JPH0526754A - Sensor utilizing change in electrostatic capacitance - Google Patents

Abstract

PURPOSE:To simplify the structure of a sensor utilizing a change in electrostatic capacitance and to enhance the detection sensitivity thereof. CONSTITUTION:A flexible substrate 60, a control substrate 70 and a fixed substrate 80 are bonded. The flexible substrate 60 consists of a center block-shaped acting part 61, an outer peripheral frame-shaped fixed part 63 and the bridge shaped beams 62 connecting both parts 61, 63 at four places. Spaces are formed by the groove D2 formed to the upper surface of the control substrate 70 and the groove D3 formed to the rear surface of the fixed substrate 80 and the acting part 61 becomes a suspended state under environment such that the periphery thereof is surrounded. Displacement electrodes 21, 23, 25 are formed to the upper surface of the acting part 61 and a fixed electrode 11 is formed to the rear surface of the fixed substrate 80. When acceleration acts on the acting part 61, the bridge-shaped beams 62 are bent and the acting part 61 is displaced and the distances between the respective electrodes are also changed. The acted acceleration can be detected on the basis of a change in the electrostatic capacitance of the capacitance element constituted of the respective electrodes.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sensor utilizing a change in electrostatic capacity, and more particularly to a sensor suitable for detecting force for each multidimensional component and applicable to detection of acceleration and magnetism.

[0002]

2. Description of the Related Art In the automobile industry, machine industry and the like, there is an increasing demand for detection devices capable of accurately detecting physical quantities such as force, acceleration and magnetism. In particular, there is a demand for a small device that can detect these physical quantities for each of two-dimensional or three-dimensional components. To meet such demand, Japanese Patent Application No. 2
No. 274299 proposes a new sensor that utilizes the change in capacitance. This sensor is
It is characterized in that physical quantities such as acceleration and magnetism can be detected for each two-dimensional or three-dimensional component, and the manufacturing cost is relatively low.

The basic constituent elements of this sensor are a flexible portion formed between a fixed portion fixed to the housing of the apparatus, an acting portion for transmitting an external force, and the fixed portion and the acting portion. A flexible substrate having three parts, a fixed substrate fixed to the device casing so as to face the flexible substrate, and a surface of the flexible substrate facing the fixed substrate. And the fixed electrode formed on the surface of the fixed substrate facing the flexible substrate. When a force from the outside is applied to the acting portion, the flexible substrate is bent and the distance between the displacement electrode and the fixed electrode is changed. Therefore, the capacitance between both electrodes changes. This change in capacitance depends on the force applied from the outside, and the force can be detected by detecting the change in capacitance. If a weight body is connected to the action portion, it can be used as an acceleration sensor that detects acceleration acting on this weight body, and if a magnetic body is connected to the action portion, it acts on this magnetic body. It can be used as a magnetic sensor for detecting magnetism.

[0004]

In order to supply the above-mentioned sensor at low cost, the structure should be as simple as possible,
It should be suitable for mass production. Further, in order to perform highly accurate measurement, it is necessary to increase the detection sensitivity.

Therefore, an object of the present invention is to simplify the structure of the sensor utilizing the change in electrostatic capacity and to increase the detection sensitivity.

[0006]

[Means for Solving the Problems]

(1) A first aspect of the invention of the present application is a flexible portion formed between a fixing portion fixed to an apparatus housing, an acting portion on which a force acts by an external factor, and the fixing portion and the acting portion. A flexible substrate having a portion, a fixed substrate fixed to the device casing so as to face the flexible substrate, and a displacement electrode formed on a surface of the flexible substrate facing the fixed substrate on the acting portion. And a fixed electrode formed on the surface of the fixed substrate facing the flexible substrate, constitute a sensor utilizing the change in capacitance, and based on the change in capacitance generated between the displacement electrode and the fixed electrode. Thus, the force acting on the acting portion can be detected.

