FR3038426A1 - METHOD FOR APPLYING AN ADHESIVE LAYER TO A SUBSTRATE, AND CORRESPONDING APPLICATION DEVICE - Google Patents

Abstract

The invention relates to a method (34) for applying an adhesive layer under pressure to a substrate, the substrate comprising one or more sheets joined together and delimiting opposite first and second faces, said substrate having a non-adhesive thickness. in which: a) the first face of the substrate is positioned (31) above, in particular on at least a partially soft support, and then b) the pressure-sensitive adhesive layer is applied (33) to the second face of the substrate; substrate, the support being configured to deform, when subjected to the application pressure of the adhesive layer, so as to compensate, at the second face, the thickness variations of the substrate. The invention also relates to an application device for implementing the above method.

Description

Background of the invention

The present invention relates to the field of methods for applying a panel to a substrate, and more particularly to the field of manufacturing processes for microcircuit cards comprising a signature panel.

The authentication means for microcircuit cards have been developed and improved to make them more reliable but also more flexible to use. Among these means, there may be mentioned the magnetic tape, the signature panel, the chip or microcircuit, or even the three-digit code CW (in English: "Card Check Value") positioned on the rear face of the card with microcircuit. These different means of authentication are further dimensioned and positioned according to a standard, ISO 7816, to ensure the proper operation of the various elements of the card with the corresponding readers, and easy authentication by the user.

The quality of realization of these different means of authentication is important because the deterioration or the disappearance of one of these means would no longer allow the user to fully use his card. Moreover, it would return to it an image of reliability and security that would be altered, which is detrimental to the issuer of the card.

Among the means of authentication, the signature panel is the only one to be deposited on the exposed surface of the card, in particular to allow the affixing of the signature of the user. The deposit of the panel on the microcircuit card must avoid any risk of delamination or detachment of the panel, and is effected in particular by striking the panel on the surface of the body of the card.

However, with the improvement of the various elements constituting a microcircuit card, and in particular the electronic part thereof, the body of the card may have different inserts, each having specific dimensions and surface conditions very different from each other. other. This non-uniformity of materials in the card can lead to defects in the application of the panel, for example by creating local detachments or deformations likely to lead to local tearing of the signature panel.

Such a defect, on one of the means of authentication, is not conceivable, and can even render illegible the signature made over it.

Furthermore, the application by typing is not completely satisfactory, because it may damage the electronic components located under the panel.

Object and summary of the invention

An object of the present invention is to overcome the disadvantages mentioned above. In particular, an object of the invention is in particular to provide a more reliable and reproducible method of applying a panel to a substrate. In particular, an object of the invention is to provide a method of applying a panel to a substrate having a non-uniform thickness. For this purpose, it is proposed a method of applying under pressure an adhesive layer on a substrate, the substrate comprising one or more sheets assembled together, and delimiting first and second opposite faces, said substrate having a non-adhesive thickness. in which: a) the first face of the substrate is positioned above, in particular on at least partially soft support, then b) the adhesive layer is applied under pressure to the second face of the substrate, the support being configured to deform, when subjected to the application pressure of the adhesive layer, so as to compensate, at the second face, the thickness variations of the substrate.

Thus, thanks to the at least partially soft support, or elastically deformable, it is possible to compensate for the differences in the thickness of the substrate during the application of the panel: the support is deformed so as to allow a uniform pressure of application of the panel on the substrate. In particular, a reception face of the substantially flat panel is obtained, thereby avoiding the panel fixing defects that could be observed in the prior art.

Preferably, the support material has a Shore A hardness measured according to ASTM D 2240 of between 50 and 101, preferably between 70 and 100, and more preferably between 90 and 100. Shore A hardness allows to characterize the behavior of a soft material, and in particular its resistance to penetration.

Preferably, the support has a thickness of between 0.2 and 0.9 mm, preferably between 0.3 and 0.8 mm, and more preferably between 0.6 and 0.7 mm.

The physical characteristics of the support (hardness and thickness in particular) are chosen so as to obtain the desired deformation.

