PHYSICAL QUANTITY SENSOR AND ELECTRONIC APPARATUS

• US 20130264661A1
• Filed: 04/05/2013
• Published: 10/10/2013
• Est. Priority Date: 04/09/2012
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: TANAKA, Satoru
• Granted Patent: US 9,073,744 B2
• Time in Patent Office: Days
• US Class Current: 257/415
• CPC Class Codes: B81B 3/0018 Structures acting upon the moving or flexible element for transforming energy into mechanical movement or vice versa, i.e. actuators, sensors, generators
• CPC Class Codes: B81B 3/0021 Transducers for transforming electrical into mechanical energy or vice versa dynamo-electric machines H02K99/00; electrostatic machines H02N1/00; piezoelectric devices H10N30/00

Abstract

A physical quantity sensor includes a substrate, a movable body which has first and second sections and in which a first movable electrode section is provided in the first section, a beam section which supports the movable body so as to be able to be displaced, and a first fixed electrode section disposed on the substrate. The first fixed electrode section is provided at a position overlapping an end of the first section in the second axis direction in plan view, and is provided in a range of 0.0500X≦L≦0.816X assuming that the width of the first section in the second axis direction is X and the width of a portion of the first fixed electrode section in the second axis direction overlapping the movable body in plan view is L.

Claims

1. A physical quantity sensor comprising:

a movable body which can be displaced with a first axis as a rotation axis and has first and second sections with the first axis as a boundary in plan view and in which a first movable electrode section is provided in the first section;

a beam section which supports the movable body; and

a first fixed electrode section disposed so as to face the first movable electrode section,

wherein the first fixed electrode section is provided at a position overlapping an end of the first section of the movable body in a direction of a second axis, which is perpendicular to the first axis, in plan view, and is provided in a range of 0.0500X≦

L≦

0.816X assuming that a width of the first section in the second axis direction is X and a width of a portion of the first fixed electrode section in the second axis direction overlapping the movable body in plan view is L.

2. The physical quantity sensor according to claim 1,

wherein the first fixed electrode section is provided in a range of 0.164X≦

L≦

0.633X.

3. The physical quantity sensor according to claim 1,

wherein, in the movable body, the width of the first section in the direction of the second axis perpendicular to the first axis is smaller than a width of the second section in the second axis direction.

4. The physical quantity sensor according to claim 1,

wherein a second fixed electrode section is provided on a substrate so as to face the second section, and

a second movable electrode section is provided in the second section of the movable body.

5. The physical quantity sensor according to claim 4,

wherein a region where the first movable electrode section and the first fixed electrode section overlap each other and a region where the second movable electrode section and the second fixed electrode section overlap each other are symmetrical with respect to the first axis in plan view.

6. The physical quantity sensor according to claim 1,

wherein the first fixed electrode section has a portion protruding from the end in plan view.

7. The physical quantity sensor according to claim 1,

wherein the mass of the first section is smaller than the mass of the second section.

8. The physical quantity sensor according to claim 1,

wherein the substrate is formed of an insulating material, and the movable body is formed of a semiconductor material.

9. An electronic apparatus comprising the physical quantity sensor according to claim 1.