Abstract:
A security arrangement for an electrical connector for connecting an electrical memory card to contacts wherein the connector includes a bottom plate made of insulating material including a series of blades for contact with a land of the card. The arrangement includes a protection element which bears at least one protection conductor circuit that at least partly surrounds the bottom plate of the connector. The bottom plate of the connector includes at least one additional contact blade including a top portion for connecting with the protection circuit of the protection element and a bottom portion for connecting with the at least one track connected to a detection circuit.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of priority to French Patent Application No. 0655259 filed Dec. 1, 2006, which is hereby incorporated by reference in its entirety. 
     BACKGROUND 
     Various fraud attempts on read/write devices equipped with a connector notably include a step aiming to reach an I/O contact blade. Such a maneuver is decisive in enabling chip card fraud. To this end, a fraudster can, for example, drill a hole in the insulating block bearing the contact blades and/or in the printed circuit board which, on its top face, is equipped with the connector. 
     Various arrangements that provide means to enable detection and prevention of fraud attempts have been used to enhance the overall security of read/write devices. For example, French Patent No. 2,875,036 describes an electrical connector including a metal plate forming a protective cage which extends facing a portion opposite the I/O contact blade, and which is electrically linked to a ground blade of the connector. Accordingly, any attempt to reach the I/O contact blade by means of a metal object, such as a metal drill, results in an electrical connection between the protective plate, which is connected to ground, and the first contact blade. As such, a short circuit is produced by grounding the first contact blade. A signal can be generated to represent a fraud attempt. 
     However such an arrangement does not effectively protect against fraud attempts by intrusion via the top and/or side faces of the duly protected connector. Moreover, the arrangement is not being concealed, which can enable a fraudster to more easily circumvent the arrangement. In addition, fraud detection occurs only “through” the blades of the connector, which can provoke a deterioration of the signal processing circuits to which the connector is linked. Furthermore, connecting the plate to the ground blade can result in complex structures and arrangements. 
     SUMMARY 
     In an embodiment, a device for an electrical connector for connecting an electrical memory card with contacts includes a bottom plate comprising an insulating material including a series of blades for contacting a land of the memory card. Each contact blade may be elastically deformable, arranged horizontally, and include a top portion for connecting with a contact land of the memory card. The contact land may project from the top face of the bottom plate of the connector. A bottom portion of each contact blade may connect with a conductive track on one side of a bottom printed circuit board including the connector. 
     The device may include a protection element including at least one protection conductor circuit that at least partly surrounds the bottom plate of the connector and connects to at least one track on a printed circuit board connected to a detection circuit. 
     In an embodiment, a security arrangement including a bottom plate of the connector includes at least one additional contact blade. The at least one additional contact blade may include a top portion for connecting with the protection circuit of the protection element and a bottom portion for connecting with the at least one track connected to a detection circuit. 
     In an embodiment, the bottom connecting portion of the additional contact blade may be similar to the blades for contact with the card. The bottom connecting portions may be coplanar and configured to be soldered and/or brazed to an associated track on the face of the printed circuit board. 
     The protection element may include a tab including at least one end of the protection circuit that extends through a slot in the bottom plate of the connector. The top connecting portion of the additional contact blade may be elastically deformable and may project into the slot so as to be electrically connected with the at least one end of the protection circuit when the tab is inserted into the slot. The top connecting portion of the additional contact blade may be oriented downwards and the at least one end of the protection circuit may be borne by the top face of the tab. 
     The contact blades for the land of the memory card may be in contact with a blade-bearing block made of insulating material on the bottom plate of the connector. The additional contact blade may be in contact with a cover on the bottom plate of the connector. 
     The protection element may include a protective cover on one side of the connector, and the protection circuit may be arranged inside the protective cover. The protective cover may include at least one fixing tab extending between the bottom plate of the connector and the top face of the printed circuit board. The protective cover may include a hole through which a post passes to fix the bottom plate of the connector. The hole may be surrounded by at least one track of the protection circuit. 
     The protection element may be produced in the form of a flexible or semi-rigid sheet. The protection element may include a protecting film of insulating material on which at least one track of the protection circuit snakes. The electrical continuity of the tracks of the protection circuit on the film and the protection element may be provided using at least one electrically conductive bridge. The conductive bridge may be electrically cut when the protection element and the film are vertically separated from each other. 
