MEMS switches with deforming membranes

• US 7,724,417 B2
• Filed: 12/19/2006
• Issued: 05/25/2010
• Est. Priority Date: 12/19/2006
• Status: Expired due to Fees

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm MEMS Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Lewis, Alan, Kogut, Lior, Tung, Ming-Hau
• Primary Examiner(s): Sugarman; Scott J
• Assistant Examiner(s): Tra; Tuyen Q
• Application Number:
  US11/641,649
• Publication Number:
  US 20080142347A1
• Time in Patent Office: 1,253 Days
• Field of Search: 359/290, 359/291, 359/292, 359/320, 359/322, 359/324, 359/220, 359/223, 359/224, 359/247, 359/212, 359/214, 359/302, 359/223.1, 310/309, 310/310
• US Class Current: 359/290
• 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 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: H01H 1/0036 Switches making use of microelectromechanical systems [MEMS] for electromagnetic relays H01H50/005; for electrostatic relays H01H59/0009
• CPC Class Codes: H01H 2001/0084 with perpendicular movement of the movable contact relative to the substrate
• CPC Class Codes: H01H 59/0009 making use of micromechanics
• CPC Class Codes: Y10T 29/49105 Switch making

Abstract

MEMS switches are formed with membranes or layers that are deformable upon the application of a voltage. The MEMS switches may comprise compliant terminals and/or contact conductors to produce contact swiping.

Claims

1. A microelectromechanical systems (MEMS) switch comprising:

at least first and second terminals;

a contact conductor that electrically connects at least a pair of said terminals when said switch is closed;

a first electrode; and

a moveable element having at least a portion thereof forming a second electrode;

wherein said moveable element is moveable in response to applied electric potentials between the second electrode and the first electrode, wherein the first and second terminals are selectively connectable depending on the position of said moveable element, wherein said contact conductor, at least one of said terminals, or both, are configured to be compliant in response to a contact force produced between said contact conductor and at least one of said terminals when said switch is closed, and wherein said contact conductor and said at least one terminal are configured to slidingly interface.

2. The MEMS switch of claim 1, wherein said terminals are relatively compliant and said moveable element is relatively rigid.

3. The MEMS switch of claim 1, wherein said terminals are relatively rigid and said moveable element is relatively compliant.

4. The MEMS switch of claim 1, wherein a dielectric material is between said first electrode and said second electrode.

5. The MEMS switch of claim 4, wherein said moveable element is prevented from contacting said dielectric material by said terminals.

6. The MEMS switch of claim 1, wherein said moveable element is supported over a substrate, and wherein a portion of at least one terminal is also supported over said substrate.

7. The MEMS switch of claim 6, wherein a first portion of said terminal is deposited on said substrate, and a second portion of said terminal is suspended over said substrate.

8. The MEMS switch of claim 1, wherein said switch is closed when said electric potential between said second electrode and said first electrode is above a threshold.

9. The MEMS switch of claim 1, wherein said switch is closed when said electric potential between said second electrode and said first electrode is below a threshold.

10. A MEMS switch comprising:

a deforming membrane;

a contact conductor coupled to said deforming membrane and configured to move in response to deformation of said membrane, said contact conductor having at least one surface that is angled with respect to said contact conductor movement;

at least one terminal having a surface that is angled to mate with said angled surface of said contact conductor in response to deformation of said membrane.

11. The MEMS switch of claim 10, wherein said angled surface of said contact conductor is configured to be compliant in response to a contact force produced between said contact conductor and at least one terminal when said switch is closed.

12. The MEMS switch of claim 10, wherein at least a portion of said contact conductor is a rigid structure.

13. The MEMS switch of claim 10, wherein said contact conductor is coupled to said at least one terminal through a dielectric material.

14. A method of making a MEMS switch, said method comprising:

forming at least one electrode layer on or over a substrate;

forming at least one dielectric layer on or over said electrode layer;

forming at least one sacrificial layer on or over said dielectric layer;

forming at least one switch terminal on or over said at least one sacrificial layer;

forming at least one additional sacrificial layer on or over said at least one switch terminal;

forming a contact conductor on or over said at least one additional sacrificial layer; and

removing said sacrificial layers.

15. The method of claim 14, comprising depositing conductive material on or over said dielectric layer prior to depositing said sacrificial layer on or over said dielectric layer.

16. The method of claim 14, wherein said forming at least one switch terminal comprises depositing conductive material onto both said sacrificial layer and onto exposed portions of said dielectric layer and/or said substrate.

17. The method of claim 14, comprising forming a second dielectric layer on or over at least a portion of said at least one additional sacrificial layer.

18. The method of claim 17, wherein forming said contact conductor comprises depositing conductive material onto both said second dielectric layer and onto exposed portions of said at least one additional sacrificial layer.

19. A MEMS switch made by the method of claim 14.

20. A MEMS switch comprising:

a substrate;

at least one switch terminal having at least a portion thereof cantilevered over said substrate;

a deformable portion suspended over said substrate, wherein at least a portion of said deformable portion comprises a contact conductor that contacts said at least one switch terminal when said deformable portion is deformed under the influence of a voltage.

21. The MEMS switch of claim 20, wherein said at least one switch terminal has a portion fixed to said substrate and a portion suspended over said substrate.

22. A method of simultaneously forming at least one MEMS display element and at least one MEMS switch, said method comprising:

forming at least one electrode layer on or over a substrate;

forming at least one dielectric layer on or over said substrate;

forming at least one sacrificial layer on or over said dielectric layer;

simultaneously forming a first switch component of a MEMS switch and a mirror component of a MEMS display element on or over said sacrificial layer;

simultaneously forming at least one additional sacrificial layer on or over said first switch component and said mirror component

simultaneously forming a second switch component of said MEMS switch and a deforming layer of said MEMS display element on or over the additional sacrificial layer; and

removing said sacrificial layers.

23. The method of claim 22, wherein said first switch component comprises a switch terminal.

24. The method of claim 22, wherein said second switch component comprises a contact conductor.

25. A display apparatus made by a method comprising:

forming at least one electrode layer on or over a substrate;

forming at least one dielectric layer on or over said substrate;

forming at least one sacrificial layer on or over said dielectric layer;

simultaneously forming a first switch component of a MEMS switch and a mirror component of a MEMS display element on or over said sacrificial layer;

simultaneously forming at least one additional sacrificial layer on or over said first switch component and said mirror component

simultaneously forming a second switch component of said MEMS switch and a deforming layer of said MEMS display element on or over the additional sacrificial layer; and

removing said sacrificial layers.