Physical quantity sensor, inertial measurement unit and manufacturing method

Abstract

To provide a physical quantity sensor and the like which can suppress deterioration in acceleration detection sensitivity by fringe capacitance.SOLUTION: In a physical quantity sensor 1, when a smaller thickness among thicknesses of first fixed electrodes 11 and 12 in a first fixed electrode portion 10 in a third direction DR3 and thicknesses of first movable electrodes 21 and 22 in a first movable electrode portion 20 in the third direction DR3 is defined as TCA, in a side view in a second direction DR2 in a stationary state, one ends of the first movable electrodes 21 and 22 on a third direction DR3 side are positioned on the third direction DR3 side by 4 μm or more and TCA / 2 or less relative to one ends of the first fixed electrodes 11 and 12 on the third direction DR3 side. When an opposite direction of the third direction DR3 is defined as a fourth direction DR4, the other ends of the first movable electrodes 21 and 22 on a fourth direction DR4 side are positioned on the third direction DR3 side relative to the other ends of the first fixed electrodes 11 and 12 on the fourth direction DR4 side.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] Patent Document 1 discloses a physical quantity sensor capable of measuring physical quantities such as acceleration, in which a first fixed electrode partially overlaps a movable electrode and a second fixed electrode partially overlaps a movable electrode when viewed from the side in the X or Y direction. With this configuration, when the movable electrode moves in the +Z direction, the area facing the first fixed electrode increases, and when the movable electrode moves in the -Z direction, the area facing the second fixed electrode decreases, allowing measurement of physical quantities. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-515353 Summary of the Invention [Problem to be solved by the invention]

[0004] The physical quantity sensor disclosed in Patent Document 1 has a problem in that it cannot detect the physical quantity with high accuracy depending on the state of overlap between the movable electrode and the fixed electrode when viewed from the side in the X or Y direction. [Means for solving the problem]

[0005] One aspect of the present disclosure relates to 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, the physical quantity sensor including: a first fixed electrode portion and a first movable electrode portion provided on a substrate; the first fixed electrode portion includes a first fixed electrode; the first movable electrode portion includes a first movable electrode that faces the first fixed electrode of the first fixed electrode portion in the second direction; when the smaller of a thickness of the first fixed electrode in the third direction and a thickness of the first movable electrode in the third direction is defined as TCA, in a side view in the second direction in a stationary state, one end of the first movable electrode on the third direction side is located 4 μm or more and TCA / 2 or less toward the third direction than one end of the first fixed electrode on the third direction side; and when the direction opposite to the third direction is defined as a fourth direction, the other end of the first movable electrode on the fourth direction side is located closer to the third direction than the other end of the first fixed electrode on the fourth direction side.

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

[0007] Another aspect of the present disclosure is a manufacturing method of 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, the method including a fixed electrode forming step of forming a first fixed electrode portion on a substrate, and a movable electrode forming step of forming a first movable electrode portion, the first fixed electrode portion including a first fixed electrode, the first movable electrode portion including a first movable electrode that faces the first fixed electrode of the first fixed electrode portion in the second direction, and The movable electrode forming process relates to a manufacturing method for forming the movable electrode portion such that, when the smaller of the thicknesses in the three directions is defined as TCA, one end of the first movable electrode on the third direction side is located 4 μm or more and TCA / 2 or less away from one end of the first fixed electrode on the third direction side in a side view in the second direction, and when the direction opposite to the third direction is defined as a fourth direction, the other end of the first movable electrode on the fourth direction side is located closer to the third direction than the other end of the first fixed electrode on the fourth direction side. [Brief explanation of the drawings]

[0008] [Figure 1] 1 shows an example of the configuration of a physical quantity sensor according to the present embodiment. [Figure 2] FIG. [Figure 3] FIG. [Figure 4] FIG. [Figure 5] FIG. 1 is an explanatory diagram of fringe capacitance. [Figure 6] FIG. 4 is an explanatory diagram of the dimensions of a fixed electrode and a movable electrode. [Figure 7] FIG. 4 is an explanatory diagram of the dimensions of a fixed electrode and a movable electrode. [Figure 8] Simulation results of fringe capacitance versus offset. [Figure 9] Simulation results of fringe capacitance versus offset. [Figure 10] Simulation results of fringe capacitance versus offset. [Figure 11] Simulation results of fringe capacitance versus offset. [Figure 12] Simulation results of fringe capacitance versus offset. [Figure 13] Simulation results of fringe capacitance versus offset. [Figure 14] 10 shows another configuration example of the present embodiment. [Figure 15] 10 shows another configuration example of the present embodiment. [Figure 16] 10 shows an example of the arrangement pattern of fixed electrodes and movable electrodes in the YZ cross section. [Figure 17] 10 shows an example of the arrangement pattern of fixed electrodes and movable electrodes in the YZ cross section. [Figure 18] 10 shows an example of the arrangement pattern of fixed electrodes and movable electrodes in the YZ cross section. [Figure 19] FIG. 2 is a plan view showing a first detailed example of the physical quantity sensor. [Figure 20] FIG. 10 is a plan view showing a modified example of the first detailed example of the physical quantity sensor. [Figure 21] FIG. 10 is a plan view showing a modified example of the first detailed example of the physical quantity sensor. [Figure 22] FIG. 10 is a plan view showing a second detailed example of the physical quantity sensor. [Figure 23] FIG. 10 is a plan view showing a modified example of the second detailed example of the physical quantity sensor. [Figure 24] FIG. 10 is a plan view showing a modified example of the second detailed example of the physical quantity sensor. [Figure 25] FIG. 10 is a plan view showing a third detailed example of the physical quantity sensor. [Figure 26] FIG. 10 is a plan view showing a fourth detailed example of the physical quantity sensor. [Figure 27] FIG. 1 is an exploded perspective view showing a schematic configuration of an inertial measurement unit having a physical quantity sensor. [Figure 28] FIG. 1 is a perspective view of a circuit board of a physical quantity sensor. [Figure 29] 1 shows a first example of a method for manufacturing a physical quantity sensor according to an embodiment of the present invention. [Figure 30] 1 shows a first example of a method for manufacturing a physical quantity sensor according to an embodiment of the present invention. [Figure 31] 1 shows a first example of a method for manufacturing a physical quantity sensor according to an embodiment of the present invention. [Figure 32] 1 shows a first example of a method for manufacturing a physical quantity sensor according to an embodiment of the present invention. [Figure 33] 1 shows a first example of a method for manufacturing a physical quantity sensor according to an embodiment of the present invention. [Figure 34] 1 shows a first example of a method for manufacturing a physical quantity sensor according to an embodiment of the present invention. [Figure 35] 1 shows a first example of a method for manufacturing a physical quantity sensor according to an embodiment of the present invention. [Figure 36] 1 shows a first example of a method for manufacturing a physical quantity sensor according to an embodiment of the present invention. [Figure 37] 1 shows a first example of a method for manufacturing a physical quantity sensor according to an embodiment of the present invention. [Figure 38] 10 is a second example of the method for manufacturing the physical quantity sensor of the present embodiment. [Figure 39] 10 is a second example of the method for manufacturing the physical quantity sensor of the present embodiment. [Figure 40] 10 is a second example of the method for manufacturing the physical quantity sensor of the present embodiment. [Figure 41] 10 is a second example of the method for manufacturing the physical quantity sensor of the present embodiment. [Figure 42] 10 is a second example of the method for manufacturing the physical quantity sensor of the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] The present embodiment will be described below. Note that the present embodiment described below does not unduly limit the content of the claims. Furthermore, not all of the configurations described in the present embodiment are necessarily essential components.

[0010] 1. Physical quantity sensors An example of the configuration 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.

[0011] Note that in FIG. 1 and the following FIGS. 2 to 26 and 29 to 42, the dimensions of each component, the spacing between components, and the like are shown schematically for ease of explanation, and not all components are shown. For example, electrode wiring, electrode terminals, and the like are not shown. In the following description, the physical quantity detected by the physical quantity sensor 1 is mainly acceleration. However, the physical quantity is not limited to acceleration and may be other physical quantities such as velocity, pressure, displacement, angular velocity, or gravity. The physical quantity sensor 1 may also be used as a pressure sensor or a MEMS switch. In FIG. 1, directions perpendicular to each other are designated as a first direction DR1, a second direction DR2, and a third direction DR3. 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, which corresponds to the Z-axis direction, is a direction perpendicular to the substrate 2 of the physical quantity sensor 1, e.g., the 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, which is a plane along the first direction DR1 and the second direction DR2, is, for example, along the horizontal plane. The fourth direction DR4 is the opposite direction to the third direction DR3, for example, the direction on the negative side of the Z-axis direction. Note that "perpendicular" includes cases where the two directions intersect at an angle slightly inclined from 90 degrees, as well as cases where the two directions intersect at a 90-degree angle.

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

[0013] As shown in FIG. 1, the physical quantity sensor 1 of this embodiment can include a first fixed electrode portion 10, a first movable electrode portion 20, a first connecting portion 30, a second fixed electrode portion 50, a second movable electrode portion 60, a second connecting portion 70, a first fixed portion 40, and a first support beam 42.

[0014] The first fixed electrode portion 10, the first movable electrode portion 20, the first connecting portion 30, the second fixed electrode portion 50, the second movable electrode portion 60, the second connecting portion 70, the first fixed portion 40, the first support beam 42, etc. constitute the first detection element 100 of the physical quantity sensor 1. The first detection element 100 detects acceleration in a direction along the third direction DR3, which is the Z-axis direction, for example, at the detection portion Z1 and the detection portion Z2. Note that the following description will be given taking as an example a configuration in which the physical quantity sensor 1 includes the second fixed electrode portion 50, the second movable electrode portion 60, and the second connecting portion 70, but these may not be provided; however, the physical quantity sensor 1 may also be configured without these.

[0015] The first fixed electrode section 10 includes first fixed electrodes 11 and 12. The first fixed electrode section 10 is provided on the substrate 2. Specifically, the first fixed electrode section 10 is fixed to the substrate 2 by fixing sections 3 and 4. The multiple first fixed electrodes 11 and 12 extend along a first direction DR1, which is, for example, the X-axis direction. For example, the first fixed electrode section 10 is a first fixed electrode group.

