Patent Publication Number: US-6210177-B1

Title: Electrical connector

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a board-to-board electrical connector, and particularly to an electrical connector for signal transmission between different circuit boards. 
     U.S. Pat. Nos. 5,277,597, and Taiwan Patent Application Nos. 86202873, 86206353 each disclose a conventional board-to-board-to-board electrical connector. Referring to FIGS. 1A and 1B, a conventional board-to-board electrical connector  3  comprises an insulative housing  4  and a plurality of terminals  5 . The insulative housing  4  includes a pair of side walls  41 ,  42  which are parallel to each other. A central portion  43  is disposed between the side walls  41 ,  42 . A plurality of passageways  46  is exposed on opposite surfaces of the central portion  43  and the passageways  46  are equally distanced from each other by spacing boards (not shown). The terminals  5  are received in corresponding passageways  46  and each terminal  5  comprises a fixing portion  51 , a contacting portion  52  and a soldering portion  53 . The contacting portion  52  and the soldering portion  53  are respectively formed at opposite ends of the fixing portion  51 . After the terminal  5  is assembled in the insulative housing  4 , the soldering portion  53  is folded with right angle to solder on a circuit board (not shown). A plurality of barbs  55  is formed on opposites edges for engaging with the spacing boards for securing in the insulative housing  4 . 
     However, the terminals  5  are assembled to the insulative housing  4  just through engagement between the barbs  55  and the spacing boards. This engagement is not reliable while an external force is exerted on the soldering portion  53  of each terminal  5 . Under the external force the terminals  5  will be buckled inwardly. Furthermore, the soldering portion  53  is folded after the terminals  5  assembled to the insulative housing  4 , thus, an additional tool is needed and planarity of the soldering portions  53  can not be properly controlled either. 
     BRIEF SUMMARY OF THE INVENTION 
     A main object of the present invention is to provide an electrical connector having an insulative housing and a plurality of terminals, each terminal being formed with a reliable structure for easily assembling and positioning the terminal to the housing. 
     To fulfill the above-mentioned object, according to a preferred embodiment of the present invention, an electrical connector comprises an insulative housing and a plurality of terminals. The insulative housing includes a central portion, a pair of side walls formed on opposite sides of the central portion, a pair of lateral walls formed on lateral sides of the central portion. The central portion and the side walls together define a receiving space for facilitating the process of assembling terminals to the insulative housing. The central portion defines a plurality of passageways therethrough for receiving corresponding terminals therein. The passageways are spaced from each other by corresponding spacing boards. Each terminal comprises a fixing portion, a contacting portion, a slanting portion and a tail portion. The contacting portion is formed at the top end thereof for electrically contacting with a mating connector. The slanting portion slantways extends from the fixing portion with an obtuse angle for dispersing an insertion force exerted thereon. A tail portion is formed at the end of the slanting portion with a pair of engaging portions formed at lateral edges thereof, the engaging portions being securely received in corresponding T-shaped slots. A soldering portion of each terminal is folded at a same plane before soldering on a circuit board. Therefore, after the terminals are assembled to the insulative housing, the soldering portions of corresponding terminals can be arranged with a proper planarity and the quality of solder process is also improved. 
     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. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1A is a side view of a conventional terminal; 
     FIG. 1B is a cross-sectional view of a conventional electrical connector; 
     FIG. 2 is a perspective view of an electrical connector in accordance the present invention; 
     FIG. 3 is a perspective, cross-sectional view of the electrical connector; 
     FIG. 4 is a partial, enlarged view of an upper portion of FIG. 3; and 
     FIG. 5 is a partial, enlarged view of a lower portion of FIG.  3 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to FIGS. 2 and 3, an electrical connector  1  comprises an insulative housing  10  and a plurality of terminals  20 . The insulative housing  10  includes a central portion  14 , a pair of side walls  12   a ,  12   b  formed on opposite sides of the central portion  14 , a pair of lateral walls  12   c ,  12   d  formed on lateral sides of the central portion  14 . A mating face  13  is formed at the top face of the central portion  14  for mating with an external connector. A pair of mating slots  15  is defined between the central portion  14  and the side walls  12   a ,  12   b  respectively. The central portion  14  and the side walls  12   a ,  12   b  together define a receiving space  16  for facilitating the process of assembling terminals  20  to the insulative housing  10 . A pair of stepped portions  17  is respectively formed at the top end of corresponding side walls  12   a ,  12   b , and a pair of cutouts  18  is respectively formed at lateral ends of the stepped portions  17 . The stepped portions  17  and the cutouts  18  are used for avoiding mistake assembly while the present connector is assembled with another connector. 
     Referring to FIGS. 4 and 5, the central portion  14  defines a plurality of passageways  130  therethrough for receiving corresponding terminals  20  therein. The passageways  130  are spaced from each other by corresponding spacing boards  131 . A plurality of receiving holes  132  is formed in the mating face  13  and communicates with corresponding passageways  130 . A plurality of spacing blocks  190  is formed on opposite inner surfaces of the side walls  12   a ,  12   b  and expose to the receiving space  16 . A plurality of T-shaped slots  19  is respectively formed between corresponding adjacent spacing blocks  190  for securing the terminals  20  therein. 
     Each terminal  20  comprises a fixing portion  21 , a contacting portion  22 , a slanting portion  23  and a tail portion  24 . The contacting portion  22  is formed at the top end thereof for electrically contacting with a mating connector. Top end  26  of each contacting portion  22  is received in corresponding receiving hole  132  for providing a preload force on each terminal  20  and properly positioning each terminal  20  after assembly. Two pairs of barbs  27  are formed at opposite edges of the fixing portion  21  for engaging with the spacing boards  131  and securing the terminals  20  to the insulative housing  10 . The distribution of the barbs  27  also can enhance the rigidity of the terminal  20 . The slanting portion  23  slantways extends from the fixing portion  21  with an obtuse angle for enhancing resilience of the terminal and dispersing an insertion force exerted thereon. A tail portion  24  is formed at the end of the slanting portion  23  with a pair of engaging portions  241  formed at lateral edges thereof, the engaging portions  241  being securely received in the T-shaped slots  19 . A soldering portion  25  of each terminal  20  is arranged at a same plane before soldering on a circuit board. Therefore, after the terminals  20  are assembled to the insulative housing  10 , the soldering portions  25  of corresponding terminals  20  can be arranged with a proper planarity and the quality of soldering process is also improved. Furthermore, the T-shaped slots  19  can securely position tail portions  24  therein, and the terminals  20  can be prevented from buckling while an external force exerted on the soldering portions  25 . 
     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.