EP0868706A1

EP0868706A1 - Process for producing a chip card for contactless operation

Info

Publication number: EP0868706A1
Application number: EP96940980A
Authority: EP
Inventors: Werner Hottinger
Original assignee: Sempac SA
Current assignee: Besi Switzerland AG
Priority date: 1995-12-22
Filing date: 1996-12-19
Publication date: 1998-10-07
Also published as: CZ197098A3; CA2240503A1; BR9612185A; CN1209210A; WO1997023843A1; ZA9610816B; AU1028897A; TW355777B; JP2001521649A; PL327234A1; KR19990076679A

Abstract

In the chip cards to be produced, besides the integrated circuit components (chip 2 and/or electronic module 12) and coupling means (coil 6, capacitor coatings 8) for contactless power and/or data transmission there is also at least one label (1) forming the outer surface of the card. The coupling means (6, 8) are applied to the inner side of said label. The label (1), thus prepared, is then inserted into an injection mould. The separately prepared integrated circuit components (12) are then positioned accurately in the mould via terminals in the coupling means (6, 8) and contacted with them. Finally the card body is moulded on the label (1) by the injection moulding process and the integrated circuit components (2, 12) are moulded into the card body. Electric connections between the coupling means (6, 8) and the integrated circuit components (12) are produced in the mould itself by various means.

Description

Method for producing a chip card for contactless operation

In addition to the known chip cards, which have a contact field on the outside and communicate via this with a (writing and) reading device, so-called contactless chip cards have also been proposed in various ways. With these, at least for data exchange, no galvanic contact connection between the card and the reader is required, but instead a wireless transmission takes place with the aid of coupling means built into the card and the reader. Depending on the application, a distinction is made between close transmission, in which the card has to be inserted into a reading device, and transmission over medium or large distances (remote coupling), which "go by" communication, ie without the introduction of the Card allowed in a reader. In addition to the prevailing inductive coupling, which, in addition to the data exchange, should also enable the contactless supply of the card circuit (chip), capacitive coupling has also been proposed, which is, however, only considered sufficient for the data transfer. Finally, cards for contactless operation which are additionally equipped with the usual external contact field (so-called hybrid or combination cards) are also taken into account (literature, for example, Sickert, K. and Wemerth, H.: Key Technology in Microelectronics, Part 24: From the Contact to the Contactless Chip Card. Elektronik 1989, No. 25, pages 66-78).

Various applications of contactless chip cards have already been proposed and corresponding, highly developed transmission and circuit systems, chips and software have also been developed. On the other hand, only a few proposals have become known regarding the production or construction of such cards, which take into account the special features of wireless transmission.

A first proposal provides for a laminate structure of the card from several welded layers (including printed cover foils or labels), an inner substrate foil with conductor tracks including two small transmission coils (for short-range transmission) and equipped with chips; a ring surrounding a chip apparently serves as mechanical protection (see publication mentioned above, pp. 75, 76, fig. 8 right and fig. 10). In addition to the necessary, precise overlaying of several film layers, the large-area welding appears problematic with regard to the embedded chips as well as the printed outer films.

Another proposal provides for a single 4x4 mm chip with a hybrid circuit and a high frequency antenna coil attached to the back of the chip. Similar to the aforementioned proposal, the card consists of a multilayer film stack, the chip having to be inserted into a recess in a film lying inside (Jurisch, R.: mιc3 - the new contactless chip card technology. Card-Forum 1995, No. 3, pages 82- 84). With regard to the multi-layer structure, the above reservations apply; but above all, the chip only offers a very limited area for the antenna coil, which in any case could exclude applications with remote transmission.

The present invention relates to a method for producing a chip card, in which inductive and / or capacitive Coupling means for contactless power and / or data ^¬ transmission and connected to the coupling means integrated circuit means (in the form of at least one chip and / or an electronic module) are provided, and wherein at least one outer face of the card is formed by a label.

The method according to the invention is intended to enable the rational, cost-effective and reliable series production of contactless chip cards, taking into account the special requirements of the coupling means for contactless operation and avoiding the expensive special chips caused by the manufacturing process as far as possible.

According to the invention, this object is achieved by

that said coupling means are applied to one side of a label facing away from the printed or to be printed outer side,

- that the label thus prepared is placed in an injection mold,

that the separately provided integrated circuit means provided with contact points for the coupling means are introduced into the injection mold and the contact points are positioned precisely over connections of the coupling means and contacted with them,

and that the card body is then cast onto the label in the injection molding process and at the same time the integrated circuit means are poured into the card body,

- With electrically conductive connections between the coupling means and the integrated circuit means in the injection mold are produced by mechanical contact pressure, electrically conductive adhesive and / or by low-melting solder.

The labels used are preferably already printed on the outer side, but blank labels can also be used and the finished cards can be subsequently printed if necessary. Both coils and capacitor covering, means for inductive and capacitive coupling can also be included in the same card. In the present context, an electronic module is understood to mean a manufactured unit which is to be inserted into the card and which has at least one chip with a protective sheath and connecting contacts. If a label is provided on each outside of the card, both labels or only one of the two can be prepared for insertion into the mold in the manner specified.

