Abstract:
A conductive contact ( 1 ) used for an electrical connector comprises a vertical base portion ( 10 ) defining a front surface ( 103 ) and a rear surface ( 101 ) opposite to each other in a thickness direction, the base portion ( 10 ) having at least one fastening slot ( 102 ) on the rear surface ( 101 ) thereof for securing the conductive contact ( 1 ) in an insulative housing of the electrical connector ( 100 ), a tail portion ( 12 ) located below said base portion ( 10 ) for mounting to a printed circuit board, an extension ( 13 ) located above said base portion ( 10 ), and a pair of arm portions ( 11 ) extending slantingly from opposite edges of the extension ( 13 ) in an upward direction.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention The present invention relates to a Zero Insertion Force (ZIF) socket type electrical connector, and particularly to an electrical connector having a plurality of reliable conductive contacts for electrically connecting an electronic package, such as a central processing unit (CPU), with a circuit substrate, such as a printed circuit board (PCB). The conductive contact defines at least one fastening slots on a rear surface thereof for firmly securing the conductive contact to a base of the electrical connector and reducing stress between the conductive contact and the base. 
         [0002]    2. Description of the Prior Art 
         [0003]    Zero Insertion Force (ZIF) socket type electrical connectors have been widely used in connecting electronic devices, such as a central processing unit (CPU) package to a printed circuit board. 
         [0004]    A conventional Zero Insertion Force (ZIF) electrical connector generally comprises a base, a cover assembled on the base and a plurality of electrical terminals received in the base. The base defines a number of passageways for receiving the electrical terminals. Each electrical terminal defines a base portion, a pair of touching pads extending from two sides of the base portion for contacting with a corresponding pin of the central processing unit (CPU) package, and a soldering pad extending from a bottom end of the base portion and being opposite to the touching pad. When the central processing unit (CPU) package is mounted on the Zero Insertion Force (ZIF) electrical connector and is pressed, each pin contacts the corresponding pair of touching pads of the electrical terminal. Accordingly, the central processing unit (CPU) package is electrically connected to the printed circuit board (PCB). 
         [0005]    Furthermore, U.S. Pat. No. 6,908,328, issued to Lei on Jun. 21, 2005 discloses a connector for electrically connecting a central processing unit (CPU) with a print circuit board (PCB). The connector includes an insulative housing, a plurality of passageways defined in the housing, and a plurality of conductive contacts secured in corresponding passageways. Each passageway includes a fastening recess. Each contact includes a soldering portion for being soldered to the PCB, a pair of contact portions for engaging with the CPU, and a body portion interconnecting the soldering portion and the contact portions. Two pairs of engaging portions are formed on opposite lateral edges of the body portion respectively. Each engaging portion includes an upper fixing part and a lower tapered guiding part. When the contact is finally fixed in its corresponding passageway, two opposite faces of the fixing parts interferentially press and engage with the fastening recess of corresponding side walls of the insulative housing. Thus the contact is secured in the passageway of the insulative housing. 
         [0006]    Generally, the contact is secured in the passage of the insulative housing by the engaging portions defined on opposite lateral edges of the body portion engaging with the side wall of the passage. Unfortunately, there will be a large interference force on the insulative housing in a transverse direction. And thus, there is a possibility that the insulative housing is likely to produce a warp in the transversal direction. In the worst scenario, the whole connector will be malfunctioned and has a poor electrical connection. 
         [0007]    In view of the above, a new electrical connector that overcomes the above-mentioned disadvantages is desired. 
       SUMMARY OF THE INVENTION 
       [0008]    Accordingly, an object of the present invention is to provide an electrical connector that has a plurality of conductive contacts reliably and electrically connecting an electronic package such as a central processing unit (CPU) with a circuit substrate such as a printed circuit board (PCB). 
         [0009]    Another object of the present invention is to provide a conductive contact can be firmly secured in a base of the electrical connector. In addition, the fixing force stressing on the base can be balanced and reduced the warp of the base of the electrical connector can be properly eliminated and softened. 
