Patent Publication Number: US-2023139926-A1

Title: Contact assembly and method of making same and electrical connector including the contact assembly

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to and benefit of U.S. Provisional Pat. Application No. 63/263,565, filed Nov. 04, 2021, and U.S. Provisional Pat. Application No. 63/267,812, filed Feb. 10, 2022. 
    
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to a contact assembly for an electrical connector, and method of making the same, and an electrical connector including the contact assembly, the contact assembly comprising: a signal contact module including an insulator and plural pairs of signal contacts insert-molded with the insulator; a plurality of ground contacts each disposed beside a corresponding pair of signal contacts; and a conductive plastic member connecting the plurality of ground contacts. 
     Description of Related Arts 
     U.S. Pat. No. 9,768,557 discloses an electrical connector in which, during manufacture, signal and ground contacts may be stamped and formed contacts defining leadframes. The leadframes arrange the contacts in an array, and carrier strips of the leadframe may be removed after stamping and forming to define a contact array. The leadframes are overmolded to form overmold bodies. Optionally, the leadframes may be overmolded in a multi-stage molding process where main bodies are molded in a first stage and lossy ground absorbers (e.g., conductive plastic members) are molded in a second stage, or vice versa. The lossy ground absorbers may be co-molded with the main bodies in a multi-shot molding process, such as a two-shot molding process, where the main bodies and the lossy ground absorbers are molded from different materials, such as a low loss plastic material and a lossy material, respectively. 
     U.S. Pat. Application Publication No. 2021/0336360 discloses methods and structures that combine metal ground conductors/terminals and plastic conductive ground shields, e.g., by stitchably mating one or more insert molded metal ground conductors with a respective ground conductive section that is part of a ground shield element. 
     SUMMARY OF THE INVENTION 
     A contact assembly for an electrical connector, comprising: a signal contact module including an insulator and plural pairs of signal contacts insert-molded with the insulator; a plurality of ground contacts each disposed beside a corresponding pair of signal contacts; and a conductive plastic member molded to connect the plurality of ground contacts; wherein each ground contact has a hole and the conductive plastic member enters the holes of the ground contacts. 
     A method of making a contact assembly comprising the steps of: molding an insulator with plural pairs of signal contacts to form a signal contact module; disposing each of a plurality of ground contacts beside a corresponding pair of signal contacts; and molding a conductive plastic member to connect the plurality of ground contacts through a hole in each ground contact for the conductive plastic member to enter. 
     An electrical connector comprises an insulative housing and a contact assembly received in the insulative housing, the contact assembly including: a signal contact module including an insulator and plural pairs of signal contacts insert-molded with the insulator; a plurality of ground contacts each disposed beside a corresponding pair of signal contacts; and a connecting member molded to connect the plurality of ground contacts; wherein each ground contact has a hole and the connecting member enters the holes of the ground contacts. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    is an exploded view of a contact assembly in accordance with the present invention connected with carrier strips; 
         FIG.  2    is an assembled view of a part of the contact assembly; 
         FIG.  3    is an assembled view of the whole contact assembly; 
         FIG.  4    is an assembled view of a varied contact assembly in accordance with the present invention connected with carrier strips; 
         FIG.  5    is an exploded view of the contact assembly in  FIG.  4   ; 
         FIG.  6    is a view similar to  FIG.  5    but from another perspective; 
         FIG.  7    is an assembled view of a part of the contact assembly in  FIG.  4   ; 
         FIG.  8    is a view similar to  FIG.  7    but from another perspective; and 
         FIG.  9    is a side cross-sectional view of the contact assembly in  FIG.  4   . 
     
