Patent Publication Number: US-7901244-B2

Title: Stacked electrical connector

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This Non-provisional application claims priority under 35 U.S.C. §119(a) on Patent Application No(s). 097129797 filed in Taiwan, Republic of China on Aug. 6, 2008, the entire contents of which are hereby incorporated by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a stacked electrical connector and, more particularly, to a stacked electrical connector completely shielded. 
     2. Description of the Related Art 
     With the development of electronic science technology, more and more types of peripheral device of a computer are increased. The connection interfaces used by the devices having the same functions have a plurality of specification. Since shapes of a motherboard and a casing for containing the motherboard are limited, it is impossible to independently assemble all the connection interfaces at peripheries of the motherboard. Therefore, there are stacked connectors on the market. However, the present stacked electrical connector just makes separate connectors stacked together, and an area of pins for the motherboard is just a sum of areas of pins of the separate connectors. In addition, since the separate connectors are stacked, more part of signal transmission terminals (pins) is exposed to outside. That is, the signal interference may deteriorate. Particularly, the connector stacked above (away from the motherboard) is greatly affected. 
     Therefore, the conventional stacked electrical connector just saves a usable and limited periphery for the motherboard, and an area of a corresponding footprint configuration on the motherboard does not decrease in reality, which fails to benefit size decrease of the motherboard. 
     BRIEF SUMMARY OF THE INVENTION 
     The objective of this invention is to provide a stacked electrical connector having a complete shielding function and suitable for a smaller area of a footprint configuration. 
     The invention provides a stacked electrical connector including a first connector, a second connector, and a conductive casing. The first connector includes a first signal connection portion and a first group of soldering pins extending along a direction. The second connector includes a second signal connection portion and a second group of soldering pins extending along the direction. The first connector is stacked on the second connector. The conductive casing has a first opening, a second opening, and a third opening. The conductive casing covers the first connector and the second connector. Thus, the first signal connection portion passes through the first opening, the second signal connection portion passes through the second opening, and the first group of soldering pins and the second group of soldering pins are exposed to the third opening. Thereby, the conductive casing can shield external interference, such that the electrical connector can still reliably transmit signals in the stacked structure. 
     The stacked electrical connector in an embodiment of the invention is applied to a video graphics array (VGA) connector and a digital visual interface (DVI) connector, and the VGA connector is closer to the third opening than the DVI connector. The soldering pins of the VGA connector may be arranged to two rows instead of conventional three rows, thus to decrease the thickness of the stacked electrical connector. In the embodiment, the whole thickness of the conductive casing vertical to the direction may be less than 12 mm. 
     Therefore, the stacked electrical connector in an embodiment of the invention has a complete shielding structure capable of effectively preventing electromagnetic interference. Further, by arranging the soldering pins properly, the thickness of the stacked electrical connector decreases, and the needed footprint configuration decreases, which benefits miniaturization of a circuit board connected with the connector. 
     These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a three-dimensional diagram showing a stacked electrical connector according to a preferred embodiment of the invention; 
         FIG. 2  is a bottom view showing a stacked electrical connector; 
         FIG. 3  is an exploded diagram showing part of a stacked electrical connector; 
         FIG. 4  is a schematic diagram showing a conductive casing partly unfolded; 
         FIG. 5  is a front view showing a second signal connection portion having connection points marked; and 
         FIG. 6  is a schematic diagram showing a footprint configuration of a circuit board suitable for a stacked electrical connector. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  is a three-dimensional diagram showing a stacked electrical connector  1  according to a preferred embodiment of the invention.  FIG. 2  is a bottom view showing the electrical connector  1 .  FIG. 3  is an exploded diagram showing part of the electrical connector  1 . Please refer to  FIG. 1 ,  FIG. 2 , and  FIG. 3 . The stacked electrical connector  1  includes a first connector  12 , a second connector  14 , a frame  16 , and a conductive casing  18 . The first connector  12  and the second connector  14  are connected with each other via the frame  16 . The conductive casing  18  covers the first connector  12 , the second connector  14 , and the frame  16  at the same time. 
