Abstract:
A cable connector assembly ( 100 ) used in high frequency signal transmission filed includes an insulative housing ( 2 ), a conductive terminals ( 3 ) retained in the housing, a number of wires ( 4 ) arrayed in a row and electrically connecting the terminals, and a conductive shell ( 5 ). The wires comprise at least one signal wire ( 40   b ) each comprising one or more conductive cores ( 401   b ) at the innermost thereof, and a grounding layer ( 403   b ) surrounding and shielding said core. The conductive shell comprises a base portion ( 510, 511, 520 ) shielding said housing and a soldering portion ( 521 ) integral with and behind said base portion. Each grounding layer abuts against and is soldered with said soldering portion of the shell, thereby simplifying grounding path.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention generally relates to a cable connector assembly, and more particularly, to a cable connector assembly used in high frequency signal transmission. 
   2. Description of the Prior Art 
   It is well known in the art that a grounding device is often used to reduce the crosstalk in an electrical connector, and particularly to reduce the crosstalk in an electrical connector terminating with a coaxial wire for transmitting data at a high speed. Such an electrical connector having a relevant grounding bus is disclosed in U.S. Pat. No. 4,781,620. The grounding bus has a base strip portion, and a plurality of axially rearwards extending tab-like fingers arranged in a row extending widthwise of the wire and bent to juxtaposition with the bent bared portions of the coaxial shield. The grounding bus connects the braidings of the coaxial wire with the grounding contacts of the electrical connector so as to establish a grounding path therebetween for crosstalk prevention. However, soldering the grounding bus to the braidings decreases the assembly efficiency compared with a simple mechanical engagement therebetween. Meanwhile, the grounding bus and the grounding contacts are partially insert molded, which also complicates the manufacture. 
   In U.S. Pat. No. 6,123,582, a cable connector assembly for contacting with a mating electrical connector includes a first and a second housing members, a wire with a plurality of wires, an upper and a lower shield members, and a plurality of contacts. Each wire has a central signal conductor and a grounding braiding layer around the signal conductor. The connector assembly is horizontally mated with the mating connector. A grounding bar is soldered to the grounding braiding of the wires. The upper and lower shield members attached onto the first housing member are engagingly jointed with each other and electrically contact with a shield member of the mating connector. Meanwhile, the upper shield member further forms a plurality of spring fingers extending inside the first housing member to electrically engage with the grounding bar received therein. Therefore, a grounding path from the wire to the mating connector is established. The grounding bar electrically connecting all the wires advances the capability in grounding, but it is a trouble to assemble the grounding bar on the wire. 
   U.S. Pat. No. 6,390,852 discloses a cable connector assembly including a wire set and an electrical connector. The wire set has a plurality of signal wires, a grounding wire and a shielding braid layer surrounding both the signal wires and the grounding wire. The connector has a dielectric housing with a plurality of terminals mounted therein, an upper shell and a lower shell defining a receiving space for receiving the housing therein. The upper shell comprises a rectangular panel, a collarlike strip connecting to the rectangular panel, and a pair of side panels. The lower shell includes a top plate, a bottom plate and side plates each defining a soldering tab thereon. The grounding wire is soldered to a soldering tab and the signal wires are soldered to corresponding terminals. The strip is crimped to the wire set. However, a grounding wire is required, and the juncture between the grounding wire and the soldering tab is not very reliable. 
   Hence, an improved cable connector assembly is desired to overcome the above problems and meet the increasing transmission demand. 
   BRIEF SUMMARY OF THE INVENTION 
   It is an object of the present invention to provide a cable connector assembly with simplified grounding path. 
   In order to attain the object above, a cable connector assembly used in the high frequency transmission field according to the present invention comprises an insulative housing adapted for mating with a complementary connector, a conductive terminals retained in the housing, a plurality of wires arrayed in a row along a longitudinal direction and electrically connecting the terminals, and a conductive shell. The wires comprises at least one signal wire each comprising one or more conductive cores at the innermost thereof and a grounding layer surrounding and shielding said cores. The conductive shell comprises a base portion shielding said housing and a soldering portion integral with and behind said base portion. Each grounding layer abuts against and is soldered with said soldering portion of the shell, thereby simplifying grounding path. 
