Abstract:
An apparatus for electroplating a master, comprising: a frame having a first frame portion ( 106 ) supporting an electroplating bath unit ( 210 ) and a second frame portion ( 104 ) for supporting electrically operated units ( 240, 250, 260, 270, 140 ) including a display unit ( 140 ). The frame forms a vertically extended construction in an operational state. The first frame portion ( 106 ) and the second frame portion ( 104 ) are interconnected ( 108, 300 ) such that the apparatus is foldable to a transport state for reducing said vertical extension of the apparatus. The first frame portion ( 106 ) and the second frame portion ( 104 ) forms a single frame in the transport state and in the operating state.

Description:
TECHNICAL FIELD OF THE INVENTION 
     The invention relates to an apparatus for electroplating on a master for obtaining a matrix. Such a matrix may be used for replication of optical discs. 
     DESCRIPTION OF RELATED ART 
     A manufacturer of optical discs having an amount of information-to-be-replicated, such as for example a music recording or computer data, needs to obtain a stamper with a pattern corresponding to that information. The pattern of the stamper is a model for information to be transferred to the optical discs. A stamper is manufactured in the following way: A master having a pattern corresponding to the pattern to be on the Optical Discs is manufactured. The patterned, i.e. structured, surface of the master plate is metallized, by depositing a thin conductive layer thereon e.g. by vacuum deposition or sputtering. The step of generating a stamper matrix with the use of the master involves deposition of nickel by electroplating in an electroplating apparatus. 
     After electroplating, the resulting nickel plate is removed from the master plate. The removal of the nickel plate from the master plate results in a nickel plate having a patterned surface, the pattern being the mirror image of the pattern on the master. That nickel plate constitutes a matrix. The matrix may be used as a stamper matrix in an injection moulding machine for moulding optical discs. 
     FIG. 1B illustrates a work station according to prior art, including an electroplating bath unit. The electroplating bath, during operation, contains aggressive chemicals and may emit hazardous gases when opening, the lid of the bath unit. FIG. 1C illustrates a cupboard according to the prior art, for use together with the work station shown in FIG.  1 B. The cupboard includes control circuitry for the electroplating process, and it is too bulky and too heavy to be lifted by only a few people, e.g by two persons on their own. The prior art work station of FIG. 1B can be used together with the cupboard of FIG. 1C as an electroplating apparatus. Such a prior art electroplating apparatus is illustrated in FIG.  1 D. The electroplating apparatus according to the prior art is higher than it is wide. The geometry of the plating apparatus according to the prior art is such that during operation it is a bit over 2 meters high. A display unit is provided in the cupboard. The electroplating bath unit provided in the work station includes parts which are not rigidly attached to the frame of the plating apparatus, but which are movable in the horizontal direction and which are not restrained in the upward direction. These freely movable parts are kept in place by gravitation and are already placed in the work station when delivered from the manufacturer. For these reasons the work station should be kept in an upright position during transport. The work station is too bulky and too heavy to be lifted by a single person. 
     SUMMARY OF THE INVENTION 
     The present invention relates to the problem of reducing the time duration from the placement of a purchase order to successful operation of a new plating apparatus at the premises of a manufacturer of optical discs. 
     The above mentioned problem is solved by providing an electroplating apparatus comprising a frame having a first frame portion supporting an electroplating bath unit and a second frame portion for supporting electrically operated units including a display unit, the frame forming a vertically extended construction in an operational state. The first frame portion and the second frame portion are interconnected such that the apparatus is foldable to a transport state for reducing said vertical extension of the apparatus, the first frame portion and the second frame portion forming a single frame in the transport state as well as in the operating state. 
     This solution has the advantageous effect of enabling delivery of the plating apparatus with any standard freighter aeroplane, while enabling an easier set up procedure of the plating apparatus after delivery, thereby minimizing the time and work required by service assembly personnel, since the machine can be assembled to a larger extent at the manufacture plant before delivery to the end user. Freighter cargo aeroplanes have restrictions for the height of a piece of cargo. The most frequent cargo aeroplanes require that the cargo has a maximum height of about 1.6 meters, whereas cargo aeroplanes allowing higher pieces of cargo are quite infrequent at many airline routes. The apparatus according to the invention enables the manufacturer/distributor of plating apparatuses to provide fast response to an order, that is fast delivery of a plating construction after receiving an order. This is because in its folded state the plating construction complies with these cargo aeroplane requirements, and hence one of the frequently flying cargo aeroplanes can be used for delivery of the plating construction. 
