Thick electronic module for a smart card having a metal body

Abstract

The invention relates to an electronic module (20) for a smart card (1) with a dual contact and contactless communication interface provided with a metal layer (3), and comprising a dielectric substrate (9) provided with metal contacts and the bottom face of which comprises a microelectronic chip (10) protected by a drop of potting resin (11), the electronic module (20) being intended to be transferred into a cavity (P1, P2) in the body (2) of a smart card (1) so that the visible surface of the electronic module (20) is positioned, to a nearest tolerance T, at the same level as the upper surface of the card body (2), characterised in that it comprises a spacer (14), the thickness (Eentretoise) of which is chosen to be greater than the thickness (Emétai) of the metal layer (3) minus the thickness (ESUbstrat) of the substrate (9) and plus the algebraic value of the tolerance T.

Description

[0001] DESCRIPTION

[0002] Title: Thick electronic module for metal body smart card

[0003] The present invention relates to a smart card with a dual contact and contactless communication interface, provided with a card body having at least one essentially metallic visible face.

[0004] STATE OF THE ART

[0005] In the field of smart cards, particularly those used for banking applications, part of the market demand tends to concentrate, for reasons of better handling and increased differentiation, on cards made heavier than traditional plastic-bodied smart cards, by the integration of a metallic layer.

[0006] Generally speaking, chip cards weighted with a metal layer must meet several conflicting requirements. They must incorporate enough metal to produce a tangible weighting and a clearly perceptible differentiation compared to plastic cards. But the metal produces an electromagnetic shielding effect, or at the very least, disruptions to the radiofrequency communication performance of this type of chip card with a remote contactless reader. However, this communication performance must be compatible with a set of standards, such as those provided for by the so-called EMVCo specifications, which impose mechanical and electrical requirements, as well as radiofrequency communication quality criteria.

[0007] Some of the known smart cards have a metal layer on only one side of the card body, the other side not being covered with metal but provided with an antenna allowing communication with a remote reader by radio frequency. However, due to the shielding effect of the metal layer, radio frequency communication with the reader is degraded. In particular, tests have shown that with this type of smart card, it was until now impossible to comply with certain standards such as those imposed by the so-called EMVCo specifications mentioned above.

[0008] In order to overcome this problem and maintain good radio frequency communication quality regardless of the orientation of the smart card relative to the remote reader, it was proposed in document FR3032294A1 to construct the smart card using a metal insert placed between two external sheets each provided with an antenna and a ferrite layer. This arrangement makes it possible to maintain a communication quality compatible with EMVCo type specifications, but the method for producing this type of card is relatively complex and expensive. Furthermore, in this embodiment, the metal insert is located between external layers of the card made of plastic, and it is therefore not directly visible from the outside, which does not contribute to creating sufficient perceptual differentiation compared to cards made entirely of plastic.

[0009] To address this, document FR3089659A1 presented a metal smart card with a dual communication interface, provided with two external aluminum plates surrounding a cavity receiving a microelectronic module that must be powered by a battery. This structure makes it possible to actively improve the radiofrequency communication capabilities of the card, despite the presence of the external aluminum layers. However, the smart cards thus obtained weigh approximately 8 grams due to the use of aluminum, which is certainly greater than the weight of a card with a plastic body, but this weight is still considered insufficient for the so-called "premium" or high-end smart card market segment, which must have a target weight of more than 12 grams, while having external faces that can be personalized by laser engraving or other means, and while remaining compatible with the so-called EMVCo banking standards.

[0010] According to another smart card described in WO2019136436A1, the card body comprises a metal layer provided with a cutout larger than that of the electronic module, into which is inserted an intermediate piece made of plastic, which in turn receives an electronic module provided with a small antenna which is coupled with a main antenna arranged in the card body. This structure makes it possible to marginally improve the radio frequency communication performance, but since the intermediate piece made of plastic is visible around the module, it is necessary to cover the metal face and the intermediate piece with a masking layer, which detracts from the desired metallic appearance. In addition, this more complex structure requires additional manufacturing operations, beyond the milling of a cavity in the card body to attach an electronic module there.These additional steps negatively impact both the appearance and the manufacturing yield and cost of this smart card.

