Micromechanical electric shunt and encoding devices made therefrom

• US 4,959,515 A
• Filed: 02/06/1987
• Issued: 09/25/1990
• Est. Priority Date: 05/01/1984
• Status: Expired due to Term

• Current Assignee: Invensys Systems Incorporated (Invensys PLC)
• Original Assignee: The Foxboro Company (Schneider Electric SE)
• Inventors: Zavracky, Paul M., Morrison, Richard H. Jr.
• Primary Examiner(s): Luebke, Renee S.
• Application Number:
  US07/012,092
• Time in Patent Office: 1,327 Days
• Field of Search: 200/181
• US Class Current: 200/181
• CPC Class Codes: G06K 19/067 Record carriers with conductive marks, printed circuits or semiconductor circuit elements, e.g. credit or identity cards also with resonating or responding marks without active components
• 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

A micromechanical electric shunt is fabricated by micromachining according to recent IC fabrication procedures. A plurality of such shunts is incorporated on a single substrate to form novel process station or post identification or signature encoding apparatus for use on a telecommunications bus or the equivalent. Such identification of signature encoding apparatus may be configured for conventional binary coding. Both frequency and current derivative mode apparatus are disclosed.

Claims

1. Micromechanical shunt exhibiting hysteresis, comprising:

(a) an insulating substrate having a planar top surface;

(b) a first contact terminal on said planar top surface;

(c) a second contact terminal on said planar top surface;

(d) a cantilever beam having a free end and a fixed end which is attached to said first contact terminal, said free end being suprajacent said second contact terminal;

(e) means for establishing an electrostatic charge attraction between said cantilever beam and said second contact terminal; and

(f) a resistance layer intermediate said cantilever beam and said second contact terminal;

whereby said free end of said cantilever beam may be deflected toward said second contact terminal by establishing an electrostatic charge between said first and second contact terminals.

2. Micromechanical shunt as in claim 1, further including a third contact terminal underlying said cantilever beam and adapted to provide electrical contact with said cantilever beam.

3. Micromechanical shunt as in claim 1, wherein said cantilever beam is primarily gold.

4. Micromechanical shunt as in claim 1, wherein said cantilever beam has a length of between 2.5×

10^-5 meters and about 5.1×

10^-3 meters.

5. Micromechanical shunt as in claim 1, wherein said cantilever beam length is preferably between about 10^-4 meters and about 3.0×

10^-3 meters.

6. Micromechanical shunt as in claim 1, wherein said cantilever beam length is not less than about 7.5×

10^-5 meters nor more than about 7.5×

10^-4 meters in length.

7. Micromechanical shunt as in claim 1, wherein said cantilever beam is between about 10^-4 and about 10^-3 meters in width.

8. Micromechanical shunt as in claim 1, wherein said cantilever beam is between about 10^-7 and about 10^-4 meters in thickness.

9. Micromechanical shunt as in claim 1, wherein said cantilever beam is between about 10^-7 and about 10^-5 meters in thickness.

10. Micromechanical shunt as in claim 1, wherein said resistance layer is spaced from said second contact terminal between about 10^-7 and about 10^-4 meters.

11. Micromechanical shunt as in claim 1, wherein said resistance layer is formed of germanium.

12. Micromechanical shunt as in claim 1, wherein said resistance layer is formed of an oxide of copper.

13. Micromechanical shunt as in claim 1, wherein said resistance layer is formed of silicon doped with aluminum.

14. Micromechanical shunt exhibiting hysteresis, comprising:

(a) an insulating substrate having a planar top surface;

(b) a first contact terminal on said planar top surface;

(c) a second contact terminal on said planar top surface;

(d) a cantilever beam formed of a uniform metal material and having a free end and a fixed end which is attached to said first contact terminal, said free end being suprajacent said second contact terminal;

(e) means for establishing an electrostatic charge attraction between said cantilever beam and said second contact terminal;

whereby said free end of said cantilever beam may be deflected toward said second contact terminal by establishing an electrostatic charge between said first and second contact terminals; and

(f) a resistance layer intermediate said cantilever beam and said second contact terminal.

15. Micromechanical shunt as in claim 14, further including a third contact terminal underlying said cantilever beam and adapted to provide electrical contact with said cantilever beam.

16. Micromechanical shunt as in claim 14, wherein said cantilever beam is primarily gold.

17. Micromechanical shunt as in claim 14, wherein said cantilever beam length is not less than about 7.5×

10^-5 meters nor more than 7.5×

10^-4 meters in length.

18. Micromechanical shunt as in claim 14, wherein said cantilever beam is between about 10^-7 and about 10^-4 meters in thickness.

19. Micromechanical shunt exhibiting hysteresis, comprising:

(a) a relatively inflexible fixed insulating substrate having a planar top surface;

(b) a first contact terminal on said planar top surface;

(c) a second contact terminal on said planar top surface;

(d) a cantilever beam having a free end and a fixed end which is attached to said first contact terminal, said free end being suprajacent said second contact terminal;

(e) means for establishing an electrostatic charge attraction between said cantilever beam and said second contact terminal; and

(f) a resistance layer intermediate said cantilever beam and said second contact terminal;

whereby said free end of said cantilever beam may be deflected toward said second contact terminal by establishing an electrostatic charge between said first and second contact terminals.

20. Micromechanical shunt as in claim 19, further including a third contact terminal underlying said cantilever beam and adapted to provide electrical contact with said cantilever beam.

21. Micromechanical shunt as in claim 19, wherein said cantilever beam is primarily gold.

22. Micromechanical shunt as in claim 19, wherein said cantilever beam has a length of between about 2.5×

10^-5 meters and about 5.1×

10^-3 meters.

23. Micromechanical shunt as in claim 19, wherein said cantilever beam length is preferably between about 10^-4 meters and about 3.0×

10^-3 meters in thickness.

24. Micromechanical shunt as in claim 19, wherein said cantilever beam length is not less than about 7.5×

10^-5 meters nor more than about 7.5×

10^-4 meters in length.

25. Micromechanical shunt as in claim 19, wherein said cantilever beam is between about 10^-4 and about 10^-3 meters in width.

26. Micromechanical shunt as in claim 19, wherein said cantilever beam is between about 10^-7 meters and about 10^-4 meters in thickness.

27. Micromechanical shunt as in claim 19, wherein said cantilever beam is between about 10^-7 and about 10^-5 meters in thickness.

28. Micromechanical shunt as in claim 19, wherein said resistance layer is spaced from said second contact terminal between about 10^-7 and about 10^-4 meters.

29. Micromechanical shunt as in claim 19, wherein said resistance layer is formed of germanium.

30. Micromechanical shunt as in claim 19, wherein said resistance layer is formed of an oxide of copper.

31. Micromechanical shunt as in claim 19, wherein said resistance layer is formed of silicon doped with aluminum.