[0016] The first movable electrode section 20 includes first movable electrodes 21 and 22. The first movable electrodes 21 and 22 extend along a first direction DR1, which is, for example, the X-axis direction. The first movable electrodes 21 and 22 are provided such that the first movable electrode 21 of the first movable electrode section 20 faces the first fixed electrode 11 of the first fixed electrode section 10, and the first movable electrode 22 of the first movable electrode section 20 faces the first fixed electrode 12 of the first fixed electrode section 10. For example, the first movable electrode section 20 is a first movable electrode group.

[0017] The second fixed electrode section 50 includes second fixed electrodes 51 and 52. The second fixed electrode section 50 is provided on the substrate 2. Specifically, the second fixed electrode section 50 is fixed to the substrate 2 by fixing sections 3 and 4. The multiple second fixed electrodes 51 and 52 extend along a first direction DR1, which is, for example, the X-axis direction. For example, the second fixed electrode section 50 is a second fixed electrode group.

[0018] The second movable electrode section 60 includes second movable electrodes 61 and 62. The second movable electrodes 61 and 62 extend along a first direction DR1, which is, for example, the X-axis direction. The second movable electrodes 61 and 62 are provided such that the second movable electrode 61 of the second movable electrode section 60 faces the second fixed electrode 51 of the second fixed electrode section 50, and the second movable electrode 62 of the second movable electrode section 60 faces the second fixed electrode 52 of the second fixed electrode section 50. For example, the second movable electrode section 60 is a second movable electrode group.

[0019] 1, the first fixed electrode section 10 is a comb-teeth fixed electrode group in which a plurality of fixed electrodes are arranged in a comb-teeth pattern when viewed in a plane in the third direction DR3, and the first movable electrode section 20 is a comb-teeth movable electrode group in which a plurality of movable electrodes are arranged in a comb-teeth pattern when viewed in a plane in the third direction DR3. Also, the second fixed electrode section 50 is a comb-teeth fixed electrode group in which a plurality of fixed electrodes are arranged in a comb-teeth pattern when viewed in a plane in the third direction DR3, and the second movable electrode section 60 is a comb-teeth movable electrode group in which a plurality of movable electrodes are arranged in a comb-teeth pattern when viewed in a plane in the third direction DR3.

[0020] In detection section Z1 of the first detection element 100, the first movable electrodes 21 of the first movable electrode section 20 and the first fixed electrodes 11 of the first fixed electrode section 10 are arranged to alternately face each other, and the first movable electrodes 22 of the first movable electrode section 20 and the first fixed electrodes 12 of the first fixed electrode section 10 are arranged to alternately face each other. In detection section Z2 of the first detection element 100, the second movable electrodes 61 of the second movable electrode section 60 and the second fixed electrodes 51 of the second fixed electrode section 50 are arranged to alternately face each other, and the second movable electrodes 62 of the second movable electrode section 60 and the second fixed electrodes 52 of the second fixed electrode section 50 are arranged to alternately face each other.

[0021] The first fixed portion 40 is fixed to the substrate 2. One end of the first support beam 42 is connected to the first fixed portion 40. For example, the first support beam 42 is a torsion spring. In FIG. 1, two support beams are provided along the second direction DR2 so as to extend from the first fixed portion 40 in the second direction DR2 and to the side opposite to the second direction.

[0022] The first connecting portion 30 connects the other end of the first support beam 42 that is not connected to the first fixed portion 40 to the first movable electrode portion 20. The second connecting portion 70 connects the other end of the first support beam 42 that is provided on the opposite side to the first support beam 42 that is not connected to the first fixed portion 40 to the second movable electrode portion 60.

[0023] The first fixed portion 40 is used as an anchor for the movable body formed by the first movable electrode portion 20 and the first connecting portion 30. The first fixed portion 40 is also used as an anchor for the second movable body formed by the second movable electrode portion 60 and the second connecting portion 70.

[0024] The movable body, which includes the first movable electrode portion 20 and the second movable electrode portion 60, swings around a rotation axis along the second direction DR2, with the first fixed portion 40 as a fulcrum. For example, the movable body swings around the rotation axis, with the first support beam 42 along the second direction DR2 as the rotation axis, while torsionally deforming the first support beam 42. In this way, the first detection element 100 with a one-sided seesaw structure is realized.

[0025] 2 is a perspective view of the fixed electrode 14 and the movable electrode 24 in the detection unit Z1 of the physical quantity sensor 1 of this embodiment. Here, the fixed electrode 14 corresponds to the first fixed electrodes 11 and 12 in FIG. 1, and the movable electrode 24 corresponds to the first movable electrodes 21 and 22 in FIG. 1. The fixed electrode 14 and the movable electrode 24 of the detection unit Z1 are provided opposite to each other so that they partially overlap when viewed from, for example, the second direction DR2. Specifically, the fixed electrode 14 and the movable electrode 24 are spaced apart from each other by a distance ΔT from the end of the movable electrode 24 in the third direction DR3 relative to the end of the fixed electrode 14 in the third direction DR3. a1The end of the fixed electrode 14 in the fourth direction DR4, which is opposite to the third direction DR3, is located on the third direction DR3 side by ΔT a2 That is, the end of the movable electrode 24 in the third direction DR3 is located on the fourth direction DR4 side by ΔT a1 The end of the fixed electrode 14 in the fourth direction DR4 is offset by ΔT toward the third direction DR3. a2 Furthermore, when the smaller of the thickness of the fixed electrode 14 and the thickness of the movable electrode 24 in the third direction DR3 is TCA, the fixed electrode 14 and the movable electrode 24 are offset in the third direction DR3 by an offset ΔT a1 is 4 μm or more and TCA / 2 or less. In FIG. 2, the thickness of the movable electrode 24 in the third direction DR3 is smaller than the thickness of the fixed electrode 14. In addition, the offset ΔT a2 is greater than zero.

[0026] 3 is a perspective view of the fixed electrode 54 and the movable electrode 64 in the detection unit Z2 of the physical quantity sensor 1 of this embodiment. Here, the fixed electrode 54 corresponds to the second fixed electrodes 51 and 52 in FIG. 1, and the movable electrode 64 corresponds to the second movable electrodes 61 and 62 in FIG. 1. The fixed electrode 54 and the movable electrode 64 of the detection unit Z2 are provided facing each other so as to partially overlap, for example, in the second direction DR2. That is, the fixed electrode 54 and the movable electrode 64 are spaced apart from each other by a distance ΔT from the end of the fixed electrode 54 in the third direction DR3 relative to the end of the movable electrode 64 in the third direction DR3. b1 The end of the movable electrode 64 in the fourth direction DR4 is located on the third direction DR3 side by ΔT b2 That is, the end of the fixed electrode 54 in the third direction DR3 is located closer to the fourth direction DR4 by ΔT than the end of the movable electrode 64 in the third direction DR3. b1 The end of the movable electrode 64 in the fourth direction DR4 is offset by ΔT toward the third direction DR3. b2Furthermore, when the smaller of the thickness of the fixed electrode 54 and the thickness of the movable electrode 64 in the third direction DR3 is TCB, the fixed electrode 54 and the movable electrode 64 are offset in the third direction DR3 by an offset ΔT b1 is 4 μm or more and TCB / 2 or less. In FIG. 3, the thickness of the movable electrode 64 in the third direction DR3 is smaller than the thickness of the fixed electrode 14. In addition, the offset ΔT b2 is greater than zero.

[0027] As described above, when the three mutually orthogonal directions are defined as the first direction DR1, the second direction DR2, and the third direction DR3, the physical quantity sensor 1 that detects a physical quantity in the third direction DR3 includes a first fixed electrode portion 10 and a first movable electrode portion 20 that are provided on the substrate 2. The first fixed electrode portion 10 includes first fixed electrodes 11 and 12, and the first movable electrode portion 20 includes first movable electrodes 21 and 22 that face the first fixed electrodes 11 and 12 of the first fixed electrode portion 10 in the second direction DR2. When the smaller of the thicknesses of the first fixed electrodes 11, 12 in the third direction DR3 and the first movable electrodes 21, 22 in the third direction DR3 is defined as TCA, one end of the first movable electrodes 21, 22 on the third direction DR3 side is positioned 4 μm or more and TCA / 2 or less toward the third direction DR3 than one end of the first fixed electrodes 11, 12 on the third direction DR3 side, in a side view in the second direction DR2 in a stationary state. When the opposite direction to the third direction DR3 is defined as a fourth direction DR4, the other end of the first movable electrodes 21, 22 on the fourth direction DR4 side is positioned closer to the third direction DR3 than the other end of the first fixed electrodes 11, 12 on the fourth direction DR4 side.

[0028] Fig. 4 is a diagram illustrating the operation of the detection units Z1 and Z2 of the physical quantity sensor 1 of this embodiment. Specifically, Fig. 4 shows cross-sectional views of the detection units Z1 and Z2 of the physical quantity sensor 1 shown in Fig. 1 as viewed from the second direction DR2, in an initial state and in a state where acceleration is applied, respectively.

[0029] In the initial state, the fixed electrode 14 and the movable electrode 24 of the detection unit Z1 are disposed opposite each other so as to partially overlap, for example, along the second direction DR2. The fixed electrode 14 and the movable electrode 24 are stationary in a state in which the end of the movable electrode 24 in the third direction DR3 is located further in the third direction DR3 than the end of the fixed electrode 14 in the third direction DR3. The fixed electrode 54 and the movable electrode 64 of the detection unit Z2 are also disposed opposite each other so as to partially overlap, for example, in the second direction DR2. The fixed electrode 54 is stationary in a state in which the end of the fixed electrode 54 in the third direction DR3 is located further in the third direction DR3 than the end of the movable electrode 64 in the third direction DR3.

