Abstract:
Disclosed is an improvement in a CF card casing structure comprising at least a cover plate having a metal sheet surrounded by and fixed to an insert-molded frame, a counter cover plate of metal sheet and a receptacle connector. The insert-molded frame has catch slots made therein; and the counter cover plate has serrated latch pieces integrally connected thereto. Each latch piece is adapted to be inserted into a corresponding catch slot for detachably fastening the cover plate to the counter cover plate, thereby providing an integral assembly.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to a casing structure for packaging a small-sized PC card, which is commonly called “Compact Flash Card” (hereinafter referred to as “CF card”), and is used in a mobile personal computer, portable telephone, digital camera and any surrounding electric/electronic device therefor.  
           [0003]    2. Description of Related Art  
           [0004]    A conventional CF card casing structure is disclosed in U.S. Pat. No. 5,397,857. Referring to FIG. 9, the conventional CF card casing structure comprises upper and lower insert-molded plates each having a metal sheet circumferentially embedded in its resin-molded frame. A chip-carrier substrate and an associated electric connector are sandwiched between the upper and lower insert-molded plates, and their resin-molded frames are super-sonic welded to form an integral package.  
           [0005]    The upper and lower plates when subjected to the supersonic welding are liable to be deviated from their alignment position. The chip-carrier substrate has SMT leads soldered to its selected conductors, but such SMT leads when subjected to supersonic vibration are likely to come off. These will lead to poor yield of final products. The supersonic welding makes it difficult to take chip-carrier substrates off from defective packages for reuse. Even though the chip-carrier substrates are removed from such defective packages for reuse, the remaining casings cannot be reused, and therefore, new cover plates are required. The manufacturing cost of extra or additional cover plates is relatively high. Also disadvantageously, the chip-carrier substrates and I/O connectors when removed from the defective packages, are likely to be damaged more or less, and the cost involved for fixing such defective chip-carrier substrates for reuse is relatively high.  
         SUMMARY OF THE INVENTION  
         [0006]    One object of the present invention is to provide an improved CF card casing structure which is free of such defects or problems as described above.  
           [0007]    To attain this object a CF card casing structure comprising at least a cover plate having a metal sheet surrounded by and fixed to an insert-molded frame, a counter cover plate of metal sheet and a receptacle connector is improved according to the present invention in that: the insert-molded frame has a plurality of catch slots made therein; and the counter cover plate has a corresponding plurality of serrated latch pieces integrally connected thereto, each latch piece being adapted to be inserted into a corresponding catch slot for fastening the cover plate to the counter cover plate, thereby providing an integral assembly.  
           [0008]    The fastening of the opposite (top and bottom) cover plates by inserting the serrated latch pieces of one of the opposite cover plates into the catch slots of the other assures that the opposite cover plates thus fastened are free of any deviation in alignment position, which would be caused for instance, in subjecting the top and bottom cover plates to the supersonic welding. Also, chip-carrier substrates and I/O connectors can be easily removed from defective packages without being damaged, leaving the cover plates free of any damages, too. Thus, such disassembled parts can be reused.  
           [0009]    The cover plate and/or the counter cover plate may have an adhesive tape on its inside, the adhesive tape having adhesive partly applied to its carrier material, thereby permitting a sticky area to be left for fixing the receptacle connector, I/O connector and the like to selected areas of the cover plate by removing the carrier material. Thus, such parts can be fixedly attached to either cover plate with ease.  
           [0010]    The opposite cover plates may be latched together to be mechanically and electrically connected, thus permitting the shielding of a chip-carrier PCB sandwiched therebetween.  
           [0011]    The cover plate may have an insulating film applied to its inner metal surface, and likewise, the counter cover plate may have an insulating film applied to its inner metal surface, whereby the parts of the chip-carrier PCB sandwiched between the opposite cover plates may be protected from ESD voltage.  
           [0012]    Other objects and advantages of the present invention will be understood from the following description of a CF card casing structure according to a preferred embodiment of the present invention, which is shown in accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]    [0013]FIG. 1 is a perspective view of a CF card casing structure according to the present invention in the state of being used;  
         [0014]    FIGS.  2 ( a ), ( b ) and ( c ) are rear, side and front views of the CF card casing structure respectively;  
         [0015]    FIGS.  3 ( a ) and ( b ) are plane views of the resin-framed metal cover plate of the CF card casing structure as seen from top and bottom sides respectively;  
         [0016]    FIGS.  4 ( a ), ( b ) and ( c ) are rear, front and side views of the resin-framed metal cover plate of the CF card casing structure respectively;  
         [0017]    FIGS.  5 ( a ), ( b ), ( c ) and ( d ) are sectional views taken along the line  5   a - 5   a,  the line  5   b - 5   b,  and the line  5   c - 5   c  in FIG. 3, and FIG. 5( d ) is an enlarged fragmental view of encircled portion “ 5   d ” in FIG. 3;  
         [0018]    [0018]FIG. 6 is a plane view of the resin-framed metal cover plate with an adhesive tape applied to its metal sheet;  
         [0019]    [0019]FIG. 7 is a plane view of the metal cover plate of the CF card casing structure;  
         [0020]    FIGS.  8 ( a ) and ( b ) are side and rear views of the metal cover plate respectively; and  
         [0021]    [0021]FIG. 9 is a sectional view of a fragment of a conventional CF card casing structure. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0022]    Referring to FIGS. 1 and 2, a CF card casing structure  1  comprises a cover plate (bottom cover)  1   a  having a metal sheet  4  surrounded by and fixed to an insert-molded frame  2  of a synthetic resin such as PPS, a counter cover plate (top cover)  3  of metal sheet such as stainless sheet and a receptacle connector  11  and a socket  10 .  
