Patent Publication Number: US-7909644-B1

Title: Card edge connector assembly with cards inserted thereinto along different directions

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a card edge connector assembly, and more particularly to a card edge connector assembly with two cards inserted thereinto along different directions. 
     2. Description of the Related Art 
     U.S. Pat. No. 7,338,307 issued to Zhang et al. on Mar. 4, 2008 discloses a card edge connector assembly comprising an upper connector and a lower connector stacked together and offsetting with each other along a front-to-rear direction for respectively receiving a card therein. The lower connector is configured into a sink type and located under the upper connector thereby both connectors can be soldered onto a same side of a printed circuit board. However, when assembling the cards, the lower card must be assembled thereinto before the upper card, and the lower card interferes with the upper connector during the assembling process, which is not convenient for the user. 
     China Utility Patent No. 200720003525.6 discloses a card edge connector assembly comprising an upper connector a lower connector respectively located at opposite sides of a printed circuit board and configured as a mirror image regarding to the printed circuit board. The upper connector defines a central slot therein for receiving an upper card in an upside-down status, and the lower connector defines a central slot therein for receiving a lower card in a downside-up status, therefore the two cards can be assembled individually. However, the upper connector and the lower connector are soldered onto different sides of the printed circuit board, which will increase the height of the card edge connector assembly. Obviously, an improved card edge connector assembly is highly desired to overcome the aforementioned problem. 
     SUMMARY OF THE INVENTION 
     Accordingly, an object of the present invention is to provide a card edge connector assembly for easily assembling cards therein. 
     In order to achieve the object set forth, a card edge connector, adapted for stacking with a first card edge connector including a first insulative housing with a plurality of first upper terminals and first lower terminals mounted therein and a first central slot defining a first insertion direction for receiving a memory module therein, said first upper terminals and lower terminals respectively forming contacting portions projecting into the first central slot, includes a second insulative housing defining a second central slot for receiving another memory module therein. Second upper terminals and lower terminals are mounted on the second insulative housing and respectively form contacting portions projecting into the second central slot. A distance between the contact portions of the first upper terminals and second upper terminals is larger than that between the contact portions of the first lower terminals and the second lower terminals under a condition that the card edge connector is stacked with the first card edge connector with both central slots facing forwardly. 
     In order to achieve the object set forth, a card edge connector assembly adapted for receiving a first and a second memory modules therein includes a first card edge connector and a second card edge connector located under the first card edge connector. The first card edge connector includes a first insulative housing mounting a first terminal group therein. The first insulative housing has an upper wall, a lower wall and a first central slot located therebetween for receiving the first memory module therein. The first terminal group defines a first mounting face on which the first card edge connector is mounted. The second card edge connector includes a second insulative housing having an upper wall, a lower wall and a second central slot located therebetween for receiving the second memory module therein. The second terminal group defines a second mounting face on which the second card edge connector is mounted, and said first mounting face and second mounting face are coplanar with each other. The first and second central slots respectively define receiving spaces extending along different directions so as to avoid interference between the first and second memory modules during the assembling process. 
     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 perspective view of a card edge connector assembly mounted onto a printed circuit board, wherein a pair of cards are respectively assembled onto the card edge connector assembly in an initial status; 
         FIG. 2  is a perspective view of the card edge connector assembly mounted onto the printed circuit board, wherein the pair of cards are respectively assembled onto the card edge connector assembly in a final status; 
         FIG. 3  is a perspective view of the card edge connector assembly mounted onto the printed circuit board; 
         FIG. 4  is an exploded perspective view of the card edge connector assembly shown in  FIG. 3 ; 
         FIG. 5  is a cross-sectional view of the card edge connector assembly shown in  FIG. 3  along line  5 - 5 ; and 
         FIG. 6  is a cross-sectional view of the card edge connector assembly shown in  FIG. 3  along line  6 - 6 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Reference will now be made to the drawing figures to describe a preferred embodiment of the present invention in detail. Referring to  FIGS. 1 and 2 , a card edge connector assembly made according to the preferred embodiment of the present invention is provided and comprises a first card edge connector  10  and a second card edge connector  20  mounted onto a printed circuit board  200 , wherein the second card edge connector  20  is located under the first card edge connector  10  and in front of the first card edge connector  10  along a front-to-rear direction. 
     Referring to  FIGS. 3 and 4 , the first card edge connector  10  comprises an elongated insulative housing  11  and a pair of arms  12  extending from opposite sides of the insulative housing  11 . The insulative housing  11  comprises an upper wall  111  and a lower wall  112 , on which a plurality of terminal grooves are defined for receiving conductive terminals  13 , and between which a central slot  113  is defined for receiving a memory module  300  therein. A key  114  is formed in the central slot  113  adjacent to one arm  12  for cooperating with a notch defined in a front end of the memory module  300 . A supporting platform  122  extends forward from each end of the central slot  113  and connects with the corresponding arm  12  for providing a supporting face when the memory module  300  is assembled. Further more, a locking portion  121  which is configured into an inverted L shape is formed at a distal end of each arm  12  for locking with the memory module  300 . As a front face of the upper wall  111  is located behind a front face of the lower wall  112 , the central slot  113  therebetween defines a receiving space facing upwardly. 