[0011] It is therefore necessary to propose a contactless or dual communication interface smart card with a higher weight than known smart cards, while presenting optimal radio frequency communication properties and suitability for graphic personalization.

[0012] The smart card covered by the invention is a card with a dual communication interface with a reader, and having a metal plate located on the front face of the card, namely the same face as that where the module is located.

[0013] In the case of a dual card with a dual contact and contactless communication interface, it is necessary to make a galvanic or inductive or capacitive connection between the module carrying the microelectronic chip and the antenna of the card body, but it is also necessary to maintain the connection pads of the electronic module on the surface of the metal plate so that they can interact with the corresponding contacts of a contact card reader.

[0014] The general structure of such a metal card is then as follows: a layer of metal on the front face, then a first layer of adhesive, then a layer of ferrite, and finally a second layer of adhesive followed by a layer integrating the antenna. This is followed by one or more other layers of plastic for cosmetic purposes or to bring the overall thickness to the 800 micrometers required for the thickness of bank cards, this thickness being necessary to ensure compatibility with the standards of contact smart card readers. Generally, this type of smart card is provided with a cavity in which the electronic module is then simply transferred and fixed. This cavity has a peripheral zone of depth PI, and a central zone of depth P2 greater than PI.The peripheral zone receives the substrate of the electronic module, generally made of epoxy glass, and the central zone receives the microelectronic chip of the module, covered by a drop of protective resin.

[0015] Usually, the depth PI does not exceed 200 pm and the depth P2 varies between 500 and 600 pm. However, the target thickness for the metal plate of a sufficiently heavy smart card is at least 300 pm, which is greater than the usual depth PI of the peripheral portion of the cavity. This implies that unless there is a change in construction, the periphery of the electronic module, which may include a module antenna, would rest inside the metal layer of the card body. This would severely restrict the radiofrequency communication capacity of the smart card. For obvious reasons of radiofrequency operation, it is necessary for the depth PI of the peripheral zone of the cavity to be greater than the thickness of the metal layer of the card body, so that the antenna of the electronic module is not opposite a metal zone.In other words, the peripheral area of ​​the module in which the module antenna or contact pads to the card body antenna are located, must be thicker than the thickness of the card body metal layer, located above the card body antenna layer.

[0016] The invention must therefore design a "thick module", in the sense that the peripheral zone of the module is thicker than the thickness of the metal layer, in order to allow the field lines or the connection wire to pass between the module and the antenna of the card body. This approach is counter-intuitive for those skilled in the art, insofar as the market trend is towards increasingly thin modules.

[0017] To achieve this result, one could imagine an electronic module using a sufficiently thick epoxy glass substrate, thicker than in known modules. But this would entail costly changes in the component supply chain and module manufacturing.

[0018] PURPOSE OF THE INVENTION

[0019] The invention therefore aims to propose a new electronic module structure capable of responding to the above problem, without modifying the usual, particularly effective processes for manufacturing the smart card and without harming the capacity for communication in contactless mode in accordance with the requirements of EMVCo type specifications.

[0020] SUBJECT OF THE INVENTION

[0021] In principle, the invention provides for producing an electronic module whose periphery is thickened, not using a thicker epoxy glass substrate, but by adding to the module substrate a component forming a spacer between the lower face of the epoxy glass substrate of the module and the bottom of the cavity of depth PI. This component, called a spacer in the following, is made of an electromagnetically inert material, so as not to interfere with the field lines passing through the module. The thickness of this spacer is chosen so that the total thickness of the periphery of the module, including the thickness of the adhesive layers and the metal layer under the module substrate, is greater than the thickness of the metal layer of the card body. The cavity of depth P2 greater than PI continues to receive the drop of resin coating the module chip.

[0022] The invention therefore relates to an electronic module for a smart card with a dual contact and contactless communication interface provided with a metal layer, this electronic module comprising a dielectric substrate whose upper face is provided with metal contacts and whose lower face comprises in a central zone a microelectronic chip protected by a drop of coating resin, said electronic module being intended to be placed in a cavity of the body of a smart card having a first zone of depth PI receiving said substrate and a second zone of depth P2 greater than PI receiving said drop of coating resin, so that the visible surface of the electronic module after insertion into the card body is positioned, to within a tolerance T, at the same level as the upper surface of the card body,characterized in that the thickness (Espacer) of the spacer is chosen to be greater than the thickness (Emetai) of the metal sheet reduced by the thickness (E, SU bstrat) of the substrate and increased by the algebraic value of the tolerance T.

