Communication connector having a printed circuit board with thin conductive layers

• US 8,915,756 B2
• Filed: 03/14/2013
• Issued: 12/23/2014
• Est. Priority Date: 01/23/2013
• Status: Active Grant

• Current Assignee: CommScope Inc. (CommScope Holding Company, Inc.)
• Original Assignee: CommScope Inc. (CommScope Holding Company, Inc.)
• Inventors: Schumacher, Richard A., Enge, Ryan E., Larsen, Wayne D., Moffitt, Bryan S., Pharney, Julian
• Primary Examiner(s): Prasad, Chandrika
• Application Number:
  US13/802,844
• Publication Number:
  US 20140206240A1
• Time in Patent Office: 649 Days
• Field of Search: 439/676
• US Class Current: 439/676
• CPC Class Codes: H01R 13/6461 Means for preventing cross-talk
• CPC Class Codes: H01R 13/6466 on substrates, e.g. printed circuit boards [PCB]
• CPC Class Codes: H01R 13/6473 Impedance matching
• CPC Class Codes: H01R 24/64 for high frequency, e.g. RJ 45
• CPC Class Codes: H05K 1/0219 Printed shielding conductors for shielding around or between signal conductors, e.g. coplanar or coaxial printed shielding conductors
• CPC Class Codes: H05K 1/0228 Compensation of cross-talk by a mutually correlated lay-out of printed circuit traces, e.g. for compensation of cross-talk in mounted connectors balanced signal pairs H05K1/0245
• CPC Class Codes: H05K 1/024 Dielectric details, e.g. changing the dielectric material around a transmission line
• CPC Class Codes: H05K 1/0245 Lay-out of balanced signal pairs, e.g. differential lines or twisted lines
• CPC Class Codes: H05K 1/117 Pads along the edge of rigid circuit boards, e.g. for pluggable connectors
• CPC Class Codes: H05K 2201/0187 with regions of different dielectrics in the same layer, e.g. in a printed capacitor for locally changing the dielectric properties
• CPC Class Codes: H05K 2201/0191 wherein the thickness of the dielectric plays an important role
• CPC Class Codes: H05K 2201/09672 Superposed layout, i.e. in different planes parallel traces in one plane H05K2201/09236
• CPC Class Codes: H05K 2201/09727 Varying width along a single conductor; Conductors or pads having different widths
• CPC Class Codes: H05K 2201/09781 Dummy conductors, i.e. not used for normal transport of current; Dummy electrodes of components
• CPC Class Codes: H05K 2201/1034 Edge terminals, i.e. separate pieces of metal attached to the edge of the PCB tab H05K2201/0397
• CPC Class Codes: H05K 2201/10356 Cables

Abstract

Communications connectors include a housing and a printed circuit board that is at least partially mounted in the housing that has a plurality of conductive paths that are arranged in pairs to form a plurality of differential transmission lines. These connectors further include a plurality of contacts, each of which is electrically connected to a respective one of the conductive paths of the printed circuit board. The printed circuit board further includes at least a first floating image plane that is located between a top surface and a bottom surface thereof, the floating image plane being electrically isolated from the plurality of conductive paths.

Claims

1. A communications connector comprising:

a housing;

a printed circuit board that has a top surface, a bottom surface and a plurality of conductive paths that are arranged in pairs to form a plurality of differential transmission lines, the printed circuit board being at least partially mounted in the housing;

a plurality of contacts, where each of the contacts is electrically connected to a respective one of the conductive paths of the printed circuit board,

wherein the printed circuit board further includes a first thin conductive layer that is located between the top surface and the bottom surface of the printed circuit board, the first thin conductive layer being electrically isolated from the plurality of conductive paths, and a second thin conductive layer that is also electrically isolated from the plurality of conductive paths, wherein the second thin conductive layer is electrically isolated from the first thin conductive layer.

2. The communications connector of claim 1, wherein the first thin conductive layer is on a first interior layer of the printed circuit board that is adjacent the top surface of the printed circuit board and the second thin conductive layer is on a second interior layer of the printed circuit board that is different from the first interior layer and that is adjacent the bottom surface of the printed circuit board.

3. The communications connector of claim 1, wherein the communications connector comprises an RJ-45 jack or the communications connector comprises an RJ-45 plug, that is combined with a communications cable to form a patch cord.

4. The communications connector of claim 1, wherein the printed circuit board is a flexible printed circuit board.

5. The communications connector of claim 1, wherein the thin conductive layer includes at least a first gap that is positioned above or below a first of the differential transmission lines and a second gap that is positioned above or below a second of the differential transmission lines.

6. The communications connector of claim 5, wherein the first gap acts as a common mode filter on the first of the differential transmission lines and wherein the second gap acts as a common mode filter on the second of the differential transmission lines.

7. The communications connector of claim 1, wherein the first thin conductive layer covers more than fifty percent of an internal layer of the printed circuit board.

8. A communications connector comprising:

a housing;

a printed circuit board that has a top surface, a bottom surface and a plurality of conductive paths that are arranged in pairs to form a plurality of differential transmission lines, the printed circuit board being at least partially mounted in the housing;

a plurality of contacts, where each of the contacts is electrically connected to a respective one of the conductive paths of the printed circuit board,

wherein the printed circuit board further includes a thin conductive layer that is located between the top surface and the bottom surface of the printed circuit board, the thin conductive layer being electrically isolated from the plurality of conductive paths,

wherein a first of the differential transmission lines includes first imbalanced region where a first of the conductive paths of the first of the differential transmission lines couples more heavily to the thin conductive layer than does a second of the conductive paths of the first of the differential transmission lines, and wherein the thin conductive layer is biased to couple more strongly to the first of the conductive paths in a second region of the first of the differential transmission lines to compensate for the first imbalanced region.

