Locally translucent contactless smart card incorporating a level 2 security element

Abstract

Locally translucent contactless smart card incorporating a level 2 security element. The invention relates to a contactless communicating wearable object (1), comprising a body in which is integrated a main antenna capable of receiving electrical energy by radio frequency from an external reader and communicating with it, and an electronic module provided with a dielectric substrate carrying a microelectronic chip, characterized in that the dielectric substrate of the electronic module is made of a translucent material and has an area bearing an opaque security pattern, and in that the layers of the body arranged opposite said security pattern are sufficiently translucent in the area of ​​the electronic module to allow visualization of said security pattern (8) under external illumination directed towards the area of ​​the security pattern. Figure for the abstract: Figure 6

Description

Title of the invention: Locally translucent contactless smart card incorporating a level 2 security element

[0001] The invention relates to secure, communicating portable objects, such as, in particular, smart identification cards or documents, equipped with a contactless microelectronic module. The communicating portable object includes an antenna integrated into its body for remote communication with a radio frequency reader.

[0002] By way of example and simplification of the exposition, the invention will be described in the context of its application to smart cards, without limiting the scope of the invention to this form factor, the invention being applicable to other portable objects or to other form factors.

[0003] However, contactless smart cards made in the standardized format according to ISO 7810 constitute the most widespread example of identification cards to which the invention applies. State of the art

[0004] For several years, a large number of contactless smart card designs have existed. A recurring problem is counterfeiting, with fake cards copying the appearance of original cards issued by legitimate issuers being placed on the market. Some of these smart cards have security features on their surface. These features are clearly visible and can also be counterfeited.

[0005] It would therefore be useful to design a smart card with one or more security features embedded in the card body, or even in the electronic module itself. This would increase the resistance of these cards to counterfeiting. Checking for the presence or absence of the security features then becomes more complex and requires specialized equipment, especially since the card body and the electronic module are generally opaque to light. Purpose of the invention

[0006] The general aim of the invention is therefore to propose a new structure for a contactless communicating portable object, in particular a new structure for a smart card or equivalent, which is free from the above disadvantages, and in particular a structure allowing the discreet integration of a level 2 security motif directly on the electronic module incorporated into the body of the smart card, while remaining visible, on demand, for verification.

[0007] Another object of the invention is to propose a new smart card structure allowing verification of the existence of a security feature by means of a simple visual check using a low-power lamp, such as that commonly available on mobile phones. Summary of the invention

[0008] In principle, the invention provides for adding a level 2 security element to the electronic module embedded in the body of the smart card, using for the electronic module a translucent structure capable of receiving a security pattern visible on demand under a certain level of lighting.

[0009] By level 2 security element, we mean an element having a level of security higher than level 1, which implies a security element directly visible to the naked eye, but lower than level 3, the detection of which requires sophisticated electronic equipment.

[0010] The invention implements the combined use of a translucent film for the substrate of the electronic module, and a specially adapted card structure in the area of ​​the electronic module to allow its examination in transmission (observation from the side opposite the light source) using a simple torch of the type commonly found as an accessory on mobile phones.

[0011] The invention therefore relates to a contactless communicating portable object, comprising a body in which is integrated a main antenna capable of receiving electrical energy by radio frequency from an external reader and communicating with it, and an electronic module provided with a dielectric substrate carrying a microelectronic chip, characterized in that the dielectric substrate of the electronic module is made of a translucent material and has an area bearing an opaque security pattern, and in that the layers of the body arranged opposite said security pattern are sufficiently translucent in the area of ​​the electronic module to allow said security pattern to be viewed under external lighting directed towards the area of ​​the security pattern from the face opposite the observation face.

[0012] According to one embodiment, the layers of the body arranged opposite said security motif are sufficiently translucent in the area of ​​the electronic module to allow said security motif to be viewed under external lighting with a minimum power of 50 lumens.

[0013] According to one embodiment, the dielectric substrate and the body are configured to exhibit differentiated light transmission rates, so as to ensure the vision of the safety pattern by contrast under the effect of external lighting.

[0014] According to one embodiment, the electronic module comprises a secondary antenna connected to the microelectronic chip and inductively coupled with the main antenna of the body.

[0015] According to one embodiment, the electronic module includes contact pads which are connected to the terminals of the main body antenna by wired galvanic connections or conductive vias.

[0016] According to one embodiment, the translucent material of the dielectric substrate of the electronic module has an optical transmission rate greater than 20% for light illumination wavelengths between 400 and 800 nm.

[0017] According to one embodiment, the stacking of the body and dielectric substrate layers has an optical transmission rate of between 1% and 5%, preferably about 3%, for light illumination wavelengths between 400 and 800 nm.

