Physical quantity sensor, inertial measurement device, electronic device, and manufacturing method for physical quantity sensor

Abstract

To provide a physical quantity sensor with excellent shock resistance.SOLUTION: A physical quantity sensor 100 includes a support substrate 1 having anchors 11, 12, a lid body 2, and an element substrate 3. The element substrate 3 has a movable body 4 and a fixed body 8. The movable body 4 includes a second torsion spring 59 connected to the anchor 11 and a rotor 40 connected to the second torsion spring 59 and having a comb-shaped electrode 45. The fixed body 8 includes a second stator bar 82 connected to the anchor 12 and having a comb-shaped electrode 85. The rotor 40 has a second longitudinal rotor bar 43 extending in the Y-axis direction and a transverse rotor bar 41 extending in the X-axis direction. The second longitudinal rotor bar 43 includes a recess 62.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] 2. Description of the Related Art As a physical quantity sensor using MEMS (Micro Electro Mechanical Systems) technology, for example, the one described in Patent Document 1 is known. Patent document 1 discloses a capacitive micromechanical accelerometer comprising a substrate defining a substrate plane extending laterally and vertically, a first sensor for measuring acceleration in a vertical axis direction perpendicular to the substrate plane, and an accelerometer package having an internal package plane adjacent to the substrate plane above and / or below the substrate plane and parallel to the substrate plane. In the document, a first sensor includes a rotor movable relative to a substrate, a rotor hanger, one or more stators stationary relative to the substrate, a rotor including transverse rotor bars, first and second longitudinal rotor bars attached to the transverse rotor bars, and one or more rotor electrodes for differential capacitance measurements. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-23613 A Summary of the Invention [Problem to be solved by the invention]

[0004] In such a physical quantity sensor, the horizontal rotor bar, the first vertical rotor bar, and the second vertical rotor bar are configured to be elongated, and therefore impact resistance against a strong impact has been an issue. [Means for solving the problem]

[0005] A physical quantity sensor according to one aspect of the present application comprises a support substrate having a first fixed portion and a second fixed portion, a lid body facing the support substrate, and an element substrate provided between the support substrate and the lid body, the element substrate having a fixed body joined to the support substrate, and a movable body joined to the support substrate and displaceable relative to the fixed body, the movable body including a support spring connected to the first fixed portion, and a rotor connected to the support spring and having a first comb-tooth electrode, the fixed body including a support portion joined to the second fixed portion and having a second comb-tooth electrode facing the first comb-tooth electrode, the rotor having a first connecting portion extending in a first direction and a second connecting portion extending in a second direction intersecting the first direction, the first connecting portion comprising a first recess.

[0006] An inertial measurement unit according to one aspect of the present application includes the above-described physical quantity sensor.

[0007] An electronic device according to one aspect of the present application includes the inertial measurement unit described above.

[0008] A manufacturing method for a physical quantity sensor according to one embodiment of the present application includes the steps of forming, on an element substrate, a movable body having a rotor connected to the support spring and including a first comb-tooth electrode consisting of a plurality of electrode fingers, and a fixed body facing the first comb-tooth electrode and having a second comb-tooth electrode consisting of a plurality of electrode fingers, and forming recesses in the rotor, some of the electrode fingers of the first comb-tooth electrode, and some of the electrode fingers of the second comb-tooth electrode. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a plan view of a physical quantity sensor according to a first embodiment. [Diagram 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Diagram 3] FIG. 2 is a cross-sectional view taken along line III-III in FIG. [Figure 4]FIG. 2 is a perspective view of region IV in FIG. [Figure 5A] FIG. 2 is a plan view of region V in FIG. 1 . [Figure 5B] FIG. 2 is a perspective view of region V in FIG. [Figure 6A] FIG. 11 is a plan view of a physical quantity sensor according to a modified example. [Figure 6B] FIG. 13 is a perspective view of a physical quantity sensor according to a modified example. [Figure 7] 4 is a flowchart showing a method for manufacturing an element substrate. [Figure 8] 1A to 1C are cross-sectional views showing one embodiment of a manufacturing process. [Figure 9] 1A to 1C are cross-sectional views showing one embodiment of a manufacturing process. [Figure 10] 1A to 1C are cross-sectional views showing one embodiment of a manufacturing process. [Figure 11] 1A to 1C are cross-sectional views showing one embodiment of a manufacturing process. [Figure 12] 1A to 1C are cross-sectional views showing one embodiment of a manufacturing process. [Figure 13] 1A to 1C are cross-sectional views showing one embodiment of a manufacturing process. [Figure 14] 1A to 1C are cross-sectional views showing one embodiment of a manufacturing process. [Figure 15] 1A to 1C are cross-sectional views showing one embodiment of a manufacturing process. [Figure 16] 1A to 1C are cross-sectional views showing one embodiment of a manufacturing process. [Figure 17] FIG. 11 is an exploded perspective view showing a schematic configuration of an inertial measurement unit according to a second embodiment. [Figure 18] FIG. 4 is a perspective view showing a circuit board on which a physical quantity sensor is mounted. [Figure 19] FIG. 11 is a perspective view showing an electronic device according to a third embodiment. [Figure 20] FIG. 11 is a perspective view showing an electronic device according to a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings, the dimensions of the components may be shown on different scales in order to make the components easier to see. For ease of explanation, the following illustrates three mutually orthogonal axes, the X-axis, the Y-axis, and the Z-axis, with the tip of the arrow showing the axial direction being the "plus side" and the base being the "minus side." In the following, the direction parallel to the X-axis is referred to as the "X-axis direction," the direction parallel to the Y-axis as the "Y-axis direction," and the direction parallel to the Z-axis as the "Z-axis direction." In the following, the view in the Z-axis direction is referred to as the "planar view," and the view of a cross section including the Z-axis from the X-axis direction is referred to as the "sectional view."

[0011] Furthermore, in the following description, for example, the term "on the substrate" refers to a substrate that is disposed in contact with the substrate, that is disposed on the substrate via another structure, or that is disposed partially in contact with the substrate and partially disposed via another structure. The term "upper surface" refers to the surface of the substrate on the positive side in the Z-axis direction, for example, "upper surface of the substrate" refers to the surface of the substrate on the positive side in the Z-axis direction. The term "lower surface" refers to the surface of the substrate on the negative side in the Z-axis direction, for example, "lower surface of the substrate" refers to the surface of the substrate on the negative side in the Z-axis direction.

