Patent Document

CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation application of application Ser. No. 13/772,232 filed on Feb. 20, 2013. This patent application is related to a U.S. patent document No. 8,715,005 B2, issued on May 6, 2014, and entitled “HIGH SPEED HIGH DENSITY CONNECTOR ASSEMBLY,” which is assigned to the same assignee as this application. This application relates to the copending application with the attorney docket numbers U.S. Ser. No. 39,402 and U.S. Ser. No. 39,657. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a high speed high density connector assembly, and more particularly, to a high speed high density connector assembly having stacked contact wafers that are completely shielded. 
         [0004]    2. Description of the Prior Art 
         [0005]    Many prior art references disclose high speed high density connector assemblies with shielding structures. U.S. Pat. No. 6,709,294 B1, issued to Cohen et al. on Mar. 23, 2004, discloses an electrical connector having electrical conductors in a plurality of rows. Each of the plurality of rows includes a housing and a plurality of electrical conductors. Each electrical conductor has a first contact end connectable to a printed circuit board, a second contact end, and an intermediate portion therebetween that is disposed within the housing. The housing includes a first region surrounding each of the plurality of electrical conductors, the first region made of insulative material and extending substantially along the length of the intermediate portion of the electrical conductors. The housing also includes a second region adjacent the first region and extending substantially along the length of the intermediate portion of the electrical conductors. The second region is made of a material with a binder containing conductive fillers providing shielding between signal conductors. Furthermore, in discussing background art in U.S. Pat. No. 6,709,294, it is mentioned that a solution is introduced to provide shields through plastics coated with metals, but there are no combination of readily available and inexpensive metals and plastics that can be used, such as the plastic lacks desired thermal or mechanical properties, available plating techniques are not selective, etc. 
         [0006]    U.S. Pat. No. 6,471,549 B1, issued to Lappohn on Oct. 29, 2002, discloses a shielded plug-in connector. The plug-in connector has a jack-in-blade strip having at least one first contact element and an edge connector having at least one second contact element corresponding to the first contact element. The edge connector, on or in its outer body areas, has at least partially shielding sheets. Shielding of the plug-in connector is achieved by, in addition to the shielding sheets provided on the edge connector, a shielding group with at least one first element arranged in the jack-in-blade strip. The first element of the shielding group is a base part in the form of a U-shaped rail. The shielding sheets on the edge connector have a planar body and angled stays. Two of the angled stays and a portion of the planar body between the two angled stays form a counterpart to the base part, wherein the counterpart and the base part together substantially encapsulate the first and second contact elements. 
         [0007]    U.S. Pat. No. 7,581,990 B2, issued to Kirk et al. on Sep. 1, 2009, discloses a waferized electrical connector incorporating electrically lossy material selectively positioned to reduce crosstalk without undesirably attenuating signals. Wafer may be formed in whole or in part by injection molding of material to form its housing around a wafer strip assembly. A two shot molding operation may be adopted, allowing the housing to be formed of two types of material having different material properties, namely an insulative portion being formed in a first shot and lossy portion being formed in a second shot. The housing may include slots that position air, or create regions of air, adjacent signal conductors in order to provide a mechanism to de-skew a differential pair of signal conductors. 
       OBJECTS OF THE INVENTION 
       [0008]    A main object of the present invention is to provide an electrical connector assembly with improved shielding performance. 
         [0009]    The present invention provides an electrical connector assembly comprising: a first connector adapted to be mounted onto a first printed circuit board, the first connector comprising: a first conductive body comprising a first mounting face for being mounted to the first printed circuit board; a plurality of first contacts received in the first conductive body; a plurality of first shielding members received in the first conductive body; and a plurality of first insulators isolating the first contacts from the first conductive body and the first shielding members; and a second connector adapted to be mounted onto a second printed circuit board and adapted for mating with the first electrical connector, the second connector comprising: a second conductive body for mating with the first conductive body, the second conductive body comprising a second mounting face for being mounted to the second printed circuit board; a plurality of second contacts received in the second conductive body for being mated with the first contacts, respectively; a plurality of second shielding members mounted to the second conductive body; and a plurality second insulators isolating the second contacts from the second conductive body and the second shielding members; wherein a total transmitting trace of the first contact and associated mating second contact between the first mating face and the second mating face are circumferentially fully shielded. 
