WO1992001088A1

WO1992001088A1 - Process for moving an item with drillings during its wet chemical treatment, e.g. galvanisation, and device for implementing the process

Info

Publication number: WO1992001088A1
Application number: PCT/DE1991/000557
Authority: WO
Inventors: Jos Van Kempen; Karl-Heinz Prehl
Original assignee: Schering Aktiengesellschaft
Priority date: 1990-07-06
Filing date: 1991-07-04
Publication date: 1992-01-23
Also published as: DE4021581A1; DE4021581C2; EP0539390A1; JPH05508744A; KR930701641A; CA2086762A1

Abstract

The invention is primarily based on a process for the to and fro movement of an item with drillings during its wet chemical treatment. In order, especially with an unfavourable ratio between the thickness of the item and the drilling diameter, to be able to be sure of removing existing residues and/or gas bubbles in the drilling, it is proposed that the item (3) be vibrated at a frequency of at least 4 - 5 Hz, the direction of vibration be at least partially and/or in time directed along the longitudinal axis (5) of the drillings and the vibration be exerted only or at least primarily on the bearing part of the item. In addition, the invention relates to a device for implementing the process, whereby several treatment stations are arranged one behind the other with the purpose of largely avoiding the drawback of prior art embodiments of the transfer of such vibrations to the stationary part of such an installation. To this end, at least one vibration generator (12) generating vibrations at a frequency of 4-5 Hz is fitted to a transport and/or supporting component by means of which the item is held during transport, insertion in the bath and its immersion therein, and between the vibration generator and the stationary parts of the installation there are blocking and at least largely damping means.

Description

"Method for moving a product having bores during its wet chemical treatment, e.g. galvanization, and device for carrying out the method"

The invention first relates to a method according to the preamble of claim 1. So far, one has proceeded so that during the stay of the goods to be treated in the treatment station (bath) by rods guided on the bath container via the goods carriers, the goods perpendicular to the goods plane with a stroke length of 2x10 to 2x40 mm and a frequency of about 20 double strokes / miπ. was moved back and forth. With this "movement of goods" the bores of the goods, in particular plate-shaped goods such as printed circuit boards, were to be cleaned of residues and, in particular, of gas bubbles formed therein due to the chemical treatment. 2 It has been shown that the aforementioned procedural measure is sufficient in many cases and in particular no longer if the ratio of the board thickness (in particular the thickness of printed circuit boards) to the diameter of the bore exceeds the value of 8: 1 (so-called aspect ratio greater than 8: 1 ).

From US Pat. No. 4,875,982 it is known to move a plate connected to the direct current source and covered with a copper layer up and down in the direction of its plane. However, this movement only serves to bring bores of the printed circuit board in front of suction slots, so that the electrolyte is moved through bores in the material to be processed by a pump. However, this has no points of contact with the invention according to claim 1 and also not with further features of the invention, in particular the method measures according to claim 8. US Pat. No. 3,461,045 shows the movement of a casting mold provided with holes and made of wax, which has approximately five oscillations per minute within an electrolyte. This vibration only affects the previous goods movement and moreover has an even lower frequency than was explained above with regard to the prior art. The present invention can therefore not be found in this reference either. DE-OS 31 95 313 only shows a vibration to detach gas bubbles adhering to the surface of plates to be galvanized. This reference, however, gives no indication that vibrations in the direction of the longitudinal axes of the bores of these plates ensure that the electrolyte liquid passes through the bores in accordance with the invention described below.

The object or problem of the invention is first of all to improve procedural measures according to the preamble of claim 1 in such a way that, in particular when the ratio of the plate thickness to the bore diameter is unfavorable for removing residues and gas bubbles from the bores, (eg with an aspect ratio 8: 1), surely any residues and / or Gas bubbles are removed. In particular, the treatment of printed circuit boards with holes is known, which is known by the abbreviation HARB (_High Aspect atio B_oards). In addition, the exchange of the treatment liquid within the bores is to be improved.