[0012] 1. Embodiment 1 The schematic configuration of the physical quantity sensor 100 according to the first embodiment will be described with reference to FIGS. 1 to 6B. FIG. 1 is a plan view showing a physical quantity sensor 100 according to a first embodiment. FIG. 2 is a cross-sectional view taken along line II-II in FIG. 1. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 1. FIG. 4 is an enlarged perspective view of a region IV in FIG. 1. FIG. 5A is an enlarged plan view of a region V in FIG. 1. FIG. 5B is an enlarged perspective view of a region V in FIG. 1. FIG. 6A is a plan view of a modified example of FIG. 5A. FIG. 6B is a perspective view of a modified example of FIG. 5B. For ease of explanation, the cover 2 is made transparent in FIG. 1.

[0013] The physical quantity sensor 100 is a MEMS device that includes a support substrate 1, a cover 2, and an element substrate 3, and has three sensor elements 101, 102, and 103 on the element substrate 3. The physical quantity sensor can be referred to as an inertial sensor.

[0014] 1.1.Support Substrate As shown in FIGS. 1 to 3, support substrate 1 has a cavity 1c formed as a recess on its upper surface, and within cavity 1c are anchors 11 and 12 and protrusions 14a, 14b, 15a, 15b, 16a, and 16b that protrude in the positive Z-axis direction.

[0015] A movable body 4 of the element substrate 3, which will be described later, is bonded to the anchor 11, and a fixed body 8 of the element substrate 3, which will be described later, is bonded to the anchor 12. The bonding method is not particularly limited, and may be appropriately selected from adhesive bonding, anodic bonding, room temperature bonding, direct bonding, siloxane bonding, and the like. In this embodiment, the anchor 11 is an example of a first fixing portion, and the anchor 12 is an example of a second fixing portion.

[0016] The protrusions 14a, 14b, 15a, 15b, 16a, and 16b are provided at positions overlapping with a movable body 4 of the element substrate 3, which will be described later, in a plan view. More specifically, the protrusions 14a and 14b are provided at positions overlapping with either one of the recesses 61 and 62 provided in the rotor 40 of the movable body 4 in a plan view. The protrusions 15a, 15b, 16a, and 16b are provided at positions overlapping with any of the recesses 63, 64, 65, and 66 provided in the suspenders 50 of the movable body 4 in a plan view.

[0017] When the rotor 40 is displaced due to a strong impact or the like, the protrusions 14a and 14b are the first to come into contact with the rotor 40 and function as stoppers that prevent further excessive displacement. When the suspenders 50 are displaced due to a strong impact or the like, the projections 15a, 15b, 16a, and 16b are the first to come into contact with the suspenders 50 and function as stoppers that prevent further excessive displacement.

[0018] In this embodiment, the support substrate 1 is made of a silicon substrate. The silicon substrate is patterned to form the support substrate 1 having a cavity 1c and the like. The support substrate 1 may be a glass substrate, a ceramic substrate, an SOI (Silicon on Insulator) substrate, or the like.

[0019] 1.2. Lid The cover 2 has a cavity 2c formed as a recess on the lower surface, and wirings 31a, 31b, 32a, 32b, 33a, and 33b are provided in the cavity 2c. In this embodiment, the lid 2 is made of a silicon substrate. The silicon substrate is patterned to form the lid 2 having the cavity 2c. Note that, like the support substrate 1, the lid 2 may be made of a glass substrate or the like.

[0020] 2, the wiring 32b is electrically connected to an external wiring 35 provided on the upper surface of the lid 2 via a through hole 2h provided in the lid 2. In this embodiment, the through hole 2h is provided at a position overlapping with a recess 64 provided in the rotor 40 of the movable body 4, but the through hole 2h may be provided at a position not overlapping with the recess 64. Although not shown, the other wirings 31a, 31b, 32a, 33a, and 33b are configured similarly to the wiring 32b. The external wiring 35 has an electrode pad 36 .

[0021] As shown in FIG. 1, the wirings 31a, 31b, 32a, 32b, 33a, and 33b have portions provided at positions overlapping the movable body 4 in a plan view. More specifically, the wirings 31a and 31b are provided at positions overlapping the recesses 61 and 62 of the rotor 40 of the movable body 4, respectively, in a plan view. The wirings 32a, 32b, 33a, and 33b are provided at positions overlapping the recesses 63, 64, 65, and 66 of the suspenders 50 of the movable body 4, respectively, in a plan view.

[0022] By providing the wirings 31a, 31b, 32a, 32b, 33a, and 33b at positions overlapping with the recesses 61, 62, 63, 64, 65, and 66 of the movable body 4, the parasitic capacitance between each wiring and the movable body 4 can be suppressed.

[0023] 1.3. Component Substrate 2 and 3, the element substrate 3 is provided between the support substrate 1 and the lid 2. In addition, the element substrate 3 has sensor elements 101, 102, and 103, as shown in FIG.

[0024] The element substrate 3 is, for example, a silicon substrate doped with impurities such as phosphorus (P), boron (B), etc. The element substrate 3 having the sensor elements 101, 102, and 103 is formed by patterning the silicon substrate.

[0025] Sensor element 101 is an acceleration sensor that detects acceleration in the Z-axis direction. Sensor element 102 is an acceleration sensor that detects acceleration in the X-axis direction. Sensor element 103 is an acceleration sensor that detects acceleration in the Y-axis direction. Therefore, physical quantity sensor 100 is a three-axis acceleration sensor that measures acceleration in three axial directions. Note that physical quantity sensor 100 may be a one-axis acceleration sensor having only sensor element 101, or a two-axis acceleration sensor having sensor element 101 and either sensor element 102 or sensor element 103.

[0026] 2 and 3, the sensor elements 101 and 103 are provided in a storage space S consisting of a cavity 1c and a cavity 2c. The same is true for the sensor element 102. The storage space S is filled with an inert gas such as nitrogen, helium, or argon, and is preferably at approximately atmospheric pressure at the operating temperature.

[0027] 1, the sensor element 101 has a movable body 4 and a fixed body 8. The movable body 4 is provided so as to be displaceable with respect to the fixed body 8 in order to detect acceleration in the Z-axis direction. In other words, the movable body 4 is configured so that the position of the movable body 4 relative to the fixed body 8 changes in response to the applied acceleration.

[0028] 1.3.1. Movable body The movable body 4 has a rotor 40, a suspender 50, a first torsion spring 58, and a second torsion spring 59.