9. The communications connector of claim 8, wherein the communications connector comprises an RJ-45 jack or the communications connector comprises an RJ-45 plug, that is combined with a communications cable to form a patch cord.

10. The communications connector of claim 8, wherein the first floating image plane includes at least a first gap that is positioned above or below a first of the differential transmission lines and a second gap that is positioned above or below a second of the differential transmission lines.

11. The communications connector of claim 8, wherein the first thin conductive layer covers more than fifty percent of an internal layer of the printed circuit board.

12. A communications connector comprising:

a housing;

a printed circuit board that has a top surface, a bottom surface and a plurality of conductive paths that are arranged in pairs to form a plurality of differential transmission lines, the printed circuit board being at least partially mounted in the housing;

a plurality of contacts, where each of the contacts is electrically connected to a respective one of the conductive paths of the printed circuit board,

wherein the printed circuit board further includes a thin conductive layer that is located between the top surface and the bottom surface of the printed circuit board, the thin conductive layer being electrically isolated from the plurality of conductive paths,

wherein the conductive paths of a first of the differential transmission lines connect to the respective contacts of a first pair of the contacts and the conductive paths of a second of the differential transmission lines connect to the respective contacts of a second pair of the contacts, wherein each contact includes a contact region that is designed to mate with a respective one of a plurality of contacts of a mating communications connector, wherein the contact regions of the first pair of contacts are sandwiched between the contact regions of the second pair of contacts, and wherein the second differential transmission line includes a first section adjacent the second pair of contacts where the conductive paths are spaced farther apart from each other than are the conductive paths in a second section of the second differential transmission line, and wherein the thin conductive layer is positioned to either lower the impedance of the first section of the second differential transmission line or to raise the impedance of the second section of the second differential transmission line.

13. A communications connector comprising:

a housing;

a printed circuit board that has a top surface, a bottom surface and a plurality of conductive paths that are arranged in pairs to form a plurality of differential transmission lines, the printed circuit board being at least partially mounted in the housing,

a plurality of contacts, where each of the contacts is electrically connected to a respective one of the conductive paths of the printed circuit board,

wherein the printed circuit board further includes a thin conductive layer that is located between the top surface and the bottom surface of the printed circuit board, the thin conductive layer being electrically isolated from the plurality of conductive paths,

wherein a first of the differential transmission lines has a first section where the pair of conductive paths are closely spaced and a second section where the pair of conductive paths are spaced farther apart than in the first section, and wherein the thin conductive layer extends under the first section of the first of the differential transmission lines and substantially does not extend under the second section of the first of the differential transmission lines.

14. The communications connector of claim 13, wherein the communications connector comprises an RJ-45 jack or the communications connector comprises an RJ-45 plug, that is combined with a communications cable to form a patch cord.

15. The communications connector of claim 13, wherein the first floating image plane includes at least a first gap that is positioned above or below a first of the differential transmission lines and a second gap that is positioned above or below a second of the differential transmission lines.

16. The communications connector of claim 13, wherein the first thin conductive layer covers more than fifty percent of an internal layer of the printed circuit board.

17. An RJ-45 plug comprising:

a housing;

a printed circuit board that has a top surface, a bottom surface and a plurality of conductive paths that are arranged in pairs to form a plurality of differential transmission lines, the printed circuit board being at least partially mounted in the housing;

a plurality of plug blades, where each of the plug blades is electrically connected to a respective one of the conductive paths of the printed circuit board,

wherein the printed circuit board further includes a thin conductive layer that is located between the top surface and the bottom surface of the printed circuit board and that covers more than fifty percent of an internal layer of the printed circuit board, the thin conductive layer being electrically isolated from the plurality of conductive paths,

wherein the first conductive layer is interposed between a first differential transmission line on the top surface of the printed circuit board and a second differential transmission line on the bottom surface of the printed circuit board, the communications plug further comprising at least one offending crosstalk circuit located adjacent the plug blades that injects crosstalk between first and second of the differential transmission lines.

18. An RJ-45 communications connector comprising:

a housing;

a printed circuit board that has first through eighth input terminals that are electrically connected to respective first through eighth wires of a communications cable, first through eighth conductive paths that are electrically connected to the respective first through eighth input terminals, the first through eighth conductive paths forming first through fourth differential transmission lines, and first through eighth contacts that are electrically connected to the respective first through eighth conductive paths, the printed circuit board being at least partially mounted in the housing;

wherein the printed circuit board further includes a thin conductive layer that is electrically isolated from the first through eighth conductive paths and wherein the thin conductive layer includes first through fourth gaps that are provided either above or below respective ones of the first through fourth differential transmission lines to create impedance discontinuities along each of the first through fourth differential transmission lines.

19. The communications connector of claim 18, wherein the first through fourth gaps act as common mode filters on the respective first through fourth differential transmission lines.

20. A communications connector comprising:

a housing;

a printed circuit board that has a top surface, a bottom surface and a plurality of conductive paths that are arranged in pairs to form a plurality of differential transmission lines, the printed circuit board being at least partially mounted in the housing;

a plurality of contacts, where each of the contacts is electrically connected to a respective one of the conductive paths of the printed circuit board,

wherein the printed circuit board further includes a first thin conductive layer and a second thin conductive layer that are vertically stacked between the top surface and the bottom surface of the printed circuit board, the first and second thin conductive layers being connected to a reference voltage via a ground connection.

21. The communications connector of claim 20, wherein a first of the differential transmission lines includes an imbalanced region, and wherein the first thin conductive layer is biased to couple more strongly to a first of the conductive paths of the first differential transmission line to compensate for the imbalanced region.