         [0010]    The total transmitting traces of the first contacts and the second contacts between the first mating face and the second mating face are circumferentially fully shielded. Therefore, the shielding performance is improved. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    The features of this invention which are believed to be novel are set fourth with particularity in the appended claims. The invention, together with its objects and the advantages thereof, may be best understood by reference to the following description taken in conjunction with the accompanying drawings, in which like reference numerals identify like elements in the figures and in which: 
           [0012]      FIG. 1  is a perspective view of a connector assembly of according to a first embodiment of the present invention; 
           [0013]      FIG. 2  is a cross-section view of the electrical connector system when cut in a line II-II shown in  FIG. 1 ; 
           [0014]      FIG. 3  is a perspective view of the stacked contact wafers with one contact wafer being exposed shown in  FIG. 1 ; 
           [0015]      FIG. 4  is a perspective view of two contact modules shown in  FIG. 1 , one in assembled condition and the other in exposed condition; 
           [0016]      FIG. 5  showing two contact wafers of a plug according to a second embodiment of the present invention, one in assembled condition and the other in exposed condition; 
           [0017]      FIG. 6  showing two contact modules of a header according to a second embodiment of the present invention, one in assembled condition and the other in exposed condition; 
           [0018]      FIG. 7  is a perspective view of a connector assembly of according to a third embodiment of the present invention; 
           [0019]      FIG. 8  is a cross-section view of the electrical connector system when cut in the line VIII-VIII shown in  FIG. 7 ; 
           [0020]      FIG. 9  is a partially exploded view of a header shown in  FIG. 7 ; 
           [0021]      FIG. 10  is a partially exploded view of a plug shown in  FIG. 7 ; 
           [0022]      FIG. 11  is another partially exploded view of the plug shown in  FIG. 7  in a different viewpoint; 
           [0023]      FIG. 12  is a partially exploded view of a header of a connector assembly according to a fourth embodiment of the present invention; 
           [0024]      FIG. 13  is a partially exploded view of a plug of a connector assembly according to the fourth embodiment of the present invention; 
           [0025]      FIG. 14  is a partially exploded view of a header of a connector assembly according to a fifth embodiment of the present invention; 
           [0026]      FIG. 15  is a partially exploded view of a plug of a connector assembly according to the fifth embodiment of the present invention; 
           [0027]      FIG. 16  showing a first method of making the contact wafer shown in  FIG. 1 ; 
           [0028]      FIG. 17  showing a second method of making the contact wafer shown in  FIG. 1 ; and 
           [0029]      FIG. 18  showing a third method of making the contact wafer shown in  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0030]    Reference will now be made to the drawing figures to describe the present invention in detail. 
         [0031]      FIGS. 1-4  show a connector assembly according to a first embodiment of present invention. The connector assembly  1  is shown to connect a daughter card (not shown) to a backplane (not shown). The connector assembly  1  includes a plug  10  mounted onto the daughter card and a header  20  mounted onto the backplane. 
         [0032]    The plug  10  includes a conductive front housing  11  and a number of contact wafers  12  stacked along a transverse direction and mounted to a rear face of the front housing  11 . The plug  10  defines a mounting face  17  adapted to be mounted onto the daughter card. The header  20  includes a mounting face  27  adapted to be mounted onto the backplane. 
         [0033]    The front housing  11  is made from die casting metal or conductive plastic, or insulating piece plated with metal plating. In a preferred embodiment, the front housing  11  is made from thermoplastic plated with metal plating, such as Chromium, Copper, Tin and Gold. The front housing  11  defines a front face  13  forwardly facing the header  20 , a rear face  14  opposite to the front face  13  and a number of holes  15  extending through the rear face  14  and the front face  13 . 
