Thick electronic module for metal-bodied smart card

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 metallic layer (3), and comprising a dielectric substrate (9) provided with metallic contacts and the lower face of which comprises a microelectronic chip (10) protected by a drop of encapsulating 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) such that the apparent surface of the electronic module (20) is positioned, within a tolerance T, at the same level as the upper surface of the card body (2), characterized in that the thickness (ESpacer) of the spacer (14) is chosen to be greater than the thickness (EMetal) of the metallic foil (3) minus the thickness (ESubstrate) of the substrate (9) and plus the algebraic value of the tolerance T. Figure for the Abstract: Figure 6

Description

Title of the invention: Thick electronic module for metallic-bodied smart card

[0001] 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 apparent face. STATE OF THE ART

[0002] In the field of smart cards, particularly those used for banking applications, part of the market demand tends to focus, for reasons of better handling and increased differentiation, on cards made heavier than traditional smart cards with plastic bodies, by the integration of a metallic layer.

[0003] In general, smart cards weighted with a metallic layer must meet several conflicting requirements. They must incorporate enough metal to produce a tangible increase in weight and a clearly perceptible differentiation from plastic cards. However, the metal produces an electromagnetic shielding effect, or at the very least, interferes with the radio frequency communication performance of this type of smart card with a remote contactless reader. This communication performance must be compatible with a set of standards, such as those stipulated by the so-called EMVCo specifications, which impose mechanical and electrical requirements, as well as radio frequency communication quality criteria.

[0004] Some known smart cards have a metallic layer on only one side of the card body, the other side being uncoated but equipped with an antenna enabling radio frequency communication with a remote reader. However, due to the shielding effect of the metallic layer, the radio frequency communication with the reader is degraded. In particular, tests have shown that with this type of smart card, it has thus far been impossible to comply with certain standards such as those imposed by the so-called EMVCo specifications mentioned above.

[0005] To remedy this problem and maintain good radio frequency communication quality regardless of the smart card's orientation relative to the remote reader, it was proposed in document FR3032294A1 to construct the smart card using a metallic insert placed between two outer sheets, each equipped with an antenna and a ferrite layer. This arrangement makes it possible to maintain communication quality compatible with EMVCo type specifications, but the process of 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 is therefore not directly visible from the outside, which does not contribute to creating sufficient perceptual differentiation compared to cards made entirely of plastic.

[0006] To address this, document FR3089659A1 presented a dual-interface metal smart card with two outer aluminum plates surrounding a cavity housing a microelectronic module powered by a battery. This structure actively improves the card's radio frequency communication capabilities, despite the presence of the outer aluminum layers. However, the resulting smart cards weigh approximately 8 grams due to the use of aluminum. While this is certainly greater than the weight of a card with a plastic body, this weight is still considered insufficient for the "premium" or high-end smart card market segment, which must have a target weight of over 12 grams, while also featuring customizable outer surfaces through laser engraving or other means, and remaining compatible with EMVCo banking standards.

[0007] According to another smart card described in document WO2019136436A1, the card body has a metallic layer with a cutout larger than the electronic module, into which an intermediate plastic piece is inserted. This intermediate piece, in turn, houses an electronic module equipped with a small antenna that is coupled to a main antenna located in the card body. This structure marginally improves radio frequency communication performance, but because the plastic intermediate piece is visible around the module, it is necessary to cover the metallic face and the intermediate piece with a masking layer, which detracts from the desired metallic appearance. Furthermore, this more complex structure requires additional manufacturing operations beyond milling a cavity in the card body to accommodate the electronic module.These additional steps negatively impact both the appearance and the manufacturing yield, as well as the cost, of this smart card.

[0008] It is therefore necessary to propose a contactless smart card or a dual communication interface card having a higher weight than known smart cards, while exhibiting optimal radio frequency communication properties and suitability for graphic personalization.

[0009] The smart card referred to in 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 on which the module is located.

[0010] In the case of a dual card with a dual contact and non-contact communication interface contact, 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 keep the connection pads of the electronic module to the surface of the metal plate so that they can interact with the corresponding contacts of a contact card reader.

[0011] The general structure of such a metallic 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 incorporating the antenna. This is followed by one or more other layers of plastic material 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 chip card readers.

[0012] Generally, this type of smart card has a cavity in which the electronic module is simply placed 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.

