Manufacturing process for a photovoltaic module and corresponding manufacturing installation

Abstract

The manufacture of a photovoltaic module (10) includes the supply of a first layer (12) having a warped shape, the manufacture of a second layer (14) having a warped shape, and then the placement of a stack including further photovoltaic cells (16) and at least one encapsulation material (181, 182) in an assembly mold (20) varying between a closed configuration delimiting a predetermined air gap (26) and an open configuration.In an assembly step, where the closing configuration of the assembly mold (20) is adopted, the temperature within the stack is maintained at a functional temperature (Tfonc) between 70°C and 180°C, and preferably between 80°C and 150°C, for an assembly period adapted according to the at least one encapsulation material (181, 182) so that the at least one encapsulation material (181, 182) undergoes at least partial melting and creates an encapsulating assembly (18) capable of adhering on the one hand to the plurality of photovoltaic cells (16) and on the other hand to the first layer (12) and / or the second layer (14). Figure 3.

Description

Title of the invention: Method for manufacturing a photovoltaic module and corresponding manufacturing installation. Technical field of the invention

[0001] The present invention relates to the field of manufacturing photovoltaic modules, which comprise a set of photovoltaic cells electrically connected to each other, and preferably so-called "crystalline" photovoltaic cells, that is to say, those based on monocrystalline or multicrystalline silicon.

[0002] More specifically, the invention relates to a method for manufacturing a photovoltaic module and a manufacturing installation comprising the material elements for implementing such a method.

[0003] The invention can be implemented for numerous applications, particularly civil and / or military, for example autonomous and / or embedded applications, being particularly relevant to applications requiring the use of lightweight, glass-plate-free photovoltaic modules, especially those with a mass per unit area of ​​less than 5 kg / m², and a thin profile, particularly less than 5 mm. It can thus be applied to buildings such as homes or industrial premises (offices, commercial buildings, etc.), for example for roofing, for the design of street furniture, for example for public lighting, road signs, or electric vehicle charging, and even for mobile applications (solar mobility), particularly for integration on vehicles such as cars, buses, or boats, drones, and airships, among others.

[0004] The invention thus proposes a solution for manufacturing a lightweight photovoltaic module that is sufficiently robust and advantageously exhibits asymmetrical shapes. In the remainder of this document, an asymmetrical shape is defined as a non-planar, curved, convex, or concave shape, and more generally, a three-dimensional shape not oriented along a principal plane. State of the art

[0005] A photovoltaic module is an assembly of photovoltaic cells arranged side by side between a first transparent layer forming a front face of the photovoltaic module and a second layer forming a rear face of the photovoltaic module.

[0006] The first layer forming the front face of the photovoltaic module is advantageously transparent to allow the photovoltaic cells to receive light. It is traditionally made of a single sheet of glass, including tempered glass, typically with a thickness between 2 and 4 mm, classically around 3 mm.

[0007] The second layer forming the back face of the photovoltaic module can be made of glass, metal or plastic, among other materials. It is often formed by a polymeric structure based on an electrically insulating polymer, for example of the polyethylene terephthalate (PET) or polyamide (PA) type, which can be protected by at least one layer based on fluorinated polymers, such as polyvinyl fluoride (PVF) or polyvinylidene fluoride (PVDF), and having a total thickness of around 300-400 pm.

[0008] Photovoltaic cells can be electrically connected to each other by front and rear electrical contact elements, called connecting conductors, and formed for example by tinned copper strips, respectively arranged against the front faces (faces facing the front face of the photovoltaic module intended to receive a light flux) and rear faces (faces facing the rear face of the photovoltaic module) of each of the photovoltaic cells, or even only on the rear face for IBC type photovoltaic cells (for "Interdigitated Back Contact" according to the appropriate Anglo-Saxon terminology).

[0009] It should be noted that IBC-type photovoltaic cells are structures in which the contacts are made on the rear face of the cell in the form of interdigitated combs. They are described, for example, in document US4478879A.

[0010] Furthermore, the photovoltaic cells, located between the first and second layers forming the front and rear faces of the photovoltaic module respectively, can be encapsulated. Typically, the encapsulant chosen is an elastomer (or rubber) type polymer, and may, for example, consist of two layers (or films) of poly(ethylene-vinyl acetate) (EVA) between which the photovoltaic cells and the cell connecting conductors are arranged. Each encapsulant layer can have a thickness of at least 0.2 mm and a Young's modulus typically between 2 and 400 MPa at room temperature.

[0011] A classic example of a photovoltaic module 1 comprising crystalline photovoltaic cells 4 has thus been partially and schematically represented, respectively in cross-section on [Fig.1] and in exploded view on [Fig.2].

[0012] As described previously, the photovoltaic module 1 has a front face 2, generally made of tempered transparent glass approximately 3 mm thick, and a back face 5, for example made of a polymer sheet, opaque or transparent, single-layer or multi-layer, having a Young's modulus greater than 400 MPa at room temperature.

[0013] Between the front faces 2 and rear faces 5 of the photovoltaic module 1 are located the cells photovoltaics 4, electrically connected to each other by connecting conductors 6 and immersed between two front 3a and rear 3b layers of encapsulating material both forming an encapsulating assembly 3.

[0014] Fig.1A further represents a variant embodiment of the example in Fig.1 in which the photovoltaic cells 4 are of type IBC, the connecting conductors 6 being only arranged against the rear faces of the photovoltaic cells 4.

[0015] Furthermore, Figures 1 and 2 also show the junction box 7 of the photovoltaic module 1, intended to receive the wiring necessary for the operation of the module. Typically, this junction box 7 is made of plastic or rubber and is completely sealed.

[0016] Typically, the process for manufacturing the photovoltaic module 1 includes a step called vacuum lamination of the different layers described above, at a temperature greater than or equal to 120°C, or even 140°C, or even 150°C, and less than or equal to 170°C, typically between 145 and 165°C, and for a lamination cycle duration of at least 10 minutes, or even 15 minutes.

[0017] During this lamination step, the encapsulation material layers 3a and 3b undergo a fusion and come together to enclose the photovoltaic cells 4, at the same time as adhesion is created at all interfaces between the layers, namely between the front face 2 and the front layer of encapsulation material 3a, the front layer of encapsulation material 3a and the front faces 4a of the photovoltaic cells 4, the back faces 4b of the photovoltaic cells 4 and the back layer of encapsulation material 3b, and the back layer of encapsulation material 3b and the back face 5 of the photovoltaic module 1. The resulting photovoltaic module 1 is then framed, typically by means of an aluminum profile.

[0018] Such a structure has now become a standard which has significant mechanical resistance thanks to the use of a front face 2 in thick glass and the aluminium frame, allowing it, in particular and in the majority of cases, to comply with the IEC 61215 and IEC 61730 standards.

[0019] However, such a photovoltaic module 1 has the disadvantage of having a high mass, in particular a mass per unit area of ​​about 10 to 12 kg / m2, and is therefore not suitable for certain applications where lightness is a priority.

[0020] This high mass of the photovoltaic module 1 comes mainly from the presence of the thick glass, approximately 3 mm thick, forming the front face 2, the glass having a high density of around 2.5 kg / m² / mm of thickness, and from the aluminum frame. To withstand the stresses during manufacturing and also for safety reasons, for example due to the risk of breakage, the The glass is tempered. However, the industrial infrastructure for thermal tempering is configured to process glass at least 3 mm thick. Furthermore, the choice of a glass thickness of approximately 3 mm is also linked to a mechanical resistance to standardized pressure of 5.4 kPa. Ultimately, the glass alone thus represents almost 70% of the mass of photovoltaic module 1, and more than 80% when including the aluminum frame around photovoltaic module 1.

[0021] Also, in order to obtain a significant reduction in the mass of a photovoltaic module to allow its use in new applications requiring lightness and shaping, there is a need to find an alternative solution to the use of thick glass on the front face of the module, by new plastic or composite materials with the primary aim of significantly reducing the surface mass.