         [0034]    Each of the wafers  12  includes a conductive board  120  defining mutual opposite first face and second face, four pairs of first signal contacts  121 , four first insulating holders  122  respectively fixing the pairs of first signal contacts  121 , a first shielding plate  123 , and four first insulating protectors  124  assembled to the conductive board  120 . Each pair of first signal contacts  121  are insert-molded with one corresponding first insulating holder  122  to form a contact module (not labeled), and thus there are four contact modules in each wafer  12  in each wafer  12 . The first shielding plate  123  has a planar portion  150  and eight grounding feet  151  extending downwardly from the planar portion  150 . The conductive board  120  is electrically connected to the first shielding plate  123  and connected to the daughter card through grounding feet  151  of the first shielding plate  123 . The metal shielding plate  123  is added to keep the insulating holders  122  from being extruding out from the conductive board  120  when the plug  10  is mounted onto the daughter card and further improve shielding performance. 
         [0035]    The conductive board  120  defines four slots  132  in the first face respectively receiving corresponding contact modules and three isolating walls  131 . Each of the first contacts  121  includes a deflectable contacting portion  140  received in the front housing  11 , a foot portion  141  extending out from the conductive board  120 , and an intermediate portion  142  connecting the contacting portion  140  and the foot portion  141 . Differential signals are transferred in the contact pair  121  in each slot  132  of the conductive board  120 . 
         [0036]    The conductive board  120  is made from die casting metal or conductive plastic, or insulating piece plated with a metal plating. In a preferred embodiment, the conductive board  120  is made from thermoplastic with a high melt point above 300 degrees Celsius, and plated with metal plating such as Chromium, Copper, Tin and Gold. Comparing to the second region made of a material with a binder containing conductive fillers to provide shielding between signal conductors, which disclosed in U.S. Pat. No. 6,709,294 B1 by Cohen et al. on Mar. 23, 2004, the plated conductive board  120  in present invention more perfectly provides shielding between adjacent wafers  12  and decreases crosstalk between adjacent contact pairs  121  received in the same wafer  12 . Further more, the contact modules are inserted into the slots  132  of the conductive board  120 , so there is no need to insert-mold the first insulating holders  122  into the slots  132  of the conductive board  120 , which decreases potential risk of destroying the metal plating of the conductive board  120 . 
         [0037]    Each of the first insulating protector  124  includes a base board  126 , a pair of side walls  161 , an intermediate wall  162 , and a pair of cavities  163  for receiving the contacting portions  140  of corresponding pair of first contacts  121 . The first insulating protectors  124  has front ends received in the front housing  11  and rear ends received in the conductive boards  120 . The cavities  163  of the insulating protectors  124  and the slots  132  open to a same side in the transverse direction. The contacting portion  140  is sheltered by the first insulating protector  124  such that the contacting portion  140  is deflectable only in the transverse direction away from the first shielding plate  123  towards the conductive board  120 . 
         [0038]    The header  20  includes a conductive shroud or body  21  and a number of contact or terminal modules  22  arrayed in the conductive shroud  21 . The conductive shroud  21  is made from die casting metal or conductive plastic, or insulating piece plated with metal plating. In a preferred embodiment, the conductive shroud  21  is made from thermoplastic, and plated with metal plating such as Chromium, Copper, Tin and Gold. The shroud  21  includes a bottom wall  23 , two upwardly extending side walls  24  and a receiving space  25  defined therebetween for receiving a portion of the plug  10 . The bottom wall  23  defines an array of holes  26  each receiving one of the second contact modules  22 . 
         [0039]    Each of the contact module  22  includes a pair of second contacts  220 , a second insulating holder or part  221  insert-molded with the pair of second contacts  220 , a second shielding plate or blade  222  assembled to the second insulating holder  221 , and a second insulating protector  223 . The second insulating holder  221  and the second insulating protector  223  are used to fix the pair of second contacts  220  and keep them isolated from the second shield  222 . 
