Method for manufacturing a printed circuit board integrating an electronic component and smart card module obtained by said method.

Abstract

The invention relates to a method for manufacturing a printed circuit board in which an electronic component (20) is fixed to the upper surface of a metal foil (10) and then covered with a first layer of dielectric material (30). Openings are made in the first layer of hardened dielectric material (30), and the whole assembly is covered with a conductive layer (50) filling the openings. The metal foil (10) and the conductive layer (50) are used to create patterns of conductors. The invention also relates to a smart card module in which an integrated circuit (20) is placed between first (10) and second (50) metal layers within a layer of dielectric material (30). Figure for the abstract: Fig. 2h

Description

Title of the invention: Method for manufacturing a printed circuit integrating an electronic component and smart card module obtained by said method. Technical field

[0001] The present invention relates to a method for manufacturing a printed circuit integrating an electronic component, as well as a smart card module obtained by said method. More generally, the invention relates to the manufacture of printed circuits integrating components in their thickness. Technological Background

[0002] In the field of smart cards, the module of a card consists of a grid of contacts to which an integrated circuit (also called a "chip") is connected, said module being inserted into the card so that the integrated circuit is located inside said card with the contacts flush with the surface of the card. The grid of contacts is produced using a single- or double-sided flexible printed circuit manufacturing technique, one etched face of which corresponds to the grid of contacts and the other face is used to receive and connect the chip to the grid of contacts. The chip is connected to the printed circuit, using a technique using a gold wire connection (better known as "Wire-Bonding") or using a technique of direct soldering of the flip-chip onto the printed circuit (better known as "Flip-Chip").Once the chip is connected, it is covered with a resin to protect it, using a technique that allows the thickness of the resin to be controlled. The module thus produced corresponds to a rectangular printed circuit board with a thickness of between 150 and 200 micrometers with a protrusion of around 300 to 400 micrometers in the center of the face opposite the contact grid.

[0003] In order to place the module in a smart card, the latter must comprise a first cavity having the shape of the rectangular pad and the thickness of the printed circuit and a second cavity placed in the center of the first cavity to receive the protuberance of the module so that the contact grid is flush with the surface of the card. Such first and second cavities can be produced by machining or by molding. The thickness of a smart card being 800 micrometers this creates a fragile zone at the level of the module which can also present a perceptible deformation after assembly. In addition, the production of the double cavity presents a significant cost.

[0004] Furthermore, the thickness of the smart card requires a printed circuit having a thickness of less than 200 micrometers in order to accommodate the integrated circuit. and its protective layer with a thickness of less than 400 micrometers. The production of such a thin printed circuit requires reducing all the thicknesses of the layers constituting the printed circuit, which makes it very flexible and limits the size of the chip to prevent it from breaking due to bending not supported by the silicon constituting the integrated circuit. Summary of the invention

[0005] The invention proposes a method for manufacturing a printed circuit which integrates a component, such as for example a silicon chip, into its thickness. Thanks to such a method, it becomes possible to produce a smart card module of uniform thickness, without protrusion, the thickness of which is less than the thickness of a module of the prior art. The printed circuit being thicker than the printed circuits of the prior art, it can be less flexible and allow the use of chips with a larger surface area. In addition, since the chip is placed and connected during the manufacture of the printed circuit, the manufacturing costs of the module are reduced.

[0006] More particularly, the invention proposes a method of manufacturing a printed circuit which comprises the steps of: - supply of a first metal sheet comprising at least one identification mark, - depositing and bonding at least one electronic component on an upper face of said metal sheet at a location located relative to the at least one reference mark, - deposition of a first layer of dielectric material on the upper face of the metal sheet and on the electronic component, - making openings in the first layer of hardened dielectric material, - depositing a first conductive layer covering the entire surface of the first layer of dielectric material, - deposition of a second conductive layer filling the openings, - etching of the first metal sheet and the first conductive layer in order to create conductor patterns.

[0007] According to a first embodiment, the steps of depositing the first and second conductive layers can be carried out simultaneously and comprise a step of depositing a conductive priming material on the first layer of dielectric material and in the openings, followed by a step of electro-deposition of copper.

[0008] According to a second embodiment, the step of depositing the first conductive layer can be carried out by depositing a second metal sheet prior to the hot rolling step and the step of making openings is carried out simultaneously simultaneously openings in the first layer of dielectric material and in the second metal sheet.

