Abstract:
A stacked electronic card connector assembly includes a Smart Card connector including a housing retaining a number of first contacts and a Card Bus connector including a header retaining a number of second contacts. An insulative frame defines an opening to receive and retain the housing of the Smart Card connector. The frame is secured to the header of the Card Bus connector for interposing and fixing the housing therebetween thereby forming a stack. A first portion of a board-to-board connector is connected to the first and second contacts by a flexible printed circuit board. A second portion of the board-to-board connector is mounted a main computer board of for example a notebook computer.

Description:
FIELD OF THE INVENTION 
     The present invention generally relates to electronic card connectors for reading/accessing electronic cards, such as memory cards, and in particular to a stacked assembly of two electronic card connectors of different types, such as a PCMCIA/Card Bus connector and a Smart Card connector. 
     BACKGROUND OF THE INVENTION 
     Electronic card connectors have been widely used in a variety of electronic devices that require additional memory. Examples of the electronic cards are PCMCIA (Card Bus) cards and Smart Cards. Each different electronic card can only be accessed by means of a unique connector. Conventionally, a PCMCIA/Card Bus connector and a Smart Card connector are individually mounted in for example a notebook computer. This not only increases the number of parts of the notebook computer, but also requires a great amount of space for accommodating these individual electronic card connectors. 
     It is thus desirable to provide a stacked assembly of a PCMCIA/Card Bus connector and a Smart Card connector for alleviating the above-discussed problems. Two other copending applications with unknown serial numbers, the same applicant, the same title, the same assignee and the same filing date, also disclose some other approaches to cure the shortcoming of the prior art. 
     SUMMARY OF THE INVENTION 
     Accordingly, an object of the present invention is to provide a stacked assembly of a PCMCIA/Card Bus connector and a Smart Card connector 
     Another object of the present invention is to provide a stacked electronic card connector assembly comprising two different electronic card connectors stacked over each other for reducing footprint of a printed circuit board that the electronic card connectors occupy. 
     A further object of the present invention is to provide an electronic card connector assembly which comprises less number of parts. 
     To achieve the above objects, in accordance with the present invention, there is provided a stacked electronic card connector assembly comprising a first electronic card connector, such as a Smart Card connector, comprising a housing retaining a number of first contacts and a second electronic card connector, such as a Card Bus connector, comprising a header retaining a number of second contacts. An insulative frame defines an opening to receive and retain the housing of the first electronic card connector. The frame is secured to the header of the second electronic card connector for interposing and fixing the housing therebetween thereby forming a stack. A first portion of a board-to-board connector is connected to the first and second contacts by a flexible printed circuit board. A second portion of the board-to-board connector is mounted a main computer board of for example a notebook computer. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will be apparent to those skilled in the art by reading the following description of a preferred embodiment thereof, with reference to the attached drawings, in which: 
     FIG. 1 is a perspective view of a stacked electronic card connector assembly constructed in accordance with the present invention; 
     FIG. 2 is a perspective view showing a first, Smart Card connector of the stacked electronic card connector assembly in accordance with the present invention; 
     FIG. 3 is a side elevational view of the Smart Card connector shown in FIG. 2; 
     FIG. 4 is an end view of the Smart Card connector shown in FIG. 2; 
     FIG. 5 is a perspective view of a retention housing of the Smart Card connector shown in FIG. 2; 
     FIG. 6 is similar to FIG. 5 but showing the Smart Card connector mounted in the retention housing of FIG. 5; 
     FIG. 7 is a perspective view of a second, PCMCIA/Card Bus connector of the stacked electronic card connector assembly in accordance with the present invention; 
     FIG. 8 is an assembled view of the Smart Card connector, as well as the retention housing thereof, and the PCMCIA/Card Bus connector; 
     FIG. 9 is a side elevational view of FIG. 8 with the retention housing of the Smart Card connector removed; and 
     FIG. 10 is a perspective view showing the stacked electronic card connector assembly mounted to a printed circuit board. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     With reference to the drawings and in particular to FIGS. 1 and 10, a stacked electronic card connector assembly constructed in accordance with the present invention, generally designated with reference numeral  10 , comprises a first electronic card connector  12  and a second electronic card connector  14  fixed to each other in a stacking fashion whereby the second electronic card connector  14  is stacked over the first electronic cad connector  12 . An electrical connector  16  is electrically connected to both the first and second electronic card connectors  12 ,  14  by means of a flexible printed circuit board  18 . In the embodiment illustrated, the electrical connector  16  is a first portion of a so called board-to-board connector which comprises a second portion  20  mounted on a printed circuit board  22  and mateable with the first portion  16  for electrically connecting the electronic card connectors  12 ,  14  to the printed circuit board  22 . The printed circuit board  22  may be a main board of a notebook computer (not shown). 
