MXPA00003223A - Method for making an electronic device with chip and/or antenna and device obtained by said method - Google Patents

Abstract

The invention concerns a method for making an electronic device with chip and/or antenna, such as a contactless chip card or hybrid integrated circuit or label, said electronic device comprising at least a surface sheet with an apparent external face (18, 18'), and at least an interface comprising an antenna (14, 28), said method comprising the following step which consists in producing the antenna on one face of the surface sheet, opposite the apparent external face, by screen printing with an electrically conductive ink. The invention also concerns the resulting electronic device.

Description

PROCEDURE FOR MANUFACTURING AN ELECTRONIC DEVICE WITH MAGNETIC PART AND / OR ANTENNA AND DEVICE OBTAINED THROUGH THIS PROCEDURE DESCRIPTION The present invention relates to a method for manufacturing an electronic device with magnetic and / or antenna part, such as a magnetic card without contact or hybrid or tag. That electronic device comprises at least one decoration sheet having an external apparent face and at least one interface comprising an antenna. The magnetic cards generally comprise a magnetic part or a magnetic module comprising at least partially an insulating substrate, for example a layer of thermoplastic material and which is connected to a flat antenna which constitutes an interface and two outer sheets of decoration of thermo material -plastic arranged each on a face of the magnetic card and which may present inscriptions or logos. If this is the case, a protective film (overlay) such as a varnish that covers the outer leaves.

Currently, the antennas that are used for magnetic cards without contact are typical: The antennas are made on an intermediate specific support sheet to be engraved with copper according to the technique of printed circuits. Then, it is inserted between an external protection sheet and the magnetic part or module. The magnetic card is generally obtained by means of a rolling or injection operation in the course of which the different sheets of thermoplastic material are welded or bonded together and / or with the substrate. This intermediate sheet of antenna support, causes an additional thickness of about 130 microns, which poses problems to respect the maximum thickness of 840 microns set by the ISO standard. On the other hand, the realization of the antenna on the intermediate support sheet constitutes an additional stage of manufacture, which increases the manufacturing cost of both the point of view of the material and the point of view of time. In addition, the fact remains that the engraving of the antenna in this way, becomes quite expensive. The antennas are wound with copper wires in the air, to the end of which the magnetic parts or modules are connected. The assembly of the coil and the module or magnetic part is called "transponder". To manufacture the card, the transponder is inserted between at least two thermoplastic sheets or two sheets or between two thermoplastic sheets and is immersed in a glue and then laminated. The difficulty of using these transponders for the manufacture of magnetic cards of the "non-contact" type comes from the handling problems encountered for the grip and the precise deposit of the transponders on the plastic sheets. The manufacturing cycle times will again be penalized by that problem. The basic problem of the invention is that of making a magnetic card without contact or cheaper hybrid that has a good behavior at the same time. Among the techniques for making cheaper antennas, screen printing with conductive ink is known. However, this technique does not adapt to the field of magnetic cards, in particular without contact. There are problems related to ink drying and ripple problems. The available inks dry at about 150 ° C, which is impossible with the materials customarily used in the field of magnetic cards, such as PVC, ABS having a softening temperature of about 60 ° C.

Other materials such as PC and PET have a higher softening temperature of approximately 120 ° C to 130 ° C, which is still lower than the optimal drying temperature of the inks. On the contrary, these materials are more expensive than those that precede them. Screen printing on sheets or films thinner than 600 μm on the materials of the magnetic cards, also poses problems of undulation of its surface visible to the natural eye. In fact, corrugations can be observed on the back of such a sheet below the turns and that constitute a defect in appearance. On the other hand, to make antennas of good behavior, it is necessary to have the best possible conductivity that can be obtained, especially for the use of wider turns and with the condition of having a good drying. The problem is that the available surface for an antenna is limited due to a reserved crimping surface.

In addition, the inks, once they are dry, do not have all a behavior in sufficient flexion compatible with the regulations in force on the magnetic cards. Due to the difficulties described above, the tendency is not to use screen printing in the field of the magnetic card especially to conduct conductive circuits of good conductivity on thin films such as antennas of good behavior.