[0018] According to one embodiment, the electronic module includes a transparent encapsulating resin droplet protecting the microelectronic chip, and said security pattern is made on the translucent dielectric substrate, outside of said encapsulating resin droplet.

[0019] According to one embodiment, said safety pattern is made on the translucent dielectric substrate, inside said drop of coating resin.

[0020] Preferably, the body comprises in its structure a white opaque layer 50 to 150 micrometers thick, and additional layers substantially transparent to visible light. In one embodiment, said security feature is a metallic pattern produced by chemical or laser etching from a metallic layer disposed on one face of the translucent dielectric substrate. Preferably, said metallic security feature is produced on the same metallic layer as that forming an antenna of the electronic module.

[0021] According to one embodiment, the portable communicating object according to the invention is made in the form of a smart card in the standardized ISO 7810 format.

[0022] Other features and advantages of the invention will become apparent upon reading the detailed description provided in the application of the invention to a smart card, and the accompanying drawings in which: - Fig. 1 represents a plan view by transparency of a smart card according to the invention. - Fig. 2 represents a view along section AA of the smart card of Fig. 1. - Fig. 3 represents a view along a BB section of the smart card of Fig. 1 according to a first embodiment. - Fig. 4 represents a view along a BB section of the smart card of Fig. 1 according to a second embodiment, and a view from below of the electronic module. - Fig. 5 represents an enlarged top view of the electronic module equipped with its level 2 security pattern. - Figure 6 represents a diagram of the procedure for controlling a smart card according to the invention. - Fig. 7 represents a transmittance curve of the smart card at the electronic module level, as a function of wavelength. Detailed description

[0023] A transparent plan view of a smart card 1 according to the invention is shown in [Fig. 1]. It comprises a body (2) in which is integrated a main antenna (3) capable of receiving electrical energy by radio frequency from an external reader and communicating with it, and an electronic module (4). As is known, this module is provided with a dielectric substrate (5) carrying a microelectronic chip (6) (visible in [Fig. 3]). In the schematic embodiment, the electronic module (4) itself comprises a module antenna (9) (visible in Figure 9) which can be electromagnetically coupled with the main antenna (3) of the card body (2).

[0024] [Fig.2] schematically represents a cross-sectional view of the smart card 1 along the section line AA of [Fig.1]. This cross-sectional view shows the stacking of the different layers that constitute the card body 2. Thus, in the example shown, the card body 2 consists of external transparent plastic layers 20, 21, 23, opaque layers 22, 24, and at least one layer 25 intended to be printed with an image customized by the smart card issuer and visible from the outside.

[0025] As can be seen in [Fig. 3], which is a cross-sectional view along section line BB of [Fig. 1] and passing through the electronic module (4), a cavity (12) is provided in the central layers of the card body to receive the electronic module (4). This module comprises a dielectric substrate (5) on one face of which is fixed a microelectronic chip (6) protected by a drop of encapsulating resin (11).

[0026] According to the invention, the substrate (5) of the electronic module (4) is made of a translucent material and includes an area bearing an opaque security pattern (8). This may, in particular, be a metallic pattern, produced, notably by engraving, in the same metallic layer as that used to produce the antenna (9) of the module, or to produce contact pads for the galvanic connection with the antenna (3) of the card body (2).

[0027] In an alternative embodiment shown in [Fig.4], the safety motif (8) is arranged outside the coating resin droplet (11).

[0028] It is important that the dielectric substrate (5) be translucent, so that lighting Directing light towards the board in the area of ​​the electronic module (4) allows the opaque shape of the security pattern (8) to be distinguished through the substrate (5), as shown in more detail in [Fig. 5]. A substrate (5) with a light transmission rate of around 30% for visible wavelengths is a possible choice, whereas the epoxy glass substrates usually used for module substrates are generally much more opaque.

[0029] The layers (20, 21, 23) of the body (2) are chosen to be sufficiently translucent, with transmittances of the order of 80-85%, while the white layers (22, 24) have a transmittance of only 10 to 20% (for light wavelengths between 400 and 800 nm). at least in the area of ​​the electronic module (4), to allow visualization of said security pattern (8) under external illumination (13) directed towards the area (7) of the security pattern (8).

[0030] Layers 20 to 24 are made of plastic material, preferably polycarbonate, but other materials such as PVC or PET may be used. Their thickness is consistent with the layers typically used for this type of card. Advantageously, at least one of these layers is customizable / markable by laser carbonization. According to a tested embodiment, in the vicinity of the security feature (8), the stack of all the layers of the card body, including the module substrate (4), may have a transmittance of only 1% to 5%, as shown in [Fig. 7], while ensuring the visibility of the security feature (8) under suitable lighting, for example, a lamp (13) with a power of approximately 50 lumens. This type of lamp is very common; it is notably found in mobile phones.