   Other objects, advantages and novel features of the invention will become more apparent from the following detailed description of the present embodiment when taken in conjunction with the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The features of this invention which are believed to be novel are set forth with particularity in the appended claims. The invention, together with its objects and the advantages thereof, may be best understood by reference to the following description taken in conjunction with the accompanying drawings, in which like reference numerals identify like elements in the figures and in which: 
       FIG. 1  is an exploded, perspective view of a cable connector assembly in accordance with the present invention; 
       FIG. 2  is a view similar to  FIG. 1 , but viewed from another aspect; 
       FIG. 3  is a perspective view after assembling wires on a housing of the cable connector assembly shown in  FIG. 1 ; 
       FIG. 4  is a perspective view after soldering wires to a lower shell of the cable connector assembly shown in  FIG. 3 ; 
       FIG. 5  is an assembled view of the cable connector assembly shown in  FIG. 1 ; 
       FIG. 6  is a view similar to  FIG. 5 , but viewed from another aspect. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Reference will now be made in detail to the preferred embodiment of the present invention. 
   As shown in  FIGS. 1-2 , a cable connector assembly  100  according to the present invention comprises an insulative housing  2 , a plurality of conductive terminals  3  held in the housing  2 , a plurality of wires  4  electrically communicating with the terminals  3 , and a conductive shell  5  shrouding the housing  2 . 
   The conductive shell  5  comprises an upper shell  51  and a lower shell  52  engagable with the upper shell  51 . The upper shell  51  comprises a rectangular base portion  510 , a pair of wing portions  511  slightly lower than the base portion  510  and extending outwards from opposite lateral sides of the base portion  510 , and a pair of middle portions  512  connecting the base portion  510  and the wing portions  511 . The rear end of each wing portion  511  is wider than other parts of the wing portion  511 . A pair of first fingers  513  with several agnails (not labeled) extend downwards from the front of the wing portions  51 , and a pair of second fingers  514  with two rectangular holes  5141  defined therein extend downwards from the rear edges of the wing portions  51  to hold the shell  5  on the housing  2 . 
   The lower shell  52  comprises a rectangular base portion  520 , and a rectangular soldering portion  521  higher than the base portion  520  and extending rearwards from the base portion  520 . Two pairs of third fingers  526 ,  527  respectively extend downwards from the front and rear edges of the base portion  520 , and two pairs of fourth fingers  528  with four pair of barbs  5281  formed thereon extend downwards from opposite lateral sides of the base portion  520  to hold the lower shell  52  on the housing  2 . The soldering portion  521  is flat. 
   The insulative housing  2  comprises a rod  21  and a main portion  23  extending rearwards from the rod  21 . The housing  2  further comprises a mating surface  210  and a jointing surface  230  opposite to the mating surface  210 . A tongue plate  22  projects forwardly from the mating surface  210  for inserting into a complementary connector (not shown). An ear portion  28  protrudes outwardly from each lateral side of the main portion  23 . A receiving space  27  is defined in a rear portion of the main portion  23  and between the pair of ear portions  28  for receiving the soldering portion  521  of the lower shell  52 . A plurality of passageways are defined through the insulative housing  2  and comprises a plurality of wire-receiving passageways  26   a ,  26   b  defined in the main portion  23 , a plurality of middle passageways  25   a ,  25   b  defined through the rod  21  in communication with the wire-receiving passageways  26   a ,  26   b , and a plurality of terminal-receiving slots  24   a ,  24   b  defined in the tongue plate  22  and communicating with corresponding middle passageways  25   a ,  25   b  defined in the rod  21 . The wire-receiving passageways  26   a  are spaced from each other at a relatively large distance for receiving corresponding terminals  3  for power transmission. The wire-receiving passageways  26   b  are spaced from each other at a relatively small distance for receiving corresponding terminals  3  for signal transmission. So do the middle passageways  25   a ,  25   b  and the terminal-receiving slots  24   a ,  24   b . A front portion of each wire-receiving passageways  26   a ,  26   b  is relatively wide for receiving a portion of a corresponding terminal  3  therein. A pair of first through holes  291  and two pairs of second through holes  292  are respectively defined adjacent to opposite lateral sides of the rod  21 , and in opposite lateral sides of the ear portions  28  for engaging with the conductive shell  5 . A pair of protrusions  2301  are formed on the jointing surface  230  for engaging with the rectangular holes  5141  of the upper shell  51 . 
