Patent Publication Number: US-11641082-B2

Title: Plug assembly and receptacle assembly with two rows

Description:
RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 15/761,870, filed Mar. 21, 2018, which in turn is a national stage of International Application No. PCT/US2016/053266, filed Sep. 23, 2016, which claims priority to U.S. application Ser. No. 62/222,310, filed Sep. 23, 2015, all of which are incorporated herein by reference in their entirety. 
    
    
     TECHNICAL FIELD 
     This disclosure relates to the field of input/output (“IO”) connectors, more specifically to the field of high data-rate capable IO connectors. 
     DESCRIPTION OF RELATED ART 
     IO connectors are commonly used to support network and server applications. Known IO connectors include SFP, QSFP, CXP and XFP style connectors, just to name a few. One issue that has resulted from the existing styles of connectors is that each style is popular for particular applications. SFP connectors are 1 X connectors (supporting one transmission channel and one receive channel) and suitable for applications where a single channel of communication is sufficient. CXP is a 12 X connector and is desirable when many more channels of communication are needed. QSFP is a 4 X connector and thus is a popular choice for many applications as it provides sufficient bandwidth and front panel density to meet a wide range of applications. Thus QSFP connectors have become a preferred style for number of applications. An embodiment of a QSFP-style plug assembly  10  (as shown in  FIG.  1   ) includes a cable  15  connected to a body  20  that includes a top flange  21  and a bottom flange  22 . The top and bottom flanges  21 ,  22  help protect a mating blade  23  that is typically formed as a circuit board and the cable  15  can include wires that are terminated to the mating blade  23  in a conventional manner. 
     While QSFP style connectors are suitable for many applications, it would be desirable to offer greater front panel density. New connector designs at smaller pitches are being proposed and should help satisfy these needed in a wide range of applications. However, a substantial number of cable assemblies, including passive and active cable assemblies, exist for the QSFP style connector and it would be beneficial to avoid the need to scrap prior designs. Accordingly, certain individuals would appreciate a way to offer increased front panel density while maintaining compatibility with existing QSFP designs. 
     SUMMARY 
     A receptacle assembly is disclosed that includes a connector inside a cage. The connector includes a first connection region and a second connection region and each connection region includes opposing rows of terminals One of connection regions can be configured to mate with a single row of pads and be compatible with the mating blade of a standard connector. The combination of the first and second connection regions can be configured to mate with a higher density plug assembly that includes mating blade configured with two rows of pads. The receptacle assembly can be stacked and provide two ports and each port can include a module that supports two connection regions. The cage can be configured to airflow through the cage so as to improve cooling of any inserted plug assemblies. 
     A plug assembly is disclosed that includes a body with a top flange, a bottom flange and a mating blade positioned between the two flanges. A first row and a second row of pads can be provided on two sides of the mating blade. The top flange has a bottom surface that faces toward the circuit card and includes first and second level, the first level being closer to the mating blade than the second level. The bottom flange that is substantially shorter than a circuit card and can be configured so that the bottom flange covers one row of pads while not covering the second. 
     In operation, the connector system can provide backward compatibility between the receptacle assembly and existing plug assemblies while enabling higher density connections between the receptacle assembly and plug assembly configured for increased data throughput. In some embodiments the connector system can be a QSFP style connector. 
    
    
     
       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 an embodiment of a prior art QSFP style plug assembly. 
         FIG.  2    illustrates a perspective view of two plug assemblies. 
         FIG.  3    illustrates a perspective view of an embodiment of a plug assembly. 
         FIG.  4    illustrates another perspective view of the embodiment depicted in  FIG.  3   . 
         FIG.  5    illustrates a bottom view of an end of an embodiment of a plug connector. 
         FIG.  6    illustrates an elevated side view of the embodiment depicted in  FIG.  5   . 
         FIG.  7    illustrates a perspective simplified view of an embodiment of a plug assembly. 
         FIG.  8    illustrates a perspective partially exploded view of a connector system. 
         FIG.  9    illustrates a perspective view of the embodiment depicted in  FIG.  8    with the plug assembly inserted into the receptacle assembly. 
         FIG.  10    illustrates a perspective view of an embodiment with two plug assemblies inserted into a receptacle assembly, the cage being partially removed. 
         FIG.  11    illustrates a simplified perspective view of terminal rows connected to a conventional plug assembly. 
         FIG.  12    illustrates a perspective view of the embodiment depicted in  FIG.  11    but with an enhanced plug assembly connected to both connection regions. 
