EP2150925A1

EP2150925A1 - Method for producing a device comprising a transponder antenna and device produced thus

Info

Publication number: EP2150925A1
Application number: EP08750265A
Authority: EP
Inventors: Jean-François MARTINENT; Laurence Robles; Blandine Alleysson
Original assignee: Gemalto SA
Current assignee: Thales DIS France SA
Priority date: 2007-05-21
Filing date: 2008-05-13
Publication date: 2010-02-10
Also published as: EP1995688A1; WO2008141977A1

Abstract

The invention relates to a method for producing a device comprising a radio frequency transponder antenna, the method comprising a step of producing the antenna with two terminal sections (7,8) by a sewing or embroidery technique. The method is characterised in comprising a step of fixing a material for stabilising and reinforcing the substrate after producing the antenna and before inclusion of a module. The invention further relates to the device produced.

Description

Method for producing a device comprising a transponder antenna and device obtained

The invention relates to the field of radio frequency transponders. In particular, it relates to a method of producing a device comprising a wired transponder antenna.

The invention aims to be used in particular in the manufacture of a radiofrequency electronic insert of small thickness and low cost and having good communication properties including range.

Such an insert comprises at least one antenna on a substrate intended to be connected to a microcircuit; it is intended in particular to be inserted in a laminate of sheets, an electronic passport cover, an identity card, any product with a radiofrequency communication function; and in fact its thickness must be very small.

Among the processes for producing a wire antenna on a substrate, the technique of inlaying wire by ultrasonic on a substrate is known, but this technology is relatively slow and expensive. For example, in the patent EP 0880 754 B1, the antenna wire made of wire encrusted in a polymer sheet overflows the contact pads of a chip already in place or its corresponding location in a cavity made before the antenna and a connection is made by welding including thermo compression.

This method has the disadvantage of being slow and expensive and for an implementation variant, to require a cavity prior to the production of the antenna for maintaining the microcircuit and / or the thickness compensation of the micro circuit

Embroidery antenna production techniques are also known from patent application JP 2002 298110 A, in which a module is first fixed on a substrate, the antenna is then attached by stitches on the substrate. For connection, the wire extends over the beaches and tightens by contacting the contact pads of the module.

In EP 1328899 B1, the antenna is made using a metal wire sewn on a sheet and contact pads previously disposed on the sheet are connected to the antenna wire. A chip is carried on the substrate and connected in particular by a welded wire connection

"wire bonding" with pellets. This technique requires a pre-positioning of the pellets beforehand and to coat the connections of the chip later. The presence of the module on the substrate before the realization of the antenna, can be a brake to the rate of production of the antenna in large series.

The invention aims in particular to solve the aforementioned drawbacks of realization of wire antenna.

It aims at a wired antenna production method that is economical and good radio performance and allows a small overall thickness, the electronic module being included. The invention lies in its concept first of all to select the seam or embroidery and to use a support extremely easy to embroider or sew with a wire to achieve high rates of antenna production;

Then, so as to be able to correctly manipulate and index the support during other steps necessary for the manufacture of an electronic insert comprising, for example, cavity production, transfer, connection - conventional steps in the card industry. chip - the support is reinforced to have a reinforced resulting support having dimensional stability characteristics at least substantially comparable or equivalent to the stability of a plastic sheet, for example PVC of about 50 microns.

Then reinforcing the support with a reinforcing material for in the frame of realization. To this end, the subject of the invention is a method of producing a device comprising a radio frequency transponder antenna, said method comprising a step of producing the antenna comprising two end portions by a sewing or embroidery technique;

The method is distinguished in that it comprises a step of fixing a stabilizing material and reinforcing the substrate after completion of the antenna and before transfer of a module.

Thus, the invention makes it possible, on the one hand, to optimize the rate of antenna production and, on the other hand, to prepare the support so that it finds properties of conventional mechanical strength enabling it to be used under operating conditions. conventional required by the subsequent steps of producing electronic insert.

