WO2024000162A1 - Photovoltaic module and method for producing a photovoltaic module - Google Patents

Photovoltaic module and method for producing a photovoltaic module Download PDF

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Publication number
WO2024000162A1
WO2024000162A1 PCT/CN2022/101902 CN2022101902W WO2024000162A1 WO 2024000162 A1 WO2024000162 A1 WO 2024000162A1 CN 2022101902 W CN2022101902 W CN 2022101902W WO 2024000162 A1 WO2024000162 A1 WO 2024000162A1
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WO
WIPO (PCT)
Prior art keywords
substrate
junction box
cell
box
photovoltaic
Prior art date
Application number
PCT/CN2022/101902
Other languages
French (fr)
Inventor
Shou PENG
Liyun MA
Ganhua FU
Xinjian Yin
Alexander Katzung
Thomas Etzrodt
Original Assignee
China Triumph International Engineering Co., Ltd.
Ctf Solar Gmbh
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by China Triumph International Engineering Co., Ltd., Ctf Solar Gmbh filed Critical China Triumph International Engineering Co., Ltd.
Priority to PCT/CN2022/101902 priority Critical patent/WO2024000162A1/en
Publication of WO2024000162A1 publication Critical patent/WO2024000162A1/en

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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02S—GENERATION OF ELECTRIC POWER BY CONVERSION OF INFRARED RADIATION, VISIBLE LIGHT OR ULTRAVIOLET LIGHT, e.g. USING PHOTOVOLTAIC [PV] MODULES
    • H02S40/00—Components or accessories in combination with PV modules, not provided for in groups H02S10/00 - H02S30/00
    • H02S40/30—Electrical components
    • H02S40/34—Electrical components comprising specially adapted electrical connection means to be structurally associated with the PV module, e.g. junction boxes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/02—Details
    • H01L31/02002—Arrangements for conducting electric current to or from the device in operations
    • H01L31/02005—Arrangements for conducting electric current to or from the device in operations for device characterised by at least one potential jump barrier or surface barrier
    • H01L31/02008—Arrangements for conducting electric current to or from the device in operations for device characterised by at least one potential jump barrier or surface barrier for solar cells or solar cell modules
    • H01L31/02013—Arrangements for conducting electric current to or from the device in operations for device characterised by at least one potential jump barrier or surface barrier for solar cells or solar cell modules comprising output lead wires elements
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/04—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices
    • H01L31/042—PV modules or arrays of single PV cells
    • H01L31/048—Encapsulation of modules

Definitions

  • the invention concerns a photovoltaic module and a method for producing such a photovoltaic module.
  • Photovoltaic modules comprise at least one or a plurality of photovoltaic cells arranged on a cell substrate, a frame for mounting the photovoltaic module to a base, for instance a roof or a wall of a building, and at least one junction box for electrically connecting the photovoltaic cell (s) of one photovoltaic module to the photovoltaic cell (s) of another photovoltaic module or to an electrical output.
  • Photovoltaic modules often comprise further substrates, for instance a front substrate arranged on a front side of the cell substrate, i.e. on a side on which light impinges onto the photovoltaic cell (s) , and/or a back substrate arranged on a back side of the cell substrate, i.e.
  • a substrate stack comprising the cell substrate and at least one further substrate may be formed.
  • the frame may be arranged on a back side of the photovoltaic module, for instance on a back side of the substrate stack, in particular on a back side of a back substrate, or may be arranged on the edge of the photovoltaic module such that it clasps the cell substrate or the substrate stack.
  • the at least one junction box into the photovoltaic module. If the photovoltaic module is not transparent, the junction box may be arranged on the back side of the photovoltaic module at any place of the lateral extension of the photovoltaic module, for instance in the centre of the photovoltaic module (with respect to its lateral extensions) . However, if the photovoltaic module is transparent, such a junction box would be visible and would therefore disturb the appearance and the functionality of the photovoltaic module with respect to its transparency.
  • WO 2013/080691 A1 describes a solar module comprising two substrates, i.e. a cell substrate and a back substrate, wherein the junction box is arranged in a corner of the solar module.
  • the substrates of the solar module are both cut, i.e. removed, in the respective corner of the solar module and the junction box is provided on the side of both substrates.
  • a frame shaped like a U clasps the edges of the substrates and the junction box. Wires protruding from the junction box and being suited for connecting the junction box to other junction boxes or to an electric terminal are fed through the frame to the side of the solar module or to the front face of the solar module.
  • US 2017/0194900 A1 discloses a similar solar module, wherein, however, only the back substrate has a cutout portion or a hole and the junction box is mounted over the cutout portion or hole such that a conductive lead may connect the photovoltaic cells with the junction box.
  • the junction box is nevertheless arranged at least partially on the back substrate.
  • the frame again is formed such that it clasps the substrate stack and surrounds the edges of it, wherein, however, the junction box may not be clasped by the frame or only a flange base portion of the junction box is clasped by the frame.
  • JP 5031698 B2 describes a solar module with a cell substrate and a front substrate, wherein the cell substrate comprises a cutout portion at a corner of the solar module.
  • a junction box has a recessed triangular shape on its front side and a square shape on its back side. The recessed shape corresponds like a negative to the cutout portion of the cell substrate and provides electrical contact to the solar cell (s) on the cell substrate.
  • the front side of the junction box is attached to the back side of the front substrate, whereas the square portion of the junction box is attached to the back side of the cell substrate.
  • Wires for connecting the junction box to other junction boxes or to an electrical terminal protrude to the centre of the solar module with respect to its lateral extensions.
  • a frame may be provided such that it clamps the edges of the substrate stack and the junction box.
  • a photovoltaic module comprises at least the following elements:
  • a substrate stack comprising at least a transparent cell substrate, at least one photovoltaic cell being arranged on the cell substrate, a back substrate, and a junction box, the junction box comprising a terminal for electrically contacting the at least one photovoltaic cell and a wire or a female or male connector for connection to other devices, and
  • the cell substrate and the back substrate are joined to each other with the at least one photovoltaic cell in between and wherein the back substrate comprises a cutout portion being arranged at an edge of the back substrate.
  • the junction box has the same shape and size as the cutout portion of the back substrate and is arranged within the cutout portion of the back substrate.
  • the junction box is directly electrically connected via its terminal to an electrical terminal of the at least one photovoltaic cell.
  • the junction box is adhesively connected with the cell substrate on a first surface of the junction box and with the back substrate on a first side surface of the junction box.
  • the wire or the female or male connector is arranged on a second side surface of the junction box different from the first side surface and being arranged at an edge of the substrate stack.
  • the frame is arranged only on and adhesively connected with a back side of the substrate stack. That is, the frame is not arranged on an edge or a front side of the substrate stack.
  • the frame has no contact to the front side of the substrate stack which is usually the case with clamped frames. Since the frame is not clamped around the edge of the substrate stack, it enables maximising the active area of the photovoltaic module.
  • the photovoltaic module according to the invention comprises a cell substrate without any cutout sections, so that the whole cell substrate can be used for arranging the at least one photovoltaic cell on.
  • the junction box is not visible from the direction sunlight enters the photovoltaic module, when it is in use, since the junction box is advantageously hidden under the frame.
  • Such a photovoltaic module is especially suitable as building integrated photovoltaic module.
  • the frame does not need to have an opening, cutout and so on for the passage of the wire or the female or the male connector.
  • the junction box is advantageously arranged within the cutout portion of the back substrate.
  • the edge of the junction box means a plane surrounding and limiting the junction box to the environment and comprising the side surfaces of the junction box.
  • a photovoltaic module according to the invention means any type of photovoltaic module, like a crystalline or a thin film photovoltaic module, preferably a thin film photovoltaic module.
  • a crystalline photovoltaic module comprises at least one crystalline photovoltaic cell being arranged on the transparent cell substrate.
  • a thin film photovoltaic module comprises at least one thin film photovoltaic cell being arranged on the transparent cell substrate.
  • the photovoltaic module is a thin film photovoltaic module with a plurality of thin film photovoltaic cells arranged on the transparent cell substrate and electrically interconnected with each other.
  • the article “a” respectively “the” also means “at least one” respectively “the at least one” , meaning that the photovoltaic module may comprise at least one junction box, the at least one junction box comprising at least one terminal for electrically contacting the at least one photovoltaic cell and at least one wire or at least one female or male connector for connection to other devices.
  • the cutout portion it is obvious that the back substrate may comprise at least one cutout portion respectively at least one cutout portion may be formed.
  • the junction box comprises two wires or a female and a male connector. In further embodiments, the junction box comprises one wire or a female or a male connector. In some embodiments, one junction box per photovoltaic module may be sufficient. In other cases, the photovoltaic module comprises at least two junction boxes. In further embodiments, the photovoltaic module comprises four junction boxes, each comprising at least one wire or a female or a male connector.
  • the at least one wire or the at least one female or male connector is arranged on the second side surface of the junction box means that the second side surface of the junction box comprises at least one opening for the passage of the at least one wire or the at least one female or male connector.
  • no adaption of the frame, like forming an opening for the passage of the at least one wire is necessary, so that manufacturing processes of the frame can be simplified.
  • the frame may be any frame suitable for holding the substrate stack when mounted at a place of use, for instance on a roof or on a wall of a building. That is, the material, size and shape of the frame may be chosen freely according to the conditions of use.
  • the frame is made of stainless steel, alloyed metallic materials such as aluminium alloys, plastics or similar materials known from the state of the art and is formed such that it runs along the circumference of the back side of the substrate stack.
  • the frame has a T-shape or a Double-T-shape or a C-shape.
  • the back substrate is preferably a transparent substrate, like for instance a glass substrate.
  • Transparent means that the cell substrate or the back substrate, respectively, is transparent for electromagnetic radiation with wavelengths in the visible range as well as wavelengths absorbed by the at least one photovoltaic cell arranged on the transparent cell substrate.
  • the at least one cutout portion of the back substrate has a triangular shape, viewed from a direction along the thickness of the substrate stack respectively back substrate. The at least one cutout portion may have any other shape as well.
  • the transparent cell substrate and/or the back substrate are glass substrates.
  • the front side of the substrate stack is directed towards sunlight when the photovoltaic module is in use.
  • the substrate stack further has a back side opposite to the front side.
  • the cell substrate of the substrate stack is always closer to the front side of the substrate stack as the back substrate.
  • the substrate stack may comprise further substrates arranged on the front side of the cell substrate and/or on the back side of the back substrate.
  • the cell substrate and the back substrate each comprise a front side and a back side, wherein the front side of the cell substrate respectively the back substrate is directed towards sunlight when the photovoltaic module is in use, and the back side of the cell substrate respectively back substrate is opposite to the front side of the cell substrate respectively back substrate.
  • the back side of the back substrate is a part of the back side of the substrate stack.
  • the cell substrate and the back substrate have the same shape and size and lie congruently above each other. Size means thereby extensions of the cell substrate respectively back substrate along a first and a second in-plane direction perpendicular to each other and each perpendicular to a thickness of the cell substrate respectively back substrate.
  • the thickness of the cell substrate respectively back substrate means an extension along the direction sunlight enters the photovoltaic module.
  • the shape of the cell substrate respectively back substrate means a polygonal shape resulting from the extensions of the cell substrate respectively the back substrate along the first and the second in-plane direction, preferably a square or rectangular shape.
  • an edge of the cell substrate and the edge of the back substrate except the cutout portion form a part of the edge of the substrate stack.
  • the edge of the any substrate of the present invention or of the substrate stack means a side surface surrounding the respective substrate or the substrate stack perpendicular to the in-plane extensions of the respective substrate or the substrate stack extending over the thickness of the respective substrate or substrate stack and limiting the respective substrate or the substrate stack along the first and second in-plane direction to the environment.
  • the cell substrate and the back substrate are joined to each other with the at least one photovoltaic cell in between, for instance via an encapsulation foil, like an PVB (polyvinyl butyral) foil, wherein the encapsulation foil comprises at least one cutout portion, identical in size and shape to the at least one cutout portion of the back substrate and arranged on the cell substrate such that the at least one cutout portion of the encapsulation foil and the at least one cutout portion of the back substrate lie congruently on top of each other.
  • the back substrate comprises at least one further cutout portion and the encapsulation foil comprises at least one further cutout portion identical in shape and size to the at least one further cutout portion of the back substrate.
  • the encapsulation foil is arranged on the cell substrate such that also the at least one further cutout portion of the encapsulation foil and the at least one further cutout portion of the back substrate lie congruently on top of each other.
  • junction box is adhesively connected with the cell substrate and/or with the at least one photovoltaic cell arranged on the cell substrate on the first surface of the junction box. Further, the junction box is adhesively connected with the back substrate such that the first side surface of the junction box adjoins an edge or side surface of the cutout portion of the back substrate.
  • the terminal of the at least one junction box may be formed as a solder joint arranged at the first surface of the junction box or in an opening in the first surface of the junction box.
  • the electrical terminal of the at least one photovoltaic cell is arranged on that surface of the cell substrate or of the at least one photovoltaic cell, which is directed towards the back substrate.
  • the electrical terminal of the at least one photovoltaic cell may be formed on or beside the at least one photovoltaic cell and may be formed as a side busbar.
  • a side busbar according to the invention is a conducting line or strip comprising a conducting material to collect and conduct electrical charge carriers generated within the thin film photovoltaic module.
  • the electrical terminal of the at least one photovoltaic cell is a cell connector, usually used to connect crystalline photovoltaic cells within a photovoltaic module to each other.
  • the junction box comprises a second surface of the junction box lying opposite to the first surface of the junction box.
  • the first and the second surface of the junction box are located along the thickness direction of the substrates respectively the substrate stack.
  • the junction box further comprises at least the first side surface and the second side surface of the junction box each perpendicular to the first surface and the second surface of the junction box.
  • the first side surface of the junction box is directed towards the substrate stack and the second side surface is directed to the outside and in direct contact with the surrounding environment.
  • the junction box comprises further side surfaces, like a third side surface, wherein further side surfaces may be directed towards the substrate stack or towards the outside.
  • the junction box has a triangular shape, wherein the third side surface is directed to the outside, and the second side surface and the third side surface of the junction box touch each other under an angle of 90 degrees.
  • the junction box is made of a polymeric material.
  • the junction box comprises at least a junction box body.
  • the junction box body comprises at least the first surface and the side surfaces of the junction box.
  • the junction box body may be filled with a potting material forming the second surface of the junction box.
  • a potting material may be a polymeric potting material, like for instance but not limiting to 2-component silicone compounds, thermosetting plastics, epoxy resins, silicone rubber gels or similar materials known from the state of the art.
  • the junction box further comprises a lid arranged and connected with the junction box body and forming at least a part of the second surface of the junction box.
  • the junction box body and the lid are formed such that a click closure between the junction box body and the lid is formed.
  • junction box is arranged at an edge of the substrate stack such that at least one side surface of the junction box is a part of an edge of the substrate stack substituting a part of the edge of the back substrate.
  • the frame is adhesively connected with the back side of the substrate stack directly or indirectly.
  • a spacer may be arranged between the back side of the substrate stack and the frame.
  • the spacer may be a polymeric spacer or a spacer made from metals or metallic alloys.
  • Adhesively connected means a connection formed via an adhesive, applied for instance as a tape, a paste, a resin, a polymer, a glue or a thermoplastic laminate known from state of the art.
  • the substrate stack has a square, i.e. quadrangular, shape and the cutout portion and the junction box are arranged at a corner of the substrate stack.
  • the second side surface and a third side surface of the junction box are directed to the outside and form a part of the edge of the substrate stack. If the substrate stack has a rectangular shape, the second side surface and the third side surface of the junction box touch each other under an angle of 90 degrees.
  • a cutout portion and a junction box may be arranged at some or each of the four corners of a square shaped substrate stack.
  • the substrate stack has a rectangular shape
  • the photovoltaic module comprises four cutout portions of the back substrate and four junction boxes, each of them being arranged at a corner of the substrate stack.
  • This enables electrical connection of a plurality of photovoltaic modules to a photovoltaic system.
  • special photovoltaic module designs like for instance submodules, may be realized.
  • a submodule means a first subset of the at least one photovoltaic cell respectively a plurality of photovoltaic cells electrically connected to each other and forming a submodule arranged on the cell substrate.
  • at least two submodules may be arranged on the cell substrate, wherein the submodules are not electrically connected to each other.
  • At least one of the four junction boxes may be used as a “dummy junction box” which is electrically connected to a terminal of the at least one photovoltaic cell, but is not electrically connected to other photovoltaic modules or other devices. That is, such a dummy junction box is like a reserve junction box which may be used as a replacement in case another junction box used for electrical connection to other photovoltaic modules or devices wears or breaks down.
  • the substrate stack further comprises a front substrate being arranged and joined to the cell substrate at a surface being opposite to the surface on which the at least one photovoltaic cell is arranged.
  • a photovoltaic module with three substrates, preferably transparent substrates like glass substrates, is achieved with increased mechanical stability.
  • the front substrate is joined to the cell substrate via an encapsulation foil.
  • the front substrate is a transparent substrate, preferably a glass substrate.
  • the front substrate has the same size and shape as the cell substrate.
  • the back side of the substrate stack is formed by the back side of the back substrate and the second surface of the junction box.
  • the frame is then arranged on and adhesively connected with the back side of the back substrate and the second surface of the junction box opposite to the first surface of the junction box.