Preferably, the support comprises, or even consists of, at least one layer of compressible fabric, preferably at least two.

Preferably, the at least partially soft support is placed on a counter-pressing table, possibly with an aluminum plate between. The at least partially soft support is added to a conventional counter-pressing table, in order to limit the modifications to the application device of the panel.

Preferentially, step a) comprises a first substep a1) in which the first face of the substrate is positioned above the at least partly soft support, and then a substep a2) in which the first step is held flat. face of the substrate above the support. The second step a2) makes it possible to keep the first face of the substrate well positioned flat above the soft support, in order to allow a correct application of the panel.

Preferentially, the sub-step a2) comprises an air intake at the interface between the first face and the support.

Preferably, the substrate also comprises an insert, disposed in an opening made through one or more adjacent sheets of the substrate. The insert may be flush with one of the faces of said adjacent sheet or sheets. The insert may in particular be a cause of the non-uniformity of thickness of the substrate: in particular, tolerances width, length and thickness accepted for the realization of the insert and its positioning in the opening, lead to variations in thickness as well as any grooves that may lead to gluing defects when the panel is applied to the substrate: the soft support makes it possible to compensate for these defects / irregularities. In particular, an example of insert element is a transparent insert for viewing a screen positioned under the insert.

Preferably, said second face of the substrate is flat. For example, the second face of the substrate may be formed by one or more sheets integrally forming the second face of the substrate, or forming the portion of the second face of the substrate intended to receive the panel. The method according to the invention makes it possible to preserve this second planar face, even when a pressure is applied on the substrate, by compensating the variations of thickness likely to lead to the deformation of the second face.

Preferably, the method described above may comprise the repetition of step b), at different points on the second face of the substrate, or the implementation of step b) simultaneously at several points on the second face of the substrate. This is the case, for example, when the substrate comprises several zones each of which must receive an adhesive layer. In this case, the support is soft everywhere below the substrate, or only under the different parts to receive an adhesive layer.

According to another aspect, there is also provided a method of manufacturing an electronic device, in particular a microcircuit card, comprising: a body with electronic elements delimited by first and second opposite faces; a coating delimited by first and second faces, the first face of the coating being intended to come into contact with the second face of the body, and - a panel, in which the panel is applied to the second face of the coating according to the method as described above, then applies, for example by cold rolling, the coating coated panel, on the second body face.

Thus, according to the method, the panel is applied under pressure on a substrate at first, then the assembly is then laminated with the electronic components in a second time. Thanks to the method according to the invention, it is therefore possible to more reliably apply the panel, including signature, a microcircuit card, while avoiding damaging the electronics of said card.

Preferably, the body comprises a display screen visible from the second face, the coating comprises a first sheet with a portion at least partially transparent positioned at the right of the display screen, and the manufacture of the coating comprises the production of a cutout in the first sheet, at the level of said at least partially transparent portion, and the positioning of an insert at least partly transparent in said cutout. In this case, the microcircuit card includes an insert for viewing a screen disposed below. However, the insert can cause variations in the thickness of the microcircuit card, or at least the coating: the method according to the invention makes it possible to make reliable the deposit of the panel on the coating, especially when it has to be placed in the above the insert.

Preferably, the coating also comprises a second sheet one of whose faces forms the second face of the coating, the method comprising a step of depositing a second sheet above the insert and the first sheet, for example by rolling with hot. The second sheet makes it possible to have a second face of the coating which is solid, that is to say filled with material, despite variations in the thickness of said coating. The method according to the invention makes it possible in particular not to deform this second face during the application of the panel, under the effect of the pressure exerted on it.

Preferably, the method comprises obtaining a first board delimited by first and second faces and comprising several bodies, for example twenty-one, each with an individual screen, obtaining a second board delimited by first and second faces and forming a coating layer, and several individual panels, for example twenty-one. According to the method, the panels are applied, for example individually, to the second face of the second plank according to the method as described above, then the second plank is applied with the panels to the second face of the first plank to form a multilayer. . Finally, the method may comprise cutting different parts of the multilayer each having a body, a coating and a panel.