The invention allows flexibility of manufacture of the device insofar as the antenna realization can be carried out in the very first step since it is completely uncoupled from the other manufacturing steps of the device including in particular the step of previously reporting the contact pads or the step of making a pre-cavity under the antenna portions to be connected, etc.

In general in the prior art the addition of a sheet is performed in order to compensate for a thickness of chip or module reported and connected; Or for the purpose of putting a layer of structure. It comprises for this purpose a cavity prior to the addition of a compensation sheet on the side of the antenna or the module side. In addition, contrary to the invention, a support was generally used which facilitates subsequent operations of module transfer, cavity machining, connection, addition of a module thickness compensation film.

According to other features of implementation, the method: - the substrate comprises a fabric; the fabric has warp and weft yarns of polyamide, polyester or poly-cotton composed of yarns of 48 to 76 dtex and / or natural resting thickness between 80 and 300 μm; This fabric is easy to embroider with a wire at high speeds. the method comprises, after the production of the antenna, a step of forming a cavity in the substrate and a sheet or reinforcing layer in the vicinity of the terminal connection portions of the antenna;

- The method comprises a step according to which is reported contact pads associated with a microcircuit facing terminal portions of the antenna, the microcircuit being inserted at least partially into the cavity and the pads connected to the contact pads;

the stabilizing material comprises a porous thermoplastic.

The invention also relates to a device comprising a radiofrequency transponder antenna with two end portions, made by a stitching or embroidery technique, on a flexible substrate;

The device is distinguished in that it comprises a stabilizing material reinforcing the substrate and fixed on one side of the substrate opposite to that carrying the end portions.

According to other features of the device:

the substrate comprises a fabric; this tissue has the properties referred to above;

- The device comprises a cavity (26) in the substrate and sheet or reinforcing layer near the terminal connection portions of the antenna.

contact pads are associated with a microcircuit (20) and arranged facing the substrate and terminal portions of the antenna resting on the substrate, whereas the microcircuit is inserted at least partly into the cavity (26) and connected on air.

The subject of the invention is also an electronic radiofrequency communication product, such as a contactless smart card, a passport comprising the above device or obtained according to the method above.

Other features and advantages of the invention will appear on reading the description which follows, given by way of illustrative and nonlimiting example, and with reference to the appended figures for which:

FIG. 1 illustrates a schematic view of a transponder that can be obtained according to an embodiment of the method of the invention; - Figure 2 illustrates a detail of the antenna of Figure 1 performed by embroidery on a woven substrate;

- Figure 3 illustrates a partial sectional view of the device according to section A-A of Figure 1 wherein the strength of the substrate is reinforced with a sheet; FIG. 4 illustrates a sectional view of a device according to a preferred embodiment of the invention;

- Figure 5 illustrates a sectional view of a device according to Figure 3 connected to a module according to a possible embodiment;

- Figure 6 illustrates a sectional view of a device according to Figure 4 connected to a module according to a preferred embodiment;

FIG. 7 illustrates a step of producing a plurality of antennas on a substrate and laminating a reinforcing sheet on the substrate;

FIG. 8 illustrates a step of connecting a contact pad in a preferred mode using a welding tool and an anvil;

FIG. 9 illustrates the steps of the method according to a preferred mode of implementation.

In FIG. 1 according to one embodiment of the invention, the device comprises a radiofrequency transponder antenna 3 with two end portions 7, 8, the antenna being made on a substrate 2f by a wire type embroidery or sewing or equivalent. The antenna is connected to a module at contact pads of a module.

In Figures 2 and 3, the antenna 3 is fixed by embroidery or stitching on a flexible substrate comprising a fabric 2f with an insulating thread 19 insulating. The material of the substrate is such that it is not a hindrance to the penetration of the embroidery needle or seam into the material and therefore a brake to sewing or embroidery rates; The support is preferably a low-woven fabric, openwork; a support having a loose mesh of threads or fibers such as that obtained by weaving.

