JP2008261772A - Inertia force sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inertia force sensor having enhanced detection sensitivity. <P>SOLUTION: This sensor is equipped with a detection element 1 having an acceleration detection part and an angular velocity detection part. The detection element 1 is constituted as follows: two orthogonal arms formed by connecting the first arms 8 to the second arm 10 approximately in the orthogonal direction are provided; each one end of the two first arms 8 is supported by a support part 12; each other end of the two first arms 8 is connected to the first fixing part 4; a weight part is connected to the tip part of the second arm 10; the first fixing part 4 is connected to the second fixing part 6 by a fixing arm 7; the first arms 8 are arranged in the X-axis direction, and the first elastic part 9 which is elastically deformable only in the X-axis direction is provided on the first fixing part 4; and a fixing arm which is the second connection part is arranged in the Y-axis direction, and the second elastic part 11 which is elastically deformable only in the Y-axis direction is provided on the second fixing part 6. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to sensors used in various electronic devices such as attitude control and navigation of moving bodies such as aircraft, automobiles, robots, ships, and vehicles.

  Hereinafter, an acceleration sensor which is one of conventional inertial force sensors will be described.

  FIG. 9 is a plan view of a detection element of a conventional acceleration sensor, FIG. 10 is an AA sectional view of the detection element, and FIG. 11 is a BB sectional view of the detection element.

  9 to 11, the conventional acceleration sensor includes a detection element 51 that detects acceleration, and a processing circuit (not shown) that detects an acceleration by performing an arithmetic process on an acceleration signal output from the detection element 51. ing. This detection element 51 has a support portion 54 that supports the weight portion 52 and a fixing portion 59 (58 is used for strain resistance) connected to the support portion 54 via a flexible portion 56. The detection element 51 is mounted on the mounting board by the fixing portion 59.

  The flexible portion 56 has an arm shape, and the flexible portion 56 is arranged in a cross shape with the support portion 54 as the center, and the pair of flexible portions 56 and the support portion 54 are arranged on the same straight line. I try to do it.

  A strain resistance element 58 is provided in the flexible portion 56, and a change in resistance value of the strain resistance element 58 is output as an acceleration signal based on a change in the state of the flexible portion 56 that is bent due to the movement of the weight portion 52. ing.

  Next, detection of acceleration will be described.

  When the flexible portion 56 composed of a cross-shaped arm is arranged in the X-axis direction and the Y-axis direction on the X-axis, Y-axis, and Z-axis that are orthogonal to each other, for example, as shown in FIG. Occurs, one of the two flexible portions 56 arranged in the X-axis direction has a positive Z-axis in order to move the weight portion 52 in the axial direction in which the acceleration occurs. In the negative direction of the Z axis in the other flexible portion 56 (the deflection occurs when the weight portion 52 tries to rotate in the Z axis direction around the support portion 54). To do). Then, the two strain resistance elements 58 provided in the two flexible portions 56 also bend in the positive and negative directions of the Z axis according to the flexure of the flexible portion 56, so that the resistance value of the strain resistance element 58 changes. This resistance value change is output as an acceleration signal to detect acceleration.

  Such an acceleration sensor is used in a posture control device, a navigation device, or the like of a moving body such as a vehicle corresponding to a detection axis to be detected.

As prior art document information related to the invention of this application, for example, Patent Document 1 is known.
Japanese Patent Laid-Open No. 10-48243

  In the above configuration, since the arm-shaped flexible portion 56 is arranged in a cross shape with the support portion 54 as the center, the weight portion 52 is formed by the flexible portion 56 arranged in the axial direction in which acceleration occurs. Movement is restricted. Of the two flexible portions 56 arranged in the X-axis direction, one of the flexible portions 56 bends in the positive direction of the Z-axis, and the other flexible portion 56 has a negative direction of the Z-axis. Deflection occurs.

  At this time, in FIG. 12, when acceleration occurs in the X-axis direction, the weight part 52 tries to move in the X-axis direction, but the movement of the weight part 52 is caused by the flexible part 56 arranged in the X-axis direction. Be regulated. Due to this restriction, the weight portion 52 tries to rotate in the Z-axis direction around the support portion 54, so that the flexible portion 56 bends, but the amount of this bend is small. This is considered due to the fact that the force in the linear direction applied to the weight portion 52 is converted into the force in the rotational direction.

