DE102017201634B3 - Strand-shaped element and method for producing a strand-like element - Google Patents

Abstract

The strand-shaped element, which is formed as an electrical line, has a core and a surrounding jacket, which is surrounded by a conductive structure. The conductive structure is applied to the cladding by means of a laser direct patterning process and forms a shielding layer. By this measure, cables with very small diameters can be reliably and effectively provided with a conductive structure, in particular shielding.

Description

The invention relates to a strand-like element which extends in a longitudinal direction and has a core and a surrounding jacket which is surrounded by a conductive structure. The invention further relates to a method for producing such a strand-shaped element.

Under strand-shaped element are generally understood to be longitudinally extending structure having preferably circular cross-section. The strand-shaped element in particular has a diameter in the range of single-digit millimeters to tens of centimeters, without being limited thereto.

From the DE 10 2011 050 895 A1 is designed as a rod-shaped plastic part to take it strand-shaped element.

In US 2017/0 068 341 A1 a pen is described, which serves for an input on an electrical device.

The US 2014/0 232 503 A1 discloses a particularly mechanically flexible electrical coil assembly and a method for their production.

The DE 10 2014 206 558 A1 describes a method for producing a Molded Interconnect Devices circuit carrier (MID circuit carrier) and a MID circuit carrier having a substrate. On at least one surface region of the substrate metallic interconnects are formed.

From the DE 103 17 433 A1 is to remove a data cable with a base body having a central signal contact, which is surrounded by a dielectric material layer and a shield.

The strand-shaped element is preferably a flexurally flexible element, such as a hose. Alternatively, the element is rigid and formed as a tube. In one embodiment as a tube or hose, the core is preferably formed by a cavity.

In particular, however, the strand-shaped element is an electrical line.

For shielding of electrical lines fundamentally different screen variants are known. In addition to braided or rope screens made from a large number of individual shielding wires, film screens are often used, especially in the case of data lines, in which the film is either folded along or also wound. The shield is generally a conductive structure.

For many applications, especially in the automotive industry lines with small outer diameter are desired, for example, for supply lines over which only small currents must be transmitted and especially for data lines. However, the latter still often require shielding in order to achieve the desired transmission characteristics, especially in high-frequency data transmissions. Due to the very small outer diameter, however, there is a problem in applying the shield layers. Thus, both the layer thickness and the stripe width of the applied screen foil are limited in terms of production technology. Too thin a film would be mechanically unstable, so that it can no longer be applied process reliable. With regard to the width of the film currently narrowest films have a width of 6 mm, over which the outer diameter is limited downwards. This typically results in a minimum outer diameter of the shell on which the shield is applied of about 2 mm.

Proceeding from this, the present invention seeks to provide a line with a small outer diameter, with a conductive structure, which is simple to apply process technology.

The object is achieved according to the invention by a strand-shaped element and by a method for producing such a strand-like element. The strand-like element extends in a longitudinal direction and has a core and a surrounding shell, which is surrounded by a conductive structure, wherein the conductive structure is applied by means of a laser direct structuring method on the jacket and this the jacket of a Plastic material is made, which has additives, wherein in the region of the conductive structure, the additives are activated by a laser treatment and on the activated regions, a metal layer is applied.

In the method for producing a strand-like element, in a first step, a surface of the shell is treated by means of at least one laser and in a second step, a metal layer is applied.

The advantages and preferred embodiments mentioned below with regard to the strand-like element are to be transferred analogously also to the process and vice versa.

In the present case, the strand-shaped element is designed as an electrical line and the conductive structure forms a shield surrounding the jacket and thus the core. The core generally has one or more transmission elements, for example optical and / or electrical transmission elements either for power transmission or for data transmission. Hereinafter, the advantages and preferred embodiments - without limiting the generality - in particular in connection with the line explained in more detail. In the simplest case, the core is a conductor, for example a conductor wire or else a stranded conductor. Core and shell form a core in this simplest embodiment, ie it is a single-core shielded cable or a coaxial cable. Alternatively, the core consists of a plurality of individual wires or sub-lines, which are surrounded by a common jacket, on which then the conductive structure is applied to form a shielding layer. Preferably, the conductive structure is still surrounded by an outer sheath.

