Abstract:
A carrier assembly is provided for solar cell laminates that include an encapsulating layer and that are conveyed through a lamination plant having a conveying surface. The assembly includes a housing of heat conductive material defining an inner volume, the housing having an upper plate for receiving the laminates and a lower plate defining a plurality of apertures, the inner volume including at least one connecting element interconnecting the first and second plates. An air supply system provides a continuous outward air flow through the apertures when the lower plate is received on the conveying surface, wherein the airflow yields an elevated pressure on the lower plate for providing lift to the housing, allowing substantially friction-free movement of the housing relative to the conveying surface. A thermal transfer system provides thermal energy to the upper plate for melting and curing the encapsulating layer.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a national phase filing, under 35 U.S.C. §371(c), of International Application No. PCT/EP2010/054601, filed Apr. 7, 2010, the disclosure of which is incorporated herein by reference in its entirety. 
     FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable 
     BACKGROUND 
     The present invention relates to a lamination plant, a carrier assembly for temporary accommodating solar cell laminates while conveyed through a lamination plant, a method of carrying solar cell laminates through a lamination plant and a method of transporting a carrier though a lamination plant. 
     Solar cells are well known in the art of energy production for producing electrical energy in an efficient and environmentally friendly way. A solar cell relies on the photovoltaic effect for generating electrical energy from visual radiation which primarily but not necessarily constitutes solar light. A typical solar cell consists of a thin silicon (Si) wafer, hereafter designated solar cell element, having a single large p-n junction applied on its upper surface which is intended to face the light. Both the upper surface and the opposite back surface of the solar cell is provided with a metal contact constituting a plus and a minus pole for generating a direct current (DC) through the solar cell element. The photons impinging on the p-n junction will excite charge carriers, which will initiate a current towards their respective poles. Solar cells may be manufactured in varying sizes and geometries. 
     The DC output current may be used directly for powering a facility or charging a rechargeable battery, or alternatively a rectifier may be employed to convert the DC current to an AC current, which may be delivered to a transmission grid. The above type of solar cell element yields a maximum voltage of between 0.3V-0.7V and typically 0.5V. The voltage is weakly dependent on the amount of radiation received by the solar cell. The above applications typically need to be provided with a higher voltage than the voltage delivered by a single cell. Therefore, to be able to achieve higher voltages, a plurality of solar cell elements have to be connected in series to form a solar module. Due to the very low voltage provided by each individual solar cell element, the solar modules may be manufactured including a large amount of solar cell elements. For example, in a typical commercial solar module for a nominal voltage of 60V, 144 solar cell elements may be connected in series. Typically a plurality of modules is further connected into a solar array and installed in places subjected to high solar radiation intensity. 
     Since the solar cell element is typically very brittle and may rupture when subjected to shocks, the solar cell elements must be encapsulated within a protective enclosure. As the solar modules are mostly located outdoors and on exposed locations such as on rooftops etc., the enclosure must be made substantially rigid. For providing improved structural strength to the solar module, the solar cell elements are typically encapsulated between two protective cover layers of substantially rigid material. The upper protective layer facing the source of solar radiation must be made of transparent material such as glass or alternatively a transparent polymeric material for allowing the solar radiation to reach the solar cell elements. The lower protective layer facing away from the source of solar radiation may be made of transparent material or alternatively a non-transparent material, i.e. an opaque material which may be reflective for allowing incoming radiation to reflect and pass the solar cell elements a second time. 
     The solar cell elements are permanently encapsulated between the upper layer and the lower layer to form a solar laminate. The upper and lower cover layers should have a certain thickness for giving the solar cell the rigidity required for the location where the solar laminate is to be installed. However, for reducing the weight of the solar module, the covering layers must not be too thick. A thick upper cover layer will additionally absorb a large quantity of the solar radiation, thereby making the solar module less effective. Typically, the thickness of the cover layers is in the mm range. 
     The upper and lower protective layers are typically permanently fixed onto the solar cell elements by an adhesive. Typically, a thin film of EVA (Ethylene-Vinyl Acetate), is used as an adhesive in the manufacturing of solar laminates. EVA film is flexible and non-adhesive at room temperature and is commercially available in the form of rolls. At a temperature of about 80° C. the EVA film melts, and at a temperature of about 130° C. the EVA film cures by polymerization. The solar cell laminate may constitute a layer of one or more solar cell elements fixed between the two protective cover layers where the film of EVA material is placed between the solar cell elements and each protective cover layer for encapsulating the layer of solar cell elements and fixing the layer of solar cell elements to the cover layers. The solar cell laminate is processed by heating for the EVA film to melt and subsequently cure. After curing the EVA film will form a solid, transparent and insulating adhesive which permanently encapsulates the solar cell elements between the cover layers. 
     During the heating of the solar laminate and in particular during the melting and curing of the EVA material, gas bubbles will occur within the solar laminate. The lamination process is therefore typically performed under vacuum conditions for removing any gas bubbles which may occur during heating. During processing, the solar laminate is placed on a heating plate and positioned inside a vacuum chamber under vacuum conditions. Vacuum is in the present context understood to mean a pressure significantly below ambient pressure. The heating plate is heated to a temperature of at least 80° C. for the EVA material to melt and encapsulate the solar cell elements. When the EVA material has reached liquid state, bubble evacuation is performed. During bubble evacuation gas bubbles generated inside the solar laminate by the melted EVA are allowed to escape. Additionally, an external force is applied onto the solar laminate and a certain time period is allowed to elapse for ensuring all gas bubbles dissipating into the vacuum chamber. Any gas bubbles remaining inside the solar laminate may cause incoming solar radiation to deflect. Additionally, since bubbles inside the solar laminate constitute voids, the structural stability of the solar laminate may be reduced and the insulating properties of the EVA material may be adversely affected by the bubbles. 
     When bubble evacuation has been performed and the EVA material is substantially bubble free, the temperature of the heating plate is increased to about 130° C. to initiate curing. The curing causes the EVA material to crosslink and thereby permanently fixes the solar cell elements to the cover layers. When the curing step is finished a permanently sealed solar module in the form of a laminate is formed. After curing, the solar laminate may be removed from the vacuum chamber and allowed to cool down to ambient temperatures. 
     The use of heating plates in solar applications is well known in the prior art. One example of a heating plate is found in the European patent EP 1 517 585, which discloses a heating plate having internal cavities in which a heat exchange medium and heating bodies are located. Another example may be found in the German patent application DE 10 584 034 64 describing a heating plate having at least one main heating area and at least one auxiliary heating area being heated independently from the main heating area. Yet a further example of a heating plate may be found in the German utility model DE 20 587 006 464. 
     Typically, the layers of the solar laminate are assembled on the heating plate outside the vacuum chamber. The layers constitute solid sheets in ambient conditions (room-temperature). The heating plate is subsequently introduced into the vacuum chamber. The current activities in the field of BIPV (Building Integrated PhotoVoltaic) have increased the demand for solar laminates having a large surface. These large surfaced solar laminates having a large active surface for receiving solar radiation are used in large solar modules/arrays and are typically mounted on buildings. Some manufacturing plants exist which produce solar laminates having an active surface of several m 2 . Since the solar laminates comprise glass and silicon, the weight of a single laminate may be considerable when the active area is in the m 2  range. Therefore the solar laminate and the heating plate is typically conveyed on a conveying surface into the lamination plant, e.g. by the use of rollers, conveyer belts or the like. It has however been observed that the use of rollers and conveyer belts are not suitable for moving the large surfaced solar laminates, since the solar laminates are still brittle before curing and may thus easily break from shocks received during transport through the lamination plant. Such shocks are typically the result of increased friction between the conveying surface and the heating plate. Increased friction may occur when the opposing conveying surfaces are uneven. The opposing conveying surfaces are typically uneven due to manufacturing tolerances and material defects, thus shocks are difficult to eliminate. For avoiding frequent breakage of non-cured solar laminates there is a need for improved conveying and transportation devices in connection with the transport of the solar cell laminate through the lamination plant. It is therefore an object of the present invention to provide a carrier assembly suitable for both transporting and heating the solar laminates in the lamination plant. 
     SUMMARY 
     The above need and object together with numerous other needs, objects and advantages which will be evident from the below detailed description of a preferred embodiment of the module according to the present invention, are according to a first aspect of the present invention obtained by carrier assembly for temporary accommodating one or more solar cell laminates while said solar laminates are conveyed through a lamination plant, said solar cell laminate comprising:
         a solar cell layer of silicon material, an upper and a lower encapsulating layer of EVA material covering the top and bottom of said solar cell layer, an upper and lower protective layer covering said upper and lower encapsulating layer, respectively, said encapsulating layer having a specific melting temperature and a specific curing temperature, said melting temperature being lower than said curing temperature, and said carrier assembly comprising:   a carrier housing of heat conductive material defining an inner volume, said carrier housing having an upper plate adapted for receiving said solar cell laminate and an opposite lower plate defining a first plurality of apertures, said inner volume including one or more connecting elements interconnecting said first and second plates,   an air supply system for providing a continuous outward airflow through said first plurality of apertures when said lower plate is received on a conveying surface of said lamination plant, said airflow yields an elevated and substantially balanced air pressure on said lower plate for providing lift or buoyancy to said carrier housing allowing a substantially friction-free movement of said carrier housing in relation to said conveying surface of said lamination plant, and   a thermal transfer system providing thermal energy to said upper plate for allowing said encapsulating layer to melt and subsequently cure and preferably is adapted to provide a temperature on said upper plate of 80-130° C.       

