Abstract:
An electrical connector ( 100 ) includes an insulative housing ( 10 ) defining a receiving room ( 110 ) for receiving a mating connector, and a receiving cavity ( 16 ) below and separated from the receiving room for receiving a portion of the mating connector. A number of contacts are supported by said insulative housing, and arranged in distinct sets of upper and lower contacts ( 20, 30 ) on opposing faces of said insulative housing. The upper and the lower contacts are inserted into the receiving room along a back-to-front direction. An elongated spacer ( 40 ) is supported by said insulative housing. The upper contacts are arranged by the elongated spacer.

Description:
This application is a continuation application of application Ser. No. 12/721,575 filed on Mar. 11, 2010 now U.S. Pat. No. 7,841,872. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an electrical connector, and more particularly to an electrical connector with a number of contacts suitable for high speed communication. 
     2. Description of Related Arts 
     U.S. Pub. No. 20070173127, published on Jul. 26, 2007, to Regnier et al. discloses a related art. According to the disclosure, a surface mount connector for high speed data transfer application is disclosed and includes an insulative housing with a circuit card-receiving slot disposed along a front face thereof. A plurality of conductive terminals are supported by the housing so that contact portions of the terminals extend into the card slot. The terminals are supported on opposite faces of the insulative housing, specifically the top and bottom faces thereof, and each of the terminals includes a tail portion, a contact portion and a retention portion that engages with the insulative housing so that the contact portions are cantilevered within the insulative housing. The insulative housing includes a hollow recess formed on its bottom that opens to the front of the insulative housing. This recess serves as a keyway that may receive a male portion of an opposing mating connector to ensure the mating connector is oriented properly before engagement. 
     The conductive terminals are retained in the insulative housing along a top-to-bottom direction so that the conductive terminal must be formed with a retention stick or tab extending transversally and beyond the signal current path for retaining in the housing. Therefore, the retention stick may form an electrical stub. It is detrimental to high speed data transfer of the conductive terminals. 
     Hence, an improved electrical connector for high speed data transfer application is required to overcome the above-mentioned disadvantages of the related art. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to provide an electrical connector that the signal current transmit through the retention portion. 
     To achieve the above-mentioned object, an electrical comprises an insulative housing defining a receiving room and a front mating opening communicating with the receiving room for receiving a mating connector, a plurality of upper and lower rear mounting holes communicating with the receiving room, and a receiving cavity below the receiving room for receiving a portion of a mating connector. A plurality of first contacts each has a first contact portion having a first free end, a first retention portion, a first soldering portion and a first connecting portion. A plurality of second contacts each has a second contact portion having a second free end, a second retention portion, a second soldering portion and a second connecting portion. The first and the second contacts are inserted into the receiving room along a back-to-front direction. The first and second contact portions are exposed in the receiving room. The first retention portions are fixed in the upper rear mounting holes respectively. The second retention portions are fixed in the lower rear mounting holes respectively. 
     According to the present invention, the first and the second contacts are inserted into the insulative housing along a back-to-front direction. It is unnecessary to form a retention stick beyond the signal current path on each of the first and the second contacts. Therefore, the signal current transmission path may go through the retention portion and the performance of the high speed data transfer is improved. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         FIG. 1  is a perspective view of an electrical connector for high speed data transfer application in accordance with the present invention; 
         FIG. 2  is another perspective view of the electrical connector as shown in  FIG. 1 ; 
         FIG. 3  is a bottom view of the electrical connector as shown in  FIG. 1 ; 
         FIG. 4  is an exploded view of the electrical connector as shown in  FIG. 1 ; 
         FIG. 5  is a cross-sectional view of the electrical connector taken along line  5 - 5  of  FIG. 1 ; and 
         FIG. 6  is a cross-sectional view of the electrical connector taken along line  6 - 6  of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Reference will now be made in detail to a preferred embodiment of the present invention. 
     Referring to  FIGS. 1 to 2 , an electrical connector  100  for high speed data transfer application made in accordance with a preferred embodiment of the present invention adapted for mating with a mating connector comprises an insulative housing  10 , a number of first and second contacts  20 ,  30  received in the insulative housing  10  and an elongated spacer  40  for arranging the first and the second contacts  20 ,  30 . In this embodiment the electrical connector  100  is a quad small form-factor pluggable connector. 
