JPH11311521A - Inertia quantity sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multiaxial inertia quantity sensor which can be formed integrally by using micromachining technology and can detect angular velocity and acceleration. SOLUTION: This inertia quantity sensor 1 consists of a device part 2 and a substrate part 3. The device part 2 is made of a silicon single crystal body and has a mass body 21, an elastic body 22, and a driving electrode 23. This driving electrode 23 is an inter-digital electrode and generates an electrostatic force by being applied with an AC voltage to rotate and vibrate the mass body 21. The substrate part 3 is equipped with a base 31 and a detection electrode 32. The base 31 is made of Pyrex<(> R<)> glass and supports the mass body 21 and driving electrode 23 so that they can freely rotate. This inertia quantity sensor can detect the acceleration along the center axis of rotation by using the detection electrode 32 which detects the angular velocity and find inertial quantities in multiaxial directions at the same time. Further, the device part 2 can be molded in one body.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a function of an acceleration sensor which can measure the angular velocity of a vibration type and multi-axis detection type for measuring the angular velocity of a moving body, and can also measure the acceleration of the moving body. Related to an inertial amount sensor. The inertial amount sensor of the present invention is used for, for example, detection of impact, attitude control, detection of camera shake of a video camera, detection of axle braking, and the like.

[0002]

2. Description of the Related Art As a micro-vibration type angular velocity sensor utilizing silicon micro-machining technology, Japanese Patent Laid-Open No.
There is a vibration gyro sensor disclosed in Japanese Patent Application Laid-Open No. 239339 and Japanese Patent Application Laid-Open No. 9-325032.

[0003]

However, in the angular velocity sensor disclosed in Japanese Patent Application Laid-Open No. 7-239339, the same output as a signal when an angular velocity is received is received in response to an external disturbance such as vibration or acceleration. In some cases, the error component increases in actual use. In the angular velocity sensor disclosed in Japanese Patent Application Laid-Open No. 9-325032, a piezoelectric element obtained by separately machining is used as a reference vibration source, and the entire sensor cannot be manufactured by micromachining technology. In addition, since there are a plurality of diaphragms, it is difficult to match the resonance frequencies of the diaphragms with high accuracy, and it has been difficult to improve the sensor sensitivity.

Further, these angular velocity sensors can detect angular velocity, but have not been used for detecting acceleration and the like. The present invention has been made in order to solve such a problem, and can be integrally manufactured by using a micromachining technology, and can detect not only an angular velocity but also an acceleration. An object of the present invention is to provide an inertial amount sensor of the invention.

[0005]

The inertial amount sensor according to the first aspect of the present invention includes a driving electrode 23, a mass body 21 that rotates and vibrates around a central axis by an electrostatic force generated by the driving electrode, and at least supports the mass body. An inertia comprising a device portion 2 made of single-crystal silicon having four elastic bodies 22 and a base portion 3 having a base 31 supporting the device portion and a detection electrode 32 provided on the base. An amount sensor, wherein the substrate unit is disposed in parallel with the device unit,
The detection electrodes are formed at two positions each on two axes orthogonal to each other on a plane perpendicular to the rotation center axis, at positions facing the center axis, and the device unit and the substrate unit are joined. It is characterized by.

[0006] To manufacture the above-mentioned "device section", SOI
(Silicon On Insulator) wafers and the like can also be used. Further, the material of the “base” can be arbitrarily selected as long as it is an insulating material that can be finely processed, and Pyrex glass or the like can be mentioned as an example. In addition, the shape of the “mass body” can be arbitrarily selected as long as it can be easily rotated and vibrated. For example, a disk or a polygonal disk (a square disk,
And a pentagonal disc). Furthermore, as for the elastic body, the configuration can be arbitrarily selected as long as the mass body can easily rotate and vibrate. For example, a spring-like body that can easily expand and contract can be used.

