Classifications

• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
  • C25D17/00—Constructional parts, or assemblies thereof, of cells for electrolytic coating
  • C25D17/10—Electrodes, e.g. composition, counter electrode
  • C25D17/12—Shape or form
• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
  • C25D17/00—Constructional parts, or assemblies thereof, of cells for electrolytic coating
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
  • H05K3/00—Apparatus or processes for manufacturing printed circuits
  • H05K3/22—Secondary treatment of printed circuits
  • H05K3/24—Reinforcing the conductive pattern
  • H05K3/241—Reinforcing the conductive pattern characterised by the electroplating method; means therefor, e.g. baths or apparatus

Definitions

• the invention relates to a device for electroplating plate-shaped objects, in particular printed circuit boards, in a horizontal pass
• a left and a right conveying device seen in the conveying direction of the objects, which act on the lateral edges of the objects and move them in the conveying direction;
• At least one anode basket which extends transversely to the conveying direction over the working width of the device and which is at least partially filled with a loose bed of parts made of the metal which is applied to the objects during the electroplating and which has the positive pole of the Galvanisier ⁇ current source is connected.
• the conveying device and contacting device are often structurally combined. Both functions are performed in particular by contacting rollers which engage on opposite edges of the circuit board and move the circuit board forward by their rotation and at the same time transfer the electroplating flow from its jacket surface to the surface (s) of the printed circuit board.
• contacting rollers which engage on opposite edges of the circuit board and move the circuit board forward by their rotation and at the same time transfer the electroplating flow from its jacket surface to the surface (s) of the printed circuit board.
• DE-PS 32 36 545 describes a device for electroplating printed circuit boards, which can also handle different formats.
• a conveying and contacting device in the form of contacting rollers on only one side of the machine, which alone takes over the forward movement of the printed circuit boards and the power supply to the latter.
• This conveying and contacting device is stationary, that is rigidly connected to the machine frame.
• the opposite edge of the circuit boards is guided by a support device, which is neither driven nor used for power supply.
• Such a simple support device takes up little space and can be adjusted transversely to the conveying direction of the printed circuit boards.
• the one-sided drive is no longer safe enough; in addition, the one-sided power supply can be the cause of an uneven galvanization which is based on the voltage drops within the printed circuit board.
• the object of the present invention is to design a device of the type mentioned in the introduction in such a way that it can also be used to electroplate circuit boards of different formats.
• each anode basket is composed of two halves which can be telescopically pushed into one another transversely to the conveying direction.
• the invention therefore initially assumes that the two lateral conveying devices and the two lateral contacting devices, which are known from the closest prior art, must be maintained in order to ensure reliable forward movement and power supply.
• the invention decides to make at least one of the two conveying devices and contacting devices, which are structurally very complex and take up a relatively large amount of space, adjustable transversely to the conveying direction. With such an adjustment movement, however, the known anode baskets would be in the way for geometric reasons. Therefore, the invention provides according to feature e of the main claim to assemble each anode basket from two halves. These can then be telescopically pushed into one another or pulled apart again in order to adapt to the variable distance between the two lateral conveying devices and contacting devices.
• each half of each anode basket is divided into parallel segments that run transversely to the direction of conveyance, with alternate closed segments that can be filled with the loose fill and empty segments that are open to the opposite half alternate in such a way that a closed segment is opposite an open segment .
• the closed segments filled with metal parts in bulk can then penetrate "finger-like" into the opposite open segments of the other half of the anode basket without the metal parts being in the way.
• the closed segments should be made of titanium, while the open segments should be made of platinum-plated titanium, at least in the base area.
• the bottoms of the open segments form an inert electrode wherever they are exposed, ie not covered by a closed segment, on which electrolysis from the electrolyte also takes place.
• Half of the anode basket can have an additional guide wall which extends at a small distance from the adjacent side wall of the corresponding segment of this half transversely to the conveying direction, such that a space is created between this guide wall and this segment in which the corresponding side wall of the opposite segment of the other half of the anode basket can be inserted. This improves the mutual displacement of the two halves of the anode basket; the telescopic movement is better guided.
