Micro-miniature switch apparatus

• US 6,291,908 B1
• Filed: 10/06/1999
• Issued: 09/18/2001
• Est. Priority Date: 10/06/1999
• Status: Expired due to Fees

• Current Assignee: TRW Inc. (Northrop Grumman Corporation)
• Original Assignee: TRW Inc. (Northrop Grumman Corporation)
• Inventors: Roth, Thomas J., Berenz, John Joseph, Tran, Dean, DePace, Ronald A., Rochin, Luis M.
• Primary Examiner(s): Ballato, Josie
• Assistant Examiner(s): DEBERADINIS, ROBERT L
• Application Number:
  US09/413,402
• Time in Patent Office: 713 Days
• Field of Search: 307/112, 307/119, 307/120, 307/121, 307/10.1, 200/61.45, 200/181, 200/61.48, 200/61.49, 200/61.53, 257/414, 257/421, 257/422, 257/531, 735/141.6, 735/142.4, 735/142.9, 735/143.2, 735/143.3, 735/143.4, 361/233
• US Class Current: 307/112
• 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 35/14 Switches operated by change of acceleration, e.g. by shock or vibration, inertia switch wherein the liquid constitutes a contact of the switch H01H29/002

Abstract

A micro-miniature switch apparatus (10) includes a substrate (12) having a surface (14) with first and second channels (16, 18) extending from the surface (14) into the substrate (12). The first and second channels (16, 18) are spaced apart from each other, with a channel axis (20) extending longitudinally through the first and second channels (16, 18). A body (68) that is movable relative to the substrate (12) includes two arms (70, 72). Each of the arms (70, 72) extends into one of the first and second channels (16, 18) to support the body (68) for movement relative to the substrate (12) between first and second electrical conditions of the switch apparatus (10).

Claims

1. A micro-miniature switch apparatus comprising:

a substrate having a surface, first and second channels extending into said substrate from said surface of said substrate, said first and second channels being spaced apart from each other, a channel axis extending longitudinally through said first and second channels; and

a body moveable relative said substrate, said body including two arms, each of said arms extending into one of said first and second channels to support said body for rocking movement relative to said substrate between first and second electrical conditions of said switch apparatus.

2. A switch apparatus as set forth in claim 1 further including a recess extending from said surface into said substrate, said recess having a pair of opposed side edges, each of said first and second channels extending longitudinally from one of said opposed side edges of said recess.

3. A switch apparatus as set forth in claim 2 further including a first electrical contact disposed on said substrate within said recess adjacent a first end of said recess, a second electrical contact being formed on said body for electrically connecting with said first electrical contact when said switch apparatus is in one of said first and second electrical conditions.

4. A switch apparatus as set forth in claim 3 wherein said switch apparatus, in response to the rocking movement of said body relative to said substrate, provides a switched output signal having an electrical characteristic indicative of the electrical condition of said switch apparatus.

5. A switch apparatus as set forth in claim 2 wherein said recess is formed in said substrate to a first depth and said first and second channels are formed in said substrate to a second depth which is less than said first depth.

6. A switch apparatus as set forth in claim 5 wherein each of said channels is defined by an elongated sidewall surface of said substrate curved about the channel axis, at least part of each of said two arms being curved to rockingly engage said sidewall surface of said substrate at the associated one of said first and second channels, thereby facilitating rocking movement of said body relative to said substrate.

7. A switch apparatus as set forth in claim 1 wherein said body is moveable relative said substrate from a first position that defines the first electrical condition to a second position that defines the second electrical condition when said switch apparatus is sufficiently accelerated along a direction substantially orthogonal to said surface of said substrate.

8. A switch apparatus as set forth in claim 7 wherein a conductive plate is disposed on said substrate, said conductive plate being operative to provide an electrostatic field that urges said body to the first position that defines the first electrical condition.

9. A switch apparatus as set forth in claim 8 wherein the electrostatic field provided by said conductive plate inhibits movement of said body relative to said substrate when said switch apparatus is exposed to less than a predetermined amount of acceleration along a direction substantially orthogonal to said surface of said substrate.

