MXPA99008742A - Method for making smart card or similar electronic device - Google Patents

Abstract

The invention concerns a method for making an electronic device, such as a smart card, comprising at least a microcircuit (44) embedded in a carrier medium (40) and comprising exit hubs (46, 48) connected to interface elements consisting of a terminal block (50, 52) and/or an antenna, characterised in that the connections (54) between the exit hubs (46, 48) and the interface elements are produced by depositing, by means of a syringe, a conductive substance with low viscosity which remains ductile after it has been applied. Advantageously, a polymer resin charged with conductive or intrinsically conductive particles is used.

Description

PROCEDURE FOR THE MANUFACTURE OF A MAGNETIC CARD OR ANALOG ELECTRONIC DEVICE DESCRIPTION The present invention relates to the manufacture of electronic devices that comprise at least one microcircuit that is immersed in a support card and that is connected to interface elements constituted by a set of terminals and / or an antenna, such as magnetic cards of integrated circuit (s) with or without contact, also called magnetic cards. The invention also applies, in particular, to electronic tags used for the identification of products and which can be assimilated to magnetic cards without contact. The present invention relates more particularly to the realization of connections between the microcircuit and the interface elements, such as a set of terminals and / or an antenna. Magnetic contact cards exist which comprise a set of interface terminals, non-contact magnetic cards comprising an antenna housed in the support card and hybrid cards or combi-cards comprising a set of terminals and an antenna. There are many methods of manufacturing magnetic contact cards. Most of these procedures are based on assembling the magnetic part into a sub-assembly called a micromodule that is assembled using traditional procedures. A first method, illustrated in FIG. 1, first comprises gluing the magnetic part or microcircuit 20. { "die attach") consisting of gluing a magnetic part 20, which comes from a small plate sectioned by saw, arranging its active face with its output pins 22, towards the top and sticking the opposite face on a dielectric support plate 28, using a glue that can be conductive; the bonding is done on a printed circuit or on a film. The micro-wiring or soldering of the connections is then carried out. { "wire bonding") which consists in carrying out, by means of solders, the connection of the output pins 22 of the magnetic part 20, with the set of contact terminals 24 of the printed circuit board. Finally, a box coating is carried out. { "pot ting") which consists of protecting the magnetic part 20 and the welded connection wires 26, using a resin 30 which can be, for example, based on silicone or polyurethane. In a variant of this method, which is illustrated in FIG. 2, a peripheral metal ring 32 is used to obtain the rigidity of the micromodule around the resin 30. In another variant of this method ("fl ip-chip") it is used a magnetic part or protuberance. { "bumps") that is placed with its active face down; The electrical connection is ensured, either by metal or polymer protuberances, or by an anisotropic adhesive. In other variants, the technique of band welding is used. { "tape automa ted bonding or "), which is illustrated in figure 3, according to which the magnetic part 34 is glued by means of a glue 36 and the different contacts of the film 38 are welded by thermo-compression on the part magnetic 34 comprising the bulky 39.

There are also magnetic contact card procedures that do not use a micromodule. A first procedure is based on the use of screen printing to form contacts and ensure the interconnection in three dimensions of card body, an addition of the magnetic part by means of a classical technology (more micro-wired bonding) or by means of of the "flip-chip" technique described above, in the procedures that use a micromodule, the associated costs are limited by the price of the film, and it is necessary many times after the operation. of encapsulation, milling the resin to reduce the thickness of the assembly.This operation is difficult since the resin polymerizes and is therefore very rigid.This milling is the main cause of manufacturing waste.In the first procedure without micromodule is described in the preceding, the latter is on the surface and therefore is subject to external efforts, which strongly increases the associated cost. Regarding the second procedure without micro-module, the number of stages is important, which increases the cost of that procedure.