         FIG.  13    illustrates an enlarged perspective view of the embodiment depicted in  FIG.  11   . 
         FIG.  14    illustrates an enlarged perspective view of the embodiment depicted in  FIG.  12   . 
         FIG.  15    illustrates a simplified perspective view of two plug assemblies mated in the first and second port with the top plug assembly only having the mating blade shown. 
         FIG.  16    illustrates an enlarged further simplified perspective view of the embodiment depicted in  FIG.  15   . 
         FIG.  17    illustrates a simplified perspective view of another embodiment of two plug assemblies, one simplified, mated to the connector. 
         FIG.  18    illustrates a simplified perspective view of two terminals in two separate rows engaging pads on two pad rows. 
         FIG.  19    illustrates a plan view of the embodiment depicted in  FIG.  18   . 
         FIG.  20    illustrates a simplified perspective view of two partial terminal rows engaging two pad rows. 
         FIG.  21    illustrates an elevated simplified side view of the embodiment depicted in  FIG.  20   . 
         FIG.  22    illustrates a perspective view of an embodiment of a receptacle assembly. 
         FIG.  23    illustrates a simplified perspective view of the embodiment depicted in  FIG.  22   . 
         FIG.  24    illustrates a perspective view of an embodiment of a connector. 
         FIG.  25    illustrates another perspective view of the embodiment depicted in  FIG.  24   . 
         FIG.  26    illustrates a perspective view of connector and a divider. 
         FIG.  27    illustrates a perspective view of a cross-section of the embodiment depicted in  FIG.  26   , taken along line  27 - 27 . 
         FIG.  28    illustrates a perspective partially exploded view of an embodiment of a connector. 
         FIG.  29    illustrates a simplified perspective view of an embodiment of a connector. 
         FIG.  30    illustrates an exploded perspective view of two modules and two vertical modules. 
         FIG.  31    illustrates a perspective view of a module with the frames removed. 
         FIG.  32    illustrates an exploded perspective view of an embodiment of a module. 
         FIG.  33    illustrates a perspective view of a cross section of a module taken along line  33 - 33  in  FIG.  30   . 
         FIG.  34    illustrates a perspective view of a cross section of a module taken along line  34 - 34  in  FIG.  30     
         FIG.  35    illustrates a perspective view of two vertical modules. 
         FIG.  36    illustrates a perspective view of an embodiment of a module and a vertical module. 
         FIG.  37    illustrates a simplified perspective view of the embodiment depicted in  FIG.  36   . 
         FIG.  38    illustrates another perspective view of the embodiment depicted in  FIG.  37   . 
         FIG.  39    illustrates an enlarged perspective view of the embodiment depicted in  FIG.  38   . 
         FIG.  40    illustrates a perspective partial view of an embodiment of a terminal row. 
         FIG.  41    illustrates a perspective partial view of terminals rows engaging a mating surface. 
         FIG.  42    illustrates a perspective partial view of an embodiment of a terminal row connected to conductors in a cable. 
     
    
    
     DETAILED DESCRIPTION 
     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. 
     The disclosed embodiments illustrates features that can be included in a high density QSFP style connector system. As can be appreciated, while a stacked receptacle assembly is disclosed that includes a top port and a bottom port, a single port connector could also be provided. In addition, ganged version could also be provided by increasing the number of connectors depicted and creating a cage that had two or more ports arranged side by side. It should be noted that while the depicted embodiment is configured to be compatible with a QSFP style connector, this disclosure is not so limited. Other known standards, such as SFP or XSFP or new standards would also be compatible with the features and discussion provided herein and the style of connector is not intended to be limiting unless otherwise noted. 
     As can be appreciated, the receptacle assembly includes a two-part housing. A first set of wafers support vertical terminals. The vertical terminals include tails but do not include contacts. A second set of wafers support horizontal terminals. The horizontal terminals include contacts but do not include tails. The first and second sets of wafers are pressed together so that there is an electrical connection between the tails and the contacts. 
     The system is designed so that it supports 25 Gbps data rates for each differential channel and thus offers the ability to support 200 Gbps systems, compared to existing QSFP systems that can support 100 Gbps with a 25 Gbps differential channel. 
     As can be appreciated, the receptacle assembly is configured to improve air flow so that the system can be cooled while still supporting light pipes. A center member includes an open channel that allows air to flow between a top and bottom port. The center member includes a center divider and apertures in two side walls. A back wall of a cage can includes apertures that allow air to flow in (or out, depending on whether the airflow is front-to-back or back-to-front) of the connector in an efficient manner. 