  Therefore, the change in resistance value of the strain resistance element 58 arranged in the flexible portion 56 is also reduced, and there is a problem that the detection sensitivity is low.

  The present invention solves the above-described problems, and an object thereof is to provide an inertial force sensor with increased detection sensitivity.

In order to achieve the above object, the present invention provides:
In particular, the detection element includes a first fixing portion in which the weight portion is connected through the first connecting portion, a second fixing portion in which the first fixing portion is connected through the second connecting portion, and a surface of the weight portion. A first counter substrate facing the side, a second counter substrate facing the back side of the weight portion, a first counter electrode disposed on the facing surfaces of the weight portion and the first counter substrate, The weight portion and a second counter electrode disposed on each of the opposing surfaces of the second counter substrate, and the acceleration detection unit includes a capacitance change amount of the first counter electrode portion and the second counter electrode. Acceleration is detected by detecting the amount of change in capacitance of the part, and the first connection part or the first connection part or The first fixing portion is provided with a first elastic portion that is elastically deformed only in the X-axis direction, and the second connecting portion is arranged in the Y-axis direction. The Rutotomoni the second connecting portion or the second fixing portion only Y-axis direction of the second elastic portion to elastically deform provided a structure mounted on the mounting substrate by the second fixing unit.

  With the above configuration, in the X axis, Y axis, and Z axis orthogonal to each other, when acceleration occurs in the X axis direction, the first elastic portion is displaced in the X axis direction, and when acceleration occurs in the Y axis direction, the second elastic portion is Displacement in the Y-axis direction. That is, the force in the linear direction in which the acceleration is generated is not converted into the force in the rotation direction, and the first elastic portion or the second elastic portion is displaced only in the same direction as the direction in which the acceleration is generated. The amount of change in capacitance of the first counter electrode part and the second counter electrode part can be easily increased, and the detection sensitivity can be improved.

  In particular, when detecting the acceleration in the X-axis direction and the Y-axis direction, the acceleration in the X-axis direction is detected when the first elastic portion is displaced only in the X-axis direction, and the acceleration in the Y-axis direction is detected by the second elastic portion. It is detected by displacing only in the Y-axis direction, and the acceleration can be detected independently without being affected by one of the accelerations, and the detection sensitivity can be improved.

  Further, the first counter electrode portion is disposed on each of the opposing surfaces of the first counter substrate and the weight portion facing the surface side of the weight portion, and the second counter electrode portion is opposed to the back surface side of the weight portion. Since the second counter substrate and the weight portion are arranged on the respective facing surfaces, for example, even if the weight portion is displaced in the Z-axis direction, the second counter electrode portion is increased if the counter distance of the first counter electrode portion is increased. If the facing distance of the first counter electrode portion decreases and the facing distance of the first counter electrode portion decreases, the facing distance of the second counter electrode portion increases.

  That is, since the total opposing distance of the opposing distance of the first opposing electrode part and the opposing distance of the second opposing electrode part does not change, even if the weight part is displaced in the Z-axis direction due to vibration or the like, the first opposing second opposing part It is possible to improve the detection accuracy without deteriorating the detection accuracy of the X-axis or Y-axis acceleration without greatly changing the amount of change in the capacitance of the entire electrode unit.

(Embodiment 1)
1 is an exploded perspective view of a detection element of a composite sensor according to a first embodiment of the present invention, FIG. 2 is a cross-sectional view taken along line AA in FIG. 1, and FIG. 3 is a cross-sectional view taken along line BB in FIG.

  In FIG. 1, the composite sensor according to the first embodiment of the present invention includes a detection element 1 having an acceleration detection unit and an angular velocity detection unit.

  The detection element 1 includes a first fixing portion 4 that connects the weight portion 3 via a first connecting portion, an opposing substrate 5 that faces the weight portion 3, and the first fixing portion via a second connecting portion. 4 and a second fixing portion 6 connected to each other.

  Specifically, the detection element 1 has two orthogonal arms in which the first arm 8 is connected to the second arm 10 in a substantially orthogonal direction, and one end of the two first arms 8 is supported by the support portion 12. The other ends of the two first arms 8 are connected to the frame-shaped first fixing portion 4, and the weight portion 3 is arranged inside the frame-shaped first fixing portion 4. The second arm 10 is bent in a U shape until it faces the second arm 10 itself, and the weight 3 is connected to the tip of the bent second arm 10. The first fixing portion 4 is connected to the second fixing portion 6 by a fixing arm 7, and the first fixing portion 4 is disposed inside the second fixing portion 6. The first arm 8 and the support portion 12 are arranged on substantially the same straight line, and the first arm 8 and the second arm 10 are arranged symmetrically with respect to the center of the detection element 1. The first arm 8 corresponds to a first connecting part that connects the weight part 3, and the fixed arm 7 corresponds to a second connecting part.

