Patent Publication Number: US-8992254-B2

Title: Integrated shielded connector

Description:
This application is a national phase of PCT Application No. PCT/US10/054,281, filed Oct. 27, 2010, which in turn claims priority to U.S. Provisional App. No. 61/255,366, filed Oct. 27, 2009, and which is incorporated herein by reference in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to the field of connectors, more specifically to the field of high data rate I/O connectors. 
     2. Description of Related Art 
     Shielded connectors have been used in external applications (e.g., applications in which the connector acts as an interface to devices external to the system in which the connector is mounted) so as to provide acceptable electromagnetic interference (EMI) and signal performance. One issue that has been noted is that as the frequencies of signaling increase, additional power is often required in order for the system to function over a similar distance. Furthermore, the use of higher signaling frequencies tends to increase the sensitivity of the connector to external noises in those higher frequencies. In addition, the terminals in the connector tend to act as radiators and emit EMI. Consequentially, the effect of increasing power and signal frequencies tends to negatively affect EMI performance. As EMI generally needs to be carefully controlled, shielded connectors face a number of challenging issues. Thus, certain individuals would appreciate improvements in shielded connector designs. 
     BRIEF SUMMARY OF THE INVENTION 
     A connector with a housing positioned in a shield includes a vertical wall that engages the shield on three sides of housing. The vertical wall may include a lip that can be surface mounted directly on a circuit board and coupled to a ground plane thereof so as to provide a substantially continuous or a pattern of coupling to the ground plane. The vertical wall may be provided via a single component or some number of separate components. If the connector includes a shield plate on a front face of the housing, a vertical wall can further engage a shield wall on a fourth side of the housing. The vertical wall can include a plurality of fingers spaced predetermined distance apart. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention is illustrated by way of example and not limited in the accompanying figures in which like reference numerals indicate similar elements and in which: 
         FIG. 1  illustrates a perspective view embodiment of a receptacle assembly. 
         FIG. 2  illustrates a perspective view the cross-section of the embodiment depicted in  FIG. 1 . 
         FIG. 3  illustrates a partially exploded perspective view of the embodiment depicted in  FIG. 1 . 
         FIG. 4  illustrates a perspective view of a simplified cross-section taken along the line  4 - 4  in  FIG. 1 . 
         FIG. 5  illustrates a perspective view of an embodiment of a housing and a vertical wall. 
         FIG. 6  illustrates a perspective view of an embodiment a vertical wall. 
         FIG. 7  illustrates a perspective view of an embodiment of a holder and a vertical wall. 
         FIG. 8  illustrates a perspective view of an embodiment of a vertical wall mounted on a printed circuit board. 
         FIG. 9  illustrates a perspective view of the vertical wall depicted in  FIG. 8 . 
         FIG. 10  illustrates another perspective view of the vertical wall depicted in  FIG. 8 . 
         FIG. 11  illustrates an elevated front view of the vertical wall depicted in  FIG. 8 . 
         FIG. 12  illustrates a perspective view of an embodiment of a vertical wall assembly. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The detailed description that follows describes exemplary embodiments and is not intended to be limited to the expressly disclosed combination(s). Therefore, unless otherwise noted, features disclosed herein may be combined together to form additional combinations that were not otherwise shown for purposes of brevity. 
     It should be noted that certain external connectors have included a cage that used fingers that were configured to be pressed into a circuit board so that there was a good electrical connection between the cage and a ground plane positioned in the circuit board. While the fingers provide acceptable shielding/grounding performance, it has been determined that the fingers, which are positioned in plated vias in the circuit board, inhibit routing of signal traces from the signal terminals provided in the connector, particularly if the fingers are provided as frequently as is desired to ensure good shielding and EMI performance. This issue has been determined to be even worse at higher signaling frequencies because there is a desire to increasingly space the fingers closer together. Thus, it has been determined that an improved grounding solution would be beneficial to address this issue. 
       FIGS. 1-11  illustrate features that can be used with a connector  10  so as to provide a good electrical connection between a shield  15  and to a ground plane in a printed circuit board  5  (the circuit board may be formed in a manner similar to how conventional printed circuit boards are formed). As depicted, the connector  10  includes a first port  21   a  and a second port  21   b . The connector  10  includes a conventional shield  15  (that includes a floor  16 ) which is configured to be pressed into the supporting printed circuit board  5 . As is known, this allows the shield  15  to be electrically connected to a ground plane (not shown for purposes of brevity) provided in the printed circuit board  5 . 
