JP2002514267A - Apparatus for electrolytically treating a plate-shaped workpiece and a method for electrically shielding an edge area of the workpiece during the electrolytic processing - Google Patents

Abstract

(57) [Summary] The apparatus according to the present invention is used for electrolytically treating a plate-shaped workpiece, preferably a printed circuit board, in a continuous feed facility arrangement, wherein the workpiece is as described above. The device according to the invention can be guided in a substantially horizontal transport direction to the transport plane through the equipment arrangement, and the device according to the invention comprises a counter-electrode ( 2) and a screen (11) arranged between the transport plane and the counter electrode for shielding a field with a high current density in the edge area of the workpiece (1), wherein the screen is used Are each formed in the form of at least two substantially parallel flat parts (12, 13), one part (13) of the screen being arranged opposite the transport plane and the other part (12) is the counter electrode The screen is displaceable in a direction (20) extending substantially parallel to the transport plane and substantially perpendicular to the transport direction (23). So that it is attached. The available area of the printed circuit board blank is extended by this device to an edge of about 12 mm, where the required tolerance of the deposited metal layer thickness is not maintained.

Description

DETAILED DESCRIPTION OF THE INVENTION Equipment for electrolytic treatment of plate-shaped workpieces For electrically shielding the edge area of the workpiece during processing   The present invention relates to an apparatus for electrolytically treating a plate-shaped workpiece. As well as a method for electrically shielding the edge area of the workpiece. Preferred In other words, the above-described apparatus and the above-described method include a conductor plate (such as a printed circuit board) and a conductor. In the case of electroplating or etching of foils, the workpiece is aligned horizontally or vertically as it passes. Used in a continuous installation arrangement.   Workpieces of various widths are generally produced in continuous electroplating equipment arrangements . The anode in the installation can handle the widest range of plates and foils without any problems It must be dimensioned as follows. Relatively narrow plates in this situation Alternatively, the foil is placed in the above-mentioned facility and the galvanic action is performed in the direction If received (electroplated), the electric field lines concentrate in the edge area Therefore, a considerably thicker metal layer is created in the edge area than in the center. . Usually, a certain tolerance for the thickness of the metal layer is set, and consequently the metallization That the actual usable area on the plate or foil is smaller than its full width. Become. When manufacturing conductor plates and foils, Only marginal tolerances for metal layer thickness due to processing requirements It is just done. In addition, conductor plates generally involve expensive materials. So Therefore, it is subject to galvanic action, also referred to as use material (blank / material piece, Nutzen). It is desirable to achieve maximum utilization of the bare conductor plate. Therefore, uniform layer thickness Is achieved up to the edge area of the conductor plate or conductor foil. Should be electroplated A known way to influence the layer thickness in the area of the edge of the object An electrically shielding screen is used in this edge region using a non-conductive screen.   In DE-P 3937926 C2, especially for the treatment of conductor plates An apparatus is described for interrupting lines of force in an electroplating facility arrangement. Including there The screens are shown in FIGS. 2 and 3 which are shown individually in themselves. It comprises a plurality of adjustable partial screens. Partial rotation around the axis By rotating the clean, the shielding effect of each individual partial screen is increased , Also decreases. The individual screens are narrow enough and therefore these screens Is large enough, the edge covering can be set optimally.   However, the drawback that must be tolerated is that it should not be actually shielded The residual shielding remains over the area of the conductor plate. Further construction of this device The cost of achieving this is substantial. Therefore, as shown in FIG. As a result, a flat screen between the edge area of the workpiece and the anode is practically preferable. Ma New However, with this arrangement of screens, an optimal contoured screen Layering is not possible and the required layer thickness tolerance is relatively large Unattainable in the box. In addition, this arrangement has the disadvantage of significant technical realization costs. is there.   Electroplating operations require strong structures. Therefore, JP-A-62 / 15159 3 is a flat and displaceable screen similar to the known ones. It was proved that. The screen used here is the edge area of the workpiece And the anode are displaced by a linearly acting drive.   The screen formed flat in this way covers the object to be treated with the screen. Depending on the distance between the screen and the anode or the surface of the workpiece. Reduces the density of field lines in the edge area of the workpiece. The distance between the anode and the workpiece, The anode and cathode current densities are also important for the electrolysis process. Screen during electrolysis The position of the lean constitutes a compromise based on these parameters, and as a result, Optimal screening must be determined in complex experiments. My goal is In the case of high current densities, without burning edges, large within the allowed tolerance Achieving the range of use. Average current density with fine conductor plate The non-usable edge has a width of about 30 mm in practice. 15A / d For current densities up to m2, the unusable edges on this screen are already about It has a width of 50 mm.   