WO2015056069A1

WO2015056069A1 - Method and system for forming laminates

Info

Publication number: WO2015056069A1
Application number: PCT/IB2014/002072
Authority: WO
Inventors: Jürg Zahnd; Thomas Söderström; Roman Polo; Roland Luethi; Matthias HÄNI
Original assignee: Meyer Burger AG
Current assignee: Meyer Burger AG
Priority date: 2013-10-15
Filing date: 2014-10-13
Publication date: 2015-04-23
Anticipated expiration: 2016-04-15
Also published as: CN105612056A

Abstract

The invention relates to methods and systems for forming the lay-up of a solar module (6), encapsulant of the module being at least partially provided as granules (2) in a structured manner. The lay-up (16) is introduced into the laminator (15) with the granules still is this form.

Description

METHOD AND SYSTEM FOR FORMING LAMINATES

[001] The invention relates in general to methods for making laminates such as solar modules, LED light panels and glazing and systems for carrying out these methods.

[002] The inventive method and system are especially suited for making solar modules that are laminated. It is suited for all technologies such as mono- and poly-crystalline solar cells and thin film technologies. The invention enables the use of a minimum of materials used as encapsulant while also reducing the effort needed to make these materials. In addition problems during lamination are counteracted. Even though the invention is mostly described in relation to solar modules, the same drawback, advantages, considerations etc. hold for other laminates with and without active components and can thus apply mutatis mutandis to those laminates as well.

[003] Most solar modules are manufactured by forming a laminate consisting of a glass plate, photo-active elements and a back cover made of glass or formed as a back sheet. These layers are held together to form a laminate by so-called encapsulants: materials adhere to the layers an fill any gaps in the laminate such as spaces between solar cells. These encapsulants may for example contain duroplasts such as EVA, TPSEs (Thermoplastic silicone elastomers), TPUs (thermoplastic polyurethane), TPOs (Thermoplastic polyfin elastomers), lonomers or thermoplasts such as PVB, silicon or polyolefin. Encapsulants are chosen based on many factors such as cost, place and function in the module (e.g. encapsulant on sunny side of the solar cell must be more transparent than the encapsulant on the shadows side), market expectance etc.

[004] Solar cell (photovoltaic) modules are typically constructed as a laminate with at least five layers in this order: (a) glass layer or other transparent Layer, (b) a first or front encapsulant layer, (c) the solar cell layer, (d) a second or back encapsulant layer, and (e) a back layer such as a back sheet or a glass layer. The manufacturing method of laminated solar cell modules generally involves placing a piece of encapsulant foil between the solar cell(s) and the other module layers, such as the glass layer and the back- layer. The state of the art uses foils of_400=500 m.-The encapsulant layers are designed to encapsulate and protect the brittle solar cell layers from environmental damage and therefore prolong their useful life. Generally, a solar cell module will incorporate at least two encapsulant layers sandwiched around the solar cell layer. The two encapsulant layers can be the same or different materials.

[005] Nowadays, the encapsulant is usually placed in the lay-up before lamination in form of a foil. The lay-up being mainly all materials (except for materials that are cut off after lamination) later formed into the laminate such as a solar panel forming multiple layers. WO201 1089473 discloses the laminating process of a solar panel in detail.

[006] The foil has to be cut, handled and placed correctly on the lay-up. Since modules are quite large this is cumbersome. Also the foil has to be placed in the lay-up correctly and may not shift. This may go wrong resulting in economic loss. Also, foils shrink during lamination. This is due to the production process of the foil. Moreover, it results from liquefying polymer granules and turning that into foil. In addition raw material gets lost during production of the foil, resulting in additional cost.

[007] For the former two reasons (alignment and shrinkage), the foils need to be made bigger than the final module. After lamination the foil (or what is left of it, a sticky mass) sticks out of the module and has to be removed which is not easy until the encapsulant becomes hard after a while, prolonging processing time. Also as long as the protruding foil is soft, it sticks to machine parts such as the conveyer belt it lays on and the membrane used for pressing it together that thus have to be cleaned regularly. Brushes can be provided for this purpose.

[008] Another problem with foils is that they have uniform thickness whereas components in the laminate such as solar cells and ribbons interconnecting them vary in thickness. This leads to the effect that encapsulant pushes them aside during lamination (cell swimming) as it becomes soft and flows to fill all voids in the laminate. This may cause the cells to move, leading to defective or at least aesthetically unacceptable or lower-grade modules. Foils also do not counteract edge-compression: edges of the module being compressed more than the rest of the module. [009] Also known from the state of the art is to apply encapsulant in liquid form; such is shown for example in US2011256657A1. This is an improvement relative to the usage of foil, has however some drawbacks: The machines for melting and handling the encapsulant are expensive and complicated. Also molten encapsulant is hard to handle and tend to contaminate the manufacturing equipment and other module materials easily. Changes to the machines are hard to make, because the sticky encapsulant must be removed first. In addition such machines get clogged when not kept on high enough temperature (which may alter the chemical composition of the encapsulant) requiring extensive cleaning when it is temporarily (e.g. overnight) not used.

[010] From WO94/29106 A1 it is known to use granules (also called pellets) as encapsulant. This does overcome some shortcomings of foils and liquid encapsulation; it however does not provide a solution to prevent edge-compression and cell swimming during lamination.

