Secured body for memory card reader
10312625 ยท 2019-06-04
Assignee
Inventors
- Jerome Andre (Montoison, FR)
- Stephane Pavageau (La Roche de Glun, FR)
- Olivier BERTHIAUD (Cornas, FR)
- Yann Granddidier (LEMPS, FR)
Cpc classification
G06K7/0091
PHYSICS
G06K7/0021
PHYSICS
G06K7/0082
PHYSICS
G06K7/0078
PHYSICS
H01R12/7005
ELECTRICITY
H01R12/712
ELECTRICITY
International classification
G06K7/00
PHYSICS
Abstract
A memory card reader body of a generally parallelepiped shape has a slot for insertion of a memory card and a housing to receive a memory card connector. The reader body has an upper cover and a lower base. The upper cover is made out of metal and the reader body further includes a printed-circuit board affixed to an upper face of the upper cover. The printed-circuit board includes at least one protection element.
Claims
1. A memory card reader body of a generally parallelepiped shape comprising: an upper cover and a lower base, wherein said upper cover is made out of metal, said lower base and upper cover form a slot for insertion of a memory card and said lower base comprising a housing to receive a memory card connector; and a printed-circuit board affixed to an upper face of said upper cover, said printed-circuit board comprising at least one protection element taking the form of at least one lattice, an etching density of said protection element being variable according to a location of said protection element.
2. The memory card reader body according to claim 1, wherein said printed-circuit board covers a major part of the upper face of said upper cover.
3. The memory card reader body according to claim 1, wherein said protection element extends substantially over a major part of said printed-circuit board.
4. The memory card reader body according to claim 1, wherein said upper cover comprises at least one protrusion extending substantially perpendicularly to said upper face of the upper cover.
5. The memory card reader body according to claim 1, wherein said upper cover comprises, in proximity to a hole passing through said upper cover, at least one metal tab extending substantially perpendicularly to a lower face of the upper cover.
6. The memory card reader body according to claim 1, wherein said upper cover comprises at least one card-landing mechanism.
7. The memory card reader body according to claim 6, wherein said card-landing mechanism comprises a mobile counter-pressure element and said upper cover comprises a housing to receive said mobile counter-pressure element, said mobile counter-pressure element being mobile between two positions: a position of reading in which said mobile counter-pressure element exerts pressure on a memory card inserted into the insertion slot of the memory card reader; a waiting position in which said mobile counter-pressure element is at least partially positioned in said receiving housing.
8. The memory card reader body according to claim 7, wherein said housing to receive the mobile counter-pressure element takes the form of a hole within said upper cover.
9. The memory card reader body according to claim 1 wherein the lower base comprises at least one card-braking device.
10. The memory card reader body according to claim 1, wherein the lower base comprises at least one electrostatic discharge zone.
11. A memory card reader terminal comprising the memory card reader body according to claim 1.
12. A method for assembling a memory card reader, comprising: affixing a memory card connector to a motherboard; positioning a lower base on said memory card connector; assembling an upper cover on said lower base, wherein said upper cover is made out of metal, said lower base and upper cover forming a slot for insertion of a memory card; affixing a printed-circuit board to an upper face of said upper cover, said printed-circuit board comprising at least one protection element taking the form of at least one lattice, an etching density of said protection element being variable according to a location of said protection element.
Description
4. FIGURES
(1) Other features and advantages of the invention shall appear more clearly from the following description of a preferred embodiment, given by way of a simple, illustratory and non-exhaustive example and from the appended figures of which:
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5. DETAILED DESCRIPTION
(14) 5.1. General Principle
(15) The general principle of the invention consists in proposing a memory card reader architecture that relies on a separation of the reader into two distinct parts or functional units: a first partthat corresponds to the memory card connectorthrough which the memory card signals travel in transit and that also comprises means for detecting the presence of a memory card (these means are called switches), and that can also carry out a part of the electrostatic discharge; a second partthat corresponds to the body of the memory card readerenabling the insertion of the memory card, carrying out on the one hand the guiding and absorption of forces of the memory card and, on the other hand, a part of the electrostatic discharge of the card, and also providing protection for the signals exchanged between the memory card and the memory card connector.
(16) According to the proposed technique, the body of the memory card reader is itself formed by three main distinct parts: a lower base, an upper cover or hood and a printed-circuit board comprising one or more protection elements that extend over a significant portion of its surface. The lower base and the upper cover can be fitted into each other and, once assembled, form an insertion slot for inserting a memory card. The upper cover and the printed-circuit board are furthermore shaped and sized so that the printed-circuit board can be fixed to the upper cover.