         [0040]    Each of the second contacts  220  includes a deflectable contacting portion  230  inserted into corresponding holes  15  of the plug  10 , a foot portion  231  extending downwardly for mounting onto the backplane, and an intermediate portion  232  connecting the contacting portion  230  to the foot portion  231 . The intermediate portion  232  is embedded in the second insulating holder  221  and isolated from the conductive shroud  21 . 
         [0041]    Each second insulating holder  221  of the header  20  defines two positioning holes  240 . The second shielding plate  222  including a planar board portion  250 , a pair of ground feet  251 , and a flexible contacting arm  252  punched from the board portion  250  and extending towards the ground feet  251 . The second insulating protector  223  forms a pair of positioning posts  260  interference fitting with the two position holes  240  of the second insulating holder  221 . The conductive shroud  21  is electrically connected to the second shielding plates  222  and further electrically connected to the backplane through the grounding feet  251  of the second shielding plates  222 . 
         [0042]    It should be understandable that when the plug  10  is mated with the header  20 , the conductive boards  120  make electrical connection with the conductive shroud  21 , and the contacting portions  252  of the second shielding plates  222  contact the front housing  11  of the plug  10 . It should be also understandable that the signal routing path, which extends from the foot portions  231  of the second contacts  220  to the foot portions  141  of the first contacts  121 , is completed shielded in all direction perpendicular to the signal routing path. Furthermore, the filling degree of the insulating holders  122  in one of the slots  132  varies along the signal path in such manner that the pair of the first contacts  121  are fixed to the conductive board  120  by two or three parts  145 ,  147 ,  148  of the insulating holders  122  along part lengths of the signal path, and part  146  of the first contacts  121  along part lengths of the signal path is exposed to the air. 
         [0043]    Referring to  FIGS. 5 and 6 , an electrical connector assembly  2  according to a second embodiment of the present invention is shown. The electrical assembly  2  has a plug (not shown) and a header (not shown) similar to the electrical connector assembly  1  except contact wafers  32  of the plug and the contact modules  42  of the header. Each of the contact wafers  32  has a conductive board  320 , four pairs of third contacts  321 , four third insulating holders  322 , four third insulating protectors  360 , and a third shielding plate  323 . A first difference for the contact wafer  32  is that the shielding plate  323  has four flat tab portions  352  forwardly extending beyond a front edge of the conductive board  320 , and each of the tab portions  352  forming a flexible contacting arm  353 . A second difference for the contact wafer  32  is that the third insulating protectors  324  are disposed between the contacting portions  340  and the tab portions  352 , and the third contacts  321  have contacting portions  340  deflectable in the transverse direction towards the tab portions  352  of the third shielding plate  323 . Each of the fourth contact modules  42  has a fourth shielding plate  422 , a fourth insulating protector  423 , a pair of fourth contacts  420 , a fourth insulating holder  421 . The main difference for the contact module  42  is that the fourth shielding plate  422  has a board portion  450 , two side walls  451  to define a U-shaped receiving slot  452  therebetween, and two flexible contacting arms  453  in the two side walls  451 , and the fourth insulating protector  423  is secured in the U-shaped slot  452  to isolate contacting portions  430  of the fourth contacts  420  from the fourth shielding plate  422 . 
         [0044]    Referring to  FIGS. 7-11 , an electrical connector assembly  3  according to a third embodiment of present invention is shown. The electrical connector assembly  3  has a plug  50  and header  60  similar to the first embodiment. The plug  50  includes a number of contact modules  502  stacked in a transverse direction and five grounding belts  53  connecting the contact modules  502 . Each of the contact modules  502  comprises a conductive board  51 , four contact modules  52  each having a pair of fifth contacts  551  and a fifth insulating holder  550  insert-molded with the pair of contacts  551 , and four insulating protectors  54 . Each of the conductive boards  51  defines a first face with a plurality of slots  562  defined therein and an opposite second face with three slits  565  defined therein. The conductive board  51  has three inner walls  561  and three ribs  564 . Each of the inner walls  561  is located between every two adjacent slots and each of the ribs  564  protruding from one of the inner walls  561 . The contact modules  52  are received in respective slot  562 . 