     It is contemplated that the lower plate of the carrier assembly has a surface substantially corresponding to the conveying surface of the lamination plant. The lower plate and the conveying surfaces are preferably both flat surfaces; however, one or both of the surfaces may comprise a track or guiding plates or the like for assisting the manoeuvring of the carrier housing. It is further evident that surface unevenness relating to the material or manufacturing tolerances is allowed. 
     The thermal transfer system is arranged to receive energy, such as electrical energy or a substance exhibiting a high thermal energy, from an external source and distribute the thermal energy on the upper plate. For flat solar laminates, the thermal transfer system typically constitutes a separate heating plate in a stationary position inside the lamination plant used for heating the carrier housing of the carrier assembly, e.g. via the lower plate. For achieving a high-energy efficiency, the heating plate typically always maintains a high temperature and the temperature of the upper surface may be caused to assume a suitable temperature profile via the carrier housing. The inner volume is supported by connecting elements, which may constitute a rim or pillar structure connecting the upper and lower plates, or alternatively constitute a single body. The inner volume may exhibit a heat capacity for allowing the upper plate to heat up in a suitable time frame, such as a few minutes, for achieving a suitable temperature profile for allowing the EVA sheet of the solar laminate to melt and cure. Especially for the above type of carrier assembly, the carrier housing must enter the lamination plant quickly for allowing a uniform temperature profile of the upper plate and avoid uneven melting and curing within one solar laminate or between several separate solar laminates positioned on the same upper plate which may be caused by the laminate entering the lamination plant at a slow pace. 
     The air supply system preferably comprises a pipe system connected to the apertures in the lower plate for conducting high-pressurised air from an external source to the apertures. The apertures should be spread over the lower plate to achieve a balanced pressure distribution. 
     The solar laminate is preferably assembled directly on the upper plate of the carrier assembly when the carrier assembly is placed at a first end of the conveying surface of the lamination plant. The upper plate should have an upper surface corresponding to the surface of the solar laminate for the contact area between the solar laminate and the upper plate to be maximised and avoiding air pockets between the upper plate and the solar laminate for optimizing the thermal energy conduction from the upper plate into the solar laminate and achieving an even temperature distribution inside the solar laminate. Typically, the upper plate is flat for accommodating standard flat solar modules. When the solar laminate is being assembled, the air supply system may be deactivated or the air flow interrupted, so that the carrier housing rests in a stable position on the conveying surface for accurately assembling the heavy solar cell element layer and cover layers. 
     When the laminate is ready to be transported into the lamination plant, the air supply system is started and pressurised air is allowed to flow through the apertures in the lower plate. The pressurised airflow impinges onto the conveying surface and is redirected towards the edge of the lower plate, which causes an elevated pressure between the conveying surface and the lower plate. The elevated pressure, which is construed to be elevated in relation to the ambient pressure, causes lift or buoyancy to the carrier housing by providing an “air cushion” between the lower plate and the conveying surface. The airflow should be provided continuously with substantially constant flow intensity for allowing a stable hovering of the carrier housing. 
     Surprisingly it has been discovered that by letting the carrier housing be supported by an air cushion, the friction between the conveying surface of the lamination plant and the carrier housing may be substantially eliminated. Since the carrier housing is lifted a small distance above the conveying surface, any minor unevenness between the lower plate and the conveying surface does not influence the friction. Thus, the cause of shocks during transport is effectively eliminated. As an additional advantage, the carrier housing will be very easy to handle and move due the very low friction between the lower plate and the conveying surface and thus the carrier housing may in some embodiments even be manoeuvred by hand thereby excluding the provision of a propulsion device such as a motor. In another embodiment the propulsion may be achieved by compressed air, a small electrical motor or the like. In a typical embodiment the carrier housing is caused to lift about 0.5-1 cm above the conveying surface for avoiding any unevenness around 1 mm, which is the typical size of unevenness and protrusions in the lower plate or conveying surface relating to the material or manufacturing tolerances. 
     When the carrier housing has assumed the proper position inside the lamination plant and the carrier housing is ready for heating, the air supply system is stopped and any hoses supplying pressurised air are removed. Preferably, the airflow is interrupted slowly to allow a smooth descent of the carrier housing for reducing the shock applied to the solar laminate when the lower plate contacts the conveying surface. It is contemplated that snap-on connectors of the well known “Gardena” type or similar may be used for rapid connection and disconnection of the air supply system. When preparations have been made for initiating the melting and subsequent curing of the encapsulating layer, the heat transfer system may be activated for providing thermal energy to the upper plate of the carrier housing of the carrier assembly. The carrier housing or at least the first plate should be made of heat conductive material such as metal for allowing the first plate to assume a temperature of preferably at least 80° C., more preferably 100° C., for melting the EVA material and preferably at least 130° C., more preferably 150° C., for allowing the EVA material to cure after bubble evacuation has been performed. In this context it is contemplated that other encapsulation materials than EVA material may occasionally be used and such materials having different melting temperatures and curing temperatures. Provided a material other than EVA is occasionally chosen, it is contemplated that the temperatures provided to the first plate may be variable according to the specific material chosen. The thermal transfer system should be adapted to provide an evenly distributed temperature over the compete upper plate so that the encapsulating film melts and subsequently cures substantially evenly for avoiding partial melting or partial curing of the solar laminate. Partial melting or partial curing would lead to solar laminate layer parts being non-adhesive, which would cause voids by bubbles and/or delamination. 
     After the curing has been performed, the solar laminate may be taken out of the lamination plant and cooled down to ambient temperature. To speed up the cooling of the solar laminates, the thermal transfer system may optionally be equipped to provide rapid cooling to the upper plate e.g. by allowing a cooling fluid from an external source to circulate though the carrier housing. A faster cooling may increase the total throughput of solar laminates by the lamination plant. The rapid cooling may increases the risk of the solar laminate rupturing due to thermal forces. Thus, the intensity of the rapid cooling must be limited and it must be ensured that the cooling is applied uniformly on the solar laminate. For reducing the risk of rupturing the solar laminate is preferably fixed during cooling 
     In a further embodiment according to the first aspect of the present invention, said thermal transfer system is being accommodated in said carrier housing. The carrier housing may have an inner volume between the upper and lower plate for accommodating the thermal transfer system. The thermal transfer system may constitute conduits for allowing thermal oil to circulate near the upper plate, or alternatively electrical conduits allowing direct electrical heating of the upper plate. Direct electrical heating of the upper plate may be especially useful for non-flat solar laminates for allowing a more even temperature distribution. 