[0013] Typically, the PI depth does not exceed 200 µm, and the P2 depth varies between 500 and 600 µm. However, the target thickness for the metallic plate of a sufficiently heavy smart card is at least 300 µm, which is greater than the usual PI depth 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 metallic layer of the card body. This would severely limit the radio frequency communication capability of the smart card. For obvious reasons related to radio frequency operation, it is necessary that the PI depth of the peripheral area of ​​the cavity be greater than the thickness of the metallic layer of the card body, so that the electronic module's antenna is not positioned opposite a metallic area.In other words, the peripheral area of ​​the module in which the module antenna or the contact pads to the antenna of the card body are located must be thicker than the thickness of the metallic layer of the card body, located above the antenna layer of the card body.

[0014] The invention must therefore design a "thick module," in the sense that the peripheral area of ​​the module is thicker than the thickness of the metallic layer, in order to allow the passage of the field lines or the connecting wire between the module and the antenna of the card body. This approach is counterintuitive for those skilled in the art, insofar as the market trend is toward increasingly thinner modules.

[0015] To achieve this result, one could imagine an electronic module using a sufficiently thick epoxy glass substrate, thicker than in known modules. However, this would entail costly modifications to the component supply chain and module manufacturing. PURPOSE OF THE INVENTION

[0016] The invention therefore aims to propose a new electronic module structure capable of addressing the above problem, without modifying the usual particularly efficient processes for manufacturing the smart card and without harming the contactless communication capability in accordance with the requirements of the EMVCo type specifications. SUBJECT OF THE INVENTION

[0017] In principle, the invention provides for the production of an electronic module whose periphery is thickened, not by means of a thicker epoxy glass substrate, but by the addition, on the module substrate, of a component forming a spacer between the underside of the epoxy glass substrate of the module and the bottom of the cavity of depth PI. This component, referred to hereafter as a spacer, 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 such that the total thickness of the module periphery, including the thickness of the adhesive layers and the metallic layer under the module substrate, is greater than the thickness of the metallic layer of the board body. The cavity, of depth P2 greater than PI, continues to receive the drop of resin encapsulating the module chip.

[0018] The invention therefore relates to an electronic module for a smart card with a dual contact and contactless communication interface provided with a metallic layer, this electronic module comprising a dielectric substrate the upper face of which is provided with metallic contacts and the lower face of which has in a central area a microelectronic chip protected by a drop of encapsulating resin, said electronic module being intended to be placed in a cavity of the body of a smart card having a first area of ​​depth PI receiving said substrate and a second area of ​​depth P2 greater than PI receiving said drop of encapsulating resin, so that the apparent surface of the electronic module after insertion into the card body is positioned, within a tolerance T, at the same level as the upper surface of the card body,characterized in that the thickness (E spacer) of the spacer is chosen to be greater than the thickness (E metal) of the metal sheet minus the thickness (E substrate) of the substrate and increased by the algebraic value of the tolerance T.

[0019] 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 the upper face of the smart card as a reference), so that the metal foil cannot interfere with the communication between the module and the antenna of the card body. Furthermore, the thickness of the spacer allows for an increase in the thickness of the metal foil, and consequently, a greater weight for the smart card.

[0020] When the upper faces of the electronic module and the card body are at the same level, T will be zero, and it will suffice for the thickness of the spacer to be chosen so that the portion of the cavity of depth PI required to integrate the electronic module into the smart card is greater than the thickness of the metal sheet.

[0021] According to one embodiment, the overall thickness (Espacer) of the spacer includes the thickness of the spacer material itself and the thickness of an adhesive, in particular a hot-activated adhesive used to fix the electronic module to the bottom of the PI depth cavity portion of the card body.

[0022] 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 recessed relative to it, or at the same level as it.

[0023] According to one embodiment, the tolerance T has an algebraic value between + 50 and - 100 micrometers.

[0024] According to one embodiment, the thickness (Esubstrate) of the substrate includes the cumulative thicknesses of the periphery of the dielectric substrate, a layer of adhesive fixing the spacer to the substrate, and a metallic layer corresponding to an antenna or contact terminals of the electronic module.

[0025] Preferably, the spacer has a thickness (Spacer), (including the thickness of the adhesive to fix the spacer to the bottom of the cavity, which is on the order of about 30 to 50 micrometers) of between 150 and 480 micrometers.

