MEMS switches with deforming membranes

• US 7,724,993 B2
• Filed: 08/05/2005
• Issued: 05/25/2010
• Est. Priority Date: 09/27/2004
• Status: Expired due to Fees

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm MEMS Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Chui, Clarence, Kothari, Manish
• Primary Examiner(s): Rahll; Jerry T
• Application Number:
  US11/198,925
• Publication Number:
  US 20060067648A1
• Time in Patent Office: 1,754 Days
• Field of Search: 385/22, 200/181
• US Class Current: 385/22
• CPC Class Codes: G02B 26/001 based on interference in an adjustable optical cavity interference filters G02B5/28; devices or arrangements using multiple reflections in spectrometry or monochromators G01J3/26
• CPC Class Codes: G02B 26/0833 the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD G02B26/0825 takes precedence; micromechanical devices in general B81B
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means

Abstract

MEMS switches are formed with membranes or layers that are deformable upon the application of a voltage. In some embodiments, the application of a voltage opens switch contacts.

Claims

1. A microelectromechanical systems (MEMS) switch comprising:

at least first and second terminals;

a first electrode; and

a deformable element having at least a portion thereof forming a second electrode and being moveable between a relaxed state and an actuated state in response to applied electric potentials between the second electrode and the first electrode, wherein the first terminal and the second terminal are selectively connectable depending on the position of said deformable element, and wherein the first terminal and the second terminal are electrically connected when the deformable element is in the relaxed state.

2. The MEMS switch of claim 1, wherein at least one of said terminals moves with said deformable element.

3. The MEMS switch of claim 1, wherein said deformable element is supported over a substrate, and said first electrode is deposited on said substrate.

4. The MEMS switch of claim 3, wherein said first electrode is covered with an insulating material.

5. The MEMS switch of claim 1, wherein said deformable element is supported over a substrate, and at least one terminal is deposited on said substrate.

6. The MEMS switch of claim 5, wherein said first electrode is deposited on said substrate.

7. The MEMS switch of claim 1, wherein said deformable element comprises a flexible material that is curved in a mechanically relaxed state.

8. The MEMS switch of claim 1, wherein the deformable element comprises a flexible material supporting a rigid plate.

9. The MEMS switch of claim 8, wherein said flexible material comprises the first terminal and the rigid plate comprises the second terminal.

10. The MEMS switch of claim 9, wherein said rigid plate comprises one or more portions extending toward said flexible material and that make contact with one or more terminals in a mechanically relaxed state.

11. The MEMS switch of claim 10, wherein said one or more rigid plate portions directly contacts said flexible material.

12. The MEMS switch of claim 10, wherein said one or more rigid plate portions contact one or more terminals attached to said flexible material.

13. The MEMS switch of claim 8, wherein said rigid plate comprises a contact conductor configured to electrically connect a pair of terminals attached to said flexible material.

14. The MEMS switch of claim 8, wherein said deformable element is supported over a substrate, at least a third terminal is deposited on said substrate, at least the first terminal is attached to said flexible layer, and wherein said rigid plate comprises the second terminal configured to contact said first terminal or said third terminal, or neither terminal, depending on the position of the deformable element.

15. The MEMS switch of claim 1, wherein said deformable element comprises a flexible plate supported from a rigid upper support structure.

16. The MEMS switch of claim 15, wherein at least a portion of the flexible plate comprises the second electrode.

17. The MEMS switch of claim 15, wherein said flexible plate comprises a contact conductor configured to contact terminals attached to said rigid upper support structure.

18. The MEMS switch of claim 17, wherein said flexible plate is supported above a substrate by said upper support structure, wherein a pair of terminals are deposited on said substrate, and wherein said flexible plate comprises a second contact conductor configured to electrically connect said pair of terminals deposited on said substrate.

19. The MEMS switch of claim 1, wherein said deformable element comprises a flexible material supported over a substrate, at least the first terminal is attached to said flexible material on a side opposite to said substrate, and wherein the second terminal is supported in a fixed location adjacent to said first terminal.

20. A method of opening a microelectromechanical systems (MEMS) switch comprising moving a deformable membrane between a relaxed state and an actuated state, thereby disconnecting a first switch terminal from an established electrical coupling to a second switch terminal when the membrane moves to the actuated state in response to an electric field.

21. The method of claim 20, wherein said first switch terminal is attached to the deformable membrane.

22. The method of claim 21, wherein said second switch terminal is fixed relative to said deformable membrane.

23. The method of claim 21, wherein said second switch terminal is also attached to said deformable membrane.

24. The method of claim 20, wherein said first switch terminal and said second switch terminal are fixed, wherein said electric field deforms a flexible plate, and wherein said flexible plate comprises a contact conductor electrically connecting said first and second terminals and said third switch terminal in the absence of said electric field.

25. A microelectromechanical systems (MEMS) switch comprising:

a deformable element comprising at least a first terminal and a first electrode on a first side of a gap;

a second terminal;

a second electrode on a second side of said gap configured to move said deformable element between a relaxed state and an actuated state based on a potential difference applied to said first and second electrodes to selectively connect said first and second terminals, the first terminal and the second terminal electrically connected when the deformable element is in the relaxed state.

26. The MEMS switch of claim 25, wherein said deformable element also comprises said second terminal.

27. The MEMS switch of claim 25, wherein the deformable element comprises a flexible layer and a plate attached to said flexible layer.

28. The MEMS switch of claim 27, wherein the plate comprises a contact conductor configured to selectively make electrical contact with each of the second terminal and a third terminal.

29. The MEMS switch of claim 28, wherein the contact conductor comprises protrusions at the points of electrical contact with each of the second terminal and the third terminal.

30. The MEMS switch of claim 28, wherein the plate further comprises the first electrode.

31. The MEMS switch of claim 30, wherein the contact conductor is electrically isolated from the first electrode.

32. The MEMS switch of claim 30, wherein the contact conductor and the first electrode are formed as a single conductor.

33. The MEMS switch of claim 25, wherein the first and second terminals are connected when a potential difference less than a threshold is applied.

34. A microelectromechanical systems (MEMS) switch comprising an element movable between first and second positions comprising first and second movable terminals, wherein the first and second movable terminals cooperatively move with the movable element to connect the first and second movable terminals when the element is in the first position and to disconnect the first and second movable terminals when the element is in the second position.

35. The MEMS switch of claim 34, wherein the switch comprises first and second electrodes, and wherein the movement between first and second positions is based on a voltage applied between the first and second electrodes.

36. The MEMS switch of claim 35, wherein the element is in the first position when the applied voltage between the electrodes is below a threshold.

37. A microelectromechanical systems (MEMS) switch comprising:

a deformable membrane moveable between a mechanically relaxed state and an actuated state;

first and second switch terminals;

means for maintaining electrical contact between said first and second switch terminals when said membrane is in the mechanically relaxed state; and

means for disconnecting the first and second switch terminals by applying a voltage difference to the MEMS switch greater than a threshold.

38. The MEMS switch of claim 37, wherein said means for maintaining electrical contact comprises a flexible layer that maintains a curved configuration in a mechanically relaxed state.

39. The MEMS switch of claim 38, wherein said means for disconnecting comprises at least one electrode associated with said flexible layer, and at least one other electrode.

40. A method of operating a microelectromechanical systems (MEMS) switch comprising a deformable membrane, the method comprising:

maintaining electrical contact between first and second switch terminals when said deformable membrane is in a mechanically relaxed state; and

disconnecting the first and second switch terminals by creating an electric field between a pair of electrode surfaces of the MEMS switch.