The method described here makes it possible to produce conductive structures on the outside of the jacket in a simple manner even with such elements. In general, these structures - in addition to the use as a shield - can be used in a variety of ways. For example, the conductive structure is used as a heating element (electrical resistance heating) for heating in particular the element itself or also generally as conductor tracks, e.g. used for data transmission or for a power supply. In addition, by suitable structuring of the conductive structure, it is also possible to use electrical components on the cladding, e.g. a coil, capacitor, antenna, etc. are formed.

According to the invention, provision is generally made for the conductive structure, in particular the shielding layer, to be applied directly to the jacket by means of the so-called LDS method (laser direct structuring). The jacket consists for this purpose of a plastic material which has additives. These are metallic, in particular organometallic, additives. In the area of the conductive structure, these additives are exposed on a surface of the cladding by a laser treatment and activated. By the laser treatment, in particular, a certain material removal or roughening of the surface has taken place, so that the laser-treated surface areas differ from those which may not have been laser-treated. The added additives are specifically designed so that they form so-called metallic nuclei due to the laser treatment. Finally, a metal layer is applied to these activated areas of the surface. The surface therefore undergoes activation by the laser treatment as a result of the introduced additives. The metal layer is deposited on the activated surface areas. Under metal layer here is understood both a flat, continuous layer as well as an interrupted layer, which is formed only by individual possibly also not interconnected metallized areas. The metal layer is in this case applied in particular by a chemical deposition process. Alternatively and in particular in addition, the metal layer is applied by a galvanic deposition process.

The LDS method is basically known and is used, for example, for the production of printed conductors on complex 3D components.

In terms of manufacturing, in this case the procedure is such that the surface of the jacket is irradiated by means of at least one laser, thereby exposing and activating the additives. Subsequently, the metallic layer is applied. This is done especially in a metallization by particular chemical deposition, through which the line is passed. The metallization process is preferably an electroless process. In this case, a copper layer is preferably deposited as the metal layer. In principle, however, other metals can be applied.

• - Aufgrund der feinen, mit einem Laser erzeugbaren Strukturen lässt sich dieses Verfahren insbesondere auch bei Leitungen mit nur geringen Außendurchmessern anwenden. Eine Miniaturisierung der Leitung ist daher nicht durch die Schirmung begrenzt.
• - Aufgrund des unmittelbaren Aufbringens durch das Abscheiden sind zudem auch extrem dünne Schichtdicken für die leitfähige Struktur ermöglicht, ohne dass Defekte in der leitfähige Struktur und damit der Schirmung zu befürchten sind. Insgesamt ist dadurch eine Metalleinsparung erzielt. Bevorzugt werden beispielsweise lediglich wenige Atomlagen aufgebracht. Die Schichtdicke ist in einfacher Weise vorzugsweise über die Verweilzeit beim Metallisieren im Metallisierungsbad einzustellen.
• - Weiterhin sind durch das Laser-Strukturieren beliebige Geometrien für die Ausbildung der leitfähigen Struktur ermöglicht, sodass die leitfähige Struktur für den jeweiligen Anwendungsfall optimiert ausgebildet werden kann. Durch diese hohe Flexibilität für die Strukturierung aufgrund von unterschiedlichen Einstellmöglichkeiten beim Laser in Kombination mit der variablen Schichtdicke lassen sich daher in einfacher Weise unterschiedlichste Strukturen mit unterschiedlichen Schichtdicken ausbilden. Beispielsweise lassen sich vollflächige, insbesondere extrem dünne (Schirm-) Lagen ausbilden oder auch einzelne diskrete (Schirm-) Bahnen, die beispielsweise eine Wendel, ein Kreuzgeflecht oder eine Spirale ausbilden.

Plastic materials with suitable additives for such an LDS process are generally commercially available. By means of the LDS method, therefore, a metallization is applied to the cladding by means of a special chemical deposition method in such a way that an effective conductive structure is thereby formed. This measure achieves a number of advantages compared to conventional shielding:

• - Due to the fine, can be generated by a laser structures, this method can be used especially for cables with only small outer diameters. A miniaturization of the line is therefore not limited by the shielding.
• - Due to the direct application by the deposition also extremely thin layer thicknesses are made possible for the conductive structure, without defects in the conductive structure and thus the shielding are to be feared. Overall, this is a metal saving achieved. For example, only a few atomic layers are preferably applied. The layer thickness can be adjusted in a simple manner, preferably over the residence time during metallization in the metallization.
• - Furthermore, any geometries for the formation of the conductive structure are made possible by the laser structuring, so that the conductive structure can be optimized for the particular application. Due to this high flexibility for the structuring due to different adjustment possibilities in the laser in combination with the variable layer thickness, it is therefore possible in a simple manner to form a very wide variety of structures with different layer thicknesses. For example, it is possible to form full-area, in particular extremely thin (screen) layers or even individual discrete (screen) webs which form, for example, a helix, a cross braid or a spiral.