  • a step would be present between the second surface of the junction box and the back side of the back substrate.
  • the adhesive may be thicker on the lower component, which is usually the back substrate.
  • a spacer may be provided to level this step and to provide a plane surface for adhesive connection of the frame to the back side of the substrate stack.
  • the substrate stack further comprises an isolation substrate, wherein the isolation substrate is arranged on and adhesively connected to the back substrate at a surface being opposite to the surface joined to the cell substrate, i.e. the back side of the back substrate. Further, the isolation substrate is arranged on and adhesively connected to the second surface of the junction box opposite to the first surface of the junction box. In both cases, the isolation substrate may be connected to the back substrate or the junction box, respectively, not across the whole extension of the back side of the back substrate or of the second surface of the junction box, but only on some places with a limited lateral extension. A gas and liquid tight sealing is formed at the edge of the isolation substrate such that a gas and liquid tight isolation space is formed between the back substrate and the isolation substrate.
  • the back side of the substrate stack is formed by a back side of the isolation substrate being that surface of the isolation substrate opposite to the surface of the isolation substrate which is connected to the back substrate.
  • Such a photovoltaic module is suitable as building integrated photovoltaic module and may be used for instance instead of an ordinary insulating glass window offering additional functionality for energy generation.
  • the isolation substrate is a transparent substrate, for instance a glass substrate. In further embodiments, the isolation substrate has the same size and shape as the cell substrate.
  • the isolation substrate comprises a front side and the back side opposite to each other, wherein the front side is directed towards the back substrate the isolation substrate is adhesively connected to.
  • a gas and liquid tight isolation space between the back substrate and the isolation substrate is formed by the gas and liquid tight sealing.
  • a gas and liquid tight sealing means a sealing material, like an edge seal commonly used in insulating glass windows. Such an edge seal may be a galvanised, aluminium, stainless steel or polymeric edge seal, for instance a polymeric composite edge seal.
  • the sealing means is arranged along the edge of the back substrate respectively isolation substrate to ensure an isolation space between the back substrate and the isolation substrate.
  • the sealing means is adhesively connected with the back side of the back substrate and the front side of the isolation substrate and sealed with another sealing material, like for instance polysulfide, polyurethane or silicone at the edge of the substrate stack.
  • the sealing means may also be arranged on and adhesively connected to the second surface of the junction box.
  • the gas and liquid tight isolation space between the back substrate and the isolation substrate is filled with an inert gas, like for instance argon.
  • the photovoltaic module comprises two photovoltaic cells which are not electrically connected to each other via electrical conductors arranged on the cell substrate or arranged between the cell substrate and the back substrate.
  • the back substrate comprises at least one further cutout portion being arranged at an edge of the back substrate at a position corresponding to the position of an electrical terminal of at least one of the two photovoltaic cells being not electrically connected to each other.
  • the substrate stack further comprises at least one connection box comprising at least one terminal for electrical contacting one of the two photovoltaic cells being not electrically connected to each other.
  • the at least one connection box has the same shape and size as the further cutout portion of the back substrate, is arranged in the further coutout portion of the back substrate and is directly electrically connected via its terminal to the electrical terminal of the one of the two photovoltaic cells being not electrically connected to each other.
  • the at least one connection box is adhesively connected with the cell substrate or at least one of the photovoltaic cells on a first surface of the connection box and with the back substrate on a first side surface of the connection box.
  • Two photovoltaic cells which are not electrically connected to each other may be at least two photovoltaic cells or at least two subsets of a plurality of electrically interconnected photovoltaic cells as described above. That is, a first photovoltaic cell or a first subset of a plurality of photovoltaic cells electrically connected to each other forms a first submodule, and a second photovoltaic cell or a second subset of a plurality of photovoltaic cells electrically connected to each other forms a second submodule. Although the first submodule and the second submodule are arranged each on the cell substrate, they are not electrically connected to each other. Of course the photovoltaic module may comprise more than two submodules.
  • the photovoltaic cells i.e. the submodules
  • the photovoltaic cells may be so called half cells, preferably crystalline half cells.
  • half cells offer known advantages like reduced resistive losses, increased performance and in particular a higher performance at partial shading conditions.
  • the at least one further cutout portion is preferably arranged at a position different from a corner of the back substrate.
  • the at least one connection box comprises a second surface of the connection box being opposite to the first surface of the connection box.
  • the first and the second surface of the connection box are located along the thickness direction of the substrates respectively substrate stack.
  • the second surface of the connection box may form a part of the back side of the substrate stack and may be adhesively connected to the frame or may be adhesively connected to an isolation substrate as described above with respect to the second surface of the junction box for different embodiments.
  • the at least one connection box further comprises at least the first side surface and a second side surface of the connection box each perpendicular to the first and the second surface of the connection box.
  • the first side surface of the connection box is directed towards the back substrate.
  • the second side surface of the connection box is arranged at the edge of the substrate stack and directed to the outside and is in direct contact with the surrounding environment.
  • the second side surface of the connection box forms a part of the edge of the substrate stack.
  • the at least one connection box comprises two terminals for electrical contacting each of the two submodules and an electrical conductor, e.g. a wire, for electrically connecting the two terminals.
  • the connection box internally connects the two submodules.
  • the at least one connection box further comprises at least one wire or at least one female or one male connector for connection to other devices and arranged at the second side surface of the connection box.
  • the at least one connection box is formed as a junction box as described above and may be used for electrically connecting at least one of the two submodules with other devices.
  • connection box may comprise more than two terminals for electrical contacting more than two submodules and may also comprise more than one electrical conductor or more than two wires or more than two female or male connectors for connection to other submodules or devices.
  • the at least one connection box has the same size and shape as the at least one further cutout portion of the back substrate and is arranged within the at least one further cutout portion of the back substrate.
  • an edge of the connection box formed at least by the second side surface of the connection box forms a part of the edge of the substrate stack, and the connection box forms a part of the substrate stack.
  • the at least one further cutout portion has a square shape, in particular a rectangular shape or a circular or elliptical shape, viewed from a direction along the thickness of the back substrate.
  • the at least one terminal of the at least one connection box may be formed as a solder joint.
  • the electrical terminals of the at least two submodules are arranged on that surface of the cell substrate or of the at least one photovoltaic cell, which is directed towards the back substrate.
  • the electrical terminals of the two submodules may be formed on or beside the respective submodule and may be formed as a side busbar or a cell connector.
  • the junction box comprises a box frame having a width in the range of 3 mm to 20 mm.
  • the width means an extension of the box frame perpendicular to the side surfaces of the junction box.
  • the box frame has a width in the range of 10 mm to 20 mm.
  • the box frame is part of the junction box body and forms the side surfaces of the junction box and respectively forms the edge of the junction box.
  • a wide box frame improves the adhesive connection between the junction box and the cell substrate or the surface of the photovoltaic cells as well as between the junction box and the frame or –if present -an isolation substrate, since it increases the size of the first and the second surface of the junction box.
  • a wide box frame improves the mechanical stability of the junction box.
  • the box frame has a width w 1 in the range of 3 mm to 20 mm, preferably in the range of 10 mm to 20 mm, at least at that side surfaces of the junction box which are directed to the outside and in direct contact with the surrounding environment, i.e. at least at the second side surface.
  • the box frame has the width w 1 also at the first side surface and/or further side surfaces of the junction box.
  • the box frame has a width w 2 smaller than the width w 1 at least at the first side surface of the junction box with which the junction box is adhesively connected to the back substrate.
  • the box frame is formed as a double-walled box frame.
  • a double-walled box frame according to the invention means a box frame with at least an inner and an outer wall with a distance to each other in the range of 3 mm to 30 mm.
  • the inner wall and the outer wall may have a width or thickness in the range of 2 mm to 10 mm, wherein the thickness of the inner wall may be different from or equal to the thickness of the outer wall.
  • the thickness of the inner wall and of the outer wall as well as the distance to each other may vary for different side surfaces of the junction box formed by the box frame.
  • the inner wall of the box frame is directed to the inside of the junction box and the outer wall is directed to the outside of the junction box and in direct contact with the back substrate or the surrounding environment.
  • the outer wall forms the side surfaces of the junction box respectively the edge of the junction box.
  • the inner and the outer wall of the double-walled box frame are connected via at least one cross strut, wherein the at least one cross strut is moulded on the inner and/or the outer wall of the double-walled frame of the junction box.
  • the stability of the double-walled frame is increased.
  • the inner and the outer wall of the double-walled box frame of the junction box are connected via a plurality of cross struts, forming a plurality of compartments within the distance between the inner and the outer wall.
  • the distance between the inner and the outer wall of the double-walled box frame respectively the plurality of compartments may be filled with a potting material, like a polymeric potting material, like for instance but not limiting 2-component silicone compounds, thermosetting plastics, epoxy resins, acrylic and butylic resins, silicone rubber gels or similar materials known from the state of the art.
  • a first part of the second surface of the junction box may be formed.
  • the lid of the junction box is attached via a click closure to the double-walled box frame, forming at least a part of the second surface of the junction box.
  • the lid of the junction box is attached via a click closure to the inner wall of the double-walled frame of the junction box, forming a second part of the second surface of the junction box.
  • any combinations of the different embodiments of the box frame are possible, e.g. a solid box frame with the width w 1 at the first side surface of the junction box and a double-walled box frame with or without cross struts at other side surfaces of the junction box directed to the outside.
  • the junction box body may further comprise a bottom forming at least a part of the first surface of the junction box and being connected to or formed integrally with the box frame.
  • the bottom may extend over the whole first surface of the junction box except the terminal of the junction box or may be smaller.
  • the bottom may have a thickness in the range of 0.5 mm to 4 mm, the thickness being measured in the direction of the thickness of the substrate stack.
  • the at least one connection box may comprise a box frame with the same characteristics as described above for the box frame of the junction box.
  • the invention also concerns a method for producing a photovoltaic module, wherein the method comprises at least the following steps:
  • junction box in the cutout portion of the back substrate and on the cell substrate such that the first surface of the junction box is arranged on the cell substrate and the first side surface of the junction box is adjacent to the back substrate and that the wire or the female or male connector is arranged on a second side surface different from the first side surface and forming an edge of the photovoltaic module, and forming an adhesive connection between the first surface of the junction box and the cell substrate and between the first side surface of the junction box and the back substrate,
  • the photovoltaic module produced by the inventive method may be a crystalline photovoltaic module or a thin film photovoltaic module, preferably a thin film photovoltaic module, wherein a crystalline photovoltaic module comprises at least one crystalline photovoltaic cell being arranged on the transparent cell substrate and a thin film photovoltaic module comprises at least one thin film photovoltaic cell being arranged on the transparent cell substrate.
  • the steps are performed in the following order a) , b) , c) , d) , e) , f) , g) and h) .
  • a glass substrate is provided as the transparent cell substrate in step a) .
  • the back substrate provided in step a) is a transparent back substrate, preferably a glass substrate.
  • the cell substrate and the back substrate have the same shape and size.
  • the junction box provided in step a) is made of a polymeric material.
  • the junction box provided in step a) comprises at least a junction box body.
  • the junction box body comprises thereby at least the first surface and the side surfaces of the junction box.
  • the junction box further comprises a lid arranged and connected with the junction box body and forming at least a part of a second surface of the junction box being opposite to the first surface of the junction box.
  • the junction box body and the lid are formed such that a click closure between the junction box body and the lid is formed.
  • step b) at least one cutout portion at an edge of the back substrate is formed by a cutting process, for instance by a laser cutting process.
  • the at least one cutout portion is formed at least at one corner of the back substrate.
  • step c) the cell substrate and the back substrate are joined to each other with the at least one photovoltaic cell arranged on the cell substrate in between by placing an encapsulation foil on that surface of the cell substrate the at least one photovoltaic cell is arranged on.
  • the encapsulation foil has the same shape and size as the cell substrate and comprises at least one cutout portion identical in shape size to the at least one cutout portion of the back substrate.
  • the encapsulation foil is placed on the cell substrate such that the at least one cutout portion of the encapsulation foil and the at least one cutout portion of the back substrate lie congruently on top of each other.
  • the adhesive in step d) may be applied as a tape, a paste, a resin, a polymer, a glue or a thermoplastic laminate.
  • the adhesive is applied on the first surface of the junction box at least along the circumference close to the edge of the junction box and on the first side surface of the junction box.
  • the adhesive in step d) may be applied on the back surface of the cell substrate and on the edge of the back substrate, in both cases in the cutout portion of the back substrate. That means, the adhesive may be applied in a region of the back side of the cell substrate with or without at least one photovoltaic cell arranged on and not covered by the encapsulation foil respectively the back substrate, i.e. the region of the cell substrate the at least one cutout portion of the encapsulation foil respectively the back substrate is arranged on, and on the cutted edge of the back substrate.
  • an adhesive connection between the first surface of the junction box and the cell substrate or the at least one photovoltaic cell arranged on the cell substrate and between the first side surface of the junction box and the back substrate, i.e. the edge of the cutout portion of the back substrate is formed by a temperature treatment, a radiation treatment or other methods known to a person skilled in the art.
  • the direct electrical contact between the terminal of the junction box and an electrical terminal of the at least one photovoltaic cell in step f) is formed by means of soldering, if the terminal of the junction box is formed as a solder joint.
  • the electrical terminal of the at least one photovoltaic cell is arranged on the back side of the cell substrate or directly on the photovoltaic cell.
  • the electrical terminal of the at least one photovoltaic cell may be formed as side busbar or as cell connector.
  • the junction box body may be filled with a potting material or a lid may be arranged on the junction box, each forming a part of the second surface of the junction box.
  • the adhesive in step g) may be applied as a tape, a paste, a resin, a polymer, a glue or a thermoplastic laminate.
  • the adhesive is applied on the back side of the substrate stack at a position corresponding to the position of the frame in the finished photovoltaic module, e.g. along the circumference of the substrate stack close to the edge of the substrate stack.
  • the substrate stack has a front side directed towards sunlight, when the photovoltaic module is in use and the back side, opposite to the front side.
  • the substrate stack may comprise further substrates arranged on the front side and/or the back side of the cell substrate or the back substrate, respectively.
  • the adhesive is applied on the frame.
  • step h) the frame is placed on the back side of the substrate stack, e.g. on the applied adhesive, and an adhesive connection between the back side of the substrate stack and the frame is formed by a temperature treatment, a radiation treatment or other methods known to a person skilled in the art.
  • the frame is placed congruent with the edge of the substrate stack.
  • the substrate stack has a square shape and the cutout portion and the junction box are arranged at a corner of the substrate stack.
  • a cutout portion and a junction box may be arranged at some or all of the four corners of a square shaped substrate stack.
  • the substrate stack has a rectangular shape
  • the photovoltaic module comprises four cutout portions of the back substrate and four junction boxes, each of them being arranged at a corner of the substrate stack.
  • the method further comprises the steps of providing a front substrate and joining it to the cell substrate at a surface being opposite to the surface on which the at least one photovoltaic cell is arranged, such that the substrate stack further comprises the front substrate.
  • the steps of providing a front substrate and joining it to the cell substrate are performed after step e) .
  • the provided front substrate may be a transparent substrate, for instance a glass substrate.
  • a photovoltaic module with three substrates, preferably transparent substrates like glass substrates, is produced.
  • the front substrate has the same size and shape as the cell substrate and is joint to the cell substrate such that the front substrate and the cell substrate lie congruently.
  • the back side of the substrate stack is formed by the second surface of the junction box being opposite to the first surface of the junction box and the back side of the back substrate, and in that an adhesive connection between the second surface of the junction box and the frame and between the back side of the back substrate and the frame is formed in step h) .
  • the second surface of the junction box is formed partly by the lid and/or the potting material as described above.
  • the method further comprises the following steps:
  • steps j) and k) are performed between steps f) and g) and wherein the substrate stack in steps g) and h) comprises also the isolation substrate, a back side of the isolation substrate forming the back side of the substrate stack.
  • this enables manufacturing a photovoltaic module suitable as building integrated photovoltaic module and for use for instance instead of an ordinary insulating glass window offering additional functionality for energy generation.
  • the isolation substrate provided in step i) is a transparent substrate, like for instance a glass substrate.
  • the provided isolation substrate has the same size and shape as the cell substrate.
  • an edge seal commonly used in insulating windows is applied as the gas and liquid tight sealing.
  • the edge seal will be arranged along the surrounding edge of the back substrate or on corresponding places of the isolation substrate to ensure an isolation space between the back substrate and the isolation substrate and will be adhesively connected with the back side of the back substrate and the front side of the isolation substrate.
  • the edge seal may be sealed with another sealing material, like for instance polysulfide, polyurethane or silicone, at the edge of the substrate stack.
  • the isolation space between the back substrate and the isolation substrate will be filled with an inert gas, like for instance argon.
  • Forming an adhesive connection between the back side of the back substrate and the isolation substrate and between the second surface of the junction box and the isolation substrate and a gas and liquid tight space between the back substrate and the isolation substrate may comprise a temperature treatment, a radiation treatment or other methods known to a person skilled in the art.
  • step a) further comprises providing two photovoltaic cells which are not electrically connected to each other and at least one connection box.
  • the method is then characterized by the following features:
  • Step b) further comprises forming a further cutout portion at an edge of the back substrate at a position corresponding to the position of an electrical terminal of at least one of the two photovoltaic cells being not electrically connected to each other, wherein the further cutout portion has the same size and shape as the at least one connection box.
