Patent Publication Number: US-8974253-B2

Title: Contact module for a receptacle assembly

Description:
BACKGROUND OF THE INVENTION 
     The subject matter herein relates generally to contact modules for receptacle assemblies. 
     Some electrical systems, such as network switches and computer servers with switching capability, include receptacle connectors coupled to circuit boards, such as backplanes, daughtercards, switch cards, line cards and the like. The receptacle connectors typically include individual contact modules or chicklets that have signal contacts configured to be terminated to the circuit boards. Some conventional contact modules include overmolded leadframes. The conductors of the leadframes are typically held during the overmolding process by pinch pins. The pinch pins are blunt round pinch pins that press against opposite sides of the conductors to hold the conductors during overmolding. 
     The conventional overmolding process is not without disadvantages. For instance, the dielectric material that is injected into the mold used to form the contact module tends to press against the conductors and cause the conductors to move during the overmolding process. Lateral offset of the conductors from the designed nominal position causes signal integrity issues. 
     A need remains for an improved contact module. A need remains for components and methods of fixing lateral positions of conductors during overmolding to maintain proper signal integrity. 
     BRIEF DESCRIPTION OF THE INVENTION 
     In one embodiment, a contact module for a receptacle assembly is provided that includes a frame assembly having first and second frames coupled together. The first and second frames each have a corresponding leadframe having a plurality of receptacle signal contacts. The first and second frames each have at least two frame members spaced apart from each other by a corresponding gap. Each frame member is overmolded over and supports corresponding receptacle signal contacts. The first and second frames are interested such that at least one frame member of the first frame is received in a corresponding gap of the second frame and such that at least one frame member of the second frame is received in a corresponding gap of the first frame. The receptacle signal contacts are supported by corresponding removable inserts during overmolding of the corresponding frame members. Each removable insert leaves a window in the corresponding frame member exposing the corresponding receptacle signal contacts. The first frame includes a first dielectric insert extending from a corresponding frame member of the first frame into the gap. The first dielectric insert is received in a corresponding window in the second frame to substantially fill the window and cover the corresponding receptacle signal contacts of the second frame. The second frame includes a second dielectric insert extending from a corresponding frame member of the second frame into the gap. The second dielectric insert is received in a corresponding window in the first frame to substantially fill the window and cover the corresponding receptacle signal contacts of the first frame. 
     Optionally, the removable insert may hold lateral positions of the receptacle signal contacts relative to each other during overmolding. The removable insert may include a finger positioned between the corresponding receptacle signal contacts to hold a lateral position of the receptacle signal contacts relative to one another. The first dielectric insert may have a complementary shape as the corresponding removable insert to substantially fill the window left by removal of the removable insert. 
     Optionally, the removable insert may include a main wall, end walls extending from the main wall and forming a receiving space therebetween, and a finger extending from the main wall in the receiving space. First and second channels may be formed between the finger and the corresponding end walls. The first and second channels may receive the receptacle signal contacts. The finger and end walls may hold the lateral positions of the receptacle signal contacts relative to each other during the overmolding process. The receiving space may be filled with dielectric material during overmolding of the corresponding frame member. 
     Optionally, the removable insert may maintain a predetermined spacing between a differential pair of receptacle signals contacts as the dielectric material of the frame member is overmolded to form the corresponding frame member. The frame members may include edges facing corresponding gaps. The edges at the windows may be inset such that the frame member is narrower at the window than along segments of the frame member adjacent the window. 
     In another embodiment, a contact module for a receptacle assembly is provided including a frame having a leadframe that includes a plurality of receptacle signal contacts and frame member overmolded over corresponding receptacle signal contacts. The frame members are separated by corresponding gaps. A removable insert is coupled to a corresponding receptacle signal contacts. The removable insert has a main wall, end walls extending from the main wall and forming a receiving space therebetween, and a finger extending from the main wall in the receiving space. First and second channels are formed between the finger and the corresponding end walls. The first and second channels receive the receptacle signal contacts. The finger and end walls hold the lateral positions of the receptacle signal contacts relative to each other during the overmolding process. The receiving space is filled with dielectric material during overmolding of the corresponding frame member. The removable insert leaves a window in the corresponding frame member after the removable insert is removed. The window exposes the corresponding receptacle signal contacts. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a connector system formed in accordance with an exemplary embodiment. 
         FIG. 2  is a front perspective view of a receptacle assembly formed in accordance with an exemplary embodiment. 
         FIG. 3  is an exploded view of a contact module of the receptacle assembly. 
         FIG. 4  illustrates a leadframe of the contact module. 
         FIG. 5  is a perspective view of a removable insert for the contact module. 
         FIG. 6  is a side perspective view of a first frame of the contact module formed in accordance with an exemplary embodiment. 
         FIG. 7  is a side perspective view of a second frame of the contact module formed in accordance with an exemplary embodiment. 
         FIG. 8  is a side perspective view of a frame assembly of the contact module. 
         FIG. 9  is an enlarged view of a portion of the first frame showing a dielectric insert formed in accordance with an exemplary embodiment. 
         FIG. 10  illustrates the frame assembly with a ground shield coupled thereto. 
         FIG. 11  illustrates a holder member formed in accordance with an exemplary embodiment. 
         FIG. 12  illustrates a frame assembly formed in accordance with an exemplary embodiment. 
         FIG. 13  illustrates a frame assembly formed in accordance with an exemplary embodiment. 
