EP0059787B1 - Apparatus for the partial electroplating of electrically conductive tapes, strips or suchlike bundled parts in a continuous process - Google Patents

Abstract

A device for electroplating portions of a continuously moving, cathodically connecting workpiece as it is moved past a plurality of anodically connected spray nozzles characterized by the spray nozzles comprising precious metal and being positioned one after another in a row along the direction of movement of the workpiece with each of the nozzles having an individual stream of electrolytes emerging unimpeded therefrom. The continuously moving workpiece is positioned so that selected portions thereof are moved along the row of nozzles to be contacted by the stream of electrolyte emerging from the individual nozzles for a free and unimpeded electroplating of the portions contacted by the streams.

Description

The invention relates to a device for the partial electroplating of parts combined with a predetermined division into electrically conductive strips, strips or the like.Continuous process, the cathodically connected strip or the like being guided along a plurality of anodically connected spray nozzles made of noble metal, which Seen in the direction of movement of the strip or the like. Arranged one behind the other and directed against the strip or the like in such a way that the electrolyte jet emerging from each individual spray nozzle strikes the region to be galvanized on the strip or the like.

Such a device for the partial electroplating of parts combined into electrically conductive strips in a continuous process is known from US-A-4 036 725. In this known device, the strips are moved on a circular path past radially aligned spray nozzles made of platinum, a radial electrolyte jet being directed from each individual spray nozzle onto the area to be galvanized on the strip.

From DE-AI-2 017 527, a method and a device for applying galvanic precipitates have become known in general, the individual parts to be treated being passed under spray nozzles with the aid of a conveyor belt. It has already been proposed here that, if necessary, a plurality of spray nozzles can be attached next to one another and / or one behind the other in the direction of movement and, if appropriate, on both sides. If the metallic deposits are to be applied by the action of current, the conveyor belt is connected as the cathode, while the anodes are arranged in a container filled with electrolyte near the spray nozzles. A partial galvanization is neither provided in this known method nor possible with this known device.

CH-A-621 825 discloses a device for partial electroplating, in which a cathodically connected strip is passed through a masking seal with at least one opening. A spray nozzle sprays the electrolyte solution through the opening or through several openings of the masking seal onto the areas of the strip to be electroplated. The spray nozzle provided with anode metal plates at its spray opening sprays the electrolyte solution continuously or intermittently. The spray nozzle can be provided with a plurality of spray openings, or alternatively a plurality of nozzles can be provided.

A similar device for partially electroplating metal strips is known from US-A-4,240,880. The areas to be electroplated are also determined here by corresponding openings in a mask, each of these openings being opposed by an anodically connected spray nozzle made of platinum or platinum-coated titanium.

The invention has for its object to improve a generic device for partial electroplating so that a particularly uniform formation of the individual spray jets and thereby bringing the nozzle ends close to the belt or the like., Higher current densities, higher deposition rates and an increase in the bagging speed be made possible.

This object is achieved according to the invention in that the distance of the spray nozzles from one another is not equal to the division or not equal to a multiple of the division of the parts combined in the band or the like.

The invention is based on the knowledge that, with such a dimensioning of the distance between the spray nozzles, the total expression across all spray nozzles is approximately the same, and thus the strength of the individual spray jets is not subject to any fluctuations. This results in a particularly uniform design of the individual spray jets.

The diameter of the nozzles and the distance of the nozzles from the strip or the like are preferably dimensioned such that a current density distribution corresponding to the desired layer thickness distribution is produced between the strip or strip and nozzles. In this way, any desired layer thickness distribution can be achieved, so that, for example in the case of knife strips, the areas which are exposed to greater wear than other areas can be provided with a thicker coating. As a result, experience has shown that precious metal contacts can be saved considerably in precious metal contacts.

A further possibility of a targeted layer ceiling distribution results from the fact that the individual spray nozzles have a smaller diameter than the width of the areas to be galvanized on the strip and that the individual spray nozzles are not only arranged one behind the other in the direction of movement, but also perpendicularly to one another such that the in the order of the first spray nozzle the one (upper) and the last spray nozzle the other (lower) range limit. In practice, this can be achieved in a simple manner by displacing the nozzles, which are preferably combined into groups and are used in a common container to form a spray cell, by inclining the container parallel to the belt. By appropriately tilting the spray cell, a more or less wide area on the strip can be partially galvanized. According to this inclination, the belt speed must then be set accordingly in order to achieve a certain layer thickness.

