MXPA98005055A

MXPA98005055A - Method for manufacturing chip cards for use in technology without conta

Info

Publication number: MXPA98005055A
Application number: MXPA/A/1998/005055A
Authority: MX
Inventors: Hottinger Werner
Original assignee: Hottinger Werner; Sempac Sa
Priority date: 1995-12-22
Filing date: 1998-06-22
Publication date: 1999-07-06

Abstract

In the chip cards to be manufactured, integrated circuit elements (chip 2 and / or electronic module 12), coupling elements (coil 6, capacitor layers 8) for the non-contact transmission of electrical power are predisposed and / or the data transfer, and at least one label (1) that forms an external surface of the card. The coupling elements (6, 8) are applied to the inner surface of the label. The label (1) thus prepared is then introduced into an injection mold. The integrated circuit elements (12) provided separately are then placed in the injection mold, to fit exactly on, and to make contact with the terminals of the coupling elements (6,8). Finally, the body of the card is molded and linked to the label, by means of an injection mold process, and at the same time the integrated circuit elements are embedded in the body of the card. Electrical connections are made between the coupling elements (6, 8) and the integrated circuit elements (12) in the mold itself, by different means.

Description

METHOD FOR MANUFACTURING CHIP CARDS TO BE USED IN CONTACT-FREE TECHNOLOGY Background In addition to well-known chip cards having an external contact area and communicating through it with a reading (and writing) unit, so-called contactless chip cards have also been proposed. These do not need an electrical contact between the card and the card reader unit, at least not for data transfer. Instead, transmission or communication is effected by means of coupling elements integrated in the card and in the card reader unit. Depending on the application, this technique makes a distinction between the close coupling that requires the introduction of the card in a card reader, and the remote coupling that allows communication over medium and large distances "when passing", that is, without the introduction of the card in a card reader. In addition to the predominant inductive coupling method (which is said to not only make data transfer possible, but also provide a non-contact power supply for the card's circuits), a capacitive coupling has also been proposed, but this it is considered only adequate for the transfer of data. Finally, cards have been proposed for non-contact use which, in addition, have the conventional external contact area - so-called hybrid or combined cards - (see: Sickert, K., and einerth, H.: Schlüsseltechnologie Mikroelektronik, 24. Teil : Von der kontaktbehafteten zur kontaktlosen Chipkarte [Key Technology Microelectronics, part 24: from contact chip cards to contactless], Elektronik 1989, No. 25, pages 66-78).

Prior Art Many applications for contactless chip cards have already been proposed, and the highly sophisticated systems, chips, and transfer and circuit software relevant thereto have been developed. But until now, only a few proposals have been published for the manufacture and construction of these cards, which appropriately take into account the peculiarities of data transfer and contactless energy transmission. A first proposition provides a laminated construction board of several layers welded together, such as films and / or printed cover labels, having an internal substrate of film or sheet, with strip conductors, two small transmission coils for a close coupling, and chips. In this type, a ring surrounds a chip, apparently for mechanical protection (see: the publication referred to on pages 75-76, Figure 8 on the right, and Figure 10). Apart from the precise adjustment that is required in the superposition of several layers of film or sheet, the welding of these large areas together seems to create problems with respect to the embedded chips and the outer printed layers of film or sheet. Another proposition provides a single chip of 4 millimeters by 4 millimeters with a hybrid circuit and a high frequency antenna coil fitted to the back of the chip. In a manner similar to the proposition referred to above, the card consists of a stack of several layers of film or sheet, and the chip must be placed in a recess in a film or inner sheet (Jurisch, R.: mic3-die neue kontaktlose Chipkartentechnologie [mic3, the new contactless chip card technology]; Card-Forum 1995, No. 3, pages 82-84). The reservations mentioned above with respect to the construction of multiple layers, also apply to this, but, above all, the chip offers only an extremely limited area for the antenna coil, and this fact in any case has the potential to make the remote coupling applications. From the European Patent Number EP-A-0, 682, 321, a method for the manufacture of a chip card containing an inductive coupling element for the non-contact transmission of energy and / or data is known., and which also contains integrated circuits in the form of at least one chip and / or electronic module. At least for an external surface of the card, a layer or a cover label is used, wherein the aforementioned coupling element is applied to the surface that faces away from the external printed surface. According to this prior art, also the body of the manufacturing card of several layers spliced by lamination.