[0029] The rotor 40 is suspended from the suspenders 50 via a first torsion spring 58 and a second torsion spring 59. The suspenders 50 may also be referred to as a suspension part or a hanging tool. In this embodiment, the first torsion spring 58 and / or the second torsion spring 59 are an example of a support spring.

[0030] The suspenders 50 are joined to the anchors 11 of the supporting substrate 1 at the anchor points 56 and are fixed to the supporting substrate 1 . First torsion spring 58 and second torsion spring 59 are provided on the rotation shaft of rotor 40 and function as the rotation shaft of rotor 40. Therefore, the rotor 40 is rotatably suspended from the suspenders 50 via the first torsion spring 58 and the second torsion spring 59. The rotor 40 may be called a seesaw because of this type of movement.

[0031] In this embodiment, the first torsion spring 58 and the second torsion spring 59 are joined to the anchors 11 of the supporting substrate 1 via the suspenders 50, but the suspenders 50 may be omitted. In other words, the first torsion spring 58 and the second torsion spring 59 may be joined to the anchors 11 of the supporting substrate 1 at the anchor points 56 and fixed to the supporting substrate 1. In this case, torsion bars may be used as the first torsion spring 58 and the second torsion spring 59.

[0032] Rotor The rotor 40 has a first vertical rotor bar 42 and a second vertical rotor bar 43 extending in the Y-axis direction, a horizontal rotor bar 41 extending in the X-axis direction, and a comb electrode 45 provided on the horizontal rotor bar 41 for differential capacitance measurement.

[0033] In this embodiment, the comb-tooth electrode 45 is an example of a first comb-tooth electrode. The first vertical rotor bar 42 and the second vertical rotor bar 43 are an example of a first connecting portion. The horizontal rotor bar 41 is an example of a second connecting portion.

[0034] The comb-tooth electrode 45 has a plurality of electrode fingers 44 arranged in a comb-teeth shape. Some of the plurality of electrode fingers 44 are provided with recesses 44c, and the remaining electrode fingers 44 are not provided with the recesses 44c.

[0035] 4, the recesses 44c are recessed from the upper surfaces of the electrode fingers 44 to the negative side in the Z-axis direction. In the present embodiment, the recesses 44c are an example of a fourth recess. The recessed degree of the recesses 44c refers to the distance from the upper surfaces of the electrode fingers 44 to the upper surface of the recesses 44c or the height difference in the Z-axis direction.

[0036] As shown in FIG. 1, the first longitudinal rotor bar 42 has a recess 61 . The second longitudinal rotor bar 43 has a recess 62 . As shown in FIG. 5B, the recess 62 is a portion recessed from the upper surface of the second vertical rotor bar 43 toward the negative Z-axis direction.

[0037] In this embodiment, the degree of recess 62 refers to the distance from the top surface of the second vertical rotor bar 43 to the top surface of recess 62 or the difference in height in the Z-axis direction; similarly, the degree of recess 61 refers to the distance from the top surface of the first vertical rotor bar 42 to the top surface of recess 61 or the difference in height in the Z-axis direction. In addition, the statement that the recessed degree of the recess 62 is the same as that of the recess 44c means that the recessed degree of the recess 62 and the recess 44c are both the same and substantially the same. The statement "substantially the same" includes the case where they differ within the range of manufacturing tolerances. Hereinafter, the same applies to the case where the recessed degree is the same.

[0038] The recess 62 is provided so as to penetrate the X-axis direction on the upper surface side of the second vertical rotor bar 43. In other words, it does not have a portion that becomes a wall in a direction intersecting the direction in which the second vertical rotor bar 43 extends. The recess 61 is configured similarly to the recess 62, and therefore a detailed description thereof will be omitted. In this embodiment, the recess 61 and / or the recess 62 is an example of a first recess.

[0039] As shown in FIGS. 5A and 5B, the recess 62 is provided at a position overlapping with the protrusion 14b in a plan view. In the second vertical rotor bar 43, the portion where the recesses 62 are provided has improved flexibility compared to other portions. Therefore, even if the second vertical rotor bar 43 collides with the protrusions 14b due to a strong impact or the like, the portion where the recesses 62 are provided collides with the protrusions 14b, so that the second vertical rotor bar 43 is less likely to crack or break than if other portions collide.

[0040] The recess 62 is provided at a position overlapping the wiring 31b in a plan view. Therefore, the distance between the wiring 31b and the second vertical rotor bar 43 can be made larger than when the recess 62 is not provided, so that the parasitic capacitance between the wiring 31b can be suppressed, and the effect on the sensor performance such as sensitivity can be suppressed.

[0041] In this embodiment, the recess 62 is provided at a position overlapping both the protrusion 14b and the wiring 31b in a plan view, but may be provided at a position overlapping at least one of the protrusion 14b and the wiring 31b. In other words, the recess 62 does not have to overlap either the protrusion 14b or the wiring 31b in a plan view.

[0042] 1, the first vertical rotor bar 42 has braking plates 481, 482. The braking plate 481 is provided on the first vertical rotor bar 42 on the positive side of the first torsion spring 58 in the Y axis direction, and the braking plate 482 is provided on the first vertical rotor bar 42 on the negative side of the first torsion spring 58 in the Y axis direction.

[0043] The second vertical rotor bar 43 has brake plates 491, 492. The brake plate 491 is provided on the second vertical rotor bar 43 on the positive side of the second torsion spring 59 in the Y axis direction, and the brake plate 492 is provided on the second vertical rotor bar 43 on the negative side of the second torsion spring 59 in the Y axis direction. The brake plates 481 , 482 , 491 , and 492 have the function of damping the movement of the rotor 40 .

[0044] Suspenders The suspenders 50 have a first horizontal hanger bar 51 and a second horizontal hanger bar 52 extending in the X-axis direction, and a first vertical hanger bar 53 and a second vertical hanger bar 54 extending in the Y-axis direction. In this embodiment, the first horizontal hanger bar 51 and / or the second horizontal hanger bar 52 are an example of a third connection portion, and the first vertical hanger bar 53 or the second vertical hanger bar 54 are an example of a fourth connection portion.

[0045] One end of the first lateral hanger bar 51 and the second lateral hanger bar 52 are joined to the anchors 11 at the anchor points 56 and fixed to the support base 1 . The other end of the first horizontal hanger bar 51 is connected to one end of a first vertical hanger bar 53. The other end of the first vertical hanger bar 53 is connected to a first torsion spring 58. The other end of the second horizontal hanger bar 52 is connected to one end of a second vertical hanger bar 54. The other end of the second vertical hanger bar 54 is connected to a second torsion spring 59.

