A solar cell interconnection structure and a solar cell module

Abstract

The present application discloses a solar cell interconnection structure and a solar cell module. The solar cell interconnection structure comprises: a printed circuit board, including a substrate, the front of the substrate is provided with a conductive pattern, an interconnection pad, and a conductive hole, and the back of the substrate is provided with a conductive pad, and the conductive pad is connected to the conductive pattern and the interconnection pad on the front of the substrate through a wire and a conductive hole; at least one solar cell unit comprises an upper and a lower electrode, the lower electrode is connected to the conductive pattern on the printed circuit board, and the upper electrode is connected to the interconnection pad on the printed circuit board; wherein a group of solar cell units are connected in series and parallel through the interconnection line on the printed circuit board to form a solar cell module, and the conductive pad on the back of the substrate forms the external positive and negative electrodes of the group of solar cell modules. The solar cell interconnection structure and solar cell module of the present application solve the problems of cumbersome interconnection packaging process, low yield, and poor reliability of ultra-thin and small-sized solar cells.

Description

Technical Field

[0001] The present application relates to the technical field of solar photovoltaic power generation, and in particular to a solar cell interconnection structure and a solar cell module. Background Art

[0002] In recent years, as fossil energy such as oil and coal are becoming increasingly depleted, environmental pollution pressure is becoming increasingly serious. Changing the traditional energy structure and developing renewable energy are important strategic goals for the country's green energy transformation. Solar energy is inexhaustible. Using the photovoltaic effect of solar cell modules to directly convert solar energy into electrical energy is currently the most ideal green energy.

[0003] A solar cell module is a device that converts solar energy into electrical energy. It is usually made of one or more solar cells (or photovoltaic cells) that are connected in series and packaged. Currently, most solar cells are connected in series by welding ribbons to the front and back electrodes of the cell. The welding temperature can usually reach 180℃-350℃. Under high temperature conditions, the difference in thermal expansion coefficients between the ribbon and the battery material will cause stress concentration at the connection between the ribbon and the cell, causing hidden cracks or fragments in the cell during the series connection process. The problem is particularly serious during the packaging and interconnection process of mobile energy modules.

[0004] Mobile energy components are usually made based on ultra-thin, small-size solar cell packages, with a high degree of customization and complex and varied application scenarios, including vehicle and ship applications, mobile portable charging packs, wearable products, and smart sensor power supply. The application end has higher requirements on the product's aesthetics, consistency, reliability, weight density, etc. The solar cell components in these application fields use traditional packaging and interconnection methods, which makes it difficult to ensure the component's aesthetics, product consistency, and long-term reliability. Summary of the invention

[0005] In view of the above problems in the prior art, the present application provides a novel solar cell interconnection structure, which effectively solves the problems of complicated interconnection packaging process, low yield, poor reliability, etc. of ultra-thin and small-sized solar cells.

[0006] A first aspect of the present application provides a solar cell interconnection structure, comprising:

[0007] A printed circuit board, the printed circuit board comprising a substrate, a front side of the substrate being provided with a conductive pattern, interconnection pads, and conductive holes, a back side of the substrate being provided with conductive pads, and the conductive pads being connected to the conductive pattern and interconnection pads on the front side of the substrate through wires and conductive holes;

[0008] At least one solar cell unit is arranged on the front side of the printed circuit board, the solar cell unit comprises an upper electrode and a lower electrode, the lower electrode of the solar cell is connected to the conductive pattern on the printed circuit board, and the upper electrode is connected to the interconnection pad on the printed circuit board;

[0009] A group of solar cell units are connected in series and parallel through interconnection lines on a printed circuit board to form a solar cell assembly, and the conductive pads on the back of the substrate form external positive and negative electrodes of the solar cell assembly.

[0010] According to some embodiments of the present application, the upper electrode of the solar cell unit is connected to the interconnection pad by a metal wire.

