DE102007037167A1 - Single layered flat coil i.e. circular antenna coil, producing method for smartcard, involves maintaining introduction of wire during winding of coil, where height of body is larger or lesser than double outside diameter of wire - Google Patents

Abstract

The method involves temporarily providing a winding body formed of a substrate (11) during winding process, and forming a winding spindle (21) pressed against with its front surface, where the winding spindle comprises a winding core and shoulder area, which is parallel to the front surface. The introduction of a wire (10) is maintained during winding of a coil by the winding spindle, where height of the winding body over the shoulder area at a region of the coil is larger or lesser than a double outside diameter of the wire. An independent claim is also included for a smartcard for radio frequency application.

Description

The The invention relates to single-layer flat coils of wire with several Windings, as used in so-called chip cards for high frequency identification systems (RFID) Find. Such a chip card comprises a coil next to the chip, as an antenna for transmitting information and electrical Performance serves. The ends of the coil wire are with contacts on electrically connected to the chip. For a given coil area and number of turns are the essential requirements for the antenna coil: low electrical resistance, low height, and high flexibility. It follows immediately that the Antenna coils generally take the form of flat coils with spirally laid turns to have.

to There are many known processes for their preparation. A coil can, as usual in microelectronics, from a metal-coated Plastic film are etched out. This process is expensive and time consuming. Alternatively, the turns through Applying spiral conductive tracks on a plastic film "to be printed. However, coils produced in this way have a relative high electrical resistance or prepare, with thicker coating, Problems related to the required flexibility. For these reasons are out in numerous applications Copper wire wound antenna coils more advantageous.

For these it is appropriate, according to the prior art, first to produce the coil separately in the form of a self-supporting coil and then glue it together with the chip onto the chip card. For this purpose, preferably used so-called back wire. This is surrounded by an adhesive layer, which can be activated by the action of heat, solvents or high-energy radiation. The coil is wound on a bobbin with this wire and the adhesive is activated during winding or subsequently. It then results in a self-supporting, inherently stable coil, which is placed on the chip and glued to it. A winding method for such coils is for example in the patent US 5,237,165 described. There and in similar processes, the coil is carried out in two layers. It thus has the height 2D, if D denotes the outer diameter of the wire. The two-layer construction is advantageous if the chip is arranged outside next to the turns of the coil, because then, according to the winding process, both wire ends lie on the outside of the coil and can be connected directly to the chip there.

The height of the antenna coil of smart cards is a basic well-known problem. The smaller the overall height of the coil including its wire ends, the more flexible the card and the better its long-term stability under bending stress. In this sense, single-layer coils are preferable to the two-layer ones, and printed or etched coils are preferable to the conventional wound wire coils. This comparison points to the possibility of producing wire spools of particularly low height by winding the spools of wire of flat cross-section so that the wire rests with its broad side on the substrate. The use of flat wire, whose cross-section has an aspect ratio of 1: 4, would approximately halve the overall height of the coil compared to a conventional coil of round wire of the same cross-sectional area. So far, however, no winding method has been specified, which is suitable for the production of such flat coils with the required orientation of the flat wire cross-section. The in the patent US 6,114,937 The proposed proposal to produce such coils by embedding copper in a superficial Rechtecknut the substrate appears to be little suitable for use in smart cards, as it is quite expensive due to the numerous necessary coating processes.

A simpler method for producing antenna coils is to lay an insulated round wire on a substrate, as in the European patent EP0753180 described. The wire is designed in single NEN, each straight sections under tension on the substrate. At the end of each section, it is selectively bonded to the substrate, such as by gluing, to create an anchor point for laying the next section. A rectangular coil with M turns therefore requires at least 4M connection points. A round coil shape can be approximated in this technique by a polygon, and thus requires much more connection points. The manufacture of flat antenna coils with many turns is therefore time-consuming even with this technique. In addition, here generally hinders any connection point with a small bead of adhesive or substrate material, the laying and bonding of the subsequent turn, so that the individual coil turns can not be installed form-fitting close together.