US-A-3862891, electroplating frame and anode, side by side Of field lines along the object to be electroplated mounted on the article carrier Electroplating apparatus having an electrically impermeable shielding screen for homogenizing Is described. The above shielding screen is fixed to the side wall and screwed with a suitable guide Consists of a number of screen parts that are tightened and tightly connected to the above device Is done. The screen parts are parallel to each other and the object to be electroplated It is oriented parallel to the anode. The screen part is the pair to be electroplated. Partially protrudes into the space between the elephant and the anode, with the screen located near the anode Screen is closer than the screen located closer to the object to be electroplated. Protrude further. With this equipment, the uniform thickness of the electroplating layer It is stated that it is achievable in terms of aspects.   With this device, the metal layer thickness is set only in the narrowest possible edge range of the workpiece. Tolerance has not been achieved and the remaining surface of the workpiece has a uniform metal layer thickness at all locations. Processing requirements for different external dimensions to be optimally treated electrolytically. It is not possible to do. Continuous operation / operation is required to allow for a short preparation period. Rolling is particularly desirable.   The object of the present invention is therefore to avoid the disadvantages of the prior art and in particular to treat plate-shaped workpieces. An object of the present invention is to provide an apparatus for electrolytically treating a physical substance. Using this device Thus, the plate or foil can be continuously subjected to electrolytic treatment. The above equipment is processed simultaneously In order to achieve a uniform distribution of the metal layer thickness on the surface of the plate or foil to be so Change the plate or foil quickly and automatically or in some cases manually. Format / width. During continuous operation / operation, Edge area of plate or foil where thickness tolerance cannot be maintained should be as small as possible Should. However, furthermore, the plate or foil is electrolyzed in a short processing time As a result, the above apparatus can process a large amount of workpieces per unit time It is necessary to use as high an electrolytic current as possible to Can be Even with large electrolytic currents, the thickness of the metal layer on the workpiece is always Should be kept as uniform as possible.   This object is achieved by an electrolytic treatment device according to claim 1 and by an electric treatment device according to claim 10. It is solved by a shielding method.   The apparatus according to the present invention is configured such that the object to be processed has a transport plane in a substantially horizontal direction of transport. A continuous equipment arrangement (system) which is guided so as to be able to be guided is substantially constituted. This series A counter electrode which is arranged substantially parallel to the transport plane in the installation arrangement; High current density between the transfer plane and the counter electrode in the edge area of the workpiece A screen is arranged for shielding the field (Stromdichtefelder). The script The shape of at least two flat portions each arranged substantially parallel to one another. One part of the screen is arranged to face the transport plane, and the other part is Is disposed so as to face the counter electrode. The screen is virtually carried Extend parallel to the transport plane and substantially transverse to the transport direction It is mounted so that it can be displaced in the direction.   In addition, the continuous equipment arrangement is an additional feature required for the electrolytic treatment, for example the processing solution Transfers containers, possibly nozzles, and liquids to individual units Pumps and piping for transporting the workpiece through the above equipment arrangement Units and guide elements for holding in the arrangement of the equipment, power supplies, electrodes and It has a contact element for a workpiece and a current supply line.   The method according to the present invention provides a method for electrolytically treating a plate-like workpiece in a continuous facility arrangement. Used to electrically shield the edge area.   The devices and methods described above include, among other things, conductor plates (such as printed circuit boards) and conductors. Suitable for electrolytic treatment of body foil. Is the object to be treated metallized (metallized) by electrolysis? , Can be etched. In one case, the workpiece is connected as a cathode, A counter electrode is connected as the anode. In the other case, the object to be treated and the counter electrode Are connected with the reversed polarity.   Preferred embodiments of the invention are set out in the dependent claims.   The part of the screen directly facing the transport plane is located between the edges of the workpiece. It is arranged so that it can be withdrawn from the rest of the screen by a distance b. It This makes it possible to very effectively shield the edge area of the workpiece from the concentration of the field lines. You. Such a recessed arrangement of the screen part (alternately stepped arrangement) Then, it is not possible to achieve an optimal uniform distribution of the metal layer thickness.   Screen in changing format of plate or foil to be processed respectively The flat parts of the screen are shifted independently of one another, in order to adapt the arrangement particularly well. (Displacement). Workpiece moving with anode The position of the screen part to be predetermined with respect to the position of the screen The position of each of the parts is determined and adjusted during passage through such a format. It is.   In particular, said spacing b can be adjusted by suitable structural elements. Preferably, the distance between the counter electrode and the flat part relative to the transport plane is also adjusted independently of one another. Can be adjusted.   For automatic adjustment of the interval b and the counter electrode, the interval between the transport plane and the flat part, For example, a controlled motor drive is provided, which allows the screen to be displaced. Noh.   