Smart card provided with a screen for displaying a dynamic code and method for manufacturing same

Abstract

The invention relates to a smart card (1) comprising a card body (2) made up of a stack of layers rigidly connected to each other and an electronic module (3) integrated into a cavity (4) formed on the upper face of the card body (2), the electronic module (3) comprising a display screen (5) on the lower face thereof, characterised in that the display screen (5) is positioned at the bottom of the cavity (4) in a transparent layer (15) of the card body (2) so as to be visible from the lower face of the smart card, and in that the card body (2) comprises a generally opaque layer (10) arranged under the transparent layer (15) and provided with a non-opaque reserve zone (7) formed opposite the display screen (5).

Description

[0001] DESCRIPTION

[0002] Title: Smart card provided with a screen for displaying a dynamic code and its manufacturing process

[0003] The present invention relates to a contact or dual contact and contactless communication interface smart card provided with a screen for displaying a dynamic security cryptogram called "dCW", an acronym for the English expression "dynamic Card Verification Value". This smart card will then be called a "dynamic CW card" or more simply a "dCW card" in the following. The invention also relates to the method for manufacturing such a dCW card.

[0004] STATE OF THE ART

[0005] A dCW card is intended to make e-commerce transactions more secure and improve users' online shopping experience, compared to older cards that simply had a fixed verification code known as "Card Verification Value", also known as CW, which is a fixed code printed on the card body.

[0006] Popular dCW cards feature a 3-digit display embedded on the back of standard credit cards. Instead of the conventional static 3-digit CW code printed on the chip card, which can be easily duplicated, this easy-to-use dynamic code solution will prevent card-not-present (CNP) fraud and is likely to give consumers, merchants, and banks more confidence in their online transactions. For example, the dynamic CW card known as “eSecu” is a classic EMV contactless payment card that displays a dynamic value that automatically refreshes based on a time-varying One Time Password (OTP).

[0007] These known dCW cards require the integration into the card body of a specific electronic module, for example such as that described in document WO 2021 / 206780 A1 (LINXENS) having both a contact terminal block compliant with the ISO 7816 standard on the front panel, and a screen on the rear panel for displaying the dCW code. This type of module, known as "all in one", has the advantage of integrating all the electronic components necessary for the operation of the smart card, in particular the microelectronic chip and its software application, in particular of the banking type, as well as the screen for displaying the dCW code.

[0008] In principle, this architecture is therefore simple and allows such a module to be integrated with all the necessary electronic components in a cavity of the card body, without requiring the integration of discrete electronic components distributed on a printed circuit integrated into the card body.

[0009] However, this known architecture poses new technical problems in practice. A first problem that arises is to obtain a solution that allows the electronic module to be integrated and bonded into the machined cavity of the card body while maintaining sufficient transparency of the cavity bottom to allow good readability of the screen after its integration into the cavity of the card body. The screen located on the back of the electronic module must indeed be clearly visible on the back of the smart card, while remaining protected from external aggression.

[0010] Another problem is that dCW modules can come from different manufacturers and have different dimensions, including varying thickness. In order to offer the lowest manufacturing costs to smart card manufacturers who intend to integrate these modules into their card bodies, it is therefore necessary for the card body structure and the manufacturing process to easily compensate for the differences in thickness of the dCW modules, along the Z axis corresponding to the thickness of the smart card.

[0011] In addition, the structure of the smart card must be compatible with the manufacturers' standard card manufacturing processes, in particular with the hot lamination phases of the card body layers.

[0012] Document US 2016 / 260005 A1 (KARAFOTIS ET AL) discloses a smart card provided with a screen encapsulated in a layer of transparent material and remaining visible through a transparent window of the card body located opposite the screen. Document US 2014 / 016286 A1 (FISCHE ET AL) describes an electronic module provided with a display screen and other discrete components, said module being intended to be incorporated into a smart card. The various discrete components and the screen have the same thickness, and the cavity of the card body receiving the module is of uniform thickness.

