Device adapted to pull a cantilever away from a contact structure

• US 6,646,215 B1
• Filed: 06/29/2001
• Issued: 11/11/2003
• Est. Priority Date: 06/29/2001
• Status: Expired due to Fees

• Current Assignee: Teravicta Technologies Incorporated
• Original Assignee: Teravicin Technologies Incorporated
• Inventors: Nelson, Richard D.
• Primary Examiner(s): SCOTT, JAMES R
• Application Number:
  US09/895,455
• Time in Patent Office: 865 Days
• Field of Search: 200/181, 333/101-108, 333/262, 735/131.4
• US Class Current: 200/181
• CPC Class Codes: B81B 2201/014 having a cantilever fixed on one side connected to one or more dimples
• CPC Class Codes: B81B 3/0008 Structures for avoiding electrostatic attraction, e.g. avoiding charge accumulation
• CPC Class Codes: G11C 23/00 Digital stores characterised by movement of mechanical parts to effect storage, e.g. using balls; Storage elements therefor
• CPC Class Codes: H01H 2001/0089 Providing protection of elements to be released by etching of sacrificial element; Avoiding stiction problems, e.g. of movable element to substrate
• CPC Class Codes: H01H 2059/0063 with stepped actuation, e.g. actuation voltages applied to different sets of electrodes at different times or different spring constants during actuation
• CPC Class Codes: H01H 59/0009 making use of micromechanics

Abstract

A device is provided which is adapted to electrostatically pull a cantilever away from a conductive pad. In particular, a microelectromechanical device is provided which includes a fulcrum contact structure interposed between two electrodes spaced under a cantilever and a conductive pad arranged laterally adjacent to one of the electrodes. The cantilever may be brought into contact with the conductive pad by residual forces within the cantilever and/or an application of a closing voltage to one of the electrodes. Such a device may be adapted bring the cantilever in contact with the fulcrum contact structure by applying an actuation voltage to the other of the electrodes. In addition, the actuation voltage may deflect the cantilever away from the conductive pad. In some cases, deflecting the cantilever from the conductive pad may include releasing the closing voltage and increasing the actuation voltage subsequent to the release of the closing voltage.

Claims

1. A microelectromechanical device, comprising:

a cantilever;

first and second electrodes spaced under the cantilever;

a fulcrum contact structure interposed between the first and second electrodes and arranged under the cantilever; and

a conductive pad arranged under a distal end of the cantilever and laterally adjacent to the second electrode.

2. The device of claim 1, wherein the conductive pad is interposed between the fulcrum contact structure and the second electrode.

3. The device of claim 1, wherein the second electrode is interposed between the fulcrum contact structure and the conductive pad.

4. The device of claim 1, wherein a spacing between the cantilever and the fulcrum contact structure is smaller than a spacing between the cantilever and first and second electrodes when the cantilever is not in contact with the conductive pad.

5. The device of claim 1, wherein an upper surface of the fulcrum contact structure is elevationally higher than an upper surface of the conductive pad.

6. The device of claim 1, wherein an upper surface of the fulcrum contact structure is elevationally lower than an upper surface of the conductive pad.

7. The device of claim 1, wherein the cantilever comprises a dimpled portion above at least one of the fulcrum contact structure and the conductive pad.

8. The device of claim 1, wherein at least one of the fulcrum contact structure and conductive pad comprises a raised section.

9. The device of claim 1, wherein the conductive pad comprises multiple sections spaced apart from each other.

10. The device of claim 1, wherein the fulcrum contact structure comprises multiple sections spaced apart from each other.

11. The device of claim 1, wherein a supported end of the cantilever is supported by an electrical terminal.

12. The device of claim 1, wherein the cantilever comprises an insulating element interposed between the supported end and the distal end of the cantilever.

13. A microelectromechanical device, comprising:

a cantilever;

a conductive pad arranged adjacent to the cantilever; and

a plurality of components adapted to electrostatically pull the cantilever apart from the conductive pad upon an application of an actuation voltage to at least one of the plurality of components.

14. The device of claim 13, wherein the plurality of components comprises:

first and second electrodes spaced under the cantilever, wherein the conductive pad is laterally adjacent to the second electrode; and

a fulcrum contact structure interposed between the first and second electrodes.

15. The device of claim 14, wherein the plurality of components is adapted to pull the cantilever apart from the conductive pad upon the application of the actuation voltage to the first electrode such that the cantilever contacts the fulcrum contact structure.

16. The device of claim 14, wherein the plurality of components is adapted to initially bring the cantilever in contact with the conductive pad by an application of a closing voltage to the second electrode.

17. The device of claim 16, wherein the plurality of components is adapted to pull the cantilever apart from the conductive pad upon:

the application of the actuation voltage to the first electrode such that the cantilever contacts the fulcrum contact structure; and

a release of the closing voltage applied to the second electrode.

18. The device of claim 16, wherein the plurality of components is adapted to pull the cantilever apart from the conductive pad upon:

the application of the actuation voltage to the first electrode such that the cantilever contacts the fulcrum contact structure;

a release of the closing voltage applied to the second electrode; and

an increase of the actuation voltage.

19. The device of claim 14, wherein the cantilever comprises internal residual forces adapted to bring the cantilever into contact with the conductive pad.

20. The device of claim 14, wherein the device plurality of components is adapted to bring the cantilever in contact with the fulcrum structure upon an application of a closing voltage to the second electrode.

21. The device of claim 14, wherein the plurality of components is further adapted to bring the cantilever in contact with the fulcrum structure upon:

an application of a closing voltage to the second electrode; and

an application of an actuation voltage to the first electrode.

22. The device of claim 14, wherein the fulcrum contact structure comprises conductive material.

23. The device of claim 14, wherein the fulcrum contact structure is arranged under the center point of the cantilever.

24. The device of claim 14, wherein the fulcrum contact structure is arranged closer to the distal end of the cantilever than the supported end of the cantilever.

25. The device of claim 14, wherein the cantilever comprises internal residual forces adapted to curl the cantilever away from the conductive pad.

26. The device of claim 25, wherein the plurality of components is further adapted to electrostatically pull the cantilever away from the fulcrum contact structure.

27. The device of claim 25, wherein the plurality of components is adapted to pull the cantilever apart from the fulcrum contact structure upon an application of a closing voltage to the second electrode such that the cantilever contacts the conductive pad.

28. The device of claim 25, wherein the plurality of components is adapted to initially bring the cantilever in contact with the fulcrum contact structure upon an application of an actuation voltage to the first electrode and a simultaneous application of a closing voltage to the second electrode.

29. The device of claim 25, wherein the plurality of components is adapted to initially bring the cantilever in contact with the fulcrum contact structure upon an application of an actuation voltage to the first electrode.

30. The device of claim 29, wherein the plurality of components is adapted to pull the cantilever apart from the fulcrum contact structure upon:

an application of a closing voltage to the second electrode such that the cantilever contacts the conductive pad; and

a release of the actuation voltage applied to the first electrode.

31. The device of claim 29, wherein the plurality of components is further adapted to pull the cantilever apart from the fulcrum structure upon:

an application of a closing voltage to the second electrode such that the cantilever contacts the conductive pad;

a release of the actuation voltage applied to the first electrode; and

an increase of the closing voltage.

32. The device of claim 16, wherein the plurality of components is further adapted to simultaneously bring the cantilever in contact with both the conductive pad and the fulcrum contact structure by application of voltages to both the first and second electrodes.