WO2011154025A2

WO2011154025A2 - Method of manufacturing a solar panel and apparatus therefore

Info

Publication number: WO2011154025A2
Application number: PCT/EP2010/004403
Authority: WO
Inventors: Abraham Jan Verschoor; Jan Bakker; Simon Den Hartigh
Original assignee: Eurotron B.V.
Priority date: 2010-06-09
Filing date: 2010-07-08
Publication date: 2011-12-15
Also published as: WO2011154025A3

Abstract

The solar panel is manufactured by provision of a stack of foils on top of a carrier table. Individual solar cells are provided between a first and a second foil of thermoplast material. An interconnect foil is present between the first foil and the carrier table, connections to the solar cells extending through the first foil. At least one module of electronic components is integrated into the solar panel. The carrier table and the interconnect foil are provided with one recess, so as to leave space for the encapsulated components. This allows the assembly of the module to the carrier table prior to the assembly of the first and second foil and the solar cells. Contact pads on the interconnect foil for connection to the module are defined in annular ring around said recess. The annular ring is filled with a filling material so as to limit spreading of thermoplast material. An apparatus comprising a carrier table with a suitable recess is also provided.

Description

Method of manufacturing a solar panel and apparatus

therefore

FIELD OF THE INVENTION

The invention relates to a method of manufacturing a solar panel provided with a plurality of solar cells, comprising the steps of:

providing a carrier table for assembly of the solar panel, with lateral dimensions at least the same as

dimensions of the solar panel;

applying an interconnect foil provided with a pattern of electrical conductors and a plurality of contact pads on the carrier table;

applying a first foil of thermoplast material, which first foil is provided with a plurality of through-holes at locations corresponding to those of at least a subset of the contact pads of the interconnect foil;

providing electrically conductive material to be present within said through-holes of the thermoplast

material ;

assembling the plurality of solar cells, each provided with contact pads, and applying a second foil of thermoplast material and a cover plate thereon;

laminating said stack of foils and solar cells to form the solar panel, wherein the thermoplast material of the first and second foil spread out to encapsulate the solar cells and wherein the electrically conductive material forms electrical connections between the contact pads of the solar cells and the interconnect foil. The invention further relates to a solar panel made in accordance with said method and to an apparatus for

manufacturing such a solar panel. BACKGROUND OF THE INVENTION

The manufacture of solar panels requires the assembly of solar cells. This assembly establishes electrical

connections between the solar cells and an interconnect foil, and provides a mechanically stable and well protected body. In comparison to assembly processes for integrated circuits, the size of a solar panel is impressive, as it can easily have dimensions of several square meters. This evidently requires specific handling. In comparison to assembly processes of displays, a major difference resides in the integration of a plurality of solar cells next to each other, so as to cover the surface as good as possible. Liquid crystalline displays are typically based on a single display component. More displays may be arranged adjacent to each other, but then the distance between them is less of a concern. In solar panels, any space between individual cells results in efficiency losses. Additionally, the solar panel needs to be flat in view of its use integrated in housing constructions or directly on top of a roof. Cables and flex foils and such large scale connectors are therefore not appropriate in the assembly of solar cells. Furthermore, its use outside at locations that are exposed to sunlight, but that further may be exposed to ice and wind, requires that a solar panel needs to be able to accommodate large

temperature differences, and hence differences in thermal expansion.

Apparatus for assembly of solar cells is for instance known from the manuscript "A novel module assembly line using back contact solar cells' as published on the IEEE Photovoltaics Specialists Conference, San Diego, USA, from May 11-15, 2008, authors M. Spath, P.C. de Jong, I.J.

Bennett, T.P. Visser and J. Bakker. The assembly line presented therein is suitable for handling extremely thin and fragile solar cells with thicknesses of less than 200 microns and even less than 150 microns. The assembly line allows an assembly process comprising the steps of as outlined above and will be further referred to as the

Eurotron assembly line. After the provision of an

interconnect foil (referred to as a conductive back sheet foil), conductive material in the form of paste is deposited on the electrical conductors of the interconnect foil. A pre-processed sheet of thermoplast material, such as

polyethylenevinylacetate (EVA) is hereon provided.

Thereafter, solar cells are assembled to the sheet of thermoplast material. Use is made of a pick and place unit for adequate positioning. It further allows coupling of the cells to the conductive material. After provision of a further sheet of thermoplast material and a cover plate, the solar panel is laminated in a vacuum laminator while

simultaneously forming connections between the contact pads of the solar cells and those of the interconnect foil. The module assembly line is capable of assembling solar panels comprising x 9 and 6 x 10 solar cells, each solar cell having a size of 156 x 156 mm² (6 x 6 inch). The assembly line is designed for supporting any type of solar cells provided with contact pads at its rear side. Examples of such solar cells include Integrated Back Contact (IBC), Heterojunction with Intrinsic thin layer (HIT) , Emitter Wrap Through (EWT) , Metallisation Wrap Through (MWT) ,

Metallisation Wrap Around (MWA) solar cells.

