MICRO-ELECTRO-MECHANICAL-SYSTEM DEVICE WITH OSCILLATING ASSEMBLY

• US 20130167635A1
• Filed: 04/30/2012
• Published: 07/04/2013
• Est. Priority Date: 12/30/2011
• Status: Active Grant

• Current Assignee: Industrial Technology Research Institute
• Original Assignee: Industrial Technology Research Institute
• Inventors: Huang, Chao-Ta, Lin, Shih-Chieh, Hsu, Yu-Wen, Su, Chung-Yuan
• Granted Patent: US 9,046,367 B2
• Time in Patent Office: Days
• US Class Current: 73/504.12
• CPC Class Codes: G01C 19/5747 each sensing mass being connected to a driving mass, e.g. driving frames

Abstract

A micro-electro-mechanical-system (MEMS) device comprising two proof masses disposed in the first frame, such that the MEMS device with oscillating assemblies senses the angular velocity in the two axes, respectively. The MEMS device with oscillating assemblies further comprises a lever structure and two oscillating assemblies connecting at two opposite ends of the lever structure, such that the oscillating assemblies move in opposite directions synchronously. The MEMS device with oscillating assemblies further comprises a spring assembly connected between the proof mass and a movable electrode, restricting the proof mass to drive the movable electrode to only move in a specific direction.

Claims

1. A micro-electro-mechanical-system (MEMS) device, being adapted to sense angular velocities in two orthogonal axes, comprising:

at least one oscillating assembly including;

a first frame having an oscillating direction along a second axis;

a third frame, disposed within the first frame;

a first proof mass, disposed within the third frame;

a plurality of torsional beams, connecting the first proof mass and the third frame; and

a plurality of first springs, connecting the first frame and the third frame along a first axis, wherein the first axis is orthogonal to the second axis.

2. The MEMS device of claim 1, further comprising:

at least one lever, wherein one end of the at least one lever is connected to one oscillating assembly, and the other end of the at least one lever is connected to another oscillating assembly, and the lever leads the two oscillating assemblies oscillating in opposite directions along the second axis.

3. The MEMS device of claim 2, further comprising:

a plurality of buffer springs, wherein each oscillating assembly is connected to a corresponding end of the lever by one buffer spring.

4. The MEMS device of claim 1, further comprising:

at least one lever;

at least one base;

at least one first assembly of springs including;

a plurality of elastic members, each of the elastic members connecting the at least one lever and the at least one base; and

a support surrounded by the elastic members, the at least one lever and the at least one base;

wherein, the at least one oscillating assembly is connected to an end of the at least one lever, and the at least one lever is connected to one portion of the support and each of the plurality of elastic members is respectively connected to another portion of the support.

5. The MEMS device of claim 1, further comprising:

at least one base;

at least one movable electrode;

a plurality of restraining springs connecting the at least one movable electrode and the at least one base, the second-axis stiffness of each of the restraining springs is greater than the first-axis stiffness of each of the restraining springs;

at least one second assembly of springs, traversing the first frame and connecting the third frame and the at least one movable electrode, including;

at least one fourth spring aligned along the second axis;

at least one movable linkage, wherein an end of the movable linkage is connected to the at least one fourth spring and a moving direction of the at least one movable linkage is the same as the moving direction of the at least one movable electrode.

6. The MEMS device of claim 1, wherein the first proof mass is connected by the torsional beams along an eccentric axis.

7. The MEMS device of claim 1, wherein the first proof mass is a second frame connected by the torsional beams along an eccentric axis.

8. The MEMS device of claim 1, wherein the torsional beams are connected to the first proof mass along a central axis, and the density of the first proof mass is not distributed symmetrically with respect to the central axis.

9. The MEMS device of claim 1, wherein the torsional beams are connected to the first proof mass along a central axis, and the first proof mass comprises at least one opening, and the mass of the first proof mass is not uniformly distributed.

10. The MEMS device of claim 1, wherein the torsional beams are connected to the first proof mass along a central axis, the contour of the first proof mass is not symmetrically shaped with respect to the central axis.

11. The MEMS device of claim 1, wherein the torsional beams are connected to the first proof mass along a central axis, the thickness of the first proof mass is varied along the axis which is orthogonal to the central axis.