[01 1] An object of embodiments of the present invention is to reduce or prevent the loss of encapsulant during assembly and manufacture of the laminate and hence to reduce the material and manufacturing cost of laminates such as solar modules while counteracting cell swimming and edge- compression, especially when both outer layers are made of glass. An advantage of embodiments of the present invention is that when only the amount of encapsulant finally required for the module is used in the lamination process, costs can be saved. Also the pre-lamination step of making the polymer granules into a foil, cutting the foil to the right size (e.g. to fill gaps or form ridges) and handling the foil or snippets thereof can be omitted, further reducing costs. Since such snippets shrink as well during lamination, they are hard to keep in position during lamination. Especially when filling (many) small voids, necessitating lots of small snippets, the cutting and handling becomes very cumbersome. An advantage of embodiments of the present invention is that a way of providing an encapsulant to the lay-up is disclosed at just the right amount and in the right place without cutting foil or adapting an application nozzle. Further, an advantage of embodiments is that machine tools getting dirty and the need to be cleaned can be avoided, which increases the uptime of the machines. Also the production line does not have to be tailor-made to the size of the module, which is normally the case with foils and curtain coating equipment. A further advantage of granules that they are easy to mix. In this way a production plant only needs a few different types of granules to manufacture modules with completely different designs. And that without the need of complex mixing equipment: the granules may be mixed by any suitable mixer or other mechanical mixing means or only "mix" as they are applied to or lay on the lay-up.

[012] These goals are met by the inventive methods and systems according to the claims.

[013] The inventive for forming a laminate such as a solar module is characterized by comprising the steps of forming a lay-up containing at least a first outer layer, a first encapsulant layer in the form of granules and a second outer layer, and pressing the lay-up together under the influence of heat and vacuum, preferably in a laminator to form the laminate, wherein the encapsulant in the form of granules is applied in structured manner. The term "structured manner" as used in this document means that granules are applied more, in this document meaning in greater amount (e.g. by weight or volume), per unit of area to a first portion than to a second portion or that granules of a first sort are applied to one region while granules of a second sort are applied to a second region. The first and second regions normally not overlapping, but this option is not excluded. The granules may be applied more per unit of area to a first portion than to a second portion. This is for example beneficial when filing gaps between photo-active elements in the lay-up.

[014] According to the invention the lay-up is introduced into the laminator with at least some, preferably all granules mainly still is this form. [015] According to the invention the encapsulant may thus be applied exactly in the quantity and/or quality needed. This may be calculated by calculating the volume required for filling all space between the two outer layers, given the final thickness of the laminate or it may be an empirical fact. The distribution (both of the quantity and the consistency of the granules) may be such as to define the flow of the encapsulant during lamination. The photo-active elements may be or contain any of photovoltaic devices such as crystalline solar cells (necessitating a mesh to fill gaps between cells), thin film solar cells, leds (the latter two primarily necessitating addition granules to prevent edge compressing), all required to contact and interconnect them or any combination thereof. The photoactive elements may also contain electronic components such as bypass diodes or other active components. . LEDs may be used for example for lighting elements, displays etc. The structure may be formed using granules of different types, such as different sizes, shapes, consistency etc. [016] With granules or particles any particle form is meant. Typically the granules have a diameter smaller than 10mm, preferably smaller than 5mm. The granules preferably result from the manufacturing process, normally containing a compounding or mixing step to add additives to obtain the desired chemical and physical properties. [017] Normally the lay-up is made by placing a glass plate on a base and placing on top of that the other materials. According to the invention the lay-up may be formed from a glass plate, first encapsulant in the form of particles, a matrix of solar cells, second encapsulant in the form of particles and a back sheet of a second glass plate. For thin film solar modules, where the photoactive component is formed on the glass plate, that may be a substrate or a superstrate, only one layer of encapsulant in the form of particles may be applied followed by a second glass plate or back sheet. The terms particles and granules are used interchangeably in this document.

[018] After the lay-up has been made, it is heated and pressed together to form the laminate. In order to prevent air from being trapped inside the laminate, this process is normally carried out under vacuum or a protective atmosphere in so-called laminators. Note that according to the invention as the lay-up enters the laminator, the encapsulant still at least partially consists of granules or particles. Surprisingly the space between the particles of the encapsulant can be evacuated fast enough so that the lamination time is not pro-longed. As known from the state of the art, the lay-up may be heated by any known means such as hybrid heating (using circulated oil and heat coil), heat coils, infra-red, microwaves etc. Vacuum in this document meaning a low enough pressure, say smaller than 250 mbar preferably smaller than 150 mbar, and it may be formed in a chamber of the laminator or inside a bag, both as known according to the state of the art.

[019] By "forming a lay-up" the placing of the layers of the lay-up on each other is meant.

Normally this is done by piling up the layers in vertical direction.

[020] Granules can be applied to the lay-up much more efficiently than e.g. stripes of foil that need to be cut to the right size (accounting for shrinkage) or dots of soft (e.g. molten) encapsulant that first needs to be made soft and is much harder to handle. The granules can be applied simply using granule application means (in this document also called means for distributing encapsulant in the form of granules or granule dispenser) such as a hopper, extruder or a spiral screw. One main advantage being that all these devices can be stopped and turned on without any problem such as the rick of the material hardening and clogging the device. Therefore no cleaning is required to prevent this.