     In a further embodiment according to the first aspect of the present invention, said upper plate further comprising a second plurality of apertures connected to said air supply system providing a continuous outwardly airflow through said second plurality of apertures when said solar laminate is received on said upper plate or said carrier housing, said airflow yields an elevated and substantially balanced air pressure on said upper plate for providing lift or buoyancy to said solar laminate allowing a substantially friction free movement of said solar laminate in relation to said carrier housing and/or for allowing rapid cooling said solar laminate by said airflow, preferably by cooling said solar laminate from about 150° C. to below about 40° C. within 4-10 minutes. Typically, the sheets making up the solar laminate are assembled by stacking them onto the carrier housing either by hand or by means of a lifting apparatus. By providing an air cushion above the carrier housing the position of the solar laminate on the carrier housing may be altered, since the airflow will cause the solar laminate to lift. Additionally, the sheets of glass or silicon material, which are brittle, may be placed on a soft air cushion instead of directly onto the upper plate, which is typically made of rigid metal. Preferably, the air supply system may have a first mode in which airflow is provided through the upper plate and a second mode in which the airflow is provided through the lower plate, or alternatively airflow is provided through both the upper and lower plates. 
     Typically, the carrier housing and the solar laminate has to be cooled down right after the curing from about 150° C. to below about 40° C. within 4-10 minutes. In the prior art, cooling of the laminate was achieved by including pins into the upper plate for elevating the solar laminate and allowing heat to dissipate to the surrounding air by natural convection. According to the present embodiment, the airflow and air cushion may alternatively or in addition to providing lift to the solar laminate be used for rapid cooling of the solar laminate. The airflow should typically have a temperature of no more than room temperature and be applied at a high pressure for allowing an efficient temperature reduction of the solar laminate by forced convection which has been showed to be much more efficient than natural convection. 
     In a further embodiment according to the first aspect of the present invention, said upper plate comprises one or more shallow grooves for individually receiving one or more of said solar cell laminates. By having a groove for accommodating the solar cell laminate, the positioning of the solar laminate is simplified and any misalignment of the solar laminate is avoided. In some embodiments according to the first aspect, the upper plate may have a multitude of shallow grooves for accommodating the same multitude of laminates individually and separately in relation to each other, thereby avoiding the risk of adhesion between the individual laminates. The groove should have a depth corresponding to the thickness of the solar laminate and its bottom should preferably form a substantially flat surface for accommodating the solar laminate. 
     In a further embodiment according to the first aspect of the present invention, said thermal transfer system comprises a heat conductive fluid such as thermal oil and where said carrier housing comprises one or more fluid inlets and one or more fluid outlets communicating with said heat transfer system. A heat conductive fluid such as thermal oil of high temperature may be introduced into the inner volume of the carrier housing through the fluid inlet and deliver thermal energy to the upper plate. The thermal oil may preferably be delivered to the fluid inlet pre-heated and leave the carrier housing through the outlet and return to an external heating system. Preferably, the external heating system includes a pump for providing a constant flow of heated thermal oil though the heating system of the carrier housing and a heating system for achieving a suitable temperature of the thermal oil. The flow properties of the thermal transfer system of the carrier housing may be optimised for heat exchange with the upper plate. It is contemplated that in a separate cooling mode, the oil may be cooled for rapid cooling of the solar laminate after the lamination process is finished. 
     In a further embodiment according to the first aspect of the present invention, said connecting elements constitute flow guiding elements for distributing said heat conductive fluid inside said carrier housing. For an optimal temperature distribution on the upper plate, the connecting elements between the upper and lower plates may be used for guiding the flow of the thermal oil within the inner volume so that the flow intensity is roughly identical over the surface of the upper plate and any flow recirculation within the inner volume is avoided. The shape of the individual connecting elements may therefore vary. Preferably, the connecting elements are made of a material having low flow resistance, such as PTFE (Teflon). 
     In a further embodiment according to the first aspect of the present invention, said connecting elements and/or said upper plate may be electrically heated. The connecting elements may be electrically heated by heating bodies integrated into the connecting elements. The heating bodies are preferably powered from an external power source. By heating the connecting elements the thermal oil is not required to be externally heated. Alternatively, the upper plate is heated directly by integrated resistors or a resistive sheet. 
     In a further embodiment according to the first aspect of the present invention, the thermal properties of said thermal transfer system and said carrier housing causes the temperature of said upper plate to increase from 80-130° C. in a time period of at least 10 minutes, preferably at least 15 minutes and more preferably at least 20 minutes, for providing sufficient time for allowing any gas bubbles accommodated within the solar laminate to escape. For allowing the solar laminate sufficient time for all gas bubbles to dissipate, the encapsulation layer should preferably remain in its molten and non-cured state for at least 10-20 minutes, and thereafter the polymerisation and curing may initiate. In some embodiments the thermal transfer system may exhibit a dual temperature mode, e.g. by in a first stage providing a temperature of at least 80° C. but not above 130° C. for allowing the encapsulation layer to melt and when the above time period has elapsed the temperature is increased to at least 130° C. for initiating the polymerisation and curing of the encapsulating layer. However, due to the thermal inertia of the upper plate and the heat transfer system it is often not possible to achieve a rapid change of temperature of the upper plate. In a particular embodiment, the thermal heat capacity of the upper plate and the thermal conductivity of the thermal transfer system are adapted so that the upper plate is subjected to a substantially uniform temperature increase from 80° C. to 130° C. during the above time period for allowing the temperature to distribute over the upper plate and at the same time avoiding premature polymerisation. 
     In a further embodiment according to the first aspect of the present invention, said upper plate is undulated for accommodating an undulated laminate, such as a BIPV (Building Integrated PhotoVoltaic). For standard photovoltaic applications the solar laminate is typically flat, thus the upper plate should be flat as well. However, for some BIPV applications, undulated solar laminates are required due to technical or architectural reasons. For undulated solar laminates a flat upper plate would not be suitable due to the air pocket between the solar laminate and the upper plate as was previously discussed. 
     For undulated laminates preferably a customised carrier housing is used having an upper plate exhibiting the same undulation as the solar laminate. 
     In a further embodiment according to the first aspect of the present invention, said carrier housing defines a substantially box-shaped structure having a length of about 3 meters, a width of about 4 meters and a height of about 0.1 meters. The carrier housing according to the present invention is preferably used in connection with a large lamination plant for laminating large solar laminates. In the present context a large solar laminate is construed to mean any solar laminate which due to its size and weight is impracticable to lift by hand. It may alternatively mean a set of solar laminates which together are impracticable to lift by hand. Such large solar laminates may be advantageously handled by a carrier housing having the above measurements. 
     The above need and object together with numerous other needs, objects and advantages which will be evident from the below detailed description of a preferred embodiment of the module according to the present invention, are according to a second aspect of the present invention obtained by a method of conveying one or more solar cell laminates through a lamination plant by providing a carrier housing, said solar cell laminate comprising:
         a solar cell layer of silicon material, an upper and a lower encapsulating layer of EVA material covering the top and bottom of said solar cell layer and an upper and lower protective layer covering said upper and lower encapsulating layer, respectively, said encapsulating layer having a specific melting temperature and a specific curing temperature, said melting temperature being lower than said curing temperature, and
 