   Now referring to  FIGS. 1-3 , a detailed description of the terminals  3  will be provided. The terminals  3  comprise a plurality of power terminals  3   a  with large size spaced from each other at a relatively large distance for power transmission, and a plurality of signal terminals  3   b  with small size spaced from each other at a relatively small distance for signal transmission. Each terminal  3  comprises a retention portion  32 , a mating portion  31  extending forwardly from the retention portion  32  for mating with a corresponding terminal of the complementary connector, and a tail portion  33  extending rearwards from the rear side of the retention portion  32  for being soldered to a wire  4 . A plurality of barbs  320  is formed on opposite lateral sides of the retention portion  32  for engaging with a corresponding middle passageway  25   a ,  25   b  defined in the rod  21 . 
   Referring to  FIGS. 1-2  in conjunction with  FIGS. 3 and 4 , the wires  4  consist of a row of juxtaposed round wires. The wires comprise a plurality of power wires  40   a  with large size for power transmission, and a plurality of signal wires  40   b  with small size for signal transmission. Each power wire  40   a  is composed of an outer jacket  402   a  at the outmost thereof, and a conductive core  401  a at the innermost thereof. Each signal wire  40   b  is composed of an outer jacket  404   b  at the outmost thereof, a grounding layer  403   b  formed below the outer jacket  404   b , a pair of inner insulative layers  402   b  formed below the grounding layer  402   b , and a pair of conductive cores  401   b  at the innermost thereof. The grounding layer is a metal braid layer. The outer jacket  402   a  of each power wire  40   a  is stripped off at a front end thereof to expose the conductive core  401   a  as a power segment which extends into the wire-receiving passageways  26   a . The outer jacket  404   b  of each signal wire  40   b  is stripped off at a front end thereof to expose the grounding layer  403   b  as being a grounding segment of the wire  40   b . The grounding segment of each signal wire  40   b  is then respectively soldered with an inner surface of the soldering portion  521  of the lower shell  52 . Each signal wire  40   b  in part is further stripped off to expose the conductive cores  401   b  as being a signal segment which extends into the wire-receiving passageways  26   b  for electrically connecting corresponding terminals  3   b.    
   Referring to  FIGS. 3-6 , in assembly, firstly, the terminals  3  are inserted into the passageways along the back-to-front direction with the mating portions  31  received in the terminal-receiving slots  24   a ,  24   b , the retention portions  32  received in the middle passageways  25   a ,  25   b , the tail portions  33  received in the wire-receiving passageways  26   a ,  26   b . Secondly, the lower shell  52  is assembled onto the housing  2  along a vertical direction perpendicular to the back-to-front direction with the third and fourth finger  526 ,  528  being respectively received in the first and second through holes  291 ,  292  of the housing  2 . Thirdly, the wires  4  are assembled onto the housing  2 , accordingly, the conductive cores  401   a ,  401   b  extending into wire-receiving passageways  26   a ,  26   b  to be soldered with the tail portions  33  of the terminals  3 , parts of the wires  4  abutting against the soldering portion  521 , and the grounding layers  403   b  which are exposed outside standing above the soldering portion  521 . Fourthly, a tin stick  44  is placed on the exposed grounding layers  403   b  and heated. A molten stick  44  will solder the grounding layers  403   b  with the soldering portion  521  of the lower shell  52 . After the molten stick  44  freezes, it reinforces the junction between the grounding layers  403   b  and the soldering portion  521 . Finally, a Kapton tape  6  is stuck to an inner surface of the base portion  510  of the upper shell  51  in order to insulate the upper shell  51  on the housing  2  from the terminals  3  and wires  4 . The upper shell  51  is assembled onto the housing  2  with the first fingers  513  received in the first through holes  291 , and the rectangular holes  5141  of the second fingers  514  receiving the protrusions  2301  which are formed on the jointing surface  230 . 
   It is to be understood, however, that even though numerous, characteristics and advantages of the present invention have been set fourth in the foregoing description, together with details of the structure and function of the invention, the disclosed is illustrative only, and changes may be made in detail, especially in matters of number, 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.