[021] Other advantages are that granule application means are fast and their position and the amount of granules they apply can be controlled electronically and very accurately. A foil may be cut in the same efficient way, but the handling (picking up, storing and placing) of the pieces afterwards is much more difficult. In addition material is lost because the foil hast to be made first, resulting in loss of material, and the foil cannot be used completely since the pieces will normally not cover the complete shape of the foil leading to waist foil that cannot be used. Granules that are not used can simply be re-introduced into the granule application means and thus be used for any module shape and design. Foils that have been cut for a certain design cannot be used for another design. [022] The granule application means may have different dispensing openings depending on the module design, normally however, this is not needed.

[023] In addition to the structured granules, the granules may form a homogenous mass after lamination over large areas of the laminate, say over at least 50% more preferably over at least 80% of the surface. Moreover, its physical, especially optical properties do not vary over this range, enabling an aesthetically pleasing module with defined optical properties. Especially the

transmission of electromagnetic radiation (going into or out of the laminate) should be constant over this range.

[024] The structured granules may be applied to any part of the lay-up selected from the group consisting of a first outer layer, a first encapsulant in the form of granules, foil or any other form, photo-active elements, a second outer layer or any combination thereof. Note that granules may beneficially be applied to a soft encapsulant layer (e.g. applied by curtain coating) since the granules are immediately fixated.

[025] If no photo-active elements or the like are present in the lay-up, the lay-up e.g. only consisting of two glass plates with encapsulant there between, granules may be applied the edge regions of the glass to prevent edge-compression.

[026] Preferably only one type or mixture of encapsulant granules is used per layer over the whole module. This is especially beneficial when using only granules as encapsulant for a certain layer or even for the complete module.

[027] Preferably the granules form the encapsulant and are the adhesive holding together the at least two preferably all layers of the module. After lamination they preferably form one single mass holding the other layers of the lay-up.

[028] During lamination the encapsulant granules change shape as they become softened or even liquefied to fill the voids in the module.

[029] Preferably the lay-up comprises at least one photo-active element for forming a solar module, a (led) lighting element, a display, a back lighting etc. Depending on the application, also circuitry needed to transport power to and/or away from the photo-active elements may be comprised. [030] Preferably at least one, preferably both outer layers of the lay-up are transparent for electromagnetic radiation, preferably transparent to the human eye, thus making the laminate is at least partially transparent to let light fall on the photo-active element or let light from the photo-active element leave the module. At least one side of the laminate thus giving a view to the layer formed by the granules. Surprisingly it was found that the granules during lamination are formed into one homogenous layer without inclusions (for example bubbles) or optical irregularities. The resulting laminate according to the invention thus obtains a visually pleasing appearance while providing the above mentioned benefits.

[031] The encapsulant in the form of granules applied in structured manner may form ridges or crests, e.g. making straight lines or a mesh.

[032] The granules may in an inner surface portion of the lay-up be applied more per unit of area to a first centre portion than to a second centre portion, preferably at least 1.5 times as much, even more preferably at least 2 times as much and/or the first centre portion and the second centre portion containing granules of a different sort. In this way different effects (e.g. cell swimming) may be counteracted by choosing the right amount or right sort of granules.

[033] The granules are preferably applied more per unit of area to a circumference portion, preferably mainly the complete circumference of any of the first outer layer, the second outer layer or both than to an inner surface portion thereof, preferably at least 1.5 times as much, even more preferably at least 2 times as much, e.g. in order to counteract edge-compression and/or the circumference portion and the inner surface portion may contain granules of a different sort, preferably granules applied to the circumference portion having a higher viscosity than the granules applied to the inner surface portion. Ideally more granules of higher viscosity are applied to the circumference portion to completely counteract edge compressing.

[034] Especially the corners of the outer layers need additional granules and/or granules of higher viscosity to prevent edge-compression. In addition or alternatively the first centre portion and the second centre portion may contain granules of a different sort, as was described above. [035] In this document "x times as much" meaning that the amount of granules per unit area is multiplied by x. The amount preferably being the weight of all the applied granules of a sort. Since weight is strongly related to the number and volume of the granules, it may also be the number or volume of granules that is compared. In this document sort meaning having different physical properties such as viscosity or size or even different chemical consistency (different materials). As used in this document "A and/or B" means only A, only B or both A and B. [036] As used here "viscosity" is the viscosity of the granules at elevated temperatures (above room temperature), such as above 100°C or above 130°C) when they are softened or even liquefied such as during lamination. When comparing viscosities of two sorts of granules they have the same elevated temperature.

[037] As measured per unit of surface area e.g. of an outer layer, ridges or crests (in this document meaning the same) have more granules (e.g. in terms of number of particles or of mass) per unit of surface area then other regions where no such ridges are formed. Ridges and crests may be elongated or be spot-like and form patches.

[038] Preferably one outer layer is made of a stiff material such as glass. Also polymers such as poly carbonate or fibre reinforced polymers may be used. The danger of such stiff outer layers is that the heat transfer between granules and outer layer and also between outer layer and the rest of the lay-up is impaired. Also, applying pressure to the stiff outer layer may cause damage to the one photo-active element since the granules would induce large local forces on the photo-active elements. It nevertheless was found that using the right recipes for the laminator (vacuum, pressure and heat as function of time) results in qualitatively good and optical pleasing laminates and modules.

