FR2790121A1 - Contactless object authentication device for jewelry has circuit buried flush in cavity formed in surface of object being authenticated - Google Patents

Abstract

A stationary device uses a coil emitting of electromagnetic energy and receiving of information. A built-in circuit (100) includes an electromagnetic energy receiving coil. The circuit (100) is buried flush an open cavity (201) formed in a surface of the object authenticated. The built-in circuit (100) has a surface area of a tenth of a square millimeter.

Description

NON-CONTACT ELECTRONIC AUTHENTICATION DEVICE

MINIATURISED

DESCRIPTION

  Technical Field The present invention relates to a miniaturized contactless electronic authentication device. It finds an application in the

  authentication of small objects, such as jewelry.

  State of the Prior Art Contactless electronic authentication devices are known, which can be seen in FIG. 1, comprising an integrated circuit (100), connected to a transmit and receive antenna (101), the 'assembly being placed on a support (102). The antenna (101) which is a coil, is in electromagnetic relation with another antenna which is also a coil, of emission and reception (103) connected to a fixed electronic terminal (104) supplying via electronic logic, the results of authentication. Often the fixed terminal (104) is connected to a computer (105) which processes the results. There are such devices

  described in patent application N 2 743 649 for example.

  Generally, the integrated circuit (100) and its antenna (101) are fixed on a support (102) which can be a label, the size of which is a few centimeters on the side. This label is then stuck on

the object to be authenticated.

  Very often also, the integrated circuit (100), and its antenna (101), are mounted on a support (102) of the credit card type, or of the transport ticket type. This is how devices have been developed for contactless reading of credit cards, identity cards and transport ticketing. The operation of these devices is well known to those skilled in the art: The antenna (103) of the fixed station, emits a wave

  electromagnetic, at a frequency often equal to 13.56 Mhz.

  The antenna (101) will receive part of this electromagnetic wave,

  which after rectification will supply electricity, the integrated circuit (101).

  The carrier frequency (13.56 MHz) is modulated in order to also transmit information to the integrated circuit (100), in particular a code which may include 32 bits, 64 bits, or 128 bits. Once detected, by the circuit (100) the code received, will be compared with a secret code, previously recorded in the integrated circuit. If the two codes are identical, then the integrated circuit will generate coded information, constituting the authentication of the object on which the label comprising the circuit

  has been attached, or the credit card, or the transport ticket.

  The distance which separates the antenna (101) from the antenna (103) can be of the order of a few centimeters to a few tens of centimeters. The electromagnetic power emitted by the antenna (103), is limited to 42 decibels / meter, for safety reasons, so that there is no risk for people who could cross the electromagnetic energy flow. 1 5 The size of the integrated circuit (100), for the smallest circuits is of the order of lmm x lmm. The antenna (101) associated, has a size of several square centimeters, in order to capture sufficient energy. The fixed antenna

  (103) is generally larger.

  Although satisfactory in certain respects, these devices according to the prior art, by their size, and by the structure of the integrated circuit (100), its associated antenna (101), and the support (102) which associate them , as well as the antenna (103), are not suitable for small objects,

such as jewelry for example.

  The object of the present invention is precisely to remedy these

disadvantages.

  Disclosure of the invention The device according to the invention comprises an integrated circuit incorporating a code, a comparison logic, a memory, means for receiving energy, and for transmitting and receiving information, including on its surface of a transmitting and receiving antenna, the total surface of the integrated circuit being of the order of a tenth of a square millimeter. The assembly is directly mounted without intermediate support, by means according to the invention, in the object to be authenticated. The integrated circuit is buried in the object, and protected by

  1 0 means according to the invention, against mechanical and chemical attack.

  A fixed terminal is connected to a device according to the invention making it possible to approach almost in contact with the integrated circuit the energy emission antenna, connected to this fixed terminal, comprising means for transmitting energy, for transmitting and receiving information. The frequency of the electromagnetic wave is high, so that the transmission yields are sufficient, taking into account the extreme small size

  of the antenna placed in the integrated circuit.

  More specifically, the present invention relates to a contactless authentication device, miniaturized, comprising an integrated circuit having a surface of the order of one tenth of a square millimeter, or approximately 0.3mm x 0.3 mm , comprising a micro-coil deposited in the surface of the circuit, covering all or part of this surface, a memory making it possible to store a code, a code comparison logic, a memory comprising information characteristic of the object to be identified, and finally means for transmitting and receiving information. The integrated circuit is fixed by means of gluing, or welding, without intermediate support, inside an open cavity, formed in the material of the object to be identified, so that the integrated circuit does not exceed not the surface in which the open cavity was made. The integrated circuit, once mounted, is protected by a

mechanical and chemical protection.

