Abstract:
An electrical connector for electrically connecting a chip module with a printed circuit board includes an upper component, a lower component assembled on the upper component and a number of terminals, the upper component includes a number of upper tabs and the lower component includes a number of lower tabs. The terminals include a number of upper terminals and a number of lower terminals matched with the upper terminals. The upper terminals received in the upper component and the lower terminals received in the lower component; wherein the pressing of the terminal can transform the vertical movement of the upper terminal to the horizontal movement of the lower terminal.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the invention 
         [0002]    The present invention relates to an electrical connector, and more particularly to an electrical connector mounted to a printed circuit board for receiving an Integrated Circuit package. 
         [0003]    2. Description of the prior art 
         [0004]    As the “Nonlinear Analysis Helps Design LGA Connectors” (Connector Specifier, February 2001) show, an electrical connector includes a base and a number of contacts assembled in the base. Each of the contacts defines an upper contacting point for contacting with a CPU and a lower contacting point for contacting with a printed circuit board, and it forms the signal transmission between the CPU and the printed circuit board. With the development of the electronic technology, the size of the electrical connector becomes smaller and smaller, but the density of the pads of the CPU and the density of the pads of the printed circuit board become larger and larger. So, the electromagnetic interference between the adjacent contacts becomes serious and it affects the quality of the signal transmission between the CPU and the printed circuit board. 
         [0005]    An electrical connector electrically connecting a chip module to a printed circuit board is described in Tai Wan Patent No. M419,248, issued to CHANG et al. on Dec. 21, 2011. The electrical connector includes a socket body with a plurality of electrical contacts secured therein. The socket body has a top surface, a low surface opposite to the top surface and a number of grooves penetrate from the top surface to the low surface. Each of the grooves includes a first groove and a second groove. The contacts secured in the first grooves respectively. The electrical connector further includes a metal shielding plate assembled in the second groove. Due to the contacts extending outwardly from the top surface and after the contacts being compressed, the space of the adjacent pads of the chip module is full filled by the contacting portion of the contacts and it affects the performance of the electrical connector, so it is not benefit to the electromagnetic shielding performance of the electrical connector. 
         [0006]    Therefore, it is needed to find a new electrical socket to overcome the problems mentioned above. 
       SUMMARY OF THE INVENTION 
       [0007]    Accordingly, an object of the present invention is to provide an electrical connector with a simple structure and can get better shielding result. 
         [0008]    In order to achieve the object set forth, an electrical connector for electrically connecting a chip module with a printed circuit board comprises an upper component, a lower component assembled on the upper component and a plurality of terminals, the upper component comprises a plurality of upper tabs and the lower component comprises a plurality of lower tabs. The terminals comprise a plurality of upper terminals and a plurality of lower terminals matched with the upper terminals. The upper terminals received in the upper component and the lower terminals received in the lower component, wherein an area that the upper tab contacts with the lower tab is plated with a metal layer. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is an isometric, assembled view of an electrical connector with a plurality of grounding elements in accordance with a preferred embodiment of the present invention; 
           [0010]      FIG. 2  is another isometric, assembled view of the electrical connector with a plurality of grounding elements as shown in  FIG. 1 ; 
           [0011]      FIG. 3  is an exploded view of the electrical connector with a plurality of grounding elements as shown in  FIG. 1 ; 
           [0012]      FIG. 4  is another exploded view of the electrical connector in  FIG. 3 ; 
           [0013]      FIG. 5  is an exploded view of the electrical connector as shown in  FIG. 1 ; 
           [0014]      FIG. 6  is another exploded view of the electrical connector as shown in  FIG. 5 ; 
           [0015]      FIG. 7  is a cross-sectional view of the electrical connector with a plurality of grounding elements taken along line  7 - 7  in  FIG. 1 ; and 
           [0016]      FIG. 8  is similar to  FIG. 7  showing the lower terminals are pressed. 
       
    
    
     DESCRIPTION OF PREFERRED EMBODIMENT 
       [0017]    Reference will now be made to the drawings to describe the present invention in detail. 
         [0018]    Referring to  FIGS. 1-4 , an electrical connector  100  according to the present invention is used for electrically connecting a chip module to a printed circuit board. The electrical connector  100  comprises an insulative housing (not labeled), a plurality of terminals received therein and a plurality of solder balls  6  used to be soldered to the printed circuit board. The insulative housing comprises an upper component  1  and a lower component  2  stacked on the upper component  1 . Each of the terminals comprises an upper terminal  3  and a lower terminal  4  matched with the upper terminal  3 . The electrical connector  100  further comprises a plurality of first solder balls  7  assembled on the chip module and a plurality of second solder balls  8  assembled on the printed circuit board. 