  • Step d) further comprises applying an adhesive on a first surface of the at least one connection box and at least on a first side surface of the at least one connection box.
  • Step e) further comprises placing the at least one connection box in the further cutout portion of the back substrate and on the cell substrate such that the first surface of the at least one connection box is arranged on the cell substrate and the first side surface of the at least one connection box is adjacent to the back substrate, and forming an adhesive connection between the first surface of the at least one connection box and the cell substrate and between the first side surface of the at least one connection box and the back substrate.
  • Step f) further comprises forming a direct electrical contact between an electrical terminal of the at least one connection box and an electrical terminal of one of the two photovoltaic cells which are not electrically connected to each other.
  • the substrate stack in steps g) and h) comprises also the at least one connection box.
  • a photovoltaic module comprising at least two submodules can be produced.
  • the at least two photovoltaic cells which are not electrically connected to each other provided in step a) are arranged each on the cell substrate and form a submodule each.
  • the encapsulation foil arranged between the cell substrate and the back substrate comprises at least one further cutout portion identical in shape size to the at least one further cutout portion of the back substrate.
  • the encapsulation foil is placed on the cell substrate such that the at least one further cutout portion of the encapsulation foil and the at least one further cutout portion of the back substrate lie congruently on top of each other.
  • the at least one connection box may electrically connect the at least two submodules with each other, or may electrically connect at least one of the two submodules with another device, if the at least one connection box is formed as a junction box.
  • connection box With respect to further characteristics of the connection box, the same applies as described with respect to the photovoltaic module above.
  • an adhesive is alternatively or additionally applied on the back surface of the cell substrate and on the edge of the back substrate, in both cases in the further cutout portion of the back substrate. That means, the adhesive may be applied in a region of the back side of the cell substrate with or without at least one photovoltaic cell arranged on and not covered by the encapsulation foil respectively the back substrate, i.e. the region of the cell substrate the at least one further cutout portion of the encapsulation foil respectively the back substrate is arranged on, and on the cutted edge of the back substrate in this further cutout portion.
  • Placing the at least one connection box in the further cutout portion of the back substrate on the cell substrate in step e) includes also arranging the at least one connection box on the at least one photovoltaic cell arranged on the cell substrate such that the terminal of the connection box and the terminal of the photovoltaic cell may be electrically connected in step f) .
  • the at least one connection box forms a part of the substrate stack, i.e. the substrate stack comprises the connection box after forming an adhesive connection between the first surface of the connection box and the cell substrate and between the first side surface of the connection box and the back substrate.
  • the at least one terminal of the at least one connection box may be formed as a solder joint.
  • the electrical terminal of the one of the at least two photovoltaic cells being not electrically connected to each other is arranged on the surface of the cell substrate the photovoltaic cells are arranged on.
  • the electrical terminal of one of the two photovoltaic cells being not electrically connected to each other may be formed as side busbar or as a cell connector.
  • Fig. 1A shows a front view of an exemplary embodiment of a photovoltaic module, viewed along a z-direction light enters the photovoltaic module, when it is in use,
  • Fig. 1B shows a back view of Fig. 1A, viewed from the opposite direction
  • Fig. 1C shows a side view of the photovoltaic module according to Fig 1A and 1B, viewed along a y-direction
  • Fig. 1D shows an enlarged perspective exploded view of the encircled detail of Fig. 1C
  • Fig. 2A shows a cross section of the photovoltaic module of Fig. 1A to 1D along line C-C of Fig. 1B,
  • Fig. 2B shows a cross section of a further embodiment of a photovoltaic module, viewed along a y-direction
  • Fig. 3 shows a front view of another embodiment of a photovoltaic module, viewed along a z-direction light enters the photovoltaic module, when it is in use,
  • Fig. 4 shows a side view of another embodiment of a photovoltaic module, viewed along a y-direction
  • Fig. 5A shows a back view of another embodiment of a photovoltaic module along a z-direction opposite to the direction light enters the photovoltaic module, when it is in use,
  • Fig. 5B shows a cross section of the photovoltaic module of Fig. 5A along line A-A’ of Fig. 5A,
  • Fig. 6A shows a front view of another embodiment of a photovoltaic module along a z-direction light enters the photovoltaic module, when it is in use,
  • Fig. 6B shows a cross section through a part of the photovoltaic module of Fig. 6A, viewed along a y-direction
  • Fig. 6C shows a front view of another embodiment of a photovoltaic module along a z-direction light enters the photovoltaic module, when it is in use,
  • Fig. 6D shows a cross section through a part of the photovoltaic module of Fig. 6C, viewed along a y-direction
  • Fig. 7A shows schematically an embodiment of a junction box in a top view
  • Fig. 7B shows another embodiment of a junction box in a perspective view
  • Fig. 8 shows a process flow of a method for producing a photovoltaic module
  • Fig. 9A shows a part of a photovoltaic module produced according to the process flow in Fig. 8 after step S3,
  • Fig. 9B shows the part of the photovoltaic module of Fig. 9A prior to step S5,
  • Fig. 9C shows the part of the photovoltaic module of Fig. 9A after step S8.
  • Fig. 1A shows a front view of a photovoltaic module 100 along a z-direction light enters the photovoltaic module 100, when it is in use. Visible is a transparent cell substrate 11 on which the at least one photovoltaic cell are arranged on (the photovoltaic cell is not illustrated here) .
  • a junction box 20 and a frame 30 are indicated by dashed lines.
  • the junction box 20 comprises at least one wire 21 for connection to other devices.
  • the junction box 20 is arranged at a corner of the photovoltaic module 100.
  • Fig. 1B shows a corresponding back view of the photovoltaic module 100 of Fig. 1A viewed from an opposite z-direction. Visible are a back substrate 13 and the frame 30 arranged on the back substrate 13. Partly visible is the junction box 20 (indicated by partly dashed lines) arranged in at least one cutout portion 131 of the back substrate 13.
  • Fig. 1C shows a side view of the photovoltaic module 100 according to Fig 1A and 1B, viewed along a y-direction.
  • the photovoltaic module 100 comprises a substrate stack 10 comprising at least the transparent cell substrate 11, at least one photovoltaic cell 12 arranged on the cell substrate, the back substrate 13 and the junction box 20.
  • the junction box 20 is arranged in the cutout portion 131 of the back substrate 13, the cutout portion 131 being shown in Fig. 1B.
  • the junction box 20 is arranged at an edge 16 of the substrate stack 10.
  • the substrate stack 10 comprises a front side 14 and a back side 15 wherein the back side 15 of the substrate stack 10 is formed by a back side 133 of the back substrate 13 and a second surface 24 of the junction box 20.
  • the edge 16 of the substrate stack 10 is part of an edge 101 of the photovoltaic module 100 and is formed by an edge of the cell substrate 11, a second side surface 26 of the junction box 20 and an edge of the back substrate 13.
  • the cell substrate 11 and the back substrate 13 are joined to each other via an encapsulation foil (not shown) with the at least one photovoltaic cell 12 in between.
  • the junction box 20 is adhesively connected via an adhesive 40 with the cell substrate 11 on a first surface 23 of the junction box 20.
  • the junction box 20 is further adhesively connected via the adhesive 40 with the back substrate 13 on a first side surface 25 directed towards the back substrate 13, wherein the first side surface 25 is adhesively connected to an edge 132 of the cutout portion of the back substrate 13.
  • the junction box 20 comprises a terminal 22 for electrically contacting the at least one photovoltaic cell 12 and the wire 21 for connection to other devices.
  • the junction box 20 is directly electrically contacted via its terminal 22 to an electrical terminal (not shown) of the at least one photovoltaic cell 12.
  • the wire 21 is arranged on the second side surface 26 of the junction box 20 directed to the surrounding environment.
  • the frame 30 is arranged only on the back side 15 of the substrate stack 10 and is adhesively connected with the back side 15 of the substrate stack 10 via the adhesive 40.
  • only one adhesive 40 is shown here which realizes all adhesive connections of the junction box 20 with the cell substrate 11 and the back substrate 13 and of the frame 30 with the back substrate 13 and the junction box 20, different adhesives may be used for different adhesive connections.
  • Fig. 1D shows an enlarged perspective exploded view of the encircled detail of the photovoltaic module 100 of Fig. 1C. Visible is the cell substrate 11 with the at least one photovoltaic cell 12 arranged on the cell substrate 11 and the back substrate 13 joined to the cell substrate 11 with the at least one photovoltaic cell 12 in between.
  • the back substrate 13 comprises the cutout portion 131 arranged at an edge of the back substrate 13.
  • the junction box 20 is arranged in the cutout portion 131 wherein the junction box 20 comprises the wire 21.
  • the frame 30 is arranged only on and adhesively connected with the back side of the back substrate 13 and the second surface of the junction box 20 as described above.
  • the wire 21 may comprise connecting means like a female or a male connector.
  • Fig. 2A shows a cross section of the photovoltaic module of Fig. 1A to 1D along line C-C of Fig. 1B.
  • the components shown in Fig. 1C are not described again.
  • the junction box 20 comprises a junction box body and a lid 28.
  • the lid 28 forms at least a part of the second surface 24 of the junction box 20.
  • the junction box body comprises at least the first surface and the first and second side surfaces of the junction box as described with respect to Fig. 1C.
  • the side surfaces of the junction box form a box frame 27. Visible is the direct electrical connection of the terminal 22 of the junction box 20 with an electrical terminal 121 of the at least one photovoltaic cell 12 arranged on a surface of the cell substrate 11.
  • Fig. 2B shows a cross section of a further embodiment of a photovoltaic module 100, viewed along a y-direction similar to Fig. 2A.
  • a special embodiment of the frame 30 is shown.
  • the frame 30 comprises a recess on that side and at that position of the frame 30 where the frame 30 is arranged on the junction box 20. That is, the junction box 20 is arranged within this recess of the frame 30. This is particularly advantageous if the difference of the height (or thickness) of the back substrate 13 and the junction box 20 is high, for instance larger than 0.5 mm.
  • Fig. 3 shows a front view of a specific embodiment of the photovoltaic module 100 along a z-direction light enters the photovoltaic module, when it is in use. Visible is the transparent cell substrate 11 and a plurality of photovoltaic cells arranged on a back side of the cell substrate 11.
  • the photovoltaic cells may be thin film cells which are serial-connected to each other. In Fig. 3, only the first photovoltaic cell 12a and the last photovoltaic cell 12b in the serial connection are referenced.
  • two electrical terminals 121 are provided, wherein in each case one terminal 121 is provided on the upper end of the respective photovoltaic cell 12a, 12b and the other terminal 121 is provided on the lower end of the respective photovoltaic cell 12a, 12b with respect to y-direction.
  • the two terminals 121 of one individual photovoltaic cell 12a, 12b may also be connected by a side busbar.
  • four junction boxes 20a to 20d are provided. Each of the junction boxes 20a to 20d comprises a wire 21 for connection to other devices as described above.
  • Each junction box 20a to 20d is arranged in a respective cutout portion 131a to 131d of the back substrate and at a corner of the photovoltaic module.
  • Each of the terminals 121 of the photovoltaic cells 12a, 12b is connected to a respective electrical terminal (not shown) of a respective junction box 20a to 20d.
  • Providing a junction box at each corner of the photovoltaic module 100 has several advantages. First, the mechanical stability of the whole photovoltaic module 100 is increased, since the frame 30 now has the same supporting point at each corner. Further, the electrical connection of the photovoltaic module 100 to other devices may be improved due to two electrical connections at each side.
  • junction box 20b and 20c may be formed as dummy junction boxes not connected to other devices, but being suitable to be used as a replacement when the respective other junction box of the same side, i.e. the junction box 20a or 20d, breaks down.
  • Fig. 4 shows a side view of another embodiment of a photovoltaic module 100 along a y-direction.
  • the photovoltaic module 100 in this embodiment further comprises a front substrate 17, preferably a transparent glass, arranged on a front side of the cell substrate 11 which is directed towards sunlight entering the photovoltaic module 100 (indicated by the arrows) .
  • the front substrate 17 has the same size and shape as the cell substrate 11 and is adhesively connected to the cell substrate 11 via an encapsulation foil.
  • the substrate stack 10 now comprises the cell substrate 11, the at least one photovoltaic cell 12, the back substrate 13, the junction box 20 and the front substrate 17.
  • a front side of the front substrate 17 forms the front side 14 of the substrate stack.
  • the photovoltaic module 100 of this embodiment is a three glass photovoltaic module 100 comprising increased mechanical stability.
  • Fig. 5A shows a back view of another embodiment of a photovoltaic module 100 along a z-direction opposite to the direction light enters the photovoltaic module 100, when it is in use.
  • the photovoltaic module 100 in this embodiment further comprises an isolation substrate 18, preferably a transparent glass.
  • the isolation substrate 18 is arranged on and adhesively connected to the back substrate and the frame 30 is arranged on the isolation substrate 18 on the side opposite to the back substrate.
  • the photovoltaic module 100 in this embodiment comprises four junction boxes 20a to 20d each arranged within a cutout portion 131a to 131d of the back substrate.
  • a sealing 50 is shown which is not really visible since hidden beneath the frame 30, but shown for better understanding.
  • the sealing 50 is arranged at the circumference of the photovoltaic module 100 and will be explained further with respect to Fig. 5B.
  • Fig. 5B shows a cross section of the photovoltaic module 100 of Fig. 5A along line A-A’ of Fig. 5A. That is, the left part of the figure shows a cross section at a position where no junction box is arranged and the right part of the figure comprises a cross section at a position including the junction box 20a.
  • the isolation substrate 18 is arranged on and adhesively connected to the back substrate 13, preferably a transparent glass back substrate 13, at a surface being opposite to the surface of the back substrate 13 joined to the cell substrate 11 respectively the at least one photovoltaic cell 12.
  • the isolation substrate 18 is further arranged on and adhesively connected to the second surface of the junction box 20a opposite to the first surface 23 of the junction box 20a.
  • the substrate stack 10 now comprises the transparent cell substrate 11, the at least one photovoltaic cell 12 arranged on the cell substrate 11, the back substrate 13, the junction boxes 20a to 20d and the isolation substrate 18.
  • the isolation substrate 18 has the same size and shape as the cell substrate 11 and a backside 182 of the isolation substrate 18 forms the back side 15 of the substrate stack 10.
  • the sealing 50 is a gas and liquid tight sealing formed at the circumference of the isolation substrate 18 such that a gas and liquid tight isolation space 181 is formed between the back substrate 13 and the isolation substrate 18. That is, the sealing 50 is formed between the back substrate 13 and the isolation substrate 18 and also between the second surface of each junction box 20a to 20d and the isolation substrate 18.
  • the frame 30 is arranged only on the back side 182 of the isolation substrate 18 and is adhesively connected with it by the adhesive 40.
  • Fig. 6A shows a front view of another embodiment of a photovoltaic module 100 along a z-direction light enters the photovoltaic module 100, when it is in use. Visible is the transparent cell substrate 11 comprising at least two photovoltaic cells 12a, 12b which are not electrically connected to each other via electrical conductors arranged on the cell substrate 11 or arranged between the cell substrate 11 and the back substrate.
  • Each of the at least two photovoltaic cells 12a, 12b means, in the embodiment shown, a plurality of photovoltaic cells 12, in particular thin film photovoltaic cells, electrically connected to each other.
  • the photovoltaic cells 12a and 12b may also be referred to as a first submodule and a second submodule, wherein the first submodule and the second submodule are not electrically connected to each other and are arranged each on the cell substrate 11.
  • Shown by dashed lines are four junction boxes 20a to 20d, each of them being arranged at a corner of the photovoltaic module 100 and within a respective cutout portion 131a to 131d of the back substrate.
  • the back substrate comprises the four cutout portions 131a to 131d identical in shape and size with the four junction boxes 20a to 20d.
  • two connection boxes 60a and 60b are two connection boxes, each arranged at an edge of the photovoltaic module 100.
  • the back substrate comprises two further cutout portions 134a, 134b identical in size and shape with the connection boxes 60a, 60b. Also shown (although not necessarily visible in the front view) are electrical terminals 121 of the photovoltaic cells 12a, 12b.
  • the junction boxes 20a to 20d and the connection boxes 60a, 60b, respectively, are directly electrically connected to the electrical terminals 121 via electrical terminals of the junction boxes 20a to 20d respectively connection boxes 60a, 60b (not shown in Fig. 6A) .
  • the frame being part of the photovoltaic module 100 has been omitted in Fig. 6A for sake of clarity.
  • Fig. 6B shows a cross section through a part of the photovoltaic module 100 of Fig. 6A, viewed along a y-direction.
  • the cross section extends along the x-direction within the encircled portion of Fig. 6A, i.e. through a portion of the photovoltaic module 100 where the further cutout portion 134a and the connection box 60a are arranged.
  • Visible are the cell substrate 11 and the back substrate 13 with the photovoltaic cells 12a, 12b being arranged in between.
  • the photovoltaic cells or submodules 12a, 12b are not electrically connected to each other via electrical conductors arranged on the cell substrate 11 or between the cell substrate 11 and the back substrate 13.
  • connection box 60a comprises two electrical terminals 61 of the connection box 60a each for electrical contacting the electrical terminal 121 of one of the at least two photovoltaic cells 12a, 12b.
