FR2828570A1 - Production of a contact-less chip support comprises laminating an insulating film on a micro-module film, laminating an adhesive film on the micro-module film, cutting the micro-module and applying an antenna to each micro-module - Google Patents

Abstract

Production of a contact-less chip support comprises: (a) laminating an insulating film (3) on a micro-module film; (b) laminating a film made from electrically conducting thermally active adhesive on the micro-module film; (c) cutting the micro-module (2); and (d) applying an antenna (11) to each micro-module. Production of a contact-less chip support comprises: (a) laminating an insulating film (3) on a micro-module film; (b) laminating a film made from electrically conducting thermally active adhesive on the micro-module film; (c) cutting the micro-module (2); and (d) applying an antenna (11) to each micro-module. The lower side of the micro-module supports the insulating layer and the adhesive layer (5) and faces the antenna so that an electrical connection to the connections (12) of the antenna is formed.

Description

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METHOD OF MANUFACTURING CONTACTLESS CHIP CARDS
AND / OR MIXED
INVENTORS: Patrick JACQUOUTON; Marc HERVIGO
The invention relates to a method of manufacturing an electronic assembly intended to be enclosed in the body of a smart card comprising at least one electronic micromodule carried on a support made of insulating material which supports a coil serving as antenna, the micromodule being intended to be electrically connected to the ends of the antenna winding.

 The invention therefore applies more particularly to the field of manufacturing contactless smart cards, that is to say smart cards capable of ensuring contactless operation, the exchange of information to the outside takes place. doing only through the antenna.

 The manufacturing method according to the invention also relates to smart cards capable of ensuring a contact operating mode and a contactless operating mode. The exchange of information with the outside is done either by the antenna (therefore without contact), or by the contacts flush with the surface of the card. Throughout the following description, this type of card will be referred to as a mixed operation card or a mixed chip card.

 Such cards are intended to carry out various operations, such as, for example, banking operations, telephone communications, identification operations, and all kinds of operations which can be carried out either by inserting

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 the card in a reader, either remotely by electromagnetic coupling (in principle of the inductive type) between a transmission-reception terminal and a card placed in the action area of this terminal.

 The antenna generally consists of a conductive element deposited in a thin layer on a plastic support sheet thus forming a winding, on the same plane, comprising at least two turns, the windings of which essentially run along the outer edge of the support sheet. Connection terminals are provided at the ends of the antenna so that the antenna can be connected to the contacts of the electronic micromodule.

 The antenna windings can be produced in different ways, by lamination, inlaying of antenna wires in the support, use of conductive ink, photoengraving or even screen printing.

 Any winding carried out on the same plane requires the installation of an insulating bridge so as to bring the outer turn to the other active components located inside the turns. If the antenna wire is embedded in the support, the wire is already insulated and the winding does not need a bridge. However, for the other types of embodiment of the winding, the installation of an insulating bridge is necessary.

 The technical problem which arises is a problem of precision and reliability of the connection between the micromodule and the antenna. Also, constraints of mechanical strength, reliability and manufacturing cost must be taken into account.

 There is a known method of making a smart card with an antenna at the ends of which there are connection pads with an electronic micromodule, which manufacturing method allows

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e l 1 antenne. un tel procédé est schématisé sur la figure 1. to obtain a free space between the antenna connection pads, in which it is possible to position the micromodule without risk of creating short-circuits, or of damaging the turns of

el 1 antenna. such a process is shown diagrammatically in FIG. 1.

 In this case, an antenna 11 comprising at least two turns is produced on a support sheet 10.

At the ends of the antenna wire 11 are provided connection pads 12. The turns of this antenna 11 are placed outside the connection pads 12, and an insulating bridge 13 is made so as to be able to connect each of the ends of the antenna respectively to a connection pad 12 without short circuit.

 This embodiment frees up the space between the connection pads 12 of the antenna since no turn passes there. This space being freed, the tracks of the antenna are not likely to be damaged during a subsequent step consisting in fixing the electronic micromodule to the connection pads of the antenna. However, this embodiment requires the installation of the insulating bridge 13. This insulating bridge 13 is produced by covering, over a zone z, the turns of the antenna with an insulating layer, a conductive element then making it possible to connect the 1 end of a turn, and in particular the end of the last turn located furthest to the outside of the support sheet 10, at one of the connection pads of the antenna.

 Thus, the establishment of such an insulating bridge proves to be an expensive solution. In addition, the series of additional steps implemented prior to assembly of the micromodule on the antenna to achieve

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 the insulating bridge does not allow a high production rate to be obtained.