[0046] The first lateral suspender bar 51 has a recess 63. The recess 63 is a portion recessed toward the negative Z-axis direction from the top surface of the first lateral suspender bar 51. The recessed degree of the recess 63 refers to the distance from the top surface of the first lateral suspender bar 51 to the top surface of the recess 63 or the height difference in the Z-axis direction.

[0047] The recess 63 is provided at a position overlapping with the protrusion 15a in a plan view. In the first horizontal suspension bar 51, the portion where the recess 63 is provided has improved flexibility compared to other portions. Therefore, even if the first horizontal suspension bar 51 collides with the protrusion 15a due to a strong impact or the like, by configuring the portion in which the recess 63 is provided to collide with the protrusion 15a, the occurrence of cracks or breaks in the first horizontal suspension bar 51 can be suppressed more than if other portions collide.

[0048] Moreover, the recess 63 is provided at a position overlapping the wiring 32a in a plan view. Therefore, the distance between the wiring 32a and the first horizontal suspension bar 51 can be made larger than when the recess 63 is not provided, so that the parasitic capacitance between the wiring 32a can be suppressed, and the effect on the sensor performance such as sensitivity can be suppressed.

[0049] In this embodiment, the recess 63 is provided at a position overlapping both the protrusion 15a and the wiring 32a in a plan view, but may be provided at a position overlapping at least one of the protrusion 15a and the wiring 32a. In other words, the recess 63 does not have to overlap either the protrusion 15a or the wiring 32a in a plan view.

[0050] The second horizontal hanger bar 52 has a recess 64. The recess 64 is provided at a position overlapping the protrusion 15b in a plan view. The recess 64 is provided at a position overlapping the wiring 32b in a plan view. The recess 64 is configured similarly to the recess 63, and therefore a detailed description thereof will be omitted. In this embodiment, the recess 63 and / or the recess 64 is an example of a second recess.

[0051] The first vertical hanger bar 53 has a recess 65. The recess 65 is a portion recessed toward the negative Z-axis direction from the top surface of the first vertical hanger bar 53. The recessed degree of the recess 65 refers to the distance from the top surface of the first vertical hanger bar 53 to the top surface of the recess 65 or the height difference in the Z-axis direction.

[0052] The recess 65 is provided at a position overlapping with the protrusion 16a in a plan view. In the first vertical hanger bar 53, the portion where the recess 65 is provided has improved flexibility compared to other portions. Therefore, even if the first vertical hanger bar 53 collides with the protrusion 16a due to a strong impact or the like, the portion where the recess 65 is provided collides with the protrusion 16a, so that the first vertical hanger bar 53 is less likely to crack or break than if other portions collide.

[0053] The recess 65 is provided at a position overlapping the wiring 33a in a plan view. Therefore, the distance between the wiring 33a and the first vertical suspension bar 53 can be made larger than when the recess 65 is not provided, so that the parasitic capacitance between the wiring 33a can be suppressed, and the effect on the sensor performance such as sensitivity can be suppressed.

[0054] In this embodiment, the recess 65 is provided at a position overlapping both the protrusion 16a and the wiring 33a in a plan view, but may be provided at a position overlapping at least one of the protrusion 16a and the wiring 33a. In other words, the recess 65 does not have to overlap either the protrusion 16a or the wiring 33a in a plan view.

[0055] The second vertical hanger bar 54 has a recess 66. The recess 66 is provided at a position overlapping the protrusion 16b in a plan view. The recess 66 is provided at a position overlapping the wiring 33b in a plan view. The recess 66 is configured similarly to the recess 65, and therefore a detailed description thereof will be omitted. In this embodiment, the recess 65 and / or the recess 66 is an example of a third recess.

[0056] 1.3.2.Fixed body As shown in FIG. 1, fixed body 8 has a first stator bar 81, a second stator bar 82, and comb-tooth electrodes 85 provided on first stator bar 81 and second stator bar 82 for differential capacitance measurement. In this embodiment, the first stator bar 81 and / or the second stator bar 82 is an example of a support portion. The comb-tooth electrode 85 is an example of a second comb-tooth electrode.

[0057] The first stator bar 81 is joined to the anchor 12 of the support substrate 1 at the anchor point 86 and fixed to the support substrate 1 . The second stator bar 82 is connected to the anchor 12 of the support substrate 1 at an anchor point 87 and is fixed to the support substrate 1 .

[0058] The comb-tooth electrode 85 has a plurality of electrode fingers 84 arranged in a comb-tooth shape. Some of the electrode fingers 84 have recesses 84c, and the remaining electrode fingers 84 do not have the recesses 84c.

[0059] 4, the recess 84c is a portion recessed toward the negative Z-axis direction from the upper surface of the electrode finger 84. In the present embodiment, the recess 84c is an example of a fifth recess. As will be described in detail later in the section on the manufacturing method, the recess 84c is recessed to the same extent as the recess 44c. In other words, in this embodiment, the recesses 44c, 84c, 61, 62, 63, 64, 65, and 66 are all recessed to the same extent.

[0060] The comb-tooth electrode 85 and the comb-tooth electrode 45 are provided opposite to each other. The plurality of electrode fingers 84 of the comb-tooth electrode 85 and the plurality of electrode fingers 44 of the comb-tooth electrode 45 are alternately arranged along the X-axis direction.

[0061] None of the plurality of electrode fingers 84 provided on the first stator bar 81 has a recess 84c. Between the plurality of electrode fingers 84 provided on the first stator bar 81, the electrode fingers 44 having the recesses 44c are disposed. On the other hand, each of the plurality of electrode fingers 84 provided on the second stator bar 82 has a recess 84c. Between the plurality of electrode fingers 84 provided on the second stator bar 82, an electrode finger 44 that does not have a recess 44c is disposed.

[0062] The electrode fingers 84 and the electrode fingers 44 are disposed so as to face each other in the X-axis direction. When physical quantity sensor 100 is subjected to acceleration in the Z-axis direction, rotor 40 rotates around first torsion spring 58 and second torsion spring 59 as a rotation axis. Along with the displacement of rotor 40, electrode fingers 44 are also displaced in the Z-axis direction. Therefore, the opposing area between electrode fingers 44 and electrode fingers 84 changes, and by detecting this change as a change in the electrostatic capacitance between electrode fingers 44 and electrode fingers 84, the acceleration in the Z-axis direction can be detected.