said carrier assembly comprising:
   a carrier housing of heat conductive material defining an inner volume, said carrier housing having an upper plate adapted for receiving said solar cell laminate and an opposite lower plate defining a first plurality of apertures, said inner volume including one or more connecting elements interconnecting said first and second plates,   a thermal transfer system providing thermal energy to said upper plate said thermal transfer system being accommodated in said inner volume,   an air supply system for providing a continuous outward airflow through said first plurality of apertures,
 
said method comprising the steps of:
   receiving said lower plate of said carrier housing on a conveying surface of said lamination plant and temporarily accommodating said solar cell laminates on said upper plate of said carrier housing,   elevating and substantially balancing the air pressure on said lower plate for providing lift or buoyancy to said carrier housing by said airflow of said air supply system,   moving substantially friction-free said carrier housing in relation to said conveying surface of said lamination plant, and   increasing the temperature on said outer surface of said first plate to preferably 80-130° C. for allowing said encapsulating layer to melt and subsequently cure.       

     It is evident that the above method according to the second aspect may be used together with the system according to the first aspect. 
     The above need and object together with numerous other needs, objects and advantages which will be evident from the below detailed description of a preferred embodiment of the module according to the present invention, are according to a third aspect of the present invention obtained by a method of laminating and conveying one or more solar laminates by providing a lamination plant, said solar laminate comprising a solar cell layer of silicon material, an upper and a lower encapsulating layer of EVA material covering the top and bottom of said solar cell layer and an upper and lower protective layer covering said upper and lower encapsulating layer, respectively, and said lamination plant comprising a frame extending horizontally from a first end to a second end and defining in a vertical direction a processing level and a carrier return level, said frame comprising:
         a loading station located at said first end and being positionable in said processing level and said carrier return level and shiftable between said levels,   a processing station comprising a sealable vacuum chamber located adjacent to said loading station at said processing level and,   an unloading station located adjacent to said processing station at said second end and being positionable in said processing level and said carrier return level and shiftable between said levels, and   a return station located between said loading station and said unloading station at said carrier return level,
 
said lamination plant further comprising a carrier for accommodating said solar laminate, said carrier having a heating element and being placeable in any of said loading station, processing station, unloading station and return station, said method further comprising performing the steps of:
   preparing said carrier by positioning said loading station in said processing level, placing said carrier in said loading station and accommodating said solar laminate on said carrier,   processing said laminate by placing said carrier in said vacuum chamber, evacuating said vacuum chamber and exhibiting said solar laminate to heat by said heating element,   unloading said solar laminate by positioning said unloading station in said processing level, placing said carrier in said unloading station and removing said solar laminate from said carrier, and   returning said carrier by positioning both said loading and unloading stations in said carrier return level and moving said carrier from said unloading station to said loading station via said return station.       