[039] Preferably the lay-up is further formed of a second encapsulant in the form of granules), preferably applied in structured manner, the first and second encapsulant in the form of granules being on opposite sides of the at least one photo-active element in the lay-up. The first and second encapsulant may for example be applied in layers. In this way, no foil is needed at all, thus leading to the described advantages. The lay-up may thus be formed by distributing the particles of the encapsulant on a glass plate, placing the matrix on top of the particles, applying a second layer of particles and then applying a back sheet or second glass plate. The particles of the first and second layer will thus merge between and next to the solar cells forming one thicker layer.

[040] If desired, the lay-up may be partially formed of a foil, preferably being any of an encapsulant foil (encapsulant serving to join two adjacent layers) and a foil for holding

interconnectors for the at least one photo-active element or any combination thereof. In this way a foil used for holding interconnection wires, as for example known from EP1547158, may be combined with the advantages of the present invention. Also, if desired the foil may be an encapsulant for example in the case where this foil does not suffer from shrinkage or if it is not readily available as granulate.

[041] Preferably the encapsulant in the form of granules, the foil or both is applied in structured manner. By (spatially) structuring the encapsulant spatially voids between the cells and ribbons can be filled, thus counteracting the movement of cells during lamination and edge compressing. Foil may thus be combined with local larger amounts of granules (forming structure) or the granules may be distributed equally and patches of foil may be used to locally increase the amount of encapsulant. Any combination of the two is also possible.

[042] It was found that especially a lay-up containing, in this order from bottom to top, a glass plate, an encapsulant foil, a solar cell matrix, granules, a second encapsulant foil and a second outer layer in the form of a glass plate or back sheet, provides a useful solution against cell drift and edge- compression for existing production lines. The granules may also be applied before, after or before and after the solar cell matrix.

[043] In order to prevent the particles from moving about the method further comprising the step of fixating at least two materials of the lay-up relative to each other prior to pressing the lay-up together under influence of heat and vacuum, preferably by electro-statically charging of any of the materials of the lay-up, heating any of the materials, dispensing an adhesive or solvent on any of the materials, applying ultra-sound to any of the materials or any combination thereof.

[044] At this stage in the process of forming the lay-up, the granules may be partially or temporarily fixed to the base (e.g. glass plate) so that they do not move during further transport. This may be done by heating them (for example by heat directly, by irradiation, ultra-sound) charging them or other parts of the lay-up electro-statically or any other suitable manner. They may also be fixated by spraying a (sticky) material on them. Note that the layers of the lay-up may be heated (pre-heated) prior to being placed on the lay-up. In that way the granules would for example stick to the glass plate right away without the need of heating the glass or granules as they are part of the lay-up for making the stick. Of cause, during the lamination step, the materials are heated more and formed into a laminate.

[045] The particles may have any shape and will normally have irregular shapes and sizes.

Preferably the encapsulant in form of granules contains granules with a diameter between 0.01 mm and 2 mm, preferably between 0.02 mm and 1 mm even more preferred between 0.05 mm and 0.5mm, preferably more than 50% of the granules having a diameter in this range, even more preferred at least 80%. Even more preferred the encapsulant in form of granules with an average diameter between 0.01 mm and 2 mm, preferably between 0.02 mm and 1 mm even more preferred between 0.05 mm and 0.5mm. By using particles or granules as they result from the manufacturing process, normally containing a compounding or mixing step to add additives, omits losses for turning them into a foil. Also the effort needed for making a foil (transport, heat, facilities, etc.) completely is no longer needed. In addition during module manufacturing there is no need to heat the granules prior to lamination for example such as with liquid application. Meaning that they will not start reacting (for example in the case of duroplasts) and they can be used right away, without the need to heat them up, except for what was explained in relation to fixating the granules in the module. In addition, the handling of granules at room temperature is much easier than in molten state since they do not stick to the equipment (cleaning up and keeping the production line clean is much easier) and do not pose a danger to operators.

[046] With the diameter of the granules the diameter of the smallest sphere enclosing a granule is meant. If the granules are too large, the heat transfer in the lay-up will be impaired and the lamination process will take too long. Making the granules too small will cause problems during evacuation of the lamination chamber because the flow of air will transport the granules out of the lay-up.

[047] The granules or particles can be of any material such as duroplasts, thermoplasts, crosslinking materials, two-component encapsulants, adhesives, resins and acrylic polymers or any combination thereof. These materials may be rnixed or-may-form different-layers or-parts thereof: Depending on the desired module design the encapsulant in form of granules are chosen from the group consisting of EVA, PVB, Silicon, TPO, PO, lonomer and TPU or any combination thereof.

[048] Preferably the inventive method further comprises at least one of the following steps, preferably all of the following steps, even more preferably in this order: supplying a first outer layer as bases for the lay-up, distributing encapsulant in form of granules on this first outer layer, preferably placing the at least one photo-active component on the encapsulant in form of granules, distributing encapsulant in form of granules for a second time and placing a second outer layer on the lay-up.

[049] Preferably more granules are applied per unit of surface area between two photo-active components and/or near an edge portion of the at least one photo-active component than to an inner portion of at least one of the photo-active components, preferably at least 1.5 times as much, even more preferably at least 2 times as much, the granules preferably forming straight lines parallel to edges of the photo-active components, even more preferably forming a mesh or grid.