  A first elastic portion in which the first arm 8 as the first connecting portion is arranged in the X-axis direction and the first fixed portion 4 is elastically deformed only in the X-axis direction in the X axis, the Y axis, and the Z axis orthogonal to each other. 9, a fixed arm that is a second connecting portion is arranged in the Y-axis direction, and the second fixed portion 6 is provided with a second elastic portion 11 that is elastically deformed only in the Y-axis direction. It is mounted on the mounting board.

  The first elastic portion 9 is formed by forming a slit 13 in a part of the first fixing portion 4 orthogonal to the first arm 8 in the Y-axis direction, and the second elastic portion 11 includes the second arm 10. A slit 13 is formed in a part of the second fixing portion 6 orthogonal to the X axis direction.

  In addition, the first counter substrate 5 is opposed to the surface side of the weight portion 3, and the first counter electrode to the fourth counter electrode are provided as first counter electrode portions on the respective facing surfaces of the weight portion 3 and the first counter substrate 5. The electrodes 14, 16, 18, and 20 are disposed, the second counter substrate 15 is opposed to the back surface side of the weight portion 3, and the second counter substrate 15 is opposed to each of the counter surfaces of the weight portion 3 and the second counter substrate 15. As the electrode portion, the fifth counter electrode to the eighth counter electrode 17, 19, 21, 23 are arranged.

  Further, a drive electrode 22 for driving and vibrating the weight portion 3 and a detection electrode 24 for detecting the drive are arranged on one of the two second arms 10 facing each other, and the other two second arms 10 facing each other. The first sensing electrode 26 and the second sensing electrode 28 for sensing the distortion of the second arm 10 are arranged. Among these electrodes, at least the drive electrode 22, the detection electrode 24, the first sensing electrode 26, and the second sensing electrode 28 are composed of an upper electrode and a lower electrode with a piezoelectric layer interposed therebetween.

  And these 1st counter electrode-4th counter electrode 14, 16, 18, 20, 5th counter electrode-8th counter electrode 17, 19, 21, 23, drive electrode 22, detection electrode 24, 1st, 2nd A signal line (not shown) is drawn from the sensing electrodes 26 and 28 to the fixed portion 7 and is electrically connected to the wiring pattern of the mounting substrate through wire bonding or the like at the end of the signal line.

  Next, the angular velocity detection unit and the acceleration detection unit will be described.

  First, the angular velocity detection unit will be described. As shown in FIG. 4, when the first arm 8 of the detection element 1 is arranged in the X-axis direction and the second arm 10 is arranged in the Y-axis direction on the X axis, the Y axis, and the Z axis orthogonal to each other, When an AC voltage having a resonance frequency is applied to the drive electrode 22, the second arm 10 is driven to vibrate starting from the second arm 10 on which the drive electrode 22 is disposed, and accordingly, the weight 3 is also opposed to the second arm 10. Drive vibration occurs in the drive vibration direction indicated by the solid arrow and the dotted arrow. Further, all of the four second arms 10 and the four weight portions 3 are synchronously driven and vibrated in a direction opposite to the second arm 10 (drive signal direction). The driving vibration direction in the detection element 1 is the X-axis direction.

  At this time, for example, when an angular velocity is generated in the counterclockwise direction of the Z axis, a direction (solid line arrow and dotted line arrow) perpendicular to the drive vibration direction with respect to the weight part 3 is synchronized with the drive vibration of the weight part 3. Since the Coriolis force is generated in the Coriolis direction (Y-axis direction) described above, distortion caused by the counterclockwise angular velocity of the Z-axis can be generated in the second arm 10. That is, a voltage is output from the first and second sensing electrodes 26 and 28 due to a change in the state of the second arm 10 that is bent due to the Coriolis force (a strain generated in the second arm 10). Based on this, the angular velocity is detected.

  Next, the acceleration detection unit will be described.