• One of the two conveying devices and one of the two contacting devices are expediently rigidly attached to the machine frame, while the other conveying device Direction and contacting device can be moved transversely to the conveying direction with respect to the machine frame.
• Each displaceable conveying device and each displaceable contacting device can be assigned a plurality of guide rails running transversely to the conveying direction, which engage in guide grooves on the underside of the conveying device or the contacting device.
• each displaceable conveying device and each displaceable contacting device is in driving connection with at least one spindle, the external thread of which cooperates with a stationary nut.
• the spindle preferably several are provided parallel to each other
• the corresponding conveying device or contact device is then moved.
• the invention is suitable both for devices in which the contacting device and the conveying device are separate structural elements, and for those in which the same elements assume the dual function of conveying and contacting.
• axles are composed of at least two axle parts which can be pushed telescopically into one another.
• the length of the axes can in this way be adapted to the distance between the two lateral conveying and / or contacting devices.
• the axles are preferably composed of two lateral axle parts and a hollow, central axle part. The two side axle parts can then be inserted more or less far into the middle axle part from both sides.
• the free-running support rollers are advantageously mounted on the latter.
• FIG. 1 shows a section through the left area of a device for electroplating printed circuit boards, as seen in the conveying direction;
• FIG. 2 shows a section through the right-hand region of the device from FIG. 1 seen in the conveying direction (with a certain overlap);
• FIG. 4 schematically, the top view of the upper anode baskets of the device of FIGS. 1 and 2 on a somewhat larger scale;
• Figure 5 shows a section along line V-V of Figure 4.
• Figures 1 and 2 taken together show a section through a device for electroplating printed circuit boards perpendicular to their direction of movement.
• the middle area of the device is shown in both figures, so that there is a certain overlap between these figures for better understanding.
• the device comprises a machine frame 1, to which a tub 2 is attached, which is filled with an electrolyte in operation.
• a first conveying and contacting device 4 extends parallel to the direction of movement of the printed circuit boards, which is described in more detail below and is stationary, that is to say firmly connected to the machine frame 1.
• FIG. 2 On the right-hand side of the machine (FIG. 2) there is a corresponding, mirror-symmetrical conveying and contacting device 5, which, in contrast to the left conveying and contacting device 4, can be adjusted perpendicular to the direction of movement, so that the device for printed circuit boards 3 of different widths can be adjusted. Details regarding the adjustment of the right conveying and contacting device 5 are also explained below.
• an anode basket ⁇ extends from the left conveying and contacting device 4 to the right conveying and contacting device 5.
• This upper anode basket 6 is partially filled with copper balls 7 in a manner to be described in more detail which form the consuming anode during the actual electrolysis.
• the dimension of the upper anode basket 6 transversely to the direction of movement of the printed circuit boards 3 corresponds to the distance between the left conveyor and
• Contacting device 4 and the right conveying and contacting device 5 can be changed, which will be discussed further below.
• anode basket 8 Extends below the path of movement of the printed circuit boards 3 there is also an anode basket 8 from the left conveying and contacting device 4 to the right conveying and contacting device 5; it is designed essentially in the same way as the upper anode basket 6 and partially filled with copper balls 7.
• the left edge of the circuit board 3 to be electroplated runs on a plurality of lower contacting rollers 9, which lie with their outer surface against the underside of the circuit board 3.
• Another set of contact rollers 10 touch the circuit board 3 with a certain contact pressure from above.
• Both the upper and the lower contacting rollers S, 1 are electrically conductive on their outer surface and can be profiled to achieve a better transport effect.
• the lower contact rollers 9 are supported by means of axes 11 in a bearing block 12 which is rigidly connected to the machine housing 1 via a mounting plate 23.
• the outer end of the axes 11 protrudes somewhat above the bearing block 12 and is here in contact with a brush 13 which is connected to the negative pole of a galvanizing current source, not shown.
• the upper contact rollers 10 are mounted in the bearing block 12 by means of their axes 14; its outwardly projecting end is in contact with a brush 15, which is also connected to the negative pole of the electroplating power source.