     The first connector  12  includes a first signal connection portion  122  and a first group of soldering pins  124  (one is marked). The first group of soldering pins  124  extends along a direction X. The second connector  14  includes a second signal connection portion  142  and a second group of soldering pins  144  (one is marked). The second group of soldering pins  144  also extends along the direction X. The conductive casing  18  has a first opening  182 , a second opening  184 , and a third opening  186 , and it has a flat surface S parallel to the direction X. The first opening  182  and the second opening  184  are located at the flat surface S. The first signal connection portion  122  passes through the first opening  182 , and a ground casing  126  of the first connector  12  contacts the conductive casing  18 . The second signal connection portion  142  passes through the second opening  184 , and a ground casing  146  of the second connector  14  also contacts the conductive casing  18 . The first group of soldering pins  124  and the second group of soldering pins  144  are exposed to the third opening  186 . In addition, the first connector  12  further includes two fastening posts  128  and two screw holes  130  corresponding to the fastening posts  128 . The fastening post  128  includes a hexangular post  128   a , a screw portion  128   b , and a screw hole  128   c  (as shown in  FIG. 3 , one is marked). The conductive casing  18  has two fastening holes  188  on the flat surface S corresponding to the screw holes  130  of the first connector  12 . By screwing the screw portions  128   b  of the fastening posts  128  into the screw holes  130 , the conductive casing  18  can be retained between the ground casing  126  and the hexangular posts  128   a  of the fastening posts  128 . The screw holes  128   c  can be used for fastening external connectors. 
     Similarly, the second connector  14  further includes two fastening posts  148  and two screw holes  140  corresponding to the fastening posts  148 . The fastening post  148  includes a hexangular post  148   a , a screw portion  148   b , and a screw hole  148   c  (as shown in  FIG. 3 , one is marked). The conductive casing  18  has two fastening holes  190  on the flat surface S corresponding to the screw holes  140  of the second connector  14 . By screwing the screw portions  148   b  of the fastening posts  148  into the screw holes  140 , the conductive casing  18  can be retained between the ground casing  146  and the hexangular posts  148   a  of the fastening posts  148 . Further, the screw holes  148   c  can be used for fastening external connectors. The difference between the fastening holes  190  and the fastening holes  188  described above is that the fastening holes  188  are formed independently, while the fastening holes  190  are formed with the second opening  184 . However, the invention is not limited thereto. It can be determined by practical design needs. 
     The outline of the first opening  182  matches the first signal connection portion  122 , and the outline of the second opening  184  matches the second signal connection portion  124 . Thereby, the conductive casing  18  can be attached to the first connector  12  and the second connector  14  to realize a complete cover, thereby providing a complete shielding function. In the preferred embodiment of the invention, without the conductive casing  18 , under the external signal frequency from 115 MHz to 667 MHz, the stacked electrical connector  1  may suffer electromagnetic interference above than 10 dB. The highest electromagnetic interference suffered by the stacked electrical connector  1  having the conductive casing  18  under the same external signal frequency (even reaching to 983 MHz) is −2.6 dB. Apparently, the stacked electrical connector  1  in the embodiment of the invention can effectively solve the serious electromagnetic interference of the stacked electrical connector. 
     Please refer to  FIG. 3  and  FIG. 4 .  FIG. 4  is a schematic diagram showing the conductive casing  18  partly unfolded. According to the preferred embodiment of the invention, the conductive casing  18  is integrally formed and includes a plurality of ground soldering pins  192  for being soldered on a ground circuit of a circuit board to provide a shielding function. The conductive casing  18  includes a plurality of retaining holes  194   a  and corresponding elastic elements  194   b . When the conductive casing  18  is bent, the retaining holes  194   a  retain the corresponding elastic elements  194   b  to form a stable shielding casing. Based on the similar reason, the conductive casing  18  further includes a plurality of elastic elements  198  extending from a side wall  196  of the conductive casing  18  toward the first opening  182  (that is, the second opening  184  or the flat surface S). After the conductive casing  18  and the frame  16  are assembled, the side wall  162  or an indentation opening  164  of the frame  16  can retain the elastic elements  198 , thereby fastening the conductive casing  18  to the frame  16  (even the first connector  12  or the second connector  14 ).  FIG. 3  is not an assembling schematic diagram exactly showing the stacked electrical connector  1 . In other words, before the conductive casing  18  in  FIG. 3  is assembled to the first connector  12  and the second connector  14 , the conductive casing  18  is unfolded as shown in  FIG. 4 . After the first opening  182  and the second opening  184  are sleeved on the first signal connection portion  122  and the second signal connection portion  142 , respectively, the retaining holes  194   a  and the elastic elements  194   b  are retained to form an appearance as shown in  FIG. 1 . 
