Physical quantity sensor and inertial measurement unit

Abstract

To provide a physical quantity sensor and the like that can realize proper fault diagnosis.SOLUTION: A physical quantity sensor 1 comprises: a fixed portion 51; a support beam 53 having one end connected to the fixed portion 51 and extending along a first direction; a movable body 3 connected to the other end of the support beam 53; a first fixed electrode portion 10 disposed in a second direction of the support beam 53 and having a first fixed electrode; a second fixed electrode portion 20 disposed in the second direction or a fourth direction of the support beam 53 and having a second fixed electrode; and a processing circuit. The movable body 3 includes a first movable electrode portion 60 having a first movable electrode, and a second movable electrode portion 70 having a second movable electrode. The processing circuit sets the second fixed electrode and the second movable electrode to the same potential in a detection mode, detects physical quantity by detection processing on the basis of capacitance, applies predetermined voltage between the first fixed electrode and the first movable electrode and between the second fixed electrode and the second movable electrode in a diagnosis mode, and performs fault diagnosis by the detection processing on the basis of the capacitance.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a physical quantity sensor, an inertial measurement unit, and the like. [Background technology]

[0002] Physical quantity sensors that detect physical quantities such as acceleration have been known for some time. For example, a sensor disclosed in Patent Document 1 is an example of such a physical quantity sensor. This physical quantity sensor is a sensor with a MEMS structure that detects acceleration in the Z direction. Patent Document 1 discloses that the length of one of the multiple first electrodes along the first direction is shorter than the length of the first conductive part along the first direction, and the length of one of the multiple second electrodes along the first direction is shorter than the length of the second conductive part along the first direction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-32819 Summary of the Invention [Problem to be solved by the invention]

[0004] In such a physical quantity sensor, it is desirable to provide a diagnostic mode for diagnosing whether the physical quantity sensor is operating properly. However, compared with a physical quantity sensor of the interelectrode area change type, a physical quantity sensor of the interelectrode distance change type generates a weaker electrostatic force for the same applied voltage, so that it is necessary to increase the voltage when performing the diagnostic mode, and there is a problem that it is difficult to realize a proper fault diagnosis. [Means for solving the problem]

[0005] One aspect of the present disclosure is a physical quantity sensor that detects a physical quantity in a third direction, where three mutually orthogonal directions are defined as a first direction, a second direction, and a third direction, and includes a fixed portion fixed to a substrate, a support beam having one end connected to the fixed portion and extending along the first direction, a movable body connected to the other end of the support beam, a first fixed electrode portion provided on the substrate, disposed in the second direction of the support beam, and having a first fixed electrode, a second fixed electrode portion provided on the substrate, disposed in the second direction of the support beam or a fourth direction that is the opposite direction to the second direction, and having a second fixed electrode, and a processing circuit, wherein the movable body has a first movable electrode facing the first fixed electrode. and a second movable electrode portion having a second movable electrode facing the second fixed electrode, wherein the processing circuit detects the physical quantity by setting the second fixed electrode and the second movable electrode to the same potential and performing a detection process based on the capacitance between the first fixed electrode and the first movable electrode in a detection mode, and applies a predetermined voltage between the first fixed electrode and the first movable electrode, and between the second fixed electrode and the second movable electrode, and performs a detection process based on the capacitance between the first fixed electrode and the first movable electrode, and between the second fixed electrode and the second movable electrode in a diagnosis mode, thereby diagnosing a fault in the physical quantity sensor.

[0006] Another aspect of the present disclosure relates to an inertial measurement unit including the above-described physical quantity sensor and a control unit that performs control based on a detection signal output from the physical quantity sensor. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a plan view showing an example of a basic configuration of a physical quantity sensor according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a plan view showing a first configuration example of the physical quantity sensor of the present embodiment. [Diagram 3] FIG. 4 is a perspective view of a detection unit and a dummy unit. [Figure 4] FIG. 4 is a perspective view of a detection unit and a dummy unit. [Diagram 5] FIG. 4 is a diagram illustrating the operation of the present embodiment in a detection mode. [Figure 6] FIG. 4 is a diagram illustrating the operation of the present embodiment in a diagnostic mode. [Figure 7] 1 shows an example of a processing circuit configuration. [Figure 8] 1 shows an example of a detection circuit configuration. [Figure 9] FIG. [Figure 10] FIG. [Figure 11] FIG. 11 is a plan view showing another configuration example of the physical quantity sensor. [Figure 12] FIG. 11 is a plan view showing another configuration example of the physical quantity sensor. [Figure 13] FIG. 11 is a plan view showing another configuration example of the physical quantity sensor. [Figure 14] FIG. 11 is a plan view showing another configuration example of the physical quantity sensor. [Figure 15] FIG. 11 is a plan view showing another configuration example of the physical quantity sensor. [Figure 16] FIG. 11 is a plan view showing another configuration example of the physical quantity sensor. [Figure 17] FIG. 11 is a plan view showing another configuration example of the physical quantity sensor. [Figure 18] FIG. 11 is a plan view showing another configuration example of the physical quantity sensor. [Figure 19] FIG. 11 is a plan view showing another configuration example of the physical quantity sensor. [Figure 20] FIG. 11 is a plan view showing another configuration example of the physical quantity sensor. [Figure 21] FIG. 1 is an exploded perspective view showing a schematic configuration of an inertial measurement unit having a physical quantity sensor. [Figure 22] FIG. 4 is a perspective view of a circuit board of the physical quantity sensor. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] The present embodiment will be described below. Note that the present embodiment described below does not unduly limit the contents of the claims. Furthermore, not all of the configurations described in the present embodiment are necessarily essential configurations.

[0009] 1. Physical quantity sensor A configuration example of the physical quantity sensor 1 of this embodiment will be described with reference to Fig. 1, taking an acceleration sensor that detects acceleration in the vertical direction as an example. Fig. 1 is a plan view of the physical quantity sensor 1 as seen in a direction perpendicular to the substrate 2. The physical quantity sensor 1 is a MEMS (Micro Electro Mechanical Systems) device, such as an inertial sensor.

[0010] In FIG. 1, FIG. 2, and FIG. 11 to FIG. 20, the dimensions of each member and the intervals between members are shown in a schematic manner for the convenience of explanation, and not all components are shown. For example, electrode wiring, electrode terminals, and the like are not shown. In the following, the physical quantity detected by the physical quantity sensor 1 is mainly described as an example of acceleration, but the physical quantity is not limited to acceleration and may be other physical quantities such as velocity, pressure, displacement, angular velocity, or gravity, and the physical quantity sensor 1 may be used as a pressure sensor or a MEMS switch. In FIG. 1, directions perpendicular to each other are defined as a first direction DR1, a second direction DR2, and a third direction DR3. The opposite direction of the second direction DR2 is defined as a fourth direction DR4. The first direction DR1, the second direction DR2, and the third direction DR3 are, for example, the X-axis direction, the Y-axis direction, and the Z-axis direction, respectively, but are not limited thereto. For example, the third direction DR3 corresponding to the Z-axis direction is, for example, a direction perpendicular to the substrate 2 of the physical quantity sensor 1, and is, for example, a vertical direction. The first direction DR1 corresponding to the X-axis direction and the second direction DR2 corresponding to the Y-axis direction are perpendicular to the third direction DR3, and the XY plane along the first direction DR1 and the second direction DR2 is, for example, along the horizontal plane. Note that "perpendicular" includes cases where the two directions intersect at an angle slightly inclined from 90°, in addition to cases where the two directions intersect at 90°.

[0011] The physical quantity sensor 1 of this embodiment is a physical quantity sensor that detects a physical quantity in the third direction DR3 when three mutually orthogonal directions are a first direction DR1, a second direction DR2, and a third direction DR3. For example, the physical quantity sensor 1 detects acceleration as a physical quantity in the third direction DR3. As shown in FIG. 1, the physical quantity sensor 1 includes a substrate 2, a fixed portion 51 fixed to the substrate 2, a support beam 53, a movable body 3, a first fixed electrode portion 10, a second fixed electrode portion 20, and a processing circuit 200 described later in FIG. 7. The movable body 3 also includes a first movable electrode portion 60 and a second movable electrode portion 70. The movable body 3 also includes a connecting portion 55 that connects the support beam 53 to the first movable electrode portion 60 and the second movable electrode portion 70.

[0012] The substrate 2 is, for example, a silicon substrate made of semiconductor silicon or a glass substrate made of a glass material such as borosilicate glass, etc. However, the material of the substrate 2 is not particularly limited, and a quartz substrate, an SOI (Silicon On Insulator) substrate, etc. may be used.

[0013] The fixed portion 51 is fixed to the substrate 2. One end of the support beam 53 is connected to the fixed portion 51 and extends along the first direction DR1. The support beam 53 is, for example, a torsion spring. The movable body 3 is connected to the other end of the support beam 53. Specifically, one end side of the connecting portion 55 of the movable body 3 is connected to the other end of the support beam 53, and the other end side of the connecting portion 55 is connected to the first movable electrode portion 60 and the second movable electrode portion 70.

[0014] The fixed portion 51 is used as an anchor for the movable body 3. The movable body 3, which has the first movable electrode portion 60 and the second movable electrode portion 70, seesaws around a rotation axis along the first direction DR1 with the fixed portion 51 as a fulcrum. For example, the movable body 3 uses the support beam 53 along the first direction DR1 as a rotation axis and swings around the rotation axis while torsionally deforming the support beam 53. This realizes a detection unit Z1 with a one-sided seesaw structure, and this detection unit Z1 detects acceleration in a third direction DR3, which is, for example, the Z-axis direction.

[0015] The first fixed electrode portion 10 is provided on the substrate 2 and arranged in the second direction DR2 of the support beam 53. The first fixed electrode portion 10 is fixed to the substrate 2 by the fixed portion 4. The first fixed electrode portion 10 has first fixed electrodes 11 and 12. For example, the first fixed electrode portion 10 has a plurality of first fixed electrodes arranged in a comb-teeth pattern. The plurality of first fixed electrodes, such as the first fixed electrodes 11 and 12, extend along the second direction DR2, which is, for example, the Y-axis direction. For example, the first fixed electrodes 11 and 12 extend along the second direction DR2 from a first fixed base portion 14 of the first fixed electrode portion 10. One end of the first fixed base portion 14 is connected to the fixed portion 4, and extends from the fixed portion 4 along the first direction DR1.

[0016] The second fixed electrode portion 20 is provided on the substrate 2 and is arranged in, for example, the second direction DR2 of the support beam 53 or a fourth direction DR4 that is the opposite direction to the second direction DR2. In FIG. 1, the second fixed electrode portion 20 is arranged in the second direction DR2 of the support beam 53, but may be arranged in the fourth direction DR4 of the support beam 53 as shown in FIGS. 12 to 18 described later. The second fixed electrode portion 20 is fixed to the substrate 2 by the fixing portion 5. The second fixed electrode portion 20 has second fixed electrodes 21 and 22. For example, the second fixed electrode portion 20 has a plurality of second fixed electrodes arranged in a comb-teeth configuration. The plurality of second fixed electrodes such as the second fixed electrodes 21 and 22 extend, for example, along the second direction DR2. For example, the second fixed electrodes 21 and 22 extend along the second direction DR2 from a second fixed base portion 24 of the second fixed electrode portion 20. The second fixed base 24 has one end connected to the fixed part 5 and extends from the fixed part 5 along the first direction DR1.

[0017] It is also possible to modify the first fixed electrode of the first fixed electrode unit 10 and the second fixed electrode of the second fixed electrode unit 20 to extend along the first direction DR1. The first fixed electrode unit 10 and the second fixed electrode unit 20 can also be referred to as a first fixed electrode group and a second fixed electrode group, respectively.

[0018] The first movable electrode section 60 of the movable body 3 has first movable electrodes 61, 62 facing the first fixed electrodes 11, 12 of the first fixed electrode section 10. For example, the first movable electrode section 60 has a plurality of first movable electrodes arranged in a comb-teeth pattern. The plurality of first movable electrodes such as the first movable electrodes 61, 62 extend, for example, along the second direction DR2. For example, the first movable electrodes 61, 62 extend from the first movable base sections 64, 65 of the first movable electrode section 60 along the second direction DR2. The first movable electrodes 61, 62 of the first movable electrode section 60 face the first fixed electrodes 11, 12 of the first fixed electrode section 10 in, for example, the first direction DR1.