(2) The second invention of the present application has a flexible portion formed between the fixed portion fixed to the apparatus housing, the acting portion on which a force acts by an external factor, and the fixed portion and the acting portion. A flexible substrate having a flexible portion, a fixed substrate fixed to the device casing so as to face the flexible substrate, and a displacement electrode formed on a surface of the flexible substrate facing the fixed substrate. And a fixed electrode formed on a surface of the fixed substrate facing the flexible substrate, and a static electrode for detecting a force applied to the acting portion based on a change in capacitance generated between the displacement electrode and the fixed electrode. In a sensor utilizing a change in capacitance, a flexible portion is provided with a through hole so that the flexible portion has flexibility.

(3) According to a third aspect of the present invention, an action portion on which a force acts due to an external factor, a fixed portion provided around the action portion and fixed to an apparatus casing, and the fixed portion to the action portion. A change in capacitance due to a bridge-shaped beam that extends and supports the action part from the surroundings, a displacement electrode provided in the action part, and a fixed electrode fixed to the device casing so as to face the displacement electrode. When a force from the outside is applied to the action part, the action part is displaced by the bending of the bridge beam, and the electrostatic force generated between the displacement electrode and the fixed electrode is configured. The force acting on the acting portion can be detected based on the change in capacitance.

(4) The fourth invention of the present application is the above-mentioned first to third inventions.
In the invention of claim 1, either one of the fixed electrode or the displacement electrode, or both of them are formed of a plurality of electrodes to form a plurality of sets of capacitive elements, and based on a change in capacitance of these capacitive elements, , The acting force can be detected for each two-dimensional or three-dimensional component.

(5) The fifth invention of the present application is the above-mentioned first to fourth inventions.
In the invention described above, the acceleration can be detected by detecting the force generated based on the acceleration acting on the acting portion.

(6) The sixth invention of the present application is the above-mentioned first to fourth inventions.
In the invention, the magnetism can be detected by detecting the force generated based on the magnetism acting on the acting portion.

[0012]

[Operation] (1) In the sensor according to the first invention of the present application, when a force acts on the acting portion, the flexible portion bends, and the distance between the displacement electrode and the fixed electrode changes. Therefore, the capacitance between both electrodes changes. This change in capacitance depends on the applied force, and the force can be detected by detecting the change in capacitance. Moreover,
Since the displacement electrode is formed on the acting portion of the flexible substrate, the displacement electrode is efficiently displaced by the action of force, which enables highly sensitive detection.

(2) In the sensor according to the second invention of the present application,
The flexible portion is formed by forming the through hole in the flexible substrate. That is, the substrate portion left between the through hole and another through hole becomes the flexible portion as it is. Therefore, the structure is very simple, and since the formed flexible portion has sufficient flexibility, highly sensitive measurement is possible.

(3) In the sensor according to the third aspect of the present invention,
A working part having a displacement electrode is supported by a bridge beam extending from a fixed part provided around the working part. Therefore,
The structure is very simple, and by adjusting the thickness and length of the bridge beam, sufficient sensitivity can be measured.

(4) In the sensor according to the fourth invention of the present application,
It is possible to detect each direction component of the applied force by using the change in capacitance of the plurality of sets of capacitive elements. Therefore, it can be used as a two-dimensional or three-dimensional force sensor.

(5) In the sensor according to the fifth aspect of the present invention,
The force generated based on the acceleration acting on the acting portion is detected. Since this force is proportional to the applied acceleration, the acceleration can be measured indirectly.

(6) In the sensor according to the sixth aspect of the present invention,
The force generated based on the magnetism acting on the acting portion is detected. Since this force is proportional to the applied magnetism,
Magnetic measurements can be made indirectly.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to illustrated embodiments. The present invention can be applied to any of a force sensor, an acceleration sensor, and a magnetic sensor. Here, an example in which the present invention is applied to an acceleration sensor will be shown.

