Process for manufacturing a card with a metallic effect

Abstract

The invention relates to a method for manufacturing an ID-1 format card according to claim 1, in which: the first plastic layer (12') comprises theoretical locations (14) each corresponding to an ID-1 format card (10), each theoretical location (14) of card (10) being defined by four edges delimiting a surface of ID-1 format card, the adhesive is deposited on the first face of the first layer (12') so as to form on each of the theoretical locations (14) at least two adhesive zones (16a, 16b), each adhesive zone (16a, 16b) being separated from another adhesive zone (16a, 16b) by an empty zone (18) devoid of adhesive connecting at least two edges of a theoretical location (14), at least one support strip (22) on which a thin metal film (24) is deposited is provided opposite the first face of the first layer (12') comprising the adhesive areas (16a, 16b),and wherein the first layer (12') comprising the metallized areas (26a, 26b) is assembled with at least one second layer so as to form a sheet of several cards with a metallized effect, and further comprising a step of cutting in the sheet according to the theoretical locations (14) of the cards (10) of ID-1 format. [Fig. 5],

Description

Title of the invention: Method for manufacturing a card with a metallic effect

[0001] The invention relates to the field of manufacturing microcircuit cards, also called smart cards, and more particularly that of cards having a visual effect, in particular a metallic effect.

[0002] This metallic effect is obtained from a current-conducting metallic film, having a very small thickness and extending over one face of the smart card. However, this type of metallized effect card has the disadvantage of causing electrostatic current discharges (ESD) to appear, which must be eliminated or limited in order to avoid disturbing the signals exchanged between the chip of the card and an external terminal.

[0003] Indeed, electrostatic charge can be accumulated and maintained on an insulating material depending on their ability to donate or capture electrons released due to frictional forces generated during the movement of one material against another material. The charge that accumulates on either material is called static (i.e., not moving) or electrostatic charge. This charge remains on the insulating material for a certain time. If the insulator retaining the charge comes into contact with a conductive material, the stored electrostatic charge can induce a charge in the conductor that can be discharged by the conductor and eventually conducted to ground.

[0004] The process of discharging electrical charge is called electrostatic discharge (ESD). When an insulator carries or contains a metallic conductor, the electrical charge stored on the insulator induces an equal and opposite charge on the conductor. These charges induced in the conductor can be conducted by the conductor into another body or to ground. If the charged insulating material, containing the conductor, is inserted into or passed near an electronic device, such as a terminal, these charges induced in the conductor can be transferred into the electronic device and disrupt the functions of the electronic device or nearby electronic devices.

[0005] It is known to limit the conduction of electrostatic charges by producing insulating zones between the metallized zones. In particular, patent EP3066617 describes the importance of producing conductive zones separated from each other by insulating plastic zones (separation zones) so that the layer comprising the metal film prevents the conduction of electrostatic discharge.

[0006] Patent EP3633555 proposes a solution consisting of carrying out an ablation partial in the conductive film using a laser to prevent the transmission of charges (ESD) from one edge of the card to the opposite edge. However, this process requires initially covering the entire surface of the card with the metal film and then carrying out a local ablation of this metal film, without damaging the plastic. However, the local sublimation of the metal film leads to local heating of the plastic, or even the formation of bubbles inside the plastic.

[0007] It is also known to carry out the ablation of the metallic film on certain areas, directly on the ribbon of the metallic film intended to be deposited on the card. This technology is described in patent EPI994489 which describes a process in which the removal of the metallic areas on the ribbon is carried out by a chemical process. This process consists of protecting the metallized areas of the ribbon which are to be deposited on the card and carrying out demetallization by chemical etching on the other areas. The chemical protection is then removed. This process is effective but requires the use of corrosive chemicals. In addition, the removal process requires an initial surface of the metallic film large enough to cover the entire card, the demetallized areas then being carried out.

[0008] The present invention proposes a new method for manufacturing a card comprising a metal film while making it possible to limit, or even avoid, electrostatic charges, this method being simple and economical.