SUMMARY OF THE DESCRIPTION The object of the invention is to enable the efficient, low-cost, and reliable series production of contactless chip cards, where at the same time the special requirements of coupling elements for the operation are taken into account. without contact, and also eliminate the risks with respect to expensive special chips during the production process, as much as possible. The object of the invention is solved by a manufacturing method in accordance with the features of claim 1. The outer surface of the labels used preferably must be pre-printed, but blank labels can also be used, and subsequent printing is carried out. cards completed as needed. The coils and the capacitor layers are both suitable for use as coupling elements, and the elements for an inductive and capacitive coupling can be comprised in a single card. For the present purposes, the term "electronic module" is applied to a prefabricated unit that fits on the card, and which has at least one chip with a protective wrap and connector contacts. If a label is provided for each of the outer surfaces of the card, either or both labels can be prepared to be inserted into the mold in the manner referred to above. The method according to the present invention gives the label, which as a rule is necessary in any way, a convenient double function. Coupling elements can be designed and configured on the label in a variety of ways without impeding handling, such as stacking, unstacking, and insertion into the mold. Practically, the entire surface of the label or card is available for the coupling element, and therefore, it is possible to provide the required coil area and the number of coils for remote coupling, or provide the capacitor layers for coupling capacitive For precise positioning of the modules or chips inside the mold, there are tools, such as manipulators, available, which have already proven their efficiency in the production of conventional chip cards. Moreover, injection molding is an efficient process technique for the production of chip cards, and ensures the soft, and yet firm, embedding of the chips and modules in the card body. Several special versions of the method according to the invention as defined in claim 1 are referred to in the dependent claims. The typical embodiments of the present invention are described in detail below, with reference to, and in conjunction with, the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS Figures 1 to 4 inclusive, show different typical embodiments of labels with coupling elements configured on the internal surface, which, after being introduced into the injection mold, are adjusted and brought into contact in different ways, with integrated circuit elements. Figure 5 shows a partial section of an injection mold, where labels and integrated circuit elements have been placed ready for the injection molding process.