[0030] When acceleration in the third direction DR3 occurs from this initial state, the movable electrode 24 of the detection unit Z1 is displaced in the fourth direction DR4, as shown in Fig. 4. The movable electrode 64 of the detection unit Z2 is also displaced in the fourth direction DR4. As a result, the opposing area between the fixed electrode 14 and the movable electrode 24 increases in the detection unit Z1, and the opposing area between the fixed electrode 54 and the movable electrode 64 decreases in the detection unit Z2. Therefore, acceleration in the third direction DR3 can be detected by detecting the increase in capacitance due to the increase in the opposing area in the detection unit Z1 and the decrease in capacitance due to the decrease in the opposing area in the detection unit Z2.

[0031] On the other hand, when acceleration in the fourth direction DR4 occurs from the initial state, the movable electrode 24 of the detection unit Z1 is displaced in the third direction DR3, as shown in Fig. 4. The movable electrode 64 of the detection unit Z2 is also displaced in the third direction DR3. As a result, the opposing area between the fixed electrode 14 and the movable electrode 24 decreases in the detection unit Z1, and the opposing area between the fixed electrode 54 and the movable electrode 64 increases in the detection unit Z2. Therefore, by detecting the decrease in capacitance due to the decrease in the opposing area in the detection unit Z1 and the increase in capacitance due to the increase in the opposing area in the detection unit Z2, acceleration in the fourth direction DR4 can be detected.

[0032] In this embodiment, as shown in FIG. 2, the fixed electrode 14 and the movable electrode 24 of the detection unit Z1 are configured such that their ends are not flush with each other in both the third direction DR3 and the fourth direction DR4. This structure allows the capacitance of the detection unit Z1 to change in response to application of acceleration in either the third direction DR3 or the fourth direction DR4. This allows for more sensitive acceleration detection than a structure in which the fixed electrode 14 and the movable electrode 24 of the detection unit Z1 are flush with each other in either the third direction DR3 or the fourth direction DR4, and acceleration in only one of the third direction DR3 or the fourth direction DR4 can be detected. Similarly, as shown in FIG. 3, the fixed electrode 54 and the movable electrode 64 of the detection unit Z2 are configured such that their ends are not flush with each other in both the third direction DR3 and the fourth direction DR4. This structure allows the capacitance of the detection unit Z2 to change in response to application of acceleration in either the third direction DR3 or the fourth direction DR4. This allows for more sensitive acceleration detection than a structure in which the ends of the fixed electrode 54 and the movable electrode 64 of the detection unit Z2 are flush with each other in either the third direction DR3 or the fourth direction DR4, and acceleration can only be detected in either the third direction DR3 or the fourth direction DR4. Furthermore, by extending the first movable electrodes 21 and 22 to both sides of the first direction DR1, the sensitivity to other axes in the first direction DR1 can be canceled. Furthermore, this embodiment is structured so that the fixed electrode 14 and the movable electrode 24 can be offset in both the +Z and -Z directions without relying on external electrical or mechanical factors. This structure does not require external factors, and therefore can achieve high-sensitivity acceleration detection with a simple configuration without adding new elements. Therefore, the physical quantity sensor 1 can achieve both high sensitivity and low cost. It is desirable that the first fixed portion 40, first support beam 42, first fixed electrode portion 10, first movable electrode portion 20, second fixed electrode portion 50, second movable electrode portion 60, etc. are all made of the same material, taking into consideration the effects on temperature characteristics such as warping due to differences in linear expansion coefficients when the different materials are used.

[0033] As a Z-direction acceleration sensor, an acceleration sensor using the above-mentioned change in facing area is disclosed in Patent Document 1. In this physical quantity sensor, the fixed electrode and one end of the movable electrode in the Z direction are not flush with each other, and the fixed electrode and one end of the movable electrode in the -Z direction are also not flush with each other.

[0034] Figure 5 shows the electric field lines that occur between the fixed electrode 14 and the movable electrode 24 when the fixed electrode 14 and the movable electrode 24 are arranged so that one end of each is not flush with the other in the +Z and -Z directions.

[0035] First, in the initial state, in the opposing area between the fixed electrode 14 and the movable electrode 24, electric lines of force are generated perpendicularly from the fixed electrode 14 to the movable electrode 24. Then, in the third direction DR3, ΔT a1 In the portion offset by ΔT in the fourth direction DR4, there is no fixed electrode 14 facing the movable electrode 24, and therefore, electric lines of force extend obliquely from the end of the fixed electrode 14 in the third direction DR3. a2 In the portion offset by .theta., there is no movable electrode 24 facing the fixed electrode 14, and therefore electric lines of force extend obliquely from the end of the movable electrode 24 in the fourth direction.

[0036] Next, the case where acceleration is applied in the fourth direction DR4 is shown in two states A and B. Here, state A shows a state in which acceleration in the fourth direction DR4 is applied and the movable electrode 24 is displaced in the third direction DR3. State B shows a state in which the movable electrode 24 is further subjected to acceleration in the fourth direction DR4 from state A and is displaced in the third direction DR3. In state A, the movable electrode 24 is displaced in the third direction DR3, so that ΔT a1 , ΔT a2 The offset, which was ΔT in the initial state, has increased. Since there is no fixed electrode 14 facing this increased offset, the number of electric field lines extending obliquely from the end of the fixed electrode 14 in the third direction has further increased. Similarly, in the fourth direction DR4, a2The offset, which was at 0° C., increases, and in the portion where there is no movable electrode 24 facing the fixed electrode 14, the number of electric field lines extending obliquely from the end portion in the fourth direction of the movable electrode 24 increases. In other words, when the movable electrode 24 moves in the +Z direction from the initial state where the offset is small, the change in the electric field lines between the fixed electrode 14 and the movable electrode 24 in the portion where the offset has increased is likely to be greater because the component of the electric field lines extending obliquely from the end portion of one of the electrodes is likely to increase.

[0037] In State B, the movable electrode 24 is further displaced in the third direction DR3 from State A, further increasing the offset. In State A, which is within a certain range from the initial state, the number of electric field lines obliquely emanating from the end of the fixed electrode 14 increases in proportion to the increase in the offset. However, if the offset increases beyond this range, the number of electric field lines obliquely emanating from the end of the fixed electrode 14 gradually saturates. State B shows the state of the electric field lines in this saturated region. That is, as the offset between the fixed electrode 14 and the movable electrode 24 increases from State A to State B, the number of electric field lines obliquely emanating from the end of the fixed electrode 14 hardly increases. That is, once the offset from the initial state increases to a certain extent, the change in the electric field lines obliquely emanating from the end of the fixed electrode 14 is considered to become gradual. The same is true for the electric field lines obliquely emanating from the end of the movable electrode 24 in the fourth direction DR4.

[0038] In this way, the electric field generated perpendicular to the area where the fixed electrode 14 and the movable electrode 24 face each other is called a fringe electric field. While the capacitance generated by the perpendicular electric field generated by the area where the electrodes face each other increases or decreases in proportion to the area of ​​the electrodes facing each other, the capacitance generated by the fringe electric field, i.e., the fringe capacitance, does not behave simply proportionally to the area of ​​the electrodes facing each other. Furthermore, when the fixed electrode 14 and the movable electrode 24 are etched, plasma ions are injected obliquely into the electrode side surfaces, worsening the roughness of the electrode side surfaces. Meanwhile, because fringe capacitance is highly sensitive to the shape of the electrode side surfaces, fringe capacitance tends to vary significantly from electrode to electrode. Thus, the fringe capacitance component included in the change in capacitance can degrade the accuracy of acceleration detection. Therefore, in physical quantity sensors that use changes in the area of ​​the electrodes facing each other, it is desirable to prevent the fringe capacitance component from being included in the change in capacitance detected.

[0039] In this regard, the physical quantity sensor disclosed in Patent Document 1, as mentioned above, employs a structure that allows offsetting of the fixed electrode and the movable electrode on both sides, thereby achieving high sensitivity in acceleration detection. However, there is no specific explanation of the effect of the offset amount at the ends of the fixed electrode and the movable electrode. As a result, it is difficult to minimize the effect of the above-mentioned fringe capacitance and detect acceleration with high accuracy. Furthermore, the physical quantity sensor has a small opposing area between the fixed electrode and the movable electrode, which narrows the movable range. In other words, there is a problem in that the range in which acceleration can be detected is narrow.

[0040] 8 to 13 show the results of simulations of the fringe capacitance between the fixed electrode 14 and the movable electrode 24 under various electrode dimensions. As shown in FIGS. 6 and 7, the thickness T of the electrodes in the third direction DR3, the width W of the electrodes in the second direction DR2, the gap S between the fixed electrode 14 and the movable electrode 24, the length L of the electrodes in the first direction DR1, and the facing length OL were all varied relative to standard dimensional conditions. Under the standard dimensional conditions, the thickness T is 30 μm, the width W is 2 μm, the gap S is 2 μm, the length L is 110 μm, and the facing length OL is 100 μm. While FIGS. 8 to 13 illustrate the fixed electrode 14 and the movable electrode 24 as an example, the fringe capacitance may also be between the fixed electrode 54 and the movable electrode 64, for example.

[0041] Figure 8 shows the results of a simulation verifying the change in fringe capacitance when the movable electrode 24 is offset from a reference plane where one end of the fixed electrode 14 and one end of the movable electrode 24 coincide in the third direction DR3, as shown in Figure 8, based on standard dimensional conditions. The fringe capacitance on the vertical axis is calculated by subtracting the capacitance calculated using the equation for calculating the capacitance of a parallel plate capacitor from the total capacitance between the fixed electrode 14 and the movable electrode 24 obtained by simulation. In other words, the fringe capacitance on the vertical axis is the capacitance corresponding to the fringe electric field generated at the ends of the fixed electrode 14 and the movable electrode 24. The thicknesses T of the fixed electrode 14 and the movable electrode 24 are equal and are varied in 10-μm increments from 10 μm to 100 μm. Data A1 corresponds to 100 μm, and data A2 corresponds to 10 μm. These results demonstrate that, for all thicknesses T, the fringe capacitance changes rapidly when the offset from the reference plane is less than 4 μm. When detecting in a range where this fringe capacitance variation is large, there is no problem if the electrode shapes of the fixed electrode 14 and the movable electrode 24 are made neatly, but in reality, there are side surface roughness and other issues.Fringe capacitance is very sensitive to the side surface shape of the electrode, so variations are likely to occur, significantly affecting detection accuracy.For this reason, in a range where fringe capacitance variation is small, with an offset of 4 μm or more, a margin can be secured to account for shape variations due to the process, enabling highly accurate detection.

