Claims
- 1. An EMI shielding gasket compressible intermediate a first interface surface and a second interface surface for providing electrical continuity therebetween, said gasket comprising:
a resilient inner member having a first surface and a second surface opposite said first surface, each said first and said second surface extending along an x-axis and a y-axis disposed generally normal to said x-axis, and said first and as second surface defining a thickness dimension of said inner member therebetween which extends along a z-axis disposed generally normal to said x-axis and said y-axis, said inner member having a plurality of vias formed through the thickness dimension thereof; and an electrically-conductive member including:
a first layer portion overlaying at least a part of said first surface and providing electrical conductivity thereacross in the direction of said x-axis and of said y-axis; a second layer portion overlaying at least a part of said second surface and providing electrical conductivity thereacross in the direction of said x-axis and of said y-axis; and one or more third portions each contained within a corresponding one of said vias and providing electrical conductivity between said first and said second layer portion in the direction of said z-axis.
- 2. The gasket of claim 1 wherein said inner member is formed of a sheet or strip of said resilient material, said first surface defining a first side of said sheet or strip, and said second surface defining a second side of said sheet or strip.
- 3. The gasket of claim 2 wherein each said first and said second side is generally planar.
- 4. The gasket of claim 1 wherein each said first and said second surface is generally planar.
- 5. The gasket of claim 1 wherein said inner member is formed of an elastomeric polymeric material.
- 6. The gasket of claim 5 wherein said elastomeric polymeric material is a foam.
- 7. The gasket of claim 5 wherein said elastomeric polymeric material is selected from the group consisting of polyethylenes, polypropylenes, polypropylene-EPDM blends, butadienes, styrene-butadienes, nitrites, chlorosulfonates, neoprenes, urethanes, silicones, and copolymers, blends, and combinations thereof.
- 8. The gasket of claim 7 wherein said elastomeric polymeric material is foamed.
- 9. The gasket of claim 1 wherein said x-axis defines a lengthwise dimension of said gasket of a given first extent, and said y-axis defines a widthwise dimension of said gasket of a given second extent, said thickness dimension of said gasket being small relative to said lengthwise and said widthwise dimension.
- 10. The gasket of claim 9 wherein said first extent of said lengthwise dimension is large relative to said second extent of said widthwise dimension.
- 11. The gasket of claim 1 wherein said first and said second layer portion, and said third layer portion of said electrically-conductive member each is formed, independently, of a material which comprises an admixture of:
one or more resin components; and one or more electrically-conductive particulate fillers.
- 12. The gasket of claim 11 wherein said one or more resin components each is selected, independently, from the group consisting of acrylics, polyurethanes, epoxies, silicones, and copolymers and blends thereof.
- 13. The gasket of claim 11 wherein said one or more resin components each is selected, independently, from the group consisting of elastomeric polymeric materials.
- 14. The gasket of claim 11 wherein said admixture comprises between about 50-90% by weight of said one or more electrically-conductive particulate fillers.
- 15. The gasket of claim 11 wherein said first and said second layer portion of said electrically-conductive member each has a thickness, independently, of between about 0.1-10 mils (0.0025-0.25 mm).
- 16. The gasket of claim 1 wherein said gasket exhibits an EMI shielding effectiveness of at least about 60 dB substantially over a frequency range of between about 10 MHz and about 10 GHz.
- 17. The gasket of claim 1 wherein:
said gasket has an electrical surface resistance of not greater than about 0.10 Ω/sq. in the direction of said x-axis and of said y-axis; and said gasket has an electrical resistance of not greater than about 0.050 Ω/in (0.050 Ω/mm) in the direction of said z-axis.
- 18. The gasket of claim 1 wherein each of said vias has an inner peripheral surface, each of said third portions being formed as a layer coating at least a part of the inner peripheral surface of each said corresponding one of said vias.
- 19. The gasket of claim 18 wherein the inner peripheral surface of each of said vias is generally cylindrical.
- 20. The gasket of claim 19 wherein each of said vias has a diametric extent of between about 0.015-0.50 mils (0.38-12.7 mm).