[0009] To this end, the present invention proposes implementing a method for manufacturing a metallized effect card comprising the following steps:

[0010] - provision of a first plastic layer delimited by four edges delimiting the same surface as the map,

[0011] - depositing by printing an adhesive on a first face of the first layer of so as to form at least two adhesive zones, each adhesive zone being separated from another adhesive zone by a void zone devoid of adhesive connecting at least two edges of the first plastic layer,

[0012] - provision of a support strip on which a thin metallic film is deposited, the thin metal film having at least one dimension equal to or greater than the card surface,

[0013] - deposition, by thermal transfer, through the support strip, of the metallic film thin on the first side of the first layer, so as to fix the metallic film on the adhesive areas,

[0014] - Resumption of the support strip so as to remove the support strip and the metal parts metallized located opposite the empty areas to form, on the first layer, metallized areas superimposed on the adhesive areas,

[0015] - assembly of the first layer comprising the metallized zones with at least a second plastic layer to form a metallic effect card.

[0016] Thanks to this new method, it is possible to manufacture a metallized effect card with empty areas devoid of metallic film, in a simple and inexpensive manner. Since the adhesive deposition technologies according to the invention do not require corrosive chemical materials, the method according to the invention can be carried out easily, in particular in chip card manufacturing plants without additional technical or security constraints.

[0017] The invention also relates to a method for manufacturing an ID-1 format card in which the first plastic layer comprises theoretical locations each corresponding to an ID-1 format card, each theoretical card location being defined by four edges delimiting an ID-1 format card surface, the adhesive is deposited on the first face of the first layer so as to form on each of the theoretical locations at least two adhesive zones, each adhesive zone being separated from another adhesive zone by an empty zone devoid of adhesive connecting at least two edges of a theoretical location, at least one support strip on which a thin metal film is deposited is brought opposite the first face of the first layer comprising the adhesive zones,and in which the first layer comprising the metallized areas is assembled with at least a second layer so as to form a sheet of several cards with a metallized effect, and further comprising a step of cutting in the sheet according to the theoretical locations of the ID-1 format cards.

[0018] Other advantageous and non-limiting characteristics of the method of the invention, taken individually or in all technically possible combinations, are the following:

[0019] - the adhesive is deposited on the first layer by screen printing,

[0020] - the empty areas form continuous lines in the surface delimited by the edges of the first plastic layer or theoretical locations,

[0021] - the empty areas form intersecting lines defining an intersection,

[0022] - the support strip on which the thin metal film is deposited is provided in form of a wound strip to ensure a continuous supply of the metal film on the first layer,

[0023] - the thin metal film is unwound in a direction parallel to an edge of the first layer or an edge of the theoretical locations,

[0024] - the metal film has a width substantially equal to a width of a zone adhesive,

[0025] - several metallic films are unrolled on the first layer, in one direction perpendicular to the width of the adhesive area, excluding empty areas without adhesive.

[0026] - the second layer is a plastic layer or a varnish layer.

[0027] [Fig. 1] [Fig. 1] represents a card produced according to the manufacturing method of the present invention,

[0028] [Fig.2][Fig.2] illustrates a manufacturing step of the method according to the invention,

[0029] [Fig.3] [Fig.3] illustrates an intermediate product obtained during the fa process brication,

[0030] [Fig.4][Fig.4] and [Fig.5] [Fig.5] illustrate two stages of carrying out the manufacturing method according to an alternative embodiment,

[0031] [Fig.6][Fig.6] represents a diagram of the stages of manufacturing a card according to the method of the invention.

[0032] [Fig.7][Fig.7] illustrates a schematic sectional view of a card according to the invention

[0033] The present invention relates to the manufacture of smart cards having an effect metallized. These cards have the shape of a rectangular parallelepiped with dimensions of 53.98mm * 85.60mm and a very small thickness, less than 1 mm, between 760 and 840 pm. These dimensions are specified by the ISO 7816 standard under the name ID-1. It is known to manufacture this type of card by superimposing several layers of plastic material and then pressing them hot during a lamination step, in order to assemble the layers together.

[0034] The plastic layers may consist of one or more polymer substrates, such as PVC, polyesters (PET, PETf or PETg), polycarbonate (PC) or even ABS. These substrates may also be printed or carry a passive electronic component such as an antenna.