     According to the preferred embodiment of the invention, the first connector  12  is a digital visual interface (DVI) connector, and the second connector  14  is a video graphics array (VGA 0  connector. Please refer to  FIG. 1  and  FIG. 2 . The second signal connection portion  142  of the second connector  14  includes 15 signal connection points arranged in three rows and electrically connected with the second group of soldering pins  144 , respectively. The second group of soldering pins  144  is arranged in two rows different from three rows in the prior art. Thereby, the footprint area on the circuit board needed by the second group of soldering pins  144  decreases. 
     Please refer to  FIG. 5  and  FIG. 6 .  FIG. 5  is a front view showing the second signal connection portion  142  having the connection points marked.  FIG. 6  is a schematic diagram showing a footprint configuration of a circuit board  3  suitable for the stacked electrical connector  1 . The circuit board  3  forms fifteen holes  32  for the second group of soldering pins  144 , thirty holes  34  for the first group of soldering pins  124 , and four holes  36  for the ground soldering pins  192  (only one is marked). In  FIG. 6 , the connection points corresponding to the holes  32  are marked to show the corresponding relation of each connection point and each hole  32  of the circuit board  3  via the second group of soldering pins  144 . The holes  32  are arranged in two rows. 
     The first row of the connection points of the second signal connection portion  142  (the connection points marked from  1  to  5 ) corresponds to a first row of the holes  32  of the circuit board  3 . The second row and the third row of the connection points (the connection points marked from  6  to  15 ) interlacingly correspond to a second row of the holes  32  of the circuit board  3 . In other words, the second row (five soldering pins) of the second group of soldering pins  144  in  FIG. 2  corresponds to the first row of the holes  32  of the circuit board  3 . The first row (ten soldering pins) of the second group of soldering pins  144  corresponds to the second row of the holes  32  of the circuit board  3 . Further, a central distance between two adjacent soldering pins of the second row of the second group of soldering pins  144  is approximately 1.14 mm. That is, a central distance between two adjacent soldering pins of the second row of the holes  32  of the circuit board  3 , such as the holes  32  with the reference marks  7  and  11 , is approximately 1.14 mm. 
     In another embodiment of the invention different from the above embodiment, the second group of soldering pins  144  electrically connected to the first and second row of the connection points of the second signal connection portion  142  (the connection points marked from  1  to  10 ) is integrated into one row. The second group of soldering pins  144  electrically connected to the third row of the connection points of the second signal connection portion  142  (the connection points marked from  11  to  15 ) directly forms another row. At that moment, the holes  32  of the circuit board  3  need to be correspondingly disposed. From the above, in the embodiment of the invention, the second group of soldering pins  144  corresponding to two adjacent rows of the connection points can be easily integrated into one row in a direct interlaced mode, thereby decreasing the area of the footprint configuration needed by the second group of soldering pins  144 . Since the second group of soldering pins  144  is not averagely rearranged into two rows as a whole to correspond to the signal connection points (three rows), the manufacturing problem of the second connector  14  and the wiring problem of the circuit board  3  can be avoided. 
     Since the second connector  14  of the stacked electrical connector  1  needs a smaller footprint area, the stacked electrical connector  1  (or the conductive casing  18 ) has a thickness less than 12 mm along a direction vertical to the flat surface S (as shown in  FIG. 3 , a reference mark W). 
     To sum up, the stacked electrical connector in the invention has a complete shielding structure capable of effectively solving the serious electromagnetic interference caused by the stacked electrical connector. Further, by arranging the soldering pins to make them interlacingly correspond to the adjacent two rows of the signal connection points, the thickness of the stacked electrical connector decreases, and the needed footprint configuration decreases, which benefits miniaturization of a circuit board connected with the connector. 
     Although the present invention has been described in considerable detail with reference to certain preferred embodiments thereof, the disclosure is not for limiting the scope of the invention. Persons having ordinary skill in the art may make various modifications and changes without departing from the scope and spirit of the invention. Therefore, the scope of the appended claims should not be limited to the description of the preferred embodiments described above.