[0019] The second movable electrode section 70 of the movable body 3 has second movable electrodes 71, 72 facing the second fixed electrodes 21, 22 of the second fixed electrode section 20. For example, the second movable electrode section 70 has a plurality of second movable electrodes arranged in a comb-teeth pattern. The plurality of second movable electrodes such as the second movable electrodes 71, 72 extend, for example, along the second direction DR2. For example, the second movable electrodes 71, 72 extend from the second movable base sections 74, 75 of the second movable electrode section 70 along the second direction DR2. The second movable electrodes 71, 72 of the second movable electrode section 70 face the second fixed electrodes 21, 22 of the second fixed electrode section 20 in, for example, the first direction DR1.

[0020] It is also possible to modify the first movable electrode of the first movable electrode portion 60 and the second movable electrode of the second movable electrode portion 70 to extend along the first direction DR1. The first movable electrode portion 60 and the second movable electrode portion 70 can also be referred to as a first movable electrode group and a second movable electrode group, respectively.

[0021] 1 and later-described Fig. 2, 4 to 6, 11 to 20, etc., the diagonal lines on the movable electrodes and fixed electrodes indicate that the thickness of the movable electrodes and fixed electrodes is small in the third direction DR3, which is the Z direction, as will be described in detail in Fig. 3 and Fig. 4. The horizontal lines on the movable electrodes and fixed electrodes indicate that the thickness of the movable electrodes and fixed electrodes is large in the third direction DR3.

[0022] 1, the first fixed electrode portion 10 and the first movable electrode portion 60 constitute a detection unit Z1 that detects a physical quantity. The second fixed electrode portion 20 and the second movable electrode portion 70 constitute a dummy unit D1. For example, the detection unit Z1 detects a physical quantity such as acceleration in the Z direction in a detection mode, which is a normal operation mode. The dummy unit D1 is also used as a unit that assists the electrostatic force in the detection unit Z1 in a diagnosis mode, as described later.

[0023] 1, for example, the first fixed electrode section 10 and the second fixed electrode section 20 are comb-teeth fixed electrode groups in which a plurality of fixed electrodes are arranged in a comb-teeth pattern when viewed in a plan view in the third direction DR3, and the first movable electrode section 60 and the second movable electrode section 70 are comb-teeth movable electrode groups in which a plurality of movable electrodes are arranged in a comb-teeth pattern when viewed in a plan view in the third direction DR3. In the detection unit Z1, the fixed electrodes of the comb-teeth fixed electrode group of the first fixed electrode section 10 and the movable electrodes of the comb-teeth movable electrode group of the first movable electrode section 60 are arranged to face each other alternately. In the dummy unit D1, the fixed electrodes of the comb-teeth fixed electrode group of the second fixed electrode section 20 and the movable electrodes of the comb-teeth movable electrode group of the second movable electrode section 70 are arranged to face each other alternately.

[0024] 2 shows a first specific configuration example of the physical quantity sensor 1 of the present embodiment. In FIG. 2, in addition to the detection unit Z1 and dummy unit D1 of FIG. 1, a detection unit Z2 and a dummy unit D2 are provided. The detection unit Z2 is arranged in, for example, a first direction DR1 of the detection unit Z1. The dummy unit D2 is arranged in, for example, a fourth direction DR4 of the detection unit Z1, and the dummy unit D1 is arranged in, for example, a fourth direction DR4 of the detection unit Z2. For example, the detection unit Z1 and the dummy unit D1 are arranged in a diagonal direction from the upper left to the lower right of FIG. 2, and the detection unit Z2 and the dummy unit D2 are arranged in a diagonal direction from the upper right to the lower left.

[0025] 2, in addition to the fixed part 51 and the support beam 53 of FIG. 1, a fixed part 52 and a support beam 54 are provided. One end of the support beam 54 is connected to the fixed part 52, and the other end is connected to a connecting part 56 of the movable body 3. The fixed parts 51 and 52 are used as anchors for the movable body 3, and the movable body 3 oscillates in a seesaw manner around a rotation axis along the first direction DR1 with the fixed parts 51 and 52 as fulcrums. This realizes detection units Z1 and Z2 with a one-sided seesaw structure, and the detection units Z1 and Z2 detect acceleration in a third direction DR3, which is, for example, the Z-axis direction.

[0026] 2, the physical quantity sensor 1 includes a third fixed electrode portion 30 and a fourth fixed electrode portion 40. The movable body 3 includes a third movable electrode portion 80 and a fourth movable electrode portion 90. The third fixed electrode portion 30 and the third movable electrode portion 80 form a detection unit Z2 that detects a physical quantity such as acceleration in the Z direction. The fourth fixed electrode portion 40 and the fourth movable electrode portion 90 form a dummy unit D2 that assists the electrostatic force in the detection unit Z2 in the diagnosis mode. In FIG. 2, the connecting portion 55 connects the support beam 53 to the first movable electrode portion 60 and the fourth movable electrode portion 90, and the connecting portion 56 connects the support beam 54 to the second movable electrode portion 70 and the third movable electrode portion 80.

[0027] Specifically, the third fixed electrode portion 30 of the detection unit Z2 is provided on the substrate 2 and arranged in the second direction DR2 of the support beams 53 and 54. The third fixed electrode portion 30 is fixed to the substrate 2 by the fixing portion 6. The third fixed electrode portion 30 has third fixed electrodes 31 and 32. For example, the third fixed electrode portion 30 has a plurality of third fixed electrodes arranged in a comb-teeth pattern. These plurality of third fixed electrodes extend, for example, along the second direction DR2. For example, the third fixed electrodes 31 and 32 extend from a third fixed base portion 34 of the third fixed electrode portion 30 along the second direction DR2. One end of the third fixed base portion 34 is connected to the fixing portion 6, and extends from the fixing portion 6 along the first direction DR1.

[0028] The fourth fixed electrode portion 40 of the dummy unit D2 is provided on the substrate 2 and is arranged in, for example, the second direction DR2 of the support beams 53, 54 or a fourth direction DR4 that is the opposite direction to the second direction DR2. In FIG. 2, the fourth fixed electrode portion 40 is arranged in the second direction DR2 of the support beams 53, 54, but may be arranged in the fourth direction DR4 of the support beams 53, 54 as shown in FIGS. 12 to 18 described later. The fourth fixed electrode portion 40 is fixed to the substrate 2 by a fixing portion 7. The fourth fixed electrode portion 40 has fourth fixed electrodes 41, 42. For example, the fourth fixed electrode portion 40 has a plurality of fourth fixed electrodes arranged in a comb-teeth configuration. These multiple fourth fixed electrodes extend, for example, along the second direction DR2. For example, the fourth fixed electrodes 41, 42 extend along the second direction DR2 from a fourth fixed base portion 44 of the fourth fixed electrode portion 40. The fourth fixed base 44 has one end connected to the fixed part 7 and extends from the fixed part 7 along the first direction DR1.

[0029] The third movable electrode section 80 of the detection unit Z2 has third movable electrodes 81, 82 facing the third fixed electrodes 31, 32 of the third fixed electrode section 30. For example, the third movable electrode section 80 has a plurality of third movable electrodes arranged in a comb-teeth pattern. These plurality of third movable electrodes extend, for example, along the second direction DR2. For example, the third movable electrodes 81, 82 extend from third movable base sections 84, 85 of the third movable electrode section 80 along the second direction DR2. The third movable electrodes 81, 82 of the third movable electrode section 80 face the third fixed electrodes 31, 32 of the third fixed electrode section 30 in, for example, the first direction DR1.

[0030] The fourth movable electrode portion 90 of the dummy unit D2 has fourth movable electrodes 91, 92 facing the fourth fixed electrodes 41, 42 of the fourth fixed electrode portion 40. For example, the fourth movable electrode portion 90 has a plurality of fourth movable electrodes arranged in a comb-teeth pattern. These plurality of fourth movable electrodes extend, for example, along the second direction DR2. For example, the fourth movable electrodes 91, 92 extend from fourth movable base portions 94, 95 of the fourth movable electrode portion 90 along the second direction DR2. The fourth movable electrodes 91, 92 of the fourth movable electrode portion 90 face the fourth fixed electrodes 41, 42 of the fourth fixed electrode portion 40 in, for example, the first direction DR1.

[0031] The configurations and arrangements of the third fixed electrode portion 30, the fourth fixed electrode portion 40, the third movable electrode portion 80, and the fourth movable electrode portion 90 are similar to those of the first fixed electrode portion 10, the second fixed electrode portion 20, the first movable electrode portion 60, and the second movable electrode portion 70, and therefore detailed explanations will be omitted.

[0032] 3 and 4 are perspective views of the detection units Z1 and Z2 and the dummy units D1 and D2. In the detection units Z1 and Z2, the thicknesses of the movable electrodes and the fixed electrodes in the third direction DR3 are different. Similarly, in the dummy units D1 and D2, the thicknesses of the movable electrodes and the fixed electrodes in the third direction DR3 are different.

[0033] 3, in the detection unit Z1, the thickness of the first movable electrode 61 of the first movable electrode portion 60 in the third direction DR3 is greater than the thickness of the first fixed electrode 11 of the first fixed electrode portion 10 in the third direction DR3. Also in the dummy unit D1, the thickness of the second movable electrode 71 of the second movable electrode portion 70 in the third direction DR3 is greater than the thickness of the second fixed electrode 21 of the second fixed electrode portion 20 in the third direction DR3.

[0034] 4, in the detection unit Z2, the thickness of the third movable electrode 81 of the third movable electrode portion 80 in the third direction DR3 is smaller than the thickness of the third fixed electrode 31 of the third fixed electrode portion 30 in the third direction DR3. Also in the dummy unit D2, the thickness of the fourth movable electrode 91 of the fourth movable electrode portion 90 in the third direction DR3 is smaller than the thickness of the fourth fixed electrode 41 of the fourth fixed electrode portion 40 in the third direction DR3.

[0035] 5 is an explanatory diagram of the operation of the detection units Z1 and Z2 in the detection mode. As shown in FIG. 5, in the initial state, for example, in a side view of the physical quantity sensor 1, the positions of the ends of the first fixed electrode 11 and the first movable electrode 61 of the detection unit Z1 on the fifth direction DR5 side match and are flush. Also, in the initial state, the positions of the ends of the third fixed electrode 31 and the third movable electrode 81 of the detection unit Z2 on the fifth direction DR5 side match and are flush. Here, the fifth direction DR5 is the opposite direction to the third direction DR3, which is the +Z direction, as shown in FIG. 3 and FIG. 4, and is, for example, the -Z direction. The +Z direction is the direction on the positive side of the Z axis direction, and the -Z direction is the direction on the negative side of the Z axis direction.

[0036] When acceleration in the third direction DR3 is applied from this initial state, the first movable electrode 61 of the detection unit Z1 and the third movable electrode 81 of the detection unit Z2 are displaced toward the fifth direction DR5, which is the opposite direction to the third direction DR3, as shown in Fig. 5. As a result, the facing area between the first fixed electrode 11 and the first movable electrode 61 is maintained in the detection unit Z1, and the facing area between the third fixed electrode 31 and the third movable electrode 81 is reduced in the detection unit Z2. Therefore, the change in capacitance due to the reduction in the facing area in the detection unit Z2 is detected by the processing circuit 200 (detection circuit 210) in Fig. 7 described later, whereby the acceleration in the third direction DR3 can be detected.

[0037] On the other hand, when acceleration in the fifth direction DR5 is applied from the initial state, the first movable electrode 61 of the detection unit Z1 and the third movable electrode 81 of the detection unit Z2 are displaced in the third direction DR3 as shown in Fig. 5. As a result, the facing area between the first fixed electrode 11 and the first movable electrode 61 in the detection unit Z1 is reduced, and the facing area between the third fixed electrode 31 and the third movable electrode 81 in the detection unit Z2 is maintained. Therefore, the change in capacitance due to the reduction in the facing area in the detection unit Z1 is detected by the processing circuit 200, whereby the acceleration in the fifth direction DR5 can be detected.

[0038] 3 to 5, the case has been described in which the end portions of the first fixed electrode 11 and the first movable electrode 61 on the fifth direction DR5 side coincide with each other, and the end portions of the third fixed electrode 31 and the third movable electrode 81 on the fifth direction DR5 side coincide with each other and are flush with each other in the initial state, but this embodiment is not limited thereto. For example, in the initial state, in the detection unit Z1, the first movable electrode 61 may be offset-displaced toward the third direction DR3 side so that both ends of the first fixed electrode 11 and the first movable electrode 61 on the third direction DR3 side and the other end on the fifth direction DR5 side do not coincide with each other. In addition, in the detection unit Z2, the third movable electrode 81 may be offset-displaced toward the fifth direction DR5 side so that both ends of the third fixed electrode 31 and the third movable electrode 81 on the third direction DR3 side and the other end on the fifth direction DR5 side do not coincide with each other. In this way, for example, when acceleration is applied in the third direction DR3, the facing area increases in the detection unit Z1 and the electrostatic capacitance increases, and the facing area decreases in the detection unit Z2 and the electrostatic capacitance decreases. On the other hand, when acceleration is applied in the fifth direction DR5, the facing area decreases in the detection unit Z1, and the capacitance decreases, while the facing area increases in the detection unit Z2, and the capacitance increases. This increases the ratio of the change in capacitance to the change in acceleration, making it possible to realize a physical quantity sensor 1 with higher sensitivity.