[050] The inner portion or inner surface portion of the lay-up or laminate is the range more than 2cm, preferably more than 5 cm away from the edge of the lay-up. The inner portion of the photoactive component is any portion thereof that does not contain an edge portion. The edge portion being a portion directly adjacent the edge of the photo-active component. The inner portion or inner surface portion of the photo-active component is the range more than 0.5 cm, preferably more than 1 cm away from the edge of the lay-up. [051] Preferably granules with lower viscosity are applied between at least two adjacent photoactive components or near an edge portion of the at least one photo-active component as compared to the viscosity of granules applied to an inner portion of at least one of the photo-active

components, preferably at least 1.5 times as low, the low viscous granules preferably forming straight lines parallel to edges of the photo-active components or an edge portion of the lay-up, even more preferably forming a mesh or grid.

[052] As used in this document, the granules with low or lower viscosity may have a viscosity lower than 6,000 Pa s, preferably lower than 5,000 Pa s, even more preferably about 4,000 Pa s. Typically the viscosity not being lower than 2,000 Pa s. As used in this document, the granules with high or higher viscosity may have a viscosity higher than 7,000 Pa s, preferably higher than 10,000 Pa s, even more preferably over 13,000 Pa s. Typically the viscosity not being higher than 16,000 Pa s.

[053] Since it is the ratio of the viscosities of the used granules that determines the fluidic behaviour during lamination, the absolutej/aLues may be chosen to optimize other features suclr as duration of the process, life-time of the laminate or aesthetical appearance such as avoiding bubbles in the laminate.

[054] In order to prevent the photo-active component from moving (called cell swimming for solar cells) during lamination, patches of granules of higher viscosity (meaning island of granules of higher viscosity surrounded by granules of lower viscosity) may be formed on the at least one, preferably mainly all photo-active components. Since these patches flow more slowly as compared to the materials around it, they will show little lateral movement and mainly only fill local voids such as voids between the granules or around small photo-active components.

[055] The granules with higher and lower viscosity may have a higher respectively lower viscosity than other materials such as an encapsulant foil or foil for holding interconnection wires that are softened when the laminate is pressing together under the influence of heat and vacuum. Important is that the flow properties of these foils have the same relation to the granules as granules would have to reach a certain desired behaviour. Therefore "granules with a higher viscosity than granules with a lower viscosity" is understood to also include "granules with a higher viscosity than the viscosity of another material that is softened during lamination with a lower viscosity" and vice versa.

[056] In this document "near" may both mean close to and overlapping the edge and close to and not overlapping the edge of the photo-active component. Applying "more granules per unit of surface area" means that after application more granules per unit of surface area are present on the surface than in another area it is compared to. [057] Preferably at least some voids between the photo-active components, such as cells and ribbons are filled with granules, such as near the edges solar cells or the corners of pseudo-square solar cells, preferably more granules being applied to those voids than to other regions per unit area and/or granules being applied to the voids with lower viscosity than granules applied to other regions. This will prevent cell swimming in an easy manner, as previously described. [058] Alternatively to applying more or fewer/less granules per unit of area, the granules may be structured by applying different types of granules, such as granules of different size (and thus thermal properties during lamination) and/or different consistency (such as viscosity). In this way cell swimming and edge-compression may be prevented by applying more mass (denser granules or granules that are smaller) to one region than to another. The advantage being that no or smaller ridges need to be formed (preventing local pressure peaks) or ridges are formed that behave differently during lamination. Ridges of smaller granules may e.g. collapse faster due to better heat transport, making them melt faster.

[059] In a further aspect of the invention a system is provided for making a laminate, preferably a laminate as described above, according to, comprising means for forming a lay-up comprising means for holding a first layer of the lay-up, first means for applying granules of a first sort in a structured manner on the first layer, preferably a hopper, means for heating up the lay-up, means for pressing the lay-up together and means for applying a vacuum to the lay-up, preferably the heating, pressing and vacuum means being integrated in a laminator. [060] In this document "on the first layer" also including applying granules to any other layer or granules on top of that first layer. The first layer normally being formed by a glass plate.

[061] A hopper being a storage container used to dispense granular materials through the use of a chute to restrict flow, sometimes assisted by mechanical agitation. The means for applying granules in a structured manner may be movable over the means for holding a first layer of the lay- up, the movable means for applying granules in a structured manner preferably being controlled by a controller. By moving the means for applying granules in a structured manner over the means for holding a first layer of the lay-up, that may comprise transporting means, the granules may be applied in any desired structure.

[062] Preferably the system further comprises second means for applying granules of a second sort in a structured manner on the first layer, these second means for applying granules preferably being movable over the means for holding a first layer of the lay-up preferably being controlled by a controller. The first and second means for applying granules thus can apply granules of different sorts, thus being able to create a structure based on different types of granules and/or based on the amount. Preferably each sort or type of granule used has at least one means for applying granules of that sort in a structured manner.

[063] The first and/or second means for distributing encapsulant in the form of granules may respectively for example be mounted on or comprise a robot or the like to be movable so that the structure and the amount of granules that are applied to the lay-up can be controlled using the controller. [064] The outlet of the first and/or second means for applying granules may comprise a mask for defining regions where the granules can leave the outlet. The first and/or second means for distributing encapsulant may be automatic, semi-automatic or handheld. Preferably the system further contains means for handling a second outer layer. Also means for handling the photo-active elements such as a solar cell matrix or web of leds may be provided.

[065] Preferably the inventive system further comprises means for fixating at least two materials of the lay-up relative to each other, upstream of the means for pressing the lay-up together and the means for applying a vacuum to the lay-up, preferably these means containing means for electrostatically charging or de-charging of any of the materials of the lay-up, means for heating any of the materials, means for dispensing an adhesive or any combination thereof, so that the location of the granules may be fixated at least temporarily so that the lay-up may be transported more easily and also air flows in the vacuum chamber do not remove granules from the lay-up.