In a preferred embodiment, the flat portion is in the same space as the workpiece and the counter electrode at the same time. Has an edge range that can occupy the edge. In this case, this edge area is defined by the opening and / or Has a recess at the edge.   Since relatively narrow material pieces can be processed efficiently, even small workpieces can be processed. The flat part is transverse to the transport direction to ensure that it is shielded in the edge area It is designed to be made wider when viewed.   In general, the counter electrodes, preferably arranged on both sides of the transport plane, are relatively long strings In the case of a continuous installation, in order to guarantee a single switch-off of the electrodes, In terms of multiple sub-segments Divided. This applies to the counter electrode where the workpiece is not Necessary to avoid current flow. Cut off current flow in these partial segments If not, the current density in the edge area will increase at the leading edge of the plate or foil. In addition, the metal layer will be deposited there with a thickness outside the required tolerance range . Preferably, the screen according to the invention has such a segmentation of the counter electrode ( Segmenting), when viewed in the transport direction, It has a length corresponding to the length.   The invention is described in detail below with reference to FIGS. FIG. 1a: cross-section through a double screen and the resulting layer thickness pattern; FIG. 1b: plan view of a double screen; Figure 2: Plan view of the edge area of various flat parts of the screen; Figure 3a: Schematic of electroplating equipment arrangement without shielding screen according to the prior art. Cross-sectional views and the resulting layer thickness patterns; 3b and 3c: schematic cross-sections and cross-sections through a screen installation arrangement according to the prior art. The resulting layer thickness pattern.   Plate in case of electroplating equipment arrangement without shielding screen according to prior art FIG. 3a shows a customarily obtained layer thickness pattern on a to-be-processed workpiece. Only su Corresponding pattern when using known screen equipment arrangement with clean part Are reproduced in FIGS. 3b and 3c.   FIG. 3a shows the shielding of eg a conductor plate after electroplating. The layer thickness d of the non-edge is shown. In the central area of the material piece, the relative layer thickness of d = 1 This is achieved in practice with a layer thickness of, for example, 0.03 mm. At the same time this layer thickness is the desired layer Make up thickness. The position of the workpiece 1, for example, the conductor plate, with respect to the anode 2 is a cross section. Is shown laterally to the transport direction. In the range 3 outside the range of the drawing, An electrical contact (not shown) is located. Conductor plate in continuous electroplating equipment arrangement The transport and guidance means for are also not shown in the drawing.   Layer thickness pattern on the lower side of the conductor plate is a mirror image of the pattern on the upper side , So only one anode is shown on one side. Anode / cathode spacing, ie anode table The distance between the surface and the surface of the workpiece is practically about It goes from 60 mm to about 120 mm. Layer thickness pattern schematically sketched here 4 is a relative distance a = 1 from a side edge (side edge) 5 of the conductor plate. The desired predetermined layer thickness (desired layer thickness, Soll-Schichtdicke) d = 1. The lines of electric force are Not only because of the field line density extending from the anode surface protruding beyond the conductor plate, Because the local current density is set in the range at the conductor plate, the conductor plate Concentrate on the side edges of Therefore, the undesired “layer thickness drop” 7 is less than d = 1. Formed with no relative thickness. The maximum layer thickness in this case is the side edge of the conductor plate Is formed directly. The so-called burning phenomenon (generally when the cathode current density is too high To avoid the formation of a granular metal layer), this peak current density It must be below the critical current density at which burning occurs. Hence the pair A correspondingly lower average current density must be adjusted (set) for the electroplating operation. No.   FIG. 3b schematically shows an electroplating equipment arrangement in which the arrangement of the anode 2 Has a flat screen 8 displaceably disposed in the vicinity of. However, this No change occurs in the basic pattern of the layer thickness. This In the case of the above, although smaller than without the use of a screen, Is generated. However, due to this weak descent, the use of conductor plate material pieces is possible. The effective range becomes large.   In the case of the equipment arrangement according to FIG. 3c, the usable range is set according to FIG. 3b. It is almost the same size as the equipment arrangement. Here, the screen 8 is a table of the workpiece 1. It is located near the surface. As the distance from the conductor plate becomes smaller, The screen edge 9 acts on the conductor plate in such a way as to concentrate the field lines more and more. It Therefore, a layer thickness swell 10 occurs at this position. This swelling of the conductor plate Continues to side edge 5. This spacing of the screen from the conductor plate also The usable range of the plant is no greater than in the case of the arrangement according to FIG. 3b.   On the contrary, the upper part of FIG. 1a is traversed by a double screen 11 according to the invention. Shown in plane. This is the flat part 1 (near the anode) directly opposite the counter electrode. 2 and a flat portion 13 (close to the cathode) directly facing the workpiece. ing. Both flat parts are provided by a structural element 14, which is preferably made of plastic. Mutual Connected. These structural elements are connected to each other and to the anode and cathode. It is possible to change their position at the location of the clean parts 12,13. this Is the distance 15 between both flat parts as well as the leading edges 16,1 of both screen parts. 