[0039] 6 is an explanatory diagram of the operation of this embodiment in a diagnosis mode. In the diagnosis mode, a voltage is applied between the fixed electrode and the movable electrode, and a change in capacitance caused by the displacement of the movable electrode at that time is detected by the processing circuit 200 to diagnose whether or not an abnormality has occurred in the physical quantity sensor 1.

[0040] For example, when no voltage is applied between the fixed electrodes and the movable electrodes in Fig. 6, the end positions of the first fixed electrode 11 and the first movable electrode 61 of the detection unit Z1 in the fifth direction DR5 and the end positions of the second fixed electrode 21 and the second movable electrode 71 of the dummy unit D1 in the fifth direction DR5 match, as in the initial state of Fig. 5. In addition, the end positions of the third fixed electrode 31 and the third movable electrode 81 of the detection unit Z2 in the fifth direction DR5 and the end positions of the fourth fixed electrode 41 and the fourth movable electrode 91 of the dummy unit D2 in the fifth direction DR5 match.

[0041] In the diagnostic mode, when a voltage is applied between the fixed and movable electrodes of the detection unit Z1 and the dummy unit D1, the first movable electrode 61 of the detection unit Z1 moves so that its center position coincides with the center position of the first fixed electrode 11, as shown in FIG. 6. The second movable electrode 71 of the dummy unit D1 is displaced so that its center position coincides with the center position of the second fixed electrode 21. As a result, the capacitance between the fixed and movable electrodes of the detection unit Z1 and the dummy unit D1 increases due to an increase in fringe capacitance, etc. This is because the fringe capacitance is maximized when the center position of the fixed electrode coincides with the center position of the movable electrode. In the diagnostic mode, when a voltage is applied between the fixed and movable electrodes of the detection unit Z2 and the dummy unit D2, the third movable electrode 81 of the detection unit Z2 moves so that its center position coincides with the center position of the third fixed electrode 31, as shown in FIG. 6. The fourth movable electrode 91 of the dummy unit D2 is displaced so that its center position coincides with the center position of the fourth fixed electrode 41. As a result, the capacitance between the fixed electrodes and the movable electrodes in the detection unit Z2 and the dummy unit D2 increases due to an increase in fringe capacitance, etc. Therefore, in the diagnosis mode, a predetermined voltage is applied between the fixed electrodes and the movable electrodes of the detection unit Z1 and the dummy unit D1, or between the fixed electrodes and the movable electrodes of the detection unit Z2 and the dummy unit D2, and a change in capacitance at that time is detected, thereby making it possible to diagnose whether or not a failure has occurred in the physical quantity sensor 1. For example, if no change in capacitance is detected even when a voltage is applied in the diagnosis mode, it can be determined that a failure such as sticking of the fixed electrodes and the movable electrodes has occurred.

[0042] In this case, if an attempt is made to detect the change in capacitance in the diagnosis mode using only the detection units Z1 and Z2 without providing the dummy units D1 and D2, problems such as the need for a high voltage to be applied between the fixed electrode and the movable electrode will arise. For example, if the voltage applied between the fixed electrode and the movable electrode is low, the movable electrode will not be displaced sufficiently, the change in capacitance will be small, and fault diagnosis of the physical quantity sensor 1 will become difficult.

[0043] In this embodiment, dummy units D1 and D2 are provided to assist the electrostatic forces of the detection units Z1 and Z2. Therefore, even if the voltage applied between the fixed electrode and the movable electrode is not so high, the movable electrode can be displaced sufficiently to detect the change in capacitance and realize proper fault diagnosis.

[0044] As described above, the physical quantity sensor 1 of this embodiment includes the fixed parts 5 and 6 fixed to the substrate 2, the support beams 53 and 54 each having one end connected to the fixed parts 5 and 6, and the movable body 3 connected to the other end of the support beams 53 and 54. The physical quantity sensor 1 also includes a first fixed electrode section 10 provided on the substrate 2, arranged in the second direction DR2 of the support beams 53 and 54, and having the first fixed electrodes 11 and 12, a second fixed electrode section 20 provided on the substrate 2, arranged in the second direction DR2 or the fourth direction DR4 of the support beams 53 and 54, and having the second fixed electrodes 21 and 22, and a processing circuit 200 described in FIG. 7. The movable body 3 also includes a first movable electrode section 60 having first movable electrodes 61 and 62 facing the first fixed electrodes 11 and 12, and a second movable electrode section 70 having second movable electrodes 71 and 72 facing the second fixed electrodes 21 and 22.

[0045] 7 to 10, in the detection mode, the processing circuit 200 sets the second fixed electrodes 21, 22 and the second movable electrodes 71, 72 of the dummy unit D1 to the same potential and performs detection processing based on the capacitance between the first fixed electrodes 11, 12 and the first movable electrodes 61, 62 of the detection unit Z1, thereby detecting a physical quantity. For example, as described in FIG. 5, a physical quantity such as acceleration is detected by detecting a change in capacitance in the detection unit Z1 constituted by the first fixed electrode portion 10 and the first movable electrode portion 60.

[0046] On the other hand, as described in detail in FIG. 7 to FIG. 10, in the diagnosis mode, the processing circuit 200 applies a predetermined voltage between the first fixed electrodes 11, 12 and the first movable electrodes 61, 62 of the detection unit Z1 and between the second fixed electrodes 21, 22 and the second movable electrodes 71, 72 of the dummy unit D1. Then, by performing a detection process based on the electrostatic capacitance between the first fixed electrodes 11, 12 and the first movable electrodes 61, 62 of the detection unit Z1 and between the second fixed electrodes 21, 22 and the second movable electrodes 71, 72 of the dummy unit D1, a fault diagnosis, which is an abnormality diagnosis of the physical quantity sensor 1, is performed. For example, as described in FIG. 6, a predetermined voltage is applied between the fixed electrodes and the movable electrodes in the detection unit Z1 and the dummy unit D1 to displace the movable electrodes, and a change in the electrostatic capacitance due to the displacement of the movable electrodes is detected to perform a fault diagnosis of the physical quantity sensor 1.

[0047] In this way, in the diagnosis mode, a predetermined voltage is applied between the first fixed electrodes 11, 12 and the first movable electrodes 61, 62, and between the second fixed electrodes 21, 22 and the second movable electrodes 71, 72, to displace the first movable electrodes 61, 62 and the second movable electrodes 71, 72, and a change in capacitance due to this displacement is detected, thereby making it possible to realize a fault diagnosis of the physical quantity sensor 1. In this embodiment, in addition to the first fixed electrode portion 10 and the first movable electrode portion 60, the second fixed electrode portion 20 and the second movable electrode portion 70 are provided. That is, a dummy unit D1 is provided in addition to the detection unit Z1. Therefore, the electrostatic force caused by the application of a voltage between the first fixed electrodes 11, 12 and the first movable electrodes 61, 62 can be assisted by the electrostatic force caused by the application of a voltage between the second fixed electrodes 21, 22 and the second movable electrodes 71, 72. Therefore, compared to the case where only the first fixed electrode portion 10 and the first movable electrode portion 60 are provided, by further providing the second fixed electrode portion 20 and the second movable electrode portion 70, it is possible to increase the change in capacitance in the diagnosis mode and achieve appropriate fault diagnosis of the physical quantity sensor 1. Furthermore, in the detection mode, which is the normal operation mode, the second fixed electrodes 21, 22 and the second movable electrodes 71, 72 of the dummy unit D1 are set to the same potential, so it is possible to prevent a situation in which the electrostatic force between the second fixed electrodes 21, 22 and the second movable electrodes 71, 72 adversely affects operation in the detection mode.

[0048] 2 includes a third fixed electrode section 30 provided on the substrate 2, arranged in the second direction DR2 of the support beams 53 and 54, and having third fixed electrodes 31 and 32, and a fourth fixed electrode section 40 provided on the substrate 2, arranged in the second direction DR2 or the fourth direction DR4 of the support beams 53 and 54, and having fourth fixed electrodes 41 and 42. The movable body 3 also includes a third movable electrode section 80 having third movable electrodes 81 and 82 facing the third fixed electrodes 31 and 32, and a fourth movable electrode section 90 having fourth movable electrodes 91 and 92 facing the fourth fixed electrodes 41 and 42. The third fixed electrode section 30 and the third movable electrode section 80 form a detection unit Z2, and the fourth fixed electrode section 40 and the fourth movable electrode section 90 form a dummy unit D2.

[0049] In the detection mode, the processing circuit 200 in FIG. 7 sets the second fixed electrodes 21, 22 and the second movable electrodes 71, 72 of the dummy unit D1 to the same potential, and sets the fourth fixed electrodes 41, 42 and the fourth movable electrodes 91, 92 of the dummy unit D2 to the same potential. The processing circuit 200 detects a physical quantity by performing a detection process based on the capacitance between the first fixed electrodes 11, 12 and the first movable electrodes 61, 62 of the detection unit Z1 and the capacitance between the third fixed electrodes 31, 32 and the third movable electrodes 81, 82 of the detection unit Z2. For example, as described in FIG. 5, the processing circuit 200 detects a physical quantity such as acceleration by detecting a change in capacitance in the detection unit Z1 composed of the first fixed electrode portion 10 and the first movable electrode portion 60 and the detection unit Z2 composed of the third fixed electrode portion 30 and the third movable electrode portion 80.

[0050] On the other hand, in the diagnosis mode, the processing circuit 200 applies a predetermined voltage between the first fixed electrodes 11, 12 and the first movable electrodes 61, 62 of the detection unit Z1 and between the second fixed electrodes 21, 22 and the second movable electrodes 71, 72 of the dummy unit D1 to perform a fault diagnosis of the physical quantity sensor 1. Specifically, the processing circuit 200 performs a detection process based on the capacitance between the first fixed electrodes 11, 12 and the first movable electrodes 61, 62 of the detection unit Z1 and between the second fixed electrodes 21, 22 and the second movable electrodes 71, 72 of the dummy unit D1 to perform a fault diagnosis of the physical quantity sensor 1. Alternatively, the processing circuit 200 applies a predetermined voltage between the third fixed electrodes 31, 32 and the third movable electrodes 81, 82 of the detection unit Z2 and between the fourth fixed electrodes 41, 42 and the fourth movable electrodes 91, 92 of the dummy unit D2 to perform a fault diagnosis of the physical quantity sensor 1. Specifically, the processing circuit 200 performs a detection process based on the capacitance between the third fixed electrodes 31, 32 and the third movable electrodes 81, 82 of the detection unit Z2, and between the fourth fixed electrodes 41, 42 and the fourth movable electrodes 91, 92 of the dummy unit D2, thereby performing a fault diagnosis of the physical quantity sensor 1.

[0051] In this way, in the diagnosis mode, a predetermined voltage is applied between the first fixed electrodes 11, 12 and the first movable electrodes 61, 62 of the detection unit Z1 and between the second fixed electrodes 21, 22 and the second movable electrodes 71, 72 of the dummy unit D1, thereby displacing the first movable electrodes 61, 62 and the second movable electrodes 71, 72. Alternatively, in the diagnosis mode, a predetermined voltage is applied between the third fixed electrodes 31, 32 and the third movable electrodes 81, 82 of the detection unit Z2 and between the fourth fixed electrodes 41, 42 and the fourth movable electrodes 91, 92 of the dummy unit D2, thereby displacing the third movable electrodes 81, 82 and the fourth movable electrodes 91, 92. Then, by detecting a change in capacitance due to this displacement, it becomes possible to realize a fault diagnosis of the physical quantity sensor 1.

