Smart card including a reinforcement element

Abstract

The invention relates to a smart card comprising a body and a microcircuit disposed in the body, said body defining the format of said smart card and being characterized in that it comprises between external layers of said body a reinforcing substrate (150) comprising a reinforcing element (151). Figure for the abstract: Fig. 2.

Description

Title of the invention: Smart card comprising a reinforcing element

[0001] The invention relates to the general field of smart cards.

[0002] In a known manner, a smart card may comprise a body and a microcircuit arranged in the body.

[0003] The body of the card defines the format of the smart card and is often formed by several layers or substrates (inlays according to the commonly used Anglo-Saxon term), arranged between two external plastic layers which respectively form external faces of the body.

[0004] The microcircuit is for example an integrated circuit dedicated to secure payment or to the storage of identity data to carry out a card-present type transaction with an external device, for example a payment transaction with a payment terminal.

[0005] The smart card is subjected during its lifetime to numerous physical constraints, typically mechanical constraints such as bending or twisting, and must successfully pass endurance tests, for example according to the ISO / IEC 10373-1 standard in its third edition, 2020-10.

[0006] These mechanical constraints are becoming increasingly severe as the lifespan of smart cards increases.

[0007] The required endurance tests are also becoming more and more demanding.

[0008] Furthermore, the microcircuit can communicate with an external device through a contact interface placed in contact with a device adapted for this communication, this type of communication being known as contact communication, for example as defined by the ISO / IEC 7816-2 standard in its second edition, 2007-10-15.

[0009] Generally, the body of the smart card thus comprises an open cavity on one face of the body in which the microcircuit and the contact interface are inserted, which creates lines of mechanical stress in the body of the chip and weakens it.

[0010] In a known manner, the smart card may further comprise another microcircuit, for example a fingerprint sensor electrically connected to the microcircuit to authenticate a user, the result of this authentication making it possible to validate or reject a transaction implemented by this smart card.

[0011] However, the presence of the other microcircuit in the body of the smart card further weakens said body.

[0012] Furthermore, the other microcircuit may be embedded in another cavity open on one side of the body, for example when the other microcircuit is a fingerprint sensor, which creates additional fragility.

[0013] The invention aims in particular to overcome these drawbacks.

[0014] To this end, the present invention proposes a smart card comprising a body and a microcircuit arranged in the body, said body defining the format of said smart card and being characterized in that it comprises between external layers of said body, a reinforcing substrate comprising a reinforcing element.

[0015] Other advantageous and non-limiting characteristics of the smart card according to the invention, taken individually or in all technically possible combinations, are the following: - the reinforcing substrate comprises an electrically insulating material and the reinforcing element is electrically conductive, - the reinforcement element does not include an electrical connection, - at least a portion of the reinforcing element crosses a diagonal or a median of the body of the chip card in a longitudinal direction forming an angle of between 80° and 100° relative to said diagonal or a median, - the body further comprises a cavity, and at least a portion of the reinforcing element crosses an edge of the cavity in a longitudinal direction forming an angle of between 80° and 100°, preferably 84° or 96°, relative to said edge of the cavity, - the cavity comprises a deep central part and a peripheral part formed by a counterbore of width LL, less deep than the deep part, and surrounding the deep part, and said at least one part of the reinforcing element which crosses an edge of the cavity in a longitudinal direction forming an angle of between 80° and 100°, preferably 84° or 96°, relative to the edge of the cavity has a width L such that L = ax LL with a having a value of between 1.5 and 1.7, - the value of a is 1.6, - the reinforcing element forms at least one zigzag portion, - the at least one zigzag portion has a pitch between 180 micrometers and 600 micrometers, - the reinforcing element is a metal wire embedded in one face of the reinforcing substrate, the wire having a diameter preferably between 60 micrometers and 150 micrometers, for example 80 micrometers, 100 micrometers, 112 micrometers or 130 micrometers, - the pitch is greater than or equal to 3 times the diameter of the wire, - the reinforcement substrate further comprises a conductive element electrically connected to the microcircuit, - the conductive element is exposed on the same face of the reinforcing substrate as the reinforcing element, - the conductive element and the reinforcing element are respectively exposed on opposite faces of the reinforcing substrate, - the body further comprises between the external layers of said body an electrical circuit substrate comprising a conductive element electrically connected to the microcircuit, - the reinforcing substrate further comprises another reinforcing element, the reinforcing element and the other reinforcing element being respectively exposed on opposite faces of the reinforcing substrate, - one face of the reinforcing substrate comprises a reinforcing zone surrounding at least one adhesion zone, the reinforcing element covering between 51% and 85% of the surface area of ​​the reinforcing zone and between 0% and 50% of the surface area of ​​said at least one adhesion zone.

[0016] Other characteristics and advantages of the present invention will emerge from the description given below, with reference to the appended figures which illustrate exemplary embodiments thereof which are not in any limiting nature.