[0009] Preferably, the step of making openings can be done by laser.

[0010] Depending on the choices of the person skilled in the art, the dielectric material may be chosen from one of the following materials: polyester, epoxy resin, polyimide.

[0011] In a preferred embodiment, the first layer of dielectric material may be a thermosetting material deposited in liquid or pasty phase and in which the method comprises a hot rolling step in order to flatten and harden the first layer of dielectric material.

[0012] In order to best control the thickness of the printed circuit, the hot rolling step can be carried out using a press with pressing height control.

[0013] In order to etch the printed circuit by photolithography, the step of etching the first metal sheet and the first conductive layer may comprise the steps of: - deposition of photosensitive layers on the first conductive layer and on the lower surface of the first metal sheet, - exposure of the photosensitive layers with a negative mask of the patterns defining the parts to be exposed, - removal of the exposed part of the photosensitive layers, - acid attack of the first conductive layer and the lower surface of the first metal foil on the areas where the exposed photosensitive layers have been removed.

[0014] To produce one or more other metallization levels at the end of the etching step of the first conductive layer, said method may comprise the following steps: - deposition of a second layer of dielectric material on the first etched conductive layer, - hot rolling to flatten and harden the second layer of dielectric material, - making openings in the second layer of hardened dielectric material, - deposition of a third conductive layer covering the entire surface of the second layer of dielectric material, - deposition of a fourth conductive layer filling the openings, - etching of the third conductive layer in order to create conductor patterns.

[0015] Like the etching of the other conductive layers, the step of etching the third conductive layer may include the steps of: - deposition of a photosensitive layer on the third conductive layer, - exposure of the photosensitive layer with a mask defining the parts to be exposed, - removal of the exposed part of the photosensitive layer, - acid attack of the third conductive layer on the areas where the exposed photosensitive layer has been removed.

[0016] According to another aspect, the invention proposes a smart card module comprising a first metal layer and a second metal layer enclosing a layer of dielectric material, the first metal layer defining a contact grid intended to be flush with the surface of a smart card, the second metal layer being etched with patterns defining metal conductors for connecting contact pads of an integrated circuit to the contact grid through openings made in the layer of dielectric material, characterized in that the integrated circuit is placed between the first and second metal layers inside the layer of dielectric material.

[0017] According to a particular embodiment, the module may comprise a third metal layer separated from the second metal layer by a second dielectric layer, the second metal layer being located between the first and third metal layers. Brief Description of the Figures

[0018] The invention will be better understood and other characteristics and advantages thereof will appear on reading the following description of particular embodiments of the invention, given as illustrative and non-limiting examples, and referring to the appended drawings, among which:

[0019] [Fig-1] shows a copper strip serving as a basis for the production of a smart card module strip according to the method according to the invention,

[0020] [Fig.2a], [Fig.2b], [Fig.2c], [Fig.2d], [Fig.2e], [Fig.2f], [Fig.2g] and [Fig.2h] illustrate the steps of a first embodiment of the method according to the invention,

[0021] [Fig.3a] and [Fig.3b] show a strip of smart card modules made by the method according to the invention,

[0022] [Fig.4a], [Fig.4b], [Fig.4c], [Fig.4d] and [Fig.4e] illustrate the steps of a second embodiment of the method according to the invention,

[0023] [Fig.5a], [Fig.5b], [Fig.5c], [Fig.5d] and [Fig.5e] illustrate the steps of a variant of implementation of the method according to the invention, Detailed description

[0024] In the following description several variant embodiments will be described. In order to simplify the description, the elements found in several figures will use the same references and will only be described once. In the different variants of embodiment only elements modified compared to a previously described example will be mentioned.

[0025] For explanatory purposes, the drawings are not drawn to scale in order to be able to represent on the same figure details which could not be visible if the scale were respected. For this purpose, it is appropriate to refer to the description to have a more precise idea of ​​the sizes represented.

[0026] The manufacturing method of the invention is particularly interesting for the production of continuous smart card modules on strips of several meters, or even several tens of meters, the width of which is generally 35 to 150 millimeters. Thus, the description mainly refers to the production of a smart card module. Nevertheless, the method of the invention can be applied to other types of printed circuits manufactured in wider strips or in large sheets.