- 21. The gasket of claim 18 wherein each of said third portions of said electrically-conductive member has a thickness, independently, of between about 0.1-10 mils (0.0025-0.25 mm).
- 22. The gasket of claim 1 wherein said electrically-conductive member is bonded to said inner member.
- 23. The gasket of claim 1 wherein substantially the entirety of said electrical conductivity between said first and said second layer portion is provided by said third portions.
- 24. The gasket of claim 1 wherein:
said first and second surface of said inner member each has a given extent along said x-axis and said y-axis defining an outer margin of said gasket; said inner member having an outer circumferential surface which extends along substantially the entirety of said outer margin; and wherein substantially the entirety of said outer circumferential surface not including said vias is substantially free of said electrically-conductive member.
- 25. The gasket of claim 24 wherein:
said inner member has at least one aperture formed through the thickness dimension thereof, said aperture having a given extent along said x-axis and said y-axis defining an inner margin of said gasket; said inner member having an inner circumferential surface which extends along substantially the entirety of said inner margin; and wherein substantially the entirety of said inner circumferential surface not including said vias is substantially free of said electrically-conductive member.
- 26. The gasket of claim 1 wherein:
said first layer portion of said electrically-conductive member is coated on said first surface of said inner member; and said second layer portion of said electrically-conductive member is coated on said second surface of said inner member.
- 27. The gasket of claim 1 further comprising a reinforcement member, said reinforcement member having an inner surface bonded to said first surface of said inner member, and an outer surface, said first layer portion of said electrically-conductive member coating the outer surface of said reinforcement member, and said vias extending through said reinforcement member.
- 28. The gasket of claim 27 wherein said reinforcement member is formed of a layer of a material selected from the group consisting of foils, films, and fabrics.
- 29. A method of EMI shielding an assembly including a first interface surface and a second interface surface, said method comprising the steps of:
(a) providing an EMI shielding gasket, said gasket comprising:
a resilient inner member having a first surface and a second surface opposite said first surface, each said first and said second surface extending along an x-axis and a y-axis disposed generally normal to said x-axis, and said first and as second surface defining a thickness dimension of said inner member therebetween which extends along a z-axis disposed generally normal to said x-axis and said y-axis, said inner member having a plurality of vias formed through the thickness dimension thereof, each of said vias having an inner peripheral surface; and an electrically-conductive member including:
a first layer portion overlaying at least a part of said first surface and providing electrical conductivity thereacross in the direction of said x-axis and of said y-axis; a second layer portion overlying at least a part of said second surface and providing electrical conductivity thereacross in the direction of said x-axis and of said y-axis; and one or more third portions each contained within a corresponding one of said vias and providing electrical conductivity between said first and said second portion in the direction of said z-axis, (b) interposing said gasket between said first interface surface and said second interface surface, said first layer portion of said electrically-conductive member being disposed opposite said first interface surface, and said second layer portion of said electrically-conductive member being disposed opposite said second interface surface; and (c) compressing the thickness dimension of said inner member of said gasket between said first and said second interface surface to provide electrical continuity therebetween.
- 30. The method of claim 29 wherein said inner member is formed of a sheet or strip of said resilient material, said first surface defining a first side of said sheet or strip, and said second surface defining a second side of said sheet or strip.
- 31. The method of claim 30 wherein each said first and said second side is generally planar.
- 32. The method of claim 29 wherein each said first and said second surface is generally planar.
- 33. The method of claim 29 wherein said inner member is formed of an elastomeric polymeric material.
- 34. The method of claim 33 wherein said elastomeric polymeric material is a foam.
- 35. The method of claim 33 wherein said elastomeric polymeric material is selected from the group consisting of polyethylenes, polypropylenes, polypropylene-EPDM blends, butadienes, styrene-butadienes, nitrites, chlorosulfonates, neoprenes, urethanes, silicones, and copolymers, blends, and combinations thereof.
- 36. The method of claim 35 wherein said elastomeric polymeric material is foamed.
