EP1409772B2 - Method for selectively electroplating a strip-shaped, metal support material - Google Patents

Abstract

A method for the continuous selective electroplating of a metallic substrate material ( 10 ) and more particularly of a substrate material band having prestamped contact elements, comprises the following steps: a) the substrate material ( 10 ) is coated in an electrophoretic coating means ( 14 ) with an electrophoretic coating composition selective with at least one composition strip, b) the at least one composition strip is removed at those parts by means of a laser ( 40 ), which are to be electroplated, c) in an electroplating process a metal layer is applied to the areas ( 42 ) deprived of composition in at least one composition strip using selective electroplating and d) the at least one composition strip is then removed.

Description

The invention relates to a method for the selective galvanization of a strip-like, metallic carrier material in a continuous pass, in particular for the galvanization of a carrier strip with pre-punched contact elements.

In such, from the DE 19934584 A1 In known processes, the support material is first completely coated with lacquer by either sprayed with lacquer or dipped in lacquer. Then, by means of a laser, those areas are freed from the paint on which contact material is to be galvanized.

In the known method can be achieved by spraying with paint as well as by immersion in paint disadvantageously only a paint layer with uneven thickness. This problem is exacerbated in a three-dimensional substrate, since the paint then sets in particular in corners and edges in extreme thickness. Furthermore, a mandatory mandatory for the process closed paint layer can only be achieved if it is relatively thick. Laser ablation at the points to be electroplated either leads to time-consuming machining or requires the use of high power lasers. Since the lacquer layer must be completely removed at the points to be electroplated, it is necessary to adjust the laser beam so that the lacquer layer is removed even in places of greatest thickness. This in turn means that at locations with a small layer thickness, the carrier material is damaged by the laser beam. Another disadvantage of the known method is that even if only very small areas must be galvanized, very large amounts of paint are required for the complete coating of the carrier material with a coating layer.
The required relatively large thickness of the lacquer layer to achieve a closed lacquer layer and in particular the extreme paint accumulations in three-dimensional support materials are made even more aggravating. It should be noted that the paint materials required for such an experience are relatively expensive.

An object of the present invention is to develop the known method so that a faster passage of the strip-like carrier material is achieved by the galvanization with significantly lower paint requirement.

This object is achieved by the method steps of claim 1.

The inventive method has the advantage that in the electrophoretic lacquer coating even at much lower paint thicknesses, a closed lacquer layer can be achieved, which has a very constant paint thickness. As a result, damage to the substrate can be effectively prevented when removing the paint layer by laser treatment. In addition, the very thin paint layer can be removed faster and with less power, which allows a higher throughput speed of the substrate. The deposition of the electrophoretic paint on the substrate is very fast, which in turn allows higher throughput speeds of the substrate. These advantages are further enhanced by the fact that only a selective lacquer layer is applied, for example a lacquer strip or several lacquer strips. These paint strips are applied only in the areas in which a galvanizing layer is applied. In addition to the saving of expensive paint material thus faster removal of the paint at the end of the treatment is possible.

The electrophoretic lacquer coating leads to uniform thin lacquer layers even with three-dimensional support materials, so that a selective electroplating is possible in these. Since the paint removal by laser action is virtually arbitrarily controllable, punctiform galvanizations can be achieved in addition to strip-like electroplating.

The measures listed in the dependent claims advantageous refinements and improvements of claim 1 method are possible.

The strip-like carrier material expires before the coating expediently a cleaning and / or activation and / or rinsing process to create optimal initial conditions.

Advantageously, several paint strips can be applied in the same or different width on the same side or on both sides of the belt-like carrier material. The width of these strips is precisely adjustable by the electrophoretic lacquer coating process, so that by optimizing the strip width, a minimization of the required lacquer material can be achieved.

The lacquer layer thickness can be adjusted as a function of the applied voltage, the lacquer composition and the speed of the support material, in particular cataphoretic or anaphoretic lacquer deposition. By thus precisely adjustable coating thickness can be completely removed at the required locations by appropriate adjustment of the laser beam, this paint layer, while still avoiding damage to the substrate is avoided.

For electrophoretic lacquer coating cathodes are covered in a housing of the paint coating device expediently compared to the carrier material by a slot-like dimming, depending on the slot width and the distance between dimming and substrate, the paint strip width can be adjusted. By dimming with multiple slots can accordingly several paint strips are formed.