[0063] More specifically, when acceleration in the positive Z-axis direction is applied to physical quantity sensor 100, electrode finger 44 is displaced in the negative Z-axis direction relative to electrode finger 84. At this time, the opposing area between electrode finger 44 and electrode finger 84 on the first stator bar 81 side is reduced, so that acceleration in the positive Z-axis direction can be detected. Conversely, when acceleration in the negative Z-axis direction is applied, electrode finger 44 is displaced in the positive Z-axis direction relative to electrode finger 84. At this time, the opposing area between electrode finger 44 and electrode finger 84 on the second stator bar 82 side decreases, making it possible to detect acceleration in the negative Z-axis direction.

[0064] 1.3.3. Variations The above-described embodiment of the recess 62 can be modified in various ways. Specific modifications of the recess 62 are exemplified below. The same can be applied to the recesses 61, 63, 64, 65, and 66.

[0065] Fig. 6A is a plan view of the physical quantity sensor 100 according to a modified example, and corresponds to Fig. 5A. Fig. 6B is a perspective view of the physical quantity sensor 100 according to a modified example, and corresponds to Fig. 5B.

[0066] In the modified example, there are two recesses, 62a and 62b. Similar to the recess 62, the recesses 62a and 62b are recessed portions in the negative Z-axis direction from the top surface of the second vertical rotor bar 43. The recesses 62a and 62b are recessed to the same extent as the recess 44c, as will be described in detail in the manufacturing method section below. The recess 62a and the recess 62b are disposed adjacent to each other in the X-axis direction in the second vertical rotor bar 43. The number of recesses may be one or three or more.

[0067] The recesses 62a and 62b are provided at positions overlapping the protrusions 14b in a plan view. In the second vertical rotor bar 43, the portion where the recesses 62a and 62b are provided has improved flexibility compared to other portions. Therefore, even if the second vertical rotor bar 43 collides with the protrusion 14b due to a strong impact or the like, the portion where the recesses 62a and 62b are provided collides with the protrusion 14b, so that the second vertical rotor bar 43 is less likely to crack or break than if other portions collide.

[0068] The recesses 62a and 62b are provided at positions overlapping the wiring 31b in a plan view. Therefore, the distance between the wiring 31b and the second vertical rotor bar 43 can be made larger than when the recesses 62a and 62b are not provided, so that the parasitic capacitance between the wiring 31b can be suppressed, and the effect on the sensor performance such as sensitivity can be suppressed.

[0069] 1.3.4. Manufacturing method of physical quantity sensor Next, a method for manufacturing the physical quantity sensor 100 will be described with reference to FIGS. Fig. 7 is a flowchart relating to a manufacturing method of the physical quantity sensor 100. Fig. 7 shows, as an example, a series of steps for simultaneously forming the recesses 44c, 84c and the recess 62 in the element substrate 3. Fig. 8 to Fig. 16 are cross-sectional views of the element substrate 3 in each manufacturing process, and are enlarged views of the portion of region VII in Fig. 2.

[0070] 8, a hard mask 91 is formed as a first etching mask on the upper surface of the element substrate 3. The hard mask 91 is an insulating film made of silicon oxide (SiO2) and can be formed by a sputtering method. The method for forming the hard mask 91 is not limited to the sputtering method, and it may be formed by a thermal oxidation method or a chemical vapor deposition (CVD) method.

[0071] An insulating film 90 is formed on the lower surface of the element substrate 3. The insulating film 90 is a thermally oxidized film formed by thermally oxidizing the element substrate 3. Note that the insulating film 90 on the upper surface of the element substrate 3 is removed before the hard mask 91 is formed. The element substrate 3 is bonded to the support substrate 1 via an insulating film 90 .

[0072] In steps S2 to S4, the hard mask 91 is etched using photolithography, as shown in FIG. First, in step S2, a resist 92 is formed as a second etching mask. In step S3, as shown in FIG.

[0073] 10, the hard mask 91 exposed from the resist 92 is etched to a desired thickness. Recesses 91a indicate portions of the hard mask 91 that have been etched to a desired thickness.

[0074] In steps S5 to S8, photolithography is used to form patterns of the second lateral suspension bar 52 of the movable body 4, the second stator bar 82 of the fixed body 8, the electrode fingers 84, etc. on the element substrate 3, as shown in FIG.

[0075] In step S5, the resist 92 is removed. In step S6, as shown in FIG. 11, a resist 93 is formed on the hard mask 91 as a third etching mask.

[0076] In step S7, resist 93 is patterned as shown in Fig. 12. The pattern of resist 93 corresponds to second lateral suspension bar 52 of movable body 4, second stator bar 82 and electrode fingers 84 of fixed body 8, and the like.

[0077] In step S8, the element substrate 3 is patterned. As shown in FIG. 13, the recess 91a exposed from the resist 93 and the element substrate 3 overlapping with the exposed recess 91a are etched to form the second lateral suspension bar 52 of the movable body 4, the second stator bar 82 and electrode fingers 84 of the fixed body 8, etc.

[0078] In steps S9 to S11, the recesses 44c, 84c, 61, 62, 63, 64, 65, and 66 including the recess 64 of the second horizontal hanger bar 52 and the recess 84c of the electrode finger 84 are simultaneously formed in the movable body 4 and the fixed body 8.

[0079] In step S9, the resist 93 is removed. In step S10, the hard mask 91 is etched to remove the recesses 91a of the hard mask 91, as shown in FIG.

[0080] In step S11, the element substrate 3 exposed from the hard mask 91 is etched to simultaneously form each of the recesses 44c, 84c, 61, 62, 63, 64, 65, and 66, including the recess 64 of the second horizontal suspension bar 52 and the recess 84c of the electrode finger 84, in the movable body 4 and the fixed body 8, as shown in FIG. 15.

[0081] In step S12, as shown in FIG. 16, the insulating film 90 on the lower surface of the element substrate 3 is removed. Thereafter, the lid 2 having the cavity 2c is prepared and bonded to the element substrate 3. Through the above steps, the physical quantity sensor 100 of this embodiment is completed.