In the inertial amount sensor according to the second aspect of the present invention, the angular velocity is obtained from the difference between the capacitances detected by the two detection electrodes on one axis of the two orthogonal axes. An inertial amount sensor, which can determine an angular velocity about two orthogonal axes from each of the angular velocities detected on the two axes. Such an inertial amount sensor is provided with two “detection electrodes” facing each other on one axis on each of two axes, so that the angular velocities around two axes orthogonal to each other are detected from the detected angular velocities. Can be measured.

In the inertial amount sensor according to the third aspect of the present invention, the acceleration in the rotation center axis direction of the mass body is obtained from the sum of the capacitances detected from all the detection electrodes formed on the base. be able to. In the inertial amount sensor according to the fourth aspect of the invention, the mass body has a disk shape, and the drive electrode is formed in a comb shape, and the comb drive electrode has an arc shape parallel to an outer periphery of the mass body. And at least two places at positions facing the rotation center axis.

In the inertial amount sensor according to a fifth aspect of the present invention, the drive electrode is formed in a slit shape, and one of the set of slit drive electrodes is formed on the mass body, and the other is formed on the base. Can be formed. In the “slit drive electrode”, the drive electrode is formed in a slit shape. Such an electrode can be formed, for example, of a set of slit-shaped drive electrodes, in which one electrode is formed on the mass body and the other electrode is formed on the base. In addition, book 6
As shown in the inertial amount sensor of the invention, both the comb-shaped drive electrode of the fourth invention and the slit-shaped drive electrode of the fifth invention can be provided as the drive electrodes.

In the inertial amount sensor according to the seventh aspect of the present invention, a part of the mass body is cut out, and the mass body can be supported by the elastic body inside the mass body. Such an elastic body may have any shape such as a linear shape or a zigzag shape.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIGS.
The inertial amount sensor of the present invention will be described in detail with reference to examples.
You. (1) Manufacture of inertia sensor  Hereinafter, a method for manufacturing the inertial amount sensor of the present invention will be described.
I do. (3-1) Production of Substrate Part First, the substrate part 3 is produced by the processing process shown in FIG.
did. First, a flat Pyrex glass with a thickness of 1 mm
Perform patterning using a photo ring
FIG. 7 (a) is obtained by etching with hard hydrofluoric acid.
A base 31 as shown was produced. This etching depth is
3 μm. After that, chrome and gold are etched
Sputtering at 500mm and 4000mm thickness respectively
By performing and patterning further, FIG.
A detection electrode 32 is formed on a base 31 as shown in FIG.
Plate part 3 was obtained.

(3-2) Preparation of Processed Wafer Next, a processed wafer 42 that finally becomes the device section 1 was prepared. First, as shown in FIG. 8C, an oxide film is formed on the surface of the single crystal silicon wafer 41 (N type, film thickness of 525 μm), and patterning by photolithography is performed, as shown in FIG. Then, the oxide film was processed into a shape such as an elastic body. After that, as shown in FIG. 8E, the single crystal silicon wafer 41 is
Reactive ion etching (RIE) is performed to a thickness of 5 μm to form a pattern of a mass body, an elastic body, and the like on the single crystal silicon wafer 41. Further, as shown in FIG. 8F, the oxide film used as a mask was removed with buffered hydrofluoric acid, and the entire surface of the single crystal silicon wafer 41 was oxidized again to obtain a processed wafer.

(3-3) Fabrication of Floating Structure A floating structure was fabricated based on the substrate 2 and the processed wafer 42 thus fabricated. First, as shown in FIG. 9G, the substrate portion 3 and the processed wafer 42 are
The surfaces on which the mass body, the elastic body, and the like are formed are joined so as to face the detection electrode forming surface of the substrate portion 3. Thereafter, as shown in FIG. 9H, the oxide film on the back surface of the processed wafer 42 (that is, the surface on which no pattern was formed) was removed, and the exposed single crystal silicon was etched with tetramethylammonium hydroxide. At this time, the single crystal silicon is etched until just before the pattern portion is exposed. In the drying after this etching, the pattern surface of the processed wafer 42 and the substrate 3
The drying process was performed by freeze-drying because the interval between the electrode and the electrode formed thereon was very small, so that the electrodes could stick to each other during drying. Thereafter, etching was performed by RIE until the pattern was exposed from the back surface of the processed wafer 42 as shown in FIG. After the etching, the oxide film formed on the pattern surface is removed with buffered hydrofluoric acid, and the freeze-drying process is performed again. The signal lines of the drive electrodes and the detection electrodes are taken out by performing wire bonding on the pads and the base. The size of the inertial amount sensor 1 thus manufactured shown in FIG. 1 is 5 mm in each of the vertical and horizontal directions, and the thickness thereof is 1.0.
5 mm.