[0019]Basic principle of sensor First, the basic principle of the sensor to which the present invention is applied
I will briefly describe this. In addition, based on this basic principle
The basic structure of the sensor is described in Japanese Patent Application No. 2-274299.
Japanese Patent Application No. 2-4161 discloses a manufacturing method thereof.
No. 88.

FIG. 1 is a side sectional view showing the structure of an acceleration sensor for explaining this basic principle. The main components of this sensor are the fixed substrate 10, the flexible substrate 20, the operating body 30, and the device housing 40. FIG. 2 shows a bottom view of the fixed substrate 10. A cross section of the fixed substrate 10 of FIG. 2 taken along the X-axis is shown in FIG. Fixed substrate 10
Is a disk-shaped substrate as shown, and the periphery is fixed to the device housing 40. A disk-shaped fixed electrode 11 is also formed on the lower surface. On the other hand, FIG. 3 shows a top view of the flexible substrate 20. A cross section of the flexible substrate 20 of FIG. 3 taken along the X-axis is shown in FIG. Flexible substrate 20
Also, as shown in the figure, it is a disk-shaped substrate, and the periphery thereof is fixed to the device housing 40. On the upper surface, fan-shaped displacement electrodes 21 to 24 and disc-shaped displacement electrode 25 are formed as shown in the figure. The action body 30 has a columnar top surface as shown by a broken line in FIG.
Is coaxially joined to the lower surface of the. The device housing 40 has a cylindrical shape and firmly fixes and supports the periphery of the fixed substrate 10 and the flexible substrate 20.

The fixed substrate 10 and the flexible substrate 20 are arranged in parallel with each other at a predetermined interval. Although both are disk-shaped substrates, the fixed substrate 10 is a substrate that has high rigidity and does not easily bend, while the flexible substrate 20 has flexibility and is a substrate that bends when a force is applied. There is. Now, as shown in FIG. 1, an action point P is defined at the center of gravity of the acting body 30, and an XYZ three-dimensional coordinate system having this action point P as an origin is defined as shown in the figure. That is, the X axis is defined in the right direction in FIG. 1, the Z axis is defined in the upward direction, and the Y axis is defined in the direction perpendicular to the paper surface and toward the back side of the paper surface. If the entire sensor is mounted on, for example, an automobile, acceleration will be applied to the action body 30 based on the traveling of the automobile. Due to this acceleration, an external force acts on the action point P.
When no force is applied to the point of action P, as shown in FIG. 1, the fixed electrode 11 and the displacement electrodes 21 to 25 are kept in parallel with each other with a predetermined interval. However, for example, when a force Fx in the X-axis direction acts on the action point P, this force Fx causes a moment force with respect to the flexible substrate 20,
As shown in FIG. 4, the flexible substrate 20 is bent. Due to this bending, the distance between the displacement electrode 21 and the fixed electrode 11 increases, but the distance between the displacement electrode 23 and the fixed electrode 11 decreases. If the force acting on the point of action P is -Fx in the opposite direction, the flexure of the opposite relationship will occur. When the force Fx or −Fx acts in this way, a change in the electrostatic capacitance regarding the displacement electrodes 21 and 23 appears, and the force Fx is detected by detecting this change.
x or -Fx can be detected. At this time, the distance between each of the displacement electrodes 22, 24, 25 and the fixed electrode 11 may partially increase or decrease, but it may be considered that the distance does not change as a whole. On the other hand, when the force Fy or −Fy in the Y direction acts, the displacement electrode 2
Similar changes occur only in the distance between 2 and the fixed electrode 11 and the distance between the displacement electrode 24 and the fixed electrode 11.
Further, when the force Fz in the Z-axis direction acts, the distance between the displacement electrode 25 and the fixed electrode 11 becomes small as shown in FIG. 5, and when the force −Fz in the opposite direction acts, this distance becomes growing. At this time, the distance between the displacement electrodes 21 to 24 and the fixed electrode 11 also becomes smaller or larger, but the change regarding the displacement electrode 25 is most remarkable. Therefore, the force Fz or -Fz can be detected by detecting the change in the capacitance of the displacement electrode 25.

