阅读说明：本技术 角速度传感器 (Angular velocity sensor ) 是由 田路翔一 相泽宏幸 平冈聪一郎 于 2020-03-05 设计创作，主要内容包括：提供了一种在尺寸上减小且在灵敏度上提高的角速度传感器。锚定器构件(7)支持框架状构件(6)。第一输入电极(81)位于框架状构件(6)的外侧以与框架状构件(6)分离,并且固定到基板(2)。第二输入电极(82)包括位于框架状构件(6)的外侧且连接到框架状构件(6)的电极部。第二输入电极(82)面对第一输入电极(81)并且在规定方向上是可位移的。第一参考电极(91)位于框架状构件(6)的内侧并且固定到基板(2)。第二参考电极(92)包括位于框架状构件(6)的内侧且连接到框架状构件(6)的电极部。第二参考电极(92)面对第一参考电极(91)并且在规定方向上是可位移的。在结构组件(3)中,在关于基板(2)限定的厚度方向上的平面图中,第一输入电极(81)与第二输入电极(82)的电极部在规定方向上位于框架状构件(6)与重量构件(4)之间。(An angular velocity sensor reduced in size and improved in sensitivity is provided. The anchor member (7) supports the frame-like member (6). The first input electrode (81) is located outside the frame-like member (6) to be separated from the frame-like member (6), and is fixed to the substrate (2). The second input electrode (82) includes an electrode portion located outside the frame-like member (6) and connected to the frame-like member (6). The second input electrode (82) faces the first input electrode (81) and is displaceable in a prescribed direction. The first reference electrode (91) is located inside the frame-like member (6) and is fixed to the substrate (2). The second reference electrode (92) includes an electrode portion located inside the frame-like member (6) and connected to the frame-like member (6). The second reference electrode (92) faces the first reference electrode (91) and is displaceable in a prescribed direction. In the structural component (3), in a plan view in a thickness direction defined with respect to the substrate (2), electrode portions of the first input electrode (81) and the second input electrode (82) are located between the frame-like member (6) and the weight member (4) in a prescribed direction.)

1. An angular velocity sensor comprising:

a substrate; and

a structural component disposed on a major surface side of the substrate,

the structural assembly includes:

a weight member for supporting the weight member,

a frame-like member aligned with the weight member in a prescribed direction orthogonal to a thickness direction defined with respect to the substrate and displaceable in the prescribed direction,

an elastic member that connects the weight member to the frame-like member and is elastically deformable in a direction orthogonal to the thickness direction and the prescribed direction defined with respect to the substrate,

an anchor member supporting the frame-like member and fixed to the substrate,

a first input electrode located outside the frame-like member to be separated from the frame-like member and fixed to the substrate,

a second input electrode including an electrode portion located outside the frame-like member and connected to the frame-like member, the second input electrode facing the first input electrode and being displaceable in the prescribed direction,

a first reference electrode located inside the frame-like member and fixed to the substrate, an

A second reference electrode including an electrode portion located inside the frame-like member and connected to the frame-like member, the second reference electrode facing the first reference electrode and being displaceable in the prescribed direction,

in the structural assembly, the electrode portions of the first and second input electrodes are located between the frame-like member and the weight member in the prescribed direction in a plan view in the thickness direction defined with respect to the substrate.

2. The angular velocity sensor according to claim 1, wherein:

in a plan view in the thickness direction defined with respect to the substrate, the weight member has an outer peripheral shape that is a polygonal shape,

the structural assembly includes a plurality of sets, each set including the elastic member, the frame-like member, the first input electrode, the second input electrode, the first reference electrode, and the second reference electrode, and

the plurality of sets are arranged such that the second input electrodes face the sides of the polygonal shape one-to-one outside the weight member.

3. The angular velocity sensor according to claim 1 or 2, wherein:

the elastic member is located outside the weight member.

4. The angular velocity sensor according to any one of claims 1 to 3, wherein:

the structural assembly further comprises a projection projecting from the frame-like member towards the anchor member,

the anchor member has a recess in which the projection is located, an

A space is provided between the convex portion and the concave portion in a plan view in the thickness direction defined with respect to the substrate.

5. The angular velocity sensor according to any one of claims 1 to 4, wherein:

a first anchor member as the anchor member is adjacent to the frame-like member in a direction orthogonal to the prescribed direction in a plan view in the thickness direction defined with respect to the substrate, and

the structural assembly further includes a second anchor member fixed to the base plate, the second anchor member being located between the first anchor member and the weight member and connected to the first anchor member in a plan view in the thickness direction defined with respect to the base plate.

6. The angular velocity sensor according to claim 5, wherein:

the structural assembly further includes a third anchor member fixed to the base plate, the third anchor member being located between the second anchor member and the weight member and connected to the second anchor member in a plan view in the thickness direction defined with respect to the base plate.

7. The angular velocity sensor according to any one of claims 1 to 6, wherein:

the first reference electrode includes a plurality of first comb teeth,

the second reference electrode includes:

a base; and

a plurality of second comb teeth as the electrode portion of the second reference electrode, the plurality of second comb teeth extending from the base,

the plurality of first comb teeth and the plurality of second comb teeth are alternately aligned one by one in the prescribed direction and are separated from each other, and

a portion of the frame-like member also serves as the base of the second reference electrode.

8. The angular velocity sensor according to any one of claims 1 to 7, wherein:

the structural assembly includes, in addition to the first elastic member as the elastic member, a second elastic member that connects the frame-like member to the anchor member and is elastically deformable,

the first elastic member has at least one first fold in a plan view in the thickness direction defined with respect to the substrate,

the second elastic member is elastically deformable in the prescribed direction, and has at least one second fold in a plan view in the thickness direction defined with respect to the substrate, and

the at least one first fold of the first elastic member is equal in number to the at least one second fold of the second elastic member.

9. The angular velocity sensor according to claim 2, wherein:

the structural assembly includes a plurality of structural assemblies, and

the angular velocity sensor further includes a third elastic member that connects, in a plan view in the thickness direction defined with respect to the substrate, frame-like members that are closest to each other of two structural assemblies that are adjacent to each other among the plurality of structural assemblies, the third elastic member being elastically deformable in a direction in which the frame-like members that are closest to each other are aligned with each other.

10. The angular velocity sensor according to claim 9, further comprising:

a lever arm member that is elongated in a plan view in the thickness direction defined with respect to the base plate, and that is aligned with the two structural components adjacent to each other in a plan view in the thickness direction defined with respect to the base plate;

a pair of fourth elastic members connecting both ends of the lever arm member in the longitudinal direction to frame-like members of the two structural components that are closest to the lever arm member, the pair of fourth elastic members being elastically deformable in the prescribed direction; and

a pair of fifth elastic members connecting a middle portion of the lever arm member in the longitudinal direction to an anchor member that is closest to the middle portion of the lever arm member of the two structural components, the pair of fifth elastic members being elastically deformable in a direction orthogonal to the thickness direction and the prescribed direction defined with respect to the base plate.

11. An angular velocity sensor comprising:

a substrate; and

a structural component disposed on a major surface side of the substrate,

the structural assembly includes:

a weight member having an outer peripheral shape that is a polygonal shape in a plan view in a thickness direction defined with respect to the substrate,

a pair of frame-like members located on one side and the other side of the weight member in a prescribed direction orthogonal to the thickness direction defined with respect to the substrate, the pair of frame-like members being displaceable in the prescribed direction,

a pair of first elastic members each connecting the weight member to a corresponding one of the pair of frame-like members and being elastically deformable in a direction orthogonal to the thickness direction and the prescribed direction defined with respect to the substrate,

a pair of anchor members, each anchor member of the pair of anchor members supporting a corresponding frame-like member of the pair of frame-like members and fixed to the substrate,

a pair of first input electrodes corresponding to the pair of frame-shaped members one-to-one, each of the pair of first input electrodes being located outside a corresponding one of the frame-shaped members to be separated from the corresponding one of the frame-shaped members and fixed to the substrate,

a pair of second input electrodes including electrode portions that correspond one-to-one to the pair of frame-like members, each of the electrode portions being located outside and connected to a corresponding one of the frame-like members, each of the pair of second input electrodes facing a corresponding one of the first input electrodes and being displaceable in the prescribed direction,

a pair of first reference electrodes corresponding one-to-one to the pair of frame-like members, each of the pair of first reference electrodes being located inside a corresponding one of the frame-like members and fixed to the substrate, an

A pair of second reference electrodes including electrode portions corresponding one-to-one to the pair of frame-like members, each of the electrode portions being located inside and connected to a corresponding one of the frame-like members, the pair of second reference electrodes facing the pair of first reference electrodes and being displaceable in the prescribed direction,

in the structural assembly, in a plan view in the thickness direction defined with respect to the substrate, a corresponding one of the electrode portions of each of the first input electrodes and the second input electrode is located between the weight member and a corresponding one of the pair of frame-like members in the prescribed direction.