(2) Configuration of Inertial Amount Sensor As shown in FIGS. 1 to 3, the inertial amount sensor 1 of the present invention comprises a device section 2 and a substrate section 3. This device section 2
It is obtained by molding a flat plate of a silicon single crystal body using a micromachining technique such as photolithography or etching. As shown in FIGS. 1 and 2, the mass body 21, the elastic body 22, and the drive electrode 23 are formed. And

The mass body 21 is disk-shaped, and rotates and vibrates about the center of the disk as a center axis C. The four elastic bodies 22a, 22b, 22c, 22
The four corners are supported by one end of d, so that it can be easily rotated (referred to as a floating structure). The elastic bodies 22a, 22b, 22c, 2
The other end of 2d is fixed to pad 25. As shown in FIGS. 1 and 2, the drive electrode 23 is an arc-shaped comb-shaped electrode parallel to the outer periphery of the pair of mass bodies 21,
Four pairs are provided at equal intervals along the outer periphery of the mass body 21. Of the pair of electrodes constituting the drive electrode 23, one drive electrode 231 is provided on the drive terminal 24, and the other drive electrode 232 is formed integrally with the mass body.
An AC voltage is applied to the drive electrode 23,
By generating an electrostatic force between 1 and 232, the mass body 21 is rotationally vibrated.

As shown in FIGS. 1 and 3, the substrate section 3 includes a base 31 and detection electrodes 32. The base 31 is made of Pyrex glass, and supports the pad 25 of the device section 2 with the support section 34 so that the mass body 21 and the drive electrode 23 can be freely rotated. Also, the detection electrode 32 is 4
Two fan-shaped detection electrodes 32a, 32b, 32c, and 32d, and two central axes each on two axes orthogonal to each other on a plane perpendicular to the central axis C of rotation of the mass body 21. It is arranged at a position facing the center C.
The detection electrode 32 detects displacement of the position of the mass body 21 as a change in capacitance.

(3) Operation of Inertial Amount Sensor The operation of the inertial amount sensor 1 of the present invention will be described with reference to FIGS. Note that the x axis is the horizontal direction in the drawing,
Positive to the right. The y-axis is the vertical direction in the drawing, and the upward direction is positive. Further, the z-axis is the front and back direction in the drawing, and the front direction is positive. As shown in FIG. 4, the inertial amount sensor 1 causes the mass body 21 to rotate around the z-axis around the central axis C by electrostatic force generated by four pairs of drive electrodes 231 and 232 formed in the device unit 2. The vibration is excited, and the initial rotational vibration required for generating the Coriolis force is given. When attention is paid to a moment of this vibration, the a part of the mass body is displaced in the positive y-axis direction, the b part is displaced in the negative x-axis direction, the c part is displaced in the negative y-axis direction, and the d part is displaced in the positive x-axis direction. .

In this state, for example, when an angular velocity about the x-axis is applied to the inertial amount sensor 1, as shown in FIG.
Coriolis force proportional to the angular velocity is applied to the a side in the negative z-axis direction, c
Is generated in the positive direction of the z-axis, and the mass 2
1 is displaced to the position of the mass body 21 '. Therefore, the substrate part 3
Changes the distance between the detection electrodes 32a and 32c provided on the mass body 21 (the detection electrode 32a moves away from the mass body 21,
Since the detection electrode 32c approaches, the capacitance between the mass body 21 and the detection electrode 32a and the mass body 21 and the detection electrode 32c
The difference between the capacitances changes. Therefore, since the capacitance difference changes in proportion to the magnitude of the angular velocity, the angular velocity of the rotational force applied to the inertial amount sensor 1 can be obtained by detecting the capacitance difference. As described above, by performing detection using the difference between the capacitances of the pair of detection electrodes, the influence of another factor such as another vibration or acceleration can be reduced.
Further, in the inertial amount sensor 1 of the present invention, since the four detection electrodes 32a, 32b, 32c, and 32d on the base 31 are formed on two axes orthogonal to each other, the angular velocities of the two axes can be simultaneously measured. In addition, they can be measured independently of each other.

