HK1102970B - Device and method for electrolytically treating flat work pieces - Google Patents

Description

Apparatus and method for electrolytically treating flat workpieces

Technical Field

The present invention relates to an apparatus and a method for electrolytically treating flat workpieces in a conveyor-type production line, more particularly for electrolytically treating electrically conductive structures that are electrically insulated from one another on the surface of workpieces that are formed in a flat shape, for example in the shape of a strip or plate.

Background

For the production of chip cards (smart cards), goods price labels or identification labels, foil-shaped plastics are used on which the electrically conductive structures required for suitable electrical functions are produced.

For example, the conventional method employs a copper coated material through which a desired metal pattern is made using an etching process. In order to reduce the cost of the method and to allow the manufacture of structures that are finer than those obtained with the etching process, there is an intention to use an electrolytic deposition method for the manufacture of metal structures. A known method for manufacturing an antenna coil is set forth in us patent No. 4560445. Thus, a metal structure can be fabricated on a polyolefin film using a process comprising the following process steps: expanding, etching, conditioning the plastic for subsequent adsorption of catalytically active metal; depositing a catalytically active metal; printing a mask in the form of a negative image; accelerating catalytically active ligation; electroless processing and electrolytic metal plating.

Processes for metal plating strips include a variety of plating methods. For many years, so-called roll-to-roll processing apparatuses have been used for this purpose on conveyor lines, through which the material is conveyed and brought into contact with the processing liquid during transport. The strips are electrically contacted for electrolytic metal deposition. Contact electrodes are suitable for this purpose. For electrolytic processing, two required electrodes (i.e., a contact electrode and a counter electrode) or only a counter electrode may be provided in the processing liquid in the processing apparatus.

For example, patent publication DE 10065643C2 describes a device for electroplating or for electrolytically etching a workpiece in the form of an electrically conductive strip, wherein both a contact roller for establishing an electrical contact and a counter electrode are arranged in a groove. A problem with this arrangement is that the contact roller is also plated with metal in the groove, so that there is a risk that the metal deposited on the contact roller damages the sensitive foil.

For the purpose of avoiding or reducing metal deposits on the cathodes in the electrolytic cell, patent publication WO 03/038158A describes an electroplating apparatus which is reinforced by an electroplating structure which has been configured to conduct electricity on the substrate in a roll-to-roll apparatus for strips, wherein both the anode and the rotating contact roller are located in the electrolytic cell. On its side rotating towards the substrate, the contact roller is connected to the negative pole of a direct current power supply and, on the side rotating away from the substrate, to the positive pole of this power supply. This is made possible by segmenting the contact roller in a similar manner to the collector electrodes of a dc motor. As a result, metal deposited on the contact roller during one revolution of the roller in normal operation can be stripped by means of redirecting the potential to the anode. The main disadvantages of this method are: as the layers deposited on the auxiliary cathode become thicker, the metal removed from the anodically polarized contact roller must be periodically removed from the machine.

Another basic disadvantage is that: only surfaces that are electrically conductive over their entire area can be electrolytically treated, but are not electrolytically insulated from each other and are desirable for producing structures such as antenna coils.

Thus, patent publication DE 19951325a1 discloses an apparatus and a method for the contactless electrolytic treatment of electrically conductive structures that are electrically insulated from each other on the surface of an electrically insulating foil (foil) material. The material is thereby conveyed on a conveying path through a treatment apparatus while being brought into contact with the treatment liquid. During transport, the material is guided through at least one electrode structure, wherein the electrode structures respectively comprise cathodically polarized electrodes and anodically polarized electrodes, which in turn are in contact with the treatment liquid. A power supply causes a current to flow through the electrodes and the conductive structure. For this purpose, the electrodes are shielded from each other in such a way that substantially no current is allowed to flow directly between the two oppositely polarized electrodes. The disadvantage of said method is that the deposited metal layer has only a reduced coating thickness, since as a result of the electrode structure, on the one hand, metal is deposited and, on the other hand, said metal is at least partially dissolved again when the workpiece is guided through the cathodically polarized electrode.

Patent publication DE 10065649a1 proposes an apparatus for the electrochemical roll-to-roll treatment of flexible strips having an electrically conductive surface, which apparatus has a cathode contact roll located outside the electrolyte. A special anode roll around which the strip is wound is rotatably arranged in the electrolyte. The anode roll is therefore provided with an electrically insulating layer which is permeable to ions and which keeps the strips at a defined and smallest possible distance from the anode. However, surfaces having structures electrically insulated from each other cannot be treated.

Patent publication DE 4413149a1 discloses a conveyorized plating line for printed circuit boards, which comprises in particular contact rollers and soluble anodes, for example in an electrolyte. In order to avoid deposition of undesired metals on the contact surface of the contact roller which provides rolling contact with the article to be metallized, contact segments are provided on the contact roller which are alternately cathodically polarized or anodized by means of a commutator and provide cathodic contact with the article while being anodically polarized in the region which rotates away from the article. As a result, self-stripping is achieved directly after the undesired metal deposition.

As a result, the known methods do not allow electrolytically treating surfaces having small and extremely small structures that are electrically insulated from each other and cost-effectively deposited on electrically insulating workpieces in the form of foil strips, for example in strip-processing or conveyorized lines.

Disclosure of Invention

The problem underlying the present invention is therefore to avoid the disadvantages of the known electrolytic treatment devices and methods and more specifically to find a device and a method which allow a continuous electrolytic treatment of electrically conductive structures which are electrically insulated from each other on the surface of an electrically insulating foil or sheet material, thereby improving the prior art. For this purpose, the device has a very compact structure and, more particularly, provides the contact element, avoiding the known problems associated with undesired metallization of the contact element. More specifically, the method and device are intended for the manufacture of foil material which is provided with extremely small electrically conductive structures and can be used as a component of chip cards, for example for marking and automatic identification and distribution of goods in distribution stations, or as electronic identification cards, for example for access control. Electronic components of this type can be manufactured on an ultra-large scale at extremely low cost. Furthermore, the method and the device can be used to manufacture printed circuit foils in printed circuit technology and printed circuit foils with circuits that are common in automotive engineering or in telecommunication electronics (for example for toys). Furthermore, the device and the method allow for an increased coating thickness.

In overcoming this problem, the present invention provides a device according to claim 1 and a method according to claim 20. Preferred embodiments of the invention are specified in the dependent claims.

The method and the device according to the invention are used for electrolytic treatment, more particularly for electrically insulating small electrically conductive structures electrically insulated from each other on the surface of a flat workpiece, or on a completely electrically conductive surface of a flat workpiece, preferably in the form of a strip or a plate, more particularly a plastic strip (plastic foil) or a chemical-resistant paper (e.g. resin-impregnated paper) provided with such electrically conductive structures. This type of structure has a size (length) of a few centimeters (for example 2 to 5 cm). Preferably, the device and the method are used to achieve a metallization and stripping process (etching, slight etching) by changing the polarity of the individual segments accordingly with respect to the respectively abutting workpiece. For reasons of simplicity, the description given subsequently relates to metallization processes.