It is therefore the task of flat as possible, so single-layer wire coils with several turns on an insulating substrate in the most economical manner to produce, ie with a minimum of time and work steps such as gluing and transfer of the coil. The need for such a method is particularly for the production of rectangular flat coils, because they allow to use the given area of a chip card better than circular coils. He also insists on flat coils Flat wire, which, in contrast to round wire with the same cross-section allows for a lower overall height of the coil.

According to the invention this task by a manufacturing method with the features of claim 1.

After that the antenna coil is produced in two steps. in the first, the coil is wound directly on the substrate, in the second it becomes mechanically and electrically with substrate and chip connected. The positive winding of the coil directly on the chip card makes the transfer of the coil and a necessary intermediate substrate Überflüs sig. The coil is wound continuously in one operation, so that the numerous interruptions of the winding process, the are required with multiple attachment of each turn, can stay undone. Instead, the bonding takes place All windings of the flat coil with each other and with the substrate together. With advantageous process control this can Bonding even at several points of the coil circumference at the same time be done, for example, by a corresponding number parallel working Ultrasonic heads, or by heating with a corresponding split laser beam. In this case, the number of bonds reduced from typically 4 · M to a single one. These features of the manufacturing process allow a significant Shortening the production time of a chip card opposite the state of the art. It should be noted that for a mass product like smart cards already a small time saving economically can be decisive.

One Another advantage of the manufacturing process by winding according to claim 1 is the improved dimensional stability of the coil and the resulting reduced Tolerance of inductance. Both follow from that at the Winding with sufficiently high winding tension all coil turns form fit lie together.

After all the method according to claim 1 has the advantage that it is suitable is for the production of flat coils made of flat wire in such orientation that the wire with its broadside up the substrate rests, which increases the height of the coil reduced.

These and other characteristics of the method will be discussed in more detail below described with reference to the figures and an explanation of the necessary Technical terms. Show it

1 the basic structure of a chip card with a chip and an antenna coil,

2 an arrangement for winding a circular antenna coil by common rotation of smart card and pressed mandrel, with fixed wire unwinding device,

3 same arrangement as 2 in a side view,

4 a mandrel for circular coils, in particular its end face and shoulder surface,

5 another embodiment of the winding method in which the chip card and winding mandrel are fixed and instead the unwinding device is rotated in the form of a winding head,

6 a mandrel for producing rectangular flat coils,

7 a further embodiment of a winding mandrel for rectangular flat coils,

8th a winding mandrel having a gap through which tools for holding the wire beginning, for contacting and for gluing the coil can be brought to the substrate,

9 (a) a circular single-layer flat coil; and

9 (b) a rectangular single-layer flat coil, also a bifilar single-ply flat coil and various cross-sections are given by flat coils here.

• "Flachspule", dass die Spule die geringstmögliche Bauhöhe hat, die bei Erfüllung aller vorgegebenen Anforderungen wie Spulenfläche, Windungszahl, Induktivität, elektrischer Widerstand, konstruktiv erreichbar ist. Dies zeichnet die einlagige Drahtspule prinzipiell gegenüber allen mehrlagigen Ausführungsformen aus. Eine solche einlagige Spule, gewickelt aus Kupferdraht, bietet auch ein Höchstmaß an Flexibilität und an mechanischer Zuverlässigkeit gegenüber Biegebeanspruchungen.
• "Flachdraht" einen Draht mit annähernd rechteckigem oder elliptischen Querschnitt, dessen minimaler Durchmesser wesentlich kleiner ist als der maximale.
• "rechteckförmig" bei einer Spule, dass jede Windung die Form eines Rechtecks mit abgerundeten Ecken hat.
• Der "Wickeldorn" 21 ist ein metallisches oder isolierendes Werkzeug. Er hat eine Stirnfläche 40 und eine Schulterfläche 41, beide mit guter Ebenheit, die zusammen die Höhe H des Wickelspaltes definieren.
• Der "Wickelkern" 42 ist der zentrale Teil des Wickeldorns. Er ist auf einer Seite durch die Stirnfläche begrenzt. Er nimmt die erste Spulenwindung auf. Er kann zusammenhängend sein wie in 6, oder sich aus mehreren Teilstücken zusammensetzen wie in den Beispielen der 7 und 8.
• Die "Schulterfläche" 41 bildet die andere Begrenzung des Wickelkerns. Sie liegt im Abstand H parallel zur Stirnfläche.
• Der "Wickelzug" ist die Kraft, mit welcher der Draht von der Abwickelvorrichtung 24 gebremst wird, damit er sich formschlüssig zunächst um den Wickelkern und dann um die jeweils vorangehende Spulenwindung legt.
• Unter "Verkleben" der fertig gewickelten Spule mit dem Substrat wird hier ganz allgemein die Ergänzung der formschlüssigen Berührung von Spule und Substrat zu einer stoffschlüssigen Verbindung mittels eines Fügeprozesses bezeichnet. Dies umfasst alle Arten des Klebens mit einem Klebstoff oder mit einem klebrigen Substrat, wobei der Klebeprozess durch Hitze, Druck, Ultraschall, energiereiche Strahlung, chemische Reaktionen oder anders aktiviert wird.
• Die "Kontaktierung" von Drahtspule und Chip stellt den elektrischen Kontakt zwischen beiden her. Sie ist durchführbar nach einem der in der Deutschen Patentschrift DE19627819 beschriebenen Verfahren: durch Thermokompressionsschweißung mittels einer Thermode oder Ultraschallkopf, durch Löten mit einem Laserstrahl oder nach einem anderen der zahlreichen, dem Fachmann geläufigen Verfahren.