The support is flexible to the extent that it has no hold, stiffness like all fine fabrics. The mesh (m) loose between warp and / or weft son is for example between 200 microns and 300 microns in both directions) polyamide of 48 dtex or 80 microns thick at rest. In addition, it is not dimensionally stable insofar as it can stretch normally by hand especially diagonally for example at least from 3% to 20%. This elongation is less than 1% in the direction of travel of the substrate sense warp or weft in production.

The device according to the invention therefore comprises, in an intermediate stage, the wire antenna on a flexible substrate made of fabric or equivalent capable of being embroidered or sewn easily at the highest rate allowed by a sewing or embroidery bench having by example dozens of embroidery or sewing heads.

Since the handling of the fabric, the support of an embroidered antenna, being very delicate (soft and porous woven material) to stabilize it, the device comprises a reinforcing material 15 in the form of a sheet or layer on one side of the substrate opposite to that on which the end portions 7, 8; A stabilizing material, such as a thermoplastic material: polyvinyl chloride (PVC), polycarbonate (PC), polyesters (eg PET), PE filled with silica; or polyurethane; or paper; or synthetic paper, reinforcing the tissue is therefore attached to the substrate. In Figure 4, the device preferably comprises a cavity 26 for housing a component at least in part and thus to limit the resulting total thickness. The cavity is advantageously made by machining in particular punching in a single operation in the two layers or materials comprising the substrate 2f and additional material 15.

In this case, if the fabric is very loose and the material is very malleable, the cavity can be made by pressing by compressing the material with a tool or by directly transferring the module.

Prior cutting in a non-dimensionally stable substrate would be difficult to position or index.

In Figure 5, the device comprises a module connected to the antenna. It may comprise perforations 17 optionally at least partially closed, resulting from a preferred method of connection described later. In FIG. 6, chip 20 with or without coating 21 is introduced at least partially into cavity 26.

In this embodiment the device comprises a connection with a hybrid antenna wire 22 insofar as the antenna wire 3 is associated with four non-conductive wires 24; however, the association can count at least one non-conducting thread. The non-conductive wires 24 are preferably heat-fusible or thermoplastic to melt under the effect of the thermal energy or energy of the ultrasound.

Referring to Figures 4, 6, 7, 8 10 will now be described a preferred embodiment of the method of the invention to meet the objectives, but first presenting the difficulties encountered.

For the manufacture of inexpensive insert, the inventors have selected in particular wire antennas for example sewn, embroidered or support equivalents comprising fabrics. Various technical problems encountered are described in part below.

The inventors have preferably targeted a production on substrates which may comprise a plurality of sewn or embroidered antennas.

In particular, in embroidery especially for productivity and ease of implementation, several antennas are first made at the same time on embroidery benches preferably on a textile support, fibrous such as a fabric, woven, non-woven, or support accepted by the embroidery or sewing machines shown in figure 9.

However, other insulating substrates are not excluded, which may be a thin synthetic leather or a material that can be sewn or embroidered, in particular fiber composite or fabric and polymer sheet.

For reasons of discretion of the insert, later laminated or added to an object, but also productivity and ease of sewing or embroidery, the support is a very fine fabric.

The substrate may have different thicknesses, generally less than or equal to that of a chip card of 0.76 mm so as to serve as an insert between two films or sheets or to support a cover sheet and / or or print. Typically the substrate may have a thickness ranging for example from 0.05 mm to 0.5 mm.

However, the inventors have noted a lack of dimensional stability or hold of certain substrates including fabric suitable for this series production especially when they are continuous and scrolling. This lack of resistance makes it difficult or impossible to precisely position the modules, microcircuits or contact pads or cavities, in particular by indexing on the substrate, before or after the production of the antennas. The addition of a sheet or reinforcing material or other fabric to the substrate, possibly with pre-established module receiving cavities as imagined by the inventors, would bring dimensional stability to the substrate but also has drawbacks: due to the fact that lack of substrate strength and difficult indexing, the cavities may be poorly positioned.