[0013] US 2014 / 0162286 A1 (TATSU JINTARO) describes a smart card with a display screen, an integrated battery, and an electrical switch. The display is not integrated into an electronic module inserted into a cavity, but is directly integrated into a layer of the card body, opposite a transparent window.

[0014] PURPOSE OF THE INVENTION

[0015] The general aim of the invention is to propose a new smart card structure provided with a module whose rear face has a screen for displaying a dynamic CW, and its manufacturing method, which is capable of solving all of the technical problems cited above.

[0016] The invention also has the particular aim of proposing a smart card structure making it possible to place the electronic module in the cavity of the card body while maintaining good transparency of the bottom of the cavity to ensure the readability of the screen located on the rear face of the electronic module through the bottom of the cavity of the card body, and while protecting the screen from external aggression.

[0017] SUBJECT OF THE INVENTION

[0018] In principle, the invention provides for using on the rear face of the card body (namely the face opposite that which carries the contact terminal block in the standardized format according to the ISO 7816 standard), a layer of transparent plastic material, in particular PVC, coated with a layer opaque to visible light, for example a white layer printed by screen printing or offset over the entire surface of the transparent PVC layer, with the exception of an unprinted area located at the position provided for the screen of the electronic module.

[0019] Several solutions are possible for producing and fixing the electronic module with its screen in the cavity of the card body, located opposite the unprinted area of ​​a white opaque layer. According to one embodiment, a transparent hot-melt adhesive is used, also called "hotmelt" in English terminology, and it is placed on the entire lower surface of the module or only along its periphery.

[0020] According to another embodiment, an optical resin or glue or a gel is used to bond the module and to wet the bottom of the machined cavity of the card body in order to improve the visibility of the screen through the bottom of the cavity. For this, the optical glue is chosen to be able to optimize the optical index of the bottom of the cavity.

[0021] According to another embodiment, microcapsules filled with a two-component pressure-activated adhesive, also known as "PSA" for "Pressure Sensitive Adhesive", or temperature-activated, are used to fix the module.

[0022] The invention also provides that the structure of the card is made up solely of layers of different materials compatible with hot lamination (notably PVC, PET, PC, etc.), and the structure of the card body must not include any electronic components or batteries, apart from the card antenna.

[0023] The invention therefore relates to a smart card comprising a card body formed by a stack of layers secured to each other and an electronic module provided on its upper face with a terminal block of metal contacts capable of interacting with the corresponding contacts of a smart card reader and comprising on its lower face a display screen, said electronic module being integrated in a cavity arranged on the upper face of the card body, and said display screen being positioned at the bottom of said cavity in a transparent layer of the card body so as to be visible from the lower face of the smart card, and said card body comprising a generally opaque layer arranged under said transparent layer and provided with a non-opaque reserve zone arranged opposite the display screen, characterized in that the bottom of said cavity has multiple machining depths,adapted to the thickness of the display screen and the thickness of other electronic components arranged on the underside of the electronic module.,

[0024] According to one embodiment, said generally opaque layer is produced by white opaque printing on a layer of the card body, and the non-opaque reserve area is produced by an absence of white opaque printing opposite the area provided for the display screen. According to one embodiment, the layers of the card body comprise in order, from the upper face of the smart card:

[0025] - A transparent top protective layer

[0026] - A first printed layer with graphic customization

[0027] - An opaque layer, particularly in white PVC

[0028] - An insert with an antenna

[0029] - A transparent layer in which the bottom of said cavity extends, coated with said opaque white printing with the exception of said reserve area

[0030] - A second printed layer with graphic customization,

[0031] - A transparent lower protective layer.

[0032] According to one embodiment, the bottom of said cavity has multiple machining depths, adapted to the thickness of the display screen and to the thickness of other electronic components arranged on the lower face of the electronic module.

[0033] According to one embodiment, the electronic module is fixed in the cavity of the card body by means of a transparent hot-melt adhesive film disposed on the underside of the electronic module on and around the display screen and other components thereof disposed in relief on the underside of the electronic module.