The Eurotron assembly line comprises a plurality of stations. In a first station the interconnect foil is provided to a carrier table. The carrier table is movable by means of a transport system so as to move the stack of foils through the stations. The carrier table is provided with vacuum means. In a second step, conductive material, such as conductive adhesive, is applied, for instance with screen printing. The subsequently provided first foil is provided with through-holes in locations aligned to those of the conductive material. A subsequent station includes vision tools for achieving precise alignment between the contact pads of the solar cells and the through-holes in the first foil of thermoplast material. Further stations are designed for applying the second foil and the cover plate and for flipping the solar panel upside down. Thereafter, it is placed into a vacuum laminator. The station for the flipping of the solar panel comprises a clamping system to avoid shifting or breakage of solar cells. Use of the assembly line provided good results in terms of yield (100%) and performance (small deviation from the average).

It is a limitation of the Eurotron's known assembly line that it is not suitable for integration of further components, such as power converters, drivers and other active devices, suitably in the form of integrated circuits, capacitors, resistors, inductors. Such integration is clearly interesting for enhancing the functionality of the solar panel, and needs to be integrated on the solar panel level, as the solar cell comprises merely a single wafer of silicon. Defining integrated circuits within the solar cell would increase manufacturing costs of the solar cells considerably if not dramatically. It would therefore be beneficial to allow integration of such components or a circuit thereof into the solar panel, but it is not clear how to achieve this within the context of the known method and corresponding assembly line. SUMMARY OF THE INVENTION.

It is therefore an object of the present invention to provide a method as recited in the opening paragraph which further allows assembly of electronic components into the solar panel, without decreasing yield of the assembly process and without endangering the ability to withstand differences in temperature during use of the solar panel. Further objects relate to the provision of a solar panel thus manufactured and an apparatus suitable for carrying out said method.

The object is achieved in a method comprising the steps of:

dimensions of the solar panel;

applying a first foil of thermoplast material, which first foil is provided with a plurality of through-holes at locations corresponding to those of at least a subset of the contact pads;

material ;

laminating said stack of foils and solar cells to form the solar panel, wherein the thermoplast material of the first and second foil spread out to encapsulate the solar cells and wherein the electrically conductive material forms electrical connections between the contact pads of the solar cells and the interconnect foil,

characterized in that at least one module of electronic components is integrated into the solar panel, which module comprises a carrier with a first side, at which are provided an encapsulation with the electronic components and a plurality of exposed contact pads, for which integration the carrier table is provided with at least one recess and the interconnect foil is provided with at least one hole at a location corresponding to the recess and with contact pads within an annular ring around said hole, and

the module is integrated by assembling the module with its contact pads facing the interconnect foil, said contact pads aligned to the contact pads in the annular ring around the hole of the interconnect foil, filling material being provided between said annular ring and said carrier of the module, and the encapsulation extending into said recess.

In accordance with the method of the invention, the carrier table has been modified so as to accommodate a module with a circuit of electronic components. The

electronic components are altogether herein encapsulated in an encapsulation extending on a first side of a carrier. Contact pads are further present on this first side of the carrier. The assembly of this module is carried out prior to the provision of the first foil of thermoplast material. This sequence of assembly steps appears to include a risk for the robustness in comparison to an alternative of applying the components only after completion of the

lamination. However, such alternative would require the provision of further protective layers and temperature steps that might have a negative impact on the stability of the stack of laminated foils The risk for insufficient robustness appears to relate first that some of the thermoplast material and-or any additional adhesive material could leak away by entering any space left in the recess. This issue is solved in that filling material is present in an annular ring around the recess between the carrier and the interconnect foil. This annular ring thus constitutes a closure of the recess.

Another risk is that the first foil can be provided

appropriately, without leading misalignment, folding and-or development of stress. Clearly, due to the large scale, the first foil is to be deposited essentially stress-free and completely flat. This issue is solved in accordance with the invention, in that the contact pads of the module are provided on an exposed, substantially non-encapsulated portion of the carrier. As a result, the thickness added locally due to the presence of the carrier can be very small .

In one suitable embodiment, the filling material is even, at least locally, heated, so as to allow that the module sinks into said filling material, that suitably is present also around the location of the module, and

preferably on substantially the complete interconnect foil.