[0052] In this case, in this embodiment, in addition to the first fixed electrode portion 10 and the first movable electrode portion 60, the second fixed electrode portion 20 and the second movable electrode portion 70 are provided. That is, in addition to the detection unit Z1, the dummy unit D1 is provided. Also, in addition to the third fixed electrode portion 30 and the third movable electrode portion 80, the fourth fixed electrode portion 40 and the fourth movable electrode portion 90 are provided. That is, in addition to the detection unit Z2, the dummy unit D2 is provided. Therefore, the electrostatic force caused by the application of the voltage in the detection unit Z1 can be assisted by the electrostatic force caused by the application of the voltage in the dummy unit D1. Alternatively, the electrostatic force caused by the application of the voltage in the detection unit Z2 can be assisted by the electrostatic force caused by the application of the voltage in the dummy unit D2. Therefore, compared to the case where only the detection units Z1 and Z2 are provided, by further providing the dummy units D1 and D2, the change in the capacitance in the diagnosis mode can be made larger. This makes it possible to realize an appropriate fault diagnosis of the physical quantity sensor 1. In the detection mode, the second fixed electrodes 21, 22 and the second movable electrodes 71, 72 of the dummy unit D1, and the fourth fixed electrodes 41, 42 and the fourth movable electrodes 91, 92 of the dummy unit D2 are set to the same potential. This makes it possible to prevent the electrostatic force between the second fixed electrodes 21, 22 and the second movable electrodes 71, 72, and the electrostatic force between the fourth fixed electrodes 41, 42 and the fourth movable electrodes 91, 92 from adversely affecting operation in the detection mode.

[0053] 2, the fourth fixed electrode portion 40 and the fourth movable electrode portion 90 of the dummy unit D2 are arranged in the fourth direction DR4 of the first fixed electrode portion 10 and the first movable electrode portion 60 of the detection unit Z1. The second fixed electrode portion 20 and the second movable electrode portion 70 of the dummy unit D1 are arranged in the fourth direction DR4 of the third fixed electrode portion 30 and the third movable electrode portion 80 of the detection unit Z2. For example, the dummy unit D2 is arranged in the fourth direction DR4 of the detection unit Z1, and the dummy unit D1 is arranged in the first direction DR1 of the dummy unit D2 and the fourth direction DR4 of the detection unit Z2. In this way, it is possible to preferably maintain the balance of the electrostatic force acting on the movable body 3 in the diagnosis mode.

[0054] For example, when a voltage is applied between the fixed electrodes and the movable electrodes of the detection unit Z1 and the dummy unit D1 in the diagnostic mode, as shown in FIG. 6, the movable electrodes of the detection unit Z1 and the dummy unit D1 are displaced in the fifth direction DR5 by, for example, the electrostatic force in the fifth direction DR5 acting thereon. For example, a line passing between the detection unit Z1 and the dummy unit D2 and the detection unit Z2 and the dummy unit D1 in FIG. 2 is taken as a center line. In this case, the same electrostatic force in the fifth direction DR5 acts on the movable electrodes of the detection unit Z1 arranged on the left side of the center line and the movable electrodes of the dummy unit D1 arranged on the right side of the center line, displacing the movable body 3 in the fifth direction DR5, and the balance of the electrostatic forces can be maintained. Also, when a voltage is applied between the fixed electrodes and the movable electrodes of the detection unit Z2 and the dummy unit D2 in the diagnostic mode, the movable electrodes of the detection unit Z2 and the dummy unit D2 are displaced in the third direction DR3 by the electrostatic force in the third direction DR3 acting thereon. Therefore, an electrostatic force in the same third direction DR3 acts on the movable electrode of dummy unit D2, which is arranged on the left side of the center line, and on the movable electrode of detection unit Z2, which is arranged on the right side of the center line, causing the movable body 3 to be displaced in the third direction DR3, thereby maintaining the balance of the electrostatic forces.

[0055] 2, in consideration of the balance of electrostatic forces as described above, the detection unit Z1 and the dummy unit D1 are arranged so that a line connecting the center points of the detection unit Z2 and the dummy unit D2 intersects with a line connecting the center points of the detection unit Z2 and the dummy unit D2. However, the physical quantity sensor 1 of the present embodiment is not limited to such an arrangement, and even if such an arrangement is not used, the effect of applying a pseudo acceleration by applying an electrostatic force to displace the movable electrode in the diagnosis mode can be obtained.

[0056] As described above, in this embodiment, the diagnosis mode is realized by applying a pseudo acceleration, which displaces the movable electrode by electrostatic force caused by applying a voltage between the fixed electrode and the movable electrode. In this case, the inter-electrode area change type physical quantity sensor generates a weaker electrostatic force for the same voltage applied between the fixed electrode and the movable electrode compared to the inter-electrode distance change type. Therefore, when attempting to realize self-diagnosis using the electrostatic force between the fixed electrode and the movable electrode, a higher voltage needs to be applied to obtain the desired displacement of the movable body. Furthermore, if the length of the movable electrode and the fixed electrode is L, the rigidity of the electrode displaced in the width direction is 1 / L. 3 Since it is proportional to , the rigidity decreases when the electrode length L is long. Therefore, if an imbalance in the distance between the fixed electrodes arranged on the left and right sides of the movable electrode occurs due to mounting stress or the like, the movable electrode and the fixed electrode will tend to stick together when a high voltage is applied, resulting in malfunction.

[0057] For example, self-diagnosis, which is necessary for in-vehicle applications, can be realized by creating a pseudo acceleration state using electrostatic force for each polarity as an initial check when the power is turned on, and checking the operation. The electrostatic force in the inter-electrode area changing type is generated by applying a voltage between the fixed electrode and the movable electrode, as explained in Figure 6. As a result, the movable electrode displaces in a direction that makes its center position in the thickness direction coincide with the center position in the thickness direction of the fixed electrode. In this case, the electrostatic force at the same voltage is weaker in the inter-electrode area changing type than in the inter-electrode distance changing type, so a higher voltage is required to obtain the desired displacement of the movable body. Furthermore, if an imbalance occurs between the fixed electrodes on the left and right sides of the movable electrode due to mounting stress, etc., the fixed electrode and the movable electrode will easily stick to one side or the other.

[0058] In this respect, in this embodiment, for example, the first fixed electrodes 11, 12 of the detection unit Z1 are extended from the first fixed base 14 on both sides, so that the length of the first fixed electrodes 11, 12 can be shortened, and the rigidity of the first fixed electrodes 11, 12 in the first direction DR1, which is the sticking direction, can be increased. Similarly, the rigidity of the third fixed electrodes 31, 32 of the detection unit Z2 can be increased. And in this embodiment, as a further measure, dummy units D1, D2 are provided, and the electrostatic force in the detection units Z1, Z2 is assisted by the electrostatic force in the dummy units D1, D2. As a result, even if the applied voltage is lowered, the desired amount of displacement can be secured, and the application of high voltage can be alleviated, making it possible to suppress sticking.

[0059] In the diagnosis mode, the potential of the fixed electrodes of the dummy units D1 and D2 is set to the same potential as the fixed electrodes of the corresponding polarity of the detection units Z1 and Z2. On the other hand, in the detection mode, the potential of the fixed electrodes of the dummy units D1 and D2 is set to the same potential as the movable body 3 having the movable electrode. By doing so, the dummy units D1 and D2 do not generate electrostatic force in the detection mode, so that the operation of the movable body 3 is not adversely affected, and only the damping effect in the first direction DR1 in the plane can be generated, thereby improving the vibration resistance and shock resistance in other axial directions. In addition, since the dummy units D1 and D2 are arranged in the region inside the movable body 3 in a plan view, the physical quantity sensor 1 can also be made smaller.

[0060] In the present embodiment, in the detection unit Z1, the first fixed electrodes 11, 12 extend from the first fixed base 14 of the first fixed electrode section 10 along the second direction DR2, and the first movable electrodes 61, 62 extend from the first movable bases 64, 65 of the first movable electrode section 60 along the second direction DR2. That is, the first fixed electrodes 11, 12 and the first movable electrodes 61, 62 extend along the second direction DR2 perpendicular to the direction of the rotation axis of the movable body 3, and the first fixed electrodes 11, 12 and the first movable electrodes 61, 62 face each other in the first direction DR1. The direction of the rotation axis of the movable body 3 is the first direction DR1 along the support beams 53, 54. In this way, the displacement of the movable body 3 in a direction parallel to the rotation axis can be suppressed by the damping effect in the first direction DR1 caused by the first fixed electrodes 11, 12 and the first movable electrodes 61, 62 that extend along the second direction DR2 and face each other. This damping effect is a damping effect of a squeeze film in the first direction DR1 caused by the first fixed electrodes 11, 12 and the first movable electrodes 61, 62. This makes it possible to improve the vibration resistance and impact resistance of the physical quantity sensor 1 in other axial directions.

[0061] In this embodiment, in the dummy unit D1, the second fixed electrodes 21, 22 extend along the second direction DR2 from the second fixed base 24 of the second fixed electrode section 20, and the second movable electrodes 71, 72 extend along the second direction DR2 from the second movable bases 74, 75 of the second movable electrode section 70. That is, the second fixed electrodes 21, 22 and the second movable electrodes 71, 72 extend along the second direction DR2 perpendicular to the direction of the rotation axis of the movable body 3, and the second fixed electrodes 21, 22 and the second movable electrodes 71, 72 face each other in the first direction DR1. In this manner, displacement in a direction parallel to the rotation axis of the movable body 3 can be suppressed by the damping effect in the first direction DR1 produced by the second fixed electrodes 21, 22 and the second movable electrodes 71, 72 extending along the second direction DR2 and facing each other, thereby improving the vibration resistance and impact resistance of the physical quantity sensor 1 in other axial directions.

[0062] In the detection unit Z2, the third fixed electrodes 31, 32 extend from the third fixed base 34 along the second direction DR2, and the third movable electrodes 81, 82 extend from the third movable bases 84, 85 along the second direction DR2. In the dummy unit D2, the fourth fixed electrodes 41, 42 extend from the fourth fixed base 44 along the second direction DR2, and the fourth movable electrodes 91, 92 extend from the fourth movable bases 94, 95 along the second direction DR2. In this way, as in the cases of the detection unit Z1 and the dummy unit D1, the displacement of the movable body 3 in a direction parallel to the rotation axis can be suppressed by the damping effect, thereby improving vibration resistance and impact resistance.

[0063] For example, in the first mode, which is a detection mode, the movable body 3 is displaced along the third direction DR3 by a seesaw motion. On the other hand, in the second mode, which is an in-plane rotation mode, the movable body 3 is displaced along the direction of the rotation axis, and in the third mode, the movable body 3 is displaced along the direction perpendicular to the rotation axis. The rigidity of the support beams 53 and 54 is the lowest in the first mode and the highest in the third mode. Therefore, the frequency of occurrence of the first mode, which is a detection mode, is the lowest, the frequency of occurrence of the second mode, which is an unwanted mode, is higher than that of the first mode, and the frequency of occurrence of the third mode, which is an unwanted mode, is the highest. Therefore, in the method in which the movable electrode and the fixed electrode of the movable body 3 extend along the first direction DR1 parallel to the rotation axis, there is a problem that the displacement in the second mode, which is the second most likely to occur after the detection mode, cannot be effectively suppressed by the damping effect.

[0064] In this regard, in this embodiment, the movable electrode and the fixed electrode of the movable body 3 extend along the second direction DR2 perpendicular to the rotation axis and face each other in the first direction DR1. Therefore, due to the damping effect in the first direction DR1 by the movable electrode and the fixed electrode, it is possible to effectively suppress the displacement in the second mode, which is the in-plane rotation mode that is most likely to occur after the detection mode, and it is possible to improve vibration resistance and impact resistance.

[0065] In this embodiment, as shown in Figs. 1, 2, and 3, the thickness of the first movable electrodes 61, 62 of the detection unit Z1 in the third direction DR3 is greater than the thickness of the first fixed electrodes 11, 12 in the third direction DR3. In this case, as shown in Figs. 1, 2, and 3, when the second fixed electrode portion 20 of the dummy unit D1 is arranged in the second direction DR2 of the support beams 53, 54, the thickness of the second movable electrodes 71, 72 of the dummy unit D1 in the third direction DR3 is greater than the thickness of the second fixed electrodes 21, 22 in the third direction DR3. On the other hand, as shown in Figs. 12 to 18 described later, when the second fixed electrode portion 20 of the dummy unit D1 is arranged in the fourth direction DR4 of the support beams 53, 54, the thickness of the second movable electrodes 71, 72 of the dummy unit D1 in the third direction DR3 is smaller than the thickness of the second fixed electrodes 21, 22 in the third direction DR3. In this way, in the diagnosis mode, by applying a voltage between the fixed electrode and the movable electrode, the movable electrode is displaced so that its center position coincides with that of the fixed electrode, as shown in Fig. 6. This creates a state in which acceleration is applied in a pseudo manner, and the change in the amount of charge at that time can be detected, making it possible to realize fault diagnosis of the physical quantity sensor 1.