[0011] According to some embodiments of the present application, the solar cell unit is attached to the conductive pattern of the printed circuit board through a conductive material, so that the lower electrode of the solar cell is connected to the conductive pattern of the printed circuit board to form a circuit.

[0012] According to some embodiments of the present application, an interconnect pad connected to an upper electrode of a solar cell unit on a printed circuit board is connected to a conductive pattern corresponding to another solar cell unit to achieve a series connection of multiple battery cells.

[0013] According to some embodiments of the present application, multiple interconnect pads on the front side of the printed circuit board are electrically connected through wires and / or conductive holes, and corresponding multiple conductive patterns are electrically connected through wires and / or conductive holes to achieve parallel connection of multiple battery cells.

[0014] According to some embodiments of the present application, a portion between the front electrode of the solar cell and the interconnection pad is provided with a transparent insulating glue, the transparent insulating glue covers the metal wire, the width of the transparent insulating glue is greater than or equal to the width of the metal wire from the front electrode of the solar cell to the interconnection pad, and the height is greater than or equal to the arc height of the metal wire.

[0015] According to some embodiments of the present application, a cell positioning frame or a positioning mark is provided on the conductive pattern on the front side of the printed circuit board, and solar cell pasting is performed according to the positioning frame or the positioning mark.

[0016] Another aspect of the present application provides a solar cell assembly, comprising:

[0017] The solar cell interconnection structure according to the first aspect; and

[0018] A transparent encapsulation layer is arranged on one side of the solar cell unit of the solar cell interconnection structure to encapsulate multiple solar cell units into an integral solar cell assembly.

[0019] According to some embodiments of the present application, the transparent encapsulation layer includes a transparent adhesive film, and the transparent adhesive film is coated on the entire printed circuit board on one side of the solar cell unit.

[0020] According to some embodiments of the present application, the transparent adhesive film is one or more of epoxy resin glue, silicone glue, EVA, POE, TPO, and PVB.

[0021] According to some embodiments of the present application, the transparent encapsulation layer further includes a transparent cover plate disposed above the transparent adhesive film.

[0022] According to some embodiments of the present application, the material of the transparent cover plate is any one of glass, PMMA, PC, PET, and polyurethane.

[0023] According to some embodiments of the present application, the transparent encapsulation layer includes a sealing adhesive and a transparent cover plate, the sealing adhesive is applied on the periphery of the printed circuit board, and the transparent cover plate is bonded to the printed circuit board by the sealing adhesive.

[0024] According to some embodiments of the present application, the space between the transparent cover plate and the solar cell is a vacuum structure or is filled with transparent glue or gas.

[0025] According to some embodiments of the present application, the filling gas is air or an inert gas.

[0026] The solar cell interconnection structure and solar cell module provided in the present application effectively solve the reliability risks such as hidden cracks, splits, and cold solder joints in the process of solar cell interconnection, and especially solve the key problems such as poor consistency, low production capacity, and low yield in the process of small-size solar cell packaging. The interconnection technology can be applied to mass production. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a front view of a printed circuit board according to an embodiment of the present application.

[0028] Figure 2 is a back view of a printed circuit board according to an embodiment of the present application.

[0029] Figure 3 It is a plan view of a solar cell after pasting according to one embodiment of the present application.

[0030] Figure 4 It is a plan view of a solar cell interconnection structure according to an embodiment of the present application.

[0031] Figure 5 is a side view of a solar cell interconnection structure according to an embodiment of the present application.

[0032] Figure 6is a side view of a solar cell interconnection structure according to an embodiment of the present application.

[0033] Figure 7 It is a side view of a solar cell interconnection structure after ball planting according to an embodiment of the present application.

[0034] Figure 8 It is a top view of a solar cell interconnection structure after being coated with insulating glue according to an embodiment of the present application.

[0035] Fig. 9 It is a side view of a solar cell interconnection structure after being coated with insulating glue according to an embodiment of the present application.