According to a first embodiment, the conductive structure is applied over the entire surface of the jacket and surrounds it completely in the circumferential direction. The conductive structure therefore forms a closed envelope completely surrounding the jacket.

In the case of cables which are subject to bending stress in use, there is the danger - especially in the case of such full-surface layers - that they will be damaged over time and form, for example, kinks or even microcracks. According to a second preferred variant, therefore, the conductive structure does not completely cover the cladding and instead is applied in a structured manner and forms a predetermined pattern. The conductive structure is optionally applied as a net-shaped, spiral, punctiform or meandering pattern on the jacket. In the case of a spiral-shaped pattern, at least one strand-shaped metallized region, also referred to below as the (shield) web, orbits around the jacket in the manner of a helix. In principle, a plurality of juxtaposed webs can form the conductive structure. Alternatively, a meandering course is provided.

In order to form the conductive structure completely circumferentially around the cladding, preferably at least two lasers and, for example, exactly three lasers are provided in the production process, which together cover the entire circumference of the cladding for activating the additives, i. H. a respective laser has a beam width and is positioned such that the lasers cover the entire circumference with their beam widths.

As an alternative to this embodiment, either the at least and preferably the exactly one laser or the line rotates about its longitudinal axis. Preferably, the laser rotates, so it is preferably a rotary laser used.

If a structured shielding layer (conductive structure) is to be applied by means of a plurality of lasers, for example, spirally encircling continuous shielding web, a highly accurate continuation of the path pattern of the first laser by the second laser is required. Due to the very fine structures, this is often not technically reliable to implement. For example, even slight vibrations of the line cause an offset between two sections of the respective screen path in the transfer area from one to the other laser, so that there would be no electrically continuous conductive connection.

To avoid this, it is expediently provided that the conductive structure has a plurality of (screen) webs, wherein a respective web is formed in each case by a laser. The webs preferably do not touch each other. Alternatively, they contact each other mutually. The webs continue to run, for example, meandering, zig-zag, etc. each only over a partial peripheral region of the shell. The partial circumferential areas, which are covered by a respective laser, preferably overlap partially, so that - viewed in a projection in the longitudinal direction of the line - the tracks overlap.

In order to improve the shielding effect, it is expedient to further provide for the conductive structure to adjoin another conductive layer. This can - depending on the application - be formed by a conventional shielding, such as a shielding foil or a braided screen.

Conveniently, however, the conductive layer is a conductive plastic sheath. This embodiment with the conductive layer is specifically intended for such screen layers, in which the conductive structure has no continuous metal layer but merely has a structured pattern. Specifically, this is used in a - for example, punctiform pattern in which the individual metallized areas of the conductive structure are not interconnected. As a result, virtually the individual non-connected sub-patterns of the conductive structure are electrically conductively connected by the further conductive layer.

Conveniently, the conductive plastic sheath is the sheath itself. In addition to the additives, therefore, this additionally expediently has additional conductive particles which lead to a - at least certain - conductivity of the plastic. Alternatively, the material used may also have intrinsic conductivity.

As an alternative to the embodiment of the jacket as a conductive plastic jacket, an additional jacket is applied to the conductive structure as a conductive plastic jacket, so that therefore the conductive structure is embedded between the jacket and the conductive plastic jacket. The conductive plastic jacket is extruded onto the conductive structure, for example.

The conductivity of the conductive layer, especially in the form of a conductive plastic jacket, is preferably well below the conductivity of metal, such as copper (for example, by at least a factor of 100 lower conductivity).

As mentioned at the beginning, this conductive structure, which is formed by means of the LDS method, lends itself to cables with only a small outer diameter. Conveniently, therefore, the jacket also has a maximum diameter of <5 mm and in particular of <2 mm or less than 1.5 mm. In principle, however, larger lines can be provided with such a method with a conductive structure.

Furthermore, the thickness of the conductive structure is greater than 20 .mu.m, in particular greater than 50 .mu.m or greater than 80 .mu.m. The thickness is furthermore in a range of preferably up to 300 μm, up to 200 μm or up to 100 μm. With such thicknesses a sufficient shielding effect is given.