[0023] In this way, it is ensured that after integration of the module into the smart card, the lower face of the module, namely the lower face of the spacer, is located beyond the plane of the lower face of the metal foil (taking as reference the upper face of the smart card), so that the metal foil cannot interfere in the communication between the module and the antenna of the card body. In addition, the thickness of the spacer makes it possible to increase the thickness of the metal foil, and consequently to make the smart card heavier.

[0024] When the upper faces of the electronic module and the card body are at the same level, T will be zero, and it will be sufficient for the thickness of the spacer to be chosen so that the portion of cavity of depth PI necessary to integrate the electronic module into the smart card is greater than the thickness of the metal sheet.

[0025] According to one embodiment, the overall thickness (Espacer) of the spacer comprises the thickness of the material of the spacer itself and the thickness of an adhesive, in particular a heat-activatable adhesive used to secure the electronic module to the bottom of the PI depth cavity portion of the card body.

[0026] According to one embodiment, the algebraic value of the tolerance T is respectively positive, negative, or zero, when the apparent surface of the electronic module is raised relative to the surface of the card body, or set back relative to it, or at the same level as it.

[0027] According to one embodiment, the tolerance T has an algebraic value between + 50 and - 100 micrometers.

[0028] According to one embodiment, the thickness (E SU (bstrat) of the substrate includes the cumulative thicknesses of the periphery of the dielectric substrate, of an adhesive layer fixing the spacer to the substrate, and of a metallic layer corresponding to an antenna or to contact terminals of the electronic module.

[0029] Preferably, the spacer has a thickness (Espacer), (including the thickness of the adhesive for securing the spacer to the bottom of the cavity, which is of the order of about 30 to 50 micrometers) of between 150 and 480 micrometers.

[0030] According to one embodiment, the spacer is made of a material taken from epoxy glass, polyimide, PVC, polycarbonate, PET, or a synthetic paper such as for example Teslin.

[0031] According to one embodiment, the outer periphery of the spacer is set back by a certain offset relative to the outer periphery of the module substrate. Preferably, said offset is approximately 350 micrometers.

[0032] According to one embodiment, the spacer is cut from a sheet of magnetically inert material, then attached and fixed to the underside of the module substrate.

[0033] Alternatively, the spacer is made by overmolding above the underside of the module substrate.

[0034] Preferably, the spacer has a central orifice provided with a marking corner or an asymmetry making it possible to mark the position of the spacer relative to the support film carrying the modules.

[0035] According to one embodiment, the module comprises contact terminals connected to the antenna of the card body by galvanic connections.

[0036] According to another embodiment, the module comprises a module antenna, inductively coupled with the card body antenna.

[0037] The invention also relates to a smart card with a dual contact and contactless communication interface, comprising a card body having on one of its faces a visible metal sheet capable of increasing the weight of the card body, a layer provided with a card body antenna, and a ferri-magnetic insulating layer interposed between said metal sheet and said antenna layer of the card body, and a cavity having a first zone or section of depth PI receiving the peripheral zone of the module and a second zone or section of depth P2 greater than PI and receiving the drop of coating resin, characterized in that said smart card comprises an electronic module as defined above.

[0038] Preferably, the metal foil has a thickness of between 250 micrometers and 600 micrometers, which makes it possible to considerably increase the weight of the smart card, without impairing its contactless communication capacity.

[0039] DETAILED DESCRIPTION

[0040] The invention will be described in more detail with the aid of the drawings, in which:

[0041] - Figure 1 shows a sectional view of the layers of a known smart card, outside the area of ​​the electronic module;

[0042] - Figure 2 represents a sectional view of an electronic module according to the state of the art, provided with a module antenna;

[0043] - Figure 3 represents a sectional view of an electronic module according to the state of the art, without an antenna but provided with galvanic contacts for connection with an antenna of the card body;

[0044] - Figure 4 represents a sectional view of a first embodiment of a thick electronic module according to the invention;

[0045] - Figure 5 represents a sectional view of a second embodiment of a thick electronic module according to the invention;