[0022] Thus, polymer sheets, such as polycarbonate (PC), polymethyl methacrylate (PMMA), polyvinylidene fluoride (PVDF), ethylene tetrafluoroethylene (ETFE), ethylene chlorotrifluoroethylene (ECTFE), or fluorinated ethylene propylene (FEP), can represent an alternative to glass. However, when only the replacement of glass with such a thin polymer sheet is considered, the photovoltaic cell becomes very vulnerable to shock, mechanical load, and differential expansion.

[0023] An alternative is the use of composite materials based on reinforcing fibers on the front surface, replacing standard glass. The weight reduction can be significant despite reduced transparency.

[0024] The replacement of the glass on the front face of photovoltaic modules has been the subject of several patents or patent applications in the prior art. Examples include French patent application FR2955051A1, US patent application US2005 / 0178428A1, and international applications WO2008 / 019229A2 and WO2012 / 140585A1. Other patents or patent applications have described the use of composite materials, such as European patent application EP2863443A1, and international applications WO2018 / 076525A1, WO2019 / 006764A1, and WO2019 / 006765A1.

[0025] However, none of these currently known solutions makes it possible to manufacture a photovoltaic module which, in addition to being lightweight (therefore glass-free) and resistant as required by the needs of practical applications and administrative standards, is shaped according to an oblique form, in particular typically shaped with a curvature which may be identical or different along two distinct axes of a reference frame associated with the photovoltaic module, and moreover produced in a simple, fast, efficient and economical way, and ideally using only recyclable materials. Object of the invention

[0026] The invention therefore aims to remedy at least partially the needs mentioned above and the disadvantages relating to the achievements of the prior art.

[0027] The invention thus relates, according to one of its aspects, to a method for manufacturing a photovoltaic module (10), comprising the following steps:

[0028] 1) supplying a first layer having an oblique shape, transparent and intended to form a front face of the photovoltaic module intended to receive a luminous flux,

[0029] E2) manufacturing a second layer having an oblique shape and intended to form the rear face of the photovoltaic module,

[0030] E3) Placement of a stack in an assembly mold, implementation after steps E1 and E2, in which:

[0031] i. the stack comprises the first layer, a plurality of photovoltaic cells arranged side by side and electrically connected to each other, the second layer and at least one encapsulation material, the stack being such that the at least one encapsulation material and the plurality of photovoltaic cells are located between the first and second layers,

[0032] ii. and the assembly mold has an ability to occupy a closed configuration and comprises a first rigid mold part defining a first left-shaped cavity complementary to the left-shaped cavity of the first layer and a second rigid mold part defining a second left-shaped cavity complementary to the left-shaped cavity of the second layer, the first mold part and the second mold part being such that, in the closed configuration of the assembly mold, the first mold part and the second mold part are separated by a predetermined gap and define between them a cavity suitable for receiving the stack,

[0033] E4) assembly, implemented after step E3, in which the configuration of With the assembly mold closed, the temperature within the stack is maintained at a functional temperature between 70°C and 180°C, and preferably between 80°C and 150°C, for an assembly period adapted according to the at least one encapsulation material so that the at least one encapsulation material undergoes at least partial melting and creates an encapsulating assembly capable of adhering on the one hand to the plurality of photovoltaic cells and on the other hand to the first layer and / or the second layer.

[0034] Some preferred but not limiting aspects are the following.

[0035] According to one embodiment, the first layer is formed in a thermal material moplastic.

[0036] According to one embodiment, the first layer is a first composite material formed from a first polymer and first fibers,

[0037] the first polymer being chosen from: ethylene chlorotrifluoroethylene (ECTFE), fluorinated ethylene propylene (FEP), ethylene tetrafluoroethylene (ETFE), polyvinylidene fluoride (PVDF), polymethyl methacrylate (PMMA), polycarbonate (PC), polyethylene terephthalate (PET), polyamide (PA), styrene acrylonitrile (SAN), polystyrene (PS),

[0038] and the first fibers being chosen from glass fibers, aramid fibers and / or natural fibers.

[0039] According to one embodiment, the first polymer is polycarbonate (PC) or styrene-acrylonitrile (SAN) and the first fibers are glass fibers.

[0040] According to one embodiment, step El comprises the following steps:

[0041] 1) preparation of the first composite material, in the form of a fiber-reinforced thermoplastic composite plate,

[0042] E12) placement of the first composite material in a preparation mold, the preparation mold having the ability to occupy a closed configuration and comprising two rigid preparation mold parts and delimiting two preparation cavities of left-handed shape complementary to the left-handed shape of the first layer, the two preparation mold parts being such that, in the closed configuration of the preparation mold, the two preparation mold parts are separated by a predetermined gap and delimit between them a cavity suitable for receiving the first composite material,

[0043] E13) heating of the first composite material to a temperature greater than or equal to at the glass transition temperature of the first composite material, the difference between said temperature and the glass transition temperature being between 0 and 20°C,

[0044] E14) application on the first composite material, by the two mold parts of preparation, with a mechanical pressure greater than or equal to 5 bars, in particular greater than 10 bars and preferably in the order of 15 bars, by placing the preparation mold in the closing configuration, while controlling the cooling until reaching a temperature between 50°C and 150°C.

[0045] According to one embodiment, the two preparation mold parts are respectively constituted by the first and second mold parts of the assembly mold, the step E1 comprising a step E10 consisting of modifying the gap separating the two preparation mold parts in the closing configuration of the preparation mold in step E14, compared to the gap present in step E4 in the closing configuration of the assembly mold.

[0046] According to one embodiment, the first layer has a thickness less than 1.5 mm, preferably in the order of 0.5 mm.

[0047] According to one embodiment, the second layer is formed in a thermoplastic material.

[0048] According to one embodiment, the second layer is a second composite material formed from a second polymer and fibers, in particular formed from a prepreg,

[0049] the second polymer being chosen from: polycarbonate (PC), polymethyl methacrylate (PMMA), thermoplastic polyurethane (TPU), polyetheretherketone (PEEK), polyetherketoneketone (PEKK), polyphenylene sulfide (PPS), polyamide (PA), polystyrene (PS),

[0050] and the fibers being chosen from glass, carbon, aramid fibers and / or natural fibers, in particular hemp, flax and / or silk.

[0051] According to one embodiment, the second polymer is thermoplastic polyurethane (TPU), polycarbonate (PC), or polyamide (PA), and the second fibers are glass fibers.

[0052] According to one embodiment, step E2 comprises the following steps:

[0053] E21) supply of the second composite material,

[0054] E22) placement of the second composite material in a manufacturing mold, the manufacturing mold having the ability to occupy a closed configuration and comprising two rigid manufacturing mold parts and delimiting two manufacturing cavities of left-handed shape complementary to the left-handed shape of the second layer, the two manufacturing mold parts being such that, in the closed configuration of the manufacturing mold, the two manufacturing mold parts are separated by a predetermined gap and delimit between them a cavity suitable for receiving the second composite material,

[0055] E23) heating of the second composite material to a temperature substantially equal (to within 10°C) to the glass transition temperature of the second material,

[0056] E24) application on the second composite material, by the two mold parts manufacturing, with a mechanical pressure greater than or equal to 5 bars, in particular in the order of 10 bars, by placing the manufacturing mold in the closed configuration, while controlling the cooling until reaching a temperature between 50°C and 150°C.

[0057] According to one embodiment, the two manufacturing mold parts are respectively constituted by the first and second mold parts of the assembly mold, step E2 comprising a step E20 consisting of modifying the air gap separating the two manufacturing mold parts in the closing configuration of the manufacturing mold in step E24, compared to the air gap present in step E4 in the closing configuration of the assembly mold.

[0058] According to one embodiment, the second layer has a thickness of less than 2 mm, preferably on the order of 1.5 mm.

[0059] According to one embodiment, during step E4, the pressure of the gas present in the cavity of the assembly mold is maintained, during the assembly period, below -0.5 bar, preferably between -0.7 bar and -1 bar.

