Physical quantity sensor, physical quantity sensor device, electronic equipment, and moving body

• US 10,641,789 B2
• Filed: 10/03/2017
• Issued: 05/05/2020
• Est. Priority Date: 08/15/2014
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Tanaka, Satoru
• Primary Examiner(s): Chapman, Jr., John E
• Application Number:
  US15/723,726
• Publication Number:
  US 20180038888A1
• Time in Patent Office: 945 Days
• CPC Class Codes: G01C 19/5755 the devices having a single sensing mass
• CPC Class Codes: G01C 19/5769 Manufacturing; Mounting; Housings
• CPC Class Codes: G01P 15/125 by capacitive pick-up
• CPC Class Codes: G01P 2015/0831 the mass being of the paddle type having the pivot axis between the longitudinal ends of the mass, e.g. see-saw configuration

Abstract

A physical quantity sensor includes: an oscillating body having a support section and a movable section which is connected to the support section through connection portions, in which the movable section has a first movable portion and a second movable portion; a first fixed electrode which is disposed to face the first movable portion; a second fixed electrode which is disposed to face the second movable portion; and a dummy electrode which is disposed to face the second movable portion so as not to overlap the second fixed electrode and has the same potential as potential of the oscillating body, in which the first fixed electrode is disposed such that a portion thereof overlaps the support section when viewed in a plan view.

Claims

1. A physical quantity sensor having an X-axis, a Y-axis, and a Z-axis that are orthogonal to each other, the physical quantity sensor comprising:

a substrate having a main surface, a first fixed electrode and a second fixed electrode being provided on the main surface, the first and second fixed electrodes being arranged along a direction from a positive side of the X-axis to a negative side of the X-axis;

a movable member including a first mass and a second mass, the first and second masses facing the first and second fixed electrodes along the Z-axis, respectively, the first mass and the second mass being arranged along the X-axis;

a support that is fixed to the substrate, the support being provided between the first mass and the second mass;

a connection member connecting between the movable member and the support, the connection member extending along the Y-axis;

a first dummy electrode that is provided on the main surface of the substrate, the first dummy electrode being located between the first fixed electrode and the second fixed electrode;

a second dummy electrode that is provided on the main surface of the substrate, the second dummy electrode facing a first edge of the first fixed electrode, the first edge being located at an opposite side of the first dummy electrode; and

a third dummy electrode that is provided on the main surface of the substrate, the third dummy electrode facing a second edge of the second fixed electrode in a direction along the X-axis, the second edge being located at an opposite side of the first dummy electrode,

wherein the movable member is movable along the Z-axis with respect to the connection member as a rotation axis,

the first, second, and third dummy electrodes are electrically insulated from the first and second fixed electrodes,

the first, second, and third dummy electrodes are electrically connected to the movable member,

a width of the second dummy electrode along the Y-axis is larger than a width of the first fixed electrode along the Y-axis in a plan view along the Z-axis,

the second dummy electrode is configured with;

a base extending along the Y-axis, the base having a first end and a second end that are opposite to each other along the Y-axis;

a first projection projecting from the first end of the base toward the negative side of the X-axis; and

a second projection projecting from the second end of the base toward the negative side of the X-axis, and

a part of the first fixed electrode is located between the first projection and the second projection along the Y-axis in the plan view along the Z-axis.

2. The physical quantity sensor according to claim 1,

wherein the movable member has a through hole passing through the movable member along the Z-axis in the plan view, and

the support is located in the through hole in the plan view.

3. The physical quantity sensor according to claim 2,

wherein the substrate has a convex on the main surface, and the convex is located between the first fixed electrode and the second fixed electrode in the plan view, and

the support is fixed to the substrate via the convex.

4. The physical quantity sensor according to claim 3,

wherein the support is configured with first and second supports, and the convex is configured with first and second convexes, and

the first support is fixed to the first convex, and the second support is fixed to the second convex.

5. The physical quantity sensor according to claim 4,

wherein each of the first and second masses has a through hole.

6. The physical quantity sensor according to claim 5, further comprising:

a lid that is fixed to the substrate so as to form a cavity between the lid and the substrate,

wherein the movable member is located in the cavity.

7. The physical quantity sensor according to claim 6,

wherein the cavity is filled with an inert gas.

8. An electronic device comprising:

the physical quantity sensor according to claim 1;

a display; and

a case that houses the physical quantity sensor and the display.

9. A movable object comprising:

the physical quantity sensor according to claim 1; and

a movable body that houses the physical quantity sensor.