         [0045]    When the contact modules  502  are transversely stacked, the ribs  564  mate into corresponding slits  565  of an adjacent contact module  502  to make complete shielding between adjacent fifth contact pairs  551 , and the conductive boards  51  jointly define a mounting face  57  to be mounted onto a daughter card  (not shown), and a front face  58 . The front face  58  forms a plurality of holes  580  therein to receive contacts  620  of the complimentary header  60 . Each of the holes  580  formed by one slot  562  of said conductive board  51  and an adjacent conductive board  51 . 
         [0046]    Each of the fifth contacts  551  has a foot  553 , a deflectable contacting portion  552  and an intermediate portion  554  connecting the foot  553  and the contacting portion  551 . The contacting portions  552  and the intermediate portions  554  of each contact pair  551  are received in corresponding slot  562 , and the feet  553  extending perpendicularly from the mounting face  57 . 
         [0047]    Each of the insulating protectors  54  is received in the holes  580  and between the contacting portions  552  of corresponding pairs of fifth contacts  551  and the bottom wall of corresponding slot  562 . The contacting portions  552  are deflectable in the transverse direction towards the bottom wall of corresponding slot  562  and front ends of the contacting portion  552  are sheltered by the insulating protector  54 . The main difference for the header  50  comparing the header  10  of the first embodiment is that there is no conductive housing  11  and no first shielding plate  123 . 
         [0048]    Jointly referring to  FIGS. 10 and 11 , similar to the first embodiment, the filling degree of the fifth insulating holders  550  in one of the slots  562  varies along the signal path in such manner that the pair of the first contacts  551  are fixed to the conductive board  51  by one of the fifth insulating holders  550  along part lengths of the signal path, and at least part of the first contacts  551  along part lengths of the path is exposed to the air. It is further shown that the part of insulating holder  52  near the contacting portion  552  defines a slot  558  to change the dielectric disposed around the fifth contact pair  551 , which make the impedance to the signal in the fifth contact pair  551  approaching a constant along the signal path. 
         [0049]    Referring to  FIGS. 7-9 , the header  60  includes a conductive shroud  61 , sixteen pairs of sixth contact modules  62 , four sixth shielding plates or blades  68 , and five grounding belts or straps  684 . Each of the sixth shielding plates  68  has four flat tabs  681  and four flexible contacting arms  682 . Each of the sixth contact modules  62  includes an insulating holder  621  and a pair of sixth contacts  620 . Each of the sixth contacts  620  has a non-deflectable contacting portion  630 . The conductive shroud  61  includes a bottom wall  63 , two upwardly extending side walls  64  and a receiving space  65  defined therebetween for receiving a portion of the plug  50 . The bottom wall  63  of he conductive housing  61  defines four through holes  66  each having pairs of ribs  663  protruding from opposite inner faces of the holes  66 , the pairs of ribs  663  dividing each of the holes  66  into four receiving spaces to receive one of the contact modules  62  and corresponding tab  681  of the shielding plates  68 . 
         [0050]    The differences for the header  60  comparing to the first embodiment is listed as below: (1) there is no insulating protector between the tabs  681  of the shielding plates  68  and the contacting portions  630 , which improve the impedance of the contact pair; (2) each hole  66  of the shroud  61  receive four sixth contact modules  62  and corresponding flat tabs  681  stacked in a column direction; (3) four flat tabs  681  corresponding to each contact module  62  are integrally formed in the sixth shielding plate  68  extending in a row direction; (4) there are grounding belts  684  extending along the column direction and connecting the sixth shielding plate  68  and the conductive shroud  61  to the backplane. 