[0060] According to one embodiment, step E4 includes a step E41 during which the first and second mold parts (22, 24) of the assembly mold exert, on the stack, a mechanical pressure less than or equal to 5 bars.

[0061] According to one embodiment, step E41 begins after the functional temperature is reached, after a predetermined non-zero period of between 0.5 min and 2 min and preferably of the order of 1 min.

[0062] According to one embodiment, step E41 is carried out for a period of between 30 s and 10 min.

[0063] According to one embodiment, the manufacturing process includes a step E5 consisting of heating the assembly mold to a temperature greater than or equal to the functional temperature, step E5 being carried out before step E4.

[0064] According to one embodiment, the manufacturing process includes a step E6 consisting of heating the stack using an infrared heat source, step E6 being carried out after step E3 and before step E4.

[0065] According to one embodiment, the manufacturing process includes a step E7 of cooling the stack, said step E7 being carried out while the first and second mold parts of the assembly mold exert, on the stack, a mechanical pressure less than or equal to 5 bars. Brief description of the drawings

[0066] Other aspects, objectives, advantages and features of the invention will become clearer upon reading the following detailed description of preferred embodiments thereof, given by way of non-limiting example, and made with reference to the accompanying drawings in which:

[0067] [Fig. 1] Figure 1 shows, in cross-section, a classic example of a photovoltaic module comprising crystalline photovoltaic cells,

[0068] [Fig.1A] [Fig.1A] represents a variant embodiment of the example in [Fig.1] in which the photovoltaic cells are of the IBC type,

[0069] [Fig.2] Fig.2 represents, in exploded view, the photovoltaic module of [Fig.1],

[0070] [Fig. 3] Fig. 3 represents, in the form of a flowchart, the different stages of a example of a manufacturing process according to the invention,

[0071] [Fig.4] Fig.4 shows, in perspective, an example of a photovoltaic module which can be obtained by implementing a manufacturing process according to the invention,

[0072] [Fig.5] Fig.5 represents, in perspective, an example of an assembly mold suitable for use in implementing a manufacturing process according to the invention,

[0073] [Fig.6] Fig.6 is a schematic visualization of the elastic return of an example of a photovoltaic module produced by implementing an example of a manufacturing process according to the invention.

[0074] [Fig.7] Fig.7 represents a curve illustrating an example of the evolution, with different successive phases, of the temperature adopted by the assembly mold as a function of time in an example of a manufacturing process according to the invention,

[0075] [Fig.8] The [Fig.8] schematically represents the behavior of the assembly mold and the stacking during the different phases corresponding to those defined on the [Fig.7]. Detailed description

[0076] Figures 1, IA and 2 have already been described in the section relating to the prior art.

[0077] Figure 3 represents in flowchart form the different steps of an example of a manufacturing process according to the invention.

[0078] The implementation of these steps makes it possible in particular to obtain a photovoltaic module 10, an example of which is shown in [Fig.4], having the particularity of presenting a general left-handed, non-planar shape, this term "left-handed shape" having been previously defined in the part relating to the state of the art.

[0079] The photovoltaic module 10 that can be obtained comprises at least:

[0080] - a first layer 12 having a curved shape, transparent and intended to form a front face of the photovoltaic module 10 intended to receive a luminous flux, - a second layer 14 having a skewed shape and intended to form a rear face of the photovoltaic module 10, - a plurality of 16 photovoltaic cells arranged side by side and electrically connected to each other, - an encapsulating assembly 18 ensuring encapsulation of all or part of the photovoltaic cells 16.

[0081] In this photovoltaic module 10 of left-handed shape, therefore not planar, the photovoltaic cells 16 and the encapsulating assembly 18 are arranged between the first layer 12 and the second layer 14. These arrangements are shown in the exploded view in [Fig.4].

[0082] Generally, the first layer 12 is formed in one or more parts, that is to say, it can be single-layer or multi-layer. The second layer 14 can also be formed in one or more parts, that is to say, it can be single-layer or multilayer.

[0083] The term “transparent” means that the first layer 12 forming the front face of the photovoltaic module 10 is at least partially transparent to visible light, allowing at least about 80% of this light to pass through. In particular, the optical transparency, between 300 and 1200 nm, of the first layer 12 may be greater than 80%.

[0084] Furthermore, by the term "encapsulating", it must be understood that the plurality of photovoltaic cells 16 is arranged in a volume, for example hermetically sealed with respect to liquids, at least partly formed by at least two layers of encapsulating material(s), joined together, at the end of the manufacturing process which will be described, to form the encapsulating assembly 18.

[0085] Indeed, initially, that is to say before the implementation of step E4 which will be described later, the encapsulating assembly 18 consists of at least one layer of an encapsulating material 181 located between the plurality of photovoltaic cells 16 and the first layer 12 and / or at least one layer of an encapsulating material 182 located between the plurality of photovoltaic cells 16 and the second layer 14. However, it is only during step E4 that this encapsulating material of the layers 181, 182 will undergo at least partial melting to form, after cooling, the solidified encapsulating assembly 18 in which the photovoltaic cells 16 are embedded.

[0086] In the example of [Fig.4], the first layer 12 is shaped with a curvature that can be identical or different along two distinct axes of a frame associated with the photovoltaic module 10. Complementarily, the second 14 is shaped with a curvature that can be identical or different along two distinct axes of a frame associated with the photovoltaic module 10. In particular, it may be provided that the curvatures are identical for the first layer 12 and for the second layer 14, guaranteeing an identity of shapes for the first and second layers 12, 14 and facilitating their superposition within the stack.

[0087] The photovoltaic cells 16 can be selected from: homojunction or heterojunction photovoltaic cells based on monocrystalline silicon (c-Si) and / or multicrystalline silicon (mc-Si), and / or IBC type photovoltaic cells, and / or photovoltaic cells comprising at least one material from amorphous silicon (a-Si), microcrystalline silicon (pC-Si), cadmium telluride (CdTe), copper-indium selenide (CIS) and copper-indium / gallium diselenide (CIGS), perovskites, among others.

[0088] Furthermore, the photovoltaic cells 16 can have a thickness between 1 and 300 pm, in particular between 1 and 200 pm, and advantageously between 70 pm and 160 pm.

[0089] The photovoltaic module 10 may further include a junction box (not (visible in [Fig. 4]), designed to receive the wiring necessary for the operation of the photovoltaic module 10 and which can be positioned on the front or rear face of the module, preferably on the front face. The method of constructing this junction box is not restrictive in itself, and any known technique can be used.

[0090] In addition, the spacing between two neighboring, consecutive or adjacent photovoltaic cells 16 can be greater than or equal to 1 mm, in particular between 1 and 30 mm, and preferably equal to 2 mm.

[0091] As can be seen in [Fig. 3], the manufacturing process includes a step E1 of supplying the first layer 12 in such a way that it has its warped shape and transparency characteristics. The manufacturing process also includes a step E2 of manufacturing the second layer 14 in such a way that it also has its warped shape. It is possible to carry out step E1 before step E2, or vice versa. Alternatively, it is possible to carry out all or part of step E1 overlapping all or part of step E2.

[0092] In general, the way of carrying out step E1 and that of carrying out step E2 are not limiting in themselves provided that each is implemented with parameters adapted to the result to be obtained in each of them, in particular with a view to obtaining at the end of the manufacturing process a photovoltaic module 10 having the desired characteristics of lightness and resistance, typically in order to meet the standards IEC 61215 and IEC 61730.

[0093] Non-limiting but advantageous implementation methods of steps E1 and E2 will be described later.

[0094] The manufacturing process also includes a step E3 of placing a stack (described below) in an assembly mold 20. Step E3 is carried out after steps E1 and E2. In one embodiment, the stack is made directly in the assembly mold 20. Alternatively, the stack is at least partially made outside the assembly mold 20 before being placed and possibly finalized in the assembly mold 20. An example of such an assembly mold 20 is shown in [Fig. 5], which is adapted for producing the photovoltaic module 10 of [Fig. 4].