10. A switch apparatus as set forth in claim 9 further including external control means electrically connected with said conductive plate to control the electrostatic field provided by said conductive plate.

11. A switch apparatus as set forth in claim 1 further including an elongated flexure connected to said body and fixed relative to said substrate for providing torsional resistance to the rocking movement of said moveable plate.

12. A switch apparatus as set forth in claim 1 further including a recess extending from said surface of said substrate into said substrate, said recess having opposed side edges, each of said first and second channels extending longitudinally from one of said opposed side edges of said recess, a pair of conductive plates disposed on said substrate within said recess, each of said conductive plates being operative to provide an electrostatic field to effect corresponding movement of said body relative to said substrate toward one of said first and second electrical conditions of said switch apparatus.

13. A micro-miniature acceleration switch apparatus comprising:

a substrate having a surface, first and second channels extending from said surface of said substrate into said substrate, each of said channels having a channel axis that is parallel with the other channel axis; and

a body moveable relative to said substrate, said body including two substantially coaxial arms, each of said arms extending from a central part of the body into a bearing relationship with one of said first and second channels to support said body for rocking movement relative to said substrate from a first switch position to a second switch position when said switch apparatus is accelerated in a direction substantially orthogonal to said surface of said substrate.

14. A switch apparatus as set forth in claim 13 further including a recess extending from said surface of said substrate into said substrate, a first electrical contact being disposed on said body, second and third electrical contacts being disposed on said substrate within said recess and spaced apart from each other, said first electrical contact electrically connecting said second and third electrical contacts when said body is in the second switch position, at least part of said body being located within said recess when said body is in the second switch position.

15. A switch apparatus as set forth in claim 13 further including a recess extending from said surface of said substrate into said substrate at a location between said channels, said recess having opposed sidewall portions that extend from said surface a depth into said substrate, each of said channels extending into said substrate a depth which is less than the depth of said sidewall portions of said recess.

16. An apparatus as set forth in claim 15 wherein each of said channels is defined by a longitudinally extending semi-cylindrical surface formed in said substrate from said surface of said substrate about the associated channel axis, said semi-cylindrical surface of each of said channels intersecting one of said opposed sidewall portions of said recess.

17. A switch apparatus as set forth in claim 16 wherein each of said arms has an elongated curved sidewall surface supported in bearing relationship by said semi-cylindrical surface of the associated one of said channels to facilitate rocking movement of said body relative to said substrate.

18. A switch apparatus as set forth in claim 13 further including a recess extending from said surface of said substrate into said substrate, said recess having first and second spaced apart ends, a conductive plate being disposed within said recess adjacent one of said ends of said recess, said conductive plate being operative to provide an electrostatic field that urges part of said body toward said substrate to define the switch first position.

19. A switch apparatus as set forth in claim 18 wherein said conductive plate is operative to provide a variable electrostatic field that defines an amount of acceleration which is sufficient to effect movement of said moveable plate from the first switch position to the switch second position.

20. A micro-miniature acceleration switch apparatus comprising:

a substrate having a surface, two fulcrum supports formed in said substrate adjacent said surface of said substrate, each of said fulcrum supports being spaced apart from the other of said fulcrum supports;

a body moveable relative to said substrate, said body comprising;

a plate positioned adjacent said surface of said substrate intermediate said fulcrum supports; and

two substantially coaxial arms, each of said arms extending longitudinally from said plate into a bearing relationship with an associated one of said fulcrum supports to permit rocking movement of said body relative said substrate, said body being moveable relative to said substrate between first and second switch positions of said switch apparatus in response to acceleration of said switch apparatus in a direction orthogonal to the surface of said substrate.

21. A switch apparatus as set forth in claim 20 wherein each of said fulcrum supports is a channel having an elongated curved sidewall extending from said surface of said substrate into said substrate substantially parallel with said surface, each of said arms being in a bearing relationship with said curved sidewall of the associated said channels to provide for rocking movement of said body relative said substrate.