With the method according to the invention, the label, which is generally required anyway, advantageously has a double function. The coupling means can be designed in numerous variations and arranged on the label, so that handling - such as stacking and unstacking and insertion into the mold - is not hindered. Practically the entire label or card area is available for the coupling means, so that coil areas and number of turns, which are required for remote transmission, or capacitor coverings for capacitive coupling can also be realized. Devices (manipulators) are available for precisely inserting the modules or chips into the mold, which are already preserved during the production of conventional chip cards. Injection molding, in turn, is a rational process technology for the production of chip cards and ensures gentle and at the same time solid embedding of chips and modules in the card body.

Special variants of the method according to the invention defined in claim 1 are given in the dependent claims. The invention is explained below with reference to exemplary embodiments in conjunction with the drawing.

1 to 4 show various examples of labels with coupling means arranged on the inside thereof, which - after being introduced into the injection mold - are equipped or integrated with integrated circuit means in different ways, and 5 shows in section a part of an injection mold with labels inserted therein and integrated circuit means, prepared for the injection molding process.

FIGS. 1-4 each show the inside of a label 1 as used for the production of chip cards in order to form an outer surface of the card. It is a plastic film from e.g. 0.1mm thickness in card format, which usually serves as a font and / or image carrier. Both of the outer surfaces of the chip card are often formed by such a label. The outside of the label, which is not visible in the figures, is preferably already printed, but subsequent printing of the finished card is also possible.

In all four exemplary embodiments, coupling means 3, 6, 8 for contactless card operation are applied to the side of the label facing away from the outside. As only indicated on the left in FIG. 1, the label 1 prepared in this way is inserted into the lower part 20 of an injection mold (see also FIG. 5). Integrated circuit means in the form of semiconductor chips 2, 2 'or electronic modules 12, 12' are also shown. As also only indicated on the right in FIG. 1, these have been provided separately and introduced into the injection mold above the label 1. The contact points (4 'in FIG. 1) have been positioned with the aid of a manipulator, not shown, over connections of the coupling means and have been contacted with them. The aforementioned procedure also applies to the embodiment variants according to FIGS. 2 to 4 described further below.

In the case of FIG. 1, a coil for inductive coupling is wound as a flat wire coil 3. The spool has a rectangular shape adapted to the card format and is glued to the edge of the label 1. The chip 2 shown separately on the right with its “underside” is provided with contact points 4 ¹ (bond pads) for the coil 3. For example, it is a single chip, the integrated circuit of which all card functions finally performs the data communication and power supply to the circuit via the coil 3. As shown, the coil ends can be connected to the chip 2 via connections 4 and optionally a wire bridge 5, the connections 4 being located on the label 1 and being in contact with the mentioned contact points 4 'of the chip 2. The chip 2 can also be glued to the label 1.

In the exemplary embodiment according to FIG. 2, a coupling coil 6 with the required number of turns in the form of a printed circuit on the label 1 has been produced. With the known technology, the coil ends 7 can at the same time be appropriately shaped for direct contacting of a chip 2. As shown, the chip can advantageously be positioned lying across the windings of the coil 6, so that a special transfer of the one coil end is omitted. If the side of the chip 2 facing the coil turns is provided with an insulating passivation layer, no further measures are necessary; if necessary, the coil 6 can also be provided with an insulating coating before the chip 2 is applied.

In the variant according to FIG. 3, a coupling coil 6, which more or less fills the card format, is applied to the label 1 as a printed circuit. At the same time, two conductive surfaces 8 have been produced with the same technology within the coil surface as capacitor coverings for capacitive coupling. An integrated circuit (chip 2) is contained in a flat electronics module 12 here. This has contact points in the form of module connections 13 for contacting both the two coil ends and the capacitor coating 8 and is expediently arranged such that it bridges the turns of the coil 6.

The integrated circuit means of the card need not be concentrated in a single chip or module, but can, in a manner known per se, be divided into two or more Components are distributed. It is then expedient to apply printed conductor tracks on the label for connecting the components mentioned to one another and / or for connecting the coupling means. A corresponding example is shown in FIG. 4, specifically for a chip card which, in addition to contactless operation, is also intended for connection via galvanic contacts. 4, a module 12 'with contacts 15 and a separate chip 2' are accordingly arranged on the label 1 within a printed coil 6.

The chip 2 'is e.g. a so-called communication chip on which the functions of the wireless data transmission and, if applicable, the feeding of the card circuit are combined. As shown, it can be connected directly to one coil end and to the other coil end via a wire bridge 5. The electronics module 12 'is of a particularly flat design, the contact field 15 of which lies in the one outer surface of the card for connection to a reading device (similar to the module as described, for example, in EP-A-0 599 194 is). The external contacts 15 have angled "feet" 16, which come to rest on the label 1. In addition, there are further contacts 17 on module 12 'which are not accessible from the outside. They are contacted with printed conductor tracks 14 on the label and use them to connect the module 12 'to the chip 2' (see also FIG. 5) - or also directly to the coupling means, if no separate communication chip is provided . Of course, further connections by means of conductor tracks 14 can, of course, also be provided between the communication chip 2 'and the module 12'.