Conveniently, an additional metallic finishing layer is additionally applied to the conductive structure. This preferably also has a comparable thickness, for example in the range of 50 microns to 200 microns. The conductive structure can therefore be considered as a base layer on which an additional cover layer is applied. This cover or finishing layer is specifically a tin layer. In principle, however, these can also be other layers, for example of silver, gold, etc. For the production of this further at least one finishing layer manufacturing technology per additional finishing layer an additional metal bath is arranged, through which the line is passed. It is therefore also possible to form multilayered shields as a whole. The finishing layer is preferably applied galvanically.

As coating materials for the base layer and in particular for the finishing layer, tin, silver, palladium or gold are generally used in addition to copper, depending on the desired requirements.

In terms of manufacturing technology, the conductive structure is expediently applied in an in-line process during production of the line in order to produce as efficiently as possible. For this purpose, the conductive structure is applied in particular immediately after an extrusion step for forming the jacket. In this case, direct is understood to mean that at least no intermediate storage of the prefabricated line with the jacket takes place. Usually, a cooling section is provided after the extrusion, for example a cooling bath or a cleaning section, for example a cleaning bath. Thereafter, first in a first step of the LDS process, the laser treatment and then the application of the metallic layer. The line is therefore continuously through the different workstations - extrusion of the jacket - laser treatment - Metallisierungsbad - out, especially pulled and then rolled up as a final or intermediate quasi as endless on a spool.

In principle, however, the application of the conductive structure is also possible in an offline process. In this case, the pre-fabricated lead with the cladding is also conveniently continuously laser-treated and then passed through the metallization bath before the lead, which is then provided with the conductive structure, is rewound onto a coil. In the metallization typically an electroless, chemical deposition of the metal takes place on the jacket.

Generally, the line for applying the metallic layer is therefore continuously passed through a bath with a predetermined residence time in the bath. The residence time is dependent on the desired process speed, a desired material thickness and the deposition rate in the bath. Generally, a process speed is set which corresponds to at least one previous process speed when applying a braid screen. In a conventional braided screen, process speeds in the range of 1m to 10m per minute are achieved.

For the electroless plating baths, the deposition rate is typically about 8 μm to 12 μm per hour, ie. H. an hour is created with this thickness. This is especially true for conventional LDS methods with an additive trace construction in electroless copper baths.

In order to achieve the highest possible process speeds, a two-stage deposition process is provided in a preferred embodiment. In a first stage, the previously described electroless, chemical deposition takes place in one first metallization, and that is achieved until a first thickness of the deposited layer. In a second stage, a galvanic deposition then takes place preferably in a second metallization bath. This is preferably arranged downstream of the first metal bath in the in-line process. For the second stage of electrochemical deposition, the electrical conductivity of the previously produced conductive structure is utilized. This forms an electrode on which the metal is deposited. In such an electrochemical deposition higher order rates can be achieved compared to the electroless purely chemical deposition. The combination of the two stages therefore combines good structurability by means of the LDS method with rapid electrochemical application.

The line is usually subsequently assembled for the particular application and this is often at least at one end a plug struck. The conductive structure is preferably connected in the installed state at a ground or ground potential, for example at a corresponding ground contact of the plug. Alternatively, no electrical connection of the shield is formed, in particular, for example, in combination with only poor conductivity of the conductive structure and / or the additional conductive layer.

The line is preferably a data line, especially a single-core or multi-core data line. It is used for example in the automotive sector.

• 1 eine Seitenansicht einer Leitung mit einer in einem Teilbereich aufgebrachten Schirmlage,
• 2 eine ausschnittsweise Querschnittsdarstellung durch einen Mantel der Leitung,
• 3 eine stark vereinfachte schematisierte Darstellung einer Herstellungsanlage,
• 4 eine schematisierte Laseranordnung, sowie
• 5A - 5C verschiedene Ausführungsvarianten für strukturierte Schirmlagen.

Embodiments of the invention will be explained in more detail with reference to FIGS. These show in schematized representations:

• 1 a side view of a line with an applied in a partial area shield layer,
• 2 a partial cross-sectional view through a jacket of the line,
• 3 a highly simplified schematic representation of a manufacturing plant,
• 4 a schematic laser arrangement, as well
• 5A - 5C various design variants for structured screen layers.