[0027] The method according to the invention begins by providing a metal sheet. In order to be able to produce a strip of modules, the metal sheet is for example a copper strip 10 35 millimeters wide, shown in [Fig.l]. The copper strip 10 has perforations 11 and 12 on the edges which are intended to allow controlled advance on a production line. Some perforations 12 are wider in order to serve as registration marks making it possible to define the position of the modules on the metal strip. The registration marks 12 are notably used in the method according to the invention to precisely define placement or machining positions.

[0028] Alternatively, it is possible for all the perforations to be registration marks. In particular if the perforations are spaced apart by a distance corresponding to the gap between two modules. Conversely, the registration marks may also be distinct from the perforations used for advancing the strip, in particular if the method is used to produce large sheet printed circuits. According to the invention, it is important to have at least one registration mark on the metal sheet or strip from which the manufacturing method is implemented. In the case of sheet manufacturing, the registration mark may correspond to a corner of the metal sheet provided that the metal sheet is cut precisely and that said sheet is sufficiently rigid so that the corner thereof is not at risk of being damaged.

[0029] The metal strip 10 is for example a copper strip whose thickness is for example 35 mm to produce a smart card module. A person skilled in the art may at will use a material other than copper, such as for example steel or aluminum and the thickness of the metal strip 10 (or of the metal sheet) may vary depending on the applications for which the printed circuit is intended.

[0030] Figures 2a to 2h illustrate the different steps implemented according to a first embodiment of the method. In [Fig.2a], the metal strip 10 is positioned under a component placement tool. The position of the strip being identified by the placement tool using the registration mark 12, the tool performs a step of removing and bonding an electronic component 20 at a location located relative to the registration mark. In the case of a smart card module, the electronic component 20 is an integrated circuit of the thinned silicon chip type directly cut from a wafer having a thickness for example of the order of 150 mm. The bonding of the electronic component 20 is carried out according to a known technique using a thin-layer adhesive 21 commonly used for the manufacture of smart card modules.The adhesive 21, for example a drop of epoxy glue, is placed on the component 20 or on the strip 10, then the component 20 is placed on the strip 10 and pressure is applied to the component reducing the drop of glue to a thin layer with a thickness of the order of 10 mm to 20 mm and ensuring bonding to the strip. Other bonding techniques can be used as long as the thickness of the glue layer is of the same order of magnitude.

[0031] In the case of printed circuits other than a smart card module, several electronic components can be placed on the metal sheet at different locations. The electronic components can be of different types such as resistors, capacitors, or integrated circuits. However, it will be appropriate to use components whose thickness is less than the thickness of the printed circuit that one wishes to obtain.

[0032] [Fig.2b] illustrates a following step of depositing a layer of a dielectric material 30. The dielectric material 30 may be epoxy resin, polyimide, polyester or any other material commonly used as a dielectric material. According to a preferred embodiment, the dielectric material 30 is deposited in a liquid or so-called pasty phase, that is to say that the liquid phase has sufficient viscosity so as not to flow without stress, the viscosity depending on the thickness of the deposited dielectric material. The deposition of the dielectric material is carried out during the advancement of the strip 10 with a flow rate of liquid material calculated to obtain a desired thickness. For a smart card module, the flow rate is controlled to obtain a thickness of the order of 200 mm on the part of the strip which does not include the chip and of the order of 35 mm on the electronic component. The dielectric layer can then be UV crosslinked or thermoset.

[0033] In order to obtain better control of the thickness of the dielectric layer 30, it is preferred to use a thermosetting type dielectric material and to carry out hot rolling by controlling the pressing height in order to flatten and harden said dielectric layer 30. In this respect, it is possible to deposit a release film on the dielectric layer in the pasty phase and then hot laminating the whole thing. The release film is removed after hot rolling.

[0034] Hot rolling can be done by moving the strip 10 covered with the dielectric layer 30 and the release film between cylinders separated by a predetermined distance corresponding to the desired distance for the dielectric layer 30. However, the use of cylinders can create a stress on a silicon chip which risks damaging it if the thickness of dielectric material is low.

[0035] In the case of a smart card module, it is desired to have the smallest possible thickness. Therefore, it is preferred to use a hot rolling technique using a controlled height press such as for example described in the French patent application filed on March 29, 2021 under number 2103188. Such a technique consists of stopping the movement of the strip 10 under a press which descends vertically to a predetermined height in order to apply pressure and heat to harden the dielectric material. The press is then opened and the strip 10 advances over a distance allowing the pressing zone to be changed. Thus it is possible to obtain a dielectric layer 30 of a controlled thickness which is relatively flat.

