HK1134959B - Radio frequency identification device medium and method for making same - Google Patents

Description

RFID device carrier and method of making the same

Technical Field

The present invention relates to rfid devices designed for construction into target objects such as security documents, and in particular to rfid device carriers and methods of manufacture thereof.

Background

Contactless Radio Frequency Identification Devices (RFID) are increasingly being used to identify people moving in areas where access is controlled or moving from one area to another. The contactless RFID is a device constituted by an antenna and a chip connected to a terminal of the antenna. The chip is normally not powered and receives its energy through electromagnetic coupling between the antenna of the reader and the antenna of the RFID, information being exchanged between the RFID and the reader, in particular information stored on the chip relating to the identity of the holder of the target object in which the RFID is located and information relating to authorizing his/her entry into the area whose access is controlled.

In this way, the passport may incorporate an RFID to identify the passport holder. The chip memory contains information such as the identity of the passport holder, his/her place of birth, his/her nationality, visas of different countries visited, date of entry, activity restrictions, biometric elements, etc. The RFID device is typically incorporated into the bottom cover sheet of the passport. The antenna is then screen printed onto the reinforced bottom cover sheet of the passport using an ink containing silver particles. The chip is then connected to the connection terminals of the antenna by gluing. The flyleaf of a passport sheet is then laminated to the back of the reinforced cover sheet. This embodiment has a disadvantage in that it is not waterproof and, in particular, passports cannot withstand passing through a washing machine. If the paper onto which the antenna is screen-printed is not waterproof, the latter will absorb water and swell, which leads to a break of the antenna and thus to a break of the electrical connection between the antenna and the chip.

This problem can be overcome by using RFID devices that are comprised of plastic "inlays". In this case, the inlay contains the antenna and the chip, the entire assembly being embedded in a plastic layer. The inlay is then bonded between the flyleaf and the passport cover. One drawback of such RFID devices is the difference in materials between the inlay and the passport. The latter are made of plastic, the adhesion between the two being not optimal.

The use of an RFID carrier having at least one of its outer sides made of paper allows this disadvantage to be overcome.

The problem with using paper depends on its ability to delaminate through its thickness in the event that it is attempted to pull it out. Delamination may also occur on the edges of the carrier after a certain period of use, which is absolutely a disadvantage when it is desired that the carrier is used in a security document whose lifetime must extend over several years.

Furthermore, a security document like a passport also means that the passport sheet and the cover carrying the RFID device will be subjected to influences due to lamination or sticking of visas, which entails a great risk of the electronic chip being destroyed.

Disclosure of Invention

The object of the present invention is therefore to solve these drawbacks by providing a radio frequency identification device carrier which has a good adhesion to the adhesion of paper and no longer delaminates in thickness and protects the RFID device from the risk of damage caused by impacts or blows.

It is therefore a further object of the present invention to provide an identity booklet such as a passport integrated with such a radio frequency identification device.

The object of the invention is therefore a radio frequency identification device characterized by a chip having an antenna screen printed on a carrier and connection terminals connected to the antenna. According to a main feature of the invention, a layer of thermoplastic and a top layer of synthetic paper are laminated on an antenna carrier to obtain an RFID device that is water and moisture resistant, so that the antenna and the chip are confined in the thermoplastic and so that the three layers cannot be separated.

Another object of the invention relates to an identity booklet comprising a Radio Frequency Identification Device (RFID) carrier according to the first object of the invention.

Finally, another object of the invention relates to a method for manufacturing a Radio Frequency Identification Device (RFID) carrier, said device being characterized by an antenna and a chip connected to the antenna, the method comprising the steps of:

-screen-printing an antenna, the antenna being characterized by having contacts on a carrier,

-placing an adhesive dielectric material between the contacts of the antenna,

-placing the chip on the carrier such that the contacts of the chip face the contacts of the antenna,

-connecting the chip to the contacts of the antenna by exerting pressure on the chip,

-placing on a carrier a layer of thermoplastic and a top layer of non-melting material, such as synthetic paper, which top layer has a cavity at the location of the chip,

-laminating the carrier, the thermoplastic layer and the top layer together.