The apparatus of the present invention comprises:

a) at least two transport paths which extend substantially parallel to one another and on which the workpieces are preferably transported successively in a respective transport direction, while structures on the workpieces are electrolytically treated,

b) at least one assembly disposed between the transport paths and comprising a first rotating contact electrode and a second rotating contact electrode, the first and second contact electrodes being associated with a respective one of the transport paths, wherein the first and second electrodes bear against the workpiece while being spaced apart from the respective other transport path, wherein

c) The first and second contact electrodes each comprise at least two sections on their periphery, which sections are insulated from one another and are connected to a power supply, wherein

d) A first section of the first contact electrode abutting the workpiece conveyed on a first conveyance path; a first section of the second contact electrode abutting the workpiece conveyed on a second conveyance path, the corresponding first sections of the first and second contact electrodes being connected to a first pole of the power supply, and wherein

a) A second section of the first contact electrode that turns toward a workpiece conveyed on the second conveyance path and is spaced apart from the second conveyance path; and a second section of the second contact electrode that turns around the workpiece conveyed on the first conveyance path and is spaced apart from the first conveyance path; the second section is connected to a second pole of the power supply so as to form an electrolytic zone E for treating the workpiece between the corresponding second sections of the first and second contact electrodes and the workpiece, through which electrolytic zone an electric current flows, and

b) the assembly and the workpiece are contacted with a treatment liquid.

It should be understood that the term "component" as used herein is defined as a component that includes a plurality of contact electrodes having the above-described features b), c), d), and e). It is therefore to be understood that the invention encompasses any arrangement in which the device comprises one or more components, each of which, or at least one of them, comprises two or more contact electrodes having the above-mentioned characteristics.

The contact electrode has an electrically conductive surface and is preferably provided with segments divided in a similar manner to the current collector in the direct current electrode. The sections are preferably insulated from each other by insulation. The current can be delivered to the different sections by means of sliding contacts, rolling contacts or mercury contacts.

Further, an electrically insulating partition wall may be provided between adjacent contact electrodes in order to prevent or reduce direct current between the adjacent contact electrodes. Furthermore, the contact electrodes may be arranged closely side by side so as to be also adapted to sufficiently contact small-sized structures.

The contact electrodes of the assembly preferably rotate at substantially the same speed. For this purpose, a synchronization device may be connected between the two contact electrodes of the assembly. Intermediate wheels in the form of toothed wheels, toothed belts, chains, etc., which connect the contact electrodes, can be used as synchronization means.

The device and method according to the invention are particularly characterized by the dual function of the rotating contact electrode: by simultaneously polarizing the contact electrode as an anode on the side turned to the first conveyance path and as a cathode on the side turned to the second conveyance path, the metal that has been undesirably deposited on the contact electrode when the side of the electrode for contacting the workpiece that is turned to the second conveyance path is cathodically polarized will be stripped off on the opposite side and deposited on the workpiece when the side of the electrode turned to the first conveyance path serves as an anode. For this purpose, the workpiece is electrically connected to a (first) pole of an electrical power supply via a first section of the first contact electrode and a first section of the second contact electrode, which bear against the workpiece on a respective one of the transport paths, respectively. The second section of the first contact electrode and the second section of the second contact electrode, which are respectively turned toward the workpieces on the respective other conveyance paths, are electrically connected to the other (second) pole of the power supply, and do not contact the workpieces conveyed on the conveyance paths. As a result, an electric current flows through an electrolytic zone E for treating the workpiece, which is formed between the corresponding second sections of the first and second contact electrodes and the contacted workpiece. The metal stripped from the second section will therefore be deposited on the work piece, for which purpose the electrolysis zones E form respective electrolysis cells. As the contact electrode of the assembly rotates, the segments change polarity accordingly, and thus a first segment will become a second segment and vice versa. Metal will likely be deposited on the previously cathodically polarized (first) segment and if the segment is anodically polarized to become the second segment, the metal will be dissolved again, which will cause the contact electrode of the assembly to peel off itself and the current used to peel off the contact electrode simultaneously metallizes the workpiece. The advantageous dual function of the contact electrode and the change in polarity of the sections of the contact electrode during rotation, depending on whether or not the sections are against the workpiece during rotation, allows to prevent metal from accumulating on the contact electrode and thus from interfering with the electroplating process.

This eliminates both the auxiliary electrode for stripping the contact electrode and the additional anode. This makes it possible to provide a device which has an efficient and compact structure, allowing good coating thicknesses to be achieved without major energy, material and maintenance costs.

For electrolytically treating the workpiece, a metal such as copper, nickel, gold, silver, platinum, tin, or alloys thereof may be deposited during the metallization process. If the workpiece is metal plated, the potential of those sections (first sections) contacting the electrode that are against or rolling on the workpiece may be changed, for example, toward the cathode, while those sections (second sections) that are not spaced from the workpiece against them are anodically polarized. As a result, a first electrolysis zone is formed between the cathodically polarized workpiece on one transport path and the anodically polarized section of the second of the two contact electrodes of the assembly, while a second electrolysis zone is correspondingly formed between the cathodically polarized workpiece on the other transport path and the anodically polarized section of the first contact electrode. If metal is electrolytically removed (stripped) from the workpiece, the corresponding section is polarized in the opposite way accordingly.

To achieve efficient electrolytic processing of the workpiece, a plurality of components may be disposed between the transport paths. A plurality of devices, each having a plurality of modules, can also be arranged in a row in the process line one behind the other and/or side by side (one above the other). In order to improve the guidance of the workpiece and more particularly the contact, an additional transfer roller can be arranged opposite the contact electrode, for example on the side facing the workpiece, which transfer roller also rolls on the workpiece. A plurality of such treatment lines may be mounted in a row and may comprise additional stations, such as drying stations, storage stations for workpieces, etc.

For the treatment, the surface of the workpiece is electrolytically treated at the side turned correspondingly towards the contact electrode. The work pieces are treated in the apparatus in various ways, such as plastic strips, chemically resistant paper (e.g. resin impregnated paper) or plates, which have small conductive structures electrically insulated from each other. For example, different workpiece flows can be processed on all transport paths with the various different flow transport directions being the same or opposite. It is also possible to lead through the apparatus and to process only one workpiece flow in the apparatus, redirecting or transferring means, such as deflecting rollers or other redirecting or transferring means, for example, being arranged in this case at respective reversal points of the apparatus, for redirecting or transferring the workpieces from one transport path to another, thus moving the workpieces past the contact electrodes on a forward path or a return path.

If an electrically conductive structure, which is electrically insulated from other structures on the same surface of the workpiece, is electrically connected to other structures placed on the respective opposite surface of the workpiece via plated through holes provided in the material, the side turned away from the contact electrode can also be electrolytically treated as the structures located on the distal side are electrically contacted through the plated through holes. In this case, an additional working electrode is provided, for example a further anode (additional anode), which is arranged on the side of the workpiece which is not turned towards the contact electrode. For two-sided processing, both soluble and insoluble anodes can be used as anodes.

