METHODS AND SYSTEMS FOR DECELERATING PROOF MASS MOVEMENTS WITHIN MEMS STRUCTURES

• US 20040112133A1
• Filed: 12/16/2002
• Published: 06/17/2004
• Est. Priority Date: 12/16/2002
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Weber, Mark W., Glenn, Max C., Platt, William P.
• Granted Patent: US 6,865,944 B2
• Time in Patent Office: Days
• US Class Current: 73/504.12
• 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
• CPC Class Codes: G01C 19/5719 using planar vibrating masses driven in a translation vibration along an axis

Abstract

A micro-electromechanical systems (MEMS) device is described which includes a substrate having at least one anchor, a proof mass having either of at least one deceleration extension extending from the proof mass or at least one deceleration indentation formed in the proof mass, a motor drive comb, and a motor sense comb. The MEMS device further includes a plurality of suspensions configured to suspend the proof mass over the substrate and between the motor drive comb and the motor sense comb, and the suspensions are anchored to the substrate. The MEMS device also includes a body attached to the substrate and at least one deceleration beam extending from the body. The deceleration extensions are configured to engage either deceleration beams or deceleration indentations and slow or stop the proof mass before it contacts either of the motor drive comb or the motor sense comb.

Claims

1. A micro-electromechanical systems (MEMS) device comprising:

a substrate comprising at least one anchor;

a proof mass comprising either of at least one deceleration extension extending from said proof mass and at least one deceleration indentation formed in said proof mass;

a motor drive comb;

a motor sense comb;

a plurality of suspensions configured to suspend said proof mass over said substrate and between said motor drive comb and said motor sense comb, said suspensions anchored to said substrate;

a body attached to said substrate; and

at least one deceleration beam extending from said body, said deceleration beams configured to engage either said at least one deceleration extension or said at least one deceleration indentation and slow or stop said proof mass before said proof mass contacts said motor drive comb and said motor sense comb.

2. A device according to claim 1 wherein said device further comprises at least one crossbeam extending between said suspensions, said body connected to said crossbeam and attached to said substrate.

3. A device according to claim 2 wherein said device further comprises an anchoring extension which is utilized to connect said body to said crossbeam.

4. A device according to claim 1 wherein said device further comprises:

at least one crossbeam extending between said suspensions; and

an anchor attached to said crossbeam and said substrate, said body connected to said crossbeam.

5. A device according to claim 1 wherein said at least one deceleration extension comprises:

a bottom surface; and

at least one raised area on said bottom surface, said raised areas configured to reduce or eliminate contact between said proof mass and components of said device under said proof mass.

6. A device according to claim 1 wherein said at least one deceleration extension comprises:

a top surface; and

at least one raised area on said top surface, said raised areas configured to reduce or eliminate contact between said proof mass and components of said device above said proof mass.

7. A device according to claim 1 wherein said proof mass is configured with at least one deceleration indentation, said proof mass further comprising:

a top surface;

a bottom surface; and

at least one raised area on either or both of said top surface and said bottom surface, said raised areas configured to reduce or eliminate contact between said proof mass and components of said device above and under said proof mass.

8. A device according to claim 1 wherein said substrate comprises at least one raised area configured to engage said deceleration extension said raised area configured to reduce or eliminate contact between said proof mass and components of said device under said proof mass.

9. A device according to claim 1 wherein said deceleration extensions and said deceleration beams are configured to bend when engaged and provide the deceleration function for said proof mass.

10. A device according to claim 1 wherein said at least one deceleration extension and said at least one deceleration beam are elongated rectangular structures.

11. A device according to claim 1 wherein said at least one deceleration indentation is elongated and rectangular.

12. A device according to claim 1 wherein said device comprises a plurality of said proof masses.

13. A device according to claim 1 wherein said device comprises at least one of a gyroscope, an inertial measurement unit, an accelerometer, a pressure sensor, and a temperature sensor.

14. A deceleration stop for a micro-electromechanical systems (MEMS) device, the MEMS device comprising a substrate and at least one proof mass, said deceleration stop comprising:

either at least one deceleration extension extending from said proof mass or at least one deceleration indentation formed in said proof mass; and

a plurality of deceleration beams anchored to the substrate, said deceleration beams extending toward said proof mass, said deceleration extensions and said deceleration indentations configured to engage at least one of said deceleration beams and cause said proof mass to slow or stop before contacting components of the MEMS device adjacent to said proof mass.

15. A deceleration stop according to claim 14 further comprising a body anchored to the substrate, said deceleration beams extending towards said proof mass from said body.

16. A deceleration stop according to claim 15 further comprising an anchoring extension which is utilized to connect said body to a crossbeam of the MEMS device.

17. A deceleration stop according to claim 14 wherein said deceleration extensions comprise:

a top surface;

a bottom surface; and

at least one raised area on at least one of said bottom surface and said top surface, said areas configured to reduce or eliminate contact between the proof mass and components of the MEMS device above and below the proof mass.

18. A deceleration stop according to claim 14 wherein said proof masses comprise:

a top surface;

a bottom surface; and

at least one raised area on at least one of said bottom surface and said top surface, said areas configured to reduce or eliminate contact between said proof mass and components of the MEMS device above and below said proof mass.

19. A deceleration stop according to claim 14 wherein said deceleration extensions and said deceleration beams are configured to bend when engaged, providing a deceleration function for said proof mass.

20. A deceleration stop according to claim 14 wherein said deceleration extensions and said deceleration beams are elongated rectangular structures.