Before with explicit reference to the individual drawing figures a detailed explanation for clarification of the method according to the invention suitable objects and their functional properties, some terms are first defined and explained in more detail, which are used in the description multiple times and to be considered as belonging to this. In the present context means:

• "Flat coil" that the coil has the lowest possible height, which is achievable in compliance with all specified requirements such as coil area, number of turns, inductance, electrical resistance, constructive. This distinguishes the single-layered wire coil in principle with respect to all multi-layered embodiments. Such a single-layer coil, wound from copper wire, also offers maximum flexibility and mechanical reliability against bending stresses.
• "Flat wire" means a wire of approximately rectangular or elliptical cross-section, the minimum diameter of which is much smaller than the maximum.
• "rectangular" in a coil, that each turn has the shape of a rectangle with rounded corners.
• The "winding mandrel" 21 is a metallic or insulating tool. He has a face 40 and a shoulder surface 41 , both with good planarity, which together define the height H of the winding nip.
• The "winding core" 42 is the central part of the winding mandrel. He is bounded on one side by the face. He picks up the first coil turn. He can be connected as in 6 , or consist of several parts as in the examples of 7 and 8th ,
• The "shoulder surface" 41 forms the other boundary of the hub. It is located at a distance H parallel to the end face.
• The "winding pull" is the force with which the wire from the unwinding device 24 is braked, so that it lays form-fitting first around the winding core and then to the respective preceding coil turn.
• By "gluing" the finished wound coil to the substrate, the addition of the positive contact of coil and substrate to a cohesive connection by means of a joining process is referred to quite generally here. This includes all sorts of bonding with an adhesive or with a tacky substrate wherein the bonding process is activated by heat, pressure, ultrasound, high energy radiation, chemical reactions or otherwise.
• The "contacting" of wire coil and chip establishes the electrical contact between the two. It is feasible according to one of the German Patent DE19627819 described method: by thermo-compression welding by means of a thermode or ultrasonic head, by soldering with a laser beam or any of the numerous, familiar to those skilled method.

to Explanation of the invention will now be to the drawing figures referenced in detail:

1 shows the basic structure of a chip card, with substrate 11 with the chip arranged in a recess of the substrate 12 , and the wire formed into a rectangular flat coil 10 , Its ends are at the contact points 13 and 14 electrically connected to the chip.