     The first portion of the frame is adapted to support the weight of the whole apparatus, since it forms a lower part of the plating apparatus in the operational state. 
     Additionally the top frame portion of the apparatus acts like a lever during the process of transforming the apparatus from its folded state to its operational state. This significantly reduces the physical effort needed for transforming the plating apparatus from the transport state to the operational state. This advantageously enables a single person to transform the plating apparatus from the transport state to the operational state in a short time. 
     According to an embodiment the apparatus further comprises electrical conductor connections for connecting electrically operated units in the second frame portion with electrically operated units in the first frame portion. The provision of electrical conductor connections in the apparatus already at the delivery eliminates the need to engage an operator for setting up electrical connections between internal units in the apparatus after delivery, at the premises of a manufacturer of optical discs. Hence, the time duration from delivery to successful operation of a new plating apparatus is reduced. 
     According to a preferred embodiment the conductor connections include cables which, in the proximity of the axis of rotation around which the apparatus is foldable, are arranged substantially parallel to said axis of rotation. This cable arrangement advantageously reduces stretching or slacking of the cables during folding or unfolding, hence contributing to reducing the probability of electric wiring errors. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1A illustrates a plating arrangement including a plating apparatus. 
     FIG. 1B illustrates a work station according to prior art, including an electroplating bath unit. 
     FIG. 1C illustrates a cupboard according to the prior art, for use together with the work station shown in FIG.  1 B. 
     FIG. 1D illustrates the work station shown in FIG. 1B in combination with the cupboard of FIG.  1 C. 
     FIG. 2 is a schematic side view of the plating apparatus of FIG.  1 A. 
     FIG. 3 is a more detailed schematic showing the plating apparatus from FIG. 2 in the unfolded operating mode. 
     FIG. 4A illustrates the plating apparatus shown in FIG. 3 in a folded state. 
     FIG. 4B is a section along the plane A—A in FIG.  4 A. 
     FIG. 5 illustrates the frame of the apparatus in a position half ways between folded and operational state. 
     FIG. 6 illustrates the frame of the apparatus in a position corresponding to the operational state of the electroplating apparatus. 
     FIG. 7 shows a guide means for holding cables. 
     FIG. 8 illustrates an embodiment of a manner of arranging cables. 
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     FIG. 1A illustrates an embodiment of a plating arrangement  30  for the production of stampers. The plating arrangement  30  includes a plating apparatus  100 , a preparation unit  110 , a spin coating station  120  and an oven  130 . The plating arrangement  30  may involve more than one of the apparatuses  100 ,  110 ,  120  or  130 . Additionally the plating arrangement may include a polishing unit  134  and a punching unit  136 . 
     FIG. 2 is a schematic side view of the plating apparatus  100 . The plating apparatus  100  includes an integral frame  102  having an upper frame portion  104  and a lower frame portion  106 . The upper frame portion  104  and the lower frame portion  106  of the frame are interconnected by a hinge mechanism  108  provided in a beam  107 . The hinge mechanism is provided at a distance less than 1.3 meters from the bottom side of the lower frame portion  106  of the apparatus  100 . 
     The lower portion  106  of the frame holds a bath unit  210 , a tank unit  220  and an exhaust unit  230 . The upper portion of the frame holds an electric power supply unit  240 , a filter unit  250 , a rectifier unit  260 , a control unit  270  and a display unit  140 . The electroplating bath unit  210  includes parts which are not rigidly attached to the frame of the plating apparatus, but which are movable in the horizontal direction and which are not restrained in the upward direction. These freely movable parts are kept in place by gravitation and are already placed in the lower frame portion of the plating apparatus when a new plating apparatus is delivered from the plating apparatus manufacturer. The filter unit includes a fan and a High Efficiency Particle filter (HEPA-filter) for supplying clean air to the electroplating work space defined by the lower and upper portions of the apparatus in the operating state. 