If the structure is not through-plated, the assemblies may also be arranged so that the workpiece is guided through the apparatus by means of a reorienting or transferring device on a plurality of transport paths, with the transport paths being located between the assemblies, so that the workpiece can be processed on either side. In this case, in a particular embodiment, a so-called template (dummy), for example a metal sheet or an endless metal belt, can be guided through the contact electrode assembly and processed, instead of the workpieces on the respective outer conveying paths, without the conveying paths being provided for the workpieces. The templates are electrically contacted, thus constituting an opposite polarity with respect to the anodically polarized outer sections of the contact electrodes. The metal that has been deposited on the template is chemically etched away after the template leaves the apparatus, or may be electrolytically removed on the return path, for example in the case of an endless metal belt. For recyclability, the template preferably comprises stainless steel. This embodiment is suitable for the case where the workpiece is guided between two adjacent modules, wherein in such an embodiment the modules share one transport path (on which the workpiece is to be processed).

The contact electrode can also preferably be used for conveying the work piece, so that the complexity of the apparatus can be further reduced by saving an apparatus only suitable for conveying, such as a conveying roller or a drum.

The spacing between the contact electrodes should be chosen small enough that very small conductive structures, for example 2 to 5cm, can still be easily electrolytically treated by supplying an electric current. The contact electrodes can also be nested with one another when viewed in the transport direction of the workpieces if the spacing cannot be reduced any more because of the selected diameter of the contact electrodes. For this purpose, the insulating partition wall disposed between the contact electrodes may have a curved shape. The curved shape of the insulating wall also allows to reduce the number of collector-shaped sections on the contact electrode, since the shielding effect provided by the insulating wall comprises a larger surrounding area. As a result, the sliding contact supplying the counter electrode side can also be selected to have a larger size than the electrode side rolling on the workpiece, so that the duration of the metallization process can be extended.

By arranging the contact electrodes in this way, even very small structures, which are electrically insulated from one another, can be reliably metallized. The smaller the spacing between adjacent contact electrodes, the smaller the difference in coating thickness between the end regions and the central region of the structure (when viewed in the transport direction). This is due to the fact that the structures are simultaneously contacted by the contact electrodes and are only located in the electrolysis zone at a certain travel distance of the transport path leading through the device of the invention. As far as the end region is concerned, this arrangement is only applicable in the case where the spacing between the contact electrodes in the device is so small that the structure can always be contacted by at least one contact electrode as the workpiece is conveyed through the device. This is only possible if the structure is rather large or if the spacing between the contact electrodes is relatively small. The spacing between the contact electrodes should therefore be at most a few centimeters to allow as uniform a metallization of structures having dimensions of only a few centimeters as is feasible.

Basically, the above principles can be implemented using a number of embodiments. A particularly preferred first embodiment comprises that the workpieces are transported in the device in a horizontal transport direction. In this case, the workpiece may be conveyed horizontally or vertically or in an inclined direction. The device comprises at least one opening at the inlet side and an opening, such as a slot, at the outlet side thereof to allow the workpiece to enter and exit the device. To prevent excessive flow of treatment liquid through the trough, sealing elements, such as sealing rollers, may be provided on the openings on the respective sides of the transport path. Furthermore, a plurality of splash guards and a collecting tank for the treatment liquid or a corresponding chamber below the passage opening can be arranged around the passage opening. The outflowing treatment liquid is collected in a collection tank and returned to the apparatus of the invention, for example by means of a suitable pump and a line.

In the device, a plurality of assemblies of contact electrodes may be arranged in a row one behind the other. Thereby, a very compact structure of the device and thus of the electrolysis zone can be achieved.

More specifically, the minimum size of the insulating structure to be treated is also determined by the minimum spacing achieved between the contact electrodes. This minimum distance depends in particular on the spatial dimensions of the contact electrodes and on the distance between the section of the contact electrodes in the electrolysis zone and the workpiece. It is therefore advantageous to configure the contact electrode as a roller with a smaller diameter so that the spacing between the longitudinal axes of the roller or the drum electrode can be selected to be very small. The compact assembly thus made possible allows electrolytic treatment of structures of dimensions of the order of 2cm or even less.

The purpose of using contact electrodes with the smallest possible dimensions (e.g. circular) to reduce the minimum spacing between the electrodes is generally contradictory to the problem of the resulting mechanical instability of the contact electrodes, more particularly when using elastic contact materials. This problem can preferably be solved by mechanically stabilizing the contact roller with the metal shaft.

When the treatment is completed on one side only, the contact electrode can contact the workpiece, for example, by means of a contact roller and an opposite currentless roller (support or transport roller).

As an alternative to rollers and drums, rotating brushes or electrically conductive sponge-shaped devices intended for wiping attached to the surface of the workpiece may be used as contact electrodes. A prerequisite for this is a power supply according to the invention that is suitable for segmenting and powering the discrete segments. Thus, deformation of the brush or conductive coating does not allow for the creation of a short circuit with an adjacent segment.

The contact electrode is pressed against the surface of the workpiece by means of the transport rollers and by means of gravity and/or by means of a spring force.

The device according to the invention can be arranged in a treatment tank which can comprise sealing elements, such as sealing lips, at the inlet and outlet of the work piece and/or scrapers for confining the liquid in the treatment tank, thereby forming an electrolysis apparatus. A pressing roller may additionally be provided, which may retain the liquid, for example when removing the foil or plate from the liquid, while reliably guiding the workpiece. The sealing means (sealing element) serves to confine the liquid in the tank as completely as possible to prevent the discharge of treatment liquid to the greatest extent possible. This is particularly important if the workpiece is to be transported horizontally in a vertical position, since in this case pressure is generated in the treatment liquid, which as a result leads to an extremely high pressure in the lower region of the passage opening. It is also possible to transfer the work pieces into the electrolysis apparatus from above through said liquid bath level, in particular if foil strip material is to be treated. In these cases, it is not necessary to provide an inlet and an outlet for the workpiece on the side wall of the treatment tank.

The contact electrode as well as the working electrode (e.g. the additional anode) are preferably elongate and more particularly may extend across the entire useful (to be processed) width of the workpiece, preferably substantially transverse to the transport direction of the workpiece.

If plate-shaped workpieces are to be processed in this line, transfer devices are provided instead of the deflecting rollers. The transfer means comprise, for example, transport or guide rollers disposed on either side of the transport path. The plate from one transport path enters the transfer device holding it. Once the plate has fully entered the transfer device, the device pivots to the return transport path and releases the plate. To prevent the space between adjacent plates on the conveying path from being too large, the transfer device may perform, for example, forward and return movements in addition to the up-and-down movement between the conveying paths. The forward and return movements are selected so large that the spacing between the plates after transfer corresponds to the spacing before transfer. If a plate-shaped workpiece is coated on only one side, the transfer device can also perform a combined rotation and forward/return movement, so that after the workpiece has changed direction, the previously downwardly turned side of the workpiece to be treated will turn upwards towards the segmented contact electrode.

The roller-shaped contact electrode may preferably be made of an elastic conductive material. As a result, on one side, a very high current can be transmitted onto the surface of the workpiece, while on the other side the spacing between the contact electrodes and the electrolysis zone will be reduced, since the contact surface between the electrodes and the surface of the workpiece, which determines this spacing, is not similar to a long narrow surface on a rigid roll but a wider surface.

