Patent Publication Number: US-6991492-B2

Title: Memory card connector

Description:
FIELD OF THE INVENTION 
   This invention generally relates to the art of electrical connectors and, particularly, to a memory card connector for mounting on a printed circuit board and including an improved tail guiding means. 
   BACKGROUND OF THE INVENTION 
   Memory cards are known in the art and contain intelligence in the form of a memory circuit or other electronic program. Some form of card reader reads the information or memory stored on the card. Such cards are used in many applications in today&#39;s electronic society, including video cameras, digital still cameras, smartphones, PDA&#39;s, music players, ATMs, cable television decoders, toys, games, PC adapters, multi-media cards and other electronic applications. Typically, a memory card includes a contact or terminal array for connection through a card connector to a card reader system and then to external equipment. The connector readily accommodates insertion and removal of the card to provide quick access to the information and program on the card. The card connector includes terminals for yieldingly engaging the contact array of the memory card. 
   The memory card connector often is mounted on a printed circuit board. The memory card, itself, writes or reads via the connector and can transmit between electrical appliances, such as a word processor, personal computer, personal data assistant or the like. With circuit board mounted connectors, the terminals of a connector include tail portions which are connected to appropriate circuit traces on the printed circuit board by various systems, such as surface mount technology where the tail portions are reflow soldered to the circuit traces. Through hole technology involves inserting the tail portions of the terminals into holes in the printed circuit board for connection, as by soldering, to circuit traces on the board and/or in the holes. Both surface mount technology and through hole technology involve relatively high temperatures and are permanent connections. If it is desired to be able to easily remove and maintain or replace a memory card connector from the printed circuit board, the tail portions of the terminals are simply maintained under pressure against the circuit traces on the board. 
   All of these systems of electrically coupling the terminals of the memory card connector to the circuit traces on the printed circuit board create problems of aligning the terminal tail portions with the circuit traces. The tail portions can be misaligned or even deformed during shipping, assembly or other handling of the memory card connector. The tail portions can even deform due to the high temperatures of a reflow soldering process which is necessary for the surface mount technology as well as the through hole technology. These problems are multiplied when a connector is designed for receiving more than one memory card, such as two different types of memory cards requiring two different arrays of terminals with two sets of tail portions. The present invention is directed to solving these problems. 
   SUMMARY OF THE INVENTION 
   An object, therefore, of the invention is to provide a new and improved memory card connector for mounting on a printed circuit board. 
   In the exemplary embodiment of the invention, the connector includes an insulating housing having a rear terminal-mounting section and at least one longitudinal side wall section extending forwardly from one end of the rear section and combining therewith to define a card-receiving space for receiving one or more memory cards. The side wall section has first and second inside longitudinal grooves for receiving first and second memory cards. An array of first terminals are mounted on the rear terminal-mounting section of the housing and have contact portions projecting into the space for engaging appropriate contacts on the first memory card and tail portions projecting downwardly for engaging appropriate circuit traces on the printed circuit board. An array of second terminals are mounted on the rear section with similar contact portions arid tail portions. A tail guiding plate is mounted to the bottom of the rear section and has first and second channels for receiving the tails portions of the first and second terminals, respectively, and aligning the tail portions with the respective circuit traces on the printed circuit board. 
   According to one aspect of the invention, the rear terminal-mounting section of the housing has a receptacle at the bottom thereof within which the tail guiding plate is mounted. Generally, interengaging orienting means are provided between the tail guiding plate and the housing to properly orient the plate with respect to the tail portions of the terminals. Specifically, the orienting means herein are provided by interengaging tongue-and-groove means between the tail guiding plate and the rear section of the housing to properly orient the plate within the receptacle. 
   According to another aspect of the invention, the arrays of first and second terminals comprise generally parallel first and second rows thereof. The channels in the tail guiding plate are arranged in a corresponding pair of rows. The channels comprise through passages through which the tail portions of the terminals project out of the bottom of the tail aligning plate for engaging the circuit traces on the printed circuit board. 
   Other features of the invention include an ejection mechanism having first and second ejecting arms for the first and second memory cards, respectively. The insulating housing includes a baffle groove between the first and second card-receiving grooves. A metallic baffle plate is positionable in the baffle groove to provide electromagnetic interference protection between the memory cards. It should be understood that the invention and advantages provided by the tail guiding plate are equally applicable for a memory card connector which receives a single memory card. 
   Other objects, features and advantages of the invention will be apparent from the following detailed description taken in connection with the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The features of this invention which are believed to be novel are set forth with particularity in the appended claims. The invention, together with its objects and the advantages thereof, may be best understood by reference to the following description taken in conjunction with the accompanying drawings, in which like reference numerals identify like elements in the figures and in which: 
       FIG. 1  is an exploded, bottom perspective view of a memory card connector embodying the concepts of the invention, in conjunction with a printed circuit board on which the connector is mounted; 
       FIG. 2  is a bottom perspective view of the connector in assembled condition; and 
       FIG. 3  is a perspective view of the assembled connector mounted on a chassis. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring to the drawings in greater detail, and first to  FIGS. 1 and 2 , the invention is embodied in a memory card connector, generally designated  10 , for mounting on a printed circuit board  12 . The connector includes an insulating or dielectric housing, generally designated  14 , which mounts a first array of terminals, generally designated  16 , and a second array of terminals, generally designated  18 . 