The object of the invention is therefore to reduce these drawbacks in order to produce an electronic device with magnetic part and / or an inexpensive antenna. For this purpose, the subject of the present invention is a method for manufacturing an electronic device of magnetic part and / or antenna, such as a magnetic card without contact or hybrid or tag. That electronic device comprises at least one decoration sheet having an external face and at least one inter- face comprising an envelope. This method comprises the following step according to which the antenna is made on a face of the decoration sheet, opposite the apparent external face, by means of screen printing of a conductive ink.

This allows to simplify the manufacturing cycle, which causes a significant reduction in the manufacturing cost. Furthermore, thanks to the invention, the intermediate support sheet is eliminated, which allows the thickness of the card to be significantly reduced and / or space reserved to accommodate the magnetic parts or modules of greater thickness. According to another feature of the invention, the sheet comprises a graphic prepress and / or transparent protective film on its apparent external face. This makes it possible to simplify the printing operation since it is carried out on the protection sheet and not on the magnetic card as a whole, thus avoiding important expenses related to printing waste. According to another feature, to perform the antenna on the decoration sheet, the method comprises the following steps: - a thin support sheet of material having a softening or degradation temperature lower than an optimum ink drying temperature is provided; - an ink comprising a metal particle rate comprised between 60% and 95% in a polymer matrix and a solvent is provided. That ink has a predetermined optimum drying temperature; after the screen printing of this ink on the support sheet, a partial drying of the ink is carried out at a temperature lower than the optimum drying temperature of the ink. Preferably, the ink comprises silver particles at a rate comprised between 70% and 85%. In this way, an antenna with acceptable behavior can be obtained by means of screen printing on materials of the magnetic card field, without altering them with drying steps. According to yet another feature of the invention, several antennas are simultaneously made on a base decoration sheet. This sheet is then cut to obtain different decoration sheets with your antenna. Afterwards, the assembly of the magnetic card can be carried out. The simultaneous realization of several sheets of protection, allows to reduce the time of manufacture and the price of cost. Advantageously, the table of the screen printing machine is subjected to a surface smoothing treatment, such as an anodization or a Teflon coating.

This arrangement makes it possible to avoid the formation of scratches on the printed side of the protection sheet.

According to still another feature of the invention, the screen-printed sheet is passed in a drying oven which thus allows to eliminate the solvent and obtain a solid conductive tape of conductive particles and of a binder. Advantageously, a protective plate is simultaneously introduced between the mesh floor of the drying oven and the screen-printed sheet. This makes it possible to isolate the outer face of the protection sheet and protect it against scratches or the like.

For this purpose, you can also use a plastic mesh floor, a treated mesh floor, for example with stainless steel or plastic tape belts. Another subject of the invention is an electronic magnetic and / or antenna device, such as a contactless or hybrid magnetic card or label obtained by the method according to the invention. It is distinguished in that it comprises an antenna made by screen printing on the non-apparent back of a decoration sheet.

According to a characteristic, the antenna comprises turns of unequal lengths, between their connecting ends. This makes it possible to increase or compensate for a conductivity insufficiency of a conductive ink, without introducing additional drawbacks, especially drying.

Other features and advantages of the invention will become apparent upon reading the description below, which is made by way of illustration and in no way restrictive, referring to the accompanying drawings in which: - Figure 1 represents, in vertical section, a magnetic card of known type; - Figure 2 represents, in vertical section, a magnetic card according to the present invention; - Figures 3 and 4 respectively represent the front and back of a base sheet before the screen printing operation; and Figure 6 is a profile view corresponding to Figure 5. One can see in Figure 1, a magnetic card of the "non-contact" or "hybrid" type comprising a flat antenna that constitutes an interface without contact. It essentially comprises a substrate 10 such as a layer of insulating material, in which a magnetic part or a module 12 is immersed which is connected to an antenna 14 which is made on an intermediate support sheet 16. The assembly is protected by two sheets external protective thermoplastics 18 and 18 '. If this is the case, a transparent protective film can coat the outer sheets. For example, the thickness of the substrate 10 with the magnetic part or module 12 is approximately 100 microns, the thickness of the outer protection sheets 18 and 18 'is approximately 200 microns and that of the intermediate sheet 16 with the antenna 14 is about 130 microns. The maximum thickness of the set is 800 microns, in accordance with the ISO standard. A magnetic card according to the present invention is shown in figure 2, always in longitudinal section. The substrate 10 is again found with its magnetic part or module 12 and the protection sheets 18 and 18 '. According to the invention, the antenna 14 is made on the inner face of one of the protection sheets 18, respectively 18 '. This first allows a thickness gain of approximately 150 microns. Therefore, for example, magnetic cards with a thickness of less than 800 microns can be manufactured, if desired.