Therefore, it can not be planned to use such technology for the manufacture of large size magnetic cards. There are two large families of non-contact magnetic card manufacturing procedures. The first uses an antenna that is made by winding that is either soldered to a micro-module that contains the magnetic part, or welded directly to a magnetic part that comprises bumps. Such a technique can be used only for magnetic parts of simple operation. The second family uses an antenna "in plane" that can have the shape of a rectangular peripheral spiral or any other appropriate shape. Such an antenna can be made by gravure, mechanical trimming, stamp printing, screen printing or offset printing of a conductive ink. The magnetic part is then added to the antenna by means of the "flip-chip" technique or by a classical technique. In those methods of manufacture of magnetic cards without contact, the manufacture of micro-modules is used which, as indicated above, comprise many stages of assembly of the magnetic part and involve a significant cost, or the "flip-chip" technique "whose cadence is limited and the installation cost is particularly high. With regard to hybrid magnetic cards, their procedures combine the aforementioned drawbacks for contactless and contactless magnetic cards. The problem at the basis of the invention is that of having a method of realizing the connections between a micro-circuit and the interface elements, in an electronic device (such as a magnetic card) comprising at least one micro- circuit that is submerged in a card holder and that comprises output pins connected to interface elements constituted by a set of terminals and / or an antenna that does not have the aforementioned drawbacks and that allows in particular to reduce the cost and the percentage of manufacturing waste and this without making micro-modules. The method according to the invention is particularly remarkable in that a drop of low viscosity conductive substance is deposited between each outlet pin and the corresponding interface element by means of a syringe or the like; this conductive substance acts by polymerization comprising conductive charges and which remains flexible after its polymerization. This procedure makes it possible to suppress the realization of a micro-module and to reduce the number of manufacturing steps. In addition, flexible connections are obtained while connections of the known type are rigid or semi-rigid and this strongly reduces the waste rate in manufacturing. Advantageously, the set of terminals is also realized by low viscosity conductive substance deposit. This allows to simplify the procedure even more, since the realization of the set of terminals and their connections is made in a single operation. Advantageously, the antenna is also realized by depositing a low viscosity conductive substance. This allows to simplify the manufacture and increase the good behavior of the antenna. Preferably, the substance is a polymer resin loaded with conductive or intrinsically conductive particles. Other features and advantages of the invention will become apparent upon reading the detailed description below for the understanding of which one will be reported to the accompanying drawings in which: Figure 1 is a cross-sectional schematic illustrating a known method of manufacture of a magnetic contact card; Figure 2 illustrates a variant of the method of Figure 1; Figure 3 illustrates another variant of the method of Figure 1; Figure 4 illustrates a first embodiment of the method of the invention applied to the manufacture of magnetic contact cards; Figure 5 illustrates a variant of Figure 4; Figure 6 illustrates an embodiment applied to the manufacture of magnetic cards without contact; Figures 7 and 10 illustrate a variant of the method of Figure 6; Figure 11 illustrates an embodiment applied to the manufacture of hybrid magnetic cards; and Figures 12 and 13 illustrate an embodiment applied to the manufacture of electronic labels. Figure 4 represents a magnetic contact card manufactured in accordance with a method according to the invention.

In a first step, a card body 40 is made, comprising a cavity 42 that can be made by injection molding or by co-lamination of thermoplastic sheets followed by a machining of the cavity. In a second step, the magnetic part 44 is placed in the cavity with its active face, in particular its outlet pins 46 and 48, upwards and fixed, for example by gluing. It is also possible to proceed to a local heating of the cavity and then to a placement of the magnetic part in the thermoplastic material melted in this way. It is not necessary that the active face of the magnetic part be at the same level as the bottom of the cavity. In a third step, the set of contact terminals and the connections with the output pins 46 and 48 are made, depositing a low viscosity conductive substance, for example, a polymer resin loaded with conductive or intrinsically conductive particles, by means of a technique called "dispensing" according to which a liquid or low viscosity substance is applied by means of a syringe or the like, with controlled flow and opening. This "dispensing" operation is carried out, for example, by means of an installation marketed under the name CAM / ALOT by the American company Camelot Systems Inc. and it is used for the realization of electronic circuits. The displacement and opening parameters of the syringe are controlled by a computer program. In this way, conductive resin deposits are made which constitute the contacts 50 and 52 of the interface terminal of the magnetic card and the connections 54 and 56 between those contacts 50 and 52 and the output pins 46 and 48 of the magnetic part. . The thickness of these deposits can be much higher than by means of a screen printing process, which allows obtaining more important sections and therefore of low contact resistance. Advantageously, the outlet pins 46 and 48 comprise a stainless metallization, for example of nickel, titanium or tungsten. It is also possible to provide these plugs with bumps in order to improve the electrical contact. To correct the errors of positioning of the magnetic part, a regulation can be provided that uses an image of the magnetic part provided by a computer-aided vision system (HOV).