[066] Additional means for distributing encapsulant in the form of granules may be provided for applying granules of a different type, such as different sizes, consistency etc. as was explained above in a non-structured manner.

[067] Further details of the invention are indicated in the figures, figure description and in the dependent claims. The list of reference marks forms part of the disclosure. The invention will now be explained in more detail in relation to embodiments shown in the drawings. In the drawings:

Fig. 1 shows a glass plate as outer layer of a module

Fig. 2 shows the glass plate from figure 1 covered with structured granules

Fig. 3 a matrix of photo-active components such as solar cells placed on the granules

Fig. 4 shows a layer of granules placed on top of the photo-active components

Fig. 5 shows a second glass plate as second outer layer of the lay-up

Fig. 6 schematically shows cross-sectional view of a lay-up

Fig. 7 shows a cross-section of a lay-up partially consisting of a foil

Fig. 8 shows a cross-section of a laminated lay-up

Fig. 9 shows a flow-chart of an embodiment of the inventive method for forming a lay-up

Fig. 10 shows a production line for making the lay-up and forming a solar module

Fig. 11 schematically shows a side view of lay-up with ridges of granules

Fig. 12 schematically shows a 3D-view of lay-up with ridges of granules

[068] The present invention will be described with reference to exemplary embodiments and the present invention is not limited to a particular embodiment or component parts thereof, except as defined in the appended claims. Embodiments of the present invention may be used with a variety of methods and systems. It will be apparent to one skilled in the art that the present invention may be practiced in a variety of ways within the scope of the claims. Any feature shown in relation to the figures may be applied in general to the invention as described in the claims.

[069] As used herein, the indefinite article ("a", "an") denotes the presence of at least one of the referenced item, and the terms multiple and 'a plurality' denotes the presence of more than one. [070] Figure 1 schematically shows a glass plate 1 that forms a first outer layer of a lay-up 16, e.g. for a solar module, to be produced. In this embodiment it forms a base for the lay-up. In figure 2 it is shown that an encapsulant 2 in the form of granules is distributed over the glass plate 1. In an edge portion 23 of the glass plate 1 the granules are distributed evenly. In an inner surface portion 24 a first centre portion 25 has more granules per unit area than a second centre portion 26, preferably at least 1.5 times as much ,_even-more preferably at least 2 times as much.

[071] At this stage in the process of forming the lay-up, the granules may be at least partially or temporarily fixed to the base 1 so that they do not move during further transport. This may be done by heating them (for example by heat directly, by irradiation, ultra-sound) charging them or other parts of the lay-up electro-statically or any other suitable manner. They may also be fixated by spraying a (sticky) material or solvent on them.

[072] In figure 3 it is shown that photo-active components, e.g. a solar cell matrix 10 of solar cells 3 is placed on the granules 2. Not shown is how the solar cells of the matrix are interconnected since this is commonly known. Also other electrical parts such as diodes, connectors for the junction-box etc. are not shown. Again the position of the photo-active components and electrical components may be at least partially fixated using any suitable means as described before.

[073] The photo-active components 3 in the figures may also be seen as light emitting elements such as LEDs. The photo-active components 3 in the figures may also be left out completely, leading to two outer layers being adhered to each other as is e.g. the case for safety glass.

[074] In figure 4 it is shown that a second encapsulant layer 4 in form of granules is places on top of the photo-active components. Here also, this layer may be at least partially fixated using the means described above.

[075] Figure 5 shows the final lay-up with a second glass plate 5 forming the second outer layer. A cross-section of the thus formed lay-up is shown in figure 6.

[076] As mentioned above, the first and second encapsulant layer 2, 4 may contain granules of different sorts. This is depicted in figure 6 by the white and grey granules. The grey granules 27 have a higher viscosity than the white granules 28 and hold the photo-active components 3 in place during lamination while the white granules flow around the photo-active components 3 to form a solid laminate. [077] Figure 7 shows a lay-up with a foil 17 and an encapsulant in the form of particles 4. [078] Note that all drawings are not to scale for clarity.

[079] Figure 8 shows the lay-up after lamination. The photo-active components 3 are enclosed by the encapsulant 18 that now forms one solid mass. The encapsulant holds the outer layers 1 , 5 and the photo-active components 3. In all figures, the interconnectors of the photo-active components are not shown. Also wires for transporting power towards and away from the photo-active components are not shown.

[080] Figure 9 shows a flow chart for forming a lay-up according to the invention. First a glass sheet is provided as base for the lay-up. Then a first layer of encapsulant is distributedjDverJhe.. glass plate, in a structured manner if desired. If needed, the granules may be fixated relative to the glass plate so that they do not move during further transport, for example by heating them (for example by heat directly, by irradiation, ultra-sound, micro-waves), charging them or other parts of the lay-up electro-statically or any other suitable manner. They may also be fixated by spraying a (sticky) material on them. [081] Then the active components are placed on the formed lay-up. They may be fixated relative to the granules and/or glass plate forming the base as well in the above described manner. Then granules are distributed over the lay-up to form a second layer, in a structured manner if desired. They too may be fixated as described above. According to the invention at least the first or second layer has structure. Finally, a second outer layer is placed on the lay-up. This may for example be a glass plate or back sheet. Again its position may be fixated as previously described.