         FIG. 14  is an enlarged view of a portion of the frame assembly. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  is a perspective view of a connector system  100  formed in accordance with an exemplary embodiment. The connector system  100  includes a midplane assembly  102 , a first connector assembly  104  configured to be coupled to one side of the midplane assembly  102  and a second connector assembly  106  configured to be connected to a second side the midplane assembly  102 . The midplane assembly  102  is used to electrically connect the first and second connector assemblies  104 ,  106 . Optionally, the first connector assembly  104  may be part of a daughter card and the second connector assembly  106  may be part of a backplane, or vice versa. The connector assemblies  104 ,  106  may be part of a cabled backplane system. The first and second connector assemblies  104 ,  106  may be line cards or switch cards. Alternatively, the connector assemblies  104 ,  106 , with modification, may be directly connected without the use of the midplane assembly  102 . 
     The midplane assembly  102  includes a midplane circuit board  110  having a first side  112  and second side  114 . The midplane assembly  102  includes a first header assembly  116  mounted to and extending from the first side  112  of the midplane circuit board  110 . The midplane assembly  102  includes a second header assembly  118  mounted to and extending from the second side  114  of the midplane circuit board  110 . The first and second header assemblies  116 ,  118  each include header signal contacts  120  electrically connected to one another through the midplane circuit board  110 . 
     The midplane assembly  102  includes a plurality of signal paths therethrough defined by the header signal contacts  120  and conductive vias that extend through the midplane circuit board  110 . Each signal path through the midplane assembly  102  is defined by a header signal contact  120  of the first header assembly  116  and a header signal contact  120  of the second header assembly  118  both received in a common conductive via through the midplane circuit board  110 . In an exemplary embodiment, the signal paths pass straight through the midplane assembly  102  along linear paths. Such a design of the midplane circuit board  110  is less complex and less expensive to manufacture than a circuit board that routes traces between different vias to connect the first and second header assemblies  116 ,  118 . 
     In an exemplary embodiment, the first and second header assemblies  116 ,  118  may be identical to one another. Having the first and second header assemblies  116 ,  118  identical to one another reduces the overall number of different parts that are needed for the connector system  100 . The first and second header assemblies  116 ,  118  may have an identical pinout allowing the first and second header assemblies  116 ,  118  to be mounted to the midplane circuit board  110  using conductive vias that pass straight through the midplane circuit board  110  between the first side  112  and the second side  114 . The first and second header assemblies  116 ,  118  are not rotated 90° relative to one another as is typical of conventional connector systems, and thus do not suffer from a loss in density or a loss in performance as is typical of such connector systems. The header assemblies  116 ,  118  may be rotated 180° relative to one another to facilitate different card positions. 
     The first and second header assemblies  116 ,  118  include header ground shields  122  that provide electrical shielding around corresponding header signal contacts  120 . In an exemplary embodiment, the header signal contacts  120  are arranged in pairs configured to convey differential signals. The header ground shields  122  peripherally surround a corresponding pair of the header signal contacts  120 . 
     The first connector assembly  104  includes a first circuit board  130  and a first receptacle assembly  132  coupled to the first circuit board  130 . The first receptacle assembly  132  is configured to be coupled to the first header assembly  116 . The first receptacle assembly  132  includes a receptacle housing  138  that holds a plurality of contact modules  140 . The contact modules  140  are held in a stacked configuration generally parallel to one another. The contact modules  140  hold a plurality of receptacle signal contacts (not shown) that are electrically connected to the first circuit board  130  and define signal paths through the first receptacle assembly  132 . Optionally, the receptacle signal contacts may be arranged in pairs carrying differential signals. 
     The second connector assembly  106  includes a second circuit board  150  and a second receptacle assembly  152  coupled to the second circuit board  150 . The second receptacle assembly  152  is configured to be coupled to the second header assembly  118 . The second receptacle assembly  152  has a header interface  154  configured to be mated with the second header assembly  118 . The second receptacle assembly  152  has a board interface  156  configured to be mated with the second circuit board  150 . In an exemplary embodiment, the board interface  156  is oriented perpendicular with respect to the header interface  154 . When the second receptacle assembly  152  is coupled to the second header assembly  118 , the second circuit board  150  is oriented perpendicular with respect to the midplane circuit board  110 . The second circuit board  150  is oriented perpendicular to the first circuit board  130 . 
     The second receptacle assembly  152  includes a receptacle housing  158  that holds a plurality of contact modules  160 . The contact modules  160  are held in a stacked configuration generally parallel to one another. The contact modules  160  hold a plurality of receptacle signal contacts  162  (shown in  FIG. 2 ) that are electrically connected to the second circuit board  150  and define signal paths through the second receptacle assembly  152 . The receptacle signal contacts  162  are configured to be electrically connected to the header signal contacts  120  of the second header assembly  118 . In an exemplary embodiment, the contact modules  160  provide electrical shielding for the receptacle signal contacts  162 . Optionally, the receptacle signal contacts  162  may be arranged in pairs carrying differential signals. Alternatively, the receptacle signal contacts may be single-ended as opposed to differential pairs. In an exemplary embodiment, the contact modules  160  generally provide 360° shielding for each pair of receptacle signal contacts  162  along substantially the entire length of the receptacle signal contacts  162  between the board interface  156  and the header interface  154 . The shield structure of the contact modules  160  that provides the electrical shielding for the pairs of receptacle signal contacts  162  is electrically connected to the header ground shields  122  of the second header assembly  118  and is electrically connected to a ground plane of the second circuit board  150 . 