A metal/plastic composite, more specifically a composite formed of an elastic plastic with a high proportion of conductive filler, may be used as the elastic material of the contact electrode. The composite material includes an elastomer, such as rubber, silicon, or other electrochemically stable elastomeric plastic, as an adherent, and a conductive filler. The adhesive body also includes an incompletely cured conductive adhesive used in the fabrication of electronic devices. The conductive filler is mixed with such materials during the manufacturing process. Thereby, a metal/plastic composite is obtained.

The filler, also referred to as a caulking composition, preferably comprises a metal in the form of a powder, fiber, needle, cylinder, bead, flake, felt, and other shapes. The percentage of filler that may be included throughout the contact material may be as high as 90 weight percent. As the percentage of filler increases, the elasticity of the metal/plastic composite will decrease, but the conductivity increases. Both of these variations are suitable for specific applications. Any electrochemically stable material that is simultaneously electrically conductive is suitable for use as the filler. Current fillers are for example titanium, niobium, platinum, gold, silver, stainless steel and electrically conductive carbon (electrocoal). Platinum-plated, silver-plated or gold-plated particles, such as beads made of titanium, copper, aluminum or glass, for example, may also be used.

In a particular embodiment of the invention, the sections contacting the electrodes may comprise borderlines which are inclined at an angle α > 0 with respect to the axis of the electrode and which are also directed at an inclination with respect to the workpiece transport direction. By this arrangement the shielding effect created by the spacing between the sections (e.g. by the spaced insulation) will no longer be transferred to a specific area on the workpiece and will be homogenized. This results in uniform deposition of metal during the metallization process. Furthermore, the angle α of the borderline may also have different values in different areas of the contact electrode, respectively. The boundary line may be configured, for example, in the form of a zigzag line.

In order to reliably provide a particularly compact structure, the contact electrodes can be accommodated as a compact assembly on a common carrier frame.

The device according to the invention is preferably an integral part of a strip processing line, each comprising at least one first and one second storage device for storing workpieces, for example storage drums (drum). Furthermore, this type of processing line usually comprises transfer means for transferring workpieces through the processing line from the at least one first storage device to the at least one second storage device. In addition, means for guiding the sensitive work pieces, such as transverse dividing rollers, so that they maintain a precise linear path, and means for adjusting the position of the transport rollers, may be provided. For this purpose, sensors may be arranged along the transport path, which continuously register the position of the outer side edges of the workpiece and, after detecting an impermissible deviation, adjust the device for transporting and/or guiding the foil.

More particularly, the apparatus is suitable for depositing metal in the shape of a strip, such as a foil, on a thin workpiece. Foils of this type may for example comprise polyester, polyamide or polyolefin, more particularly polyethylene.

More specifically, a coil-shaped structure can be made on a plastic foil material using the claimed device. Coil-shaped structures of this type can be used as antennas for contactless data transmission on data carriers (smart cards); a carrier comprising an antenna of this type may for example carry an integrated circuit which is electrically connected to the antenna by leads, so that electrical pulses generated in the antenna are transmitted to the integrated circuit, where they are for example stored or data received by means of the antenna are processed into electrical signals. The signal processing allows, for example, to convert the supplied data taking into account other data already stored, which data thus obtained is in turn stored and/or transmitted to the antenna. The data transmitted by the antenna can then be received in a receiving antenna, so that the transmitted data can be compared with the data received by the antenna, for example on a data carrier. Data carriers of this type can be used, for example, in the logistics and retail sectors, for example as contactless readable price tags or identification tags on goods, but also as person-related data carriers, for example ski cards, RFID (radio frequency induction) tags and identification cards for access control or as identification devices for cars.

Further fields of application for foils provided with electrically insulating metal structures are, for example, the manufacture of simple circuits in automotive engineering or in communication electronics, for example for toys or watches. These materials may also be used for active and passive electromagnetic shielding of equipment or as shielding mesh materials on building and clothing fabrics.

The data carrier may be made of a foil, such as a polyester foil or a polyvinyl chloride foil, on which an electrically insulating structure has been electrolytically produced using the device according to the invention. For this purpose, the foil provided with the metallization structure and produced with the device is divided into discrete foil pieces corresponding to the dimensions of the respective data carrier, according to the structural pattern produced thereon in a multiple-printing manner. The integrated circuit can then be applied to a foil member and the metal structure electrically connected to the applied integrated circuit. More specifically, an adhesive treatment may be used for this purpose. Not only can the integrated circuit be implemented in the form of a chip which is not provided with a carrier and is finally packaged, but it can also be applied to a carrier, such as a TAB carrier (TAB-tape automated bonding), and placed on the foil. After the integrated circuit has been electrically contacted, the foil member is processed to a final data carrier, said foil member being for example further laminated with other foils, thus forming a card with an antenna soldered therein.

More specifically, the electrically insulating structure on the data carrier can be manufactured in the following manner:

on the storage drum on which the foil is wound, a foil material is provided, preferably in strip form and having a thickness in the range from 20 to 50 μm and a width of 20cm, 40cm or 60cm, for example.

First, the strip is provided with a structure to be produced, wherein an activator lacquer or an activator paste (paste) is printed, for example, on the surface of the foil. For this purpose, the lacquer or paste may, for example, comprise a noble metal compound, more particularly a palladium compound, preferably an organopalladium complex (complex). In addition, the lacquer or paste contains the adhesive as well as other current components, such as solvents, dyes and thixotropic agents. The lacquer or paste is preferably printed by means of a roller on a foil guided through the roller, more particularly by means of a lithographic, gravure or photolithographic printing process, but also by means of screen printing or by means of a roller-screen printing process. For this purpose, the lacquer or paste is transferred from a reservoir onto a distribution roll, from the distribution roll onto the printing roll and from the printing roll onto the foil. Excess paint or paste is scraped from the dispensing roll and from the printing roll using a suitable squeegee. The printing roll may be coated, for example, with hard chrome. The foil is pressed against the printing roller by means of a soft counter-pressure roller ("soft roller") in order to apply the ink efficiently. In a station subsequent to the activator printing station, the ink printed on the foil is dried. For this purpose, the strip-shaped foil material is conveyed through a drying path which is formed, for example, by an IR radiator or a hot air blower, or may also comprise a UV radiator if the adhesive in the activator lacquer or the activator paste is to be dried (preferably without solvent) by reaction under the action of UV radiation. These drying devices are preferably arranged in a drying tunnel through which the strip-shaped material is conveyed. After having passed the drying station, the strip-shaped material arrives at another strip storage facility, which is more particularly formed by a drum. The material is guided and stretched by means of rollers (drum-to-drum method) on its way from the first storage drum, where it unwinds, to the second storage drum, where it is recollected.

Next, the strip-shaped foil, which has been printed with the activator lacquer or the activator paste, is metal-plated in an electroless and/or electrolytic manner to form the metallic structure.

For this purpose, the foil, which has been printed with activator lacquer or paste, is unwound from the storage drum and guided through the various successive treatment stations of the treatment line, the strip-shaped material being guided and stretched adhering to a turning roll (drum-type method). Basically, the strip-shaped material can also be transferred directly from the printing process to the wet-chemical treatment without any further intermediate storage of the material.

