DE29623930U1 - Integrated circuit paper - Google Patents

Description

Paper with integrated circuit Description

The present invention relates to an integrated circuit paper.

In general, there is a considerable interest in protecting legally relevant documents from unlawful copying. Various measures are used in the state of the art to achieve this protection. One measure, for example, is to use a special, manufacturer-specific paper that is protected from imitation by its manufacturing measures and is only distributed under controlled conditions. The most common paper of this type is banknotes, which are protected from counterfeiting by watermarks, UV-reflecting particles, magnetic printing inks and a metal thread. Similarly protected paper of this type is used in the financial sector and in contracts and includes, for example, checks or mortgage bonds.

The purpose of the protective measures mentioned above is to make the production of counterfeits technically impossible or at least unprofitable. Furthermore, they should be easy to verify and control.

Historically, the protective measures implemented to date reflect the respective state of technical development and are based either on local variations in paper production (watermarks, texture, impurities) or in printing technology (colours, fine patterns below the level of copyability).

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EP 0564051 A1 relates to an identification card with a reusable inner part, in which a card has a reusable part and a replaceable housing. The reusable part consists of a plastic card which contains an electronic circuit and an antenna in the form of a coil. This electronic circuit with the antenna enables contactless information exchange. The card can be programmed before or after arranging the inner part within the housing, and the replaceable housing comprises a plastic frame and further two thin plastic films.

DE 41 2 0 2 65 A1 relates to a card without connection contacts with an integrated circuit. The integrated circuit comprises a CPU as well as a plurality of memories and an input/output control circuit. The integrated circuit is provided on a substrate and the card is formed by applying an outer shell which encloses the integrated circuit.

DE 42 24 390 A1 describes a contactless portable carrier which comprises a voltage supply receiving device for contactlessly receiving a supply voltage from a connection unit.

DE 42 26 396 A1 relates to a security system with a card in which an integrated semiconductor chip is arranged within the card, in which the identification characters are fixed in an unchangeable manner during production. A conventional credit card comprises a magnetic strip as well as a readable chip 3.

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DE 43 11 385 A1 relates to an identification card with an intelligent memory chip and means for contactless data exchange. This card includes an optical sensor that blocks or limits data exchange without optical influence.

DE 3687330 T2 deals with a code system for a locking device that uses an M-conversion alloy. A card body that contains the other electronic elements of the code system must be made of a material, e.g. paper, that has sufficient self-supporting properties within the temperature range in which the M-conversion alloy used operates.

Based on this prior art, the present invention is based on the object of creating a novel paper.

This object is achieved by a paper according to claim 1.

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The advantage of the present invention with regard to forgery security is that it opens up the possibility of carrying out so-called crypto-programming of the integrated circuit.

A further advantage of the present invention in terms of increasing security against counterfeiting is the complexity of the manufacturing process. Despite their low price, the integrated circuits used with the present invention require a large number of process steps (many hundreds) and modern techniques in their manufacture, which significantly increases security against counterfeiting.

A further advantage of the present invention is that the invention creates an "electronic" paper which includes a particularly simple, contactlessly interrogable integrated circuit which tolerates printing treatment of the paper and which can be advantageously used for numerous applications, in particular identification and authorization systems.

Preferred developments of the present invention are defined in the subclaims.

In the following, preferred embodiments of the present invention are described with reference to the accompanying drawings

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described in more detail. Shown are:

Fig. 1 is an isometric plan view of the base material according to the invention; and

Fig. 2 is an enlarged cross-sectional view of the base material from Fig. 1 along the line II-II.

The present invention is described in more detail below with reference to Fig. 1. In Fig. 1, the base material according to the invention is provided with the reference number 100. As indicated by the dashed lines in Fig. 1, at least one integrated circuit 102, in the embodiment according to Fig. 1 two, is enclosed in the base material 100. The base material 100 is, for example, paper in which the integrated circuits 102 are enclosed. These integrated circuits 102 are so-called contactless interrogable circuits, which are also known under the name identification circuits or transponders. The circuit 102 can, for example, contain a programmable number combination that can be supplied with energy and read out in a few milliseconds by an external reader (not shown).

According to a preferred embodiment of the present invention, the integrated circuit 102 is embedded in the paper pulp.