In another embodiment, the carrier of the module is optically opaque or reflective and the lamination step comprises a first illumination treatment in which the stack of panel is irradiated through the cover, such that the carrier protects the underlying filling material from spreading. This opaque or reflecting character of the carrier is effectively a barrier against irradiation in the first illumination treatment. Application of this treatment is deemed beneficial for improving the consistency of the stack of foils prior to turning the solar panel upside down. Its result is believed to be that the foils get attached to each other without spreading so as to fill any gaps.

In a further embodiment, the filling material is applied as a layer or a foil, which extends on at least substantially the complete interconnect foil. The carrier of the module is provided, at a second side opposite to the first side, with a coating material structurally similar to the filling material. This embodiment provides that the exposed surface of the carrier is chemically similar to that of the filling material. This is first of all advantageous, in that the surface chemistry plays an important role in adhesion between layers. When thus desiring a uniform application of a large sized foil, an identical or similar surface structure helps to arrive at similar interaction and adhesion. A further advantage is that upon spreading such similar or identical materials are better able to mix and crosslink together, so as to form a single layer.

Several options are available for the provision of the electrically conductive material. Use can be made of screen printed dots applied on the interconnect foil. Both solder and glue materials may be applied. Solder is typically applied as solder paste, though alternatively use is made of solder balls. Alternatively, use may be made of an

anisotropically conductive glue that extends over a

substantial portion of the interconnect foil. Said

substantial portion may be the complete interconnect foil, but does not need to be. The choice of the conductive material is further dependent on the size of contact pads and the distance between individual contact pads, in order to meet requirements with respect to electrical resistance of the connection and electrical isolation between

neighbouring connections. In a further alternative, use may be made of anisotropically conductive glue for the electrical coupling of the module to the interconnect foil, whereas use is made of solder for the coupling between the solar cells and the interconnect foil. The reverse (solder for the module, and conductive glue for the solar cells) is a further

alternative. This can be advantageous in that small solder balls may be used and may define the distance between the module and the interconnect foil precisely. Moreover, modules of electronic components could be provided with solder paste separately. Furthermore, underfill materials are known which may be applied around solder balls, or can liquefy upon heating, so that the solder balls sink through the underfill material. This allows the provision of such underfill material onto the interconnect foil, and the solder balls on the contact pads of the electronic module, which appears a practically workable manner of making a good connection .

Additionally, the recess allows the provision of a filling material - electrically insulating or

anisotropically conductive - locally on the interconnect foil, without the risk of spreading. The provision may occur by any known means, including screen printing, inkjet printing, spraying or the like. The provision is suitably done prior to the provision of the module. Upon assembly of the module, optionally with a gentle heating step at for instance 40-70 °C, the filling material will be pushed out, so that it certainly extends in the annular ring around the recess .

The first foil of thermoplast material is suitably provided by means of transfer from a vacuum carrier to the carrier table. Such transfer process advantageously

comprises the steps of: attaching the first foil to a vacuum carrier provided with means for local application of vacuum;

providing through-holes in the first foil at predefined locations, the vacuum being applied outside of said

predefined locations;

positioning the vacuum carrier and the carrier table to each other, so that the locations of the through-holes are aligned with said contact pads of the said subset on the interconnect foil;

transferring the first foil to the carrier table by removing the vacuum, and

removing the vacuum carrier from the carrier table.

For such transfer process, use is advantageously made of an apparatus known from EP-A 2110213, which is herein included by reference. The transfer process as described above, and for which suitably the known apparatus is used, has the advantage that the first foil can be applied to the interconnect foil or any material thereon, substantially free of stress.

In a further embodiment herein, the vacuum is removed in accordance with a pattern, such that the foil is

effectively transferred from the vacuum carrier to the carrier table in the form of a wave. The wave may be applied from left to right (e.g. linear), or from a center to edges (e.g. radially) .

In another embodiment, through-holes are applied in the first foil at locations corresponding to those of the module of electronic components. These through-holes are not intended for the provision of an electrical connection, but may be used for removal of air as present between the vacuum carrier and the carrier table during positioning. Such venting through-holes may be provided according to a regular pattern. It is not excluded that such venting through-holes are also present in other areas not corresponding to the location of the one or more modules.

The carrier table as used in the present invention preferably comprises a moving table suitable for moving said stack of foils in different stages of said method between stations for carrying out steps of the method. In one embodiment, it is provided with vacuum means for local application of vacuum. It is observed for clarity that the term 'vacuum' as used in the context of the present

invention refers to a situation of controlled underpressure relative to the atmospheric pressure. Suitably, this

pressure is 1 promille (0.1%) or less of the atmospheric pressure as known to the skilled person in the art. A suitable moving table comprising means for generating a vacuum - a vacuum generator - is for instance known from EP- A 2182549, which is included by reference herein. This known moving table is provided with vacuum chambers that allow the limitation of the vacuum to selected areas only (e.g. also referred to herein as local application of vacuum) . In a most preferred implementation disclosed in EP-A 2182549 use is made of a vacuum generator comprises one venturi device, and an overpressure tank is present. The venturi device is provided with a suction side and a pressure side, of which the suction side is connected to an aperture in the moving table. The pressure side is connected to the overpressure tank. Such a carrier table is typically made of metal such as steel or aluminum and intended for reuse.