Preferably, resins are selected whose activation temperatures are lower than the softening temperature of the thermoplastic material of the card body. Figure 5 illustrates a variant of the aforementioned process in which a cavity of two levels is made, that is to say a cavity 58 that has a recess 60 in its bottom. The dimensions of this hollowing are sufficient to receive the magnetic part 44 and its depth is practically equal to the thickness of the magnetic part in such a way that the active face thereof is at the level of the bottom 62 of the cavity 58. Thanks to this In this arrangement, a second slope change of the resin cords in the cavity is prevented, which facilitates the contact of the conductive resin with the output pins 46 and 48. In a fourth and last stage, an encapsulation is performed. { "potting") which consists of protecting the magnetic part using a resin, for example based on silicone or polyurethane. Figure 6 represents a magnetic card without contact made in accordance with a method according to the invention. It comprises an antenna "in plan", constituted by a track that has, for example, the shape of a rectangular spiral arranged in the periphery of the card as shown in figure 9. In a first stage, a bonding of a magnetic part with its active face upwards in the selected place for the connection using a procedure and a classic equipment of "die attach" using a glue 66 that allows a bonding on a printed circuit or a film. A glue compatible with the maximum use temperature of the antenna support is selected, for example an adhesive that reticles under the effect of an exposure to ultraviolet radiation. The cadence of this gluing operation can be particularly high, for example from five to six thousand pieces per hour with a single head. An amount of perfectly mastered glue will be sought in the area of the perimeter of the magnetic part in front of the connection free portions 68 and 70 of the antenna. In a second step, electrical connections 72 and 74 of resin are made between the output pins 76 and 78 of the magnetic part 80 and the connection free spaces 68 and 70 of the antenna. This second stage can also be carried out with the same high rate of the step of bonding the magnetic part. These two stages can be performed on the same equipment. According to a first variant, the antenna "in plane" is made with a "dispensing" technique and the gluing of the magnetic part is carried out by means of the "flip-chip" technique described in the foregoing. According to another variant illustrated in figures 7 to 10, the magnetic part is fixed first and the antenna is made by a "dispensing" technique passing over the active face of the magnetic part. In a first step (FIG. 7), an insulating adhesive 82, for example of the epoxy type, is deposited by means of "dispensing", on a support 84, for example, of polyvinyl chloride or polyethylene, in the place where it will be placed then a magnetic part provided with contact protuberances. In this way, adhesives intended for the "die a ttach" technique adapted to the support could be used. In a second step (figure 8), a magnetic part 86 with its active side facing upwards is placed on the adhesive 82 to perform a "die a ttach" type bonding. The interest of the contact protuberances is that of improving the electrical contact between the output pins 88 and 90 of the magnetic part and the antenna. The non-functional output pins will eventually be insulated, depositing a dielectric varnish. In a third step (FIG. 9), the antenna 92 is made by means of a "dispensing" technique of a conductive substance, for example, an ink or a glue, with displacement of the syringe, using for example the CAM / ALOT cited in the preceding.

It can be seen in figure 10 that the ends 94 and 96 of the rectangular spiral constituting the antenna 92 cover, respectively, the contact pins 88 and 90 of the magnetic part 86. In a last and fourth stage, an operation is performed of co-lamination to finish the card. Figure 11 represents a hybrid card manufactured in accordance with a method according to the invention. In this case, two procedures are combined that are described in the foregoing. In a first step, a card body 98 is made, comprising a built-in antenna 99 comprising two contact pins 101 and 103. In a second step, a cavity 100 is made in the body of the card. In a third step, the magnetic part 102 is fixed with its active face and its output pins 104, which preferably comprise a stainless metallization, in the cavity, for example, by gluing.

In a fourth step, the contact terminal 106 and its connections 108 are made with the output pins 104 of the magnetic part and the connections 105 of the contact pins 101 and 103 of the antenna with the output pins 104, depositing a conductive resin 105 by means of a "dispensing" technique. The pins 104 may comprise contact protuberances. The angular position errors of the magnetic part 102 can be corrected as described above, using computer-aided vision equipment. In a fifth and last stage, the encapsulation of the magnetic part is performed. The invention applies to the manufacture of all electronic devices that comprise at least one microcircuit that is immersed in a support card and that comprises output pins connected to interface elements constituted by a set of terminals and / or a antenna. In particular, the invention makes it possible to manufacture electronic labels as shown in FIGS. 12 and 13. A support 110 comprises a cavity 112 at the bottom of which an antenna 114. is made. A micro-circuit 116 is then fixed with its exit pins 118 upwards. A conductive resin 120 is applied by a "dispensing" technique to make the connections between the antenna 114 and the output pins 118 of the magnetic part. An encapsulation is then carried out with an insulating resin 122. It is noted that the invention makes it possible to suppress the realization of a micro-module and, in particular, the milling operation. It also turns out that the rate of manufacturing waste is greatly reduced. On the other hand, the number of stages is reduced, which greatly simplifies manufacturing and causes a significant decrease in the cost price. This effect is further increased due to the fact that certain operations of gluing the magnetic part and making the connections can be carried out with the same equipment. The invention does not use expensive equipment, which reduces manufacturing costs. The realization of the antenna by means of the technique of "dispensing", allows to obtain a maximum surface and, later, to increase the good behavior of the antenna in relation to the classic built-in antennas.