[0066] 1, 2, and 4, in the detection unit Z2, the thickness of the third movable electrodes 81, 82 in the third direction DR3 is smaller than the thickness of the third fixed electrodes 31, 32 in the third direction DR3. In this case, when the fourth fixed electrode portion 40 of the dummy unit D2 is arranged in the second direction DR2 of the support beams 53, 54 as shown in FIGS. 1, 2, and 3, the thickness of the fourth movable electrodes 91, 92 of the dummy unit D2 in the third direction DR3 is smaller than the thickness of the fourth fixed electrodes 41, 42 in the third direction DR3. On the other hand, when the fourth fixed electrode portion 40 of the dummy unit D2 is arranged in the fourth direction DR4 of the support beams 53, 54 as shown in FIGS. 12 to 18, the thickness of the fourth movable electrodes 91, 92 of the dummy unit D2 in the third direction DR3 is larger than the thickness of the fourth fixed electrodes 41, 42 in the third direction DR3. In this way, in the diagnosis mode as shown in Figure 6, by applying a voltage between the fixed electrode and the movable electrode, the movable electrode is displaced so that its center position coincides with that of the fixed electrode, and the change in the amount of charge at that time is detected, thereby making it possible to realize fault diagnosis.

[0067] In this embodiment, the thickness of the first movable electrodes 61, 62 of the detection unit Z1 in the third direction DR3 may be smaller than the thickness of the first fixed electrodes 11, 12. In this case, when the second fixed electrode portion 20 of the dummy unit D1 is arranged in the second direction DR2 of the support beams 53, 54 as shown in Figs. 1, 2, and 3, the thickness of the second movable electrodes 71, 72 of the dummy unit D1 in the third direction DR3 is smaller than the thickness of the second fixed electrodes 21, 22 in the third direction DR3. On the other hand, when the second fixed electrode portion 20 of the dummy unit D1 is arranged in the fourth direction DR4 of the support beams 53, 54 as shown in Figs. 12 to 18, the thickness of the second movable electrodes 71, 72 of the dummy unit D1 in the third direction DR3 is larger than the thickness of the second fixed electrodes 21, 22 in the third direction DR3. In this manner, similar to the operation of detection unit Z2 and dummy unit D2 in Figure 6, in the diagnosis mode, a voltage is applied between the fixed electrode and the movable electrode, the movable electrode is displaced so that its center position coincides with the center position of the fixed electrode, and the change in the amount of charge at that time is detected, thereby enabling fault diagnosis to be achieved.

[0068] In this case, the thickness of the third movable electrodes 81, 82 of the detection unit Z2 in the third direction DR3 may be made larger than the thickness of the third fixed electrodes 31, 32. Then, when the fourth fixed electrode portion 40 of the dummy unit D2 is arranged in the second direction DR2 of the support beams 53, 54 as shown in Figs. 1, 2 and 3, the thickness of the fourth movable electrodes 91, 92 of the dummy unit D2 in the third direction DR3 is made larger than the thickness of the fourth fixed electrodes 41, 42 in the third direction DR3. On the other hand, when the fourth fixed electrode portion 40 of the dummy unit D2 is arranged in the fourth direction DR4 of the support beams 53, 54 as shown in Figs. 12 to 18, the thickness of the fourth movable electrodes 91, 92 of the dummy unit D2 in the third direction DR3 is made smaller than the thickness of the fourth fixed electrodes 41, 42 in the third direction DR3.

[0069] 2. Processing circuit FIG. 7 shows a configuration example of the processing circuit 200 of this embodiment. In FIG. 7, the processing circuit 200 includes a detection circuit 210, a control circuit 220, a drive circuit 230, a voltage generation circuit 240, and switches SW1 to SW8. In FIG. 7, CZ1 and CZ2 indicate capacitance forming parts formed by the fixed electrodes and movable electrodes of the detection units Z1 and Z2, and CD1 and CD2 indicate capacitance forming parts formed by the fixed electrodes and movable electrodes of the dummy units D1 and D2. The electrostatic capacitances of the capacitance forming parts CZ1, CZ2, CD1, and CD2 correspond to the electrostatic capacitances between the fixed electrodes and movable electrodes of the detection units Z1 and Z2 and the dummy units D1 and D2. The terminal COM is a terminal connected to one end of the capacitance forming parts CZ1, CZ2, CD1, and CD2, and is a common terminal. The terminals ZP and ZN are terminals connected to the other ends of the capacitance forming parts CZ1 and CZ2. The terminals ZD1 and ZD2 are terminals connected to the other ends of the capacitance forming parts CD1 and CD2. One end side of the capacitance forming parts CZ1, CZ2, CD1, and CD2 is, for example, a movable electrode side, and the other end side is, for example, a fixed electrode side. The terminals SLD1 and SLD2 are terminals connected to a ground pattern for shielding provided in the physical quantity sensor 1, and are set to, for example, VSS=0V. These terminals correspond to terminals of a circuit device such as a semiconductor chip that realizes the processing circuit 200. Note that the processing circuit 200 is not limited to the configuration in FIG. 7, and various modifications are possible, such as omitting some of the components, adding other components, or replacing some of the components with other components.

[0070] The detection circuit 210 is a circuit that performs detection processing of the capacitances of the capacitance forming parts CZ1, CZ2, CD1, and CD2. The detection circuit 210 will be described in detail in FIG. 8 below. The control circuit 220 is a circuit that controls the detection circuit 210, the drive circuit 230, the voltage generation circuit 240, and the switches SW1 to SW8, and is configured by, for example, a logic circuit or the like. The drive circuit 230 generates a drive signal DRV for the physical quantity sensor 1 based on a clock signal generated by an oscillation circuit (not shown). The drive circuit 230 generates and outputs the drive signal DRV that changes in the order of, for example, voltages VCOM, VDD, and VSS. VDD is a power supply voltage on the high potential side. VSS is a power supply voltage on the low potential side, for example, VSS=0V. VCOM is a common voltage that serves as a reference voltage, for example, a voltage where VCOM=VDD / 2. The voltage generation circuit 240 supplies voltages such as VDD, VSS, and VCOM. The switches SW1 to SW8 are configured, for example, by MOS transistors and are turned on or off by a control signal from the control circuit 220.

[0071] 8 shows an example of the configuration of the detection circuit 210. The detection circuit 210 includes a Q / V amplifier 212, a programmable gain amplifier 214, an A / D conversion circuit 216, and an offset control circuit 218. The Q / V amplifier 212 converts the differential charge signals PIN and NIN from the terminals ZP and ZN in FIG. 7 into differential voltage signals AQP and AQN and outputs them. The programmable gain amplifier 214 amplifies the signals AQP and AQN from the Q / V amplifier 212 by a set gain and outputs differential voltage signals PQP and PQN. The A / D conversion circuit 216 performs A / D conversion on the signals PQP and PQN from the programmable gain amplifier 214 and outputs a digital signal ADQ. This makes it possible to output the detection results of the capacitance between the fixed electrodes and the movable electrodes in the detection units Z1 and Z2 and the dummy units D1 and D2 to the control circuit 220 as a digital signal ADQ. The control circuit 220 performs various types of determination processing based on the signal ADQ from the A / D conversion circuit 216, and performs various types of control such as turning on and off the switches SW1 to SW8 of the processing circuit 200. The offset control circuit 218 is a circuit that performs zero point adjustment by offset control for the signals PIN and NIN, and is constituted by a capacitor etc.

[0072] 9 and 10 are diagrams for explaining the operation of the processing circuit 200. In the detection mode as shown in FIG. 9, the switches SW1, SW3, and SW8 in FIG. 7 are turned on, and the switches SW2, SW4, SW5, SW6, and SW7 in FIG. 7 are turned off. When the switch SW1 is turned on, the drive signal DRV is output from the terminal COM as shown in FIG. 10, and this drive signal DRV is input to one end of the capacitance forming parts CZ1, CZ2, CD1, and CD2. When the switches SW3 and SW8 are turned on, the drive signal DRV is output from the terminals ZD1 and ZD2, and is input to the other end of the capacitance forming parts CD1 and CD2 of the dummy units D1 and D2. The terminals ZP and ZN connected to the other ends of the detection units Z1 and Z2 are set to a voltage VCOM=VDD / 2. The terminals SLD1 and SLD2 are set to VSS in both the detection mode and the diagnosis mode.

[0073] On the other hand, in the diagnostic mode, the switches SW2, SW4, SW5, SW6, and SW7 are turned on and the switches SW1, SW3, and SW8 are turned off as shown in Fig. 9. When the switch SW2 is turned on, the terminal COM is set to VDD as shown in Fig. 10.

[0074] In the ZP side diagnostic mode using the detection unit Z1 and dummy unit D1, the terminals ZP and ZD1 are set to VSS by turning on the switches SW4 and SW5, and the terminals ZN and ZD2 are set to VDD by turning on the switches SW6 and SW7. As a result, a voltage of the potential difference VDD-VSS is applied between one end and the other end of the capacitance forming parts CZ1 and CD1 of the detection unit Z1 and the dummy unit D1, while both ends of the capacitance forming parts CZ2 and CD2 of the detection unit Z2 and the dummy unit D2 are set to the same voltage VDD.

[0075] In the ZN side diagnostic mode using the detection unit Z2 and dummy unit D2, the terminals ZP and ZD1 are set to VDD when the switches SW4 and SW5 are turned on, and the terminals ZN and ZD2 are set to VSS when the switches SW6 and SW7 are turned on. As a result, a voltage of the potential difference VDD-VSS is applied between one end and the other end of the capacitance forming parts CZ2 and CD2 of the detection unit Z2 and the dummy unit D2, while both ends of the capacitance forming parts CZ1 and CD1 of the detection unit Z1 and the dummy unit D1 are set to the same voltage VDD.

[0076] In this manner, in the detection mode, the driving signal DRV from the terminal COM is input to one end of the capacitance forming parts CZ1 and CZ2 of the detection units Z1 and Z2, and the capacitance of the capacitance forming parts CZ1 and CZ2 is detected by the processing circuit 200, thereby detecting the acceleration. In this case, by making the frequency of the driving signal DRV sufficiently higher than the resonance frequency of the physical quantity sensor 1, the fixed electrode and the movable electrode are prevented from sticking to each other. For example, in the capacitance forming parts CZ1 and CZ2, when a voltage is applied between the fixed electrode and the movable electrode, an electrostatic force acts, and when viewed from the movable electrode, the electrostatic forces act in the opposite directions, so that a balanced state is maintained. However, if one of the electrostatic forces varies due to some factor, the movable electrode moves in the direction in which the electrostatic force is stronger, and the detection accuracy deteriorates. For this reason, by making the frequency of the driving signal DRV sufficiently higher than the resonance frequency of the physical quantity sensor 1, the movable electrode is made difficult to move, thereby preventing sticking and the like from occurring. In the dummy units D1 and D2, in the detection mode, the same drive signal DRV is input to both ends of the capacitance forming parts CD1 and CD2 of the dummy units D1 and D2, so that the fixed electrodes and movable electrodes of the dummy units D1 and D2 are set to the same potential, thereby preventing the dummy units D1 and D2 from adversely affecting the detection operation of the detection units Z1 and Z2.

[0077] On the other hand, in the diagnosis mode on the ZP side, a predetermined voltage corresponding to the potential difference of VDD-VSS is applied between one end and the other end of the capacitance forming parts CZ1, CD1 of the detection unit Z1 and the dummy unit D1, and both ends of the capacitance forming parts CZ2, CD2 of the detection unit Z2 and the dummy unit D2 are set to the same voltage VDD. By applying a voltage between one end and the other end of the capacitance forming parts CZ1, CD1 in this way, it becomes possible to perform fault diagnosis by displacing the movable electrodes of the detection unit Z1 and the dummy unit D1, as described in FIG. 6.

[0078] In the diagnosis mode on the ZN side, a predetermined voltage corresponding to the potential difference of VDD-VSS is applied between one end and the other end of the capacitance forming parts CZ2, CD2 of the detection unit Z2 and the dummy unit D2, and both ends of the capacitance forming parts CZ1, CD1 of the detection unit Z1 and the dummy unit D1 are set to the same voltage VDD. By applying a voltage between one end and the other end of the capacitance forming parts CZ2, CD2 in this manner, the movable electrodes of the detection unit Z2 and the dummy unit D2 can be displaced to perform fault diagnosis, as described in FIG. 6.