When a force is applied in the positive z-axis direction in the vibration state shown in FIG. 4, the mass body 21 'is moved toward the base 31 by inertial force as shown in FIG. , The mass 21 and the detection electrodes 32a, 32b,
The sum of the capacitances between 32c and 32d changes. At this time, since the sum of the capacitances changes in proportion to the magnitude of the acceleration, it can be obtained by converting the acceleration of the force applied to the inertial amount sensor 1.

(4) Evaluation of Characteristics of Inertial Amount Sensor FIG. 10 shows resonance characteristics of the mass body 21 around the central axis C.
As shown in FIG. 4, the mass body 21 formed in the device section 2 is moved to the center axis C by the electrostatic force generated by the drive electrode 23.
By rotating around and measuring the change in capacitance between the pair of drive electrodes 231 and 232 due to the vibration displacement of the drive electrode 23, the resonance characteristics shown in FIG. 10 were obtained. At this time, the resonance frequency was 2.134 kHz, and the mechanical Q value in a vacuum was about 8000. In addition, by observing the resonance state of the rotational vibration of the mass body 21 under a scanning electron microscope, the vibration amplitude at the outer periphery of the mass body 21 in a vacuum when the AC drive voltage of 30 V is applied is about 30 μm. Was confirmed.

FIG. 1 shows an angular velocity detection characteristic of the inertial amount sensor 1.
It is shown in FIG. By placing the inertial amount sensor 1 on a turntable and measuring a change in capacitance between the mass body 21 and the detection electrode 32 when an angular velocity around the x-axis is applied as shown in FIG. The result shown in FIG. 11 was obtained. The output sensitivity was 0.1 mV / (rad / s). FIG. 12 shows output electric characteristics with respect to the acceleration applied to the inertial amount sensor 1. This is done by placing the inertial amount sensor 1 on a shaker, applying an acceleration in the z-axis direction as shown in FIG. 6, and measuring a change in capacitance between the mass body 21 and the detection electrode 32. I asked. The output sensitivity of the inertial sensor 1 is 2 mV /
G.

FIG. 13 shows an electric circuit system for detecting the angular velocity applied to the inertial amount sensor. Detection electrode 3
To 2a, 32b, 32c, and 32d, alternating voltages having frequencies of fa and phases different from each other by 90 ° are applied. Assuming that Ca, Cb, Cc, and Cd are the capacitances between the mass body and the detection electrodes 32a, 32b, 32c, and 32d, respectively, the output V0 changes at the frequency fa.
An output signal proportional to the difference between a and Cc and an output signal proportional to the difference between Cb and Cd whose phases are shifted by 90 ° are added to each other and output. Therefore, in order to extract the difference component between Ca and Cc from the output V0, it is sufficient to perform synchronous detection using a signal synchronized with the difference component as a reference signal. For this purpose, the signal applied to the capacitor Ca is used as the reference signal. It may be used. An output V1 is obtained by this synchronous detection.

Similarly, in order to extract the difference component between the capacitances Cb and Cd from the output V0, it is sufficient to perform synchronous detection using the signal applied to Cb as the reference signal.
2 is obtained. Here, when the angular velocity is not applied, the output voltage of V0 is 0 because there is no difference between Ca and Cc or Cb and Cd, but when the angular velocity is applied, the Coriolis force generated in proportion to the angular velocity As a result, a difference occurs in the capacity, and an output appears. Since this Coriolis force is generated in synchronization with the initial rotational vibration of the mass body, Ca and C
The difference between c and the difference between Cb and Cd changes in synchronization with the initial rotational vibration. Therefore, a final output proportional to the applied angular velocity can be obtained by performing synchronous detection on the outputs V1 and V2 using the drive voltage signal that excites the initial rotational vibration as a reference signal.