[0095] During step E3, the stack comprises the first layer 12, the plurality of photovoltaic cells 16 arranged side by side and electrically connected to each other, the second layer 14 and at least one encapsulation material 181, 182. As previously indicated, the at least one encapsulation material 181, 182 and the plurality of photovoltaic cells 16 are located between the first and second layers 12, 14.

[0096] For the implementation of step E3, the assembly mold 20 is configured so as to be able to occupy a closed configuration, in particular in varying between this closed configuration (not shown) and an open configuration (shown in [Fig. 5]). The assembly mold 20 generally comprises a first rigid mold part 22 defining a first cavity 220 having a left-hand shape complementary to the left-hand shape of the first layer 12. The assembly mold 20 also comprises a second rigid mold part 24 defining a second cavity 240 having a left-hand shape complementary to the left-hand shape of the second layer 14. Depending on the design of the assembly mold 20, the transition from the closed configuration to the open configuration and vice versa can be achieved by a relative movement between the first mold part 22 and the second mold part 24, this relative movement being a combination of:

[0097] - a translation along a first axis of the frame associated with the photovoltaic module 10 to be obtained and oriented along the direction in which the different layers and elements of the stack are stacked, - and / or a pivoting around a second axis of this frame oriented transversely to the first axis.

[0098] The first mold part 22 and the second mold part 24 are such that, in the closed configuration of the assembly mold 20, the first mold part 22 and the second mold part 24 are separated by a predetermined first gap 26 and define between them a cavity 28 suitable for receiving the stack defined above. The predetermined gap 26 and the cavity 28 are shown schematically in Figure 8, detailed below, in which it should be noted that a first seal 222 of the first mold part 22 comes into contact with a second seal 242 of the second mold part 24 in order to ensure a seal such that, in the closed configuration, the cavity 28 can be placed under negative pressure compared to the ambient pressure outside the assembly mold 20. It is optionally possible to have a negative pressure in the cavity without pressurizing the part.

[0099] The setting of the first predetermined air gap 26 in the closing configuration can result from the mechanical butting of a first stop integral with the first part of the mold 22 against a second stop integral with the second part of the mold 24, the mechanical butting of these first and second stops being accompanied by the setting of the seal described in the preceding paragraph by means of the first and second seals 222, 242.

[0100] Preferably, the assembly mold 20 includes adjustment elements configured to adjust the value of the predetermined air gap 26, ultimately allowing adaptation to the value of the stack thickness and the thickness of the manufactured photovoltaic module 10.

[0101] According to one embodiment, these adjustment elements can be selected from:

[0102] - elements allowing the position of the first stop to be varied relative to the rest of the first part of the mold 22, - elements allowing the position of the second stop to be varied relative to the rest of the second part of mold 24, - shims of variable heights suitable for being positioned between the first stop and the second stop in the closing configuration of the assembly mold 20.

[0103] The manufacturing process then includes an assembly step E4, implemented after step E3. During step E4, the closing configuration of the assembly mold 20 is adopted and the temperature within the stack is maintained at a functional temperature (denoted Tfonc on [Fig.7]) between 70°C and 180°C, preferably between 80°C and 150°C, for an assembly period adapted according to the at least one encapsulation material 181, 182 so that the at least one encapsulation material 181, 182 undergoes at least partial melting and creates the encapsulating assembly 18 capable of adhering on the one hand to the plurality of photovoltaic cells 16 and on the other hand to the first layer 12 and / or the second layer 14.

[0104] The manufacturing process described here therefore has the particularity of providing the first layer 12 and the second layer 14 of the photovoltaic module 10 before the latter is assembled in accordance with step E4. In other words, the first and second layers 12, 14 are not manufactured at the same time as the assembly of the different layers of the photovoltaic module 10 obtained by the manufacturing process.

[0105] This is particularly advantageous because it is then possible to plan the execution of step El and step E2 under pressure and / or temperature conditions that would not be supported by step E4. In particular, it is possible to implement step El and step E2 under conditions where the temperature would be between 180 and 300°C and where the mechanical pressure applied respectively on the first layer 12 during step El, and on the second layer 14 during step E2, would be greater than 5 bars.However, such conditions would not be supported (due to the odd shape of all the folds or layers of the stack) by at least one encapsulation material 181, 182 except by resulting in a thinning of the latter likely to generate real problems both in the resistance of the photovoltaic module 10 and for its homogeneity and the repeatability of the manufacturing process, with displacement of the photovoltaic cells and a break in the electrical connections or of the cells.

[0106] Furthermore, the use of an assembly mold 20 having two mold parts 22, 24 made of an advantageously rigid material and configured to adopt a A predetermined air gap ensures the presence of an air gap with a perfectly repeatable value, independent of the mechanical pressure applied by the assembly mold 20 on the photovoltaic module 10 and independent of the pressure of the gas present in the cavity 28. These provisions guarantee excellent repeatability of the assembly step E4 and good reliability of the manufactured photovoltaic modules 10.

[0107] These arrangements are distinct from commonly used techniques where the manufacture of a flat photovoltaic module is carried out by lamination, in which the flat layers forming the front and rear faces of the photovoltaic module are at least partially manufactured at the same time as the encapsulating assembly is formed, and where a sheet is used to apply homogeneous pressure during pressurization of the stack in the case of irregular shapes. Implementing such techniques for irregular shapes would present significant difficulties because applying homogeneous pressure with the sheet to a stack of uneven thickness, due to a thinning of the encapsulating material towards lower points of the mold resulting from the heating conditions, would inevitably lead to a photovoltaic module with an uneven thickness.Using an assembly mold 20 in accordance with steps E3 and E4 addresses these issues.

[0108] The manufacturing process allows the production of a photovoltaic module 10 which is:

[0109] - compatible with a wide range of unit area mass from a few kg / m2 up to several tens of kg / m2, - resistant as required by practical application requirements and administrative standards, typically IEC 61215 and IEC 61730, - of oblique shape, in particular typically formed with a curvature which may be identical or different along two distinct axes of a frame associated with the photovoltaic module.

[0110] It should be noted that the left shape of the photovoltaic module 10, in itself, can contribute to providing a large resistance to the photovoltaic module 10 manufactured.

[0111] The manufacturing process also has the advantage of being very fast and easy to implement, making it easily automatable on a large scale, of being efficient and economical, of offering excellent repeatability and good reliability of the photovoltaic modules manufactured.

[0112] The manufacturing process has the additional advantage of being able to be implemented using only recyclable materials.

[0113] Preferably, at least one encapsulation material 181, 182 has a thickness between 100 and 2000 pm and is a thermoplastic elastomer selected including: polyolefin, silicone, thermoplastic polyurethane, polyvinyl butyral, functional polyolefin, ionomer.

[0114] Preferably, the first layer 12 is formed from a thermoplastic material, which offers an eco-design advantage in terms of recyclability, as well as theoretically faster shaping because it does not require an unavoidable curing time. According to one embodiment, the numerous tests and simulations carried out by the Applicant have led to the conclusions that the first layer 12 can, in particular, be a first composite material formed from a first polymer and first fibers, where:

[0115] - the first polymer is chosen from: ethylene chlorotrifluoroethylene (ECTFE), fluorinated ethylene propylene (FEP), ethylene tetrafluoroethylene (ETFE), polyvinylidene fluoride (PVDF), polymethyl methacrylate (PMMA), polycarbonate (PC), polyethylene terephthalate (PET), polyamide (PA), styrene-acrylonitrile (SAN), polystyrene (PS) - and the first fibers are chosen from glass fibers, aramid fibers and / or natural fibers.

[0116] Among the many tests, it has been determined that it is very advantageous to provide that the first polymer is polycarbonate (PC) or styrene-acrylonitrile (SAN) and that the first fibers are glass fibers.

[0117] Nevertheless, it is possible to adapt the manufacturing process so that the first layer 12 is formed in a thermosetting material.

