SHIELDING TAPE WITH MULTIPLE FOIL LAYERS

• US 20110011639A1
• Filed: 10/26/2009
• Published: 01/20/2011
• Est. Priority Date: 07/16/2009
• Status: Active Grant

• Current Assignee: PCT International Incorporated (Andes Industries Incorporated)
• Original Assignee: PCT International Incorporated (Andes Industries Incorporated)
• Inventors: Visser, Leonard
• Granted Patent: US 9,728,304 B2
• Time in Patent Office: Days
• US Class Current: 174/350
• CPC Class Codes: H01B 11/1008 Features relating to screening tape per se
• CPC Class Codes: H01B 11/1016 composed of a longitudinal lapped tape-conductor
• CPC Class Codes: H01B 11/1813 Co-axial cables with at least one braided conductor
• CPC Class Codes: H01B 11/1826 Co-axial cables with at least one longitudinal lapped tape-conductor
• CPC Class Codes: H05K 9/0098 for shielding electrical cables
• CPC Class Codes: Y10T 29/49123 Co-axial cable

Abstract

A coaxial cable of the present invention comprises a center conductor, a dielectric surrounding the center conductor, a shielding tape surrounding the dielectric, a braided metal surrounding the shielding tape, and an outer jacket surrounding the braided metal. The shielding tape comprises: (i) a first shielding layer bonded to a first separating layer; (ii) a second shielding layer bonded to the first separating layer and a second separating layer; and (iii) a third shielding layer bonded to the second separating layer. The present invention eliminates the potential problem of the outer shielding structures separating and interfering with connector attachment. Furthermore, the use of three or more shielding layers in the shielding tape of the present invention improves the flex life of the shield tape by covering micro-cracks in the metal layers with additional shielding layers, thus reducing signal egress or ingress. Accordingly, the present invention provides cost savings and/or an improvement in shielding performance.

Claims

1. A coaxial cable comprising:

(a) a center conductor;

(b) a dielectric surrounding the center conductor;

(c) a shielding tape surrounding the dielectric, the shielding tape comprising;

(i) a first shielding layer bonded to a first separating layer;

(ii) a second shielding layer bonded to the first separating layer and a second separating layer; and

(iii) a third shielding layer bonded to the second separating layer;

(d) a braided metal surrounding the shielding tape; and

(e) an outer jacket surrounding the braided metal.

2. The coaxial cable of claim 1 that further comprises a second shielding tape surrounding the braided metal.

3. The coaxial cable of claim 2, wherein the second shielding tape comprises:

(a) a first shielding layer bonded to a first separating layer;

(b) a second shielding layer bonded to the first separating layer and a second separating layer; and

(c) a third shielding layer bonded to the second separating layer.

4. The coaxial cable of claim 3 that further comprises a second braided metal surrounding the second shielding tape.

5. The coaxial cable of claim 1, wherein the braided metal comprises one or more of the group consisting of:

aluminum, copper, copper-plated steel, tinned copper, and copper-clad steel.

6. The coaxial cable of claim 1, wherein the braided metal is comprised of wire between 32 gauge and 40 gauge.

7. The coaxial cable of claim 1, wherein the center conductor comprises one or more of copper, copper-clad steel, copper-plated steel, and copper-plated aluminum.

8. The coaxial cable of claim 1, wherein the center conductor is between about 0.014″

and about 0.200″

in diameter.

9. The coaxial cable of claim 1, wherein the dielectric is between about 0.040″

and about 0.600″

in diameter.

10. The coaxial cable of claim 1, wherein the dielectric comprises one or more of the group consisting of:

foam polyethylene, polypropylene and fluorinated ethylene propylene.

11. The coaxial cable of claim 1, wherein the outer jacket is between about 0.007″

and 0.080″

thick.

12. The coaxial cable of claim 1 that is an RG-6 type 75-Ohm coaxial cable.

13. The coaxial cable of claim 1 that is a 50-Ohm coaxial cable.

14. The coaxial cable of claim 1, wherein the outer jacket comprises one or more of the group consisting of:

polyvinyl chloride (“

PVC”

), polyethylene, nylon, and TEFLON.

15. The coaxial cable of claim 1, further comprising an adhesive applied to the third shielding layer, the adhesive for attaching the shielding tape to a component of the coaxial cable.

