Patent Publication Number: US-8523616-B2

Title: Electrical connector including contacts and housing recesses and air pockets for improved impedance

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an electrical connector, and more particularly to a high speed, high density backplane connector. 
     2. Description of Related Art 
     U.S. Pat. No. 7,074,086 issued to Cohen et al. on Jul. 11, 2006 discloses a high speed backplane connector. The backplane connector includes a housing, a plurality of signal contacts and grounding contacts secured in the housing. The housing includes a bottom wall, a pair of side walls rising from opposite edges of the bottom wall. The bottom wall defines a plurality of passageways for insertion of the signal contacts and the grounding contacts. 
     U.S. Pat. No. 6,976,886 issued to Winings et al. on Dec. 20, 2005 discloses a high speed backplane connector. The connector includes a housing defining a plurality of recesses and a plurality of contacts inserted into the recesses. Each contact has a pair of shoulders for being reliably secured in the recesses. 
     U.S. Pat. No. 6,669,514 issued to Wiebking et al. on Dec. 30, 2003 discloses a connector including a plurality of contact modules. Each contact module has a frame and a plurality of contacts integrated with the frame. Each frame defines a plurality of air pockets for improving the impedance of the contacts. U.S. Pat. No. 6,981,883 issued to Raistrick et al. on Jan. 3, 2006 discloses a connector including a plurality of contact modules. Each contact module has a frame and a plurality of contacts secured on the frame. Two contact modules have a plurality of air pockets between the contact of one contact frame and the contact of another contact frame. 
     An electrical connector including contacts having improved impedance is desired. 
     SUMMARY OF THE INVENTION 
     Accordingly, an object of the present invention is to provide an electrical connector including a housing defining air pockets, and a plurality of contacts facing the air pockets to obtain improved characteristic impedance. 
     In order to achieve the object set forth, an electrical connector includes a housing having a securing structure and a number of contacts. The securing structure defines a number of passageways each extending therethrough along a thickness direction thereof, a number of securing recesses each across and in communication with a corresponding passageway along a width direction thereof, and a number of air pockets each across and in alignment with a corresponding passageway along a length direction thereof. Each contact has a body portion inserted through the passageway, and a widen portion secured in the securing recess and facing a corresponding air pocket. 
     The contact is secured in the securing recess via the widen portion and has an impedance thereof improved by air in the air pocket. 
     Other objects, advantages and novel features of the invention 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 an assembled perspective view showing an electrical connector in accordance with the present invention; 
         FIG. 2  is an exploded perspective view showing the electrical connector shown in  FIG. 1 ; 
         FIG. 3  is a view similar to  FIG. 2 , taken from another aspect; 
         FIG. 4  is a perspective view showing a stiffener as shown in  FIG. 2 ; 
         FIG. 5  is an enlarged view showing part of the stiffener as marked in  FIG. 4 ; 
         FIG. 6  is a cross-sectional view showing the electrical connector, taken along line  6 - 6  of  FIG. 1 ; and 
         FIG. 7  is a cross-sectional view showing the electrical connector, taken along line  7 - 7  of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Reference will now be made in detail to the preferred embodiment of the present invention. 
     Referring to  FIGS. 1 to 3 , an electrical connector  100  in accordance with the present invention includes a housing (not labeled) having a base  10  and a stiffener  20 , and a plurality of contacts  30  inserted in the housing. 
     The base  10  includes a bottom wall  11 , a pair of side walls  12  rising from the bottom wall  11 , and a cavity  13  defined between the pair of side walls  12 . Each side wall  12  defines a pair of first indentations  120  facing the cavity  13 . 
     In conjunction with  FIGS. 6 and 7 , the bottom wall  11  defines a plurality of passageways  40  extending therethrough along a thickness direction thereof, a plurality of securing recesses  42  each across and open upwardly in communication with an associated passageway  40 , and a plurality of air pockets  41  each across and in alignment with the associated passageway  40  along a length direction thereof. Each air pocket  41  defined in the bottom wall  11  extends obliquely downwardly into a deeper level. 
     In conjunction with  FIGS. 3-5 , the stiffener  20  defines two pairs of second indentations  200  associated with the two pairs of first indentations  120  for engaging with two pairs of protrusions of a mating connector (not shown). The stiffener  20  defines another plurality of passageways  40  extending therethrough along a thickness direction thereof, another plurality of securing recesses  42  each across and open downwardly in communication with an associated passageway  40 , and another plurality of air pockets  41  each across and in alignment with the associated passageway  40  along a length direction thereof. Each air pockets  41  defined in the stiffener  20  extends obliquely upwardly into a deeper level. 
     Referring to  FIGS. 2 ,  3  and  6 , each contact  30  includes a body portion  32 , a widen portion  31  formed in the body portion  32  and having a width greater than that of the body portion  32 , and a tail portion  35  having a press-fit configuration. 
     Referring to  FIGS. 1-7 , in assembling of the electrical connector  100 , the stiffener  20  is disposed on the bottom wall  11  of the base  10 . The plurality of contact  30  are inserted through the passageways  40  defined in the stiffener  20  and passageways  40  defined in the base  10  along the thickness direction. The widen portion  31  of each contact  30  is partially secured in the securing recess  42  defined in the bottom wall  11  and partially secured in an associated securing recess  42  defined in the stiffener  20 , along the width direction. The widen portion  31  of each contact  30  faces to the air pocket  41  defined in the bottom wall  11  and an associated air pocket  41  defined in the stiffener  20 , to improve an impedance of the contact  30  by air in the air pockets  41 . The tail portion  35  of each contact  30  is exposed outwardly of the base  10 . 
     In this embodiment, the stiffener  20  is mounted on the base  10  to form a strengthened housing. The bottom wall  11  and the estiffener  20  are combined into a securing structure. The air pockets  41  are defined both in the bottom wall  11  and the stiffener  20 . Optionally, the air pockets  41  could be defined in either the bottom wall  11  or the stiffener  20 . 
     In another embodiment, the housing consists of the base  10  only. The bottom wall  11  forms a securing structure. The passageways  40 , the securing recesses  42  and the air pockets  41  are only defined in the bottom wall  11 . The widen portion  31  of each contact  30  is substantially completely received in the securing recess  42  of the base  10  for facing the air pocket  41  of the base  10 . 
     It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of 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.