[0042] FIG. 9 shows the simulation results when the thickness T of the movable electrode 24 is fixed at 30 μm under standard dimensional conditions and the thickness of the fixed electrode 14 is varied within a range equal to or less than the thickness of the movable electrode 24. Data for a fixed electrode 14 thickness T of 30 μm corresponds to A3, and data for a thickness T of 10 μm corresponds to A4. In this case, as in the case of FIG. 8, it can be seen that fringe capacitance fluctuations are large when the offset from the reference plane is less than 4 μm. FIG. 10 shows the simulation results when the fixed electrode 14 thickness T is fixed at 30 μm under standard dimensional conditions and the thickness of the movable electrode 24 is varied within a range equal to or less than the thickness of the fixed electrode 14. Data for a movable electrode 24 thickness T of 30 μm corresponds to A5, and data for a thickness T of 10 μm corresponds to A6. In this case, it can be seen that fringe capacitance fluctuations are large when the offset from the reference plane is less than 4 μm. As a result of simulating the pattern in which the opposing area decreases, it is clear that there is a tendency for the fringe capacitance fluctuation to increase when the fixed electrode 14 is displaced within a range of less than 4 μm from the reference plane that is flush with the movable electrode 24 on the third direction DR3 side or the fourth direction DR4 side.

[0043] Figure 11 shows the simulation results for fringe capacitance when the thickness T of the fixed electrode 14 and the movable electrode 24 is fixed at 30 μm under standard dimensional conditions, and the width W of both electrodes in the second direction DR2 is changed to 2 μm, 5 μm, and 10 μm. Data for a width W of both electrodes of 10 μm corresponds to A7, and data for 2 μm corresponds to A8. As before, fringe capacitance fluctuations are large when the offset from the reference plane is less than 4 μm. A more detailed trend is that when the width W of both electrodes is increased to 10 μm, the offset range in which fringe capacitance fluctuations are large is 4 μm or more. Note that increasing the electrode width W makes it difficult to miniaturize the device, so it is desirable to keep the width W to 5 μm or less.

[0044] Figure 12 shows the simulation results of fringe capacitance variation when the thickness T of the fixed electrode 14 and the movable electrode 24 is fixed at 30 μm under standard dimensional conditions, and the space S between the two electrodes is changed to 2 μm, 5 μm, and 10 μm. Data for a space S of 2 μm corresponds to A9, and data for a space S of 10 μm corresponds to A10. As before, fringe capacitance variation is large when the offset from the reference plane is less than 4 μm. A more detailed trend is that when the space S is wider, such as 10 μm, the offset range where fringe capacitance variation is large is 4 μm or more, and abrupt variations disappear. Note that if the space S is too large, the electrostatic capacitance decreases, resulting in a problem of reduced acceleration detection sensitivity. For this reason, it is desirable to keep the space S to 5 μm or less.

[0045] Figure 13 shows the simulation results for fringe capacitance when the thickness T of the fixed electrode 14 and the movable electrode 24 is fixed at 30 μm and the facing length OL of the two electrodes is changed to 50 μm, 100 μm, 200 μm, and 300 μm under standard dimensional conditions. Data for a facing length OL of 300 μm corresponds to A11, and data for a facing length OL of 50 μm corresponds to A12. As before, fringe capacitance fluctuates significantly when the facing length OL is less than 4 μm offset from the reference plane. Note that an excessively long facing length OL can lead to sticking problems and weaken the rigidity of the electrodes. For this reason, it is desirable to keep the facing length OL below approximately 300 μm. Regarding the dimensions described above, for example, the thickness T of each electrode should be designed so that the facing area between the electrodes at the detection sections Z1 and Z2 is approximately the same to minimize the capacitance offset. The length L of each electrode and the interelectrode spacing S may also be varied as long as the capacitance offset does not increase.

[0046] When the dimensions of fixed electrode 14 and movable electrode 24 are changed under these standard dimensional conditions, the fringe capacitance fluctuates significantly if the offset from the reference plane where one end of each electrode coincides in the third direction DR3 is less than 4 μm. Therefore, by ensuring that the offset from the reference plane of fixed electrode 14 and movable electrode 24 is 4 μm or more, the movable electrode 24 can move in a region where the fringe capacitance fluctuates slowly, avoiding regions where abrupt fluctuations occur, enabling highly accurate acceleration detection.

[0047] Furthermore, by setting the offset equal to or less than the thickness TCA, the movable range of the movable electrode 24 in the third direction DR3 and the fourth direction DR4 can be maximized. As described above, by ensuring an offset of 4 μm or more, the region where abrupt fluctuations in fringe capacitance occur can be avoided. However, if the offset is large, the opposing area between the fixed electrode 14 and the movable electrode 24 decreases, limiting the movable range of the movable electrode 24. In other words, the range in which acceleration can be detected narrows. Therefore, it is desirable to maximize the movable range while avoiding the region where abrupt fluctuations in fringe capacitance occur. It is also desirable to ensure the same movable range in both the third direction DR3 and the fourth direction DR4. From this perspective, by setting the upper limit of the offset equal to or less than half the thickness TCA of the smaller of the fixed electrode 14 or the movable electrode 24, the same movable range can be ensured for acceleration in either the third direction DR3 or the fourth direction DR4, thereby avoiding narrowing of the movable range in either direction. Therefore, by ensuring that the offset is 4 μm or more and is less than half the smaller of the thicknesses TCA of the fixed electrode 14 and the movable electrode 24, it is possible to achieve both high accuracy in acceleration detection and maximization of the detectable range of acceleration.

[0048] In addition, by setting the lower limit of the offset to a value of 6 to 8 μm or more, it is possible to more reliably prevent abrupt fluctuations in fringe capacitance. That is, if the movable electrode 24 is displaced significantly in the fourth direction DR4, the offset in the third direction DR3 may fall within a range of less than 4 μm, at which point the fringe capacitance changes abruptly. For this reason, if the TCA is set to 30 μm, for example, it is desirable to set the lower limit of the offset to 6 to 8 μm or more and the upper limit to 15 μm or less.

[0049] In addition, in this embodiment, the other end of the first movable electrodes 21, 22 on the fourth direction DR4 side may be located more than 4 μm and less than a thickness TCA / 2 on the third direction DR3 side than the other end of the first fixed electrodes 11, 12 on the fourth direction DR4 side.

[0050] In the portions of the fixed electrode 14 and the movable electrode 24 near their ends in the -Z direction, the surface shape is likely to become uneven due to the effect of plasma ions bouncing off the bottom of the grooves and being implanted during processing processes such as etching. On the other hand, the fringe electric field described above is sensitive to the roughness of the electrode surface, and when the roughness deteriorates near the ends of the electrodes, the fringe electric field becomes larger and the change in response to the displacement of the movable electrode 24 also becomes larger. In other words, the change in fringe capacitance tends to be larger on the fourth direction DR4 side, and the detection accuracy of acceleration is also likely to deteriorate. Therefore, according to this embodiment, the offset ΔT in a stationary state on the third direction DR3 side a1 , and the offset ΔT on the fourth direction DR4 side a2 Since a gap of 4 μm or more can be secured for each of the fourth direction DR4 and DR5, a large change in fringe capacitance can be avoided, particularly on the fourth direction DR4 side, and acceleration can be detected with high accuracy.

[0051] In this embodiment, the electrode assembly includes a second fixed electrode unit 50 and a second movable electrode unit 60 provided on the substrate 2, the second fixed electrode unit 50 including second fixed electrodes 51, 52, and the second movable electrode unit 60 including second movable electrodes 61, 62 facing the second fixed electrodes 51, 52 of the second fixed electrode unit 50 in the second direction DR2. When the smaller of the thicknesses of the second fixed electrodes 51, 52 in the third direction DR3 and the second movable electrodes 61, 62 in the third direction DR3 is denoted by TCB, one end of the second movable electrodes 61, 62 on the fourth direction DR4 side is positioned 4 μm or more and TCB / 2 or less away from one end of the second fixed electrodes 51, 52 on the fourth direction DR4 side in a side view in a stationary state. The other ends of the second movable electrodes 61 and 62 on the third direction DR3 side are located closer to the fourth direction DR4 than the other ends of the second fixed electrodes 51 and 52 on the third direction DR3 side.

[0052] The effect of the sudden change in fringe capacitance described above is not only felt in the fixed electrode 14 and movable electrode 24 of detection unit Z1, but also in the fixed electrode 54 and movable electrode 64 of detection unit Z2. Therefore, according to this embodiment, it is possible to avoid the region in detection unit Z2 where the sudden change in fringe capacitance occurs due to the offset of the movable electrode 64 in the fourth direction DR4. This makes it possible to detect acceleration with high accuracy in both detection units Z1 and Z2, and to maximize the detectable range of acceleration.

[0053] In addition, in this embodiment, the other end of the first movable electrodes 21, 22 on the third direction DR3 side may be positioned more than 4 μm and less than TCB / 2 on the fourth direction DR4 side than the other end of the first fixed electrodes 11, 12 on the third direction DR3 side.

[0054] In this way, for each of the detection sections Z1 and Z2, changes in capacitance can be detected while avoiding areas where sudden changes in fringe capacitance occur on both the third direction DR3 side and the fourth direction DR4 side, making it possible to detect acceleration with high accuracy.

[0055] 14 and 15 show modified examples of the configuration shown in FIG. 1. FIG. 14 shows an example in which the arrangement pattern of the detection unit Z1 and the detection unit Z2 is different from that shown in FIG. 1. Specifically, the detection unit Z1 is sandwiched between the detection units Z2 in the second direction DR2. By arranging the detection units Z1 and Z2 in this manner, the position of the center of gravity of the movable body including the movable electrodes 24 and 64 can be stabilized. That is, the detection units Z1 and Z2, which have different thickness patterns of the movable electrodes, are arranged symmetrically with respect to a line along the X-axis indicated by the dashed line in FIG. 14. This eliminates mass imbalance due to the configuration positions of the movable electrodes 24 and 54, enabling highly accurate acceleration detection. In this embodiment, either or both of the detection units Z1 and Z2 may be arranged separately, or the detection unit Z2 may be sandwiched between the detection units Z1.