The solution to this problem, starting from the preamble of claim 1, is first seen in the features of the characterizing part of claim 1. It has been shown that this shaking movement of the good solves the aforementioned task, even with an aspect ratio? 8: 1. The frequency should at least have the specified value. In contrast, however, it can also be significantly higher. According to a preferred embodiment of the invention, it is 50

Hz. These vibrations have a relatively small amplitude. The size of the amplitude is usually up to 2 mm. However, it could possibly also be larger, i.e. up to about 3 mm. There is an intensive exchange of the treatment liquid in the holes in the material. Gas bubbles resulting from electro-chemical processes are removed from the bore channels. The vibrations have an advantageous effect only on the goods and the parts carrying them, but not on the stationary components of the system.

To support the effect according to the invention, one or more of the procedural measures according to claims 2 to 9 can be provided.

By rotating or pivoting according to claim 2, the angle between the longitudinal axis of the bores of the material and the shaking direction is constantly changed. This promotes the removal of gas bubbles from the holes. In addition, this promotes the exchange of treatment liquid between plate-shaped parts to be treated which are arranged at a distance from one another, which in turn results in further promotion of the exchange of treatment liquid in the bores. The aforementioned advantages and effects can also be achieved by means of a method according to saying 3 reachable. The incline can be selected differently depending on the desired result. For example, with an approximately vertical course of the longitudinal axes of the bores and also the generation of vibrations in the direction of this longitudinal axis, the buoyancy of the gas bubbles within the liquid can be utilized to the maximum and thereby a particularly easy separation of the gas bubbles from the walls of the holes.

The measure according to claim 4 also facilitates detachment of the gas bubbles from the relevant surfaces or walls of the goods. The same applies to the process measures of claims 5 and 6. Passing through different frequency ranges has proven to be particularly advantageous for the detachment of the gas bubbles.

The features of claims 8 and 9 include the combination of the vibrations according to the invention with the slow back and forth movement ("movement of goods") of e.g. 20 double strokes / min. and a correspondingly large amplitude of e.g. 2x10 - 2x40 mm, which is known from the prior art.

The invention further aims to solve the problem or problem of creating an arrangement for carrying out the method according to one or more of the claims 1 to 9 already explained, whereby, while avoiding the disadvantages of the explained prior art, a transfer of such Vibrations on the stationary part of such a system, especially the bath tank, should be largely avoided.

The solution to this problem, starting from the features of the preamble of claim 10, is first seen in the characterizing features of claim 10. The proposed positioning of the vibration generator has the consequence, in accordance with the method explained at the outset, that the vibrations of which almost exclusively reach the material to be treated, but are not or only slightly passed on to the stationary part of the system, in particular the container. According to the teaching of claim 1, the main direction of the vibrations produced by the vibration generator runs in the direction of the bores of the material to be treated, ie the vibration generator is positioned with respect to the receiving or carrying means of the material so that it is in the direction the longitudinal axis bores of the material vibrate. However, a direction of oscillation is also possible which takes a certain angle with the longitudinal axis of the bores, for example when using the corresponding procedural measure, which have already been discussed above, including a constant change in the position of the bores by rotating the material

Help of a basket or the like. As can be seen in more detail from the following explanations, the vibration generators can be provided at different points between the goods carrier and the goods, e.g. also on the support rod of a basket receiving the good parts, on support frames, on the

Product carrier rail and other holding or carrying means of the goods. In all of the abovementioned attachment options for the vibration generator, it is located on a component on which the material to be treated is also located, so that there is direct mechanical contact with the vibration transmitting the material.