     For achieving high quality solar laminates the lamination process requires costly equipment such as vacuum chambers, heating plates etc. The lamination method according to the third aspect of the present invention may improve the usage of the vacuum chambers and other equipment. 
     The loading station, the processing station and the unloading station defines the conveying direction of the solar laminate and should be arranged adjacent to each other in the above order. The conveying direction preferably defines a straight line, however, other conveying directions are possible. The particular conveying direction is related to the factory floor area. The solar laminate has the same structure as described above in connection with the first aspect of the present invention. 
     The lamination plant is built on the frame and defines the horizontal conveying direction from the first end to the second end. In the vertical direction the frame defines the processing level and the carrier return level. The processing level is preferably located below the carrier return level, however, it&#39;s equally feasible to arrange the processing level above the carrier return level. The loading station and the unloading station are both shiftable between the processing level and the carrier return level. The shifting between the levels may be performed e.g. by a hydraulic lift or the like. The loading station may be used for manually or automatically assembling the solar laminate. The unloading station may consequently be used for manually or automatically removing the solar laminate from the carrier. In some embodiments further stations may be provided before the loading station and/or after the unloading station, e.g. a testing station or a packing station. The processing station includes the vacuum chamber and the carrier should be able to fit into the vacuum chamber. The vacuum chamber should include a vacuum pump for evacuating air and other gases resulting from the lamination process from the interior of the vacuum chamber. Suitable pressures for inside the vacuum chamber when evacuation has been performed range from about 0.1 mbar to about 1 mbar, and typically 0.5 mbar, for achieving sufficient bubble evacuation in the solar laminate when the solar laminate is being heated. The vacuum chamber will typically include connectors for allowing the heating plate to receive thermal energy, e.g. electrical energy or thermal oil, for allowing the carrier to heat up. 
     The carrier is being delivered with the lamination plant as an accessory and is reusable, i.e. when the solar laminates have been removed from the carrier at the unloading station the carrier should be transported back to the loading station for being reloaded with non-processed laminates. For optimal usage of factory floor area, the lamination plant may accommodate several carriers, i.e. a first carrier may be loaded at the loading station while a second carrier performs lamination in the processing station and a third carrier is being unloaded at the unloading station. Thus, the carrier at the unloading station typically cannot return to the loading station via the processing station, since it would cause an obstruction by going against the solar laminate conveying direction. Instead, the carrier will be shifted to the carrier return level and transported back to the loading station via the return station. 
     The individual stations (i.e. the loading station, the processing station, the unloading station and the return station) should be capable of temporarily accommodating the carrier and conveying the carrier to the subsequent station. For this purpose a conveying belt, conveying chain or conveying wheels may be used. In a particular advantageous embodiment according to the present invention the carrier may be of the same type as the carrier according to the first aspect, however, other carriers may be used as well. The heating element should be included in the carrier for heating at least the upper surface of the carrier which is facing the solar laminate. The carrier may e.g. be electrically heated or heated by thermal oil, as previously has been discussed. 
     It is further contemplated that additional processing levels and/or return levels may be installed in the frame. Since the standard laminates are substantially flat, the stations may be shallow and thus it may be contemplated that the lamination plant may be realised as a multilevel lamination tower having a multitude of processing levels. A multitude of processing levels permits the installation of the same multitude of lamination stations for allowing parallel lamination and thereby increasing the total throughput of laminates through the lamination plant without increasing the need for factory floor area. 
     In a further embodiment according to the third aspect of the present invention, said processing station further comprising a pressure chamber being separated from said vacuum chamber by a flexible membrane, said solar laminate being located between said carrier and said flexible membrane and when said pressure chamber is evacuated, said flexible membrane is caused to contact said solar laminate by the pressure difference between said pressure chamber and said vacuum chamber thereby fixing said solar laminate between said carrier and said flexible membrane. During bubble evacuation there is a risk of misalignment between the sheets of the solar laminate, caused by thermal expansion and flow effects in the sheets of the solar laminate. For achieving a correct alignment and positioning of the solar laminate and a quick bubble evacuation, the solar laminate should preferably be fixed during the processing. For this purpose preferably a flexible membrane is used. The flexible membrane should be made of temperature resistant and pressure tight material such as rubber or the like. When the vacuum chamber is evacuated the pressure inside the pressure space causes the flexible membrane to expand and apply a pressure onto the solar laminate so that the solar laminate is fixed between the carrier and the flexible membrane. 
     In a further embodiment according to the third aspect of the present invention, said frame further comprising a cooling station located between said processing station and said unloading station at said processing level, said method including the additional step of cooling said solar laminate by introducing said carrier into said cooling station and actively drawing heat from said solar laminate. After curing, the solar laminate is allowed to cool to room temperature. By providing a separate cooling station between the processing station and the unloading station, the solar laminate may be allowed to cool before unloading. The cooling station includes an active cooling which preferably includes cooling of the carrier, which due to the heat conductive properties of the carrier may rapidly cool the solar laminate to room temperature. In this way the production efficiency may be increased since the time needed for cooling is reduced. Rapid cooling may involve introducing chilled thermal oil into the carrier or subjecting the laminate to an air cushion as described above. 
     The above need and object together with numerous other needs, objects and advantages which will be evident from the below detailed description of a preferred embodiment of the module according to the present invention, are according to a fourth aspect of the present invention obtained by a lamination plant for laminating and conveying one or more solar laminates, said solar laminate comprising a solar cell layer of silicon material, an upper and a lower encapsulating layer of EVA material covering the top and bottom of said solar cell layer and an upper and lower protective layer covering said upper and lower encapsulating layer, respectively, and said lamination plant comprising a carrier for accommodating said solar laminate and a frame extending horizontally from a first end to a second end and defining in a vertical direction a processing level and a carrier return level, said frame comprising:
         a loading station located at said first end and being positionable in said processing level and said carrier return level and shiftable between said levels, when in said processing level   a processing station comprising a sealable vacuum chamber located adjacent said loading station at said processing level and,   an unloading station located adjacent said processing station at said second end and being positionable in said processing level and said carrier return level and shiftable between said levels, and   a return station located between said loading station and said unloading station at said carrier return level,
 
said carrier having a heating element and being placeable in any of said loading station, processing station, unloading station and return station.
       

     It is evident that the lamination plant according to the fourth aspect of the present invention may be used together with any of the systems and methods according to the first, second and third aspects of the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A brief description of the figures follows below: 
         FIG. 1  is a lamination plant for processing solar laminates. 
         FIG. 2  is a series describing a conveying path of a carrier in a lamination station. 
         FIG. 3   a - c  are a series describing a lamination process inside a lamination station. 
         FIG. 4   a - c  are close-up views of alternative embodiments of a carrier. 
         FIG. 5   a - b  are views of an air supply system of a carrier. 
         FIG. 6   a - b  are views of a thermal oil supply of a carrier. 
         FIG. 7   a - b —are further embodiments of the carrier having direct electrical heating without thermal oil. 
     