  • the connection box 60a is adhesively connected via an adhesive 40 to the cell substrate 11 on a first surface 62 of the connection box 60a and to the back substrate 13 on a first side surface 63 of the connection box 60a.
  • first side surface 63 is each side surface of the connection box 60a which faces the back substrate 13.
  • connection box 60a A side surface of the connection box 60a not facing the back substrate 13, but instead the surrounding environment or outside of the photovoltaic module 100 is called a second side surface of the connection box, which is however not referenced by a reference number in Fig. 6A and 6B.
  • the photovoltaic module 100 is shown here without the frame which is arranged on the back substrate 13 and on a second surface 64 of the connection box 60a, the second surface 64 lying opposite to the first surface 62.As described above with respect to the junction boxes, the frame is adhesively connected to the connection box 60a by the adhesive 40.
  • Fig. 6C shows a front view of another embodiment of a photovoltaic module 100 similar to Fig. 6A along a z-direction opposite to the direction light enters the photovoltaic module 100, when it is in use.
  • the photovoltaic module 100 comprises four connection boxes 60a to 60d (shown by dashed lines) , wherein always two of the four connection boxes 60a to 60d are arranged at a same edge of the back substrate 13.
  • the back substrate 13 comprises two further cutout portions 134a, 134b arranged at an edge of the back substrate 13.
  • Each of the further cutout portions 134a, 134b has a size and shape suitable for arranging two of the connections boxes 60a to 60d within the further cutout portion 134a, 134b. In other embodiments, there may be four further cutout portions each having a size and shape suitable for arranging one of the connections boxes 60a to 60d within the further cutout portion. In the embodiment shown here, in each of the two further cutout portions 134a, 134b, the two connection boxes 60a, 60d or 60b, 60c, respectively, are arranged adjacent to each other and such that each connection box 60a to 60d forms a part of an edge of the photovoltaic module 100. Each of the connection boxes 60a to 60d comprises at least one wire 21 or at least one female or one male connector.
  • each connection box 60a to 60d is formed like and serves as a junction box.
  • An electrical connection 602 electrically connects adjacent connection boxes 60a and 60d or 60b and 60c, respectively.
  • the individual connection boxes 60a to 60d may be electrically connected by wires 21 to other devices.
  • Fig. 6D shows a cross section through a part of the photovoltaic module 100 of Fig. 6B, viewed along a y-direction.
  • the cross section extends along the x-direction within the encircled portion of Fig. 6C, i.e. through a portion of the photovoltaic module 100 where the further cutout portion 134a and the connection boxes 60a and 60d are arranged. Visible are the cell substrate 11 and the back substrate 13 with the photovoltaic cells 12a, 12b being arranged in between.
  • Fig. 6D differs from Fig.
  • connection box 60a and 60d are arranged in the cutout portion 134a, wherein each connection box 60a, 60d comprises the wire 21 (not shown here) , which is internally electrically connected to the electrical terminal 61 of the respective connection box 60a or 60d and which is suited for being connected to other devices.
  • the two connection boxes 60a, 60d are adhesively connected via an adhesive 40 to the cell substrate 11 and the back substrate 13, but also to the other connection box 60a, 60d.
  • the frame is not shown in Fig. 6D although it is present in the photovoltaic module 100.
  • Fig. 7A shows schematically an embodiment of a junction box 20 in a top view on a second surface 24 of the junction box 20.
  • the second surface 24 is that surface of the junction box 20 which lies opposite to a surface of the junction box 20 which is adhesively connected to a cell substrate 11.
  • the junction box 20 comprises a wire 21 or at least one female or one male connector arranged at a second side surface 26 of the junction box 20 and a box frame 27 of the junction box 20.
  • the box frame 27 of the junction box 20 has a width w 1 in the range of 3 mm to 20 mm, preferably 10 mm to 20 mm, at least at the side surfaces of the junction box which are directed to the outside and in direct contact with the surrounding environment, for instance the second side surface 26 of the junction box 20.
  • the box frame 27 of the junction box 20 has a width w 2 smaller than w 1 at a first side surface 25 of the junction box 20, wherein the first side surface 25 is that side surface with which the junction box 20 will adhesively connected to a back substrate 13.
  • the junction box 20 further comprises a lid 28 closing the junction box 20 at the second surface 24 and being connected to the box frame 27. In other embodiments, the lid 28 may be omitted.
  • Fig. 7B shows another embodiment of a junction box 20 in a perspective view on a first side surface 25 and a top or second surface 24 of the junction box 20.
  • the first side surface 25 is that side surface facing a back substrate when the junction box 20 is mounted in a photovoltaic module.
  • the second surface 24 is that surface which lies opposite to a first surface connected to a cell substrate when the junction box is mounted in a photovoltaic module.
  • the junction box 20 in this embodiment comprises a double-walled box frame 27.
  • the double-walled box frame 27 comprises at least an outer wall 271 and an inner wall 272 with a distance to each other in the range of 3 mm to 25 mm.
  • the outer wall 271 is directed to the outside and in direct contact with the surrounding environment and forms the side surfaces, in particular the first and the second side surface 25, 26 of the junction box 20, respectively the edge of the junction box 20.
  • the inner wall 272 of the box frame 27 is directed to the inside of the junction box 20 and is formed only at that side surfaces of the junction box 20 which do not face the back substrate when mounted, i.e. is formed only with respect to the second side surface 26.
  • the inner and the outer wall 272, 271 of the double-walled box frame 27 are connected via at least one cross strut 273, wherein the at least one cross strut 273 is moulded on the inner and/or the outer wall 272, 271 of the double-walled box frame 27 of the junction box 20.
  • the inner and the outer wall 272, 271 of the double-walled box frame 27 are connected via a plurality of cross strut 273, forming a plurality of compartments 274 within the distance between the inner and the outer wall 272, 271.
  • the distance between the inner and the outer wall 272, 271 of the double-walled box frame 27 respectively the plurality of compartments 274 may be filled with a potting material, like a polymeric potting material, like for instance but not limiting to 2-component silicone compounds, thermosetting plastics, epoxy resins, silicone rubber gels or similar materials known from the state of the art.
  • the potting material may form a first part of the second surface 24 of the junction box 20.
  • the junction box 20 further comprises a lid 28 of the junction box 20 attached via a click closure 281 to the outer wall 271 of the double-walled box frame 27 at the first side surface 25 and to the inner wall 272 of the double-walled box frame 27 at the side surfaces facing the outside, i.e. at least the second side surface 26, in this embodiment.
  • the lid 28 forms at least a part of the second surface 24 of the junction box 20, e.g. a second part.
  • the lid 28 may be attached to the outer wall 271 of the double walled box frame 27, e.g. by a click closure, at all side surfaces of the junction box 20. In this case, the lid 28 forms the second surface 24 of the junction box.
  • Fig. 8 shows an exemplary process flow of a method for producing a photovoltaic module 100.
  • a transparent cell substrate 11, at least one photovoltaic cell 12 being arranged on the cell substrate 11, a back substrate 13, a junction box 20 comprising a terminal 22 for electrically contacting the at least one photovoltaic cell 12 and a wire 21 or a female or a male connector for connection to other devices, and a frame 30 are provided.
  • a cutout portion 131 at an edge of the back substrate 13 is formed, wherein the cutout portion 131 has the same shape and size as the junction box 20.
  • step S3 the cell substrate 11 and the back substrate 13 are joined to each other, for instance by an encapsulation foil, such that the at least one photovoltaic cell 12 is arranged in between.
  • step S4 an adhesive 40 is applied on a first surface 23 of the junction box 20 and a first side surface 25 of the junction box 20.
  • step S5 the junction box 20 is placed in the cutout portion 131 of the back substrate 13 and on the cell substrate 11 such that the first surface 23 of the junction box 20 is arranged on the cell substrate 11 and the first side surface 25 of the junction box 20 is adjacent to the back substrate 13 and that the wire 21 or the female or male connector is arranged on a second side surface 26 of the junction box 20.
  • the second side surface 26 is different from the first side surface 25 and forms an edge of the photovoltaic module 100.
  • step S5 an adhesive connection between the first surface 23 of the junction box 20 and the cell substrate 11 and between the first side surface 25 of the junction box 20 and the back substrate 13 is formed.
  • step S6 a direct electrical contact between the electrical terminal 22 of the junction box 20 and an electrical terminal 121 of the at least one photovoltaic cell 12 is formed.
  • step S7 an adhesive 40 is applied on a back side 133 of a substrate stack 10, wherein the substrate stack 10 comprises at least the cell substrate 11, the at least one photovoltaic cell 12, the back substrate 13 and the junction box 20.
  • the adhesive 40 is applied to the frame 30.
  • step S8 the frame 30 is placed on the back side 133 of the substrate stack 10 and an adhesive connection between the back side 133 of the substrate stack 10 and the frame 30 is formed.
  • Fig. 9A shows a photovoltaic module 100 produced according to the process flow in Fig. 8 after step S3. Visible is a back view of the photovoltaic module 100, viewed along a z-direction opposite to the direction light enters the photovoltaic module 100 when it is in use.
  • the cell substrate 11 with the at least one photovoltaic cell 12 (shown by dashed lines) arranged on and the back substrate 13 are already joined together by an encapsulation foil (not shown) .
  • the back substrate 13 has the cutout portion 131 formed in step S2 having the same size and shape as the junction box 20 provided in step S1.
  • the encapsulation foil comprises a cutout portion, identical in size and shape to the cutout portion 131 of the back substrate 13 and arranged on the cell substrate 11 such that the cutout portion of the encapsulation foil and the cutout portion 131 of the back substrate 13 lie congruently on top of each other. Also visible by a dashed line is a side busbar forming an electrical terminal 121 of the at least one photovoltaic cell 12, the electrical terminal 121 being arranged in the cutout portion 131 of the back substrate 13.
  • Fig. 9B shows a photovoltaic module 100 produced according to the process flow in Fig. 8 prior to step S5. Shown is the photovoltaic module 100 from Fig. 9A and the junction box 20 with an applied adhesive (not shown) on a first surface of the junction box (not shown) and a first side surface 25 of the junction box 20. The first surface of the junction box 20 is opposite to a second surface 24 of the junction box 20.
  • Step S5 the junction box 20 will be placed in the cutout portion 131 of the back substrate 13 as indicated by the arrow and will be adhesively connected on its first surface with the cell substrate 11 and on its first side surface 25 with the back substrate 13.
  • Fig. 9C shows a photovoltaic module 100 produced according to the process flow in Fig. 8 after step S8. Visible is the frame 30 adhesively connected to a back side of a substrate stack, wherein the substrate stack comprises the cell substrate 11, the back substrate 13, the at least one photovoltaic cell 12 in between, and the junction box 20.
  • the junction box 20 is fully covered by the frame 30 in this embodiments and is therefore not visible.
  • connection box
  • connection box 63 First side surface of the connection box

Abstract

The invention concerns a photovoltaic module comprising a substrate stack and a frame. The substrate stack comprises a cell substrate, at least one photovoltaic cell being arranged on the cell substrate, a back substrate, and a junction box. The cell substrate and the back substrate are joined to each other with the at least one photovoltaic cell in between and the back substrate comprises a cutout portion being arranged at an edge of the back substrate. The junction box has the same shape and size as the cutout portion of the back substrate, is arranged within the cutout portion of the back substrate, and is adhesively connected with the cell substrate on a first surface of the junction box and with the back substrate on a first side surface of the junction box. The frame is arranged only on and adhesively connected with a back side of the substrate stack.

Description

Photovoltaic module and method for producing a photovoltaic module
The invention concerns a photovoltaic module and a method for producing such a photovoltaic module.
Photovoltaic modules comprise at least one or a plurality of photovoltaic cells arranged on a cell substrate, a frame for mounting the photovoltaic module to a base, for instance a roof or a wall of a building, and at least one junction box for electrically connecting the photovoltaic cell (s) of one photovoltaic module to the photovoltaic cell (s) of another photovoltaic module or to an electrical output. Photovoltaic modules often comprise further substrates, for instance a front substrate arranged on a front side of the cell substrate, i.e. on a side on which light impinges onto the photovoltaic cell (s) , and/or a back substrate arranged on a back side of the cell substrate, i.e. a side opposite the front side. Thus, a substrate stack comprising the cell substrate and at least one further substrate may be formed. The frame may be arranged on a back side of the photovoltaic module, for instance on a back side of the substrate stack, in particular on a back side of a back substrate, or may be arranged on the edge of the photovoltaic module such that it clasps the cell substrate or the substrate stack. There are different ways for including the at least one junction box into the photovoltaic module. If the photovoltaic module is not transparent, the junction box may be arranged on the back side of the photovoltaic module at any place of the lateral extension of the photovoltaic module, for instance in the centre of the photovoltaic module (with respect to its lateral extensions) . However, if the photovoltaic module is transparent, such a junction box would be visible and would therefore disturb the appearance and the functionality of the photovoltaic module with respect to its transparency.
WO 2013/080691 A1 describes a solar module comprising two substrates, i.e. a cell substrate and a back substrate, wherein the junction box is arranged in a corner of the solar module. To this end, the substrates of the solar module are both cut, i.e. removed, in the respective corner of the solar module and the junction box is provided on the side of both substrates. A frame shaped like a U clasps the edges of the substrates and the junction box. Wires protruding from the junction box and being suited for connecting the junction box to other junction boxes or to an electric terminal are fed through the frame to the side of the solar module or to the front face of the solar module.
US 2017/0194900 A1 discloses a similar solar module, wherein, however, only the back substrate has a cutout portion or a hole and the junction box is mounted over the cutout portion  or hole such that a conductive lead may connect the photovoltaic cells with the junction box. The junction box is nevertheless arranged at least partially on the back substrate. The frame again is formed such that it clasps the substrate stack and surrounds the edges of it, wherein, however, the junction box may not be clasped by the frame or only a flange base portion of the junction box is clasped by the frame.
JP 5031698 B2 describes a solar module with a cell substrate and a front substrate, wherein the cell substrate comprises a cutout portion at a corner of the solar module. A junction box has a recessed triangular shape on its front side and a square shape on its back side. The recessed shape corresponds like a negative to the cutout portion of the cell substrate and provides electrical contact to the solar cell (s) on the cell substrate. The front side of the junction box is attached to the back side of the front substrate, whereas the square portion of the junction box is attached to the back side of the cell substrate. Wires for connecting the junction box to other junction boxes or to an electrical terminal protrude to the centre of the solar module with respect to its lateral extensions. A frame may be provided such that it clamps the edges of the substrate stack and the junction box.
The solutions of the prior art have some drawbacks. For instance, if the cell substrate is cut, the active area of the photovoltaic cell (s) is decreased. Feed throughs for wires for connecting the junction box with other solar modules or with an electrical terminal allow only the use of special frames adapted to the position of the junction box. If wires are directed to the centre of the solar module in order to avoid feed throughs through the frame, more space is needed, the transparency is reduced and the connection to other solar modules may be complicated. If the junction box is arranged on the back side of the substrate stack, the thickness of the whole solar module is increased.
It is an object of the invention to provide a photovoltaic module with an alternative arrangement of the junction box which may reduce or avoid some of the drawbacks of the prior art. Furthermore, it is an object of the invention to provide a method for forming such a photovoltaic module.
The object is solved by a photovoltaic module and a method according to the independent claims. Preferred embodiments are given in the dependent claims.
According to the invention a photovoltaic module comprises at least the following elements:
- a substrate stack comprising at least a transparent cell substrate, at least one photovoltaic cell being arranged on the cell substrate, a back substrate, and a junction box, the  junction box comprising a terminal for electrically contacting the at least one photovoltaic cell and a wire or a female or male connector for connection to other devices, and
- a frame,
wherein the cell substrate and the back substrate are joined to each other with the at least one photovoltaic cell in between and wherein the back substrate comprises a cutout portion being arranged at an edge of the back substrate.
According to the invention the junction box has the same shape and size as the cutout portion of the back substrate and is arranged within the cutout portion of the back substrate. The junction box is directly electrically connected via its terminal to an electrical terminal of the at least one photovoltaic cell. The junction box is adhesively connected with the cell substrate on a first surface of the junction box and with the back substrate on a first side surface of the junction box. The wire or the female or male connector is arranged on a second side surface of the junction box different from the first side surface and being arranged at an edge of the substrate stack. Furthermore, according to the invention, the frame is arranged only on and adhesively connected with a back side of the substrate stack. That is, the frame is not arranged on an edge or a front side of the substrate stack.
Advantageously, the frame has no contact to the front side of the substrate stack which is usually the case with clamped frames. Since the frame is not clamped around the edge of the substrate stack, it enables maximising the active area of the photovoltaic module. Moreover, the photovoltaic module according to the invention comprises a cell substrate without any cutout sections, so that the whole cell substrate can be used for arranging the at least one photovoltaic cell on. Furthermore, the junction box is not visible from the direction sunlight enters the photovoltaic module, when it is in use, since the junction box is advantageously hidden under the frame. Such a photovoltaic module is especially suitable as building integrated photovoltaic module. Furthermore advantageously, the frame does not need to have an opening, cutout and so on for the passage of the wire or the female or the male connector. Due to the same shape and size of the at least one junction box and the at least one cutout portion of the back substrate, the junction box is advantageously arranged within the cutout portion of the back substrate. A part of an edge of the junction box, the part comprising at least the second side surface of the junction box, forms a part of the edge of the substrate stack. The edge of the junction box means a plane surrounding and limiting the junction box to the environment and comprising the side surfaces of the junction box.