[0046] - Figure 6 represents a sectional view of a smart card integrating a thick electronic module in accordance with Figure 5;

[0047] - Figure 7 represents a variant of Figure 6 in which the surface of the module is positioned by a tolerance T below the plane of the surface of the card body;

[0048] - Figure 8 shows another variant of the smart card of Figure 7;

[0049] - Figure 9 shows a variant of Figure 6 in which the surface of the module is positioned by a tolerance T above the plane of the surface of the card body;

[0050] - Figure 10 represents a top view of a first embodiment of the spacer of the thick module of Figure 5; - Figure 11 represents a top view of an electronic module integrating the spacer of Figure 10;

[0051] - Figure 12 represents a top view of a second embodiment of the spacer of the thick module of Figure 4;

[0052] - Figure 13 represents a top view of an electronic module integrating the spacer of figure 12;

[0053] - Figure 14 represents a step in the method of assembling a thick electronic module according to the invention.

[0054] Referring to Figure 1, a partial longitudinal section of a smart card is shown, outside the area of ​​the electronic module, with layer thicknesses exaggerated compared to reality, for greater clarity.

[0055] Identical elements in different figures are designated by the same reference numbers.

[0056] The smart card 1 comprises a card body 2 composed of a stack of layers, namely, starting from the top, a metal layer 3, an adhesive layer 4, a ferrite-based complex 5, another adhesive layer 4, a layer 6 integrating an antenna (not shown) of the card body, a layer 7 typically made of printed PVC, and a transparent protective layer 8.

[0057] The ferritic complex 5 is formed by a layer of ferrite taken between the two adhesive layers 4 constituted for example by a heat-activated adhesive, also called "hotmelt" in English terminology. Ferrite is a ferrimagnetic material which has the particularity of modifying the path taken by the electromagnetic field lines. To ensure the correct radiofrequency operation of the smart card, the ferrite-based complex must imperatively be placed between the metal layer 3 and the antenna layer 6 of the card body. It then makes it possible to limit the shielding effect of the metal layer 3 with respect to the antenna of the card body.

[0058] The electronic module 8 known and represented in figure 2 conventionally comprises a dielectric substrate 9 which carries on its lower face a microelectronic chip 10, protected by a drop of coating resin 11. Being a module for a card with contactless operation or with mixed contact and contactless operation, it also comprises a module antenna 12 whose turns surrounding the area of ​​the microelectronic chip 10 can be seen.

[0059] Another known variant of electronic module 8 is shown in Figure 3. This module differs from that of Figure 2 in that it is a module without an antenna, but provided on the lower face of the substrate 9 with contact pads 12' which are connected on the one hand to terminals of the microelectronic chip (not shown), and on the other hand to ends of an antenna located in the card body, by connection wires or conductive vias (not shown).

[0060] The electronic module 8 of figures 2 and 3 is intended to be inserted into a machined cavity of the card body 2 which typically comprises two zones or sections at different machining planes, namely a first machining plane of depth PI, noted PI in the figures, defining a first cavity portion receiving in particular the substrate 9 of the electronic module 8, and a second machining plane of depth P2, noted P2, machined more deeply and forming a second smaller and deeper cavity portion in which the drop of coating resin 11 which protects the microelectronic chip 10 is positioned.

[0061] In both cases of Figure 2 and Figure 3, the dielectric substrate 9 of the known module is relatively thin, with a thickness typically between 75 and 110 micrometers, and the depth PI of the cavity of the card body, which corresponds to the thickness of the dielectric substrate 9 and a thin layer of adhesive 13, is not sufficient to pass through the metal layer 3 of the card body, if the latter is chosen to be thick, i.e. with a thickness of more than 300 micrometers.

[0062] In order to solve this problem, a first thick module 20 according to the invention is shown in Figure 4. It comprises a dielectric substrate 9 identical to that of the known modules 8 of Figures 2 and 3. This is a module conventionally comprising a thin substrate 9 typically made of epoxy glass, as well as a microelectronic chip 10 and a drop of coating resin 11. This new electronic module 20 differs from the previous ones in that its periphery 22 is thickened by the addition of a spacer 14 made of a material which does not interfere with the electromagnetic field lines likely to pass through the module 20. This spacer 14 can in particular be made of a material taken from epoxy glass, polyimide, PVC, polycarbonate, PET, or Teslin.