On the other hand there is a sheet of less to index, which causes a gain in matter and in time for the cost price. In the case of magnetic cards without contact, this suppresses the operation of double deposit (dispense) of matter on the two faces of the bare intermediate sheet or perforation of the intermediate sheet to allow the combination of the resin through this sheet. This results in a significant additional gain over the cycle time. Thanks to the invention, the thickness of the magnetic card or the module can be reduced for a card without contact; the interface between the magnetic part or the module and the antenna is farthest from the center of the magnetic card, therefore, for an equal thickness of the magnetic part or the module, the thickness of the card in this area will be better controlled. In particular, the hard points of the card will be further away from the outer protection sheets. The invention also makes it possible to use magnetic parts or thicker modules and, as a consequence, for example, to suppress a thickness reduction operation (backlap), for example, by means of milling. Finally, the invention makes it possible to avoid printing defects in the event that the protection sheet is not preprinted, but provided white and printed after the card is manufactured. Advantageously, as shown in Figures 3 to 6, several antenna support sheets, for example three, are simultaneously made on a base thermoplastic sheet 20 comprising, on its outer face 22, three logos 24 preprinted and on the inner face 26 of which three antennas 28 are made by means of screen printing. Then, this base sheet is cut out to obtain three antenna support protection sheets. This makes it possible to reduce the cost of manufacturing, in particular by suppressing operations for placing pre-printed protection sheets. The magnetic card according to the present invention can be manufactured in the following manner. Three logos 24 are printed on the back face of the base thermoplastic sheet 20; this impression can possibly be protected by a laminating operation of a protective layer (overlay) or by application of a lacquer. Of course, if you want to manufacture "white" magnetic cards without printing, this first operation is deleted. It is then passed to the realization of antennas.According to the invention, the manufacture of a magnetic electronic device and / or antenna, such as a magnetic card without contact or hybrid or tag, comprising at least one decoration sheet having an apparent external face (18, 18 '). and at least one interface comprising an antenna (14, 28) comprises the following essential stage. According to this step, the antenna is made on one face of the decoration sheet, opposite the apparent external face, by means of screen printing with a conductive ink. In that way, a basic elementary device can be obtained, constituted by a decoration sheet or that can receive an impression and which comprises at least one antenna. Other conductive elements can be made in the same way. Electronic elements, in particular a magnetic part or a magnetic module, can be connected later and / or coated. The method may furthermore comprise a step according to which at least one layer of insulating material is arranged on the opposite side so as to cover the antenna, at least in part. This leads to the realization of an electronic device, especially of the magnetic card type. Additional protective films can also be added.

The layer of insulating material can be made in various ways and especially by means of a hot or cold rolling operation, a second sheet or by means of injection or spraying. The interface constituted by at least one antenna and / or contacts can be connected to a magnetic part or magnetic module before or after the embodiment of the layer of insulating material. In the latter case, the antenna connections may be accessible either by means of an access reservation, or by means of an access machining. The decoration sheet comprises a polymer material but may optionally be made on any other changeable or deformable material such as a sheet of paper. In an example of putting the process into operation, the preprinted sheet is placed on the table of a screen printing machine, for example of the MPM type, with its printed side against the table. To avoid the formation of scratches on the printed back, the table is subjected to a treatment that allows to sweeten the surface of the table suppressing the asperities; for example, a treatment can be carried out by means of anodization or a coating with Teflon.