[0056] The configuration example shown in FIG. 15 differs from that shown in FIG. 1 in the shape of the first connecting portion 30. While the detecting portions Z1 and Z2 are arranged side by side along the second direction DR2 in the configuration example shown in FIG. 15, they are arranged side by side along the first direction DR1 in the configuration example shown in FIG. 15. A second detecting element 102 is provided in the space surrounded by the first connecting portion 30. The second detecting element 102 is, for example, a physical quantity sensor that detects acceleration in the first direction DR1 or the second direction DR2. The first fixed electrode portion 10, the first movable electrode portion 20, the second movable electrode portion 60, the second fixed electrode portion 50, the first connecting portion 30, the second detecting element 102, the first connecting portion 30, and the first fixed portion 40 are arranged side by side in this order along the first direction DR1. This configuration also achieves the same effect as the configuration example shown in FIG. 1, and is capable of detecting acceleration in the first direction DR1 or the second direction DR2 as well as acceleration in the third direction DR3.

[0057] 16 shows a cross-sectional structure of the detection units Z1 and Z2 of the physical quantity sensor 1 of this embodiment as viewed from the first direction DR1 side. As described above, the offset ΔT from the reference plane on the third direction DR3 side a1 , 4 μm ≦ ΔT a1 ≦TCA / 2, and the offset ΔT from the reference plane on the fourth direction DR4 side a2is zero or more, or 4μm≦ΔT a1 16 shows an example of a pattern where the relationship ≦TCA / 2 is satisfied. Specifically, the end of the movable electrode 24 of the detection unit Z1 on the third direction DR3 side is flush with the end of the fixed electrode 54 of the detection unit Z2 on the third direction DR3 side, and the end of the fixed electrode 14 of the detection unit Z1 on the fourth direction DR4 side is flush with the end of the movable electrode 64 of the detection unit Z2 on the fourth direction DR4 side. Here, the end of the fixed electrode 14 of the detection unit Z1 in the third direction DR3 is positioned differently from the end of the movable electrode 64 of the detection unit Z2 in the third direction DR3. Furthermore, the end of the movable electrode 24 of the detection unit Z1 in the fourth direction DR4 is positioned differently from the end of the fixed electrode 54 of the detection unit Z2 in the fourth direction DR4.

[0058] That is, in the physical quantity sensor 1 of this embodiment, when viewed from the side in a stationary state, the position of one end of the first movable electrodes 21, 22 on the third direction DR3 side may coincide with the position of the other end of the second fixed electrodes 51, 52 on the third direction DR3 side, and the position of the other end of the first fixed electrodes 11, 12 on the fourth direction DR4 side may coincide with the position of one end of the second movable electrodes 61, 62 on the fourth direction DR4 side.

[0059] The positions of the ends of the fixed electrodes 14, 54 and the movable electrodes 24, 64 in the third direction DR3 are part of the wafer surface after a surface polishing process such as CMP (Chemical Mechanical Polishing) or a processing process such as etching. If the processed surface is represented by the "contours" shown by dashed lines in FIG. 16 , the pattern shown in FIG. 16 has six contours. Because the number of contours directly increases manufacturing costs and the difficulty of the manufacturing process, it is desirable to adopt an electrode arrangement pattern that minimizes the number of contours. Therefore, according to this embodiment, the positions of one end of the movable electrode 24 and the fixed electrode 54 in the third direction DR3 coincide, and the positions of one end of the fixed electrode 14 and the movable electrode 64 in the fourth direction DR4 coincide, thereby reducing the number of contours. This makes it possible to manufacture a physical quantity sensor 1 capable of detecting acceleration with high accuracy at low cost.

[0060] Like Fig. 16, Fig. 17 also shows a cross-sectional structure of the detection units Z1 and Z2 of the physical quantity sensor 1 of this embodiment, as seen from the first direction DR1 side. Fig. 17 shows an electrode arrangement pattern different from that shown in Fig. 16. The difference from the arrangement pattern shown in Fig. 16 is that the position of one end of the fixed electrode 14 in the detection unit Z1 in the third direction DR3 is flush with the position of one end of the movable electrode 64 in the detection unit Z2 in the third direction DR3. Furthermore, the position of one end of the movable electrode 24 in the detection unit Z1 in the fourth direction DR4 is also flush with the position of one end of the fixed electrode 54 in the detection unit Z2 in the fourth direction DR4.

[0061] That is, in the physical quantity sensor 1 of this embodiment, when viewed from the side in a stationary state, the position of the other end of the first movable electrodes 21, 22 on the fourth direction DR4 side may coincide with the position of one end of the second fixed electrodes 51, 52 on the fourth direction DR4 side, and the position of one end of the first fixed electrodes 11, 12 on the third direction DR3 side may coincide with the position of the other end of the second movable electrodes 61, 62 on the third direction DR3 side.

[0062] In the layout pattern shown in Fig. 16, the number of contour lines indicated by dashed lines is six, but in the layout pattern shown in Fig. 17, the number of contour lines is reduced to four. Therefore, by doing so, it becomes possible to manufacture a physical quantity sensor 1 that can detect acceleration with higher accuracy at lower cost because the number of contour lines is reduced.

[0063] As described above, several variations in the arrangement patterns of the fixed electrodes 14, 54 and the movable electrodes 24, 64 are possible. FIG. 18 illustrates possible arrangement patterns of the fixed electrodes 14, 54 and the movable electrodes 24, 64. The upper row of FIG. 18 shows, from left to right, arrangement patterns when the number of contour lines is 8, 7, and 6, while the lower row of FIG. 18 shows arrangement patterns when the number of contour lines is 5 and 4. The arrangement pattern shown in FIG. 17 is the same as the example shown on the right side of the lower row of FIG. 18. In any of the arrangement patterns shown in FIG. 18, the offset of the electrode ends can be kept within a predetermined range, allowing changes in capacitance to be detected while avoiding areas where sudden fluctuations in fringe capacitance occur. However, as mentioned above, the number of contour lines directly increases manufacturing costs and the difficulty of the manufacturing process. Therefore, it is desirable to adopt an electrode arrangement pattern that minimizes the number of contour lines. In this regard, if an arrangement pattern in which the number of contour lines is the smallest, 4, as shown in FIG. 17 is adopted, it is possible to manufacture a physical quantity sensor 1 capable of detecting acceleration with the highest accuracy at the lowest cost.

[0064] 2. Detailed configuration example Next, detailed configuration examples of the physical quantity sensor 1 of this embodiment will be described. FIGS. 19 to 21 show an example in which the configuration example of FIG. 1 is modified to have a double-sided seesaw structure. FIG. 19 shows a first detailed example of this embodiment. Compared to the configuration example shown in FIG. 1, the first detailed example has first movable electrode portions 20A and 20B and second movable electrode portions 60A and 60B provided on both sides of the first support beam 42. Therefore, the first connecting portion 30 is also divided into first connecting portions 30A and 30B extending to the left and right from the first support beam 42. Furthermore, as shown in FIG. 19, the movable body including the first movable electrode portions 20A and 20B and the second movable electrode portions 60A and 60B of the first detailed example has an asymmetric shape with respect to the Y-axis including the first support beam 42. Specifically, the thicknesses of the connecting portions 30B provided between the first fixed electrode portion 10B and the second fixed electrode portion 50B and the first support beam 42 are different. This shape is used to avoid a situation where, if the shape of the movable body is made symmetrical with respect to the rotation axis including the support beam 42, torque is balanced with respect to acceleration in the Z direction, preventing seesaw motion. This also applies to the configuration examples shown in Figs. 20 and 21 described below. Note that the shape of the movable body that is asymmetric with respect to the rotation axis including the support beam 42 is not limited to the shape shown in Fig. 19. According to the first detailed example, electrodes for detecting capacitance can be provided on both sides of the rotation axis, thereby enabling high sensitivity in acceleration detection.

[0065] In addition, in the first detailed example, the first fixed portion 40, which corresponds to the anchor portion of the one-sided seesaw in the configuration example of FIG. 1, is fixed by two anchors, the first fixed portions 40A and 40B. Here, the movable body including the first movable electrode portions 20A and 20B and the second movable electrode portions 60A and 60B is fixed to the substrate 2 by the two fixed portions, the first fixed portions 40A and 40B, thereby increasing rigidity against swinging motion in the XY plane. Therefore, when an impact is applied in the XY plane, the rotation axis including the first support beam 42 is less likely to be displaced, improving impact resistance. This improves the detection accuracy of the physical quantity sensor 1 when detecting acceleration in the third direction DR3.

[0066] FIG. 20 is a modified example of the first detailed example. The difference from the first detailed example is the arrangement pattern of the detection units Z1 and Z2. In the modified example shown in FIG. 20, the detection unit Z1 is provided on the first movable electrode unit 20, and the detection unit Z2 is provided on the first movable electrode unit 60. That is, the detection unit Z1 is provided on one side of the double seesaw, and the detection unit Z2 is provided on the other side. With this configuration, as described in FIG. 14, it is possible to eliminate the mass imbalance caused by arranging the detection units Z1 and Z2 with different electrode thickness patterns along the second direction DR2, and it becomes possible to detect acceleration with high accuracy.

[0067] FIG. 21 shows another modification of the first detailed example. Similar to the modification, this example changes the arrangement pattern of the detectors Z1 and Z2. Specifically, the detectors are arranged in the order of detector Z1, detector Z2, detector Z2, and detector Z1 along the first direction DR1 in the XY plane. Because detectors Z1 and Z2 are not arranged side by side along the second direction DR2, mass imbalance can be avoided. Furthermore, the detectors are arranged symmetrically with respect to the first support beam 42 along the first direction DR1, eliminating mass imbalance across the entire double seesaw, enabling more accurate acceleration detection. Note that if the movable electrodes 24 extend on both sides of the first base movable electrodes 23A and 23B and the movable electrodes 64 extend on both sides of the second base movable electrodes 63A and 63B, the detectors Z1 and Z2 must be arranged so that the thickness of the electrodes varies between the first direction DR1 and the opposite side to suppress other-axis sensitivity.