Detailed Description of the Invention Figures 1 to 4 each show the internal surface of a label 1 as used in the production of chip cards, to form the outer surface of the card. This is a film or sheet of plastic in a card format, typically approximately 0.1 millimeter thick, which normally acts as a substrate for a printed text and / or an image. Often two of these labels form the two outer surfaces of a chip card. The external surface of the label - not visible in these Figures - is preferably pre-printed, but subsequent printing of the finished card is also possible. In the four modalities, the surface shown is the side of the label that faces away from its external surface. Coupling elements 3, 6, 8 for non-contact use or operation of the card, are applied to this internal surface. As indicated only in Figure 1 to the left, the label 1 prepared hitherto is inserted in the lower section 20, of an injection mold (see also Figure 5). Also shown are integrated circuit elements in the form of semiconductor chips 2, 2 'or electronic modules 12, 12'. As indicated again in Figure 1 only, on the right, these elements have been provided separately, and inserted into the injection mold on the label 1. Its contact elements or link bearings (4 'in Figure 1) ) are placed precisely by means of a manipulator (not shown) to fit over and in contact with the terminals of the coupling elements. The aforementioned method also applies to the other different embodiments described below in conjunction with Figures 2 to 4. In the case of Figure 1, a coil for inductive coupling is wound up as a coil of flat wire 3. The coil is in a rectangular shape to suit the format of the card, and adheres to the label 1 along the edges of the label. The "bottom side" of the chip 2 shown separately to the right, has link bearings 4 'as contact elements for the coil 3. For example, the chip can be a single chip whose integrated circuit performs all the functions of the card , including, by means of coil 3, data communication and the supply of electrical power to the circuits. The electrical connection of the ends of the coil with the chip 2 can be made, as shown, by means of the terminals 4, if necessary through a wire bridge 5, where the terminals 4 are on the label and linked by contact with the aforementioned 4 'link couplings of the chip 2. In addition, the chip 2 can be attached to the tag 1, by means of an adhesive. In the embodiment shown in Figure 2, a coupling coil 6 with the required number of turns has been created, as a printed circuit on the label 1. The known technique for making the coil ends can also be used at the same time. suitable for a direct contact link with a chip 2. It may be desirable to place the chip through the turns of the coil 6, as shown, so as not to require special elements that coax one end of the coil through the coils. same. If the surface of chip 2 facing the coil is provided with an insulating passivating layer, no further action is required; but if necessary, an insulating coating can be applied to the coil 6 before the chip 2 is applied. In the embodiment shown in Figure 3, a coupling coil 6 is again applied to the label 1 as a printed circuit that more or less makes use of all the format of the card. At the same time, the same technique has been used to create two conductive areas 8 within the area of the coil, as capacitor layers for capacitive coupling. In this case, an integrated circuit (chip 2) is contained inside a flat electronic module 12. It has contact elements or link pads in the form of module terminals 13 for the contact connection with the two ends of the module. coil and the coatings of the capacitor 8, and preferably it is again placed to bridge through the coil turns 6. The integrated circuit elements of the card do not need to be concentrated on a single chip or module, but can be divided between two or more of these components in a known manner. If so, it may be useful to apply printed circuits to the label to connect the aforementioned components with one another, and / or with the coupling elements. Figure 4 shows a typical embodiment of this class, and in this case a chip card designed not only for contactless operation, but also suitable for direct electrical contact. In accordance with the above, Figure 4 shows a module 12 'with the contacts 15 and a separate chip 2' placed inside the area of a printed coil 6 on the label 1. For example, the 2 'chip can be a so-called chip of communication that performs the functions of data transfer without contact, and if necessary, the supply of electrical power to the circuits of the card. As shown, this chip can be connected directly to one end of the coil and through a wire bridge 5 to the other. The electronic module 12 'is of a particularly planar design whose contact area 15 forms part of one of the external surfaces of the card for electrical connection with a card reader (similar to the module described, for example, in the European Patent Number EP-A-0, 599, 194). The external contacts 15 have angled "legs" 16 resting on the label 1. In addition, the module 12 'has other contacts 17 not accessible from the outside. These are linked by contact to the fringes of the printed circuit 14 on the label, and provide the connections between the module 12 'and the chip 2' (see also Figure 5) either through these, or if a connection is not provided. Separate communication chip, directly with the coupling elements. Obviously, if necessary, one additional strip conductor 14 can provide other connections between the communication chip 2 'and the module 12'. The coupling elements on the label can obviously be designed to suit the requirements of the card system; in particular, for example, two coupling coils can also be placed one next to the other. Although the typical embodiments shown in Figures 1 to 4 refer to a single label 1, if each of a pair of labels forms one of the two external surfaces of the card, it is also possible to provide both labels with the coupling elements. For example, one or more coils can be applied to one of the labels on the card, and capacitor layers on the other, or both labels can each have a capacitor layer, and so on. In this case, in order to make a link by contact with the coupling elements, the integrated circuit elements on both sides must be provided with the required link bearings or module terminals. As mentioned, the prepared labels (in some cases only one per card) and the integrated circuit elements are inserted one after the other into an injection mold. Figure 5 shows this mold in a diagrammatic way, formed of two mold halves 20 and 21, with a channel 22 in the dividing plane. The embodiment shown is based on a label prepared as described for Figure 4. In the mold 20, 21, this is the lower label la, and a second label Ib is placed in the upper mold half 21. In established practice , this upper label Ib has a rectangular cut 18 occupied by the contact area 15 of the module 12 '. The other contacts 17 of the module, on the other hand, are not exposed on the outer surface of the card, but are covered by the lower label the. Finally, when the labels and integrated circuit elements have been assembled, and the mold has been closed (for example, as in Figure 5), the card body is formed by the injection molding process, by injection plastic to fill the vacuum 23 formed in the mold. In this process, the injected material is bonded and combined with the internal surface of the labels, and at the same time, surrounds the integrated circuit elements, and embeds them in the body of the card. Now the chip card contains all the necessary components for non-contact use, and can be removed from the mold. There are different processes known per se available for the formation of electrically conductive connections between the integrated circuit elements and the coupling elements and / or the strip conductors inside the injection mold. One possibility is to make the connections through the local application of an electrically conductive adhesive. But it is also possible to make direct metal-to-metal connections, simply by means of a mechanical contact pressure, if necessary with the support of ultrasonic welding. As shown by the embodiment of Figure 5, if a module 12 'which occupies practically the entire thickness of the card is used, its terminals 17 are compressed against the strip conductors 14 in the closed mold 20, 21, and this promotes the link by contact inside the mold. In this context, in order to make the connections, the strong forces applied during injection molding on the inserted components can be exploited, as a result of the high pressures in the plastic molding material. For the electrical contact link, one can also take advantage of the high temperatures that occur in injection molding, for example, by using an adhesive that will react with heat and set in the mold, or by simultaneous application of pressure and high temperature, the so-called thermocompression, for metal-metal bonding. Finally, it is also possible to secure the electrically conductive connections by using soft solder portions (welding preforms) that melts in the injection mold.

