Patent Publication Number: US-7223107-B2

Title: Board-mounted electrical connector with balanced solder attachment to a circuit board

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention is related to an electrical connector, and more particularly to a board-mounted electrical connector for use in a notebook computer. 
     2. Description of Related Art 
     An electrical connector mostly comprises a dielectric housing and a plurality of conductive terminals received in the dielectric housing. The plurality of conductive terminals generally include power terminals, signal terminals and grounding terminals. Generally, the power terminal has a width greater than the signal terminal and the grounding terminal for the electrical current that the power terminals conduct is larger than that of the signal terminals. However, because the width of the power terminal is added, the soldering portion of the power terminal has higher soldering intensity than the signal terminal. When the power and signal terminals are distributed asymmetrically in the electrical connector and the electrical connector is mounted onto a printed circuit board, the electrical connector will have unbalanced soldering intensity. Consequently, the soldering area between the signal terminal and the printed circuit board is easily broken off when the electrical connector repeatedly connects with/detaches from a complementary connector or due to an accidental external force, thereby resulting in deformation of the electrical connector and even leading to break the electrical interconnection between the electrical connector and the printed circuit board and thus affect normal signal transmission. 
     Hence, it is requisite to provide an electrical connector having balanced soldering intensity and improved connector reliability to overcome the above-mentioned disadvantages of the related art. 
     SUMMARY OF THE INVENTION 
     Accordingly, an object of the present invention is to provide an electrical connector having balanced soldering intensity so as to be securely assembled onto a printed circuit board and ensure a reliable signal transmission of the whole electrical connector. 
     In order to achieve the object set forth, an electrical connector in accordance with the present invention comprises a dielectric housing, a plurality of power terminals at one end of the dielectric housing, signal terminals, and solder pad contacts disposed at the other end of the dielectric housing opposite to the power terminals. The dielectric housing includes a base portion and a bottom portion integrally connecting with the base portion and defines a plurality of passageways extending through the bottom portion. The terminals received in the passageways each have a contact portion for mating with a complementary connector and a solder foot extending beyond the bottom portion for electrically engaging with a printed circuit board. The solder pad contacts have a width greater than the signal terminals. The solder pad contacts are upwardly inserted into the base portion from the bottom portion of the dielectric housing and each comprise a retention portion for interferentially mating with the base portion and a solder foot extending beyond the bottom portion for mechanically connecting with the printed circuit board. 
     Other objects, advantages and novel features of the invention will become more apparent from the following detailed description of the present embodiment when taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a top plan view of an electrical connector in accordance with the present invention; 
         FIGS. 1A and 1B  are enlarged views of circle portions of FIG  1 . 
         FIG. 2  is a front plan view of the electrical connector; 
         FIG. 3  is a bottom plan view of the electrical connector; 
         FIG. 4  is a cross-sectional view of the electrical connector taken along line  4 — 4  of  FIG. 2 ; 
         FIG. 5  is a cross-sectional view of the electrical connector taken along line  5 — 5  of  FIG. 2 ; and 
         FIG. 6  is a cross-sectional view of the electrical connector taken along line  6 — 6  of  FIG. 2 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Reference will now be made in detail to the preferred embodiment of the present invention. 
     Referring to FIG  1 , an electrical connector  1  in accordance with the present invention comprises a dielectric housing  2 , a shielding shell  3  attached on the dielectric housing  2 , a plurality of power terminals  4 , signal terminals  5 , and solder pad contacts  6  received in the dielectric housing  2 . 
     Referring to  FIGS. 1 to 3  in conjunction with  FIGS. 4 and 5 , the dielectric housing  2  is rectangular and comprises a base portion  20  and a bottom portion  21  integrally connecting with the base portion  20 . The base portion  20  has a mating surface  200  for mating with a complementary connector (not shown) and the bottom portion  21  has an engaging surface  210  parallel to and for mounting to a top surface of a printed circuit board (not shown). The base portion  20  defines an elongated plug-receiving chamber  201  and the chamber  201  is divided longitudinally by a central partition  211  projecting upwardly from the bottom portion  21 . A plurality of passageways  212 ,  213 ,  215  are defined in two opposite sides of the central partition  211  and downwardly extending through the bottom portion  21  of the dielectric housing  2 . The dielectric housing  2  has a pair of circular guiding holes  202  exposed at two opposite ends of the mating surface  200  for providing insertion of guiding pins of the complementary connector, and a pair of locating posts  214  at two opposite ends of the engaging surface  210  for retaining the electrical connector  1  onto the printed circuit board. Additionally, the dielectric housing  2  provides a plurality of latch bosses  203  projecting outwardly from two opposite side surfaces of the base portion  20  thereof. 