Further advantages and features of the invention can be found in the further subclaims and the following description and the associated drawing of exemplary embodiments according to the invention. The drawing shows:

1: a first embodiment in side view, partly. cut,

2: a partial representation in a view according to arrow II in FIG. 1, 6 FIG. 3: a view in the direction of arrow III in FIG. 2,

4: a plan view in the direction of arrow IV in FIG. 2,

5: a representation approximately according to FIG. 2 with additional contact means, before lowering the goods carrier,

10

6: a view according to FIG. 5 after the product carrier has been lowered,

7 shows a further embodiment of the invention in the side view,

FIG. 8 shows another embodiment of the Erfin-making in the form of a supporting bar or a supporting frame with means for the rod Aπbriπ- ₀ supply of plates in an inclined position,

9: a detail of FIG. 6 in a perspective view and with the omission of the printed circuit boards,

25

10: another possible embodiment of the invention schematically and in plan view,

11: a further possibility of executing the

30

Invention schematically and in the front view.

In the essentially schematic drawings, only the components necessary for the explanation of the present invention are shown; but not the other known ones Components and devices that are necessary for the operation of a wet chemical treatment system of this type.

1 shows the container 1 of a treatment station 2 through which the material 3 to be treated, here printed circuit boards provided with holes, is carried out in the transport direction 4 hiπ. The aforementioned bores are not shown for drawing reasons. Their longitudinal axes run according to number 5. The ratio of the thickness of the plates 3 to the bore diameter is preferably greater than 8: 1. A plurality of treatment stations 2 are generally arranged one behind the other in the transport and processing direction 4. The treatment liquid (this can also be a rinsing liquid) is indicated by number 6.

Goods carriers 7 are provided which (see also FIGS. 2 to 4) consist of a goods carrier rail 8 and support arms 9 holding these. At the upper Abwiπklungeπ 9 * of the support arms 9 engages a lifting device 10 (indicated here only by dash-dotted lines), which lifts the support arms 9 with their fork-shaped ends 9 "from a so-called instruction 11 of the container and also pulls the material to be treated out of the bath, transported to the next station, lowered there and so on. While the material to be treated is in the bathroom (see FIGS. 1 to 5 and 8, 9), vibratory generators are active, which are numbered 12 throughout.

In the exemplary embodiment in FIGS. 1 to 4, the vibration generators 12 generate vibration vibrations in the direction of the double arrow 13. This vibration direction runs essentially horizontally. The Schwiπguπgsgenerator 12 are attached to the goods carrier Schieπeπ 8 in this example. This exemplary embodiment also shows (see FIGS. 2 and 4) that a plurality of vibration generators, here two vibration generators 12, are provided at a distance from one another on each goods carrier rail 8. This can create an even shaking effect can be reached over the entire length of the respective goods carrier rail 8. If necessary, more than two vibration generators can be attached to the product carrier rail, if necessary. at different distances from each other, as well as at selected distances from the ends of the rails 8, so that so-called "antinodes" and "vibrating pads" are avoided on the goods carrier rail that participates in the vibration. The Rüttelschwingungeπ are transferred from the respective goods support rail 8 to the respective support frame 14, on which, as indicated, the circuit boards or the like 3 to be treated are attached by means of clips or the like 15. Depending on the type of vibration generator 12, vibrations can also be generated, which run not only parallel to the direction of the double arrow 13 and are also transmitted to the material to be treated.

Appropriate means are provided to keep the vibrating vibrations generated by the invention completely or at least largely away from the stationary part of the system. This can e.g. can be achieved in such a way that the goods carrier rail 8 is very elastic in the shaking direction 13, e.g. 1 has the thin cross section to be seen in particular. This thin cross-section, with its long side perpendicular to the direction of vibration 13, can thus yield slightly elastically and elastically in the direction of vibration. In connection with the elasticity of the material used for the goods carrier rail, this results in a transmission of the vibrations of the vibration generator 12 exclusively, or almost exclusively, to the goods carrier rail, and from there onto the goods held thereby. A further possible embodiment for keeping the aforementioned vibrations away from the stationary part of the system would be e.g. elastic bearings 27 of the instructions 11 on the rods 17 explained in more detail below.