 Another method of manufacturing contactless smart cards of the prior art is illustrated in FIG. 2. In this method, the electronic micromodule 600 spans the turns of the antenna 200 produced on the support sheet 100. In this configuration , the antenna is in the form of a spiral and comprises at least two turns. The turns of the antenna pass between the connection terminals 250 of this antenna. The electronic micromodule is therefore deferred so that its metal grid, comprising contact pads, is oriented towards the turns of the antenna. The establishment of an insulating bridge prior to the transfer of the micromodule is therefore necessary to avoid the appearance of short circuits between the antenna and the metal grid of the micromodule during the transfer of the latter.

 Thus, an insulating bridge 300 is produced, partially covering the antenna turns 200 with the exception of part of the connection terminals 250. A drop of filling material 500 is then deposited on the insulating bridge before transferring the micromodule against the insulating bridge and the filling material so as to establish an electrical connection of the micromodule to the antenna connection terminals.

 The insulating bridge 300 provides electrical insulation of the antenna tracks and of the metal grid of the micromodule and the filling material makes it possible to fill the space between the micromodule and the insulating bridge. The insulating bridge is preferably produced by screen printing of a liquid resin, then polymerization under ultraviolet rays. The construction of the insulating bridge partially covering the front antenna turns

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 the transfer of the micromodule to the antenna therefore requires the implementation of complex and costly steps. In addition, due to the very structure of the device in FIG. 2 with the micromodule spanning the antenna turns and the contact pads of the metal grid of the micromodule directly connected to the antenna connection terminals, it is very difficult to control the insulation on the one hand between the tracks of the antenna and, on the other hand, between the antenna and the metal grid of the micromodule. Thus, the insulating bridge 300 does not appear sufficiently robust.

 Also, an object of the invention is to manufacture a contactless and / or mixed smart card, comprising a component of the electronic micromodule type or simple metal latch, depending on the type of card to be produced, connected to an antenna between its interior turns. and external and making it possible to overcome the drawbacks associated with the methods of the prior art.

 To this end, the invention provides in a first embodiment for depositing an insulator in the form of a film which is cut and laminated on the component film itself instead of being deposited on the sheet comprising the antennas. In a second embodiment, the insulator is not laminated on the component film but is intended to be deposited on each component in the form of an insulating pad after the components have been cut and before they are transferred to an antenna support. Thus, it is the component itself, which after this treatment simultaneously acts as an insulating bridge when it is carried over the antenna so as to span it.

 The insulation thus gains in robustness and its implementation is very simplified, since it is made at the level of the micromodule film.

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 The invention therefore more particularly relates to a method of manufacturing a contactless chip carrier comprising an electronic assembly comprising an antenna forming a spiral at the ends of which are provided connection terminals and at least one electronic micromodule connected to the antenna, characterized in that it comprises the following steps consisting in: - laminating on a micromodule film, where a set of micromodules are grouped together, an insulating film where openings corresponding to the area of the electrical contact pads are located at the respective ends of each of the micromodules; laminating on said micromodule film a film of electrically conductive thermoactivatable adhesive material where apertures corresponding to the central zone of the micromodules situated on either side of their contact pads are previously made; - cut the micromodules; - for each micromodule, transfer the micromodule to the antenna, underside of the micromodule comprising the layers of insulating material and conductive adhesive previously laminated facing the antenna, so as to establish an electrical connection with the connection terminals of the 'antenna.

 Other features and advantages of the present invention will appear more clearly on reading the description given by way of illustrative and nonlimiting example and made with reference to the appended figures in which: - Figure 1, already described, illustrates a first prior art method of removing a bridge

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 insulator on an antenna winding for the transfer of an electronic micromodule in good operating conditions; FIG. 2, already described, illustrates a second method of the prior art for depositing an insulating bridge on an antenna coil, with an electronic micromodule coming to span this antenna coil when it is deferred; Figures 3A, 3B, 3C and 4 illustrate the different steps of the method according to the invention, Figure 4 being an exploded view.

 The method according to the invention therefore firstly consists in implementing a certain number of operations directly at the level of the micromodule film before the cutting and transfer of the electronic micromodules to their respective antenna. These operations are illustrated in FIGS. 3A to 3C.

 FIG. 3A indeed shows a portion of micromodule film 1 in which a set of electronic micromodules are grouped 2. Each transverse row of micromodules on the film 1 comprises three micromodules in the example of FIG. 3A, without this being in any way limiting of the scope of the present invention.