[0068] 22 to 24 show a configuration example in which the one-sided seesaw structure of the configuration example shown in FIG. 1 is replaced with two elements. FIG. 22 shows a second detailed example of this embodiment. The second detailed example differs from the configuration example shown in FIG. 1 in that the first detection element 100 has a first element portion 91 and a second element portion 92. In the configuration example of FIG. 1, the first fixed portion 40 serves as an anchor, and the movable body having the first connecting portion 30 and the first movable electrode portion 20 performs one-sided seesaw motion, thereby changing the opposing area between the fixed electrodes 14, 54 and the movable electrodes 24, 64. In contrast, in the second detailed example, two such one-sided seesaw elements are provided, and each element is capable of detecting acceleration in the third direction DR3.

[0069] 1, the detection unit Z1 and the detection unit Z2 are arranged side by side in a single seesaw structure along the second direction DR2, which is the axis of rotation, whereas in the second detailed example, one detection unit Z1 is provided in the first element unit 91 and one detection unit Z2 is provided in the second element unit 92. Furthermore, while in the configuration example shown in FIG. 1, one side of the seesaw is fixed by one anchor in the first fixing unit 40, in the second detailed example, it is fixed by two anchors in the first fixing units 40A and 40B. The second element unit 92 has a configuration similar to that of the first element unit 91 and is arranged side by side along the first direction DR1 so as to be symmetrical with respect to the Y axis.

[0070] FIG. 23 shows a modified example in which the arrangement pattern of the detectors Z1 and Z2 is changed from that of the second detailed example. Specifically, in the first element portion 91, the detectors Z1 and Z2 are arranged next to each other along the second direction DR2, with the detector Z2 followed by the detector Z1. Similarly, in the second element portion 92, the detectors Z1 and Z2 are arranged next to each other along the second direction DR2, with the detector Z2 followed by the detector Z1. This type of configuration with two single-sided seesaw structures is more sensitive to acceleration detection than the double-sided seesaw structures shown in FIGS. 19 to 21. Furthermore, with the same spring structure, this configuration allows for greater displacement and improves acceleration detection sensitivity.

[0071] 24 is a modified example of the second detailed example of this embodiment. The difference from the second detailed example is that in each of the first element portion 91 and the second element portion 92, the detection units Z1 and Z2 are arranged side by side along the first direction DR1.

[0072] That is, the physical quantity sensor 1 of this embodiment may include first fixed portions 40A, 40B, a first support beam 42 having one end connected to the first fixed portions 40A, 40B, a first connecting portion 30 connecting the other end of the first support beam 42 to the first movable electrode portion 20, second fixed portions 80A, 80B, a second support beam 82 having one end connected to the second fixed portions 80A, 80B, and a second connecting portion 70 connecting the other end of the second support beam 82 to the second movable electrode portion 60.

[0073] In this way, acceleration can be detected with two elements, which makes it possible to achieve higher sensitivity in acceleration detection compared to the configuration example shown in Figure 1. Also, since the detection units Z1 and Z2 are provided along the second direction DR2, the imbalance in mass in the second direction DR2 can be eliminated, making it possible to detect acceleration with high accuracy. Also, compared to the examples of the double-sided seesaw structure shown in Figures 19 to 21, it is possible to achieve higher sensitivity in acceleration detection for the same size. Also, for the same acceleration detection sensitivity, it is possible to increase the spring rigidity and improve impact resistance.

[0074] FIG. 25 shows a third detailed example of this embodiment. Similar to the configuration examples shown in FIGS. 22 to 24, the third detailed example has a configuration in which a first element portion 91 and a second element portion 92, each having a one-sided seesaw structure, are arranged side by side along the first direction DR1. The configuration examples shown in FIGS. 22 to 24 differ from those shown in FIGS. 22 to 24 in the shapes of the first element portion 91 and the second element portion 92. Specifically, the first element portion 91 and the second element portion 92 of the third detailed example each have the same shape as the first detection element 100 of the configuration example shown in FIG. 15. The second fixing portion 80, the second support beam 82, and the fourth portion 71 of the second element portion 92 are arranged in the space surrounded by the first portion 31, the second portion 32, and the third portion 33 of the first connecting portion 30 of the first element portion 91. The first fixed portion 40, first support beam 42, and first portion 31 of the first element portion 91 are arranged in the space surrounded by the fourth portion 71, fifth portion 72, and sixth portion 73 of the second connecting portion 70 in the second element portion 92. That is, the first element portion 91 and the second element portion 92 are arranged side by side along the first direction DR1, with the anchor portions of the other element portion being arranged in the space created in part of each connecting portion.

[0075] That is, in the physical quantity sensor 1 of this embodiment, when viewed in a plane in the third direction DR3, the first movable electrode portion 20, the second fixed portion 80, the first fixed portion 40, and the second movable electrode portion 60 may be arranged side by side along the first direction DR1 in the order of the first movable electrode portion 20, the second fixed portion 80, the first fixed portion 40, and the second movable electrode portion 60.

[0076] According to the third detailed example, the second fixed portion 80 can be arranged using the space between the first fixed portion 40 and the first movable electrode portion 20, and the first fixed portion 40 can be arranged using the space between the second fixed portion 80 and the second movable electrode portion 60. This allows the first movable electrode portion 20, the second fixed portion 80, the first fixed portion 40, and the second movable electrode portion 60 to be arranged compactly side by side along the first direction DR1. This allows the physical quantity sensor 1 to be miniaturized, and also allows the first fixed portion 40 and the second fixed portion 80 to be arranged close to each other, minimizing deterioration in the accuracy of acceleration detection due to the influence of warping of the substrate 2 of the physical quantity sensor 1, etc. This makes it possible to achieve both miniaturization and high accuracy in the physical quantity sensor 1.

[0077] FIG. 26 shows a fourth detailed example of the physical quantity sensor 1 of this embodiment. Unlike the examples employing torsional motion due to a seesaw structure described in the previous configuration examples, the fourth detailed example employs an element structure that displaces purely in the out-of-plane direction as a method for detecting acceleration in the third direction DR3. The configuration example shown in FIG. 26 includes a fixed electrode 14, a movable electrode 24, first support beams 43A, 43B, 43C, and 43D, and first fixed portions 40A, 40B, 40C, and 40D. In this embodiment, the movable electrode 24 is disposed to face the fixed electrode 14 in the second direction DR2. The movable electrode 24 is fixed to the substrate 2 by the first fixed portions 40A, 40B, 40C, and 40D via the first support beams 43A, 43B, 43C, and 43D, respectively, in the +X direction, the -X direction, the +Y direction, and the -Y direction. The first support beams 43A, 43B, 43C, and 43D each function as a spring that pulls back the movable electrode 24 when the movable electrode 24 moves along the third direction DR3.

[0078] Even in this case, the offset ΔT between the end portions of the fixed electrode 14 and the movable electrode 24 in the third direction a1 4 μm ≦ ΔT a1 ≦TCA / 2, and ΔT a2 4 μm ≦ ΔT a2 By setting the range to TCA / 2 or less, it is possible to achieve both high accuracy in acceleration detection and maximization of the range in which acceleration can be detected.

[0079] 3. Inertial Measurement Unit Next, an example of the inertial measurement unit 2000 of this embodiment will be described with reference to Fig. 27 and Fig. 28. The inertial measurement unit 2000 (IMU) shown in Fig. 27 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 acceleration sensors that detect accelerations ax, ay, and az in directions along three axes, and angular velocity sensors that detect angular velocities ωx, ωy, and ωz about the three axes.

[0080] The inertial measurement unit 2000 has a rectangular parallelepiped shape with a substantially square planar shape. Screw holes 2110 serving as mounts are formed near two diagonal vertices of the square. Two screws can be inserted into these two screw holes 2110 to secure the inertial measurement unit 2000 to the mounting surface of a mounting body such as an automobile. By selecting appropriate 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 in a smartphone or digital camera, for example.

[0081] Inertial measurement unit 2000 has outer case 2100, joining member 2200, and sensor module 2300, and is configured such that sensor module 2300 is inserted into outer case 2100 with joining member 2200 interposed therebetween. Sensor module 2300 has inner case 2310 and circuit board 2320. Inner case 2310 is formed with recess 2311 for preventing contact with circuit board 2320 and opening 2312 for exposing connector 2330, which will be described later. Circuit board 2320 is bonded to the bottom surface of inner case 2310 via adhesive.

[0082] 28, a connector 2330, an angular velocity sensor 2340z that detects angular velocity around the Z axis, and an acceleration sensor unit 2350 that detects acceleration in the directions of the X, Y, and Z axes are mounted on the top surface of circuit board 2320. Furthermore, an angular velocity sensor 2340x that detects angular velocity around the X axis and an angular velocity sensor 2340y that detects angular velocity around the Y axis are mounted on the side surface of circuit board 2320.

[0083] The acceleration sensor unit 2350 includes at least the physical quantity sensor 1 for measuring acceleration in the Z-axis direction described above, and can detect acceleration in one axis direction, or in two or three axes directions as necessary. Note that the angular velocity sensors 2340x, 2340y, and 2340z are not particularly limited, but for example, vibration gyro sensors that utilize the Coriolis force can be used.

[0084] A control IC 2360 is mounted on the underside of the circuit board 2320. The control IC 2360, which serves as a control unit that performs control based on the detection signal output from the physical quantity sensor 1, is, for example, an MCU (Micro Controller Unit), and has a built-in storage unit including a nonvolatile memory, an A / D converter, and the like, and controls each unit of the inertial measurement unit 2000. Note that a plurality of other electronic components are also mounted on the circuit board 2320.

[0085] 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. This inertial measurement unit 2000 uses the acceleration sensor unit 2350 that includes the physical quantity sensor 1, and therefore 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.