[0017] In the figures:

[0018] [Fig. 1] schematically represents a first example of a smart card according to the invention;

[0019] [Fig.2] schematically represents an example of a reinforcement substrate, of the smart card of [Fig.l];

[0020] [Fig.3] schematically represents a first example of a partial sectional view of the reinforcing substrate of [Fig.2];

[0021] [Fig.4] schematically represents a second example of a partial sectional view of the reinforcing substrate of [Fig.2];

[0022] [Fig.5] schematically represents a second example of a smart card according to the invention;

[0023] [Fig.6] schematically represents an example of a reinforcement substrate, of the smart card of [Fig.5];

[0024] [Fig.7] schematically represents another example of a reinforcement substrate with an example of an electrical circuit substrate for the smart card of [Fig.5];

[0025] [Fig.8] schematically represents a first example of a partial sectional view of a superposition of a reinforcement substrate and an electrical circuit substrate for a smart card according to the invention;

[0026] [Fig.9] schematically represents a second example of a partial view in section of a superposition of a reinforcement substrate and an electrical circuit substrate for a smart card according to the invention;

[0027] [Fig. 10] schematically represents mechanical stress lines in the body of the chip chip of [Fig.5];

[0028] [Fig. 11] schematically represents a cavity and a reinforcing element of a third example of a smart card according to the invention; and

[0029] [Fig. 12] schematically represents a reinforcement zone surrounding at least one adhesion zone.

[0030] [Fig.l] schematically represents an example of a smart card 100 according to the invention.

[0031] The smart card 100 comprises a body 110 and a microcircuit 120 disposed in the body 110.

[0032] The body 110 of the card 100 defines the format of the smart card and can be formed by several layers or substrates (inlays according to the commonly used English term), arranged between two external layers which respectively form external faces of the body.

[0033] The body 110 preferably complies with the ISO / IEC 7810 standard (for example in its fourth edition, 2019-12) and / or the ISO / IEC 7813 standard (for example in its sixth edition, 2006-07-01), in particular with the ID1 format specified by at least one of these standards.

[0034] The microcircuit 120 may be an integrated circuit dedicated to secure payment or to the storage of identity data to carry out a card-present type transaction with an external device, for example a payment transaction with a payment terminal.

[0035] The microcircuit 120 may comprise a processor, a memory and a communication interface with another electronic entity, for example a contact communication interface.

[0036] The card 100 may also comprise a contact interface (not visible in [Fig.l]) electrically connected to the contact communication interface of the microcircuit 120. Thus, the microcircuit 120 can communicate with an external device through the contact interface placed in contact with a device suitable for this communication, this type of communication being known as contact communication, for example as defined by the ISO / IEC 7816-2 standard (for example in its second edition, 2007-10-15).

[0037] The body 110 of the smart card 100 comprises between the external layers of said body a reinforcing substrate (not visible in [Fig.l]) comprising a reinforcing element.

[0038] The function of the reinforcing element is to increase the mechanical strength and durability of the smart card body with respect to mechanical stresses such as twisting and bending, and not to impact the operation of the smart card in the event of breakage.

[0039] [Fig.2] schematically represents an example of a reinforcement substrate 150 of the smart card 100 of [Fig.1].

[0040] The reinforcing substrate 150 is for example formed from a sheet configured to be laminated with at least one other layer to form the body of the smart card. The reinforcing substrate 150 comprises an upper face 156. The upper face 156 is considered to be planar.

[0041] The reinforcing substrate 150 comprises an electrically insulating material 155 (referenced in [Fig. 3]), typically plastic or paper, and the reinforcing element 151.

[0042] The reinforcing element is electrically conductive.

[0043] Typically, the reinforcing element 151 is made of metal.

[0044] The reinforcing substrate and the reinforcing element can thus be manufactured with existing tools and methods, usually used by those skilled in the art to manufacture an electrical circuit substrate comprising a conductive element, typically a substrate comprising an antenna which will have an electrical connection with the microcircuit, or a substrate comprising one, or more, electrical connections electrically connected to the microcircuit and to another electronic component of the smart card to establish an electrical connection between them.

[0045] The reinforcing element 151 does not include an electrical connection.

[0046] That is to say that the reinforcing element is not electrically connected to any microcircuit or electronic component, for example diode, resistor or transistor.

[0047] Thus, a possible breakage of the reinforcing element has no consequences for the proper functioning of the smart card because this reinforcing element is not used in an electrical connection.

[0048] For example, as shown in [Fig.2], the reinforcing element 151 forms at least one zigzag portion.

[0049] A zigzag reinforcing element here designates a reinforcing element which is for example deposited by forming successive back and forth movements, thus forming rectilinear segments connected to each other by detours forming loops. The rectilinear segments are for example parallel to each other, and two adjacent rectilinear segments are for example connected to each other by a portion which is most often curved, for example in an arc of a circle.

[0050] The at least one zigzag portion 151 has a pitch P and a width L.