7 means that the position is adjustable. Therefore, the screen beyond part 13 The protruding length 18 (interval b) of the connection portion 12 can be set. Double screen 11 It is supported by a bearing 19 so that it can be shifted laterally with respect to the transport direction.   Of course, other structural solutions for the relative setting of the screen parts to each other The decision is also selectable.   If the screen parameters are set correctly, the dual screen 11 The "fall" 7 and the thickness buildup 10 are almost completely compensated (lower part of FIG. reference). Adjustable screen parameters include spacing 15, protrusion length 18 (spacing b ) And the position of the double screen at the distance between the anode and the workpiece.   The distance between the screen part 12 near the anode to the anode and the cathode to the workpiece The distance between the close screen parts 13 is suitable for the purpose after assembling the continuous equipment arrangement. Adjustment of the spacing 15 and the protrusion length 18 (spacing b) is generally not changed anymore. It must simply be performed manually at the start of operation. Control not shown Possible drives are double screens 11 and / or 12 transverse to the transport direction. Of motion 20.   When only conductive plate material pieces with a certain width are processed In order to obtain a predetermined covering 21 in the edge area of the conductor plate, Need only be set once by hand.   However, if the width of the conductor plate changes constantly, Is preferably set by a motor driving device provided with a known control / driving means.   The length of the screen transverse to the transport direction should be at least the narrowest conductor plate It must be of such a size that sufficient edge covering is possible even with a piece of material.   Basically, the screens 12 and 13 are not firmly connected to each other, It is also possible to displace laterally with respect to the transport direction. This is the electroplating equipment This is especially useful when large current density differences occur from one workpiece to another in the arrangement. It is profitable. The screen 13 close to the cathode is used to avoid edge burning. It can be set as optimal.   In FIG. 1b a further double screen 11 is shown in plan view towards the anode 1. . Bearings 19 for holding the screen are arranged between the double screens and at the same time Carry the anode. The anode is divided into segments, electrically insulated from each other, and They are individually switched when the workpieces are placed in a continuous installation in the transport direction. It can be turned on when the workpiece is exited from the facility arrangement. this The function is described in the publication DE-P 3939681 A1. This publication Referenced. The required width 22 of the double screen is the width of the anode segment for the purpose Depends on. To be treated The transport direction is indicated by arrow 23.   In FIG. 2, an example for a given embodiment of the flat parts 12, 13 is reproduced. . Perforating the front area of the screen area reduces some edge effects I do. The formation of recesses at the leading edges 16, 17 also results in a uniform distribution of the metal layer. Such perforations and / or addition of recesses are well suited for fine adjustment.   All of the approaches according to the present invention, even in the fine conductor technology, The usable range of the material strip is practically reduced to at least 12 mm at the conductor plate edge. Bring to reach by. Further fine adjustment is required for both flat screens 12,1 This can be achieved by placing a third screen portion between the three. This additional The mounting of the additional screen part requires only one piece of conductor plate material with a uniform width. When processed in a continuous installation, it is particularly advantageous and leads to low costs. Motor drive to adapt screen position to changing format Is omitted in this case.   All of the disclosed features as well as combinations of the disclosed features are Unless explicitly indicated, the subject is a subject matter. Reference number list: 1. Objects to be processed (for example, printed circuit boards) 2 Counter electrode (eg anode) 3 Contact range 4 Layer thickness pattern 5 Conductor plate edge 6. Protruding counter electrode range 7 "Descent of layer thickness" 8 Single screen according to the prior art 9 Front edge of single screen 8 10 layer thickness rise 11 Double screen 12 Screen part directly facing the counter electrode (close to the anode) 13 Screen part directly facing the object (close to the cathode) 14. Structural elements for adjusting the screen parts 12, 13 15 Spacing between screen parts 12, 13 16 Front edge of screen part 12 17 Front edge of screen part 13 18 Screen facing the counter electrode beyond the screen 13 facing the workpiece Length of protrusion 12 (interval b) 19 Bearings for holding double screens 20 Screen movement 21 Conductor plate cover 22 screen width 23 Transport direction

[Procedure of Amendment] Article 184-8, Paragraph 1 of the Patent Act [Submission date] May 7, 1999 (1999.5.7) [Correction contents] The formation of recesses at the leading edges 16, 17 also results in a uniform distribution of the metal layer. That's it The perforations and / or the addition of recesses are well suited for fine adjustment.   All of the approaches according to the present invention, even in the fine conductor technology, The usable range of the material strip is practically reduced to at least 12 mm at the conductor plate edge. Bring to reach by. Further fine adjustment is required for both flat screens 12,1 This can be achieved by placing a third screen portion between the three. This additional The mounting of the additional screen part requires only one piece of conductor plate material with a uniform width. When processed in a continuous installation, it is particularly advantageous and leads to low costs. Motor drive to adapt screen position to changing format Is omitted in this case.