[0036] Fig.10 It is a structural diagram of a glue-coated packaging component according to an embodiment of the present application.

[0037] Fig.11 is a structural diagram of a laminated packaging stack according to an embodiment of the present application.

[0038] Fig.12 is a side view of a laminated packaged solar cell assembly according to one embodiment of the present application.

[0039] Fig.13 1 is a side view of a structure of a cover package without filler according to an embodiment of the present application.

[0040] Fig.14 1 is a side view of a structure in which a cover plate is encapsulated with a filler according to an embodiment of the present application.

[0041] Fig.15 It is a side view of a transparent adhesive material+cover plate packaging structure according to an embodiment of the present application. DETAILED DESCRIPTION

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following is a brief introduction to the drawings required for the description of the embodiments. In the drawings, components with the same or similar functions are indicated by the same or similar reference numerals. In addition, for some components that are not directly related to the concept of the present invention, their illustrations may be omitted. The description of the drawings and specific embodiments is only for a better understanding of the present invention, and the present invention is not limited to the embodiments illustrated in the drawings and described in the specification.

[0043] The technical terms or scientific terms used in the present invention should be the common meanings understood by people with ordinary skills in the field to which the present invention belongs. The use of "including" or "comprising" and similar words in the present invention indicates an open meaning, and does not exclude other elements, components, parts or items except for the elements, parts, parts or items clearly listed. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly. "First", "second" and the like are used to distinguish different components and do not indicate a specific order.

[0044] On the one hand, the present invention provides a novel solar cell interconnection structure, see attached Figure 1-9 , comprising a printed circuit board 1 and at least one solar cell unit 2 arranged on the printed circuit board 1. Figure 10-15 As shown, multiple solar cell units 2 can be connected to form a solar cell module through interconnection lines on a printed circuit board 1. The printed circuit board 1 can be a single-layer board, a double-layer board, or a multi-layer board, and the substrate material of the printed circuit board 1 can be any one of ceramic, aluminum, copper, alloy, FR4, FPC, epoxy resin, and fiberboard. The solar cell unit 2 can be any one of crystalline silicon, silicon thin film, copper indium gallium selenide, gallium arsenide, perovskite, dye-sensitized and perovskite stacked solar cells, and the solar cell 2 can be a rigid cell or a flexible cell.

[0045] Figure 1 is a front view of a printed circuit board according to an embodiment of the present application. Figure 2 FIG. 1 is a back view of a printed circuit board according to an embodiment of the present application. Figure 1-2 As shown, the printed circuit board 1 includes a substrate 1-1, and one or more mutually insulated conductive patterns 1-2, interconnection pads 1-3, and conductive holes 1-4 are arranged on the front side of the substrate 1-1, and the conductive pattern 1-2 is composed of a conductive layer. A conductive pad 1-5 is arranged on the back side of the substrate 1-1, and the conductive pad 1-5 is connected to the conductive pattern 1-2 and / or the interconnection pad 1-3 on the front side of the substrate through a wire 1-6 and a conductive hole 1-4. The conductive pattern 1-2 can be arranged in a square, rectangle, triangle, circle, or arc shape. The conductive layer, the interconnection pad, and the surface coating of the conductive pad can be metal copper, aluminum, gold, silver, or an alloy material, and the thickness of the metal coating is greater than 10nm.

[0046] like Figure 3-7As shown, the solar cell unit 2 includes an upper metal electrode 2-1 and a lower metal electrode 2-2. The conductive pattern 1-2 on the front of the printed circuit board 1 is connected to the lower electrode metal layer 2-2 of the solar cell 2, and the upper electrode 2-1 of the solar cell 2 is connected to the interconnect pad 1-3. The solar cell unit 2 can be attached to the conductive pattern 1-2 of the printed circuit board 1 through a conductive material, so that the lower metal electrode 2-2 of the solar cell 2 and the conductive layer in the conductive pattern 1-2 of the printed circuit board form a circuit connection through the conductive material, and the conductive material includes silver glue, solder paste, conductive tape, etc. A cell positioning frame or positioning mark can be set on the front of the printed circuit board 1, and the solar cell is attached according to the positioning frame or positioning mark.