In another aspect, there is also provided a device for applying under pressure an adhesive layer on a substrate, comprising a pressing assembly, and a counter-pressing assembly. The counter-pressing assembly comprises an upper surface formed by an at least partly soft support.

Preferably, the counter-pressing assembly comprises a counter-pressing table, an at least partially soft support disposed above the counter-pressing table, and optionally a plate, for example of aluminum, placed between the counter-pressing table and support at least partly soft.

Preferably, the device also comprises holding means on the counter-pressing assembly, for example air suction means mounted in the counter-pressing assembly and around the at least partially soft support.

Preferably, the device is configured to apply simultaneously or successively in different places an adhesive layer on the substrate. For example, the substrate may comprise twenty-one areas for receiving an adhesive layer, and the device may apply the adhesive layers successively or simultaneously on the twenty-one areas of the substrate.

Preferably, the counter-pressing assembly may have on its upper surface, alternatively at least partly soft supports, and holding means, the at least partly soft supports being positioned so as to position themselves under the zones of the substrate. intended to receive an adhesive layer.

BRIEF DESCRIPTION OF THE DRAWINGS Other characteristics and advantages of the invention will become apparent in the light of the description which follows, given with reference to the appended drawings in which: FIG. 1 is a schematic representation of an exploded perspective view of a first embodiment of realization of a microcircuit card; FIG. 2 diagrammatically represents a sectional view of the coating of a second embodiment of a microcircuit card, during the application of the adhesive layer; FIG. 3 illustrates, in the form of a diagram, the steps implemented in the manufacturing method according to the invention.

Detailed description of an embodiment

FIG. 1 shows an electronic device that can be manufactured by the method according to the invention. This device is designated by the general reference 10. It is noted that the figures are not to scale.

In the example described in this application, the electronic device 10 is a microcircuit card as recommended in IS07816 and ISO7810. In a variant, the device may be a memory card of the MMC (in English: "multimedia card") or SD (in English: "Secure Digital") type.

As shown in Figure 1, the card 10 comprises a body 12 in the general form of a card delimited by opposite faces: a first face 12A and a second face 12B. On the other hand, the card 10 also has a coating 14 applied to the second face 12B of the body 12, and delimited by opposite faces: a first face 14A disposed on the second face 12B of the body 12, and a second face 14B. The first face 14A is said internal face, and the second face 14B is said external face because it is turned towards the outside of the card 10. Finally, a panel 16 is glued on the second face 14B of the coating 14.

In this embodiment, the body 12 delimits the outer dimensions of the card 10. In this example, and preferably, the dimensions of the card 10 are defined by the ID-1 format of the ISO 7810 standard which is the conventionally used format. for bank cards of dimensions 86 mm by 54 mm for a thickness of 0.85 mm. Of course, other card formats may also be used.

Conventionally, the card body 12 comprises a microcircuit (not shown) able to exchange, process and / or store data.

In Figure 1, the card body 12 is shown as a single layer for simplification purposes. However, the card body 12 is generally composed of several layers, for example PVC or a combination of several PVC, PET materials, and in particular a layer composed of a very thin substrate (for example 50 μm) on which are mounted electronic components separate from the microcircuit and possibly, but not necessarily, connected thereto.

In this embodiment, the card body 12 comprises a digital electronic screen 18 having a display area 18A and a technical peripheral area 18B. The display area 18A comprises in particular the individually controlled pixels which allow the display of the desired information, while the technical peripheral zone 18B has visible electronic elements necessary for the operation of the screen 18. It should be noted that the zone d 18A may also include an outline devoid of pixel but of homogeneous color or the like with the rest of the display area. The screen 18 is preferably formed by an electronic paper. Electronic paper, or "E-paper", is a means of display seeking to imitate the appearance of a printed sheet. Unlike conventional display techniques, which use energy to read pixels, such as backlighting means or emitting pixels, the electronic paper uses ambient light. Moreover, the pixels of such a screen have several distinct stable states, so that only the state changes require an energy input, and not a particular state of the pixels. Electronic paper can thus display the same information for a long time, without consuming energy.

