MXPA00007960A - Electronic device with contactless electronic memory, and method for making same - Google Patents

Abstract

The invention concerns a contactless electronic device (10) such as a card, a label, a ticket or a token, comprising at least an electronic microcircuit (20) arranged in the thickness of a rigid or semirigid support and comprising pads (26) connected to an interface antenna (24) arranged in the thickness of the support, the latter comprising at least two opposite, lower (12) and upper (14), protective sheets. The invention is characterised in that it comprises a stack:of a lower protective sheet (12) whereof the inner face (22) bears at least one electronic microcircuit and at least one interface antenna (24);of an intermediate bonding sheet (14) whereof the two opposite faces lower and upper are provided with adhesive;and of an upper protective sheet (16).

Description

ELECTRONIC ELECTRONIC MEMORY DEVICE WITHOUT CONTACT, AND PROCEDURE FOR MANUFACTURING A DEVICE OF THIS TYPE DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a flexible, thin-walled, flexible, non-contacting electronic device (10), such as a card, a label, a ticket or token, which includes at least one electronic microcircuit (20). ) which is provided in the thickness of a support and which comprises connecting terminals connected to an interconnection antenna (24), provided in the thickness of the support, the latter including at least two opposite, lower (12) and upper (16) sheets ), of protection, said procedure comprises the following consecutive stages. Numerous examples of such electronic devices are known, currently called microcircuit cards or flea, which are either rigid cards where the support is made of plastic material, or labels, called "electronic labels", for the labeling of consumer products which are for single use, that is to say that they are intended to be adhered only once to a product and which consist essentially of a sheet of paper. There is thus a need for an electronic device of the aforementioned type, for example a small-thickness contactless microcircuit card (for example approximately 400 μm, even 280 μm thick) and flexible or foldable in two, which can be be used several times, whose cost is particularly reduced as well as its thickness to be used in many applications by using an electronic memory microcircuit for which today it is impossible, for reasons of cost and / or thickness of the support, use cards, tags, tickets and / or electronic memory cards without contact. There is also a need for more resistant devices that authorize handling without precaution, or some folding in two without altering its operation. This is the case, for example, of subway tickets.

Alternatively, there is a need for non-contact devices, very thin and of excellent surface quality, which can support high-quality printing. This is the case mainly of cards or identity cards. For this purpose, the invention provides a method of manufacturing an electronic device of the aforementioned type, comprising the following consecutive steps: a) making a lower protection sheet: al) placing at least one electronic microcircuit on the internal surface of the lower sheet; a2) making at least one interconnection antenna on the inner face of the lower sheet, mainly by screen printing; a3) electronically splicing the junction terminals of the electronic microcircuit to the interconnection antenna; b) carrying out a stack by superimposing the lower protection sheet, an intermediate gluing sheet whose two lower and upper opposite sides are provided with glue or glue, and an upper protective sheet; c) assemble the three superimposed sheets by compressing them. According to other characteristics of the method according to the invention: the assembly step c) consists of a hot rolling operation; the intermediate gluing sheet includes an empty space to the right of the electronic microcircuit; the intermediate sizing sheet is a hot melt adhesive sheet; the intermediate gluing sheet is a paper sheet whose two lower and upper opposite sides are provided with a layer of hot melt adhesive; at the time of step a) of carrying out the lower protection sheet, operations a), a2) and a3) are carried out successively; at least one of the protection sheets is paper based; the method includes a supplementary step of printing on one and / or another of the outer faces of the two lower and upper sheets, protecting the support. Preferably, printing is done before the antenna and / or microcircuit report; this includes a supplementary step of trimming the electronic device, according to a certain contour of the card, the label, the ticket or the card; several electronic devices are produced simultaneously from protection sheets and from a roller sizing sheet, and the electronic devices are separated at the time of the additional trimming step. The invention also relates to a non-contact electronic device, of the type mentioned above, characterized in that it comprises a stack: of a lower protection sheet whose internal face carries at least one electronic microcircuit and at least one interconnection antenna; - an intermediate gluing sheet whose two lower and upper opposite faces are provided with glue or glue; and a superior protection sheet. According to other characteristics of the device according to the invention: _ ^ _ Mßa-tla? - - - * - _ £ * ifift¡gKtHtM £ rii & -i the intermediate gluing sheet includes an empty space to the right of the electronic microcircuit; the intermediate sizing sheet is a hot melt adhesive or glue sheet; the intermediate gluing sheet is a sheet of paper whose two opposite lower and upper faces are provided with a layer of hot melt adhesive; - at least one of the protection sheets is paper based; the device has a thickness of less than 400 μm, even of 280 μm, the support sheet of the antenna and the microcircuit (the flea) has a thickness less than or equal to 75 μm. Other characteristics and advantages of the invention will appear on reading the following detailed description, for the understanding of which reference will be made to the attached drawings in which: Figure 1 is a schematic longitudinal sectional view of a first embodiment of a microcircuit or flea card made according to the teachings of the invention and on which the stacking of the three sheets constituting it is illustrated before the operation of hot rolling; Figure 2 is a view similar to that of Figure 1, illustrating a second embodiment of a microcircuit card made in accordance with the teachings of the invention; Figures 3A to 3C schematically illustrate the three operations that allow to make a lower sheet of paper protection, for an electronic device according to the teachings of the invention; and Figure 4 is a schematic view illustrating the embodiment of stacking by superimposing three supporting sheets of a microcircuit card made according to the teachings of the invention. In the subsequent description, identical, similar or analogous elements will be designated by the same reference numerals, and in the description and in the claims, the terms "lower," "superior," "vertical," etc., will be used in a non-limiting manner with reference to the figures to facilitate the explanations.