[0035] The lamination operation is carried out by means of presses equipped with lamination plates between which the layers are heated and pressed to obtain an assembly of layers by fusion of the material at the interface of the layers.

[0036] Traditionally, the layers are initially in the form of large format plates typically grouping 24 or 48 ID-1 format microcircuit card locations. After lamination of the layers, the cards are individually cut to ID-1 dimensions by punching. According to a variant, the layers have the dimensions adapted to form a single card.

[0037] In order to obtain aesthetic effects, it is known to provide ink prints on the layers. The printing techniques are, for example, the lithography technique (offset) or the screen printing technique (silkscreen printing). It is also known to produce cards with a metallic effect. This effect is obtained from a thin metallic film, with a thickness of less than 0.0 μm, deposited on a plastic layer, for example a Polyester substrate (also called PET polyethylene terephthalate). The plastic layer is covered with the metallic film and is then laminated with other plastic layers to form the card.

[0038] As explained in the preamble of the present description, it is sought to avoid electrostatic discharges from metallized effect cards to avoid disturbances to terminals communicating with these cards. For this purpose it is known to produce empty areas without metallic film to avoid the conduction of these electrostatic charges.

[0039] The invention proposes a new method for manufacturing cards with a metallized effect comprising empty areas devoid of metallic film 24. These areas are illustrated schematically on the card 10 of [Fig. 1] [Fig. 1].

[0040] The method according to the invention comprises several steps as indicated in the diagram of [Fig.6][Fig.6]. The first step consists of providing a first plastic layer 12 forming one of the layers of the card 10. This first layer 12 has a thickness of the order of 150-500 μm. It is delimited by four edges defining a rectangular ID-1 card format, namely 53.98 mm * 85.60 mm. According to an alternative embodiment, the first plastic layer 12' consists of a large format plate comprising the theoretical locations 14 of several ID-1 format cards, each card location 14 being defined by four edges delimiting an ID-1 format card surface.

[0041] The method then comprises a step of depositing an adhesive on a first face of the first layer 12, 12' so as to form at least two adhesive zones 16a, 16b separated by an empty zone 18 devoid of adhesive. The adhesive has adhesion properties at room temperature to the material constituting the first plastic layer on one face and has adhesion properties to the metal film 24 on an opposite face.

[0042] Preferably the adhesive is deposited by screen printing. This type of printing consists of placing, above the plastic layer, a screen printing screen comprising a fabric part permeable to the adhesive, the shape of which defines the printing pattern, and a part made impermeable to the adhesive. The adhesive is deposited in liquid form on the screen and, by pressing it with a squeegee against the screen, it is caused to deposit on the plastic layer. Screen printing is a known technique and traditionally implemented in the card manufacturing industry for printing ink. Adapting this technique to an adhesive requires some parameterization of the screen mesh, as known to those skilled in the art.

[0043] The adhesive is deposited so as to form adhesive zones 16a, 16b and so as to define empty zones 18 devoid of adhesive which extend between two edges of the first plastic layer when the latter has the same surface as the card to be manufactured. When the first plastic layer is a large plate comprising the theoretical locations 14 of several ID-1 format cards, the empty zones 18 are produced so as to extend between two of the four edges delimiting the theoretical location 14 of the ID-1 format card.

[0044] According to a variant, the empty zones 18 form continuous intersecting lines, that is to say which intersect with each other with intersection 20 located in the surface delimited by the edges of the first plastic layer or of the theoretical location 14 of the ID-1 card.

[0045] After depositing the adhesive on the first plastic layer 12, 12', an assembly is obtained as shown diagrammatically in [Fig.2][Fig.2]. This [Fig.2][Fig.2] also illustrates the following step of the manufacturing process in which a support strip 22 provided with a thin metal film 24 is provided and positioned above the assembly formed by the first plastic layer 12, 12' and the adhesive. When the first layer 12 has the same surface area as the card 10 to be manufactured, it is advantageous to produce a metal film 24 having a surface area equal to or greater than that of the card 10. Thus, a single depositing step is necessary to position the thin metal film 24, which makes the manufacturing process faster and simpler.