It has proven to be expedient if the angle between the nozzle axis and the belt plane is set to be less than 90 °, so that the sprayed electrolyte flows off in a preferred direction. This allows the exit speed speed of the electrolyte from the nozzles can be increased. The more this angle deviates from the perpendicular to the strip, the better the flow distribution, so that at least partially sharply delimited areas of the coating result.

If both sides of the strip are to be partially galvanized, spray nozzles are arranged on both sides of the strip in a manner known per se which, according to the invention, are at a distance from one another so that the nozzles do not interfere with one another.

If the electrolyte is sprayed at a very high speed, it is inevitable that the electrolyte is also sprayed onto areas which are not to be galvanized and which may then have to be cleaned again later. In this case, it is advantageous that at least these areas of the band are covered by at least one mask in a manner known per se. It is expedient here if the mask forms part of the guidance of the band. If, for example, plug strips, plug pins or the like are to be partially galvanized with the aid of masks, it is advantageous that the masks move with the belt or the strips in a speed-compatible manner at least over the length of the spray cell.

As has already been explained above, it is advantageous that the spray nozzles arranged at least on one side of the belt are used to form a spray cell in a common container which is designed and held under pressure such that each of the electrolyte jets emerging from the individual spray nozzles has approximately the same strength. A particularly simple construction of a spray cell results in accordance with the invention in that the spray cell consists of a noble metal tube, e.g. Platinum, existing spray nozzles in a tubular container made of corrosion-resistant material, e.g. Titanium are used, which is preferably closed on one side and has a connecting piece for electrolyte liquid on the other side. So that approximately the same electrolyte pressure arises at all spray nozzles, it is advantageous that a preferably concentrically arranged distributor pipe is arranged in the interior of the tubular container, via which the electrolyte is supplied and in which holes are provided in a corresponding distribution on the side facing away from the spray nozzles.

Such a container can be easily adjusted with respect to the belt or the like so that the distance of the spray nozzles from the belt and the direction of the spray nozzles to the belt can be changed. The spray direction can be changed in a simple manner in that the container is designed to be pivotable about its longitudinal axis.

• Figur 1 eine perspektivische Ansicht einer Vorrichtung mit einer Sprühzelle zum partiellen Galvanisieren von zu leitenden Bändern oder Streifen zusammengefassten elektrischen Bauteilen, wobei mit strichpunktierten Linien angedeutet ist, wie die zu beschichtenden Bänder oder Streifen kontaktiert und bewegt werden,
• Figur 2 einen teilweise vergrössert dargestellten Teil des zu beschichtenden Bandes,
• Figur 3 eine Vorrichtung mit zwei Sprühzellen, die zu beiden Seiten des Bandes angeordnet sind,
• Figur 4 eine Seitenansicht der Vorrichtung gemäss Fig. 3 im Schnitt in verkleinerter Darstellung,
• Figur 5 in vergrösserter Darstellung einen Teil eines beschichteten Stiftes eines Bandes und
• Figur 6 eine bevorzugte Ausführung einer Sprühzelle im Schnitt.

The invention is explained in more detail with the aid of the drawing, in which several exemplary embodiments are shown in part purely schematically. Show it:

• FIG. 1 shows a perspective view of a device with a spray cell for the partial electroplating of electrical components combined to strips or strips to be conducted, dash-dotted lines indicating how the strips or strips to be coated are contacted and moved,
• FIG. 2 shows a part of the strip to be coated, partially shown enlarged,
• 3 shows a device with two spray cells which are arranged on both sides of the belt,
• FIG. 4 shows a side view of the device according to FIG. 3 in section in a reduced representation,
• Figure 5 is an enlarged view of part of a coated pin of a tape and
• Figure 6 shows a preferred embodiment of a spray cell in section.

As FIG. 1 shows, the parts 1 to be coated are combined to form a conductive tape 2. After the coating and other treatment, the parts 1 are separated in a manner known per se. The tape 2 is usually wound on a roll and is drawn off by an unwinder, not shown in the drawing, and runs into the electroplating system. It travels through a number of pretreatment stations in a manner known per se and then finally runs into the actual electroplating cell 4, the principle of which is shown in FIG. The tape 2 is drawn into the plating cell 4 in the direction of the arrow 3. Immediately in front of the actual spray cell, a pair of contact rollers 5 are provided for contacting the belt 2, which also serve as a guide. Due to a slight inclination of these contact rollers 5 to the direction of travel, the tape is pressed slightly against a stop. This gives an exact position of the belt to the spray cell. Immediately after the spray cell, a pair of contact rollers 6 are also provided, which also serve for contacting and guiding the belt. The tape 2 then continues through the plant and is wound up again on a roll at the end with the aid of a winding device.