     Turning to  FIGS.  2 - 7   , a plug assembly  50  is disclosed. The plug assembly  50  includes a body  55  that supports a release member  56  that is connected to a latching system  57 . Translation of the release member  56  causes the latching system  57  to actuate. The body  55  includes a top flange  60  with a front end  60   c , a bottom flange  65  with a front end  66  and a mating blade  70  with a front end  77  that is positioned between the top flange  60  and the bottom flange  65 . As can be appreciated, the top flange  60  can include notches and can be configured to have a particular shape so as to mate with a corresponding receptacle assembly system. Thus, the depicted shape is not required and can be modified as desired. 
     The top flange  60  includes a first lower surface  60   a  and a second lower surface  60   b  and the first lower surface  60   b  is offset from the second lower surface  60   b . Thus the first distance between the first lower surface  60   a  and the mating blade  70  is less than a second distance between the second lower surface  60   b  and the mating blade. 
     The mating blade  70  includes a top surface  70   a  that supports a first pad row  72 , a second pad row  74  and a third pad row  76  that are positioned between the first and second rows of pads  72 ,  74 . The mating blade  70  also includes a bottom surface  70   b  that supports a fourth pad row  72 ′, a fifth pad row  74 ′ and a sixth pad row  76 ′ that are positioned between the first and second rows of pads  72 ′,  74 ′. As can be appreciated, the fourth, fifth and sixth pad rows can be arranged the same as the first, second and third pad rows but are positioned on the opposite side of the mating blade  70 . In an embodiment the top flange  60  can cover the first, second and third pad rows  72 ,  74 ,  76  and can extend past the front end  77  while the bottom flange  65  covers just the fifth pad row  74 ′ on the bottom. While not required, one potential advantage of such a configuration is that it allow the plug assembly to be interchangeable with a system that allows for two different plug assemblies to be alternatively inserted into the same port, as will be disclosed below. 
     The first row  72  include short pads  82  that can be configured as signal pads for higher data rates and longer pads  81  that can be used as ground pads or low data rate pads. As shown, the short pads  82  are arranged so as to provide a differential pair  83 . In operation, the first pad row  72  will slide past a second connection region  174  and mate with a first connection region  172  while the second pad row  74  mate with the second connection region (as will be discussed below). To ensure the connection with the first and second connection regions  172 ,  174  are reliable it has been determined beneficial to include the third pad row  76  to protect the first connection region. The third pad row  76  can include long pads  84  positioned between two pairs of short pads and further include intermediate pads  85  positioned between long pads  81 . Naturally, the depicted configuration is intended to have the first pad row  72  and second pad row  74  be configured substantially the same. If such a configuration is not required then the third pad row  76  may have a different configuration of pads. Regardless, it is preferred that the pads in the third pad row  76  be longer than the short pads  82  in the first and second pad rows  72 ,  74  so as to ensure good electrical separation between the first and second pad rows  72 ,  74 . 
     It should be noted that the plug assembly is depicted as a copper-based configuration but could readily be provided as a copper/optical solution (e.g., a transceiver). In such a configuration the internal part of the plug would include a desired optical engine (such as is available from OPLINK or other providers) and would convert the copper signals to optical signals and would be configured to transmit those optical signals over optical fibers, as is known. 
     As can be appreciated from  FIGS.  8 - 42   , a receptacle assembly  100  can be mounted on a circuit board  105  if desired and includes a top port  110  and a bottom port  115 . The receptacle assembly  100  includes a connector  150  positioned in a cage  120  and the cage  120  helps define the ports  110 ,  115  and can be configured to be mounted to a bezel  103 . In operation a plug assembly is inserted into the port in an I direction. The connector include a mating face  150   a  and a mount face  150   b . The cage  120  includes a front face  116 , a top wall  131 , a plurality of side walls  135 , a bottom wall  132  and a rear wall  138 . The side walls  135  can include side vents  136  and the rear wall  138  can include rear vents  139  to aid in air flow. Thus the cage  120  can include vents to allow for air to flow through the cage  120 . The cage  120  can include retention members  122  that are configured to engage the latching system  57  so as to allow a plug assembly to be releasably mated to the receptacle assembly. As can be appreciated from  FIG.  10   , the depicted receptacle assembly can accept a plug assembly  10  or a plug assembly  50 , the plug assembly  50  including two rows of pads or contacts, in either the top or the bottom port. 