Generally, the electrostatic capacitance C of a capacitive element is determined by C = εS / d, where S is the electrode area, d is the electrode spacing, and ε is the dielectric constant. Therefore, the capacitance C increases as the distance between the opposing electrodes decreases, and the capacitance C decreases as the distance between the electrodes decreases. This sensor utilizes this principle to measure the change in capacitance between the electrodes, and based on this measurement value, the action point P
The external force that acts on, that is, the acceleration that acts is detected. That is, the acceleration in the X-axis direction is applied to the displacement electrode 2
Based on the change in capacitance between the fixed electrodes 11 and 23, Y
The axial acceleration is detected based on the capacitance change between the displacement electrodes 22 and 24 and the fixed electrode 11, and the Z-axis acceleration is detected based on the capacitance change between the displacement electrode 25 and the fixed electrode 11. .

Now, the capacitive element C1 is constructed by the combination of the displacement electrode 21 and the fixed electrode 11, and the displacement electrode 2
2 and the fixed electrode 11 combine to form the capacitive element C2.
The displacement element 23 and the fixed electrode 11 are combined to form a capacitive element C3, the displacement electrode 24 and the fixed electrode 11 are combined to form a capacitive element C4, and the displacement electrode 25 and the fixed electrode 11 are combined. Assuming that the capacitive element C5 is configured by, the acceleration in the X-axis, Y-axis, and Z-axis directions can be detected by the detection circuit as shown in FIG. With this detection circuit, the CV conversion circuit 51
To 55 have a function of converting the electrostatic capacity of each of the capacitive elements C1 to C5 into voltage values V1 to V5. For example, C
The capacitance value C may be converted into the frequency value f by the R oscillator or the like, and then the frequency value f may be further converted into the voltage value V by the frequency / voltage conversion circuit. Of course, a means for directly converting the electrostatic capacitance value into a voltage value may be used. The differential amplifier 55 takes the difference between the voltage values V1 and V3, and outputs this difference voltage to the terminal Tx as the X-axis direction component ± Fx. As shown in FIG. 4, when the force Fx in the X-axis direction acts, the capacitance value of the capacitive element C1 decreases and the capacitance value of the capacitive element C3 increases. Therefore, it can be understood that the voltage value (V1-V3) output to the terminal Tx corresponds to the X-axis direction component of the force to be detected. Similarly, the differential amplifier 56 takes the difference between the voltage values V2 and V4,
This difference voltage is output to the terminal Ty as a Y-axis direction component ± Fy. Further, the voltage V5 corresponding to the capacitance value of the capacitive element C5 is directly output to the terminal Tz as the Z-axis direction component ± Fz.

[0024]Structure of the sensor according to the invention The present invention provides a concrete structure of the sensor based on the above principle.
To be presented. FIG. 7 shows an embodiment of the present invention.
It is a sectional side view which shows the structure of a sensor. This sensor is
Three boards: a flexible board 60, a control board 70, and a fixed board 80.
It has a laminated structure. In this example, the flexible
The substrate 60 is a silicon substrate, and the control substrate 70 and
The fixed substrate 80 is composed of a glass substrate.
The respective substrates are joined by anodic bonding. Figure
FIG. 8 shows a top view of the flexible substrate 60. Flexible base shown in FIG.
A cross section of plate 60 taken along section line 7-7 is shown in FIG.
The cross section taken along section line 9-9 is shown in FIG.
Will be shown. As shown in FIG.
Four L-shaped through holes H1 to H4 are formed in the substrate 60.
And is surrounded by the through holes H1 to H4.
The side portion serves as the acting portion 61, and the outer portion serves as the fixed portion 63. So
Then, four flexible portions 62 are formed between the adjacent through holes.
To be done. In FIG. 8, the substrate portion and the through-hole portion are
In order to clearly recognize the
It is shown. As shown in FIG. 7, a groove is formed below the flexible portion 62.
Since D1 is dug, the thickness of the four flexible parts 62 is
It is smaller than the other parts of the flexible substrate 60,
It will form a bridge-shaped beam that should be called a cantilever.
Therefore, the overall structure of the flexible substrate 60 is shown in FIG.
As shown clearly, a square-shaped action portion 61 is formed in the center.
Is arranged, and the fixing portion 63 is arranged so as to surround the periphery.
And is composed of a bridge-shaped beam that extends inward from the fixed portion 63.
When the action portion 61 is supported by the flexible portion 62,
Become. This flexible portion 62 is sufficiently thinner than the thickness of the substrate.
Since it is composed of a large plate, it is sufficient even if it is relatively short
Flexibility is obtained.