[082] Figure 10 shows a manufacturing line for solar modules according to the invention and especially for forming and laminating the lay-up as described in relation to figures 1 through 5 with the method described in relation to figure 10.

[083] Means for holding a first layer here contain a conveyor belt 7 that holds and transports a glass plate 1 for holding the other materials 10, 14 of the lay-up. It first passes underneath a granule dispenser such as a hopper 8 and a homogenous layer of granules is applied. A robot arm 9 places the cell matrix 10 onto the granules (not shown) and a second layer of granules is applied by first and/or second granule application means such hoppers 11 , 1 1'. Also the first hopper may be used for the second layer of granules by moving the lay-up backwards. The first and/or second granule application means 1 1 , 1 1' may each apply granules of different sort to the lay-up thus forming as structured layer. In addition the hoppers may each apply their granules in a structured manner.

[084] Means for electro-statically fixing materials of the lay-up 16 relative to each other are here realized as a device 12 for electrostatically charging the granules and the cell matrix 10, fixating them before a back-sheet 14 is placed on the lay-up 16 by robot arm 13, completing the lay-up 16. The completed lay-up is now transported to laminator 15 to be formed into a laminate such as a solar panel.

[085] Figure 11 shows a Lay-up 16 consisting of a first glass plat 1 , a first layer of encapsulant in form of granules 2, photo-active components 3, a second layer of granules 4 and a second glass plate 5. The granules of the second layer 4 are applied in a structured manner here forming ridges of granules19. The ridges 19 extend between and near edge portions 21 of the cells 3, extending out of the plane of the drawing. Fewer granules are provided in the inner portions 20 of the cells.

[086] As shown in figure 11 , the ridges 19 overlap with the photo-active components. According to the invention this is notnecessary-and the ridges may be applied near edge portions of the photoactive components without overlapping them. As measured per unit of surface area of the glass plate, the ridges 19 have more granules (e.g. in terms of number of particles or of mass) per unit of surface area.

[087] Figure 12 shows a first glass plate 1 with a first layer of encapsulant in form of granules 2 and photo-active components 3 on top of that first layer. In addition granules are applied in a structured manner by forming ridges 19 over edge portions 21 of the photo-active components 3, applying less granules to the inner portion 20 of the photo-active components 3. The ridges may be applied between all solar cells 3 and/or along the edge portion 23 of the first glass plate 1. In the figure only two (straight) lines of structured granules are shown for clarity. Inner portions 22 of the glass plate 1 , such as the portions covered by solar cells 3 will have fewer granules than the edge portions 23 of the glass plate 1 thus forming structure. Ideally the ridges 19 form a mesh or grid enclosing all photo-active components 3. In this way cell swimming and edge compressing during lamination can effectively be prevented, while maintaining the benefit of using granules.

[088] The invention is not restricted to the embodiments shown. Single or multiple combinations thereof are possible. Features of the shown embodiment may also be applicable to other concepts and embodiments, shown and not shown in the figures, and more particularly to the invention, especially as described in the claims. List of reference marks

1 First glass plate 13 Robot arm

2 First layer of encapsulant in 14 back-sheet

form of particles or granules 15 Laminator

3 photo-active components 16 Lay-up

such as solar cells 17 Foil

4 Second layer of encapsulant 18 Encapsulant

in form of granules 19 Ridges of granules

5 Second glass plate 20 Inner portion

6 Solar module 21 Edge portion

7 Conveyor belt 22 Inner portion of glass plate

8 Hopper 23 Circumference or edge

9 Robot arm portion of glass plate 24

10 Solar cell matrix Centre potion

1 1 First Granule application 25 First centre portion

means such as a Hopper 26 Second centre portion i r Second granule application 27 Granules with higher means such as a Hopper viscosity

12 means for fixating layers of 28 Granules with lower

the lay-up viscosity

29 Controller

Claims

1. Method for forming a laminate such as a solar module (6), characterized by comprising the steps of forming a lay-up (16) containing at least a first outer layer (1), a first encapsulant layer in the form of granules (2) and a second outer layer (5), and pressing the lay-up together under the influence of heat and vacuum, preferably in a laminator (15) to form the laminate (6), wherein the encapsulant in the form of granules (2, 4) is applied in structured manner (19).

2. Method according to claim 1 , characterized in that in an inner surface portion (24) of the lay-up granules are applied more per unit of area to a first centre portion (25) than to a second centre portion (26), preferably at least 1.5 times as much, even more preferably at least 2 times as much and/or the first centre portion (25) and the second centre portion (26) containing granules of a different sort.

3. Method according to any of claims 1 and 2, characterized in that granules are applied more per unit of area to a circumference portion (23), preferably mainly the complete circumference of any of the first outer layer (1 ), the second outer layer (5) or both than to an inner surface portion

(24) thereof, preferably at least 1.5 times as much, even more preferably at least 2 times as much and/or the circumference portion (23) and the inner surface portion (24) containing granules of a different sort, preferably granules applied to the circumference portion (23) having a higher viscosity than the granules applied to the inner surface portion (24) 4. Method according to any of the preceding claims, characterized in that at least one, preferably both outer layers (1 , 5) are transparent for electromagnetic radiation, preferably transparent to the human eye.

5. Method according to any of the preceding claims, characterized in that the lay-up (16)

comprises at least one photo-active element (3). 6. Method according to any of the preceding claims, characterized in that at least one outer layer (1 , 5) is made of a stiff material such as glass.

