Patent Publication Number: US-11050176-B2

Title: Electrical connector with therein embedded grounding bar secured by conductive adhesive and method of making the same

Description:
BACKGROUND OF THE DISCLOSURE 
     1. Field of the Disclosure 
     The present invention relates to an electrical connector, and particular to the electrical connector equipped with an embedded grounding bar secured by conductive adhesive. 
     2. Description of Related Arts 
     China Patent No. CN203813128U discloses an electrical connector forms a plurality of through hole extend through a plurality of grounding sheets and filled with conductive adhesive for electrical unification consideration. Anyhow, because the grounding sheet requires to form corresponding hole in alignment with those through hole for moving of liquid adhesive, there is less engagement area between the conductive adhesive and the corresponding grounding sheet, thus lessening the mechanical and electrical connection between the conductive adhesive and the grounding sheet in advantageously. 
     An improved electrical connector having a reliable mechanical and electrical connection between the conductive adhesive and the grounding part is desired. 
     SUMMARY OF THE DISCLOSURE 
     Accordingly, an object of the present disclosure is to provide an electrical connector with a contact module having an insulative body, a plurality of contacts retained to the body, and a grounding bar embedded within the body. The contacts include a plurality of differential pair contacts and a plurality of grounding contacts. The ground bar forms a plurality of spring tangs. The body forms a plurality of cavities and the corresponding spring tangs of the grounding bar extend into the corresponding cavities to contact the corresponding grounding contacts. Conductive adhesive is filled within each cavity and solidified to secure all the spring tang, the corresponding grounding contact and the body together. The electrical connector is formed by a pair of contact modules back to back secured to together by an insulative case either by assembling or via an over-molding process. The cavities and the corresponding conductive adhesive of each contact module is hidden from the exterior. 
     A method of making the aforementioned electrical connector includes the steps as follow: providing a first contact module with a first insulator integrally formed with a plurality of first contacts and a second contact module with a second insulator integrally formed with a plurality of second contacts wherein each of said first insulator and said second insulator includes a plurality of cavities to expose the corresponding grounding contacts, respectively; providing a grounding bar sandwiched between the first contact module and the second contact module wherein the grounding tangs of the grounding bar extend into and contact the corresponding grounding contacts, respectively; filling conductive adhesive into the corresponding cavities and solidifying the conductive adhesive to secure the grounding tangs and the grounding contacts in the cavities; and applying an insulative case upon the pair of contact modules to commonly form the finalized electrical connector. 
     Other objects, advantages and novel features of the disclosure will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an electrical connector according to the invention; 
         FIG. 2  is another perspective view of the electrical connector of  FIG. 1 ; 
         FIG. 3  is an exploded perspective view of the electrical connector of  FIG. 1 ; 
         FIG. 4  is an exploded perspective view of the contact unit of the electrical connector of  FIG. 3 ; 
         FIG. 5  is another exploded perspective view of the contact unit of  FIG. 4 ; 
         FIG. 6  is an exploded perspective view of the first insulator with the associated grounding bar and the conductive adhesive removed away from the corresponding cavities thereof of  FIG. 5 ; 
         FIG. 7  is an exploded perspective view of the first insulator with the associated grounding bar and the conductive adhesive, and the second contact module of  FIG. 4 ; 
         FIG. 8  is an enlarged perspective view of a portion of the contact unit of  FIG. 4 ; 
         FIG. 9  is a cross-sectional view of the electrical connector of  FIG. 1 ; and 
         FIG. 10  is another cross-sectional view of the electrical connector of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Reference will now be made in detail to the embodiments of the present disclosure. 
     An electrical connector  100  for mounting to a printed circuit board (not shown) and mating to a complementary connector (not shown), includes an elongated insulative housing with a plurality of contacts secured thereto, and a metallic grounding bar embedded within the insulative housing and securing the grounding bar with the corresponding grounding contacts for performing the grounding effect. 
     Referring to  FIGS. 1-4 , the insulative housing includes a base  11  and a mating tongue  12  extending from the base  11  in configuration, and structurally includes a case  13  enclosing the contact unit which is essentially consisted of the first insulator  14  of the first contact module, the second insulator  15  of the second contact module, and the grounding bar  3  therebetween. The first contacts  21  are integrally formed within the first insulator  14  to form the first contact module, and the second contacts  22  are integrally formed within the second insulator  15  to form the second contact module. The first insulator  14  forms a plurality of first cavities  141  and the second insulator  15  forms a plurality of second cavities  151 . A receiving recess  140  is formed in the first insulator  14  to receive the grounding bar  3  therein. 