 This type of micromodule film is typically a 35mm film packaged on a reel and ready to be used on equipment which is commonly used in the traditional insertion of smart cards.

 FIGS. 3B and 3C then illustrate the two separate operations to be carried out on the micromodule film 1. It is important to note that the two operations described below with reference to FIGS. 3B and 3C can be carried out in any order.

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 With reference to FIG. 3B, a first operation consists in laminating on the first micromodule film 1 a second film 3 consisting of an insulating film covered with an adhesive so as to locally electrically isolate each of the micromodules. Preferably, the insulating film 3 consists of a very thin polyester support covered on at least one side with a heat-activated adhesive adhesive or the like. The deposition of this insulator by lamination on the micromodule film has the function of neutralizing the internal turns of the antenna during the insertion of the micromodule on the antenna.

 In fact, during the insertion of the micromodule, the turns of the antenna pass under the component and therefore touch the metallic contact part of the component, hence the need for this electrical insulation step to avoid short circuits between the central metallic zone of the component located on either side of its contact pads and the turns of the antenna winding. The adhesive with heat-activated glue covering at least one face of the polyester support forming an insulator also makes it possible to ensure good mechanical strength when the electronic micromodule is transferred to the antenna.

 However, the insulator must not cover the zone corresponding to the electrical contact pads of the micromodules, a part by which the electronic micromodule is electrically connected to the connection terminals of the antenna. Only the central area of the micromodules which will be in contact with the antenna turns must therefore be isolated.

 Thus, before laminating the insulating film 3 on the micromodule film 1, openings 4, corresponding to the area of the contact pads of the electronic micromodules located at the ends

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 respective of each of the micromodules, are carried out online on the insulating film 3 by means of an appropriate tool such as a die punch.

 In the example of FIG. 3B, the insulating film 3 does not cover the entire micromodule film 1 and the openings 4 made in the insulating film 3 are four in number for each transverse row of micromodules in the micromodule film.

 In a variant, a wider insulating film (not shown in FIG. 3B) is used so as to completely cover the micromodule film 1 (apart from the film drive holes). The openings 4 made on the insulating film are then six in number for each transverse row of micromodules of the micromodule film 1. In the example of FIG. 3B, each row in fact comprises three micromodules.

 The openings therefore correspond to the areas of the contact pads of the micromodules used for the electrical connection with the antenna.

 After laminating the insulating film 3 provided with its openings 4, the portion of insulation remaining on the micromodules will allow the antenna to be isolated from the micromodule when the micromodule is inserted on the antenna.

 In another variant, a set of separate and continuous insulating strips 7, three in number in the example of FIG. 3B, are laminated on the micromodule film 1 so as to cover only the central area of the micromodules located between their pads electric contact.

 The three continuous insulating strips 7 are preferably in three different coils laminated together on the micromodule film at the correct spacing corresponding to the overlap of the zones.

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 central micromodules only. They can also be presented in a single coil packaged offline with a protector, which protector is then peeled after the laminating operation on the micromodule film.

 With reference to FIG. 3c, the following operation consists in laminating on the micromodule film 1 a film of electrically conductive heat-activatable adhesive material 5 known as ACF, acronym for the English expression Anisotropic Conductive Film.

 Preferably, the ACF 5 film consists of a traditional heat-activatable adhesive adhesive in which there are randomly distributed metallic spheres coated with gold which allow, after pressing, to carry out an electrical conduction along an axis perpendicular to the film.

 The purpose of depositing the adhesive ACF 5 is therefore, on the one hand, to maintain the electronic micromodule on the antenna during its insertion thereon and, on the other hand, to make the electrical connections between the antenna and micromodule.

 This film 5 being electrically conductive, it is preferable to remove from the ACF film 5 before lamination on the micromodule film 1, the part complementary to the first lamination operation corresponding to the central metallic zone of the electronic micromodules, so as to avoid any electrical conduction between this area of the micromodules and the turns of the winding when a micromodule is transferred to an antenna.

 Thus, before this second rolling operation, openings 6 corresponding to the central area of the micromodules located on either side of their contact pads, are made in line on the ACF film 5 by means of an appropriate tool. such as

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 die punch. These openings 6 make it possible, during the rolling of the film 5, not to cover with ACF the portions of insulation previously laminated on the micromodule film 1. After this rolling operation, only the contact pads of the micromodules will be covered with ACF.

