Patent Publication Number: US-6699055-B2

Title: Electrical connector with terminal insertion guide mechanisms

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an electrical connector for electrically interconnecting an electrical package such as a central processing unit (CPU) with a circuit substrate such as a printed circuit board (PCB), and particularly to an electrical connector with terminal guide mechanisms that facilitate assembly of the electrical connector. 
     2. Description of Related Art 
     Socket connectors are widely used in personal computers (PCs) to electrically interconnect CPUs with PCBs. A conventional socket connector is disclosed in “PGA SOCKETS” (Connector Specifier Magazine, February 2000) and U.S. Pat. Nos. 6,132,222, 6,116,923 and 5,609,495. The socket connector comprises an insulative base, a cover slidably attached on the base, an actuating device assembled with the base and the cover, and a multiplicity of conductive terminals retained in the base. The base comprises a multiplicity of passageways extending from a top surface to a bottom surface thereof, for receiving the terminals. Each terminal comprises a contact portion located adjacent the top surface of the base and adapted to electrically engage with leads of the CPU, and a soldering portion located adjacent the bottom surface of the base and adapted to be soldered to the PCB. Typically, each passageway has a relatively large opening at the bottom surface of the base. When the terminal is received in the passageway, the soldering portion of the terminal occupies the opening. However, a gap still remains between the soldering portion and the bottom surface of the base. When the soldering portion is soldered to the PCB, solder is prone to enter the gap and wick from the soldering portion to the contact portion of the terminal. Such “soldering wicking” can seriously degrade the electrical connection between the CPU leads and the contact portion of the terminal, and can even result in failure of the electrical connection between the CPU and the PCB. 
     China Pat. No. ZL99239496.1 discloses a socket connector having a base defining a multiplicity of passageways receiving a multiplicity of electrical terminals. Each passageway comprises a fastening recess to guide insertion of the corresponding terminal into the passageway. A width of the fastening recess is about the same as a width of the terminal. However, the terminals cannot always be accurately inserted into the passageways. For example, a terminal may inserted at an oblique angle relative to the fastening recess. A distal end of the terminal may strike a wall of the base at the passageway. This can result in deformation of the terminal and damage to the base. 
     In view of the above, a new electrical connector that overcomes the above-mentioned disadvantages is desired. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to provide an electrical connector having a guide mechanisms that protect the terminals and a base of the connector from damage when the terminals are inserted into passageways of the connector. 
     In order to achieve the above object, an electrical connector of the present invention is for electrically connecting a CPU and a PCB. The electrical connector comprises: an insulative base having a top surface and a bottom surface, and defining a multiplicity of passageways; a cover slidably mounted on the top surface; a multiplicity of terminals received in the passageways; and an actuating device assembled with the cover and base. Each passageway is bounded by two opposite first walls, two opposite second walls interconnecting the first walls, and a bottom wall adjacent the PCB. Each first wall defines a through slot, and one of the second walls forms a slanted guiding portion spanning from the top surface to adjacent the bottom wall. The bottom wall forms a chamfer portion at the passageway adjacent said one of the second walls. The guiding portion and the chamfer portion cooperate to ensure that when each terminal is inserting into a corresponding passageway, the terminal does not unduly rub the second walls or the bottom wall. This protects both the terminal and the base from damage. 
    
    
     Other objects, advantages and novel features of the present invention will be drawn from the following detailed description of a preferred embodiment of the present invention with attached drawings, in which: 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an exploded, isometric and simplified view of an electrical connector in accordance with a preferred embodiment of the present invention; 
     FIG. 2 is an enlarged, isometric view of one terminal of the electrical connector of FIG. 1, viewed from another aspect; 
     FIG. 3 is an enlarged, isometric cut-away view of part of the electrical connector of FIG. 1, showing one terminal inserted into one passageway of the connector; 
     FIG. 4 is an enlarged view of a circled portion IV of FIG. 3; and 
     FIG. 5 is a side plan view of FIG.  3 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Reference will now be made to the drawings to describe the present invention in detail. 
     Referring to FIGS. 1 and 3, a socket connector  1  in accordance with the present invention is for electrically connecting a CPU (not shown) and a PCB (not shown). The socket connector  1  comprises an insulative base  10 , a cover  12  slidably mounted on the base  10 , an actuating device  14  assembled with the cover  12  and base  10 , and a multiplicity of conductive terminals  16  respectively received in a multiplicity of passageways  101  defined in the base  10 . 
     Referring particularly to FIG. 2, each terminal  16  comprises an elongate retention portion  161 , and a pair of resilient contact portions  162  extending from the opposite sides respectively of an upper part of the retention portion  161 . A pair of barbs  1611  is respectively formed at the opposite sides of the upper part of the retention portion  161 , for interferentially securing the terminal  16  in a corresponding passageway  101  of the base  10 . An elongate rib  1612  is formed on a main face of the retention portion  161 , below the barbs  1611 . 
     Referring also to FIGS. 4 and 5, the base  10  comprises a bottom surface  103  and a top surface  104 . The bottom surface  103  is supported on the PCB, and the top surface  104  is engaged with the cover  12 . Each passageway  101  of the base  10  is bounded by two opposite first walls  1018 , two opposite second walls  1019  interconnecting the first walls  1018 , and a bottom wall  1013  interconnecting the first walls  1018  adjacent the PCB. Each first wall  1018  defines a through slot  10   11  adjacent one of the second walls  1019 , the through slot  1011  spanning from the top surface  104  to the bottom surface  103 . Each through slot  1011  comprises a securing recess  1017  for receiving a corresponding barb  1611  of a corresponding terminal  16 . Each first wall  1018  also defines a receiving recess  1016 , for receiving a corresponding contact portion  162  of the terminal  16 . The bottom wall  1013  defines an opening (not labeled) adjacent said one of the second walls  1019 , for insertion of the terminal  16  therethrough. A blind hole  105  is defined in the bottom wall  1013  at the bottom surface  103 , for preventing the base  10  from deforming when the base  10  is subjected to high temperatures during soldering of the socket connector  1  to the PCB. 
     Said one of the second walls  1019  forms a slanted guiding portion  1012  spanning from the top surface  104  to adjacent the bottom wall  1013 . The guiding portion  1012  is located generally between the through slots  1011 . The bottom wall  1013  forms a chamfer portion  1014  at the passageway  101  adjacent said one of the second walls  1019 . The chamfer portion  1014  is located generally between the through slots  1011 . A receiving slot  1015  is defined in a face of the bottom wall  1013  that opposes said one of the second walls  1019 . Said one of the second walls  1019  has a supporting surface  1020  connecting between the guiding portion  1012  and the bottom surface  103 . The supporting surface  1020  is perpendicular to the bottom surface  103 . 
     In assembly, the retention portion  161  of each terminal  16  is inserted into the corresponding passageway  101  at the through slots  1011 . The rib  1612  of the terminal  16  slides along the receiving slot  1015 . The barbs  1612  of the terminal  16  interferentially engage in the securing recesses  1017 , and the resilient contact portions  162  of the terminal  16  are received in the receiving recesses  1016 . The guiding portion  1012  and the chamfer portion  1014  cooperate to ensure that when the terminal  16  is inserted into the passageway  101 , the terminal  16  does not unduly rub the second walls  1019  or the bottom wall  1013 . This protects both the terminal  16  and the base  10  from damage. 
     Although the present invention has been described with reference to a particular embodiment, it is not to be construed as being limited thereto. Various alterations and modifications can be made to the embodiment without in any way departing from the scope or spirit of the present invention as defined in the appended claims.