     In order to define the two ports more fully, a divider  190  is positioned between the top port  110  and the bottom port  115 . The divider  190  includes a first wall  191  and a second wall  192 . The first wall  191  that helps define the top port  110  and the second wall  192  helps define the bottom port  115 . The divider  190  also provides a channel for air to flow between the ports in direction B-B so that air can flow pass through front vents  107  in center wall  106  (path A-A) or through rear vents (path C-C), through path B-B and then through path C-C or AA. If the vents  136  are provided then another path of air through the vents is also possible. More will be said about the air flow below. 
     The connector  150  includes a first module  160  and a second module  165  that respectively provide the mating contacts positioned in the top and bottom ports  110 ,  115 . It should be noted that each of the modules  160 ,  165  are depicted as being different because in some embodiments it will be desirable to connect terminals  230  (or some of the terminals  230 ) to the supporting circuit board. Thus, as depicted the first module  160  includes a first terminal row  181  supported by a frame  181   a , a second terminal row  182  supported by a frame  182   a , a third terminal row  183  supported by a frame  183   a  and a fourth terminal row  184  supported by a frame  184   a . In a similar fashion, the second module  165  provides a first terminal row  186  supported by frame  186   a , a second terminal row  187  supported by a frame  187   a , a third terminal row  188  supported by a frame  188   a  and a fourth terminal row  189  supported by a frame  189   a . Each of the frames can include cutouts  198  to modify the impedance of the terminal. 
     The depicted terminals  230  have different lengths but generally have a contact  231 , a cantilevered portion  231   a , a wide body portion  232   a , a narrow body portion  232   b  and a tail  233 . The depicted tail  233  is configured to be pressed on a mating terminal as will be discussed below but could also be configured to be attached to a conductor of a cable assembly. For example, as shown in  FIG.  42   , a terminal  431  and a terminal  432  could be arranged as a differential pair and a ground terminal  433  could be positioned beside the differential pair. A cable  450 , which could include a shield layer  456 , would have an insulation layer  455  supporting two conductors  451 ,  452  that would be attached to terminals  431 ,  432  (respectively) and a drain wire  453  could be attach to ground terminal  433 . The attachments between the terminals and the conductors could be as desired (including but not limited to solder or welding) and would allow the terminals to be connected to wires without the need to enter the circuit board. Thus, the configuration of the tail is not limited and the depicted connector  150  configuration is not intended to be limiting unless otherwise noted. As can be further appreciated, if the module was configured with cable attachment such as is depicted in  FIG.  42    then the same module could be used repeatedly and it would also become optional as to whether the cage was mounted on a circuit board. 
     Each module  160 ,  165  provides two connection regions. Specifically, module  160  includes first connection region  172  and second connection region  174  while module  165  includes first connection region  172 ′ and second connection region  174 ′. The first connection region is provided by contacts in by the first terminal row  181  and in the second terminal row  184  (which provide rows of opposing contacts) while the second connection region is provided by contacts in the second terminal row  182  and the third terminal row  183  (which again provide row of opposing contacts). As can be appreciated, two terminal rows (the depicted terminal rows  186  and  187  in  FIG.  41    or terminal rows  181  and  182  if the module  160  was used as an example) are configured to engage a mating surface defined by plane M from a first side while having tails that end on the same first side of plane M. In addition, two other terminal rows will be positioned and extend along a second side of the plane M and in an embodiment none of the terminal rows will cross plane M. 
     In operation, a plug assembly can be inserted into the top port  110  and a mating blade will engage the second connection region  174 . If the plug assembly is a standard design then the mating blade has a single pad row that will only engage the second connection region. If the plug assembly has two pad row design (e.g., a high density design) then the first pad row on the mating blade will first engage the second connection region and then as the plug assembly is fully inserted into the port, the first pad row will slide past the second connection region  174  and engage the first connection region  172 . Accordingly, for a plug assembly with two pad rows of signal contacts on each side, the first pad row  72  will engage the first connection region  172  while the second pad row  74  will engage the second connection region  174 . If desired the first connection region  172 ′ and second connection region  174 ′ can be similarly configured and can operate similarly. This can be appreciated from  FIGS.  16  and  17   . 