 Once the various laminating operations at the micromodule film have been carried out as previously described, a micromodule 2 cutting operation is implemented so as to allow their transfer to an antenna support by means of a specific machine carry, called inserter. The micromodules are therefore cut in line by means of a die punch with the layers of insulation 3 and conductive adhesive 5 previously laminated.

 The insertion of micromodule 2 on an antenna is illustrated in Figure 4.

 The antenna 11 is for example made on a plastic substrate by etching a copper or aluminum film. It can also be carried out by screen printing of conductive ink, such as a silver ink which is subsequently dried.

In an alternative embodiment, the antenna can be produced according to other known techniques such as inlaying a conductive wire.

 The antenna 11 is in the form of a spiral and comprises at least two turns. The antenna further comprises, at its ends, two connection terminals intended to provide the electrical connection with the electronic micromodule 2. In addition, the antenna is produced in the form of a spiral so that the turns d antenna pass between connection terminals 12.

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 The last operation consists in interconnecting the antenna 11 with the electronic micromodule 2. The micromodule 2 is transferred with its previously laminated layers so that it comes to span the turns of the antenna 11. Its underside, facing the antenna, comprising the various laminated films, respectively the film of conductive adhesive 5 covering the contact pads at the ends of the micromodule and the insulating film 3 covering the middle of the micromodule between its contact pads, is therefore applied opposite the connection terminals 12 of the antenna 11. The central area of the micromodule 2 located between its contact pads and covered with the layer of insulation 3 previously laminated is therefore placed against the turns of the antenna 11. The micromodule is then carried over by applying pressure to this predefined location.

 Thus, the film of conductive adhesive of ACF type laminated respectively to the ends of the electronic micromodule ensures the mechanical strength of the micromodule on the antenna while allowing good electrical conduction between the connection terminals of the antenna and the contacts of the micromodules. As for the insulating film 3 laminated between the contact pads of the micromodule, it ensures good electrical insulation between the turns of the antenna and the middle of the micromodule. In addition, the adhesive with heat-activated glue covering the underside of the laminated insulating film, as described above in the description, makes it possible to reinforce the mechanical strength of the micromodule on the antenna.

 Thus, the method according to the invention consisting in implementing the laminating operations respectively of an insulating adhesive film and a film

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 ACF (in this order or in a different order) on the micromodule film before cutting the micromodules and transferring the micromodules to an antenna support, makes it possible to avoid making a bridge or isolating the antenna.

 However, according to a second particular embodiment of the invention, the deposition of the insulator on each micromodule can be envisaged in a different way. More specifically, the removal of the insulator can be implemented after the micromodules have been cut, before they are transferred to an antenna support. In this particular embodiment, the insulator is no longer deposited in the form of a film which is cut and then laminated on the micromodule film itself, as seen previously with reference to FIG. 3B.

 Thus, in a first step of this second embodiment of the invention, see FIG. 3C, only the ACF film 5, where the openings 6 corresponding to the central area of the micromodules 2 located on either side of the device are previously made. their contact pads (area where the insulation must therefore be deposited), will be laminated on the micromodule film 1. Then, the micromodules are cut in line by means of a die punch. Each micromodule then simply comprises the layer of conductive adhesive 5 previously laminated and covering only its electrical contact pads.

 The insulator will then be deposited on the central metal area of each micromodule in the form of an insulating tablet. The dimensions of the insulating pad are provided to correspond exactly to those of the central area of the micromodules located on either side of their contact pads, so as to completely cover this area and thus ensure a

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 good insulation when transferring the micromodules to an antenna support. Each insulating patch consists for example of a polyester support covered on at least one side with a heat-activated adhesive adhesive.

 Preferably, the insulating pellets are removed after the micromodule cutting operation by means of a die punch, is carried out during the transfer of the cut micromodules between the counter-punches of the cutting tool and the recovery by l inserter. In this way, the grouped situation of the micromodules as it is on the micromodule film before cutting is preserved, facilitating the removal of the insulating pellets on the central area of each micromodule.

 The transfer of the micromodules to an antenna support is then carried out exactly in the manner already explained above with reference to FIG. 4.

The solution proposed, according to one or other of the embodiments, to allow the assembly of an electronic micromodule on an antenna, before lamination thereof in a card body, is therefore both simpler , more economical and more robust compared to the solutions of the prior art.

 Finally, the method according to the invention can also be applied to cards with mixed operation. For such an application, it is necessary to make a bridge to bring the two antenna connection terminals inside the antenna turns. The bridge therefore spans the antenna turns.