    
    
     DETAILED DESCRIPTION 
     The present invention will now be described in more detail with reference to the figures. Words such as upper, lower, above, below, top bottom etc should be understood in relation to the figures. 
       FIG. 1  shows a lamination plant  10  according to the present invention. The lamination plant  10  comprises a frame structure  12  which is divided into several stations: a loading station  14  is accommodated at the first end of the frame structure  12 . The loading station  14  comprises a flat conveying platform  16  which is vertically movable by a lift  18 . The conveying platform  16  of the loading station  14  is movable between a lower level, a middle level and an upper level, which will be described in more detail in connection with  FIG. 2 . A carrier  58  is accommodated on the conveying platform  16 . The carrier  58  is heatable during the processing of the solar laminate. A solar laminate  48  is accommodated on the carrier  58 . The solar laminate  48  and the carrier  58  will be described in greater detail in connection with  FIG. 3 . The conveying platform  16  of the loading station  14  is located adjacent to a processing station  20 . The processing station  20  comprises a vacuum chamber (not shown) which will be described in detail in connection with  FIG. 3 . An optional auxiliary processing station  20 ′ is provided below the main processing station  20 . The carrier  58  may enter the processing station  20  from the loading station when the loading station has been elevated to the middle level as shown. A cooling station  22  is located adjacent to the processing station  20 . An optional auxiliary cooling station  22 ′ is provided below the main cooling station  22 . The cooling station  22  is used for temporarily accommodating the solar laminate  48  and the carrier  58  after processing for allowing the solar laminate  48  to chill down to room temperature. At the second end of the frame structure  12 , adjacent to the cooling station  22  an unloading station  24  is located. The unloading station resembles the loading station and defines a conveying platform  16 ′ and a lift  18 ′. 
     The auxiliary processing and cooling stations  20 ′,  22 ′ are optionally provided on the lower level for parallel processing of several solar laminates  48  or alternatively as a backup in case of a breakdown of the main processing and cooling stations  20   22 . 
     The solar laminate conveying direction is thus defined on the middle level from the loading station  14 , via the processing station  20 , the cooling station  22  to the unloading station  24 , or alternatively on the lower level from the loading station  14 , via the auxiliary processing station  20 ′, the auxiliary cooling station  22 ′ to the unloading station  24 . On top of the frame structure  12 , and above the processing and cooling stations  22 ,  24  on the top level a respective return station  26 ,  26 ′ is located. The return station is used for returning the carrier  58  to the loading station  14  when the solar laminates  48  have been unloaded at the unloading station  24 . The carrier  58  is thereby transported in a direction opposite the conveying direction of the solar laminate  48  at the upper level, which will be further illustrated in connection with  FIG. 2 . 
       FIG. 2   a - f  show the conveying path of the carrier  58 . The lamination plant  10  defines a conveying direction of the solar laminate  48  from the loading station  14  to the unloading station  24  at the middle level or alternatively the lower level. The carrier  58  defines a conveying path further comprising the return of the carrier from the unloading station  24  to the loading station  14  on the upper level. 
       FIG. 2   a  show the solar laminate  48  being assembled on the carrier  58 , which in turn is accommodated on the conveying platform  16  of the loading station  14 . The loading station  14  is presently at the lower level. The loading station  14  is subsequently elevated to the middle level to be adjacent to the processing station  20 . 
     In  FIG. 2   b  the carrier  58  and the solar laminate  48  is conveyed in the conveying direction indicated by the arrow into the processing station  20  for being processed. The processing of the solar laminate will be further discussed in detail in connection with  FIG. 3 . 
       FIG. 2   c  shows the carrier  58  and the solar laminate  48  being conveyed in the conveying direction indicated by the arrow into the cooling station  22  for being chilled to room temperature. 
       FIG. 2   d  shows the carrier  58  and the solar laminate  48  being conveyed in the conveying direction indicated by the arrow to the unloading station  24 . The unloading station has previously been shifted to the middle level for being adjacent to the cooling station  22 . At the unloading station  24  the solar laminate  48  is being unloaded. 
       FIG. 2   e  shows the unloading station  24  being shifted to the upper level in direction of the arrow, while still accommodating the carrier  58 . 
       FIG. 2   f  shows the carrier  58  being temporarily accommodated in the return station  26  on the upper level while being conveyed in the direction of the arrow from the unloading station  24  to the loading station  14 , both being at the upper level. When the carrier  58  is received in the loading station  14  the loading station  14  may be shifted back to the lower level for being reloaded with a new solar laminate  48  to be processed in the processing station  20 . 
     The conveying surfaces in the stations are preferably flat for being used with the carrier  58  as described in  FIG. 5   a - b . In an alternative embodiment the conveying surfaces include belts, chains or wheels or providing a forward motion to the carrier. Preferably, several carriers  58  are being used simultaneously. The above configuration makes most efficient use of factory floor space and avoids the risk of empty carriers  58  obstructing the conveying direction of the solar laminate  48 . 
       FIG. 3   a  shows a cut-out side view of a vacuum chamber  28 . The vacuum chamber  28  is included in the processing station of the lamination plant shown in  FIG. 1-2 . The vacuum chamber is made of rigid metal and defines an inner space  44  for accommodating a carrier  58 . The vacuum chamber comprises a base part  30  and a lid  32 , which may be separated as indicated for receiving the carrier  58 . A pressure seal  34  seals the interface between the lid  32  and the base plate  30  when the vacuum chamber  28  is closed. The upper surface of the base plate  30  forms a conveying surface for accommodating the lower plate  62  of the carrier  58  and receiving/delivering the carrier  58  from/to an adjacent station. The base plate  30  further comprises a thermal oil hose  46  which provides thermal oil from a source located outside the vacuum chamber  28  to the carrier  58  when the carrier is accommodated in the inner space  44  of the vacuum chamber. The thermal oil hose  46  is connected to the carrier  58  by a thermal oil inlet  78 . Additionally, a thermal oil outlet  80  is provided in the carrier  58  opposite the thermal oil inlet  78  for allowing the thermal oil to leave the carrier  58 . A thermal oil outlet hose  38  is connected to the thermal oil outlet  80  which allows the thermal oil to leave the vacuum chamber, reheat by an outside source and circulate the carrier  58  via the thermal oil hose  46 . 
     Both the thermal oil hoses  46 ,  38  and the thermal oil inlet and outlet  78 ,  80  are reinforced to sustain the vacuum condition inside the vacuum chamber  28 . The base plate  30  further comprises a vacuum hose  42  which is connected to a vacuum pump (not shown) located outside the vacuum chamber  28 . The vacuum pump is used for evacuating the inner space  44  of the vacuum chamber  28 . The ducts in the vacuum chamber  28  where the thermal oil hose  46  and the vacuum hose  42  are fed through should be made pressure-tight for avoiding any leakage from the outside into the inner space  44  of the vacuum chamber  28 . The lid  32  of the vacuum chamber  28  defines a pressure space  40  being separated from the inner space  44  by a rubber membrane  36 . The rubber membrane  36  is made substantially flexible but pressure resistant and heat resistant. Alternatively to thermal oil the upper plate may be electrically heated by providing electrical conduits, or yet alternatively the base plate  30  of the vacuum chamber  28  may be heated. 
     The solar laminate  48  is located in the inner space  44  on the upper plate  60  of the carrier  58  between the carrier  58  and the rubber membrane  36  of the lid  32 . The solar laminate comprises a central layer of solar cell elements  50 . The solar cell elements  50  comprise silicon wafers defining a single p-n junction which typically has an upwardly facing active surface for receiving solar radiation. The solar cell elements  50  are connected in a series configuration by a metallic connector grid  52 . The solar cell elements  50  are covered on each side by a upper and lower layer of EVA  54 ,  54 ′. The EVA layers  54 ,  54 ′ are in turn covered by an upper and lower cover  56 ,  56 ′, respectively. The upper cover  56  is preferably made of glass for allowing solar radiation to penetrate without any substantial losses. The lower cover  56 ′ may be made of glass, however preferably a metallic lower cover  56 ′ is used. 
       FIG. 3   b  shows the vacuum chamber  28  of  FIG. 3   a  when the lid  32  has been attached to the base plate  30  and the inner space  44  has been evacuated by use of the vacuum hose  42 . The pressure in the inner space  44  is in the range of 1 mbar to 0.1 mbar. When the inner space  44  is evacuated, the pressure space  40  will remain at ambient pressure and consequently the pressure difference will cause the rubber membrane  36  to expand towards the carrier  58  and apply a pressure on the solar laminate  48 . The pressure applied by the rubber membrane  36  onto the solar laminate  48  will act as a fixation force for ensuring the solar laminate  48  remains in a correct position during the lamination process. The low pressure in the vacuum chamber  28  will remove any air pockets which may possibly exist within the solar laminate  48 . In some embodiments the pressure in the pressure space  40  may be variable for allowing a variable force by the rubber membrane  36 . 