         [0023]    As seen from FIG. 3, the resin-framed metal cover plate  1   a  is like a rectangular box, and it is for instance, about 36 mm long, about 43 mm wide and about 3.3 mm thick.  
         [0024]    As seen from FIG. 5, a metal sheet  4  is circumferentially embedded in a surrounding resin frame  2  in inject-molding, thus providing a resin-framed metal cover plate  1   a.    
         [0025]    The resin-molded frame  2  has an opening  5  made on its rear side (upper side in FIG. 3 a ) for accommodating the socket  10 , which a cable adapter  9  can be applied to for connecting a mobile electronic device. Also, it has another opening  6  made on its front side (lower side in FIG. 3 a ) for accommodating the receptacle connector  11 , which the pin-header of a CF card can be applied to.  
         [0026]    The resin-molded frame  2  has guide slots  7  made on its opposite sides for insertion into an associated electric/electronic device. Also, it has a finger catch  8  projecting from its rear, lower edge for withdrawal from the associated electric/electronic device.  
         [0027]    Referring to FIGS.  3  to  6 , particularly FIG. 6, the resin-molded frame  2  has engagement slots  12  made lengthwise in the rear, lateral side and engagement slots  13  made lengthwise in the opposite, longitudinal sides. These engagement slots  12  and  13  are adapted to catch the counter projections of the cover plate (top cover)  3 , as later described. Also, the resin-molded frame  2  has notches  2   a  made in the opposite, longitudinal sides. These notches  2   a  are adapted to catch the hook-like engagement projections of the top cover  3 , as later described, too.  
         [0028]    Referring to FIG. 6, a resin framed metal plate or bottom cover  1   a  has an insulating adhesive tape or sheet  14  applied to its inside. As shown in the drawing, the adhesive sheet  14  has a flap  14   a  extending from its front edge. The adhesive sheet  14  can be removed from the back of the bottom cover  1   a  along the broken lines “a” by pulling the flap  14  to leave the adhesive area delimited by the outer circumference and broken lines “a” of the adhesive sheet. The socket  10  and the receptacle connector  11  are fixed to the adhesive area thus exposed. The adhesive agent-free area  14   d  is defined inside the broken line “a”.  
         [0029]    Referring to FIGS. 7 and 8, the top metal cover  3  has serrated latch pieces  3   a  and  3   d  integrally connected to and standing upright from its rear, lateral and opposite longitudinal sides, and hook-like engagement pieces  3   b  and  3   c  integrally connected to and standing upright from its opposite longitudinal sides.  
         [0030]    The serrated latch pieces  3   a  and  3   d  are adapted to be caught by the catch slots whereas the hook-like engagement pieces  3   d  and  3   e  are adapted to be caught by the notches  2   a  of the bottom cover  1   a.  More specifically, when the top metal cover  3  is applied to the bottom framed-metal cover  1   a,  the serrated latch pieces  3   a  and  3   d  are pushed in the catch slots  13  to be caught thereby. The serration of each latch piece effectively prevents the slipping-off of the top cover  3  from the bottom cover  1   a.  When the top metal cover  3  is applied to the bottom framed-metal cover  1   a,  the hook-like engagement pieces  3   b  and  3   c  are pushed in the notched recesses  2   a  with their resilient hook ends  3   d  and  3   e  yieldingly bent inward, and then, the hook-like engagement pieces  3   b  and  3   c  are caught by the outer surface of the bottom cover  1   a  by allowing their resilient hook ends  3   d  and  3   e  to expand to their stress-free positions.  
         [0031]    As seen from FIG. 7, the top metal cover  3  has an insulating adhesive sheet  15  applied to the whole inner surface thereof. As shown, the insulating adhesive sheet has perforation  15   a  made therein, and a flap  15   b  projecting from the metal cover  3 . The area of the insulating adhesive sheet  15  which is delimited by the outer circumference and the perforation  15   a  can be removed by pulling the flap  15   b  to leave the adhesive area behind. The insulating adhesive sheet has no adhesive applied to its center area encircled by the broken line “b”.  
         [0032]    In assembling the top and bottom plates  3  and  1   a,  the receptacle connector  11  and the socket  10  into a card package  1 , first, the insulating adhesive sheet  14  is partly removed along the perforation line “a” from the framed metal cover  1   a  to leave the center adhesive-free area on the bottom plate  1   a  (see FIG. 6), and then the receptacle connector  11  is put on the adhesive area thus exposed, and a printed circuit substrate is putted on the center insulating area. The socket  10  is put on the rear side of the framed metal cover  1   a.    
         [0033]    Likewise, the insulating adhesive sheet  15  is partly removed from the top metal cover  3  along the perforation line  15   a , and then the top metal cover  3  is applied to the bottom cover  1   a  with its serrated and hook-like engagement pieces  3   a ,  3   d , and  3   b ,  3   c  caught by the catch slots  13  and notches  2   a . Thus, the card package  1  is provided as shown in FIG. 1.  
         [0034]    All parts are fixedly fastened in positions by means of latching means and by fixing the top and bottom covers in their adhesive circumferences. The chip-carrier PCB is pinched between the upper and lower insulating sheets of adhesive carrier material, and the top and bottom metal sheets are electrically connected by their hook-like engagement pieces  3   b ,  3   c , thereby permitting the chip-carrier PCB and associated contacts to be grounded to the surrounding shield thus provided.