Abstract:
A socket connector ( 100 ) for electrically connecting a central process unit (CPU) to a printed circuit board includes a housing ( 1 ), and a number of electrical contacts ( 2 ) received in the housing. The housing, being of a frame defining an opening, is constructed by joining pieces of separate housing-plates ( 1   a,    1   b,    1   c,    1   d ) end by end. Each housing-plate defines a number of channels ( 105 ) therethrough. The electrical contacts are respectively received in the channels, and each has a contact beam ( 21 ) projecting out to electrically connect with the CPU.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to a socket connector for electrically connecting a central process unit (CPU) to a printed circuit board (PCB).  
         [0003]     2. Description of Related Art  
         [0004]     Socket connectors for mounting CPUs on a PCB are well known. The socket connector may be mounted to the PCB, while the CPU is snap-fitted into the socket connector. One advantage of this arrangement is that, unlike CPUs that are soldered directly on the PCB, a CPU that is mounted in a socket connector can be easily disconnected from the PCB for testing and replacement. However, the relatively dense layout and small size of electrical contacts on some CPUs necessitates precise alignment both between the socket connector and the PCB, and between the CPU and the socket connector.  
         [0005]     In general, a socket connector includes an insulative housing and a plurality of electrical contacts received in the insulative housing. For example, U.S. Pat. Nos. 6,196,849 and 6,786,738 disclose such a socket connector comprising a housing defining an array of holes therethrough corresponding to an array of contacts of the CPU, and a plurality of electrical contacts received in the holes. The housing that is molded from an insulative material is of a single-piece structure. However, as the housing is a thin, flat plate, after it is molded, during the cooling course, it will be warped. Thus the holes in the housing will be shoved or skewed. As a result, the electrical contacts cannot be placed in the holes correctly. Or even through the electrical contacts are placed into the holes, precise alignment between the CPU and the socket connector cannot be ensured. That causes electrical connection between the CPU and the PCB to become unreliable.  
         [0006]     Thereby, an improved socket connector is required to overcome the disadvantages of the prior art.  
       SUMMARY OF THE INVENTION  
       [0007]     An object of the present invention is to provide a socket connector which has reliable structure and can perform securely electrical connection between a central process unit (CPU) and a printed circuit board (PCB).  
         [0008]     In order to achieve above-mentioned objects, a socket connector in accordance with a preferred embodiment of the present invention includes a housing, and a number of electrical contacts received in the housing. The housing, being of a frame defining an opening, is constructed by joining pieces of separate housing-plates end by end. Each housing-plate defines a number of channels therethrough. The electrical contacts are respectively received in the channels, and each has a contact beam projecting out to electrically connect with the CPU.  
         [0009]     Other objects, advantages and novel features of the present 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  
       [0010]      FIG. 1  is a simplified, exploded, perspective view of a socket connector in accordance with the preferred embodiment of the present invention;  
         [0011]      FIG. 2  is an inverted perspective view of  FIG. 1 , but springs and electrical contacts are removed;  
         [0012]      FIG. 3  is a partly assembled view showing housing-plates of  FIG. 1  assembled to form a housing;  
         [0013]      FIG. 4  is view showing the socket connector of  FIG. 1  after assembled, and a pick up cap to be assembled to the socket connector; and  
         [0014]      FIG. 5  is an assembled view of  FIG. 4 , showing the pick up cap being assembled on the socket connector. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0015]     Reference will now be made to the drawing figures to describe the present invention in detail.  
         [0016]     Referring to  FIG. 1 , a socket connector  100  in accordance with the preferred embodiment of the present invention comprises a housing  1 , a plurality of electrical contacts  2  to be received in the housing  1 , a cover  3  for closing the electrical contacts  2 , and springs  4  for linking the cover  3  and the housing  1 .  
         [0017]     The housing  1  comprises four pieces of separate housing-plates  1   a ,  1   b ,  1   c ,  1   d . As each piece of housing-plate  1   a ,  1   b ,  1   c ,  1   d  is much smaller than a single-piece housing, it will suffer a littler warp during the cooling course after it is molded. Therefore flatness and reliability of the housing  1  can be controlled more easily. As the four housing-plates  1   a ,  1   b ,  1   c ,  1   d  are of the same structure, we will refer to the housing-plate  1   c  to be typical of all the housing-plates  1   a ,  1   b ,  1   c ,  1   d  to describe their structure. Each housing-plate is longitudinal and comprises a first end  11 , a second end  12 , and a middle portion  10 . The two ends  11  and  12  are both thinner than the middle portion  10 ,wherein the first end  11  has an under surface upper than that of the middle portion  10  and the second end  12  has an upper surface lower than that of the middle portion  10 . The first end  11  defines a binding hole  112  and a first aligning hole  111 . The second end  12  has a binding tab  122  and a second aligning hole  121 .  