 For the realization of such a bridge, it is possible to postpone a simple metal blade, said metal latch, with the portions of ACF film and of film.

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 insulator as described for application to an electronic micromodule.

 Thus, instead of applying the method according to the invention to a micromodule film as previously described with reference to FIG. 3A, a film is used at the start of the process grouping together a set of metal latches. This film is then subjected to either the steps according to the first embodiment of the invention, or the steps according to the second embodiment of the invention.

 By keeping the same process for a so-called electronic micromodule component or for a metal latch with a surface and thickness identical to that of the micromodules, it is therefore also possible to make bridges on antennas intended for cards with mixed operation.

Claims (10)

1. Method for manufacturing a contactless chip carrier comprising an electronic assembly comprising an antenna (11) forming a spiral at the ends of which connection terminals (12) are provided and at least one electronic micromodule (2) connected to the antenna (11), characterized in that it comprises the following stages consisting in: - laminating on a micromodule film (1), where a set of micromodules (2) are grouped, an insulating film (3) where are previously made openings (4) corresponding to the area of the electrical contact pads located at the respective ends of each of the micromodules (2); - laminate on said micromodule film (1) a film of electrically conductive heat-activatable adhesive material (5) where openings (6) are previously made corresponding to the central area of the micromodules (2) located on either side of their pads contact ; - cut the micromodules (2); - for each micromodule, transfer the micromodule (2) to the antenna (11), underside of the micromodule (2) comprising the layers of insulation (3) and conductive adhesive (5) previously laminated facing the antenna (11), so as to establish an electrical connection with the connection terminals (12) of the antenna.  2. Method according to claim 1, characterized in that the openings (4 and 6) made respectively in the insulating film (3) and the film <Desc / Clms Page number 17>  electrically conductive adhesive material (5) prior to lamination of said films on the micromodule film (1) are produced in line by means of a die punch.  3. Method according to claim 1, characterized in that the first step of laminating an insulating film (3) where openings (4) are previously carried out is replaced by a step consisting in laminating a micromodule film (1) set of separate and continuous insulating strips (7), so as to cover only the central area of the micromodules located on either side of their electrical contact pads.  4. Method according to claim 1, 2 or 3 characterized in that the step of laminating on the micromodule film (1) the film of electrically conductive thermally activatable material (5) is carried out before the step of laminating the insulator ( 3,7), the other steps remaining unchanged.  5. Method for manufacturing a contactless chip carrier comprising an electronic assembly comprising an antenna (11) forming a spiral at the ends of which connection terminals (12) are provided and at least one electronic micromodule (2) connected to the antenna (11), characterized in that it comprises the following stages consisting in: - laminating on a micromodule film (1) a film of electrically conductive heat-activatable adhesive material (5) where corresponding openings (6) are made beforehand to the central area of the micromodules (2) located on either side of their contact pads; <Desc / Clms Page number 18>  - cut the micromodules (2); - deposit an insulating pad on the central area of each micromodule (2) located on either side of their contact pads, so as to completely cover this said area; - for each micromodule, transfer the micromodule (2) to the antenna (11), underside of the micromodule (2) comprising the layers of insulation (3) and conductive adhesive (5) previously laminated facing the antenna (11), so as to establish an electrical connection with the connection terminals (12) of the antenna.  6. Method according to one of the preceding claims, characterized in that the electronic micromodule (2) is arranged on the antenna (11) so that the central area of the micromodule located between its contact pads and covered with the layer insulation (3,7) is disposed against the antenna turns (11).  7. Method according to one of the preceding claims, characterized in that the electronic micromodule (2) is transferred to the antenna (11) by application of pressure on said micromodule at the predefined location making it possible to establish a connection electric with the connection terminals (12) of the antenna (11).  8. Method according to one of the preceding claims, characterized in that the insulator (3,7) consists of a very thin polyester support covered on at least one side with a heat-activated adhesive adhesive or the like. <Desc / Clms Page number 19>  9. Method according to one of the preceding claims, characterized in that the film of electrically conductive heat-activatable adhesive material (5) consists of a heat-activatable adhesive adhesive in which there are randomly distributed metallic spheres coated with gold. which allow, after pressing, to carry out an electrical conduction along an axis perpendicular to the film.  10. Method according to one of the preceding claims, characterized in that it applies to the manufacture of a chip support with mixed operation, that is to say with contact and without contact, the micromodule film (1) then being replaced at the start of the process by a film grouping together a set of metal latches, said metal latches having a surface and a thickness identical to said electronic micromodules (2).