2 schematically illustrates a first possibility, following the inventive concept, to produce an antenna coil directly on the chip by winding wire. Although rectangular antenna coils according to 9 (b) are of greater practical interest, it goes in 2 the better view, according to a circular antenna coil according to 9 (a) , In this case, the winding mandrel 21 with its bottom face on the substrate 11 pressed, and winding mandrel and substrate together are about an axis 25 turned. The wire 10 then spins in the direction 26 from an unwinding device 24 from. The latter is positioned so that the wire runs substantially in the plane of the substrate and wraps around the winding mandrel at its lower edge. Crucial for the fact that the resulting flat coil is einlagig, is the formation of this edge. He has an annular shoulder that in 4 . 5 and 6 even clearer. This shoulder together with the substrate forms a winding body with a gap-shaped winding space. In it, the wire lays in the rotation. In the sense of conventional coil winding technique, the shoulder surface of the winding mandrel is the one flange of the bobbin, the substrate the other. The axially measured height H of the winding space, here by the reference numeral 22 marked, must be chosen slightly larger for spools of round wire as the outer diameter D of the wire, so that it can lie down casually in the winding space. The wire diameter is here with 23 designated. On the other hand, the winding space height H must be smaller than twice the outer diameter of the wire, 2D, in order to avoid that turns can overlap in the axial direction. It is optimal for a problem-free winding and low overall height, if the winding space height of the inequality 1.1 · D <H <1.4 · D is sufficient. To produce a perfect winding, it is necessary that the wire during winding is kept constantly under a certain tensile stress F _z . It ensures that each new coil winding overlaps the previous one with a positive fit. The size of this winding pull is according to experience in the range of 1/100 to 1/10 of the tensile strength of the wire. The winding tension can be generated in a known manner by a tension regulator, the part of the unwinding device 24 is.

The Winding a coil made of flat wire is analogous. To the required, lying flat on the substrate orientation To reach the wire, the winding room height H has to Possibility of inequality 1.1 · D <H <1,2 · D suffice, but here for D the minimum diameter of the flat wire is to be used. The winding gap is so narrow chosen that the flat wire only in the "upright" orientation fits. Compared to the inequality mentioned above for round wire, the upper limit of the gap width is smaller here chosen to avoid that the wire is only partially oriented is.

3 is a side view of the winding device 2 , The frame 30 is intended to denote the winding body described, which therefore only temporarily, during the winding process and the subsequent bonding consists. The power 31 , with which the winding mandrel 21 is pressed against the substrate, must be sufficiently large to ensure that the wire can not jam between mandrel and substrate. For this a force of 10-100 N is sufficient. This power 31 corresponds to the same counterforce 32 with which the substrate must be supported on its back. In a flexible substrate is therefore a rigid support plate 33 appropriate. Furthermore, in 3 some already laid wire turns 34 indicated in cross section. The laying angle 35 between the supplied wire and the substrate must be kept as small as possible to run the wire easily into the winding nip. On the other hand, a non-disappearing laying angle, for example in the range of 1 ° -3 °, ensures that small unevenness of the rotating chip card substrate does not catch and tear off the wire. The safe shrinkage of the wire in the winding nip is conveyed by the fact that the winding mandrel at the edge of its lateral surface which is adjacent to the shoulder surface, with a well-polished flat bevel or rounding 36 is provided.

4 shows these details of the winding mandrel 21 for a circular flat coil even clearer, because the end face 40 points upwards in this view. The already mentioned annular shoulder surface 41 is parallel to the face 40 arranged. The distance 22 Both surfaces defines the decisive height H of the winding nip. This is at the same time the height of the central hub 42 , The radial width of the shoulder surface 41 must be at least large enough to accommodate all coil turns on the shoulder surface. Outside this range is the chamfer or rounding described above 36 which guides the wire into the winding nip.

5 is another embodiment of the coil production according to the features of claim 1. The temporarily formed of substrate and pressed mandrel winding body is here at rest, while the wire together with the unwinding device 24 around the axis 25 rotates. A pulley 51 or -Öse brings the wire in the necessary, almost parallel to the substrate direction. The components mentioned can be advantageous to a winding head 50 summarize, comparable to those in the patents US 5,237,165 and US 4,564,9583 described devices.

Contrary to the execution after 2 is the in 5 sketched winding device also suitable to produce on a large substrate many coils in succession, so that in the end results by disassembly of the substrate, a variety of individual smart cards. The rotating winding head with wire unwinding device 24 , Spool and wire tension control is more advantageous for this task because the difficulty of rotating a substrate increases with its size. However, if the mechanical engineering effort for a winding head after 5 becomes uneconomical, the device is after 2 with fixed unwinding device 24 preferable.