[0047] like Figure 4-7 As shown, the upper electrode 2-1 of the solar cell unit 2 can be connected to the interconnection pad 1-3 by a metal wire 3. The material of the metal wire 3 can be gold wire, silver wire, aluminum wire, copper wire, alloy wire, and the cross-sectional shape of the metal wire 3 can be circular, elliptical, rectangular, square and other irregular shapes; the interconnection shape of the metal wire 3 can be arc-shaped, conical, straight or wavy.

[0048] During the welding process of the metal wire 3, the front electrode 2-1 of the solar cell 2 can be used as the first welding point, and the interconnection pad 1-3 can be used as the second welding point. The first welding point is welded before the second welding point. Figure 5 As shown; the interconnect pad 1-3 may also be used as the first welding point, the solar cell front electrode 2-1 may be used as the second welding point, and the first welding point may be welded before the second welding point, such as Figure 6 According to different welding sequences, different arc shapes of interconnected metal wires can be formed to meet different usage requirements.

[0049] In addition, during the welding process of the above-mentioned metal wire 3, in order to further improve the firmness of the welding wire on the front electrode 2-1 of the solar cell 2 or the interconnection pad 1-3 and avoid damage to the solar cell 2 such as cracks and hidden cracks during the welding process, before welding the interconnection metal wire 3, a gold ball 3-1 can be pre-planted at the welding wire of the front electrode 2-1 of the solar cell 2 and the welding wire of the interconnection pad 1-3, and then the welding wire is performed on the planted gold ball 3-1 to complete the metal wire welding between the front electrode 2-1 of the solar cell and the interconnection pad 1-3, such as Figure 7 shown.

[0050] Attached Figure 1-9The schematic diagram shows a structure in which two solar cell units 2 are interconnected through a printed circuit board 1. In fact, any number of solar cell units can be connected in series and parallel through interconnection lines on the printed circuit board according to the use requirements to form a solar cell module with different output voltages. The positive and negative electrodes of the solar cell module are led out from the conductive pads 1-5 on the back of the substrate, that is, the conductive pads 1-5 on the back of the substrate form the external positive and negative electrodes of the solar cell module.

[0051] For example, see Figure 1 , 4 -7, the interconnection pad 1-3 connected to the upper electrode 2-1 of a solar cell unit 2 on the printed circuit board 1 is connected to the conductive pattern 1-2 corresponding to another solar cell unit 2, realizing the series connection of the two battery cells. Alternatively, the multiple interconnection pads 1-3 on the front of the printed circuit board 1 can be electrically connected through wires and / or conductive holes, and the corresponding multiple conductive patterns 1-2 can be electrically connected through wires and / or conductive holes to realize the parallel connection of multiple battery cells. Therefore, the solar cell module of the present application can conveniently carry out the series-parallel combination of single solar cells by designing the interconnection lines on the printed circuit board to form a solar cell standard module that meets different output power requirements; and it can realize mass production of solar cell standard modules, and finally only needs to cut the modules.

[0052] According to some embodiments of the present invention, Figure 8 and 9 As shown, a transparent insulating adhesive 4 is applied to the portion between the front electrode 2-1 of the solar cell 2 and the interconnection pad 1-3. The insulating adhesive 4 can be any one of epoxy resin adhesive, PSA, insulating tape, silicone, butyl rubber and other thermosetting materials. The width of the transparent insulating adhesive 4 is greater than or equal to the length of the metal wire 3 between the front electrode 2-1 of the solar cell 2 and the interconnection pad 1-3, and the height is greater than or equal to the arc height of the metal wire 3. The transparent insulating adhesive 4 can fix the metal wire 3 to prevent collapse and short circuit, and can also protect the metal wire in the subsequent battery assembly packaging process to prevent damage.