[0063] In order to prevent the field lines between the antenna 12 of the module and the antenna of the card body from being blocked by a layer of metal, the thickness of the spacer 14 is chosen to be such that the depth PI of the cavity necessary to integrate the electronic module (20) into the smart card (1) is greater than the thickness of the metal layer (3).

[0064] In the case (figure 6) where the apparent surface of the module 20 and the surface of the card body are at the same level, this will mean that the thickness of the spacer 14 must be sufficient so that the thickness of the periphery 22 of the module 20 (including the thickness of the adhesive 13 and of the antenna 12 of the module) is greater than the thickness of the metal layer 3 of the card body. This spacer 14 can therefore have differentiated thicknesses, in particular depending on the thickness chosen for the metal layer 3 of the card body. If we aim for a thickness of 250 to 600 micrometers for the metal layer 3, the spacer 14 will usefully have a thickness of 120 and 450 micrometers excluding adhesive 18, i.e. a total thickness of approximately 150 to 480 micrometers taking into account a layer of adhesive 18 of 30 micrometers.

[0065] For example, if the cumulative thickness of the substrate 9, the adhesive 13 and the antenna 12 of the module is 150 micrometers, the overall thickness of the electronic module 20 in its peripheral zone 22 (i.e. all of the layers 9, 12, 13, 14, 18) will be between 300 and 630 micrometers (with a spacer 14 with a total thickness of between 150 and 480 micrometers), which makes it possible to use for the card body a metal sheet with a thickness of between 250 and 600 micrometers, sufficient to significantly increase the weight of the smart card without affecting its radiofrequency communication capabilities.

[0066] Figure 5 shows a module 20 similar to that of Figure 4, except that the spacer 14 is a little less thick, but above all the periphery 15 of the spacer is slightly set back from the periphery 16 of the substrate 9, by a small offset 17, of the order of 350 micrometers. This offset 17 makes it possible on the one hand to absorb the positioning tolerances of the spacer 14 on the substrate 9, and on the other hand makes it possible not to have to cut through the material of the spacer 14 when individualizing the modules 20 from their support 30 (Figure 14). This makes it possible not to have to modify the cutting step on the module manufacturing line.

[0067] Figure 6 represents a sectional view of a smart card 1 integrating an electronic module 20 conforming to that of Figure 5. As can be seen, thanks to the addition of the spacer 14, the lower face of the peripheral zone 22 of the module 20 is constituted by the lower face of the spacer 14. This is located below the level of the lower face of the metal layer 3, so that the field lines between the antenna 12 of the module and the antenna of the card body (not shown) are not blocked by a layer of metal.

[0068] Figure 7 shows a view similar to that of Figure 6, except that the cavity of depth PI receiving the periphery of the module is located lower than in Figure 6. As a result, the surface of the module 20 is sunk below the level of the surface of the card body. This variability, which will be noted T, may be due to manufacturing tolerances, in particular milling tolerances.

[0069] By convention, we will assume that the value of T will be positive if the surface of module 20 is raised relative to the surface of the card body, and the value of T will be negative if the surface of module 20 is located below the plane of the surface of the card body. Module 20 can therefore be “buried” relative to the surface of the card, or be raised relative to it.

[0070] The ISO 7816-1 standard admits that the apparent surface of a module can be buried up to 100 pm below the level of the surface of the board (meaning that T can be up to - 100 pm), or on the contrary exceed this surface of the board up to 50 pm (meaning that T can be up to + 50 pm).

[0071] In order to prevent the metal sheet 3 from passing under the periphery 22 of the module, which would block the field lines between the module and the antenna of the card body, it is necessary that the thickness of the periphery of the module, which combines the thickness of the substrate 9, the adhesive 13, the antenna 12 of the module and the spacer 14 provided with its adhesive 18, and taking into account the positioning tolerance T, is greater than the thickness of the metal sheet 3. We will therefore have the condition: [Math 1] Esubstrat + EEntretoise + T > Emétai

[0072] Where Esubstrate combines the thicknesses of the substrate 9, the adhesive 13 and the metal 12 of the antenna or the contacts of the module, ESpacer designates the thickness of the spacer 14 including its adhesive 18), EMetal designates the thickness of the metal sheet 3, and T designates the positioning tolerance, positive or negative, of the surface of the module relative to the surface of the card body.