[0082] As described above, the physical quantity sensor 100 of this embodiment can provide the following effects. The physical quantity sensor 100 of this embodiment includes a support substrate 1 having an anchor 11 as a first fixing portion and an anchor 12 as a second fixing portion, a lid body 2 facing the support substrate 1, and an element substrate 3 provided between the support substrate 1 and the lid body 2. The element substrate 3 includes a fixed body 8 bonded to the support substrate 1, and a movable body 4 bonded to the support substrate 1 and displaceable relative to the fixed body 8. The movable body 4 includes a second torsion spring 59 as a support spring connected to the anchor 11, and a comb tooth electrode connected to the second torsion spring 59. The rotor 40 includes a rotor 40 having a tooth electrode 45, the fixed body 8 includes a second stator bar 82 as a support part joined to the anchor 12 and having a comb tooth electrode 85 as a second comb tooth electrode facing the comb tooth electrode 45, the rotor 40 has a second vertical rotor bar 43 as a first connecting part extending in the Y-axis direction as a first direction, and a horizontal rotor bar 41 as a second connecting part extending in the X-axis direction as a second direction intersecting the Y-axis direction, and the second vertical rotor bar 43 is provided with a recess 62 as a first recess.

[0083] In this manner, the second vertical rotor bar 43 includes the recess 62. Therefore, the recess 62 improves the flexibility of the second vertical rotor bar 43, and can improve the impact resistance against a strong impact. Thus, a highly reliable physical quantity sensor 100 can be realized.

[0084] The physical quantity sensor 100 of this embodiment is provided on the support substrate 1 and includes a protrusion 14b that overlaps with the recess 62 in a plan view. Therefore, when the second vertical rotor bar 43 moves significantly due to a strong impact or the like, the second vertical rotor bar 43 comes into contact with the protrusion 14b at the portion where the recess 62 is provided. In the second vertical rotor bar 43, the portion where the recess 62 is provided is more flexible than other portions. Therefore, the impact resistance can be improved.

[0085] The physical quantity sensor 100 of this embodiment includes a wiring 31b that is provided on the lid 2 and overlaps with the recess 62 in a plan view. Therefore, the distance between the second vertical rotor bar 43 and the wiring 31b can be increased, so that the parasitic capacitance between the wiring 31b can be suppressed. As a result, the sensor element 101 can be realized with excellent sensor performance such as sensitivity.

[0086] In the physical quantity sensor 100 of this embodiment, the movable body 4 is provided with a suspender 50 between the anchor 11 and the second torsion spring 59, which connects the anchor 11 and the second torsion spring 59, and the suspender 50 is joined to the anchor 11 and includes a second horizontal suspension bar 52 as a third connecting part extending in the X-axis direction, and a second vertical suspension bar 54 as a fourth connecting part connected to the second horizontal suspension bar 52 and extending in the Y-axis direction, and the second horizontal suspension bar 52 is provided with a recess 64 as a second recess.

[0087] Therefore, the recess 64 improves the flexibility of the second horizontal suspension bar 52, and improves the impact resistance against a strong impact. Thus, a highly reliable physical quantity sensor 100 can be realized.

[0088] In the physical quantity sensor 100 of the present embodiment, the second vertical suspension bar 54 has a recess 66 as a third recess. Therefore, the recess 66 improves the flexibility of the second vertical suspension bar 54, and improves the impact resistance against a strong impact. Thus, a highly reliable physical quantity sensor 100 can be realized.

[0089] In the physical quantity sensor 100 of this embodiment, the comb-tooth electrode 45 includes electrode fingers 44 having recesses 44c as fourth recesses, and the comb-tooth electrode 85 includes electrode fingers 84 having recesses 84c as fifth recesses, and the recesses 62, 44c, and 84c are each recessed to the same degree. In this way, by making each recess have the same recess depth, the recesses can be formed in the same process, and therefore the physical quantity sensor 100 can be produced with excellent productivity.

[0090] In the physical quantity sensor 100 of this embodiment, the comb-tooth electrode 45 includes electrode fingers 44 having recesses 44c as fourth recesses, and the comb-tooth electrode 85 includes electrode fingers 84 having recesses 84c as fifth recesses, and the recesses 62, 64, 44c, and 84c are all the same in recession degree. In this way, by making each recess have the same recess depth, the recesses can be formed in the same process, and therefore the physical quantity sensor 100 can be produced with excellent productivity.

[0091] In the physical quantity sensor 100 of this embodiment, the comb-tooth electrode 45 includes electrode fingers 44 having recesses 44c as fourth recesses, and the comb-tooth electrode 85 includes electrode fingers 84 having recesses 84c as fifth recesses, and the recesses 62, 64, 66, 44c, and 84c are all the same in recession degree. In this way, by making each recess have the same recess depth, the recesses can be formed in the same process, and therefore the physical quantity sensor 100 can be produced with excellent productivity.

[0092] A manufacturing method for the physical quantity sensor 100 of this embodiment includes a step of forming, on an element substrate 3, a movable body 4 having a rotor 40 connected to the second torsion spring 59 as a support spring and a comb-tooth electrode 45 as a first comb-tooth electrode consisting of a plurality of electrode fingers 44, and a fixed body 8 facing the comb-tooth electrode 45 and having a comb-tooth electrode 85 as a second comb-tooth electrode consisting of a plurality of electrode fingers 84; and a step of forming recesses 62, 44c, 84c in the rotor 40, some of the plurality of electrode fingers 84 of the comb-tooth electrode 85, and some of the plurality of electrode fingers 44 of the comb-tooth electrode 45, respectively. In this way, since the recesses are formed in the same process, the method for manufacturing the physical quantity sensor 100 can be made with excellent productivity.

[0093] In the manufacturing method of the physical quantity sensor 100 of this embodiment, the process of forming the fixed body 8 and the movable body 4 includes step S1 as a process of forming a hard mask 91 as a first etching mask on the element substrate 3, steps S2 and S3 as processes of forming a resist 92 as a second etching mask on the hard mask 91, step S4 as a process of etching the hard mask 91 using the resist 92, steps S6 and S7 as processes of forming a resist 93 as a third etching mask on the hard mask 91, and step S8 as a process of forming the movable body 4 and the fixed body 8 using the resist 93, and the process of forming the recesses includes step S10 as a process of etching the hard mask 91 and step S11 as a process of forming the recesses 62, 44c, 84c using the hard mask 91.

[0094] In this manner, by using the hard mask 91, the resist 92, and the resist 93, each recess can be formed in the same process, and therefore a method for manufacturing the physical quantity sensor 100 with excellent productivity can be achieved.