Technical Field

The present disclosure relates generally to angular velocity sensors, and more particularly to angular velocity sensors including a weight member.

Background

As an angular velocity sensor, a gyroscope produced by a batch micromachining process for an SOI wafer is known (patent document 1).

The gyroscope described in patent document 1 includes four structural components (teeth 40). The structural assembly includes a weight member (proof mass 24), an anchor member (anchor 20), four frame-like members (drive-mode shuttle 26, sense-mode shuttle 22) surrounding the weight member, a drive section (differential transverse comb or parallel plate electrode 34), and a detection section (differential parallel plate electrode 36).

An angular velocity sensor that is improved in sensitivity and reduced in size is desired.

Reference list

Patent document

Patent document 1: US 8322213B 2

Disclosure of Invention

It is an object of the present disclosure to provide an angular velocity sensor with reduced size and improved sensitivity.

An angular velocity sensor according to one aspect of the present disclosure includes a substrate and a structural assembly. The structural component is disposed on the major surface side of the substrate. The structural assembly includes a weight member, a frame-like member, an elastic member, an anchor member, a first input electrode, a second input electrode, a first reference electrode, and a second reference electrode. The frame-like member is aligned with the weight member in a prescribed direction orthogonal to a thickness direction defined with respect to the substrate, and is displaceable in the prescribed direction. The elastic member connects the weight member to the frame-like member, and is elastically deformable in a direction orthogonal to a thickness direction and a prescribed direction defined with respect to the substrate. The anchor member supports the frame-like member and is fixed to the substrate. The first input electrode is located outside the frame-like member to be separated from the frame-like member, and is fixed to the substrate. The second input electrode includes: an electrode portion located outside the frame-like member and connected to the frame-like member. The second input electrode faces the first input electrode and is displaceable in a prescribed direction. The first reference electrode is located inside the frame-like member and fixed to the substrate. The second reference electrode includes: an electrode portion located inside the frame-like member and connected to the frame-like member. The second reference electrode faces the first reference electrode and is displaceable in a prescribed direction. In the structural assembly, the electrode portions of the first and second input electrodes are located between the frame-like member and the weight member in the prescribed direction in a plan view in the thickness direction defined with respect to the substrate.

An angular velocity sensor according to one aspect of the present disclosure includes a substrate and a structural assembly. The structural component is disposed on the major surface side of the substrate. The structural assembly includes a weight member, a pair of frame-like members, a pair of first elastic members, a pair of anchor members, a pair of first input electrodes, a pair of second input electrodes, a pair of first reference electrodes, and a pair of second reference electrodes. In a plan view in a thickness direction defined with respect to the substrate, the weight member has an outer circumferential shape that is a polygonal shape. The pair of frame-like members are located on one side and the other side of the weight member in a predetermined direction orthogonal to a thickness direction defined with respect to the substrate. The pair of frame-like members is displaceable in a predetermined direction. Each of the pair of first elastic members connects the weight member to a corresponding one of the pair of frame-like members, and is elastically deformable in a direction orthogonal to a thickness direction and a prescribed direction defined with respect to the substrate. Each of the pair of anchor members supports a corresponding one of the pair of frame-like members and is fixed to the substrate. The pair of first input electrodes correspond to the pair of frame-like members one to one. Each of the pair of first input electrodes is located outside a corresponding one of the frame-like members and fixed to the substrate. The pair of second input electrodes includes electrode portions corresponding to the pair of frame-shaped members one by one. Each of the electrode portions is located outside the corresponding one of the frame-like members and is connected to the corresponding one of the frame-like members. Each of the pair of second input electrodes faces a corresponding one of the first input electrodes and is displaceable in a prescribed direction. The pair of first reference electrodes correspond to the pair of frame-like members one to one. Each of the pair of first reference electrodes is located inside a corresponding one of the frame-like members and fixed to the substrate. The pair of second reference electrodes includes electrode portions corresponding to the pair of frame-like members one by one. Each of the electrode portions is located inside and connected to the corresponding one of the frame-like members. The pair of second reference electrodes face the pair of first reference electrodes and are displaceable in a prescribed direction. In the structural assembly, in a plan view in a thickness direction defined with respect to the substrate, each of the first input electrodes and a corresponding one of the electrode portions of the second input electrode are located between the weight member and a corresponding one of the pair of frame-like members in the prescribed direction.

Drawings

Fig. 1 is a plan view of an angular velocity sensor according to a first embodiment;

FIG. 2 is a cross-sectional view of the angular velocity sensor along line A-A of FIG. 1;

FIG. 3 is a cross-sectional view of the angular velocity sensor along line B-B of FIG. 1;

fig. 4 is a diagram of an angular velocity sensor, in which a plan view corresponding to fig. 1 is shown in another schematic way;

fig. 5 is a plan view of an angular velocity sensor according to a second embodiment;

fig. 6 is a diagram of an angular velocity sensor, in which a plan view corresponding to fig. 5 is shown in another schematic manner; and

fig. 7 is a schematic diagram of an angular velocity sensor according to a modification of the second embodiment.

Detailed Description

The drawings described in the following embodiments are schematic diagrams, and the ratio of the size and the ratio of the thickness of the components in the drawings do not necessarily reflect the actual size ratio.

(first embodiment)

Referring to fig. 1 to 4, an angular velocity sensor 1 according to a first embodiment will be described below.

(1) Overview

As shown in fig. 1 to 4, an angular velocity sensor 1 according to the first embodiment includes a substrate 2 and a structural component 3. The structural component 3 is disposed on the main surface 21 side of the substrate 2. It is to be noted that the main surface 21 of the substrate 2 is one of two surfaces of the substrate 2, which are transverse to the thickness direction D1 defined with respect to the substrate 2, and which faces the structural component 3.

The structural assembly 3 includes a weight member 4, a frame-like member 6, an elastic member 5, an anchor member 7, a first input electrode 81, a second input electrode 82, a first reference electrode 91, and a second reference electrode 92.

The angular velocity sensor 1 includes a driving portion 8 for driving (vibrating) the weight member 4. Each driving section 8 includes a first input electrode 81 and a second input electrode 82. Each of the driving portions 8 is an electrostatic driving type driving portion configured to drive the weight member 4 by an electrostatic force generated between the first input electrode 81 and the second input electrode 82.

The angular velocity sensor 1 includes a detection portion 9 for detecting an angular velocity. Each detection section 9 includes a first reference electrode 91 and a second reference electrode 92. In each detection section 9, the capacitance of the capacitor including the first reference electrode 91 and the second reference electrode 92 changes according to the angular velocity.

The angular velocity sensor 1 converts, for example, an angular velocity into an electric signal. That is, the angular velocity sensor 1 functions as a transducer configured to convert angular velocity into an electrical signal. The angular velocity sensor 1 can be used in, for example, home appliances, portable terminals, cameras, wearable terminals, game machines, vehicles (including automobiles, two-wheeled vehicles, and the like), robots, construction machines, unmanned planes, aircraft, or ships.

(2) Details of

The configuration of the angular velocity sensor 1 according to the first embodiment will be described in detail with reference to fig. 1 to 4.

In the following description, for example, an orthogonal coordinate having three axes (i.e., X, Y, and Z axes orthogonal to each other) is specified, wherein, specifically, an axis along the thickness direction D1 defined with respect to the substrate 2 (and the thickness direction defined with respect to the weight member 4) is defined as a "Z axis", and an axis along the vibration (driving) direction of the weight member 4 is defined as an "X axis". The "Y axis" is orthogonal to both the Z axis and the X axis. The axis along the vibration (driving) direction of the weight member 4 is not limited to the X axis, but may be the Y axis. The X, Y, and Z axes are virtual axes, and arrows representing "X", "Y", and "Z" in the drawings are shown only for convenience of description, and are not combined with entities. It is to be noted that these directions should not be construed as limiting the directions in which the angular velocity sensor 1 is used. It is to be noted that the origin of the orthogonal coordinates may be defined at the center of the structural assembly 3 (in the example shown in fig. 1, the center of the weight member 4) in a plan view on the thickness direction D1 defined with respect to the base plate 2, for example.

With the angular velocity sensor 1 according to the first embodiment, the sensing target is, for example, the angular velocity around the Z axis. The Z-axis is an axis along the thickness direction D1 defined with respect to the base plate 2 and the thickness direction defined with respect to the weight member 4, and therefore, the angular velocity sensor 1 detects an angular velocity acting on the angular velocity sensor 1 caused by the rotation of the angular velocity sensor 1 around the center axis of the weight member 4 as a sensing target. That is, the angular velocity sensor 1 outputs an electric signal according to the angular velocity around the center axis of the weight member 4. Therefore, based on the output from the angular velocity sensor 1, the magnitude of the angular velocity around the center axis (around the Z axis) of the weight member 4 can be measured.