[0031] To verify the existence of a security pattern (8) within the smart card according to the invention, a controller (14) simply needs to proceed as schematically shown in [Fig. 6], by transmitting the light from the lamp (13) onto one side of the smart card, while observing the opposite side. The opaque nature of the security pattern will be visible by contrast with the translucent substrate (5) and the transparent layers of the card body. The positions of the controller and the light beam can be interchanged for this observation. Advantages of the invention

[0032] Ultimately, the invention enables a portable communicating object, in particular a smart card or an electronic passport, to achieve the intended goals.

[0033] In particular, the invention makes it possible to incorporate into the smart card a level 2 security pattern, invisible from the outside in normal use, but whose presence is simply detectable during a visual examination of the smart card using a simple flashlight of moderate power.

[0034] The security motif can take on a wide variety of forms, and it remains safe at The inside of the smart card is protected from erasure and counterfeiting attempts. Its creation requires no additional manufacturing step, as it can be etched into the metallic layer of the electronic module's antenna and produced simultaneously. The verification process is non-destructive.

[0035] In addition, the structure of the smart card allows the continued use of existing manufacturing processes and equipment, making it possible to form card bodies consisting of a stack of layers of plastic material and a cavity in which an electronic module is placed and fixed.

Claims

Claims

1. Portable communicating object (1) with contactless operation, comprising a body (2) in which is integrated a main antenna (3) capable of receiving electrical energy by radio frequency from an external reader and communicating with it, and an electronic module (4) provided with a dielectric substrate (5) carrying a microelectronic chip (6), characterized in that the dielectric substrate (5) of the electronic module (4) is made of a translucent material and comprises a zone (7) carrying an opaque security pattern (8), and in that the layers of the body (2) arranged opposite said security pattern (8) are sufficiently translucent in the zone of the electronic module (4) to allow said security pattern (8) to be viewed under external lighting (13) directed towards the zone (7) of the security pattern (8) from the face opposite the observation face.

2. Portable communicating object (1) according to claim 1, characterized in that the layers of the body (2) arranged opposite said security pattern (8) are sufficiently translucent in the area of ​​the electronic module (4) to allow said security pattern (8) to be viewed under external lighting (13) with a minimum power of 50 lumens.

3. Portable communicating object (1) according to claim 1 or claim 2, characterized in that the dielectric substrate (5) and the body (2) are configured so as to have differentiated light transmission rates, so as to ensure the vision of the security pattern (8) by contrast under the effect of the external lighting (13).

4. Portable communicating object (1) according to any of the preceding claims, characterized in that the electronic module (4) comprises a secondary antenna (9) connected to the microelectronic chip (6) and inductively coupled with the main antenna (3) of the body (2).

5. Portable communicating object (1) according to one of claims 1 to 3, characterized in that the electronic module (4) comprises contact pads (10) which are connected to the terminals of the main antenna (3) of the body by wired galvanic connections or conductive vias.

6. Portable communicating object (1) according to any one of the preceding claims, characterized in that the translucent material of the dielectric substrate (5) of the electronic module (4) has an optical transmission rate greater than 20% for wavelengths light illumination between 400 and 800 nm.

7. Portable communicating object (1) according to any one of the preceding claims, characterized in that the stack of layers of the body (2) and of the dielectric substrate (5) has an overall optical transmission rate of between 1% and 5%, preferably approximately 3%, for light illumination wavelengths of between 400 and 800 nm.

8. Portable communicating object (1) according to any one of the preceding claims, characterized in that the electronic module (4) comprises a drop of transparent coating resin (11) protecting the microelectronic chip (6), and in that said security pattern (8) is produced on the translucent dielectric substrate (5), outside said drop of coating resin (11).

9. Portable communicating object (1) according to any one of claims 1 to 7, characterized in that the electronic module (4) comprises a drop of transparent coating resin (11) protecting the microelectronic chip (6), and in that said security pattern (8) is produced on the translucent dielectric substrate (5), inside said drop of coating resin (11).

10. Portable communicating object (1) according to any one of the preceding claims, characterized in that the body (2) comprises in its structure white opaque layers (22, 24) of 50 to 150 micrometers in thickness, and layers (20, 21, 23) substantially transparent to visible light.

11. Portable communicating object (1) according to any one of the preceding claims, characterized in that said security pattern (8) is a metallic pattern produced by chemical or laser etching from a metallic layer arranged on one face of the translucent dielectric substrate (5).

12. Portable communicating object (1) according to claim 11, characterized in that said metallic security pattern is produced on the same metallic layer as that forming an antenna (9) of the electronic module (4).

13. Portable communicating object (1) according to any one of the preceding claims, characterized in that it is produced in the form of a chip card in the standardized ISO 7810 format.

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