Abstract:
A LGA connector ( 100 ) adapted for being mounted to a printed circuit board, includes a housing ( 30 ), a number of contacts mounted in the housing, a stiffener ( 50 ) coupled with the housing and defining a number of non-circular mounting holes ( 502 ), a lever ( 70 ) and a cover ( 60 ) respectively mounted on the stiffener, and a number of standoffs ( 90 ) inserted into the mounting holes of the stiffener. Each mounting hole has a long diameter and a short diameter. Each standoff defines a pinhole ( 910 ) for permitting a screw including a screw cap having a diameter larger than the short diameter of the mounting hole to insert through the pinhole.

Description:
1. FIELD OF THE INVENTION 
       [0001]    The present invention relates to an electrical connector, and particularly to a land grid array (LGA) connector for electrically connecting an electronic package such as an IC package and a circuit substrate such as a printed circuit board (PCB). 
       2. DESCRIPTION OF RELATED ART 
       [0002]    A land grid array connector electrically connecting an IC package to a PCB is described in U.S. Patent Publication No. 2007/0020963, which was published on Jan. 25, 2007. The connector comprises a stiffener having a front wall and a rear wall, a housing received within the stiffener for supporting the IC package, a plurality of contacts retained within the housing, a cover and a lever respectively rotatably mounted on the rear wall and the front wall of the stiffener. The stiffener has a plurality of circular mounting holes defined at four corner portions thereof. A plurality of screws insert throughout the circular mounting holes for fixing the connector onto the PCB. 
         [0003]    Only the screw whose screw cap has the diameter larger than that of the circular mounting hole could be applied in the connector. The type of available screws is thereby limited. 
         [0004]    Hence, an improved land grid array connector is required to overcome the above-mentioned disadvantages of the related art. 
       SUMMARY OF THE INVENTION 
       [0005]    An object of the present invention is to provide a land grid array connector, wherein more types of screws could be applied to mount the connector to a PCB. 
         [0006]    To achieve the aforementioned objects, a LGA connector adapted for being mounted to a PCB comprises a housing defining a plurality of slots, a plurality of contacts mounted in the slots of the housing, a stiffener coupled with the housing and defining a first window surrounding the housing and a plurality of non-circular mounting holes, a lever and a cover respectively mounted at a front and a rear portion of the stiffener, and a plurality of standoffs inserted into the mounting holes of the stiffener. Each mounting hole has a long diameter and a short diameter. Each standoff defines a pinhole for permitting a screw having a screw cap having a diameter larger than the short diameter of the mounting hole to insert through the pinhole. 
         [0007]    In the conventional art, only the screws whose screw cap having a diameter larger than the conventional circular mounting hole could be used. In this application, the mounting hole is designed non-circular and has a short diameter shorter than the long diameter, which is equal to that of the conventional circular mounting hole. Therefore, the screws whose screw cap has the diameter larger than the short diameter, but not the long diameter, could be applied in this application. The type of screws adapted for being used is increased. 
         [0008]    Other objects, advantages and novel features of the invention will become more apparent from the following detailed description of a preferred embodiment when taken in conjunction with the accompanying drawings. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is an assembled perspective view of a LGA connector in accordance with the present invention; 
           [0010]      FIG. 2  is an exploded perspective view of the LGA connector as shown in  FIG. 1 ; 
           [0011]      FIG. 3  is a partially assembled perspective view of the LGA connector as shown in  FIG. 1 , with the lever and the cover being removed; and 
           [0012]      FIG. 4  is a partially assembled perspective view similar to  FIG. 3 , with a standoff being removed. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0013]    Reference will now be made to the drawing figures to describe the present invention in detail. Referring to  FIGS. 1-4 , a LGA connector  100  in accordance with the preferred embodiment of the present invention is adapted for electrically connecting an IC package (not shown) and a PCB (not shown). The LGA connector  100  comprises a housing  30 , a plurality of contacts (not shown) inserted within the housing  30 , a stiffener  50  defining a first window  503  for surrounding the housing  30 , a cover  60  and a lever  70  respectively rotatably mounted on the stiffener  50 , a ring  80 , and a plurality of standoffs  90  mounted on the stiffener  50 . The LGA connector  100  is mounted onto the PCB via a plurality of screws (not shown). 
         [0014]    Referring to  FIG. 2 , the housing  30  is of a rectangular configuration and comprises a conductive region  304  having a supporting wall  305 , a mounting wall  306  opposite to the supporting wall  305  for being mounted on the PCB, a plurality of periphery walls  308  surrounding the conductive region  304 , and a plurality of slots  307  defined in the conductive region  304  for receiving the contacts. 