The integrated circuits used in the present invention are commercially available integrated circuits of extreme thinness. At present, integrated circuits with residual thicknesses in the range of 60 μηι to about 10 μηι can be realized. Such circuits, which have a thickness of about 10 μια, are flexible within certain limits, but are also at risk of breakage due to their crystallinity. In order to increase the mechanical stability of the integrated circuit 102, it can be laminated onto a rigid carrier 104, as shown in Fig. 2. This

The rigid carrier can be, for example, an organic film or a metal foil. Common processes for this construction technology are known from chip card production, for example.

In a preferred embodiment of the present invention, an integrated circuit 102 is produced using known silicon technology methods in which a multi-digit code is stored by appropriate programming. This integrated circuit 102 also has all the necessary elements for contactless querying. In integrated circuits of this type that have already been implemented, special transmission methods are provided for the data and the energy transfer for the power supply for contactless bidirectional communication between a read/write device and the integrated circuit. In such integrated circuits, data transmission takes place by modulating an alternating voltage inductively or capacitively. The operating voltage for a microcontroller and a memory of the integrated circuit is recovered from an induced voltage using an interface. The interface also serves to provide the data stored in the memory, such as the code and the system clock. In addition to reading the integrated circuit inductively or capacitively, this reading can also take place using light. In a preferred embodiment of the present invention, the memory provided in the integrated circuit is a so-called ROM memory.

In a further preferred embodiment of the present invention, bidirectionality is not required. For integrated circuits that have an embossed identification number, a unidirectional connection is sufficient. Such integrated circuits are manufactured as chips, on the surface of which, for example, a miniaturized coil for inductive transmission is contained. Such chips are available with edge lengths of significantly less than 1

mm. In order to embed these chips in the base material, they are thinned to a few 10 μm and embedded during the production of the paper webs or introduced into the base material by gluing two sheets of paper together. The thinning just mentioned is carried out by grinding, etching or other methods known in specialist circles" and is therefore not described separately here. As already mentioned above, the thinning of these chips leads to a deterioration in their mechanical stability, so that stabilization is necessary. In order to increase the mechanical stability of these chips, they are laminated to a carrier, for example using an organic adhesive. This carrier can be, for example, a metal foil, which for reasons of mechanical handling is preferably a ferromagnetic foil, such as made of steel or nickel. In particular, if the base material is paper, it is necessary to protect the chips for further processing during paper production or packaging. This is done by means of a chemically resistant passivation layer 106 (see Fig. 2), which resists the influence of liquids, bleaching agents, light, the printing process, etc., and thus protects the chips and thus the integrated circuit.

According to a preferred embodiment, the integrated circuits, which are also referred to as micro-modules, with typical dimensions of approximately 800 x 800 x 50 μm, are integrated in the paper manufacturing process. The micro-modules are completely embedded in the paper pulp, from which certain requirements are derived for their chemical, thermal and mechanical resistance.

By using the ferromagnetic carrier on which the integrated circuits are arranged, the handling of the micro-modules during placement, horizontal alignment parallel to the paper surface and, if necessary, during removal from the paper pulp during recycling is significantly simplified.

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The same applies to the localization of the embedded chips, which is necessary for the positioning of the readout process, which is only effective over a few mm to cm.

As already mentioned above, in the simplest case, only chips are used that contain a mask-programmed ROM and can only be read. If the base material is paper, a defined production number can be engraved on the chips, which can also contain the date or series of manufacture and other specifications.

However, the present invention is not limited to the use of unidirectional integrated circuits, but bidirectional chips can also be used, which allow a user to program the chip with a personal code number. Absolutely forgery-proof crypto programming techniques that are known from chip card technology already exist to prevent unauthorized writing. It should be noted that the use of programmable chips will not be used in the field of increased forgery security of banknotes, checks, mortgage bonds, etc., since in this field it is undesirable for individual end users to have the option of entering their personal codes or identification numbers into such chips. The use of bidirectional chips for programming personal code numbers or identification numbers is particularly advantageous in the case of "electronic" paper, which is used, for example, in conjunction with identification and authorization systems. In general, it can be said that the technical significance of the "electronic" paper described above goes far beyond the aspects of pure forgery security. In principle, the base material according to the invention represents a particularly simple, printable, contactless interrogable integrated circuit that has a wide range of possible applications.