     With reference to  FIGS. 3–5 , the power terminals  4  and the signal terminals  5  are respectively received in corresponding passageways  212 ,  213  of the dielectric housing  2 . The power terminals  4  are arranged in one end of the dielectric bowing  2  and have a width greater than the signal terminals  5  (as shown in  FIG. 1A ). Each power terminal  4  includes a contact portion  40  (FIG  4 ) extending to the mating surface  200  and each signal terminal  5  has resilient contact portions  50  ( FIG. 5 ) which project laterally outwardly into the plug-receiving chamber  201  for mating with corresponding conductive contacts of the complementary connector. Each power/signal terminal  4 ,  5  comprises a soldering foot  41 / 51  opposite to the contact portion  40 / 50  and extending beyond the engaging surface  210  of the dielectric housing  2  for mechanically and electrically connecting with the printed circuit board. 
     With reference to  FIGS. 3 and 6 , the solder pad contacts  6  are arranged in the other side of the dielectric housing  2  opposite to the power terminals  4  and have a width greater than the signal terminals  5  (as shown in FIG  1 B). Each solder pad  6  includes a retention portion  60  received in the passageway  215  for interferentially mating with the base portion  21  and a solder foot  61  extending beyond the engaging surface  210  of the dielectric housing  2  for mechanically engaging with the printed circuit board. 
     With reference to  FIGS. 2 and 3  along with  FIGS. 4–6 , the shielding shell  3  comprises an inner frame overlaid with inner walls of the received chamber  201  a casing  31  partly enclosing the base portion  20  of the dielectric housing  2 , two pairs of locking tabs  32  having rectangular holes (not labeled) for receiving the latch bosses  203 , and a pair of wing sections  33  integrally and downwardly extending from two opposite longitudinal sides of the casing  31 . Each wing section  33  provides a pair of solder feet  330  in a bottom edge thereof and perpendicular to the engaging surface  210  of the dielectric housing  2 . 
     Referring to  FIGS. 1–6 , in assembly, both the power terminals  4  and the signal terminals  5  are upwardly inserted therein from the engaging surface  210  of the dielectric housing  2  and respectively received in corresponding passageways  212 ,  213  with the contact portions  40 ,  50  thereof extending to the mating surface  200  and the solder feet  41 ,  51  extending beyond the engaging surface  210 . Similarly, the solder pad contacts  6  are upwardly inserted in corresponding passageways  215  of the dielectric housing  2  from the engaging surface  210  with the solder feet  61  protruding beyond the engaging surface  210 . The retention portions  60  of the solder pad contacts  6  pass through the bottom portion  21  of the dielectric housing  2  to interfere with the base portion  20  so as to retain the solder pad contacts  6  in the dielectric housing  2 . The shielding shell  3  is attached to the dielectric housing  2 . The casing  31  of the shielding shell  3  firstly encloses the base portion  20  of the dielectric housing  2  so that the shielding shell  3  is preliminarily positioned on the dielectric housing  2 . Then the locking tabs  32  of the shielding shell  3  snappingly engage with corresponding latch bosses  203  of the base portion  20 , thus the shielding shell  3  is securely fixed to the dielectric housing  2  with the solder feet  330  extending beyond the engaging surface  210  of the dielectric housing  2 . 
     When the electrical connector  1  is mounted onto the printed circuit board, the solder feet  61  of the solder pad contacts  6  are soldered on the printed circuit board, thereby increasing the soldering intensity between the electrical connector  1  and the printed circuit board. Because the solder pad contacts  6  are disposed in one end of the dielectric housing  2  opposite to the power terminals  4 , the electrical connector  1  has balanced soldering intensity to ensure a reliable electrical connection between the signal terminals  5  and the printed circuit board. By increasing the solder pad contacts  6 , the electrical connector  1  can be securely retained in the printed circuit board so that the electrical connector  1  has better and reliable signal transmission quality. Furthermore, the solder pad contacts  6  in accordance with the present invention are simple in structure and easily acquired by changing the existing power terminals  4  minorly. 
     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.