As shown in FIG. 8, the acting portion 61 is a square block when viewed from above, and is supported by four flexible portions (bridge beams) 62 from four sides. . Then, five displacement electrodes 2 are provided on the upper surface.
1 to 25 are formed. This displacement electrode has the same function as the displacement electrodes 21 to 25 shown in FIG.
Here, the same reference numerals will be used. Action part 61
When the acceleration acts on, a force corresponding to the mass of the acting portion 61 acts. As a result, the flexible portion 62 is bent and the acting portion 61 is displaced. Control board 7 shown in FIG.
0 has a function of limiting the displacement of the acting portion 61 within a predetermined range. That is, the shallow groove D2 is formed on the upper surface of the control board 70, and the downward displacement of the acting portion 61 is limited to the range of the depth of the groove D2. Even when the downward acceleration is excessively applied to the acting portion 61, the bottom portion of the acting portion 61 abuts the bottom surface 71 of the groove D2, and further displacement is limited.

A fixed substrate 80 is fixed to the upper surface of the flexible substrate 60. A groove D3 is formed on the bottom surface of the fixed substrate 80.
Is formed, and the fixed electrode 11 is formed on the bottom surface 81 of the groove D3. This fixed electrode has the same function as the fixed electrode 11 shown in FIG. 2, and will be denoted by the same reference numeral here. In FIG. 10, the fixed substrate 8
0 shows a bottom view of 0. Displacement electrodes 21 to 25 shown in FIG.
It can be understood that the fixed electrode 11 shown in FIG. 10 is opposed to the fixed electrode 11 with the groove D3 in between, and five capacitive elements C1 to C5 are formed.

As shown in FIG. 7, with respect to the operating portion 61, the fixed substrate 80 is provided above and the control substrate 7 is provided below.
0, and the fixing portions 63 are arranged on the sides, and in the space surrounded by these, the operating portion 61 has 4
It is in a state of being supported only by one flexible portion (bridge beam) 62. Therefore, when the acting portion 61 is subjected to the action of acceleration, it is displaced in this space, the distance between the displacement electrodes 21 to 25 and the fixed electrode 11 changes, and the capacitance values of the capacitance elements C1 to C5 change. Occurs. As described above, the acting acceleration can be measured for each of the three-dimensional components by detecting the change in the capacitance value using the detection circuit shown in FIG.

The features and advantages of the above structure are as follows. (1) Features: In the flexible substrate 60, the ratio of the acting portion 61 is relatively large, and the displacement electrodes 21 to 25 are formed on the upper surface of the acting portion 61. Advantage: Due to such a structure, the displacement of the acting portion 61 is efficiently transmitted to the displacement electrodes 21 to 25, which enables highly sensitive measurement. Further, if the ratio occupied by the action portion 61 is increased, the mass of the action portion 61 itself also increases, so that acceleration can be efficiently converted into force, and from this point also improvement in sensitivity can be expected. Further, since it can be realized with a simple structure in which three substrates are laminated, the manufacturing cost can be reduced. (2) Characteristics: The flexible portion 62 is formed by opening the through holes H1 to H4 in the flexible substrate 60. Advantage: Through hole H
Since 1 to H4 are formed, it is possible to secure sufficient flexibility in the flexible portion 62 and increase the sensitivity. (3) Features: The central action portion 61 is supported by a bridge-like beam (flexible portion 62) from the periphery thereof. Advantage: By reducing the thickness of the bridge beam, sufficient flexibility can be secured and sensitivity can be increased. Also,
Such a bridge-like beam structure is a structure that can be easily processed by an etching method or the like, and the manufacturing process is also easy.