• the contact rollers 9 and 10 are rotated in a manner known per se by a drive shaft 16 in rotation. sets, which extends parallel to the direction of movement of the printed circuit boards 3 within the conveying and contacting device 4 and whose rotary movement by means of gears 17, 18 on the axes 11, 14 of the contacting rollers 9, 10 will carry over.
• a space 19 is recessed in the conveying and contacting device, which is delimited at the bottom by an auxiliary cathode 20.
• the auxiliary cathode 20 is connected to the negative pole of an auxiliary voltage source, the positive pole of which is connected to the negative pole of the electroplating current source. It is used in a manner of no interest here to remove metallic deposits which result from the contacting rollers 9 due to the electroplating process.
• a space 21 is recessed above the upper contacting rollers 10 within the conveying and contacting device 4, which is delimited at the top by an auxiliary cathode 22.
• the auxiliary cathode 22 is also connected to the negative pole of the auxiliary voltage source already mentioned and serves to remove deposits which have deposited on the outer surface of the upper contact rollers 10.
• the right conveying and contacting device 5 shown in FIG. 2 is completely correct with the just described left conveying and contacting device as far as the lower and upper contact rollers, their drive and their electrical connection to the electroplating power source are concerned 4 match. This also applies to the spaces left in the right conveying and contacting device 5, which are delimited by auxiliary electrodes. In this regard, reference can be made to the above description. However, while the left conveying and contacting device 4 is seated on the mounting plate 23, which is firmly connected to the machine frame 1 and is therefore not movable, the right conveying and contacting device in FIG. 2 can be adjusted perpendicular to the direction of movement of the printed circuit boards 3.
• FIG. 1 For this purpose, several parallel profile guide rails 24 are placed on the right half of the mounting plate 23, which extend transversely to the direction of movement of the printed circuit boards 3 and have a dovetail hollow profile.
• the bearing block 12 of the right-hand conveying and contacting device 5 is provided on its underside with complementarily shaped guide grooves 25 which overlap the guide rails 24.
• a plurality of parallel spindles 26, which extend in the direction of displacement, pass through a driving part 27 fastened to the bearing block 12 Spindle 26 is attached and rests in the inner side surface of the driving part 27.
• the spindle 26 extends on the outer side surface of the driving part 27 via a step 30.
• a thread 31 of the spindles 26 interacts with a nut 32 which is rigidly connected to the frame 1.
• the arrangement is obviously such that when the spindles 26 are rotated in the same direction and uniformly, the entire right conveying and contacting device 5 can be displaced on the guide rails 24 in the spindle direction, that is to say transversely to the conveying direction of the printed circuit boards 3.
• the lower contacting rollers 9 of the left conveying and contacting device 4 are connected to the lower contacting rollers 9 of the right conveying and contacting device 5 via axes 33.
• the axes 33 are composed of two lateral, solid axis parts 33a and 33b and one middle tubular axle part 33c assembled.
• the lateral axis parts 33a and 33b project telescopically into the central axis part 33c and can move axially relative to the latter. In this way, the entire axis 33 can be changed in length depending on the position of the right-hand conveying and contacting device 5.
• a plurality of free-running support rollers 34 are supported on the central axis part 33c, which rest against the printed circuit boards 3 from the underside.
• the upper contacting rollers 10 of the left conveying and contacting device 4 are connected to the upper contacting rollers 10 of the right conveying and contacting device 5 by axes 35, which are composed of two lateral, solid axis parts 35a, 35b and a central tubular axis part 35c .
• the length of the axes 35 can be adapted to the distance between the two conveying and contacting devices 4, 5 by telescopically pushing their parts 35a to 35c together.
• Freewheeling rollers 36 which roll on the upper side of the printed circuit board 3, are in turn mounted on the central axis part 35c.
• FIGS. 4 to 6 The lower anode basket 8 is shown schematically in these. This comprises two segmented halves 8a, 8b, which can be pushed one into the other like a drawer, so that the overall width of the anode basket 8 can be adjusted.
• the left half 8a of the anode basket 8 is divided into four parallel segments 40, 41, .42, 43 extending transversely to the direction of movement of the printed circuit boards 3, all of which are open at the top.
• the bottom segment 40 in FIG. 4 is provided with an end wall 44 on the inside end face and filled with copper balls 7.
• the second segment 41, which adjoins upwards in FIG. 4, is open towards the center, ie has no end wall here and is empty.
• the third segment 42 of the left half 8a of the anode basket 8 is again with a middle one
• End wall 45 equipped and loaded with copper balls 7.