[0036] The dielectric layer 30 having been hardened, a step of producing openings 40 is then made, as illustrated in [Fig.2c]. The production of the openings 40 is carried out for example using a YAG type laser which will vaporize the dielectric material at locations corresponding to contact locations. The contact locations are located relative to the registration mark so that the openings correspond to contact pads of the integrated circuit 20 and to locations where it is desired to make contact with the metal strip 10. For greater precision or alternatively, the location of the contact terminal locations of the integrated circuit 20 can also be done by reading the position by X-rays.

[0037] Then a deposition of a conductive layer 50 is carried out as illustrated in [Fig.2d]. The conductive layer 50 is deposited to cover the entire dielectric layer 30 and to fill the openings 40. For example, the conductive layer 50 is deposited in two stages. In a first stage, a deposit of conductive priming material is deposited over the entire surface and then an electro-deposition of more conductive metal, for example copper, is then carried out on the layer of conductive priming material to improve the conductivity of the conductive layer 50. The conductive priming material can be of different nature and the deposition method can vary depending on the material. According to a preferred embodiment, the conductive priming material is for example carbon, graphite or palladium and the deposition is carried out by immersing the strip in a bath containing the conductive priming material so that it is deposited on the dielectric layer 30. Once the dielectric layer 30 is covered with a thin layer of conductive material, the strip is taken into a second bath to carry out the electro-deposition until a copper layer thickness of the order of 35 mm is obtained. The conductive layer 50 thus produced is connected to the metal strip 10 and to the contact zones of the chip 20.

[0038] Alternatively, the conductive layer 50 can be produced by vacuum sputtering of a metal. Sputtering can be used for the deposition of a conductive priming layer or for the complete deposition of the conductive layer 50. However, the implementation of sputtering deposition is more expensive to implement, in particular if the quantity of metal to be deposited is large.

[0039] To produce the printed circuit, a step of etching the conductive layer 50 and the metal strip 10 is then carried out according to a known technique. As a preferred example, the etching step is carried out by photolithography and acid etching. However, other etching methods could be used. In the preferred example, as shown in [Fig. 2e], layers 60 of photosensitive material are deposited on the metal layer 50 and on the lower surface of the metal strip 10. The parts 70 to be removed from the photosensitive layers 60 are then exposed to UV using a mask (not shown) and then these parts 70 are removed, as shown in [Fig. 2f]. The strip is then passed through an acid bath in order to make openings 80 in the metal strip 10 and in the conductive layer 50.

[0040] The remainder of the photosensitive layers 60 is then completely removed, leaving visible on the rear face of the module, shown in [Fig. 3a], an antenna 90 and the metal conductors 91 which connect the contact pads of the integrated circuit to the contact grid 92 of the front face of the module, shown in [Fig. 3b]. The modules thus produced have a thickness which is for example 270 mm, which is much less than the thickness of the modules of the state of the art. The person skilled in the art can use greater thicknesses of metal and dielectric material if he wishes to have a more rigid module, while being able to obtain a module thickness less than a module of the state of the art. In addition, the module being flat, the machining of the smart card is simplified.

[0041] Figures 4a to 4e illustrate a second embodiment of the method according to the invention. [Fig.4a] illustrates the deposition and bonding of an integrated circuit 20 on the metal strip 10, identical to what is done in [Fig.2a]. Then a layer of a dielectric material 30 is deposited in liquid phase to cover the metal strip 10 and the integrated circuit 20, as shown in [Fig.4b]. In this second example, the dielectric material is a thermosetting material whose viscosity is high enough to avoid fining under the effect of its own weight. In [Fig.4c], a second metal strip 51 is deposited on the layer of dielectric material 30 before a hot rolling step. The second metal strip 51 is for example a 35mm thick copper strip which makes it possible to avoid the use of a release film. Thus the hot rolling is carried out using a press with controlled pressing height to roll the two metal strips 10 and 51 enclosing the layer of dielectric material 30 and to heat the assembly until the dielectric layer is crosslinked.

[0042] A step of making openings is carried out, as illustrated in [Fig.5d]. The making of openings 40 is carried out for example using a YAG type laser which will vaporize the metal of the second metal strip 51 and the dielectric material at locations corresponding to contact locations. The contact locations are located relative to the registration mark so that the openings correspond to contact pads of the integrated circuit 20 and to locations where it is desired to make contact with the metal strip 10.