         [0015]    The stiffener  50  comprises a primary portion  501 , a rectangular first window  503  defined in a center of the primary portion  501 , a plurality of non-circular mounting holes  502  defined at four corner portions of the primary portion  501 , a depression  513  defined at a front portion of the primary portion  501 , a front wall  508  and a rear wall  504  respectively upstanding from front and rear edges of the primary portion  501 . A pair of opposite side edges of the primary portion  501  has a pair of blocking portions  506  upstanding from front portions thereof, and a pair of supporting portions  512  extending forwardly from front ends thereof. One side edge of the primary portion  501  has a latch  507  extending outwardly from a rear portion thereof. The front wall  508  has a pair of substantially L-shaped engaging portions  510  each defining an engaging slot  511 . The rear wall  504  has a pair of engaging holes  509  defined thereon. 
         [0016]    In conjunction with  FIG. 4 , in this embodiment, the mounting hole  502  is shaped by interconnecting a pair of symmetrical arc-like edges  5021  and a pair of opposite parallel edges  5022 . Such a mounting hole  502  has a long diameter between the two arc-like edges  5021 , and a short diameter between the two parallel edges  5022  shorter than the long diameter. Optionally, the mounting hole  502  could be punched into ellipse or other shapes, if only having two different diameters. 
         [0017]    The cover  60  comprises a primary plate  601  having a second window  607  defined therein, a pivotal portion  602 , a tongue portion  606  opposite to the pivotal portion  602 , and a pair of side portions  604  surrounding the second window  607 . The pivotal portion  602  has a pair of hooks  603  projecting rearwardly therefrom and a rearwardly extending tail portion  605  formed between the pair of hooks  603 . The tongue portion  606  is provided with a depressing portion  610  inclining downwardly and then tilting upwardly and adapted for being depressed by the lever  70 . Each side portion  604  has a side wall  608  extending downwardly therefrom. 
         [0018]    The lever  70  comprises a shaft  702  and an actuator  704  perpendicular to the shaft  702  to thereby form the lever as a L-shape. The shaft  702  has an U-shaped bending portion  706  bending inwardly from a middle portion thereof. The actuator  704  is provided with a handle  708  at a free end thereof. 
         [0019]    Referring to  FIG. 4 , each standoff  90  comprises a circular base portion  91  defining a pinhole  910 , a plurality of teeth  921  extending upwardly from the base portion  91 . The standoff  90  is punched by leaving out some teeth along the diameter direction of the pinhole  910 , to thereby form a pair of indentations  922  symmetrically defined between adjacent teeth  921 . 
         [0020]    Referring to  FIGS. 1-4 , in assembly of the LGA connector  100 , the plurality of contacts are pre-loaded within the housing  30 . The housing  30  together with the contacts is then mounted within the first window  503  of the stiffener  50 . The cover  60  and the lever  70  are respectively assembled to the rear wall  504  and the front wall  508  of the stiffener  50 . The hooks  603  of cover  60  are inserted in the engaging holes  509  to make the cover  60  pivotable around the rear wall  504 . The tail portion  605  is disposed above the rear wall  504  for preventing an excessive rotation of the cover  60 . 
         [0021]    The shaft  702  of the lever  70  is inserted in the engaging slots  511  and is upheld by the supporting portions  512 , with the bending portion  706  depressing the depressing portion  610  of the cover  60 . The ring  80  is assembled to a free end of the shaft  702  of the lever  70  and resists against one supporting portion  512 . The insertion portions  92  of the standoffs  90  are inserted in the mounting holes  502  in a bottom-to-top direction. The teeth  921  of the standoff  90  couple with the arc-like edges  5021 . A plurality of screws insert throughout the pinholes  910  of the standoffs  90  for mounting the LGA connector  100  to the PCB. 
         [0022]    In operation, the actuator  704  of the lever  70  is rotated upwardly to an open position due to an external force exerted on the handle  708 . The depressing portion  610  of the cover  60  is released by the bending portion  706  and the cover  60  is rotated to the open position. The IC package is mounted on the supporting wall  305  of the housing  30  and would be electrically connected to the PCB via the contacts. The cover  60  is rotated to a horizontal closed position, with the side walls  608  thereof resisting against the blocking portions  506  of the stiffener  50 . The actuator  704  is driven to the horizontal closed position by the handle  708  and the bending portion  706  depresses the depressing portion  610  into the depression  513 . The actuator  704  engages with latch  507  to keep itself together with the cover  60  in the horizontal closed position. 
         [0023]    The conventional mounting hole is designed circular. Thus, only the screws whose screw cap has the diameter longer than the diameter of the conventional circular mounting hole could be used. The mounting hole  502  in this application is designed to reduce a distance between a certain part of opposite edges of conventional mounting hole. The mounting hole  502  in this application thereby has a long diameter equal to that of the conventional mounting hole, and a short diameter shorter than the long diameter. Therefore, the screws whose screw cap has the diameter larger than the short diameter could be applied in this application. More type of screws could be used. 
         [0024]    However, the disclosure is illustrative only, changes may be made in detail, especially in matter of shape, size, and arrangement of parts within the principles of the invention. For example, in this embodiment in a top view there are two teeth and two regions of the stiffener, i.e., two plus two, alternately arranged around the mounting hole so as to form a capsular configuration thereof. Understandably, arrangement of four plus four or six plus six or even more may be used in the instant invention.