[0079] 3.Other configuration examples Next, various configuration examples of the physical quantity sensor 1 of this embodiment will be described. Fig. 11 is a plan view showing a second configuration example of the physical quantity sensor 1. Note that in Fig. 11, the diagonal lines on the movable electrodes and fixed electrodes indicate that the thickness of the movable electrodes and fixed electrodes is small, and the horizontal lines indicate that the thickness of the movable electrodes and fixed electrodes is large. The same applies to Figs. 12 to 20 described later.

[0080] The second configuration example in Fig. 11 has the same basic configuration as the first configuration example in Fig. 2, but dummy units D3 and D4 are added in Fig. 11. The dummy unit D3 is composed of a fifth fixed electrode section 110 having fifth fixed electrodes 111 and 112, and a fifth movable electrode section 130 having fifth movable electrodes 131 and 132. The fifth fixed electrode section 110 is fixed to the substrate 2 by a fixing section 8. The dummy unit D4 is composed of a sixth fixed electrode section 120 having sixth fixed electrodes 121 and 122, and a sixth movable electrode section 140 having sixth movable electrodes 141 and 142. The sixth fixed electrode section 120 is fixed to the substrate 2 by a fixing section 9.

[0081] The fifth fixed electrodes 111, 112 and the fifth movable electrodes 131, 132 of the dummy unit D3 and the sixth fixed electrodes 121, 122 and the sixth movable electrodes 141, 142 of the dummy unit D4 extend along a first direction DR1 parallel to the rotation axis of the movable body 3. In this way, the dummy units D1 and D2 can generate a damping effect in the direction of the rotation axis of the movable body 3, and the dummy units D3 and D4 can generate a damping effect in a direction perpendicular to the rotation axis of the movable body 3. As a result, the damping effect is generated not only in one direction but also in two directions in the plane, so that the vibration resistance and shock resistance in the other axis directions can be further improved. In addition, since the dummy units D1, D2, D3, and D4 are arranged in the internal region of the movable body 3 in a plan view, the physical quantity sensor 1 can be made smaller.

[0082] Here, the optimal condition for the arrangement of the dummy units from the viewpoint of damping will be described. In an in-plane rotational motion in which the movable body 3 is displaced in a direction parallel to the rotation axis (the second mode described above), the displacement of the movable body 3 is greater at locations farther from the rotation axis, so damping can be effectively generated by a dummy unit arranged at a location farther from the rotation axis. On the other hand, in an operation in which the movable body 3 is displaced in a direction perpendicular to the rotation axis (the third mode), the displacement of the movable body 3 is the same at any location, so the location of the dummy unit does not matter. Therefore, it is desirable to arrange the dummy units D3 and D4 that generate damping in the second direction DR2 perpendicular to the rotation axis near the rotation axis of the movable body 3, and to arrange the dummy units D1 and D2 that generate damping in the first direction DR1 parallel to the rotation axis farther from the rotation axis.

[0083] Fig. 12 is a plan view showing a third configuration example of the physical quantity sensor 1. The basic configuration is similar to the first configuration example in Fig. 2, but in Fig. 12, dummy units D1 and D2 are arranged in a fourth direction DR4 of the support beams 53 and 54 that are the rotation axis. In this manner, the dummy units D1 and D2 may be arranged in the second direction DR2 of the rotation axis as shown in Fig. 2, or may be arranged in the fourth direction DR4 of the rotation axis as shown in Fig. 12.

[0084] In addition, in Fig. 12, dummy units D1 and D2 are arranged in the fourth direction DR4 of the rotation axis, and thus the thickness relationship between the fixed electrodes and the movable electrodes in the dummy units D1 and D2 is different from that in Fig. 2. For example, in Fig. 2, the second movable electrodes 71 and 72 in the dummy unit D1 are thicker in the third direction DR3 than the second fixed electrodes 21 and 22, and the fourth movable electrodes 91 and 92 in the dummy unit D2 are thinner than the fourth fixed electrodes 41 and 42. In contrast to this, in Fig. 12, the second movable electrodes 71 and 72 in the dummy unit D1 are thinner than the second fixed electrodes 21 and 22, and the fourth movable electrodes 91 and 92 in the dummy unit D2 are thicker than the fourth fixed electrodes 41 and 42. 12, for example, in order to assist the displacement of the movable electrodes of the detection units Z1 and Z2 in the fifth direction DR5 (downward) in the diagnostic mode, it is necessary to displace the movable electrodes of the dummy units D1 and D2 in the third direction DR3 (upward). Also, in order to assist the displacement of the movable electrodes of the detection units Z1 and Z2 in the third direction DR3 in the diagnostic mode, it is necessary to displace the movable electrodes of the dummy units D1 and D2 in the fifth direction DR5.

[0085] 13, stoppers 160, 161, 162, 163, 164, 165, 166, and 167 are provided for the in-plane displacement of the movable body 3, and stoppers 168 and 169 are provided for the out-of-plane displacement of the movable body 3. For example, stoppers 161 and 163 provided at the upper right and lower left of the movable body 3 in the drawing function for displacement in the positive X-axis direction along the rotation axis, and stoppers 160 and 162 provided at the upper left and lower right of the movable body 3 function for displacement in the negative X-axis direction along the rotation axis. Stoppers 164 and 165 provided on the upper side of the movable body 3 function for displacement in the positive Y-axis direction perpendicular to the rotation axis, and stoppers 166 and 167 provided on the lower side of the movable body 3 function for displacement in the negative Y-axis direction perpendicular to the rotation axis. The out-of-plane movements of the movable body 3 include a movement in which the movable electrodes of the detection units Z1 and Z2 are displaced in the third direction DR3 and the movable electrodes of the dummy units D1 and D2 are displaced in the fifth direction DR5, and a movement in which the movable electrodes of the detection units Z1 and Z2 are displaced in the fifth direction DR5 and the movable electrodes of the dummy units D1 and D2 are displaced in the third direction DR3. Stoppers 168 and 169 provided on both sides of the support beams 53 and 54, which are the rotation axes, function against the displacements of both of these movements.

[0086] FIG. 14 is a plan view showing a fourth configuration example of the physical quantity sensor 1. The basic configuration is the same as the third configuration example in FIG. 13, but in FIG. 14, dummy units D3 and D4 are additionally arranged in the second direction DR2 of the support beams 53 and 54 that are the rotation axis. By providing the dummy units D3 and D4 in addition to the dummy units D1 and D2 in this way, a reduction in the applied voltage due to a further increase in electrostatic force can be realized in the diagnosis mode, and damping can be applied to the displacement in two directions in the plane in the detection mode, improving the vibration resistance and shock resistance in the other axis directions. Note that the same effect can be obtained even if the arrangement of the dummy units D1 and D2 and the dummy units D3 and D4 in FIG. 14 are interchanged.

[0087] Thus, the physical quantity sensor 1 in FIG. 14 and the above-described FIG. 11 includes the fifth fixed electrode portion 110 of the dummy unit D3 and the sixth fixed electrode portion 120 of the dummy unit D4. The fifth fixed electrode portion 110 is provided on the substrate 2, is disposed in the second direction DR2 or the fourth direction DR4 of the support beams 53 and 54, and has fifth fixed electrodes 111 and 112. The sixth fixed electrode portion 120 is provided on the substrate 2, is disposed in the second direction DR2 or the fourth direction DR4 of the support beams 53 and 54, and has sixth fixed electrodes 121 and 122. For example, in FIG. 14 and FIG. 11, the fifth fixed electrode portion 110 and the sixth fixed electrode portion 120 are provided in the second direction DR2 of the support beams 53 and 54, but the fifth fixed electrode portion 110 and the sixth fixed electrode portion 120 may be provided in the fourth direction DR4 of the support beam like the second fixed electrode portion 20 of the dummy unit D1 and the fourth fixed electrode portion 40 of the dummy unit D2.

[0088] 14 and 11, the movable body 3 includes a fifth movable electrode portion 130 of the dummy unit D3 and a sixth movable electrode portion 140 of the dummy unit D4. The fifth movable electrode portion 130 has fifth movable electrodes 131, 132 facing the fifth fixed electrodes 111, 112. The sixth movable electrode portion 140 has sixth movable electrodes 141, 142 facing the sixth fixed electrodes 121, 122.

[0089] 14 and 11, in the diagnosis mode, the processing circuit 200 applies a predetermined voltage between the first fixed electrodes 11, 12 and the first movable electrodes 61, 62 of the detection unit Z1, between the second fixed electrodes 21, 22 and the second movable electrodes 71, 72 of the dummy unit D1, and between the fifth fixed electrodes 111, 112 and the fifth movable electrodes 131, 132 of the dummy unit D3. Alternatively, the processing circuit 200 applies a predetermined voltage between the third fixed electrode 31 and the third movable electrodes 81, 82 of the detection unit Z2, between the fourth fixed electrodes 41, 42 and the fourth movable electrodes 91, 92 of the dummy unit D2, and between the sixth fixed electrodes 121, 122 and the sixth movable electrodes 141, 142 of the dummy unit D4, to perform a fault diagnosis of the physical quantity sensor.

[0090] 14 and 11, in addition to the first fixed electrode portion 10 and the first movable electrode portion 60, the second fixed electrode portion 20 and the second movable electrode portion 70, and the fifth fixed electrode portion 110 and the fifth movable electrode portion 130 are provided. That is, in addition to the detection unit Z1, dummy units D1 and D3 are provided. Also, in addition to the third fixed electrode portion 30 and the third movable electrode portion 80, the fourth fixed electrode portion 40 and the fourth movable electrode portion 90, and the sixth fixed electrode portion 120 and the sixth movable electrode portion 140 are provided. That is, in addition to the detection unit Z2, dummy units D2 and D4 are provided. Therefore, the electrostatic force caused by the voltage application in the detection unit Z1 can be assisted by the electrostatic force caused by the voltage application in the dummy units D1 and D3. Also, the electrostatic force caused by the voltage application in the detection unit Z2 can be assisted by the electrostatic force caused by the voltage application in the dummy units D2 and D4. Therefore, by further providing dummy units D1, D2, D3, and D4, the change in capacitance in the diagnosis mode can be made larger than when only detection units Z1 and Z2 are provided, making it possible to realize appropriate fault diagnosis of the physical quantity sensor 1.

[0091] Fig. 15 is a plan view showing a fifth configuration example of the physical quantity sensor 1. The basic configuration is similar to the third configuration example in Fig. 13, but the detection unit Z1 is divided and arranged on the left and right sides of the detection unit Z2 in the second direction DR2 of the support beams 53, 54 which are the rotation axis. In addition, the dummy unit D2 is divided and arranged on the left and right sides of the center line in the fourth direction DR4 of the support beams 53, 54, and the dummy unit D1 is also divided and arranged. For example, the dummy units D1, D2, D2, and D1 are arranged in this order along the first direction DR1.

[0092] 13, for example, the first movable electrodes 61, 62 are thicker in the detection unit Z1 arranged on the left side of the center line, and the third movable electrodes 81, 82 are thiner in the detection unit Z2 arranged on the right side of the center line. Also, the fourth movable electrodes 91, 92 are thicker in the dummy unit D2 arranged on the left side of the center line, and the second movable electrodes 71, 72 are thiner in the dummy unit D1 arranged on the right side of the center line. Therefore, there is a problem that the mass balance of the movable body 3 is not even between the left and right sides of the center line.

[0093] In this regard, in the fifth configuration example in Fig. 15, the detection unit Z2 having the third movable electrodes 81, 82 with a small thickness is arranged in the center where the center line passes, and the detection unit Z1 having the first movable electrodes 61, 62 with a large thickness is divided and arranged on the left and right sides of the detection unit Z2. Also, the dummy units D1, D2 are divided and arranged, for example, line-symmetrically with respect to the center line. Therefore, compared to the third configuration example in Fig. 13, the weight balance of the movable body 3 can be made uniform, and the imbalance of the electrostatic force can be suppressed.

[0094] 15, the fixed parts 4, 6 serving as anchors for the detection units Z1, Z2 and the fixed parts 51, 52 serving as anchors for the movable body 3 are arranged so as to be concentrated in, for example, the center of the physical quantity sensor 1. By concentrating the fixed parts 4, 6, 51, 52 serving as anchors in this manner, the sensor is less susceptible to adverse effects due to warping of the substrate 2 during mounting, and output fluctuations due to external stress and temperature changes can be suppressed.

[0095] In addition, in the detection mode, the dummy units D1 and D2 are set to the same potential as the movable body 3 and do not affect the characteristics, so the positions of the fixed parts 5 and 7 that act as anchors do not matter and they do not need to be arranged in a concentrated manner.