The band 2 is guided along a row of nozzles 7, which are inserted in a tubular container 8 designed as a spray cell. As indicated by an arrow 9, electrolyte is pumped into the tubular container 8, which then exits through the nozzles 7. The nozzles 7 are directed against the area B to be coated, the diameter d of the nozzles 7 and the distance a from the strip 2 being matched to one another such that the current density distribution corresponds approximately to the desired layer thickness distribution (FIG. 2).

FIG. 2 shows, on an enlarged scale, the arrangement of the nozzles 7 in relation to the area B to be galvanized of the parts 1 on the strip 2. In FIG. 2, the nozzle 7 is directed approximately perpendicularly towards the strip 2. This is expedient if, as shown in FIG. 2, the area B of the part 1 to be coated is curved is. If this is not the case, it may be advantageous that the angle a between the nozzle axis 10 and the ribbon plane is made smaller than 90 ^{the 0th} This adjustment of the angle can be carried out in a simple manner in such a way that the tubular container 8 is correspondingly rotated about its longitudinal axis 11. The nozzles 7 used in the tubular container 8 are preferably arranged at the same distance D from one another, but the distance D is not equal to a multiple of the distance t of the components combined in the band 2.

As indicated in FIG. 1, the area of the strip 2 that is not to be galvanized can be covered. This can be done, for example, by means of corresponding masks 12 and 13, which are pressed elastically against the band 2. However, if the belt consists of individual parts e.g. There is contact pins that are more or less free, so there is a risk that these parts 1 are bent and damaged. In this case, it is expedient if the masks 12 and 13 move according to FIG. 1 with the belt in a speed-compatible manner. This can be accomplished in a simple manner if circumferential belts are used as masks 12 and 13, as are also used, for example, in a device described in DE-OS 2 928 904. As a result, there is also the possibility of partially galvanizing parts combined into strips, such as pin combs or the like, and also circuit boards.

FIGS. 3 and 4 show an embodiment with two spray cells, contact pins 14 being combined into a band to be galvanized at the lower free end, from both sides. In this case, tubular containers 8 and 8 'with spray nozzles 7 and 7' are provided on both sides of the belt and are directed against the area to be plated on the contact pins 14. The arrangement and configuration of the nozzles 7 and 7 'essentially corresponds to the configuration according to FIG. 1, but in this case the opposing nozzles 7 and 7' are offset from one another so that the electrolyte jets emerging from the individual nozzles 7 and 7 ' do not influence each other. The two tubular containers 8 and 8 'are arranged within an electrolyte trough 15, as shown in FIG. 4.

If, for example, the lower end of a contact pin 14 is to be galvanized in such a way that the distribution of the layer 26 shown in FIG. 5 is produced, such a uniform layer thickness distribution can only be achieved if the diameter d of the individual nozzles 7 is significantly smaller than the area to be galvanized B of the connector pin 14 and if the nozzles 7A to 7N are also offset transversely to the direction of movement of the strip, in total by an amount c. This can be achieved in a simple manner in the spray cells according to FIGS. 1 and 3 in that the container or containers 8 are inclined parallel to the belt by the amount c, so that, for example, the first spray nozzle 7A in the order, the upper and the last spray nozzle 7N detected the lower range limit. For the sake of clarity, the amount c is chosen exaggerated. As already mentioned at the beginning, any desired layer thickness distribution can be achieved in this way.

Figure 6 shows an advantageous embodiment of a spray cell, in particular for partial gold plating. The cell consists of a tube 16 made of corrosion-resistant material, e.g. Titanium, in which tubes 17 made of precious metal, for example platinum, serving as nozzles 7 are used. For this purpose, the tube 16 is provided with corresponding bores into which the tubes 17 are inserted, for example by pressing. At one end of the tube 16 is a plug 18 made of corrosion-resistant material, for. B. plastic inserted, which seals the tube 16 tightly. The other end of the tube 16 has a connecting piece 19 for connection to an electrolyte supply, as indicated by an arrow 20. So that the electrolyte jet emerges uniformly from all tubes 17, a distributor tube 21 is arranged inside the tube 16, preferably concentrically to the latter, one end of which is pushed over a molded part 22 of the stopper and the other end of which is centered in a corresponding bore 23 of the connecting piece 19 is. The distributor tube 21 is provided on the side facing away from the tube 17 with openings in the form of bores 24, through which the electrolyte exits and pours around the distributor tube 21 on both sides before it reaches the tube 17 and exits there.