[0053] The novel interconnection structure provided by the present invention realizes the positive and negative connection of solar cells through a conductive substrate and metal wire welding method, which effectively reduces the welding work on the battery cells during the interconnection process, and can effectively avoid the reliability risks such as cold soldering, cracks, hidden cracks, etc. in the series connection process of solar cells. At the same time, the novel interconnection structure is used to replace the process steps of string welding, stacking, lamination, etc. in the traditional solar cell packaging process. The novel interconnection structure and packaging method can effectively shorten the solar cell interconnection and packaging process steps, improve production energy efficiency, improve product yield, and further reduce product costs.

[0054] On the other hand, an embodiment of the present invention provides a solar cell assembly, see attached Figure 10-15 , showing examples of solar cell modules of different structures, the solar cell modules including for example Figure 3-9 The solar cell interconnection structure shown in the figure; in addition, the solar cell assembly further comprises a transparent encapsulation layer, which is arranged on one side of the solar cell unit 2 of the solar cell interconnection structure to encapsulate multiple solar cell units 2 into an integral solar cell assembly. The printed circuit board 1 not only assumes the function of the backplane of the solar cell assembly, but also assumes the circuit interconnection function of the solar cell assembly.

[0055] In some embodiments, Fig.10 As shown, the transparent encapsulation layer includes a transparent adhesive film 5, and the transparent adhesive film 5 is coated on the entire printed circuit board on one side of the solar cell unit 2. The transparent adhesive film 5 can be, for example, epoxy resin glue or silicone. The transparent adhesive film 5 encapsulates the solar cell unit 2 together with the metal wire 3 on the printed circuit board 1 to form an integral solar cell module. Optionally, in the case where the solar cell interconnection structure includes a transparent insulating adhesive 4, a transparent encapsulation layer is applied to the printed circuit board 1, the solar cell 2, the insulating adhesive 4, and the metal interconnection wire 3, and the transparent encapsulation layer covers the entire printed circuit board, the solar cell, the insulating adhesive, and the metal interconnection wire to form a solar cell module.

[0056] In other embodiments, Fig.11 , 12 As shown in Figure 15, the transparent encapsulation layer further includes a transparent cover plate 6 disposed above the transparent adhesive film 5. The material of the transparent cover plate 6 can be glass, and the transparent cover plate material can be any one of glass, PMMA, PC, PET, and polyurethane. Providing the transparent cover plate 6 can better protect the solar cell assembly and improve the integrity of the solar cell assembly.

[0057] Or, in other embodiments, Fig.13 and 14 As shown, the transparent encapsulation layer includes a sealing adhesive 9 and a transparent cover plate 6. The sealing adhesive 9 is applied to the periphery of the printed circuit board 1. The transparent cover plate 6 is bonded to the printed circuit board 1 through the sealing adhesive 9. The solar cell 2, the interconnecting metal wire 3, the transparent insulating adhesive 4, etc. are encapsulated on the printed circuit board 1 to form an integral solar cell assembly. The space 10 between the transparent cover plate 6 and the solar cell 2 can be a vacuum structure or filled with transparent adhesive or gas. When filled with gas, the gas can be air or an inert gas.

[0058] The solar cell assembly of the embodiment of the present invention can conveniently combine single solar cells in series and parallel by designing interconnection lines on a printed circuit board to form a standard solar cell assembly that meets different output power requirements; moreover, it can realize batch production of standard solar cell assemblies, and finally only needs to cut the assemblies, which can effectively shorten the solar cell interconnection and packaging process steps, improve production energy efficiency, increase product yield, further reduce product costs, and solve the problems of cumbersome packaging process, low yield, and poor reliability of ultra-thin and small-size solar cells.