A photovoltaic module according to the invention means any type of photovoltaic module, like a crystalline or a thin film photovoltaic module, preferably a thin film photovoltaic module. A crystalline photovoltaic module comprises at least one crystalline photovoltaic cell being arranged on the transparent cell substrate. A thin film photovoltaic module comprises at least one thin film photovoltaic cell being arranged on the transparent cell substrate. In embodiments, the photovoltaic module is a thin film photovoltaic module with a plurality of thin film photovoltaic cells arranged on the transparent cell substrate and electrically interconnected with each other.
The article “a” respectively “the” also means “at least one” respectively “the at least one” , meaning that the photovoltaic module may comprise at least one junction box, the at least one junction box comprising at least one terminal for electrically contacting the at least one photovoltaic cell and at least one wire or at least one female or male connector for connection to other devices. The same applies to the cutout portion: it is obvious that the back substrate may comprise at least one cutout portion respectively at least one cutout portion may be formed.
In embodiments, the junction box comprises two wires or a female and a male connector. In further embodiments, the junction box comprises one wire or a female or a male connector. In some embodiments, one junction box per photovoltaic module may be sufficient. In other cases, the photovoltaic module comprises at least two junction boxes. In further embodiments, the photovoltaic module comprises four junction boxes, each comprising at least one wire or a female or a male connector.
The at least one wire or the at least one female or male connector is arranged on the second side surface of the junction box means that the second side surface of the junction box comprises at least one opening for the passage of the at least one wire or the at least one female or male connector. Advantageously, no adaption of the frame, like forming an opening for the passage of the at least one wire is necessary, so that manufacturing processes of the frame can be simplified.
The frame may be any frame suitable for holding the substrate stack when mounted at a place of use, for instance on a roof or on a wall of a building. That is, the material, size and shape of the frame may be chosen freely according to the conditions of use. In embodiments, the frame is made of stainless steel, alloyed metallic materials such as aluminium alloys, plastics or similar materials known from the state of the art and is formed such that it runs along the circumference of the back side of the substrate stack. In embodiments, the frame has a T-shape or a Double-T-shape or a C-shape.
The back substrate is preferably a transparent substrate, like for instance a glass substrate. Transparent means that the cell substrate or the back substrate, respectively, is transparent for electromagnetic radiation with wavelengths in the visible range as well as wavelengths absorbed by the at least one photovoltaic cell arranged on the transparent cell substrate. In embodiments, the at least one cutout portion of the back substrate has a triangular shape, viewed from a direction along the thickness of the substrate stack respectively back substrate. The at least one cutout portion may have any other shape as well. In embodiments, the transparent cell substrate and/or the back substrate are glass substrates.
The front side of the substrate stack is directed towards sunlight when the photovoltaic module is in use. The substrate stack further has a back side opposite to the front side. The cell substrate of the substrate stack is always closer to the front side of the substrate stack as the back substrate. In embodiments, the substrate stack may comprise further substrates arranged on the front side of the cell substrate and/or on the back side of the back substrate.
The cell substrate and the back substrate each comprise a front side and a back side, wherein the front side of the cell substrate respectively the back substrate is directed towards sunlight when the photovoltaic module is in use, and the back side of the cell substrate respectively back substrate is opposite to the front side of the cell substrate respectively back substrate. In embodiments, the back side of the back substrate is a part of the back side of the substrate stack.
In embodiments, the cell substrate and the back substrate have the same shape and size and lie congruently above each other. Size means thereby extensions of the cell substrate respectively back substrate along a first and a second in-plane direction perpendicular to each other and each perpendicular to a thickness of the cell substrate respectively back substrate. The thickness of the cell substrate respectively back substrate means an extension along the direction sunlight enters the photovoltaic module. The shape of the cell substrate respectively back substrate means a polygonal shape resulting from the extensions of the cell substrate respectively the back substrate along the first and the second in-plane direction, preferably a square or rectangular shape. In embodiments, an edge of the cell substrate and the edge of the back substrate except the cutout portion form a part of the edge of the substrate stack.
The edge of the any substrate of the present invention or of the substrate stack means a side surface surrounding the respective substrate or the substrate stack perpendicular to the in-plane extensions of the respective substrate or the substrate stack extending over the thickness of the respective substrate or substrate stack and limiting the respective substrate or the substrate stack along the first and second in-plane direction to the environment.
The cell substrate and the back substrate are joined to each other with the at least one photovoltaic cell in between, for instance via an encapsulation foil, like an PVB (polyvinyl butyral) foil, wherein the encapsulation foil comprises at least one cutout portion, identical in size and shape to the at least one cutout portion of the back substrate and arranged on the cell substrate such that the at least one cutout portion of the encapsulation foil and the at least one cutout portion of the back substrate lie congruently on top of each other. In further embodiments, the back substrate comprises at least one further cutout portion and the encapsulation foil comprises at least one further cutout portion identical in shape and size to the at least one further cutout portion of the back substrate. In this case, the encapsulation foil is arranged on the cell substrate such that also the at least one further cutout portion of the encapsulation foil and the at least one further cutout portion of the back substrate lie congruently on top of each other.
The junction box is adhesively connected with the cell substrate and/or with the at least one photovoltaic cell arranged on the cell substrate on the first surface of the junction box. Further, the junction box is adhesively connected with the back substrate such that the first side surface of the junction box adjoins an edge or side surface of the cutout portion of the back substrate.
In embodiments, the terminal of the at least one junction box may be formed as a solder joint arranged at the first surface of the junction box or in an opening in the first surface of the junction box. In further embodiments, the electrical terminal of the at least one photovoltaic cell is arranged on that surface of the cell substrate or of the at least one photovoltaic cell, which is directed towards the back substrate. The electrical terminal of the at least one photovoltaic cell may be formed on or beside the at least one photovoltaic cell and may be formed as a side busbar. Side busbars are known and usually applied to a first and a last cell of the thin film photovoltaic module and are arranged close to the edge of the cell substrate, wherein the individual series-connected thin film cells of the thin film photovoltaic module are arranged next to one another along a first in-plane direction of the transparent cell substrate. A side busbar according to the invention is a conducting line or strip comprising a conducting material to collect and conduct electrical charge carriers generated within the thin film photovoltaic module. In further embodiments, the electrical terminal of the at least one photovoltaic cell is a cell connector, usually used to connect crystalline photovoltaic cells within a photovoltaic module to each other.
The junction box comprises a second surface of the junction box lying opposite to the first surface of the junction box. The first and the second surface of the junction box are located along the thickness direction of the substrates respectively the substrate stack. The junction box  further comprises at least the first side surface and the second side surface of the junction box each perpendicular to the first surface and the second surface of the junction box. The first side surface of the junction box is directed towards the substrate stack and the second side surface is directed to the outside and in direct contact with the surrounding environment. In embodiments, the junction box comprises further side surfaces, like a third side surface, wherein further side surfaces may be directed towards the substrate stack or towards the outside. In embodiments, the junction box has a triangular shape, wherein the third side surface is directed to the outside, and the second side surface and the third side surface of the junction box touch each other under an angle of 90 degrees.
In embodiments, the junction box is made of a polymeric material. In further embodiments, the junction box comprises at least a junction box body. The junction box body comprises at least the first surface and the side surfaces of the junction box. In embodiments, the junction box body may be filled with a potting material forming the second surface of the junction box. A potting material may be a polymeric potting material, like for instance but not limiting to 2-component silicone compounds, thermosetting plastics, epoxy resins, silicone rubber gels or similar materials known from the state of the art.
In embodiments, the junction box further comprises a lid arranged and connected with the junction box body and forming at least a part of the second surface of the junction box. In further embodiments, the junction box body and the lid are formed such that a click closure between the junction box body and the lid is formed.
The junction box is arranged at an edge of the substrate stack such that at least one side surface of the junction box is a part of an edge of the substrate stack substituting a part of the edge of the back substrate.
In embodiments, the frame is adhesively connected with the back side of the substrate stack directly or indirectly. Indirectly means that a spacer may be arranged between the back side of the substrate stack and the frame. The spacer may be a polymeric spacer or a spacer made from metals or metallic alloys.
Adhesively connected means a connection formed via an adhesive, applied for instance as a tape, a paste, a resin, a polymer, a glue or a thermoplastic laminate known from state of the art.
In embodiments, the substrate stack has a square, i.e. quadrangular, shape and the cutout portion and the junction box are arranged at a corner of the substrate stack. In embodiments, the second side surface and a third side surface of the junction box are directed to the outside and form a part of the edge of the substrate stack. If the substrate stack has a rectangular shape, the second side surface and the third side surface of the junction box touch each other under an angle of 90 degrees.
In embodiments, a cutout portion and a junction box may be arranged at some or each of the four corners of a square shaped substrate stack.
In embodiments, the substrate stack has a rectangular shape, and the photovoltaic module comprises four cutout portions of the back substrate and four junction boxes, each of them being arranged at a corner of the substrate stack. This enables electrical connection of a plurality of photovoltaic modules to a photovoltaic system. Furthermore, special photovoltaic module designs, like for instance submodules, may be realized. A submodule means a first subset of the at least one photovoltaic cell respectively a plurality of photovoltaic cells electrically connected to each other and forming a submodule arranged on the cell substrate. In embodiments, at least two submodules may be arranged on the cell substrate, wherein the submodules are not electrically connected to each other.
In some embodiments, at least one of the four junction boxes may be used as a “dummy junction box” which is electrically connected to a terminal of the at least one photovoltaic cell, but is not electrically connected to other photovoltaic modules or other devices. That is, such a dummy junction box is like a reserve junction box which may be used as a replacement in case another junction box used for electrical connection to other photovoltaic modules or devices wears or breaks down.
In embodiments, the substrate stack further comprises a front substrate being arranged and joined to the cell substrate at a surface being opposite to the surface on which the at least one photovoltaic cell is arranged.
Advantageously, a photovoltaic module with three substrates, preferably transparent substrates like glass substrates, is achieved with increased mechanical stability.
In embodiments, the front substrate is joined to the cell substrate via an encapsulation foil. In further embodiments, the front substrate is a transparent substrate, preferably a glass substrate. In embodiments, the front substrate has the same size and shape as the cell substrate.
In embodiments, the back side of the substrate stack is formed by the back side of the back substrate and the second surface of the junction box. The frame is then arranged on and adhesively connected with the back side of the back substrate and the second surface of the junction box opposite to the first surface of the junction box.
In case the junction box has a height different from the thickness of the back substrate, a step would be present between the second surface of the junction box and the back side of the back substrate. In order to level this step, the adhesive may be thicker on the lower component, which is usually the back substrate. In other embodiments, a spacer may be provided to level this step and to provide a plane surface for adhesive connection of the frame to the back side of the substrate stack.
In embodiments, the substrate stack further comprises an isolation substrate, wherein the isolation substrate is arranged on and adhesively connected to the back substrate at a surface being opposite to the surface joined to the cell substrate, i.e. the back side of the back substrate. Further, the isolation substrate is arranged on and adhesively connected to the second surface of the junction box opposite to the first surface of the junction box. In both cases, the isolation substrate may be connected to the back substrate or the junction box, respectively, not across the whole extension of the back side of the back substrate or of the second surface of the junction box, but only on some places with a limited lateral extension. A gas and liquid tight sealing is formed at the edge of the isolation substrate such that a gas and liquid tight isolation space is formed between the back substrate and the isolation substrate. The back side of the substrate stack is formed by a back side of the isolation substrate being that surface of the isolation substrate opposite to the surface of the isolation substrate which is connected to the back substrate.
Advantageously such a photovoltaic module is suitable as building integrated photovoltaic module and may be used for instance instead of an ordinary insulating glass window offering additional functionality for energy generation.
In embodiments, the isolation substrate is a transparent substrate, for instance a glass substrate. In further embodiments, the isolation substrate has the same size and shape as the cell substrate.
The isolation substrate comprises a front side and the back side opposite to each other, wherein the front side is directed towards the back substrate the isolation substrate is adhesively connected to.
The gas and liquid tight isolation space between the back substrate and the isolation substrate is formed by the gas and liquid tight sealing. A gas and liquid tight sealing means a sealing material, like an edge seal commonly used in insulating glass windows. Such an edge seal may be a galvanised, aluminium, stainless steel or polymeric edge seal, for instance a polymeric composite edge seal. The sealing means is arranged along the edge of the back substrate respectively isolation substrate to ensure an isolation space between the back substrate and the isolation substrate. The sealing means is adhesively connected with the back side of the back substrate and the front side of the isolation substrate and sealed with another sealing material, like for instance polysulfide, polyurethane or silicone at the edge of the substrate stack. In embodiments, the sealing means may also be arranged on and adhesively connected to the second surface of the junction box.
In further embodiments, the gas and liquid tight isolation space between the back substrate and the isolation substrate is filled with an inert gas, like for instance argon.
In embodiments, the photovoltaic module comprises two photovoltaic cells which are not electrically connected to each other via electrical conductors arranged on the cell substrate or arranged between the cell substrate and the back substrate. Furthermore, the back substrate comprises at least one further cutout portion being arranged at an edge of the back substrate at a position corresponding to the position of an electrical terminal of at least one of the two photovoltaic cells being not electrically connected to each other. The substrate stack further comprises at least one connection box comprising at least one terminal for electrical contacting one of the two photovoltaic cells being not electrically connected to each other. The at least one connection box has the same shape and size as the further cutout portion of the back substrate, is arranged in the further coutout portion of the back substrate and is directly electrically connected via its terminal to the electrical terminal of the one of the two photovoltaic cells being not electrically connected to each other. The at least one connection box is adhesively connected with the cell substrate or at least one of the photovoltaic cells on a first surface of the connection box and with the back substrate on a first side surface of the connection box.
Two photovoltaic cells which are not electrically connected to each other may be at least two photovoltaic cells or at least two subsets of a plurality of electrically interconnected photovoltaic cells as described above. That is, a first photovoltaic cell or a first subset of a plurality of photovoltaic cells electrically connected to each other forms a first submodule, and a second photovoltaic cell or a second subset of a plurality of photovoltaic cells electrically connected to each other forms a second submodule. Although the first submodule and the second submodule are arranged each on the cell substrate, they are not electrically connected to each  other. Of course the photovoltaic module may comprise more than two submodules. In embodiments, the photovoltaic cells, i.e. the submodules, may be so called half cells, preferably crystalline half cells. Advantageously, such half cells offer known advantages like reduced resistive losses, increased performance and in particular a higher performance at partial shading conditions.
The at least one further cutout portion is preferably arranged at a position different from a corner of the back substrate.
The at least one connection box comprises a second surface of the connection box being opposite to the first surface of the connection box. The first and the second surface of the connection box are located along the thickness direction of the substrates respectively substrate stack. The second surface of the connection box may form a part of the back side of the substrate stack and may be adhesively connected to the frame or may be adhesively connected to an isolation substrate as described above with respect to the second surface of the junction box for different embodiments. The at least one connection box further comprises at least the first side surface and a second side surface of the connection box each perpendicular to the first and the second surface of the connection box. The first side surface of the connection box is directed towards the back substrate. The second side surface of the connection box is arranged at the edge of the substrate stack and directed to the outside and is in direct contact with the surrounding environment. Thus, the second side surface of the connection box forms a part of the edge of the substrate stack.
In embodiments, the at least one connection box comprises two terminals for electrical contacting each of the two submodules and an electrical conductor, e.g. a wire, for electrically connecting the two terminals. In this case, the connection box internally connects the two submodules.
In embodiments, the at least one connection box further comprises at least one wire or at least one female or one male connector for connection to other devices and arranged at the second side surface of the connection box. In this case, the at least one connection box is formed as a junction box as described above and may be used for electrically connecting at least one of the two submodules with other devices.
Of course, the connection box may comprise more than two terminals for electrical contacting more than two submodules and may also comprise more than one electrical conductor or more than two wires or more than two female or male connectors for connection to other submodules or devices.
The at least one connection box has the same size and shape as the at least one further cutout portion of the back substrate and is arranged within the at least one further cutout portion of the back substrate. Thus, an edge of the connection box formed at least by the second side surface of the connection box forms a part of the edge of the substrate stack, and the connection box forms a part of the substrate stack. In embodiments, the at least one further cutout portion has a square shape, in particular a rectangular shape or a circular or elliptical shape, viewed from a direction along the thickness of the back substrate.
In embodiments, the at least one terminal of the at least one connection box may be formed as a solder joint. In further embodiments, the electrical terminals of the at least two submodules are arranged on that surface of the cell substrate or of the at least one photovoltaic cell, which is directed towards the back substrate. The electrical terminals of the two submodules may be formed on or beside the respective submodule and may be formed as a side busbar or a cell connector.
In embodiments, the junction box comprises a box frame having a width in the range of 3 mm to 20 mm. The width means an extension of the box frame perpendicular to the side surfaces of the junction box. In embodiments, the box frame has a width in the range of 10 mm to 20 mm.
The box frame is part of the junction box body and forms the side surfaces of the junction box and respectively forms the edge of the junction box. Advantageously, a wide box frame improves the adhesive connection between the junction box and the cell substrate or the surface of the photovoltaic cells as well as between the junction box and the frame or –if present -an isolation substrate, since it increases the size of the first and the second surface of the junction box. Furthermore, a wide box frame improves the mechanical stability of the junction box.