         [0010]    To fulfill the above-mentioned objects, an improved electrical connector is provided to resolve the disadvantages described above. The electrical connector made in accordance with the present invention for electrically connecting a central processing unit with a printed circuit board, comprises a base assembled with a plurality of conductive contacts, a cover movably mounted on the base, an actuator received between the base and the cover. The base defines a plurality of passageways therein for receiving the correspondingly conductive contacts. The actuator can move between an open position and a closed position. Each conductive contact comprises a base portion, a tail portion located below said base portion for mounting to a printed circuit board, an extension located above said base portion and a pair of arm portions. The vertical base portion defines a front surface and a rear surface opposite to each other in a thickness direction. The base defines at least one fastening slots on the rear surface thereof for firmly securing the conductive contact to the base of the electrical connector and reducing stress between the conductive contact and the base. The pair of arm portions extends slantingly from opposite edges of the extension in an upward direction. 
         [0011]    Other objects, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings, in which: 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  is an isometric view of a conductive contact in accordance with the preferred embodiment of the present invention; 
           [0013]      FIG. 2  is a side view of the conductive contact shown in  FIG. 1 ; 
           [0014]      FIG. 3  is an exploded, isometric view of an electrical connector with the conductive contact in accordance with the preferred embodiment of the present invention; 
           [0015]      FIG. 4  is an assembled, isometric view of the electrical connector shown in  FIG. 3 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0016]    Reference will now be made to the drawings to describe the present invention in detail. 
         [0017]    Referring to  FIGS. 1-4 , an electrical connector  100  in accordance with a preferred embodiment of the present invention is used for electrically connecting an electronic package such as a central processing unit (CPU) (not shown), with a circuit substrate such as a printed circuit board (PCB) (not shown). The electrical connector  100  comprises a base  2  assembled with a plurality of conductive contacts  1 , a cover  3  and an actuator  4 . The base  2  defines a multiplicity of passageways  22  for receiving correspondingly conductive contacts  1  therein. The cover  3  can be movably mounted on the base  2 . The actuator  4  is received between the base  2  and the cover  3  and used to actuate the cover  3  to move on the base  2  from an open position to a closed position. 
         [0018]    Referring to  FIG. 3 , the base  2  includes a head portion  20  for receiving the actuator  4  and a receiving portion  21  adjacent to the head portion  20 . The head portion  20  is higher than the receiving portion  21  and defines a slot  201  for receiving the actuator  4 . The receiving portion  21  defines a multiplicity of the passageways  22  there through, for receiving a corresponding number of the conductive contacts  1  therein. 
         [0019]    Referring to  FIG. 3 , the cover  3  is formed from a dielectric material by insert molding. The cover  3  includes a projecting portion  30  defining a groove  301  corresponding to the slot  201  of the head portion  20  of the base  2  and a supporting portion  31  corresponding to the receiving portion  21  of the base  2  for supporting the CPU (not shown). The supporting portion  31  defines a plurality of through holes  32  corresponding to the passageways  22  of the base  2  for insertion of the pins (not shown) of the CPU (not shown). A top surface  35  of the supporting portion  31  defines some protrusions  33  for supporting the CPU (not shown). A pair of sidewalls  34  extending downwardly from the supporting portion  31  for latching on the base  2 . 
         [0020]    Referring to  FIGS. 3-4 , the actuator  4  in the preferred embodiment is a lever. The actuator  4  comprises a loading lever  41  received between the slot  201  defined on the base  2  and the groove  301  defined on the cover  3 , and a handle  43  extending perpendicularly from an end of the loading lever  41 . The actuator  4  could be in any other forms, as is known to one of ordinary skill in the pertinent art, used in all kinds of ZIF socket connectors, for example a cam extending in corners of the base and the cover, on the only condition that it can be manipulated to move the cover with respect to the base in use. 
         [0021]    Each conductive contact  1  is made by stamping a metal plate and followed by subsequent forming operations. The conductive contact  1  comprises a base portion  10 , an extension  13  is formed on an upper end of the base portion  10 , and a pair of arm portions  11  extending slantingly from opposite edges of the extension  13  in an upward direction, and a tail portion  12  extending from a lower end of the base portion  10 . 