[0051] According to a first example of implementation, the reinforcing element 151 is a metal wire, for example made of copper, embedded in a face of the reinforcing substrate 150, typically the upper face 156.

[0052] The reinforcement substrate 150 can thus be manufactured with existing tools and methods usually used by those skilled in the art to manufacture an electrical circuit substrate comprising an antenna which will have an electrical connection with the microcircuit or an electrical circuit substrate comprising one, or more, electrical connections electrically connected to the microcircuit and to another electronic component of the smart card to establish an electrical connection between them.

[0053] Such a reinforcing substrate 150 is for example manufactured by extending the conductive metal wire over the substrate, typically on the upper face 156, by means of a tool, such as a sonotrode, moving above the substrate and distributing the wire. The wire is embedded in the reinforcing substrate 150 by means of ultrasonic vibrations transmitted to the wire from the tool. The vibrations are transmitted perpendicular to the reinforcing substrate 150 to embed the wire in the thickness of the substrate.

[0054] The wire is for example surrounded by an insulating sheath which is heated, for example for a very short time, to improve the adhesion of the sheath to the substrate.

[0055] The tool is controlled to define the path for laying the wire. It is thus possible to wind the wire into several turns and / or to lay it along lines of various shapes, for example a sinuous line 151 as illustrated in [Fig.2], such as for example a zigzag, which alternately comprises rectilinear segments and detours.

[0056] The diameter of the wire is preferably between 60 micrometers and 150 micrometers, typically 80 micrometers, 100 micrometers, 112 micrometers or 130 micrometers.

[0057] The pitch P is preferably between 180 micrometers and 600 micrometers, typically 400 micrometers.

[0058] The body 110 of the smart card thus retains flexibility compatible with the ISO / IEC 10373-1 standard (for example in its third edition, 2020-10) and has better mechanical resistance and durability with respect to mechanical constraints such as twisting and bending.

[0059] Furthermore, the pitch P is preferably greater than or equal to 3 times the diameter of the wire. The radius of curvature of the loops of the zigzag is thus adapted to the diameter of the wire.

[0060] According to a second example of implementation, the reinforcement element 151 is a metal track printed on one face of the reinforcement substrate 150, typically a copper track on a flexible printed circuit board (PCB).

[0061] The periphery of the reinforcing element 151 of the reinforcing substrate 150 delimits a zone 161 of the upper face 156 of the reinforcing substrate 150, called the reinforcing zone.

[0062] A zigzag reinforcing element 151 makes it possible to establish a large surface area of ​​reinforcement with relatively little material.

[0063] [Fig.3] schematically represents a first example of a partial sectional view of the reinforcing substrate of [Fig.2].

[0064] The reinforcing element 151 is here a metal wire, for example copper, embedded in the upper face 156 of the reinforcing substrate 150.

[0065] [Fig.4] schematically represents a second example of a partial sectional view of the reinforcing substrate of [Fig.2].

[0066] As for [Fig.3], the reinforcing element 151 is here a metal wire, for example made of copper, embedded in an upper face 156 of the reinforcing substrate 150.

[0067] But the reinforcing substrate 150 further comprises another reinforcing element 152 on the opposite face 157 of said reinforcing substrate 150.

[0068] Thus, the reinforcing substrate 150 comprises the reinforcing element 151 and the other reinforcing element 152, the reinforcing element 151 and the other reinforcing element 152 being respectively located on opposite faces of the reinforcing substrate 150.

[0069] Thus, the reinforcing element 151 and the other reinforcing element 152 are exposed, i.e. printed or inlaid, on opposite faces of the reinforcing substrate 150.

[0070] It is therefore possible to further increase the mechanical resistance of a part of the body of the smart card by superimposing another reinforcing element where there is a reinforcing element, using a single reinforcing substrate.

[0071] The other reinforcing element 152 is here a metal wire, for example copper, embedded in the opposite face 157 of the reinforcing substrate 150.

[0072] As understood by a person skilled in the art, according to an alternative, the other reinforcing element 152 may be a metal track printed on the opposite face 157 of the reinforcing substrate 150, typically a copper track on a flexible printed circuit board (PCB), in particular when the reinforcing substrate 150 is according to the second example of implementation described above.

[0073] [Fig. 5] schematically represents another example of a smart card 200 in accordance with the invention.

[0074] The smart card 200 comprises a body 210 and a microcircuit 220 disposed in the body 210.

[0075] The body 210 of the card 200 defines the format of the smart card and can be formed by several layers or substrates (inlays according to the commonly used English term), arranged between two external layers which respectively form external faces of the body.

[0076] The body 210 preferably complies with ISO / IEC 7810 (e.g., its fourth edition, 2019-12) and / or ISO / IEC 7813 ... its sixth edition, 2006-07-01), including in the ID1 format specified by at least one of these standards.

[0077] The microcircuit 220 may be an integrated circuit dedicated to secure payment or to the storage of identity data to carry out a card-present type transaction with an external device, for example a payment transaction with a payment terminal. The microcircuit 220 may comprise a processor and a memory and comprises a contactless communication interface with another electronic entity.