(2.1) general configuration of angular velocity sensor

As described above, the angular velocity sensor 1 according to the first embodiment includes the substrate 2 and the structural component 3. The structural component 3 is disposed on the main surface 21 side of the substrate 2.

As described above, the structural assembly 3 includes the weight member 4, the frame-like member 6, the elastic member 5 (hereinafter also referred to as the first elastic member 51), the anchor member 7 (hereinafter also referred to as the first anchor member 71), the first input electrode 81, the second input electrode 82, the first reference electrode 91, and the second reference electrode 92. Furthermore, the structural component 3 comprises a second elastic member 52. Furthermore, the construction assembly 3 comprises a second anchor member 72. Furthermore, the construction assembly 3 comprises a third anchor member 73.

Fig. 4 is a schematic diagram schematically showing the configuration of the angular velocity sensor 1. In fig. 4, the shape and the like of each component may be different from the actual shape and the like. For example, in fig. 4, the first elastic member 51 and the second elastic member 52 are schematically represented by "spring" symbols, which do not represent actual shapes of the first elastic member 51 and the second elastic member 52. Note that the direction in which one end and the other end of each "spring" symbol are aligned corresponds to the direction in which elastic deformation easily occurs. For example, the first elastic member 51 in fig. 4 on the upper side of the weight member 4 is easily elastically deformed in the X-axis direction, and the second elastic member 52 in fig. 4 connected to the frame-like member 6 on the top is easily elastically deformed in the Y-axis direction.

The sensing target of the angular velocity sensor 1 according to the first embodiment is the angular velocity around the Z axis (around the center axis of the weight member 4). Therefore, the angular velocity sensor 1 outputs an electric signal according to the angular velocity around the Z axis. The angular velocity sensor 1 is a vibrating structure gyro sensor, and senses an angular velocity around the Z axis by using coriolis force (deflection force). That is, the angular velocity sensor 1 causes the weight member 4 to vibrate, and in this state, the angular velocity sensor 1 senses the coriolis force generated by the rotational force acting on the weight member 4 from the outside, thereby sensing the angular velocity acting on the weight member 4 of the angular velocity sensor 1. For example, when an angular velocity around the Z axis is input while the weight member 4 vibrates in the X axis direction due to the electrostatic force generated at each driving section 8 (the first input electrode 81 and the second input electrode 82), the angular velocity sensor 1 according to the first embodiment can detect an angular velocity in the Y axis direction by each detecting section 9 (the first reference electrode 91 and the second reference electrode 92).

In the angular velocity sensor 1 according to the first embodiment, the weight member 4 has an outer peripheral shape that is a polygonal shape (e.g., a substantially square shape) in a plan view in the thickness direction D1 defined with respect to the base plate 2. The structural component 3 comprises: a plurality of (four) sets, each set including two elastic members 5, a frame-like member 6, a first input electrode 81, a second input electrode 82, a first reference electrode 91, and a second reference electrode 92. The plurality of sets are arranged such that the second input electrodes 82 face the sides of the polygonal shape one-to-one outside the weight member 4. The plurality of sets are preferably arranged to have rotational symmetry about a central axis of the weight member 4 along a thickness direction D1 defined with respect to the base plate 2 as a rotation axis. In the angular velocity sensor 1 according to the first embodiment, each of the plurality of sets includes two second elastic members 52. It is to be noted that the substrate 2 has an outer peripheral shape that is a square shape in a plan view in the thickness direction D1 defined with respect to the substrate 2, but the outer peripheral shape of the substrate 2 is not limited to this example. The outer peripheral shape of the substrate 2 may be, for example, a rectangular shape.

In the angular velocity sensor 1 according to the first embodiment, the structural component 3 has a plurality of (in this embodiment, four) frame-like members 6. Four frame-like members 6 are arranged to surround one weight member 4 in a plan view in the thickness direction D1 defined with respect to the base plate 2. Specifically, the frame-like members 6 are provided one by one on both sides in the Y-axis direction and both sides in the X-axis direction of the weight member 4. The weight member 4 is separated from each frame-like member 6.

Each frame-like member 6 is aligned with the weight member 4 in a prescribed direction orthogonal to the thickness direction D1 defined with respect to the base plate 2, and is displaceable in the prescribed direction. In the angular velocity sensor 1 according to the first embodiment, the structural component 3 includes the plurality of frame-like members 6 as described above, and for each of the plurality of frame-like members 6, a prescribed direction in which the weight members 4 are aligned is prescribed, and therefore, the prescribed direction is hereinafter also referred to as a prescribed direction corresponding to the frame-like members 6. That is, the prescribed direction corresponding to the frame-like member 6 at the top in fig. 1 among the frame-like members 6 is different from the prescribed direction of the frame-like member 6 at the left in fig. 1.

Each of the four frame-like members 6 has a rectangular frame shape and includes four frame pieces 61 to 64. Two frame pieces 61 and 62 of the four frame pieces 61 to 64 each have a length direction orthogonal to a prescribed direction in which the frame-like member 6 is aligned with the weight member 4, and the length of each of the two frame pieces 61 and 62 is longer than the length of each of the two frame pieces 63 and 64, and the two frame pieces 63 and 64 each have a length direction corresponding to the prescribed direction. That is, the length of each of the four frame-like members 6 in the direction orthogonal to the predetermined direction is longer than the length in the predetermined direction. Further, in each of the four frame-like members 6, the length of the frame piece 61 in the length direction is longer than the length of the side of the weight member 4 facing the frame-like member 6 (one side of the weight member 4 having a square shape).

In the angular velocity sensor 1, the weight member 4 and each of the four frame-like members 6 are connected to each other via a pair of first elastic members 51. The pair of first elastic members 51 have respective one end portions connected to a diagonal corner of the weight member 4 and the other end portion connected to the frame piece 61 closest to the weight member 4 among the four frame pieces 61 to 64 of the frame-like member 6.

The first elastic member 51 connects the weight member 4 to the frame-like member 6, and is elastically deformable in a direction orthogonal to the thickness direction D1 defined with respect to the substrate 2 and a direction orthogonal to a prescribed direction corresponding to the frame-like member 6. For example, the first elastic member 51 connected to the frame-like member 6 at the top in fig. 1 of the four frame-like members 6 is configured to be elastically deformed more easily in the X-axis direction than in the Y-axis direction and the Z-axis direction. Further, the first elastic member 51 connected to the frame-like member 6 on the left side in fig. 1 of the four frame-like members 6 is configured to be elastically deformed more easily in the Y-axis direction than in the X-axis direction and the Z-axis direction. Further, the first elastic member 51 connected to the frame-like member 6 located at the bottom in fig. 1 of the four frame-like members 6 is configured to be elastically deformed more easily in the X-axis direction than in the Y-axis direction and the Z-axis direction. Further, the first elastic member 51 connected to the frame-like member 6 on the right side in fig. 1 of the four frame-like members 6 is configured to be elastically deformed more easily in the Y-axis direction than in the X-axis direction and the Z-axis direction. The rigidity of the first elastic member 51 configured to be easily elastically deformed in the X-axis direction is smaller in the X-axis direction than in the Y-axis direction and the Z-axis direction. The rigidity of the first elastic member 51 configured to be easily elastically deformed in the Y-axis direction is smaller in the Y-axis direction than in the X-axis direction and the Z-axis direction.

Each of the plurality of first elastic members 51 is a spring. Each of the plurality of first elastic members 51 has a first folded portion 513 in a plan view in a thickness direction D1 defined with respect to the base plate 2. The first fold 513 has a U-shape in plan view in the thickness direction D1 defined with respect to the base plate 2. Each of the plurality of first elastic members 51 has two first folded portions 513, and thus has a curved shape.

Each of the plurality of first elastic members 51 is located outside the weight member 4 in a plan view in the thickness direction D1 defined with respect to the base plate 2.

The four first anchor members 71 each have a substantially quadrangular shape in plan view in the thickness direction D1 defined with respect to the base plate 2. Four first anchor members 71 are fixed to the base plate 2.

The four first anchor members 71 are arranged to surround the weight member 4 together with the four frame-like members 6. In the structural assembly 3, the four first anchor members 71 and the four frame-like members 6 are alternately arranged one by one in the outer peripheral direction of the weight member 4. In this case, in a plan view in the thickness direction D1 defined with respect to the base plate 2, two first anchor members 71 of the four first anchor members 71 are aligned on a straight line including one diagonal line of the weight member 4 having the square shape, and the remaining two first anchor members 71 are aligned on a straight line including the other diagonal line. In the angular velocity sensor 1 according to the first embodiment, four first anchor members 71 are arranged one by one at four corners of the base plate 2.

Each of the four frame-like members 6 is supported by two adjacent ones of the first anchor members 71 via the second elastic members 52. In the angular velocity sensor 1, each of the four frame-like members 6 is connected to a corresponding one end portion of two of the second elastic members 52. In this case, the other end portions of the two second elastic members 52 are connected to different anchor members 7.

