The present invention relates to electrical connectors and, more particularly, to a paddle-card termination for a shielded electrical cable.
The speed and capacity of computing systems are constantly on the rise. Furthermore, computing systems are being interconnected in increasingly complex networks. In order to keep pace with these developments, new interconnect systems such as, for example, the InfiniBand architecture have been proposed. The InfiniBand architecture is an industry standard, channel-based, switched fabric, interconnect architecture, with a primary application in the area of server interconnection. InfiniBand promises to provide reliable interconnect performance at speeds ranging from 2.5 to 30 Gbits/second.
The InfiniBand standard, and others like it such as, for example, 10 Gbit Ethernet, represent notable advances in interconnect speeds. At the relatively high speeds provided by these technologies, the highest levels of electrical performance are required of the physical interconnect devices. For example, creating a stable contact interface with precise impedance matching is essential. Likewise, electromagnetic interference and leakage must be minimized. Furthermore, these characteristics must be provided in a physical form that is mechanically operable in real world situations and capable of being manufactured consistently in large quantities.
Paddle-card terminations are commonly used an interface between electrical cables and electrical components.
Each of the cables 11 comprises a pair of conductors 20a, 20b suitable for conducting differential electrical signals. The conductors 20a, 20b are each covered by a respective layer of insulation 22a, 22b. Each cable 11 also comprises a drain line (not shown, for clarity). The cables 11 each include a shielded jacket 24 that covers the two conductors 20a, 20b, their respective insulation layers 22a, 22b, and the drain line (not shown).
The paddle-card termination 100 comprises a board 102 formed from an insulative material such as molded plastic. The board 102 has a first major surface 104 that forms a first side of the board 102, and a second major surface 106 that forms an opposing second side of the board 102.
A first of electrically-conductive pads 108a are disposed on the first major surface 104, proximate a first end of the board 102. A plurality of electrically-conductive pads 108b are disposed on the second major surface 106, proximate the first end of the board 102. The pads 108a, 108b are adapted to mate with the conductors 20a, 20b of the cables 11, as described in detail below.
A plurality of electrically-conductive pads 109a are disposed on the first major surface 104 of the board 102, proximate a second end of the board 102. A plurality of electrically-conductive pads 109b are disposed on the second major surface 106, proximate the second end of the board 102.
The pads 109a, 109b are substantially identical. Each pad 109a is substantially aligned with a corresponding pad 109b. In other words, each pad 109a is located directly above one of the pads 109b, as depicted in FIG. 7B. Each vertically-aligned pair of pads 109a, 109b is each adapted to contact a respective vertically-aligned pair of contacts on the contact on the mating component. This contact electrically couples the paddle-card termination 100 and the mating component.
As mentioned above, the mating component has a vertical pin-out requirement. In other words, the contacts on the electrical component that mate with the paddle-card termination 100 are arranged in at least two rows, with the first rows being located directly below the second. This requirement is satisfied in conventional prior art paddle-card terminations as follows, with reference to
A plurality of conductive traces 114 are disposed on the board 102 to electrically couple the pads 108a, 108b with the pads 109a, 109b. A first plurality of the traces 114 each extend between one of the pads 108a and one of the pads 109a, as shown in
Each of the cables 11 is connected to one of the pads 108a or one of the pads 108b by conventional means such as soldering. More particularly, each of the conductors 20a is electrically and mechanically coupled to a corresponding one of the pads 108a. Each of the conductors 20b is likewise electrically and mechanically coupled to a corresponding one of the pads 108b.
Moreover, the conductors 20a, 20b of each cable 11 are coupled to vertically-aligned pairs of pads 108a, 108b. Each vertically-aligned pair of pads 108a, 108b, in turn, is electrically coupled to a corresponding vertically-aligned pair of pads 109a, 109b. Hence, differential signals from the conductors 20a, 20b of each cable 11 are transmitted to a corresponding pair of vertically-oriented contacts on the mating component, thereby satisfying the vertical pin-out requirement of the mating component.
