Claims
- 1. A method for making an electronic component comprising providing a nonmetallic pultruded composite member having a plurality of small diameter conductive fibers in .a polymer matrix said plurality of fibers being oriented in said matrix in a direction substantially parallel to the axial direction of said member and being continuous from one end of said member to the other to provide a plurality of electrical point contacts at each end of said member, directing, a laser beam to one end of said member, controlling said laser beam to volatilize the polymer matrix at said one end and expose the plurality of conductive fibers to provide a laser fibrillated brush-like structure having a densely distributed filament contact wherein the terminating ends of the fibers in the brush-like structure define an electrically contacting surface.
- 2. The method of claim 1 wherein said pultruded member is an elongated member and wherein said laser beam is controlled to cut through the pultruded member adjacent said one end.
- 3. The method of claim 2 wherein said laser beam is controlled to simultaneously cut the pultrusion and volatilize the polymer matrix.
- 4. The method of claim 1 wherein said beam is from a focused carbon dioxide laser.
- 5. The method of claim 1 wherein said laser beam is controlled to provide the fibers of said brush-like structure with a substantially uniform free fiber length.
- 6. The method of claim 1 wherein said laser beam is controlled to provide a well defined zone of demarcation between the pultruded potion and the brush-like structure.
- 7. The method of claim 1 wherein said polymer matrix absorbs the energy of the fibrillating laser.
- 8. The method of claim 5 wherein said fibers have a length less than about 3 millimeters.
- 9. The method of claim 1 wherein said conductive fibers are carbon fibers.
- 10. The method of claim 9 wherein said carbon fibers are carbonized polyacrylonitrile fibers.
- 11. The method of claim 1 wherein the fibers are generally circular in cross section and have a diameter of from about 4 micrometers to about 50 micrometers.
- 12. The method of claim 11 wherein the fibers have a diameter of from about 7 micrometers to about 10 micrometers.
- 13. The method of claim 1 wherein the fibers have a DC volume resistivity of from about 1.times.10.sup.-5 ohm-cm to about 1.times.10.sup.10 ohm-cm.
- 14. The method of claim 13 wherein the fibers have a DC volume resistivity of from about 1.times.10.sup.-4 ohm-cm to about 10 ohm-cm.
- 15. The method of claim 1 wherein said fibers comprise at least 5% by weight of the component.
- 16. The method of claim 15 wherein said fibers comprise at least 50% by weight of the component.
- 17. The method of claim 16 wherein said fibers comprise about 90% by weight of the component.
- 18. The method of claim 1 wherein said polymer matrix is a structural thermoplastic or thermosetting resin.
- 19. The method of claim 18 wherein said resin is a polyester, vinylester or epoxy.
- 20. The method of claim 18 wherein said polymer is a crosslinked silicone elastomer.
- 21. The method of claim 1 wherein said brush-like structure has a fiber density of at least 1000 fibers per square millimeter.
- 22. The method of claim 21 wherein said brush-like structure has a fiber density of at least 15,000 fibers per square millimeter.
- 23. The method of claim 1 wherein the fibers in the brush-like structure have a length greater than five times the fiber diameter and are resiliently flexible behaving elastically as a mass when deformed.
- 24. The method of claim 1 wherein the fibers in the brush-like structure have a length shorter than five times the fiber diameter and the terminating ends provide a relatively rigid contacting surface.
Parent Case Info
The application is a divisional of Ser. No. 07/806,062, filed Dec. 11, 1991, now U.S. Pat. No. 5,270,106, which is a continuation-in-part of Ser. No. 07/516,000, filed Apr. 16, 1990, now abandoned.
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
5250756 |
Swift et al. |
Oct 1993 |
|
5282310 |
Rommelmann et al. |
Feb 1994 |
|
Divisions (1)
|
Number |
Date |
Country |
Parent |
806062 |
Dec 1991 |
|
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
516000 |
Apr 1990 |
|