In one further embodiment of such a carrier table, the recess is variable in size. The size variation may be a variation of diameter (or alternatively length and width, dependent on the shape of the module) , but can also be a variation of depth. A combination of both is evidently applicable. Suitably, a plurality of recesses is defined in the carrier table, of which at least some may be closed. This leaves design freedom for any designer of solar panels to choose a number of modules and/or to choose an optimum location. Various implementations are envisageable for this variability in size. Inserts can be provided. The recess ma have a bottom of which the vertical position may be variabl manually or through a motor.

In an alternative embodiment, the carrier table comprises a body in which the recess is defined and which constitutes part of the solar panel after the manufacture. Such a body may comprise a material such as glass or a moulding material such as polycarbonate or epoxy. This has the advantage that there is no need to apply any further protective layers after completion of the lamination process .

The module of electronic components suitably defines a circuit that optimizes operation of the solar panel. Typica functions include those of a power converter, a battery and/or capacitor, drivers and logical functions. In one embodiment, the module further comprises terminals for external access to and from the solar panel, which terminal is exposed after completion of the laminating step. Such a module defining terminals for the solar panel may also be present as a second module in addition to a module with other functionality.

In a further aspect, the invention provides resulting solar panel, comprising a laminate of a carrier; an interconnect foil provided with a pattern of electrical conductors and a plurality of contact pads on the carrier; a plurality of solar cells, each provided with contact pads, sandwiched between a first and a second foil of thermoplast material spread out to encapsulate the solar cells, which first foil is provided with a plurality of through-holes at locations corresponding to those of at least a subset of the contact pads of the solar cells and the interconnect foil;

electrically conductive material present within said

through-holes of the thermoplast material and coupling said contact pads of the solar cells and corresponding ones of the interconnect foil; an optically transparent cover plate on the second foil.

The solar panel in accordance with the invention is characterized in that at least one module of electronic components is integrated into the solar panel, which module comprises a carrier with a first side, at which are provided an encapsulation with the electronic components and a plurality of exposed contact pads, for which integration the carrier table is provided with at least one recess and the interconnect foil is provided with at least one hole at a location corresponding to the recess and with contact pads within an annular ring around said hole, and which contact pads face the interconnect foil, said contact pads aligned to the contact pads in the annular ring around the hole of the interconnect foil, filling material being present between said annular ring and said carrier of the module, and the encapsulation extending into said recess.

In another aspect, the invention provides an apparatus for use in manufacturing a solar panel provided with a plurality of solar cells, comprising a carrier table for assembly of the solar panel, with lateral dimensions at least the same as dimensions of the solar panel, which carrier table comprises a moving table suitable for moving said stack of foils in different stages of said method between units for carrying out steps of the manufacturing of the solar panel and which carrier table is provided with a recess suitable for accommodating a top portion of a module of electronic components in an encapsulation.

Embodiments discussed with reference to the

manufacturing method, also apply to and may be combined with the solar panel and to the apparatus of the invention, and vice versa.

In again a further aspect, a second manufacturing method is provided for manufacturing a solar panel provided with a plurality of solar cells. This method comprises the steps of :

dimensions of the solar panel;

material ;

laminating said stack of foils and solar cells to form the solar panel, wherein the thermoplast material of the first and second foil spread out to encapsulate the solar cells and wherein the electrically conductive material forms electrical connections between the contact pads of the solar cells and the interconnect foil. The application of the first foil on top of the interconnect foil comprises the steps of:

attaching the first foil to a vacuum carrier provided with means for application of vacuum;

defining through-holes in the first foil at predefined locations ;

transferring the first foil to the carrier table by removing the vacuum, and

removing the vacuum carrier from the carrier table.

This method specifically addresses the application of the first foil. It makes use of a transfer process. This transfer process is a solution for an engineering problem with several requirements: first, the through-holes in the first foil must be perfectly aligned with the contact pads of the interconnect foil; secondly, deposition of the first foil onto the interconnect foil should be planar, i.e.

without folding or inclusion of air bubbles. A lack of planarity would give rise to assembly problems in the subsequent step of providing the solar cells, and may lead to stresses and/or cracks as a result of heating and thermal cycling in further manufacturing steps and/or during use. Furthermore, deposition of the first foil in liquid form, e.g. by spincoating, dipcoating or any form of printing, is undesired, as it would lead to manufacturing complexity.