[0096] FIG. 16 is a plan view showing a sixth configuration example of the physical quantity sensor 1. The basic configuration is the same as the fifth configuration example of FIG. 15, but the extending direction of the movable electrodes in the dummy units D1 and D2 is opposite to that in the fifth configuration example. For example, in FIG. 16, in the dummy unit D1, the second movable electrodes 71 and 72 extend from the movable base in both the second direction DR2 and the fourth direction DR4. In the dummy unit D2, the fourth movable electrodes 91 and 92 extend from the movable base in both the second direction DR2 and the fourth direction DR4. With this structure, the mass of the movable body 3 on the dummy unit side, which is the fourth direction DR4 side with respect to the rotation axis, is reduced, and the rotation torque acting on the movable body 3 in the detection mode is increased. As a result, the physical quantity sensor 1 can be made more sensitive when compared with the same area, and the physical quantity sensor 1 can be made more compact when compared with the same sensitivity.

[0097] Fig. 17 is a plan view showing a seventh configuration example of the physical quantity sensor 1. The basic configuration is similar to the sixth configuration example of Fig. 16, but the extension direction of the fourth fixed electrodes 41, 42 and the fourth movable electrodes 91, 92 of the dummy unit D2 differs by 90 degrees from that of Fig. 16. That is, in Fig. 17, the fourth fixed electrodes 41, 42 and the fourth movable electrodes 91, 92 extend along the first direction DR1. In this way, the dummy units D1 and D2 can provide a damping effect in two directions within the plane, and vibration resistance and impact resistance in other axial directions can be improved.

[0098] FIG. 18 is a plan view showing an eighth configuration example of the physical quantity sensor 1. The basic configuration is the same as the third configuration example of FIG. 13, but the fixed parts 4 and 6 serving as anchors for the detection units Z1 and Z2 and the fixed parts 51 and 52 serving as anchors for the movable body 3 are arranged in a concentrated manner. A space is provided between the dummy unit D1 and the dummy unit D2, and another physical quantity sensor 180 is arranged in this space. For example, when the physical quantity sensor 1 is a sensor that detects a physical quantity such as acceleration in the Z-axis direction, the other physical quantity sensor 180 may be a sensor that detects a physical quantity in the X-axis direction or the Y-axis direction, or an integrated sensor that detects a physical quantity in two axes. Alternatively, the other physical quantity sensor 180 may be a sensor that detects a different object to be detected, such as an air pressure sensor. According to the eighth configuration example of FIG. 18, the chip area can be effectively utilized, so that the sensor can be miniaturized.

[0099] The physical quantity sensor 1 of this embodiment is not limited to the configuration described above, and various modifications are possible. For example, in this embodiment, the case where the movable electrode and the fixed electrode have two pair rows has been mainly described as an example, but the pair rows may be three or more rows. In this way, the electrode length of the fixed electrode and the movable electrode can be shortened and the rigidity can be increased, so that the adhesion of the fixed electrode and the movable electrode can be further suppressed. For example, FIG. 19 shows an example where the movable electrode and the fixed electrode have three pair rows in the detection units Z1 and Z2. For example, in FIG. 19, in the detection unit Z1, the first fixed electrodes 11 and 12 extend on both sides from the first fixed base 14, and the first fixed electrode 13 extends from the first fixed base 15. In addition, the first movable electrode 61 extends from the first movable base 64, and the first movable electrodes 62 and 63 extend from the first movable base 65 on both sides. These fixed electrodes and movable electrodes face each other. In the detection unit Z2, third fixed electrodes 31, 32 extend on both sides from the third fixed base 34, and a third fixed electrode 33 extends from the third fixed base 35. A third movable electrode 81 extends from the third movable base 84, and third movable electrodes 82, 83 extend on both sides from the third movable base 85. These fixed electrodes and movable electrodes face each other. Note that while Fig. 19 shows an example configuration of the detection units Z1, Z2, a similar configuration can be adopted for the dummy units D1, D2, etc.

[0100] 20, the movable body 3 may be provided with recessed grooves 150, 152. In the grooves 150, 152, the recesses are formed with a depth direction in a fifth direction DR5, which is the negative side of the Z direction, for example. By providing such grooves 150, 152, the mass of the movable body 3 in the fourth direction DR4 of the support beams 53, 54, which are the rotation axis, can be reduced. This makes it easier for the movable body 3 to generate a rotational torque, and enables the physical quantity sensor 1 to have a higher sensitivity.

[0101] In addition, the inter-electrode gap between the fixed electrode and the movable electrode in the dummy unit may be narrower than the inter-electrode gap in the detection unit. For example, on the side closer to the rotation axis, a larger electrostatic force is required to move the movable body 3 due to torque. Therefore, by narrowing the gap between the fixed electrode and the movable electrode of the dummy unit arranged near the rotation axis, a larger electrostatic force can be obtained, and for example, a further reduction in the voltage applied in the diagnostic mode can be achieved.

[0102] 4. Inertial Measurement Unit Next, an example of the inertial measurement unit 2000 of this embodiment will be described with reference to Fig. 21 and Fig. 22. The inertial measurement unit 2000 (IMU) shown in Fig. 21 is a device that detects inertial momentum such as the attitude and behavior of a moving body such as an automobile or a robot. The inertial measurement unit 2000 is a so-called six-axis motion sensor that includes an acceleration sensor that detects accelerations ax, ay, and az in directions along three axes, and an angular velocity sensor that detects angular velocities ωx, ωy, and ωz about the three axes.

[0103] The inertial measurement unit 2000 is a rectangular parallelepiped with a substantially square planar shape. Screw holes 2110 are formed as mounts near two vertices located diagonally across the square. The inertial measurement unit 2000 can be fixed to a mounting surface of a mounting body such as an automobile by passing two screws through the two screw holes 2110. By selecting parts and modifying the design, it is possible to reduce the size of the inertial measurement unit 2000 to a size that can be mounted on a smartphone or digital camera, for example.

[0104] The inertial measurement device 2000 has an outer case 2100, a joint member 2200, and a sensor module 2300, and is configured such that the sensor module 2300 is inserted inside the outer case 2100 with the joint member 2200 interposed therebetween. The sensor module 2300 has an inner case 2310 and a circuit board 2320. The inner case 2310 is formed with a recess 2311 for preventing contact with the circuit board 2320 and an opening 2312 for exposing a connector 2330 described later. The circuit board 2320 is joined to the bottom surface of the inner case 2310 via an adhesive.

[0105] 22, a connector 2330, an angular velocity sensor 2340z that detects an angular velocity around the Z-axis, an acceleration sensor unit 2350 that detects acceleration in the directions of the X-axis, Y-axis, and Z-axis, and the like are mounted on the upper surface of the circuit board 2320. In addition, an angular velocity sensor 2340x that detects an angular velocity around the X-axis and an angular velocity sensor 2340y that detects an angular velocity around the Y-axis are mounted on the side surface of the circuit board 2320.

[0106] The acceleration sensor unit 2350 includes at least the physical quantity sensor 1 for measuring the acceleration in the Z-axis direction described above, and can detect the acceleration in one axis direction, or the acceleration in two or three axis directions as necessary. Note that the angular velocity sensors 2340x, 2340y, and 2340z are not particularly limited, but for example, a vibration gyro sensor using the Coriolis force can be used.

[0107] In addition, a control IC 2360 is mounted on the lower surface of the circuit board 2320. The control IC 2360, which serves as a control unit that performs control based on a detection signal output from the physical quantity sensor 1, is, for example, an MCU (Micro Controller Unit), has a built-in storage unit including a non-volatile memory, an A / D converter, and the like, and controls each unit of the inertial measurement device 2000. Note that a plurality of other electronic components are also mounted on the circuit board 2320.

[0108] As described above, the inertial measurement unit 2000 of this embodiment includes the physical quantity sensor 1 and the control IC 2360 as a control unit that performs control based on the detection signal output from the physical quantity sensor 1. Since the inertial measurement unit 2000 uses the acceleration sensor unit 2350 including the physical quantity sensor 1, it is possible to provide an inertial measurement unit 2000 that can enjoy the effects of the physical quantity sensor 1 and achieve high accuracy, etc.

[0109] It should be noted that the inertial measurement unit 2000 is not limited to the configurations shown in Figures 21 and 22. For example, the inertial measurement unit 2000 may be configured to have only the physical quantity sensor 1 as an inertial sensor, without providing the angular velocity sensors 2340x, 2340y, and 2340z. In this case, the inertial measurement unit 2000 may be realized by housing, for example, the physical quantity sensor 1 and a control IC 2360 that realizes a control unit in a package that is a housing container.

[0110] As described above, when three mutually orthogonal directions are defined as a first direction, a second direction, and a third direction, the physical quantity sensor of this embodiment for detecting a physical quantity in the third direction includes a fixed part fixed to a substrate, a support beam having one end connected to the fixed part and extending along the first direction, and a movable body connected to the other end of the support beam. The physical quantity sensor also includes a first fixed electrode part provided on the substrate, disposed in the second direction of the support beam, and having a first fixed electrode, a second fixed electrode part provided on the substrate, disposed in the second direction of the support beam or a fourth direction opposite to the second direction, and having a second fixed electrode, and a processing circuit. The movable body includes a first movable electrode part having a first movable electrode facing the first fixed electrode, and a second movable electrode part having a second movable electrode facing the second fixed electrode. In a detection mode, the processing circuit detects the physical quantity by setting the second fixed electrode and the second movable electrode to the same potential and performing a detection process based on the electrostatic capacitance between the first fixed electrode and the first movable electrode. In addition, in the diagnostic mode, the processing circuit applies a predetermined voltage between the first fixed electrode and the first movable electrode, and between the second fixed electrode and the second movable electrode, and performs detection processing based on the capacitance between the first fixed electrode and the first movable electrode, and between the second fixed electrode and the second movable electrode, thereby diagnosing faults in the physical quantity sensor.

[0111] According to this embodiment, in the diagnosis mode, a predetermined voltage is applied between the first fixed electrode and the first movable electrode and between the second fixed electrode and the second movable electrode, thereby displacing the first movable electrode and the second movable electrode, and a change in capacitance due to this displacement is detected, thereby making it possible to realize a fault diagnosis of the physical quantity sensor. In this embodiment, the electrostatic force caused by the application of a voltage between the first fixed electrode and the first movable electrode can be assisted by the application of a voltage between the second fixed electrode and the second movable electrode. Therefore, compared to the case where only the first fixed electrode portion and the first movable electrode portion are provided, by further providing the second fixed electrode portion and the second movable electrode portion, the change in capacitance in the diagnosis mode can be made larger, making it possible to realize an appropriate fault diagnosis of the physical quantity sensor.

[0112] In addition, in this embodiment, the first fixed electrode may extend along the second direction from a first fixed base that the first fixed electrode portion has, and the first movable electrode may extend along the second direction from a first movable base that the first movable electrode portion has.

[0113] With this configuration, displacement of the movable body in a direction parallel to the rotation axis can be suppressed by a damping effect in the first direction by the first movable electrode and the first fixed electrode that extend along the second direction and face each other.

[0114] In addition, in this embodiment, the second fixed electrode may extend along the second direction from a second fixed base portion of the second fixed electrode portion, and the second movable electrode may extend along the second direction from a second movable base portion of the second movable electrode portion.

[0115] With this configuration, displacement of the movable body in a direction parallel to the rotation axis can be suppressed by a damping effect in the first direction by the second fixed electrode and the second movable electrode that extend along the second direction and face each other.

[0116] In this embodiment, the thickness of the first movable electrode in the third direction may be greater than the thickness of the first fixed electrode in the third direction, and the thickness of the second movable electrode in the third direction may be greater than the thickness of the second fixed electrode in the third direction when the second fixed electrode portion is disposed in the second direction of the support beam, and may be smaller than the thickness of the second fixed electrode in the third direction when the second fixed electrode portion is disposed in the fourth direction of the support beam.

[0117] In this manner, in the diagnostic mode, by applying a voltage between the fixed electrode and the movable electrode, the movable electrode is displaced so that its central position coincides with the central position of the fixed electrode, and the change in the amount of charge at that time can be detected to realize fault diagnosis of the physical quantity sensor.

[0118] In this embodiment, the thickness of the first movable electrode in the third direction may be smaller than the thickness of the first fixed electrode in the third direction, and the thickness of the second movable electrode in the third direction may be smaller than the thickness of the second fixed electrode in the third direction when the second fixed electrode portion is disposed in the second direction of the support beam, and may be larger than the thickness of the second fixed electrode in the third direction when the second fixed electrode portion is disposed in the fourth direction of the support beam.