[0026] According to one embodiment, the spacer is made of a material taken from among epoxy glass, polyimide, PVC, polycarbonate, PET, or a synthetic paper such as, for example, Teslin.

[0027] According to one embodiment, the outer periphery of the spacer is recessed by a certain offset relative to the outer periphery of the module substrate. Preferably, said offset is approximately 350 micrometers.

[0028] According to one embodiment, the spacer is cut from a sheet of material that is magnetically inert, then attached and fixed to the underside of the module substrate.

[0029] Alternatively, the spacer is made by overmolding above the lower face of the module substrate.

[0030] Preferably, the spacer has a central opening provided with a locating corner or an asymmetry allowing the position of the spacer to be located relative to the support film carrying the modules.

[0031] According to one embodiment, the module includes contact terminals connected to the antenna of the card body by galvanic connections.

[0032] According to another embodiment, the module includes a module antenna, inductively coupled with the antenna of the card body.

[0033] 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 an apparent metallic foil suitable for increasing the weight of the card body, a layer provided with a card body antenna, and a ferrimagnetic insulating layer interposed between said metallic foil 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.

[0034] Preferably, the metal foil has a thickness between 250 micrometers and 600 micrometers, which makes it possible to considerably increase the weight of the smart card, without affecting its contactless communication capability. DETAILED DESCRIPTION

[0035] The invention will be described in more detail with reference to the drawings, in which: - Fig. 1 represents a cross-sectional view of the layers of a known smart card, outside the area of ​​the electronic module; - Fig. 2 represents a cross-sectional view of an electronic module according to the prior art, equipped with a module antenna; - Fig. 3 represents a cross-sectional view of an electronic module according to the prior art, without an antenna but equipped with galvanic contacts for connection with an antenna on the card body; - Fig. 4 represents a cross-sectional view of a first embodiment of a thick electronic module according to the invention; - Fig. 5 represents a cross-sectional view of a second embodiment of a thick electronic module according to the invention; - Fig. 6 represents a cross-sectional view of a smart card incorporating a thick electronic module conforming to Fig. 5; - Figure 7 represents a variant of Figure 6 in which the module surface is positioned by a tolerance T below the plane of the body surface of the map; - Fig. 8 represents another variant of the smart card from Fig. 7; - Figure 9 represents a variant of Figure 6 in which the surface of module is positioned with a tolerance T above the plane of the surface of the card body; - Fig. 10 represents a top view of a first embodiment of the spacer of the thick module of Fig. 5; - Fig. 11 represents a top view of an electronic module incorporating the spacer of Fig. 10; - Fig. 12 represents a top view of a second embodiment of the spacer of the thick module of Fig. 4; - Fig. 13 represents a top view of an electronic module incorporating the spacer of Fig. 12; - Fig. 14 represents a step in the assembly process of a thick electronic module according to the invention.

[0036] Reference is made to [Fig.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.

[0037] Identical elements in the different figures are designated by the same reference numbers.

[0038] The smart card 1 comprises a card body 2 consisting of a stack of layers, namely, from top to bottom, a metallic layer 3, an adhesive layer 4, a ferrite-based complex 5, another adhesive layer 4, a layer 6 incorporating an antenna (not shown) of the card body, a layer 7 typically made of printed PVC, and a transparent protective layer 8.

[0039] The ferritic complex 5 is formed by a layer of ferrite sandwiched between two adhesive layers 4, which are, for example, made of a heat-activated adhesive, also known as "hotmelt" in Anglo-Saxon terminology. Ferrite is a ferrimagnetic material that has the property of altering the path taken by electromagnetic field lines. To ensure proper radio frequency operation of the smart card, the ferrite-based complex must be placed between the metallic layer 3 and the antenna layer 6 of the card body. It thus limits the shielding effect of the metallic layer 3 with respect to the antenna of the card body.

[0040] The known electronic module 8, shown in [Fig. 2], conventionally comprises a dielectric substrate 9 on whose underside a microelectronic chip 10 is carried, protected by a drop of encapsulating resin 11. As it is a module for a contactless or mixed contact / contactless card, it further comprises a module antenna 12, the turns of which surrounding the area are visible. of the microelectronic chip 10.

[0041] Another known variant of electronic module 8 is shown in [Fig.3]. This module differs from that of [Fig.2] in that it is a module without an antenna, but provided on the underside of the substrate 9 with contact pads 12' which are connected on one side to terminals of the microelectronic chip (not shown), and on the other side to ends of an antenna located in the card body, by connecting wires or conductive vias (not shown).

