MASS FOR USE IN A MICRO-ELECTRO-MECHANICAL-SYSTEM SENSOR AND 3-DIMENSIONAL MICRO-ELECTRO-MECHANICAL-SYSTEM SENSOR USING SAME

• US 20110162453A1
• Filed: 01/05/2010
• Published: 07/07/2011
• Est. Priority Date: 01/05/2010
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: PixArt Imaging Incorporated
• Inventors: Lee, Sheng-Ta, Wang, Chuan-Wei
• Granted Patent: US 8,424,383 B2
• Time in Patent Office: Days
• US Class Current: 73/514.32
• CPC Class Codes: G01P 15/125 by capacitive pick-up
• CPC Class Codes: G01P 15/18 in two or more dimensions
• CPC Class Codes: G01P 2015/082 for two degrees of freedom of movement of a single mass

Abstract

A 3-dimensional MEMS sensor, comprising: a first axis fixed electrode; a second axis fixed electrode; a third axis fixed electrode; a movable electrode frame including a first axis movable electrode, a second axis movable electrode, a third axis movable electrode, and a connection part connecting the movable electrodes, wherein the first axis movable electrode and the first axis fixed electrode form a first capacitor along the first axis, the second axis movable electrode and the second axis fixed electrode form a second capacitor along the second axis, and the third axis movable electrode and the third axis fixed electrode form a third capacitor along the third axis, the connection part including a center mass, wherein the center mass is at least connected with one of the first, second and third axis movable electrodes, and has an outer periphery and a first interconnecting segment connecting at least two adjacent sides of the outer periphery; at least one spring connecting with the movable electrode frame; and at least one anchor connecting with the spring, wherein the first, second and third axes are not parallel to one another such that they define a 3-dimensional coordinate system.

Claims

1. A 3-dimensional MEMS sensor, comprising:

a first axis fixed electrode;

a second axis fixed electrode;

a third axis fixed electrode;

a movable electrode frame including a first axis movable electrode, a second axis movable electrode, a third axis movable electrode, and a connection part connecting the movable electrodes, wherein the first axis movable electrode and the first axis fixed electrode form a first capacitor along the first axis, the second axis movable electrode and the second axis fixed electrode form a second capacitor along the second axis, and the third axis movable electrode and the third axis fixed electrode form a third capacitor along the third axis, the connection part including a center mass, wherein the center mass is connected with at least one of the first, second and third axis movable electrodes, and has an outer periphery and a first interconnecting segment connecting at least two adjacent sides of the outer periphery;

at least one spring connecting with the movable electrode frame; and

at least one anchor connecting with the spring,

wherein the first, second and third axes are not parallel to one another such that they define a 3-dimensional coordinate system.

2. The 3-dimensional MEMS sensor of claim 1, wherein the third axis fixed electrode and the movable electrode frame are in different planes.

3. The 3-dimensional MEMS sensor of claim 1, wherein the first axis is x-axis, the second axis is y-axis, and the third axis is z-axis, wherein the three axes are perpendicular to one another, and the movable electrode frame is symmetrical along the x-axis, y-axis, or both x-and y-axes.

4. The 3-dimensional MEMS sensor of claim 1, wherein the connection part further includes at least one extended connection body by which the center mass is connected with at least one of the first, second, and third axis movable electrodes.

5. The 3-dimensional MEMS sensor of claim 1, wherein the first axis movable electrode and the second axis movable electrode are located at locations extending from four sides of the center mass.

6. The 3-dimensional MEMS sensor of claim 1, wherein the first axis movable electrode and the second axis movable electrode are located at locations extending from four corners of the center mass.

7. The 3-dimensional MEMS sensor of claim 1, wherein the third axis movable electrode is located at locations extending from four sides of the center mass.

8. The 3-dimensional MEMS sensor of claim 1, wherein the third axis movable electrode is located at locations extending from four corners of the center mass.

9. The 3-dimensional MEMS sensor of claim 1, wherein the center mass further includes a second interconnecting segment connecting to the first interconnecting segment.

10. The 3-dimensional MEMS sensor of claim 1, wherein the center mass further includes a second interconnecting segment connecting at least two opposite sides of the outer periphery.

11. The 3-dimensional MEMS sensor of claim 1, wherein the connection part further includes at least one periphery mass connecting with the first axis movable electrode, the second axis movable electrode, or both.

12. The 3-dimensional MEMS sensor of claim 11, wherein the periphery mass has an opening.

13. The 3-dimensional MEMS sensor of claim 11, wherein the periphery mass has a plurality of openings not totally in alignment.

14. The 3-dimensional MEMS sensor of claim 1, wherein the first axis fixed electrode, the second axis fixed electrode, or both, have a fixing stud which is located closer to the center of the movable electrode frame than to the periphery of the movable electrode frame.

15. A mass for a MEMS sensor, the MEMS sensor including a fixed electrode and a movable electrode, wherein the movable electrode is movable relatively to the fixed electrode, the mass being connected with the movable electrode and comprising:

an outer periphery, and a first interconnecting segment connecting at least two adjacent sides of the outer periphery.

16. The mass of claim 15, further comprising a second interconnecting segment connecting to the first interconnecting segment.

17. The mass of claim 15, further comprising a second interconnecting segment connecting at least two opposite sides of the outer periphery.

18. The mass of claim 15, wherein the MEMS sensor is a single axis sensor and the movable electrode is movable relatively to the fixed electrode in one dimension.

19. The mass of claim 15, wherein the MEMS sensor is a dual-axis sensor, and wherein the movable electrode includes a first axis movable electrode and a second axis movable electrode, and the fixed axis electrode includes a first axis fixed electrode and a second axis fixed electrode;

the first axis movable electrode being movable relatively to the first axis fixed electrode along the first axis, and the second axis movable electrode being movable relatively to the second axis fixed electrode along the second axis, wherein the first and second axes are not parallel to each other.

20. The mass of claim 15, wherein the MEMS sensor is a tri-axis sensor, and wherein the movable electrode includes a first axis movable electrode, a second axis movable electrode, and a third axis movable electrode, and the fixed axis electrode includes a first axis fixed electrode, a second axis fixed electrode, and a third axis fixed electrode;

the first axis movable electrode being movable relatively to the first axis fixed electrode along the first axis, the second axis movable electrode being movable relatively to the second axis fixed electrode along the second axis, and the third axis movable electrode being movable relatively to the third axis fixed electrode along the third axis, wherein the first, second and third axes are not parallel to one another.