FIG. 14 shows an electric circuit system for simultaneously detecting the applied angular velocity and acceleration. An AC voltage having a frequency fb is further superimposed on the AC voltage shown in FIG. 13 and applied to the detection electrodes 32a, 32b, 32c, and 32d. Here, the frequency fa and the frequency fb are different frequencies. The signal of the frequency fb is output from the detection electrode 32a,
32b, 32c, and 32d are applied in the same phase, so that the output V3 includes Ca, Cb,
An output signal proportional to the sum of Cc and Cd is generated by being added to the output appearing at V0. In order to obtain an output proportional to the acceleration applied from the output signal V3, synchronous detection may be performed using a reference signal synchronized with the sum component of Ca, Cb, Cc, and Cd. On the other hand, a signal of frequency fb applied in phase may be used.

Since the inertial force generated by the applied acceleration does not change in synchronization with the initial rotational vibration, this output is a final output proportional to the acceleration. On the other hand, the method of detecting the angular velocity is exactly the same as the method shown in FIG. 13, so that the electric circuit system shown in FIG. 14 can simultaneously detect the angular velocity and the acceleration.

(5) Effects of Embodiment According to the inertial amount sensor 1 of this embodiment, since the mass body 21 which is the only vibrating body is rotationally vibrated, resonance required for a plurality of vibrating bodies is required. No complicated process such as frequency tuning is required. In addition, the mass body 21 and the elastic body 22
In addition, since the drive electrode 23 has a floating structure that does not come into contact with the base 31, it is possible to cause rotational vibration without hindering each movement.

Further, since all the detection electrodes 32 for detecting the angular velocity and the acceleration are provided on the base 31, the mass body which is a vibrating body can be simplified, and the angular velocity about two axes can be detected. be able to. Further, the acceleration in the rotation center axis direction can be detected by using the detection electrode 32 for detecting the angular velocity, and a plurality of inertia amounts in the multi-axis directions can be obtained at the same time. Further, since the angular velocity is detected from the difference in capacitance measured from the pair of detection electrodes 32 facing each other, it is possible to suppress the influence from disturbance such as vibration, acceleration, and temperature change. Furthermore, since the drive electrode 23 can be integrally formed with the mass body 21, the manufacturing process of the inertial amount sensor 1 can be simplified.

It should be noted that the present invention is not limited to the above-described embodiment, but may be variously modified within the scope of the present invention depending on the purpose and application. That is, in the above embodiment, the semiconductor device is manufactured using a single crystal silicon wafer. However, the present invention is not limited to this, and SOI (Silicon On In) is used.
A wafer may be used. In this case, the thickness of the device portion can be formed with high precision and uniformity, and further, it is suitable for a vacuum sealing structure.

Further, the drive electrode for rotating and vibrating the mass body on the inertial amount sensor may have any configuration. For example, as shown in FIG. 15, as means for applying rotational vibration to the mass body 21, slit drive electrodes 231 'and 232' are formed on the base 31 and the mass body 21, and the slit drive electrodes 231 'and 232' are formed. By applying an AC voltage between them, the mass body 21 can be rotationally vibrated by the electrostatic force. Such slit-shaped drive electrodes 231 ′, 23
2 ′ is provided on the base 31 of the substrate section 3 and on the mass body 21 of the device section 2, respectively. This device section 2
The side slit-shaped drive electrode 232 ′ is formed by providing a radial through hole 211 with the central axis C as an axis in the mass body 21. Further, the slit-shaped drive electrode 231 ′ on the substrate section 3 side is formed so as to face an electrode formed on the mass body 21 with respect to a plane perpendicular to the central axis C of the mass body 21. When the mass body 21 is rotationally vibrated by such means, a short circuit between the comb-teeth-shaped drive electrodes due to minute dust in the air, which may occur when the rotational vibration is performed by the comb-teeth-shaped drive electrode, or the like. In addition, it is possible to solve the problem of the contact between the comb-shaped electrodes at the time of rotational vibration due to insufficient processing accuracy of the comb-shaped drive electrodes. The detection of the angular velocity and the acceleration in the inertial amount sensor having this configuration can be performed in the same manner as the inertial amount sensor using the comb-shaped drive electrodes in the embodiment.