[0078] For communication of the microcircuit 220 with an external device, the smart card 200 comprises an antenna 230 integrated in the body 210 and electrically connected to the microcircuit 220. The antenna 230 is a conductive element.

[0079] Thus, the microcircuit 220 can communicate with an external device through the antenna 230, this communication being known as contactless communication, for example according to the ISO / IEC 14443 standard (for example in its fourth edition) or the NFC / ISO / IEC 15693 standard (for example in its third edition).

[0080] The card 200 may also include a contact interface (not visible in [Fig.5]). Thus, the microcircuit 220 can also communicate with an external device through the contact interface placed in contact with a device suitable for this communication.

[0081] Furthermore, the smart card 200 comprises another microcircuit 240 arranged in the body 210 and electrically connected to the microcircuit 220 by several electrical connections 260. Each electrical connection 260 is a conductive element.

[0082] The other microcircuit 240 is for example a biometric sensor making it possible to authenticate a user of the smart card 200 and thus to secure a card-present type transaction with an external device, typically a payment transaction with a payment terminal.

[0083] The body 210 of the smart card 200 comprises between the external layers of said body a reinforcing substrate (not visible in [Fig.5]) comprising a reinforcing element.

[0084] As already indicated, the function of the reinforcing element is to increase the mechanical strength and durability of the body of the smart card with respect to mechanical stresses such as twisting and bending, and not to impact the operation of the smart card in the event of breakage.

[0085] [Fig.6] schematically represents an example of a reinforcement substrate 250 of the smart card 200 of [Fig.5].

[0086] The reinforcing substrate 250 is for example formed from a sheet configured to be laminated with at least one other layer to form a card body. It comprises an upper face 256. The upper face 256 is considered to be planar.

[0087] The reinforcing substrate 250 comprises an electrically insulating material, typically plastic or paper, and three reinforcing elements: a first reinforcing element 251a, a second reinforcing element 251b and a third reinforcing element 251c.

[0088] The reinforcing elements 251a, 251b, 25le may be identical to the reinforcing element 151 described for FIGS. 2 to 4.

[0089] It will be noted, however, that in this example, the second reinforcing element 215b comprises a portion 251b' which has a width L' different from the width L of the rest of said second reinforcing element.

[0090] A reinforcing element can therefore advantageously comprise portions of different widths, in particular to adapt to the presence of other elements such as a conductive element (for example an electrical connection 260).

[0091] In this example, the reinforcement substrate 250 further comprises several conductive elements electrically connected to the microcircuit 220.

[0092] More precisely, the reinforcement substrate 250 further comprises the several electrical connections 260 and the antenna 230 of the smart card 200.

[0093] This limits the number of substrates in the smart card, which makes it easier to comply with the maximum thickness authorized for the smart card body, typically by standards such as ISO / IEC 7810 (for example in its fourth edition, 2019-12) and / or ISO / IEC 7813 (for example in its sixth edition, 2006-07-01).

[0094] Furthermore, the use of a single substrate to reinforce the body of the smart card and establish an electrical connection to the microcircuit makes it possible to facilitate the manufacturing process by limiting the number of substrates to be used to manufacture the card body.

[0095] It will be noted that a reinforcing substrate is said to be “reinforcing” in that it contains a reinforcing element, any breakage of which has no impact on the proper functioning of the smart card. However, it is advantageous for the reinforcing substrate to further comprise a conductive element electrically connected to the microcircuit, i.e. a functional element any breakage of which impacts the proper functioning of the smart card, in order to save a substrate. However, the reinforcing substrate is always said to be “reinforcing” because it comprises the reinforcing element.

[0096] The choice of implementation for the connection of the electrical links 260 to the microcircuit 220 and to the other microcircuit 240, and for the connection of the antenna 230 to the microcircuit 220, is left to those skilled in the art.

[0097] For example, the ends of each electrical connection 260 are here arranged in a zigzag shape to constitute a means of electrical contact with the microcircuit 220 or the other microcircuit 240.

[0098] Furthermore, the antenna 230 of the smart card 200 has its two ends arranged in a zigzag shape to constitute means of electrical contact with the microcircuit 220.

[0099] However, those skilled in the art can use other means of contact.

[0100] A variant is possible, in which the substrate 250 does not include all the conductive elements which are connected to the microcircuit 220, among the plurality of electrical connections 260 and the antenna 230 of the smart card 200.

[0101] According to a first example of implementation, the conductive elements are made of metal wires, for example copper, embedded in one face of the reinforcing substrate 250, typically the upper face 256.

[0102] According to a second example of implementation, the conductive elements are metal tracks printed on one face of the reinforcement substrate 250, typically a copper track on a flexible printed circuit board (PCB).

[0103] The first implementation example is preferred when the reinforcing elements 251 are metal wires embedded in one face of the reinforcing substrate 250.