6 shows the general form of a winding mandrel for rectangular coils. He has the same characteristics as the spine of the circular, 4 , With respect to the winding, it differs in that here varies the local curvature of each turn along the coil circumference. Straight sections 62 without curvature alternate with sections 61 particularly high curvature in the corners. This places increased demands on the train control. The radius of curvature at the corners 61 is critical. For an antenna coil, it is to be determined as a compromise between the opposite requirements for the largest possible coil area on the one hand and the lowest possible fluctuations in the flow rate of the wire, which reaches a maximum at each corner of the rectangular cross section, on the other. Furthermore, the fact plays a role here, that the straight sections 62 where the wire does not require support, provide the opportunity to install slots or holes in the winding mandrel through which the wound coil turns are accessible for contacting and bonding. This is related to 8th explained in more detail. At the bottom, the radius of curvature is limited in the sense that it must in any case be considerably larger than the wire diameter in order to avoid shearing off the wire. Practically useful radii of curvature are in the range 1-10 mm.

7 and 8th show a further possible embodiment of a mandrel for producing rectangular flat coils. In this embodiment, the end face in 4 sections 70 disassembled, which are respectively wrapped at 90 ° of its circumference of the coil turns. This arrangement offers the possibility of making the winding mandrel adjustable in order to be able to produce rectangular flat coils of different sizes with a single mandrel. Such an adjustment is also advantageously used to reduce the adhesion of the innermost coil turn on the winding core, which may still be due to the winding tension after bonding of the coil at the take-off of the winding mandrel. For this purpose, the distances of the sections are slightly reduced (some 1/10 mm) at the time of acceptance.

After winding, the coil must be mechanically bonded to the substrate at several points of its circumference, and it must be electrically connected to the contacts of the chip. As is known to the person skilled in the art, the mechanical connection can be achieved by means of various bonding methods. Therefore, the possibility is mentioned here merely as an example of a particularly advantageous bonding method to wind the coil of so-called back wire and after completion of the Winding to heat the adjacent wire windings and the surrounding substrate by means of a laser beam, so that they stick together. Alternatively, an ultrasound head could also be used for this purpose. In any case, it is necessary to gain direct access to the wire windings lying on the substrate and in particular to the contacts of the chip with the laser beam or another tool.

8th shows how for this purpose the winding mandrel with an axial slot 80 is provided. It reaches from the substrate of the 2 from down to the level of the shoulder surface. Of course, a hole can be used instead of the slot. Such slots and bores do not hinder the winding process when they are placed at the locations where the course of the coil wires 81 is straight, where they do not require the radial support by the winding core. Several such points are denoted by the reference numeral 82 marked. Their positions are chosen so that they are as close as possible to the sections of the winding core, which are touched by the wire and deflect it with it. Here attaching the winding to the substrate is particularly important.

at a circular coil is the way Such attachment points through slots or holes on rectilinear To place the winding circumference is, strictly speaking, not given. But it can be realized in a good approximation by the slot width is minimized. This problem is of more theoretical interest than in practice Rectangular antenna coils are preferred for chip cards.

9 shows in (a) and (b) the two basic forms of single-pancake flat coils: circular and rectangular, 9 (c) is the schematic representation of a bifilar single-plex flat coil, which can be used as a transformer. It can be prepared by the method of claim 1 by instead of a single wire two wires are wound, preferably those with the same diameters. 9 (d) illustrates a problem that occurs when both ends of a single-pinned flat coil to be connected to the chip on the same side of the coil, the inside or the outside to lie. One of the wire ends then has to be routed over the turns of the spool to the side of the other end. The 9 (e-h) are the in 9 (d) indicated cross sections AA 'and BB' by a sol che coil with over the wire end. They will be explained below.