(17) The general principle of the invention is described in greater detail with reference to
(18) The memory card connector 20 is independent of the body of the memory card reader 21. In other words, the memory card connector 20 is not assembled with the body of the memory card reader 21 before being assembled with the motherboard of the reader terminal: according to the proposed technique, the memory card connector 20 is affixed firstly to the motherboard and then the body of the memory card reader 21 is assembled above the connector 20.
(19) As described previously, the body of the memory card reader 21 itself comprises three main parts: a lower part 21A, an upper cover 21B and a printed-circuit board 21C, that surmounts the upper cover 21B. The lower base 21A comprises a housing to receive the memory card connector 20. This housing takes the form of a hole passing through the lower base 21A from one side to the other; the connector 20 gets housed in this hole when the lower base 21A is positioned on the motherboard. In other words, the memory card connector 20 is first of all affixed to the motherboard, and then the lower base 21A of the body of the memory card reader is positioned on the motherboard in a second stage, around the previously installed connector. The upper cover 21B is then joined to the lower base 21A so as to form a slot for inserting a memory card within the reader. Finally, the printed-circuit board 21C is affixed to the upper face of the upper cover so as to cover a major part of it, ideally its entirety. As an alternative, it can happen that the block formed by the upper cover 21B and the printed-circuit board 21C has been pre-assembled, before the phase for mounting the memory card reader. In this case, it is the totality of this pre-assembled block that is positioned on the lower base 21A during the mounting of the reader.
(20) The printed-circuit board 21C comprises at least one protection element that takes for example the form of one or more intrusion-detecting lattice elements or the form of one or more intrusion-detecting continuous tracks (for example a ground circuit and two lattices at different potentials). This protection element or these protection elements are positioned so as to cover a major part on the surface of the printed-circuit board 21C. Ideally, they are distributed on the entire surface of the printed-circuit board 21C so as to provide increased securing of the memory card reader.
(21) This three-part architecture of the body of the memory card reader 21 has numerous advantages as compared with the prior art solutions.
(22) The fact is that the joining and affixing of the memory card reader to the motherboard are simplified and can be carried out in a limited number of steps. The implementing of the reader body, of which the insertion slot is formed by means of two nesting parts (lower base and upper cover) furthermore enables the simple application of complementary characteristics that would have been difficult and/or costly to implement with a body made in only one piece, owing to the technical nature of these characteristics. Examples of such characteristics are described in detail here below, with reference to the presentation of one particular embodiment of the proposed technique.
(23) Besides, the coupling between an upper cover and a printed-circuit board provides for a promising compromise between, on the one hand, the level of securing of the reader once it is assembled and, on the other hand, the complexity and cost of production of the parts of the component, especially when this approach is compared with complex prior art solutions based on the production of MID parts by means of the LDS technique for example. Indeed, with the proposed technique, the printed-circuit board can take the form of a classic printed-circuit board on an epoxy support, the robustness of which is reinforced by the thickness of the upper cover onto which it is fixed. Preferably, the upper cover is made of metal. Thus, it has increased mechanical resistance as compared with traditional solutions based on plastic materials while offering the advantage of being capable undergoing large-scale production at lower cost through the use of known techniques for cutting out and embossing metal plates for example.
(24) Here below, a specific embodiment of the invention is described, it being understood that this embodiment in no way limits the scope of the invention. More particularly, in other embodiments of the invention, the shapes of the lower base and of the upper cover and their respective assembling means are not limited to those described here below.