     The second card edge connector  20  is a sink type and comprises an elongated insulative housing  21  and a pair of arms  22  disposed at opposite sides thereof. The insulative housing  21  comprises an upper wall  211 , a lower wall  212 , a central slot  213  between the upper and lower walls, and a key  214  formed in the central slot  213 . The key  214  is in alignment with the key  114  along the rear-to-front direction. As a front face of the upper wall  211  is located behind a front face of the lower wall  212 , the central slot  213  therebetween defines a receiving space facing downwardly, which is different from the receiving space of the first card edge connector  10 . An extending section  215  extends rearward from the lower wall  212  of the insulative housing  21  for retaining conductive terminals  23  mounted in the upper and lower walls  211 ,  212 . Each terminal  23  forms a solder portion extending away from the extending section  215  and toward the upper wall  211 . A retaining portion  222  is formed at a lateral side of each arm  22  for securing the second card edge connector  20  onto the printed circuit board  200 . Moreover, a locking portion  221  is formed at a distal end of each arm  22  for locking with the memory module  300 . 
     Referring to  FIG. 4  to  FIG. 6 , the terminals  13  in the first card edge connector comprises first upper terminals  132  retained in the upper wall  111  and first lower terminals  131  retained in the lower wall  112 . Each first upper and lower terminals  132 ,  131  comprises contact portions  1321 ,  1311  projecting into the central slot  113  and solder portions  1322 ,  1312  extending downwardly. The contact portion  1321  of each first upper terminal  132  is located behind the contact portion  1311  of each first lower terminal  131 , i.e. the contact portion  1321  is closer to an inner side of the central slot  113  than the contact portion  1311 . The memory module  300  is inserted into the central slot  113  in an upside-down manner and conductive pads on a lower face of the memory module  300  are firstly engaging with the contact portions  1311  of the first lower terminals  131  at an initial status, then conductive pads on an upper face of the memory module  300  are engaging with the contact portions  1321  of the first upper terminals  132 . The solder portions  1322 ,  1312  are SMT (surface mounting technology) type and respectively mounted onto a first mounting face  130  on an upper side of the printed circuit board  200 . 
     The terminals  23  in the second card edge connector  20  comprises second upper terminals  232  retained in the upper wall  211  and second lower terminals  231  retained in the lower wall  212 . Each second upper and lower terminals  232 ,  231  comprises contact portions  2321 ,  2311  projecting into the central slot  213  and solder portions  2322 ,  2312  extending upwardly. The contact portion  2321  of each second upper terminal  232  is located in front of the contact portion  2311  of each second lower terminal  231 , i.e., the contact portion  2311  of each second lower terminal  231  is closer to an inner side of the central slot  213  than the contact portion  2321 . It should be pointed out that as the terminal arrangement of the first and second card edge connectors are different, a distance between the contact portion  1321  of the first upper terminal  132  and the contact portion  2321  of the second upper terminal  232  is larger than that between the contact portion  1311  of the first lower terminal  131  and the contact portion  2311  of the second lower terminal  231 . 
     The memory module  300  is inserted into the central slot  213  in a downside-up manner, therefore it can not interfere with the first card edge connector  10  during the assembling process, that is to say, the two memory modules  300  can be separately assembled onto the card edge connector assembly individually, which is convenient for the user to operate. The conductive pads on the upper face of the memory module  300  are firstly engaging with the contact portions  2321  of the second upper terminals  232  at the initial status, then conductive pads on the lower face of the memory module  300  are engaging with the contact portions  2311  of the second lower terminals  231 . 
     Referring to  FIG. 3 , the solder portions  2322 ,  2312  of the second upper terminal  232  and the second lower terminal  231  are configured as pin type configuration and extend upward from the extending section  215  so as to be soldered onto a second mounting face  230  defined on the upper side of the printed circuit board  200 . As the first mounting face  130  and the second mounting face  230  are coplanar with each other and commonly defined at a same side of the printed circuit board  200 , the soldering process can be accomplished efficiently. 
     The first card edge connector  10  is located on the upper side of the printed circuit board  200  where the first mounting face  130  is defined, and the second card edge connector  20  is located on the lower side of the printed circuit board  200  with the pin shaped solder portion  2312 ,  2322  passing through the printed circuit board  200  and soldered on the second mounting face  230  which is in front of the first mounting face  130 . The retaining portions  222  attach to the lower side of the printed circuit board  200  so as to secure the second card edge connector  20  on the printed circuit board  200 . The extending portion  215  engages with the lower side of the printed circuit board  200  and the upper wall  221  of the second card edge connector  20  is located a little higher than the upper side of the printed circuit board  200 , hence the thickness of the printed circuit board  200  can be absorbed by the lower card edge connector  20  and the height of the card edge connector assembly can be reduced. It is also noted that because the instant invention requires two modules are inserted into the corresponding two connectors in opposite directions, those two connectors are optimally configured to be one standard type and one reverse type as disclosed in U.S. Pat. No. 5,882,211 for simplifying the circuit trace arrangement on the corresponding mother board. 
     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.