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
     Referring to  FIGS.  1 - 3   , a contact assembly  100  for an electrical connector comprises: a signal contact module  10  including an insulator  12  and plural pairs of signal contacts  14  insert-molded with the insulator  12 , the plural pairs of signal contacts  14  being arranged in the lateral direction; a plurality of ground contacts  16  each disposed beside a corresponding pair of signal contacts  14 ; and a conductive plastic member  18  molded to connect the plurality of ground contacts  16  in order to mechanically and electrically connect the ground contacts  16  together but not electrically connectihng the signal contacts  14 . In a varied design, the conductive plastic member  18  may be replaced by or combined with liquid metal ink or conductive ink that flows and then is cured in place. Each of the ground contacts  16  and the signal contacts  14  includes a front deflectable contact portion, a rear tail portion opposite the contact portion, and a connection portion therebetween. The connecting portion includes a horizontal portion connected to the contact portion, a vertical portion connected to the tail portion, and an inclined portion located therebetween. The electrical connector may be an electrical receptacle mounted onto a host board and include an insulative housing receiving one or more such contact assemblies, such as a receptacle connector disclosed in U.S. Pat. No. 10,367,308, or it may suitably be a plug connector or a receptacle connector connected to a cable. 
     The signal contact module  10  shows a signal contact lead-frame with discrete molded insulating features and is molded in a first shot molding process. The insulator  12  of the signal contact module  10  includes plural discrete portions each receiving a corresponding pair of signal contacts  14 . Specifically, in this embodiment, three discrete portions are formed on each pair of the signal contacts and are arranged along the length of the signal contacts, with two discrete portions being formed in the horizontal portion in the front-rear direction and one discrete portion being formed in the vertical portion. The ground contact lead-frame is stamped and formed to have positioning holes  162  for locating purpose during a second shot molding of conductive plastic and flow-thru holes  164  for conductive plastic to flow through in the second shot molding process. In the present invention, the signal contacts  14  and the ground contacts  16  are respectively formed by stamping different metal sheets. Before molding, the signal contacts  14  are connected to a carrier strip  124  and the ground contacts  16  are connected to another carrier strip  120 . Before the second shot molding, both the plural pairs of signal contacts  14  and the plurality of ground contacts  16  are assembled into a mold. Pilot holes  122  and  126  on both carrier strips  120  and  124  will locate the lead-frames in the second shot mold. Second shot conductive plastic passes through the ground contact lead-frame flow-thru holes  164  and joins only the ground contacts  16  to reduce crosstalk resonance peaks and facilitate the transmission of high-speed signals. The molded conductive plastic member  18  also structurally molds to the insulator  12  for a robust completed assembly. The conductive plastic member  18  is shown as a one-piece component molded to embed a portion of each ground contact  16 . It should be noted that the conductive plastic member  18  are not formed on the signal contacts  14 . The conductive plastic member  18  is spaced apart from the signal contacts  14  by the insulator  12 . The conductive plastic member  18  includes two laterally extending portions formed on the horizontal portion of the ground contacts  16  and one laterally extending portion formed on the vertical portion of the ground contacts  16 . The two laterally extending portions of the horizontal portion are connected together on lateral sides thereof to form a whole unit. 
     Referring to  FIGS.  4 - 9   , a varied contact assembly  200  for an electrical connector comprises: a signal contact module  20  including an insulator  22  and plural pairs of signal contacts  24  insert-molded with the insulator  22 ; a plurality of ground contacts  26  each disposed beside a corresponding pair of signal contacts  24 ; and a conductive plastic member  28  molded to connect the plurality of ground contacts  26 . The varied contact assembly  200  is different from the contact assembly  100  primarily in having a one-piece insulator  22  and a conductive plastic member  28  with plural discrete portions at different parts of the ground contacts  26 . Each discrete portions extends in a lateral direction. Each discrete portion of the conductive plastic member  28  mechanically and electrically connects the plurality of ground contacts  26 . In this embodiment, the horizontal portion is provided with two discrete portions, and the vertical portion is provided with one discrete portion. The insulators  22  provided in the horizontal portion are connected together on the sides in the lateral direction to form a whole unit. The one-piece insulator  22  has respective channels  220  on both sides of each pair of signal contacts  24 . One or more of the channels  220  may have one or more positioning posts  222  for locating corresponding positioning hole  262  of the ground lead-frame. Chamfers  224  may be provided on the insulator  22  near the channel entrance for ease of insertion of the ground contacts  26  in a top-to-bottom direction. After the ground contacts  26  are inserted into the channels  220 , conductive plastic member  28  may be conveniently molded in place in a suitable manner. The conductive plastic member  28  may enter an associated flow-thru hole of each ground contact  26  for adhesion on two or more sides of the ground contact  26 .