Further, as shown in FIG. 16, the comb-shaped drive electrode 23 and the slit-shaped drive electrode 231 '
232 'may be provided at the same time. As a method of giving such a rotational vibration, the effect of the electrostatic force by the comb-shaped drive electrodes 23 and the effect of the electrostatic force by the slit-shaped drive electrodes 231 ′ and 232 ′ are added, and the amplitude of the rotational vibration is increased. Therefore, the detection sensitivity of the angular velocity can be improved as compared with the case where the excitation is performed by only one of the comb-shaped driving electrodes 23 or the slit-shaped driving electrodes 231 ′ and 232 ′.

As another means for supporting the mass body 21, as shown in FIG. 17, a portion 212 in which a part of the mass body 21 is cut out in the longitudinal direction of the elastic body 22 is provided.
1 can be supported more centrally.
By supporting the mass body 21 in this manner, the resonance frequency in the rotational vibration mode in the rotational motion as shown in FIG. 4 is reduced by about 30%, and is generated when the angular velocity as shown in FIG. 5 is further applied. The resonance frequency of the detected vibration mode is reduced by about 10%. At the same time, as the elastic body becomes longer, the overall rigidity of the elastic body decreases, and the vibration amplitude increases about three times. These effects can improve the angular velocity detection sensitivity.

[0032]

According to the inertial amount sensor according to the first invention,
Since the detection electrodes for detecting the angular velocity and the acceleration are provided on the base, the mass body as the vibrator can be simplified. Further, since the mass body that is the only vibrating body is rotationally vibrated, a complicated process such as tuning of the resonance frequencies of the plurality of vibrating bodies is not required. Further, since the angular velocity is detected from the difference between the capacitances measured from two opposing detection electrodes, it is possible to suppress the influence from disturbance such as vibration, acceleration, and temperature change. Furthermore, the angular velocity around two axes can be obtained by the detection electrodes arranged orthogonally as shown in the second invention, and the acceleration in the rotation axis direction can also be obtained as shown in the third invention.

Since the comb-shaped driving electrode according to the fourth aspect of the present invention can be integrally formed with the mass body, the manufacturing process of the inertial sensor can be simplified. In addition, by forming the comb electrode in an arc shape parallel to the mass body, sufficient rotational vibration can be easily obtained. By using the driving electrode of the mass as the slit-shaped driving electrode shown in the fifth invention, short-circuiting due to minute dust in the air does not occur, and it can be used even with low processing accuracy. As shown in the sixth aspect of the present invention, by using both the comb drive electrode and the slit drive electrode, the amplitude of the rotational vibration is increased, and the detection sensitivity of the angular velocity can be improved.

By supporting the mass body 21 closer to the center as shown in the seventh invention, the resonance frequency in each mode is reduced, and the detection sensitivity of the angular velocity can be improved.

[Brief description of the drawings]

FIG. 1 is an explanatory perspective view illustrating an appearance of an inertial amount sensor according to an embodiment.

FIG. 2 is a plan view for explaining a device section constituting an inertial amount sensor according to the embodiment.

FIG. 3 is a plan view for explaining a substrate unit constituting the inertial amount sensor in the embodiment.

FIG. 4 is a plan view for explaining an initial rotational vibration state of a mass body in the device section.

FIG. 5 is a schematic diagram for explaining a state of displacement of a mass body when an angular velocity around an x-axis is applied to the inertial amount sensor of the present invention.

FIG. 6 is a schematic diagram for explaining a state of displacement of a mass body when acceleration in the z-axis direction is applied to the inertial amount sensor of the present invention.

FIG. 7 is a schematic diagram for explaining a process of manufacturing a substrate in each step of manufacturing the inertial amount sensor according to the embodiment.