By definition, flexible means a mechanical property identical to that of the cards. According to the case, the product of the invention is designed so that it can be manipulated like a meter ticket, rolled up, even folded by hand without altering its emitter-receiver operation. It has been represented in Figure 1 a microcircuit card 10 which is constituted by a vertical stack of three sheets 12, 14 and 16. The lower sheet 12 is a first sheet of paper whose thickness is for example equal to 75 micrometers made of paper "Maine" marketed by the company Arj o-Wiggins. The lower sheet of paper 12 constitutes a lower protection sheet of the card 10, while the upper sheet 16 of the same constitution and of the same thickness as the lower sheet 12, constitutes an upper protection sheet, of paper, of the 10. The intermediate sheet 14 is a sheet of mutual gluing of the two lower sheets 12 and upper 16 which, in this first embodiment, is a hot melt adhesive or glue sheet, also known as a "Fusion sheet". Hot ", of a thickness of 100 micrometers, marketed by the company Polyconcept. This hot melt sheet has the advantage of being soft at room temperature and not damaging the microcircuit at the time of stacking. According to a feature of the invention, when the intermediate gluing sheet 14 is hard like paper, it may optionally include an empty space or window 18 which is provided vertically to the right of an electronic microcircuit 20, or flea, placed on the upper internal face 22 of the lower sheet 12. The electronic microcircuit 20 is connected to an interconnection antenna 24 which, according to a known technique, is for example elaborated by screen printing on the upper face 22 by means of a conductive ink based on silver which is for example the E520 ink marketed by the company Dupont de Nemours. The electronic microcircuit 20 is for example a "Chip Mifare Amtel AT 8100" whose thickness is reduced, for example, to 70 micrometers. This can be fixed on the face 22 for example by gluing. The electrical connection of the terminal of the electronic microcircuit or electronic module 20 to the interconnection antenna 24 is realized, according to a known technique, preferably by the conductive adhesive cords 26, which is for example the glue sold under the name "Ablestick Silver Glue". The second embodiment illustrated in Figure 2 differs from the first embodiment to be described by the structure of the intermediate sizing sheet 14. Indeed, the sizing sheet 14 is here constituted by an intermediate sheet of paper 14A where the two opposite external faces are coated with a layer of hot melt adhesive 14B, the composite thus constituting the intermediate gluing sheet 14 is interposed between the lower sheets 12 and upper sheet 16 of paper protection in the same manner as the sheet of paper. gluing 14 of Figure 1 which is constituted solely by a hot melt glue film.

An example of a method of manufacturing the cards 10 illustrated in Figure 1 or Figure 2 will now be described. In order to propose an industrial process that allows large-scale manufacture of electronic devices, such as cards 10, they are several devices are processed simultaneously and / or in a row, using mainly, for the three sheets 12, 14 and 16, continuous bands or rollers. First, the lower paper protection sheets 12 must be prepared. With this aim, as that already illustrated in Figure 3A, part of a sheet of paper 12 on the upper face 22 of which is glued, for each electronic device to be made, an electronic microcircuit or module 20. Next, as illustrated in Figure 3B, the antennas 24 are made, preferably by screen printing on the upper face 22.

