of claims 3 to 6,
T1 = T2
A physical quantity sensor that satisfies In any one of claims 2 to 7,
The distance between the second portion and the lid is d1,
When a separation distance between the second portion and the adjustment electrode is d2,
1/3 <d1 / d2 <3
The physical quantity sensor that is satisfied. In claim 8,
1/2 <d1 / d2 <2
The physical quantity sensor that is satisfied. In claim 8 or 9,
d1 = d2
The physical quantity sensor that is satisfied. In any one of claims 2 to 10,
In the plan view,
The area of the second portion is S1,
When an area of a region where the second portion and the adjustment electrode overlap is S2,
S1 = S2
The physical quantity sensor that is satisfied. In any one of claims 2 to 11,
The distance between the second portion and the adjustment electrode is d2,
When a separation distance between the first portion and the second fixed electrode and a separation distance between the first mass portion and the first fixed electrode are d3
d2> d3
The physical quantity sensor that is satisfied. In any one of claims 1 to 12,
The adjustment electrode is a physical quantity sensor connected to a ground. In any one of claims 1 to 13,
The lid is a physical quantity sensor connected to a ground. A physical quantity sensor according to any one of claims 1 to 14,
A control circuit that controls driving of the physical quantity sensor;
An inertial measurement device comprising: An inertial measurement device according to claim 15;
A receiver for receiving a satellite signal on which position information is superimposed from a positioning satellite;
An acquisition unit that acquires position information of the reception unit based on the received satellite signal;
An arithmetic unit that calculates the attitude of the moving object based on the inertial data output from the inertial measurement device;
And a calculator configured to calculate the position of the mobile body by correcting the position information based on the calculated attitude. A physical quantity sensor according to any one of claims 1 to 14,
A case containing the physical quantity sensor;
A processing unit housed in the case and processing output data from the physical quantity sensor;
A display unit housed in the case;
A translucent cover closing the opening of the case;
A portable electronic device characterized by including. A physical quantity sensor according to any one of claims 1 to 14,
Control circuit,
A correction circuit,
An electronic device characterized by including. A physical quantity sensor according to any one of claims 1 to 14,
A posture control unit,
A mobile unit characterized by including.

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