(25) 5.2. Detailed Description of One Embodiment
(26) This embodiment is presented more particularly with reference to
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(28) 5.2.1 Upper Cover and Printed-circuit Board
(29) The upper cover 21B of the body of the memory card reader 21 is presented in greater detail with reference to
(30) Embossing
(31) In one particular embodiment, the upper cover 21B is embossed so as to have protrusions 33 that form a set of protuberances on the upper face 30S (only some protrusions are referenced in
(32) Acting as supporting surfaces for the printed-circuit board, the protrusions 33 are present on the upper cover 21B can also serve as surfaces for affixing the printed-circuit board to the upper cover. Different embodiments can then be envisaged to obtain this affixation. When the upper cover is metallic, the printed-circuit board 23C can for example be soldered to the upper cover 21B at the level of these protrusions 33 using for example an SMC (surface-mounted component) reflow soldering technique. In this case, it is necessary to plan in advance for shapes, locations and/or special routings on the printed-circuit board 21C enabling such solders to be made. In particular, soldering zones for grounded soldering are needed. In another embodiment, the affixing can be done by the use of a dual-face adhesive located at the protrusions 33 or throughout the main surface of the upper cover 21B. In this case, it is no longer necessary to provide for particular routings on the printed-circuit board 21C. Other modes of affixing the printed-circuit board to the upper surface can also be planned within the framework of the proposed technique as a complement or alternative to an affixation at the level of the protrusions 33. Thus, in one particular embodiment, the upper cover comprises at least one metal strip 35 extending substantially perpendicularly to its main surface 30, on its upper face 30S side. These metal blades 35 are for example formed during the embossing of the upper cover 21B when this cover is made of metal. These metal blades have a height greater than that of the protrusions 33. In this embodiment, the printed-circuit board 21C comprises metalized via holes that are shaped and sized so that each of them is capable of receiving a corresponding metal strip 35 of the upper cover 21B. The affixing of the printed-circuit board to the upper cover is then provided by means of a soldering operation of a via-component soldering type. The shape and position of the holes can be planned so as to prevent inaccurate mounting of the printed-circuit board on the upper cover (they then act not only as position-correcting elements but also as centering points that ensure accurate positioning of the printed-circuit board so as to ensure a reliable connection of this printed-circuit board with the motherboard in particular when such a connection is provided by a Zebra type elastomer connector). Such metalized holes 38 can for example be seen in
(33) The protrusions 33 of the upper cover furthermore have a reinforcement role: through their generally rectilinear shape and their distribution throughout the main surface 30 of the upper cover, they reinforce the robustness of the upper cover 21B. The result of this is that this upper cover 21B is more resistant to folding for example. Besides, the affixing of a metal part (i.e. the upper cover 21B thus honeycombed by the presence of these protrusions 33) to the printed-circuit board 21C (generally made of epoxy resin, i.e. thin and relatively brittle) adds a high degree of stiffness to the entire body of the memory card reader.
(34) Protection Elements
(35) As already explained here above, the printed-circuit board 21C comprises at least one protection element. According to one particular characteristic, this protection element (or the plurality of protection elements) extends substantially throughout the surface of the printed-circuit board, and the printed-circuit board 21C is shaped and sized so that, once it is fixed to the upper cover 21B of the body of the reader, it covers its entire upper surface or at least a major part of this surface. In this way, the surface covered by the protection element is substantial and secures the body of the memory card reader efficiently. The mechanical resistance of the upper cover, especially when it is made of metal, further reinforces this securing. Besides, the use of a classic printed-circuit board proves to be less costly and simpler to implement than other prior-art techniques, such as the one in which MID and LDS technologies are used to directly plot a protection element (taking for example the form of a circuit) within the upper cover of the body of the memory card reader. The proposed solution therefore offers a worthwhile compromise because it ensures a major level of security while at the same time being less complex and less costly to implement then the prior-art solutions. Advantageously, the printed-circuit board 21C also offers a surface that can be used for the integration, in addition to the protection element or elements, of other tracks and components necessary to fulfill various other ancillary functions. In this respect, the presence of protrusions 33 on the upper cover 21B can also be of interest in that the elevation obtained for the printed-circuit board enables the exploitation of the internal face of the circuit too (the one that faces the upper face 30S of the upper cover) for the installation of various electronic components.
(36) In one particular embodiment, the protection element takes the form of electronic tracks that form at least one protection lattice. Several lattice densities can be implemented. More particularly, a high density zone corresponds to immediate protection (against direct piercing above the connector to access sensitive signals). A lower density zone corresponds to protection against indirect attacks (piercing, then insertion of objects slantwise to access sensitive signals as described here above). Such a solution is advantageous because it reduces the cost of manufacture of the printed-circuit board without however impairing security. The lowest density zone more particularly lends itself to the possible integration of tracks and components to fulfill the possible ancillary functions mentioned here above.
(37) Passive Baffles
(38) The protection of sensitive signals liable to be exchanged at the connector is also reinforced in one particular embodiment by the use of passive baffles. The term passive baffles is understood to mean shapes that make it more complicated, inside the assembled memory card reader, to access the zones in which such sensitive signals travel. These are therefore passive securing devices that complement the active lattice protection for example. The goal of these shapes is for example to make it more difficult to carry out any attempt to introduce a tool seeking to obtain access to such sensitive zones. These passive baffles can be implemented in different ways.