  First, acceleration in the X-axis direction will be described. As shown in FIGS. 1 and 5, when the first counter substrate 5 and the second counter substrate 15 are arranged on the XY plane in the X axis, the Y axis, and the Z axis orthogonal to each other, if no acceleration is generated, The opposing end (X1) of the first opposing electrode 14 on the opposing surface of the first opposing substrate 5 and the weight 3 and the opposing end of the second opposing electrode 16 on the opposing surface of the first opposing substrate 5 and the weight 3 (X2) is at a position slightly deviated from each other, and the second counter substrate 15 and the counter end portion (X1) of the fifth counter electrode 17 on the counter surface of the weight portion 3, and the first counter substrate 5 and the weight portion 3 The opposed end portions (X2) of the sixth opposed electrode 19 on the opposed surface are also slightly shifted from each other. Although not shown, the opposing end of the third opposing electrode 18 and the opposing end of the fourth opposing electrode 20 are also slightly shifted from each other, and the opposing end of the seventh opposing electrode 21 and the eighth opposing electrode 23 The opposite end is also slightly displaced.

  That is, when the weight portion 3 moves in the X-axis direction, the capacitance change amount of the first counter electrode 14 and the capacitance change amount of the second counter electrode 16 are made different from each other, and the third counter electrode 18 is changed. The capacitance change amount of the fourth counter electrode 20 is different from the capacitance change amount of the fourth counter electrode 20, and the capacitance change amount of the fifth counter electrode 17 and the capacitance change amount of the sixth counter electrode 19 are And the capacitance change amount of the seventh counter electrode 21 and the capacitance change amount of the eighth counter electrode 23 are made different.

  At this time, for example, when acceleration occurs in the X-axis direction, as shown in FIGS. 1 and 6, the first elastic portion 9 is displaced in the X-axis direction, and the force in the linear direction in which the acceleration occurs is the rotational direction. The first elastic part 9 is displaced only in the same direction as the X-axis direction in which the acceleration occurs without being converted into a force. As a result, the opposing end (X1) of the first opposing electrode 14 on the opposing surface of the first opposing substrate 5 and the weight portion 3 and the second opposing electrode 16 on the opposing surface of the first opposing substrate 5 and the weight portion 3 The opposing end portions (X2) are displaced from each other by (W), the opposing end portion (X1) of the fifth opposing electrode 17 on the opposing surface of the second opposing substrate 15 and the weight portion 3, the second opposing substrate 15 and the weight. The opposite end portions (X2) of the sixth counter electrode 19 on the surface facing the portion 3 are also displaced from each other by (W). Although not shown, the opposing end of the third opposing electrode 18 and the opposing end of the fourth opposing electrode 20, the opposing end of the seventh opposing electrode 21, and the opposing end of the eighth opposing electrode 23 are also mutually (W). Only the position shifts.

  Next, the acceleration in the Y-axis direction will be described. As shown in FIGS. 1 and 7, when the first counter substrate 5 is arranged on the XY plane in the X axis, the Y axis, and the Z axis orthogonal to each other, if no acceleration is generated, The opposing end (X1) of the first opposing electrode 14 on the opposing surface of the weight 3 and the opposing end (X2) of the third opposing electrode 18 on the opposing surface of the first opposing substrate 5 and the weight 3 are slightly different from each other. It is in a shifted position, and the opposing end (X1) of the fifth opposing electrode 17 on the opposing surface of the second opposing substrate 15 and the weight 3 and the seventh opposing of the opposing surface of the second opposing substrate 15 and the weight 3 The opposed end portions (X2) of the electrodes 21 are also slightly shifted from each other. Although not shown, the opposing end of the second opposing electrode 16 and the opposing end of the fourth opposing electrode 20 are also slightly displaced from each other, and the opposing end of the sixth opposing electrode 19 and the eighth opposing electrode 23 Opposing ends are also slightly displaced from each other.

  That is, when the weight portion 3 moves in the Y-axis direction, the capacitance change amount of the first counter electrode 14 and the capacitance change amount of the third counter electrode 18 are made different from each other, and the second counter electrode 16 is changed. The capacitance change amount of the fourth counter electrode 20 is different from the capacitance change amount of the fourth counter electrode 20, and the capacitance change amount of the fifth counter electrode 17 and the capacitance change amount of the seventh counter electrode 21 are The capacitance change amount of the sixth counter electrode 19 and the capacitance change amount of the eighth counter electrode 23 are made different.