A microcontroller (not shown), of a type known to those skilled in the art, is inserted in the card and controls the screen 18. In known manner, this microcontroller is connected to the screen 18, possibly via a control circuit, and possibly possesses other peripherals, such as a battery, a switch, a keyboard or an antenna.

The coating 14 is for example PVC or other plastic. The coating 14 has a thickness of at least 120 μm, preferably at least 160 μm. In FIG. 1, the coating 14 comprises a single sheet, but it can also be formed of several sheets associated with each other, for example a transparent protective sheet and a printed sheet, as represented in FIG. 2.

Furthermore, one of the faces of the coating 14, preferably the second face 14B, may comprise printed personalization information different from one card to another and / or security information, for example a hologram.

The coating 14 comprises in particular a portion 20 at least partially transparent. The portion 20 is positioned in the assembled card 10 at the right of at least the display area 18A. The portion 20 can thus be an area of the coating 14 unprinted and left transparent, or an insert, for example a particularly transparent insert, disposed in a cut made in the sheet of the coating 14. It is considered in the following the description, that the portion 20 is an insert in the form of a transparent insert positioned in a cut of the sheet of the coating 14.

For practical reasons, the insert may have imposed dimensions independent of the size and positioning constraints related to the card 10. Thus, the insert may have a size very different from the size of the display area 18A of the 18. Similarly, for reasons of making the coating 14, the insert may have dimensions slightly smaller than those of the cut in which it is positioned, leaving a thin circumferential groove between it and the sheet of the coating 14. Finally, the insert may have a thickness slightly different from that of the sheet of the coating 14.

The panel 16 is intended to solve the various aesthetic and technical difficulties posed by the realization of the coating 14 described above. The panel 16 is conventionally a writable panel, at least in part, to receive the signature of the user for example, and disposed on the exposed surface of the card 10, in this case the second face 14B of the coating 14. The panel 16 can thus include a material with patterns, to authenticate the signature affixed to it, including colored patterns.

The panel 16 is positioned according to the requirements imposed by the certifying bodies of payment cards, when the card complies with this standard. The dimensions of the panel 16 may be provided to be greater than those of the insert 20. It is thus possible to hide the circumferential groove that can separate the insert and the sheet of the coating 14.

Furthermore, the panel 16 also comprises a so-called reading zone 22 making it possible to see at least part of the display area 18A of the screen 18. Thus, the zone 22 has dimensions smaller than those of the insert , and less than or equal to that of the display area 18A. The reading zone 22 makes it possible to clearly and accurately define the area of the screen that will be visible to the user and in which the information displayed by the screen 18 will be read. The reading zone 22 makes it possible in particular to hide the technical peripheral zone 18B of the screen 18, as well as the contours of the insert 20.

The reading zone 22 can be easily made by cutting a portion of the panel 16, by not removing a portion of the panel 16, or by producing a zone of transparent material in the panel 16. The positioning correct panel 16, in particular required by the standards established by the certifying bodies, allows to directly obtain the reading zone 22 in the right place.

According to one embodiment, the screen 18 makes it possible to display a code, in particular the three-digit code called CW. Thus, the code can be changed regularly and displayed by the screen 18.

The panel 16 is conventionally deposited under pressure on the second face 14B of the coating 14 by transfer. Such a method involves the positioning of the panel 16 above the coating 14, then the application of a pressure, possibly accompanied by an increase in temperature, on the panel 16 to fix it on the second face 14B of the coating 14 However, and as mentioned above, the insert 20 may have a thickness different from that of the sheet of the coating 14. In such a case, when applying the pressure to fix the panel 16 on the coating 14, this the last is deformed under the effect of the pressure, and then has a second non-planar face 14B: the panel 16 can thus poorly adhere to the second face 14B and cause, immediately or eventually, detachments, delaminations, tears, ...

In order to solve this problem, the method according to the invention proposes to position the coating 14 on a soft support, during the application of the panel 16 under pressure. Such a process step is thus shown in Figure 2, in section.