16. The coaxial cable of claim 15, wherein the adhesive is one or more of EAA and EMAA.

17. The coaxial cable of claim 15, wherein the adhesive is at least 8 microns thick.

18. The coaxial cable of claim 15, wherein the adhesive is between 8-25 microns thick.

19. The coaxial cable of claim 17, wherein the adhesive is about 25 microns thick.

20. The coaxial cable of claim 1, wherein each shielding layer is at least 3 microns thick.

21. The coaxial cable of claim 1, wherein each shielding layer is between 3 and 9 microns thick.

22. The coaxial cable of claim 20, wherein each shielding layer is about 9 microns thick.

23. The coaxial cable of claim 1, wherein each separating layer is at least 4 microns thick.

24. The coaxial cable of claim 1, wherein each separating layer is between 4 and 12 microns thick.

25. The coaxial cable of claim 23, wherein each separating layer is about 12 microns thick.

26. A cable comprising:

(a) a center conductor; and

(b) a shielding tape surrounding the center conductor, the shielding tape comprising;

(i) a first shielding layer bonded to a first separating layer;

(ii) a second shielding layer bonded to the first separating layer and a second separating layer; and

(iii) a third shielding layer bonded to the second separating layer.

27. The cable of claim 26 that further comprises a braided metal surrounding the shielding tape.

28. The cable of claim 27 that further comprises a second shielding tape surrounding the braided metal.

29. The cable of claim 28, wherein the second shielding tape comprises:

(a) a first shielding layer bonded to a first separating layer;

(b) a second shielding layer bonded to the first separating layer and a second separating layer; and

(c) a third shielding layer bonded to the second separating layer.

30. The cable of claim 28 that further comprises a second braided metal surrounding the second shielding tape.

31. The cable of claim 26 that further comprises an outer jacket surrounding the braided metal.

32. The cable of claim 31, wherein the outer jacket is formed from one or more of the group consisting of:

polyvinyl chloride (“

PVC”

), polyethylene, nylon, and TEFLON.

33. The cable of claim 26 that further comprises a second center conductor, wherein the shielding tape surrounds the second center conductor.

34. The cable of claim 33 that further comprises:

(a) a third center conductor;

(b) a fourth center conductor; and

(c) a second shielding tape surrounding the third center conductor and the fourth center conductor, the second shielding tape comprising;

(i) a first shielding layer bonded to a first separating layer;

(ii) a second shielding layer bonded to the first separating layer and a second separating layer; and

(iii) a third shielding layer bonded to the second separating layer.

35. The cable of claim 34, further comprising an adhesive applied to the third shielding layer, the adhesive for attaching the shielding tape to a component of the cable.

36. The cable of claim 35, wherein the adhesive is one or more of EAA and EMAA.

37. The cable of claim 35, wherein the adhesive is at least 8 microns thick.

38. The cable of claim 35, wherein the adhesive is about 25 microns thick.

39. The cable of claim 34, wherein each shielding layer is at least 3 microns thick.

40. The cable of claim 34, wherein each shielding layer is about 9 microns thick.

41. The cable of claim 34, wherein each separating layer is at least 4 microns thick.

42. The cable of claim 34, wherein each separating layer is about 12 microns thick.

43. A shielding tape comprising:

(a) a first shielding layer bonded to a first separating layer;

(b) a second shielding layer bonded to the first separating layer and a second separating layer; and

(c) a third shielding layer bonded to the second separating layer.

44. The shielding tape of claim 43, wherein one or more of the first shielding layer, the second shielding layer, and the third shielding layer comprise a material selected from one or more of the group consisting of:

aluminum, copper, silver, a magnetic alloy and combinations thereof.

45. The shielding tape of claim 43, wherein one or more of the first separating layer, and the second separating layer, comprise a material selected from one or more of the group consisting of:

polyethylene terephthalate (“

PET”

), polyolefin and combinations thereof.

46. The shielding tape of claim 43, further comprising an adhesive applied to the third shielding layer, the adhesive for attaching the shielding tape to a component in a cable.

47. The shielding tape of claim 46, wherein the adhesive is one or more of EAA and EMAA.

48. The shielding tape of claim 46, wherein the adhesive is at least 8 microns thick.

49. The shielding tape of claim 46, wherein the adhesive is about 25 microns thick.

50. The shielding tape of claim 43 that further comprises a third separating layer bonded to the third shielding layer and a fourth shielding layer bonded to the third separating layer.

51. The shielding tape of claim 43 that further includes up to four additional shielding layers, wherein each shielding layer is separated from the other shielding layers by one or more separating layers.

52. The shielding tape of claim 43, wherein each shielding layer is attached to adjacent separating layers by an adhesive.

53. The shielding tape of claim 43, wherein each shielding layer is at least 3 microns thick.

54. The shielding tape of claim 43, wherein each shielding layer is about 9 microns thick.

55. The shielding tape of claim 43, wherein each separating layer is at least 4 microns thick.

56. The shielding tape of claim 43, wherein each separating layer is about 12 microns thick.