  At this time, for example, when acceleration occurs in the Y-axis direction, as shown in FIGS. 1 and 8, the second elastic portion 11 is displaced in the Y-axis direction, and the force in the linear direction in which the acceleration occurs is the rotational direction. The second elastic part 11 is displaced only in the same direction as the Y-axis direction in which the acceleration occurs without being converted into a force. As a result, the opposing end (X1) of the first opposing electrode 14 on the opposing surface of the first opposing substrate 5 and the weight 3 and the third opposing electrode 18 on the opposing surface of the first opposing substrate 5 and the weight 3 are shown. The opposing end portions (X2) are displaced from each other by (W), the opposing end portion (X1) of the fifth opposing electrode 17 on the opposing surface of the second opposing substrate 15 and the weight portion 3, the second opposing substrate 15 and the weight. The opposite end portions (X2) of the seventh counter electrode 21 on the surface facing the portion 3 are also displaced from each other by (W). Although not shown, the opposing end of the second opposing electrode 16 and the opposing end of the fourth opposing electrode 20, the opposing end of the sixth opposing electrode 19, and the opposing end of the eighth opposing electrode 23 are also (W). Only the position shifts.

  That is, since the capacitance between the electrodes changes, acceleration in the X-axis direction or Y-axis direction is detected based on the change in capacitance.

  With the above configuration, the acceleration detection unit causes the first counter electrode to the fourth counter electrodes 14, 16, 18, 20, the weight unit 3 and the second counter electrode disposed on the opposing surfaces of the weight unit 3 and the first counter substrate 5. The acceleration is detected by detecting the capacitance change of the fifth counter electrode to the eighth counter electrode 17, 19, 21, and 23 arranged on the respective opposing surfaces of the substrate 15, and the angular velocity detector causes the Coriolis force. Since the first and second sensing electrodes 26 and 28 can detect the change in the state of the flexible part that bends and can detect the acceleration and the angular velocity with one detection element 1, the mounting area can be reduced and the size can be reduced.

  In particular, when detecting the acceleration in the X-axis direction and the Y-axis direction, the acceleration in the X-axis direction is detected when the first elastic portion 9 is displaced only in the X-axis direction, and the acceleration in the Y-axis direction is detected as the second elastic portion. 11 is detected by displacement only in the Y-axis direction, and the acceleration can be detected independently without being influenced by one of the accelerations, and the detection sensitivity can be improved.

  Further, when viewed from the Z-axis direction, the first counter electrode to the fourth counter electrodes 14, 16, 18, and 20 are respectively configured such that the electrode disposed on the weight portion 3 and the electrode disposed on the first counter substrate 5 are the X-axis. Since the position of the weight portion 3 is moved in the X-axis direction or the Y-axis direction, the respective capacitances in the movable range are shifted. Since the capacitance changes continuously and the respective capacitances are different, it can be distinguished whether the weight portion 3 has moved in the positive direction or the negative direction in the X-axis direction. For example, according to FIG. 6, the capacitance of the first counter electrode 14 continuously decreases according to the acceleration, and the capacitance of the second counter electrode 16 increases continuously according to the acceleration. It can be seen that the axis has moved in the negative direction. Similarly, the moving direction can be distinguished for the fifth counter electrode to the eighth counter electrode 17, 19, 21, 23 and the Y-axis direction.

  Further, as the first counter electrode portion, the first counter electrode to the fourth counter electrodes 14, 16, 18, and 20 are respectively opposed to the first counter substrate 5 and the weight portion 3 facing the surface side of the weight portion 3. The fifth counter electrode to the eighth counter electrodes 17, 19, 21, and 23 are arranged on the surface, and the second counter substrate 15 and the weight portion 3 are opposed to the back surface side of the weight portion 3. For example, even if the weight portion 3 is displaced in the Z-axis direction, the opposing distance of the second opposing electrode portion is reduced if the opposing distance of the first opposing electrode portion is increased, even if the weight portion 3 is displaced in the Z-axis direction. When the facing distance of the one counter electrode portion is reduced, the facing distance of the second counter electrode portion is increased.

  That is, since the total opposing distance of the opposing distance of the first counter electrode part and the opposing distance of the second counter electrode part does not change, even if the weight part 3 is displaced in the Z-axis direction due to vibration or the like, the first and second It is possible to improve the detection accuracy without deteriorating the detection accuracy of the X-axis or Y-axis acceleration without greatly changing the amount of change in the capacitance of the entire counter electrode portion.