     In the illustrated embodiment, the first circuit board  130  is oriented generally horizontally. The contact modules  140  of the first receptacle assembly  132  are orientated generally vertically. The second circuit board  150  is oriented generally vertically. The contact modules  160  of the second receptacle assembly  152  are oriented generally horizontally. The first connector assembly  104  and the second connector assembly  106  have an orthogonal orientation with respect to one another. The signal contacts within each differential pair, including the receptacle signal contacts of the first receptacle assembly  132 , the receptacle signal contacts  162  of the second receptacle assembly  152 , and the header signal contacts  120 , are all oriented generally horizontally. The contact modules  140  and/or  160  may be configured to be terminated to cables rather than circuit boards, with conductors of the cables terminated to corresponding conductors of the contact modules  140 , and/or  160 . 
       FIG. 2  is a front perspective view of the second receptacle assembly  152  showing one of the contact modules  160  poised for loading into the receptacle housing  158 . The receptacle housing  158  includes a plurality of signal contact openings  300  and a plurality of ground contacts openings  302  at a mating end  304  of the receptacle housing  158 . The mating end  304  defines the header interface  154  of the second receptacle assembly  152 . The contact modules  160  are coupled to the receptacle housing  158  such that the receptacle signal contacts  162  are received in corresponding signal contact openings  300  and the ground contact openings  302  receive corresponding header ground shields  122  (shown in  FIG. 1 ) and grounding members, such as grounding beams of the contact modules  160 . 
       FIG. 3  is an exploded view of the contact module  160 . The contact module  160  includes a conductive holder  310 , which in the illustrated embodiment includes a first holder member  312  and a second holder member  314  that are coupled together to form the holder  310 . The conductive holder  310  has a mating end  316  and a mounting end  318 . 
     The holder members  312 ,  314  are fabricated from a conductive material. For example, the holder members  312 ,  314  may be die cast from a metal material. Alternatively, the holder members  312 ,  314  may be stamped and formed or may be fabricated from a plastic material that has been metalized or coated with a metallic layer. By having the holder members  312 ,  314  fabricated from a conductive material, the holder members  312 ,  314  may provide electrical shielding for the second receptacle assembly  152 . When the holder members  312 ,  314  are coupled together, the holder members  312 ,  314  define at least a portion of a shield structure to provide electrical shielding for the receptacle signal contacts  162 . The conductive holder  310  may be manufactured from a single piece rather than the two holder members  312 ,  314 . In other embodiments, the holder  310  may not be conductive, but rather may rely on separate shields or may be unshielded. 
     The conductive holder  310  holds a frame assembly  320 , which includes the receptacle signal contacts  162 . The holder members  312 ,  314  provide shielding around the frame assembly  320  and receptacle signal contacts  162 . The holder members  312 ,  314  include tabs  322 ,  324  that extend inward toward one another to extend into the frame assembly  320 . The tabs  322 ,  324  define at least a portion of a shield structure that provides electrical shielding around the receptacle signal contacts  162 . The tabs  322 ,  324  are configured to extend into the frame assembly  320  such that the tabs  322 ,  324  are positioned between pairs of the receptacle signal contacts  162  to provide shielding between the corresponding pairs of the receptacle signal contacts  162 . 
     The frame assembly  320  includes a first frame  330  and a second frame  332  that surround corresponding receptacle signal contacts  162 . Optionally, the first frame  330  may be manufactured from a dielectric material overmolded over the corresponding receptacle signal contacts  162 . The second frame  332  may be manufactured from a dielectric material overmolded over the corresponding receptacle signal contacts  162 . The first and second frames  330 ,  332  are coupled together to form the frame assembly  320 . In alternative embodiments, rather than having the two frames  330 ,  332 , the frame assembly  320  may include only a single frame or may include more than two frames. 
     In an exemplary embodiment, the receptacle signal contacts  162  of the first frame  330  form part of a common leadframe  360  (shown in  FIG. 4 ) defining the receptacle signal contacts  162  that is then overmolded with dielectric material during an overmolding process. The receptacle signal contacts  162  of the second frame  332  form part of a common leadframe (not shown but similar to the leadframe  360 ), separate from the leadframe of the first frame  330 , that is separately overmolded to encase the corresponding receptacle signal contacts  162 . Other manufacturing processes may be utilized to form the dielectric frames  330 ,  332  other than overmolding leadframes. In an exemplary embodiment, during the overmolding process, pairs of receptacle signal contacts  162  are held and supported by metal inserts that are part of the mold or are inserted into the mold prior to overmolding. The metal inserts hold the lateral positions of the receptacle signal contacts  162  relative to one another during the overmolding process, such as to resist movement of the receptacle signal contacts  162  by the injection forces of the dielectric material. 
     The holder members  312 ,  314  provide electrical shielding between and around respective pairs of the receptacle signal contacts  162 . The holder members  312 ,  314  provide shielding from electromagnetic interference (EMI) and/or radio frequency interference (RFI). The holder members  312 ,  314  may provide shielding from other types of interference as well. The holder members  312 ,  314  prevent crosstalk between different pairs of receptacle signal contacts  162 . The holder members  312 ,  314  provide electrical shielding around the outside of the first and second frames  330 ,  332 , and thus around the outside of all of the receptacle signal contacts  162 , as well as between the receptacle signal contacts  162 , such as between pairs of receptacle signal contacts  162  separated by the tabs  322 ,  324 . The holder members  312 ,  314  control electrical characteristics, such as impedance control, crosstalk control, and the like, of the receptacle signal contacts  162 . The holder members  312 ,  314  provide shielding for the receptacle signal contacts  162  from adjacent contact modules. 