[0034] According to another embodiment, the electronic module is secured in the cavity of the card body by means of an opaque hot melt adhesive film laminated to the periphery of the underside of the electronic module around the display screen and other components thereof.

[0035] According to another embodiment, the electronic module is fixed in the cavity of the card body by means of a transparent glue dispensed at the bottom of the cavity so as to surround and cover the display screen.

[0036] According to another embodiment, the electronic module is fixed in the cavity of the card body by means of the combination of a hot-melt adhesive film laminated around the periphery of the electronic module, and a transparent glue dispensed at the bottom of the cavity in the area intended to be opposite the display screen. In this case, the invention provides that the transparent glue is taken from:

[0037] A UV-curable acrylic or cyanoacrylate glue

[0038] A single-component epoxy adhesive pre-activated by UV

[0039] A two-component epoxy adhesive that cures at room temperature. An acrylic-based, pressure-sensitive liquid adhesive.

[0040] A two-component polyurethane adhesive that cures at approximately 80°C.

[0041] The invention also relates to a method for producing a smart card as described above, comprising steps consisting of forming a laminated multilayer card body, machining in the card body a cavity intended to receive an electronic module provided on its lower face with a display screen, transferring and gluing the electronic module in said cavity by orienting the lower face of the electronic module towards the lower face of the smart card, characterized in that the step of forming the card body comprises a step consisting of printing on a layer of the card body located under the electronic module, an opaque layer, in particular white, provided with a transparent reservation in the area intended to be located opposite the display screen after integration of the electronic module.

[0042] DETAILED DESCRIPTION

[0043] The invention will be described in more detail with the aid of the drawings, in which:

[0044] - Figures 1A and 1B represent an electronic module for a smart card, provided with a screen, the module being represented respectively in top view from the contact terminal block side, and in bottom view from the screen side.

[0045] - Figure 2 represents a schematic view of the electronic module of Figure 1A, in cross-section.

[0046] - Figures 3A and 3B represent respectively in top view (front) and in bottom view (back) a smart card integrating an electronic module of figures 1A and 2 provided with a display screen.

[0047] - Figure 4 represents an exploded perspective view of a smart card according to the invention.

[0048] - Figure 5 represents a schematic sectional view of a card body according to the invention, before machining the cavity intended to receive the electronic module. - Figure 6 represents a schematic sectional view of a card body according to the invention, after machining the cavity intended to receive the electronic module.

[0049] - Figure 7 represents a schematic sectional view of a smart card according to the invention, after insertion of the electronic module into the cavity of the card body.

[0050] Reference is made to Figures 1 and 2 showing an electronic module 3 for a smart card. This electronic module 3 is provided on the upper face (Figure 1A) with a terminal block of metal contacts capable of interacting with the corresponding contacts of a smart card reader, as is well known. This electronic module 3 is provided on its lower face (Figure 1B) with a display screen 5 and one or more discrete or integrated electronic components 8, such as for example a conventional security electronic component ensuring the identification of the user of the smart card, or resistors or capacitors.

[0051] As visible in the cross-section of Figure 2, the electronic module 3 comprises a dielectric substrate 6 on which the contact terminal block (not shown) is mounted in the upper part, and the display screen 5 and the electronic components 8 in the lower part. The figures do not represent the possible electrical interconnections between the different components of the electronic module 3.

[0052] Figures 3A and 3B show a smart card 1 according to the invention, respectively in top view and in bottom view. It integrates an electronic module 3 according to Figures 1 and 2, the terminal block of the module 3 being visible on the upper face of the smart card 1 (Figure 3A), and the display screen of the module 3 being visible on the lower face of the smart card 1 (Figure 3B). Thanks to this structure, all the electronic components of the smart card, except a possible antenna for radiofrequency communication with a contactless reader, are integrated into the electronic module.