The spray cells shown in FIGS. 1, 3 and 4 are preferably also designed in the same way as the spray cell according to FIG. 6. Such a cell can be inserted into a simple holder which allows rotation about its longitudinal axis 25 as well as adjustment of a certain one Inclined position C parallel to the strip for setting a defined coating width B and also setting an optimum distance for the galvanization of the nozzle ends from the areas to be galvanized is permitted.

Claims (16)

1. Apparatus for the partial electroplating of parts (1) with a predetermined separation (t) which are combined in electrically conductive tapes (2), strips or the like, in a continuous process, wherein the cathodically-connected tape (2) or the like is led along a plurality of anodically- connected spray nozzles (7) which are made of a noble metal and, viewed in the direction of movement of the tape (2) or the like, are consecutively arranged in such a manner and are directed against the tape (2) or the like in such a manner that the electrolyte jet which issues from each individual spray nozzle (7) hits the region to be electroplated on the tape (2) or the like, characterised in that the spacing (D) of the spray nozzles (7) from one another does not correspond to the separation (t) of the parts (1) which are combined in the tape (2) or the like, or to a multiple of the separation (t).

2. Apparatus as claimed in Claim 1, characterised in that the diameter (d) of the nozzles (7) and the spacing of the nozzles (7) from the tape (2) or the like have values such that a distribution of current density corresponding to the required distribution of layer thickness prevails between the tape (2) and the nozzles (7).

3. Apparatus as claimed in Claim 1 or 2, characterised in that the diameter (d) and the spacing (D) of the individual spray nozzles (7) from one another is so selected that the electrolyte jets issuing from the spray nozzles (7) do not affect one another.

4. Apparatus as claimed in one of Claims 1 to 3, characterised in that the individual spray nozzles (7) have a smaller diameter (d) than the width of the regions (B) to be electroplated on the tape (2) or the like; and that the individual spray nozzles (7) are offset, not only in the direction of movement but also at right angles thereto, in such manner that the spray nozzle (7A) which is the first in the sequence comprehends the one (upper) and the last spray nozzle (7N) comprehends the other (lower) boundary of the region.

5. Apparatus as claimed in one of Claims 1 to 4, characterised in that the angle (a) between the nozzle axis (10) and the plane of the tape is set to be smaller than 90°.

6. Apparatus as claimed in one of Claims 1 to 5, characterised in that on both sides of the tape (2) or the like, spray nozzles (7a, 7b) are arranged which are spaced from one another.

7. Apparatus as claimed in one of Claims 1 to 6, characterised in that at least one region of the tape (2) or the like is covered by at least one mask (12, 13).

8. Apparatus as claimed in Claim 7, characterised in the mask forms part of the guide of the tape (2) or the like.

9. Apparatus as claimed in Claim 7 or 8, characterised in that the mask (12, 13) moves together with the tape (2) or the like, at a compatible speed, at least over the length of the nozzle arrangement.

10. Apparatus as claimed in Claim 9, characterised in that as mask (12, 13), endless tapes are used, between which a section of the tape (2) or the like is clamped.

11. Apparatus as claimed in one of Claims 1 to 10, characterised in that the spray nozzles (7) which are arranged at least on one side of the tape (2) or the like, are inserted in a common container (8) which is so designed and so maintained under pressure that each of the electrolyte jets issuing from the individual spray nozzles (7) has approximately the same strength.

12. Apparatus as claimed in Claim 11, characterised in that the spray nozzles which in each case consist of a noble metal tube (17), e.g. of platinum, are inserted into a tubular container which is made of a corrosion-resistant material, e.g. titanium, and which is preferably but not essentially closed at one place and has a connection nipple (19) for liquid electrolyte at the other side.

13. Apparatus as claimed in Claim 12, characterised in that in the interior of the tubular container (16) a distributing pipe (21) is arranged, preferably but not essentially concentric therewith, through which the electrolyte is supplied and in which, at the side facing away from the spray nozzles (17) bores (24) are provided which are so arranged that approximately the same electrolyte pressure prevails at all the spray nozzles (17).

14. Apparatus as claimed in one of Claims 11 to 13, characterised in that the container(s) (8) is (are) adjustable relative to the tape (2) or the like in such manner that the spacing of the spray nozzles (7) from the tape (2) or the like and the direction of the spray nozzles (7) with respect to the tape are adjustable.

15. Apparatus as claimed in Claim 14, characterised in that the tubular container (8) is pivotable about its longitudinal axis (11).

16. Apparatus as claimed in one of Claims 11 to 15, characterised in that with long containers (8), the supply of the electrolyte is carried out at a plurality of locations, in particular, at the two ends.

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