Physical quantity sensor, electronic apparatus, and moving body

• US 9,746,490 B2
• Filed: 08/04/2015
• Issued: 08/29/2017
• Est. Priority Date: 08/13/2014
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Tanaka, Satoru
• Primary Examiner(s): Kwok, Helen
• Application Number:
  US14/817,324
• Publication Number:
  US 20160047837A1
• Time in Patent Office: 756 Days
• CPC Class Codes: B81B 2201/0235 Accelerometers
• CPC Class Codes: B81B 2201/0242 Gyroscopes
• CPC Class Codes: B81B 2201/033 Comb drives
• CPC Class Codes: B81B 2207/097 Interconnects arranged on the substrate or the lid, and covered by the package seal
• CPC Class Codes: B81B 3/0013 Structures dimensioned for mechanical prevention of stiction, e.g. spring with increased stiffness
• CPC Class Codes: B81C 2203/0109 Bonding an individual cap on the substrate
• CPC Class Codes: B81C 2203/031 Anodic bondings
• CPC Class Codes: G01C 19/5719 using planar vibrating masses driven in a translation vibration along an axis
• CPC Class Codes: G01P 15/125 by capacitive pick-up
• CPC Class Codes: G01P 2015/0814 for translational movement of the mass, e.g. shuttle type

Abstract

A physical quantity sensor includes: a base substrate; a movable portion; a plurality of movable electrode fingers which are provided in the movable portion; a fixed electrode finger which is provided on the base substrate; and a fixing portion which fixes the movable portion to the base substrate. In the movable electrode fingers, a movable electrode finger which opposes the fixing portion in the first direction is included. A clearance between the movable electrode finger and the fixing portion is smaller than a clearance between the movable electrode finger and the fixed electrode finger. The width of the movable electrode finger is greater than the width of other movable electrode finger.

Claims

1. A physical quantity sensor comprising:

a base substrate;

a movable portion which is displaceable in a first direction with respect to the base substrate;

a plurality of movable electrode fingers which are provided on the movable portion and disposed along the first direction, the plurality of movable electrode fingers including a first movable electrode finger and a second movable electrode finger;

a fixed electrode finger which is provided on the base substrate, and disposed to oppose the first movable electrode finger in the first direction; and

a fixing portion which fixes the movable portion to the base substrate and is displaceable in the first direction,

wherein the second movable electrode finger opposes the fixing portion in the first direction,

wherein a clearance between the second movable electrode finger and the fixing portion in the first direction is smaller than a clearance between the first movable electrode finger and the fixed electrode finger in the first direction, and

wherein a width of the second movable electrode finger is greater than a width of other movable electrode fingers.

2. The physical quantity sensor according to claim 1,

wherein a part of the fixing portion in the first direction defines a pair of protections that extend toward the second movable electrode finger.

3. The physical quantity sensor according to claim 1,

wherein a width of each of the plurality of movable electrode fingers decreases as a distance from the fixing portion increases.

4. The physical quantity sensor according to claim 1,

wherein one pair of fixing portions are provided to oppose each other in the first direction via the movable portion, and

wherein the movable portion is fixed to the one pair of fixing portions in both end portions in the first direction.

5. The physical quantity sensor according to claim 4,

wherein the second movable finger is located at a terminal end of the movable portion.

6. The physical quantity sensor according to claim 1,

wherein a width of the fixed electrode finger is smaller than the width of the first movable electrode finger.

7. The physical quantity sensor according to claim 1,

wherein a part of the fixing portion defines a pair of projections that extend toward the second movable electrode in a longitudinal direction of the fixing portion.

8. An electronic apparatus comprising:

the physical quantity sensor according to claim 1.

9. An electronic apparatus comprising:

the physical quantity sensor according to claim 2.

10. An electronic apparatus comprising:

the physical quantity sensor according to claim 3.

11. An electronic apparatus comprising:

the physical quantity sensor according to claim 4.

12. An electronic apparatus comprising:

the physical quantity sensor according to claim 5.

13. An electronic apparatus comprising:

the physical quantity sensor according to claim 6.

14. An electronic apparatus comprising:

the physical quantity sensor according to claim 7.

15. A moving body comprising:

the physical quantity sensor according to claim 1.

16. A moving body comprising:

the physical quantity sensor according to claim 2.

17. A moving body comprising:

the physical quantity sensor according to claim 3.

18. A moving body comprising:

the physical quantity sensor according to claim 4.

19. A moving body comprising:

the physical quantity sensor according to claim 5.

20. A moving body comprising:

the physical quantity sensor according to claim 6.