[0118] In accordance with [Fig.3], according to a particular embodiment, step El comprises the following steps:

[0119] 1) preparation (or supply) of the first composite material, in the form of a fiber-reinforced thermoplastic composite plate,

[0120] E12) placing the first composite material from step E1 in a mold preparation, the preparation mold having an ability to occupy a closed configuration and comprising two rigid preparation mold parts and delimiting two preparation cavities of left-handed shape complementary to the left-handed shape of the first layer, the two preparation mold parts being such that, in the closed configuration of the preparation mold, the two preparation mold parts are spaced by a second predetermined gap and delimit between them a cavity suitable for receiving the first composite material,

[0121] E13) heating of the first composite material to a temperature greater than or equal to at the glass transition temperature of the first composite material, the difference between said temperature and the glass transition temperature being between 0 and 20°C (typically a temperature between 180°C and 300°C and preferably between 180°C and 200°C),

[0122] E14) application on the first composite material, by the two mold parts of preparation, with a mechanical pressure greater than or equal to 5 bars, in particular greater than 10 bars and preferably in the order of 15 bars, by placing the preparation mold in the closing configuration, while controlling the cooling until reaching a temperature between 50°C and 150°C.

[0123] One advantage of implementing these steps is that it facilitates subsequent assembly. Alternatively, it could be a simple thermoforming process where only steps Eli to E13 are present and where the overpressure of step E14 is not applied.

[0124] The preparation mold may be any type of mold provided it is suitable for carrying out steps E1 to E14. It is not shown in detail and is not limiting. A person skilled in the art may use all their knowledge and appropriate techniques for carrying out steps E1 to E14.

[0125] The first thermoplastic composite material in the form of such a fiber-reinforced thermoplastic composite sheet is also known, in the relevant technical field, by the term "organosheet". In other words, an organosheet is an assembly of already compacted composite plies.

[0126] The first composite material used in step El 1 may have a surface mass between 25 and 600 g / m2, in particular between 300 and 600 g / m2, typically in the order of 450 g / m2.

[0127] In certain variants, it is possible to provide that the two parts of the preparation mold are respectively constituted by the first and second parts of the mold 22, 24 of the assembly mold 20, the step E1 then comprising a step E10 consisting of modifying the air gap separating the two parts of the preparation mold in the closing configuration of the preparation mold in step E14, with respect to the predetermined air gap 26 present in step E4 in the closing configuration of the assembly mold 20. This modification of the air gap as indicated here can be carried out by means of the adjustment elements which have been previously described.

[0128] One advantage is the ability to use the assembly mold 20 as a preparation mold for use in step E1, thereby reducing the number of parts and overall costs. Another advantage is the ability to avoid or minimize transfers between step E1 and step E3. However, particularly in high-volume production applications, it is entirely possible for the preparation mold used in step E1 to be separate from the assembly mold 20 used in step E4, enabling series production on lines operating with assembly stations.

[0129] Advantageously, the first layer 12 has a thickness of less than 1.5 mm, preferably on the order of 0.5 mm. One advantage is to improve the transparency of the first layer 12 as much as possible: the smaller the thickness, the better the optical transmission.

[0130] The manufacturing process detailed in this document, carried out in step E4 in an assembly mold 20, in particular a closed mold and, for example, under a heated press, and which makes it possible to reach the pressure and temperature ranges necessary for assembly in accordance with step E4, also makes it possible to reach the pressure and temperature ranges necessary for compacting the first thermoplastic composite material during step E1, without causing undesirable thinning of the encapsulation materials 181, 182 located between the first and second layers 12, 14 due to an otherwise excessive temperature. This is necessary to allow the shaping of the first thermoplastic composite material, according to the desired left-handed shape for the first layer 12, and is suitable for the integration of the photovoltaic cells 16.In general, it is not necessarily required to provide a heated press, in the sense that the heating means can be either internal or external to the tooling of the assembly mold.

[0131] According to a particular embodiment, step E13 can be carried out before step E12, by means of an infrared heating system, with step E14 then being carried out using a preparation mold potentially at room temperature.

[0132] Furthermore, preferably, the second layer 14 is formed from a thermoplastic material, which offers an eco-design advantage due to its recyclability, as well as theoretically faster shaping because it does not require an unavoidable curing time. Moreover, this type of material is generally known for its ability to dissipate impact energy better than thermosetting materials. According to one embodiment, the numerous tests and simulations carried out by the Applicant have led to the conclusions that the second layer 14 can, in particular, be a second composite material formed from a second polymer and fibers, notably formed from a prepreg, where:

[0133] - the second polymer is chosen from: polycarbonate (PC), polymethyl methacrylate (PMMA), thermoplastic polyurethane (TPU), polyetheretherketone (PEEK), polyetherketoneketone (PEKK), polyphenylene sulfide (PPS), polyamide (PA), polystyrene (PS), - and the fibers are chosen from glass, carbon, aramid fibers and / or natural fibers, including hemp, flax and / or silk.

[0134] Among the many tests, it was determined that it is very advantageous to provide that the second polymer is thermoplastic polyurethane (TPU), polycarbonate (PC), or polyamide (PA), and that the second fibers are glass fibers.

[0135] Nevertheless, it is possible to adapt the manufacturing process so that the second layer 14 is formed in a thermosetting material.

[0136] In accordance with [Fig.3], according to a particular embodiment, step E2 comprises the following steps:

[0137] E21) supply of the second composite material,

[0138] E22) placement of the second composite material from step E21 in a manufacturing mold, the manufacturing mold having an ability to occupy a closed configuration and comprising two rigid manufacturing mold parts and delimiting two manufacturing cavities of left-handed shape complementary to the left-handed shape of the second layer, the two manufacturing mold parts being such that, in the closed configuration of the manufacturing mold, the two manufacturing mold parts are separated by a predetermined third gap and delimit between them a cavity suitable for receiving the second composite material,

[0139] E23) heating the second composite material to a temperature substantially equal (to within 10°C) to the glass transition temperature of the second material (typically a temperature between 180°C and 300°C and preferably between 220°C and 260°C),

[0140] E24) application on the second composite material, by the two mold parts manufacturing, with a mechanical pressure greater than or equal to 5 bars, in particular in the order of 10 bars, by placing the manufacturing mold in the closed configuration, while controlling the cooling until reaching a temperature between 50°C and 150°C.

[0141] One advantage of implementing these steps is that it facilitates subsequent assembly. Alternatively, it could be a simple thermoforming process where only steps E21 to E23 are present and where the overpressure of step E24 is not applied.

[0142] The manufacturing mold may be any type provided it is suitable for carrying out steps E21 to E24. It is not shown in detail and is not limiting. A person skilled in the art may use all their knowledge and appropriate techniques for carrying out steps E21 to E24.

[0143] In certain variants, it is possible to provide that the two parts of the manufacturing mold are respectively constituted by the first and second parts of the mold 22, 24 of the assembly mold 20, the step E2 then comprising a step E20 consisting of modifying the air gap separating the two parts of the manufacturing mold in the closing configuration of the manufacturing mold in step E24, with respect to the predetermined air gap 26 present in step E4 in the closing configuration of the assembly mold 20. This modification of the air gap as indicated here can be carried out by means of the adjustment elements which have been previously described.

[0144] One advantage is being able to use the assembly mold 20 as a manufacturing mold usable in step E2, in order to limit the number of parts and overall costs. Another advantage is being able to avoid or limit transfers between step E2 and step E3. However, particularly in high-volume production applications, it is entirely possible that the manufacturing mold used in step E2 is separate from the assembly mold 20, allowing series production on lines operating assembly stations.

[0145] For example, the second layer 14 has a thickness of less than 2 mm, preferably on the order of 1.5 mm. This thickness allows for high resistance, particularly to external impacts such as hail for example.