[0104] It will be noted that when the reinforcing elements 251a, 251b, 251c are metal wires embedded in one face of the reinforcing substrate 250, the diameter of the metal wire used for each reinforcing element can be chosen according to the mechanical stresses undergone by the card body where the associated reinforcing element is. Thus the metal wire of a reinforcing element of the smart card can have a diameter that is identical to or different from another reinforcing element of said smart card.

[0105] The second implementation example is preferred when the reinforcing elements 251 are metal tracks printed on a face of the reinforcing substrate 250.

[0106] In this illustrated example [Fig.6], the reinforcing elements 251 and the conductive elements, i.e. the electrical connections 260 and the antenna 230, are on the upper face 256 of the substrate 250.

[0107] Thus, a conductive element is exposed, i.e. printed or inlaid, on the same face of the reinforcing substrate as a reinforcing element.

[0108] The manufacture of the reinforcing substrate is thus economical and easy and can be carried out with existing equipment which is currently used to produce electrical circuit substrates for smart card bodies and comprising a conductive element to be connected to an electronic component of said smart card.

[0109] Nevertheless, a person skilled in the art understands that he can adapt the substrate 250 so that at least one element among the reinforcing elements 251, the electrical connections 260 and the antenna 230 is not exposed on the upper face 256 of the substrate 250 but is exposed on the opposite face of the substrate 250.

[0110] For example, it may adapt the substrate 250 such that a conductive element, i.e. an electrical connection 260 or the antenna 230, and a reinforcing element are respectively exposed on opposite faces of the reinforcing substrate 250.

[0111] The body of the smart card can thus be reinforced by superimposing an element of reinforcement where there is a conductive element.

[0112] [Fig.7] schematically represents another example of reinforcement substrate 450 with an example of electrical circuit substrate 350 for the smart card of [Fig.5],

[0113] The reinforcing substrate 450 is for example formed from a sheet configured to be laminated with at least one other layer to form a card body. It comprises an upper face 456. The upper face 456 is considered to be planar.

[0114] The reinforcing substrate 450 comprises an electrically insulating material, typically plastic or paper, and three reinforcing elements: a first reinforcing element 451a, a second reinforcing element 451b and a third reinforcing element 451c.

[0115] For example, the reinforcing elements 451a, 451b, 451c are identical to the reinforcing element 151 described for FIGS. 2 to 4 and / or to the reinforcing elements 251 described for [Fig.6],

[0116] Unlike the reinforcing substrate of [Fig.6], the reinforcing substrate 450 of this example only comprises the reinforcing elements 451a, 451b, 451c.

[0117] The electrical connections 260 and the antenna 230 of the smart card 200 are implemented by another substrate 350, called the electrical circuit substrate.

[0118] In this example, the body 210 of the smart card 200 illustrated [Fig.5] therefore comprises between the external layers of said body, the reinforcement substrate 450 and the electrical circuit substrate 350.

[0119] The body of the smart card therefore comprises between the external layers of said body an electrical circuit substrate comprising a conductive element electrically connected to the microcircuit.

[0120] It is therefore possible to reinforce the body of the smart card by superimposing a reinforcing element where there is a conductive element, in particular by using a reinforcing substrate comprising the reinforcing element, and any other possible reinforcing element, exposed on only one of its faces. In addition, the electrical circuit substrate may comprise a conductive element, and any other possible conductive element, exposed on only one of its faces. The manufacture of the reinforcing substrate and the manufacture of the electrical circuit substrate are thus economical and easy. They can be carried out with existing equipment which is currently used to produce electrical circuit substrates for smart card bodies, these electrical circuit substrates comprising at least one conductive element to be connected to an electronic component of said smart card.

[0121] The electrical circuit substrate 350 is for example formed from a sheet configured to be laminated with at least one other layer to form a card body. It comprises an upper face 356. The upper face 356 is considered to be planar.

[0122] The electrical circuit substrate 350 comprises an electrically insulating material, typically plastic or paper, the antenna 230 and the electrical connections 260.

[0123] The antenna 230 and the electrical connections 260 may be identical to the antenna 230 and the electrical connections 260 described for [Fig.6].

[0124] [Fig.8] schematically represents a first example of a partial sectional view of a superposition of a reinforcement substrate and an electrical circuit substrate for a smart card according to the invention, typically a superposition of the reinforcement substrate 450 and the electrical circuit substrate 350 described with [Fig.7] for the smart card 200 illustrated [Fig.5].

[0125] The third reinforcing element 25 1c and the conductive element 260 are here metal wires, for example copper, respectively embedded in the upper face 456 of the reinforcing substrate 450 and the upper face 356 of the electrical circuit substrate 350.

[0126] In this example, the face of the electrical circuit substrate 350 opposite the upper face 356 of said electrical circuit substrate 350 covers the face of the reinforcing substrate 450 opposite the upper face 456 of said reinforcing substrate 450.