The vibrators are preferred using a indicated electric motor 16 driven. The current transmission takes place with the help of contacts, which are shown in more detail in FIGS. 5 and 6, and which are closed when the fork-like ends 8 'are gripped by the respective instruction 11. 5 shows the goods carrier 7, which is lowered into the treatment station 2 according to the arrows 27. An upper contact part 28 is provided on the support arm 9 of the goods carrier and an associated lower contact part 29 is provided at the treatment station 2. As soon as the aforementioned lowering process has ended, ie the lowered end position according to FIG. 6, in which the material to be treated is located in the bath 3, has been reached, the contacts 28, 29 abut one another. As indicated by a dot-dash line with number 30, the current is then supplied to the electric drives 16 of the vibrating generators. This closing of the contacts and thus the start-up of the vibration generator 12 thus takes place automatically after the good has been introduced into the bath 6. When the good is removed from the bath, the aforementioned contacts are then automatically opened again. The same contact arrangement can be provided if an electromagnetic vibration generator is provided instead of an electric motor. Vibration generation would, however, also be possible by non-electrical means, for example by means of compressed air.

It is also possible to provide vibration generators which each achieve acceleration values of different strengths and act alternately in different directions (not shown in the drawing). Thus, for example, a magnet can attract the goods carrier rail 8 or the like in one direction, while after the magnet is switched off by a spring, the goods carrier rail can be moved back again, whereupon the magnet then operates again, etc. With appropriate coordination of the two vibration generators, in a pumping action is produced in the holes in the material, where the gas bubbles are pushed out of the hole to a certain extent. The size of the unbalance of a vibration generator and its frequency can be adapted to the respective conditions or requirements. As already mentioned, continuous or discontinuous changes in the vibration frequency are also possible, the latter also by repeatedly switching the vibration generator on and off.

If the vibrating vibrators according to the invention interact in conjunction with a slow back and forth movement of the material with a very low frequency of about 20 double strokes / min. should take place (see explanation of this back and forth movement at the beginning of the description), adjusting rods 17 are provided for this purpose, which are moved back and forth in the longitudinal direction by a device (not shown) in the aforementioned sense in the direction of the double arrows 13 , namely relative to the container 1. With the rods 17, the instructions 11 are firmly connected and therefore transfer their movement to the good 3rd

The exemplary embodiment in FIG. 7 shows a goods carrier rail 8 with support arms 9 and a support rod 18 which hangs on the goods carrier rail 8 and holds a basket 20 via a carrier 19 which holds a stack of plate-like goods 3 to be treated 3 serves. The plates, preferably also the above-mentioned circuit boards, are at a certain distance from one another so that the treatment liquid can flow between the plates. The Schwinguπgsgenerator 12 with drive 16 is attached to the support rod 18. For the rest, the configurations and possibilities that were described with reference to FIGS. 1 to 4 can also be used here analogously. Basically, therefore, the construction, applications and procedural measures explained in one of the exemplary embodiments can also be provided in one of the other exemplary embodiments. When the combination of a higher-frequency vibration according to the invention and a low-frequency back and forth movement with the aid of the rod 17 is explained, the overlapping of the two vibrations can result in corresponding effects (harmonics).

The basket 20 can be rotated about an axis of rotation, here a horizontally extending axis of rotation 21, in the direction of one or both arrows 22, 23, or can also be pivoted back and forth. The movement of the plates 3 achieved in this way is superimposed on the vibration by the vibration generator 12, which here too mainly takes place in the direction of the double arrow 13. This results in a more intensive exchange of the treatment liquid in the gaps between the individual plates and also in a more intensive flushing of the holes in the plates and the separation or detachment of the gas bubbles. This is achieved in particular by the fact that, with the aforementioned turning or pivoting, the holes in the plates do not always run horizontally, but periodically also obliquely or perpendicularly to the horizontal.