12. An MEMS device, being adapted to control the displacement direction of two oscillating units comprising:

at least one base;

at least one lever;

at least one first assembly of springs including;

two elastic members, each of the elastic members connecting the at least one lever and the at least one base; and

at least one support connecting the at least one lever and the two elastic members; and

two oscillating units, wherein one oscillating unit is connected to an end of the at least one lever and another oscillating unit is connected to another end of the at least one lever.

13. The MEMS device of claim 12, wherein the at least one support is surrounded by the two elastic members, the at least one lever and the at least one base;

wherein the at least one lever is connected to one portion of the at least one support and the two elastic members are respectively connected to other portions of the at least one support.

14. The MEMS device of claim 12, wherein the two oscillating units are two oscillating assemblies, each of the oscillating assemblies comprising:

at least one first frame connected to an end of the at least one lever;

at least one third proof mass disposed within the first frame;

at least one movable electrode;

a plurality of restraining springs connecting the at least one movable electrode and the at least one base, wherein the second-axis stiffness of each of the restraining springs is greater than the first-axis stiffness of each of the restraining springs;

at least one second assembly of springs, traversing the first frame and connecting the third proof mass and the at least one movable electrode, including;

at least one fourth spring aligned along the second axis; and

at least one movable linkage, wherein an end of the movable linkage is connected to the at least one fourth spring and the moving direction of the at least one movable linkage is the same as the moving direction of the at least one movable electrode.

15. The MEMS device of claim 12, wherein the two oscillating units are two oscillating assemblies which are respectively connected to the two corresponding ends of the lever;

wherein each of the oscillating assemblies includes;

a first frame having an oscillating direction along a second axis;

at least one third frame disposed within the first frame;

at least one first proof mass disposed within the third frame;

a plurality of torsional beams connecting the at least one first proof mass and the at least one third frame; and

a plurality of first springs connecting the first frame and the at least one third frame along a first axis.

16. The MEMS device of claim 12, wherein the two oscillating units are two identical proof masses.

17. The MEMS device of claim 12, wherein the at least one support further comprises:

a lateral beam, an end of the lateral beam connecting one of the elastic members, and another end of the lateral beam connecting another elastic member; and

a longitudinal beam connecting the lateral beam and the lever.

18. The MEMS device of claim 12, wherein the at least one support further comprises:

an U-shaped beam with two ends connecting the lever; and

two lateral beams, wherein each of the two lateral beams connects an outer portion of the U-shaped beam and one of the elastic members.

19. The MEMS device of claim 12, wherein the at least one support further comprises:

an U-shaped beam with two ends connecting the lever;

a longitudinal beam connecting a concave portion of the U-shaped beam and the lever; and

two lateral beams, wherein each of the lateral beam connects an outer portion of the U-shaped beam and one of the elastic members.

20. The MEMS device of claim 12, wherein the support, being in a shape of an underlined plus sign, further comprises:

two lateral beams, wherein one end of each of the two lateral beams connects one of the elastic member; and

a longitudinal beam connecting the two lateral beams and the lever.

21. The MEMS device of claim 12, wherein the at least one support comprises:

a U-shaped beam with two ends connecting the lever;

a plurality of lateral beams, wherein two of the plurality of lateral beams connect an outer portion of the U-shaped beam and one corresponding elastic members, and another two of the plurality of lateral beams connect another outer portion of the U-shaped beam and another corresponding elastic member; and

at least one longitudinal beam connecting a concave portion of the U-shaped beam and the lever.

22. An MEMS device, being adapted to restrict the moving direction of movable electrode, comprising:

at least one base;

at least one oscillating assembly including;

a first frame having an oscillating direction along a second axis;

at least one third proof mass disposed within the first frame;

a plurality of restraining springs connecting the at least one movable electrode and the at least one base;

at least one second assembly of springs traversing the first frame and connecting the at least one third proof mass and the at least one movable electrode, wherein the second assembly of springs includes;

at least one fourth spring aligned along the second axis;

at least one movable linkage, wherein an end of the movable linkage is connected to the at least one fourth spring and a moving direction of the at least one movable linkage is the same as the moving direction of the at least one movable electrode.

23. The MEMS device of claim 22, wherein the second-axis stiffness of each of the restraining springs is greater than the first-axis stiffness of each of the restraining springs.