[0127] [Fig.9] schematically represents a second example of a partial sectional view of a superposition of a reinforcement substrate and an electrical circuit substrate for a smart card according to the invention, typically a second example of a superposition of the reinforcement substrate 450 and the electrical circuit substrate 350 described with [Fig.7] for the smart card 200 illustrated [Fig.5].

[0128] This example differs from the example of [Fig.8] in that the face of the electrical circuit substrate 350 opposite the upper face 356 of said electrical circuit substrate 350 covers the upper face 456 of the reinforcing substrate 450.

[0129] Other examples of superposition of a reinforcement substrate and an electrical circuit substrate are possible for a smart card according to the invention.

[0130] In particular, another substrate, or several other substrates, may be interposed between a reinforcing substrate and an electrical circuit substrate whose faces are arranged according to the example of [Fig.8] or according to the example of [Fig.9].

[0131] [Fig. 10] schematically represents mechanical stress lines in the body 210 of the chip 200 of [Fig. 5].

[0132] As already mentioned, cards are subject to numerous twists and bends during the numerous handlings of this card by its holder. A corresponding test, according to the ISO / IEC 10373-1 standard (for example in its third edition, 2020-10), is thus imposed to attest to the conformity of the card produced with the ISO / IEC 7816 standard.

[0133] [Fig. 10] illustrates on the smart card 200 of [Fig. 5], the maximum stress zones that could be measured during such a test.

[0134] The diagonals 900 of the body 210 of the smart card 200 correspond to the zones of maximum torsional stress.

[0135] The small median 901a and the large median 901b of the body 210 of the smart card 200 represent the zones of maximum bending stress.

[0136] Thus, advantageously, at least a portion of a reinforcing element of the chip card crosses a diagonal or a median of the body of the chip card in a longitudinal direction forming an angle of between 80° and 100° relative to said diagonal or a median of the body of the chip card.

[0137] This feature makes it possible to reinforce a part of the body of the smart card subjected to the greatest mechanical stress. In addition, the angle of approximately 90 degrees plus or minus 10 degrees between a longitudinal part of the reinforcing element and a diagonal or a median of the body of the smart card makes it possible to obtain better mechanical resistance for said diagonal or median of the reinforced body.

[0138] The example of reinforcement substrate 250 of [Fig.6], and the example of reinforcement substrate 450 of [Fig.7], comprise a first reinforcement element of which at least a portion crosses a median of the body of the chip card 200 of [Fig.5] in a longitudinal direction forming an angle of between 80° and 100° relative to said median.

[0139] Each rectilinear segment of the zigzag portion of the first reinforcing element 25la, 45la may be at least one part of the reinforcing element crossing the small median 901a, i.e. at a median, of the body of the chip card in a longitudinal direction forming an angle of between 80° and 100° relative to the small median 901a.

[0140] Typically, the card body 210 includes a cavity formed to house the microcircuit 220 and the possible contact interface allowing the microcircuit 220 to communicate with an external device.

[0141] Lines 905 correspond to the zones of maximum torsional and bending stress, induced by the presence of the cavity. Lines 905 also correspond to the edges of the cavity and their rectilinear extension near said cavity, that is to say up to a distance from the cavity substantially equal to the length of the edge thus extended.

[0142] Typically, the card body 210 may also include another cavity formed to house the other microcircuit 240, for example when the other microcircuit is a biometric sensor such as a fingerprint sensor or an electrocardiogram sensor.

[0143] Lines 915 correspond to the zones of maximum torsional and bending stress, induced by the presence of the other cavity. Lines 915 also correspond to the edges of the other cavity and their rectilinear extension near said other cavity, that is to say up to a distance from the other cavity substantially equal to the length of the edge thus extended.

[0144] Thus, advantageously, at least a portion of a reinforcing element of the chip card crosses an edge of a cavity of the body of the chip card in a longitudinal direction forming an angle of between 80° and 100° relative to said edge of a cavity.

[0145] This feature makes it possible to reinforce a part of the body of the smart card which has mechanical fragility. This fragility is induced by the presence of a cavity.

[0146] The angle of approximately 90 degrees plus or minus 10 degrees between a longitudinal portion of the reinforcing element and an edge of a cavity makes it possible to obtain the best mechanical resistance of the smart card body for this edge of the cavity.

[0147] The example of reinforcement substrate 250 of [Fig.6], and the example of reinforcement substrate 450 of [Fig.7], thus comprise a second reinforcement element of which at least one part crosses an edge 915 of the other cavity of the body of the chip card 200 of [Fig.5], in a longitudinal direction forming an angle of between 80° and 100° relative to said edge 915 of the other cavity.

[0148] Furthermore, the example of reinforcement substrate 250 of [Fig. 6], and the example of reinforcement substrate 450 of [Fig. 7], comprise a third reinforcement element of which at least a portion crosses an edge 905 of the cavity of the body of the chip card 200 of [Fig. 5], in a longitudinal direction forming an angle of between 80° and 100° relative to said edge 905 of the cavity.