     Referring to  FIGS. 1 to 3 , the insulative housing  10  comprises a mating face  101  with a mating opening  11 , a rear wall  102  opposite to the mating face  101 , a top wall  13 , a bottom wall  14  spaced apart from and parallel to the top wall  13  and a pair of parallel and spaced side walls  15  connecting with the top and the bottom walls  13 ,  14 . The mating face  101 , rear, top, bottom and side walls  102 ,  13 ,  14 ,  15  cooperate to define a receiving room  110  and communicating with the mating opening  11  for mating with the mating connector. Both of the side walls  15  have a bottom portion extending beyond the bottom wall  14  from the top wall  13  to the bottom wall  14  direction defining a receiving cavity  16  for receiving a portion of the mating connector. Each side wall  15  has a rear portion  150  extending beyond the rear wall  102  defining a mounting slot  151 . The rear wall  102  defines a number of rear mounting holes  12  opposite to the mating opening  11  and connecting with the receiving room  110 . The rear mounting holes  12  comprises a number of upper rear mounting holes  12   a  and lower rear mounting holes  12   b  offset from the upper rear mounting holes  12   a  respectively. The top wall  13  defines a number of top through holes  131  each defining a top cutout portion  133  for impedance matching and a flat portion  132  for being vacuum suctioned by an automatic pick-up device. The bottom wall  14  defines a number of bottom through holes  141  each defining a bottom cutout portion  143  for impedance matching and a pair of mounting posts  142  for positioning the electrical connector  100  to the PCB. In other words, each of the top through holes  131  comprises a wide portion  133  for impedance matching and a narrow portion  135  for arranging respective first contact  20 , and each of the bottom through holes  141  comprises a wide portion  143  for impedance matching and a narrow portion  145  for arranging respective second contact  30 . The insulative housing  100  defines respective preloading portions  111  at the top and bottom sides of the receiving room  110  adjacent to the mating opening  11 . 
     Referring to  FIGS. 4 and 5 , each first contact  20  comprises a first retention portion  23 , a first horizontal arm  22  connecting with the first retention portion  23 , a first contact portion  21  extending from the first horizontal arm  22  and having a first free end  211 , a first soldering portion  26  and a first connecting portion  24  connecting with the first retention portion  23  and the first soldering portion  26 . Each first connecting portion  24  comprises a horizontal portion  241  extending from the first retention portion  23 , a vertical portion  25  connecting with the first soldering portion  26  and an oblique portion  242  extending obliquely to the first soldering portion  26  and connecting with the horizontal portion  241  and the vertical portion  25 . Each first retention portion  23  defines a first concave portion  231  to reduce the cross sectional area of the first retention portion  23  for improving the performance of the high speed data signal transfer. 
     Referring to  FIGS. 4 and 6 , each second contact  30  comprises a second retention portion  33 , a second horizontal arm  32  connecting with the second retention portion  33 , a second contact portion  31  extending from the second horizontal arm  32  and having a second free end  311 , a second soldering portion  35  and a second connecting portion  34  extending in a vertical direction from the second retention portion  33  and connecting with the second retention portion  33  and the second soldering portion  35 . Each second retention portion  33  defines a second concave portion  331  to reduce the cross sectional area of the second retention portion  33  for improving the performance of the high speed data signal transfer. 
     Referring to  FIGS. 4 to 6 , the first contacts  20  are inserted into the insulative housing  10  through the upper rear mounting holes  12   a  along a back-to-front direction. The first contacts  20  are fixed or securely retained in the insulative housing  10 , with the first retention portion  23  having an interference with the upper rear mounting holes  12   a . The second contacts  30  are inserted into the insulative housing  10  through the lower rear mounting holes  12   b  along a back-to-front direction. The second contacts  30  are fixed in the insulative housing  10 , with the second retention portions  33  having an interference with the lower rear mounting holes  12   b . It is unnecessary to form a retention stick in each of the first and the second contacts  20 ,  30  so that the high speed data transmits through the first and the second retention portions  23 ,  33 . Therefore, the performance of the high speed data transmission is improved. The first and the second horizontal arms  22 ,  32  and the first and the second contact portions  21 ,  31  are exposed in the receiving room  110 . The first free ends  211  abut against the top side preloading portion  111 . The second free ends  311  abut against the bottom side preloading portion  111 . The first contact portions  21  and the first horizontal arms  22  are disposed below the top through holes  131  of the top wall  13  respectively. The second contact portions  31  and second horizontal arms  32  are disposed above the bottom through holes  141  of the bottom wall  14  respectively. Therefore, the first and the second contacts  20 ,  30  may expose much more area in the air which in turn may improve the impendence matching. The first contacts  20  may be offset from the second contacts  30  respectively. 
     Referring to  FIGS. 2 to 6 , the elongated spacer  40  comprises a first side  40   a  disposed adjacent to the insulative housing  10 , a second side  40   b  opposite to the first side  40   a , a first end  40   c  and a second end  40   d  opposite to the first end  40   c . The first side  40   a  preferably is distanced from the lower second contacts so as not to affect their performance and may comprise a projection portion  41  defining a number of first slots  42   a  for receiving only some of the second connecting portions  34  of the second group contacts  30  that are used to transmit low frequency signal. The projection portion  41  is disposed at a middle portion of the first side  40   a  of the elongated spacer  40 . The second side  40   b  defines a number of second slots  42   b  for receiving the first vertical portions  25  of the first contacts  20  respectively. This may be desired because the connecting portion of the upper contact is comparatively longer than the connecting portion of the lower contact and a true position of upper contact connecting portions is needed. The first and the second ends  40   c ,  40   d  both have a mounting block  43  for engaging with the mounting slots  151  of the insulative housing  10 . 
     It is to be understood, however, that even though numerous characteristics and advanarmes 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.