         [0051]    Referring to  FIGS. 12-13 , a connector assembly according to a fourth embodiment is shown. The connector assembly includes a plug  70  and a header  80 . The header  80  includes four contact wafers  820  and a guide wafer  840  stacked in a transverse direction, and two sawtooth organizers  830  latching opposite sides of the wafers  820 ,  840 . Each of the contact wafers  820  includes a conductive board  822  and four contact modules  850 . Each of the contact modules  850  has similar structure to aforementioned contact module  42 . The plug  70  includes four contact wafers  71  and one guide wafer  740  stacked in a transverse direction, and three organizers  730  latching the wafers  71 ,  740 . The metal shielding plate  720  is added to keep the contact module  716  from being extruding out from the conductive board  710  when the plug  70  is mounted onto the daughter card and further improve shielding performance. 
         [0052]    Referring to  FIGS. 14-15 , a connector assembly according to a fifth embodiment is shown. The connector assembly includes a plug  90  and a header  91 . The header  91  has similar structure to the aforementioned header  80 . The plug  90  has similar structure to the aforementioned plug  70  except that each contact wafer  920  adds two contacting plates  901 ,  904  extending across four pairs of contacts  921  aside the contacting portions  922  to improve shielding performance and mating durability, wherein the contacting plate  901  is integral with a shielding plate  900  covering aside the contact wafer  920 . 
         [0053]    Referring to  FIG. 16 , a method for making the contact wafer  12  of the plug  10  is shown. The method includes the following steps: (1) punching a metal strip to form a contact pair  121  including a left contact  170  and a right contact  171 , the left contact  170  and the right contact  171  being carried in a planar in an edge-to-edge manner; (2) insert-molding the contact pair  121  into an insulating holder  122  with a left edge  173  of the left contact  170  and a right edge  175  of the right contact  171  embedded in the insulating holder  122 , and a right edge  174  of the left contact  170  and a left edge  176  of the right contact  171  exposed to air; (3) assembling the contact module formed in step (2) into a slot  132  of a conductive board  120 ; (4) covering a shielding plate  123  over a side of the conductive board  120 . Jointly referring to  FIG. 3 , it could also be described that each pair of contacts  170 ,  171  are kept in a planar surface with near edges  174 ,  176  facing to each other and far edges  173 ,  175  backing away from each other, the far edges  173 ,  175  of the intermediate portions embedded in the first insulating holder  122  and the near edges  174 ,  176  of the intermediate portions exposed to air in part length of the signal path, which make the pair of contacts  170 ,  171  firmly fixed by the first insulating holders  122 , and at the same time there is void between the near edges  174 ,  176  to improve the impedance of the contact pair  170 ,  171 . 
         [0054]    Referring to  FIG. 17 , a second method for making the contact wafer  12  is shown. The method includes the following steps: (1) providing a conductive board  130  having slots  132  therein; (2) insert-molding a first plastic  180  on a bottom wall of the slot  132 ; (3) putting a contact pair  170 ,  171  punched from a metal strip into the slot  132  and on the first plastic  180 , and insert-molding a second plastic  181  in the slot  132  on the first plastic  180  and the contact pair  170 ,  171 ; (4) covering a shielding plate  123  over a side of the conductive board  120 . 
         [0055]    Referring to  FIG. 18 , a third method for making an alternative contact wafer  12  is shown. The method includes the following steps: (1) providing a conductive board  130  having through holes  132  therein; (2) insert-molding a contact pair  170 ,  171  and an insulating holder  122  into the through holes  132  with near edges  174 ,  176  exposed to air and far edges  173 ,  175  embedded in the insulating holder  122 ; (3) covering two metal plate  123  over opposite sides of the conductive board  120 . 
         [0056]    It is to be understood, however, that even though numerous, characteristics and advantages of the present invention have been set fourth in the foregoing description, together with details of the structure and function of the invention, the disclosed is illustrative only, and changes may be made in detail, especially in matters of number, shape, size, and arrangement of parts 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.

Technology Category: 5