24. The MEMS device of claim 22, wherein the at least one third proof mass is a third frame with an opening that are connected by the two ends of the at least one fourth spring.

25. The MEMS device of claim 22, wherein the at least one movable electrode includes a notch that is connected by an end of the at least one movable linkage.

26. The MEMS device of claim 22, wherein the MEMS device further comprises:

at least one unbalanced proof mass;

a plurality of torsional beams; and

a plurality of first springs;

wherein the at least one third proof mass is a third frame and the at least one unbalanced proof mass is disposed within the third frame;

wherein each of the plurality of torsional beams connects the at least one unbalanced proof mass and the third frame;

wherein each of first springs, respectively connects the first frame and the third frame along a first axis.

27. The MEMS device of claim 22, further comprising:

at least one lever;

at least one first assembly of springs including;

two elastic members, each of the elastic members connecting the at least one lever and the at least one base; and

at least one support surrounded by the two elastic members, the at least one lever and the at least one base;

wherein the at least one lever is connected by at least one portion of the at least one support, and each of the elastic members is connected by at least one another portion of the at least one support.

28. The MEMS device of claim 24, the second assembly of springs further comprising:

a central turning region of the fourth spring;

two turning regions of the fourth spring disposed symmetrically with respectively to a central turning region of the fourth spring; and

at least one support linkage connecting two turning regions of the fourth spring along the second axis;

wherein, an end of the at least one movable linkage is connected to the central turning region of the fourth spring.

29. The MEMS device of claim 22, wherein the movable linkage of the second assembly of springs further comprising:

two first linkages, each of the first linkages connecting the fourth spring and the third proof mass; and

at least one second linkage, connecting the fourth spring and the movable electrode.

30. The MEMS device of claim 22, wherein the movable linkage of the second assembly of springs further comprising:

two first linkages, each of the first linkages connecting the fourth spring and the movable electrode; and

at least one second linkage connecting the fourth spring and the third proof mass.

31. The MEMS device of claim 29, wherein one end of the at least one second linkage connects a transition region which is located at the central portion of the fourth spring and is closer to the third proof mass.

32. The MEMS device of claim 29, wherein one end of the at least one second linkage connects a transition region which is located at the central portion of the fourth spring and is closer to the movable electrode.

33. The MEMS device of claim 30, wherein one end of the at least one second linkage connects a transition region, which is located at the central portion of the fourth spring and is closer to the third proof mass.

34. The MEMS device of claim 30, wherein one end of the at least one second linkage connects a transition region, which is located at the central portion of the fourth spring and is closer to the movable electrode.

35. The MEMS device of claim 22, wherein the second assembly of springs comprises:

two fourth springs;

a plurality of the movable linkages including;

two first linkages;

two second linkages disposed between the two first linkages;

wherein one end of each of the fourth springs connects the first linkages and the another end of each of the fourth springs connects the second linkages.

36. An MEMS device, being adapted to sense angular velocities in two orthogonal axes, comprising:

at least one base;

at least one lever;

at least one first assembly of springs including;

a plurality of elastic members connecting the at least one lever and the at least one base;

a support surrounded by the plurality of elastic members, the at least one lever and the at least one base;

wherein the at least one lever is connected by at least one portion of the support, and each of the plurality of elastic members is respectively connected by at least one other portion of the support;

two oscillating assemblies, each of the oscillating assemblies including;

a first frame connected to an end of the at least one lever, the first frame oscillating along a second axis;

a third frame disposed within the first frame;

an unbalanced proof mass disposed within the third frame;

at least one torsional beam connecting the unbalanced proof mass and the third frame;

at least one first spring connecting the first frame and the third frame along a first axis;

at least one movable electrode;

a plurality of restraining springs connecting the at least one movable electrode and the at least one base, wherein the second-axis stiffness of each of the restraining springs is greater than the first-axis stiffness of each of the restraining springs;

at least one second assembly of springs traversing the first frame and connecting the third frame and the at least one movable electrode, including;

at least one fourth spring disposed along the second axis, wherein two ends of the at least one fourth spring is connected to the third frame; and

at least one movable linkage connecting the at least one fourth spring and the at least one movable electrode, wherein the moving direction of the at least one movable linkage is the same as the moving direction of the at least one movable electrode.