         [0019]    Referring to  FIGS. 3-6 , the upper component  1  is made of insulating material and comprises a first base  10 . The first base  10  comprises a top surface  11 , a bottom surface  12  opposite to the top surface  11 , a plurality of upper receiving slots  16  depressed from the bottom surface  12 , a plurality of terminal receiving passageways  17  depressed from the top surface  11 . Each of the terminal receiving passageways  17  is communicated with one upper receiving slot  16  and the first base  10  also comprises a plurality of receiving holes  18  penetrated from the top surface  11  to the bottom surface  12  and each of the receiving holes  18  is communicated with one upper receiving slot  16 . Each of the upper terminals  3  is received in one terminal receiving passageway  17  and one upper receiving slot  16  respectively. The lower terminals  4  are received in the upper receiving slots  16  respectively. The upper component  1  also comprises a plurality of upper tabs (not labeled) and each of the upper tabs comprises a first tab  13  protruding from the top surface  11 , a second tab  14  protruding from the bottom surface  12  and an upper connecting portion  15  connects the first tab  13  with the second tab  14 . An area of the upper connecting portion  15  exposed in the receiving hole  18  is plated with a metal layer  5 . The metal layer  5  extending upwardly to cover the first tab  13  partly and extending downwardly to cover the second tab  14  partly. The length of the second tab  14  is larger than that of the first tab  13  so as to match with the lower component  2 . 
         [0020]    The lower component  2  is made of insulating material and comprises a second base  20 . The second base  20  comprises an upper surface  21 , a lower surface  22  opposite to the upper surface  21  and a plurality of lower receiving slots  26  penetrated from the upper surface  21  to the lower surface  22 . The lower terminals  4  are also received in the receiving slots  26  respectively. The lower component  2  also comprises a plurality of retention slots  27  communicated with the lower receiving slots  26  respectively for securing the lower terminals  4 . The lower component  2  further comprises a plurality of lower tabs (not labeled) and each of the lower tabs comprises a third tab  23  protruding from the lower surface  22 , a fourth tab  24  protruding from the upper surface  21  and a lower connecting portion  25  connects the third tab  23  with the fourth tab  24 . An area of the lower connecting portion  25  exposed in the lower receiving slot  26  is plated with the metal layer  5 . The metal layer  5  extending downwardly to cover the third tab  23  partly and the metal layer  5  extending upwardly to cover the fourth tab  24  partly. The length of the fourth tab  24  is larger than that of the third tab  23  so as to match with the upper component  1 . 
         [0021]    Referring to  FIGS. 5-6 , each of the upper terminals  3  comprises a main body  30  and a projecting portion  31  extending downwardly and outwardly from the main body  30  to electrically connecting with the lower terminal  4 . The projection portion  31  is configured with arc shape and is about half of the cylindrical. The top of the main body  30  has a V-cut  32  to connect with the chip module stably. Each of the lower terminals  4  comprises a base portion  40 , a bending portion  41  extending upwardly and outwardly from one side of the base portion  40  and a spring beam  42  extending upwardly and outwardly from the bending portion  41 . Each of the lower terminals  4  also comprises a soldering portion  44  extending downwardly from the base portion  40  and a pair of retention portions  43  extending downwardly from two sides of the base portion  40 . The retention portion  43  is secured in the retention slot  27 . The solder balls  6  are received in the lower receiving slots  26  respectively and are fixed in the second base  20  by the soldering portion  44  and the sidewall of the lower receiving slot  26 . 
         [0022]    The first solder balls  7  are assembled on the first tabs  13  respectively and are electrically connected with the metal layer  5  plated on the first tab  13 . The second solder balls  8  are assembled on the third tabs  23  respectively and are electrically connected with the metal layer  5  plated on the third tab  23 . Thus, the electrical contacting of the metal layer  5  and the first solder balls  7 , the second solder balls  8  electrical connects the chip module, the electrical connector  100  and the printed circuit board, so as to provide a route for communicating the electromagnetic shielding and getting better shielding effect. 
         [0023]    Referring to  FIGS. 7-8 , after the electrical connector  100  is assembled, the upper component  1  is stacked on the lower component  2 , the second tab  14  is received in the lower receiving slot  26  and the fourth tab  24  is received in the receiving hole  18 . An area that the upper tab contacts with the lower tab is plated with the metal layer  5 . The upper tab and the lower tab are wedge-shape that have been reversed. The second tab  14  and the upper connecting portion  15  contact with the fourth tab  24  and the lower connecting portion  25 , the contacting area is plated with the metal layer  5 . The upper terminal  3  is received in the terminal receiving passageway  17  and it can moves up and down in the terminal receiving passageway  17  and the upper receiving slot  16 . The terminal receiving passageway  17  has a receiving portion  19  that receives the projecting portion  31 . The lower terminal  4  is fixed in the retention slot  27 , the spring beam  42  is received in the upper receiving slots  16  and it can moves in the upper receiving slots  16 . 
         [0024]    After the chip module is assembled to the electrical connector  100 , the upper terminal  3  moves downwardly due to the pressing of the chip module and then the projecting portion  31  slides along the spring beam  42 . So, the projecting portion  31  presses the spring beam  42  to make it move downwardly and horizontally. The projecting portion  31  presses the spring beam  42  moving downwardly and also pushes the spring beam  42  of the lower terminal  4  moving in horizontal. Referring to  FIG. 8 , the upper terminal  3  contacts the lower terminal  4  while the upper terminal  3  has being pressed to a limit state. The projecting portion  31  can prevent the upper terminal  3  being come off from the upper component  1  after the electrical connector has been assembled. 
         [0025]    Although the present invention has been described with reference to particular embodiments, it is not to be construed as being limited thereto. Various alterations and modifications can be made to the embodiments without in any way departing from the scope or spirit of the present invention as defined in the appended claims.