────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Praise Wolfgang             Germany Day 16816 Noil             Appin Bechlinder Shoessee             131 (72) Inventor Vechter Ralph Peter             Germany Day 90518 Arte             Ndorf Industriestrasse               5 bases [Continuation of summary] Extends to an edge of about 12 mm.

Claims (1)

[Claims] 1. To process plate-shaped workpieces electrolytically in a continuous feed facility arrangement A method of transporting an object to be processed substantially horizontally through the above continuous feed equipment arrangement. A device that can be guided to a transport plane in a direction, a. A counter electrode (2) positioned substantially parallel and opposite to the transport plane, and b. In the edge area of the object to be processed (1) arranged between the transport plane and the counter electrode For shielding high current density fields (11) Has, c. In this case, the screens are each at least two substantially parallel to each other One part of the screen is formed in the shape of the arranged flat parts (12, 13) (13) is disposed so as to face the transport plane, and the other portion (12) is a counter electrode. Is arranged to face d. At this time, the screen is substantially parallel to the transport plane and in the transport direction. (23) so that it can be displaced in a direction (20) extending substantially perpendicularly. Is attached Such a device. 2. The portion (13) of the screen (11) directly opposed to the transport plane is , The other side of the edge of the object to be processed (1) by the distance b 2. The device as claimed in claim 1, wherein the device is arranged to retract from the portion (12). Devices that follow. 3. The flat portions (12, 13) are mounted so that they can be displaced independently of each other. Apparatus according to any one of the preceding claims, characterized in that: 4. The distance b can be adjusted by a suitable structural element (14). Apparatus according to any one of the preceding claims. 5. The distance between the flat portions (12, 13) with respect to the counter electrode (2) and the transport plane is Claim 1 characterized in that it is adjustable independently of each other. Equipment to follow. 6. A controllable motor drive is provided, whereby the screen (11 Device according to any one of the preceding claims, wherein the device is displaceable. . 7. The flat portions (12, 13) are the same as the object (1) and the counter electrode (2). Have edge regions that can occupy space, these edge regions being recessed in the openings and / or edges Apparatus according to any one of the preceding claims, comprising: 8. The flat portions (12, 13) are narrow when viewed perpendicularly to the transport direction (23). The object to be processed (1) should be wide so that the edge area can be reliably shielded. Apparatus according to any one of the preceding claims, characterized in that: 9. The counter electrode (2) forms a number of partial segments when viewed in the transport direction (23). The screen (11) is divided Having a length in the transport direction corresponding to the length of the partial segment of the counter electrode (2) Apparatus according to any one of the preceding claims, characterized in that: 10. The edge region of the plate-shaped object is set so that the object is substantially horizontal. During the electric field treatment in a continuous feeder arrangement that can be guided to the transport plane in the transport direction, In a way to shield a. A screen for shielding from a high current density field in the edge region of the workpiece (1) A lean (11) is disposed opposite the transport plane and substantially parallel to each other. Arranged between the opposed electrodes (2) b. In that case, at least the screens are each arranged substantially parallel to each other. Is also formed in the shape of two flat parts (12, 13) and one part of the screen ( 13) is opposed to the transport plane, and the other part (12) is opposed to the counter electrode. Yes, c. The screen is then substantially parallel to the transport plane and in the transport direction (2 3) mounted to be displaceable in a direction (20) extending perpendicular to Is Way like.