Each of the four frame-like members 6 is displaceable in a prescribed direction in which the frame-like member 6 is aligned with the weight member 4, and each of the four frame-like members 6 is also displaceable in a direction orthogonal to the prescribed direction and the thickness direction D1 defined with respect to the substrate 2.

The second elastic member 52 is not fixed to the substrate 2 and is separated from the main surface 21 of the substrate 2. Each second elastic member 52 connects the anchor member 7 and the frame-like member 6 adjacent to each other. That is, each anchor member 7 supports the frame-like member 6 via the second elastic member 52. Each second elastic member 52 is elastically deformable in a prescribed direction corresponding to the frame-like member 6 connected thereto. For example, the two second elastic members 52 connected to the frame-like member 6 at the top in fig. 1 of the four frame-like members 6 are configured to be elastically deformed more easily in the Y-axis direction than in the X-axis direction and the Z-axis direction. Further, the two second elastic members 52 connected to the frame-like member 6 on the left side in fig. 1 of the four frame-like members 6 are configured to be elastically deformed more easily in the X-axis direction than in the Y-axis direction and the Z-axis direction. Further, the two second elastic members 52 connected to the frame-like member 6 located at the bottom in fig. 1 of the four frame-like members 6 are configured to be elastically deformed more easily in the Y-axis direction than in the X-axis direction and the Z-axis direction. Further, the two second elastic members 52 connected to the frame-like member 6 on the right side in fig. 1 of the four frame-like members 6 are configured to be elastically deformed more easily in the X-axis direction than in the Y-axis direction and the Z-axis direction. The rigidity of the second elastic member 52 configured to be easily elastically deformed in the Y-axis direction is smaller in the Y-axis direction than in the X-axis direction and the Z-axis direction. The rigidity of the second elastic member 52 configured to be easily elastically deformed in the X-axis direction is smaller in the X-axis direction than in the Y-axis direction and the Z-axis direction.

Each of the plurality of second elastic members 52 is deflectable (elastically deformable). In this case, each of the plurality of second elastic members 52 has the second folded portion 523 in a plan view in the thickness direction D1 defined with respect to the base plate 2. The second fold portion 523 has a U-shape in a plan view in the thickness direction D1 defined with respect to the base plate 2. Each of the plurality of second elastic members 52 has one second fold 523.

Each of the second anchor members 72 is fixed to the substrate 2, and is connected to one of the first anchor members 71 adjacent thereto. Each third anchor member 73 is fixed to the substrate 2, and is connected to one of the second anchor members 72 adjacent thereto.

The above-described first anchor member 71 is aligned with the frame-like member 6 in a direction orthogonal to a prescribed direction in which the weight member 4 and the frame-like member 6 are aligned with each other in a plan view in the thickness direction D1 defined with respect to the substrate 2. In a plan view in the thickness direction D1 defined with respect to the base plate 2, the second anchor member 72 is located between the first anchor member 71 and the weight member 4 to be connected to the first anchor member 71. Further, in a plan view in the thickness direction D1 defined with respect to the substrate 2, the third anchor member 73 is located between the second anchor member 72 and the weight member 4 to be connected to the second anchor member 72.

Each of the first input electrodes 81 is located outside a corresponding one of the frame-like members 6 to be separated from the corresponding one of the frame-like members 6, and is fixed to the substrate 2.

Each of the second input electrodes 82 includes: and an electrode portion (second comb 822) which is located outside a corresponding one of the frame-like members 6 and is connected to the corresponding one of the frame-like members 6. Each of the second input electrodes 82 faces a corresponding one of the first input electrodes 81. Each of the second input electrodes 82 is displaceable in a prescribed direction corresponding to the frame-like member 6 connected thereto. For example, the second comb tooth 822 connected to the frame-like member 6 located at the top in fig. 1 among the four frame-like members 6 may be displaced in the Y-axis direction, the second comb tooth 822 connected to the frame-like member 6 located at the left side may be displaced in the X-axis direction, the second comb tooth 822 connected to the frame-like member 6 located at the bottom may be displaced in the Y-axis direction, and the second comb tooth 822 connected to the frame-like member 6 located at the right side may be displaced in the X-axis direction.

The driving portion 8 drives the weight member 4 to vibrate the weight member 4. Each driving section 8 includes a first input electrode 81 and a second input electrode 82. It is to be noted that each of the driving portions 8 has a function of converting an electric signal (electric quantity) input between the first input electrode 81 and the second input electrode 82 into a displacement (mechanical quantity) of the second input electrode 82.

Each of the first input electrodes 81 is a comb electrode and has: a first comb base portion 811 facing a corresponding one of the frame-like members 6; and a plurality of first comb teeth 812 extending from the first comb base 811 toward the corresponding one of the frame-like members 6 in a plan view in a thickness direction D1 defined with respect to the substrate 2.

Each of the second input electrodes 82 is a comb electrode and has: a second comb base portion 821 including a portion of the first comb base portion 811 (a portion of the frame member 61) facing the frame-like member 6; and a plurality of second comb teeth 822 (electrode portions) extending from the second comb base portion 821 toward the first comb base portion 811 in a plan view on a thickness direction D1 defined with respect to the substrate 2.

In each of the drive sections 8, in a plan view in a thickness direction D1 defined with respect to the substrate 2, the plurality of first comb teeth 812 and the plurality of second comb teeth 822 are alternately aligned one by one in a direction orthogonal to a direction in which the first comb base 811 and the second comb base 821 face each other to be separated from each other. That is, each first comb 812 and its adjacent second comb 822 face each other with a space provided therebetween.

When a rotational force (angular velocity) acts on the weight member 4 from the outside, each detection portion 9 outputs an electric signal according to the angular velocity as a sensing target by outputting an electric signal related to the motion of the weight member 4. As described above, each detection section 9 includes the first reference electrode 91 and the second reference electrode 92. It is to be noted that each detection section 9 has a function of converting the displacement (mechanical amount) of the second reference electrode 92 relative to the first reference electrode 91 into an electrical signal (electrical amount) between the first reference electrode 91 and the second reference electrode 92.

Each of the first reference electrodes 91 is located inside a corresponding one of the frame-like members 6 and fixed to the substrate 2.

Each of the second reference electrodes 92 includes an electrode portion (second comb tooth 922) which is located inside a corresponding one of the frame-like members 6 and is connected to the corresponding one of the frame-like members 6. Each of the second reference electrodes 92 faces a corresponding one of the first reference electrodes 91. Each of the second reference electrodes 92 is displaceable in a prescribed direction corresponding to the frame-like member 6 connected thereto. For example, the electrode portion (second comb tooth 922) connected to the frame-like member 6, which is located at the top in fig. 1, of the four frame-like members 6 may be displaced in the Y-axis direction. Further, the electrode portion (second comb tooth 922) connected to the frame-like member 6 on the left side in fig. 1 of the four frame-like members 6 is displaceable in the X-axis direction. Further, the second comb teeth 922 connected to the frame-like member 6 located at the bottom in fig. 1 of the four frame-like members 6 are displaceable in the Y-axis direction. Further, the second comb tooth 922 connected to the frame-like member 6 on the right side in fig. 1 of the four frame-like members 6 is displaceable in the X-axis direction.

The first reference electrode 91 has a comb shape in a plan view in the thickness direction D1 defined with respect to the substrate 2. Each first reference electrode 91 has: a first comb base portion 911 disposed in a direction in which the weight member 4 is aligned with a corresponding one of the frame-like members 6; and a plurality of (in the example shown in the drawings, six) first comb teeth 912 extending, in a plan view in the thickness direction D1 defined with respect to the base plate 2, from the first comb base portion 911 toward a portion (the frame piece 63 and the frame piece 64) of a corresponding one of the frame-like members 6 that faces the first comb base portion 911. Six first comb teeth 912 include: three first comb teeth 912 extending toward one 63 of the four frame pieces 61 to 64 of the frame-like member 6; and three first comb teeth 912 extending toward the frame member 64.

Each second reference electrode 92 has: a base section 921 constituted by a corresponding one of the frame-like members 6; and a plurality of (in the example shown in the drawings, four) second comb teeth 922 extending from the base 921 toward the first comb base 911 of the first reference electrode 91. That is, in the angular velocity sensor 1, each frame-like member 6 also serves as a part of a corresponding one of the second reference electrodes 92 (the base 921). In this case, in the second reference electrode 92, two second comb teeth 922 extend from each of the two frame pieces 63 and 64 in the frame-like member 6 toward the first comb base 911. Further, in the second reference electrode 92, the two frame pieces 61 and 62 also serve as second comb teeth extending from the two frame pieces 63 and 64, respectively.

In each detection section 9, the plurality of first comb teeth 912 and the plurality of second comb teeth 922 are alternately aligned one by one, separated from each other in a direction orthogonal to the direction in which the first comb teeth 912 extend, in a plan view in the thickness direction D1 defined with respect to the substrate 2. In this case, each of the second comb teeth 922 is set to: of the two first comb teeth 912 adjacent thereto, the distance from the first comb tooth 912 farther from the weight member 4 is greater than the distance from the first comb tooth 912 closer to the weight member 4. Further, in the second reference electrode 92, the two frame pieces 61 and 62 also serve as second comb teeth extending from the two frame pieces 63 and 64, respectively.