7. Method according to any of claims 5 and 6, characterized in that the lay-up (16) is further

formed of a second encapsulant in the form of granules (4), preferably applied in structured manner, the first and second encapsulant in the form of granules (2, 4) being on opposite sides of the at least one photo-active element (3) in the lay-up (16).

8. Method according to any of the preceding claims, characterized in that the lay-up (16) is further formed of a foil (17), preferably being any of an encapsulant foil, a foil (17) for holding interconnectors for the at least one photo-active element or any combination thereof.

9. Method according to any of the preceding claims, characterized in that the encapsulant in the form of foil (17) is applied in structured manner.

10. Method according to any of the preceding claims, characterized in the method further

comprising the step of fixating at least two materials (1 , 2, 3, 4, 5, 17) of the lay-up (16) relative to each other prior to pressing the lay-up together under influence of heat and vacuum, preferably by electro-statically charging of any of the materials (1 , 2, 3, 4, 5, 17) of the lay-up (16), heating any of the materials, dispensing an adhesive on any of the materials, applying ultra-sound to any of the materials or any combination thereof.

1 1. Method according to any of the preceding claims, characterized in the encapsulant in form of granules~(-2-4)-eontains-granules with-a-diameter-between 0:01 mm and-2 mrrvrpreferably between, 0.02 mm and 1 mm even more preferred between 0.05 mm and 0.5mm, preferably more than 50% of the granules having a diameter in this range, even more preferred at least

80%.

12. Method according to any of the preceding claims, characterized in the encapsulant in form of granules (2, 4) having an average diameter between 0.01 mm and 2 mm, preferably between 0.02 mm and 1 mm even more preferred between 0.05 mm and 0.5mm.

13. Method according to any of the preceding claims, characterized in the encapsulant in form of granules (2, 4) chosen from the group consisting of duroplasts, thermoplasts, crosslinking materials, two-component encapsulants, adhesives, resins and acrylic polymers or any combination thereof.

14. Method according to any of the preceding claims, characterized in the material of the

encapsulant (2, 4) in form of granules are chosen from the group consisting of EVA, PVB, Silicon, TPO, PO, lonomer and TPU or any combination thereof.

15. Method according to any of the preceding claims, characterized in that it further comprises at least one of the following steps, preferably all of the following steps, even more preferably in this order: supplying a first outer layer as bases for the lay-up (1), distributing encapsulant in form of granules (2) on this first outer layer (1), preferably placing the at least one photo-active component (3) on the encapsulant in form of granules (2), distributing encapsulant in form of granules (4) for a second time; and placing a second outer layer on the lay-up (5).

16. Method according to any of the claims 5 to 15, characterized in that more granules (19) are applied per unit of surface area between two photo-active components (3) and/or near an edge portion (21) of the at least one photo-active component (3) than to an inner portion (20) of at least one of the photo-active components (3), preferably at least 1.5 times as much, even more preferably at least 2 times as much, the granules preferably forming straight lines parallel to edges of the photo-active components (3), even more preferably forming a mesh or grid.

17. Method according to any of the claims 5 to 16, characterized in that granules (19) with lower viscosity are applied between at least two adjacent photo-active components (3) or near an edge portion (21 ) of the at least one photo-active component (3) as compared the viscosity of granules applied to an inner portion (20) of at least one of the photo-active components (3), preferably at least 1.5 times as low, the low viscous granules preferably forming straight lines parallel to edges of the photo-active components (3) or an edge portion of the lay-up (23) , even more preferably forming a mesh or grid. 18. Method according to any of the claims 5 to 17, characterized in that patches of granules of higher viscosity (27) being formed on the at least one photo-active component (3).

19. Method according to any of the claims 5 to 18, characterized in that, voids between photo-active components (3) are filled with granules, such as near the edges solar cells or the corners of pseudo-square solar cells, preferably more granules being applied to those voids than to other regions and/or granules being applied to the voids with lower viscosity than granules applied to other regions.

20. System for making a laminate, preferably according to any of the preceding claims, comprising means for forming a lay-up (16) comprising means (7) for holding a first layer (1 ) of the lay-up (16), first means for applying granules of a first sort in a structured manner (11 ) on the first layer (1) , preferably a hopper, means for heating up the lay-up, means for pressing the lay-up together and means for applying a vacuum to the lay-up, preferably the heating, pressing and vacuum means being integrated in a laminator (15).

21. System according to claim 20, characterized in that the means for applying granules in a

structured manner (11 ) are movable over the means (7) for holding a first layer (1 ) of the lay-up (16), the movable means for applying granules in a structured manner (1 1) preferably being controlled by a controller (29).

22. System according to claim 20 or 21 , characterized in that it further comprises second means for applying granules of a second sort in a structured manner (1 1') on the first layer, these second means for applying granules (11 ') preferably being movable over the means (7) for holding a first layer (1) of the lay-up (16) preferably being controlled by controller (29).

23. System according to any of the claims 20 to 22, characterized in that it comprises means for fixating (12) at least two materials (1 , 2, 3, 4, 5, 17) of the lay-up (16) relative to each other upstream of the means for pressing the lay-up together and the means for applying a vacuum to the lay-up, preferably these means (12) containing means for electro-statically charging or charging of any of the materials of the lay-up (16), means for heating any of the materials, means for dispensing an adhesive, means containing an ultra-sound generator or any combination thereof.