Thereby obtaining an RFID device that is water and moisture resistant such that the antenna and chip are confined within the thermoplastic and such that the three layers cannot be separated.

Drawings

The objects, objects and features of the present invention will become more apparent from the following description when taken in conjunction with the accompanying drawings, in which:

figure 1 shows a front view of an antenna carrier to which an RFID device is adhered,

figure 2 shows a cross-sectional view of an antenna carrier to which an RFID device is adhered,

figure 3 shows a cross-sectional view of the various layers that make up the RFID device carrier,

figure 4 shows a cross-sectional view of an RFID device carrier according to the invention,

figure 5 shows the mounting of the RFID device carrier on the cover of an identity booklet,

figure 6 shows a cross-sectional view of the cover of the booklet and the mounting of the RFID device carrier,

figure 7 shows a cross-sectional view of an RFID device carrier according to a variant of the invention,

figure 8 shows a cross-sectional view of the cover of the booklet and the mounting of the RFID device carrier according to this variation,

fig. 9 shows a knife attachment of an inner page of the booklet.

Detailed Description

Referring to fig. 1, the first layer 20 is used as a carrier for the antenna and has dimensions corresponding to those of a closed passport, that is to say approximately 88 x 125 mm. The material of layer 20 is a non-melting material and therefore does not deform irreversibly when the temperature is raised. The material of layer 20 is preferably one whose adhesion does not change much during the thermal lamination operation performed when pressure is applied. The antenna 12, an important element of an RFID device, is made up of one or more turns that are screen printed using a conductive polymer ink containing a conductive element such as silver, copper or carbon. Each end of the antenna is connected to one of the two contacts 17 and 19 of the antenna, which are also screen printed. The turns are interconnected by a bridge 21, most commonly referred to as "crossover". A dielectric ink insulating strip 23 is screen printed between the crossover and certain turns of the antenna 12 to allow the turns of the antenna to overlap without electrical contact. According to a preferred embodiment of the invention, the antenna is screen printed onto the material in several steps. The first step is to screen print the turns of the antenna 12 and the two contacts 17 and 19 of the antenna. The second step is to screen print a dielectric strip 23 to allow the turns of the antenna 12 to overlap. The third step is to screen print the bridge 12 which connects the outermost turns of the antenna 12 of the wire turn set.

The next step is to connect the chip to the contacts of the antenna 12. An adhesive dielectric material is disposed on the antenna carrier 20 between the two contacts 17 and 19 of the antenna 12. The adhesive material is applied before the chips are placed on the carrier, unlike the conventional "flip chip" process in which adhesive is applied as soon as the chips are connected. This step is therefore simpler to perform and the output results are better. The adhesive used is preferably an epoxy resin which crosslinks at 150 ℃. It is also possible to use a glue of the cyanoacrylate type, which polymerizes at room temperature.

Once the adhesive material has been applied, the chip 10 is placed on the antenna carrier so that the contacts 17 and 19 of the chip are opposite the contacts of the antenna, as shown in the cross-sectional view in fig. 2. Pressure is then applied to the chip 10 so that the non-deformable contacts of the chip sink into the contacts 17 and 19 of the antenna 12. Under the applied pressure, the contacts of the antenna are then deformed. Under the pressure exerted on the chip, the carrier 20 of the antenna is compressed and can also be deformed. It is then noted that the contact surface between the contacts of the chip and the contacts of the antenna 12 is maximal, even when no more pressure is applied. The contacts of the chip are preferably conical in shape. As a result of this pressure, the adhesive dielectric material 20 spreads out and covers the entire surface of the chip between the contacts and penetrates to the depth of the antenna carrier. This therefore allows the mechanical assembly between the chip 10 and the antenna carrier 20 (and thus also the electrical contact between the chip and the antenna) to be enhanced. The adhesive dielectric material used is preferably liquid and has a strong permeability. The support is then passed through an oven to achieve cross-linking of the viscose.