The invention makes it possible to manufacture complex and large cards in a simple and inexpensive manner. The realization of the connections by means of the technique of "dispensing" a substance that remains flexible after its activation, allows to reduce the rigidity and to considerably increase the resistance to bending-torsion of the magnetic cards. In this way, the magnetic cards manufactured in accordance with the invention have a good conduct in relation to the efforts, behavior that is much higher than that imposed by the current standards. The invention makes it possible to obtain, with a very small waste rate, as indicated above, high production rates, for example of 4000 magnetic cards per hour.

Claims (19)

1. CLAIMS 1.- Method of manufacturing an electronic device, such as a magnetic card, comprising at least one microcircuit that is immersed in a support card and that comprises output pins connected to interface elements constituted by an assembly of terminals and / or an antenna, characterized in that connections are made between the output pins and the interface elements, by depositing by means of a syringe or the like, a conductive substance of low viscosity that remains flexible after its application .
2. 2. Method according to claim 1, characterized in that the set of terminals is also carried out by depositing a conductive substance of low viscosity.
3. 3. Method according to claim 1, characterized in that an antenna is also made by depositing a conductive substance of low viscosity.
4. 4. Method according to any of claims 1 to 3, characterized in that the substance is a polymer resin loaded with conductive particles.
5. 5. - Process according to any of claims 1 to 3, characterized in that the substance is a polymer resin loaded with intrinsically conductive particles.
6. Method according to any of claims 1 to 5, characterized in that the deposit of low viscosity conductive substance is carried out with a relative displacement of the electronic device and the syringe.
7. Method according to claim 6, characterized in that the movement is controlled by a computer program.
8. Method according to claim 7, characterized in that a position correction is carried out, by taking an image of the magnetic part provided by means of a computer-assisted visualization system.
9. 9. Method according to claim 4, characterized in that the temperature of activation of the substance is lower than the softening temperature of the thermoplastic material that constitutes the body of the card.
10. 10. Method according to any of claims 1 to 9, characterized in that the output pins comprise a stainless metallization.
11. 11. Method according to claim 2, characterized in that the device is a magnetic contact card, in which a card body comprising a cavity is made, in which the micro-circuit with its active face is fixed upwards in the cavity, in which the set of terminals and the connections is made by depositing a conductive substance and in which an encapsulation of the micro-circuit is carried out.
12. 12. Process for manufacturing a magnetic contact card according to claim 11, characterized in that the microcircuit comprises contact protuberances.
13. 13. Process for manufacturing a magnetic contact card according to claim 11, characterized in that the cavity has a recess in its bottom designed to receive the microcircuit.
14. 14. Method according to claim 1, characterized in that the device is a magnetic card without contact or an electronic label, in which an antenna is made "in plane", in which the microcircuit is fixed on the card with its active face towards above, and in which connections are made between the output pins of the micro-circuit and the pins of the antenna, by means of depositing a conductive substance of low viscosity.
15. 15. Method according to claim 3, characterized in that the device is a magnetic card without contact or an electronic tag, in which an antenna is made "in plane" by depositing a conductive substance of low viscosity, in which protuberances are made of contact on the micro-circuit and on which the micro-circuit is fixed with its active face downwards.
16. 16. Method according to claim 3, characterized in that the device is a magnetic card without contact or an electronic tag, in which is deposited by means of a syringe or the like, an insulating adhesive on a support, in which the micro-circuit is stuck with its active face upwards, in which an antenna is made "in plane" directly on the micro- circuit by depositing a conductive substance of low viscosity, and in which a final co -mination operation is carried out.
17. Method according to claim 2, characterized in that the device is a hybrid magnetic card, in which a card body comprising an incorporated antenna is realized, in which a cavity is made in the card body, in which it is fixed the micro-circuit with its active face upwards in the cavity, in which the set of terminals and their connections is made by depositing a conductive substance of low viscosity, and in which an encapsulation is carried out.
18. 18. Process for manufacturing a hybrid magnetic card according to claim 17, characterized in that the microcircuit comprises contact protuberances.
19. 19. Process for manufacturing a hybrid magnetic card according to claim 17, characterized in that the deposit of a conductive substance of low viscosity is carried out correcting the errors of angular positioning of the microcircuit by means of a computer assisted vision system.