[0042] 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 has two zones or sections with different machining planes, namely a first machining plane of depth PI, noted PI in the figures, defining a first portion of the cavity receiving in particular the substrate 9 of the electronic module 8, and a second machining plane of depth P2, noted P2, machined deeper and forming a second smaller and deeper portion of the cavity in which the drop of encapsulating resin 11 which protects the microelectronic chip 10 is positioned.

[0043] In both cases of [Fig.2] and [Fig.3], the dielectric substrate 9 of the known module is relatively thin, typically between 75 and 110 micrometers thick, 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 metallic layer 3 of the card body, if the latter is chosen to be thick, i.e. more than 300 micrometers thick.

[0044] To solve this problem, a first thick module 20 according to the invention is shown in [Fig. 4]. It comprises a dielectric substrate 9 identical to that of the modules 8 known from Figures 2 and 3. This module conventionally comprises a thin substrate 9, typically made of epoxy glass, as well as a microelectronic chip 10 and a drop of encapsulating 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 that does not interfere with the electromagnetic field lines that may pass through the module 20. This spacer 14 can, in particular, be made of a material such as epoxy glass, polyimide, PVC, polycarbonate, PET, or Teslin.

[0045] 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 required to integrate the electronic module (20) into the smart card (1) is greater than the thickness of the metal sheet (3).

[0046] In the case ([Fig.6]) where the apparent surface of 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 the module's antenna 12) is greater than the thickness of the metallic layer 3 of the card body. This spacer 14 can therefore have different thicknesses, particularly depending on the thickness chosen for the metallic layer 3 of the card body. If a thickness of 250 to 600 micrometers is targeted for the metallic layer 3, the spacer 14 will usefully have a thickness of 120 to 450 micrometers excluding the adhesive 18, i.e., a total thickness of approximately 150 to 480 micrometers taking into account an adhesive layer 18 of 30 micrometers.

[0047] By way of 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 area 22 (i.e. the whole of the layers 9, 12, 13, 14, 18) will be between 300 and 630 micrometers (with a spacer 14 of total thickness between 150 and 480 micrometers), which makes it possible to use for the card body a metallic sheet of thickness between 250 and 600 micrometers, sufficient to significantly increase the weight of the smart card without affecting its radio frequency communication capabilities.

[0048] Figure 5 represents a module 20 similar to that of Figure 4, except that the spacer 14 is slightly thinner, but more importantly, the periphery 15 of the spacer is slightly recessed relative to the periphery 16 of the substrate 9, by a small offset 17, on the order of 350 micrometers. This offset 17 allows, on the one hand, for the absorption of positioning tolerances of the spacer 14 on the substrate 9, and on the other hand, avoids the need to cut through the material of the spacer 14 when separating the modules 20 from their support 30 (Figure 14). This eliminates the need to modify the cutting step on the module manufacturing line.

[0049] Figure 6 shows a cross-sectional view of a smart card 1 incorporating 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 area 22 of the module 20 is formed 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 metal layer.

[0050] Figure 7 shows a view similar to that of Figure 6, except that the depth cavity PI receiving the periphery of the module is located lower than in Figure 6. As a result, the surface of module 20 is recessed below the level of the surface of the card body. This variability, which will be denoted T, may be due to manufacturing tolerances, particularly milling tolerances.

[0051] By convention, we will assume that the value of T will be positive if the surface of the module 20 is raised relative to the map body surface, and the value of T will be negative if the surface of module 20 is located below the plane of the map body surface. Module 20 can therefore be "buried" relative to the map surface, or be raised relative to it.

[0052] ISO 7816-1 allows that the apparent surface of a module can be buried up to 100 pm below the level of the surface of the map (meaning that T can be up to -100 pm), or on the contrary, protrude up to 50 pm above this surface of the map (meaning that T can be up to +50 pm).

[0053] 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, be greater than the thickness of the metal sheet 3.

[0054] We will therefore have the condition: [Math 1] Esubstrat + EEntretOiSe + T > Emétai

[0055] Where Esubstrat combines the thicknesses of the substrate 9, the adhesive 13 and the metal 12 of the antenna or the contacts of the module, EEntretOise designates the thickness of the spacer 14 including its adhesive 18), Emétai designates the thickness of the metal foil 3, and T designates the positioning tolerance, positive or negative, of the surface of the module relative to the surface of the card body.