• the uppermost segment 43 in FIG. 4 again corresponds in its construction to segment 41, that is to say it is open to the right and contains no copper balls.
• the right half 8b of the anode basket 8 is likewise composed of four segments 46, 47, 48, 49 which extend transversely to the direction of movement of the printed circuit boards 3.
• the construction of the individual segments alternates:
• the bottom segment 46 of the right half 8b of the anode basket 8 is empty and open to the left.
• the second segment 47 adjoining at the top in FIG. 4 has an end wall 50 on the left side and is filled with copper balls 7.
• each segment of one half 8a or 8b which is provided with copper balls 7 and is closed off with an end wall, is an empty, inwardly open semant of the other half 8a, 8b across from.
• the segment filled with copper balls can therefore be inserted into the opposite, empty segment, so that the individual segments, as shown in FIG.
• the respectively empty segments 41, 43, 46 and 48 are made from a platinized perforated titanium plate. They act as an inert electrode during operation of the device.
• the segments 40, 42, 47 and 49 of the anode basket 8, each filled with copper balls 7, are made of non-platinized titanium expanded metal. The copper balls 7 located in them act as consuming electrodes during operation of the device.
• An additional guide wall 52 is attached to the edge-side segment 49 of the right half 8b of the anode basket 8 in FIG. 4, which serves as an additional side guide for the outermost side wall of the segment 43 of the opposite left half 8a of the anode basket 8.
• the lower anode basket 8 rests laterally on steps 60 of the
• the movable half 6b of the upper anode basket 6 is suspended laterally at 62 on the right bearing block 12.
• the stationary half 6a of the anode basket 6 is detachably fastened laterally and in the middle to a cover plate 64 via fastening parts 63.
• the two halves 8a, 8b of the lower anode basket 8 (the same applies to the upper anode basket 6) are pulled apart as far as possible, so that the segments 40, 42, 47, 49 of each half filled with copper balls 7 8a only barely dip into the opposite segment 46, 41, 48, 43 of the other half of the anode basket 8. In this position, relatively large floor areas of empty segments are exposed; the percentage of inert anode surface is relatively large.
• the alternating arrangement of filled segments in the two anode basket halves 8a, 8b ensures that active electrode areas are always available over the full machine width.
• the printed circuit boards 3 to be electroplated are grasped at their lateral edges by the lower and upper contact rolls 9, 10 of the left and right conveying and contacting devices 4 and perpendicular to the plane of the drawing
• Figures 1 and 2 promoted to the rear.
• the electrically conductive layers on the surfaces of the printed circuit boards 3 are connected to the electroplating current source via the contacting rollers 9, 10 and the brushes 13, 14 in such a way that they are connected cathodically.
• an electrolysis takes place during the passage of the printed circuit boards 3 through the device, through which the electrically conductive layers of the circuit boards 3 metallic copper layers are built.
• the right conveying and contacting device 5 is shifted to the left by turning the spindles 26 on the guide rails 24 in FIG. 2, that is to say towards the center of the machine.
• the axes 33 and 35 are telescopically compressed.
• the individual segments of the left half 8a and the right half 8b of the lower anode basket 8 (the same happens analogously for the upper anode basket 6) are pushed further into one another.
• the segments 40, 42, 47, 49 filled with copper balls 7 each abut the outer end wall of the associated empty segment 41, 43, 46, 48 of the other half. With this working width, the entire effective area of the anode basket 8 is covered by copper balls 7; there is therefore no appreciable inert portion of the electrode.
• Embodiment is dispensed with the segment-like division.
• the anode baskets here are composed of two undivided halves, which can be telescopically pushed into one another and are completely filled with copper balls.
• the circuit board format which has the smallest width is treated first at the start of work.
• the two halves of the anode baskets can be pulled apart to set a larger printed circuit board width, the balls rolling partly apart, but in some cases refilling of balls is necessary. In this way, increasingly wider circuit boards are galvanized by pulling apart the two halves of the anode baskets.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Electrochemistry (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Manufacturing Of Printed Wiring (AREA)
• Electroplating Methods And Accessories (AREA)

Applications Claiming Priority (2)

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ID=6441743

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Citations (2)

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• 1991
  • 1991-09-28 DE DE19914132418 patent/DE4132418C1/de not_active Expired - Fee Related
• 1992
  • 1992-09-18 WO PCT/EP1992/002157 patent/WO1993007310A1/de active Application Filing

Patent Citations (2)

Non-Patent Citations (2)

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