[0043] Then a deposition of a conductive layer 52 is carried out as illustrated in [Fig.5e]. The conductive layer 52 is deposited to fill the openings 40. For example, the conductive layer 52 is deposited locally by cathodic sputtering of metal or by any other metallization method making it possible to control the location of the metal deposition.

[0044] To complete the printed circuit, a step of etching the metal strips 10 and 51 is then carried out according to a known technique. As a preferred example, the etching step is carried out by photolithography and acid etching as illustrated using Figures 2e to 2h.

[0045] Those skilled in the art will appreciate that the second embodiment has fewer manufacturing steps although the metallization of the openings is more complex. In addition, this second example makes it possible to obtain a better surface condition for the conductors located on the rear part of the module.

[0046] The smart card module produced according to one of the two exemplary embodiments comprises a near-field antenna 90 whose size is limited in the center by the metal conductors 91. Furthermore, in order to be able to close the antenna 90, it is connected to the contacts C4 and C8 of the contact grid, which is only possible for modules having eight contacts. The advantage of obtaining such a thin module also makes it possible to add a third conductive layer while having a thickness less than the thickness of a module of the state of the art. The use of a third conductive layer makes it possible to produce an antenna on the third layer without it being limited by the metal conductors or requiring it to be connected to contact pads.

[0047] Figures 5a to 5f illustrate an exemplary embodiment of a method for adding a third conductive layer to a module according to the invention. In [Fig.5a], an etched module obtained from one of the preceding examples is supplied in strip form. Such a module has, for example, a thickness of 270 mm.

[0048] A layer of dielectric material 530 is deposited on the metal layer 50 in liquid phase to a thickness of the order of 60 mm. The dielectric layer is then hot rolled to be hardened in the same way as described in the first embodiment example in relation to [Fig.2b]. However, the hot rolling height is set to reduce the layer to 50 mm thick so that the layer of dielectric material fills the openings 80 of the metal layer 50 well. After hardening, openings 540 are then made in the dielectric layer 530. The openings 540 are made for example using a YAG type laser which will vaporize the dielectric material at locations corresponding to contact locations.The contact locations are located relative to the registration mark such that the openings correspond to conductor areas of the metal layer 50 for which electrical contact is desired with the third metal layer.

[0049] Then a deposition of a conductive layer 550 is carried out as illustrated in [Fig.5c]. The conductive layer 550 is deposited to cover the entire dielectric layer 530 and to fill the openings 540. As a preferred example, the conductive layer 550 is deposited in two stages. In a first stage, a conductive priming material is deposited over the entire surface and then an electro-deposition of metal, for example copper, is then carried out on the carbon layer to improve the conductivity of the conductive layer 550. The electro-deposition is carried out until a copper layer thickness of the order of 35 mm is obtained. The conductive layer 550 thus produced is connected to conductor zones of the metal layer 50 which allow an interconnection to the metal strip 10 and / or to the contact zones of the chip 20.

[0050] The conductive layer 550 is then etched, as illustrated in [Fig.5d]. The step of etching the conductive layer 550 is carried out according to a known technique. As a preferred example, the etching step is carried out by photolithography and acid etching. Layers 560 of photosensitive material are deposited on the metal layer 550 and on the lower surface of the metal strip 10. However, only the photosensitive layer 560 deposited on the metal layer 550 is exposed to UV using a mask, the photosensitive layer 560 deposited on the metal strip serving only as protection for the metal strip 10 during the acid bath. When the strip passes through the acid bath, openings 580 are made in the conductive layer 550.

[0051] The photosensitive layers 560 are then completely removed using a solvent, as shown in [Fig.5e]. Thus, the rear face of the module can include an antenna 590 connected to metal conductors 91 located on the metal layer 50. The module thus produced, although having three metal layers, has a thickness of 345 mm, which is much less than a module of the state of the art.

[0052] Although the production of a smart card module is particularly interesting for the implementation of the method and makes it possible to manufacture a module that is much thinner than the modules of the prior art, the method of the invention is not limited to the production of smart card modules and can be applied to other types of printed circuits. Thus, it is possible to use metal and dielectric layers having greater thicknesses than those indicated in the preceding description. Also, one or more active or passive components can be placed in the dielectric layer; it will be appropriate to adapt the thickness of the dielectric layer to the height of the thickest component.