- 37. The method of claim 29 wherein said x-axis defines a lengthwise dimension of said gasket of a given first extent, and said y-axis defines a widthwise dimension of said gasket of a given second extent, said thickness dimension of said gasket being small relative to said lengthwise and said widthwise dimension.
- 38. The method of claim 37 wherein said first extent of said lengthwise dimension is large relative to said second extent of said widthwise dimension.
- 39. The method of claim 29 wherein said first and said second layer portion, and said third layer portion of said electrically-conductive layer each is formed, independently, of a material which comprises an admixture of:
one or more resin components; and one or more electrically-conductive particulate fillers.
- 40. The method of claim 39 wherein said one or more resin components each is selected, independently, from the group consisting of acrylics, polyurethanes, epoxies, silicones, and copolymers and blends thereof.
- 41. The method of claim 39 wherein said one or more resin components each is selected, independently, from the group consisting of elastomeric polymeric materials.
- 42. The method of claim 39 wherein said admixture comprises between about 50-90% by weight of said one or more electrically-conductive particulate fillers.
- 43. The method of claim 39 wherein said first and said second layer portion of said electrically-conductive member each has a thickness, independently, of between about 0.1-10 mils (0.0025-0.25 mm).
- 44. The method of claim 29 wherein said gasket exhibits an EMI shielding effectiveness of at least about 60 dB substantially over a frequency range of between about 10 MHz and about 10 GHz.
- 45. The method of claim 29 wherein:
said gasket has an electrical surface resistance of not greater than about 0.10 Ω/sq. in the direction of said x-axis and of said y-axis; and said gasket has an electrical resistance of not greater than about 0.050 Ω/in (0.050 Ω/mm) in the direction of said z-axis.
- 46. The method of claim 29 wherein each of said vias has an inner peripheral surface, each of said third portions being formed as a layer coating at least a part of the inner peripheral surface of each said corresponding one of said vias.
- 47. The method of claim 46 wherein the inner peripheral surface of each of said vias is generally cylindrical.
- 48. The method of claim 47 wherein each of said vias has a diametric extent of between about 0.015-0.50 mils (0.38-12.7 mm).
- 49. The method of claim 46 wherein each of said third portions of said electrically-conductive member has a thickness, independently, of between about 0.1-10 mils (0.0025-0.25 mm).
- 50. The method of claim 29 wherein said electrically-conductive member is bonded to said inner member.
- 51. The method of claim 29 wherein substantially the entirety of said electrical conductivity between said first and said second layer portion is provided by said third portions.
- 52. The method of claim 29 wherein:
said first and second surface of said inner member each has a given extent along said x-axis and said y-axis defining an outer margin of said gasket; said inner member having an outer circumferential surface which extends along substantially the entirety of said outer margin; and wherein substantially the entirety of said outer circumferential surface not including said vias is substantially free of said electrically-conductive member.
- 53. The method of claim 52 wherein:
said inner member has at least one aperture formed through the thickness dimension thereof, said aperture having a given extent along said x-axis and said y-axis defining an inner margin of said gasket; said inner member having an inner circumferential surface which extends along substantially the entirety of said inner margin; and wherein substantially the entirety of said inner circumferential surface not including said vias is substantially free of said electrically-conductive member.
- 54. The method of claim 29 wherein:
said first layer portion of said electrically-conductive member is coated on said first surface of said inner member; and said second layer portion of said electrically-conductive member is coated on said second surface of said inner member.
- 55. The method of claim 29 further comprising a reinforcement member, said reinforcement member having an inner surface bonded to said first surface of said inner member, and an outer surface, said first layer portion of said electrically-conductive member coating the outer surface of said reinforcement member, and said vias extending through said reinforcement member.
- 56. The method of claim 55 wherein said reinforcement member is formed of a layer of a material selected from the group consisting of foils, films, and fabrics.
CROSS-REFERENCE TO RELATED CASES
[0001] The present application claims the benefit of the filing date of U.S. Provisional Application Serial No. 60/326,550; filed Oct. 2, 2001, the disclosure of which is expressly incorporated herein by reference.
Provisional Applications (1)
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Number |
Date |
Country |
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60326550 |
Oct 2001 |
US |