Once the chip 10 is secured to the carrier, the next step is to laminate together the RFID device and the layers that will make up the RFID device carrier. The described embodiments are adapted such that the obtained RFID device carrier can be manufactured as an identity booklet like a passport.

According to this preferred embodiment of the invention, the layers making up the RFID device carrier as shown in fig. 3 include an antenna carrier 20, a thermoplastic layer 22 and a top layer 24.

Once the chip is fixed on the antenna carrier 20, the device is made by laminating the layers. A first layer of thermoplastic 22 is placed on the antenna carrier 20. The thickness of the thermoplastic layer is between 40 and 80 μm and preferably in the order of 50 μm. The top layer 24 features cavities 26 that are positioned in such a way that it overlaps the chip and has a surface area that is larger than the surface area of the chip so that the pressure applied during the lamination step does not reach the chip because the pressure is applied uniformly over the entire surface of the sheet, but not at the location of the cavities above the location of the chip. The cavity 26 is preferably circular with a diameter of the order of 6 mm.

The lamination step comprises soldering by hot press moulding of the layers 20, 22, 24 in order to obtain the RFID device carrier 2 shown in fig. 4. The temperatures and pressures reached are of the order of 160 ℃ and 200bar, respectively. As previously described, the antenna carrier 20 is preferably made of a material that does not melt and therefore does not deform irreversibly when the temperature is raised to 160 ℃. Furthermore, the material cannot delaminate over time, whether intentional or not. The carrier 20 is preferably made of synthetic paper comprising between 40 and 80% mineral of a single polymeric non-oriented layer of polyethylene or polypropylene. Its component provides it with 0.57g/m³Due to its microporous network and its thickness of the order of 180 μm. The thickness may be smaller without departing from the scope of the invention. Even if the thermoplastic layer 22 in direct contact with the chip is not penetrated by the cavity at the location of the chip, the pressure applied during lamination is not transmitted to the chip to such an extent that it is destroyed.

At the temperature and pressure values used during the lamination step, the thermoplastic comprising layer 22 softens and melts when sandwiched between the two respective layers of antenna carrier 20 and top layer 24. During lamination, the antenna carrier provides a device consisting of the antenna 10 and the chip 12, with a stiffness and adhesion that prevents any electrical rupture, since the material forming the layers of the antenna carrier is resistant to deformation and does not creep, in particular at the temperature and pressure of the lamination step. The hardened thermoplastic layer 22 limits the protrusion design of the antenna carrier 20 so that the antenna 10 and the chip 12 are embedded in the thermoplastic 22. The cross-section of the layers 20, 22, 24 shows that the antenna 10 and the chip 12 are moulded into a thermoplastic 22 which has covered the chip at the location of the cavity 26. In this way, it is the thermoplastic layer that provides the RFID device carrier with a stiffness and adhesion that resists any electrical cracking in a humid environment. The thermoplastic enables the two layers 20 and 24 to be welded together and acts as a glue between the two layers.

The top layer 24 having a thickness of 180 μm is preferably of the same material as the antenna carrier 20 and is thus a synthetic paper as described above. The RFID device carrier 2, which is made by laminating the layers 20, 22, 24 and is shown in cross-section in fig. 3, has a thickness of about 350 μm.

The flexibility of the RFID device carrier 2 depends on the thickness of the thermoplastic layer 22 used. The more the thickness of the thermoplastic layer is reduced, the more flexible the RFID device carrier.

According to fig. 5, the RFID device carrier 2 is glued to one of the two cover sheets 11 of the identity booklet, preferably to the bottom cover sheet 14, but may also be glued to the top cover sheet 16. The side of the RFID device carrier opposite the antenna carrier and chip and thus layer 24 is glued to the cover sheet of the identity booklet to try to protect the chip from impacts that may occur inside the booklet. More generally, the RFID device carrier 2 is glued using a glue that, once dried, cannot be dissolved in water.