Alternatively, the antenna can be prepared before the module is fixed and connected. Finally, as shown in Figure 3C, the electrical connections or connections of the electronic microcircuits 20 to the antennas 24 are processed by depositing the conductive tail cords 26. Thus, at the end of the operation illustrated in Figure 3C, a band or a roll of a lower paper sheet 12 is placed which must then be associated by stacking to the other sheets 14 and 16. This next step is illustrated in Figure 4 on which is represented schematically in perspective, in exploded view, the stacking of the lower sheet 12, previously made, of an intermediate gluing sheet 14 in which, according to the case, windows have been previously prepared or cutouts 18, and of a top sheet 16 of protection, of paper. The stack or sandwich made in this way is immediately, at the time of a next step, not shown in the figures, assembled by hot pressing the three overlapping sheets 12, 14 and 16, for example in the course of a hot rolling operation , that is to say at a temperature that allows to cause the melting of the hot-melt glue that constitutes in itself the intermediate sheet 14 (Figure 1) or constituting the tail layers 14B of the intermediate gluing sheet 14 (Figure 2). This rolling operation, also called lamination, makes it possible to permanently associate the three sheets of the stack and reduce the total thickness of the electronic device produced in this way, to a value less than or equal to 260 micrometers. In the course of the rolling operation, the presence of a window 18 to the right of each electronic microcircuit 20 makes it possible to avoid damaging it. In order to ensure the matching of the windows 18 with the microcircuits 20, it is understood that it is necessary to provide means for indexing the rollers or bands of the sheets 12 and 14. At the exit of the assembly stage by rolling in hot, there is a band or a roll in which the electronic devices, whether they are cards, labels, tickets or chips, must be cut short by known means, for example, according to a technique by punch.

It is, of course, possible to print one and / or another of the outer faces of the lower sheets 12 and upper 16 of paper protection at the time of an additional stage, prior to or after the cutting of the electronic devices. The invention thus allows to have electronic electronic memory devices without contact, reduced cost, and reduced thickness, which allow to replace other products that include identification means, such as for example the flexible tickets for magnetic track or with code of bars, being these new electronic devices, biodegradable. The invention is not limited to the embodiments and procedure that have just been described. The different operations that mainly allow to reach the realization of the lower sheet of paper protection 12, provided with the electronic microcircuit 20 and with the antenna 24, can be elaborated according to other known technologies, the antenna being able to be elaborated for example in a first time and the splicing of the electronic microcircuit is carried out automatically at the moment of placing the latter with their contact conductor terminals turned towards the upper face 22 and placed directly on the conductive sections of the antenna 24 ("Flip Chip"). The junction of an electronic microcircuit 20 to the antenna 24 can be made according to a technique of micro-wiring or welding of connections ("Wire Bonding") but it would be more fragile and more cumbersome in terms of thickness. The presence of the hot-melt adhesive, irrespective of the structure of the intermediate sizing sheet 14, makes it possible to avoid resorting to a box coating ("Potting") which consists of protecting the electronic microcircuit 20 and its connections using a resin. The nature of the hot-melt adhesive used can also be such that it is slightly adherent to cold contact in order to ensure a pre-assembly of the three-ply stack prior to the hot-rolling operation. The paper protection sheet (12, 16) as well as the sheet 14 can also be made from a polymer, mainly among those commonly used in the field of microcircuit cards (PVC, PE, PP).