         [0018]     Referring to  FIGS. 1 and 3 , the four pieces of housing-plates  1   a ,  1   b ,  1   c ,  1   d  are joined end by end. Now, a process how to join the housing-plate  1   a  with other two housing-plates will be described as an example. The housing-plates  1   a  and  1   b  are disposed in a position that they are perpendicular to each other. Then the first end  11   a  of the housing-plate  1   a  is overlapped onto the second end  12   b  of the housing-plate  1   b , together to make up a thickness proximate to that of the middle portion  10 , while the first aligning hole  111   a  aligning with second aligning hole  121   b  to form a unitary hole  14 , and the binding tab  122   b  being received in the binding hole  112   a  to bind the two plates  1   a ,  1   b . As the binding tab  122   b  has a diameter slightly larger than that of the binding hole  112   a , the two plate  1   a ,  1   b  are toughly assembled together after the binding tab  122   b  is forced into the binding hole  112   a . Alike, the housing-plates  1   a  and  1   d  are joined in a similar way, that the second end  12   a  of the housing-plate  1   a  is overlapped to the first end  12   d  of the housing-plate  1   d  with the second aligning hole  121   a  aligning with the first aligning hole  111   d  and the binding tab  122   a  received within the binding hole  112   d.    
         [0019]     The middle portion  10  of each housing-plate defines a plurality of channels  105  (only partially shown) therethrough for receiving the electrical contacts  2 . Each electrical contact  2  has a contact beam  21  to project out of the housing  1  to electrically connect with a central process unit (CPU) (not shown), as shown in  FIG. 3 .  
         [0020]     At the middle portion  10  adjacent to the two ends  11  and  12  respectively, there are a rim  104  protruding from outer edges thereof, a pair of spring receiving holes  102  for accommodating one ends of the springs  4 , and a recess  103  between the spring receiving holes  102 . Additionally, an ear  101  projects outwardly from a longitudinal middle of the middle portion  10 . The ear  101  defines a slot therethrough. Corresponding to the four pieces of housing-plates  1   a ,  1   b ,  1   c ,  1   d , the cover  3  comprises four pieces of cover-plates  3   a ,  3   b ,  3   c ,  3   d . As shown in  FIG. 2 , each cover-plate has a pair of middle legs  32  and a pair of end legs  33  at each end thereof to be respectively inserted into the slot of the ear  101  and recess  103  in housing-plate, and defines second spring receiving holes  34  for accommodating the other ends of the springs  4 . Then the cover-plates are assembled to corresponding housing-plate to cover the middle portion  10 .  
         [0021]     The assembled view of the socket connector  100  is shown in  FIG. 4 . The cover-plates are enabled to float up and down relative to the housing-plates via the springs  4  and define a plurality of parallel slots  31  therethrough for the contact beams  21  (shown in  FIG. 3 ) to pass through while the cover-plates floating down. The slots  31  are defined along a breadth direction perpendicular to the longitudinal direction of corresponding housing-plate, each slot  31  corresponding to an array of contact beams  21  along the breadth direction. Thus, when the CPU is assembled on the socket connector  100 , the cover  3  is pressed to float down and the contact beams  21  project out of the cover  3  through the slot  31  to electrically connect the CPU, wherein the CPU is restricted in a flange formed by the rims  104  against unexpected displacement. But before the socket connector  100  is loaded, for example, during carrying or transmitting of the socket connector  100 , the cover  3  is supported by the springs  4  in a position closing the contact beams  21  to prevent them from accidental damage.  
         [0022]     Moreover,  FIG. 4  shows a pick up cap  5  to be assembled to the socket connector  100 . The pick up cap  5  comprises a flat plate  51  defining a circle of through holes  52  therein, and four retention posts  53  respectively extending down from four corners of the flat plate  51  to be received in the unitary hole  14  of the housing  1  to retain the pick up cap  5  to the socket connector  100 .  FIG. 5  shows the pick up cap  5  being assembled to the socket connector  100 . During transmitting of the socket connector  100 , the pick up cap can be catch up by a cupula. Thus, in virtue of the pick up cap  5 , the socket connector  100  can be picked up conveniently.  
         [0023]     The disclosure is illustrative only, changes may made in detail, especially in matter of shape, size, and arrangement of parts within the principles of the invention.