     In an exemplary embodiment, the contact module  160  includes a first ground shield  350  and a second ground shield  352  that provide shielding for the receptacle signal contacts  162 . The ground shields  350 ,  352  make ground terminations to the header ground shields  122  (shown in  FIG. 1 ) and the second circuit board  150  (shown in  FIG. 1 ). In an exemplary embodiment, the ground shields  350 ,  352  are internal ground shields positioned within the conductive holder  310 . The ground shields  350 ,  352  are inlaid within the conductive holder  310 . For example, the first ground shield  350  is laid in the first holder member  312  and positioned between the first holder member  312  and the frame assembly  320 . The second ground shield  352  is laid in the second holder member  314  and positioned between the second holder member  314  and the frame assembly  320 . 
     The first ground shield  350  includes grounding beams  354  extending from a front thereof. The second ground shield  352  includes grounding beams  356  extending from a front thereof. The grounding beams  354 ,  356  extend along different sides of the receptacle signal contacts  162  to provide electrical shielding and electrical grounding. The grounding beams  354 ,  356  are configured to engage and be electrically connected to the header ground shields  122  (shown in  FIG. 1 ) when the second receptacle assembly  152  is coupled to the second header assembly  118 . The grounding beams  354 ,  356  are deflectable. 
       FIG. 4  illustrates a leadframe  360  of the first frame  330 . The receptacle signal contacts  162  are formed as part of the leadframe  360 . The leadframe  360  is a stamped and formed structure and is initially held together by a carrier with connecting portions between each of the conductors defining the receptacle signal contacts  162 . The carrier is later removed after the receptacle signal contacts  162  are held by the frame members  400  (shown in  FIG. 6 ). 
     As illustrated in  FIG. 4 , the leadframe  360  is generally planar and defines a leadframe plane. Mating and mounting portions  364 ,  366  of the receptacle signal contacts  162  are integrally formed with the conductors of the leadframe  360 . The conductors extend along predetermined paths between each mating portion  364  and corresponding mounting portion  366 . The receptacle signal contacts  162  have a lateral spacing defined between adjacent receptacle signal contacts, such lateral spacing may vary along the length of the contacts or between different contacts. The mating portions  364  are configured to be mated with and electrically connected to corresponding header signal contacts  120  (shown in  FIG. 1 ). The mounting portions  366  are configured to be electrically connected to the second circuit board  150  (shown in  FIG. 1 ). For example, the mounting portions  366  may include compliant pins that extend into conductive vias in the second circuit board  150 . 
     A removable insert  370  is illustrated in  FIG. 4 . The removable insert  370  is used to hold corresponding receptacle signals contacts  162 , such as a differential pair of the receptacle signal contacts  162 . The removable insert  370  maintains a predetermined spacing  371  between the differential pair of receptacle signals contacts  162 , such as when the dielectric material is overmolded over the leadframe  360 . After overmolding, the removable insert  370  is removed from the first frame  330  (shown in  FIG. 3 ) leaving a window or space that is devoid of the dielectric material. The removable insert  370  may be a separate piece held in the mold or may be part of the mold that is removed from the contact module after the molding process. As described in further detail below, a dielectric insert or plug fills the window to maintain signal integrity of the receptacle signal contacts  162 . For example, the dielectric insert may reduce the amount of the conductors that are exposed to air. 
     The removable insert  370  holds the nominal positions of the differential pair of receptacle signal contacts  162  relative to each other during overmolding. For example, the removable insert  370  stops one or both receptacle signal contacts  162  from moving toward or away from one another and/or from moving out of the plane of the leadframe  360 . Any of the receptacle signal contacts  162  may be held by removable inserts  370  and any number of removable inserts  370  may be used as necessary to hold the receptacle signal contacts  162 . For example, shorter lengths of the receptacle signal contacts  162  (e.g. the interior pairs of receptacle signal contacts  162 ) may not need removable inserts  370  as the receptacle signal contacts  162  may be sufficiently held by the carrier without significant movement thereof. 
       FIG. 5  is a perspective view of the removable insert  370 . The removable insert  370  includes a main wall  372 , end walls  374 ,  376  extending from the main wall  372  and forming a receiving space  378  therebetween, and fingers  380  extending from the main wall  372  in the receiving space  378 . An opening  382  is formed in the main wall  372  between the fingers  380 . First and second channels  384 ,  386  are formed between the fingers  380  and the corresponding end walls  374 ,  376 . The first and second channels  384 ,  386  receive the receptacle signal contacts  162  (shown in  FIG. 4 ). The fingers  380  and end walls  374 ,  376  hold the lateral positions of the receptacle signal contacts  162  relative to each other during the overmolding process. Widths  388  of the channels  384 ,  386  may be substantially equal to the widths of the receptacle signal contacts  162  to restrict lateral movement relative to the removable insert  370 . The receiving space  378  is filled with dielectric material during overmolding of the frames  330 ,  332  (shown in  FIG. 3 ). The removable insert  370  may have other shapes or features in alternative embodiments. 