[0046] When the first plastic layer 12′ is a large plate comprising the theoretical locations 14 of several ID-1 format cards, it is advantageous to deposit several metal films 14 having a width, substantially identical to a dimension of an adhesive zone 16a, 16b. This is illustrated by FIGS. 4 and 5, in which the adhesive zones 16a, 16b are represented by a rectangular shape and the metal films have a width equal to a dimension of the rectangular adhesive zone 16a, 16b, here the length of the rectangle. This method is advantageous in that it is possible not to cover the central empty zone 18 during the manufacturing process, and therefore to avoid scrapping the quantity of metal film 24 not deposited in this empty zone 18.

[0047] According to a variant illustrated in [Fig.5] [Fig.5], the thin metal film strip 24 has a width substantially equal to a width of an adhesive zone 16a, 16b. It is then necessary to provide several thin metal film strips 24 to cover the adhesive zones 16a, 16b. In this case it is advantageous for the thin metal film strips 24 to be unwound on the first layer 12', in a direction perpendicular to the width of the adhesive zone, outside the empty zones 18 devoid as illustrated in [Fig.5] [Fig.5]. This arrangement allows easier and more homogeneous distribution of the metal films 24 relative to the direction of movement on the production lines.

[0048] As an example, a first layer 12' forming a plate, called a format, generally of 48 theoretical card locations 10 has the following dimensions: length: 594 mm, width 495 mm taking into account the spaces between the locations and the space between the outline of the plate and the locations. The total surface area of ​​this plate is therefore 294030mm2 (2940.30 cm2). In this example, the adhesive zones 16a, 16b have the dimension 42.3 mm * 21.49mm, are spaced of empty areas 18 with a width of 10 mm as shown diagrammatically in figures 1, 4 and 5. It is therefore possible to save in a given direction, for example in the width direction as illustrated in [Fig.5] [Fig.5], the following metal film surface: 10 mm*53.98*8 (rows of cards)*6 (columns of cards), or 25910.4mm2 of metal film 24, at a minimum. Indeed, it is also possible not to deposit metal foil on the contour of the plate. This represents a significant advantage in terms of cost and reduction of waste.

[0049] The metal film 24 is then deposited by transfer through the support strip 22 onto the first face of the first layer 12, 12', so as to fix the metal film 24 onto the adhesive zones 16a, 16b. The transfer is carried out by applying heat between 90°C and 170°C, under pressure, locally onto the metal film 24 through the support strip 22.

[0050] Preferably, the metal film 24 on its support strip 22 is delivered in a reel and unwound above the first layer covered with adhesive zones 16a, 16b. It is thus possible to ensure a continuous supply of the metal film 24 on its support strip 22 above a production line of an assembly formed by the first layer 12, 12' covered with adhesive zones 16a, 16b.

[0051] Then the manufacturing method comprises a step of taking up the support strip 22 so as to remove the strip 22 and the metallized parts located opposite the empty zones 18 devoid of adhesive and therefore not bonded to the adhesive. The intermediate product obtained is schematically represented in [Fig.3] [Fig.3] in which the metallized zones 26a, 26b are superimposed on the adhesive zones 16a, 16b.

[0052] The method further comprises a step of assembling the first layer 12, 12' covered with the metallized areas 26a, 26b with at least one second layer 28 so as to form a card body. According to a first variant, this second layer 28 is a transparent protective plastic layer, positioned on the side of the adhesive areas, and laminated, i.e. hot-pressed with the first layer so as to form a plastic card with a metallized effect. The lamination step is carried out at a temperature below the glass transition temperature of the first layer 12 to avoid deformation of the metallized film.

[0053] According to a second variant, the second layer 28 is a protective varnish deposited on the first layer and covering a metallized film, possibly laminated to flatten it.