[0053] Figure 4 shows an exploded perspective view of the smart card 1 of Figure 3A. It comprises the electronic module 3, integrated into a card body formed by a stack of several layers of plastic material laminated together by a hot lamination process, i.e. at around 140°C + / - 20 degrees. In detail, the card body comprises:

[0054] - A transparent protective top layer 11, also called “Overlay” in Anglo-Saxon terminology, typically made of PVC with a thickness of around 40pm to 60pm.

[0055] - A 13 layer of white PVC, 200pm to 250pm thick, provided on its upper face with a graphic personalization 12 corresponding to the issuer of the smart card.

[0056] - An antenna insert 14 composed of a layer of PVC or PET and comprising the turns of an aluminum antenna / booster B, the assembly having a thickness of the order of 200pm to 250pm.

[0057] - A complex 15 formed by a layer of transparent PVC comprising on its lower face an opaque layer 10 (figure 5), in particular a white opaque layer formed by screen printing or offset printing, and the opaque layer 10 being provided on its lower face with a printed graphic personalization 16. The entire complex 15 has a thickness of the order of 200 pm to 250 pm. In order to ensure the visibility of the display screen 5 of the module 3 from the lower face of the smart card, it is essential that the opaque layer 10 of the complex 15 comprises a reservation 7 devoid of opaque material, opposite the area which will be occupied by the display screen 5. In other words, the opaque layer 10 will be printed over the entire surface of the complex 15, with the exception of the area located opposite the display screen 5.

[0058] - Finally, a lower transparent protective layer 17, also called “Overlay” in Anglo-Saxon terminology, typically made of PVC with a thickness of around 40pm to 60pm.

[0059] Figures 5 to 7 represent a cross-sectional view of the smart card 1, passing through the area of ​​the electronic module 3, at various stages of manufacture. The same elements bear the same reference numbers in the different figures. The thicknesses of the layers represented are modified compared to reality, for greater clarity. Figure 5 shows the structure of the card body 2 composed of the laminated stack of the layers 11 to 17 described in relation to Figure 4, before the machining of a cavity 4 intended to receive the electronic module 3. In particular, Figure 5 shows the zone 7 for reserving the opaque layer 10, as described above.

[0060] Figure 6 represents the same structure of card body 2, after machining of a cavity 4 intended to receive the electronic module 3. The bottom of the cavity 4 located in the transparent layer 15 is machined at several machining depths P1, P2, P3, depending on the thickness of the substrate of the module 3, of the screen 5 and of the other electronic components 8 which are in relief on the lower face of the electronic module 3.

[0061] Figure 7 shows the smart card 1 in sectional view, after integration of the electronic module 3. As can be seen, the display screen 5 of the module 3 is located at the bottom of the cavity 4, opposite a part of the transparent complex 15, and especially opposite the reservation 7 arranged in the opaque layer 10 thereof. As the lower layer 17 is also transparent, it follows that the display screen 5 is clearly visible from the lower face of the smart card 1. On the other hand, the other electronic components 8 are not placed opposite the reservation 7 of the opaque layer 10. They therefore remain invisible from the outside of the smart card 1.

[0062] Since the display screen 5 and the discrete components 8 typically have different thicknesses, it is useful for the bottom of the cavity 4 to have machining at multiple and differentiated depths, adapted on a case-by-case basis depending on the thickness of the display screen 5 and the discrete components 8 corresponding to the different types of electronic modules 3 to be integrated into the card body. In this way, the fixing of the electronic module 3 in the cavity 4 using an adhesive will be optimal. Several methods are possible to optimize the fixing of the electronic module 3 in the cavity 4 of the card body 2, and to optimize the visibility of the display screen 5 from the lower face of the smart card.

[0063] According to a first method of fixing, the electronic module 3 is fixed in the cavity 4 of the card body 2 by means of a thermofusible adhesive film 9 (also called “hotmelt”) arranged on the lower face of the electronic module 3 on and around the display screen 5 and the other components 8 thereof which are in relief on the lower face of the electronic module.

[0064] In this case, the hot-melt adhesive 9 must be transparent because it covers the entire lower surface of the module 3, including the screen 5. The hot-melt adhesive 9 may in particular be a co-polyamide thermoplastic film or an epoxy-based film.