The foregoing description is limited to the essential aspects of the disclosed manufacturing process. It will be apparent to those skilled in the art that many other aspects are important to the successful application of the method. In particular, a wire cutting device is required for automated coil production, to a so-called wire clamp and possibly a wire conveyor. The wire cutting device, after completion of the winding-before or after gluing the coil and contacting the chip-by means of a punching or cutting tool must separate the coil wire from the subsequent wire. At the same time, the end of the subsequent wire coming from the unwinding device must first be held in a defined manner and then possibly conveyed forward a few millimeters, so that it is available as the beginning of the winding during the production of the next reel. Furthermore, holding devices for the coil wire ends may be necessary, especially at the beginning of the winding, and at the end during the bonding of the coil to the substrate. Suitable fixtures typically operate with mechanical, magnetic or pneumatic actuators that press the wire against the substrate or against the winding mandrel. The need for such fixtures is eliminated if the coil starting wire is already connected to the chip before the beginning of winding, such as in 1 sketched way on contact 13 , and the coil end wire after completion of winding at the contact 14 ,

at Use of wire coated with hot melt adhesive the finished wound coil is glued by the wire turns with a hot tool (Thermode) or with an ultrasonic head (Sonotrode) are depressed to the substrate and adhere there. In a series production is this bonding method not without problems, because there is a risk that the pressure tool contaminated with adhesive residues that the wire held on the tool adheres to the substrate, or that the tool the wire surface injured. For these reasons is a non-contact bonding method preferable, for example by heating by means of a laser beam. Also while it is necessary to depress the wire turns on the substrate, to the bond by a common wetting by the molten Adhesive to initiate. Without such a holddown would already Minimal bending of the wire and unevenness of the substrate surface prevent wetting.

After the German patent application DE 10 2006 037 093.7 For example, the required pressure force can be generated by electrostatic attraction between the wire and a counter electrode under the substrate. This possibility of bonding with electrostatic holddown is in 5 indicated. The counterelectrode is the metal plate which is present anyway to support the substrate 33 , You and the wire are over the connections 53 and 54 connected to a high voltage of the order of 1000 volts. The resulting electric field pushes the wire turns against the surface of the substrate. The pressure force is sufficient to improve the positive engagement so that when the adhesive melts the common wetting occurs. This electrostatically assisted bond works with both a mandrel of insulating material and a metallic mandrel.

In addition, the electrostatic force is also advantageous during winding of the coil. It presses the wire against the substrate already in the area 37 of the 2 and 5 where he should run into the narrow winding nip. This makes it possible to produce coils of very thin wire, with diameters in the range of 0.01-0.10 mm, which otherwise, due to its low rigidity, runs the risk of missing the gap due to vibrations during winding. When supporting the winding by the electrostatic attraction, the laying angle 35 who in 3 is indicated to be larger, thereby improving the reliability of the production.

Generally is to be noted for bonding that they are single-layer coils easier is possible than with multilayer, because over the first wire layer located further layers the passage of the Generally hinder adhesive and / or the activating agent would.

Antenna coil and chip of a chip card must be coordinated, not only electrically, but also mechanically, especially in their heights and their relative arrangement to each other. Generally, a reduction in the height of both components is desired, and it is the flatter arrangement next to each other instead of one above the other preferred. However, one-layer flat coils have a problem because their wire ends are on different sides of the winding, one in the outside space, the other inside. The contacting then requires either the superposition of coil and chip, as in 1 , or it must be performed on juxtaposition of one of the two wire ends over the winding away on the other side, as in 9 (d) outlined. 9 (g) shows the lying over the winding wire in cross section. He practically causes a doubling of the coil height and also harbors the risk of short circuit due to friction of coil windings on each other at long-lasting bending load of the chip card. For this reason, the antenna coil is often carried out in two layers with side-by-side arrangement, for example according to the patent US 5,237,165 because with the two-ply construction, the problem of the over-routed wire end is avoidable and the coil is still not thicker than the single-layer with the wire end over it.

Here is the possibility of reducing the height of the single-layer coil by placing the wire locally, in the section 91 - 92 of the 9 (d) , flat presses. It then results in the 9 (h) illustrated situation. Experience has shown that this plastic deformation of a round wire in a flat wire without too much impairment of the mechanical stability of the wire is possible, as long as the reduction of the wire thickness is less than 50%. In this way, the overall height of the coil and the transfer wire can be reduced from about 2 · D to about 1.5 · D by flattening the wire. The process of flattening the selected wire section can be done either before or after the winding of the coil. The printing device can be made quite simple, because the length of the wire section to be pressed is only in the range of 1 mm.