In embodiments, the box frame has a width w 1 in the range of 3 mm to 20 mm, preferably in the range of 10 mm to 20 mm, at least at that side surfaces of the junction box which are directed to the outside and in direct contact with the surrounding environment, i.e. at least at the second side surface. In further embodiments, the box frame has the width w 1 also at the first side surface and/or further side surfaces of the junction box.
In further embodiments, the box frame has a width w 2 smaller than the width w 1 at least at the first side surface of the junction box with which the junction box is adhesively connected to the back substrate.
In further embodiments, the box frame is formed as a double-walled box frame. A double-walled box frame according to the invention means a box frame with at least an inner and an outer wall  with a distance to each other in the range of 3 mm to 30 mm. The inner wall and the outer wall may have a width or thickness in the range of 2 mm to 10 mm, wherein the thickness of the inner wall may be different from or equal to the thickness of the outer wall. The thickness of the inner wall and of the outer wall as well as the distance to each other may vary for different side surfaces of the junction box formed by the box frame. The inner wall of the box frame is directed to the inside of the junction box and the outer wall is directed to the outside of the junction box and in direct contact with the back substrate or the surrounding environment. The outer wall forms the side surfaces of the junction box respectively the edge of the junction box. In further embodiments, the inner and the outer wall of the double-walled box frame are connected via at least one cross strut, wherein the at least one cross strut is moulded on the inner and/or the outer wall of the double-walled frame of the junction box. Advantageously, the stability of the double-walled frame is increased. In further embodiments, the inner and the outer wall of the double-walled box frame of the junction box are connected via a plurality of cross struts, forming a plurality of compartments within the distance between the inner and the outer wall.
In embodiments, the distance between the inner and the outer wall of the double-walled box frame respectively the plurality of compartments may be filled with a potting material, like a polymeric potting material, like for instance but not limiting 2-component silicone compounds, thermosetting plastics, epoxy resins, acrylic and butylic resins, silicone rubber gels or similar materials known from the state of the art. Thereby, a first part of the second surface of the junction box may be formed. In embodiments, the lid of the junction box is attached via a click closure to the double-walled box frame, forming at least a part of the second surface of the junction box. In embodiments, the lid of the junction box is attached via a click closure to the inner wall of the double-walled frame of the junction box, forming a second part of the second surface of the junction box.
Furthermore, any combinations of the different embodiments of the box frame are possible, e.g. a solid box frame with the width w 1 at the first side surface of the junction box and a double-walled box frame with or without cross struts at other side surfaces of the junction box directed to the outside.
The junction box body may further comprise a bottom forming at least a part of the first surface of the junction box and being connected to or formed integrally with the box frame. The bottom may extend over the whole first surface of the junction box except the terminal of the junction box or may be smaller. The bottom may have a thickness in the range of 0.5 mm to 4 mm, the thickness being measured in the direction of the thickness of the substrate stack.
If present, the at least one connection box may comprise a box frame with the same characteristics as described above for the box frame of the junction box.
The invention also concerns a method for producing a photovoltaic module, wherein the method comprises at least the following steps:
a) providing a transparent cell substrate, at least one photovoltaic cell being arranged on the cell substrate, a back substrate, a junction box comprising a terminal for electrically contacting the at least one photovoltaic cell and a wire or a female or a male connector for connection to other devices, and a frame,
b) forming a cutout portion at an edge of the back substrate, wherein the cutout portion has the same shape and size as the junction box,
c) joining the cell substrate and the back substrate to each other such that the at least one photovoltaic cell is arranged in between,
d) applying an adhesive on a first surface and a first side surface of the junction box,
e) placing the junction box in the cutout portion of the back substrate and on the cell substrate such that the first surface of the junction box is arranged on the cell substrate and the first side surface of the junction box is adjacent to the back substrate and that the wire or the female or male connector is arranged on a second side surface different from the first side surface and forming an edge of the photovoltaic module, and forming an adhesive connection between the first surface of the junction box and the cell substrate and between the first side surface of the junction box and the back substrate,
f) forming a direct electrical contact between the terminal of the junction box and an electrical terminal of the at least one photovoltaic cell,
g) applying an adhesive on a back side of a substrate stack comprising at least the cell substrate, the at least one photovoltaic cell, the back substrate and the junction box, or applying an adhesive to the frame, and
h) placing the frame on the back side of the substrate stack and forming an adhesive connection between the back side of the substrate stack and the frame.
Advantageously such a method enables easy manufacturing of a photovoltaic module with an alternative arrangement of the junction box which may reduce or avoid some of the drawbacks of the prior art.
The photovoltaic module produced by the inventive method may be a crystalline photovoltaic module or a thin film photovoltaic module, preferably a thin film photovoltaic module, wherein a crystalline photovoltaic module comprises at least one crystalline photovoltaic cell being  arranged on the transparent cell substrate and a thin film photovoltaic module comprises at least one thin film photovoltaic cell being arranged on the transparent cell substrate.
In embodiments, the steps are performed in the following order a) , b) , c) , d) , e) , f) , g) and h) .
In embodiments, a glass substrate is provided as the transparent cell substrate in step a) . In further embodiments, the back substrate provided in step a) is a transparent back substrate, preferably a glass substrate. The cell substrate and the back substrate have the same shape and size.
In embodiments, the junction box provided in step a) is made of a polymeric material. In further embodiments, the junction box provided in step a) comprises at least a junction box body. The junction box body comprises thereby at least the first surface and the side surfaces of the junction box. In embodiments, the junction box further comprises a lid arranged and connected with the junction box body and forming at least a part of a second surface of the junction box being opposite to the first surface of the junction box. In further embodiments, the junction box body and the lid are formed such that a click closure between the junction box body and the lid is formed.
In further embodiments, in step b) , at least one cutout portion at an edge of the back substrate is formed by a cutting process, for instance by a laser cutting process. In preferred embodiments, the at least one cutout portion is formed at least at one corner of the back substrate.
In step c) , the cell substrate and the back substrate are joined to each other with the at least one photovoltaic cell arranged on the cell substrate in between by placing an encapsulation foil on that surface of the cell substrate the at least one photovoltaic cell is arranged on. The encapsulation foil has the same shape and size as the cell substrate and comprises at least one cutout portion identical in shape size to the at least one cutout portion of the back substrate. The encapsulation foil is placed on the cell substrate such that the at least one cutout portion of the encapsulation foil and the at least one cutout portion of the back substrate lie congruently on top of each other.
The adhesive in step d) may be applied as a tape, a paste, a resin, a polymer, a glue or a thermoplastic laminate. The adhesive is applied on the first surface of the junction box at least along the circumference close to the edge of the junction box and on the first side surface of the junction box. Alternatively, or additionally, the adhesive in step d) may be applied on the back surface of the cell substrate and on the edge of the back substrate, in both cases in the cutout  portion of the back substrate. That means, the adhesive may be applied in a region of the back side of the cell substrate with or without at least one photovoltaic cell arranged on and not covered by the encapsulation foil respectively the back substrate, i.e. the region of the cell substrate the at least one cutout portion of the encapsulation foil respectively the back substrate is arranged on, and on the cutted edge of the back substrate.
In embodiments, in step e) , an adhesive connection between the first surface of the junction box and the cell substrate or the at least one photovoltaic cell arranged on the cell substrate and between the first side surface of the junction box and the back substrate, i.e. the edge of the cutout portion of the back substrate, is formed by a temperature treatment, a radiation treatment or other methods known to a person skilled in the art.
In embodiments, the direct electrical contact between the terminal of the junction box and an electrical terminal of the at least one photovoltaic cell in step f) is formed by means of soldering, if the terminal of the junction box is formed as a solder joint. The electrical terminal of the at least one photovoltaic cell is arranged on the back side of the cell substrate or directly on the photovoltaic cell. The electrical terminal of the at least one photovoltaic cell may be formed as side busbar or as cell connector.
In embodiments, before step g) , the junction box body may be filled with a potting material or a lid may be arranged on the junction box, each forming a part of the second surface of the junction box.
The adhesive in step g) may be applied as a tape, a paste, a resin, a polymer, a glue or a thermoplastic laminate. The adhesive is applied on the back side of the substrate stack at a position corresponding to the position of the frame in the finished photovoltaic module, e.g. along the circumference of the substrate stack close to the edge of the substrate stack. The substrate stack has a front side directed towards sunlight, when the photovoltaic module is in use and the back side, opposite to the front side. In embodiments, the substrate stack may comprise further substrates arranged on the front side and/or the back side of the cell substrate or the back substrate, respectively. Alternatively, or additionally, the adhesive is applied on the frame.
In step h) , the frame is placed on the back side of the substrate stack, e.g. on the applied adhesive, and an adhesive connection between the back side of the substrate stack and the frame is formed by a temperature treatment, a radiation treatment or other methods known to a person skilled in the art. In embodiments, the frame is placed congruent with the edge of the substrate stack.
In embodiments, the substrate stack has a square shape and the cutout portion and the junction box are arranged at a corner of the substrate stack.
In embodiments, a cutout portion and a junction box may be arranged at some or all of the four corners of a square shaped substrate stack.
In embodiments, the substrate stack has a rectangular shape, and the photovoltaic module comprises four cutout portions of the back substrate and four junction boxes, each of them being arranged at a corner of the substrate stack.
In embodiments, the method further comprises the steps of providing a front substrate and joining it to the cell substrate at a surface being opposite to the surface on which the at least one photovoltaic cell is arranged, such that the substrate stack further comprises the front substrate.
In embodiments, the steps of providing a front substrate and joining it to the cell substrate are performed after step e) .
In embodiments, the provided front substrate may be a transparent substrate, for instance a glass substrate. Advantageously, a photovoltaic module with three substrates, preferably transparent substrates like glass substrates, is produced.
The front substrate has the same size and shape as the cell substrate and is joint to the cell substrate such that the front substrate and the cell substrate lie congruently.
In embodiments, the back side of the substrate stack is formed by the second surface of the junction box being opposite to the first surface of the junction box and the back side of the back substrate, and in that an adhesive connection between the second surface of the junction box and the frame and between the back side of the back substrate and the frame is formed in step h) .
In embodiments, the second surface of the junction box is formed partly by the lid and/or the potting material as described above.
In embodiments, the method further comprises the following steps:
i) providing an isolation substrate,
j) applying an adhesive to a second surface of the junction box being opposite to the first surface of the junction box and a gas and liquid tight sealing to a back side of the back substrate or to the isolation substrate,
k) placing the isolation substrate on the back side of the back substrate and on the second surface of the junction box and forming an adhesive connection between the back side of the back substrate and the isolation substrate and between the second surface of the junction box and the isolation substrate and a gas and liquid tight space between the back substrate and the isolation substrate,
wherein steps j) and k) are performed between steps f) and g) and wherein the substrate stack in steps g) and h) comprises also the isolation substrate, a back side of the isolation substrate forming the back side of the substrate stack.
Advantageously, this enables manufacturing a photovoltaic module suitable as building integrated photovoltaic module and for use for instance instead of an ordinary insulating glass window offering additional functionality for energy generation.
In embodiments, the isolation substrate provided in step i) is a transparent substrate, like for instance a glass substrate. In further embodiments, the provided isolation substrate has the same size and shape as the cell substrate.
In embodiments, an edge seal commonly used in insulating windows is applied as the gas and liquid tight sealing. The edge seal will be arranged along the surrounding edge of the back substrate or on corresponding places of the isolation substrate to ensure an isolation space between the back substrate and the isolation substrate and will be adhesively connected with the back side of the back substrate and the front side of the isolation substrate. The edge seal may be sealed with another sealing material, like for instance polysulfide, polyurethane or silicone, at the edge of the substrate stack. In further embodiments, the isolation space between the back substrate and the isolation substrate will be filled with an inert gas, like for instance argon.
Forming an adhesive connection between the back side of the back substrate and the isolation substrate and between the second surface of the junction box and the isolation substrate and a gas and liquid tight space between the back substrate and the isolation substrate may comprise a temperature treatment, a radiation treatment or other methods known to a person skilled in the art.
Claim 15
In embodiments, step a) further comprises providing two photovoltaic cells which are not electrically connected to each other and at least one connection box. The method is then characterized by the following features:
- Step b) further comprises forming a further cutout portion at an edge of the back substrate at a position corresponding to the position of an electrical terminal of at least one of the two photovoltaic cells being not electrically connected to each other, wherein the further cutout portion has the same size and shape as the at least one connection box.
- Step d) further comprises applying an adhesive on a first surface of the at least one connection box and at least on a first side surface of the at least one connection box.
- Step e) further comprises placing the at least one connection box in the further cutout portion of the back substrate and on the cell substrate such that the first surface of the at least one connection box is arranged on the cell substrate and the first side surface of the at least one connection box is adjacent to the back substrate, and forming an adhesive connection between the first surface of the at least one connection box and the cell substrate and between the first side surface of the at least one connection box and the back substrate.
- Step f) further comprises forming a direct electrical contact between an electrical terminal of the at least one connection box and an electrical terminal of one of the two photovoltaic cells which are not electrically connected to each other.
- The substrate stack in steps g) and h) comprises also the at least one connection box.
Advantageously, a photovoltaic module comprising at least two submodules can be produced.
The at least two photovoltaic cells which are not electrically connected to each other provided in step a) are arranged each on the cell substrate and form a submodule each.
During joining the cell substrate and the back substrate in step c) , the encapsulation foil arranged between the cell substrate and the back substrate comprises at least one further cutout portion identical in shape size to the at least one further cutout portion of the back substrate. The encapsulation foil is placed on the cell substrate such that the at least one further cutout portion of the encapsulation foil and the at least one further cutout portion of the back substrate lie congruently on top of each other.
The at least one connection box may electrically connect the at least two submodules with each other, or may electrically connect at least one of the two submodules with another device, if the at least one connection box is formed as a junction box.
With respect to further characteristics of the connection box, the same applies as described with respect to the photovoltaic module above.
In embodiments, in step d) , an adhesive is alternatively or additionally applied on the back surface of the cell substrate and on the edge of the back substrate, in both cases in the further cutout portion of the back substrate. That means, the adhesive may be applied in a region of the back side of the cell substrate with or without at least one photovoltaic cell arranged on and not covered by the encapsulation foil respectively the back substrate, i.e. the region of the cell substrate the at least one further cutout portion of the encapsulation foil respectively the back substrate is arranged on, and on the cutted edge of the back substrate in this further cutout portion.
Placing the at least one connection box in the further cutout portion of the back substrate on the cell substrate in step e) includes also arranging the at least one connection box on the at least one photovoltaic cell arranged on the cell substrate such that the terminal of the connection box and the terminal of the photovoltaic cell may be electrically connected in step f) . The at least one connection box forms a part of the substrate stack, i.e. the substrate stack comprises the connection box after forming an adhesive connection between the first surface of the connection box and the cell substrate and between the first side surface of the connection box and the back substrate.
In embodiments, the at least one terminal of the at least one connection box may be formed as a solder joint. In further embodiments, the electrical terminal of the one of the at least two photovoltaic cells being not electrically connected to each other is arranged on the surface of the cell substrate the photovoltaic cells are arranged on. The electrical terminal of one of the two photovoltaic cells being not electrically connected to each other may be formed as side busbar or as a cell connector.
For realization of the invention it is advantageous to combine the described embodiments and features of the claims as described above. However, the embodiments of the invention described in the foregoing description are examples given by way of illustration and the invention is nowise limited thereto. Any modification, variation and equivalent arrangement as well as combinations of embodiments should be considered as being included within the scope of the invention.
Exemplary embodiments
The accompanying drawings are included to provide a further understanding of embodiments of the invention and are incorporated in and constitute a part of this specification. The drawings illustrate the embodiments of the present invention and together with the description serve to explain the principles. Other embodiments of the invention and many of the intended advantages will be readily appreciated, as they become better understood by reference to the following detailed description. The elements of the drawings are not necessarily to scale relative to each other. Like reference numbers designate corresponding similar parts. Dashed lines refer to components, which do not lie on the surface of the shown view, but are visible due to transparency of other components or which place should be shown with respect to the visible components.
Fig. 1A shows a front view of an exemplary embodiment of a photovoltaic module, viewed along a z-direction light enters the photovoltaic module, when it is in use,
Fig. 1B shows a back view of Fig. 1A, viewed from the opposite direction,
Fig. 1C shows a side view of the photovoltaic module according to Fig 1A and 1B, viewed along a y-direction,
Fig. 1D shows an enlarged perspective exploded view of the encircled detail of Fig. 1C,
Fig. 2A shows a cross section of the photovoltaic module of Fig. 1A to 1D along line C-C of Fig. 1B,
Fig. 2B shows a cross section of a further embodiment of a photovoltaic module, viewed along a y-direction,
Fig. 3 shows a front view of another embodiment of a photovoltaic module, viewed along a z-direction light enters the photovoltaic module, when it is in use,
Fig. 4 shows a side view of another embodiment of a photovoltaic module, viewed along a y-direction,
Fig. 5A shows a back view of another embodiment of a photovoltaic module along a z-direction opposite to the direction light enters the photovoltaic module, when it is in use,
Fig. 5B shows a cross section of the photovoltaic module of Fig. 5A along line A-A’ of Fig. 5A,
Fig. 6A shows a front view of another embodiment of a photovoltaic module along a z-direction light enters the photovoltaic module, when it is in use,
Fig. 6B shows a cross section through a part of the photovoltaic module of Fig. 6A, viewed along a y-direction,
Fig. 6C shows a front view of another embodiment of a photovoltaic module along a z-direction light enters the photovoltaic module, when it is in use,
Fig. 6D shows a cross section through a part of the photovoltaic module of Fig. 6C, viewed along a y-direction,
Fig. 7A shows schematically an embodiment of a junction box in a top view,
Fig. 7B shows another embodiment of a junction box in a perspective view,
Fig. 8 shows a process flow of a method for producing a photovoltaic module,
Fig. 9A shows a part of a photovoltaic module produced according to the process flow in Fig. 8 after step S3,
Fig. 9B shows the part of the photovoltaic module of Fig. 9A prior to step S5,
Fig. 9C shows the part of the photovoltaic module of Fig. 9A after step S8.