It goes without saying that the coupling means on the label can be designed according to the requirements of the card system, in particular two coupling coils can also be arranged side by side. Although the examples according to FIGS. 1 to 4 relate to a single label 1, both labels can also be provided with coupling means on cards whose two outer surfaces are each formed by a label. Example one or more coils can be applied to one label of the card and capacitor coatings can be applied to the other label, or each of the two labels can be provided with a capacitor coating, etc. The integrated switching means are then available for contacting the coupling means two labels, on both sides with the corresponding Bontakt¬ points or module connections.

The prepared labels (possibly only one per card) and the integrated circuit means, as expected, are placed one after the other in an injection mold. FIG. 5 schematically shows such a shape with the mold halves 20 and 21 and the sprue 22 arranged in the parting plane. The example shown was based on a prepared label according to FIG. 4. This forms the lower label la in the form 20, 21, and a second label lb m the upper mold half 21 has been inserted. This upper label 1b (as is known per se) has a rectangular cutout 18 in which the contact field 15 of the module 12 'comes to lie. The other contacts 17 of the module, however, are not free on the outer surface of the card, but are covered by the lower label la.

After the injection mold has been fitted with the label or labels and the integrated circuit means and the mold is closed (example, FIG. 5), the card body is finally produced by filling the mold cavity 23 with plastic in the injection molding process. The injected material connects to the inside of the label (s), and at the same time the integrated circuit means are enveloped by the material, i.e. poured into the card body. The finished chip card, provided with all the components required for contactless operation, can then be removed from the mold.

In order to produce electrically conductive connections between the integrated circuit means and the coupling means or conductor tracks in the injection mold, various, per se known methods are used. Connection by means of an electrically conductive adhesive to be applied locally is an option. On the other hand, however, direct metal-to-metal connections can only be established by mechanical contact pressure, supported at most by ultrasonic welding. As can be seen in the example according to FIG. 5, in the case of a module 12 'which takes up practically the entire card thickness, its contacts 17 m of the closed mold 20, 21 are pressed onto the conductor tracks 14, which accommodates contact within the mold. It is possible to use the strong forces that are exerted during injection molding on the injected parts as a result of the high pressures in the plastic molding compound when making the connections. The high temperatures that occur during injection molding can also be used advantageously for contacting, for example by using a heat-reacting adhesive that is already curing in the mold, or by simultaneously applying pressure and elevated temperature (thermocompression) in the case of metallic contacting. Finally, contacting by means of preformed soft solder portions (preforms) is also conceivable, which melt in the injection mold.

Claims

Claims: Sll-P12a

1. A method for producing a chip card, the inductive and / or capacitive coupling means (3, 6, 8) for contactless energy and / or data transmission as well as integrated circuit means (2, 12) in the form of at least one chip and connected to the coupling means / or contains an electronic module, at least one outer surface of the card being formed by an label (1), characterized in that

that said coupling means (3, 6, 8) are applied to one side of a label (1) which faces away from the printed or to be printed outer side,

- that the label (1) thus prepared is introduced into an injection mold (20, 21),

- That the separately provided, provided with contact points (4 ', 13) for the coupling means (3, 6, 8) integrated circuit means (2, 12) above the label (1) in the injection mold (20, 21) and the contact points (4 ', 13) are positioned precisely over connections (4, 7) of the coupling means and contacted with them,

- and that the card body is then cast onto the label (1) in the injection molding process and at the same time the integrated circuit means (2, 12) are poured into the card body,

- With electrically conductive connections between the coupling means (3, 6, 8) and the integrated circuit means (2, 12) in the injection mold (20, 21) by mechanical contact) <t pressure, electrically conductive adhesive and / or by medrigschmeJ zendes Lot are made.

2. The method according to claim 1, characterized in that at least one coil for inductive coupling in the form of a flat, wound wire coil (3) is applied to the label (1).

3. The method according to claim 1, characterized in that one generates the coupling means (6, 8) on the label (1) in the form of a printed circuit.

4. The method according to claim 3, characterized in that in a printed coil (6) a chip (2) or an electronics module (12) is positioned transversely over its turns and the outer and inner coil ends are contacted therewith.

5. The method according to any one of the preceding claims, characterized in that printed on the label (1) printed conductor tracks (4, 14) for connecting the coupling means (3, 6, 8) to integrated circuit means (2, 12) and / or for connecting integrated circuit means to one another.

6. The method according to any one of claims 1 to 5, characterized in that a heat-reacting (thermosetting) conductive adhesive is used to produce electrically conductive connections.

7. The method according to any one of claims 1 to 5, characterized in that the contacting in the Spritzguεsform is supported by ultrasonic welding.

8. The method according to any one of claims 1 to 5, characterized in that the contacting in the injection mold by means of thermal compression, ie simultaneous application of elevated temperature and pressure.

9. The method according to any one of claims 1 to 5, characterized in that preformed soft solder portions (preforms) are used for contacting in the injection mold.

10. The method according to any one of the preceding claims, characterized in that an electronic module (12 ') is used which has an external contact field (15) for galvanic connection and further contacts (17) for connection to the coupling means.