Device for holding printed circuit boards - allowing vertical boards to be loaded in horizontal direction into a carrier frame, esp. for dipping into galvanic bath

(42) Date of commencement of the patent: 15. 7.1994 (45) Date of issue: 27. 3.1995 (51) Int.Ci.⁶ : H05K 3/00 C25E 17/08 (56) Documentation:

EP-A2 / A3-294235

DE-OS-3006045 (73)

Patentee:

LENHARD SOCIETY MBH

A-4952 WENG IN THE INNKREIS, UPPER AUSTRIA (AT).

QQ (54) Device for holding printed circuit boards (57) Device for holding printed circuit boards, in particular for immersion in galvanic baths od. Like., With a support frame, which is a substantially horizontally verlendes support member which is equipped with spring-loaded terminals, de are provided for holding and electrical contacting of printed circuit boards at the Seitenrandem, and a substantially horizontally extending retaining strut for fixing the opposite sides of the support member having. In order to enable in such a device a simple Beschikken with printed circuit boards (17) is provided that the support frame is formed by a substantially rectangular frame, wherein the support member as the upper spar (7) and the Haitestrebe as the lower spar (12) of the rectangular Frame is ausgebiidet, and also on the lower beam (12) terminals (10) for holding the circuit boards (17) are provided.

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AT 399 074

DÖS 0078336

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The invention relates to a device for holding printed circuit boards, in particular od for immersion in galvanic baths. The like., With a support frame, which has a substantially horizontally extending support member which is equipped with spring-loaded terminals for holding and electrical contacting of printed circuit boards are provided at the side edges, and has a substantially horizontally extending retaining strut for fixing the opposite sides of the support member.

From EP-A 0 294 235 a holding device of the type mentioned is known. The upright printed circuit boards are stacked, parallel next to each other with their lower edges in elongated terminal strips inserted and fixed with a transverse to the plates holding strut. Packages for a plurality of plates are brought in each case a mobile support frame by a conveyor from one processing station to the next. The fixtures are primarily designed for manual loading, although in the document an automatic loading of the supporting frames with printed circuit boards is considered possible. A corresponding note about the nature of such an automatic loading device, however, the publication is not apparent. Due to the design of the support frames is in the independent loading and unloading the acute risk of damage to the circuit boards by collision with frame parts or other circuit boards, so that an automatic loading and unloading would be feasible only with a fairly complex manipulation device with a complex sequence of movements and accurate guidance.

In other known such devices for holding printed circuit boards only a substantially horizontally extending support is provided, are held on the terminals. In these terminals, the two parts are pivotally held on an axle which is connected to the carrier.

In these known solutions there is the disadvantage that the male from the device boards can be inserted only from below into the terminals. However, this is only possible by hand, but not by means of today's usual feed robots. Furthermore, in these known devices also has the disadvantage that they are only suitable for relatively thick and therefore rigid circuit boards, as it comes when immersed in a bath due to the buoyancy occurring to bending forces. These can only be taken up by appropriately thick printed circuit boards with thicknesses of 2mm to 3mm, but are not absorbed by today's printed circuit boards with a thickness of 0.4mm. In addition, in the known device, the power supply to the circuit board takes place only on one side thereof.

Furthermore, in DE-OS 3,006,045 a method and an apparatus for treatment, especially cleaning of flat objects, such as Printed circuit boards, described. The printed circuit boards are suspended individually movable on a horizontal transport system and moved past the spray nozzles. For power supply serving resilient terminals are not provided in this arrangement, so that, for example, a galvanic bath treatment of printed circuit boards in contrast to the devices described is not possible. Even an independent loading and removal of the circuit board could only be realized with great design effort.

The aim of the invention is to avoid these disadvantages and to propose a device of the type mentioned, which allows a simple loading of printed circuit boards and a gentle treatment thereof.

According to the invention this is achieved in that the support frame is formed by a substantially rectangular frame, wherein the support member is designed as an upper spar and the Haitestrebe as a lower spar of the rectangular frame, and also provided on the lower spar terminals for holding the printed circuit boards.

In this way it is possible to hold the printed circuit boards also at their lower edge and thereby prevent bending of the printed circuit boards when immersed in a bath safely. It is also possible to supply current to both sides of the circuit boards this, whereby a very uniform order is achieved in electroplating the circuit boards.

According to a further feature of the invention can be provided that the substantially vertically extending side rails are adjustable in length and lockable.

By these measures, the possibility is created to adapt the device to the size of the male circuit boards, always printed circuit boards of the same size are provided per load.