     Also referring to FIGS. 2-6, in the embodiment illustrated, the first electronic card connector  12  is a Smart Card connector comprising a number of first conductive contacts  24  retained in a first insulative housing  26 . The first contacts  24  have a resilient or elastically deformable portions  25  extend beyond the first housing  26  for electrically engaging a Smart Card (not shown). One way to fix the first contacts  24  in the first housing  26  is insert molding. This is well known and thus no further detail is needed herein. The first housing  26  forms step-like flanges  28  on opposite sides thereof, A cylindrical projection  30  is formed on the flange  28 . A slot  32  is defined in each flange  28 . 
     The first electronic card connector  12  also comprises a retention housing  34  comprises an insulative frame  36  supporting a first shielding shell  38  made of a conductive material, such as metal. The frame  36  comprises two spaced and opposite portions  40  defining an interior space therebetween for guiding and receiving a Smart Card (not shown). An opening  42  is defined in the frame  36  for accommodating the first electronic card connector  12 . Two steps  44  are formed along opposite side walls of the opening  42  and each step  44  defines a bore  46 . The first electronic card connector  12  is received in the opening  42  with the side flanges  28  positioned on and supported by the steps  44  of the opening  42 . The cylindrical projections  30  of the side flanges  28  receivingly engage the bores  46  of the steps  44  for properly positioning the first housing  26  in the frame  36 . If desired, a force fit may be formed between the projections  30  and the bores  46  for retaining the first electronic card connector  12  in the retention housing  34 . 
     The first housing  26  of the first electronic card connector  12  has an inner end wall  48  in which a cavity  50  is defined. Corresponding to the cavity  50 , the first shielding shell  38  forms a tab  52  received in and engaging the cavity  50  for attaching the parts together and for positioning these parts with respect to each other. 
     Also referring to FIG. 7, in the embodiment illustrated, the second electronic card connector  14  is a PCMCIA/Card Bus connector comprising an insulative header  54  retaining a number of second conductive contacts  56  extending beyond the header  54  in opposite sides of the header  54 . An outward-facing surface  58  is stacked on the first electronic card connector  12  and partly the insulative frame  36  for interposing the first electronic card connector  12  between the frame  36  and the second electronic card connector  14 . Two latches  60  are formed on and extending from the outward-facing surface  58 , each comprising a barb  62  extending in opposite directions. The latches  60  extend into the slots  32  defined in the first housing  26  with the barbs  62  engage edges of the slots  32  to secure the second electronic card connector  14  to the first electronic card connector  12 . If desired, recesses  64  can be formed in the steps  44  of the frame  36  of the first electronic card connector  12 , corresponding to and aligned with the slots  32  for accommodating the portions of the latches  60  that extend beyond the first housing  26  of the first electronic card connector  12 . If desired, the latches  60  can be dimensioned to extend through both the slots  32  and the recesses  64  for securing the second electronic card connector  14  and the first electronic card connector  12  to the frame  36  of the retention housing  34 . However, it is understood that the second electronic card connector  14  can be secured to the first electronic card connector  12  and the frame  36  by any known means, such as bolts. 
     A shielding plate  66  is attached to the header  54  opposite to the outward-facing surface  58 . The shielding plate  66  substantially covers the second contacts  56  for EMI (Electro-Magnetic Interference) protection and grounding purposes. 
     Two guide arms  68  extend from opposite ends of the header  54  forming an interior space  69  therebetween for accommodating a PCMCIA card (not shown). A guiding slot  70  is defined in an inside face  72  of each arm  68  for guiding the PCMCIA card toward the second contacts  56  and thus establishing electrical engagement therebetween. 
     referring to FIGS. 8 and 9, the electronic card connectors  12 ,  14  are connected to a first one of a pair of mateable connectors,  16 ,  20 . As mentioned above, the pair of mateable connectors  16 ,  20  is a board-to-board connector comprising a first portion  16  and a second portion  20  that are mateable with each other. The first connector  16  is electrically connected to the electronic card connectors  12 ,  14  by a flexible circuit board  18  on which a conductive pattern is formed. The first connector  16  is mounted to the flexible circuit board  18  and is electrically connected to the conductive pattern. Holes (not labeled) are defined in the flexible circuit board  18  corresponding to the conductive pattern. Tails  27 ,  57  of the first and second contacts  24 ,  56  that extend beyond the first housing  26  and header  54  of the first and second electronic card connectors  12 ,  14  are received in the holes and soldered to the conductive pattern to establish electrical connection therebetween. The shielding plate  64  forms a number of projections  74  received in corresponding holes (not labeled) defined in the flexible circuit board  18  and soldered thereto for forming grounding connection. 
     Also referring to FIG. 10, a second, outer shielding shell  76  is attached to and supported by the first shielding shell  36  defining a space continuous with the interior space  69  of the header  54  for receiving and accommodating the PCMCIA card. The second shielding shell  76  is provided with extensions (not shown) received in and engaging with slits  78  defined in the first shielding shell  38  for securing the first shielding shell  76  to the first shielding shell  38 . Other known securing means may also be employed to secure the parts of the connector assembly  100  together. Details are not needed herein. 
     Although the present invention has been described with reference to the preferred embodiment thereof, it is apparent to those skilled in the art that a variety of modifications and changes may be made without departing from the scope of the present invention which is intended to be defined by the appended claims.