Furthermore, in the angular velocity sensor 1, the structural component 3 further includes a projection 65. Each projection 65 projects from a corresponding one of the frame-like members 6 toward the first anchor member 71 adjacent to the corresponding one of the frame-like members 6. Each first anchor member 71 has a recess 75, with a corresponding one of the projections 65 being located in the recess 75. A space is provided between each convex portion 65 and each concave portion 75 in a plan view in the thickness direction D1 defined with respect to the base plate 2. The projection 65 is not fixed to the substrate 2. In the angular velocity sensor 1, the displacement of the frame-like member 6 caused by the vibration of the weight member 4 brings the convex portion 65 into contact with the inner side surface of the concave portion 75, which limits the amount of displacement of the frame-like member 6.

In fig. 1, the components fixed to the substrate 2 and the components not fixed to the substrate 2 in the structural component 3 are distinguished by the form of shading with dots. That is, in fig. 1, the components (the first anchor member 71, the second anchor member 72, the third anchor member 73, the first input electrode 81, and the first reference electrode 91) having the hatching of the dots of relatively high density are fixed to the substrate 2, but the components (the weight member 4, the first elastic member 51, the second elastic member 52, the frame-like member 6, the projecting portion 65, the second input electrode 82, and the second reference electrode 92) having the hatching of the dots of relatively low density are not fixed to the substrate 2.

In the angular velocity sensor 1, the weight member 4, the eight first elastic members 51, the four frame-like members 6, the four second input electrodes 82, the four second reference electrodes 92, the eight second elastic members 52, the four first anchor members 71, the four second anchor members 72, and the four third anchor members 73 are bonded to each other. Further, in the angular velocity sensor 1, the four first input electrodes 81 and the four first reference electrodes 91 are independent of each other. Further, in the angular velocity sensor 1, the weight member 4, the eight first elastic members 51, the eight second elastic members 52, the four frame-like members 6, the eight projections 65, the four second input electrodes 82, and the four second reference electrodes 92 have the same dimension in the Z-axis direction along the thickness direction D1 defined with respect to the substrate 2. Further, in the angular velocity sensor 1, the four first anchor members 71, the four second anchor members 72, the four third anchor members 73, the four first input electrodes 81, and the four first reference electrodes 91 have the same size in the Z-axis direction along the thickness direction D1 defined with respect to the substrate 2.

The angular velocity sensor 1 according to the first embodiment is formed by processing, for example, a silicon-on-insulator (SOI) wafer by a manufacturing technique of a Micro Electro Mechanical System (MEMS) or the like. The SOI wafer includes a silicon substrate, an insulating layer (e.g., an embedded oxide film) formed on the silicon substrate, and a silicon layer formed on the insulating layer. In the angular velocity sensor 1 according to the first embodiment, part of the silicon substrate of the SOI wafer constitutes the substrate 2, and part of the silicon layer constitutes the structural component 3. Thus, the material for the structural component 3 comprises silicon. The above-mentioned silicon layer includes impurities, and the structural component 3 has a conductive property. The angular velocity sensor 1 according to the first embodiment includes: and an insulating unit 23 provided between the main surface 21 of the substrate 2 and each of the plurality of components (the anchor member 7, the first input electrode 81, the first reference electrode 91, and the like) fixed to the substrate 2 among the structural components 3. Further, the angular velocity sensor 1 according to the first embodiment has the space 24 between the substrate 2 and each of the plurality of components (the weight member 4, the elastic member 5, the frame-like member 6, the second input electrode 82, the second reference electrode 92, and the like) that are not fixed to the substrate 2. Each insulating element 23 is constituted by a portion of the insulating layer of the SOI wafer. The plurality of components fixed to the substrate 2 among the structural components 3 are fixed to the substrate 2 via the insulating unit 23.

The angular velocity sensor 1 is, for example, housed in a package and used in this state, but this should not be construed as a limitation, and the angular velocity sensor 1 may include, for example, a chip-size package formed by a wafer-level packaging technique or the like. The package has an internal space which is, for example, a nitrogen atmosphere or a reduced pressure atmosphere (vacuum), and the space 24 between the structural component 3 and the substrate 2 is also a nitrogen atmosphere or a reduced pressure atmosphere (vacuum).

(2.2) operation of angular velocity sensor

The angular velocity sensor 1 according to the first embodiment senses the angular velocity around the Z axis, for example, by using the coriolis force (deflection force) acting on the weight member 4 in a state where the weight member 4 vibrates in the X axis direction.

Specifically, for example, when the drive circuit applies a drive voltage signal between the first input electrode 81 and the second input electrode 82 of each of the drive sections 8 on the left and right sides in fig. 1, an electrostatic force that vibrates the weight member 4 in the X-axis direction is generated between the first input electrode 81 and the second input electrode 82.

In this way, it is assumed that the angular velocity around the Z axis acts on the weight member 4 of the angular velocity sensor 1 in a state where the weight member 4 vibrates in the X axis direction. In this case, coriolis force (deflection force) acts on the weight member 4, and therefore, the weight member 4 vibrates in the Y-axis direction, so that each of the frame-like members 6 at the top and bottom in fig. 1 vibrates in the Y-axis direction.

When the two frame-like members 6 aligned in the Y-axis direction vibrate in the Y-axis direction, a change in the length of the interval between the first reference electrode 91 and the second reference electrode 92 of the detection section 9 corresponding to each of the two frame-like members 6 is caused. The change in the interval length is output to the processing circuit as a change in the electrostatic capacitance. Therefore, electric signals corresponding to the angular velocity around the Z axis acting on the angular velocity sensor 1 (the weight member 4) are output from the detection portion 9 (the first reference electrode 91 and the second reference electrode 92). Note that the detection section 9 adjacent to the drive section 8 to which a voltage is input may be used to monitor the displacement during driving.

The angular velocity sensor 1 is electrically connected to, for example, a signal processing device, and is used in this state. The signal processing device is, for example, an Application Specific Integrated Circuit (ASIC). The signal processing apparatus includes, for example, a drive circuit and a processing circuit. The drive circuit supplies a drive voltage signal to the angular velocity sensor 1. The processing circuit performs signal processing on the electric signal output from the angular velocity sensor 1. For example, the processing circuit may convert an analog electric signal (analog signal) output from the angular velocity sensor 1 into a digital signal, and perform appropriate arithmetic processing to obtain the angular velocity around the Z axis.

(2.3) layout of structural Components in an angular velocity sensor

In the structural assembly 3, the electrode portions (second comb teeth 822) of the first input electrode 81 and the second input electrode 82 are located between the frame-like member 6 and the weight member 4 in a prescribed direction in a plan view on the thickness direction D1 defined with respect to the substrate 2. Therefore, in the angular velocity sensor 1 according to the first embodiment, the first reference electrode 91 and the second reference electrode 92 are farther from the weight member 4 than the electrode portions (the second comb teeth 822) of the first input electrode 81 and the second input electrode 82. Therefore, in the angular velocity sensor 1 according to the first embodiment, it becomes easy to increase the area occupied by the first reference electrode 91 and the second reference electrode 92 in a plan view on the thickness direction D1 defined with respect to the substrate 2, and it becomes easy to further increase the area where the first reference electrode 91 and the second reference electrode 92 face. Therefore, in the angular velocity sensor 1 according to the first embodiment, it becomes easy to increase the capacitance of the capacitor including the first reference electrode 91 and the second reference electrode 92.

(3) Advantages of the invention

In the angular velocity sensor 1 according to the first embodiment, the electrode portions (the second comb teeth 822) of the first input electrode 81 and the second input electrode 82 are located between the frame-like member 6 and the weight member 4 in a prescribed direction in a plan view on the thickness direction D1 defined with respect to the substrate 2, and therefore the angular velocity sensor 1 can be downsized while improving the sensitivity.

(second embodiment)

Referring to fig. 5 and 6, an angular velocity sensor 1A according to a second embodiment will be described below. In the angular velocity sensor 1A according to the second embodiment, components similar to those in the angular velocity sensor 1 according to the first embodiment are denoted by the same reference numerals as those in the first embodiment, and the description thereof will be omitted.

The angular velocity sensor 1A according to the second embodiment differs from the angular velocity sensor 1 according to the first embodiment, for example, in that: the four structural components 3 of the angular velocity sensor 1 according to the first embodiment are disposed on the main surface 21 side of the substrate 2.