In order to maintain the same thickness throughout the cover of the booklet, one or more carriers 3 formed to have a total thickness equal to that of the RFID device carrier 2 as shown in fig. 6 are affixed to the other cover sheet of the booklet that does not carry the RFID device carrier. The carrier 3 is therefore preferably of the same size as the device carrier 2. For example and according to fig. 6, such a carrier 3 can be manufactured: the RFID device is not constructed from a single layer of synthetic paper 50 or alternatively a synthetic paper layer, a thermoplastic layer and another synthetic paper layer may be laminated together, the thickness of the single layer or the total thickness of a group of layers being the same as the total thickness of all of the layers 20, 22 and 24. The support 3 thus produced is then glued to the second cover 11 of the booklet, leaving a free strip of the cover at the joining point of the booklet.

According to a variant of the invention, the carriers 2 and 3 may be manufactured together with a single top layer of synthetic paper 64 to be joined to each other to form an RFID device carrier 4 as shown in fig. 7. A first layer of thermoplastic 22 is placed on the antenna carrier 20 with a thickness between 40 and 80 μm but preferably in the order of 50 μm. A second layer of thermoplastic is also placed on the second layer 60 of synthetic paper. The width of the same size layers 20, 22, 60 and 62, having a length comparable to the size of the closed identity booklet, is slightly less than the width of the nearest identity booklet. Top layer 64 is placed over layers 22 and 62 such that a space is left between them. Layer 64 is characterized by a cavity 26 which is placed in such a way that it overlaps the chip and has a surface area which is larger than the surface area of the chip, so that the pressure applied during the lamination step does not reach the chip, because the pressure is applied uniformly over the entire surface of the sheet, but not at the location of the cavity located above the location of the chip. The cavity 26 is preferably circular with a diameter of the order of 6 mm. The laminating step includes welding by thermo-compression molding of the layers 20, 22, 60, 62 and 64.

A carrier 4 for use as an RFID device carrier for the variant of the invention is shown in cross-section in fig. 8. It has the same dimensions as the size of an open identity booklet and comprises two thickness sections 42 and 43, the section 42 containing the RFID devices, the two sections overlapping on the cover sheets 14 and 16 of the booklet and the thinner section being designed to cover the join of the identity booklet.

However, the RFID device carrier 2 may also be integrated into a booklet by adhering one side thereof (preferably on the side of the antenna carrier) to any type of target object, such as clothing, books, paper documents, packages, cardboard boxes, etc.

The identity booklet 1 shown schematically in figure 9 is fully formed by fitting a knife inner page 37. The method of making is by connecting them to each other using a security thread to make a knife inner page. In the manufacture of a conventional passport, a flyleaf is laminated on the cover sheet, a flyleaf 36 is laminated with the top cover sheet, and a bottom flyleaf 34 is laminated with the bottom cover sheet 14. In this way, according to the invention, the back of the bottom flyleaf 34 of a quire page of an identity booklet is glued and then pressed against the RFID device carrier 2 glued on the bottom cover sheet of the cover of the booklet. Or alternatively, according to a variant described previously, the back of the bottom flyleaf 34 of a quire of the identity booklet is glued and then pressed against a portion 42 of the carrier 4, this portion 42 containing the chip and the antenna, while the front of the flyleaf 36 is glued and then pressed against a portion 43 of the carrier 4. The gum used is preferably one that is insoluble in water once dried.

The use of synthetic paper in the manufacture of RFID device carriers is an undoubted advantage of the present invention.

On the one hand, the use of synthetic paper simplifies the lamination operation at temperatures of the order of 160 ℃ since it is stable at these temperatures, in contrast to thermoplastic materials such as PVC or PETG. The RFID device carrier 2 or 4 made according to the present invention has synthetic paper on both of its sides, which simplifies its bonding and optimizes its integration on an identity booklet because bonding is done from paper to paper. Thus, due to its microporous structure, the synthetic paper has a low density, which provides it with a good binding force to paper, in contrast to conventional plastic materials such as PVC or PET. The identity booklet thus obtained has a large adhesion between all the parts that make up it, in particular between the RFID device carrier and the identity booklet itself. The glue penetrates deeply into the synthetic paper as it penetrates into the paper, and therefore in particular into the paper constituting the cover of the booklet, which makes it impossible to remove the layers 20, 22 and 24 from each other, which makes the three layers constituting the support inseparable.