[0095] 2. Embodiment 2 2.1. Overview of the Inertial Measurement Unit Next, an inertial measurement unit (IMU) 300 including the above-described physical quantity sensor 100 will be described with reference to FIGS. Fig. 17 is an exploded perspective view showing a schematic configuration of an inertial measurement unit 300 according to this embodiment. Fig. 18 is a perspective view showing a circuit board 315 that is mounted on the inertial measurement unit 300 and on which the physical quantity sensor 100 is mounted.

[0096] The inertial measurement unit 300 is mounted on a wearable device such as an automobile, a robot, a smartphone, or a portable activity monitor, and is used as a device for detecting the attitude, behavior, etc. of the wearable device.

[0097] As shown in FIG. 17, the inertial measurement device 300 includes an outer case 301, a joint member 310, and a sensor module 325, and is configured such that the sensor module 325 is fitted or inserted inside the outer case 301 with the joint member 310 interposed therebetween.

[0098] Outer case 301 is a box-shaped container with a rectangular parallelepiped exterior and no lid, and its interior is an internal space surrounded by walls. The material of outer case 301 is, for example, aluminum. However, other metals such as zinc or stainless steel, resin, or a composite material of metal and resin may also be used.

[0099] Through holes 302 are formed near two diagonal vertices on the top surface of the outer case 301. The through holes 302 are used when attaching the inertial measurement unit 300 to the device to be mounted. The sensor module 325 is composed of an inner case 320 and a circuit board 315 .

[0100] Inner case 320 is a member that supports circuit board 315, and has a shape that fits inside outer case 301. As the material for inner case 320, the same material as that for outer case 301 can be used. The bottom surface of inner case 320 is formed with recess 331 for preventing contact with circuit board 315 and opening 321 for exposing connector 316 .

[0101] The configuration of the circuit board 315 on which the physical quantity sensor 100 is mounted will be described with reference to FIG. The circuit board 315 is, for example, a multi-layer board with a plurality of through holes, and may be a glass epoxy board. However, it is not limited to a glass epoxy board, and may be a rigid board such as a composite board or a ceramic board.

[0102] On the top and side surfaces of the circuit board 315, a connector 316, a physical quantity sensor 100, and angular velocity sensors 317x, 317y, and 317z are mounted. The connector 316 is a plug-type connector and has two rows of connection terminals arranged at equal pitch in the X-axis direction. In this embodiment, the connector has two rows of connection terminals with 10 pins per row, for a total of 20 pins, but the number of connection terminals may be changed as appropriate depending on the design specifications.

[0103] The angular velocity sensor 317z is a gyro sensor that detects a one-axis angular velocity in the Z-axis direction. For example, a vibration gyro sensor that uses a quartz crystal as an oscillator and detects the angular velocity from the Coriolis force applied to a vibrating object can be used. Note that the present invention is not limited to a vibration gyro sensor, and a sensor using ceramic or silicon as an oscillator may also be used.

[0104] Furthermore, angular velocity sensor 317x that detects angular velocity along one axis in the X-axis direction is mounted on a side surface of circuit board 315 in the X-axis direction, with the mounting surface perpendicular to the X-axis. Similarly, angular velocity sensor 317y that detects angular velocity along one axis in the Y-axis direction is mounted on a side surface of circuit board 315 in the Y-axis direction, with the mounting surface perpendicular to the Y-axis. Note that angular velocity sensors 317x, 317y, and 317z may be configured in a single package.

[0105] The physical quantity sensor 100 is a three-axis acceleration sensor for measuring acceleration in the X-axis, Y-axis, and Z-axis directions, but may be a one-axis or two-axis acceleration sensor as described above.

[0106] A control IC 319 serving as a control unit is mounted on the lower surface of the circuit board 315. Control IC 319 is an MCU (Micro Controller Unit) that has a built-in storage unit including a non-volatile memory, a communication I / F (interface), an A / D converter (Digital Analog Converter), and the like, and controls each part of inertial measurement unit 300. The storage unit stores a program that specifies the order and content for detecting acceleration and angular velocity, a program that digitizes the detected data and incorporates it into packet data, associated data, and the like. Note that multiple other electronic components are also mounted on circuit board 315.

[0107] In this way, since the above-described physical quantity sensor 100 is employed in the inertial measurement unit 300, it is possible to provide an inertial measurement unit 300 that has excellent shock resistance and improved reliability.

[0108] As described above, according to the inertial measurement unit 300 including the physical quantity sensor 100 of this embodiment, in addition to the effects of the first embodiment, it is possible to provide an inertial measurement unit with high reliability.

[0109] 3. Embodiment 3 In the third embodiment, an electronic device including the inertial measurement unit 300 of the second embodiment will be described. In the following, examples of electronic devices will be described, including a moving object such as an automobile and a portable device such as a smartphone.

[0110] 3.1. Overview of the Mobile Unit FIG. 19 is a perspective view of a moving object as an electronic device according to the third embodiment, showing the configuration of an automobile 1100 as an example of the moving object.

[0111] The automobile 1100 is equipped with an inertial measurement unit 300 equipped with the above-mentioned physical quantity sensor 100. The inertial measurement unit 300 detects the attitude of the vehicle body 1101 and outputs a detection signal. The detection signal includes an angular velocity signal and an acceleration signal. The detection signal of the inertial measurement unit 300 is supplied to a vehicle body attitude control device 1102 that controls the attitude of the vehicle body 1101. The vehicle body attitude control device 1102 detects the attitude of the vehicle body 1101 based on the signal, and controls the hardness of the suspension and the brakes on each wheel 1103 according to the detection result.

[0112] In addition, the detection signal of the inertial measurement unit 300 may also be used in ECUs (Electronic Control Units) such as keyless entry, immobilizers, car navigation systems, car air conditioners, anti-lock braking systems (ABS), airbags, TPMS (Tire Pressure Monitoring Systems), engine controls, control equipment for inertial navigation for autonomous driving, and battery monitors for hybrid and electric vehicles.

[0113] The inertial measurement unit 300 may be mounted on a moving body other than the automobile 1100. For example, the inertial measurement unit 300 is mounted on a moving body such as a bipedal robot, a train, a radio-controlled airplane, a radio-controlled helicopter, a drone, an agricultural machine, or a construction machine. This allows the moving body to utilize the detection signal of the inertial measurement unit 300 for controlling the attitude of the moving body, measuring the position, or the like.

[0114] Thus, in this embodiment, a moving body such as an automobile 1100 is equipped with an inertial measurement unit 300 including the above-described physical quantity sensor 100. Therefore, according to this embodiment, the reliability of the automobile 1100 can be improved.