In the 1 is as the preferred application example of a strand-shaped element an electrical line 2 shown. This is formed in the embodiment as a shielded single-core cable and has a core 4 on, which is formed by an electrical conductor. This core 4 is from a coat 6 surround. Alternatively, it may be at the core 4 Also around several veins trade, for example, are twisted together. On the coat 6 is a conductive structure 8th applied, which forms a shielding layer. This is structured in the embodiment and has for this purpose individual screen paths 10 on, spiraling around the mantle 6 to run around. The administration 2 extends in a longitudinal direction 9 along a longitudinal axis 11 , The conductive structure 8th is only shown in a section. However, it usually extends generally over the entire length of the pipe 2 , The administration 2 preferably also has an outer sheath, not shown here, which is concentric with the longitudinal axis 11 is formed and, for example, directly on the conductive structure 8th is applied.

The conductive structure 8th is applied by means of the so-called LDS process. This is for the coat 6 a special plastic material used with additives 12 is provided, as indicated by the 2 is shown greatly simplified. A surface 14 of the coat 6 is used in this method with at least one laser 16 (cf 4 ) and treated. This is an activation of the laser 16 irradiated area 18 the surface 14 , In this area 18 a certain material removal or roughening takes place, in particular an exposure of the additives 12 , which are also activated as a result of the laser treatment. By the laser treatment form thereby generally in the area 18 on the surface there exposed, activated metal nuclei 20 out. After the laser treatment, a metal layer is formed in this activated region 18 22 formed, which at least one Schirmbahn 10 or conductive structure 8th formed. This metal layer 22 in this case has a thickness D, which is preferably in the range between 80 .mu.m to 200 .mu.m. The formation of at least a partial thickness of the metal layer 22 takes place by a chemical deposition in a metal bath 24 ( 3 ) in a conventional manner. The (partial) thickness can be determined by the residence time in the metal bath 24 to adjust.

In addition, in the embodiment of 2 still a conductive location 25 shown on the coat 6 and in particular to the formed metal layer 22 or conductive structure 8th is applied. This conductive layer 25 is, in particular, a (semi) conductive plastic sheath, which preferably has the conductive structure 8th provided coat 6 is extruded.

The application of the conductive structure 8th takes place preferably in an in-line process during the production of the line 2 all in all. This in-line process is based on the 3 explained in more detail:

First, the core 4 from a first coil 26 unwound and an extrusion line 28 supplied by means of which on the core 4 the coat 6 is extruded. In a subsequent step, the line becomes 2 through a laser device 30 guided, in which the laser structuring of the surface of the shell 6 follows. The structuring is chosen such that a desired screen pattern is set by the laser treatment. Before the laser structuring, the line 2 be pulled through a cooling and / or cleaning bath.

Below to the laser device 30 becomes the conduit 2 through the metal bath 24 drawn. Conveniently, within this metal bath 24 The administration 2 over several pulleys 32 led, so that the length L of the metal bath 24 located area of the line 2 a multiple of the length of the metal bath 24 equivalent. This length L is preferably over 50 m.

After application of the metal layer 24 and hence the conductive structure 8th in the metal bath 24 becomes the conduit 2 for example, back to a second coil 34 wound. Before or afterwards, the conductive layer can still be 25 and / or an outer sheath not shown here are extruded. The administration 2 is preferably continuously and in particular at a constant speed, for example in the range of 1 -10 m / s pulled through the system.

In a preferred variant, the application of the metal layer takes place 24 in two stages. After applying a partial thickness of the metal layer, for example of up to 10 microns or from up to 15 microns in the electroless metal bath 24 by a purely chemical deposition process, then the metal layer 24 applied to the desired final thickness of eg 100 .mu.m to 200 .mu.m by means of an electrochemical (galvanic) deposition process. For this purpose, for example, an additional metal bath is provided (not shown).

In 4 is an exemplary arrangement for the laser device 30 shown. In this embodiment, a total of three lasers 16 provided, evenly around the electrical line 2 are arranged distributed around. A respective radiation cone of the respective laser 16 covers a peripheral area of the pipe 2 such that the full extent of the line 2 is laser treated. In this case, the laser treated area 18 preferably over the entire surface and fully around the coat 6 guided around and forms a closed, cylindrical shell. Accordingly, the later applied conductive structure 8th formed as a closed, cylindrical shell.