Fig. 1A shows a front view of a photovoltaic module 100 along a z-direction light enters the photovoltaic module 100, when it is in use. Visible is a transparent cell substrate 11 on which the at least one photovoltaic cell are arranged on (the photovoltaic cell is not illustrated here) . A junction box 20 and a frame 30 are indicated by dashed lines. The junction box 20 comprises at least one wire 21 for connection to other devices. The junction box 20 is arranged at a corner of the photovoltaic module 100.
Fig. 1B shows a corresponding back view of the photovoltaic module 100 of Fig. 1A viewed from an opposite z-direction. Visible are a back substrate 13 and the frame 30 arranged on the back substrate 13. Partly visible is the junction box 20 (indicated by partly dashed lines) arranged in at least one cutout portion 131 of the back substrate 13.
Fig. 1C shows a side view of the photovoltaic module 100 according to Fig 1A and 1B, viewed along a y-direction. The photovoltaic module 100 comprises a substrate stack 10 comprising at least the transparent cell substrate 11, at least one photovoltaic cell 12 arranged on the cell substrate, the back substrate 13 and the junction box 20. The junction box 20 is arranged in the cutout portion 131 of the back substrate 13, the cutout portion 131 being shown in Fig. 1B. Furthermore, the junction box 20 is arranged at an edge 16 of the substrate stack 10. The substrate stack 10 comprises a front side 14 and a back side 15 wherein the back side 15 of the substrate stack 10 is formed by a back side 133 of the back substrate 13 and a second surface 24 of the junction box 20. Sunlight enters the photovoltaic module 100 from the front side 14 of the substrate stack 10, indicated by arrows. The edge 16 of the substrate stack 10 is part of an  edge 101 of the photovoltaic module 100 and is formed by an edge of the cell substrate 11, a second side surface 26 of the junction box 20 and an edge of the back substrate 13. The cell substrate 11 and the back substrate 13 are joined to each other via an encapsulation foil (not shown) with the at least one photovoltaic cell 12 in between. The junction box 20 is adhesively connected via an adhesive 40 with the cell substrate 11 on a first surface 23 of the junction box 20. The junction box 20 is further adhesively connected via the adhesive 40 with the back substrate 13 on a first side surface 25 directed towards the back substrate 13, wherein the first side surface 25 is adhesively connected to an edge 132 of the cutout portion of the back substrate 13. The junction box 20 comprises a terminal 22 for electrically contacting the at least one photovoltaic cell 12 and the wire 21 for connection to other devices. The junction box 20 is directly electrically contacted via its terminal 22 to an electrical terminal (not shown) of the at least one photovoltaic cell 12. The wire 21 is arranged on the second side surface 26 of the junction box 20 directed to the surrounding environment. The frame 30 is arranged only on the back side 15 of the substrate stack 10 and is adhesively connected with the back side 15 of the substrate stack 10 via the adhesive 40. Although only one adhesive 40 is shown here which realizes all adhesive connections of the junction box 20 with the cell substrate 11 and the back substrate 13 and of the frame 30 with the back substrate 13 and the junction box 20, different adhesives may be used for different adhesive connections.
Fig. 1D shows an enlarged perspective exploded view of the encircled detail of the photovoltaic module 100 of Fig. 1C. Visible is the cell substrate 11 with the at least one photovoltaic cell 12 arranged on the cell substrate 11 and the back substrate 13 joined to the cell substrate 11 with the at least one photovoltaic cell 12 in between. The back substrate 13 comprises the cutout portion 131 arranged at an edge of the back substrate 13. The junction box 20 is arranged in the cutout portion 131 wherein the junction box 20 comprises the wire 21. The frame 30 is arranged only on and adhesively connected with the back side of the back substrate 13 and the second surface of the junction box 20 as described above. As can be seen here, the wire 21 may comprise connecting means like a female or a male connector.
Fig. 2A shows a cross section of the photovoltaic module of Fig. 1A to 1D along line C-C of Fig. 1B. The components shown in Fig. 1C are not described again. The junction box 20 comprises a junction box body and a lid 28. The lid 28 forms at least a part of the second surface 24 of the junction box 20. The junction box body comprises at least the first surface and the first and second side surfaces of the junction box as described with respect to Fig. 1C. The side surfaces of the junction box form a box frame 27. Visible is the direct electrical connection of the terminal 22 of the junction box 20 with an electrical terminal 121 of the at least one photovoltaic cell 12 arranged on a surface of the cell substrate 11.
Fig. 2B shows a cross section of a further embodiment of a photovoltaic module 100, viewed along a y-direction similar to Fig. 2A. A special embodiment of the frame 30 is shown. The frame 30 comprises a recess on that side and at that position of the frame 30 where the frame 30 is arranged on the junction box 20. That is, the junction box 20 is arranged within this recess of the frame 30. This is particularly advantageous if the difference of the height (or thickness) of the back substrate 13 and the junction box 20 is high, for instance larger than 0.5 mm.
Fig. 3 shows a front view of a specific embodiment of the photovoltaic module 100 along a z-direction light enters the photovoltaic module, when it is in use. Visible is the transparent cell substrate 11 and a plurality of photovoltaic cells arranged on a back side of the cell substrate 11. For instance, the photovoltaic cells may be thin film cells which are serial-connected to each other. In Fig. 3, only the first photovoltaic cell 12a and the last photovoltaic cell 12b in the serial connection are referenced. For each of the first photovoltaic cell 12a and the last photovoltaic cell 12b, two electrical terminals 121 are provided, wherein in each case one terminal 121 is provided on the upper end of the respective  photovoltaic cell  12a, 12b and the other terminal 121 is provided on the lower end of the respective  photovoltaic cell  12a, 12b with respect to y-direction. The two terminals 121 of one individual  photovoltaic cell  12a, 12b may also be connected by a side busbar. In this specific embodiment, four junction boxes 20a to 20d are provided. Each of the junction boxes 20a to 20d comprises a wire 21 for connection to other devices as described above. Each junction box 20a to 20d is arranged in a respective cutout portion 131a to 131d of the back substrate and at a corner of the photovoltaic module. Each of the terminals 121 of the  photovoltaic cells  12a, 12b is connected to a respective electrical terminal (not shown) of a respective junction box 20a to 20d. Providing a junction box at each corner of the photovoltaic module 100 has several advantages. First, the mechanical stability of the whole photovoltaic module 100 is increased, since the frame 30 now has the same supporting point at each corner. Further, the electrical connection of the photovoltaic module 100 to other devices may be improved due to two electrical connections at each side. Moreover, one junction box at each side, for  instance junction box  20b and 20c may be formed as dummy junction boxes not connected to other devices, but being suitable to be used as a replacement when the respective other junction box of the same side, i.e. the  junction box  20a or 20d, breaks down.
Fig. 4 shows a side view of another embodiment of a photovoltaic module 100 along a y-direction. The photovoltaic module 100 in this embodiment further comprises a front substrate 17, preferably a transparent glass, arranged on a front side of the cell substrate 11 which is directed towards sunlight entering the photovoltaic module 100 (indicated by the arrows) . The front substrate 17 has the same size and shape as the cell substrate 11 and is adhesively  connected to the cell substrate 11 via an encapsulation foil. The substrate stack 10 now comprises the cell substrate 11, the at least one photovoltaic cell 12, the back substrate 13, the junction box 20 and the front substrate 17. A front side of the front substrate 17 forms the front side 14 of the substrate stack. The photovoltaic module 100 of this embodiment is a three glass photovoltaic module 100 comprising increased mechanical stability.
Fig. 5A shows a back view of another embodiment of a photovoltaic module 100 along a z-direction opposite to the direction light enters the photovoltaic module 100, when it is in use. The photovoltaic module 100 in this embodiment further comprises an isolation substrate 18, preferably a transparent glass. The isolation substrate 18 is arranged on and adhesively connected to the back substrate and the frame 30 is arranged on the isolation substrate 18 on the side opposite to the back substrate. The photovoltaic module 100 in this embodiment comprises four junction boxes 20a to 20d each arranged within a cutout portion 131a to 131d of the back substrate. Further, a sealing 50 is shown which is not really visible since hidden beneath the frame 30, but shown for better understanding. The sealing 50 is arranged at the circumference of the photovoltaic module 100 and will be explained further with respect to Fig. 5B.
Fig. 5B shows a cross section of the photovoltaic module 100 of Fig. 5A along line A-A’ of Fig. 5A. That is, the left part of the figure shows a cross section at a position where no junction box is arranged and the right part of the figure comprises a cross section at a position including the junction box 20a. As can be seen, the isolation substrate 18 is arranged on and adhesively connected to the back substrate 13, preferably a transparent glass back substrate 13, at a surface being opposite to the surface of the back substrate 13 joined to the cell substrate 11 respectively the at least one photovoltaic cell 12. The isolation substrate 18 is further arranged on and adhesively connected to the second surface of the junction box 20a opposite to the first surface 23 of the junction box 20a. The substrate stack 10 now comprises the transparent cell substrate 11, the at least one photovoltaic cell 12 arranged on the cell substrate 11, the back substrate 13, the junction boxes 20a to 20d and the isolation substrate 18. The isolation substrate 18 has the same size and shape as the cell substrate 11 and a backside 182 of the isolation substrate 18 forms the back side 15 of the substrate stack 10. The sealing 50 is a gas and liquid tight sealing formed at the circumference of the isolation substrate 18 such that a gas and liquid tight isolation space 181 is formed between the back substrate 13 and the isolation substrate 18. That is, the sealing 50 is formed between the back substrate 13 and the isolation substrate 18 and also between the second surface of each junction box 20a to 20d and the isolation substrate 18. The frame 30 is arranged only on the back side 182 of the isolation substrate 18 and is adhesively connected with it by the adhesive 40.
Fig. 6A shows a front view of another embodiment of a photovoltaic module 100 along a z-direction light enters the photovoltaic module 100, when it is in use. Visible is the transparent cell substrate 11 comprising at least two  photovoltaic cells  12a, 12b which are not electrically connected to each other via electrical conductors arranged on the cell substrate 11 or arranged between the cell substrate 11 and the back substrate. Each of the at least two  photovoltaic cells  12a, 12b means, in the embodiment shown, a plurality of photovoltaic cells 12, in particular thin film photovoltaic cells, electrically connected to each other. Therefore, the  photovoltaic cells  12a and 12b may also be referred to as a first submodule and a second submodule, wherein the first submodule and the second submodule are not electrically connected to each other and are arranged each on the cell substrate 11. Shown by dashed lines are four junction boxes 20a to 20d, each of them being arranged at a corner of the photovoltaic module 100 and within a respective cutout portion 131a to 131d of the back substrate. Accordingly the back substrate comprises the four cutout portions 131a to 131d identical in shape and size with the four junction boxes 20a to 20d. Visible by dashed lines as well are two  connection boxes  60a and 60b, each arranged at an edge of the photovoltaic module 100. Therefore, the back substrate comprises two  further cutout portions  134a, 134b identical in size and shape with the  connection boxes  60a, 60b. Also shown (although not necessarily visible in the front view) are electrical terminals 121 of the  photovoltaic cells  12a, 12b. The junction boxes 20a to 20d and the  connection boxes  60a, 60b, respectively, are directly electrically connected to the electrical terminals 121 via electrical terminals of the junction boxes 20a to 20d respectively  connection boxes  60a, 60b (not shown in Fig. 6A) . Further, the frame being part of the photovoltaic module 100 has been omitted in Fig. 6A for sake of clarity.
Fig. 6B shows a cross section through a part of the photovoltaic module 100 of Fig. 6A, viewed along a y-direction. The cross section extends along the x-direction within the encircled portion of Fig. 6A, i.e. through a portion of the photovoltaic module 100 where the further cutout portion 134a and the connection box 60a are arranged. Visible are the cell substrate 11 and the back substrate 13 with the  photovoltaic cells  12a, 12b being arranged in between. The photovoltaic cells or  submodules  12a, 12b are not electrically connected to each other via electrical conductors arranged on the cell substrate 11 or between the cell substrate 11 and the back substrate 13. However, the  photovoltaic cells  12a, 12b are electrically connected to each other via an internal connection 601 within the connection box 60a. In this embodiment the connection box 60a comprises two electrical terminals 61 of the connection box 60a each for electrical contacting the electrical terminal 121 of one of the at least two  photovoltaic cells  12a, 12b. The connection box 60a is adhesively connected via an adhesive 40 to the cell substrate 11 on a first surface 62 of the connection box 60a and to the back substrate 13 on a first side  surface 63 of the connection box 60a. Here, the first side surface 63 is each side surface of the connection box 60a which faces the back substrate 13. A side surface of the connection box 60a not facing the back substrate 13, but instead the surrounding environment or outside of the photovoltaic module 100 is called a second side surface of the connection box, which is however not referenced by a reference number in Fig. 6A and 6B. The photovoltaic module 100 is shown here without the frame which is arranged on the back substrate 13 and on a second surface 64 of the connection box 60a, the second surface 64 lying opposite to the first surface 62.As described above with respect to the junction boxes, the frame is adhesively connected to the connection box 60a by the adhesive 40.
Fig. 6C shows a front view of another embodiment of a photovoltaic module 100 similar to Fig. 6A along a z-direction opposite to the direction light enters the photovoltaic module 100, when it is in use. In contrast to Fig. 6A, the photovoltaic module 100 comprises four connection boxes 60a to 60d (shown by dashed lines) , wherein always two of the four connection boxes 60a to 60d are arranged at a same edge of the back substrate 13. The back substrate 13 comprises two  further cutout portions  134a, 134b arranged at an edge of the back substrate 13. Each of the  further cutout portions  134a, 134b has a size and shape suitable for arranging two of the connections boxes 60a to 60d within the  further cutout portion  134a, 134b. In other embodiments, there may be four further cutout portions each having a size and shape suitable for arranging one of the connections boxes 60a to 60d within the further cutout portion. In the embodiment shown here, in each of the two  further cutout portions  134a, 134b, the two  connection boxes  60a, 60d or 60b, 60c, respectively, are arranged adjacent to each other and such that each connection box 60a to 60d forms a part of an edge of the photovoltaic module 100. Each of the connection boxes 60a to 60d comprises at least one wire 21 or at least one female or one male connector. That is, each connection box 60a to 60d is formed like and serves as a junction box. An electrical connection 602 electrically connects  adjacent connection boxes  60a and 60d or 60b and 60c, respectively. In other embodiments, the individual connection boxes 60a to 60d may be electrically connected by wires 21 to other devices.
Fig. 6D shows a cross section through a part of the photovoltaic module 100 of Fig. 6B, viewed along a y-direction. The cross section extends along the x-direction within the encircled portion of Fig. 6C, i.e. through a portion of the photovoltaic module 100 where the further cutout portion 134a and the  connection boxes  60a and 60d are arranged. Visible are the cell substrate 11 and the back substrate 13 with the  photovoltaic cells  12a, 12b being arranged in between. Fig. 6D differs from Fig. 6B in that the two  connection boxes  60a and 60d are arranged in the cutout portion 134a, wherein each  connection box  60a, 60d comprises the wire 21 (not shown here) ,  which is internally electrically connected to the electrical terminal 61 of the  respective connection box  60a or 60d and which is suited for being connected to other devices. The two  connection boxes  60a, 60d are adhesively connected via an adhesive 40 to the cell substrate 11 and the back substrate 13, but also to the  other connection box  60a, 60d. Again, the frame is not shown in Fig. 6D although it is present in the photovoltaic module 100.
Fig. 7A shows schematically an embodiment of a junction box 20 in a top view on a second surface 24 of the junction box 20. The second surface 24 is that surface of the junction box 20 which lies opposite to a surface of the junction box 20 which is adhesively connected to a cell substrate 11. The junction box 20 comprises a wire 21 or at least one female or one male connector arranged at a second side surface 26 of the junction box 20 and a box frame 27 of the junction box 20. In this embodiment, the box frame 27 of the junction box 20 has a width w 1 in the range of 3 mm to 20 mm, preferably 10 mm to 20 mm, at least at the side surfaces of the junction box which are directed to the outside and in direct contact with the surrounding environment, for instance the second side surface 26 of the junction box 20. Furthermore, the box frame 27 of the junction box 20 has a width w 2 smaller than w 1 at a first side surface 25 of the junction box 20, wherein the first side surface 25 is that side surface with which the junction box 20 will adhesively connected to a back substrate 13. The junction box 20 further comprises a lid 28 closing the junction box 20 at the second surface 24 and being connected to the box frame 27. In other embodiments, the lid 28 may be omitted.