In the present solution, the foil is first laid out, preferably rolled out. The vacuum carrier is used herein as a reference. Any air or bubbles remaining between the vacuum carrier and the foil may be removed by application of underpressure, particularly vacuum. The vacuum or underpressure may be applied either prior, during or after that the first foil is provided on the vacuum carrier.

Suitably, the first foil and the vacuum carrier have a contact area that increases gradually, for instance from the one to the other end in the form of a wave. Alternatively, the contact area may increase stepwise, or discretely, e.g. in that the first foil approaches the carrier or vice versa.

Subsequently, through-holes are defined in the first foil. Use is made herein of tools that are located within the vacuum carrier. It is an issue, however, that the vacuum in the vacuum carrier disturbs the provision of through- holes when using punching.

In a first embodiment, this is solved in that the vacuum is applied only locally in the vacuum carrier, i.e. in a first area. The first area suitably extends throughout the vacuum carrier around locations for the through-holes. However, it is not excluded that a second area and

optionally further areas are defined for the application of the vacuum. Preferably at least one area extends

substantially along both a length and a width of the first foil, for instance as an annular ring, in a L-shape, a T- shape, a S-shape, a V-shape, a W-shape, a 0-shaped (i.e.

filled field) or the like. The tools are preferably punching or cutting tools.

In an alternative embodiment, through-holes may be provided chemically or optically, i.e. by local application of an etching material or by irradiating. Means for

disposing chemicals and/or irradiating means may be provided within the vacuum carrier. This has the advantage that the vacuum need not be local. However, a local application of vacuum is not excluded. Furthermore, the through-holes may be defined with smaller dimensions and/or at mutually reduced distances. Irradiating with laser light or the like may locally remove the foil, typically due to liquefying or evaporating. Irradiating with a predefined wavelength may give rise to a structural change, such as cross-linking. The cross-linked areas may thereafter be selectively removed, as known from photolithography. Use may for instance be made of dipping or spraying of an etchant. Alternatively, such removal may be deferred until after the assembly onto the interconnect foil.

Thereafter, the first foil is transferred to the interconnect foil. This transferring is evidently preceded by a positioning step, so as to align the first foil and the interconnect foil. The transferring occurs by removal of the vacuum. Mere transfer turns out sufficient so as to arrive at a stack of foils on top of which solar cells can be provided. The presence of the through-holes appears

advantageous in this respect so as to get rid of any air in between of the two foils, though it is not deemed essential.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects of the invention will be further elucidated with reference to the figures, in which

Fig. 1 shows in a diagrammatical cross-sectional view solar panel of a first embodiment in accordance with the invention

The Figure is not drawn to scale and intended for illustrative purposes only, and diagrammatical in nature.

ELABORATED DESCRIPTION OF AN ILLUSTRATIVE EMBODIMENT

Fig. 1 shows in a diagrammatical and cross-sectional view a solar panel 10 of a first embodiment in accordance with the invention. The solar panel 10 is shown, for reasons of clarity, in a semi-manufactured state, wherein the individual layers 1-6 have not yet been laminated together. Moreover, the carrier table 7 is shown as part of the solar panel 10, whereas in a suitable embodiment of the invention, this is part of a manufacturing apparatus. The solar panel 10 thus comprises a stack of foils including an interconnect foil 6, a first foil of thermoplast material 4, a second foil of thermoplast material 2 and a cover plate 1. A plurality of solar cells 3 is present between the first foil 4 and the second foil 2. The first foil 4 is provided with through-holes 14, that are aligned with contact pads on the interconnect foil 6 and on the solar cells 3. It is observed that the contact pads are not shown in this figure.

Electrically conductive material 5 is provided on the interconnect foil 6 and at the location of said through- holes 1 . A module 8 of electronic components is integrated into the solar panel. Thereto, a recess 18 is provided in the carrier table 7, and a hole (not indicated with a reference numeral) is provided in the interconnect foil 6, at a location aligned with the recess 18. The module 8 is provided with a carrier 20 having a first side 21 and an opposite second side 22. An encapsulation 23 is provided on the first side 21, in which the electronic components (not shown) of the module 8 are encapsulated. Contact pads (not shown) are exposed on the first side 21 of the carrier 20 outside the encapsulation 23. Electrically conductive material 5 establishes a connection between the module 8 and the interconnect foil 6.