       FIG. 6  is a side perspective view of the first frame  330  formed in accordance with an exemplary embodiment. The first frame  330  includes a plurality of frame members  400  each supporting different differential pairs of receptacle signal contacts  162 . The frame members  400  are separated by gaps  402 . Any number of frame members  400  may be provided. In the illustrated embodiment, three frame members  400  are used corresponding to three differential pairs of receptacle signal contacts  162  of the first frame  330 . 
     The frame members  400  extend between a mating end  404  of the first frame  330  and a mounting end  406  of the first frame  330 . In the illustrated embodiment, the mating end  404  is generally perpendicular with respect to the mounting end  406 ; however other orientations are possible in alternative embodiments. The mating portions  364  of the receptacle signal contacts  162  extend from the frame members  400  beyond the mating end  404  and the mounting portions  366  extend from the frame members  400  beyond the mounting end  406  for electrical termination to other components such as the second header assembly  118  and the second circuit board  150  (both shown in  FIG. 1 ), respectively. 
     The frame members  400  are connected by bridges  408  that span the gaps  402 . The bridges  408  position the frame members  400  with respect to one another. In an exemplary embodiment, the bridges  408  are located proximate to the mating end  404  and the mounting end  406  of the first frame  330 . The bridges  408  are co-molded with the frame members  400 . The bridges  408  define flow paths for the dielectric material of the frame members  400  during the molding (e.g. injection molding) process. For example, the dielectric material may be injected into the mold at gating points (generally identified at points GP) which are located along the outer-most frame member  400  and the dielectric material flows through the bridges into the interior frame members  400  to mold the entire frame  330 . Any number of gating points may be provided. The gating points GP may be located on interior frame members  400  in addition to, or in lieu of, the outer frame member  400 . The force from the injection of the dielectric material at the gating points may cause pressure and shifting of the receptacle signal contacts  162  of the leadframe  360  (shown in  FIG. 4 ). The removable inserts  370  are used to hold the receptacle signal contacts  162  during the injection process to resist shifting caused by the force of the dielectric material being injected into the mold. 
     During the overmolding process, a majority of the leadframe  360  is encased in a dielectric material which forms the frame members  400 . The mating portions  364  extend from the mating end  404  along an edge of the frame members  400  (e.g. a front edge), and the mounting portions  366  extend from the mounting end  406  along another edge of the frame members  400  (e.g. a side edge). 
     The receptacle signal contacts  162  are arranged in pairs. One of the receptacle signal contacts  162  in each pair defines a radially inner receptacle signal contact (measured from the intersection between the mating and mounting ends of the contact module  160 ), while the other receptacle signal contact  162  in each pair defines a radially outer receptacle signal contact. The inner and outer receptacle signal contacts  162  have different lengths between the mating portions  364  and the mounting portions  366 . In an exemplary embodiment, the radially outer receptacle signal contacts  162  are exposed to air through the frame members  400  for electrical compensation, such as to reduce electrical skew. 
     The frame members  400  include locating posts  430  extending therefrom. The locating posts  430  are configured to be received in corresponding openings in the conductive holder  310  (shown in  FIG. 3 ) to locate and/or secure the first frame  330  within the conductive holder  310 . In an exemplary embodiment, the bridges  408  near the mounting end  406  include locating channels  432  formed therethrough. The locating channels  432  receive tabs or other features of the conductive holder  310  to position and or secure the first frame  330  with respect to the conductive holder  310 . 
     In an exemplary embodiment, at least some of the frame members  400  include troughs  434 . The troughs  434  are recessed areas that are configured to receive portions of the second frame  332  (shown in  FIG. 3 ). Optionally, the troughs  434  may be generally aligned with the bridges  408 . Optionally, at least one frame coupling member (not shown) is located within each trough  434 . The frame coupling member is configured to extend into the second frame  332  to position the first frame  330  with respect to the second frame  332 . 
     In an exemplary embodiment, the bridges  408  include coupling members  438  that interact with corresponding coupling members of the second frame  332  to secure the first frame  330  with respect to the second frame  332 . In the illustrated embodiment, the coupling members  438  constitute openings extending through the bridges  408 . The openings receive posts or other types of coupling members therein. Other types of coupling members  438  may be provided on the bridges  408 , such as posts, slots, latches, or other types of fasteners. 
     In an exemplary embodiment, the first frame  330  includes dielectric inserts  440  extending from one or more of the frame members  400 . The dielectric inserts  440  are integral with the frame members  400 . The dielectric inserts  440  are co-molded with the frame members  400 . The dielectric inserts  440  are molded at the same time as the frame members  400  and extend outward from corresponding edges  442  of the frame members  400 . The dielectric inserts  440  are configured to fill the windows or voids left in the second frame  332  (shown in  FIG. 3 ) by the removable inserts  370  when the first frame  330  is coupled to the second frame  332 . The dielectric inserts  440  have a complementary shape to the removable insert  370 . The dielectric inserts  440  have a complementary shape to the window or void left in the second frame  332  by the removable insert  370 . In alternative embodiments, the dielectric inserts  440  may be separate from the first and second frames  330 ,  332 , such as separate pieces that are plugged into the frames  330 ,  332 . In other alternative embodiments, the dielectric inserts  440  may be formed with the same frame  330  or  332  and pivotably or hingedly attached thereto, such as at a living hinge that may be folded over into position. 