In a first process step, the printed material is transferred to a reducing agent, typically a strongly reducing agent in aqueous solution, such as sodium borohydride, an amino borane (e.g. dimethyl amino borane), or a hypophosphite. In the reducing agent, the oxidized noble metal contained in the lacquer or the paste is reduced to a noble metal (metallic noble metal), for example to metallic palladium. After reduction, the strip is conveyed to a rinsing station where excess reducing agent is rinsed away with water. A spray rinsing station is preferably used for this purpose. Next, a very thin (0.2 to 0.5 μm thick) layer of copper is deposited electrolessly on the activator structure. Copper deposition on the structure is initiated by a noble metal core formed within the reducing formulation, while no copper is deposited on the non-printed areas. An electrolytic cell containing formaldehyde and tartrate, ethylene diamine tetraacetate (ethylene diamine tetraacetate) or tetra- (propan-2-ol-yl) -ethylenediamine (tetra kis- (propane-2-ol-yl) -ehtylene) may be used as the copper electrolytic cell. After copper plating, the strip-shaped material is conveyed to a rinsing station where excess copper plating solution (bath) is stripped by means of a shower rinse with water.

Next, the strip-shaped material is conveyed to the device according to the invention, wherein the now electrically conductive material is selectively coated with an additional metal, for example copper. Preferably, copper is deposited. Any known electrolytic copper plating bath may be used for electrolytic copper deposition, for example, a bath comprising pyrophosphate, sulfuric acid, methanesulfonic acid (methane sulfonic acid), sulfamic acid (amidosulfuric acid), or tetrafluoroboric acid (tetrafluoroboric acid). For example, a particularly suitable plating bath is a sulfuric acid plating bath that may contain copper sulfate, sulfuric acid, and small amounts of chloride, as well as additives such as organosulfur sulfonate compounds, polyglycol ether compounds, and polyvinyl alcohol. The sulfuric acid plating bath is preferably operated at a temperature near room temperature with as high a cathodic current density as possible. If e.g. 10A/dm is to be selected²The cathodic current density (of the active structure surface) will deposit copper at a rate of about 2 μm/min. With a wire length of about 2.5 to 7.5m, a copper layer of from 5 to 15 μm thickness can be deposited, if the speed of the foil strip conveyed through the apparatus according to the invention is 1m/min, while the workpiece is passed once. If the material is conveyed through the apparatus multiple times, the line can be shortened accordingly or metal can be deposited to provide a greater coating thickness.

The current can be supplied to the workpiece and the electrodes in the inventive device in the form of a direct current. In particular embodiments, pulsed currents may also be employed. The pulsed current is advantageous for producing as high a current density as possible, since in these states also metal layers, for example copper layers, can be deposited with good properties, such as smoothness, low roughness, uniform coating thickness, good ductility, high surface quality of the electrical conductivity. For this purpose, use is preferably made of a so-called reverse pulse current, i.e. a pulse current which comprises both cathodic current pulses and anodic current pulses. Basically, also unipolar pulsed currents are of course advantageous. With reverse pulse current, the pulse heights of the cathodic and anodic current pulses, the respective pulse widths and, if desired, the pulse pauses between the individual pulses are optimized to optimize the deposition state.

If copper is deposited, compounds of the redox system (more specifically, such as FeSO)₄And Fe₂(SO4)₃Fe (b) of²⁺And Fe³⁺Compound) is preferably added to the plating bath to maintain the concentration of copper ions in the deposition solution when an insoluble anode is used. Fe contained in plating bath²⁺Ions oxidize at the insoluble anode to form Fe³⁺Ions. Said Fe³⁺The ions are transferred to a metallic copper sheet, preferably contained in another tank (regeneration column) containing said metallic copper sheet. In the regeneration tower, the copper sheet is in the Fe³⁺Oxidation by ions to form Cu²⁺And Fe²⁺Ions. Due to the two reactions (Fe)²⁺Anodic oxidation of ions to form Fe³⁺Oxidation of ions and copper sheets to form Cu²⁺With formation of Fe²⁺Ions) are carried out simultaneously, so that the copper ion concentration in the deposition solution can be kept substantially constant.

After the foil strip has passed through the device according to the invention during the metallization process, the material is again conducted to a spray rinsing station, in which excess deposition solution is rinsed away. The strip material may then be transferred to another station of the process line where it will be in contact with a passivating tool that will prevent tarnishing of the copper. The strip-shaped foil material is dried in a drying station before it is wound up to another storage drum. For this purpose, the equipment used may be similar to those used for drying activator paints or activator pastes.

The stations for carrying out the method steps are provided with suitable guiding and conveying cylinders or rollers, with equipment for treating the treatment liquid (e.g. filter pumps, chemical dosing stations) and with heating and cooling systems.

Drawings

The present invention will be described with reference to the following drawings. The different figures show:

FIG. 1 shows a top view of the inventive device for electrolytically coating a workpiece;

FIG. 2 shows a cross-sectional view of the inventive device for a first segmented contact electrode of an assembly;

fig. 3 shows a cross-sectional view of a second contact electrode of the assembly according to fig. 2; figures 2 and 3 together show an assembly according to the invention;

fig. 4 shows the device according to fig. 1, but with a specially shaped insulating wall between the contact electrodes;

fig. 5 shows another embodiment of the invention according to fig. 4 with specially shaped insulating walls for handling particularly small structures;

FIG. 6 shows an apparatus according to the present invention having a very compact structure similar to that of FIG. 1 for uniform deposition of metal on either side of a workpiece;

FIG. 7 shows a front view of the inventive device with vertically oriented work pieces and horizontal transport direction (with the tank cut away);

FIG. 8 shows a side view of an apparatus according to the invention for electrolytically treating a plate-shaped workpiece on either side;

fig. 9 shows a side view according to fig. 8, in which the workpieces are conveyed in the same conveying direction on both conveying paths;

FIG. 10 illustrates a contact electrode of a device having a particular embodiment of a segment;

fig. 11 shows another embodiment of a segment similar to fig. 10.

Detailed Description

In the drawings, like numbering represents like elements.

Fig. 1 is a top view (or side view) of the device of the invention with an assembly a of two rows of contact electrodes arranged side by side between two respective transport paths T', T ", said assembly comprising a first contact electrode 2 and a second contact electrode 8. The apparatus further comprises a power source (not shown) and a treatment tank having a wall 15, wherein said wall 15 comprises a plurality of openings arranged in the form of slots for the passage of the workpieces 1 at their inlet and outlet locations. The workpiece 1 is a foil strip, on either side of which e.g. insulating, electrically conductive structures are printed. The sealing roller 16 prevents large liquid losses from the tank. The lost liquid is collected in a chamber 21 located outside the tank and returned to the tank via a pump and a line not shown here. The work pieces 1 are guided in the conveying direction 18 into, through and out of the tank. Furthermore, an additional anode 14 and a deflection roller 13 are arranged in the tank, wherein said deflection roller 13 serves to redirect the work pieces 1 from the transport path T' to another transport path T ″ within one row of assemblies a and between the two rows of assemblies. Support or transport rollers or wheels 11 for transporting the work pieces 1 are provided beside or on either side of the transport path of the work pieces 1. These may be insulating rollers or wheels, for example steel rollers provided with a rubber-like coating. Since the first and second contact electrodes 2, 8 are arranged very close to each other, they are spaced apart from each other by the insulating wall 12 when viewed in the conveying direction 18 to prevent a large amount of current from flowing directly from the second contact electrode 8 to the first contact electrode 2, since this would result in the cathodically polarized side of the adjacent contact electrode being coated instead of the workpiece 1 or possibly causing a short circuit.