Conversely, the addition of this reinforcement, without cavity, would bring dimensional stability to the substrate, but this would increase the difficulty of a connection of practice and quality by ultra-sound or thermo-compression as far as it there would be no cavity to introduce a chip or module and bring the contact pads of the connection portions of the antenna and perform a good weld.

The inventors have found that the electronic components or contact pads must preferably be carried on the substrate after completion of the antenna for reasons of ease of sewing the antenna, production rate, and because of the difficulty of the placement of the antenna. Module module and connection to realize an economical antenna.

In addition, the antenna may be sheathed with an insulator, in particular to make an insulating bridge crossing the turns or be associated with non-conductive wires or fibers, in particular for reasons of strength, preventing breakage of the wire or fixing on the support. . In this case, it can occur contamination, pollution of the welding tool during the connection by ultrasonic welding or thermo compression since the welding tool (thermode) being applied on the wire, it is put in contact with Pollutant materials surrounding the antenna wire in a configuration where the module is postponed adjacent to or below the coils of the antenna.

In addition, since the wired antenna rests on the substrate, the inventors have imagined a transfer and connection of the ranges made from above, the antenna may have a tendency to drive into the sheet or fibrous mass added under the effect of the pressure of the welding means according to the nature of the materials used.

Thus, the method of the figure is elaborated as hereinafter. In step 100, the method of producing a device comprising a radio frequency transponder antenna, said method comprising a step of producing the antenna with two end portions by a sewing or embroidery technique. Several antennas are made at the same time as shown in Figure 7.

The antenna wire 3, 7, 8 (fig.6) may comprise at least one insulating coating on its entire surface; It can also cumulatively or alternatively be in contact with insulating wires 24 in places. The antenna wire is fixed on the substrate using a non-conductive wire 19, called embroidery or sewing thread.

Preferably, the antenna wire is a hybrid wire associated with at least one non-conductive wire 19 to allow such a better rate without breaking the wire. This non-conductive wire at least partially surrounds the antenna wire and is somehow an insulating cladding in places.

Preferably, the non-conductive wire is heat fusible or thermoplastic to allow their removal or elimination at the weld zone.

The embodiment of the embroidery antenna may preferably comprise a step of producing a stitching point (not shown) of sewing antenna thread, embroidery, knitting at the end of at least one of said portions. and a step of eliminating said stopping point comprising removing material from the support facing the stopping point and possibly forming a cavity. The terminal portions of the antenna or stopping points may be superimposed or made in an area of the support to be eliminated. In case of elimination, of a point stopping by punching the corresponding terminal portion extends to the edge of a cavity.

In step 200 Next, according to one characteristic, the method comprises a step according to which a reinforcing material (FIG 7) is in the form of a sheet or layer on one face of the substrate opposite to that carrying the end portions. This material stabilizes the lack of hold of the fabric.

The reinforcing layer or sheet is disposed directly after the antenna has been made so as not to interfere with the rate of antenna production.

The stabilizing material in the example comprises a porous thermoplastic known under the trademark Teslin diffused in particular in sheet form.

The assembly can be achieved by thermal welding (melting of the materials) or addition of an adhesive (film, liquid) by hot or cold lamination.

An effect similar to the addition of a sheet may be obtained by impregnating or coating a layer or spraying a product such as a coating, a primer, a resin, a polymer foam capable of dimensionally stabilizing the substrate.

In step 300, the support being stabilized, it is then possible to manipulate it and perform more conventional steps, including more easily transfer contact pads on the substrate.

However, in a preferred embodiment (FIG 4) according to another characteristic, there is proceeded to a step of forming a cavity 26 in the substrate and / or sheet or reinforcing layer near the terminal connection portions of the antenna in order to introduce the chip or module. The cavity is made by punching, but one could consider forming by pressing or stamping or other at least partial machining of the substrate.

In step 400, (FIG 8) the ranges are reported so as to have a surface facing a terminal connection portion of the antenna resting on the substrate; If necessary, a chip can be reported including chip returned to the beaches or the substrate or a contact pad for a conventional connection by any known means, or even welded wire type.