As by the arrow 36 indicated, in one embodiment, an at least partial rotation of the respective laser 16 provided so that they generate in the circumferential direction, for example, a line pattern. By the simultaneous forward movement of the line 2 This allows, for example, a zigzag-shaped, wavy, spiral or meander-shaped course of structuring. Alternative to partial rotation of the lasers 16 becomes only the laser beam with fixed laser 16 moves to create the desired pattern. A respective laser beam of a laser 16 preferably covers a partial angle of at least 120 °.

Alternative to the variant with the three lasers 16 is just a laser 16 provided, which relative to the line 2 completely around the circumference. This is done optionally by a rotation of the line 2 around its longitudinal axis 11 , but preferably by a rotation of the preferably single laser 16 around the longitudinal axis 11 , The laser generates 16 a continuous spiral path.

Overall, can be through the laser device 30 different patterns for the conductive structure 8th generate, as in the example 5A . 5B . 5C are shown. These each show a partial plan view of the trained conductive structure 8th ,

In the embodiment of the 5A each are four separate screen paths 10 preferably each by a separate laser 16 formed, wherein the individual screen paths 10 Form sub-patterns that are not connected to each other. The through the individual lasers 16 Partial patterns produced are preferably constructed identically and in particular interlaced, therefore interlock, preferably without touching.

The conductive structure 8th according to 5B has several, in the embodiment, three mutually discrete screen paths 10 on, which are formed continuously continuous and run approximately in a zig-zag shape. Both in the variant according to the 5A as well as the 5B Therefore overlap the screen paths 10 longitudinal 9 considered.

5C finally shows a dot pattern of the conductive structure 8th ,

In addition to the patterns shown, these can, for example, at recurring length positions, for example, every 10 cm, 20 cm, 50 cm, etc. in a subsection a completely closed circumferential conductive structure 8th form (annular). As a result, for example, the individual screen paths 10 eg the variant of 5B be contacted with each other.

In particular, embodiments in which the conductive structure 8th by separate screen paths 10 or metal layers 22 are formed, such as the embodiment of the 5C with the individual, discrete screen ply points, be with the conductive layer 25 combined, as related to the 2 was discussed.

Claims (14)

A strand-like element extending in a longitudinal direction and formed as an electrical line and having thereto a core and a surrounding sheath which is surrounded by a conductive structure, wherein the conductive structure by means of a laser direct structuring method on the sheath is applied and forms a shielding layer and for this purpose the jacket consists of a plastic material having additives, wherein in the region of the conductive structure, the additives are activated by a laser treatment and on the activated regions, a metal layer is applied. Strand-shaped element after Claim 1 in which the conductive structure is applied over the entire surface of the jacket. Strand-shaped element after Claim 1 in which the conductive structure is not completely covered by the jacket and is applied in a structured manner. Strand-shaped element after Claim 3 in which the conductive structure is applied to the cladding as a net, helical, dot or meandering pattern. Strand-shaped element according to one of Claims 3 or 4 in which the conductive structure has multiple tracks. Strand-shaped element according to one of Claims 1 to 5 in which the conductive structure is adjacent to a conductive layer. Strand-shaped element according to one of Claims 1 to 6 in which the jacket has a maximum diameter of less than 5 mm. Strand-shaped element according to one of Claims 1 to 7 in which the conductive structure has a thickness in the range of at least 20 μm. Strand-shaped element according to one of Claims 1 to 8th in which an additional metallic finishing layer is applied to the conductive structure. A method for producing a strand-like element which extends in a longitudinal direction and is formed as an electrical line and for this purpose has a core and a surrounding jacket, which is surrounded by a conductive structure, wherein the conductive structure by means of a laser direct structuring Method is applied to the jacket and forms a shield layer, wherein in a first step, a surface of the shell is treated by means of at least one laser and in a second step, a metal layer is applied. Method according to Claim 10 in which several lasers are used covering the entire circumference of the strand-like element. Method according to one of Claims 10 to 11 in which the conductive structure is applied in an in-line process during the production of the strand-like element and for this purpose, after an extrusion step for forming the shell, a laser treatment and then the application of the metal layer takes place. Method according to one of Claims 10 to 12 in which the strand-shaped element for applying the metallic layer is continuously passed through a bath with a predetermined residence time in the bath. Method according to one of Claims 10 to 13 in which the metal layer is applied in a two-stage deposition process, wherein a galvanic deposition takes place in a second stage.

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