The first turning roll 13, which reverses the conveying direction of the work 1 in the row of modules a, is located farthest away from the entry position of the work, so that the opposite conveying direction (forward and backward) can be obtained in the row of modules. The second contact electrode 8 is biased in the opposite transport direction with respect to the first contact electrode 2. The contact electrodes 2, 8 each comprise two oppositely polarized sections 9, 10 (only schematically shown in fig. 1 by means of dark and light areas at the contact electrodes), wherein one first pole of the power supply contacts a respective one of the first sections 10 of the contact electrodes 2, 8 resting against the workpiece in the transport path T ', T "for electrically contacting said workpiece, while the other second pole of the power supply contacts the second section 9 of the contact electrode 2, 8 rotating towards and spaced from the workpiece in the transport path T', T" for forming a plurality of electrolysis zones E between the second section 9 of the contact electrode 2, 8 spaced from said workpiece and said workpiece in said transport path.

The second section 9 of the contact electrodes 2, 8 comprises the same polarity as the additional anode 14 in order to form an additional electrolytic zone when through-plating the work piece. By means of the deflection roller 13, the workpiece is guided through the device back and forth a number of times, while both surfaces of the workpiece 1 can be treated to the same extent. Adjacent to the inlet and outlet sides of the tank, there are provided turning rolls 13 for redirecting the work piece 1 between the two rows of assemblies a. At the end of the second row of modules, the work pieces are caused to exit the tank at the sealing rollers 16 and are directed, for example, to other processing stations, such as a rinse station or a dry station.

By reorienting the workpiece 1 several times, a long processing path is obtained in a small space, on which also thicker coatings can easily be achieved.

As can be seen from fig. 2 and 3: the contact electrodes 2 and 8 are each divided into six sections 9, 10. Said section is fastened to an insulating ring 6, which in turn sits rigidly on a shaft 7. The shaft 7 may be made of metal to reinforce its strength. The individual segments 9, 10 are electrically insulated from one another by means of the insulation 3. Current is supplied to the sections 9, 10 of the contact electrodes by means of respective cathodically and anodically connected pole shoes (shoe) 4. The pole shoes 4 are arranged: in the case of a metallization process, the current always flows from the negative pole of the power supply 5 to the first section 10 immediately adjacent to the surface in contact with the workpiece 1. As a result, the workpiece 1 is electrically contacted in a cathodic manner. The positive pole of the power source 5 is connected to an opposite second section 9, the second section 9 being rotated towards and spaced from the structure to be treated located on the work pieces 1, wherein said work pieces 1 are on their return route on the other respective transport path of the assembly, while said second section 9 is not in contact with said work pieces there. An electrolysis zone E is formed between the second section 9 and the workpiece 1. As a result of this segmentation and the supply of the segments 9, 10 with a specific current via the pole shoes 4, discrete electrolysis zones E are formed in succession to one another, wherein the second segment 9 of the contact electrodes 2, 8 forms the anode and the opposite workpieces, which are each contacted by the first segment 10 of the contact electrodes 2, 8, form the cathode. The two figures 2 and 3 together show an assembly according to the invention.

Even if an insulating wall is provided between the contact electrodes, a small amount of metal may be deposited on the first section 10 if the first section 10 is cathodically polarized. However, since as the contact electrodes 2, 8 are rotated further, the potential of the first sections 10 changes towards the anode to form an anodic second section 9 which assumes a cathodically polarized metallic structure relative to the opposing work pieces 1, the deposited metal is momentarily re-dissolved and deposited onto the work pieces 1. As a result, it is no longer necessary to carry out costly stripping of the contact electrode which is continuously connected to the cathode in contact with the treatment liquid (conductive electrolyte). Furthermore, the current used to dissolve the metal can be used to deposit the metal on the workpiece 1.

Fig. 4 shows a plated line according to fig. 1, which however has a specially shaped insulating wall 12 between the contact electrodes 2, 8 of the inventive device, in order to accelerate the metal deposition as a result of which a higher current density can be produced. Only the sections 9, 10 are schematically depicted in the figure. The assembly of the two contact electrodes 2, 8 is schematically depicted at a. The structure S to be metallized is electrically contacted via the cathodically polarized first section 10 by means of a contact electrode and at the same time extends into the electrolysis zone E. There, the structure is electrolytically metallized. For metallization the side of the workpiece 1 that is rotated away from the assembly a, an additional anode 14 is also provided, which is also connected to a power supply (not shown). Only when the workpiece 1 is also contacted on this side is an electric current generated between the anode 14 and the workpiece 1. In this case, this is achieved in that the established electrically conductive connection is diverted laterally from the electrical contact to the component a (through-plating).

Furthermore, a supporting and conveying roller 11 of the driven type (conveying roller) or the non-driven type (supporting roller) is provided. In the latter case, the contact electrodes 2, 8 are driven and themselves serve as transport rollers.

Fig. 5 shows a further example corresponding to fig. 4 with an insulating wall 12, wherein the insulating wall 12 has a specific shape and is used for handling particularly small structures. The particular shape of the insulating wall adopted allows to be sufficient also to contact very small structures. In this example, the insulating wall 12 is coiled around the contact electrodes 2, 8. As a result, the spacing between adjacent contact electrodes 2, 8 can be further reduced. Since the spacing between the two cathode first sections 10 is narrowed, if the contact electrodes have a small diameter of, for example, 3cm, a structure having a length, viewed in the transport direction, of less than, for example, 2.5cm can still be sufficiently contacted, while the first and second contact electrodes 2, 8 overlap one another.

Fig. 6 shows a special embodiment of the device according to the invention, similar to fig. 1. This device is used to deposit metal evenly on either side of the workpiece with the additional anode 14 (which is disposed between the two rows of assemblies in fig. 1) removed. A very compact embodiment of the device according to the invention is shown for coating a structure of a workpiece 1 insulated from each other on either side including a through-going plated hole. The apparatus includes three rows of modules. The modules of one row formed between the two outer rows do not have their own conveying path associated with them, but use the conveying path T of the adjacent module located on the outside. Basically and according to the invention, the portions T' and T ″ of the conveying path T differ, but are not shown here for a better understanding of the figures.

On the inlet side and the outlet side of the workpiece 1, electrolysis zones E are formed on either side of the transport path between the workpiece 1, which is contacted on the one hand by the first section 10 of the contact electrodes 2, 8, and the second section 9, which is the additional anode 14 and the contact electrodes 2, 8, respectively, on the other hand. After the first reorientation, a first contact electrode 2 and a second contact electrode 8 are always positioned opposite one another, while their first sections 10 are in direct contact with both sides of the workpiece 1 in a cathodic manner. The gaps at their respective sides form an electrolysis zone E, which is located between the contacted workpiece 1 and the second section 9 of the adjacent contact electrode 2, 8. The plating current is allowed to flow from the oppositely anodically polarized second section 9 of the contact electrodes 2, 8 to the workpiece 1.