         [0022]    The base portion  10  defines a front surface  103  and a rear surface  101  opposite to each other in a thickness direction. The rear surface  101  of the base portion  10  is faced to an inner surface of the passageway  22  when the conductive contact  1  is assembled in the base  2 . Two fastening slots  102  are defined on the rear surface  101  for engaging with the inner sidewall (not labeled) of the passageway  22  to secure the conductive contact  1  in the base  2 . The two fastening slots  102  are approximately in a parallel in an up and down direction. Each fastening slot  102  is a triangle flume in a side view. When the conductive contact  1  is assembled in the passageway  22  of the base  2 , the base portion  10  interferes with the inner sidewall (not labeled) of the passageway  22 . At this time, part of the inner sidewall (not labeled) of the passageway  22  having a distortion is received in the fastening slots  102 , and the rear surface  101  of the base portion  10  snugly engages with the inner sidewall (not labeled) of the passageway  22 . And thus the conductive contact  1  is firmly and reliably secured in the passageway  22  of the base  2 . 
         [0023]    The fastening slots  102  on the rear surface  101  of the base portion  10  can engage with the passageway  22  when the conductive contact  1  is inserted into the base  2 . The fastening slots  102  can provide a fixing force not only in a vertical direction but also in a horizontal direction. Thus the fastening slots  102  provide a reliable fixing function, and the conductive contact  1  is firmly secured in the passageway  22  of the base  2 . At the same time, it could avoid the warp of the base  2  because the force stressing on the base  2  is balanceable. 
         [0024]    Each arm portion  11  has a contacting portion  112  at a top end of thereof and a distal portion  111  extending from the contacting portion  112  for electrical connecting with a pin (not shown) of the CPU (not shown). The contacting portions  112  are spaced from each other and are arranged to converge toward each other whereby a distance between the contacting portions  112  is reduced to a minimum gap  113  between the distal portions  111 . The convergent configuration of the contacting portions  112  functions to lead the pin (not shown) of the CPU (not shown) into the gap  113  between the distal portions  111 . The angularly offset arm portions  11  allows flexibility in setting and adjusting performance parameters of the conductive contact  1 , such as the gap  113  between the distal portion  111  and the spring rate of the arm portions  11  and the contacting portions  112  experienced by the pins (not shown) of the CPU (not shown). 
         [0025]    The tail portion  12  comprises a solder pad  121  connected to the lower end of the base portion  10  by a neck portion  122 . The neck portion  122  is bent an angle of approximately 90 degrees. The solder pad  121  can carry a solder ball (not shown) for connecting the conductive contact  1  to the printed circuit board PCB (not shown) by Surface Mount Technology (SMT). However, that is well known and no further description is necessary herein. 
         [0026]    When the electrical connector  100  at an opening position, the CPU (not shown) is initially disposed on the cover  3  and the pins (not shown) of the CPU (not shown) extend through the through holes  32  of the cover  3  into the passageways  22  of the base  2  without electrically contacting with the electrical contacts  1 . When the electrical connector  100  at a closed position, the pins (not shown) of the CPU (not shown) received in the gap (not labeled) between the distal portions  111  and engaging with the distal portions  111  of the conductive contact  1 . Thus it realizes a reliable electrical connection between the CPU (not shown) and a print circuit board (PCB). 
         [0027]    The conductive contact  1  defines a pair of fastening slots  102  on the rear surface  101  of the base portion  10  at a thickness direction for engaging with the inner sidewall (not labeled) of the passageway  22  when the conductive contact  1  is inserted into the base  2 . Thus the conductive contact  1  can be firmly secured in the passageway  22  of the base  2 . The rear surface  101  of the base portion  10  of the conductive contact  1  engages with the inner sidewall (not labeled) passageway  22  to avoid the conductive contact  1  to rock in the passageway  22  of the base  2 . In addition, the fixing force stressing on the base  2  can be balanced, so the warp of the base  2  can be avoided. Thus the electrical connector  100  can realize a reliable electrical connection between the CPU (not shown) and the print circuit board (PCB) (not shown). 
         [0028]    It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of 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.