In Figure 2, only the coating 14 of the microcircuit card 10 is shown. It comprises in particular two sheets: a printed sheet 13 with a thickness of 100 μm with a cut-out in which the insert 20 is positioned, and a transparent protective sheet 15 with a thickness of 60 μm, covering the surface of the printed sheet 13 and the surface of the insert 20.

When the panel 16 is applied, the first face 14A of the coating 14 is placed on a soft support 24, for example two layers of fabric having a Shore A hardness measured according to the ASTM D 2240 standard, of 95, and a thickness of 0.65 mm. The soft support 24 is also positioned on a rigid element, for example a counter-pressing plate 26, possibly with an aluminum plate placed between. The soft support 24 and the counter-pressing plate thus form part of an application device 28 for an adhesive layer according to the present invention.

When applying the pressure to glue the panel 16, the coating 14 will deform the soft support 24, and in particular at the thickness variations of the coating 14. For example, and as shown in FIG. 2, the support The slack 24 will deform at the level of the insert 20 to compensate for the smaller thickness of the latter with respect to the printed sheet 13 of the coating 14. Thus, a flat transparent protective sheet 15 is maintained during the application of the panel 16, that is to say substantially parallel to the counter-pressing table 26, at least on the portion intended to receive the panel 16. The panel 16 can thus be stuck reliably over its entire contact surface with the second face 14B of the coating 14.

Similarly, when the insert 20 has dimensions slightly smaller than those of the cut in which it is positioned, the soft support 24 will also deform during the application of the pressure, so as to fill the fine circumferential groove present between the insert 20 and the sheet of the coating 14. Here again, we will compensate for variations in thickness so that the transparent protective sheet 15 is substantially maintained parallel to the counter-pressing table 26, at least on the portion intended to receive the panel 16.

In order to maintain the coating 14 in position during the step of applying the panel 16, the application device 28 may in particular comprise holding means, for example air suction means (not shown) allowing creating a gap between the soft support 24 and the first face 14A of the coating 14.

In particular, the application device 28 can be configured to operate on a board having several adjacent zones, called poses, each relating to a microcircuit card. Thus, during the method, a board delimited by first and second faces and forming a coating layer 14 for microcircuit cards, is positioned in the application device 28, on the counter-pressing assembly. The board can then be held flat against the counter-pressing assembly by holding means, for example air suction means arranged alternately with soft supports on the upper surface of the counter-pressing assembly. . Then, the application device 28 applies under pressure a panel 16 successively or simultaneously on each zone of the board.

The board thus coated with the panels 16, can then be applied to a board comprising microcircuit card bodies disposed adjacently, for example by cold rolling, before being cut to form microcircuit cards.

FIG. 3 illustrates an exemplary flow diagram of a method of manufacturing a microcircuit card according to the invention. According to the method 30, in a first step 31, the first face of a substrate, for example the coating 14, is positioned on the soft support. Then, in a second optional step 32, the substrate is held flat on the soft support.

Then, in a third step 33, the adhesive layer is applied, for example the panel 16, under pressure on the second face of the coating 14. Due to the deformation of the soft support 24, the application of the panel can be done satisfactorily on the entire surface of said panel 16.

The adhesive layer is preferably applied by heat transfer, by means of a press whose tool has the geometry of the panel 16. Thus, the tool can have a substantially rectangular geometry, with an internal cavity defining a zone of no depositing the adhesive layer corresponding to the reading zone 22.

Steps 31 to 33 thus form a method 34 of applying under pressure an adhesive layer on a substrate.

Finally, in a step 35, the coating 14 coated with the panel 16 is applied to a body, for example that of the microcircuit card. Step 35 can in particular be implemented by cold rolling. Step 35 makes it possible, in particular, to assemble the various elements of the microcircuit card, in the cold state, and after the application of the panel 16 to the coating 14. It is thus avoided to carry out these steps above the electronic components of the card, which could damage them.

