Patent Publication Number: US-2010130030-A1

Title: Ic socket having an improved locking arrangement and method of making the same

Description:
FIELD OF THE INVENTION 
     The present invention relates to an IC socket, and more particularly to IC socket having an improved locking arrangement capable of simplifying the process of mounting the IC socket to a printed circuit board (PCB). 
     DESCRIPTION OF PRIOR ART 
     IC sockets are widely used in the computer field to interconnect two separate electronic components, i.e. an IC package and a motherboard, so as to establish electrical connection therebetween. U.S. Pat. No. 7,404,728 issued to Ma on Jul. 29, 2008 discloses an IC socket that includes an insulative housing, a plurality of contacts received in the housing, a stiffener plate surrounding the housing and a load plate pivotally coupled to the stiffener plate for loading an IC package into the housing. The stiffener plate is fixed to a PCB by four screws respectively located at four corners thereof. The screws are separate from the stiffener plate before the socket is mounted to the PCB. When the socket is mounted to the PCB, the stiffener plate is firstly disposed to a predetermined position on the PCB, and then the screws are inserted into corresponding mounting holes of the stiffener plate and the PCB so as to stably fix the stiffener plate on the PCB. However, such an assembling process is complicated and thereby decreases efficiency of mounting the socket to PCB. 
     Thus, there is a need to provide a new IC socket that overcomes the above-mentioned problems. 
     SUMMARY OF THE INVENTION 
     It is therefore the object of the present invention to provide an IC socket having an improved locking arrangement that is inseparably combined into a stiffener plate of the IC socket. 
     In accordance with the present invention, an IC socket mounted on a printed circuit board for receiving an IC package includes a socket body, a plurality of contacts received in the socket body, a stiffener plate surrounding the socket body, and a locking arrangement securing the stiffener plate to the printed circuit board. The locking arrangement includes a ferrule fixed on the stiffener plate and a screw and a screw disposed within the ferrule before the stiffener plated mounted onto the printed circuit board. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other objects, advantages and novel features of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  is an assembled, perspective view of an IC socket in accordance with a preferred embodiment of the present invention mounted on a printed circuit board, and an IC package is received in the IC socket; 
         FIG. 2  is an exploded, perspective view of  FIG. 1 ; 
         FIG. 3  is an exploded, perspective view of a locking arrangement of the IC socket in accordance with the preferred embodiment of the present invention; 
         FIG. 4  is a perspective view of a ferrule of the IC socket in accordance with the preferred embodiment of the present invention; 
         FIG. 5  is a perspective view of a stiffener plate of the IC socket in accordance with the preferred embodiment of the present invention, wherein the locking arrangement is combined with the stiffener plate; and 
         FIG. 6  is a cross-sectional view of the socket fixed on the printed circuit board by the locking arrangement. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENT 
     Referring to  FIG. 1  and  FIG. 2 , an IC socket  1  made in accordance with a preferred embodiment of the present invention is mounted on a printed circuit board  9  for receiving an IC package  10 . The IC socket  1  includes a socket body  2 , a plurality of contact  3  received in the socket body  2 , a stiffener plate  4  surrounding the socket body  2 , and a load plate  5  and a load lever  6  pivotally coupled to opposite ends of the stiffener plate  4 . The load plate  5  is able to load the IC package  10  into the socket body  2  to make electrical connection with the contacts  3 . The load lever  6  locks the load plate  5  into a closed position. In an alternative embodiment, the IC package  10  should be directly secured into the socket body  2  by a heat sink (not shown) without employing the load plate  5  and the load lever  6 . 
     Referring to  FIG. 2  to  FIG. 6 , the stiffener plate  4  is made of metal with a frame structure, and surrounds the socket body  2  to reinforce the socket body  2 . There are four mounting holes  40  respectively located at each corner of the stiffener plate  4  to combine a locking arrangement  7  which is used for fixing the stiffener plate  4  onto the printed circuit board  9 . A gasket  8  is positioned under the mounting hole  40  and upwardly bended to clip the stiffener plate  4 . The locking arrangement  7  includes a ferrule  70  riveted within the mounting hole  40  and a screw  71  inseparably mounted within the ferrule  70 . The ferrule  70  includes a through hole  700  and a cavity  701  above the through hole  700  and communicating with the through hole  700 . The cavity  701  has a bigger diameter than that of the through hole  700 . A guiding portion  702  and a riveting portion  703  are formed at a tip end of the ferrule  70 , and jointly define a containing groove  704  therebetween. The guiding portion  702  has a smaller diameter than that of the mounting hole  40  of the stiffener plate  4  so as to provide guidance for inserting the ferrule  70  into the mounting hole  40 . The riveting portion  703  interferes tightly with the mounting hole  40  to fix the ferrule  70  onto the stiffener plate  4 . The containing groove  704  could be used for receiving metal scrap detached from the riveting portion  703  during the riveting process. The screw  71  includes a cylindrical neck portion  710 , a head portion  711  above the neck portion and a locking portion  712  under the neck portion  710 . Then the neck portion  712  is formed with screw thread thereon after it passes through the through hole  700 , and the formed neck portion  712  has a bigger diameter than that of the through hole  700  so that the screw  71  can not escape away from the ferrule  70 . 
     When the locking arrangement  7  is assembled to the stiffener plate  4 , the screw  71  is firstly combined into the ferrule  70 , and then the ferrule  70  is riveted within the mounting hole  40  and thereby immovably fixed on stiffener plate  4 . The ferrule  70  also works as a constraining means for the screw  71 , whereby the screw  71  is able to achieve a better assembling performance. Due to the combination therebetween, the locking arrangement  7  and the stiffener plate  4  could be simultaneously shipped and then mounted onto the printed circuit board  9 , and thus the mounting efficiency is improved. The locking portion  712  of the screw  71  is finally locked into a back plate  11  under the printed circuit board  9 . In addition, a dielectric plate  12  is provided between the printed circuit board  9  and the back plate  12 . 
     Alternatively, in another preferred embodiment, the ferrule of the present invention should be combined with the stiffener plate via soldering means or other means instead of the riveting method. 
     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.