     The protection element may include several separate protection circuits each arranged snake-wise to form a protection circuit. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a top perspective view, which illustrates an arrangement according to a first embodiment, including a connector for a chip card topped by a protective cover. 
         FIG. 2  is a bottom perspective view of the connector of  FIG. 1 , illustrating the fixing and electrical connection of the protective cover to the contact blades by the bottom plate. 
         FIG. 3  is a bottom perspective view which illustrates the protective cover of  FIG. 1 . 
         FIG. 4  is a diagrammatic cross-sectional view which illustrates the arrangement of the tracks of the protection circuits on the vertical walls of the protective cover of  FIG. 1 . 
         FIG. 5  is a perspective exploded view which illustrates the protective cover of  FIG. 1  and a protective film. 
         FIG. 6  is an exploded perspective diagrammatic view which illustrates the conductive bridges for connecting electrical tracks of the protective cover of  FIG. 1  to electrical tracks of the protective film. 
         FIG. 7  is an electrical circuit diagram which illustrates the routing of the electrical tracks of two protection circuits which extend on the protective cover and the protective film. 
         FIG. 8  is a bottom perspective view which illustrates a block supporting the contact blades of the bottom plate of the connector of  FIG. 1 . 
         FIG. 9  is a top perspective view which illustrates a front cover and a rear cover for the contact blades of the connector of  FIG. 1 . 
         FIG. 10  is a top perspective view which illustrates the contact blades and the additional contact blades of the connector of  FIG. 1 . 
         FIG. 11  is a bottom perspective view which illustrates the rear cover of  FIG. 9  bearing the additional contact blades of the connector of  FIG. 1 . 
         FIG. 12  is a bottom perspective view which illustrates a second embodiment of the arrangement. 
         FIG. 13  is a bottom perspective view which illustrates the protective cover and the arrangement of the contact blades and of the additional contact blades of the connector of  FIG. 12 . 
     
    
    
     DETAILED DESCRIPTION 
     In the description that follows, identical, similar or analogous components are designated by the same reference numbers. 
     As a non-limiting example, to assist in understanding the description and the claims, the terms “vertical,” “horizontal,” “bottom,” “top,” “up,” “down,” “transversal,” “longitudinal,” and so on will be adopted with reference to the L, V, T trihedron indicated in the Figures. 
       FIG. 1  and FIG,  2  represent a connector  10  having a body  12 , or housing, which is implemented, for example, in an insulating material, such as plastic. The body  12  may be produced, for example, by molding. The general design of the connector  10  with its insulating body  12  may correspond to the connector described in U.S. Pat. No. 5,775,949. However, other connectors may be used within the scope of this disclosure. 
     The body  12  may include a top cover  14  and a bottom horizontal plate  16  which, once fitted together, delimit between them a longitudinal slot  18  for inserting, from front to rear in the direction indicated by the arrow “I” in  FIG. 1 , a chip card (not represented). In an embodiment, the top cover  14  may be molded together with the bottom horizontal plate  16 , so that the body  12  forms a single piece. 
     The bottom plate  16  of the connector  10  also makes it possible to fit and fix the connector  10  on a printed circuit board (PCB) of a read/write device (not represented), using, for example, two vertical posts  35 , such as those represented in  FIG. 2 . The chip card may include, on a bottom face oriented facing a top face  20  of the bottom horizontal plate  16  of the connector  10 , conductive lands. 
     As shown in  FIG. 1  and  FIG. 2 , the top cover  14  may include a top horizontal plate  22 , two vertical lateral side plates  24  and  26  which extend in the longitudinal direction “L,” and a bottom vertical lateral plate  28  which extends in the transverse direction “T.” 
     The two lateral plates  24  and  26  may oppose each other and provide lateral guidance of the chip card in the longitudinal direction “L,” limiting its transverse displacement. The bottom plate  28  may be perpendicular to the lateral plates  24  and  26  and delimit the bottom of the card insertion slot  18 . 