     The provision of a unitary frame comprising an upper frame portion and a lower frame portion connected by a hinge mechanism  108  enables the apparatus to be folded. This solution has the advantageous effect of enabling an easy transformation of the apparatus from a transport state (FIG. 4A) to an operational state (FIG.  3 ), or vice versa. 
     A mechanism  300  is provided for releasably locking the apparatus in the operational state, as indicated in FIGS. 2,  3  and  4 . According to one version the locking mechanism includes a threaded nut  310  firmly attached to the lower frame portion  106  and a projection  320  firmly attached to the upper frame portion. The projection  320  has an opening through which bolt  330  is mounted so as to be inserted in the nut  310 . FIG. 4B is a section along the plane A—A in FIG. 4A illustrating the beam  107  when the apparatus  100  is folded. 
     According to one embodiment the plating apparatus also includes a mechanism  340 A,  340 B for releasably locking the apparatus in the folded state. FIG. 2 illustrates schematically a projection  340 A provided on the upper rear side of the apparatus  100 . The lower rear frame portion of the apparatus  100  is provided with a shaped portion  340 B which is positioned so as to receive the projection  340 A when the apparatus is in the folded state. The projection  340 A and the shaped portion  340 B are provided with openings  350 A,  350 B for receiving a locking bolt  330 . According to a preferred embodiment the same bolt  330  may be used for both locking mechanisms  350  and  300 . 
     The machine shown in FIG. 3 requires a floor area less than 3 m 2 . More precisely the width of the plating apparatus is about 1.34 meters whereas the depth of the plating apparatus is about 1.15 meters, rendering a floor area of 1.54 m 2 . In the operational state shown in FIG. 3 the height of the plating apparatus is about 2.3 meters. In the folded state illustrated in FIG. 4 the height is less than 1.3 meters. 
     Since the plating apparatus is lower than 1.6 m in the folded state it is possible to make delivery transports with the use of deliver cargo aeroplanes of a common type which flies very often between all major airports in the world. In effect, the use of a hinge mechanism to connect the two frame portions of the plating apparatus significantly reduces the minimum time from purchase order to installation of the purchased plating apparatus, since a much wider choice of transportation is made available. Quick delivery is an important competitive edge on the market. Thereby the customer having bought the plating apparatus is enabled to quickly start producing articles after having ordered the plating apparatus. A wider choice of transportation also makes it possible to reduce the cost for transportation since freight can be provided by a larger number of alternative freight companies. 
     The folded plating construction has the advantage of satisfying both of the conflicting requirements of minimizing construction floor area and still obtaining a low construction height during transport while minimizing the bulkiness of the total construction. During transport the folded plating construction is contained in one single piece. The prior art apparatus on the other hand is divided into two, three or more pieces during transport, which complicates the transport procedure. 
     A further advantage is that it is a lot quicker and easier to move a plating apparatus according to the invention, as compared to that of the prior art. Instead of being obliged to disassemble the apparatus it is possible to simply fold it and move it. In the folded state (FIG. 4A) the centre of gravity is significantly lowered, leading to stable and safe transport of the plating apparatus in one single piece including the top frame portion  104  as well as the bottom frame portion  106 . 
     According to an embodiment of the invention the top portion of the apparatus including the electric power supply unit  240 , the control unit  270  and the display unit  140 , but excluding the filter unit  250  and the rectifier unit  260 , weighs about 160 kg. When the apparatus has been moved to its new location the process of transforming the apparatus to its operational state is made less strenuous since the personnel never has to lift the whole top part of the apparatus. In the process of transforming the apparatus from its folded state to its operational state a large proportion of the weight rests on the hinge mechanism  108  and additionally the top frame portion  104  acts like a lever. FIG. 5 illustrates the apparatus in a position half ways between folded and operational state. The centre of gravity of the top portion  104  at that position is illustrated by reference  400  and the path along which the centre of gravity moves is indicated by reference  410 . At the position shown in FIG. the mass, denoted  m , acts on the lever with lengths  a - b as indicated in the figure. 