     The first contacts  21  include a plurality of signal contacts and grounding contacts  21 G, and the second contacts  22  include a plurality of signal contacts and grounding contacts  22 G. The contacting sections of the first contacts  21  are exposed upon the lower surface of the first insulator  14 . The first cavities  141  are formed in the an upper surface of the first insulator  14 . The contacting sections of the second contacts  22  are exposed upon the upper surface of the second insulator  15 . The second cavities  151  are formed in a lower surface of the second insulator  15 . The lower surface of the second insulator  15  and the upper surface of the first insulator  14  intimately contact each other during assembling. 
     The grounding bar  3  is sandwiched between the upper surface of the first insulator  14  and the lower surface of the second insulator  15 , and electrically and mechanically connects to the corresponding grounding contacts  21 G and  22 G. The conductive adhesive fills the cavities  141  and  151  to secures the corresponding grounding contacts  21 G and  22 G. In detail, the grounding bar  3  includes a plurality of first spring tangs  31  extending into the corresponding first cavities  141  to contact the corresponding first grounding contacts  21 G, and the second spring tangs  32  extending into the corresponding second cavities  151  to contact the corresponding second grounding contacts  22 G. The first spring tang  32  includes a front spring tang  311  and a rear spring tang  312  connecting the same first grounding contact  21 G wherein the front spring tang  311  is located in the mating tongue  12  and the rear spring tang  312  is located in the base  11 . The grounding bar  3  further includes a pair of elongated bars  30  with a plurality crossbars  34  therebetween to form a plurality of openings  33  in which the corresponding first spring tangs  31  and the second spring tangs  32  extend. Notably, some first tangs  31  have their own openings in a one-to-one relation while each of the other first spring tangs  31  requires to share the same opening with other spring tangs. 
     The conductive adhesive includes a plurality of first conductive adhesive blocks  41  received within the corresponding cavities  141  to have the corresponding first spring tangs  31  electrically and mechanically connected to the corresponding first grounding contacts  21 G, and a plurality of second conductive adhesive blocks  42  received within the corresponding cavities  151  to have the corresponding second spring tangs  32  electrically and mechanically connected to the corresponding second grounding contacts  22 G. Notably, the first conductive adhesive block  41  and the second conductive adhesive block  42  forms bulged structures on two sides for enhancing retention. 
     The method of making the electrical connector  100  includes the following steps: 
     providing a first contact module with a plurality of first contacts integrally formed within a first insulator via a first insert-molding process, wherein the first insulator forms a plurality of first cavities to expose the corresponding first grounding contacts, respectively; 
     providing a second contact module with a plurality of second contacts integrally formed within a second insulator via a second insert-molding process, wherein the second insulator forms a plurality of second cavities to expose the corresponding second grounding contacts, respectively; 
     providing a metallic grounding bar with a plurality of first spring tangs extending into the corresponding first cavities to contact the corresponding first grounding contacts, respectively, and a plurality of second spring tangs ready to extend into the corresponding second cavities to contact the corresponding second grounding contacts, respectively; 
     filling and solidifying, via heating, conductive adhesive into the corresponding first cavities to form a plurality of first conductive adhesive blocks within the corresponding first cavities for securing all the first insulator, the first spring tangs and the corresponding first grounding contacts together; 
     filling conductive adhesive into the corresponding second cavities, stacking the first module and the second contact module together to have the second spring tangs extend into the corresponding second cavities, and solidifying conductive adhesive within the corresponding second cavities for securing all the second insulator, the second spring tangs and the corresponding second grounding contacts together; and 
     over-molding an insulative case upon the stacked first contact module and second contact module to finalize the whole electrical connector. 
     Compared with the traditional designs which use either the conductive adhesive or the grounding bar for shorting all grounding contacts together, the invention uses the conductive adhesive as an auxiliary piece to assist the primary grounding bar for assuring the reliable grounding/shorting effect among all grounding contacts. In other words, the conductive adhesive not only secures the spring tang of the grounding bar to the corresponding grounding contact around the cavity but also assures the electrical conduction between therebetween. In opposite, in some traditional designs using only the discrete grounding bar, the corresponding spring tangs may not properly and strongly press the corresponding grounding contacts, thus jeopardizing the grounding/shorting effect. In addition, the conductive adhesive is unexposed and embedded within the whole contact unit, thus preventing external factors applied thereupon, including the environmental humidity or direct impacting.