Cross talk between the conductors 20a, 20b the cables 11 can produce errors in the data being transmitted through the cables 11, and should therefore be limited. Moreover, the ongoing increases in signal speeds being achieved in the electronics industry can exacerbate the adverse effects of cross talk. Conventional cable terminations 100 of the prior art such as the cable termination 100 can be a source of such cross talk. A need therefore exists for a cable termination that minimizes cross talk transmitted through the cable termination.
A preferred embodiment of a cable harness assembly comprises a shielded cable comprising a first and a second conductor for conducting a pair of differential signals and a shield at least partially covering the first and the second conductors. The cable harness assembly further comprises a paddle-card termination comprising a generally planar board having a first and a second electrically-conductive trace formed thereon and having a first and a second major surface. The first trace is electrically coupled to the first conductor at a first location on the first major surface and extends along the first major surface to a second location on the first major surface. The second trace is electrically coupled to the second conductor at a third location on the first major surface and extends along the first and the second major surfaces to a fourth location on the second major surface.
Another preferred embodiment of a cable harness assembly comprises a paddle-card termination comprising a generally planar board having a first and a second electrically-conductive trace formed thereon and having a first and a second major surface, a first, second, and third electrically-conductive pad disposed on the first major surface, a fourth electrically-conductive pad disposed on the second surface, a first electrically-conductive trace extending between the first and the third pads, and a second electrically-conductive trace extending between the second and the fourth pads. The cable harness assembly also comprises a shielded cable comprising a first conductor electrically and mechanically coupled to the first pad and a second conductor electrically and mechanically coupled to the second pad.
A preferred embodiment of a plug assembly adapted to electrically couple a receptacle adapted to mate with the plug assembly and a shielded cable comprising a first and a second conductor comprises an insulative body having a first and a second electrically-conductive trace formed thereon and each being adapted to engage a respective contact on the receptacle. The plug assembly also comprises a paddle-card termination comprising a generally planar board having a first and a second major surface, and a first and a second electrically-conductive pad disposed on the first surface and adapted to be electrically and mechanically coupled to the respective first and second conductors.
The plug assembly further comprises a first and a second contact mounted on the body and coupled to a respective one of the first and second electrically-conductive traces. The first contact is mechanically coupled to the first major surface and electrically coupled to the first electrically-conductive pad and the second contact is mechanically coupled to the second major surface and electrically coupled to the second conductor.
A preferred embodiment of a connector system comprises a plurality of shielded cables each comprising a first and a second conductor for conducting a pair of differential signals. The connector system also comprises a plug assembly comprising an insulative body, a plurality of contacts mounted on the body in a first and a second row, and a paddle-card termination at least partially disposed between the first and the second rows. The first and the second conductors of each of the cables are mechanically coupled to a common side of the board, the first conductor of each of the cables is electrically coupled to one of the contacts in the first row, and the second conductor of each of the cables is electrically coupled to one of the contacts in the second row.
The connector system also comprises a receptacle adapted to mate with the plug assembly. The receptacle comprises a plurality of contacts each being adapted to electrically contact a respective one of the contacts of the plug assembly when the receptacle is mated to the plug assembly.
The foregoing summary, as well as the following detailed description of a preferred embodiment, is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, the drawings show an embodiment that is presently preferred. The invention is not limited, however, to the specific instrumentalities disclosed in the drawings. In the drawings:
A connector system comprising a preferred embodiment of a paddle-card cable termination 10 is depicted in
The paddle-card termination 10 forms part of a plug assembly 62. The plug assembly 62 is adapted to mate with a receptacle 64 having a specific fixed and predetermined vertical pin-out requirement (see FIG. 2). The receptacle 64 is adapted to be mounted on and electrically coupled to a substrate 68. The plug assembly 62 and the receptacle 64 form a connector system for electrically coupling the cable 11 and the substrate 68. The connector system is described in detail for exemplary purposes only, as the preferred embodiment of the cable termination can be used in conjunction with any connector system requiring a paddle-card cable termination.