[0073] Or again: [Math 2] ESpacer > Emetal - Esubstrate +T

[0074] In other words, the thickness of the spacer (14) is chosen to be greater than the thickness (Emetai) of the metal layer (3) reduced by the thickness (Esubstrat) of the substrate (9) and increased by the algebraic value of the tolerance T.

[0075] Figure 8 illustrates the use of a metal plate 3 having for example a thickness of 400 pm with a module 20 whose periphery thickness (including the thickness of the substrate 9, the adhesive 13, the antenna metal 12, the spacer 14 and its adhesive 18) is less than the thickness of the metal plate 3, it is for example only 340 pm. Thus, by burying the surface of the module at a depth T of (- 80) pm relative to the surface of the card, this card will remain compliant with the ISO 7816-1 standard without needing a module 20 whose total periphery thickness exceeds the thickness of the metal plate 3.

[0076] Figure 10 illustrates the use of a spacer 14 thicker than that of Figure 9, allowing the use of a metal sheet 3 that is also thicker. In addition, the surface of the module 20 is raised relative to the surface of the card body, by a value T of up to + 50 micrometers.

[0077] Figure 10 shows the profile of the spacer 14 in top view. It has a central orifice 21 for receiving the coating drop 11 of the module 20. This central orifice 21 usefully has a discontinuity or an asymmetry, for example in the form of a corner 22, which can serve as a reference point when positioning the spacer 14 on the lower face of the substrate 9 of the module, as in the manufacturing step shown diagrammatically in Figure 14.

[0078] Figure 11 shows the spacer 14 of Figure 10 once positioned on the lower face of the substrate of the module 20 according to the invention. As can be seen, this is the spacer of the module of Figure 5, the periphery 15 of which is set back relative to the periphery 16 of the module, thus providing an offset 17 between the external edge 15 of the spacer 14 and the external edge 16 of the substrate 9.

[0079] Figure 12 represents a wider spacer 14, corresponding to that of the module of Figure 4. As visible in Figure 13 representing the bottom view of the module integrating the spacer of Figure 12, the external edge 15 of this wider spacer 14 corresponds in this case to the external edge 16 of the module substrate.

[0080] The spacer 14 of the module according to the invention can be produced in at least two distinct ways. It can be manufactured separately, in particular by cutting from a sheet of material, and then transferred and fixed to the lower face of the electronic module 20. Alternatively, it can be manufactured by overmolding on the lower face of the module, or by dispensing material on the lower face of the module. In this case, this dispensing can usefully be carried out during the step of dispensing the drop of coating resin 11 onto the microelectronic chip 10 of the module.

[0081] Figure 14 represents the step of feeding a film 30 carrying several modules 20 before their individualization by cutting from the film 30. The modules 20 reveal their lower face, provided with a module antenna 12 and a microelectronic chip 10. As the film 30 advances on the machine, a spacer 14 is transferred and fixed to the lower face of each module 20, before separating the modules 20 from their supporting film 30.

[0082] ADVANTAGES OF THE INVENTION

[0083] The invention achieves the set objectives. Tests have shown that radio frequency communication with a contactless reader is of good quality and meets the standards of a smart card without a metal layer, and in particular compliance with EMVCo specifications regardless of the card's orientation, and without requiring a slot in the metal layer.

[0084] The upper face of the metal sheet 3 of the smart card according to the invention is directly visible, without requiring a masking layer as in certain embodiments of the prior art. This metallic appearance is obtained without compromising the quality of radiofrequency communication. It gives the smart card a beautiful appearance, a weight that can be greater than 12 grams in the case of the use of steel in accordance with the needs of the premium card market, and a good grip. The manufacture of the smart card according to the invention makes it possible to continue to use conventional and proven manufacturing methods and tools, consisting of transferring an electronic module into a cavity of the card body as well as the pre-fixing and lamination of the layers of the card body.

[0085] The electronic module with its spacer can have either 6 or 8 contacts.

[0086] Ultimately, the metal-faced chip card according to the invention works in the same way as a plastic card or a known heavy card, but it also fully complies with the EMVCO contact or contactless banking standard.