     The force F which the operator has to apply for raising the top flame portion  104  is significantly lower than the mass  m . This advantageously means that it is possible for two persons to transform the plating apparatus from the transport state to the operational state in a short time. This is particularly advantageous because plating apparatuses are often installed in buildings having a ceiling too low to allow for mechanical means of lifting assistance such as an electric hoist. Such low ceiling height leads to the necessity for manually putting the apparatus into operational state. 
     In prior art apparatuses which are delivered with an electroplating work station and a cupboard with control circuitry as separate entities, it is necessary for the assembly personnel to install cables for connecting e.g. a control panel or power supply in the cupboard with the electroplating bath unit in the work station only after having assembled the two separate pieces at the site where it is to be operated. This is a complex work which is quite time consuming. For the purpose of further reducing the time duration from the placement of a purchase order to successful operation of a new plating apparatus at the premises of a manufacturer of optical discs by reducing the installation time, the apparatus according to an embodiment of the invention includes cabling which is already installed before delivery. The cables connect the electrically operated units in the lower portion  106  of the apparatus with the electric power supply unit  240 , the rectifier unit  260 , the control unit  270  and the display unit  140  in the top frame portion  104 . The electrical connections include power cables for supplying power from the power supply unit  240  as well as cables for supplying rectified current from the rectifier unit  260  to the electrodes in the bath unit. There is also a plurality of signal lines for providing sensor values from the tank unit and from the bath unit to the control unit and to the display unit. Such sensor values include measurement values for indicating liquid levels in the bath and in the tank. 
     FIG. 7 illustrates guide means  420  for holding cables  430 . Such guide means is provided along a rear wall of the plating apparatus. The guide means  420  may consist of a piece of bent sheet-metal. FIG. 8 illustrates the manner in which the cables are arranged where the plating apparatus is foldable. FIG. 6 illustrates the axis of rotation  415  around which the top frame portion  104  turns. The cables  430  are arranged parallel to the axis of rotation  415  (FIG. 8) along a certain length, thereby avoiding unfavourable stretching or slacking of the cables  430  during the folding or unfolding of the plating apparatus  100 . During the folding/unfolding process the cables  430  will be slightly twisted. 
     The filter unit  250  and the rectifier unit  260  are plug-in units with electrical connectors which mate with corresponding connectors in the top portion  104  of the plating apparatus  100  when plugged in, according to an embodiment. 
     The apparatus  100  is also provided with recesses  440  adapted for receiving the forks of a fork-lift truck (See FIG.  4 A). These recesses allows for quick and easy transportation of the apparatus e.g. within the premises of a manufacturer of optical discs. The apparatus includes two recesses facing the side of the apparatus, and two other recesses facing the front of the apparatus. The front recesses are formed by a horizontally arranged hollow beam  450 , as indicated in FIG.  4 A. 
     In the operational state shown in FIG. 3, the plating apparatus may be operated as described below. A master matrix is mounted on a holding fixture. The holding fixture with the attached master matrix is lowered into the liquid in the bath unit  210 . A nickel layer is grown on the master by electrolysis so as to create a father matrix. Thereafter the holding fixture with the attached master and father matrices are brought to the preparation unit  10  (See FIG. 1) for separating the father matrix from the master. The father matrix is cleaned, and the information surface is passivated. The passivation is achieved by placing the father matrix in a bath with a suitable liquid. 
     The father matrix is mounted on a holding fixture. The holding fixture with the attached father matrix is lowered into the liquid in the bath unit  210  for growing a mother matrix on the father matrix. Thereafter the holding fixture with the attached father and mother matrices are brought to the preparation unit  110  for separating the mother matrix from the father matrix. The information surface of the mother matrix is passivated. One father matrix may be used for producing a plurality of mother matrices in this manner. 
     The mother matrix is subsequently mounted on the holding fixture and used for growing a stamper matrix on the mother matrix in the same manner. Thereafter the holding fixture with the attached mother and stamper matrices are brought to the preparation unit  110  for separating the stamper matrix from the mother matrix. A plurality of stamper matrices may be produced from one mother matrix in this manner.