  The fixed terminal is connected to a device having the shape of a pen, of small dimension, - able to be approached almost in contact with the integrated circuit. When the object to be authenticated is a ring, the device must be able to penetrate inside the ring of the ring, where the integrated circuit carrying the authentication code is embedded. This device comprises a means for transmitting energy, as well as a means for transmitting and receiving information. This small device is connected to a fixed station which processes the information received. The frequency of the electromagnetic wave is greater than 500 MHz. The characteristics of the invention will appear better in light

of the description which follows.

Brief description of the drawings.

  * Figures 1, shows the devices according to the prior art.

  * Figure 2 shows, the assembly of the integrated circuit in the object to be authenticated, as well as its protection * Figures 3A and 3 B show the integrated circuit with its

  transmitting and receiving antenna.

  + Figure 4 shows the integrated circuit according to a preferred embodiment of the invention. * Figure 5 shows the device connected to the fixed terminal, with its energy transmission means, and transmission and reception

of information.

+ Figure 6 shows the assembly

  + Figure 7 shows the assembly in use.

  Detailed description of embodiments

  Figure 1 has already been described in the prior art.

  Figure 2 shows, the assembly of the integrated circuit (100) in the object

  to identify, which according to the example given, but not limiting, is a ring.

  Inside the ring, where the usual punches are placed, an open cavity (201) is produced by techniques well known to those skilled in the art, such as punching for example. The cavity (201) according to the invention has a dimension of the order of 350 microns by 350 microns, and a depth less than or equal to 200 microns. Is placed inside this cavity, the integrated circuit (100), having its active face which carries the transistors and the transmitting and receiving antenna, facing the open part of the cavity (201). Next, an encapsulation resin well known to those skilled in the art is placed in the cavity. According to a preferred embodiment of the invention, a glass powder melting at low temperature is placed in the cavity, forming a perfect seal around the integrated circuit (100). According to another preferred embodiment of the invention, a layer of a metal melting at low temperature and compatible with the metal of the object to be authenticated (200) is deposited at the rear of the integrated circuit (100). An annealing is then carried out, which, depending on the chosen encapsulant, will harden the resin for the first, will melt the glass or the metal for the second and the third. In all the cases described, the volume of the encapsulant and the position of the circuit (100) will be adjusted so that, once the encapsulation is complete, the surface covering the integrated circuit (100) does not exceed the surface in which the open cavity has been made. Once the encapsulation is complete, the integrated circuit is covered by a thin layer of a dielectric material, such as resin or glass, ensuring a perfect seal against mechanical and chemical attack. This layer, as shown in the section in FIG. 2, is at the same level or in slight depression relative to the surface in

which the cavity was made.

  With regard to jewelry, the skilled person who will practice encapsulation, will ensure that, for example by choosing the right colors of the encapsulant, or an adapted shape of the cavity, that once the '' operation completed, the appearance of the cavity including its integrated circuit,

  confuses with the other punches commonly used in jewelry.

  Figure 3A shows the integrated circuit (100) seen in perspective. The integrated circuit (100) uses the electromagnetic energy transmitted by the antenna connected to the fixed terminal, for its supply. There is a coil (300) deposited on the active surface of the integrated circuit (100). This coil will be used both to capture the electromagnetic energy from the antenna connected to the fixed terminal, and to transmit information from the integrated circuit (100). The coil (300) is produced in thin layers of aluminimu, gold, copper, according to microelectronic technologies, such as sputtering, vacuum deposition, or electrolysis. The coil can have a size of 200 µm x 200 µm, rectangular or circular in shape. It has a number of revolutions between 5 and 60. Its inductance is around 100 nil, and its resistance is around 20 ohms. An overvoltage coefficient of the order of 20 is therefore obtained, for an excitation carrier frequency of approximately 600 MHz, ie greater than 500 MHz. The coil is usually connected to a tuning capacitor. The capacity (301) adapted to the device according to the invention has a value of the order of picofarad, between 0.2 and 3 picofarads. It is carried out, according to known techniques of microelectronics, during the manufacture of the integrated circuit as shown in Figure 3 A. Figure 3 B shows the integrated circuit (100) seen in section. On the silicon substrate (304), all of the transistors constituting the integrated circuit have been produced, which are shown in section (302). We then find the capacity (301) and finally the coil (300). Figures 4A, 4B show another preferred embodiment of the invention. According to this preferred mode, the capacitor consists of the thin layer constituting the coil (300), which is isolated by a thin dielectric layer (401) preferably SiO2, from a ground plane (400) located under the turns of the coil, as shown in Figure 4A in perspective, and 4 B in section. The capacity is defined by the facing surfaces between the coil (300) and the conducting plane (400), as well as by the

  choice and the thickness of the dielectric (401) which separates them.