8 shows a possible inclined position of the goods (here also plates 3) which are held by brackets 25 of the carrying frame 14 by slots 24 which run correspondingly obliquely to the vertical. For this purpose, the plates are inserted with their lateral edges into the slots 24; if necessary also secured by clamping screws or the like. FIG. 8, in particular also FIG. 9, show that in this exemplary embodiment three holding brackets 25 lying one above the other are provided with slots 24, 24 'and 24 ", the direction of which extends obliquely to the longitudinal axis of the supporting frame 14 and which are offset in this way on the holders 25 are provided that these slots are aligned with one another and can accommodate the edge of a plate 3. In this example is the arrangement of the plates such that they run obliquely to the vertical and thus also give the longitudinal axis of the holes to be cleaned a corresponding oblique position to the horizontal, the plates 3 being arranged perpendicular to the direction of vibration 13.

In principle, FIG. 10 shows a different variant, in which the plates 3 have an inclined position which forms an acute angle with the direction of vibration 13. This facilitates a flow through and thus exchange of the treatment liquid in the spaces 26 between the plates. The inclined positions according to FIGS. 8, 9 on the one hand and FIG. 10 on the other hand can also be provided in combination.

11 shows a further variant of the attachment of a

Vibration generator 12, namely between two supporting frames 14 which hang on the goods carrier rail 8. The vibration generator 12 is designed so that its main vibration is perpendicular to the plane of the drawing in FIG. 11. Plates to be treated are numbered 3.

All of the features shown and described are essential to the invention, unless they have been expressly designated as known.

Claims

1. Method for the back and forth movement of a product having bores, in particular of circuit boards with a ratio of circuit board thickness to bore diameter 8: 1, in the case of its wet chemical treatment, e.g. Electroplating, during the stay of the goods in the respective treatment station, the rest of the excavated goods being transported along the treatment stations, characterized in that the goods (3) are vibrated with vibrations of a frequency of at least 4-5 Hz, that the direction of vibration is at least partially and / or temporarily runs in the direction of the longitudinal axis (5) of the bores, and that the vibrations are only or at least predominantly exerted on the supporting part of the goods.

2. The method according to claim 1, characterized in that the material (3) is rotated or pivoted during shaking in the bathroom (1).

3. The method according to claim 1 or 2, characterized gekennzeich¬ net that the good (3) during the shaking an oblique would be such that the longitudinal axis (5) of the holes extends at an angle to the direction of vibration (13).

Method according to one of claims 1 to 3, characterized in that impacts or sudden impacts are exerted on the material (3) during the vibration.

Method according to one of Claims 1 to 4, characterized in that the frequency of the vibrating vibrations is changed either continuously or discontinuously during a treatment.

A method according to claim 5, characterized in that the vibrating vibration is switched off and on again several times during a treatment.

Method according to one of claims 1 to 6, characterized in that the vibrating frequency is equal to the mains frequency (50 Hz).

Method according to one of claims 1 to 7, characterized in that, in addition to the vibrating vibration on the goods, a known backwards and forwards movement of the goods with a frequency of, for example, substantially lower frequency than the vibrating frequency. 20 double strokes / min. is exercised, the low-frequency movement running in the same direction as the vibrating vibration.

9. The method according to claim 8, characterized by an amplitude of the higher-frequency vibration in the range of about 0.5 to 3 mm and an amplitude of the low-frequency back and forth movement of 2x10 to 2x40 mm.

10. Arrangement for carrying out the method according to one of claims 1 to 9, wherein a plurality of containers or treatment stations for receiving the respective treatment liquid (also from a rinsing liquid) in the

Treatment transport direction (4) are provided one after the other, and the goods (3) are introduced into the respective bath container by means of goods carriers (7, 8) and are lifted out of the bath container again after the treatment and are transported further, characterized in that at least one Vibration generator (12), which generates vibrations with a frequency of at least 4-5 Hz, is attached to a transport and / or support part, by means of which the goods are transported, during introduction into the bath and while they are in the bath Bad is kept, and that between vibration generator and stationary system parts the vibration transmission blocking, at least largely damping means are provided.

11. The arrangement according to claim 10, characterized in that at least one vibration generator is attached to the goods carrier, in particular the goods carrier rail (8).