   More particularly, housing  14  of memory card connector  10  includes a rear terminal-mounting section  20  and a pair of side wall sections  22  which extend forwardly from opposite ends of the rear section to form a generally U-shaped configuration which defines a card-receiving space, generally designated  24 , for receiving one or more memory cards. Rear section  20  of the housing has a rectangular receptacle  26  which is provided with vertical grooves  28  in the opposite end faces of the receptacle. Each side wall section  22  includes a pair of upper and lower longitudinal grooves  30  for receiving two memory cards. The lower groove  30  is quite visible in  FIGS. 1 and 2 , but the upper groove is not visible because of the presence of a metal baffle plate  32  which will be described hereinafter. A pair of through holes  34  are formed through the housing at opposite ends of rear section  20  and near the front of side wall sections  22  for securing the connector to circuit board  12  through holes  36  in the board. Finally, a plurality of positioning or mounting posts  38  project downwardly from the housing for insertion into a plurality of mounting holes  40  in the printed circuit board. 
   All of the terminals  16  and  18  in the first and second arrays thereof include contact portions which project into space  24  for engaging appropriate contacts on the first and second memory cards inserted into longitudinal grooves  30 . Contact portions  18   a  of terminals  18  are visible in  FIGS. 1 and 2 . Again, the contact portions of terminals  16  are not visible because of the presence of baffle plate  32 . Terminals  16  and  18  also include bent portions  16   b  and  18   b , respectively, which lead to tail portions  16   c  and  18   c , respectively, as is seen clearly in the drawings. Tails portions  16   c  of terminals  16  are engageable with circuit traces  42  ( FIG. 1 ) on circuit board  12 , and tail portions  18   c  of terminals  18  are engageable with circuit traces  44  on the circuit board. It can be seen that terminals  16  and  18  are arranged in two generally parallel rows across rear section  20  of the housing which results in tail portions  16   c  and  18   c  being in two generally parallel linear arrays corresponding to the two generally parallel or linear arrays of circuit traces  42  and  44  on the circuit board. 
   In order to guide tail portions  16   c  and  18   c  of terminals  16  and  18 , respectively, into alignment with circuit traces  42  and  44 , respectively, on circuit board  12 , the invention contemplates the provision of a tail guiding plate, generally designated  50 . The guiding plate is rectangular and sized to fit into rectangular receptacle  26  in the bottom of housing  14  along the rear terminal-mounting section  20  of the housing. The plate has a linear array of channels in the form of through passages  52  for receiving tail portions  16   c  of terminals  16  therethrough. The plate also has a linear array of channels in the form of through passages  54  for receiving tail portions  18   c  of terminals  18  therethrough. The plate has a plurality of ribs or tongues  56  for positioning in grooves  28  of receptacle  26 . The tongues and grooves are asymmetrical to ensure proper orientation of the plate. 
   Guiding plate  50  is positioned into receptacle  26  in the direction of arrow  A ( FIG. 1 ). Tail portions  16   c  and  18   c  of terminals  16  and  18 , respectively, will pass through the channels or passages  52  and  54 , respectively, of the guiding plate so that the tail portions are exposed at the bottom of the plate for engaging circuit traces  42  and  44 , respectively, on printed circuit board  12 . The plate prevents the tail portions from moving and precisely aligns the tail portions with the circuit traces regardless of the process used to connect the tail portions to the circuit traces, whether the process is a surface soldering process or a surface pressure process. In addition, it should be understood that the guiding plate would be equally applicable for use with tail portions which are inserted into holes in the printed circuit board. 
   Connector  10  includes a baffle groove  58  in the inside surface of each side wall section  22  of the housing between the upper and lower longitudinal grooves  30  which receive the two memory cards. Baffle plate  32  is inserted into baffle grooves  58 . The baffle plate is fabricated of metal material and provides electromagnetic interference (EMI) protection between the memory cards by providing a metal barrier therebetween. 
   Connector  10  also includes an ejection mechanism, generally designated  60 , mounted on one of the side walls sections  22  of the housing. The ejection mechanism includes a pair of independently operable ejecting arms  62  and  64  for ejecting one or both of the two memory cards which are insertable into the connector. 
   It can be seen in  FIGS. 1 and 2  that the first array of terminals  16  extends completely across the rear of the card-receiving space  24 , with the tail portions  16   c  of the terminals also in a long row. Printed circuit board  12  also has a corresponding long row of circuit traces  42  for engaging tail portions  16   c . However, terminals  18  are in a shorter row thereof with a shorter row of tail portions  18   c  for engaging the shorter row of circuit traces  44  on the printed circuit board. Terminals  16  may be applicable for engaging the contacts on a “card bus” type memory card, while the shorter array of terminals  18  might be applicable for engaging the contacts of a “newcard” type memory card inserted into the connector. 
     FIG. 3  shows memory card connector  10  mounted in a chassis, generally designated  66 , of an electrical appliance. The chassis has an outer wall  68  with an elongated opening  70  and a smaller opening  72 . First and second memory cards  74  and  76  are shown as having been inserted through opening  70  and into the card-receiving space  24  of memory card connector  10 . Ejecting arms  62  and  64  of the ejection mechanism are shown projecting through opening  72  and exposed for manual manipulation by an operator. Finally,  FIG. 3  shows that the memory card connector includes a metal top plate  78  which is not visible in the previously described depictions in  FIGS. 1 and 2 . 
   It will be understood that the invention may be embodied in other specific forms without departing from the spirit or central characteristics thereof. The present examples and embodiments, therefore, are to be considered in all respects as illustrative and not restrictive, and the invention is not to be limited to the details given herein.