(39) Thus, according to one particular embodiment, the upper cover comprises passive baffles that take the form of metal tabs (36, 37) obtained for example very simply during the cutting-out and embossing operations performed in order to form the upper cover in question. Such metal tabs can be seen, for example, in
(40) Other types of passive baffles can be implemented, as a complement or as an alternative to the passive baffles formed at the upper metal cover 21B. These additional passive baffles take the form of metal parts (one example of which is given with reference to
(41) Card-landing Mechanism
(42) In one particular embodiment, the upper cover 21B comprises a mechanism called a card-landing mechanism (sometimes also known in the literature as landing contact) that have the advantage of minimizing wear and tear in the contacts of the memory card and the metal blades of the connector during numerous insertions and withdrawals of memory cards in the reader. In this embodiment, presented by schematically with reference of
(43) The reading position corresponds to a position in which the mobile counter-pressure element 39 exerts pressure on a memory card inserted into the insertion slot of the memory card reader. This position is the position in which a memory card is read by the reader. The pressure is exerted towards the connector, when the memory card is inserted completely (in other words, up to the stop point) into the insertion slot of the memory card reader. This position ensures reliable contact between the contacts of the card and the metal blades of the connector.
(44) The waiting position corresponds to a position in which the mobile counter-pressure element 39 is at least partially disposed in its receiving housing within the upper cover. This position is occupied by the mobile counter-pressure element 39 when no memory card is inserted into the reader or when a card is only partially inserted therein (in other words, the stop point of the card has not yet been reached). The mobile counter-pressure element then does not exert any pressure on the card or else very low pressure which limits or does not enable contact between the contacts the card and the metal blades of the connector.
(45) According to one particular characteristic, the receiving housing for the mobile counter-pressure element 39 can take the form of a hole in the upper cover 21B. Once fixed, the printed-circuit board 21C then acts as a lid or a roof for this receiving housing in covering and therefore protecting this hole. In this way, the memory card reader remains compact without sacrificing security. As an alternative, the upper cover 21B has no hole and the mobile counter-pressure element 39 is placed against the lower wall of the upper cover or inner hollow made in the upper cover in its waiting position. Such an implementation is more robust but requires increased thickness of the upper cover and therefore of the memory card reader.
(46) If the card-landing function is known per se, its implementation in the context of the present embodiment differs from the prior-art solutions in which the card-landing mechanism is generally a point of weakness for the securing of the reader. Indeed, with the proposed technique, the printed-circuit board 21C completely protects the card-landing mechanism by covering it totally.
(47) 5.2.2 Lower Base
(48) The lower base 21A of the body of the memory card reader 21 is presented in greater detail with reference to
(49) As already described here above, the lower base 21A also comprises a housing to receive the memory card connector during the mounting of the memory card reader. This housing takes the form of hole 62 passing through the lower base 21A from one side to the other. The shape of this receiving housing 62 is substantially complementary to the shape of the memory card connector 20. In one particular embodiment, the lower base 21A comprises centering pins 65, to carry out accurate centering of the lower base on the connector 20 during the mounting (the memory card connector 20 then comprises complementary holes 42, which can be seen in
(50) In the embodiment presented, the lower base 21A of the body of the connector has the main function of guiding the card when it is inserted into the memory card reader. In addition, ingeniously, in at least one variant, the lower base 21A comprises one or more of the following characteristics: it integrates card-braking elements to avoid impact on the card stops; such card-braking elements are presented, by way of an example, on the lower base 21A illustrated in
(51) These complementary characteristics ingeniously flow from the use of a reader body that has an insertion slot obtained by the assembling of two parts that can be fitted to each other (lower base and upper cover). Indeed, such characteristics cannot be implemented with a reader body formed by a single part because the technical level of these characteristics prevents it. Thus, for example, it would be highly complicated (and costly) to make a reader body that might comprise a transparent portion and an opaque portion. In the embodiment presented with reference to
(52) The characteristics presented in the different embodiments described can naturally be combined individually or as a group, with the general principle described here above without departing from the framework of the invention.
(53) 5.3. Complementary Characteristics and Assembling Method
(54) According to another particular characteristic of the proposed technique, the connection between the printed-circuit board and the motherboard is obtained by means of an elastomer connector for example the Zebra type. Thus, there is no need for a complex mechanism for soldering the body of the memory card reader to the motherboard: indeed, since the connection is provided by means of an elastomer connector, the mounting of the assembly formed by the memory card connector, the elastomer connector and the memory card reader body is made easier. The exploded view of
(55) Referring to
(56) Thus, all that are needed are a few simple steps to assemble and affix the memory card reader to the motherboard. As already described here above, the printed-circuit board can be affixed to the upper cover prior to the mounting of the memory card reader. In this case, the steps 74 and 75 are replaced by a single assembling step for the joining, to the lower base, of the pre-assembled unit formed by the upper cover surmounted by the printed-circuit board.