[0065] According to a second method of fixing, shown in Figure 7, the electronic module 3 is fixed in the cavity 4 of the card body 2 by means of an opaque hot-melt adhesive film 9 laminated only on the periphery of the lower face of the electronic module 3 around the display screen 5 and the other components 8 thereof. The hot-melt adhesive 9 may in this case be a nitrile phenolic film, a co-polyamide thermoplastic film or an epoxy-based film.

[0066] According to a third method of fixing, the electronic module 3 is fixed in the cavity 4 of the card body 2 by means of a transparent glue 20 dispensed at the bottom of the cavity 4 so as to completely surround and cover the display screen 5. In this case there is no lamination of the adhesive. The gluing of the module 3 in the cavity 4 is simply carried out using a transparent liquid glue 20. The latter can also improve the readability of the screen 5 using its optical properties. Indeed, the bottom of the cavity 4 being machined, the PVC of the complex 15 may therefore have been “scratched” by the machining operation. The liquid glue 20 will be able to fill the roughness caused by the machining and thus improve the readability of the screen 3 through the transparent PVC window of the complex 15 and through the reservation 7 of its opaque layer 10.

[0067] A fourth method of fixing the electronic module 3 consists of combining the use of a hot-melt adhesive 9 and a liquid glue 20. In this case, the electronic module 3 is fixed in the cavity 4 of the card body 2 by means of the combination of a hot-melt adhesive film 9 laminated around the periphery of the electronic module 3, and a transparent glue 20 dispensed only at the bottom of the cavity 4 in the area intended to be opposite the display screen 5. In this case, the hot-melt adhesive 9 is laminated only on the periphery of the module and not on the screen 5. The hot-melt adhesive 9 can be a nitrile phenolic film, a co-polyamide thermoplastic film or an epoxy-based film. The liquid glue 20 is dispensed only in the deepest areas of the cavity 4, and not in the shallowest areas (PI) which are covered by the hot-melt adhesive 9.In the case where the hot melt adhesive is sufficient to ensure sufficient adhesion of the module 3 in the cavity 4, then the liquid glue 20 can be used only to improve the readability of the screen 5 using its optical properties.

[0068] The transparent liquid glue 20 used can be:

[0069] A UV-curable acrylic or cyanoacrylate adhesive A single-component epoxy adhesive that can be pre-activated by UV A two-component epoxy adhesive that cures at room temperature A liquid acrylic-based pressure-sensitive adhesive A two-component polyurethane adhesive that cures at approximately 80°C.

[0070] ADVANTAGES OF THE INVENTION

[0071] The invention achieves the set objectives. In particular, it has the advantage of integrating in a clearly legible manner into a smart card a display screen embedded in the rear of the module while simultaneously gluing the module in the cavity and ensuring good readability of the display, in particular the display of a dCW code. However, the invention is applicable to other types of smart cards and applications, as long as the smart card has a display screen.

[0072] The invention makes it possible to obtain a smart card provided with a transparent window showing the screen from the back face of the smart card. The opaque white layer placed outside the screen area will make it possible to opaque everything that one does not want to see in the card and under the electronic module, in particular the antenna of the card body, the electronic components and the module substrate. In addition, the opaque unprinted area will allow only the module screen to be seen. The graphic personalization of the smart card can then be printed on this opaque white layer, as on conventional smart cards without a screen.

[0073] The integration of the electronic module with its screen is particularly clean, without requiring buttons or other components in the card body or on its surface.

[0074] In addition, the invention makes it possible to avoid having a module opening out on the back of the smart card, and the transparent lower layer will protect the screen from external aggressions, while ensuring its perfect visibility.

[0075] Ultimately, the solution according to the invention makes it possible to advantageously replace dCW cards which embed the screen and its control electronics on a PCB substrate located in the card body, away from the electronic module.

[0076] A smart card provided with such a module having on its rear face a dCW display screen can be manufactured using a process using proven, reliable and economical techniques, including machining a cavity in the card body, then transferring and gluing the electronic module in the cavity.

