Electrostatically switched integrated relay and capacitor

• US 5,051,643 A
• Filed: 08/30/1990
• Issued: 09/24/1991
• Est. Priority Date: 08/30/1990
• Status: Expired due to Term

• Current Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Dworsky, Lawrence, Chason, Marc K.
• Primary Examiner(s): Budd, Mark O.
• Assistant Examiner(s): Dougherty, Thomas M.
• Application Number:
  US07/575,092
• Time in Patent Office: 390 Days
• Field of Search: 310/309, 200/181
• US Class Current: 310/309
• 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 59/0009 making use of micromechanics

Abstract

An electrostatically energized and integrable relay is disclosed that has dimensions that permit closure and maintenance of a contact between electrodes using electrostatic forces exclusively. The physical dimensions are such that it could be formed using integrated circuit fabrication techniques. Small spacing between the electrodes of the relay permit the device to be usable in an integrated form, perhaps on an integrated circuit substrate.

Claims

1. An electrostatically operated relay having an armature and stator and contacts that are closed by electrostatic forces existing between the armature and the contacts comprised of:

deflectable beam means, having at least first and second sides, fixed to a substrate at at least one point, for supporting at least first and second electrodes coupled to said first side of deflectable beam means, both said first and second electrodes having contact surfaces and having first and second thickness respectively, said first thickness being greater than said second thickness, said first and second electrodes respectively carrying first and second electrical signals, said deflectable beam means having a first non-deflected position and at least a second deflected position; and

third electrode means, fixed to said substrate, for establishing an electric field between said third electrode and said second electrode and for electrically coupling signals from said first electrode to said third electrode, said third electrode being separated from said contact surfaces by a first separation distance when said deflectable beam means is in said first non-deflected position, said third electrode being at an electric reference potential for signals carried on said first and second electrodes such that an electric field established between said second electrode and said third electrode causes said deflectable beam means to deflect to said second deflected position whereat an electrical coupling is established between said first and third electrodes.

2. The relay of claim 1 where said deflectable beam means is a cantilevered beam.

3. The relay of claim 1 where said deflectable beam means is a supported beam fixed at two opposite ends such that a center portion of said supported beam translates with deflection of said supported beam.

4. The relay of claim 1 where said substrate is at least partially conductive material.

5. The relay of claim 4 where said third electrode is formed with said substrate.

6. The relay of claim 1 where said third electrode is formed by a material deposition technique.

7. The relay of claim 1 where said beam and said electrodes are integrated onto a substrate.

8. The relay of claim 1 where said first separation distance is less than 25 microns.

9. The relay of claim 1 where said electric reference potential is ground potential.

10. The relay of claim 1 where said signal on said second electrode is a D.C. signal.

11. The relay of claim 1 including a dielectric layer between said first and third electrode means.

12. An electrostatically operated relay having an armature and stator and contacts that are closed by electrostatic forces existing between the armature and at least one of the contacts, said relay comprised of:

deflectable beam means, fixed to a substrate at at least one point for conducting electrical signals and for deflecting in response to electrostatic forces exerted upon it, said deflectable beam means having a first non-deflected position and at least a second deflected position; and

first and second substantially stationary, substantially planar, electrodes, fixed to said substrate, said first and second electrodes each having contact surfaces and having first and second thickness respectively, said first thickness being greater than said second thickness, said first and second electrodes respectively carrying first and second electrical signals for establishing an electric field between said deflectable beam means and said second electrode, said deflectable beam means being separated from said contact surfaces by a first separation distance when said deflectable beam means is in said first non-deflected position such that an electric field established between said second electrode and said deflectable beam means causes said deflectable beam means to deflect to said second deflected position whereat an electrical coupling is established between said first electrode and said deflectable beam means.

13. The relay of claim 12 where said deflectable beam means is a cantilevered beam.

14. The relay of claim 12 where said deflectable beam means is a supported beam fixed at two opposite ends such that a center portion of said supported beam translates with deflection of said supported beam.

15. The relay of claim 12 where said substrate is at least partially conductive material.

16. The relay of claim 12 where said first and second electrodes are formed with said substrate.

17. The relay of claim 12 where said third electrode is formed by a material deposition technique.

18. The relay of claim 12 where said beam and said electrodes are integrated onto a substrate.

19. The relay of claim 12 where said first separation distance is less than 25 microns.

20. The relay of claim 12 where said electric reference potential is ground potential.

21. The relay of claim 12 where said signal on said second electrode is a D.C. signal.

22. The relay of claim 12 where said first and second substantially planar electrodes are concentric circles.

23. An electrostatically operated relay having an armature and stator and contacts that are closed by electrostatic forces existing between the armature and the contacts comprised of:

a supported beam, fixed to a substrate at two opposite ends such that a center portion of said supported beam translates with deflection of said supported beam, for supporting at least a first electrode coupled to said supported beam, said first electrode having a contact surface, said first electrode respectively carrying a first electrical signal, said supported beam having a first non-deflected position and at least a second deflected position; and

second electrode means, fixed to said substrate, for establishing an electric field between said second electrode and said first electrode and for electrically coupling signals from said first electrode to said second electrode, said second electrode being separated from said contact surface by a first separation distance when said supported beam is in said first non-deflected position, said second electrode being at an electric reference potential for signals carried on said first electrode such that an electric field established between said first and second electrode causes said supported beam to deflect to said second deflected position whereat an electrical coupling is established between said first and second electrodes; and

a dielectric layer coupled to at least one of said first and second electrodes, said dielectric layer and said first and second electrodes forming a capacitor having increased capacitance when said deflectable beam means is in said second position.

24. An electrostatically operated relay having an armature and stator and contacts that are closed by electrostatic forces existing between the armature and the contacts comprised of:

deflectable beam means, fixed to an at least partially conductive substrate at at least one point, for supporting at least a first electrode coupled to said deflectable beam means, said first electrode having a contact surface, said first electrode respectively carrying a first electrical signal, said deflectable beam means having a first non-deflected position and at least a second deflected position; and

second electrode means, fixed to said substrate, for establishing an electric field between said second electrode and said first electrode and for electrically coupling signals from said first electrode to said second electrode, said second electrode being separated from said contact surface by a first separation distance when said deflectable beam means is in said first non-deflected position, said second electrode being at an electric reference potential for signals carried on said first electrode such that an electric field established between said first and second electrode causes said deflectable beam means to deflect to said second deflected position whereat an electrical coupling is established between said first and second electrodes; and

a dielectric layer coupled to at least one of said first and second electrodes, said dielectric layer and said first and second electrodes forming a capacitor having increased capacitance when said deflectable beam means is in said second position.

25. An electrostatically operated relay having an armature and stator and contacts that are closed by electrostatic forces existing between the armature and the contacts comprised of:

deflectable beam means, fixed to a substrate at at least one point, for supporting at least a first electrode coupled to said deflectable beam means, said first electrode having a contact surface, said first electrode respectively carrying a first electrical signal, said deflectable beam means having a first non-deflected position and at least a second deflected position; and

second electrode means, fixed to said substrate, for establishing an electric field between said second electrode and said first electrode and for electrically coupling signals from said first electrode to said second electrode, said second electrode being separated from said contact surface by a distance less than 25 microns when said deflectable beam means is in said first non-deflected position, said second electrode being at an electric reference potential for signals carried on said first electrode such that an electric field established between said first and second electrode causes said deflectable beam means to deflect to said second deflected position whereat an electrical coupling is established between said first and second electrodes; and

a dielectric layer coupled to at least one of said first and second electrodes, said dielectric layer and said first and second electrodes forming a capacitor having increased capacitance when said deflectable beam means is in said second position.