The plug assembly 62 comprises an insulative body 70, a plurality of contacts 74, a casing 78, and the paddle-card termination 10. The contacts 74 are mounted on the body 70 (see FIG. 4). Half of the contacts 74 are arranged in a first, or upper, row 80, and the remaining contacts 74 are arranged in a second, or lower, row 82.
The contacts 74 in the upper row 80 are spaced apart from the contacts 74 in the lower row 82. Each of the contacts 74 in the upper row 80 is vertically aligned with a corresponding contact 74 in the lower row 82. In other words, each contact 74 in the lower row 82 is located directly below a corresponding contact 74 in the upper row 80 when the plug assembly 62 is oriented as shown in the figures. (It should be noted that directional terms such as “upper,” “lower,” “vertical,” etc. are used with reference to the component orientations depicted in the figures. These terms are used for illustrative purposes only, and are not intended to limit the scope of the appended claims.)
Each of the contacts 74 has a beam portion 74a and an adjoining pin portion 74b (see FIG. 4). The pin portion 74b of each contact 74 is mounted in the body 70. This arrangement causes the beam portion 74a to extend from the body 70.
The beam portions 74a of the contacts 74 engage the paddle-card termination 10. More particularly, and end portion of the paddle-card termination 10 is positioned between the upper and lower rows 80, 82 of contacts 74, i.e., the upper and lower rows 80, 82 of contacts 74 straddle an end portion of the paddle-card termination 10. The beam portions 74a are mechanically and electrically coupled to the paddle-card termination 10. Further details concerning the interface between the contacts 74 and the paddle-card termination 10 are presented below.
The body 70 of the plug assembly 62 has a main portion 70a and a shelf portion 70b that extends from the main portion 70a. Electrically-conductive traces 84 are disposed on upper and lower surfaces 70c, 70d of the shelf portions 74b of the contacts 74 each extend through the main portion 70a, and contact a respective trace 84.
The body 70, contacts 74, and paddle-card termination 10 are housed in the casing 78 (see FIGS. 1 and 3). The casing 78 is preferably formed from a material, such as nickel-plated zinc, that shields the plug assembly 62 from externally-generated electromagnetic interference. The plug assembly 62 also includes a cable collar 79 that secures the cables 11 to the casing 78.
The receptacle 64 comprises a plurality of contacts 90 housed in a shell 98 (see FIG. 2). Half of the contacts 90 are arranged in a first, or upper, row 92, and the remaining contacts 90 are arranged in a second, or lower, row 94. The contacts 90 in the upper row 92 are spaced apart from the contacts 90 in the lower row 94. Moreover, each of the contacts 90 in the upper row 92 is vertically aligned with a corresponding contact 90 in the lower row 94. In other words, the receptacle 64 must have a vertical pin out requirement that corresponds to that of plug assembly 62.
The contacts 90 are adapted to engage the traces 84 of the plug assembly 62. In particular, the contacts 90 in the upper row 92 and the contacts 90 in the lower row 94 straddle the shelf portion 70b of the body 70 when the plug assembly 62 is mated with the receptacle 64. Moreover, the contacts 90 are arranged so the each of the contacts 90 substantially aligns with and contacts a corresponding trace 84 when the plug assembly 62 and the receptacle 64 are mated, thereby establishing electrical contact between the plug assembly 62 and the receptacle 64.
Further details relating to the receptacle 64 are not necessary to an understanding of the invention, and therefore are not presented herein.
The concept of the invention was achieved when Applicant was trying to reduce the cross-talk in the receptacle while working within the constraints of the specific vertical pin out requirements that cannot be changed.
Applicant has found that coupling the conductors 20a, 20b of a particular cable 11 to the same side of the board 12 provides substantial advantages relating to crosstalk reduction. In particular, the noted coupling arrangement minimizes the amount of shielding 24 that must be removed from the cable 11 to permit the conductors 20a, 20b to be mated with the pads 18a, 18b.