  In addition to the secret code recorded in the integrated circuit, a comparison logic, and transmission and reception means, the integrated circuit includes a memory which describes the characteristics of the object to be authenticated. For example jewelry, we will find in this memory, for example the percentage of pure gold, the weight, its date

  manufacturing, or any other indication useful for the characterization of the jewelry.

  FIG. 5 shows the device (500) connected to the fixed terminal (104), comprising its means for transmitting energy, transmitting and receiving information. It is in the form of a cylinder with a diameter of approximately 5 to millimeters, and a length of approximately 10 centimeters. It is connected to the fixed terminal (104) by a flexible cord. Its size and shape allow it to be easily manipulated by hand, in order to present it almost in contact with the integrated circuit (100), inside the ring when the object to be identified is a ring. The device (500) comprises means for emitting energy. The energy emission means comprise a coil (501) of up or a few millimeters on the side, consisting of a few tens of turns, connected to a high frequency current generator. The same coil (501) is also used for transmitting and

receipt of information.

  Figure 6 shows the assembly in operation. We find the object to be identified (200) which, according to the example chosen, is a ring. Inside the ring, we see the circuit (100) encapsulated, according to the invention, inside the ring when it is a ring, the device (500) connected by a flexible cord to the fixed terminal (104), comprising its means for generating energy, transmitting / receiving and processing information. It further comprises an acoustic means (600) which emits an audible signal as soon as a dialogue between the integrated circuit (100) and the device (500) has taken place. Finally, it includes the necessary means (601) for displaying information relating to the authentication of the object.

(200).

  FIG. 7 shows the use of the device according to the invention for authenticating jewelry, when the jewelry is ready for sale. In this case, the jewelry (200) is placed in a plastic envelope (701), often sealed, in order to avoid any degradation of the jewelry, in particular surface scratches. In this case, it is through the protective envelope that the device (500) performs the authentication, by deforming the plastic envelope, in order to be placed facing the cavity (201) comprising the integrated circuit (100 ), without opening this envelope,

as shown in figure 7.

Claims (11)

  1. A miniature contactless electronic authentication device, comprising: --- A fixed terminal (104) connected to a coil (501) for transmitting electromagnetic energy and transmitting and receiving information --- A integrated circuit (100) comprising a memory in which a code is recorded, means for receiving and transmitting information, a code comparison logic, the terminal (104) and the circuit (100) being able to exchange information, characterized in that the integrated circuit (100) has a surface less than or equal to one tenth of a square millimeter, that the coil (501) has a dimension of one to a few square millimeters, and that the coil (501 ) is positioned manually opposite the integrated circuit (100), to be placed almost in contact with it, during exchanges between the coil (501) and the circuit (100).   2. Contactless miniature electronic authentication device according to claim 1, characterized in that the transmission and reception coil (300) of the integrated circuit (100) is produced in the active surface of the integrated circuit (100).   3. Contactless miniaturized electronic authentication device according to claim 1, characterized in that the electromagnetic wave carrier emitted by the coil (501) has a higher frequency at 500MHz.   4. Contactless miniature electronic authentication device according to claim 2, characterized in that the tuning capacity (301) of the coil (300) of the integrated circuit (100) has a value between 0.2 and 3 picofarads.   5. Contactless miniaturized electronic authentication device according to claim 4 characterized in that the tuning capacity (301) is constituted by two frames, one being the coil (300), the other a conducting plane ( 400) located under the coil (300) and separated from it by a dielectric. 6. A miniaturized contactless electronic authentication device according to claim 1, characterized in that the memory of the integrated circuit (100) includes information describing the characteristics of   the object to be authenticated in which the integrated circuit (100) is encapsulated.   7. contactless miniaturized electronic authentication device according to claim 1 characterized in that the integrated circuit (100) is encapsulated in an open cavity (201) made in the material of the object to be authenticated, the active face of the circuit integrated which features the   coil (300), being oriented towards the open part of the cavity (201).   8. miniaturized contactless authentication device according to claim 7, characterized in that the integrated circuit (100) is encapsulated in the open cavity (201) by resin, low temperature glass solder, or low temperature metal solder, and covered with a dielectric protective layer against   mechanical and chemical attacks.   9. Contactless miniaturized electronic authentication device,   according to any one of claims 1 to 8, characterized in that the   cavity including the integrated circuit resembles a punch like those used to mark jewelry, and is located among standard punches,   commonly practiced on the object to be authenticated.   10. Contactless miniaturized electronic authentication device,   according to any one of claims I to 9, characterized in that it   is applied to jewelry authentication.   11. Contactless miniaturized electronic authentication device according to claim 10, characterized in that the authentication is carried out through the sealed plastic envelope which protects it, when the hijoux is ready for sale.