Sensor element, electronic apparatus and moving object

• US 9,476,905 B2
• Filed: 05/01/2014
• Issued: 10/25/2016
• Est. Priority Date: 05/16/2013
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Takagi, Shigekazu
• Primary Examiner(s): CHAPMAN JR, JOHN E
• Application Number:
  US14/267,331
• Publication Number:
  US 20140338451A1
• Time in Patent Office: 908 Days
• Field of Search: 735/143.2
• US Class Current: 1/1
• CPC Class Codes: B81B 2201/0235 Accelerometers
• 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
• CPC Class Codes: G01P 2015/0871 using stopper structures for limiting the travel of the seismic mass

Abstract

A sensor element includes: a detection electrode section; a movable body that is provided to face the detection electrode section; and a protruding section that is provided in a region where the detection electrode section is provided in a plan view of the detection electrode section seen in a vertical direction and protrudes toward the movable body. At least a part of a surface of the protruding section is made of an insulating material.

Claims

1. A sensor element comprising:

a substrate that has a first protrusion protruding upwardly from an upper surface of the substrate;

a first detection electrode that is formed on the upper surface of the substrate and a top surface of the first protrusion, the first detection electrode providing first information for detecting a physical quantity detected by the sensor element;

a first insulating member that is formed on the first detection electrode which is located on the to surface of the first protrusion so that the first insulating member and the first detection electrode are stacked on the to surface of the first protrusion; and

a movable body that moves with respect to a moving axis and that is provided to face the first detection electrode so that the movable body is spaced apart form the first insulating member via a first air gap, the first air gap being chanced when the movable body moves.

2. The sensor element according to claim 1, further comprising:

a second protrusion that protrudes upwardly from the upper surface of the substrate;

a second protrusion electrode that is formed on the upper surface of the substrate and a top surface of the second protrusion, the second detection electrode providing second information for detecting the physical quantity detected by the sensor element; and

a second insulating member that is formed on the second detection electrode which is located on the top surface of the second protrusion so that the second insulating member and the second detection electrode are stacked on the to surface of the second protrusion, wherein

the movable body faces the second detection electrode so that the movable body is spaced apart from the second insulating member via a second air gap, and the second air gap is changed when the movable body moves, and

the first detection electrode is electrically insulated from the second detection electrode.

3. The sensor element according to claim 2,

wherein the second protrusion is provided integrally with the substrate.

4. The sensor element according to claim 2, further comprising:

a second dummy electrode that is formed on the upper surface of the substrate so as to face the movable body in at least a part thereof, the second dummy electrode being electrically insulated from the second detection electrode.

5. The sensor element according to claim 4,

wherein a groove is provided in the bottom of the recess, the groove is provided in one of a region between the second detection electrode and the second dummy electrode and a region between the first detection electrode and the second detection electrode.

6. The sensor element according to claim 4,

wherein the first and second dummy electrodes are electrically connected to the movable body.

7. The sensor element according to claim 1,

wherein the first protrusion is provided integrally with the substrate.

8. The sensor element according to claim 1, further comprising:

a first dummy electrode that is formed on the upper surface of the substrate so as to face the movable body in at least a part thereof, the first dummy electrode being electrically insulated from the first detection electrode.

9. A sensor element comprising:

a substrate that has a recess and a peripheral ledge;

a lid that has a lid peripheral, the lid peripheral being fixed to the peripheral ledge so as to create an inner space;

a movable body that is provided in the inner space, the movable body having first and second members continuously formed via a rotation axis, and the first and second members rotate with respect to the rotation axis;

a first detection electrode that is formed on a bottom of the recess so as to face the first member via a first air gap;

a second detection electrode that is formed on the bottom of the recess so as to face the second member via a second air gap;

a first protruding member that is formed on the bottom of the recess so as to face the first member via a third air gap, the first protruding member being surrounded by the first detection electrode in a plan view;

a second protruding member that is formed on the bottom of the recess so as to face the second member via a fourth air gap, the second protruding member being surrounded by the second detection electrode in the plan view;

a first dummy electrode that is provided on the bottom of the recess between the peripheral ledge and an edge of the first detection electrode, the first dummy electrode being laterally shifted from the first detection electrode and the first member in the plan view;

a second dummy electrode that is provided on the bottom of the recess between the peripheral ledge and an edge of the second detection electrode, the second dummy electrode being laterally shifted from the second detection electrode in the plan view, the second dummy electrode being overlapped with the second member in the plan view, wherein

the first and second air gaps are the same size, and

the first and second dummy electrodes and the lid have a same electric potential.

10. The sensor element according to claim 9,

wherein an insulating material is provided on top surfaces of the first and second protruding members, and the insulating material comes into contact with the movable body.

11. The sensor element according to claim 9,

wherein a groove is provided in the bottom of the recess, the groove is provided in one of a region between the second detection electrode and the second dummy electrode and a region between the first detection electrode and the second detection electrode.

12. The sensor element according to claim 11, further comprising:

a third protruding member that is provided on the bottom of the recess, that protrudes toward the movable body in the vicinity of the rotation axis, and that is provided along an outer edge of the groove.

13. The sensor element according to claim 11,

wherein the first and second dummy electrodes are electrically connected to the movable body.

14. The sensor element according to claim 9,

wherein the first and seconddummy electrodes are electrically connected to the movable body.

15. An electronic apparatus comprising the sensor element according to claim 9 that is mounted therein.

16. A moving object comprising the sensor element according to claim 9 that is mounted therein.