On the other hand, the table of the screen printing machine is provided with fast indexing points which limit the slippage of the sheet on the surface of the table. During the screen printing cycle, conductive ink is transferred from the surface of the screen to the protection sheet according to the pattern of the antenna, for example, in a "square" spiral as shown in figure 5.

At the time of this screen printing phase, for optimal results, it is recommended to control the screen parameters that may act more or less on the quality of the results, such as: - the absence of contact between the screen and the protection sheet; - the speed of screen printing; - pressure of screen printing; the nature and configuration of the silkscreen screen; the nature and geometry of the scrapers of the screen printing machine, for example, using polyurethane scrapers. The dimensions of the screen screen, for example, a silk-screen screen with fabric, determine the number of antennas that can be made on the same base sheet 20.

After the screen printing step, the sheet assembly is extracted with liquid ink from the screen printing machine and transferred in a drying oven, such as an oven known under the OPTIMA trade name. At the time of passage in the furnace, the solvent contained in the conductive ink evaporates and the antenna takes a solid form formed by conductive particles and by a binder. The drying parameters that can influence the result are: - the temperature of the different zones of the oven; - the duration of drying; and - the air or nitrogen flow injected into the furnace. The ability to reproduce antennas with the desired properties without deformation of the protection sheet at the time of drying depends on the parameters mentioned above. The deformation can be induced by means of too high a temperature or too great a withdrawal of the ink. The mesh floor of the oven is isolated from the protection sheet by means of a plastic protection plate that is inserted in the oven at the same time as the protection sheets. This protection plate protects the printed side of the protection sheet from scratches. To make this protection, you can also equip the drying oven, with a floor of plastic mesh or treated or belts made with plastic tapes. Next, manufacturing is continued in a known manner to manufacture a contactless or hybrid card. A solid connection of the magnetic part or module 12 with the antenna 14 is made without deforming or damaging the printed side of the protection sheet. The last operation is a magnetic card assembly by means of cold rolling or hot rolling or by injection in conditions that do not highlight the trace of the antenna on the printed side of the protection sheet which becomes a visible face of the fine card. Good undulatory results were obtained with the following operating conditions on sheets of PVC or ABS or even paper: ink: reference D-5028 or E-520 of the Dupont de Nemours Company; - Optimum drying temperature of the ink: approximately 150 ° C. - Oven temperature: 50 ° C to 80 ° C; - Duration of drying: from 3 to 10 minutes. The process finds its preference preferably on sheets of less than 600 μm thickness. Good results were obtained on very thin polymer films of thickness ranging from 100 μm to approximately 15 μm. In the case of a sheet or film of P.C. or PET, the oven temperature can be between 120 ° C and 130 ° C. In order to respect an area of the card reserved for a crimp, while preserving the good behavior of the antenna, together with its conductivity, the electrical or electronic device of the invention comprises turns of unequal width between its connection ends. Good results were obtained with a width ratio between the widest turns and the narrowest turns, which vary from two to five; the narrow value is equal to approximately 0.5 mm. For example, in that way, a magnetic card could be obtained which is provided with a four-turn antenna along its side borders. It comprises a narrow area for the antenna that extends up to 5 mm from the bottom edge of the card, in which four turns of approximately 0.4 mm are silk-screened; the antenna has at that level, a total width of 4 mm. On the other hand, along the other edges of the card, especially the opposite edge or the adjacent edge of the card, it comprises turns each having a width equal to about 1.8 mm; the antenna has at that level, a width of 8 mm. This arrangement and shape of the antenna makes it possible to increase or compensate for a conductivity insufficiency of the conductive ink. Also, when it is particularly dried. The efficiency of the radio communication is not affected, having obtained in this way, a range of the antenna equal to 8 mm.