The thermoplastic material used for layers 22 and 52 is preferably polyvinyl chloride (PVC), but may also be polyester (PET, PETG), polypropylene (PP), Polycarbonate (PC) or Acrylonitrile Butadiene Styrene (ABS).

Further, it is not possible to intentionally pull out the RFID device carrier constructed into the booklet because the synthetic paper is not laminated in thickness.

During or after lamination, the exterior of the cover of the booklet may be placed in a tray with a special protrusion design, creating special particles on the cover to make the identity booklet tamper-resistant.

Advantageously, the RFID device carrier and the identity booklet according to the invention can be placed in a washing cycle in a washing machine without the electrical connection between the chip and the antenna being altered, thus maintaining the ability to read these items by electromagnetic coupling with a card reader provided for this purpose.

The RFID device carrier and the RFID device may also be produced in the ISO format of a smart card so that they can be used to produce a contactless smart card. The two outer layers of synthetic paper and thermoplastic are of the ISO format of the smart card and the antenna is also adapted so that the size of the turns is slightly smaller than the ISO format of the smart card. In this case, an additional step in the above-described manufacturing method is to customize the card by printing on one or both sides of the card.

Claims (9)

1. A carrier (4) for radio frequency identification devices, characterized by a chip (10) having an antenna (12) screen-printed on a carrier (20) and connection terminals (17 and 19) connected to the antenna,

the method is characterized in that:

the radio frequency identification device carrier further comprising a layer (22) of thermoplastic material laminated on the antenna carrier (20), and the layer (22) of thermoplastic material in direct contact with the chip (10) is not penetrated by a cavity at the location of the chip (10), the layer (22) of thermoplastic material covering the chip (10) on the chip (10),

laminating a second layer (62) of thermoplastic on the layer (60) of synthetic paper and laminating a top layer (64) of synthetic paper on said layer (22) of thermoplastic and on the second layer (62) of thermoplastic, so as to leave a space between said layer (22) of thermoplastic and the second layer (62) of thermoplastic,

and the resulting rfid device carrier comprises two thick portions (42 and 43), one (42) of which contains an rfid device.

2. The rfid device carrier (4) according to claim 1, wherein the top layer (64) comprises a cavity (26) arranged in a manner covering the chip (10).

3. The rfid device carrier (4) according to claim 1 or 2, wherein the chip (10) is glued onto the antenna carrier (20) using an adhesive dielectric material such that the contacts of the chip are located opposite the contacts (17 and 19) of the antenna (12).

4. The rfid device carrier (4) according to claim 3, wherein the adhesive dielectric material is an epoxy resin that is cross-linked at 150 ℃.

5. The rfid device carrier (4) according to claim 1 or 2, wherein the lamination is done at values of temperature and pressure in the order of 160 ℃ and 200 bar.

6. The rfid device carrier (4) according to claim 1 or 2, wherein the synthetic paper of the top layer (24, 64) is made of a material that does not creep, which material does not deform when the temperature increases.

7. The radio frequency identification device carrier (4) according to claim 1 or 2, wherein the layer of thermoplastic material (22) has a thickness of 50 μ ι η.

8. An identity booklet (1) characterised by having an rfid device carrier (4) according to any of claims 1 to 7, wherein the rfid device carrier (4) has the same dimensions as the dimensions of an open identity booklet and the two thick portions (42 and 43) cover the cover sheets (14 and 16) of the cover (11) of the booklet, the rfid device carrier (4) further comprising a thinner portion designed to cover the binding points of the identity booklet.

9. Identity booklet according to claim 8, wherein the radio frequency identification device carrier (4) is glued inside the identity booklet (1) using a glue that does not dissolve in water once it has dried.