In the angular velocity sensor 1A according to the second embodiment, four structural components 3 are arranged in a 2 × 2 two-dimensional array (matrix), and the four structural components 3 are bonded to each other on the main surface 21 side of the substrate 2. The angular velocity sensor 1A according to the second embodiment further includes a third elastic member 53. More specifically, the angular velocity sensor 1A includes four third elastic members 53. In a plan view in the thickness direction D1 of the substrate 2 (see fig. 2 and 3), each of the four third elastic members 53 connects the frame-like members 6, which are closest to each other, of the corresponding two adjacent ones of the structural components 3, and each of the four third elastic members 53 is elastically deformable in a direction in which the frame-like members 6, which are closest to each other, are aligned with each other. Each of the third elastic members 53 has a loop portion elongated in a direction orthogonal to a direction in which the frame-like members 6 closest to each other are aligned with each other.

For convenience of explanation, when four structural components 3 are distinguished from each other in the following description, the structural component 3 on the upper right in fig. 5 may be referred to as a structural component 31, the structural component 3 on the upper left may be referred to as a structural component 32, the structural component 3 on the lower left may be referred to as a structural component 33, and the structural component 3 on the lower right may be referred to as a structural component 34. Similarly, when four weight members 4 are distinguished from each other, the weight member 4 on the upper right in fig. 5 may be referred to as a weight member 41, the weight member 4 on the upper left may be referred to as a weight member 42, the weight member 4 on the lower left may be referred to as a weight member 43, and the weight member 4 on the lower right may be referred to as a weight member 44.

In the angular velocity sensor 1A, the third elastic member 53 connecting the frame-like members 6 closest to each other of the structural component 31 and the structural component 32 aligned in the X-axis direction is configured to be elastically deformed more easily in the X-axis direction than in the Y-axis direction and the Z-axis direction. Further, in the angular velocity sensor 1A, the third elastic member 53 connecting the frame-like members 6 closest to each other of the structural components 33 and 34 aligned in the X-axis direction is configured to be elastically deformed more easily in the X-axis direction than in the Y-axis direction and the Z-axis direction. Further, in the angular velocity sensor 1A, the third elastic member 53 connecting the frame-like members 6 closest to each other of the structural component 31 and the structural component 34 aligned in the Y-axis direction is configured to be elastically deformed more easily in the Y-axis direction than in the X-axis direction and the Z-axis direction. Further, in the angular velocity sensor 1A, the third elastic member 53 connecting the frame-like members 6 closest to each other of the structural component 32 and the structural component 33 aligned in the Y-axis direction is configured to be elastically deformed more easily in the Y-axis direction than in the X-axis direction and the Z-axis direction.

The angular velocity sensor 1A includes the third elastic members 53 each connecting the frame-like members 6 of the two adjacent structural assemblies 3 that are closest to each other, which enable the weight members 4 of the two adjacent structural assemblies 3 to vibrate in opposite phases in synchronization with each other.

Further, the angular velocity sensor 1A according to the second embodiment further includes the lever arm member 10, a pair of fourth elastic members 54, and a pair of fifth elastic members 55. The angular velocity sensor 1A includes four synchronization sets, each set including one lever arm member 10, a pair of fourth elastic members 54, and a pair of fifth elastic members 55.

The lever arm member 10 is elongated in plan view in the thickness direction D1 defined with respect to the base plate 2. The lever arm member 10 is aligned with two adjacent structural components 3 in a plan view in the thickness direction D1 defined with respect to the base plate 2. A pair of fourth elastic members 54 connect both ends of the lever arm member 10 in the longitudinal direction to the frame-like members 6 of the two structural components 3 that are closest to the lever arm member 10. The pair of fourth elastic members 54 is configured to be easily elastically deformed in a prescribed direction corresponding to the frame-like member 6. A pair of fifth resilient members 55 connect the middle of the lever arm member 10 in the longitudinal direction to the anchor member 7 of the two structural assemblies 3 that is closest to the middle of the lever arm member 10. The pair of fifth elastic members 55 are configured to be easily elastically deformed in a direction orthogonal to the thickness direction D1 defined with respect to the substrate 2 and the prescribed direction.

The pair of fourth elastic members 54 is elastically deformable in a prescribed direction corresponding to the frame-like member 6 connected thereto. In this case, the pair of fourth elastic members 54 connected to the lever arm member 10 at the top in fig. 5 is configured to be elastically deformed more easily in the Y-axis direction than in the X-axis direction and the Z-axis direction. Further, the pair of fourth elastic members 54 connected to the lever arm member 10 at the bottom in fig. 5 is configured to be elastically deformed more easily in the Y-axis direction than in the X-axis direction and the Z-axis direction. Further, the pair of fourth elastic members 54 connected to the lever arm member 10 on the left side in fig. 5 is configured to be elastically deformed more easily in the X-axis direction than in the Y-axis direction and the Z-axis direction. Further, the pair of fourth elastic members 54 connected to the lever arm member 10 on the right side in fig. 5 is configured to be elastically deformed more easily in the X-axis direction than in the Y-axis direction and the Z-axis direction. The rigidity of the fourth elastic member 54 configured to be easily elastically deformed in the Y-axis direction is smaller in the Y-axis direction than in the X-axis direction and the Z-axis direction. The rigidity of the fourth elastic member 54 configured to be easily elastically deformed in the X-axis direction is smaller in the X-axis direction than in the Y-axis direction and the Z-axis direction.

Each of the plurality (eight) of fourth elastic members 54 is a spring. Each of the plurality of fourth elastic members 54 has a folded portion in a plan view in the thickness direction D1 defined with respect to the base plate 2. The folded portion has a U-shape in a plan view in the thickness direction D1 defined with respect to the base plate 2. Each of the plurality of fourth elastic members 54 has one folded portion.

The pair of fifth elastic members 55 are elastically deformable in a direction orthogonal to the prescribed direction corresponding to the frame-like member 6 connected via the lever arm member 10 and the thickness direction D1 defined with respect to the base plate 2. In this case, the pair of fifth elastic members 55 connected to the lever arm member 10 at the top in fig. 5 is configured to be elastically deformed more easily in the X-axis direction than in the Y-axis direction and the Z-axis direction. Further, the pair of fifth elastic members 55 connected to the lever arm member 10 at the bottom in fig. 5 is configured to be elastically deformed more easily in the X-axis direction than in the Y-axis direction and the Z-axis direction. Further, the pair of fifth elastic members 55 connected to the lever arm member 10 on the left side in fig. 5 is configured to be elastically deformed more easily in the Y-axis direction than in the X-axis direction and the Z-axis direction. Further, the pair of fifth elastic members 55 connected to the lever arm member 10 on the right side in fig. 5 is configured to be elastically deformed more easily in the Y-axis direction than in the X-axis direction and the Z-axis direction. The rigidity of the fifth elastic member 55 configured to be easily elastically deformed in the X-axis direction is smaller in the X-axis direction than in the Y-axis direction and the Z-axis direction. The rigidity of the fifth elastic member 55 configured to be easily elastically deformed in the Y-axis direction is smaller in the Y-axis direction than in the X-axis direction and the Z-axis direction.

Each of the plurality (eight) of fifth elastic members 55 is a spring. Each of the plurality of fifth elastic members 55 has a folded portion in a plan view in the thickness direction D1 defined with respect to the base plate 2. The folded portion has a U-shape in a plan view in the thickness direction D1 defined with respect to the base plate 2. Each of the plurality of fifth elastic members 55 has one folded portion.

In the angular velocity sensor 1A, the four third elastic members 53, the four lever arm members 10, the eight fourth elastic members 54, and the eight fifth elastic members 55 are components that are not fixed to the substrate 2, and are separated from the main surface 21 of the substrate 2 in the thickness direction D1 (see fig. 2 and 3) of the substrate 2.

In the angular velocity sensor 1A according to the second embodiment, the four third elastic members 53, the four lever arm members 10, the eight fourth elastic members 54, and the eight fifth elastic members 55 have the same size in the Z-axis direction along the thickness direction D1 defined with respect to the substrate 2, and have the same size in the Z-axis direction as other components that are not fixed to the substrate 2. This facilitates production and design in relation to the degree of rigidity and the like of the angular velocity sensor 1A. In the angular velocity sensor 1A, the four structural components 3, the four third elastic members 53, the four lever arm members 10, the eight fourth elastic members 54, and the eight fifth elastic members 55 are constituted by different portions of the silicon layer of the SOI wafer.

Fig. 6 is a schematic diagram schematically showing the configuration of an angular velocity sensor 1A according to the second embodiment. In fig. 6, the shape and the like of each component may be different from the actual shape and the like. For example, in fig. 6, the first elastic member 51, the second elastic member 52, the third elastic member 53, the fourth elastic member 54, and the fifth elastic member 55 are schematically represented by "spring" symbols, which do not represent actual shapes of the first elastic member 51, the second elastic member 52, the third elastic member 53, the fourth elastic member 54, and the fifth elastic member 55. Note that the direction in which one end and the other end of each "spring" symbol are aligned corresponds to the direction in which elastic deformation easily occurs.