Claims

CLAIMS 1. Electronic module (20) for a smart card (1) with a dual contact and contactless communication interface provided with a metal layer (3), this electronic module (20) comprising a dielectric substrate (9) whose upper face is provided with metal contacts and whose lower face comprises in a central zone a microelectronic chip (10) protected by a drop of coating resin (11), said electronic module (20) being intended to be placed in a cavity (P1, P2) of the body (2) of a smart card (1) having a first zone of depth PI receiving said substrate (9) and a second zone of depth P2 greater than PI and receiving said drop of coating resin (11), so that the visible surface of the electronic module (20) is positioned, to within a tolerance T, at the same level as the upper surface of the card body (2),characterized in that the electronic module (20) comprises a spacer (14) whose thickness (Espacer) is chosen to be greater than the thickness (Emetai) of said metal layer (3) reduced by the thickness (E, SU bstrat) of the substrate (9) and increased by the algebraic value of the tolerance T.

2. Electronic module (20) according to claim 1, characterized in that the overall thickness (Espacer) of the spacer (14) comprises the thickness of the material of the spacer (14) itself, and the thickness of a heat-activatable adhesive (18) for fixing the electronic module (20) to the bottom of the cavity of depth PI of the card body (2).

3. Electronic module (20) according to claim 1 or claim 2, characterized in that the algebraic value of the tolerance T is respectively positive, negative, or zero, when the apparent surface of the electronic module (20) is in relief relative to the surface of the card body (2), or set back relative to it, or at the same level as it.

4. Electronic module (20) according to one of the preceding claims, characterized in that the tolerance T has an algebraic value between + 50 and - 100 micrometers.

5. Electronic module (20) according to one of the preceding claims, characterized in that the thickness (E SU bstrat) of the substrate (9) includes the thicknesses cumulated from the periphery (22) of the dielectric substrate (9), an adhesive layer (13) fixing the spacer (14) to the substrate (9), and a metal layer (12) corresponding to an antenna or contact terminals (12 7) of the electronic module.

6. Electronic module (20) according to one of the preceding claims, characterized in that the spacer (14) has an overall thickness (Espacer), including the thickness of the adhesive (18), of between 150 and 480 micrometers.

7. Electronic module (20) according to one of the preceding claims, characterized in that the spacer (14) is made of a material taken from epoxy glass, polyimide, PVC, polycarbonate, PET, or synthetic paper.

8. Electronic module (20) according to one of the preceding claims, characterized in that the external periphery (15) of the spacer (14) is set back by an offset (17) relative to the external periphery (16) of the substrate (9) of the module.

9. Electronic module (20) according to claim 8, characterized in that said offset (17) is approximately 350 micrometers.

10. Electronic module (20) according to any one of the preceding claims, characterized in that the spacer (14) is cut from a sheet of magnetically inert material, then attached and fixed to the lower face of the substrate (9) of the module.

11. Electronic module (20) according to any one of claims 1 to 9, characterized in that the spacer (14) is produced by overmolding above the lower face of the substrate (9) of the module.

12. Electronic module (20) according to any one of the preceding claims, characterized in that the spacer (14) comprises a central orifice (21) provided with a corner or an asymmetry (24) serving as a positioning mark relative to a support film (30) carrying the modules.

13. Electronic module (20) according to one of the preceding claims, characterized in that it comprises contact terminals (12) connected to the antenna of the card body (2) by galvanic connections.

14. Electronic module (20) according to one of claims 1 to 13, characterized in that it comprises a module antenna (12), inductively coupled with the antenna of the card body.

15. Smart card (1) with dual contact and contactless communication interface, comprising a card body (2) having on one of its faces a visible metal layer (3) capable of increasing the weight of the card body (2), a layer (6) provided with a card body antenna, and a ferri magnetic insulating layer (5) interposed between said metal layer (3) and said antenna layer (6) of the card body, and a cavity having a first section of depth PI receiving the peripheral zone (22) of the module and a second section of depth P2 greater than PI and receiving the drop of coating resin (11), characterized in that it comprises an electronic module (20) according to any one of claims 1 to 12.

16. Chip card according to claim 15, characterized in that the metal layer (3) has a thickness of between 250 micrometers and 600 micrometers.

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