After this the electrical connections of the coil with the chip by contacting and the mechanical connection of the coil to the substrate Bonding are made, the winding mandrel can be removed from the substrate become.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - US 5237165 [0003, 0029, 0042]
• - US 6114937 [0004]
• EP 0753180 [0005]
• - DE 19627819 [0022]
• US 45649583 [0029]
• - DE 102006037093 [0039]

Claims (15)

A method for producing flat single-layer coils of insulated wire on an insulating substrate in two steps, wherein in the first step, the wire is wound in the winding space of a temporarily formed bobbin and in the second step, the turns of the wire coil are at least partially cohesively connected to each other and to the substrate , characterized in that - the winding body ( 30 ) temporarily during the winding process from the substrate ( 11 ) and one with its end face ( 40 ) pressed mandrel ( 21 ), - that this mandrel ( 21 ) at least one winding core ( 42 ) and at least one to its end face ( 40 ) parallel shoulder surface ( 41 ), - that the beginning of the wire ( 10 ) during winding of the mandrel ( 21 ), and that the height H of the winding core ( 40 ) over the shoulder surface ( 41 ) in the area ( 41 ) of the coil is larger than the simple and smaller than twice the outer diameter of the wire. Method according to claim 1, characterized in that the mandrel ( 21 ) and substrate ( 11 ) formed winding bodies ( 30 ) about an axis perpendicular to the substrate ( 25 ), while that of a fixed unwinding device ( 24 ) incoming wire ( 10 ) is wound to the spool. A method according to claim 1, characterized in that a winding head ( 50 ), which has a wire unwinding device ( 24 ) to an axis perpendicular to the substrate ( 25 ) is rotated while the wire ( 10 ) by wrapping the wound body ( 30 ) to the coil. Method according to one of the preceding claims, characterized in that the end face ( 40 ) of the winding mandrel ( 21 ) from several coplanar faces ( 70 ) is composed. Method according to one of the preceding claims, characterized in that the mandrel ( 21 ) at the transition between its shoulder surface and its lateral surface a polished chamfer ( 36 ) or rounding off. Method according to one of the preceding claims, characterized in that the winding mandrel ( 21 ) in the area of the coil turns ( 81 ) at least one slot ( 80 ) or a hole that has access to the on the substrate ( 11 ) allow resting winding. Method according to one of the preceding claims, characterized in that the winding mandrel ( 21 ) comprises an actuator that holds the wire beginning while winding. Method according to claim 7, characterized in that that the actuator the wire beginning when winding against the substrate suppressed. Method according to claim 8, characterized in that that the at least partially cohesive connection the coil turns with the substrate by gluing done. Method according to one of the preceding claims, characterized in that the at least locally cohesive connection of the coil turns with the substrate by means of adhesive bonding, which passes through a slot ( 80 ) or a bore of the wound body ( 21 ) is activated by means of a thermode, a sonotrode, a laser beam or other high-energy radiation, or by supplying a reaction-triggering substance. Method according to one of the preceding claims, characterized in that the wire ( 10 during winding by electrostatic attraction of at least one electrode ( 33 ) in that area ( 37 ), which immediately before the entry of the wire into the chamfer ( 36 ), is pressed against the substrate. Method according to one of the preceding claims, characterized in that the wire ( 10 during gluing in the region of the coil by electrostatic attraction of at least one electrode ( 33 ) is pressed against the substrate. Method according to one of the preceding claims, characterized in that one of the two wire ends of the coil is passed over the coil turns ( 9d ) and in this area ( 91 - 92 ) is plastically deformed by applying lateral pressure so that the wire cross-section is flattened in this area ( 9h ). Method for producing a flat coil having two or more windings, in particular according to one of the preceding claims, characterized in that during winding a corresponding number of wires are fed simultaneously ( 9c ). Chip card for RFID applications with at least a transponder comprising a wire wound antenna coil, characterized by their preparation using the procedures according to one of the preceding claims.