     The lamination process is initiated by introducing hot thermal oil into the carrier  58 . The thermal oil is preferably allowed to circulate, which will be further explained in  FIG. 6 . The temperature of the thermal oil may be around 150° C. The thermal oil will heat the carrier  58  and the overlying laminate  48 . The high temperature will cause the EVA layers  54 ,  54 ′ to assume a liquid state and due to the pressure from the rubber membrane  36  the liquid EVA  54  will fill any space between the solar cell elements  50  and between the covers  56 ,  56 ′ to completely encapsulate the central layer. During the heating phase gas bubbles will accumulate within the solar laminate  48 , mainly within the liquid EVA  54 . Due to the low pressure inside the inner space  44  and the pressure applied from the rubber membrane  36  the gas bubbles will dissipate from the solar laminate provided the 10-20 minute time frame is allowed for the process before curing is initiated. A bubble-free laminate is essential for a high quality solar module. 
       FIG. 3   c  shows the vacuum chamber  28  of  FIG. 3   b  when curing has been initiated. The carrier preferably has thermal properties for allowing the temperature of the solar laminate to increase from 80° C. to 130° C. during the above-mentioned 10-20 minutes. When the liquid EVA  54  reaches 130° C. curing by polymerisation is initiated. The curing solidifies the EVA layer  54  and fixes the covers  56 ,  56 ′ permanently to the layer of solar cell elements  50 . The EVA material forms a substantially transparent, dielectric and temperature resistant encapsulating layer inside the solar laminate  48 . After the curing has finished, the solar laminate  48  should be allowed to cool down to room temperature. Rapid cooling may be provided by allowing chilled thermal oil to enter and circulate the carrier  58  and/or by subjecting the solar laminate to an air cushion. The fixation force by the rubber membrane  36  prevents cracking of the solar laminate due to thermal stress. When the solar laminate  48  has assumed room temperature, the inner space  44  is re-pressurised and the rubber membrane  36  is allowed to resume its non-expanded state. Subsequently, the lid  32  may be opened and the processed solar laminate  48  may be removed. 
       FIG. 4   a  shows a cut-out side view of the vacuum chamber  28 ′ including a further embodiment of the carrier  58 ′. The carrier  58 ′ has an upper plate  60  exhibiting a convex undulation for accommodating a laminate  48 ′ having a corresponding concave undulation for allowing good thermal conduction into the solar laminate  48 ′. Such laminates  48 ′ may typically be used for BIPV. 
       FIG. 4   b  shows a cut-out side view of the vacuum chamber  28 ″ including a further embodiment of the carrier  58 ″. The carrier  58 ″ has an upper plate  60  exhibiting a number of concave undulations for accommodating a laminate  48 ″ having corresponding convex undulations for allowing good thermal conduction to the solar laminate  48 ″. Such laminates  48 ″ may typically feature a reflective lower cover  56 ″ allowing incoming solar radiation to be focused on specific points within the solar laminate  48 ″ where a solar cell element may be accommodated. 
       FIG. 4   c  shows a cut-out side view of the vacuum chamber  28 ′″ including a further embodiment of the carrier  58 ′″. The carrier  58 ′″ has an upper plate  60  exhibiting a number of shallow cavities constituting slots for accommodating a smaller solar laminate  48 ′″. In this way the solar laminates  48 ′″ are sidewardly supported, well positioned and additionally the risk of several smaller laminates attaching each other is avoided. 
       FIG. 5   a  shows a cut-out side view of a carrier  58 . The carrier  58  has lower and upper air inlet  64 ,  64 ′ for receiving compressed air from an external source (not shown). The compressed air is distributed inside the carrier  58  by a lower and upper air pipe  66 ,  66 ′ and leaves the carrier  58  by a number of apertures  68 ,  68  in the respective lower and upper plate  60 ,  62  of the carrier  58 . When the carrier  20  is accommodated on a flat conveying surface (not shown) and is about to be moved, a constant flow of compressed air is propagated through the lower air pipe  66  and the lower apertures  68  for achieving an air cushion having an increased pressure at the lower plate  62  of the carrier  58  when the airflow is deflected between the lower plate  62  of the carrier  58  and the conveying surface. The increased pressure on the lower plate  62  will apply an upwardly force for elevating the carrier  58  about 1 cm above the conveying surface. When the carrier  58  is elevated, the carrier  58  may be moved easily even by hand. 
     When a heavy solar laminate (not shown) is placed on or removed from the upper plate  60  of the carrier  58 , compressed air may be propagated through the upper air pipe  66 ′ and the upper apertures  68 ′. In this way an air cushion having an increased pressure will form between the solar laminate and the upper plate  60  of the carrier  58  and thereby the solar laminate may be positioned very easily, even by hand. The air cushion also provides rapid cooling of the solar laminate. Typically, the carrier  58  and the solar laminate have to be cooled down right after the curing is finished. The flow of cold compressed air will provide efficient cooling by forced convection and typically allow the solar laminate to cool down from the curing temperature of 130° C.-150° C. to a temperature not exceeding 40° C. within no more than 4-10 minutes after curing is finished. 
       FIG. 5   b  shows a perspective view of the carrier  58  as shown in  FIG. 5   a . The apertures  68  in the lower and upper plates  60 ,  62  should be distributed evenly over the surface of the plates  60 ,  62  for providing stability and the airflow should be substantially constant and uniform. In some embodiments a skirt (not shown) made of rubber may be employed as a rim encircling the lower plate  62  of the carrier  58  for allowing less air to escape from the air cushion and thus a less amount of compressed air must be provided to the carrier  58 . The present embodiment may optionally include a thermal transfer system or alternatively be heated by a separate heating plate. 
     For illustrative purposes the carrier  58  is shown here having a separate air supply hose  70  connected to each air pipe (not shown), and each air pipe supplies a row of apertures  68 . The air hoses  70  are all connected to a joint compressor  72  generating a flow of compressed air though each air supply hose  70 . The air supply hoses  70  are connected to the air inlet  64  of the carrier by snap-on connectors for allowing rapid connection when the carrier  58  is about to be moved and rapid disconnection when the carrier  58  is accommodated inside the vacuum chamber (not shown). It is of course contemplated that in some embodiments a single air supply hose  70  may be used for the distribution of air to each of the apertures  68  for allowing rapid connection and disconnection of the air supply hose  70 . 
       FIG. 6   a  shows a top cut-out view and  FIG. 6   b  shows a cut-out perspective view of the carrier  58 . The carrier  58  has an inner volume  74  for receiving thermal oil. The inner volume  74  is defined by a rim  44  and by the upper and lower plates  8  (not shown in the present perspective) of the carrier  58 . The rim further accommodates the thermal oil inlet  78  and an oppositely located thermal oil outlet  80 . The inner volume  74  further defines guiding elements  82  connecting the upper and lower plates of the carrier  58 . The guiding elements  82  function as flow deflectors for allowing the flow of thermal oil to distribute over the complete upper plate of the carrier  58 . The guiding elements  82  further provoke turbulence, which enhances the thermal conductivity towards the upper plate of the carrier  58 . Suitable temperature of the thermal oil is about 150° C. for allowing the EVA layer of the solar laminate (not shown) to melt and subsequently cure. 
       FIG. 7   a  shows a cut-out view of a further embodiment of a carrier  58  having direct electrical heating. The carrier  58  comprises an upper surface  60  which is undulated and which rests on a metal sheet  86 . Alternatively, Teflon may be used instead of metal. Between the upper surface  60  and the metal sheet  86  an electrical heating sheet  84  is located. The electrical heating sheet may comprise a flexible and resistive sheet which may be heated by electricity. Such sheets are known in the art and commercially available from various companies, such as the Danish company JEVI. For allowing a high thermal transfer rate between the electrical heating sheet  84  and the upper surface  60 , the upper surface  60  and the metal sheet  86  should be fixed together by bolts  88 , or alternatively screws. 
     By omitting the thermal oil and providing direct heating by electricity a separate heating plate may be omitted for allowing the upper surface  60  to heat-up quicker and a better controlled temperature profile to be achieved. This is especially important for undulated solar laminates. 
       FIG. 7   b  shows a cut-out view of a further embodiment of a carrier  58  similar to  FIG. 7   a . The present embodiment features a flat upper surface  60  for accommodating a flat solar laminate. It is contemplated that a separate heating plate may be used in combination with a thermal transfer system inside the carrier. The thermal transfer system in the carrier may provide a pre-heating of about 60° to the solar laminate for shortening the time needed for lamination. 
     A carrier according to the present invention allows the solar laminates to be introduced quickly into the lamination plant for ensuring a uniform heating. 
     
