Multi-Stage Stopper System for MEMS Devices

• US 20120228725A1
• Filed: 01/16/2008
• Published: 09/13/2012
• Est. Priority Date: 01/16/2007
• Status: Active Grant

• Current Assignee: Analog Devices, Inc.
• Original Assignee: Analog Devices, Inc.
• Inventors: Zhang, Xin, Judy, Michael W.
• Granted Patent: US 8,516,891 B2
• Time in Patent Office: Days
• US Class Current: 257/415
• CPC Class Codes: B81B 2201/0235 Accelerometers
• CPC Class Codes: B81B 2201/0242 Gyroscopes
• CPC Class Codes: B81B 3/0051 For defining the movement, i.e. structures that guide or limit the movement of an element mechanical arrangements for preventing or damping vibration or shock H01H3/60

Abstract

A MEMS sensing system includes a movable mass having at least one contact surface, a stopper system for stopping the movement of the mass, the stopper system having at least one contact surface that contacts a corresponding contact surface of the mass if a sufficient movement of the mass occurs in a direction, at least one stopper gap formed between the at least one contact surface of the stopper system and the corresponding contact surface of the mass, and a spring system in communication with the at least one stopper gap.

Claims

1. A MEMS system comprising:

a movable mass having at least one contact surface;

a stopper system for stopping the movement of the mass, the stopper system having at least one contact surface that contacts a corresponding contact surface of the mass if a sufficient movement of the mass occurs in a direction;

at least one stopper gap formed between the at least one contact surface of the stopper system and the corresponding contact surface of the mass; and

a spring system in communication with the at least one stopper gap.

2. The MEMS system of claim 1, wherein a portion of the spring system is serpentine shaped.

3. The MEMS system of claim 1, wherein the spring system is formed in the mass, in the stopper system, or both.

4. The MEMS system of claim 1, wherein the stopper system comprises a stopper and the spring system comprises at least two spring structures, each spring structure in communication with a different stopper gap around the stopper.

5. The MEMS system of claim 1, wherein the stopper system comprises a stopper and the spring system comprises at least two spring structures in communication with the same stopper gap along one side of the stopper.

6. The MEMS system of claim 1, wherein the stopper system comprises a plurality of stoppers, each stopper and the mass having at least one stopper gap between at least one contact surface of the stopper and the corresponding contact surface of the mass, wherein the spring system is in communication with at least one stopper gap in at least one of the plurality of stoppers.

7. The MEMS system of claim 6, wherein the spring system comprises at least two spring structures, each spring structure in communication with at least one stopper gap in each of the plurality of stoppers.

8. The MEMS system of claim 1, wherein the stopper system comprises a stopper and the stopper and the mass are arranged to form at least one protrusion protruding into at least one stopper gap.

9. A MEMS system comprising:

a movable mass having at least one contact surface;

a plurality of stoppers for stopping the movement of the mass, each stopper having at least one contact surface that contacts a corresponding contact surface of the mass if a sufficient movement of the mass occurs in a direction;

stopper gaps between each of the at least one contact surface of the stopper and the corresponding contact surface of the mass; and

a spring system in communication with at least one of the stopper gaps.

10. The MEMS system of claim 9, wherein a portion of the spring system is serpentine shaped.

11. The MEMS system of claim 9, wherein the spring structure is formed in the mass, in the stopper, or both.

12. The MEMS system of claim 9, wherein the spring system comprises at least two spring structures, each spring structure in communication with a different stopper gap around the stopper.

13. A method of producing an impact resistant MEMS sensor, the method comprising:

providing a movable mass having at least one contact surface;

providing a stopper system for stopping the movement of the mass, the stopper system having at least one contact surface that contacts a corresponding contact surface of the mass if a sufficient movement of the mass occurs in a direction;

forming at least one stopper gap between the at least one contact surface of the stopper system and the corresponding contact surface of the mass; and

forming a spring system that abuts the at least one stopper gap.

14. The method of claim 13, wherein the spring system is formed in a serpentine shape.

15. The method of claim 13, wherein the spring system is formed in the mass, in the stopper system, or both.

16. The method of claim 13, wherein the stopper system comprises a stopper and forming a spring system comprises forming at least two spring structures, each spring structure abutting a different stopper gap around the stopper.

17. The method of claim 13, wherein the stopper system comprises a stopper, and forming a spring system comprises forming at least two spring structures abutting the stopper gap along one side of the stopper.

18. The method of claim 13, wherein the stopper system comprises a plurality of stoppers and forming at least one stopper gap comprises forming the at least one stopper gap between at least one contact surface of each stopper and the corresponding contact surface of the mass, and forming a spring system comprises forming more than one spring structure, each spring structure abutting at least one stopper gap in at least one of the plurality of stoppers.

19. The method of claim 18, wherein each spring structure abuts at least one stopper gap in each of the plurality of stoppers.

20. The method of claim 13, further comprising forming at least one protrusion protruding into the at least one stopper gap.