The solar panel is built up step-wise, for technical reasons staring at the interconnect foil 6. During assembly, the solar panel 10 (i.e. the stack of foils) is aligned and presented to the assembly line by the carrier table. The stack of foils remains on the carrier table 7 until it is ready for lamination. In order that the different steps may be carried out at different stations, the carrier table 7 is mobile, i.e. it is a moving table. Prior to lamination, the solar panel 10 is removed from the carrier table, which moves back towards the first end of the assembly line. For moving the carrier table 7, the equipment preferably

comprises moving means. Typical examples of moving means include a rail system, a band of typically rubber material, support frames with wheels. Most suitably, the carrier table 7 is provided with means for attachment to a rail or a support frame. Use may be made of mechanical means, i.e. an exposed edge or a plurality of hooks. Alternatively or additionally, use can be made of other means, such as the use of (electro) magnets, pressure contacts, and the like known to the skilled person. The moving means first of all smoothen transport between individual stations. Moreover, when properly chosen, the moving means constitute a

positioning reference. This is particularly the case in that the moving means and the carrier table are provided with mutually fitting features. Furthermore, the moving means are arranged such that the transport between individual stations has merely limited degrees of freedom, i.e. for instance only transport in the x-direction, no transport in y- direction and z-direction. Preferably, the moving means further include means for optically positioning a carrier table relative to a station. These means for positioning typically include optical sensors and alignment features. The optical sensors are suitably integrated in each of the stations, the alignment features are suitably integrated in the carrier table.

At a first station which may be a manual work station, an interconnect foil 6 is deposited manually. The

interconnect foil 6 is typically a material also known as a flexible PCB made of an epoxy or tape (f.i. polyimide based) material. The pattern of its conductors is preferably defined prior to the deposition. Other processes for

defining the interconnect foil are not excluded. Alignment of the interconnect foil is in the manual work station carried out by an operator with the use of for instance two microscopes. After the alignment step, vacuum can be

activated by means of a foot pedal.

An automatic lay up station for the interconnect foil 6 may be used alternatively. Use is made of a robot for picking up individual interconnect foils from a storage pile. Two storage positions are provided, enabling the lay up station to swap to another pile of interconnect foils as soon as the previous one is gone. Each interconnect passes a digital vision system which images the interconnect foil for optical alignment. Depending on the results, the robot will receive re-calculated coordinates for deposition of the interconnect foil upon the carrier table, resulting in a technical alignment that is adequate for the interconnect foil. While the interconnect foil is suitably provided with a hole at a location corresponding to the recess in the carrier table in advance of its provision on the carrier table, this can also be done in situ, i.e. in the lay-up station or directly thereafter.

In a second phase, the moving table moves to the next station, the interconnection unit. In this unit, the moving table will be positioned below an adapted screen printing device. This device will descend towards the interconnect foil. It will deposit a present amount of conductive

adhesive or solder paste on each contact pad. Suitably, an annular ring around the recess is filled completely with the anisotropically conductive adhesive, if thus applied.

Alternatively, filling material is put into the recess in the carrier table. The filling material preferably is made fluid (or is fluid) at a temperature lower than the temperature at which the adhesive will start spreading, in case adhesive is applied.

In a third phase, the modules of electronic components are assembled onto the interconnect foil. The modules are placed in a flip-chip orientation, with the carrier pads of the module and the interconnect foil facing each other and with the encapsulation extending into the recess. In the event that filling material has been applied in the recess in advance, it is deemed beneficial to carry out the

assembly at a temperature at which the filling material is liquid or viscous, i.e. able to spread, such that an

adequate electrical connection between the first foil and the interconnect foil is established. A test of the electric connection between the contact pads may be carried out using one of the other contact pads as a test pad. Suitably the modules of electronic components have also been pre-tested.

In a fourth phase, the moving table moves to the processing unit for application of the first foil of

thermoplast material, such as EVA. A thermoplast material is a polymer material, which is able to flow upon heating. It is more specifically a thermosoftening plastic, which turns into a liquid when heated and freezes to a glassy state when cooled sufficiently. In the context of the present

invention, the thermoplast material is to flow around the individual solar cells. Thereafter, the thermoplast material may be hardened by cross-linking. Such cross-linking is suitably initialized by means of irradiation at a predefined wavelength, for instance in the ultraviolet range. The processing unit unwinds the first foil, directly from a roll, cuts the first foil on a preset length and presents the first foil on a pick-up table. The first foil will be automatically picked up by means of a vacuum head and will be provided with through-holes on a step-by-step punching process. The pattern of through-holes exactly matches the grid of the contact pads, provided on the interconnect foill. After making of the through-holes, the first foil will be deposited upon the interconnect foil, leaving the conductive adhesive or solder paste free. It is important to observed that the pick-up table, also referred to as the vacuum carrier, provides vacuum locally. It includes pins or similar means for carrying out the punching process, which extends through the vacuum carrier. The local vacuum is not present at the location of such pins. Thereto, the vacuum carrier suitably comprises vacuum chambers and a venturi system for the generation of the vacuum.