10. A physical quantity sensor having an X-axis, a Y-axis, and a Z-axis that are orthogonal to each other, the physical quantity sensor comprising:

a substrate having a main surface, a first fixed electrode and a second fixed electrode being provided on the main surface, the first and second fixed electrodes being arranged along a direction from a positive side of the X-axis to a negative side of the X-axis;

a movable member including a first mass and a second mass, the first and second masses facing the first and second fixed electrodes along the Z-axis, respectively, the first mass and the second mass being arranged along the X-axis;

a support that is fixed to the substrate, the support being provided between the first mass and the second mass;

a connection member connecting between the movable member and the support, the connection member extending along the Y-axis;

a first dummy electrode that is provided on the main surface of the substrate, the first dummy electrode being located between the first fixed electrode and the second fixed electrode;

a second dummy electrode that is provided on the main surface of the substrate, the second dummy electrode facing a first edge of the first fixed electrode, the first edge being located at an opposite side of the first dummy electrode; and

a third dummy electrode that is provided on the main surface of the substrate, the third dummy electrode facing a second edge of the second fixed electrode in a direction along the X-axis, the second edge being located at an opposite side of the first dummy electrode,

wherein the movable member is movable along the Z-axis with respect to the connection member as a rotation axis,

the first, second, and third dummy electrodes are electrically insulated from the first and second fixed electrodes,

the first, second, and third dummy electrodes are electrically connected to the movable member,

a width of the first dummy electrode along the Y-axis is larger than a width of the first fixed electrode along the Y-axis in a plan view along the Z-axis,

the first dummy electrode is configured with;

a base extending along the Y-axis, the base having a first end and a second end that are opposite to each other along the Y-axis;

a first projection projecting from the first end of the base toward the positive side of the X-axis; and

a second projection projecting from the second end of the base toward the positive side of the X-axis, and

a part of the first fixed electrode is located between the first projection and the second projection along the Y-axis in the plan view along the Z-axis.

11. The physical quantity sensor according to claim 10,

wherein the movable member has a through hole passing through the movable member along the Z-axis in the plan view, and

the support is located in the through hole in the plan view.

12. The physical quantity sensor according to claim 11,

wherein the substrate has a convex on the main surface, and the convex is located between the first fixed electrode and the second fixed electrode in the plan view, and

the support is fixed to the substrate via the convex.

13. The physical quantity sensor according to claim 12,

wherein the support is configured with first and second supports, and the convex is configured with first and second convexes, and

the first support is fixed to the first convex, and the second support is fixed to the second convex.

14. The physical quantity sensor according to claim 13,

wherein each of the first and second masses has a through hole.

15. The physical quantity sensor according to claim 14, further comprising:

a lid that is fixed to the substrate so as to form a cavity between the lid and the substrate,

wherein the movable member is located in the cavity.

16. A physical quantity sensor having an X-axis, a Y-axis, and a Z-axis that are orthogonal to each other, the physical quantity sensor comprising:

a substrate having a main surface, a first fixed electrode and a second fixed electrode being provided on the main surface, the first and second fixed electrodes being arranged along a direction from a positive side of the X-axis to a negative side of the X-axis;

a movable member including a first mass and a second mass, the first and second masses facing the first and second fixed electrodes along the Z-axis, respectively, the first mass and the second mass being arranged along the X-axis;

a support that is fixed to the substrate, the support being provided between the first mass and the second mass;

a connection member connecting between the movable member and the support, the connection member extending along the Y-axis;

a first dummy electrode that is provided on the main surface of the substrate, the first dummy electrode being located between the first fixed electrode and the second fixed electrode;

a second dummy electrode that is provided on the main surface of the substrate, the second dummy electrode facing a first edge of the first fixed electrode, the first edge being located at an opposite side of the first dummy electrode; and

a third dummy electrode that is provided on the main surface of the substrate, the third dummy electrode facing a second edge of the second fixed electrode in a direction along the X-axis, the second edge being located at an opposite side of the first dummy electrode,

wherein the movable member is movable along the Z-axis with respect to the connection member as a rotation axis,

the first, second, and third dummy electrodes are electrically insulated from the first and second fixed electrodes,

the first, second, and third dummy electrodes are electrically connected to the movable member,

a width of the first fixed electrode along the Y-axis is larger than a width of the second dummy electrode along the Y-axis in a plan view along the Z-axis,

the first fixed electrode is configured with;

a base extending along the Y-axis, the base having a first end and a second end that are opposite to each other along the Y-axis;

a first projection projecting from the first end of the base toward the positive side of the X-axis; and

a second projection projecting from the second end of the base toward the positive side of the X-axis, and

a part of the second dummy electrode is located between the first projection and the second projection along the Y-axis in the plan view along the Z-axis.

17. The physical quantity sensor according to claim 16,

wherein the movable member has a through hole passing through the movable member along the Z-axis in the plan view, and

the support is located in the through hole in the plan view.

18. The physical quantity sensor according to claim 17,

wherein the substrate has a convex on the main surface, and the convex is located between the first fixed electrode and the second fixed electrode in the plan view, and

the support is fixed to the substrate via the convex.

19. The physical quantity sensor according to claim 18,

wherein the support is configured with first and second supports, and the convex is configured with first and second convexes, and

the first support is fixed to the first convex, and the second support is fixed to the second convex.

20. The physical quantity sensor according to claim 19,

wherein each of the first and second masses has a through hole.