[0149] Each rectilinear segment of the zigzag portion of the second reinforcing element 251b, 451b, respectively of the third reinforcing element 251c, 451c, may be at least one part of the reinforcing element having a longitudinal shape forming an angle of between 80° and 100° relative to the edge 915 of the other cavity, respectively relative to the edge 905 of the cavity, of the body of the chip card.

[0150] It will be noted that a zigzag reinforcing element makes it possible to multiply the intersections between the reinforcing element and a particular axis of mechanical stress, typically a diagonal or a median of the body of the smart card, or an edge of a cavity formed in the body of the smart card, which makes it possible to further increase the mechanical strength and durability of the body with respect to mechanical stresses of the axis concerned while allowing the body to retain suitable flexibility, typically compatible with the ISO / IEC 10373-1 standard (for example in its third edition, 2020-10).

[0151] Preferably, at least one part of the second reinforcing element crosses an edge 915 of the other cavity of the body of the chip card 200 of [Fig. 5], in a longitudinal direction forming an angle of 84° or 96° relative to said edge 915 of the other cavity.

[0152] Similarly, at least one part of the third reinforcing element crosses an edge 905 of the cavity of the body of the chip card 200 of [Fig.5], in a longitudinal direction preferably forming an angle of 84° or 96° relative to said edge 905 of the cavity.

[0153] These angles make it possible to limit the risk of these reinforcement elements being torn off when a machining tool is passed over them to manufacture the cavity, for example by milling.

[0154] [Fig. 11] schematically represents a cavity and a reinforcing element of a third example of a smart card 1000 according to the invention.

[0155] The smart card 1000 comprises a body 1010 comprising a cavity 1080 formed to house a microcircuit, and optionally a contact interface allowing the microcircuit to communicate with an external device through the contact interface.

[0156] A central area 1081 of the cavity 1080 is configured to form a deep portion of the cavity.

[0157] A peripheral zone 1082 of the cavity is configured to form a peripheral part, called a counterbore, of width LL, less deep than the deep part and surrounding the deep part of the cavity.

[0158] The body 1010 of the smart card 1000 further comprises a reinforcing substrate, not shown, comprising a reinforcing element 1151 of which at least one part crosses an edge 1005 of the cavity 1080 in a longitudinal direction forming an angle of between 80° and 100° relative to said edge 1005 of the cavity 1080.

[0159] Preferably, the reinforcing element 1151 has a width L such that L = ax LL with a having a value between 1.5 and 1.7.

[0160] For example, the value of a is 1.6.

[0161] Thus the reinforcing element can cover 80% of the width of the counterbore of the cavity and be centered in its width relative to an edge 1005 of said cavity 1080.

[0162] The part of the counterbore not covered by the reinforcing element thus has sufficient width so that the reinforcing element is not cut during machining of the central zone due to the precision limits of the machining tool.

[0163] Typically, the counterbore of the cavity of the card 1000 has a width LL of 2.1 millimeters. The reinforcing element 1151 thus preferably has a width L of 3.4 millimeters.

[0164] It will be noted that the deeper the deep part and / or the peripheral part, the more fragile the card body is around the cavity.

[0165] Thus, when at least part of a reinforcing element is a metal wire and crosses an edge of the cavity, it is advantageous to use a wire diameter that is all the greater the deeper the deep part and / or the peripheral part of the cavity.

[0166] Furthermore, when at least a portion of a reinforcing element forms a zigzag portion and crosses an edge of the cavity, it is advantageous for the pitch of the zigzag portion to be smaller the deeper the deep portion and / or the peripheral portion of the cavity.

[0167] [Fig. 12] schematically represents a reinforcement zone 561 surrounding at least one adhesion zone 951.

[0168] As already described, a reinforcement zone is a portion of a face of the reinforcement substrate delimited by the periphery of a reinforcement element of said reinforcement substrate.

[0169] Here, the periphery of a reinforcing element 551 delimits a reinforcement zone 561.

[0170] Advantageously, the reinforcing element 551 covers between 51% and 85% of the surface area of ​​the reinforcing zone 561.

[0171] Preferably, the reinforcing element covers 80% of the surface area of ​​the reinforcing zone, which offers the best compromise for improving the mechanical strength and durability of the smart card body where the maximum stress zones are located, while maintaining flexibility of the card body compatible with the ISO / IEC 10373-1 standard (for example in its third edition, 2020-10).

[0172] However, coverage of between 51% and 85% of the reinforcement zone by the reinforcement element may cause adhesion problems between the reinforcement substrate and another layer of the card body covering said reinforcement zone.

[0173] To remedy this, it is advantageous to provide at least one adhesion zone in the reinforcement zone such that the reinforcement element only covers between 0% and 50% of the surface area of ​​said at least one adhesion zone.

[0174] There is thus a face of the reinforcement substrate comprising a reinforcement zone surrounding at least one adhesion zone, the reinforcement element covering between 51% and 85% of the surface of the reinforcement zone and between 0% and 50% of the surface of said at least one adhesion zone.

