Physical quantity sensor, electronic device, and moving object

• US 10,197,591 B2
• Filed: 03/13/2018
• Issued: 02/05/2019
• Est. Priority Date: 08/06/2013
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Tanaka, Satoru
• Primary Examiner(s): Schmitt, Benjamin R
• Application Number:
  US15/919,527
• Publication Number:
  US 20180203033A1
• Time in Patent Office: 329 Days
• Field of Search: 7351432
• CPC Class Codes: B81B 2203/04 Electrodes
• CPC Class Codes: B81B 3/0008 Structures for avoiding electrostatic attraction, e.g. avoiding charge accumulation
• 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 according to the embodiment includes: a substrate; a movable body including a movable electrode portion; and a support which supports the movable body around a first shaft to be displaced, in which, when the movable body is divided into a first portion and a second portion with the first shaft as a boundary, the physical quantity sensor includes a first fixed electrode portion which is disposed on the substrate to oppose the first portion, and a second fixed electrode portion which is disposed on the substrate to oppose the second portion, and a guard portion which suppresses an electrostatic force generated between the movable body and the substrate is provided in an inter-electrode area between the first fixed electrode portion and the second fixed electrode portion, on the substrate.

Claims

1. A physical quantity sensor comprising:

a substrate;

a movable body including a movable electrode; and

a support configured to support the movable body to be displaced around a first shaft;

wherein the movable body is divided into a first portion and a second portion by the first shaft, the first portion and the second portion being arranged along a direction orthogonal to the first shaft,

in a plan view, a distance from the first shaft to an opposing end of the first portion is larger than a distance from the first shaft to an opposing end of the second portion in the direction orthogonal to the first shaft,

a first fixed electrode and a second fixed electrode are disposed on the substrate, the first fixed electrode being opposed to the first portion and the second fixed electrode being opposed to the second portion,

a first electrode is electrically connected to the movable body and a second electrode is electrically connected to the movable body, the first electrode and the second electrode being disposed on the substrate,

the first electrode is disposed in a first region of the substrate and a second region of the substrate in the plan view, the first region s arranged between the first fixed electrode and the second fixed electrode in the plan view, and the second region overlaps the movable body and includes an area between the opposing end of the first portion and the first fixed electrode in the plan view, and

the second electrode is disposed in a third region of the substrate different from the first region and the second region, the third region not overlapping the movable body in the plan view, and the second electrode is provided on a side of the second fixed electrode opposite the support and separated from the second fixed electrode.

2. The physical quantity sensor according to claim 1,

wherein the first electrode in the first region is provided in a position overlapped with the support in a plan view.

3. The physical quantity sensor according to claim 1,

wherein a groove is provided between the first electrode in the first region and the first fixed electrode, between the first electrode in the first region and the second fixed electrode, or between the first electrode in the second region and the first fixed electrode.

4. The physical quantity sensor according to claim 1,

wherein a protrusion which projects toward the movable body is provided on at least one of the electrode, the first fixed electrode and the second fixed electrode.

5. The physical quantity sensor according to claim 1,

wherein a plurality of slits are provided in the movable body.

6. The physical quantity sensor according to claim 1,

wherein the substrate is formed of an insulating material.

7. The physical quantity sensor according to claim 1,

wherein the movable body is a semiconductor.

8. The physical quantity sensor according to claim 7,

wherein the semiconductor has conductivity.

9. The physical quantity sensor according to claim 1,

wherein the first fixed electrode, the second fixed electrode, the first electrode, and the second electrode are aluminum, gold or indium-tin-oxide.

10. An electronic apparatus comprising:

the physical quantity sensor according to claim 1.

11. A vehicle comprising:

the physical quantity sensor according to claim 1.