These sheets can also be made up of cellulose loaded with polymer to improve some of its properties (hermeticity, mechanical resistance, etc.). The invention has needed to gather several parameters. Beyond the resources for microcircuits of small size (less than 70 μm), and to thin protection sheets, this has had to resort preferably to a thermofusible intermediate layer or thermoadhesive called "hot melt" for the assembly of the assembly. This layer, due to its cold ductility, has the advantage of not harming the silicon microcircuit that comes directly in its contact during rolling. For this purpose, an empty space in the intermediary layer is not indispensable. The recourse to hot rolling with the smooth plates allows to improve the initial surface state of the protection sheets. It is possible to use paper sheets that are cheaper than some polymer sheets previously indicated. For the realization of the antenna, it has been preferred to resort to screen printing. Indeed, numerous tests with engraving (aluminum, copper, etc.) on sheets of paper show chemical alterations of the paper, which result in undulations and a yellowing of the latter. On the other hand, it is impossible to pre-print the protection sheet before carrying out the antenna by screen printing (the advantage being that it is possible to control the printing and avoid waste after the assembly of the microcircuit). Another problem can be imposed on the resource for the technique of screen printing on thin protective sheets, mainly paper or polymer, in the absence of particular precautions. It is the appearance of surface ripples that result from the drying of the ink. This problem and the solution provided are described in patent application FR 97/13734 of 03/10/97. These are included by reference in the process of the invention, to elaborate the devices that present an excellent surface quality (absence of undulations). Screen printing according to the previous application has the advantage of making antenna tracks or of precise contour, of good conduction quality (silver particles). Being the polymer based ink and being partially dried according to the procedure described in the previous application, the device can be folded several times by hand, 5 times for example without prejudice to the antenna. In addition, the resource for a silver-loaded screen antenna, facilitates at a lower cost the connection of the antenna to the microcircuit by means of a connection element later on in the present, comparatively to the resource of an antenna elaborated by means of engraving. The connecting element is preferably either a glue string or silver-loaded conductive glue, the microcircuit being fixed at the site either by a conductive glue point, the microcircuit being fixed on the back (flip-chip). These connections have, comparatively to the connections of the type of welded wires (connection with wire), the advantage of being of small thickness and of better resisting the mechanical constraints.

Claims (15)

1. Method of manufacturing a non-contact, flexible and foldable electronic device of small thickness, such as a card, a label, a ticket or token, which includes at least one electronic microcircuit which is provided in the thickness of a support, and which includes terminals connected to an interconnection antenna accommodated in the thickness of the support, the latter including at least two opposite, lower and upper protection sheets, the procedure comprises the following consecutive steps: a) making a lower protection sheet: a) placing at least one electronic microcircuit on the inner face of the lower sheet; a2) making at least one interconnection antenna on the inner face of the lower sheet, mainly by screen printing; a3) by electrically connecting the terminals of the electronic microcircuit to the interconnection antenna; b) making a stack by superimposing the lower protection sheet, an intermediate gluing sheet whose two lower and upper opposite sides are provided with glue or glue, and a top protective sheet; c) assemble the three superimposed sheets by compressing them.

2. Method according to claim 1, characterized in that the assembly step c) consists of a hot rolling operation.

3. Method according to any of the preceding claims, characterized in that the intermediate sizing sheet includes an empty space to the right of the electronic microcircuit.

4. Method according to any of claims 1 to 3, characterized in that the intermediate sizing sheet is a thermofixable glue sheet.

5. Method according to any of claims 1 to 3, characterized in that the intermediate gluing sheet is a sheet of paper whose two lower and upper opposite sides are provided with a layer of hot melt adhesive.

6. Method according to any of the preceding claims, characterized in that, at the time of the step a) of carrying out the lower sheet, operations a), a2) and a3) are carried out successively.

7. Method according to any of the preceding claims, characterized in that it includes an additional step of printing on one and / or the other of the external faces of the lower and upper support protection sheets.

8. Method according to any of the preceding claims, characterized in that it includes a supplementary step of trimming the electronic device, according to a ^ * ^ ammm imi * l --- ií £ ^ - certain outline of card, label, ticket or card.

9. Method according to the preceding claim, characterized in that several electronic devices are simultaneously made from protection sheets and a roll sizing sheet, and because the electronic devices are separated at the time of said additional step of trimming.

10. Method according to the preceding claim, characterized in that at least one of the protection sheets is made of paper.

11. Non-contact electronic device, such as a card, a label, a ticket or a card, which includes at least one electronic microcircuit which is installed in the thickness of a flexible support and which includes terminals connected to an interconnection antenna accommodated in the thickness of the support, the latter includes at least two opposite, lower and upper protection sheets, characterized in that it comprises a foldable stack of less than 400 μm: of a lower protection sheet whose internal face includes at least one electronic microcircuit and at least one antenna of interconnection; of an intermediate gluing sheet whose two lower and upper opposite faces are provided with glue; and of a superior sheet of protection.

12. Electronic device according to the preceding claim, characterized in that the intermediate sizing sheet includes an empty space on the right the electronic microcircuit.

13. Electronic device according to any of claims 11 or 12, characterized in that the intermediate gluing sheet is a hot-melt adhesive sheet.

14. Electronic device according to any of claims 11 or 12, characterized in that the intermediate gluing sheet is a sheet of paper whose two lower and upper opposite sides are provided with a layer of hot melt adhesive.

15. Electronic device according to any of claims 11 or 12, characterized in that at least one of the protection sheets is made of paper.