In addition to the possibility of so-called crypto-programming, the security of the circuits is primarily due to the complexity of the manufacturing process of the integrated circuits used with the base material. Despite the comparatively low integration density and the resulting low price of less than 0.50 DM for a micromodule, the integrated circuits described above are the product of many hundreds of process steps that require the most modern technology, which will require considerable investment in the foreseeable future and thus only exist in very limited, manageable numbers. The integrated circuits are therefore largely forgery-proof; security is increased considerably by the embedding of the micromodules in the base material or paper and the resulting lack of access, at least not without destructive means.

A further advantage of the present invention is that the engraved code number can be read quickly and fully electronically.

A disadvantage of the protection methods known in the state of the art, such as watermarks and surface texture, UV or magnetic inks, chemical additives, metal threads, etc., is that they can be counterfeited with comparatively easy effort and, in addition, offer little possibility of distinction or differentiation.

Although the figures describe an embodiment in which two integrated circuits are embedded in a base material, only a single module can be used, or a plurality of modules can be implemented in a single piece of paper for redundancy reasons. This ensures that at least some of the modules survive the processing of the paper or the base material and the subsequent treatment in a functional manner.

The inductive query described above is, among other things,

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a function of the dimensions of the coil arranged on the chip. The transmission properties of this coil can be improved by using the ferroelectric carrier described above, and amplification and energy concentration by ferrite coatings is also possible.

If transmission over longer distances is desirable, antennas, coils with a larger wrap area or dipoles can be arranged on the chip in the known manner.

An embodiment that is particularly applicable to banknotes can be based on the integration of the chip in the already existing metal thread, which can be designed as a dipole for this purpose and enables the transmission of information in the meter range.

According to a further embodiment of the present invention, an "intelligent" electronic paper is created which includes an embedded bidirectional chip. In this embodiment, the embedded bidirectional chip is written to via an interface, for example with the content of the text printed on the paper, so that this text is also available in electronically readable form. It is obvious that other information can be stored on the chip instead of or in addition to the text printed on the paper, which information should not be readily visible to unauthorized persons, for example. This information includes, for example, details about the time of the last writing or the last storage.

Claims (17)

1. Paper with an integrated circuit ( 102 ) which contains predetermined data, can be read out without contact and is embedded in the paper mass in a non-detachable manner, wherein the integrated circuit ( 102 ) has a thickness which is small compared to the thickness of the paper ( 100 ) and is embedded in the paper mass in such a way that the paper can be treated by printing technology, with a passivation layer ( 106 ) which at least partially surrounds the integrated circuit ( 102 ). 2. Paper according to claim 1, wherein the integrated circuit is embedded in the paper pulp by laminating between two sheets of paper. 3. Paper according to claim 1 or 2, wherein the integrated circuit is between 10 µm and 60 µm thick. 4. Paper according to one of claims 1 to 3, wherein the integrated circuit ( 102 ) can be read capacitively, inductively or by means of light. 5. Paper according to claim 4, wherein the inductive or capacitive reading of integrated circuits includes a modulation of an alternating voltage. 6. Paper according to claim 4 or 5, wherein the integrated circuit ( 102 ) has an interface which derives from an induced voltage an operating voltage for a microcontroller and a memory which are included in the integrated circuit ( 102 ). 7. Paper according to claim 6, wherein the memory is a ROM memory. 8. Paper according to one of claims 1 to 7, with a rigid carrier ( 104 ) on which the integrated circuit ( 102 ) is arranged in order to increase the mechanical stability of the latter. 9. Paper according to claim 8, wherein the rigid carrier ( 104 ) is a metal foil consisting of a ferromagnetic material. 10. Paper according to one of claims 1 to 9, wherein the integrated circuit ( 102 ) is designed to enable bidirectional communication so that the integrated circuit is programmable, whereby the predetermined data is changeable. 11. Paper according to one of claims 1 to 10, wherein the predetermined data includes a multi-digit identification number. 12. Paper according to one of claims 1 to 11, wherein the integrated circuit ( 102 ) has a dimension of approximately 800 × 800 × 50 µm. 13. Paper according to one of claims 1 to 12, wherein the integrated circuit ( 102 ) is in the form of a chip having an edge length of less than 1 mm. 14. Device according to one of claims 1 to 13, wherein the integrated circuit ( 102 ) is designed to enable uni-directional communication. 15. Paper according to one of claims 1 to 14, wherein the paper is a banknote. 16. Paper according to one of claims 1 to 15, wherein the integrated circuit ( 102 ) is thinned to the desired thickness by grinding. 17. Paper according to one of claims 1 to 16, wherein a plurality of integrated circuits are arranged in the paper.