     As previously noted, the top flange  60  includes the first lower surface  60   a  and the second lower surface  60   b . The modules  160 ,  165  are configured to support a nose portion  320   a ,  320   b  and the nose portions include a first nose surface  323   a  that is configured to be aligned with the first lower surface  60   a  and may include a nose wall  323   b  that provides a transition to a second nose surface  323   c  that is aligned with the second lower surface  60   b.    
       FIG.  19    illustrates two differential pairs  229   a ,  229   b  engaging the second pad row  174  and first pad row  172 , respectively. As can be appreciated from the FIGS., the terminals supported by the frames include cantilevered portions  221  and supported portions  223 . The terminal row  161  (and the terminal row  164   a ) also includes an angled portion  222  that allows the cantilevered portion  221  to be positioned so that it can engage a mating blade while allowing the supported portion  223  to be positioned a suitable distance from the terminals row  162  supported by the frame  162   a . Thus, as can be appreciated from  FIGS.  20 - 21   , when second terminal row  182  is position on pad row  72 , first terminal row  181  is positioned on second pad row  74 . A break exists between the third pad row  76  and first pad row  72  and that break can form a pad gap  73 . In an embodiment, a vertical plane D positioned at the intersection between the angle portion  222  and the cantilevered portion  221  and a vertical plane F positioned at the intersection between the angled portion  222  and the supported portion  223  defined a horizontal space and a vertical plane E aligned with the pad gap  73  is positioned in that space between the vertical place D and the vertical place F. Preferably a vertical plane G aligned with a contact point between the first pad row and the second terminal row will be positioned outside of that horizontal space. It should be noted that both connection regions have contact points G, G′ and as depicted the angled portion  222  is between the contact points G, G′. 
     As can be appreciated, the connector  150  includes a first card slot  331  aligned with the top port  110  and a second card slot  332  aligned with the bottom port  115 . The card slots  331 ,  332  are recessed away from the front face  116 , in an embodiment the cage has a length L and the cards slots are recessed a distance that is at least ⅓ L. The connector also includes a top air path  345  that provides for a ventilation path in the top port. In order to improve cooling in the bottom port  115 , a center member  340  is provided. The center member  340  can be positioned between a first nose portion  320   a  that defines the first card slot  331  and a second nose portion  320   b  that defines the second card slot  332 . The center member  340  include outer walls  340   a ,  340   b  that each include side vents  342 , the center member  340  further includes a center wall  341  that helps split and direct the air passing through the divider  190  toward the two outer walls  340   a ,  340   b . Because the outer walls  340   a ,  340   b  are recessed in compared to the cage, the space between the outer walls  340   a ,  340   b , the side walls  135  and the shoulders  321 ,  322  of respective nose portions  320   a ,  320   b  creates an air channel  344  that allow air to flow past the connector  150  and out through the rear vents  139 . 
     The top air path  345  accepts a rear section  346  that can be mounted to the top air path  345  and extends the air path toward the rear wall  138 . The second nose portion  320   b  can be connected to back bracket  352 , which can help provide for additional rigidity. It should be noted however, that the first nose portion  320   a  and second nose portion  320   b  do not need to be a single structure and thus can be separately attached to the respective module and supported by the center member  340 . As can be appreciated, the depicted nose portions  320   a ,  320   b  include terminal grooves  326  that help support the contacts with a comb-like structure. While terminal grooves  326  are not required it is beneficial to provide them for the connection region that makes the first contact with a mating blade being inserted in the I direction. 
     In order to mount the modules  160 ,  165  on a circuit board, vertical modules  205 ,  210  are provided. The depicted vertical modules provide a stepped configuration, as can be appreciated from  FIG.  30   , and allow for terminals in wafers  206 ,  207 ,  211  to engage the tails of terminals rows supported by the frames. 
     It should be noted that while a stacked configuration is shown, a single port configuration is also contemplated. For example, the module  165  and the vertical module  210  could be used by themselves to provide a single port design (as compared to a stacked configuration). In such a configuration a single nose portion could be used and the center module could be omitted. It should also be noted that while a press-fit configuration is depicted, a version design for SMT mounting is also contemplated and within the scope of the disclosure as a person of skill in the art would generally be able to replace a standard press-fit tail with an SMT tail. 
     Regardless of the mounting type, assuming there is a mounting to circuit board, terminals  230  are connected to vertical terminals  290 . The depicted vertical terminals  290  include a tail  291 , a shoulder  292  and a vertical riser  293  that is configured to engage the tail  233 . As depicted, the engagement is an interference fit between the vertical riser  293  and an aperture  233   a.    
     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.