FLAT SUBSTRATES FOR IDENTIFICATION CARDS AND MANUFACTURING METHODS OF THE SAME

FIELD OF THE INVENT ION The instant invention relates to f lat substrates for identi f ication cards , manufacturing methods of the same , and antennas for contactles s RFI D card .

BACKGROUND OF THE INVENT ION

The present invention relates generally to a flat substrate for an identification card, and cards comprising the same. It further relates to a manufacturing method of such flat substrates and cards. Identification cards having dual functionalities of RFID and smart card (also called combi cards) come in a variety of formats, but generally comprise a separate antenna element and smart card element. These cards are generally formed using lamination techniques to form typically four layers comprising the antenna and the chip for the smart card.

This manufacturing technique however is laborious and inefficient as the separate lamination need be manufactured separately, carefully aligned and processed into conventional cards.

Furthermore, these pieces are rigid and do not lend themselves to easy handling or continuous high speed roll- to-roll processes.

SUMMARY OF THE INVENTION

The present invention seeks to mitigate these drawbacks by proposing a substrate that is more efficient to manufacture . The invention thus relates to a flat substrate for an

identification card, made of a flexible material and having two opposite main faces, the flat substrate comprising: a loop shaped antenna for contactless communication, disposed on at least one main face, and - a plurality of contacts for establishing, on one of said two main faces, an electrical connection by contact with a card reader terminal .

These dispositions permit high-speed production using reel- to-reel technology, thanks to the flexible nature of the flat substrate.

Furthermore, the substrate made of a single layer of polymeric material permits easier manufacturing and disposal of the substrate. In some embodiments, one may also use one or more features corresponding to claims 2 to 9.

According to other aspects, the invention is a SIM-format card or an ISO-format card, for instance an injection molded card, comprising the flat substrate of the invention . According to another aspect, the invention is a phone comprising SIM-card reader terminals and a SIM-format card, wherein the contacts of the SIM-format card are electrically connected by contact with the terminals of the SIM-card reader, the antenna providing contactless communication of the phone.

According to another aspect, the invention relates to a method of manufacturing a flat substrate destined for an identification card, comprising the following steps: -providing a flexible material having two opposite main faces,

-forming a loop shaped antenna for contactless communication, disposed on at least one main face; -forming a plurality of contacts for establishing an electrical connection by contact with a card reader terminal on one of said two main faces.

In some embodiments, one may also use one or more of the features of claims 15 to 20.

According to another aspect, the invention relates to an antenna for a contactless-card RFID reader, the antenna having a first loop portion adapted for contactless communication with an antenna suitable to be borne by an ISO-format card, and a second loop portion adapted for contactless communication with an antenna suitable to be borne by a SIM-format card, said first and second loop portion having dissimilar loop dimensions and being electrically connected to one another. For instance, the first loop portion may be about of the dimensions of an ISO-format card and the second loop portion may be about the dimensions of a SIM-format card. According to another aspect, the invention relates to a system comprising such an RFID antenna.

BRIEF DESCRIPTION OF THE DRAWINGS

Other characteristics and advantages of the invention will readily appear from the following description of two of its embodiments, provided as non-limitative examples, and of the accompanying drawings . On the drawings :

-Fig. 1 is a lateral schematic view of an installation of manufacture of flat substrates according to one embodiment of the invention,

-Fig. 2 is a partial view of a ribbon comprising a flat substrate obtained from the installation of Fig. 1,

-Fig. 3a is a perspective view of the top face of an individual flat substrate,

-Fig. 3b is an exploded perspective view of the back face of the flat substrate of Fig. 3a and a chip for connection to the flat substrate,

-Fig. 4 is a sectional view of Fig. 3a, -Fig. 5 is a perspective exploded view of an ISO-

format card incorporating the flat substrate of Fig. 3a and 3b, and

-Fig. 6 is a plan top view of an RFID-Tag according to an embodiment of the invention. On the different figures, the same reference signs designate like or similar elements .

DETAILED DESCRIPTION

On Fig. 1, an apparatus 1 is shown for continuous high-speed manufacturing of electronic parts. The apparatus 1 comprises a treatment enclosure 2 for the treatment of a flat substrate 3 continuously unwound from a take-off roll 4 and wound ontO an intake roll 5. The flat substrate is a flexible substrate comprising a layer of dielectric polymeric material, for example glass epoxy material, the thickness of which is suitable for being wound and unwound as shown, while ensuring to stay mechanically viable during the manufacturing process. For example, the layer of dielectric material has a thickness of between 50 an 250 micrometers. In some embodiments, the thickness is chosen between 75 and 110 micrometers, for example 100 micrometers.