[0029]Other examples FIG. 11 is a side sectional view of a sensor according to another embodiment of the present invention.
Indicates. This embodiment is a supplement to the embodiment shown in FIG.
A substrate 90 is added. That is, the flexible substrate 6
A new auxiliary board 90 is inserted between 0 and the control board 70.
Has been done. The auxiliary substrate 90 includes a weight body 91 at the center.
And a stand shaped like a frame surrounding it
And a seat 92. Weight body 91 is horizontal
It is a block with a square cross section, and its upper surface is the action part.
It is joined to the lower surface of 61. The pedestal 92 is the control board 7
0 is a member for connecting the fixing portion 63 and
And a control member for limiting the horizontal displacement of the weight body 91.
Also functions as. In such a structure, the working portion 6
1 and the weight body 91 function as one block,
The acceleration acting on this block responds to both masses.
It will be converted into the same force. Therefore, the
It is possible to further increase the sensitivity as compared with the embodiment. Well
Also, by joining the weight body 91 to the action portion 61,
The center of gravity of the body moves. This will increase the sensitivity of each axis
You can change it.

Another difference in this embodiment is that the fixed substrate 8 faces the five displacement electrodes 21 to 25.
This is the point that five fixed electrodes 11a to 15a are formed on the bottom surface 81 of 0. In the above-described embodiment, the fixed electrode 11 is a common counter electrode common to all the displacement electrodes 21 to 25, but in this embodiment, five displacement electrodes 21 to 21 are used.
No. 25, five fixed electrodes 11a to 15a are formed at positions symmetrical with respect to No. 25, and five capacitive elements C1 to C5 are formed.
Are composed of independent electrode pairs. in this way,
The number of electrodes used can be changed appropriately in design.
It is also possible to use a larger number of electrodes. It should be noted that although wirings for transmitting the change in capacitance are actually required, these wirings are not shown in the drawings.

The present invention can be implemented in various modes other than the above-mentioned embodiments. In particular, all of the above-described embodiments apply the present invention to the acceleration sensor, but the present invention can also be applied to the force sensor and the magnetic sensor. For example, in the force sensor, the above-mentioned action part 6
1 may have a structure in which a probe for transmitting a force from the outside is connected, and in the magnetic sensor, the above-mentioned action part 6 is used.
1 or the weight body 91 may be made of a magnetic material.

[0032]

As described above, according to the sensor of the present invention which utilizes the change of electrostatic capacity, the working body is supported by the bridge beam by opening the through hole in the substrate. Since the displacement electrode is formed above, the structure can be simplified and the detection sensitivity can be improved.

[Brief description of drawings]

FIG. 1 is a side sectional view showing the structure of an acceleration sensor for explaining the basic principle of the present invention.

FIG. 2 is a bottom view of a fixed substrate 10 of the sensor shown in FIG. A cross section of the fixed substrate 10 of FIG. 2 taken along the X-axis is shown in FIG.

3 is a top view of a flexible substrate 20 of the sensor shown in FIG. A cross section of the flexible substrate 20 of FIG. 3 taken along the X-axis is shown in FIG.

4 is a force F in the X-axis direction applied to a point of action P of the sensor shown in FIG.
It is a sectional side view which shows the bending state of a sensor when x acts.

FIG. 5 is a diagram showing a force F in the Z-axis direction applied to a point of action P of the sensor shown in FIG.
It is a sectional side view which shows the bending state of a sensor when z acts.