Claims

NOVELTY OF THE INVENTION - Having described the foregoing invention, it is considered as a novelty, and therefore, the content of the following is claimed as property: CLAIMS

1. A method for manufacturing a chip card containing inductive and / or capacitive coupling elements, for non-contact transmission of electrical power and / or data, integrated circuit elements connected to the coupling elements in the form of at least a chip and / or electronic module, - wherein at least one external surface of the card is formed by a label, by means of which the aforementioned coupling elements are applied to the surface of the label that faces away from the external surface that is printed or to be printed; - wherein the label thus prepared is inserted in an injection mold; wherein the integrated circuit elements provided separately, which provide contact elements for the coupling elements, are inserted in the injection mold above the label, thus placing precisely the contact elements on the terminals of the elements of coupling, and making contact with those terminals; wherein the card body is then formed and linked to the label by an injection molding process, wherein at the same time the integrated circuit elements are embedded in the card body; and wherein electrically conductive connections are formed between the coupling elements and the integrated circuit elements, inside the injection mold, by mechanical contact pressure, electrically conductive adhesive, and / or soft solder of low melting point.

The method according to claim 1, characterized in that at least one coil is applied for the inductive coupling to the label in the form of a coil of flat coiled wire.

3. The method according to claim 1, characterized in that the coupling elements are formed on the label in the form of a printed circuit.

The method according to claim 3, characterized in that a chip or an electronic module is placed through the turns of a printed coil, and the outer and inner end terminals of the coil are brought into contact with the coil. the same.

5. The method according to claim 1 of the preceding claims, characterized in that printed strip conductors are applied to the label for the connection of the coupling elements with the integrated circuit elements and / or the integrated circuit elements. with others .

6. The method according to claim 1 of claim 1, characterized in that a conductive thermorereactive (thermoformable) adhesive is used to obtain the electrically conductive connections.

The method according to claim 1 of claim 1, characterized in that the contact link in the injection mold is supported by ultrasonic welding.

The method according to claim 1 of claim 1, characterized in that the contact bond in the injection mold is obtained by thermocompression, that is, by the simultaneous application of a high temperature and pressure.

9. The method according to claim 1 of claim 1, characterized in that the contact bond in the injection mold is obtained by using previously formed portions of soft solder. The method according to claim 1 of one of the preceding claims, characterized in that an electronic module having an externally accessible contact area and additional terminals for connecting to the coupling elements is used.