Fig. 7B shows another embodiment of a junction box 20 in a perspective view on a first side surface 25 and a top or second surface 24 of the junction box 20. The first side surface 25 is that side surface facing a back substrate when the junction box 20 is mounted in a photovoltaic module. The second surface 24 is that surface which lies opposite to a first surface connected to a cell substrate when the junction box is mounted in a photovoltaic module. The junction box 20 in this embodiment comprises a double-walled box frame 27. The double-walled box frame 27 comprises at least an outer wall 271 and an inner wall 272 with a distance to each other in the range of 3 mm to 25 mm. The outer wall 271 is directed to the outside and in direct contact with the surrounding environment and forms the side surfaces, in particular the first and the  second side surface  25, 26 of the junction box 20, respectively the edge of the junction box 20. The inner wall 272 of the box frame 27 is directed to the inside of the junction box 20 and is formed only at that side surfaces of the junction box 20 which do not face the back substrate when mounted, i.e. is formed only with respect to the second side surface 26. The inner and the  outer wall  272, 271 of the double-walled box frame 27 are connected via at least one cross strut 273, wherein the at least one cross strut 273 is moulded on the inner and/or the  outer wall  272, 271 of the double-walled box frame 27 of the junction box 20. In this embodiment, the inner and  the  outer wall  272, 271 of the double-walled box frame 27 are connected via a plurality of cross strut 273, forming a plurality of compartments 274 within the distance between the inner and the  outer wall  272, 271. The distance between the inner and the  outer wall  272, 271 of the double-walled box frame 27 respectively the plurality of compartments 274 may be filled with a potting material, like a polymeric potting material, like for instance but not limiting to 2-component silicone compounds, thermosetting plastics, epoxy resins, silicone rubber gels or similar materials known from the state of the art. The potting material may form a first part of the second surface 24 of the junction box 20. The junction box 20 further comprises a lid 28 of the junction box 20 attached via a click closure 281 to the outer wall 271 of the double-walled box frame 27 at the first side surface 25 and to the inner wall 272 of the double-walled box frame 27 at the side surfaces facing the outside, i.e. at least the second side surface 26, in this embodiment. The lid 28 forms at least a part of the second surface 24 of the junction box 20, e.g. a second part. In other embodiments, the lid 28 may be attached to the outer wall 271 of the double walled box frame 27, e.g. by a click closure, at all side surfaces of the junction box 20. In this case, the lid 28 forms the second surface 24 of the junction box.
Fig. 8 shows an exemplary process flow of a method for producing a photovoltaic module 100. In a first step S1, a transparent cell substrate 11, at least one photovoltaic cell 12 being arranged on the cell substrate 11, a back substrate 13, a junction box 20 comprising a terminal 22 for electrically contacting the at least one photovoltaic cell 12 and a wire 21 or a female or a male connector for connection to other devices, and a frame 30 are provided. In the following step S2, a cutout portion 131 at an edge of the back substrate 13 is formed, wherein the cutout portion 131 has the same shape and size as the junction box 20. Afterwards in step S3, the cell substrate 11 and the back substrate 13 are joined to each other, for instance by an encapsulation foil, such that the at least one photovoltaic cell 12 is arranged in between. In step S4, an adhesive 40 is applied on a first surface 23 of the junction box 20 and a first side surface 25 of the junction box 20. In step S5, the junction box 20 is placed in the cutout portion 131 of the back substrate 13 and on the cell substrate 11 such that the first surface 23 of the junction box 20 is arranged on the cell substrate 11 and the first side surface 25 of the junction box 20 is adjacent to the back substrate 13 and that the wire 21 or the female or male connector is arranged on a second side surface 26 of the junction box 20. The second side surface 26 is different from the first side surface 25 and forms an edge of the photovoltaic module 100. Further in step S5, an adhesive connection between the first surface 23 of the junction box 20 and the cell substrate 11 and between the first side surface 25 of the junction box 20 and the back substrate 13 is formed. In the following step S6, a direct electrical contact between the electrical terminal 22 of the junction box 20 and an electrical terminal 121 of the at least one  photovoltaic cell 12 is formed. Afterwards in step S7, an adhesive 40 is applied on a back side 133 of a substrate stack 10, wherein the substrate stack 10 comprises at least the cell substrate 11, the at least one photovoltaic cell 12, the back substrate 13 and the junction box 20. In other embodiments, the adhesive 40 is applied to the frame 30. Finally in step S8, the frame 30 is placed on the back side 133 of the substrate stack 10 and an adhesive connection between the back side 133 of the substrate stack 10 and the frame 30 is formed.
Fig. 9A shows a photovoltaic module 100 produced according to the process flow in Fig. 8 after step S3. Visible is a back view of the photovoltaic module 100, viewed along a z-direction opposite to the direction light enters the photovoltaic module 100 when it is in use. The cell substrate 11 with the at least one photovoltaic cell 12 (shown by dashed lines) arranged on and the back substrate 13 are already joined together by an encapsulation foil (not shown) . The back substrate 13 has the cutout portion 131 formed in step S2 having the same size and shape as the junction box 20 provided in step S1. Accordingly, the encapsulation foil comprises a cutout portion, identical in size and shape to the cutout portion 131 of the back substrate 13 and arranged on the cell substrate 11 such that the cutout portion of the encapsulation foil and the cutout portion 131 of the back substrate 13 lie congruently on top of each other. Also visible by a dashed line is a side busbar forming an electrical terminal 121 of the at least one photovoltaic cell 12, the electrical terminal 121 being arranged in the cutout portion 131 of the back substrate 13.
Fig. 9B shows a photovoltaic module 100 produced according to the process flow in Fig. 8 prior to step S5. Shown is the photovoltaic module 100 from Fig. 9A and the junction box 20 with an applied adhesive (not shown) on a first surface of the junction box (not shown) and a first side surface 25 of the junction box 20. The first surface of the junction box 20 is opposite to a second surface 24 of the junction box 20. In Step S5, the junction box 20 will be placed in the cutout portion 131 of the back substrate 13 as indicated by the arrow and will be adhesively connected on its first surface with the cell substrate 11 and on its first side surface 25 with the back substrate 13.
Fig. 9C shows a photovoltaic module 100 produced according to the process flow in Fig. 8 after step S8. Visible is the frame 30 adhesively connected to a back side of a substrate stack, wherein the substrate stack comprises the cell substrate 11, the back substrate 13, the at least one photovoltaic cell 12 in between, and the junction box 20. The junction box 20 is fully covered by the frame 30 in this embodiments and is therefore not visible.
Figure PCTCN2022101902-appb-000001
Reference signs
100                       Photovoltaic module
101                       Edge of the photovoltaic module
10                        Substrate stack
11                        Cell substrate
12, 12a, 12b              Photovoltaic cell
121                       Electrical terminal of the photovoltaic cell
13                        Back substrate
131, 131a-131d            Cutout portion
132                       Edge of the cut out portion
133                       Back side of the back substrate
134a, 134b                Further cutout portion
14                        Front side of the substrate stack
15                        Back side of the substrate stack
16                        Edge of the substrate stack
17                        Front substrate
18                        Isolation substrate
181                       Isolation space
182                       Back side of the isolation substrate
20, 20a-20d               Junction box
21                        Wire
22                        Electrical terminal of the junction box
23                        First surface of the junction box
24                        Second surface of the junction box
25                        First side surface of the junction box
26                        Second side surface of the junction box
27                        Box frame of the junction box
271                       Outer wall of a double-walled box frame
272                       Inner wall of a double-walled box frame
273                       Cross strunt
274                       Compartment
28                        Lid of the junction box
281                       Click closure
30                        Frame
40                        Adhesive
50                        Sealing
60a, 60b                  Connection box
61                        Electrical terminal of the connection box
62                        First surface of the connection box
63                        First side surface of the connection box
64                        Second surface of the connection box
601                       Internal connection within the connection box
602                       Electrical connection of different connection boxes

Claims (15)

  1. Photovoltaic module comprising at least the following elements:
    - a substrate stack comprising at least a transparent cell substrate, at least one photovoltaic cell being arranged on the cell substrate, a back substrate, and a junction box, the junction box comprising a terminal for electrically contacting the at least one photovoltaic cell and a wire or a female or a male connector for connection to other devices, and
    - a frame,
    wherein the cell substrate and the back substrate are joined to each other with the at least one photovoltaic cell in between and wherein the back substrate comprises a cutout portion being arranged at an edge of the back substrate,
    characterized in that
    - the junction box has the same shape and size as the cutout portion of the back substrate, is arranged within the cutout portion of the back substrate, is directly electrically connected via its terminal to an electrical terminal of the at least one photovoltaic cell, and is adhesively connected with the cell substrate on a first surface of the junction box and with the back substrate on a first side surface of the junction box, and the wire or the female or male connector is arranged on a second side surface of the junction box different from the first side surface and being arranged at an edge of the substrate stack,
    - the frame is arranged only on and adhesively connected with a back side of the substrate stack.
  2. Photovoltaic module according to claim 1, characterized in that the substrate stack has a square shape and the cutout portion and the junction box are arranged at a corner of the substrate stack.
  3. Photovoltaic module according to claim 1, characterized in that the substrate stack has a rectangular shape, and the photovoltaic module comprises four cutout portions of the back substrate and four junction boxes, each of them being arranged at a corner of the substrate stack.
  4. Photovoltaic module according to one of the claims 1 to 3, characterized in that the substrate stack further comprises a front substrate being arranged and joined to the cell substrate at a surface being opposite to the surface on which the at least one photovoltaic cell is arranged.
  5. Photovoltaic module according to one of claims 1 to 4, characterized in that the back side of the substrate stack is formed by a back side of the back substrate and in that the frame is further arranged on and adhesively connected with a second surface of the junction box opposite to the first surface of the junction box.
  6. Photovoltaic module according to one of the claims 1 to 4, characterized in that the substrate stack further comprises an isolation substrate, wherein the isolation substrate is arranged on and adhesively connected to the back substrate at a surface being opposite to the surface joined to the cell substrate and is arranged on and adhesively connected to a second surface of the junction box opposite to the first surface of the junction box, and wherein a gas and liquid tight sealing is formed at the edge of the isolation substrate such that a gas and liquid tight isolation space is formed between the back substrate and the isolation substrate, and in that the back side of the substrate stack is formed by a back side of the isolation substrate.
  7. Photovoltaic module according to one of the claims 1 to 6, characterized in that
    - the photovoltaic module comprises two photovoltaic cells which are not electrically connected to each other via electrical conductors arranged on the cell substrate or arranged between the cell substrate and the back substrate,
    - the back substrate comprises at least one further cutout portion being arranged at an edge of the back substrate at a position corresponding to the position of an electrical terminal of at least one of the two photovoltaic cells being not electrically connected to each other, and
    - the substrate stack further comprises at least one connection box comprising at least one terminal for electrical contacting one of the two photovoltaic cells being not electrically connected to each other, wherein the at least one connection box has the same shape and size as the further cutout portion of the back substrate, is arranged in the further coutout portion of the back substrate and directly electrically connected via its terminal to the electrical terminal of the one of the two photovoltaic cells being not electrically connected to each other, and is adhesively connected with the cell substrate  on a first surface of the connection box and with the back substrate on a first side surface of the connection box.
  8. Photovoltaic module according to one of the claims 1 to 7, characterized in that the junction box comprises a box frame having a width in the range of 3 mm to 20 mm.
  9. Method for producing a photovoltaic module comprising at least the following steps:
    a) providing a transparent cell substrate, at least one photovoltaic cell being arranged on the cell substrate, a back substrate, a junction box comprising a terminal for electrically contacting the at least one photovoltaic cell and a wire or a female or male connector for connection to other devices, and a frame,
    b) forming a cutout portion at an edge of the back substrate, wherein the cutout portion has the same shape and size as the junction box,
    c) joining the cell substrate and the back substrate to each other such that the at least one photovoltaic cell is arranged in between,
    d) applying an adhesive on a first surface and a first side surface of the junction box,
    e) placing the junction box in the cutout portion of the back substrate and on the cell substrate such that the first surface of the junction box is arranged on the cell substrate and the first side surface of the junction box is adjacent to the back substrate and that the wire or the female or male connector is arranged on a second side surface different from the first side surface and forming an edge of the photovoltaic module, and forming an adhesive connection between the first surface of the junction box and the cell substrate and between the first side surface of the junction box and the back substrate,
    f) forming a direct electrical contact between the terminal of the junction box and an electrical terminal of the at least one photovoltaic cell,
    g) applying an adhesive on a back side of a substrate stack comprising at least the cell substrate, the at least one photovoltaic cell, the back substrate and the junction box, or applying an adhesive to the frame, and
    h) placing the frame on the back side of the substrate stack and forming an adhesive connection between the back side of the substrate stack and the frame.
  10. Method according to claim 9, characterized in that the substrate stack has a square shape and the cutout portion and the junction box are arranged at a corner of the substrate stack.
  11. Method according to claim 9, characterized in that the substrate stack has a rectangular shape, and the photovoltaic module comprises four cutout portions of the back substrate and four junction boxes, each of them being arranged at a corner of the substrate stack.
  12. Method according to one of the claims 9 to 11, characterized in that the method further comprises the steps of providing a front substrate and joining it to the cell substrate at a surface being opposite to the surface on which the at least one photovoltaic cell is arranged, such that the substrate stack further comprises the front substrate.
  13. Method according to one of the claims 9 to 12, characterized in that the back side of the substrate stack is formed by a second surface of the junction box being opposite to the first surface of the junction box and a back side of the back substrate, and in that an adhesive connection between the second surface of the junction box and the frame and between the back side of the back substrate and the frame is formed in step h) .
  14. Method according to one of the claims 9 to 12, characterized in that the method further comprises the following steps:
    i) providing an isolation substrate,
    j) applying an adhesive to a second surface of the junction box being opposite to the first surface of the junction box and a gas and liquid tight sealing to a back side of the back substrate or to the isolation substrate,
    k) placing the isolation substrate on the back side of the back substrate and on the second surface of the junction box and forming an adhesive connection between the back side of the back substrate and the isolation substrate and between the second surface of the junction box and the isolation substrate and a gas and liquid tight space between the back substrate and the isolation substrate,
    wherein steps j) and k) are performed between steps f) and g) and wherein the substrate stack in steps g) and h) comprises also the isolation substrate, a back side of the isolation substrate forming the back side of the substrate stack.
  15. Method according to one of the claims 9 to 14, characterized in that
    - step a) further comprises providing two photovoltaic cells which are not electrically connected to each other and at least one connection box,
    - step b) further comprises forming a further cutout portion at an edge of the back substrate at a position corresponding to the position of an electrical terminal of at least one of the two photovoltaic cells being not electrically connected to each other, wherein  the further cutout portion has the same size and shape as the at least one connection box,
    - step d) further comprises applying an adhesive on a first surface of the at least one connection box and on a first side surface of the at least one connection box,
    - step e) further comprises placing the at least one connection box in the further cutout portion of the back substrate and on the cell substrate such that the first surface of the at least one connection box is arranged on the cell substrate and the first side surface of the at least one connection box is adjacent to the back substrate, and forming an adhesive connection between the first surface of the at least one connection box and the cell substrate and between the first side surface of the at least one connection box and the back substrate,
    - step f) further comprises forming a direct electrical contact between an electrical terminal of the at least one connection box and an electrical terminal of one of the two photovoltaic cells which are not electrically connected to each other, and
    - the substrate stack in steps g) and h) comprises also the at least one connection box.
PCT/CN2022/101902 2022-06-28 2022-06-28 Photovoltaic module and method for producing a photovoltaic module WO2024000162A1 (en)

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JP2001217449A (en) * 2000-02-07 2001-08-10 Fuji Electric Co Ltd Solar cell module
WO2011039951A1 (en) * 2009-09-30 2011-04-07 Fujifilm Corporation Solar cell module
CN102148272A (en) * 2010-02-08 2011-08-10 杜邦太阳能有限公司 Photovoltaic module with embedded junction box and photovoltaic window with the same
CN202678363U (en) * 2012-07-04 2013-01-16 深圳金粤幕墙装饰工程有限公司 Photovoltaic assembly
US20130056047A1 (en) * 2011-09-02 2013-03-07 Markus E. Beck Photovoltaic module with sealed perimeter and method of formation
CN207458961U (en) * 2017-10-27 2018-06-05 无锡英富光能有限公司 A kind of photovoltaic module being easily installed

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001217449A (en) * 2000-02-07 2001-08-10 Fuji Electric Co Ltd Solar cell module
WO2011039951A1 (en) * 2009-09-30 2011-04-07 Fujifilm Corporation Solar cell module
CN102148272A (en) * 2010-02-08 2011-08-10 杜邦太阳能有限公司 Photovoltaic module with embedded junction box and photovoltaic window with the same
US20130056047A1 (en) * 2011-09-02 2013-03-07 Markus E. Beck Photovoltaic module with sealed perimeter and method of formation
CN202678363U (en) * 2012-07-04 2013-01-16 深圳金粤幕墙装饰工程有限公司 Photovoltaic assembly
CN207458961U (en) * 2017-10-27 2018-06-05 无锡英富光能有限公司 A kind of photovoltaic module being easily installed

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