     The connector  10  includes a u-brace  40  that helps to define the two ports. A plug  50  can be positioned in a front portion of the u-brace  40 . A housing  60  is positioned in the shield  15  and includes projections  65  that are aligned with the two ports  21   a ,  21   b . As can be appreciated, each projection can include one or more card slots  67 . The housing  60  can support a plurality of wafers  70 ,  71 ,  72 . This can be appreciated from  FIG. 4 , the shield  15  engages a vertical wall  100 . As the vertical wall  100  is electrically coupled to a ground plane provided in the printed circuit board  5 , the vertical wall  100  helps ensure a consistent shield extends around the housing  60 . As can be appreciated, the vertical wall  100  includes a plurality of fingers  105  that regularly engage the shield  15 . This ensures that the gap between points of contact between the vertical wall  100  and the shield  15  is less than a desired maximum distance. Controlling the gap allows one to define the size of a potential opening that could allow EMI to radiate from the connector  10 . 
     As depicted, a front wall  80  is included and the front wall  80  helps prevent EMI from radiating into the ports  21   a ,  21   b . The front wall  80  can also be electrically connected to the vertical wall  100 . As can be appreciated, therefore, the vertical wall  100  can include four sides  101  the defined a rectangular area. It should be noted, however, that the vertical wall  100  could omit a side facing the port  21   b ,  21   b  openings. If the four sides  101  used and are separate pieces, a holder  110  can be used to support the sides  101  while they are being soldered to a circuit board. As can be appreciated, sides  201  could also be coupled together by a bridge  203 . In an embodiment, for example, the vertical wall could be a single piece with one opening at location A (as illustrated in  FIG. 12 ). 
     In general, therefore, a vertical wall is positioned on the circuit board and attached to a ground plane in the circuit board (e.g., using surface mount technology or SMT to attach the vertical wall to the ground plane) so that lip  107  is securely and substantially continuously coupled to the circuit board. The coupling electrically connects the vertical wall to the ground plane while providing support for the vertical wall. Consequentially, the vertical wall is positioned adjacent an insulative housing that is position in the cage and engages at least three walls of the cage when the cage is installed. 
     This can be appreciated, if the vertical wall  100  includes a plurality of separate components that are each separately coupled to the circuit board, a holder  110  may be provided that supports each of the separate components during the fastening process. However, if the vertical wall  100  is a single component then the shape of the structure will help ensure the vertical wall  100  remains upright during the attachment process. 
     As can be appreciated, the vertical wall  100  extends in a first direction (as depicted, orthogonal to a plane defined by a top surface of the circuit board). Fingers  105 , which are flexible, are positioned at some predetermined frequency (e.g., at least every other 2.0 mm or 1.5 mm) which may be fixed or vary as desired. Thus, in an embodiment the fingers can be spaced apart at a 1.5 mm pitch. Decreasing the pitch will intend to increase the frequency at which the connector  10  is effective at managing EMI. The fingers  105  can be cut out of apertures  106  and are configured to engage a cage mounted over the housing  60 . When the cage engages the vertical wall  100 , the fingers  105  are deflected in a direction that is transverse to the direction the vertical wall extends. Thus, the vertical wall  100  extends in a first direction and the fingers  105  are deflected in a second direction and the second direction may be orthogonal to the first direction. If the vertical wall  100  is configured so as to include the orthogonal relationship, the configuration helps ensure a good electrical connection between the fingers  105  and the corresponding walls of the cage while the finger geometry can be adjusted to help address and account for tolerance in the shape and position of the cage. 
     In an embodiment, the vertical wall  100  can be positioned in a notch in the housing so as to minimize the required space. Depending on the design of the vertical wall and the housing  60 , sufficient space may be maintained between the vertical wall and the housing to support light pipes. Thus, the depicted embodiments can provide for high performance connector while also allowing for a feature-rich connector system. 
     One benefit of the depicted system is that a reliable intellectual connection can be made between the shield  15  and a corresponding ground plane in the printed circuit board  5  without the need to have tails from the shield  15  extending into the printed circuit board  5 . This has the benefit of providing greater flexibility for route out of traces that extend from the terminals provided by the connector  10  while still providing desirable EMI performance. 
     It should be noted that while the depicted connector  10  is a stacked connector (e.g., has two ports in a vertical alignment), the vertical wall could also be used with a single port connector. In addition, the vertical wall could also be used with a ganged connector (e.g., a 1×2 or a 1×4 or a 2×8). 
     The disclosure provided herein describes features in terms of preferred and exemplary embodiments thereof. Numerous other embodiments, modifications and variations within the scope and spirit of the appended claims will occur to persons of ordinary skill in the art from a review of this disclosure.