Each of the cables 11, as noted previously, comprises a pair of conductors 20a, 20b suitable for conducting differential electrical signals. The two conductors 20a, 20b are each covered by a respective layer of insulation 22a, 22b. Each cable 11 also comprises a drain line 25 (see
The cables 11 each include a shielded jacket 24 that covers the two conductors 20a, 20b, their respective insulation layers 22a, 22b, and drain line 25 of the cable 11. (It should be noted that several of the cables 11 are not depicted in
Details concerning to the paddle-card termination 10 are as follows. The paddle-card termination 10 comprises a board 12 formed from an insulative material such as molded plastic. The board 12 has a first major surface 14 that forms a first side of the board 12, and a second major surface 16 that forms an opposing second side of the board 12 (see FIGS. 4-6B).
A first plurality of electrically-conductive pads 18a are disposed on the first major surface 14, proximate a first end of the board 12. A second plurality of electrically-conductive pads 18b are disposed on the second major surface 16, proximate the first end of the board 12.
The pads 18a, 18b are substantially identical. Each of the pads 18a is substantially aligned with a corresponding one of the pads 18b. In other words, each pad 18a is located directly above one of the pads 18b when the paddle-card termination 10 is oriented as depicted in the Figures.
A third plurality of electrically-conductive pads 19a are disposed on the first major surface 14 of the board 12, proximate a second end of the board 12. A fourth plurality of electrically-conductive pads 19b are disposed on the second major surface 16, proximate the second end of the board 12.
The pads 19a, 19b are substantially identical. Each pad 19a is substantially aligned with a corresponding pad 19b. In other words, each pad 19a is located directly above one of the pads 19b when the paddle-card termination 10 is oriented as depicted in the figures.
The pads 19a, 19b are each electrically and mechanically coupled to a beam portion 74a of a corresponding one of the contacts 74 (see FIG. 4). In other words, the pads 19a, 19b are arranged on the board 12 so that each of the pads 19a, 19b substantially aligns with and contacts a corresponding beam portion 74a when the paddle-card termination 10 is mated with the body 70 and the contacts 74. The beam portions 74a are preferably coupled to the corresponding pads 19a, 19b by soldering.
Each of pads 18a, 18b are electrically and mechanically connected to pads 19a, 19b by circuit traces, as described below.
Each of the cables 11 is connected to one of the pads 18a or one of the pads 18b by conventional means such as soldering. More particularly, the conductors 20a, 20b of a first plurality of the cables 11 are electrically and mechanically coupled to adjacent ones of the pads 18a on first major surface 14 of board 12. The conductors 20a, 20b of a second plurality of the cables 11 are likewise electrically and mechanically coupled to adjacent ones of the pads 18b on second major surface 16 of board 12. Hence, the conductors 20a are located on alternating ones of the pads 18a or the pads 18b, and the conductors 20b are likewise located on the other of alternating ones of the pads 18b or the pads 18a.
The jacket 24 is removed from an end portion of each cable 11 before the cable 11 is coupled to the pads 18a, 18b. In addition, the insulation layers 22a, 22b are stripped from the respective ends of the conductors 20a, 20b to expose the conductors 20a, 20b. These actions facilitate mating of the conductors 20a, 20b to the pads 18a, 18b.
The length of the jacket 24 and insulation layers 22a, 22b removed from each cable 11 can now be reduced from the prior art and thus minimized. More particularly, the portion of the jacket 24 and insulation layers 22a, 22b removed from each cable 11 is preferably limited to that only necessary to allow the conductors 20a, 20b of that cable 11 to reach adjacent ones of the pads 18a or the pads 18b. The significance of this feature is discussed below.
The shielding 24 reduces or eliminates cross talk between the cables 11. Hence, increasing the amount of shielding 24 that remains on the cables 11 reduces the cross talk that occurs between the cables 11. In other words, minimizing the amount of shielding 24 that must be removed from the cables 11 to mate the cables 11 with the board 12 minimizes the cross-talk that occurs between the cables 11.
The paddle-card termination 10, by accommodating the conductors 20a, 20b from a particular cable 11 on a common side of the board 12, is believed to minimize the cross talk between the cables 11. Moreover, the paddle-card termination 10 can achieve this characteristic while satisfying the vertical pin out requirement of the receptacle 64.