The angular velocity sensor 1A according to the second embodiment is configured to vibrate the four weight members 41 to 44, respectively. In the angular velocity sensor 1A, for example, when the weight member 41 and the weight member 42 move toward each other, the weight member 43 and the weight member 44 move apart from each other, but when the weight member 41 and the weight member 42 move apart from each other, the weight member 43 and the weight member 44 move toward each other. Further, in the angular velocity sensor 1A, for example, when the weight member 41 and the weight member 44 move toward each other, the weight member 42 and the weight member 43 move apart from each other, but when the weight member 41 and the weight member 44 move apart from each other, the weight member 42 and the weight member 43 move toward each other. In summary, in the angular velocity sensor 1A according to the second embodiment, the weight members 4 of two structural assemblies 3 aligned in the row direction (X-axis direction) among the four structural assemblies 3 aligned in a 2 × 2 two-dimensional array move in phase opposition in a synchronized manner, the weight members 4 of two structural assemblies 3 aligned in the column direction (Y-axis direction) move in phase opposition in a synchronized manner, and the weight members 4 of two structural assemblies 3 aligned in the diagonal direction move in phase in a synchronized manner. The above-described synchronization sets, each including the lever arm member 10, the pair of fourth elastic members 54, and the pair of fifth elastic members 55, constitute a lever mechanism for driving and synchronizing the weight members 4 of two adjacent structural assemblies 3 in phase opposition. Therefore, in the angular velocity sensor 1A, the signal processing apparatus vibrates and synchronizes the weight members 4 of two adjacent structural components 3 in phase opposition. In this case, the signal processing device is configured to control the driving portions 8 of the four structural components 3, respectively, and the processing circuit is configured to perform differential detection based on the outputs of the detection portions 9 corresponding to the weight members 4 having different phases.

In the angular velocity sensor 1A according to the second embodiment, similarly to the angular velocity sensor 1 of the first embodiment, the electrode portions (the second comb teeth 822) of the first input electrode 81 and the second input electrode 82 are located between the frame-like member 6 and the weight member 4 in a prescribed direction in a plan view on the thickness direction D1 defined with respect to the substrate 2, and therefore, the angular velocity sensor 1A can be increased in sensitivity while being reduced in size.

Fig. 7 is a schematic diagram schematically showing an angular velocity sensor 1B according to a first modification of the second embodiment. The angular velocity sensor 1B according to the first modification is different from the angular velocity sensor 1A according to the second embodiment in that: two structural components 3 are joined to one another instead of four structural components 3. In the angular velocity sensor 1B according to the first modification of the second embodiment, components similar to those in the angular velocity sensor 1A according to the second embodiment are denoted by the same reference numerals as those in the second embodiment, and the description thereof will be omitted. It is to be noted that fig. 7 is a schematic diagram schematically showing the configuration of the angular velocity sensor 1B. In fig. 7, the shape and the like of each component may be different from the actual shape and the like.

In the angular velocity sensor 1B according to the first modification of the second embodiment, similarly to the angular velocity sensor 1 of the first embodiment, the electrode portions (the second comb teeth 822) of the first input electrode 81 and the second input electrode 82 are located between the frame-like member 6 and the weight member 4 in a prescribed direction in a plan view on the thickness direction D1 defined with respect to the substrate 2, and therefore, the angular velocity sensor 1B can be increased in sensitivity while being reduced in size.

(variants)

The embodiments described are merely examples of various embodiments of the disclosure. Various modifications may be made in accordance with the design and the like as long as the object of the present disclosure is achieved.

As long as the outer peripheral shape of the weight member 4 in a plan view in the thickness direction D1 defined with respect to the base plate 2 is a polygonal shape, it is not limited to a square shape, but may be, for example, a hexagonal shape. Further, the outer peripheral shape of the weight member 4 is not limited to the polygonal shape, but may be, for example, a circular shape.

Further, the angular velocity sensor 1A, and the angular velocity sensor 1B need not be produced by using an SOI wafer, but may be produced by using a silicon wafer and a glass wafer, for example, by a production technique of MEMS, anodic bonding technique, or the like. The material used for the glass wafer is, for example, borosilicate glass.

Further, in the structural assembly 3, the number of the first folds 513 of each first elastic member 51 is different from the number of the second folds 523 of the second elastic member 52, but this should not be construed as a limitation, and the number of the first folds 531 may be the same as the number of the second folds 523.

Further, as long as the first elastic member 51 has a meandering shape in a plan view, the shape of the first elastic member 51 is not limited to a curved shape, but may be a wave shape (e.g., a sine wave shape). Further, the shape of the first elastic member 51 is not limited to a meandering shape, but may be, for example, a shape having one or more loop portions. The opening shape of each loop portion is not limited to a rectangular shape, but may be, for example, an elliptical shape, a rhombic shape, or a hexagonal shape.

Further, the shape of the second elastic member 52 to the fifth elastic member 55 is not limited to a zigzag shape, but may be, for example, a shape having one or more loop portions. Further, the first elastic member 51, the second elastic member 52, the third elastic member 53, the fourth elastic member 54, and the fifth elastic member 55 are not limited to springs, but are at least elastic bodies. Further, the number of each of the first elastic member 51, the second elastic member 52, the third elastic member 53, the fourth elastic member 54, and the fifth elastic member 55 may be modified accordingly.

Further, the material for the first elastic member 51, the second elastic member 52, the third elastic member 53, the fourth elastic member 54, and the fifth elastic member 55 is not limited to silicon, but may be, for example, metal, alloy, conductive resin, or the like.

Further, each frame-like member 6 is not limited to a completely closed frame in a plan view in the thickness direction D1 defined with respect to the base plate 2, but may have a partially cut-off frame shape, and may be, for example, a C-shape or a U-shape. Further, the plurality of frame-like members 6 are not limited to having the same shape, but may have different shapes.

(facet)

The angular velocity sensor (1; 1A; 1B) according to the first aspect comprises a substrate (2) and a structural component (3). The structural component (3) is arranged on the main surface (21) side of the substrate (2). The structural assembly (3) includes a weight member (4), a frame-like member (6), an elastic member (5), an anchor member (7), a first input electrode (81), a second input electrode (82), a first reference electrode (91), and a second reference electrode (92). The frame-like member (6) is aligned with the weight member (4) in a prescribed direction orthogonal to a thickness direction (D1) defined with respect to the substrate (2), and is displaceable in the prescribed direction. The elastic member (5) connects the weight member (4) to the frame-like member (6), and is elastically deformable in a direction orthogonal to a thickness direction (D1) defined with respect to the substrate (2) and a prescribed direction. The anchor member (7) supports the frame-like member (6) and is fixed to the base plate (2). The first input electrode (81) is located outside the frame-like member (6) to be separated from the frame-like member (6), and is fixed to the substrate (2). The second input electrode (82) includes an electrode portion (second comb tooth 822) located outside the frame-like member (6) and connected to the frame-like member (6). The second input electrode (82) faces the first input electrode (81) and is displaceable in a prescribed direction. The first reference electrode (91) is located inside the frame-like member (6) and is fixed to the substrate (2). The second reference electrode (92) includes an electrode portion (second comb tooth 922) located inside the frame-like member (6) and connected to the frame-like member (6). The second reference electrode (92) faces the first reference electrode (91) and is displaceable in a prescribed direction. In the structural component (3), the electrode portions (second comb teeth 822) of the first input electrode (81) and the second input electrode (82) are located between the frame-like member (6) and the weight member (4) in a prescribed direction in a plan view in the thickness direction (D1) defined with respect to the substrate (2).

The angular velocity sensor (1; 1A; 1B) according to the first aspect has an improved sensitivity while being reduced in size.

In an angular velocity sensor (1; 1A; 1B) of a second aspect referring to the first aspect, the weight member (4) has an outer peripheral shape that is a polygonal shape in a plan view in a thickness direction (D1) defined with respect to the substrate (2). The structural assembly (3) comprises a plurality of sets, each set comprising an elastic member (5), a frame-like member (6), a first input electrode (81), a second input electrode (82), a first reference electrode (91) and a second reference electrode (92). The plurality of sets are arranged such that the second input electrodes (82) face the sides of the polygonal shape one-to-one outside the weight member (4).

In the angular velocity sensor (1; 1A; 1B) of the second aspect, the vibration of the weight member (4) is stabilized in a state where no angular velocity acts on the weight member (4), thereby improving the performance.

In an angular velocity sensor (1; 1A; 1B) of a third aspect referring to the first aspect or the second aspect, the elastic member (5) is located outside the weight member (4).

In the angular velocity sensor (1; 1A; 1B) of the third aspect, deformation of the weight member (4) is suppressed, thereby improving performance as compared with, for example, a case where the weight member (4) has a cutout and the elastic member (5) is located in the cutout.