[0086] It should be noted that inertial measurement unit 2000 is not limited to the configurations shown in Figures 27 and 28. For example, inertial measurement unit 2000 may be configured to include only physical quantity sensor 1 as an inertial sensor, without including angular velocity sensors 2340x, 2340y, and 2340z. In this case, inertial measurement unit 2000 may be realized by housing physical quantity sensor 1 and control IC 2360 that realizes a control unit in a package that is a housing container.

[0087] 4. Manufacturing method Finally, a manufacturing method of this embodiment will be described. FIGS. 29 to 37 show a first example of the manufacturing method of this embodiment. First, as shown in FIG. 29, recesses are formed in a support substrate 200 by etching. Then, as shown in FIG. 30, the recesses are filled with a sacrificial layer 202, and the surface is planarized. Next, as shown in FIG. 30, protrusions are formed on the surface of the sacrificial layer 202 formed in FIG. 30 by etching. Then, as shown in FIG. 32, a structural layer 204 is provided on the surface, and the surface is planarized. Next, as shown in FIG. 33, a hard mask 206 is provided on the surface of the structural layer 204 planarized in FIG. 32, and electrodes are patterned so as not to reduce the thickness from the surface of the structural layer 204. Then, as shown in FIG. 34, a resist mask 208 is provided, and electrodes are patterned so as to reduce the thickness from the surface of the structural layer 204. Next, as shown in FIG. 35, the structural layer 204 is processed by etching to form a structure. Then, as shown in FIG. 36, the resist mask 208 is removed, and the structural layer 204 is processed by etching. 37, the hard mask 206 and the sacrificial layer 202 are removed by wet etching or the like. In this way, the physical quantity sensor 1 of this embodiment can be manufactured.

[0088] 38 to 42 show a second example of the manufacturing method of this embodiment. The manufacturing steps shown in FIGS. 29 to 33 are the same as those of the first example. In the second example, a structural layer 204 is provided and planarized as shown in FIG. 33 . Then, a hard mask 206 is provided on the surface of the structural layer 204 as shown in FIG. 38 . The hard mask 206 is then etched to reduce the thickness of the structural layer 204 in areas where electrodes are to be reduced in thickness. Next, as shown in FIG. 39 , a resist mask 208 is used to pattern the structural shape, and the hard mask 206 is then etched. Then, as shown in FIG. 40 , the resist mask 208 is removed, and the structural layer 204 is etched using the hard mask 206 as a mask. Since the hard mask 206 is also etched, etching of the structural layer 204 begins at a later time in areas where the structural layer 204 is thinner. Then, as shown in FIG. 41 , etching of the structural layer 204 continues, forming the fixed electrode 14 and the movable electrode 24. Finally, as shown in FIG. 42, the hard mask 206 and the sacrificial layer 202 are removed by wet etching or the like. In this way, the physical quantity sensor 1 of this embodiment can also be manufactured. Note that, for example, RIE etching or the like can be used for the etching process described above. Furthermore, a polishing process such as CMP can be used for the planarization process.

[0089] As described above, when three mutually orthogonal directions are defined as the first direction DR1, the second direction DR2, and the third direction DR3, the manufacturing method of this embodiment is a manufacturing method of the physical quantity sensor 1 that detects a physical quantity in the third direction DR3, and includes a fixed electrode forming step of forming the first fixed electrode portion 10 on the substrate 2, and a movable electrode forming step of forming the first movable electrode portion 20. Furthermore, the first fixed electrode portion 10 includes first fixed electrodes 11 and 12, and the first movable electrode portion 20 includes first movable electrodes 21 and 22 that face the first fixed electrodes 11 and 12 of the first fixed electrode portion 10 in the second direction DR2. When the smaller of the thicknesses of the first fixed electrodes 11, 12 in the third direction DR3 and the first movable electrodes 21, 22 in the third direction DR3 is defined as TCA, in the movable electrode formation step, one end of the first movable electrodes 21, 22 on the third direction DR3 side is positioned 4 μm or more and TCA / 2 or less toward the third direction DR3 than one end of the first fixed electrodes 11, 12 on the third direction DR3 side. When the direction opposite to the third direction DR3 is defined as a fourth direction DR4, the first movable electrode unit 20 can be formed so that the other end of the first movable electrodes 21, 22 on the fourth direction DR4 side is positioned closer to the third direction DR3 than the other end of the first fixed electrodes 11, 12 on the fourth direction DR4 side.

[0090] As described with reference to FIGS. 16 to 18 , achieving a double-offset structure in which one end of the fixed electrode 14 and one end of the movable electrode 24 are not flush with each other in the +Z direction and the −Z direction requires many manufacturing steps, making the manufacturing process more difficult. This also increases manufacturing costs. It is important to realize such a shape at low cost and through a simple manufacturing process. In this regard, according to this embodiment, the sacrificial layer 202 is formed in advance on the fourth direction DR4 side of the structural layer 204. After processing the portions corresponding to the fixed electrode 14 and the movable electrode 24, the sacrificial layer 202 can be isotropically peeled off by wet etching. Therefore, it is possible to form the fixed electrode 14 and the movable electrode 24 into a double-offset shape while reducing the number of manufacturing steps and the process difficulty.

[0091] Although the first and second embodiments described above are examples of manufacturing methods using a thin-film process, an SOI (Silicon On Insulator) process may also be used. For example, a wafer bonding technique may be used. Compared to the thin-film processes shown in the first and second embodiments, the SOI process can suppress parasitic capacitance between the substrate 2 and the fixed electrode 14, the movable electrode 24, etc., thereby enabling higher accuracy in acceleration detection.

[0092] As described above, in the physical quantity sensor of this embodiment, when three mutually orthogonal directions are defined as a first direction, a second direction, and a third direction, the physical quantity sensor detecting a physical quantity in the third direction includes a first fixed electrode portion and a first movable electrode portion provided on a substrate. The first fixed electrode portion includes a first fixed electrode, and the first movable electrode portion includes a first movable electrode facing the first fixed electrode of the first fixed electrode portion in the second direction. When the smaller of the thickness of the first fixed electrode in the third direction and the thickness of the first movable electrode in the third direction is defined as TCA, one end of the first movable electrode on the third direction side is located 4 μm or more and TCA / 2 or less away from one end of the first fixed electrode on the third direction DR3 side in a stationary state, as viewed from the side in the second direction. When the direction opposite the third direction is defined as a fourth direction, the other end of the first movable electrode on the fourth direction side is related to a physical quantity sensor located closer to the third direction than the other end of the first fixed electrode on the fourth direction side.

[0093] According to this embodiment, by ensuring an offset of 4 μm or more and making it half or less of TCA, it is possible to achieve both high accuracy in detecting physical quantities and maximizing the detectable range.

[0094] In addition, in this embodiment, the other end of the first movable electrode on the fourth direction side may be located more than 4 μm and less than a thickness TCA / 2 on the third direction side than the other end of the first fixed electrode on the fourth direction side.

[0095] This ensures that the offsets in the third and fourth directions are each 4 μm or more, which makes it possible to avoid sudden changes in fringe capacitance even in the fourth direction, where changes in fringe capacitance are more pronounced, and enables highly accurate detection of physical quantities.

[0096] The physical quantity sensor of this embodiment also includes a second fixed electrode unit and a second movable electrode unit provided on substrate 2. The second fixed electrode unit includes a second fixed electrode, and the second movable electrode unit includes a second movable electrode facing the second fixed electrode of the second fixed electrode unit in the second direction. When the smaller of the thickness of the second fixed electrode in the third direction and the thickness of the second movable electrode in the third direction is TCB, one end of the second movable electrode on the fourth direction side is located 4 μm or more and TCB / 2 or less away from one end of the second fixed electrode on the fourth direction side in a side view in a stationary state. The other end of the second movable electrode on the third direction side may be located closer to the fourth direction side than the other end of the second fixed electrode on the third direction side.

[0097] This makes it possible to avoid regions where sudden fluctuations in fringe capacitance occur in any of the detection portions of the first detection element, thereby enabling more accurate detection of physical quantities and maximizing the detectable range of physical quantities.

[0098] In addition, in this embodiment, the other end of the second movable electrode on the third direction side may be positioned more than 4 μm and not more than TCB / 2 toward the fourth direction side from the other end of the second fixed electrode on the third direction side.

[0099] In this way, in any of the detection portions of the first detection element, changes in capacitance can be detected while avoiding the areas where sudden changes in fringe capacitance occur on the third and fourth direction sides, making it possible to detect physical quantities with higher accuracy.

[0100] In addition, in this embodiment, when viewed from the side in a stationary state, the position of one end of the first movable electrode on the third direction side may coincide with the position of the other end of the second fixed electrode on the third direction side, and the position of the other end of the first fixed electrode on the fourth direction side may coincide with the position of one end of the second movable electrode on the fourth direction side.

[0101] This reduces the number of manufacturing steps, making it possible to manufacture a highly accurate physical quantity sensor at low cost.

[0102] In addition, in this embodiment, when viewed from the side in a stationary state, the position of the other end of the first movable electrode on the fourth direction side may coincide with the position of one end of the second fixed electrode on the fourth direction side, and the position of one end of the first fixed electrode on the third direction side may coincide with the position of the other end of the second movable electrode on the third direction side.

[0103] In this way, the number of manufacturing steps can be further reduced, and a highly accurate physical quantity sensor can be manufactured at low cost.

[0104] In addition, this embodiment may include a first fixed portion, a first support beam having one end connected to the first fixed portion, a first connecting portion connecting the other end of the first support beam to the first movable electrode portion, a second fixed portion, a second support beam having one end connected to the second fixed portion, and a second connecting portion connecting the other end of the second support beam to the second movable electrode portion.

[0105] This allows acceleration to be detected with two elements, making it possible to achieve high sensitivity in acceleration detection. In addition, it eliminates the imbalance in mass in the second direction, enabling highly accurate acceleration detection.