Fig. 7 shows a sectional front view of the device according to the invention (with the cell tank sectioned), with the work pieces 1 oriented vertically, said work pieces 1 being transported through the device on two transport paths T', T "and in a horizontal transport direction. The wall 15 forms a tank which comprises a passage opening, not shown in the figures, in the front wall, for the passage of the work pieces 1 into and out of the tank. The passage opening is almost completely closed by a sealing roller, which is also not shown in the figures. The treatment liquid escaping from the inlet and outlet openings is collected under the sealing rollers and returned to the treatment tank via lines, pumps and possibly a nozzle system, also not shown here, so that the bath level in the tank, which is indicated by the line 19, can be kept constant at all times.

Depending on the method used, known heating and cooling systems, also not described here, filters and dispensing nozzles for dispensing the treatment liquid can be provided in the tank.

The contact electrodes 2, 8 are mounted vertically in the tank and are held at the top and at the bottom by means of suitable bearings (only partially shown). The first contact electrode 2, which is shown by way of example only and has a first section 10 of one cathodic polarization, is located behind the second contact electrode 8, which is shown by way of example only and has a second section 9 of one anodic polarization, when viewed in the conveying direction. The second contact electrode 8 arranged on the left is spaced apart from the workpiece shown on the right in the can and contacts the workpiece shown on the left in the can via a first section 10. In contrast, the contact electrode 2 shown on the right (which is partially shielded by the contact electrode 8 shown on the left) is spaced apart from the left workpiece and contacts the right workpiece by means of its first section 10. The insulation 3 is located between the corresponding sections.

To apply pressure to the contact electrodes 2, 8, the transfer and support roller 11 may be carried in an oval bearing (not shown) or an elongated hole (not shown) and pressed by a compression spring (ping spring) 20. At the upper end of the contact electrodes 2, 8, a collector 22 with a pole shoe 4 is provided. Respective ones of the pole shoes 4 are arranged at the sides. The current is transmitted from both poles of the power source 5 to a corresponding one of the respective sections 9 and 10 of the contact electrode (the current is not shown here to be transmitted from the collector electrode to the sections 9, 10). The negative pole of the power source 5 is connected to the outer pole piece 4, which supplies the first section 10 of the contact electrodes 2, 8 contacting the workpiece 1. The positive pole of the power supply is connected to the inner pole shoe 4, the inner pole shoe 4 supplying the second section 9 of the contact electrode 2, 8 turned towards the respective other transport path of the workpiece and spaced apart therefrom. The collector electrode 22 is disposed above the fluid level 19. Which are connected to the respective segments of the contact electrodes via lines not shown in the figure.

The deviation (spacing) of the contact electrodes 2 and 8 from one another and thus the diameter of the deflection rollers, not shown, should be chosen small enough to prevent a short circuit between the workpiece 1 and the anodically polarized sections of the contact electrodes 2, 8.

Fig. 8 shows a side view of an apparatus according to the invention for electrolytically treating each side of a plate-shaped workpiece 1. The workpieces 1 are oriented horizontally and conveyed in a horizontal conveying direction 18. Before entering the treatment tank, the plate is guided through the chamber 21 at an upper position between the sealing rollers 16 on the forward path of the transport path T'. The tank is shown in semi-cut for added clarity. Accordingly, an electrolysis region E, E' is again formed on the forward path between the cathodically polarized workpiece 1 and the anodically connected second contact electrode 8 and the additional anode 14. At the end of this forward course, a transfer device 17 is provided which is adapted to transfer the plate-shaped workpiece 1. The transfer device 17 is movably carried and adapted to be moved up and down and back and forth in the directions indicated by the arrows by means of a drive device not shown in the drawings. The workpiece 1, which is moved uniformly in the direction of the arrow 18, enters the transfer device 17 between the upper conveying roller 11 and the lower conveying roller 11. As long as only the transport rollers 11 of the transfer device hold the workpiece 1, the transfer device is moved to the lower return position, i.e. to the other transport path T ″ of the components of the device. After the workpiece has reached the lower position, the conveying roller 11 is driven in the reverse rotational direction, and conveys the workpiece on the lower return conveying path T ″. Here, the workpiece 1, which is held together by the contact electrode 8 and the transport roller 11, is contacted and transported through the apparatus towards its outlet 18 and further processed. At the end of the row of assemblies, the work pieces 1 leave the tank via the trough sealed by the sealing rollers 16 and can be further processed according to the method sequence.

The back and forth movement of the transfer device is provided to maintain the same spacing between adjacent plates during plate transfer. Sensors, not shown here, can be provided for this purpose, which register the position of the preceding plate-shaped workpiece and accordingly control the forward and backward movement of the transfer device, so that the spacing between successive plates 1 is kept constant. If the workpiece is processed on only one side, the transfer device can perform a rotary motion instead of an up-and-down motion, wherein the rotary motion has the same diameter as the turning roll for strip-shaped workpieces, so that the workpiece 1 is guided to the return conveying path T "of the device. The same spacing between adjacent plates can then be maintained by having the transfer device perform a faster or slower rotational movement.

With this preferred embodiment, it is thus possible to electrolytically treat the mutually insulated structures on the non-conductive carrier substrate at low cost and with little maintenance effort.

Basically, fig. 9 corresponds to fig. 8, but no transfer device 17 is provided at the end of the row of assemblies. While the workpiece 1 is made to leave the tank via an outlet area similar to the inlet area (trough, sealing rollers, chamber). Thus, two parallel plate flows are directed through the device. Such a circuit is suitable for processing both plate-shaped and strip-shaped workpieces. For processing the workpiece 1 on each side, it is necessary in this case to electroplate the workpiece through, since no separate electrical contact is provided which is done on the side turned away from the assembly.

Fig. 10 shows the contact electrode 8 of the device, in which the contact electrode 8 is shown broken at its center and has sections 9, 10 implemented in a specific manner. The segments, which are seated on the body of the electrode 8 and are electrically insulated from one another by means of the insulation 3, have boundaries which are inclined by an angle α > 0 relative to the direction of the axis 7 of the electrode 8 and, as a result, are directed at an oblique angle relative to the conveying direction of the workpieces. With this arrangement the shielding effect created by the insulation 3 between the sections 9, 10 will not be transferred to a specific area on the work piece but will be homogenized.

Fig. 11 shows another embodiment of the segments 9, 10 according to fig. 10, the angle α of the borderlines of the segments with respect to the axis 7 of the electrodes 2, 8 having different values in one segment.

It should be understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications and changes in light thereof will be suggested to persons skilled in the art and are to be included within the spirit and purview of this application and scope of the appended claims. All publications, patent documents, and patent application documents cited herein are incorporated by reference herein.