In an angular velocity sensor (1; 1A; 1B) of a fourth aspect referring to any one of the first to third aspects, the structural component (3) further includes a projection (65). The projection (65) projects from the frame-like member (6) toward the anchor member (7). The anchor member (7) has a recess (75) in which the projection (65) is located. In a plan view in a thickness direction (D1) defined with respect to the substrate (2), a space is provided between the convex portion (65) and the concave portion (75).

In an angular velocity sensor (1; 1A; 1B) according to the fourth aspect, a projection (65) that is in contact with a recess (75) limits the displacement of a frame-like member (6) and prevents an elastic member (5) and the like from being damaged. Further, in the angular velocity sensor (1; 1A; 1B) of the fourth aspect, deformation of the frame-like member (6) is reduced, thereby improving performance as compared with a case where the protrusion (65) protrudes from the anchor member (7) and the frame-like member (6) has the recess (75).

In an angular velocity sensor (1; 1A; 1B) of a fifth aspect referring to any one of the first to fourth aspects, a first anchor member (71) as the anchor member (7) is adjacent to the frame-like member (6) in a direction orthogonal to a prescribed direction in a plan view in a thickness direction (D1) defined with respect to the substrate (2). The structural assembly (3) further comprises a second anchor member (72). The second anchor member (72) is fixed to the substrate (2), is located between the first anchor member (71) and the weight member (4), and is connected to the first anchor member (71), in a plan view in a thickness direction (D1) defined with respect to the substrate (2).

In the angular velocity sensor (1; 1A; 1B) of the fifth aspect, the substrate (2) supports the structural component (3) more stably, thereby improving performance.

In an angular velocity sensor (1; 1A; 1B) of a sixth aspect with reference to the fifth aspect, the structural assembly (3) further comprises a third anchor member (73). In a plan view in a thickness direction (D1) defined with respect to the substrate (2), the third anchor member (73) is fixed to the substrate (2), is located between the second anchor member (72) and the weight member (4), and is connected to the second anchor member (72).

In the angular velocity sensor (1; 1A; 1B) of the sixth aspect, the substrate (2) supports the structural component (3) more stably, thereby improving performance.

In an angular velocity sensor (1; 1A; 1B) of a seventh aspect referring to any one of the first to sixth aspects, the first reference electrode (91) includes a plurality of first comb teeth (912). The second reference electrode (92) includes a base (921) and a plurality of second comb teeth (922) as an electrode portion of the second reference electrode (92), and the plurality of second comb teeth (922) extend from the base (921). The plurality of first comb teeth (912) and the plurality of second comb teeth (922) are alternately aligned one by one in a prescribed direction and are separated from each other. A portion of the frame-like member (6) also serves as a base (921) of the second reference electrode (92).

The angular velocity sensor (1; 1A; 1B) of the seventh aspect has an improved sensitivity while being reduced in size.

In an angular velocity sensor (1; 1A; 1B) of an eighth aspect with reference to any one of the first to seventh aspects, the structural component (3) includes a second elastic member (52) in addition to the first elastic member (51) as the elastic member (5). The second elastic member (52) connects the frame-like member (6) to the anchor member (7) and is elastically deformable. The first elastic member (51) has at least one first fold (513) in a plan view in a thickness direction (D1) defined with respect to the substrate (2). The second elastic member (52) is elastically deformable in a prescribed direction, and has at least one second fold (523) in a plan view in a thickness direction (D1) defined with respect to the substrate (2). The at least one first fold (513) of the first elastic member (51) is equal in number to the at least one second fold (523) of the second elastic member (52).

In the angular velocity sensor (1; 1A; 1B) of the eighth aspect, the vibration of the weight member (4) is also stabilized, thereby improving the performance.

In an angular velocity sensor (1A; 1B) of a ninth aspect with reference to the second aspect, the structural component (3) includes a plurality of structural components (3). The angular velocity sensor (1A; 1B) of the ninth aspect further includes a third elastic member (53). The third elastic member (53) connects, in a plan view in a thickness direction (D1) defined with respect to the substrate (2), frame-like members (6) that are closest to each other of two structural components that are adjacent to each other among the plurality of structural components (3). The third elastic member (53) is elastically deformable in a direction in which the frame-like members (6) closest to each other are aligned with each other.

In the angular velocity sensor (1A; 1B) of the ninth aspect, the vibrations of the weight members (4) of two structural components (3) adjacent to each other are synchronized in antiphase, thereby improving the performance.

The angular velocity sensor (1A; 1B) of the tenth aspect with reference to the ninth aspect further includes a lever arm member (10), a pair of fourth elastic members (54), and a pair of fifth elastic members (55). The lever arm member (10) is elongated in a plan view in a thickness direction (D1) defined with respect to the base plate (2). The lever arm member (10) is aligned with two structural components (3) adjacent to each other in a plan view in a thickness direction (D1) defined with respect to the base plate (2). A pair of fourth elastic members (54) connect both ends of the lever arm member (10) in the longitudinal direction to the frame-like member (6) closest to the lever arm member (10) of the two structural components (3). The pair of fourth elastic members (54) are elastically deformable in a predetermined direction. A pair of fifth elastic members (55) connect the middle of the lever arm member (10) in the longitudinal direction to the anchor member (7) closest to the middle of the lever arm member (10) of the two structural components (3). The pair of fifth elastic members (55) are elastically deformable in a direction orthogonal to a thickness direction (D1) defined with respect to the substrate (2) and a predetermined direction.

In an angular velocity sensor (1A; 1B) of a tenth aspect, the weight members (4) of two structural assemblies (3) adjacent to each other are driven in anti-phase and in synchronization with each other.

The configurations of the second to tenth aspects are not essential configurations of the angular velocity sensor (1; 1A; 1B) and thus may be omitted accordingly.

An angular velocity sensor (1; 1A; 1B) according to the eleventh aspect comprises a substrate (2) and a structural component (3). The structural component (3) is arranged on the main surface (21) side of the substrate (2). The structural assembly (3) includes a weight member (4), a pair of frame-like members (6), a pair of first elastic members (51), a pair of anchor members (7), a pair of first input electrodes (81), a pair of second input electrodes (82), a pair of first reference electrodes (91), and a pair of second reference electrodes (92). The weight member (4) has an outer peripheral shape that is a polygonal shape in a plan view in a thickness direction (D1) defined with respect to the substrate (2). The pair of frame-shaped members (6) are positioned on one side and the other side of the weight member (4) in a predetermined direction that is orthogonal to a thickness direction (D1) defined with respect to the substrate (2). The pair of frame-shaped members (6) are displaceable in a predetermined direction. Each of the pair of first elastic members (51) connects the weight member (4) to a corresponding one of the pair of frame-like members (6), and is elastically deformable in a direction orthogonal to a prescribed direction and a thickness direction (D1) defined with respect to the substrate (2). Each of the pair of anchor members (7) supports a corresponding one of the pair of frame-like members (6) and is fixed to the base plate (2). The pair of first input electrodes (81) corresponds one-to-one to the pair of frame-like members (6). Each of the pair of first input electrodes (81) is located outside a corresponding one of the frame-like members (6), is separated from the corresponding one of the frame-like members (6), and is fixed to the substrate (2). The pair of second input electrodes (82) includes electrode portions corresponding to the pair of frame-like members (6) one by one. Each of the electrode portions is located outside a corresponding one of the frame-like members (6), and is connected to the corresponding one of the frame-like members (6). Each of the pair of second input electrodes (82) faces a corresponding one of the first input electrodes (81) and is displaceable in a prescribed direction. The pair of first reference electrodes (91) corresponds one-to-one to the pair of frame-like members (6). Each of a pair of first reference electrodes (91) is located inside a corresponding one of the frame-like members (6) and fixed to the substrate (2). The pair of second reference electrodes (92) includes electrode portions corresponding to the pair of frame-like members (6) one by one. Each of the electrode portions is located inside a corresponding one of the frame-like members (6), and is connected to the corresponding one of the frame-like members (6). The pair of second reference electrodes (92) faces the pair of first reference electrodes (91) and is displaceable in a prescribed direction. In the structural assembly (3), each of the first input electrodes (81) and a corresponding one of the electrode portions of the second input electrode (82) are located between the weight member (4) and a corresponding one of the pair of frame-like members (6) in a prescribed direction in a plan view in a thickness direction (D1) defined with respect to the substrate (2).

List of reference numerals

1, 1A, 1B angular velocity sensor

2 base plate

21 major surface

3 structural component

4 weight member

5 elastic member

51 first elastic member

513 first fold

52 second elastic member

523 second folding part

53 third elastic member

54 fourth elastic member

55 fifth elastic member

6 frame-like member

65 bulge

7 Anchor component

71 first anchor member

72 second Anchor Member

73 third anchor member

75 recessed part

8 drive part

81 first input electrode

811 first comb base

812 first comb teeth

82 second input electrode

821 second comb base

822 second comb

9 detection part

91 first reference electrode

911 first comb base

912 first comb tooth

92 second reference electrode

921 base part

922 second comb tooth

10 Lever arm Member

D1 thickness direction.