[0119] In this way, in the diagnosis mode, a voltage is applied between the fixed electrode and the movable electrode, causing the movable electrode to be displaced so that its central position coincides with that of the fixed electrode, and the change in the amount of charge at that time is detected, thereby making it possible to realize fault diagnosis.

[0120] In the present embodiment, the physical quantity sensor may include a third fixed electrode section provided on the substrate, arranged in the second direction of the support beam, and having a third fixed electrode, and a fourth fixed electrode section provided on the substrate, arranged in the second direction or the fourth direction of the support beam, and having a fourth fixed electrode. The movable body may include a third movable electrode section having a third movable electrode facing the third fixed electrode, and a fourth movable electrode section having a fourth movable electrode facing the fourth fixed electrode. In the detection mode, the processing circuit may set the second fixed electrode and the second movable electrode to the same potential, set the fourth fixed electrode and the fourth movable electrode to the same potential, and detect the physical quantity by performing detection processing based on the capacitance between the first fixed electrode and the first movable electrode and the capacitance between the third fixed electrode and the third movable electrode. In the diagnosis mode, the processing circuit may perform fault diagnosis of the physical quantity sensor by applying a predetermined voltage between the first fixed electrode and the first movable electrode, and between the second fixed electrode and the second movable electrode, or by applying a predetermined voltage between the third fixed electrode and the third movable electrode, and between the fourth fixed electrode and the fourth movable electrode.

[0121] In this way, in the diagnosis mode, the first movable electrode and the second movable electrode can be displaced by applying a predetermined voltage between the first fixed electrode and the first movable electrode, and between the second fixed electrode and the second movable electrode. Alternatively, in the diagnosis mode, the third movable electrode and the fourth movable electrode can be displaced by applying a predetermined voltage between the third fixed electrode and the third movable electrode, and between the fourth fixed electrode and the fourth movable electrode. Then, by detecting a change in capacitance due to this displacement, it becomes possible to realize a fault diagnosis of the physical quantity sensor.

[0122] In addition, in this embodiment, the fourth fixed electrode portion and the fourth movable electrode portion may be arranged in a fourth direction of the first fixed electrode portion and the first movable electrode portion, and the second fixed electrode portion and the second movable electrode portion may be arranged in a fourth direction of the third fixed electrode portion and the third movable electrode portion.

[0123] In this way, the balance of the electrostatic forces acting on the movable body can be appropriately maintained in the diagnostic mode.

[0124] In the present embodiment, the physical quantity sensor may include a fifth fixed electrode section provided on the substrate, arranged in the second or fourth direction of the support beam, and having a fifth fixed electrode, and a sixth fixed electrode section provided on the substrate, arranged in the second or fourth direction of the support beam, and having a sixth fixed electrode. The movable body may include a fifth movable electrode section having a fifth movable electrode facing the fifth fixed electrode, and a sixth movable electrode section having a sixth movable electrode facing the sixth fixed electrode. In the diagnosis mode, the processing circuit may apply a predetermined voltage between the first fixed electrode and the first movable electrode, between the second fixed electrode and the second movable electrode, and between the fifth fixed electrode and the fifth movable electrode, or apply a predetermined voltage between the third fixed electrode and the third movable electrode, between the fourth fixed electrode and the fourth movable electrode, and between the sixth fixed electrode and the sixth movable electrode, to perform a fault diagnosis of the physical quantity sensor.

[0125] In this way, the electrostatic force caused by application of a voltage between the first fixed electrode and the first movable electrode can be assisted by the electrostatic force caused by application of a voltage between the second fixed electrode and the second movable electrode and the electrostatic force caused by application of a voltage between the fifth fixed electrode and the fifth movable electrode. Alternatively, the electrostatic force caused by application of a voltage between the third fixed electrode and the third movable electrode can be assisted by the electrostatic force caused by application of a voltage between the fourth fixed electrode and the fourth movable electrode and the electrostatic force caused by application of a voltage between the sixth fixed electrode and the sixth movable electrode. This makes it possible to increase the change in capacitance in the diagnosis mode and realize appropriate fault diagnosis of the physical quantity sensor.

[0126] This embodiment also relates to an inertial measurement unit including a control unit that performs control based on a detection signal output from the physical quantity sensor.

[0127] Although the present embodiment has been described in detail as above, it will be easily understood by those skilled in the art that many modifications are possible without substantially departing from the novel matters and effects of the present disclosure. Therefore, all such modifications are intended to be included in the scope of the present disclosure. For example, a term described at least once in the specification or drawings together with a different term having a broader meaning or synonymy can be replaced with that different term anywhere in the specification or drawings. In addition, all combinations of the present embodiment and modifications are also included in the scope of the present disclosure. In addition, the configurations and operations of the physical quantity sensor and the inertial measurement device are not limited to those described in the present embodiment, and various modifications are possible. [Explanation of symbols]

[0128] 1...physical quantity sensor, 2...substrate, 3...movable body, 4, 5, 6, 7, 8, 9...fixed portion, 10...first fixed electrode portion, 11, 12, 13...first fixed electrode, 14, 15...first fixed base, 20...second fixed electrode portion, 21, 22...second fixed electrode, 24...second fixed base, 30...third fixed electrode portion, 31, 32, 33...third fixed electrode, 34, 35...third fixed base, 40...fourth fixed electrode portion, 41, 42...fourth fixed electrode, 44...fourth fixed base, 51, 52...fixed portion, 53, 54...support beam, 55, 56...connecting portion, 60...first movable electrode portion, 61, 62, 63...First movable electrode, 64, 65...First movable base, 70...Second movable electrode part, 71, 72...Second movable electrode, 74, 75...Second movable base, 80...Third movable electrode part, 81, 82, 83...Third movable electrode, 84, 85...Third movable base, 90...Fourth movable electrode part, 91, 92 ...Fourth movable electrode, 94...Fourth, 95...Fourth movable base, 110...Fifth fixed electrode part, 111, 112...Fifth fixed electrode, 120...Sixth fixed electrode part, 121, 122...Sixth fixed electrode, 130...Fifth movable electrode part, 131, 132...Fifth movable electrode, 140...Sixth movable electrode part , 141, 142...sixth movable electrode, 150, 152...groove portion, 160 to 169...stopper, 180...other physical quantity sensor, 200...processing circuit, 210...detection circuit, 212...Q / V amplifier, 214...programmable gain amplifier, 216...A / D conversion circuit, 218...offset control circuit, 220...control circuit, 230...drive circuit, 240...voltage generation circuit, 2000...inertial measurement unit, 2100...outer case, 2110...screw hole, 2200...joint member, 2300...sensor module, 2310...inner case, 231 1...recess, 2312...opening, 2320...circuit board, 2330...connector, 2340x, 2340y, 2340z...angular velocity sensor, 2350...acceleration sensor unit, CD1, CD2, CZ1, CZ2...capacitance forming portion, D1, D2, D3, D4...dummy unit, DR1...first direction, DR2...second direction, DR3...third direction, DR4...fourth direction, DR5...fifth direction, DRV...drive signal, COM, SLD1, SLD2, ZD1, ZD2, ZN...terminal, ZP...terminal, SW1 to SW8...switch, Z1, Z2...detection unit

Claims

1. A physical quantity sensor that detects a physical quantity in a third direction, where three directions perpendicular to each other are a first direction, a second direction, and a third direction, and A fixed portion fixed to a substrate; a support beam having one end connected to the fixed portion and extending along the first direction; A movable body connected to the other end of the support beam; a first fixed electrode portion provided on the substrate, disposed in the second direction of the support beam, and having a first fixed electrode; a second fixed electrode portion provided on the substrate and disposed in the second direction of the support beam or a fourth direction opposite to the second direction, the second fixed electrode portion having a second fixed electrode; A processing circuit; Including, The movable body is a first movable electrode portion having a first movable electrode facing the first fixed electrode; a second movable electrode portion having a second movable electrode facing the second fixed electrode; having The processing circuitry includes: in a detection mode, the second fixed electrode and the second movable electrode are set to the same potential, and a detection process is performed based on an electrostatic capacitance between the first fixed electrode and the first movable electrode, thereby detecting the physical quantity; A physical quantity sensor characterized in that, in a diagnostic mode, a predetermined voltage is applied between the first fixed electrode and the first movable electrode, and between the second fixed electrode and the second movable electrode, and a detection process is performed based on the electrostatic capacitance between the first fixed electrode and the first movable electrode, and between the second fixed electrode and the second movable electrode, thereby diagnosing a fault in the physical quantity sensor.

2. 2. The physical quantity sensor according to claim 1, the first fixed electrode extends from a first fixed base portion of the first fixed electrode portion along the second direction, The physical quantity sensor, wherein the first movable electrode extends along the second direction from a first movable base portion of the first movable electrode portion.

3. 2. The physical quantity sensor according to claim 1, The second fixed electrode extends from a second fixed base portion of the second fixed electrode portion along the second direction, The physical quantity sensor, wherein the second movable electrode extends along the second direction from a second movable base portion of the second movable electrode portion.

4. 2. The physical quantity sensor according to claim 1, The thickness of the first movable electrode in the third direction is is greater than the thickness of the first fixed electrode in the third direction, The thickness of the second movable electrode in the third direction is When the second fixed electrode portion is disposed in the second direction of the support beam, the thickness of the second fixed electrode portion is larger than the thickness of the second fixed electrode portion in the third direction, A physical quantity sensor, characterized in that when the second fixed electrode portion is disposed in the fourth direction of the support beam, the thickness of the second fixed electrode portion is smaller than the thickness of the second fixed electrode portion in the third direction.

5. 2. The physical quantity sensor according to claim 1, The thickness of the first movable electrode in the third direction is a thickness of the first fixed electrode in the third direction; The thickness of the second movable electrode in the third direction is When the second fixed electrode portion is disposed in the second direction of the support beam, the thickness of the second fixed electrode portion is smaller than the thickness of the second fixed electrode portion in the third direction, A physical quantity sensor, characterized in that when the second fixed electrode portion is disposed in the fourth direction of the support beam, the thickness of the second fixed electrode portion is greater than the thickness of the second fixed electrode in the third direction.

6. 2. The physical quantity sensor according to claim 1, a third fixed electrode portion provided on the substrate, arranged in the second direction of the support beam, and having a third fixed electrode; a fourth fixed electrode portion provided on the substrate, arranged in the second direction or the fourth direction of the support beam, and having a fourth fixed electrode; Including, The movable body is a third movable electrode portion having a third movable electrode facing the third fixed electrode; a fourth movable electrode unit having a fourth movable electrode facing the fourth fixed electrode; having The processing circuitry includes: in the detection mode, the second fixed electrode and the second movable electrode are set to the same potential, and the fourth fixed electrode and the fourth movable electrode are set to the same potential, and a detection process is performed based on an electrostatic capacitance between the first fixed electrode and the first movable electrode and an electrostatic capacitance between the third fixed electrode and the third movable electrode, thereby detecting the physical quantity; a first fixed electrode and a first movable electrode, and a second fixed electrode and a second movable electrode, respectively; and a second fixed electrode and a second movable electrode, respectively.

7. The physical quantity sensor according to claim 6 , the fourth fixed electrode portion and the fourth movable electrode portion are disposed in the fourth direction of the first fixed electrode portion and the first movable electrode portion, The physical quantity sensor, characterized in that the second fixed electrode portion and the second movable electrode portion are arranged in the fourth direction of the third fixed electrode portion and the third movable electrode portion.

8. The physical quantity sensor according to claim 6 , a fifth fixed electrode portion provided on the substrate, arranged in the second direction or the fourth direction of the support beam, and having a fifth fixed electrode; a sixth fixed electrode portion provided on the substrate, arranged in the second direction or the fourth direction of the support beam, and having a sixth fixed electrode; Including, The movable body is a fifth movable electrode portion having a fifth movable electrode facing the fifth fixed electrode; a sixth movable electrode portion having a sixth movable electrode facing the sixth fixed electrode; having The processing circuitry includes: a first fixed electrode and a second movable electrode, a second fixed electrode and a third movable electrode, and a sixth fixed electrode and a sixth movable electrode, wherein the first fixed electrode and the third movable electrode are electrically connected to the first movable electrode, and the sixth fixed electrode and the sixth movable electrode are electrically connected to the second movable electrode, and the sixth fixed electrode and the sixth movable electrode are electrically connected to the third movable electrode.

9. The physical quantity sensor according to claim 1 , A control unit that performs control based on a detection signal output from the physical quantity sensor; 1. An inertial measurement device comprising:

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