Furthermore, it can be provided in that the clamps have a part which is fixedly connected to the support frame and a part which is held pivotable relative to the latter on a part connected to it, wherein the pivotably held parts of the clamps are arranged on the same side of the support frame and have an opening path, in the projection on a vertical plane corresponds at least to the overlap of the circuit board to be held by the terminal, so that a vertical printed circuit board in the horizontal direction can be inserted into the open terminals.

In this way, a simple loading of the device by means of a conventional robot is possible.

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Furthermore, it can be provided that the pivotally held parts of the arranged at the lower horizontally extending beam terminal rotating test are connected to a shaft which is preferably rotatable about a radially projecting from the shaft arm and a hinged at its free end portion push rod.

In this way, a very robust design of those parts of the drive arranged at the lower horizontal beam terminals that are immersed in the baths possible. This makes it possible to arrange more sensitive parts of the drive so that they always remain above the bath level.

Furthermore, it can be provided that the clamps arranged at the upper horizontally extending beam can be actuated individually, but preferably in pairs.

This makes it possible to clamp the individual circuit boards immediately after their insertion into the terminals and to keep clamped even with individual removal until removal, whereby they are kept accordingly safe. In principle, it is also possible to operate the arranged on the upper rail terminals together.

Furthermore, it can be provided that the fixed parts of the clamps are provided with guides and positioning means for the printed circuit boards, whereby the insertion of the printed circuit boards is facilitated.

In order to improve the power supply to the circuit boards held in the device, it may further be provided that the fixed parts of the terminals are provided with contacts which are connected to a Kupferseeie running in the interior of the horizontal bars.

Furthermore, it can be provided that the push rod is articulated to actuate the one clamps actuated shaft to a stop member which is held verschiebar on a vertically extending rail and spring-loaded against the lower horizontal rail.

In this way, a simple drive for the arranged on the lower beam terminals. It can be provided to use the device according to the invention for receiving printed circuit boards in a rack from above, wherein the stop member abuts when lowering the device to a stop while adjusting the push rod, whereby the arranged on the lower beam terminals are opened.

The invention will now be explained in more detail with reference to the drawing. 1a and 1b show a front view of a device according to the invention in a frame, Fig. 1c shows a detail of a device according to Figs. 1a and 1b with elongated vertical bars, Fig. 2 and 3 schematically shows a side view of the device with closed and opened 4 schematically shows a drive for the arranged on the lower Hoim terminals.

The device has an upper spar 7, which is made of copper or other electrically conductive material or even made of a chemically very resistant material such as stainless steel and are held on the terminals 6. At the ends of the upper spar 7, a head 1 is arranged, in which vertical bars 13 are held adjustable.

Here, a clamping device are each arranged on the heads 1, which presses a piston 3 and a terminal block 2 connected thereto, which presses against the vertical bar 13 in order to clamp it.

The vertical bars 13 are supported in supports 8, which are arranged in a frame 14 which is held vertically adjustable by means of threaded spindles 16. This frame 14 serves to receive the device in a loading and unloading station.

The lower end of each vertical spar 13 is closed with a ball 15, which are supported in a respective bearing 8.

The vertical bars 13 are connected to each other via a lower, horizontally extending Hoim 12, are held on the terminals 10. These clamps 10 are rotatably connected to a shaft 11 which are provided at their ends with radially projecting arms 21 which are hingedly connected to push rods 9.

These push rods 9 are pivotally connected to stop body 5, which are slidably held on the vertical bars 13. In this case, the stopper body 5 is biased by a spring 22 downwards. As a result, the shaft 11 is loaded via the push rod 9 in the sense of closing the clamps 10.

Now, if the device is inserted from above into the frame 14, the stopper body 5 strike against stops 23 before the vertical bars 13 rest on the supports 8. As a result, the stopper body 5 is displaced upwardly on the vertical bar 13 and thereby the clamps 10 are opened.

As can be seen from Fig. 3, carries the spar 12, which is provided with a soul, not shown, made of copper, stops 19 for the male circuit boards 17, wherein the stops 19 form arranged on the shaft 11 clamping brackets 20, the terminals 10 ,

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The clamps 6 have a fixed part 24 connected to the upper horizontal spar 7, which holds an axis about which the movable part 25 is pivotable and which is biased by a spring 26 against the closed position of the clamp 6.

To control the terminals 6 cylinder piston arrangements can be provided which act on a respective terminal 6. In the illustrated embodiment, shaft pieces 18 are provided, from which project radially arms 27, each shaft piece controls two terminals 6.

As can be seen from Fig. 3, the terminals 6, 10 can be opened so far that their opening path in the projection on a vertical plane at least the degree of coverage of the circuit board 17 by the clamps 6, 10 achieved in its closed position, as can be seen from a comparison of the position of the dashed lines indicated circuit board 17 with the terminals 6.10.