     As shown in  FIG. 8 , the bottom plate  16  of the connector  10  forms a blade-bearing insulating block  30  that supports a front group of elastically deformable electrical contact blades  32   a  and a rear group of elastically deformable electrical contact blades  32   b.  The bottom plate  16  may have a central part in transverse direction “T.” The overall design of the blade-bearing block  30  and blades  32   a ,  32   b  may include the blade-bearing block described and represented, for example, in U.S. Pat. No. 6,447,338. However, other connectors and blocks may be used within the scope of this disclosure. 
     Each contact blade  32   a ,  32   b , which are represented in detail in  FIG. 9  and  FIG. 10 , is disposed in parallel to the other contact blades and includes a top portion  31  for electrical connection with a contact land of the chip card that projects from the top face  20  of the horizontal bottom plate  16  of the connector  10 . Furthermore, each blade  32   a ,  32   b  includes a bottom portion  33  for electrically connecting the contact blade  32   a ,  32   b  with a conductive track on the top face of the printed circuit board (PCB) which includes the connector  10  to be connected to the read/write device. 
     The front group of contact blades  32   a  may be partly covered by a front cover  29   a  and the rear group of contact blades  32   b  may be covered by a rear cover  29   b , as illustrated in detail in  FIG. 9 . Each cover  29   a ,  29   b  may be interposed between the groups of blades  32   a ,  32   b  respectively and the printed circuit board (PCB) and may include, for example, four holes opening out vertically, for the bottom connecting portions  33  of the contact blades  32   a ,  32   b  to pass through. In an embodiment, the bottom connecting portions  33  may be connected to a conductive track on the top face of the PCB. Each cover  29   a ,  29   b  may further include two holes. Each hole may include a crimped post  27  that extends vertically downwards from the bottom face  19  of the plate  16  of the connector  10  to fix the covers  29   a ,  29   b  to the plate  16 . In an embodiment, at least one of the two covers  29   a ,  29   b  may, for example, support a metal protective cage or a metal protective plate, such as those described in French Patent Nos. 2,875,036 or 2,875,037. 
     Embodiments described herein seek to preferentially protect all the contact blades  32   a ,  32   b  against a fraud attempt by intrusion, for example, by creating an electrical contact with the contact blades  32   a ,  32   b  by means of a metal object or by drilling the connector  10 . To this end, the arrangement includes a protection element, such as the protective cover  34  represented in  FIG. 3 . 
     The protective cover  34  may be made of an insulating material, such as plastic. The protective cover  34  may overlap the top cover  14  in order to cover each plate  22 ,  24 ,  26 ,  28  of the top cover  14 , as illustrated in  FIG. 1  and  FIG. 2 . The protective cover  34  may include a horizontal top wall  36 , two vertical lateral walls  38 ,  40  and a vertical bottom wall  42 . 
     In an embodiment, the protective cover  34  has, for example, three pairs of fixing tabs  44 , such as those represented in  FIG. 3 . Each tab  44  may extend horizontally from a bottom edge  39 ,  41 ,  43  of a wall  38 ,  40 ,  42  vertically with respective to the protective cover  34  between the bottom plate  16  of the connector  10  and the top face of the printed circuit board (PCB). Each tab  44  may include a hole  46  which is passed through by a fixing post  48  associated with the bottom plate  16  of the connector  10 , as shown in  FIG. 1 . 
     The posts  48  may each extend vertically from the bottom face  19  of the bottom plate  16 , and may include a free end which is crushed and crimped on the associated tab  44 , to ensure the fixing of the protective cover  34  to the connector  10 . 
     Before being fixed to the connector  10 , the protective cover  34  initially takes the form of a pressed part, which is, for example, obtained by swaging. In an embodiment, the initial form of the protective cover  34  can be obtained by molding. In this initial form, the walls  38 ,  40 ,  42  of the protective cover  34  and its fixing tabs  44  extend perpendicularly to the top wall  36 . The protective cover  34  may be mounted on the connector  10  in this initial form, and the fixing tabs  44  of the protective cover  34  may be bent back against the bottom plate  16  of the connector  10 . 