       
         
               
             
               
               
             
           
               
                   
               
               
                 List of parts with reference to the FIGURES: 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 10. Lamination plant 
               
               
                   
                 12. Frame structure 
               
               
                   
                 14. Loading station 
               
               
                   
                 16. Conveying platform 
               
               
                   
                 18. Lift 
               
               
                   
                 20. Processing station 
               
               
                   
                 22. Cooling station 
               
               
                   
                 24. Unloading station 
               
               
                   
                 26. Return station 
               
               
                   
                 28. Vacuum chamber 
               
               
                   
                 30. Base plate 
               
               
                   
                 32. Lid 
               
               
                   
                 34. Pressure seal 
               
               
                   
                 36. Rubber membrane 
               
               
                   
                 38. Thermal oil outlet hose 
               
               
                   
                 40. Pressure space 
               
               
                   
                 42. Vacuum hose 
               
               
                   
                 44. Inner space 
               
               
                   
                 46. Thermal oil hose 
               
               
                   
                 48. Solar laminate 
               
               
                   
                 50. Solar cell element (Silicon wafer) 
               
               
                   
                 52. Connector grid 
               
               
                   
                 54. EVA layer 
               
               
                   
                 56. Cover layer 
               
               
                   
                 58. Carrier 
               
               
                   
                 60. Upper surface (of carrier) 
               
               
                   
                 62. Lower surface (of carrier) 
               
               
                   
                 64. Air inlet 
               
               
                   
                 66. Air pipe 
               
               
                   
                 68. Apertures 
               
               
                   
                 70. Air supply hose 
               
               
                   
                 72. Compressor 
               
               
                   
                 74. Inner volume (of carrier) 
               
               
                   
                 76. Rim 
               
               
                   
                 78. Thermal oil inlet 
               
               
                   
                 80. Thermal oil outlet 
               
               
                   
                 82. Guiding elements 
               
               
                   
                 84. Electrical heating sheet 
               
               
                   
                 86. Metal sheet 
               
               
                   
                 88. Bolt