After the coating, the support material is expediently rinsed and dried, in particular in an oven or by UV light. Furthermore, the carrier material is expediently rinsed after laser removal.

The laser-stripped areas can now be electroplated by one or more of the following selective plating methods: selective dipping in a plating bath, covering the areas outside of the at least one paint strip by means of mechanical mask masks, in particular belt tools, applying the electrolyte agent by means of wheel technology, spotter or brush technique.

Fig. 1

eine schematische Darstellung der einzelnen Stationen einer Anlage zur selektiven Galvanisierung zur Durchführung des erfindungsgemäßen Verfahrens,

Fig. 2

eine schematische Darstellung einer Lackbeschichtungszelle zur Aufbringung eines Lackstreifens gewünschter Breite,

Fig. 3

eine Stirnansicht eines Trägermaterialbands mit drei Lackstreifen an Vorder- und Rückseite,

Fig. 4

eine perspektivische Darstellung des in Fig. 3 dargestellten Trägermaterialbands,

Fig. 5

eine Stirnansicht eines gestanzten Trägermaterialbands mit zwei Lackstreifen,

Fig. 6

eine perspektivische Darstellung des in Fig. 4 dargestellten Trägermaterialbands,

Fig. 7

eine Stirnansicht eines drei-dimensionalen Trägermaterialbands mit einem Lackstreifen am ausgeformten Bereich,

Fig. 8

eine perspektivische Darstellung des in Fig. 7 dargestellten Trägermaterialbands,

Fig. 9

eine Stirnansicht eines weiteren drei-dimensionalen Trägermaterialbands mit einem Lackstreifen,

Fig. 10

eine perspektivische Darstellung des in Fig. 9 dargestellten Trägermaterialbands,

Fig. 11

eine Stirnansicht eines Trägermaterialbands mit einem Lackstreifen, in dem durch Laserbehandlung ein streifenförmiger Bereich entlackt ist, und mit einer Abdeckung zur selektiven Galvanisierung und

Fig. 12

eine perspektivische Darstellung des in Fig. 11 dargestellten Trägermaterialbands.

Embodiments of the invention are illustrated in the drawings and explained in more detail in the following description. Show it:

Fig. 1

a schematic representation of the individual stations of a selective electroplating plant for carrying out the method according to the invention,

Fig. 2

a schematic representation of a paint coating cell for applying a paint strip desired width,

Fig. 3

an end view of a carrier tape with three paint strips on the front and back,

Fig. 4

a perspective view of the in Fig. 3 illustrated carrier material bands,

Fig. 5

an end view of a stamped carrier tape with two paint strips,

Fig. 6

a perspective view of the in Fig. 4 illustrated carrier material bands,

Fig. 7

an end view of a three-dimensional carrier strip with a paint strip on the formed area,

Fig. 8

a perspective view of the in Fig. 7 illustrated carrier material bands,

Fig. 9

an end view of another three-dimensional carrier strip with a paint strip,

Fig. 10

a perspective view of the in Fig. 9 illustrated carrier material bands,

Fig. 11

an end view of a carrier strip with a paint strip in which a strip-shaped area is stripped by laser treatment, and with a cover for selective galvanization and

Fig. 12

a perspective view of the in Fig. 11 illustrated carrier material bands.

In the Fig. 1 illustrated galvanizing plant for selective galvanization of a carrier strip is designed as a so-called reel-to-reel system, wherein the metallic carrier strip 10 unwound continuously from a first roll or spool 11, passed through the system and behind again on a second roll or coil 12 as Finished tape is wound up. Belt speeds of 20 m / min or even higher speeds are possible.

First, the substrate tape 10 passes through a preparation station 13, where it is cleaned, activated and rinsed.

Subsequently, the substrate strip 10 is passed through a Belakkungsstation 14, where a selective electrophoretic coating takes place. The lacquering station 14 may have one or more lacquer cells 15, as shown in FIG Fig. 2 are shown schematically. Such a Belackungszelle consists in principle of an example encapsulated housing which is shielded so that an uncontrolled paint deposition is avoided at undesirable areas. For this purpose, shields 17, 18, which, like the other housing areas, consist for example of Teflon or another non-conductive plastic, are arranged such that they cover the regions of the carrier material strip 10 which are not to be coated with respect to a flat anode 19. As a result of the slit 20 formed by the two shields 17, 18, a paint strip corresponding to the width on the substrate tape 10 is formed by electrophoretic paint deposition. The anode 19 is made of stainless steel, but may also be platinum plated from titanium.