[0056] Or again: [Math 2] EEntretoise > Emétai - Esubstrat+T

[0057] In other words, the thickness of the spacer (14) is chosen to be greater than the thickness (Emetal) of the metal sheet (3) less the thickness (Esubstrate) of the substrate (9) and increased by the algebraic value of the tolerance T.

[0058] Figure 8 illustrates the use of a metal plate 3, for example, 400 µm thick, 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; for example, it is only 340 µm thick. Thus, by burying the surface of the module at a depth T of (-80) µm relative to the surface of the board, this board will remain compliant with ISO 7816-1 without requiring a module 20 whose total periphery thickness exceeds the thickness of the metal plate 3.

[0059] Figure 10 illustrates the use of a spacer 14 that is 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.

[0060] Figure 10 shows the profile of the spacer 14 in top view. It has a central opening 21 for receiving the coating droplet 11 of the module 20. This central orifice 21 usefully presents a discontinuity or asymmetry, in the form for example of a corner 22, which can serve as a reference when positioning the spacer 14 on the lower face of the substrate 9 of the module, as in the manufacturing step schematically shown in [Fig. 14].

[0061] Figure 11 represents the spacer 14 of Figure 10 once positioned on the underside of the substrate of module 20 according to the invention. As can be seen, it is the spacer of the module of Figure 5, the periphery 15 of which is recessed relative to the periphery 16 of the module, thus creating an offset 17 between the outer edge 15 of the spacer 14 and the outer edge 16 of the substrate 9.

[0062] Fig. 12 represents a wider spacer 14, corresponding to that of the module in Fig. 4. As can be seen in Fig. 13, which shows the bottom view of the module incorporating the spacer of Fig. 12, the outer edge 15 of this wider spacer 14 corresponds in this case to the outer edge 16 of the module substrate.

[0063] The spacer 14 of the module according to the invention can be made 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 onto the underside of the electronic module 20. Alternatively, it can be manufactured by overmolding onto the underside of the module, or by dispensing material onto the underside of the module. In this case, this dispensing can usefully be carried out during the step of dispensing the drop of encapsulating resin 11 onto the microelectronic chip 10 of the module.

[0064] Fig. 14 represents the step of bringing 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 placed and fixed on the lower face of each module 20, before separating the modules 20 from their support film 30. ADVANTAGES OF THE INVENTION

[0065] The invention achieves the stated objectives. Tests have shown that radio frequency communication with a contactless reader is of good quality and regains compliance with the standards of a smart card without a metallic layer, and in particular compliance with the EMVCo specifications regardless of the orientation of the card, and without requiring a slot in the metallic layer.

[0066] The upper surface of the metallic foil 3 of the smart card according to the invention is directly visible, without requiring a masking layer as in some prior art embodiments. This metallic appearance is achieved without compromising the quality of radio frequency communication. It gives the smart card an attractive appearance, a weight that can exceed 12 grams in the case of using steel that meets the requirements of the premium card market, and a good grip. hand.

[0067] The manufacture of the smart card according to the invention makes it possible to continue to use the classic and proven manufacturing processes and tools, consisting of transferring an electronic module into a cavity in the card body as well as the pre-fixing and lamination of the layers of the card body.

[0068] The electronic module with its spacer can indifferently have 6 or 8 contacts.

[0069] In conclusion, the metal-faced smart 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 (PI, 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 thickness (Espacer) of the spacer (14) is chosen to be greater than the thickness (Emetai) of the metal sheet (3) reduced by the thickness (Esubstrat) 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 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 is in relief relative to the surface of the card body, 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 (Esubstrate) of the substrate (9) includes the cumulative thicknesses of the periphery (22) of the dielectric substrate (9), of an adhesive layer (13) fixing the spacer (14) to the substrate (9), and of a metal layer (12) corresponding to an antenna or to contact terminals (12') 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 (E spacer), 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 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 sheet (3) capable of increasing the weight of the card body (2), a layer (6) provided with a card body antenna, and a ferrimagnetic insulating layer (5) interposed between said metal sheet (3) and said card body antenna layer (6), 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 sheet (3) has a thickness of between 250 micrometers and 600 micrometers.

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