[0054] According to a variant, the first layer 12 may consist of several plastic layers, such as an inlay and a printed layer and a protective overlay, on the side opposite the foil to form a first complex layer. [Fig.7][Fig.7] illustrates a sectional view of a card according to the invention. The first card layer illustrated in [Fig.7][Fig.7] comprises several substrates including an inlay 30, meaning “inlay layer” and forming an inner layer adapted to receive an antenna, a back print layer 32 and a transparent protective layer 34. [Fig.7][Fig.7] is given for illustration purposes only and other combinations of plastic substrates can be made to form a card body.

[0055] When the first plastic layer 12' has a large format comprising the theoretical locations 14 of several ID-1 format cards, and when the second layer is made of plastic, the latter has substantially the same dimensions as the first layer 12' and the first and second layers are assembled by lamination to form a sheet of several cards 10 with a metallized effect, each corresponding to a theoretical location 14. A cut is made at each of the theoretical locations 14 to form the ID-1 format cards.

Claims

Claims

1. A method of manufacturing a card (10) with a metallic effect, the card having a surface and a thickness, comprising the following steps: - addition of a first plastic layer (12) delimited by four edges delimiting the same surface as the card, - depositing by printing an adhesive on a first face of the first layer so as to form at least two adhesive zones (16a, 16b), each adhesive zone (16a, 16b) being separated from another adhesive zone (16a, 16b) by an empty zone (18) devoid of adhesive connecting at least two edges of the first plastic layer (12), - providing a support strip (22) on which a thin metal film (24) is deposited, the thin metal film (24) having at least one dimension equal to or greater than the card surface - depositing, by thermal transfer, through the support strip (22), the thin metal film (24) on the first face of the first layer (12), so as to fix the metal film (24) on the adhesive zones (16a, 16b), - Resumption of the support strip (22) so as to remove the support strip (22) and the metallized parts located opposite the empty zones (18) to form, on the first layer (12), metallized zones (26a, 26b) superimposed on the adhesive zones (16a, 16b), - assembly of the first layer (12) comprising the metallized zones (26a, 26b) with at least one second layer so as to form a card (10) with a metallized effect.

2. A manufacturing method according to claim 1, wherein: - the first plastic layer (12') comprises theoretical locations (14) each corresponding to a card (10) of ID-1 format, each theoretical location (14) of card (10) being defined by four edges delimiting a surface of card of ID-1 format, - the adhesive is deposited on the first face of the first layer (12') so as to form on each of the theoretical locations (14) at least two adhesive zones (16a, 16b), each adhesive zone (16a, 16b) being separated from another adhesive zone (16a, 16b) by an empty zone (18) devoid of adhesive connecting at least two edges of a theoretical location (14), - At least one support strip (22) on which a film is deposited thin metallic (24) is brought opposite the first face of the first layer (12') comprising the adhesive zones (16a, 16b), - and in which the first layer (12') comprising the metallized zones (26a, 26b) is assembled with at least a second layer so as to form a sheet of several cards with a metallized effect, - and further comprising a step of cutting in the sheet according to the theoretical locations (14) of the ID-1 format cards (10).

3. Manufacturing method according to one of the preceding claims, in which the adhesive is deposited on the first layer (12, 12') by screen printing.

4. Manufacturing method according to one of the preceding claims, wherein the empty areas (18) form continuous lines in the surface delimited by the edges of the first plastic layer (12) or theoretical locations (14).

5. A method according to claim 4, wherein the empty areas (18) form intersecting lines defining an intersection (20).

6. Method according to one of the preceding claims, in which the support strip (22) on which the thin metal film (24) is deposited is provided in the form of a wound strip to ensure a continuous supply of the metal film (24) on the first layer (12, 12').

7. Method according to the preceding claim, in which the thin metal film (24) is unwound in a direction parallel to an edge of the first layer (12) or an edge of the theoretical locations (14).

8. Method according to one of claims 2 to 7, in which the metallic film (24) has a width substantially equal to a width of an adhesive zone (16a, 16b).

9. Method according to claim 8, in which several metallic films (24) are unwound on the first layer, in a direction perpendicular to the width of the adhesive zone (16a, 16b), outside the empty zones (18) devoid of adhesive.

10. Method according to one of the preceding claims, in which the second layer (28) is a plastic layer or a varnish layer.

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