PHYSICAL QUANTITY SENSOR, PHYSICAL QUANTITY SENSOR DEVICE, ELECTRONIC EQUIPMENT, AND MOVING BODY

• US 20160047839A1
• Filed: 08/10/2015
• Published: 02/18/2016
• 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
• Granted Patent: US 9,810,712 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• 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 comprising:

a movable electrode having a support section and a movable section which is connected to the support section through a connection portion and can oscillate with respect to the support section, in which the movable section has a first movable portion which is provided on one side with respect to the connection portion, and a second movable portion which is provided on the other side;

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

an opposite 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 movable electrode,

wherein the first fixed electrode is disposed such that a portion thereof overlaps the support section when viewed in a plan view.

2. The physical quantity sensor according to claim 1, wherein the second fixed electrode is disposed such that a portion thereof overlaps the support section when viewed in a plan view, and when an area of a region overlapping the support section, of the first fixed electrode, is set to be S1 and an area of a region overlapping the support section, of the second fixed electrode, is set to be S2, a relationship of S1>

S2 is satisfied.

3. The physical quantity sensor according to claim 2, wherein when capacitance which is generated between the first fixed electrode and the support section is set to be C1, capacitance which is generated between the second fixed electrode and the support section is set to be C2, and capacitance which is generated between the second fixed electrode and the opposite electrode is set to be C3, a relationship of (C2+C3)×

0.9≦

C1≦

(C2+C3)×

1.1 is satisfied.

4. The physical quantity sensor according to claim 1, wherein the opposite electrode is disposed on the side opposite to the support section, of the second fixed electrode.

5. The physical quantity sensor according to claim 1, wherein when the movable section is viewed in a plan view, the second movable portion has a larger area than the first movable portion.

6. The physical quantity sensor according to claim 1, wherein the support section is disposed in an opening and located between the first movable portion and the second movable portion when viewed in a plan view.

7. The physical quantity sensor according to claim 6, wherein the movable section has an opening portion between the first movable portion and the second movable portion, and the support section is disposed in the opening portion.

8. A physical quantity sensor device comprising:

the physical quantity sensor according to claim 1; and

an electronic component which is electrically connected to the physical quantity sensor.

9. Electronic equipment comprising:

the physical quantity sensor according to claim 1.

10. A moving body comprising:

the physical quantity sensor according to claim 1.

11. A physical quantity sensor comprising:

a substrate;

a support section which is fixed to the substrate;

a movable section which is connected to the support section through a connection portion and can oscillate with respect to the support section; and

a fixed electrode which is disposed on the substrate to face the movable section,

wherein the movable section includes a first mass portion which is provided on one side with respect to the connection portion, a second mass portion which is provided on the other side and has larger mass than the first mass portion, a first movable electrode disposed in the first mass portion, and a second movable electrode disposed in the second mass portion,

the fixed electrode includes a first fixed electrode which is disposed to face the first mass portion, a second fixed electrode which is disposed to face the second mass portion, and a dummy electrode which is disposed to face the movable section so as not to come into contact with the first fixed electrode and the second fixed electrode and has the same potential as potential of the movable section,

the dummy electrode includes a first dummy electrode provided between the first fixed electrode and the second fixed electrode, a second dummy electrode provided on the side opposite to the first dummy electrode, of the first fixed electrode, and a third dummy electrode provided on the side opposite to the first dummy electrode, of the second fixed electrode, and

the fixed electrode and the dummy electrode are disposed such that a capacity offset is smaller than a capacity offset in a case where distances between the first fixed electrode and the first and second dummy electrodes and distances between the second fixed electrode and the first and third dummy electrodes are the same.

12. The physical quantity sensor according to claim 11, wherein when a distance between the first fixed electrode and the first dummy electrode is set to be w1, a distance between the second fixed electrode and the first dummy electrode is set to be w2, a distance between the first fixed electrode and the second dummy electrode is set to be w3, and a distance between the second fixed electrode and the third dummy electrode is set to be w4, a relationship of w1<

w2 and w3=w4 is satisfied.

13. The physical quantity sensor according to claim 11, wherein when a distance between the first fixed electrode and the first dummy electrode is set to be w1, a distance between the second fixed electrode and the first dummy electrode is set to be w2, a distance between the first fixed electrode and the second dummy electrode is set to be w3, and a distance between the second fixed electrode and the third dummy electrode is set to be w4, a relationship of w1<

w2 and w3<

w4 is satisfied.

14. The physical quantity sensor according to claim 11, wherein when a distance between the first fixed electrode and the first dummy electrode is set to be w1, a distance between the second fixed electrode and the first dummy electrode is set to be w2, a distance between the first fixed electrode and the second dummy electrode is set to be w3, and a distance between the second fixed electrode and the third dummy electrode is set to be w4, a relationship of w1<

w2 and w3>

w4 is satisfied.

15. The physical quantity sensor according to claim 11, wherein when a distance between the first fixed electrode and the first dummy electrode is set to be w1, a distance between the second fixed electrode and the first dummy electrode is set to be w2, a distance between the first fixed electrode and the second dummy electrode is set to be w3, and a distance between the second fixed electrode and the third dummy electrode is set to be w4, a relationship of w1>

w2 and w3<

w4 is satisfied.

16. The physical quantity sensor according to claim 11, wherein the substrate is a glass substrate.

17. A physical quantity sensor comprising:

a substrate;

a support section which is fixed to the substrate;

a movable section which is connected to the support section through a connection portion and can oscillate with respect to the support section; and

a fixed electrode which is disposed on the substrate to face the movable section,

wherein the movable section includes a first mass portion which is provided on one side with respect to the connection portion, and a second mass portion which is provided on the other side and has larger mass than the first mass portion,

the fixed electrode includes a first fixed electrode which is disposed to face the first mass portion, a second fixed electrode which is disposed to face the second mass portion, and a dummy electrode which is disposed to face the movable section so as not to come into contact with the first fixed electrode and the second fixed electrode and has the same potential as potential of the movable section, and

when an axial direction in which the movable section is oscillated is set to be a Y-axis direction, at least one of a width in the Y-axis direction of the dummy electrode disposed alongside the first fixed electrode and a width in the Y-axis direction of the first fixed electrode is larger than a width in the Y-axis direction of the second fixed electrode.

18. The physical quantity sensor according to claim 17, wherein the dummy electrode has a first portion which is disposed to face the first fixed electrode in the Y-axis direction.

19. The physical quantity sensor according to claim 18, wherein the first portion is provided in a pair so as to be located on both sides in the Y-axis direction of the first fixed electrode.

20. The physical quantity sensor according to claim 17, wherein the first fixed electrode has a second portion which is disposed to face the dummy electrode in the Y-axis direction.