[0175] Said at least one adhesion zone, by its associated coverage rate of the reinforcing element, makes it possible to improve the adhesion of the reinforcing substrate to another substrate of the body of the smart card while having a large surface area of ​​reinforcement zone where the reinforcing element has an optimal coverage rate for improving the mechanical strength and durability of the body.

[0176] It will be noted that certain elements generally present in a smart card have been voluntarily omitted because they are not necessary for understanding the present invention.

[0177] It should also be noted that the smart cards and the reinforcement substrates shown in the figures constitute only exemplary embodiments, other implementations being possible within the scope of the invention.

[0178] Certain elements of the smart cards are described here only to facilitate understanding of the invention, these elements not being obligatory for implementing the invention.

[0179] For example, the body 210 of the smart card 200 comprises two cavities and a reinforcing element for one edge of each cavity. But a reinforcing element for one edge of each cavity is not mandatory to implement the invention. There may be no reinforcement for the edges of the cavity and / or the other cavity of the smart card 200 according to a first example. The card 200 could only comprise one cavity according to a second example. The card 200 could not comprise a reinforcing element crossing at least in part a diagonal or a median of the body of the smart card, but only one, or more, reinforcing elements crossing at least in part an edge of a cavity of the body of the smart card.

[0180] A person skilled in the art will understand that the embodiments, examples, variations, and various features described above may be combined with each other in various combinations to the extent that they are not incompatible or mutually exclusive.

[0181] A person skilled in the art also understands that he can adapt the location of the reinforcing elements and the shape of the reinforcing elements.

Claims

Claims

1. A smart card (100, 200, 1000) comprising a body (110, 210, 1010) and a microcircuit (120, 220) disposed in the body (110, 210, 1010), said body defining the format of said smart card and comprising between outer layers of said body a reinforcing substrate (150, 250, 450) comprising a reinforcing element (151, 251a, 251b, 251c, 451a, 451b, 451c, 1151), said smart card being characterized in that the reinforcing element (151, 251a, 251b, 251c, 451a, 451b, 451c, 1151) does not comprise an electrical connection and forms at least one portion in zigzag.

2. A smart card according to claim 1, wherein the reinforcing substrate (150, 250, 450) comprises an electrically insulating material (155) and the reinforcing element (151, 251a, 251b, 251c, 451a, 451b, 451c, 1151) is electrically conductive.

3. A smart card according to any one of claims 1 to 2, wherein at least a portion of the reinforcing element (251a, 451a) crosses a diagonal (900) or a median (901a, 901b) of the body (210) of the smart card (200) in a longitudinal direction forming an angle of between 80° and 100° relative to said diagonal (900) or a median (901a, 901b).

4. A smart card according to any one of claims 1 to 3, wherein the body further comprises a cavity, and wherein at least a portion of the reinforcing element (251b, 251c, 451b, 451c) intersects an edge (905, 915) of the cavity in a longitudinal direction forming an angle of between 80° and 100° relative to said edge (905, 915) of the cavity.

5. A smart card according to any one of claims 1 to 4, wherein the at least one zigzag portion (151, 251a, 251b, 251c, 451a, 451b, 451c, 1151) has a pitch (P) of between 180 micrometers and 600 micrometers.

6. A smart card according to any one of claims 1 to 5, wherein the reinforcing element (151, 251a, 251b, 251c, 451a, 451b, 451c, 1151) is a metal wire embedded in one face of the reinforcing substrate (150, 250, 450), the wire having a diameter preferably between 60 micrometers and 150 micrometers.

7. A smart card according to any one of claims 1 to 6, wherein the reinforcing substrate (250) further comprises a conductive element (230, 260) electrically connected to the microcircuit (220).

8. A smart card according to claim 7, wherein the conductive element (230, 260) is exposed on the same face of the reinforcing substrate (250) as the reinforcing element (251a, 251b, 251c).

9. A smart card according to claim 7, wherein the conductive element (230, 260) and the reinforcing element (251a, 251b, 251c) are respectively exposed on opposite faces of the reinforcing substrate (250).

10. A smart card according to any one of claims 1 to 9, the body (210) further comprising between the outer layers of said body an electrical circuit substrate (350) comprising a conductive element (230, 260) electrically connected to the microcircuit (220).

11. A smart card according to any one of claims 1 to 10, wherein the reinforcing substrate (150) further comprises a further reinforcing element (152), and wherein the reinforcing element (151) and the further reinforcing element (152) are respectively exposed on opposite faces (156, 157) of the reinforcing substrate (150).

12. A card according to any one of claims 1 to 11, wherein one face of the reinforcing substrate comprises a reinforcing zone (561) surrounding at least one adhesion zone (951), the reinforcing element (551) covering between 51% and 85% of the surface area of ​​the reinforcing zone and between 0% and 50% of the surface area of ​​said at least one adhesion zone.

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