Claims (22)

1. R E I V I N D I C T I O N S 1. Procedure for manufacturing an electronic device of magnetic part and / or antenna, such as a magnetic card without contact or hybrid or tag; said electronic device comprises at least one decoration sheet having an external apparent face and at least one interface comprising an antenna; this method comprises the following step according to which the antenna is made on a face of the decoration sheet, opposite the apparent external face, by means of screen printing of a conductive ink, characterized in that the sheet comprises a graphic prepress and / or a transparent protective film on its apparent external face.
2. 2. Process for manufacturing an electronic device of magnetic part and / or antenna, such as a magnetic card without contact or hybrid or label; said electronic device comprises at least one decoration sheet having an external apparent face and at least one interface comprising an antenna; this method comprises the following step according to which the antenna is made on a face of the decoration sheet, opposite to the apparent external face, by means of screen printing of a conductive ink, characterized in that, to realize the antenna on the sheet of decoration: - a thin support sheet of material having a softening or degradation temperature lower than an optimum ink drying temperature is provided; - an ink is provided comprising a metal particle rate comprised between 60% and 95% in a polymeric matrix and a solvent; that ink has a predetermined optimum drying temperature; after the screen printing of this ink on the support sheet, a partial drying of the ink is carried out at a temperature lower than the optimum drying temperature of the ink.
3. 3. Method according to claim 2, characterized in that the sheet comprises a graphic prepress and / or transparent protective film on its apparent external face.
4. 4. Method according to claim 1, characterized in that, to realize the antenna on the decoration sheet: - a thin support sheet of material having a softening or degradation temperature lower than an optimum drying temperature of the ink; - an ink is provided comprising a metal particle rate comprised between 60% and 95% in a polymeric matrix and a solvent; that ink has a predetermined optimum drying temperature; after the screen printing of this ink on the support sheet, a partial drying of the ink is carried out at a temperature lower than the optimum drying temperature of the ink.
5. Method according to any of claims 1 to 4, characterized in that it also comprises a stage according to which at least one layer of insulating material is arranged on the opposite face, so as to cover the antenna at least in part.
6. 6. Method according to any of claims 1 to 5, characterized in that the layer of insulating material can be made in various ways and especially by means of a hot or cold rolling operation of a second sheet or by injection or spray.
7. Method according to any of claims 1 to 6, characterized in that a connection of the interface to a magnetic part or magnetic module is made prior to the realization of the layer of insulating material.
8. 8. - Method according to any of claims 1 to 6, characterized in that a connection of the interface to a magnetic part or magnetic module is made, after the implementation of the layer of insulating material, the connections of the antenna being accessible.
9. 9. Method according to any of claims 1 to 6, characterized in that the decoration sheet comprises a polymer material.
10. 10. Method according to any of the preceding claims, characterized in that the ink comprises the silver particles and at a rate comprised between 70% and 85%.
11. 11. Method according to any of the preceding claims, characterized in that the sheet has a thickness less than 600 μm.
12. 12. Method according to any of the preceding claims, characterized in that the sheet has a thickness comprised between 15 μm and 100 μm.
13. 13. Method according to any of the preceding claims, characterized in that the drying temperature is equal to approximately 60 ° C.
14. 14. Method according to any of the preceding claims, characterized in that the decoration sheet is paper.
15. 15. Method according to any of the preceding claims, characterized in that a screen printing machine is used comprising a table that has been subjected to a surface smoothing treatment, such as an anodization or a coating with Teflon.
16. 16. Method according to any of the preceding claims, characterized in that the support sheet is passed in the oven comprising a mesh floor, and in which a protective plate is simultaneously inserted between the mesh floor and the sheet of screen-printed support.
17. 17. Method according to claim 16, characterized in that the mesh floor is made of plastic or stainless steel.
18. 18. Method according to claim 16, characterized in that the drying oven comprises belts made of strips of plastic material.
19. 19. Method according to any of the preceding claims, characterized in that several antennas are simultaneously made on a base decoration sheet and then cut to obtain several decoration sheets.
20. 20. Electronic device with magnetic part and / or antenna, such as a magnetic card without contact or hybrid or label that is obtained according to the method according to any of the preceding claims.
21. 21. Electronic device according to the claim 20, characterized in that the antenna comprises turns of unequal width between its connecting ends.
22. 22. Electronic device according to the claim 21, characterized in that the width ratio between the widest turns with the narrowest turns, varies from two to five.