     As illustrated in  FIG. 4  and  FIG. 5 , the bottom face of the protective cover  34  may include electrically conductive tracks which belong to protection circuits C 1  and C 2  and which snake without crossing. More specifically, the tracks of the protection circuits C 1  and C 2  may extend on the internal face of the horizontal wall  36 , of the two vertical lateral walls  38 ,  40  and of the bottom wall  42  of the protective cover  34  to form a protection network. The two lateral walls  38 ,  40  and the bottom wall  42  of the protective cover  34  may extend overall to the top face of the printed circuit board (PCB). In an embodiment, the protection circuits C 1 , C 2  may be, for example, printed using conductive ink. In an alternate embodiment, the protective circuits C 1 , C 2  may be chemically machined from a solid layer made of electrically conducting material. As will be discussed in more detail, the protection circuits C 1 , C 2  are connected to a detection circuit located on the top face of the printed circuit board (PCB) that can emit a signal representative of a fraud attempt. 
     Furthermore, as can he seen in  FIG. 5  and  FIG. 6 , the internal face of the protective cover  34  includes a protective film  52  comprising an insulating material, such as plastic. The internal face of the film  52  includes a set of tracks which snake, are produced using an electrically conductive material, such as copper, and belong to one of the protection circuits C 1 , C 2 . The protective film  52  may be bonded to the internal face of the protective cover  34  by means of, for example, an adhesive tape or glue. Thus, the protective cover  34  includes two protection circuits C 1 , C 2 , the tracks of which extend, overlaid, on the internal face of the protective cover  34  and on the internal face of the protective film  52 , forming a protection network. 
     The diagram of  FIG. 7  illustrates the arrangement of the various tracks of the protection circuits C 1 , C 2 . The first protection circuit C 1  includes a first track P 1  which snakes on the protective cover  34  from an input end E 1 , to a first electrically conductive bridge  54 . The first conductive bridge  54  is connected to a second track P 2  of the protection circuit C 1 , which snakes on the film  52  to a second conductive bridge  56 . Finally, the second conductive bridge  56  is connected to a third track P 3  of the protection circuit C 1 , which snakes on the protective cover  34  to an output end S 1 . 
     The second circuit C 2  is produced in the same way; it includes a fourth track P 4  which snakes on the protective cover  34  from an input end E 2 , to a third electrically conductive bridge  58 . The third conductive bridge  58  is connected to a fifth track P 5  of the protection circuit C 2 , which snakes on the film  52  to a fourth conductive bridge  60 . Finally, the fourth conductive bridge  60  is connected to a sixth track P 6  of the protection circuit C 2 , which snakes on the protective cover  34  to an output end S 2 . 
     Advantageously, the designs of the circuits C 1  and C 2  are different and complementary, such that the circuits C 1  and C 2  form a dense network of conductive tracks. 
     As shown in  FIG. 6 , the bridges that provide the electrical continuity of the tracks may each include a terminal  54   a ,  56   a ,  58   a ,  60   a  made of a conductive material, such as copper. Each terminal  54   a ,  56   a ,  58   a ,  60   a  of the bridge may extend horizontally on the top face of the film  52 , and include a first face in electrical contact with a track of the film  52  and a second opposing face in contact with a complementary track of the protective cover  34 , such that, when the film  52  and the protective cover  34  are vertically offset from one another, the bridges do not provide electrical continuity. As such, at least one protection circuit C 1 , C 2  may be an open circuit. 
     The protective cover  34  may include a tab  62 , such as the one illustrated in  FIG. 3 , which extends horizontally from the bottom edge  43  of the bottom wall  42  of the protective cover  34 . The tab  62  of the protective cover  34  may be inserted into slot  64  of the rear cover  29   b . The slot  64  may include a transverse opening which is arranged in a rear edge  66  of the rear cover  29   b . When inserted, tab  62  may contact the contact blades  32   b.    
     The tab  62  of the protective cover  34  may include, on its top face, the input ends E 1 , E 2  and the output ends S 1 , S 2  of each of the two protection circuits C 1  and C 2 , in the manner of a connecting ribbon cable. In an embodiment, the bottom plate  16  of the connector  10  includes, for example, four additional contact blades  68  for connecting the input ends E 1 , E 2  and output ends S 1 , S 2  with an associated track connected to the detection circuit. The four additional contact blades  68  may be located on the rear cover  29   b , as shown in  FIG. 9  and  FIG. 11 . 