[0115] 3.2. Overview of mobile devices FIG. 20 is a perspective view of a mobile device as an electronic device according to the third embodiment, and shows the configuration of a smartphone 1200 as an example of the mobile device.

[0116] The smartphone 1200 is equipped with an inertial measurement unit 300 that includes the above-mentioned physical quantity sensor 100. The detection signal detected by the inertial measurement device 300 is output to the control circuit 1201, and the control circuit 1201 recognizes the attitude and behavior of the smartphone 1200 from the received detection signal, and can change the image displayed on the display unit 1202, sound an alarm or sound effect, or drive a vibration motor to vibrate the main body.

[0117] In addition, the inertial measurement unit 300 may be mounted on a portable device other than the smartphone 1200. For example, the inertial measurement unit 300 may be mounted on a portable device such as a smartwatch, a portable activity meter, a head mounted display (HMD), a mobile personal computer (PC), a tablet PC, a camera, or a personal digital assistant (PDA). This enables the portable device to recognize the attitude and behavior of the portable device based on a detection signal from the inertial measurement unit 300, and to change the displayed image, sound an alarm or sound effect, or drive a vibration motor to vibrate the main body.

[0118] Thus, in this embodiment, a mobile device such as a smartphone 1200 is equipped with an inertial measurement unit 300 including the above-described physical quantity sensor 100. Therefore, according to this embodiment, the reliability of the smartphone 1200 equipped with the physical quantity sensor 100 can be improved.

[0119] As described above, the automobile 1100 and the smartphone 1200 serving as electronic devices according to this embodiment include the inertial measurement unit 300 described above. Therefore, the reliability of the automobile 1100 and the smartphone 1200 can be improved.

[0120] Although the preferred embodiment has been described above, the present invention is not limited to the above embodiment. Furthermore, the configuration of each part of the present invention can be replaced with any configuration that exhibits the same function as the above embodiment, and any configuration can be added. [Explanation of symbols]

[0121] 1...support substrate, 1c...cavity, 11, 12...anchors, 14a, 14b, 15a, 15b, 16a, 16b...projections, 2...lid, 2c...cavity, 2h...through hole, 3...element substrate, 31a, 31b, 32a, 32b, 33a, 33b...wiring, 35...external wiring, 36...electrode pad, 4...movable body, 40...rotor, 41...horizontal rotor bar, 42...first vertical rotor bar, 43...second vertical rotor bar, 44...electrode finger, 44c...recess, 45...comb electrode, 481, 482, 491, 492...brake plate, 50...suspender, 51...first horizontal hanger bar, 52...second horizontal hanger bar, 53...first vertical hanger bar, 54...second vertical hanger bar, 56...anchor point, 58...first torsion spring, 59...second torsion spring, 61, 62, 62a, 62b, 63, 64, 65, 66...recess, 8...fixed body, 81...first stator bar, 82...second stator bar, 84...electrode finger, 84c...recess, 85...comb-tooth electrode, 86, 87...anchor point, 90...insulating film, 91...hard mask, 91a...recess, 92, 93...resist, 100...physical quantity sensor, 101, 102, 103...sensor element, 300...inertial measurement unit, 301...outer case, 302...through hole, 310...jointing member, 315...circuit board, 316...connector, 317x, 317y, 317z...angular velocity sensor, 320...inner case, 321...opening, 325...sensor module, 331...recess, 1100...automobile, 1101...vehicle body, 1102...vehicle attitude control device, 1103...wheel, 1200...smartphone, 1201...control circuit, 1202...display unit.

Claims

1. A support substrate having a first fixing portion and a second fixing portion; a cover body facing the support substrate; an element substrate provided between the support substrate and the lid; the element substrate includes a fixed body joined to the support substrate, and a movable body joined to the support substrate and displaceable with respect to the fixed body, the movable body includes a support spring connected to the first fixed portion, and a rotor connected to the support spring and having a first comb electrode, the fixed body includes a support portion joined to the second fixed portion and having a second comb-teeth electrode facing the first comb-teeth electrode, The rotor has a first connecting portion extending in a first direction and a second connecting portion extending in a second direction intersecting the first direction, The first coupling portion includes a first recess. Physical quantity sensor.

2. a protrusion provided on the support substrate and overlapping with the first recess in a plan view; The physical quantity sensor according to claim 1 .

3. A wiring provided on the lid and overlapping with the first recess in a plan view. The physical quantity sensor according to claim 1 .

4. the movable body includes a suspender between the first fixed portion and the support spring, the suspender connecting the first fixed portion and the support spring, the suspenders include a third connecting portion joined to the first fixing portion and extending in the second direction, and a fourth connecting portion connected to the third connecting portion and extending in the first direction, The third connecting portion includes a second recess. The physical quantity sensor according to claim 1 .

5. The fourth connecting portion includes a third recess. The physical quantity sensor according to claim 4 .

6. the first comb electrode includes an electrode finger having a fourth recess, the second comb electrode includes an electrode finger having a fifth recess, The first recess, the fourth recess, and the fifth recess are recessed to the same degree. The physical quantity sensor according to claim 1 .

7. the first comb electrode includes an electrode finger having a fourth recess, the second comb electrode includes an electrode finger having a fifth recess, The first recess, the second recess, the fourth recess, and the fifth recess are recessed to the same degree. The physical quantity sensor according to claim 4 .

8. the first comb electrode includes an electrode finger having a fourth recess, the second comb electrode includes an electrode finger having a fifth recess, The first recess, the second recess, the third recess, the fourth recess, and the fifth recess have the same recessed degree, The physical quantity sensor according to claim 5 .

9. An inertial measurement device comprising the physical quantity sensor according to claim 1 .

10. An electronic device comprising the inertial measurement device according to claim 9.

11. forming, on an element substrate, a movable body having a rotor including a support spring and a first comb electrode having a plurality of electrode fingers connected to the support spring, and a fixed body having a second comb electrode having a plurality of electrode fingers facing the first comb electrode; forming recesses in the rotor, some of the electrode fingers of the first comb electrode, and some of the electrode fingers of the second comb electrode, A method for manufacturing a physical quantity sensor.

12. The step of forming the fixed body and the movable body includes: forming a first etching mask on the element substrate; forming a second etching mask on the first etching mask; Etching the first etching mask using the second etching mask; forming a third etching mask on the first etching mask; forming the movable body and the fixed body using the third etching mask; The step of forming the recess includes: Etching the first etching mask; forming the recess using the first etching mask; The method for manufacturing the physical quantity sensor according to claim 11 .

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