Preferably, the tracks are already connected to an electronic microcircuit such as a chip; And the microcircuit is inserted at least partly in the cavity, the remaining beaches outside the cavity resting on the track portions or terminal antenna ends themselves resting on the support as shown in Figure 6.

In step 500 (FIG 6) their connection is made to the terminal portions of the antenna; The connection is made in the form of a welding by energy input between the beaches and the terminal portions, the welding energy is applied directly to the beaches using a thermode for a thermo-compression type welding or an ultrasonic probe for ultrasonic welding.

For welding, an anvil is preferably used which bears against the insertion of the terminal portion of the antenna into the support. The anvil is all the more recommended that the antenna wire has a tendency to sink into the substrate due to the fineness of the wire and / or softness of the substrate and / or reinforcing material.

The anvil E pierces at least the sheet or reinforcing layer facing the terminal portion to be connected so that the portion to be connected is supported by the anvil during welding. The section of the rectangular anvil may have a rectangular or square section for example between 0.3 x 1 mm ² to 1 x 5 mm ²

Due to the presence of the non-conductive wires 19 and 24, according to the invention, the tool (thermode) (T) is applied to the metal pad 16, which has the effect of melting the fixing wire and / or wire associates passing underneath and without pollution of the welding tool.

Other connections are possible such as, for example, machining at least the surface of the conductive son in case they are sheathed with varnish, then a conductive adhesive connection.

In step 600, the support is assembled with at least one sheet on the side opposite to the reinforcing sheet. The sheets may for example be made of materials used for sheets or passport cover or smart card or other object. We then proceed to cuts in the format. If necessary, cutting can be done at other stages.

Claims

1. A method of producing a device comprising a radio frequency transponder antenna, said method comprising a step of producing the antenna (3) with two end portions (7, 8) by a sewing or embroidery technique, characterized in that it comprises a step of fixing a stabilizing material (15) and reinforcing the substrate (2f) after producing the antenna and before transfer of a module.

2. Method according to the preceding claim, characterized in that the substrate comprises a fabric (2f).

3. Method according to the preceding claim, characterized in that the fabric has a thickness of between 80 microns and 300 microns at rest and / or uses 48 to 76 dtex son.

4. Method according to one of the preceding claims, characterized in that the method comprises after completion of the antenna, a step of forming a cavity (26) in the substrate and sheet or layer of reinforcement (15) to proximity of the terminal portions (7, 8) of connection of the antenna.

5. Method according to one of the preceding claims characterized in that the method comprises a step according to which one reports contact pads (5, 6) associated with a microcircuit (20) facing terminal portions (7, 8) of the antenna, the microcircuit being inserted at least partly into the cavity (26) and the pads are connected to the contact pads.

6. Method according to one of the preceding claims, characterized in that the stabilizing material (15) comprises a thermoplastic material such as polyvinyl chloride (PVC), polycarbonate (PC), polyesters, polyethylene (PE) loaded silica or polyurethane (PU) or natural paper or synthetic paper.

7. Device comprising a radiofrequency transponder antenna having two end portions (7, 8) made by a sewing or embroidery technique, on a flexible substrate (2f), characterized in that it comprises a stabilizing material (15) reinforcing the substrate and attached to a face of the substrate opposite to that carrying the terminal portions of the antenna.

8. Device according to the preceding claim, characterized in that the substrate comprises a fabric (2f).

9. Device according to the preceding claim, characterized in that the fabric has a thickness of between 80μ and 300μ and / or son of 48 and

76 dtex.

10. Device according to one of claims 7 to 10, characterized in that it comprises a cavity (26) in the substrate and sheet or reinforcing layer near the terminal connection portions of the antenna.

11. Device according to claim 10, characterized in that contact pads are associated with a microcircuit (20) and disposed facing the substrate and terminal portions of the antenna resting on the substrate, while the microcircuit is inserted at less partially in the cavity (26) and connected to the antenna.

12. Electronic radiofrequency communication product, such as a contactless smart card, a passport, comprising the device according to one of claims 7 to 12.