In a fifth phase, the carrier table moves towards the cell placing unit, which is provided with, in this

embodiment, two robots. Each of the robots will pick up the solar cells out of one common cartridge. The cell placing unit is provided with a couple of cartridges, offering a buffer for solar cells. Picking up takes place with use of a Bernoulli nozzle system in order to reduce breakage. Each individual solar cell passes a digital vision system which will image the cells on the contact pads for optical

alignment. Depending on the results, the robots will receive re-calculated coordinates for deposition of the cells on the first foil. During optical alignment, the digital vision system will also inspect the cells on breakage (by imaging at least a part of the outer edges) and possible shifting printing patterns. By this process, the cells are touched only one time, thus reducing possible risk on breakage. Due to very careful handling, solar cells down to 130 micron thickness can be processed. Evidently, also solar cells with a larger thickness may be processed, for instance in the range up to 300 microns. It is not excluded that solar cells with a substrate thickness that is even further reduced, can be processed. Discarded cells will be collected into an empty cartridge for further inspection by the operator.

After placement of the cells upon the first foil, the carrier table moves through an optical inspection station, which checks on missing cells, alignment of cells and broken corners of cells. As soon as a problem is detected, the stack of foils is discarded out of the assembly line and placed on one of four repair stations. Above each repair station, a monitor is mounted, showing the problem spot for that particular stack of foils. After manual repair, the stack of foils is brought back into the assembly line at first possibility.

Subsequently, the moving carrier table moves towards the 2^nd EVA processing unit. In this processing unit, the second foil of thermoplast material is provided. This comprises the steps of unwinding the second foil, directly from a roll, cutting the second foil on a present length and presenting the second foil on a pick-up table. The second foil will be automatically picked up by means of a vacuum head which will deposit the second foil on top of the first foil and the solar cells.

The carrier table advances towards the glass placing unit, which is connected with a glass unpiling robot or glass washing machine. The glass sheet will be aligned based on the centre of the glass, which averages possible

differences in glass size. After alignment, a vacuum

pick&place unit takes the glass and places it on the second foil.

Thereafter, the carrier table proceeds towards the turn unit. Here, a clamp belt system turns upon the carrier table. As the solar panel is in between the belt and the carrier t able, it will be clamped. The turn unit takes the complete package and flips it over for 180°. The carrier table, which is now on top of the solar panel, will be lifted and finally, the clamp belt system conveys the solar panel out of the system, whereby the glass sheet is below and allows ease of transportation. In case that a glass plate or a ceramic or optionally polymer plate is used as the carrier table, such turning around is not deemed

necessary. The glass or ceramic plate is then part of the solar panel resulting from the manufacturing. A heat- conductive ceramic plate may be advantageous so as to enable heat dissipation during use. However, it has the

disadvantage of relatively high weight and possible

breakage. A polymer plate, such as an insert moulded body is less heavy, but needs to be sufficiently thermally stable for the lamination process. Moulding compounds with

sufficient thermal stability are however thermally

available .

The solar panel is now available for further

finalisation, like lamination, trimming, framing, flash- testing and sorting. The empty carrier table descends by a descend lift unit and moves back towards the begin of the line on a second transportation level. This level also buffers empty carrier tables which are not in use. At the begin of the line, an ascend lift unit brings the carrier tables back to the normal process height for a next round.

In summary, the present invention provides a method of manufacturing a solar panel, a resulting solar panel and an apparatus for manufacturing. The solar panel is manufactured by provision of a stack of foils on top of a carrier table. Individual solar cells are provided between a first and a second foil of thermoplast material. An interconnect foil is present between the first foil and the carrier table, connections to the solar cells extending through the first foil. At least one module of electronic components is integrated into the solar panel. The carrier table and the interconnect foil are provided with one recess, so as to leave space for the encapsulated components. This allows t assembly of the module to the carrier table prior to the assembly of the first and second foil and the solar cells. Contact pads on the interconnect foil for connection to th module are defined in annular ring around said recess. The annular ring is filled with a filling material so as to limit spreading of thermoplast material. An apparatus comprising a carrier table with a suitable recess is also provided .

Claims

CLAIMS 1. A method of manufacturing a solar panel provided with a plurality of solar cells, comprising the steps of:

dimensions of the solar panel;

- applying an interconnect foil provided with a pattern of electrical conductors and a plurality of contact pads on the carrier table;

material ;

- assembling the plurality of solar cells, each provided with contact pads, and applying a second foil of thermoplast material and a cover plate thereon;

2. The method as claimed in Claim 1, wherein the carrier table comprises a moving table suitable for moving said stack of foils in different stages of said method between stations for carrying out steps of the method. d in CI

foil on

ises th

foil to

ication

predefined locations;

transferring the first foil to the carrier table by removing the vacuum, and

removing the vacuum carrier from the carrier table.