To convert the row pad pattern of the first end of board 12 to the fixed predetermined specific vertical pin out pattern of the second end of board 12 a novel trace pattern was needed. An exemplary of such a trace pattern is set forth below.
A plurality of conductive traces 24a, 24b, 26a, 26b are disposed on the board 12 to electrically couple the pads 118a, 18b with the pads 19a, 19b. Details concerning the routing of the traces 24, 26 are as follows. For clarity, the conductive traces are depicted in
Each of the traces 24a, 24b is electrically coupled to a respective conductor 20a of the cable 11. The traces 24a each extend between one of the pads 18a and one of the pads 19a. The traces 24a are disposed entirely on the first major surface 14 of the board 12.
The traces 24a each extend between a pad 18a and a pad 19a that are offset with respect to the lengthwise (“x”) direction of the board 12 (see FIG. 6B). (The “x” direction is denoted on a common coordinate system 21 included in each figure.) More particularly, each of the pads 18a is substantially aligned with a respective one of the pads 19a with respect to the lengthwise direction of the board 12. Each trace 24a extends between a pad 18a, and a pad 19a adjacent to the pad 19a that is aligned with that particular pad 18a.
The traces 24b each extend between one of the pads 18b and one of the pads 19b. The traces 24b are disposed entirely on the second major surface 16 of the board 12.
The traces 24b each extend between a pad 18b and a pad 19b that are offset with respect to the lengthwise direction of the board 12. More particularly, each of the pads 18b is substantially aligned with a respective one of the pads 19b with respect to the lengthwise direction of the board 12. Each trace 24b extends between a pad 18b, and a pad 19b adjacent to the pad 19b that is aligned with that particular pad 18b.
Each of the traces 26a, 26b is electrically coupled to a respective conductor 20b of the cable 11. The traces 26a each extend between one of the pads 18a and one of the pads 19b, as shown in FIG. 6A.
Each trace 26a extends between a pad 18a and a pad 19b that are substantially aligned in relation to the lengthwise direction of the board 12. The traces 26a are each disposed partially on the first major surface 14, and partially on the second major surface 16 of the board 12. More particularly, each trace 26a extends along the first major surface 14, between a corresponding one of the pads 18a and a plated via 28 formed in the board 12. The trace 26a passes from the first major surface 14 to the second major surface 16 through the via 28. The trace 26a subsequently extends along the second major surface 16, between a corresponding via 28 and one of the pads 19b.
Each trace 26b extends between a pad 18b and a pad 19a that are substantially aligned in relation to the lengthwise direction of the board 12. The traces 26b are each disposed partially on the first major surface 14, and partially on the second major surface 16 of the board 12. More particularly, each trace 26b extends between a corresponding pad 18b and one of the vias 28. The trace 26b passes from the second major surface 16 to the first major surface 14 through the via 28. The trace 26b subsequently extends along the first major surface 14, between a corresponding via 28 and one of the pads 19a.
The above-noted routing of the traces 24a, 24b, 26a, 26b makes the paddle-card termination 10 compatible with the receptacle 64. More particularly, the receptacle 64 is adapted to mate with vertically-aligned pairs of electrically-conductive traces 84, as noted previously. This requirement is satisfied in the paddle-card termination 10 by routing the traces 24a, 26b between the first and second major surfaces 14, 16 through the vias 28. The vertical pin-out requirement is also satisfied by routing the traces 24a between pads 18a and 19a that are offset with respect to the lengthwise direction of the board 12, and by routing the traces 24b between pads 18b and 19b that are likewise offset.
It is to be understood that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, the disclosure is illustrative only and changes may be made in detail within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 60/383,403, which was filed on May 24, 2002 and is hereby incorporated by reference in its entirety. The present application is related to co-pending U.S. patent application Ser. No. 10/391,388, filed Mar. 18, 2003, and co-pending U.S. patent application Ser. No. 10/417,521, filed Apr. 17, 2003.
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Number | Date | Country | |
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