[0146] The manufacturing process detailed in this document, carried out in step E4 in the assembly mold 20, typically closed and under a heated press, and which makes it possible to reach the pressure and temperature ranges necessary for assembly in accordance with step E4, also makes it possible to reach the pressure and temperature ranges necessary for compacting the second thermoplastic composite material during step E2, without causing undesirable thinning of the encapsulation materials 181, 182 located between the first and second layers 12, 14 due to an otherwise excessive temperature. This is necessary to allow the shaping of the second thermoplastic composite material, according to the desired left-handed shape for the second layer 14, and is suitable for the integration of the photovoltaic cells 16.

[0147] According to one embodiment, step E23 is carried out before step E22. Alternatively, steps E23 and E24 are carried out at least partially simultaneously, for example by combining a heated press with the manufacturing mold.

[0148] According to a particular embodiment, during step E4, the gas pressure in the cavity 28 of the assembly mold 20 is maintained, during the assembly period, below -0.5 bar, preferably between -0.7 bar and -1 bar. In other words, step E4 is carried out under near-vacuum conditions to avoid defects in the final part (bubbles, delamination, etc.).

[0149] Preferably, step E4 includes a step E41 during which the first and second mold parts 22, 24 of the assembly mold 20 exert a mechanical pressure of 5 bar or less on the stack. This mechanical pressure, indicated by the arrows Fl in [Fig. 8] during phases P2 and P3, can be obtained by having the assembly mold 20 connected to a press capable of exerting this mechanical pressure, for example, a heated press also adapted to bring it up to the temperature required for carrying out step E4.

[0150] Thus, step E4 is preferably carried out at a pressure below 5 bar and a temperature between 70 and 180°C, preferably between 80°C and 150°C, which temperature allows the integration of the photovoltaic cells 16 into the encapsulating assembly 18. The temperature of this implementation must be carefully adjusted to avoid, as far as possible, the melting of the encapsulating assembly. 18, favored by the left-handed shape of the photovoltaic module 10. Similarly, the air gap 26 of the assembly mold 20 must be precisely adjusted so as not to damage the photovoltaic cells 16.

[0151] Preferably, step E41 begins after the functional temperature Tfonc (see [Fig. 7]) is reached, after a predetermined non-zero period of between 0.5 min and 2 min, and preferably on the order of 1 min. This period is, for example, visible in [Fig. 7] and denoted A. In practice, the functional temperature Tfonc can correspond to the melting temperature of the encapsulant. This non-zero duration allows time for the vacuum to be drawn into the cavity and for the thermal diffusion of the mold temperature to the core of the part to soften the encapsulant.

[0152] Alternatively, and even though this presents a slightly greater risk of breakage due to a lack of fluidity of the encapsulant at the moment when it has just crossed the glass transition temperature, it remains conceivable that step E41 can begin as soon as the functional temperature Tfonc mentioned in connection with step E4 is reached.

[0153] According to a preferred embodiment, step E41 is carried out for a period of between 30 s and 10 min. This duration must again be carefully adjusted to avoid as much as possible the thinning of the encapsulating assembly 18, which is favored by the oblique shape of the photovoltaic module 10, once the encapsulating materials have melted sufficiently to penetrate between the photovoltaic cells 16 and to be able to adhere, after cooling, to the first layer 12, the second layer 14 and the photovoltaic cells 16.

[0154] In general, it is advantageous to plan for step E4 to be as short as possible to optimize the cycle time, while taking care, of course, to adjust the temperature and duration parameters in order to achieve the result defined for step E4 with respect to the encapsulating assembly 18 to be obtained, in particular depending on the nature and thickness of at least one encapsulating material 181, 182.

[0155] According to a particular embodiment, the manufacturing process includes a step E5 consisting of heating the assembly mold 20 to a temperature greater than or equal to the functional temperature Tfonc, step E5 being carried out before step E4.

[0156] Alternatively to or in combination with step E5, the manufacturing process may include a step E6 consisting of heating the stack using an infrared heat source, step E6 being carried out after step E3 and before step E4.

[0157] Finally, the manufacturing process includes a step E7 for cooling the stack, said step E7 being carried out while the first and second mold parts 22, 24 of the assembly mold 20 exert, on the stack, a The mechanical pressure applied during step E7, during which the two mold parts 22 and 24 of the assembly mold 20 undergo a temperature decrease and the photovoltaic module 10, as produced in step E4, transfers heat to the assembly mold 20 for cooling, may be different from or equal to the mechanical pressure Fl exerted during step E41 described previously, depending on the requirements. This step E7 may be carried out in a different mold than those used in the previous steps, provided that the appropriate air gap is maintained. The pressure must be kept to a minimum level.

[0158] In what has just been described, the first predetermined air gap 26 used for the implementation of step E4 is preferably at least equal to a value equal to the sum of the thicknesses of each ply or layer belonging to the stack less a certain gap within a range between 0.1 and 0.3 mm and preferably equal to 0.2 mm, and preferably at most equal to the sum of the thicknesses of each ply or layer belonging to the stack.

[0159] Figures 7 and 8 represent the different situations at four successive phases PI to P4 of an example of a manufacturing process incorporating the general lessons listed above, these phases PI to P4 being associated in particular with the implementation of step E4.

[0160] These successive phases PI to P4 are notably applied to a stack comprising the first layer 12, the photovoltaic cells 16 sandwiched between two encapsulation materials 181, 182, and the second layer 14, where the first layer 12 and the second layer 14 each have a warped shape, in particular typically formed with a curvature which may be identical or different along two distinct axes of a frame associated with the photovoltaic module, and moreover possibly made using only recyclable materials.

[0161] In a first PI phase, the temperature of the assembly mold 20 is increased. This is why, in the PI phase, the curve illustrated in [Fig. 7] (which represents the evolution of the temperature (on the y-axis) of the assembly mold 20 as a function of time (on the x-axis)) takes the form of a profile increasing over time, for example, in a straight line. As an example, the assembly mold 20 is connected to a heated press and its temperature increases at a rate of 4°C / min, until it reaches a nominal temperature at the end of the PL phase. This nominal temperature, which can be between 80°C and 150°C, is strictly higher than the functional temperature Tfonc mentioned previously.It should be noted that the PI phase can be initiated after the implementation of step E3, which then implies that the stacking (which then has a thickness noted El) is already in place between the two mold parts 22, 24 of the. Assembly mold 20. The heat input to the stack due to the heating of the assembly mold 20 is shown schematically by the arrows FO. Alternatively, the assembly can be carried out outside the assembly mold 20, and simultaneously with the heating of the assembly mold 20, saving time, as the stack is then deposited into the already heated assembly mold 20.

[0162] Then the second phase P2 begins, which corresponds concretely to the implementation of step E41. The time lag between the moment when the functional temperature Tfonc was reached and the start of phase P2 corresponds to the period A already described, between 0.5 min and 2 min and preferably on the order of 1 min. For the implementation of phase P2, the two mold parts 22, 24 undergo a relative approach, schematically represented by the arrow Dl, until they are separated from each other by a distance equal to the value of the first predetermined air gap 26. In this relative approach of the mold parts 22, 24, the assembly mold 20 exerts the mechanical pressure (for example, of approximately 5 bar), schematically represented by the arrows Fl, mentioned in connection with step E41, which implies a compression of the stack present in the cavity 28 of the assembly mold 20.The stack then undergoes a reduction in thickness, from the value Kl to a value denoted K2. Throughout phase P2, the assembly mold 20 is maintained at its nominal temperature (which is why, in phase P2, the curve illustrated in [Fig. 7] appears as a constant profile over time) and continues to heat the stack, hence the presence of the arrows F0 in phase P2 in [Fig. 8]. Phase P2 is carried out for a period of between 30 s and 10 min, specifically between 3 min and 5 min, and preferably around 4 min.This duration must be carefully adjusted to avoid as much as possible the fining of the encapsulating assembly 18, favoured by the left-handed shape of the photovoltaic module 10, once at least one encapsulating material 181, 182 has melted sufficiently to penetrate between the photovoltaic cells 16 and to be able to adhere, after cooling, to the first layer 12, the second layer 14 and the photovoltaic cells 16. .

