Compliant shaped EMI shield

• US 6,713,672 B1
• Filed: 12/06/2002
• Issued: 03/30/2004
• Est. Priority Date: 12/07/2001
• Status: Expired due to Fees

• Current Assignee: Laird Technologies Incorporated (DuPont de Nemours, Inc.)
• Original Assignee: Laird Technologies Incorporated (DuPont de Nemours, Inc.)
• Inventors: Stickney, William
• Primary Examiner(s): Reichard, Dean A.
• Assistant Examiner(s): OLIVA, CARMELO B
• Application Number:
  US10/314,456
• Time in Patent Office: 480 Days
• Field of Search: 174/35.GC, 174/35.C, 174/35.R, 174/65.R, 174/52.1, 361/816, 361/818, 439/607, 439/608, 439/609, 439/610, 439/927, 439/939
• US Class Current: 174/382
• CPC Class Codes: H05K 9/0018 with provisions to reduce aperture leakages in walls, e.g. terminals, connectors, cables
• CPC Class Codes: Y10S 439/927 Conductive gasket

Abstract

Disclosed are devices for shielding one or more connection ports from electromagnetic interference emissions. In one embodiment, the device includes a conformal member having a proximal aperture, a distal aperture, and a channel extending therethrough. The distal aperture has a maximum cross-sectional dimension that is less than about one half of a cutoff wavelength, thereby forming a waveguide for attenuating EMI signals that have a wavelength greater than a predetermined cutoff wavelength. In another embodiment, the conformable member includes first conformable element and a second conformable element. The conformable elements, when mated, form a proximal aperture, a distal aperture, and a channel extending therethrough having substantially the dimensional characteristics described above.

Claims

1. An apparatus for reducing a transfer of electromagnetic interference (EMI) across a conductive boundary defining an aperture in a structure, the apparatus comprising:

a conformable member comprising;

a conductive external surface along at least a portion thereof, the conductive external surface being in electrical communication with a conductive boundary defining an aperture in a structure when installed therein; and

a first conductive channel defined by the conformable member extending therethrough, the first conductive channel having a predetermined minimum length, being adapted for receiving at least a portion of a cable assembly, and being in electrical communication with the conductive external surface, the first conductive channel forming;

a first aperture at a proximal end of the channel; and

a second aperture at a distal end of the channel, the second aperture having a predetermined maximum cross-sectional dimension less than about one half of a predetermined cut-off wavelength, wherein the maximum cross-sectional dimension and the minimum length determine an attenuation value relating to the transfer of EMI therethrough.

2. The apparatus of claim 1, wherein the conformable member further comprises a proximal end adapted to contact a support element of the structure when installed therein.

3. The apparatus of claim 1, wherein the first conductive channel comprises a bore.

4. The apparatus of claim 1, wherein the first conductive channel comprises a groove.

5. The apparatus of claim 4, further comprising a conductive member, the conductive member and the groove forming, when mated, a bore.

6. The apparatus of claim 1, wherein the conformable member comprises a first conformable element and a second conformable element, the first and second conformable elements forming, when mated, a conductive bore extending therethrough.

7. The apparatus of claim 1, wherein the conformable member comprises conductive flexible polymeric material.

8. The apparatus of claim 1, wherein the conformable member comprises flexible polymeric material including a conductive coating.

9. The apparatus of claim 1, wherein the conformable member further defines a second conductive channel having a third aperture at a proximal end and a fourth aperture at a distal end, the fourth aperture having a predetermined maximum cross-sectional dimension less than about one half of a predetermined cut-off wavelength, each conductive channel being adapted for receiving at least a respective portion of a cable assembly.

10. The apparatus of claim 9, wherein the first aperture and the third aperture comprise a common aperture.

11. The apparatus of claim 1, wherein the conformable member is adapted to mate with a portion of a circuit board.

12. The apparatus of claim 1, further comprising an electrically conductive flange having:

a first surface in electrical communication with the conformable member, the first surface being adapted for slideably engaging the conformable member; and

a second surface in electrical communication with the boundary, the second surface being fixedly attached to the conductive boundary.

13. The apparatus of claim 1, wherein the conductive member is disposed on a first side of the aperture defined by the conductive boundary.

14. The apparatus of claim 1, wherein the conductive member comprises a grommet, at least a portion of which extends through the aperture defined by the conductive boundary.

15. The apparatus of claim 2, wherein the proximal end of the conformable element is adapted to conform to an angled surface.

16. The apparatus of claim 1, wherein the minimum length is at least two times greater than the maximum cross-sectional dimension of the first conductive channel.

17. The apparatus of claim 1, wherein the maximum cross-sectional dimension is less than about one-eighth of the cut-off wavelength.

18. A method for reducing a transfer of electromagnetic interference (EMI) across a conductive boundary defining an aperture in a structure, the apparatus comprising:

providing a conformable member comprising;

a conductive external surface along at least a portion thereof, the conductive external surface being in electrical communication with a conductive boundary defining an aperture in a structure when installed therein; and

a first conductive channel defined by the conformable member extending therethrough, the first conductive channel having a predetermined minimum length, being adapted for receiving at least a portion of a cable assembly, and being in electrical communication with the conductive external surface, the first conductive channel forming;

a first aperture at a proximal end of the channel; and

a second aperture at a distal end of the channel, the second aperture having a predetermined maximum cross-sectional dimension less than about one half of a predetermined cut-off wavelength, wherein the maximum cross-sectional dimension and the minimum length of the first conductive channel determine an attenuation value relating to the transfer of EMI therethrough; and

installing the conformable member in the structure.

19. The method of claim 18, further comprising adapting a proximal end of the conformal member to contact a support element of the structure when installed therein.

20. The method of claim 18, further comprising providing a conductive member, the conductive member and the channel forming, when mated, a bore.

21. The method of claim 18, wherein providing a conformable member comprises providing a first conformable element and a second conformable element, the first and second conformable elements forming, when mated, a conductive bore extending therethrough.

22. The method of claim 18, wherein providing a conformable member comprises providing conductive flexible polymeric material.

23. The method of claim 18, wherein providing a conformable member comprises providing flexible polymeric material including a conductive coating.

24. The method of claim 18, further comprising adapting the conformable member to mate with a portion of a circuit board.

25. The method of claim 18, further comprises adapting the conductive member to function as a grommet, at least a portion of the conductive member extending through the aperture defined by the conductive boundary.

26. The method of claim 18, further comprising adapting the proximal end of the conformable element to conform to an angled surface.

27. The method of claim 18, wherein the minimum length is at least two times greater than the maximum cross-sectional dimension of the first conductive channel.

28. The method of claim 18, wherein the maximum cross-sectional dimension is less than about one-eighth of the predetermined cut-off wavelength.

29. A device for shielding EMI, the device comprising:

a conductive element forming an aperture adapted to receive a cable, the conductive element, comprising;

a first end including a conductive gasket adapted to contact a support structure; and

a second end including a conductive gasket adapted to contact a circuit board; and

a conformable element positioned partially within the aperture and adapted to receive the cable, the conformable element forming a channel extending therethrough and forming a waveguide having an aperture with a maximum cross-sectional dimension less than about one half of a predetermined cut-off wavelength, wherein the waveguide attenuates EMI signals having a wavelength greater than the cut-off wavelength.