The illustrated coating cell 15 is designed for anaphoretic paint deposition, for which purpose an anaphoretic paint is used. Such a lacquer layer is resistant to acidic media, such as a nickel, gold or tin bath, and can be removed in an alkaline medium. For anaphoretic lacquer deposition, the anode 19 is connected to the positive pole of a galvanizing voltage, while a contacting unit 21 is arranged in front of the cell by supplying current to the carrier material band 10. Alternatively, a cataphoretic lacquer deposition with cataphoretic lacquer is possible. The cataphoretic lacquer is resistant to alkaline media and can be removed in an acidic environment. The polarity is reversed, that is, instead of the anode 19, a cathode occurs.

The varnish cell 15 is designed so that the paint strip formed or the varnish-coated areas are no longer damaged after the coating process. This is achieved for example by guide rollers, not shown, which are mounted in front of and behind the coating cell 15 and which position the carrier material in both vertical and horizontal directions exactly so that the area coated with the paint strip 22 is not in contact with areas of the housing 16 arrives. The distance between the substrate tape 10 and the dimming 17, 18 is chosen so that on the one hand a sufficient dimming effect is present, but that no points of contact arise.

The paint located in a storage tank, not shown, is supplied via nozzles of the coating cell 15. A pump located in the storage tank is connected via a pipe to the paint cell, wherein the amount of the supplied paint can be set or controlled via a likewise not shown intermediate throttle valve. A filter arrangement may also be provided. The Paint Conveyor Pump is designed to prevent electrical charges by using light-weight materials on all moving parts surrounded by paint, otherwise the paint will come into contact with moving parts that can become electrically charged and into contact with the paint come, can take place.

In the FIGS. 3 to 10 various carrier material bands are shown as examples, which are provided with differently arranged paint strips.

In the in the 3 and 4 shown carrier strip three paint strips 24 - 26 of different width on the front and back are applied. This can be carried out either with successively arranged coating cells 15 or with coating cells which has a plurality of slits 20 and dips and anodes or cathodes arranged on both sides of the carrier material band 23.

That in the FIGS. 5 and 6 shown carrier strip 27 is pre-punched so that already individual contacts are formed, which can be canceled or cut off after completion. There are two paint strips 28, 29 applied.

That in the FIGS. 7 and 8 shown substrate strip 30 is also pre-punched to form individual contacts, said contacts on one side of a holding strip 31, which holds them together, semi-circular formations 32, so that the carrier material strip 30 is formed three-dimensionally. A paint strip 33 is applied to the outside of the formations 32.

That in the FIGS. 9 and 10 shown carrier material strip 34 is also formed three-dimensional, wherein retaining strips 35 connect the individual contact elements 36 at their ends. These contact elements 36 are box-shaped in the central region, wherein a paint strip 37 extends over the central region of the box-like formations. The selective paint strip (or more) is applied over the entire spatial depth in 3D carrier material bands, as in the Fig. 7 to 10 is recognizable.

After the application of one or more paint strips, the substrate tape 10 according to Fig. 1 passed through a drying station 38. The drying and thus a partial polymerization is carried out in an oven of the drying station 38, in which a uniform temperature distribution is present. Alternatively, the paint strips can also be dried with UV light and partially polymerized.

Next, the substrate tape 10 is passed through a selective de-paint laser station 39. By means of the laser beam of a laser 40 those lacquer areas are removed from the paint strip or stripes, which are to be galvanized later. In this case, both a strip-like Entlakkung and the Entlackung on singular surfaces is possible, for example, by the laser oscillating processed these surfaces. Of course, a plurality of strip-shaped paint erosions can be made by means of the laser within a paint strip. The tolerances of Lackabtrags and the subsequent electroplating are low and amount to about 50 μ m. The substrate is not damaged by the laser beam and paint removal is complete. This is ensured by the exact setting of the laser energy, wavelength, strength and duration of the pulses. In the FIGS. 11 and 12 It is shown that a strip-shaped region 42 in the laser station 39 has been stripped of the paint strip 22 applied to the substrate tape 10.