Finally, when the preceding steps have been implemented (successively or simultaneously) on boards comprising several zones, called poses, each corresponding to microcircuit cards, the method may comprise a last step of cutting said zones, to form the cards. with microcircuit.

Thus, thanks to the invention, it is possible to reliably and reproducibly produce a microcircuit card comprising on the one hand electronic components, and on the other hand a coating with a glued panel. Moreover, the method requires few modifications compared to those of the prior art, thus facilitating its implementation.

Claims (14)

claims A method of applying (34) under pressure an adhesive layer (16) to a substrate (14), the substrate comprising one or more sheets (13, 15) assembled together and delimiting first (14A) and second ( 14B) opposite sides, said substrate having a non-uniform thickness, wherein: a) positioning (31) the first face (14A) of the substrate above an at least partly soft support (24), then b the adhesive layer is applied under pressure to the second face of the substrate, the support (24) being configured to deform, when subjected to the application pressure of the adhesive layer, so as to compensate, at the level of the second face, variations in the thickness of the substrate. 2. Application method (34) according to claim 1, wherein the support material (24) has a Shore A hardness measured according to ASTM D 2240 between 50 and 101, preferably between 70 and 100, and more preferably between 90 and 100. 3. Application method (34) according to claim 1 or 2, wherein the support (24) has a thickness of between 0.2 and 0.9 mm, preferably between 0.3 and 0.8 mm, and more preferably between 0.6 and 0.7 mm. 4. Application method (34) according to any one of the preceding claims, wherein the support (24) comprises at least one layer of compressible fabric, preferably at least two. 5. Application method (34) according to any one of the preceding claims, wherein the support at least partly soft (24) is placed on a counter-pressing table (26), possibly with an aluminum plate between . 6. Application method (34) according to any one of the preceding claims, wherein step a) comprises a first substep a1) (32) in which is positioned (31) the first face (14A) of the substrate above the at least partly soft support (24), then a substep a2) (33) in which the first substrate face (14A) is held flat above the support (24). 7. Application method (34) according to the preceding claim, wherein the substep a2) comprises a suction of air at the interface between the first face (14A) and the support (24). The method of application (34) according to any one of the preceding claims, wherein the substrate (14) further comprises an insert (20) disposed in an opening through one or more adjacent sheets (13, 15). of the substrate. 9. A method (30) for manufacturing an electronic device, in particular a microcircuit card (10), comprising: a body (12) with electronic elements delimited by first and second opposing faces; a coating (14); ) delimited by first and second faces, the first face of the coating being intended to come into contact with the second face of the body, and - a panel (16), in which the panel (16) is applied to the second face of the coating (14) according to the method of any one of claims 1 to 8, then is applied, for example by cold rolling, the coating coated with the panel, on the second body face (12). 10. Method (30) according to the preceding claim, wherein: - the body (12) comprises a display screen (18) visible from the second face (12B), and - the coating (14) comprises a first sheet ( 13) with an at least partly transparent portion positioned at the right of the display screen, and wherein the manufacture of the coating comprises making a cut in the first sheet (13), at said portion at least in part transparent, and the positioning of an insert (20) at least partially transparent in said cut. 11. Method (30) according to the preceding claim, wherein the coating (14) also comprises a second sheet (15), one of the faces forms the second face of the coating, the method comprising a step of removing the second sheet (15). ) above the insert (20) and the first sheet (13), for example by hot rolling. 12. Apparatus for applying under pressure (28) an adhesive layer on a substrate for carrying out the method according to any one of claims 1 to 11, comprising a pressing assembly, and a set of counter-pressing , characterized in that the counter-pressing assembly comprises an upper surface formed by an at least partly soft support (24). 13. Device (28) according to the preceding claim, wherein the counter-pressing assembly comprises a counter-pressing table (26), a support at least partly soft (24) disposed above the counter table. pressing (26), and possibly a plate, for example of aluminum, disposed between the counter-pressing table (26) and the at least partly soft support (24). 14. Device (28) according to claim 12 or 13, also comprising holding means on the counter-pressing assembly, for example air suction means mounted in the counter-pressing assembly and around the support at least partly soft (24).