FIG. 8 is a schematic diagram for explaining how to manufacture a processed wafer serving as a device section in each step of manufacturing the inertial amount sensor according to the embodiment.

FIG. 9 is a schematic diagram for explaining that an inertial amount sensor is manufactured from a processed wafer and a substrate in each step of manufacturing the inertial amount sensor according to the embodiment.

FIG. 10 is a graph illustrating resonance characteristics of the inertial amount sensor according to the embodiment when the sensor is rotated.

FIG. 11 is a graph showing angular velocity detection characteristics of the inertial amount sensor according to the embodiment.

FIG. 12 is a graph showing acceleration detection characteristics of the inertial amount sensor according to the embodiment.

FIG. 13 is an explanatory diagram of an electric circuit system for detecting a two-axis angular velocity using the inertial amount sensor of the present invention.

FIG. 14 is an explanatory diagram of an electric circuit system for detecting the two-axis angular velocity and the z-axis direction acceleration using the inertial amount sensor of the present invention.

FIG. 15 is an explanatory diagram illustrating a configuration of an inertial amount sensor according to another embodiment.

FIG. 16 is an explanatory diagram illustrating a configuration of an inertial amount sensor according to another embodiment.

FIG. 17 is an explanatory diagram illustrating a configuration of an inertial amount sensor according to another embodiment.

[Explanation of symbols]

1; inertia sensor, 2; device section, 21; mass body, 2
2; elastic body, 23, 23a to 23d; drive electrode, 24;
Drive terminal, 25; pad, 3; substrate, 31; base, 3
2; detection electrode, 33; detection terminal, 34;
Single crystal silicon wafer, 42; processed wafer, C: central axis.

Continued on the front page (72) Inventor Takuya Mizuno 14-18, Takatsuji-cho, Mizuho-ku, Nagoya-shi Inside Japan Special Ceramics Co., Ltd. (72) Inventor Toshiyuki Matsuoka 14-18, Takatsuji-cho, Mizuho-ku, Nagoya City Inside Japan Special Ceramics Co., Ltd. (72) Inventor Takafumi Oshima 14-18 Takatsujicho, Mizuho-ku, Nagoya

Claims (7)

[Claims] A drive electrode, a mass body that rotates and vibrates around a central axis by electrostatic force generated by the drive electrode.
1, and at least four elastic bodies 2 supporting the mass body
A device unit 2 made of single-crystal silicon comprising:
An inertial quantity sensor comprising: a substrate section 3 having a base 31 supporting the device section and a detection electrode 32 provided on the base section, wherein the substrate section is arranged in parallel with the device section; The detection electrodes are formed at two positions each on two axes orthogonal to each other on a plane perpendicular to the rotation center axis, at positions facing the center axis, and the device unit and the substrate unit are joined. An inertial amount sensor characterized by the above-mentioned. 2. An inertial amount sensor wherein an angular velocity is obtained from a difference between capacitances detected by two detection electrodes on one axis of the two orthogonal axes. 2. The inertial amount sensor according to claim 1, wherein an angular velocity around two orthogonal axes is obtained from each of the angular velocities detected on two axes. 3. The acceleration in the rotation center axis direction of the mass body is obtained from the sum of capacitances detected from all the detection electrodes formed on the base.
Inertial amount sensor as described. 4. The mass body has a disk shape, the drive electrode is formed in a comb shape, the comb drive electrode is formed in an arc shape parallel to an outer periphery of the mass body, and 4. The inertial amount sensor according to claim 1, wherein at least two positions are formed at positions opposed to the rotation center axis. 5. The drive electrode according to claim 1, wherein one of the set of slit-shaped drive electrodes is formed on the mass body and the other is formed on the base. 4. The inertial amount sensor according to 2 or 3. 6. The inertial amount sensor according to claim 1, wherein the drive electrode comprises both the comb drive electrode according to claim 4 and the slit drive electrode according to claim 5. 7. The inertial amount sensor according to claim 1, wherein a part of the mass body is cut out, and the mass body is supported by the elastic body inside the mass body.