[ description of main reference numerals ]

1 workpiece

2 first segment type contact

3 insulating part

4 pole shoe

5 Power supply

6 insulating ring

7 shaft

8 second segment type contact electrode

9 section (c)

10 section

11 transfer cylinder/backup roll

12 insulating wall

13 reorientation/transfer device

14 additional electrode/anode

15 tank wall

16 seal roller

17 transfer device

18 direction of conveyance of the work 1

19 liquid level

20 compression spring

21 mudguard chamber with collecting tank for treatment liquid

22 collector electrode

S component

T, T' transmission path

E, E' electrolysis zone

Claims (23)

1. An apparatus for electrolytically treating a flat workpiece (1), the apparatus comprising:

a) at least a first transport path (T ') and a second transport path (T'), which extend substantially parallel to each other for transporting the work pieces on them,

b) at least one assembly (A) arranged between the transport paths and comprising a first rotating contact electrode (2) and a second rotating contact electrode (8), while the first rotating contact electrode (2) and the second rotating contact electrode (8) are associated with a respective one of the transport paths, wherein the first rotating contact electrode (2) and the second rotating contact electrode (8) are in abutment against the workpiece (1) while being spaced apart from the respective other transport path while being spaced apart from the same

c) The first rotary contact electrode (2) and the second rotary contact electrode (8) each comprise at least two sections (9, 10) on their periphery, which are insulated from each other and connected to a power supply (5), respectively

d) A first section (10) of the first rotary contact electrode (2) which abuts against the work pieces (1) conveyed on a first conveying path (T ') and a first section (10) of the second rotary contact electrode (8) which abuts against the work pieces (1) conveyed on a second conveying path (T'); each first segment (10) is connected to a first pole of the power supply (5) and

e) a second section (9) of the first rotating contact electrode (2) directed towards the work pieces (1) conveyed on the second conveying path (T ') and spaced apart from the second conveying path, and a second section (9) of the second rotating contact electrode (8) directed towards the work pieces (1) conveyed on the first conveying path (T ') and spaced apart from the first conveying path (T '); each second segment (9) is connected to a second pole of the power supply (5) such that an electrolysis zone (E) for treating the workpiece (1) is formed between the corresponding second segment (9) of the first and second rotary contact electrodes (2, 8) and the workpiece (1), through which electrolysis zone (E) an electric current flows, and

f) the assembly (A) and the workpiece (1) are in contact with a treatment liquid.

2. The device according to claim 1, characterized in that the workpiece (1) comprises electrically conductive structures (S) electrically insulated from each other on its surface and having a length of 2cm to 5 cm.

3. Device according to any one of the preceding claims, characterized in that the flat workpiece (1) is in the form of a strip or a plate.

4. The device according to claim 1 or 2, characterized in that the workpiece (1) is conveyed by means of the rotating contact electrode (2, 8).

5. The device according to claim 1 or 2, characterized in that at least one working electrode (14) is additionally provided, which is arranged on a side of the workpiece (1) turned away from the assembly (a) and which extends substantially transversely to the conveying direction (18) of the workpiece.

6. Device according to claim 1 or 2, characterized in that an insulating wall (12) is provided between the rotating contact electrodes (2, 8) of the assembly (a).

7. Apparatus according to claim 1 or 2, characterized in that reorientation or transfer means are provided for reorienting or transferring the work pieces (1) from the first transport path (T') to the second transport path (T ").

8. The device according to claim 7, characterized in that the work pieces (1) are transported in the device back and forth a plurality of times on the transport path (T', T ") by means of the redirecting or transferring device.

9. Device according to claim 1 or 2, characterized in that at least two modules (a) are provided, arranged one after the other in a row.

10. Device according to claim 9, characterized in that between two adjacent modules (a) there is an insulating wall (12).

11. The device according to claim 9, characterized in that the spacing between two first rotary contact electrodes (2) or two second rotary contact electrodes (8) of adjacent assemblies (a) arranged in a row is so small that the electrically conductive structure (S) is permanently in contact with at least one of the first rotary contact electrodes (2) or second rotary contact electrodes (8), respectively, wherein the first rotary contact electrodes (2) or second rotary contact electrodes (8) abut against the work pieces (1) on one common transport path (T).

12. Device according to claim 1 or 2, characterized in that at least two assemblies (a) are arranged so that they are adjacent side by side, comprising a common transport path (T) between them.

13. Device according to claim 1 or 2, characterized in that at least two adjacent rows of modules (a) are provided.

14. Device according to claim 13, characterized in that the respective transport paths of the first and second transport paths (T', T ") of the row of modules (a) are connected to each other by means of the redirecting or transferring means.

15. The device according to claim 1 or 2, characterized in that the work pieces (1) are oriented substantially horizontally and are conveyed on a first conveying path (T') or a second conveying path (T ") extending substantially horizontally.

16. The device according to claim 1 or 2, characterized in that the first and second sections (9, 10) extend axially on the first and second rotating contact electrodes (2, 8).

17. A method of electrolytically treating a flat workpiece (1), comprising:

a) -conveying the work pieces on at least two conveying paths (T', T ") extending substantially parallel to each other;

b) contacting the workpiece with a treatment liquid;

c) -bringing the workpiece (1) into contact with at least one assembly (a), wherein the assembly (a) is arranged between the transport paths and comprises a first rotating contact electrode (2) and a second rotating contact electrode (8);

d) electrically connecting the workpiece to a first pole of a power supply (5) by means of a first section (10) of the first rotary contact electrode (2) and a first section (10) of the second rotary contact electrode (8), wherein the first section (10) of the first rotary contact electrode (2) bears against the workpiece transported on a first transport path (T '), the first section (10) of the second rotary contact electrode (8) bears against the workpiece transported on a second transport path (T'), and

e) electrically connecting the second section (9) of the first rotating contact electrode (2) and the second section (9) of the second rotating contact electrode (8) to a second pole of the power source (5), wherein a second section (9) of the first rotating contact electrode (2) is directed to the workpiece (1) conveyed on the second conveying path (T'), a second section (9) of the second rotating contact electrode (8) is directed towards the work piece (1) conveyed on the first conveying path (T'), and is spaced apart from the first conveying path so as to form an electrolysis zone (E) for treating the workpiece (1) between the corresponding second sections (9) of the first and second rotating contact electrodes (2, 8) and the workpiece (1), such that an electric current flows through the electrolysis zone (E).

18. Method according to claim 17, characterized in that the workpiece (1) comprises electrically conductive structures (S) electrically insulated from each other on its surface and having a length of 2cm to 5 cm.

19. Method according to claim 17 or 18, characterized in that the work pieces (1) are treated by means of a row of adjacent modules (a).

20. Method according to claim 19, characterized in that the spacing between two first rotating contact electrodes (2) or two second rotating contact electrodes (8) is adjusted to be small enough so that the electrically conductive structure (S) is permanently in contact with at least one of the first or second rotating contact electrodes (2, 8), respectively, wherein the two first rotating contact electrodes (2) or the two second rotating contact electrodes (8) bear against the workpiece (1) and belong to adjacent assemblies (a) arranged in a row.

21. Method according to claim 17 or 18, characterized in that the work pieces (1) are transported back and forth several times through a treatment tank filled with treatment liquid by means of a redirecting or transferring device (13).

22. Method according to claim 17 or 18, characterized in that an insulating wall (12) mounted between the first and second rotating contact electrodes (2, 8) prevents a short circuit between the first and second segments (9, 10) provided on the adjacent rotating contact electrode (2, 8).

23. A method according to claim 17 or 18, characterized in that the first section (10) against the work piece (1) is cathodically polarised and the second section (9) spaced from the work piece is anodically polarised so that metal is deposited on the work piece.