     The frame members  400  include voids or windows  444  left behind when the removable inserts  370  (shown in  FIG. 5 ) are removed from the first frame  330  and the mold used to form the frame members  400 . In an alternative embodiment, the removable insert  370  may form part of the mold used to form the first frame  330 , such removable insert  370  being removable from the formed frame members  400  but not from the mold. Because the receptacle signal contacts  162  are held against the removable inserts  370  (e.g. in the channels  384 ,  386  (shown in FIG.  5 )), the windows  444  expose the receptacle signal contacts  162 . A post  446  remains in each window  444  after being formed in the opening  382  (shown in  FIG. 5 ) in the removable insert  370 . The post  446  is used to connect the first frame  330  to the second frame  332  during assembly. 
       FIG. 7  is a side perspective view of the second frame  332  formed in accordance with an exemplary embodiment. The second frame  332  includes a plurality of frame members  450  each supporting different differential pairs of receptacle signal contacts  162 . The frame members  450  are separated by gaps  452 . Any number of frame members  450  may be provided. In the illustrated embodiment, four frame members  450  are used corresponding to four differential pairs of receptacle signal contacts  162  of the second frame  332 . 
     The frame members  450  extend between a mating end  454  of the second frame  332  and a mounting end  456  of the second frame  332 . In the illustrated embodiment, the mating end  454  is generally perpendicular with respect to the mounting end  456 ; however other orientations are possible in alternative embodiments. The receptacle signal contacts  162  extend from the frame members  450  beyond the mating end  454  and beyond the mounting end  456  for electrical termination to other components, such as the second header assembly  118  and the second circuit board  150  (both shown in  FIG. 1 ). 
     The frame members  450  are connected by bridges  458  that span the gaps  452 . The bridges  458  position the frame members  450  with respect to one another. In an exemplary embodiment, the bridges  458  are located proximate to the mating end  454  and the mounting end  456  of the second frame  332 . The bridges  458  are co-molded with the frame members  450 . The bridges  458  define flow paths for the dielectric material of the frame members  450  during the molding (e.g. injection molding) process. For example, the dielectric material may be injected into the mold at gating points (generally identified at points GP) which are located along the outer-most frame member  450  and the dielectric material flows through the bridges  458  into the interior frame members  450  to mold the entire frame  332 . Any number of gating points may be provided. The gating points GP may be located on interior frame members  450  in addition to, or in lieu of, the outer frame member  450 . The force from the injection of the dielectric material at the gating points may cause pressure and shifting of the receptacle signal contacts  162  of the leadframe. The removable inserts  370  (shown in  FIG. 5 ) are used to hold the receptacle signal contacts  162  during the injection process to resist shifting caused by the force of the dielectric material being injected into the mold. 
     In an exemplary embodiment, the second frame  332  includes a leadframe, similar to the leadframe  360  (shown in  FIG. 4 ), where like components are identified by like reference numerals. The frame members  450  are overmolded over the receptacle signal contacts  162  defined by the leadframe. The receptacle signal contacts  162  are arranged in pairs. The mating portions  364  extend from the mating end  454  along an edge of the frame members  450  (e.g. a front edge), and the mounting portions  366  extend from the mounting end  456  along another edge of the frame members  450  (e.g. a side edge). 
     The frame members  450  include locating posts  480  extending therefrom. The locating posts  480  are configured to be received in corresponding openings in the conductive holder  310  (shown in  FIG. 3 ) to locate and/or secure the second frame  332  within the conductive holder  310 . In an exemplary embodiment, the bridges  458  near the mounting end  456  include locating channels  482  formed therethrough. The locating channels  482  receive tabs or other features of the conductive holder  310  to position and or secure the second frame  332  with respect to the conductive holder  310 . 
     In an exemplary embodiment, at least some of the frame members  450  include troughs  484 . The troughs  484  are recessed areas that are configured to receive portions of the first frame  330  (shown in  FIG. 6 ). Optionally, the troughs  484  may be generally aligned with the bridges  458 . Optionally, at least one frame coupling member  486  is located within each trough  484 . The frame coupling member  486  is configured to extend into the first frame  330  to position the first frame  330  with respect to the second frame  332 . Optionally, the frame coupling members  486  may also be used as locating posts, such as when the frame coupling members  486  are longer and are configured to extend into the conductive holder  310  in addition to extending through the coupling member  438  (shown in  FIG. 6 ) of the first frame  330 . 
     In an exemplary embodiment, the bridges  458  include coupling members  488  that interact with corresponding coupling members of the first frame  330  to secure the first frame  330  with respect to the second frame  332 . In the illustrated embodiment, the coupling members  488  constitute openings extending through the bridges  458 . The openings receive posts or other types of coupling members therein. Other types of coupling members  488  may be provided on the bridges  458 , such as posts, slots, latches, or other types of fasteners. 
     In an exemplary embodiment, the second frame  332  includes dielectric inserts  490  extending from one or more of the frame members  450 . The dielectric inserts  490  are integral with the frame members  450 . The dielectric inserts  490  are co-molded with the frame members  450 . The dielectric inserts  490  are molded at the same time as the frame members  450  and extend outward from corresponding edges  492  of the frame members  450 . The dielectric inserts  490  are configured to fill the voids or windows  444  left in the first frame  332  (shown in  FIG. 6 ) by the removable inserts  370  when the first frame  330  is coupled to the second frame  332 . The dielectric inserts  490  have a complementary shape to the removable insert  370 . The dielectric inserts  490  have a complementary shape to the void or window  444  left in the second frame  332  by the removable insert  370 . 