[0077] The resulting smart card is fully compatible with the existing credit card system, easy to deploy for both merchants and users.

Claims

CLAIMS 1. Smart card (1) comprising a card body (2) formed by a stack of layers secured to each other and an electronic module (3) provided on its upper face with a terminal block of metal contacts capable of interacting with the corresponding contacts of a smart card reader and comprising on its lower face a display screen (5), said electronic module being integrated in a cavity (4) arranged on the upper face of the card body (2), and said display screen (5) being positioned at the bottom of said cavity (4) in a transparent layer (15) of the card body (2) so as to be visible from the lower face of the smart card, and said card body (2) comprising a generally opaque layer (10) arranged under said transparent layer (15) and provided with a non-opaque reserve zone (7) arranged opposite the display screen (5), characterized in that the bottom of said cavity (4) has multiple machining depths,adapted to the thickness of the display screen (5) and to the thickness of other electronic components (8) arranged on the underside of the electronic module (3)., 2. Chip card according to claim 1, characterized in that said generally opaque layer (10) is produced by white opaque printing on a transparent layer (15) of the card body, and in that the non-opaque reserve area (7) is produced by an absence of white opaque printing opposite the area provided for the display screen (5).

3. Chip card (1) according to one of the preceding claims, characterized in that the layers of the card body (2) comprise in order: - A transparent top protective layer (11) - A first printed layer (13) provided with graphic personalization (12) - An insert (14) provided with an antenna - A transparent layer (15) in which the bottom of said cavity (4) extends, coated with said opaque white printing (10) with the exception of said reserve zone (7) - A second printed layer (16) provided with graphic personalization, - A transparent lower protective layer (17).

4. Chip card (1) according to one of the preceding claims, characterized in that the electronic module (3) is fixed in the cavity (4) of the card body (2) by means of a transparent hot-melt adhesive film (9) arranged on the underside of the electronic module (3) on and around the display screen (5) and the other components (8) thereof arranged in relief on the underside of the electronic module (3).

5. Chip card (1) according to one of claims 1 to 3, characterized in that the electronic module (3) is fixed in the cavity (4) of the card body (2) by means of an opaque hot-melt adhesive film (9) laminated on the periphery of the lower face of the electronic module (3) around the display screen (5) and the other components (8) thereof.

6. Chip card (1) according to one of claims 1 to 3, characterized in that the electronic module (3) is fixed in the cavity (4) of the card body (2) by means of a transparent liquid glue (20) dispensed at the bottom of the cavity (4) so ​​as to surround and cover the display screen (5).

7. Smart card (1) according to one of claims 1 to 3, characterized in that the electronic module (3) is fixed in the cavity (4) of the card body (2) by means of the combination of a hot-melt adhesive film (9) laminated around the periphery of the electronic module (3), and a transparent liquid glue (20) dispensed at the bottom of the cavity (4) in the area intended to be opposite the display screen (5).

8. Chip card (1) according to claim 6 or claim 7, characterized in that the transparent liquid glue (20) is taken from: - A UV-curable acrylic or cyanoacrylate glue - A single-component epoxy glue pre-activated by UV - A two-component epoxy adhesive that cures at room temperature - An acrylic-based pressure-sensitive liquid glue - A two-component polyurethane adhesive that cures at around 80°C.

9. Method for producing a smart card (1) according to one of the preceding claims, comprising steps consisting of forming a card body (2) laminated multilayer, machining in the card body a cavity (4) intended to receive an electronic module (3) provided on its lower face with a display screen (5), transferring and gluing the electronic module (3) in the cavity (4) by orienting the lower face of the electronic module (3) towards the lower face of the smart card, characterized in that the step of forming the card body (2) comprises a step consisting of printing on a layer (15) of the card body (2) located under the electronic module (3), an opaque white layer (10) provided with a transparent reservation (7) in the area intended to be located opposite the display screen (5) after integration of the electronic module

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