12. The arrangement according to claim 11, characterized in that a relatively thin cross-section of the product carrier rail is provided with a low modulus in the direction of vibration (13).

13. Arrangement according to one of claims 10 to 12, characterized in that between the or the Schwiπgungser¬ generators carrying supporting part and stationary parts elastic vibration damper (27) are provided.

14. Arrangement according to one of claims 11 to 13, characterized in that at least two Schwinguπgsgenerator (12) are mounted at a distance from each other on a goods carrier rail (8).

15. Arrangement according to one of claims 10 to 14, characterized in that one or more vibration generators are attached to support parts which are held on the one hand by the goods carrier rail (8) and on the other hand carry the goods (3).

16. The arrangement according to claim 15, characterized by the attachment of one or more Schwinguπgsgenerator (12) on a support rod or on support rods (18).

17. The arrangement according to claim 15, characterized by one or more Schwinguπgsgenerator (12) on a Tragge¬ stell (14).

18. Arrangement according to claim 15, characterized by the attachment of one or more vibration generators to brackets which, on the one hand, engage on the goods carrier rail (8) and, on the other hand, on the goods to be treated (3).

19. Arrangement according to one of claims 10 to 18, gekenn¬ characterized by the type and arrangement of the respective vibration generator (12) such that the amplitude of its vibrating vibration mainly runs in a vibrating direction (13).

20. Arrangement according to one of claims 10 to 18, gekeπn- drawn by a Schwinguπgsgenerator of a type and arrangement such that its vibrating frequency has amplitudes in all directions.

21. Arrangement according to one of claims 10 to 20, gekenπ- characterized by an arrangement of several Schwingungserzeu¬ ger on a product carrier rail or the like. In such a way that the amplitude of the vibrating vibration over the entire length of the product carrier rail (12) is approximately the same, so that " Vibration bellies "and" Schwingungsknoteπ "of the vibration amplitude on the rail are essentially avoided.

22. Arrangement according to one of claims 10 to 11, gekenn¬ characterized by an electric drive of the Schwin¬ guπgsgenerator (12).

23. The arrangement according to claim 22, characterized in that for the transmission of electricity to the electric drive of the vibration generator (s) (12) at or near stationary instructions (11) for the ware carrier arms (9, 9 ") and on the ware carrier arms (9, 9 ") Contacts (28, 29) of associated electrical lines are provided in such a way that when the merchandise support arms (9, 9") are seated on the instructions, the contacts are closed and the current is conducted to the electrical drive (16) of the vibration generator (12) ( 30) is.

24. The arrangement as claimed in one of claims 10 to 23, characterized by frequency converter for changing the vibrating frequency of the oscillator (s) (12).

25. Arrangement according to one of claims 10 to 24, gekenn¬ characterized by means which give the material to be treated (3) during the treatment an inclined position such that the longitudinal axis (5) of the holes extends at an acute angle to the direction of vibration (13) .

26. Arrangement according to claim 25, characterized by holding ridges (25) with obliquely and offset to one another slots (24, 24 ', 24 ") for receiving and holding the side edges of the plate-shaped material to be treated ( ³ ) -

27. The arrangement according to claim 25, characterized in that the good (3) is located in a treatment basket (20) which hangs on the goods carrier 'nieπe (7) via suspension means (18, 19).

28. The arrangement according to claim 27, characterized in that the treatment basket (20) can be rotated or pivoted about an axis, preferably a horizontal axis (21), with respect to its support means (19), that means for generating this rotation or pivoting of the basket (20) are provided, and that the goods is secured in the basket against falling out.

29. Arrangement according to one of claims 10 to 28, gekenn¬ characterized by blows or impacts on the good (3) or its holding means generating devices, e.g. an air operated ram or hammer.

30. Arrangement according to one of claims 10 to 29, characterized in that vibration generators of differently strong acceleration values are provided and are arranged in relation to the material to be treated in such a way that vibration generators of an acceleration value in one direction and vibration generators of another acceleration value in the opposite direction are provided.