The flat substrate 3 further comprises a layer of copper on both sides of the layer of epoxy material. The layers of copper are for example each between 10 and 50 micrometers thick, for instance 35. These layers of copper may for example be applied on the epoxy layer as a first manufacturing process step in enclosure. The treatment enclosure is suitable for continuously treating the above-described flat substrate 3 into an electronic component. It may comprise a plurality of treatment chambers in series for performing various manufacturing steps on the substrate. These steps are in their principles well known from the one skilled in the art. These steps include for example etching the copper

layer and Nickel-Gold metallisation by electrolytic deposition, on one or both faces of the flat substrate. For instance, the antenna tracks resulting from etching are of about 125μm width and about 250μm spaced apart at the closest. When exiting the treatment enclosure 2, the flat substrate is sensibly as shown on Fig. 2 according to this embodiment of the invention. It comprises a plurality of juxtaposed modules 6 which will later be separated into individual modules for manufacturing individual cards. For example, individual modules of the size of a SIM-format card (15x25 millimetres) are formed.

As shown in a general manner on Fig. 2 and in more detailed manner on Fig. 3a and 3b, each of these modules comprises contacts 7 suitable for establishing an electrical connection by contact between the card which will comprise the flat substrate 3 and a terminal of a complementary contacting card reader outside the card. For example, each of the contacts 7 has a rectangular shape and the whole contact area forms a rectangular footprint. An antenna 8 is provided in the module. The antenna is provided with a number of turns suitable for contactless communication with a suitable contactless complementary device at a distance of at least four centimetres. For example, the turns are disposed on the main face 10a of the flexible flat substrate 3 receiving the contacts, or on the opposite main face 10b. In order to integrate even more turns in a substrate of a size as low as the size of a SIM- format card, the antenna could be provided, as in the embodiment shown on Fig. 3a, 3b and 4, in the form of a first loop 8a on the main face of the substrate 3 which receives the contacts 7, and a second loop 8b provided on the opposite face. The first loop is mainly provided side by side with the contacts 7, and wires 9 extend from the first loop to be connected to some of the contacts 7. Possibly, some turns are provided around the contacts 7 for

increasing the length of the antenna. As shown, the second loop is directly opposite the first loop. Some turns of the second loop could also extend around the chip (not shown) . The two loops 8a and 8b are electrically connected together through metallised holes 11 extending through the layer of epoxy material.

As shown on Fig. 3b, connecting features 12 are provided on the back main face lob of the substrate for connection of the chip 13. These connecting features are for example blind holes formed in the back main face of the substrate, and electrically connected by a conductive layer to the contacts 7 through the remaining thickness of epoxy material. The chip is also connected to the antenna, which is connected to at least two of the contacts at its extremities. The substrate as shown on Fig. 3a and 3b, with its integrated chip, can be readily integrated into a SIM

(Subscriber Identity Module) -format card by injection moulding. The obtained SIM-format card can be readily inserted into a mobile phone comprising a card reader comprising terminals contacting the contacts 7 of the SIM- format card for enabling use of the mobile phone. Further, the mobile phone comprising the SIM-format card of the invention will provide contactless communication to some adapted contactless complementary reader antenna external to the phone through the antenna provided on the SIM-format card.

According to another embodiment as shown on Fig. 5, the manufactured flat substrate of Fig. 3a and 3b can be integrated into an ISO-format card of standard dimensions 86x54 millimetres. This integration may be performed in a standard way such as by injection moulding or by laminating two PVC sheets 15. A window 16 is provided in one of the PVC sheets 15 for enabling contact of the contacts 7 with a complementary contacting reader. For either the described SIM-format card or the ISO-format

card of Fig. 5, or any other card obtainable from the flat substrate of Fig. 3a and 3b, contactless communication is performed by communication with a complementary RFID antenna. Although any kind of existing RFID antenna would be suitable for contactless communication with such a card, Fig. 6 provides with an example of an RFID-antenna 17 which is expected to be particularly suitable for a good contactless communication with both the cards integrating the above-described flat substrates and most of the already-existing contactless cards which are most often ISO-format cards. The RFID-antenna 17 of Fig. 6 comprises a first loop 18a which corresponds to about the dimensions of the ISO-format card. The reader antenna 18 further comprises a second loop 18b connected to the first loop 18a and encompassed in a rectangle of the size of a SIM-format card. This antenna provides with a good magnetic coupling both with regular ISO-format RFID cards (or dual cards) and with SIM-format cards as described above. A mark can be performed on a cover sheet that covers the antenna 18, at the place where the first and/or the second loop is designed, so that the user will identify how he should place his/her contactless-card/phone for a better coupling with the reader.