[0163] Then the third phase P3 begins, during which the temperature of the assembly mold 20 is reduced. This is why, in phase P3, the curve illustrated in [Fig. 7] takes the form of a profile decreasing over time, for example, in a straight line. This is the implementation of step E7 described previously. As an example, the temperature of the assembly mold 20 decreases at a rate of 8°C / min until it reaches the initial temperature at the beginning of phase PL. The heat transfer from the photovoltaic module 10 to the assembly mold 20 is schematically represented by the arrows F2. Furthermore, throughout phase P3, mechanical pressure continues to be exerted by the mold. assembly 20. The mechanical pressure applied while the two mold parts 22, 24 of the assembly mold 20 undergo the temperature decrease can be equal to the mechanical pressure exerted during phase P2 described previously (this is why in phase P3 on [Fig.8] the mechanical pressure is schematically represented by the same arrows Fl as during phase 2), or can be different depending on the requirements.

[0164] Finally, the fourth phase P4 begins, during which the two mold parts 22, 24 undergo a relative separation, schematically represented by the arrow D2, until they are separated from each other by a distance strictly greater than the value of the first predetermined air gap 26. In this relative separation of the mold parts 22, 24, the assembly mold 20 releases the previously exerted mechanical pressure and the photovoltaic module 10 remains in its thus obtained left-handed shape and with the thickness E2, up to a potential elastic return phenomenon.

[0165] The process just described has been implemented for an example of a photovoltaic module and [Fig.6] represents a schematic visualization of the elastic return of the photovoltaic module thus produced.

[0166] To obtain the photovoltaic module of [Fig.6], the following stacking was used (going from the front face to the rear face):

[0167] - a first composite material, in the form of a thermoplastic composite plate based on glass fiber reinforced polycarbonate, transparent and with a surface mass of 450 g / m2, intended to constitute the first layer 12 at the end of the process (in particular, two layers of polycarbonate and glass fibers may be provided for a total thickness of 0.5 mm or three layers of polycarbonate and glass fibers for a total thickness of 0.75 mm), - a transparent thermoplastic polyurethane encapsulation material with a thickness of 620 µm, - Monocrystalline silicon photovoltaic cells with dimensions of 125 x 125 mm2, - a transparent thermoplastic polyurethane encapsulation material with a thickness of 620 µm, - a second composite material in the form of a laminate, for example with 8 plies, alternating thermoplastic polyurethane and glass fibers, with a surface mass of 575 g / m2 and a thickness of 2 mm, intended to constitute the second layer 14 at the end of the process.

[0168] In this example, the value of the curvature to be obtained along a first axis of curvature was 1 meter while the curvature to be obtained along a second axis of curvature, perpendicular to the first axis of curvature, was 2 meters.

[0169] According to [Fig. 6], it can be seen that the values ​​VI and V2 of the elastic return at points of the photovoltaic module arranged symmetrically along the second axis of curvature are substantially equal: the measurements VI and V2 are 2.3 and 2.4 mm, respectively. In addition, the values ​​V3 and V4 of the elastic return at points of the photovoltaic module arranged symmetrically along the first axis of curvature are substantially equal: the measurements V3 and V4 are -0.4 and -0.05 mm, respectively.

[0170] Another advantage of the manufacturing process described here is that the first layer 12, the second layer 14, and then the photovoltaic module 10, can all be obtained by identical techniques using a rigid-parts mold, typically the same mold whose air gap is varied according to the part to be obtained, respectively at steps E1, E2 and E4.

[0171] Post-implementation electroluminescence imaging showed that no degradation of the photovoltaic cells 16 had occurred, thus confirming the compatibility of the materials used and the double curvature with the thermocompression assembly technique of step E4 for the manufacture of photovoltaic modules 10. The electrical performance of the modules manufactured during the tests is entirely acceptable compared to that of standard modules (a maximum power difference of less than 5% depending on the transmittance of the front face used). IK7 impact tests in accordance with the specific standard NF 60068-2-75 did not cause any breakage of the photovoltaic cells 16, demonstrating the compatibility of the first layer 12 used as the front face.

[0172] It should be noted that the known lamination technique, in addition to the drawbacks already described, would involve complicated management of the forces applied to the front and rear faces of the photovoltaic module to be manufactured, due to at least one curvature resulting from the required warped shape, which is one of the problems to be solved within the scope of the present invention. The manufacturing process described in this document addresses this problem.

[0173] It is emphasized that the values ​​of the various parameters (temperature, time, mechanical pressure), dimensions (thicknesses of the different layers, air gap values, etc.) and material choices detailed in this document are not arbitrary and were not directly accessible to a person skilled in the art. During step E4, the pressure / temperature / air gap combination of the assembly mold 20 was carefully calibrated to avoid damaging the photovoltaic cells 16. This degradation could otherwise result from excessive thinning of the encapsulant, due to temperature, curvature, and adjusting the stack thickness to the predetermined air gap 26 of the assembly mold 20. It could also be related to localized overpressure, for example at the connectors, due to the The lack of space due to the predetermined fixed air gap 26 of the assembly mold 20 required adjustment of this pressure / temperature / air gap combination, taking into account analyses, particularly rheological analyses, of the encapsulation materials 181, 182 used and a design of experiments on sheets of encapsulation material incorporating unconnected photovoltaic cells 16. Similarly, to avoid immediate pressurization, the thickness of the seals 222, 242 of the assembly mold 20 was adjusted to allow for sealing without yet being in perfect contact with the stack. Each seal 222, 242 can have a thickness of 1 cm in its natural (uncrushed) state and a thickness of approximately 7 mm in the mold closure configuration.

[0174] NOMENCLATURE

[0175] 1: photovoltaic module (prior art)

[0176] 2: front view (prior art)

[0177] 3: encapsulating assembly (prior art)

[0178] 3a: front layer (prior art)

[0179] 3b: back layer (prior art)

[0180] 4: Photovoltaic cells (prior art)

[0181] 4a: front face of the cells (prior art)

[0182] 4b: rear face of the cells (prior art)

[0183] 5: rear face (prior art)

[0184] 6: connecting conductors (prior art)

[0185] 7: junction box (prior art)

[0186] 10: photovoltaic module

[0187] 12: first layer

[0188] 14: second layer

[0189] 16 photovoltaic cells

[0190] 18: encapsulating assembly

[0191] 181: encapsulation material

[0192] 182: encapsulation material

[0193] 20 assembly mold

[0194] 22: first part of mold

[0195] 220: first impression of the assembly mold

[0196] 222: first joint

[0197] 24: second part of mold

[0198] 240: second impression of the assembly mold

[0199] 242: second joint

[0200] 26: first predetermined air gap

[0201] Functional temperature: functional temperature

[0202] DI: relative reconciliation

[0203] D2: relative distance

[0204] PI: first phase

[0205] P2: second phase

[0206] P3: third phase

[0207] P4: fourth phase

[0208] El: step of supplying a first layer

[0209] E2: step in manufacturing a second layer

[0210] E3: Step of placing a stack in an assembly mold

[0211] E4: Assembly step

[0212] E5: step consisting of heating the assembly mold

[0213] E6: step consisting of heating the stack

[0214] E7: Stack cooling step

[0215] F0: the heat input to the stack

[0216] Fl: mechanical pressure

[0217] F2: Heat transfer from the photovoltaic module to the assembly mold

[0218] A: predetermined period

[0219] E10: step consisting of modifying the air gap separating the two mold parts of the pre preparation

[0220] El 1: Preparation / supply step of the first composite material

[0221] E12: Placement of the first composite material from step E1 in a preparation mold

[0222] E13: Heating of the first composite material

[0223] E14: application on the first composite material, by the two mold parts of preparation, of a mechanical pressure

[0224] E20: step consisting of modifying the air gap separating the two mold parts of fa briccation

[0225] E21: Supply of the second composite material

[0226] E22: Placement of the second composite material from the step in a mold manufacturing

[0227] E23: heating of the second composite material

[0228] E24: application on the second composite material, by the two mold parts manufacturing, mechanical pressure