[0106] In addition, in this embodiment, when viewed in a plane in the third direction, the first movable electrode portion, the second fixed portion, the first fixed portion, and the second movable electrode portion may be arranged in a line along the first direction in the order of the first movable electrode portion, the second fixed portion, the first fixed portion, and the second movable electrode portion.

[0107] This allows the physical quantity sensor to be miniaturized. Also, since the first fixed portion and the second fixed portion can be arranged close to each other, it is possible to minimize deterioration in the accuracy of physical quantity detection due to the influence of warping of the substrate, etc. Therefore, it is possible to achieve both miniaturization and high accuracy in the physical quantity sensor.

[0108] This embodiment also relates to an inertial measurement unit including a control unit that performs control based on detection signals output from the physical quantity sensors.

[0109] Furthermore, a manufacturing method of this embodiment is a manufacturing method of 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 electrode forming step of forming a first fixed electrode portion on a substrate and a movable electrode forming step of forming a first movable electrode portion. The first fixed electrode portion includes a first fixed electrode, and the first movable electrode portion includes a first movable electrode that faces the first fixed electrode of the first fixed electrode portion in the second direction. When the smaller of the thickness of the first fixed electrode in the third direction and the thickness of the first movable electrode in the third direction is defined as TCA, in the movable electrode forming step, one end of the first movable electrode on the third direction side is positioned 4 μm or more and TCA / 2 or less toward the third direction than one end of the first fixed electrode on the third direction side, as viewed from the side in the second direction. The present invention relates to a manufacturing method for forming a first movable electrode portion such that, when the direction opposite to the third direction is the fourth direction, the other end of the first movable electrode on the fourth direction side is positioned closer to the third direction than the other end of the first fixed electrode on the fourth direction side.

[0110] According to this embodiment, a sacrificial layer is formed in advance on the fourth direction side of the structural layer, and after processing of the portions corresponding to the fixed electrode and the movable electrode is completed, the sacrificial layer can be isotropically peeled off by wet etching. Therefore, it is possible to form the fixed electrode and the movable electrode in a shape that is offset from each other on both sides while reducing the number of manufacturing steps and the degree of difficulty of the process.

[0111] Although the present embodiment has been described in detail above, it will be readily apparent to those skilled in the art that many modifications are possible without substantially departing from the novel features and advantages of the present disclosure. Therefore, all such modifications are intended to be included within 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 or equivalent meaning may be replaced with that different term anywhere in the specification or drawings. Furthermore, all combinations of the present embodiment and modifications are also included within the scope of the present disclosure. Furthermore, the configurations and operations of the physical quantity sensor, inertial measurement unit, and manufacturing method are not limited to those described in the present embodiment, and various modifications are possible. [Explanation of symbols]

[0112] 1...physical quantity sensor, 2...substrate, 3...fixed portion, 4...fixed portion, 10...first fixed electrode portion, 11...first fixed electrode, 12...first fixed electrode, 14...movable electrode, 14...fixed electrode, 20...first movable electrode portion, 20A...first movable electrode portion, 20B...first movable electrode portion, 21...first movable electrode, 22...first movable electrode, 23...first base movable electrode, 23A...first base movable electrode, 23B...first base movable electrode, 24...movable electrode, 30...first connecting portion, 30A...first connecting portion, 30B...first connecting portion, 31...first 1 part, 32...2nd part, 33...3rd part, 40...1st fixed part, 40A...1st fixed part, 40B...1st fixed part, 42...1st support beam, 43A...1st support beam, 43B...1st support beam, 43C...1st support beam, 43D...1st support beam, 50...2nd fixed part Constant electrode part, 51... second fixed electrode, 52... second fixed electrode, 54... fixed electrode, 60... second movable electrode part, 61... second movable electrode, 62... second movable electrode, 64... movable electrode, 70... second connecting part, 71... fourth part, 72... fifth part, 73... sixth part, 80...second fixing portion, 80A...second fixing portion, 80B...second fixing portion, 82...second support beam, 91...first element portion, 92...second element portion, 100...first detection element, 102...second detection element, 200...support substrate, 202...sacrificial layer, 204...structural layer, 206...hard mask, 208...resist mask, 2000...inertial measurement unit, 2100...outer case, 2110...screw hole, 2200...joint member, 2300...sensor module, 2310...inner case, 2311...recess, 2 312...opening, 2320...circuit board, 2330...connector, 2340x...angular velocity sensor, 2340y...angular velocity sensor, 2340z...angular velocity sensor, 2350...acceleration sensor unit, A...state, B...state, DR1...first direction, DR2...second direction, DR3...third direction, DR4...fourth direction, IC2360...control, OL...opposing length, QV...differential amplifier circuit, S...space, T...thickness, Z1...detection unit, Z2...detection unit, ax...acceleration, ay...acceleration, az...acceleration, ΔT a1 …offset, ΔT a2 …offset, ΔT b1 …offset, ΔT b2 …offset, ωx…angular velocity

Claims

1. When three mutually orthogonal directions are defined as a first direction, a second direction, and a third direction, A physical quantity sensor for detecting a physical quantity in the third direction, a first fixed electrode portion provided on the substrate; a first movable electrode portion; A first fixed portion; a first support beam having one end connected to the first fixed portion; a first connecting portion connecting the other end of the first support beam and the first movable electrode portion; A second movable electrode portion; A second fixed portion; a second support beam having one end connected to the second fixed portion; a second connecting portion connecting the other end of the second support beam and the second movable electrode portion; Including, the first fixed electrode portion includes a first fixed electrode, the first movable electrode portion includes a first movable electrode facing the first fixed electrode of the first fixed electrode portion in the second direction, When the smaller of the thickness of the first fixed electrode in the third direction and the thickness of the first movable electrode in the third direction is TCA, 8 μm≦TCA Fulfilling when viewed from a side in the second direction in a stationary state, one end of the first movable electrode in the third direction is positioned 4 μm or more and TCA / 2 or less away from one end of the first fixed electrode in the third direction, When the direction opposite to the third direction is defined as a fourth direction, the other end of the first movable electrode in the fourth direction is located closer to the third direction than the other end of the first fixed electrode in the fourth direction, In a plan view in the third direction, The first movable electrode portion, the second fixed portion, the first fixed portion, and the second movable electrode portion, A physical quantity sensor, characterized in that the first movable electrode portion, the second fixed portion, the first fixed portion, and the second movable electrode portion are arranged in this order along the first direction.

2. 2. The physical quantity sensor according to claim 1, A physical quantity sensor characterized in that the other end of the first movable electrode on the fourth direction side is located 4 μm or more and TCA / 2 or less toward the third direction side than the other end of the first fixed electrode on the fourth direction side.

3. The physical quantity sensor according to claim 1 or 2, a second fixed electrode portion provided on the substrate; Including, the second fixed electrode portion includes a second fixed electrode, the second movable electrode portion includes a second movable electrode facing the second fixed electrode of the second fixed electrode portion in the second direction, When the smaller of the thickness of the second fixed electrode in the third direction and the thickness of the second movable electrode in the third direction is defined as TCB, When viewed from the side in the stationary state, one end of the second movable electrode in the fourth direction is positioned on the fourth direction side by 4 μm or more and TCB / 2 or less than one end of the second fixed electrode in the fourth direction, A physical quantity sensor, characterized in that the other end of the second movable electrode on the third direction side is located on the fourth direction side of the other end of the second fixed electrode on the third direction side.

4. The physical quantity sensor according to claim 3 , a second movable electrode disposed on the third direction side and positioned on the fourth direction side by 4 μm or more and TCB / 2 or less than the second fixed electrode disposed on the third direction side.

5. The physical quantity sensor according to claim 3 or 4, When viewed from the side in the stationary state, a position of the one end of the first movable electrode on the third direction side coincides with a position of the other end of the second fixed electrode on the third direction side, A physical quantity sensor, characterized in that the position of the other end of the first fixed electrode on the fourth direction side coincides with the position of the one end of the second movable electrode on the fourth direction side.

6. The physical quantity sensor according to claim 5 , a position of the other end of the first movable electrode on the fourth direction side coincides with a position of the one end of the second fixed electrode on the fourth direction side in the side view in the stationary state, A physical quantity sensor, characterized in that the position of one end of the first fixed electrode on the third direction side coincides with the position of the other end of the second movable electrode on the third direction side.

7. 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 unit comprising:

8. When three mutually orthogonal directions are defined as a first direction, a second direction, and a third direction, a first fixed electrode portion provided on the substrate; a first movable electrode portion; A first fixed portion; a first support beam having one end connected to the first fixed portion; a first connecting portion connecting the other end of the first support beam and the first movable electrode portion; A second movable electrode portion; A second fixed portion; a second support beam having one end connected to the second fixed portion; a second connecting portion connecting the other end of the second support beam and the second movable electrode portion; A method for manufacturing a physical quantity sensor for detecting a physical quantity in the third direction, comprising: a fixed electrode forming step of forming the first fixed electrode portion on the substrate; a movable electrode forming step of forming the first movable electrode portion; Including, the first fixed electrode portion includes a first fixed electrode, the first movable electrode portion includes a first movable electrode facing the first fixed electrode of the first fixed electrode portion in the second direction, When the smaller of the thickness of the first fixed electrode in the third direction and the thickness of the first movable electrode in the third direction is TCA, 8 μm≦TCA Fulfilling When the direction opposite to the third direction is defined as a fourth direction, the other end of the first movable electrode in the fourth direction is located closer to the third direction than the other end of the first fixed electrode in the fourth direction, In a plan view in the third direction, In the movable electrode forming step, when viewed from a side in the second direction, one end of the first movable electrode in the third direction is positioned in the third direction by 4 μm or more and TCA / 2 or less than one end of the first fixed electrode in the third direction, When the direction opposite to the third direction is defined as a fourth direction, The other end of the first movable electrode in the fourth direction is the first movable electrode portion is formed so as to be located closer to the third direction side than the other end of the first fixed electrode on the fourth direction side; The first movable electrode portion, the second fixed portion, the first fixed portion, and the second movable electrode portion, A manufacturing method characterized in that the first movable electrode portion, the second fixed portion, the first fixed portion, and the second movable electrode portion are arranged in this order along the first direction.

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