The substrate strip 10 is then passed through a galvanizing station 43, in which galvanization of the area 42 stripped by the laser takes place. This is achieved by a selective electroplating process known per se. According to Fig. 12 In this case, the regions of the carrier material strip 10 outside the paint strip 20 are covered by means of two continuously circulating belts 44. The speed of the belt 44 is adapted to the passage speed of the carrier material strip 10, so that the belt 44 run along accordingly. The released area between the two belts 44 is then wetted by means of a cloth, a brush or the like with galvanizing solution and thereby galvanized. This can be done in several stages depending on the desired layer thickness. If the lacquer strip is located at an edge region of the carrier material strip 10, the selective galvanization can also take place by selective immersion in a plating bath. Alternatively, other mechanical Abdeckmasken can be used, which may be mentioned as further known methods for selective galvanization, the mocking technique and brushing.

As a last step, the substrate tape 10 is completely stripped in a Entlackungsstation 45 by being passed through a corresponding aqueous solution. Depending on whether cataphoretic or anaphoretic lacquer deposition was used, the aqueous solution is acidic or alkaline.

Of course, various materials, such as gold, palladium, silver and zinc, can also be electroplated on the carrier strip 10, which is usually made of brass, copper or a copper alloy. Different plating layers can also be superimposed, for which purpose the necessary steps take place one after the other. For example, the substrate tape 10 may also already have a plating layer applied in a classical manner, for example selective galvanization without paint coverage.

The method according to the invention can be carried out, as described, with carrier material tapes which, in accordance with FIGS Fig. 5 to 10 already pre-punched contacts or other elements or which are still full-surface, for example according to the Fig. 3, 4 . 11 and 12 , In the latter case, stamping operations can still be carried out after the galvanization, but this requires a larger amount of lacquer and galvanization metals.

Claims (9)

1. Method for the selective electroplating of a strip-like, metal base material in a continuous run, in particular a base material strip with pre-stamped contact elements, wherein

   a) the base material (10, 23, 27, 30, 34) is coated selectively in an electrophoretic paint coating unit (14, 15) with an electrophoretic paint in one or more paint strips (22, 24-26, 28, 29, 33, 37),

   b) the paint strip or strips (22, 24-26, 28, 29, 33, 37) is or are removed by means of a laser (40) at those points (42) which are to be electroplated,

   c) electrodes (19) in a housing (16) of the paint coating unit (14, 15) are covered from the base material (10) by a slit-like screen (17, 18), with the paint strip width being adjusted depending on the slit width (20) and the distance between the screen (17, 18) and the base material (10),

   d) in an electroplating process a metal layer is applied to the decoated points (42) in the paint strip or strips (22, 24-26, 28, 29, 33, 37) by selective electroplating, and

   e) the paint strip or strips (22, 24-26, 28, 29, 33, 37) are then removed.
2. Method according to claim 1, characterised in that the strip-like base material (10, 23, 27, 30, 34) passes through a cleaning and/or activation and/or rinsing process before painting.
3. Method according to claim 1 or 2, characterised in that several paint strips (24-26, 28, 29) are applied at the same or varying width to the same side or to both sides of the strip-like base material (23, 27).
4. Method according to any of the preceding claims, characterised in that the paint coating thickness is adjusted depending on the voltage applied, the paint composition and the speed of movement of the base material, wherein in particular cataphoretic or anaphoretic paint deposition takes place.
5. Method according to any of the preceding claims, characterised in that the base material (10, 23, 27, 30, 34) is rinsed and dried after painting, in particular in a stove (28) or by UV light.
6. Method according to any of the preceding claims, characterised in that strips and/or singular electroplating points (42) are formed by the laser paintstripping.
7. Method according to any of the preceding claims, characterised in that the base material (10, 23, 27, 30, 34) is rinsed after laser paint-stripping.
8. Method according to any of the preceding claims, characterised in that the points (42) stripped of paint by laser (40) are electroplated by one or more of the following selective electroplating processes: selective dipping in an electroplating bath, covering of the areas outside the paint strip or strips by means of mechanical resist masks (44), in particular belt tools, application of the electrolyte by means of wheel, spotter or brush systems.
9. Method according to any of the preceding claims, characterised in that the paint strip or strips (22, 24-26, 28, 29, 33, 37) is or are completely removed after electroplating in an alkaline or acid aqueous solution.

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