6 is a circuit diagram showing an example of a detection circuit used in the sensor shown in FIG.

FIG. 7 is a side sectional view showing a structure of an acceleration sensor according to an embodiment of the present invention.

8 is a flexible substrate 60 in the acceleration sensor shown in FIG.
FIG. The flexible substrate 60 shown in FIG.
A cross section taken along line 7 is shown in FIG. 7, and a cross section taken along section line 9-9 is shown in FIG.

9 is a side sectional view showing another section of the acceleration sensor shown in FIG.

FIG. 10 is a fixed substrate 8 in the acceleration sensor shown in FIG.
It is a bottom view of 0.

FIG. 11 is a side sectional view showing a structure of an acceleration sensor according to another embodiment of the present invention.

[Explanation of symbols]

10 ... Fixed substrate 11, 11a to 15a ... Fixed electrode 20 ... Flexible substrate 21-25 ... Displacement electrode 30 ... acting body 40 ... Device housing 51-55 ... CV conversion circuit 60 ... Flexible substrate 61 ... Action part 62 ... Flexible part (bridge beam) 63 ... Fixed part 70 ... Control board 71 ... bottom surface 80 ... Fixed substrate 81 ... bottom surface 90 ... Auxiliary substrate 91 ... Weight body 92 ... Pedestal D1-D3 ... Groove H1 to H4 ... through holes P ... point of action

Claims (6)

[Claims] 1. A fixing portion fixed to the apparatus housing, an acting portion on which a force acts by an external factor, and a flexible portion having flexibility, which is formed between the fixing portion and the acting portion. A flexible substrate, a fixed substrate fixed to the apparatus casing so as to face the flexible substrate, and a displacement electrode formed on a surface of the flexible substrate facing the fixed substrate on the acting portion. And a fixed electrode formed on a surface of the fixed substrate facing the flexible substrate, and acting on the acting portion based on a change in electrostatic capacitance generated between the displacement electrode and the fixed electrode. A sensor utilizing a change in capacitance, which is characterized by detecting the generated force. 2. A fixing portion fixed to the apparatus housing, an acting portion on which a force acts due to an external factor, and a flexible portion having flexibility formed between the fixing portion and the acting portion. A flexible substrate having: a fixed substrate fixed to the device casing so as to face the flexible substrate; a displacement electrode formed on a surface of the flexible substrate facing the fixed substrate; A fixed electrode formed on a surface facing the flexible substrate, and detecting a force acting on the acting portion based on a change in capacitance between the displacement electrode and the fixed electrode. In the sensor, a sensor utilizing change in capacitance is characterized in that the flexible portion is made to have flexibility by forming a through hole in the flexible substrate. 3. An action portion to which a force acts due to an external factor, a fixed portion provided around the action portion and fixed to an apparatus housing, and a fixed portion extending from the fixed portion to the action portion and surrounding the action portion. A bridge-shaped beam supported by the action part, a displacement electrode provided in the action part, and a fixed electrode fixed to the device casing so as to face the displacement electrode, and the action part receives an external force. When
The acting portion is configured to be displaced by the bending of the bridge beam, and the force acting on the acting portion is detected based on the change in the capacitance generated between the displacement electrode and the fixed electrode. A sensor that utilizes the change in electrostatic capacitance. 4. The sensor according to claim 1, wherein either one of the fixed electrode and the displacement electrode, or both of them are composed of a plurality of electrodes, thereby forming a plurality of sets of capacitive elements. A sensor utilizing a change in capacitance, which is formed so that the acting force can be detected for each two-dimensional or three-dimensional component based on the change in capacitance of these capacitive elements. . 5. The sensor according to claim 1, wherein the acceleration can be detected by detecting the force generated based on the acceleration acting on the acting portion. A sensor that utilizes the change in capacitance. 6. The sensor according to claim 1, wherein the magnetic force can be detected by detecting the force generated based on the magnetism acting on the acting portion. A sensor that utilizes the change in capacitance.