     When the tab  62  of the protective cover  34  is arranged in the slot  64  of the rear cover  29   b , each of the input ends E 1 , E 2  and the output ends S 1 , S 2  may be electrically connected with the associated additional contact blades  68 , as illustrated in  FIG. 10 . Each additional contact blade  68  may extend in a vertical plane and may include, at a first end, a bottom portion  72  connecting with an associated track of the detection circuit. The bottom connecting portion  72  of each additional contact blade  68  may extend horizontally in the same plane as the bottom connecting portions  33  of the contact blades  32   a ,  32   b  so as to solder or braze each bottom connecting portion  33 ,  72  of the blades  32   a ,  32   b ,  68  to an associated track of the printed circuit board (PCB). 
     Each additional contact blade  68  may include, at a second end, a top portion  70  connecting with an input end E 1 , E 2  or output end S 1 , S 2  of the protection circuits C 1  and C 2 . Each top connecting portion  70  may be concave, incurved downwards, and may project in the slot  64  for insertion of the tab  62  of the protective cover  34 , so as to electrically connect to an associated input end E 1 , E 2  or output end S 1 , S 2 . To this end, each top connecting portion  70  may be elastically deformed, for example, when passed through the tab  62  of the protective cover  34 . 
     Each additional contact blade  68  may include a bent middle portion  69  which connects the top connecting portion  70  with the bottom connecting portion  72 . Each middle portion  69  may include a vertical strand and a horizontal strand. Each strand may include transverse projections in order to ensure the fixing and the positioning of the blade  68 , such as in the rear cover  29   b . The four additional contact blades  68  may be identically shaped, produced by bending and made of an electrically conductive material, such as copper or copper alloy. According to a second embodiment represented in  FIG. 12  and  FIG. 13 , the protective cover  34  includes a first tab  74  and a second tab  76  each of which extends horizontally and transversally from a bottom edge  39 ,  41  respective to the vertical walls  38 ,  40  of the protective cover  34  and facing the bottom face of the bottom plate  16  of the connector  10 . The first tab  74  includes, on its top face, the input end E 1  and the output end S 1  of the protection circuit C 1  and the second tab  76  includes, on its top face, the input end E 2  and the output end S 2  of the protection circuit C 2 . 
     According to this second embodiment, the bottom plate  16  of the connector  10  includes, for example, four additional contact blades  78 , which extend in opposing pairs in a transverse direction. Each additional contact blade  78  may include, at a first end, a bottom portion  82  for connecting with an associated track of the detection circuit. The bottom connecting portion  82  of each additional contact blade  78  may extend horizontally in the same plane as the bottom connecting portions  33  of the contact blades  32   a ,  32   b  so as to solder or braze each bottom connecting portion  33 ,  72  of the blades  32   a ,  32   b ,  78  to an associated track of the printed circuit board (PCB). 
     Each additional contact blade  78  may further include a middle portion  79  which ensures the fixing and the positioning of the blade  78  on the bottom plate  16  of the connector  10 . To this end, each middle portion may include a hole passed through by a post  84  which extends vertically downwards from the bottom face  19  of the bottom plate  16 . Advantageously, the free end of each post  84  may be crushed and crimped with the associated additional contact blade  78  to ensure the fixing of the additional contact blades  78  on the connector  10 . 
     Each additional contact blade  78  may further include, at a second end, a top portion  80  for connecting with an associated input end E 1 , E 2  or output end S 1 , S 2  of the protection circuits C 1  and C 2 . Each top connecting portion  80  may be concave, incurved downwards, so as to be electrically connected to the associated input end E 1 , E 2  or output end S 1 , S 2 . 
     The additional contact blades  78  may be identically shaped, produced by bending, and made of an electrically conductive material, such as copper or copper alloy. 
     The tab  74  and the tab  76  may each include a hole configured to be passed through by a post  75  extending vertically from the bottom face  19  of the bottom plate  16  of the connector  10 . Advantageously, the free end of each post  75  may be crushed and crimped on the associated tab  74 ,  76 , so as to lock the tabs  74 ,  76  on the connector  10 . 