4. The method as claimed in any of the previous Claims, wherein the carrier of the module is optically opaque or reflective and the lamination step comprises a first

illumination treatment in which the stack of panel is irradiated through the cover, such that the carrier protects the underlying filling material from spreading.

5. The method as claimed in any of the previous claims, wherein the filling material is applied as a layer or foil extending on at least substantially the complete first foil, and wherein the integration of the module comprises the step of heating at least a first portion of said filling

material, so that the module sinks into said layer of filling material.

6. The method as claimed in any of the previous claims 1 to 4, wherein the filling material is applied on the carrier of the module.

7. The method as claimed in Claim 5 or 6, wherein the filling material is an anisotropically conductive glue.

8. The method as claimed in any of the previous claims, wherein the filling material is applied as a layer or foil extending on at least substantially the complete

interconnect foil, and wherein the carrier of the module is provided, at a second side opposite to the first side, with a coating material structurally similar to the filling material .

9. The method as claimed in Claim 1 or 2, wherein the carrier table comprises a body in which the recess is defined and which constitutes part of the solar panel after the manufacture.

10. The method as claimed in Claim 1 or 2, wherein the carrier table is removed from the solar panel after

completion of the lamination step and comprises means for setting size of the recess.

11. The method as claimed in Claim 1 or 2, wherein the orientation of the solar panel is reversed after at least part of the lamination step, and the carrier table is removed after completion of the lamination step, therewith exposing the encapsulation of the module, after which removal a further protective layer is applied to the

encapsulation for defining a carrier for the solar panel.

12. The method as claimed in Claim 1 or 11, wherein the module further comprises terminals for external access to and from the solar panel, which terminal is exposed after completion of the laminating step.

13. A solar panel comprising a laminate of:

a carrier;

an interconnect foil provided with a pattern of

electrical conductors and a plurality of contact pads on the carrier;

a plurality of solar cells, each provided with contact pads, sandwiched between a first and a second foil of thermoplast material spread out to encapsulate the solar cells, which first foil is provided with a plurality of through-holes at locations corresponding to those of at least a subset of the contact pads of the solar cells and the interconnect foil; electrically conductive material present within said through-holes of the thermoplast material and coupling said contact pads of the solar cells and corresponding ones of the interconnect foil;

an optically transparent cover plate on the second foil;

characterized in that at least one module of electronic components is integrated into the solar panel, which module comprises a carrier with a first side, at which are provided an encapsulation with the electronic components and a plurality of exposed contact pads, for which integration the carrier table is provided with at least one recess and the interconnect foil is provided with at least one hole at a location corresponding to the recess and with contact pads within an annular ring around said hole, and which contact pads face the interconnect foil, said contact pads aligned to the contact pads in the annular ring around the hole of the interconnect foil, filling material being present between said annular ring and said carrier of the module, and the encapsulation extending into said recess.

14. An apparatus for use in manufacturing a solar panel provided with a plurality of solar cells, comprising a carrier table for assembly of the solar panel, with lateral dimensions at least the same as dimensions of the solar panel, which carrier table comprises a moving table suitable for moving said stack of foils in different stages of said method between units for carrying out steps of the

manufacturing of the solar panel and which carrier table is provided with a recess suitable for accommodating a top portion of a module of electronic components in an

encapsulation .

3D

15. The apparatus as claimed in Claim 14, wherein the carrier table further comprises vacuum means for providing a vacuum locally in and at a first surface of the carrier table, so as to hold any foils during manufacturing of the solar panel.

16. A method of manufacturing a solar panel provided with a plurality of solar cells, comprising the steps of:

dimensions of the solar panel;

applying a first foil of thermoplast material , which first foil is provided with a plurality of through-holes at locations corresponding to those of at least a subset of the contact pads;

material ;

wherein application of the first foil on top of the

interconnect foil comprises the steps of: attaching the first foil to a vacuum carrier provided with means for application of vacuum;

providing through-holes in the first foil at predefine locations ;

positioning the vacuum carrier and the carrier table t each other, so that the locations of the through-holes are aligned with said contact pads of the said subset on the interconnect foil;

transferring the first foil to the carrier table by removing the vacuum, and

removing the vacuum carrier from the carrier table.

17. The method as claimed in Claim 16, wherein the vacuum is applied locally and outside the predefined locations for provision of the through-holes.

18. The method as claimed in Claim 16 or 17, wherein the through-holes are provided with tools defined in the vacuum carrier .

19. The method as claimed in Claim 18, wherein the tool is a punching tool, a cutting tool, a light source or a disposer of a chemical agent.