21. A deceleration stop according to claim 14 wherein said deceleration indentations are elongated and rectangular.

22. A gyroscope comprising:

a substrate;

at least one crossbeam anchored to said substrate;

at least one proof mass, each said proof mass comprising either at least one deceleration extension or at least one deceleration indentation;

a plurality of suspensions connected to a respective one of said crossbeams and configured to suspend said proof masses above said substrate;

motor drive combs adjacent each said proof mass;

motor sense combs adjacent each said proof mass;

at least one body attached to each said crossbeam; and

a plurality of deceleration beams extending from said body, said deceleration extensions and said deceleration indentations configured to engage at least one of said deceleration beams and cause said proof masses to slow or stop before contacting said motor drive comb and said motor sense comb.

23. A gyroscope according to claim 22 wherein said body is anchored to said substrate.

24. A gyroscope according to claim 22 further comprising an anchoring extension utilized to connect said body to said crossbeam.

25. A gyroscope according to claim 22 wherein said deceleration extensions comprise:

a top surface;

a bottom surface; and

at least one raised area on at least one of said bottom surface and said top surface, said raised areas configured to reduce or eliminate contact between said proof masses and components of said gyroscope above and below said proof masses.

26. A gyroscope according to claim 22 wherein said proof masses comprise:

a top surface;

a bottom surface; and

at least one raised area on at least one of said bottom surface and said top surface, said raised areas configured to reduce or eliminate contact between said proof masses and components of said gyroscope above and below said proof masses.

27. A gyroscope according to claim 22 wherein said deceleration extensions and said deceleration beams are configured to bend when engaged, providing deceleration for said proof masses.

28. A gyroscope according to claim 22 wherein said deceleration extensions and said deceleration beams are elongated rectangular structures.

29. A gyroscope according to claim 22 wherein said deceleration indentations are elongated and rectangular.

30. A method for reducing impacts and a speed of impacts between proof masses and adjacent components in micro-electromechanical systems (MEMS) devices, said method comprising:

configuring the proof masses with at least one deceleration extension which extends from the proof mass; and

providing a plurality of deceleration beams which extend towards the proof mass, the deceleration extensions configured to engage at least one of the deceleration beams and cause the proof mass to slow or stop before contacting any component of the MEMS device adjacent to the proof mass; and

providing an anchor for the deceleration beams.

31. A method according to claim 30 further comprising configuring at least one of an upper surface and a bottom surface of the deceleration extensions with at least one raised area, the raised areas configured to reduce or eliminate contact between the proof mass and components of the MEMS device which are above or below the proof mass.

32. A method for reducing impacts and a speed of impacts between proof masses and adjacent components in micro-electromechanical systems (MEMS) devices, said method comprising:

configuring the proof masses with at least one deceleration indentation formed in the proof mass; and

providing a plurality of deceleration beams which extend towards the proof mass, the deceleration extensions configured to engage at least one of the deceleration indentations and cause the proof mass to slow or stop before contacting any component of the MEMS device adjacent to the proof mass; and

providing an anchor for the deceleration beams.

33. A method according to claim 32 further comprising configuring at least one of an upper surface and a bottom surface of the proof masses with at least one raised area, the raised areas configured to reduce or eliminate contact between the proof mass and components of the MEMS device which are above or below the proof mass.

34. A method for reducing impacts and a speed of impacts between proof masses and adjacent components in micro-electromechanical systems (MEMS) devices, the proof masses being suspended above a substrate by a plurality of suspensions, said method comprising:

providing an anchor for the suspensions on the substrate;

forming a body which extends towards a proof mass;

anchoring the body;

configuring the body with a plurality of deceleration beams which extend towards the proof mass; and

configuring the proof mass with either at least one deceleration extension extending from the proof mass or at least one deceleration indentation formed in the proof mass, the deceleration extensions and deceleration indentations configured to engage at least one of the deceleration beams and cause the proof mass to slow or stop before contacting any component of the MEMS device adjacent the proof mass.

35. A method according to claim 34 further comprising configuring at least one of an upper surface and a bottom surface of the deceleration extension with at least one raised area, the raised areas configured to reduce or eliminate contact between the proof mass and components of the MEMS device which are above or below the proof mass.

36. A method according to claim 34 further comprising configuring at least one of an upper surface and a bottom surface of the proof masses with at least one raised area, the raised areas configured to reduce or eliminate contact between the proof mass and components of the MEMS device which are above or below the proof mass.

37. A method according to claim 34 further comprising configuring the substrate with at least one raised area configured to engage a bottom surface of the deceleration extension or the proof mass, engagement of the raised area and the bottom surface reducing or eliminating contact between the proof mass and components of the MEMS device which are below the proof mass.

38. A method according to claim 34 wherein anchoring the body comprises anchoring the body directly to the substrate, the body also providing the anchor for the suspensions.

39. A method according to claim 34 wherein providing an anchor for the suspensions comprises:

providing a crossbeam between suspensions; and

anchoring the crossbeam to the substrate.

40. A method according to claim 39 wherein anchoring the body comprises attaching the body to the crossbeam.

41. A method according to claim 40 wherein anchoring the crossbeam to the substrate comprises connecting an anchoring extension between the body and the crossbeam.

42. A deceleration stop for a micro-electromechanical systems (MEMS) device, the MEMS device comprising a substrate, at least one proof mass suspended above said substrate, and a body attached said substrate, said deceleration stop comprising:

at least one deceleration extension extending from said proof mass; and

at least one deceleration indentation formed in said body;

said at least one deceleration extension configured to engage said at least one deceleration indentation and cause said proof mass to slow or stop before contacting components of the MEMS device adjacent to said proof mass.