     When a fraudster tries to drill the top cover  14  to reach one of the contact blades  32   a ,  32   b  of the connector  10 , such as by using a metal drill, the fraudster may cut at least one of the tracks of circuit C 1  and/or C 2 . As such, current no longer circulates in the broken track, and the detection circuit detects the discontinuity of the cut track and emits a signal representative of a fraud attempt. This detection mode has the advantage of being effective even if the device used to drill is not made of conductive material. 
     If a drill instead damages one or more tracks of the circuit C 1  and/or C 2  by reducing its cross-sectional area at the point of drilling, the fraud attempt may be detected by measuring the variation of resistance of the damaged track because the resistance of a wire, or of a track may be reduced. This may occur because the resistance is inversely proportional to its cross-sectional area. As such, the resistance of the damaged track may be less than its initial resistance. 
     In a third scenario, the fraudster may drill a hole with a metal drill between two separate tracks of the circuit C 1  and/or C 2 . In this case, the two drilled tracks may come into electrical contact via the metal drill, which enables the detection circuit to detect a short circuit between the two tracks and emit a signal representative of a fraud attempt. 
     In a fourth scenario, the fraudster may try to remove the protective cover  34  from the connector  10 , which cannot be done without tearing at least one fixing tab  44  of the protective cover  34  because the hole  46  of each fixing tab  44  which is passed through by a post  48  of the connector  10  is surrounded by at least one track of one of the two protection circuits C 1 , C 2 . The detection circuit may detect the discontinuity of the cut track and emit a signal representative of a fraud attempt. 
     In a fifth scenario, the fraudster may try to shunt a part of one of the two protection circuits C 1  or C 2  in order to be able to cut the shunted part without detection by the detection circuit. However, because the tracks of the protection circuits C 1  and C 2  cannot be discerned from one another, the fraudster risks creating a short circuit that can be detected by the detection circuit. 
     In at least these five detection cases, any communication between the chip card and the read/write device may be prevented to avoid any fraud or any spoofing. 
     Furthermore, the tab  62  of the protective cover  34  which includes the input ends E 1 , E 2  and the output ends S 1 , S 2  of each of the two protection circuits C 1  and C 2  is ideally arranged under the connector  10 . The tab  62  may be arranged inside the protective cover  34 , such that access to the tab  62  is limited. Tabs  74 ,  76  of the protective cover  34  may be similarly well protected. 
     According to a variant of an embodiment represented in  FIG. 4 , the external face of the protective cover  34  may include an external electrically-conductive protection layer comprising, for example, copper, electrically connected to ground. To this end the external protection layer of the protective cover  34  may include two soldering areas electrically connected to ground via a track of the top face of the printed circuit board (PCB). 
     As can he seen in  FIG. 4 , the portions of the bottom face which are facing the two soldering areas Z 1 , Z 2  do not include conductive tracks of the protection circuits C 1 , C 2  in order to avoid soldering the tracks to ground. Such an embodiment may offer an additional level of protection. 
     If a fraudster drills the protective cover  34  using, for example, a metal drill, at least one track of one of the protection circuits C 1 , C 2  may come into electrical contact with ground via the external protection layer and via the metal drill. This may enable the detection circuit to detect a short circuit between the two tracks and emit a signal representative of a fraud attempt. 
     By way of variants not represented, there are various embodiments of connector including a blade-bearing block  30 , independently of the design of the card guidance means, the latter being able to be fitted in any orientation relative to the blade-bearing block  30 . Similarly, the variants of embodiment described previously can be combined. 
     Similarly, the tracks of the protection circuits C 1  and C 2  can be formed by deposition techniques like pad printing or screen printing using a conductive ink or paint. The arrangement makes it possible to produce an electrical connector for connecting a chip card which is fitted with an effective protective cover for detecting fraud attempts, notably through the arrangement of the additional contact tabs. In practice, the additional contact tabs are arranged so as to be protected by the protective cover. Furthermore, the assembly formed by a connector and a protective cover produced according to the embodiments forms a product which is able to operate after a simple operation connecting the product to the PCB.