Claims

Claims

1. A method of manufacturing a smart card module characterized in that it comprises the steps of: - providing a first metal sheet (10) comprising at least one identification mark (12), - depositing and bonding at least one electronic component (20) on an upper face of said metal sheet (10) at a location located relative to the at least one identification mark (12), - depositing a first layer of dielectric material (30) on the upper face of the metal sheet (10) and on the electronic component, - making openings (40) in the first layer of hardened dielectric material (30), - depositing a first conductive layer (50, 51) covering the entire surface of the first layer of dielectric material, - depositing a second conductive layer (50, 52) filling the openings, - etching the first metal sheet (10) and the first conductive layer (50,51) in order to produce conductor patterns, etching the first metal sheet (10) forming a contact grid (92) of a smart card.,

2. A method of manufacturing a smart card module according to claim 1, wherein the steps of depositing the first and second conductive layers (50) are carried out simultaneously and comprise a step of depositing a conductive priming material on the first layer of dielectric material and in the openings, followed by a step of electro-depositing copper.

3. A method of manufacturing a smart card module according to claim 1, wherein the step of depositing the first conductive layer is carried out by depositing a second metal sheet (51) prior to the hot rolling step and the step of making openings simultaneously makes openings (40) in the first layer of dielectric material (30) and in the second metal sheet (51).

4. Method of manufacturing a smart card module according to one of the preceding claims, in which the step of making openings is carried out by laser.

5. Method of manufacturing a smart card module according to one of the re- preceding claims, wherein the dielectric material (30) is chosen from one of the following materials: polyester, epoxy resin, polyimide.

6. A method of manufacturing a smart card module according to one of the preceding claims, wherein the first layer of dielectric material (30) is a thermosetting material deposited in liquid or pasty phase and wherein the method comprises a hot rolling step in order to flatten and harden the first layer of dielectric material.

7. A method of manufacturing a smart card module according to the preceding claim, wherein the hot rolling step is carried out using a press having a control of the pressing height.

8. Method of manufacturing a smart card module according to one of the preceding claims, in which the electronic component (20) is an integrated circuit.

9. A method of manufacturing a smart card module according to one of the preceding claims, wherein the step of etching the first metal sheet (10) and the first conductive layer (50) comprises the steps of: - depositing photosensitive layers (60) on the first conductive layer (50, 51) and on the lower surface of the first metal sheet (10), - exposing the photosensitive layers (60) with a negative mask of the patterns defining the parts to be exposed, - removing the exposed part (70) from the photosensitive layers (60), - acid etching the first conductive layer (50, 51) and the lower surface of the first metal sheet (10) on the areas where the exposed photosensitive layers have been removed.

10. Method for manufacturing a smart card module according to one of the preceding claims, wherein, at the end of the step of etching the first conductive layer, said method comprises the following steps: - depositing a second layer of dielectric material (530) on the first etched conductive layer (50, 51), - hot rolling in order to flatten and harden the second layer of dielectric material (530), - making openings (540) in the second layer of hardened dielectric material (530), - depositing a third conductive layer (550) covering the entire surface of the second layer of dielectric material (530), - depositing a fourth conductive layer (550) filling the openings, - etching the third conductive layer (550) in order to produce conductor patterns.

11. Method for manufacturing a smart card module according to the preceding claim, in which the step of etching the third conductive layer (550) comprises the steps of: - depositing a photosensitive layer (560) on the third conductive layer, - exposing the photosensitive layer (560) with a mask defining the parts to be exposed, - removing the exposed part of the photosensitive layer (560), - acid etching of the third conductive layer (550) on the areas where the exposed photosensitive layer has been removed.

12. Smart card module comprising a first metal layer (10) and a second metal layer (50) enclosing a layer of dielectric material (30), the first metal layer (10) defining a contact grid (92) intended to be flush with the surface of a smart card, the second metal layer (50) being etched with patterns defining metal conductors (91) for connecting contact pads of an integrated circuit to the contact grid (92) through openings made in the layer of dielectric material (30), characterized in that an integrated circuit (20) is placed between the first (10) and second (50) metal layers inside the layer of dielectric material (30).

13. Smart card module according to the preceding claim, which comprises a third metal layer (550) separated from the second metal layer (50) by a second dielectric layer (530), the second metal layer (50) being located between the first (10) and third (550) metal layers.

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