  Instead of providing the first elastic portion 9 in the first fixing portion, the first elastic portion 9 that is elastically deformed only in the X-axis direction is provided in the first connecting portion, or the second elastic portion 11 is provided in the second fixing portion. Instead of providing, the second connecting portion may be provided with the second elastic portion 11 that is elastically deformed only in the Y-axis direction. Further, the drive electrode, the detection electrode, and the detection electrode can be arbitrarily set in addition to the above embodiment.

  Since the inertial force sensor according to the present invention can improve the detection sensitivity, it can be applied to various electronic devices.

The disassembled perspective view of the detection element of the composite sensor in the 1st Embodiment of this invention AA sectional view of FIG. BB sectional view of FIG. Operation state diagram of the detection element during angular velocity detection AA cross-sectional view when the counter substrate is placed Operation state diagram of the detection element when detecting acceleration in the X-axis direction BB cross section when counter substrate is placed Operation state diagram of the detection element when detecting acceleration in the Y-axis direction Plan view of conventional detector AA sectional view of FIG. BB sectional view of FIG. Operation state diagram of the detector

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Detection element 3 Weight part 4 1st fixing | fixed part 5 Opposite substrate 6 2nd fixing | fixed part 7 Fixed arm 8 1st arm 9 1st elastic part 10 2nd arm 11 2nd elastic part 12 Supporting part 13 Slit 14 1st counter electrode DESCRIPTION OF SYMBOLS 15 2nd counter substrate 16 2nd counter electrode 17 5th counter electrode 18 3rd counter electrode 19 6th counter electrode 20 4th counter electrode 21 7th counter electrode 22 Drive electrode 23 8th counter electrode 24 Detection electrode 26 1st sensing Electrode 28 Second sensing electrode

Claims (5)

A detection element having an acceleration detection unit;
The detection element includes a first fixing portion that connects a weight portion via a first connecting portion, a second fixing portion that connects the first fixing portion via a second connecting portion, and a surface side of the weight portion A first counter substrate opposed to the second counter substrate, a second counter substrate opposed to the back side of the weight portion, a first counter electrode portion disposed on each of the counter surfaces of the weight portion and the first counter substrate, The weight portion and a second counter electrode portion disposed on each of the opposing surfaces of the second counter substrate, wherein the acceleration detector includes a capacitance change amount of the first counter electrode portion and the second counter electrode portion. Acceleration is detected by detecting the amount of change in capacitance of the counter electrode,
In the X axis, Y axis, and Z axis orthogonal to each other,
A first elastic portion that is arranged in the X-axis direction and is elastically deformed only in the X-axis direction in the first connection portion or the first fixing portion;
The second connecting portion is disposed in the Y-axis direction, and a second elastic portion that is elastically deformed only in the Y-axis direction is provided in the second connecting portion or the second fixing portion, and the mounting substrate is formed by the second fixing portion. Mounted inertial force sensor. 2. The inertial force sensor according to claim 1, wherein the first elastic part is formed with a slit in the Y-axis direction, and the second elastic part is formed with a slit in the X-axis direction. 2. The inertial force sensor according to claim 1, wherein the first fixing portion is a frame body portion, the weight portion is connected via two first connecting portions, and the weight portion is disposed inward of the first fixing portion. . The first counter electrode portion and the second counter electrode portion have a plurality of counter electrodes. When the weight portion moves in the X-axis direction or the Y-axis direction, the static electrode of one counter electrode of the first counter electrode portion is static. The amount of change in capacitance and the amount of change in capacitance of the other counter electrode are made different so that the amount of change in capacitance of one counter electrode of the second counter electrode portion and the capacitance of the other counter electrode The inertial force sensor according to claim 1, wherein the amount of change is different. An angular velocity detection unit is provided in the detection element,
The detection element includes two orthogonal arms formed by connecting the first arm to the second arm in the orthogonal direction, and a support portion supporting the two first arms, and the first arm is the first arm. The connecting portion is connected to the tip of the second arm, and the weight portion is connected to the tip portion of the second arm. In the angular velocity detecting portion, the weight portion is driven to vibrate to detect a change in the state of the detecting element due to the Coriolis force. The inertial force sensor according to claim 1, wherein the angular velocity is detected.

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