[0229] Kl: first value of the air gap

[0230] K2: second value of the air gap

Claims

1. Claims Method of manufacturing a photovoltaic module (10), comprising the following steps: El) provision of a first layer (12) having a left, transparent shape and intended to form a front face of the photovoltaic module (10) intended to receive a luminous flux, E2) manufacturing a second layer (14) having a left shape and intended to form a rear face of the photovoltaic module (10), E3) placing a stack in an assembly mold (20), implemented after steps E1 and E2, in which: i. the stack comprises the first layer (12), a plurality of photovoltaic cells (16) arranged side by side and electrically connected to each other, the second layer (14) and at least one encapsulation material (181, 182), the stack being such that the at least one encapsulation material (181, 182) and the plurality of photovoltaic cells (16) are located between the first and second layers (12, 14), ii. and the assembly mold (20) has an ability to occupy a closed configuration and comprises a first rigid mold part (22) delimiting a first impression (220) of left shape complementary to the left shape of the first layer (12) and a second rigid mold part (24) delimiting a second impression (240) of left shape complementary to the left shape of the second layer (14), the first mold part (22) and the second mold part (24) being such that, in the closed configuration of the assembly mold (20), the first mold part (22) and the second mold part (24) are spaced apart by a predetermined air gap (26) and delimit between them a cavity (28) capable of receiving the stack, E4) assembly, implemented after step E3, in which the closing configuration of the assembly mold (20) being adopted, the temperature within the stack is maintained at a functional temperature (Tfonc) of between 70°C and 180°C, and preferably between 80°C and 150°C, for an assembly period adapted in function of the at least one encapsulation material (181, 182) so that the at least one encapsulation material (181, 182) undergoes at least partial fusion and creates an encapsulating assembly (18) capable of adhering on the one hand to the plurality of photovoltaic cells (16) and on the other hand to the first layer (12) and / or to the second layer (14).

2. A manufacturing method according to claim 1, wherein the first layer (12) is formed from a thermoplastic material.

3. Manufacturing method according to claim 2, wherein the first layer (12) is a first composite material formed from a first polymer and first fibers, the first polymer being chosen from: ethylene chlorotrifluoroethylene (ECTFE), fluorinated ethylene propylene (FEP), ethylene tetrafluoroethylene (ETFE), polyvinylidene fluoride (PVDF), polymethyl methacrylate (PMMA), polycarbonate (PC), polyethylene terephthalate (PET), polyamide (PA), styrene-acrylonitrile (SAN), polystyrene (PS), and the first fibers being chosen from glass fibers, aramid fibers and / or natural fibers.

4. A manufacturing method according to claim 3, wherein the first polymer is polycarbonate (PC) or styrene-acrylonitrile (SAN) and the first fibers are glass fibers.

5. Manufacturing method according to one of claims 3 or 4, in which step E1 comprises the following steps: E11) preparation of the first composite material, in the form of a fiber-reinforced thermoplastic composite plate, E12) placing the first composite material in a preparation mold, the preparation mold having an ability to occupy a closed configuration and comprising two rigid preparation mold parts and delimiting two preparation imprints of left shape complementary to the left shape of the first layer, the two preparation mold parts being such that, in the closed configuration of the preparation mold, the two preparation mold parts are spaced apart by a predetermined air gap and delimit between them a cavity capable of receiving the first composite material,El3) heating the first composite material to a temperature greater than or equal to the glass transition temperature of the first composite material, the difference between said temperature and the temperature of, glass transition being between 0 and 20°C, E14) application on the first composite material, by the two parts of the preparation mold, of a mechanical pressure greater than or equal to 5 bars, in particular greater than 10 bars and preferably of the order of 15 bars, by placing the preparation mold in the closed configuration, while controlling the cooling until reaching a temperature between 50°C and 150°C.

6. Manufacturing method according to claim 5, in which the two preparation mold parts are respectively constituted by the first and second mold parts (22, 24) of the assembly mold (20), step E1 comprising a step E10 consisting of modifying the air gap separating the two preparation mold parts in the closed configuration of the preparation mold in step E14, compared to the air gap (26) present in step E4 in the closed configuration of the assembly mold (20).

7. Manufacturing method according to one of claims 1 to 6, in which the first layer (12) has a thickness of less than 1.5 mm, preferably of the order of 0.5 mm.

8. A method according to any one of claims 1 to 7, wherein the second layer (14) is formed from a thermoplastic material.

9. Manufacturing method according to claim 8, wherein the second layer (14) is a second composite material formed from a second polymer and fibers, in particular formed from a prepreg, the second polymer being chosen from: polycarbonate (PC), polymethyl methacrylate (PMMA), thermoplastic polyurethane (TPU), polyetheretherketone (PEEK), polyetherketoneketone (PEKK), polyphenylene sulfide (PPS), polyamide (PA), polystyrene (PS), and the fibers being chosen from glass, carbon, aramid fibers and / or natural fibers, in particular hemp, linen and / or silk.

10. The manufacturing method of claim 9, wherein the second polymer is thermoplastic polyurethane (TPU), polycarbonate (PC), or polyamide (PA), and the second fibers are glass fibers.

11. Manufacturing method according to one of claims 9 or 10, in which step E2 comprises the following steps: E21) supplying the second composite material, E22) placing the second composite material in a manufacturing mold, the manufacturing mold having the ability to occupy a closed configuration and comprising two rigid manufacturing mold parts and delimiting two manufacturing cavities of left shape complementary to the left shape of the second layer, the two manufacturing mold parts being such that, in the closed configuration of the manufacturing mold, the two manufacturing mold parts are spaced apart by a predetermined air gap and delimit between them a cavity capable of receiving the second composite material, E23) heating the second composite material to a temperature substantially equal (to within 10°C) to the glass transition temperature of the second material, E24) applying to the second composite material, by the two manufacturing mold parts, a mechanical pressure greater than or equal to 5 bars,in particular of the order of 10 bars, by placing the manufacturing mold in the closing configuration, while controlling the cooling until reaching a temperature between 50°C and 150°C.,

12. Manufacturing method according to claim 11, wherein the two manufacturing mold parts are respectively constituted by the first and second mold parts (22, 24) of the assembly mold (20), step E2 comprising a step E20 consisting of modifying the air gap separating the two manufacturing mold parts in the closed configuration of the manufacturing mold in step E24, compared to the air gap (26) present in step E4 in the closed configuration of the assembly mold (20).

13. Manufacturing method according to one of claims 1 to 12, in which the second layer (14) has a thickness of less than 2 mm, preferably of the order of 1.5 mm.

14. Manufacturing method according to any one of claims 1 to 13, wherein during step E4, the pressure of the gas present in the cavity (28) of the assembly mold (20) is maintained, during the assembly period, below -0.5 bar, preferably between -0.7 bar and -1 bar.

15. Manufacturing method according to any one of claims 1 to 14, wherein step E4 comprises a step E41 during which the first and second mold parts (22, 24) of the assembly mold (20) exert, on the stack, a mechanical pressure (Fl) less than or equal to 5 bars.

16. Manufacturing method according to claim 15, in which step E41 begins after the functional temperature (Tfonc) is reached, after a predetermined non-zero period (A) of between 0.5 min and 2 min and preferably of the order of 1 min.

17. Manufacturing method according to one of claims 15 or 16, in which step E41 is carried out during a period of between 30 s and 10 min.

18. Manufacturing method according to any one of claims 1 to 17, comprising a step E5 consisting of heating the assembly mold (20) to a temperature greater than or equal to the functional temperature (Tfonc), step E5 being implemented before step E4.

19. A manufacturing method according to any one of claims 1 to 17, comprising a step E6 consisting of heating the stack by means of an infrared heat source, step E6 being carried out after step E3 and before step E4.

20. Manufacturing method according to any one of claims 1 to 19, comprising a step E7 of cooling the stack, said step E7 being carried out while the first and second mold parts (22, 24) of the assembly mold (20) exert, on the stack, a mechanical pressure less than or equal to 5 bars.

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