     The frame members  450  include voids or windows  494  left behind when the removable inserts  370  (shown in  FIG. 5 ) are removed from the second frame  332  and mold used to form the frame members  450 . In an alternative embodiment, the removable insert  370  may form part of the mold used to form the second frame  332 , such removable insert  370  being removable from the formed frame members  450  but not from the mold. Because the receptacle signal contacts  162  are held against the removable inserts  370  (e.g. in the channels  384 ,  386  (shown in FIG.  5 )), the windows  494  expose the receptacle signal contacts  162 . A post (not shown) remains in each window  494  after being formed in the opening  382  (shown in  FIG. 5 ) in the removable insert  370 . The post is used to connect the first frame  330  to the second frame  332  during assembly. 
       FIG. 8  is a side perspective view of the frame assembly  320  showing the first frame  330  and the second frame  332  coupled together. The first and second frames  330 ,  332  are internested such that the frame members  400  of the first frame  330  are received in corresponding gaps  452  of the second frame  332  between frame members  450  of the second frame  332 . The first and second frames  330 ,  332  are internested such that the frame members  450  of the second frame  332  are received in corresponding gaps  402  of the first frame  330  between frame members  400  of the first frame  330 . The first and second frames  330 ,  332  are internested such that the frame members  400 ,  450  of the first and second frames  330 ,  332  are generally coplanar. The frame members  400 ,  450  are arranged in an alternating sequence (e.g. frame member  400 , frame member  450 , frame member  400 , frame member  450 ). Internesting the frame members  400 ,  450  positions the differential pairs of receptacle signal contacts  162  of the first frame  330  interspersed between corresponding differential pairs of receptacle signal contacts  162  of the second frame  332 , and vice versa. 
     When the first and second frames  330 ,  332  are coupled together, the bridges  408  span across and engage corresponding frame members  450  of the second frame  332 . For example, the bridges  408  are received in corresponding troughs  484 . Similarly, the bridges  458  (shown in  FIG. 7 ) of the second frame  332  span across and engage corresponding frame members  400  of the first frame  330 . For example, the bridges  458  are received in corresponding troughs  434  (shown in  FIG. 6 ) in the frame members  400 . The coupling members  438  engage corresponding frame coupling members  486  to secure the first frame  330  with respect to the second frame  332 . 
     When the first and second frames  330 ,  332  are coupled together, the dielectric inserts  440  of the first frame  330  are received in corresponding windows  494  of the second frame  332 . The dielectric inserts  440  substantially fill the windows  494 . The dielectric inserts  440  cover the receptacle signal contacts  162  to limit exposure of the receptacle signal contacts  162  to air, which has a different dielectric constant than the dielectric material and which would impact or degrade the signal integrity. The dielectric inserts  440  may compensate from air around the signal contacts  162 . Covering of the receptacle signal contacts  162  maintains the signal integrity of the receptacle signal contacts  162 . Similarly, when the first and second frames  330 ,  332  are coupled together, the dielectric inserts  490  of the second frame  332  are received in corresponding windows  444  of the first frame  330 . The dielectric inserts  490  substantially fill the windows  444 . The dielectric inserts  490  cover the receptacle signal contacts  162 . 
     In an exemplary embodiment, the gaps  402 ,  452  are sufficiently wide to accommodate the corresponding frame members  450 ,  400 . For example, a width of the gaps  402  is wider than a width of the frame members  450 . Similarly, a width of the gaps  452  is wider than a width of the frame members  400 . In an exemplary embodiment, slots are defined between the frame members  400 ,  450 . Widths of the slots may vary depending on the widths of the gaps and the widths of the frame members  450 ,  400 . In an exemplary embodiment, the slots are sized and shaped to receive the tabs  322 ,  324  (shown in  FIG. 3 ) of the conductive holder  310  (shown in  FIG. 3 ). Having the tabs  322 ,  324  in the slots provides electrical shielding between each of the differential pairs of receptacle signal contacts  162 . 
     Having the first frame  330  manufactured separately from the second frame  332  allows adequate spacing between the receptacle signal contacts  162  for stamping and forming the mating portions  364  of the receptacle signal contacts  162 . For example, a dimension of material that is required to form the mating portions  364  may be greater than the desired spacing. In order to have the tight spacing between the receptacle signal contacts  162 , the two frames  330 ,  332  are separately manufactured and coupled together. 
       FIG. 9  is an enlarged view of a portion of the first frame  330 , showing details of the dielectric inserts  440 . Each of the dielectric inserts  440  includes a main wall  502 , end walls  504 ,  506  extending from the main wall  502  and forming a receiving space  508  therebetween, and fingers  510  extending from the main wall  502  in the receiving space  508 . The end walls  504 ,  506  are configured to extend along sides of the frame members  450  (shown in  FIG. 7 ) in the windows  494  (shown in  FIG. 7 ). The end wall  504  may be integral with the frame member  400 . 
     An opening  512  is formed in the main wall  502  between the fingers  510 . The opening  512  is configured to receive a corresponding post of the second frame  332  (shown in  FIG. 7 ). 
     First and second channels  514 ,  516  are formed between the fingers  510  and the corresponding end walls  504 ,  506 . The first and second channels  514 ,  516  receive the receptacle signal contacts  162  (shown in  FIG. 7 ) of the second frame  332 . The fingers  510  are positioned between the receptacle signal contacts  162  and are configured to be loaded through the frame members  450 . 
     In an exemplary embodiment, the dielectric inserts  440  include angled side walls  518 ,  520  extending between the end walls  504 ,  506 . The side walls  518 ,  520  are narrower at the top and wider at the bottom (or vice versa). The side walls  518 ,  520  define a wedge shaped piece configured to be plugged into the window  494  in the second frame  332 . The angled side walls  518 ,  520  are aligned with the conductors of the second frame  332  when coupled thereto to provide improved coverage of the conductors, which may improve the signal integrity of the conductors. 
     The dielectric inserts  440  may have other shapes or features in alternative embodiments. The dielectric inserts  490  (shown in  FIG. 7 ) may have similar shapes and features as the dielectric inserts  440 . 
       FIG. 10  illustrates the frame assembly  320  with the second ground shield  352  coupled thereto. The ground shield  352  includes crossbars  600  extending between ground frames  602 . The crossbars  600  span across the bridges  408 ,  458  (shown in  FIGS. 6 and 7 ) and the dielectric inserts  440 ,  490  (shown in  FIGS. 6 and 7 ). The crossbars  600  provide electrical shielding and/or impedance compensation in the areas of the bridges  408 ,  458  and the dielectric inserts  440 ,  490 . Widths of the crossbars  600  may be selected to provide adequate electrical shielding. 
       FIG. 11  illustrates the first holder member  312 . The tabs  322  are illustrated forming individual channels that receive corresponding frame members  400  (shown in  FIG. 6 ). The tabs  322  include slots  604  in select locations. The slots  604  allow portions of the cross bars  600  (shown in  FIG. 10 ), bridges  408 ,  458  (shown in  FIGS. 6 and 7 ) and the dielectric inserts  440 ,  490  (shown in  FIGS. 6 and 7 ) all to span between the channels. Optionally, the slots  604  may only be provided in one of the holder members  312  or  314  and not both holder members  312  and  314 . 
       FIG. 12  illustrates a frame assembly  700  formed in accordance with an exemplary embodiment. The frame assembly  700  is similar to the frame assembly  320  (shown in  FIG. 3 ), however the frame assembly  700  includes a single frame  702  supporting single ended receptacle signal contacts  704 , as opposed to differential pairs of contacts. The signal contacts  704  are overmolded with dielectric material that form frame members  706 , with each frame member  706  holding an individual signal contact  704 . A gating point (GP) is defined at an interior position of the frame  702 . 
     In an exemplary embodiment, one of the signal contacts  704  closest to, and exterior of, the gating point is held by a removable insert (not shown) during overmolding, thus forming a window  708  around a portion of the signal contact  704  and frame member  706 . A dielectric insert  710  is configured to be coupled to the frame  702  at the window  708 . The dielectric insert  710  plugs the window to reduce effects of air exposure to the signal contact  704 . Optionally, when multiple removable inserts are used to hold different signal contacts  704 , thus forming multiple windows, multiple dielectric inserts  710  may be molded together, such as with bridges therebetween, to be coupled to the frame  702  as a single piece. 
       FIG. 13  illustrates a frame assembly  800  formed in accordance with an exemplary embodiment.  FIG. 14  is an enlarged view of a portion of the frame assembly  800 . The frame assembly  800  is similar to the frame assembly  700  (shown in  FIG. 12 ). Optionally, the frame assembly  800  may include a single frame  802  supporting differential pairs of receptacle signal contacts  804 . Alternatively, the frame assembly  800  may include multiple frames that are internested, in a similar manner as the frame assembly  320  (shown in  FIG. 3 ). The signal contacts  804  are overmolded with dielectric material that form frame members  806 , with each frame member  806  holding a differential pair of signal contacts  804 . A gating point (GP) is defined at an interior position of the frame  802 . 
     In an exemplary embodiment, one or more pairs of the signal contacts  804 , such as those closest to the gating point, is held by a removable insert (not shown) during overmolding, thus forming a window  808  around a portion of the signal contacts  804  and corresponding frame member  806 . A dielectric insert  810  is configured to be coupled to the frame  802  at the window  808 . The dielectric insert  810  plugs the window to reduce effects of air exposure to the signal contact  804 . 
     A post  812  (shown in  FIG. 14 ) is formed in the window  808  by the removable insert. The post  812  is used to connect the dielectric insert  810  to the  802 . Openings  814  (shown in  FIG. 14 ) are formed between the pair of signal contacts  804 . Legs of the dielectric insert  810  are loaded into the openings  814  during assembly. 
     It is to be understood that the above description is intended to be illustrative, and not restrictive. For example, the above-described embodiments (and/or aspects thereof) may be used in combination with each other. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its scope. Dimensions, types of materials, orientations of the various components, and the number and positions of the various components described herein are intended to define parameters of certain embodiments, and are by no means limiting and are merely exemplary embodiments. Many other embodiments and modifications within the spirit and scope of the claims will be apparent to those of skill in the art upon reviewing the above description. The scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. In the appended claims, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” Moreover, in the following claims, the terms “first,” “second,” and “third,” etc. are used merely as labels, and are not intended to impose numerical requirements on their objects. Further, the limitations of the following claims are not written in means—plus-function format and are not intended to be interpreted based on 35 U.S.C. §112, sixth paragraph, unless and until such claim limitations expressly use the phrase “means for” followed by a statement of function void of further structure.