[0059] The preparation process of the solar cell module is described in detail below by taking solar cell interconnection structures and solar cell modules of different structures as examples.

[0060] Example 1

[0061] This embodiment provides a method for interconnecting and manufacturing solar cells, comprising the following steps:

[0062] (1) Providing one or more solar cells with upper and lower metal electrodes

[0063] The solar cell is any one of gallium arsenide, crystalline silicon, silicon thin film, copper indium gallium selenide, perovskite and other types of solar cells. The solar cell includes a front electrode, a semiconductor functional layer, and a back metal electrode. The front electrode includes a metal grid line or a metal electrode. The electrode material can be any one of gold, silver, copper, aluminum and other metal or alloy materials. The thickness is 10nm-5um, and the thickness of the solar cell is 1um-650um.

[0064] (2) Providing a printed circuit board with a conductive pattern

[0065] like Figure 1-2 The printed circuit board 1 includes a substrate 1-1, on which a conductive pattern 1-2, an interconnect pad 1-3, a conductive hole 1-4, a wire 1-6, and an insulating coating are arranged. The back of the printed circuit board includes a conductive pad 1-5 for leading out the positive and negative electrodes of the solar cell module. The back conductive pad 1-5 is connected to the front conductive pattern 1-2 or the conductive pad 1-3 through the wire 1-6 and the conductive hole 1-4. The thickness of the printed circuit board substrate is 50-5000um, and the back conductive pad of the printed circuit board includes "+", "-" electrode marks.

[0066] The printed circuit board can be a single-layer board, a double-layer board, or a multi-layer board. The printed circuit board material can be any one of ceramic, aluminum, copper, alloy, FR4, FPC, epoxy resin, and fiberboard.

[0067] The conductive pattern can be set to a square, rectangle, triangle, circle, arc and other shapes, and can be composed of one or more of the above shapes. The surface coating of the conductive pattern and the conductive pad can be copper, aluminum, gold, silver and other metal or alloy materials, and the thickness of the metal coating is greater than 10nm.

[0068] (3) Solar cell patch

[0069] Conductive glue is coated on the conductive pattern 1-2 on the front of the printed circuit board 1, so that the conductive glue is evenly covered on the printed circuit board pattern 1-2. The conductive glue can be in the form of dots, lines or figures and covered on the conductive pattern 1-2 of the printed circuit board 1. The thickness of the conductive glue can be 1-200um. According to the solar cell patch positioning frame pattern on the printed circuit board 1, the solar cell is attached to the conductive pattern 1-2 coated with the conductive glue, or the patch is performed by setting a positioning mark. The positioning mark can be a mark in the form of dots, lines, etc., such as Figure 3 As shown. The conductive glue is cured by high temperature so that the solar cell 2 forms a good ohmic contact with the conductive pattern 1-2 of the printed circuit board 1. The curing temperature is 80-200°C and the curing time is 10-240 minutes. The conductive glue can be any one of silver glue, solder paste and conductive tape. Preferably, when the upper and lower metal electrode materials of the solar cell are active metal materials such as silver and copper, gas protection is applied during the curing process to prevent oxidation.

[0070] (4) Solar cell interconnection

[0071] like Figure 3-7 , a back electrode 2-2 of a solar cell 1 is connected to a front conductive pattern 1-2 of a printed circuit board 1 through a conductive adhesive, and the front conductive pattern 1-2 of the printed circuit board 1 is connected to a back conductive pad 1-5 of the printed circuit board 1 through a wire and a conductive hole, that is, the back electrode 2-2 of the solar cell 1 is led out from the back conductive pad 1-5 of the printed circuit board 1;

[0072] The front electrode 2-1 of the first solar cell 2 is connected to the interconnection pad 1-3 (usually the negative electrode) through the metal wire 3, and the interconnection pad 1-3 is connected to the conductive pattern 2 corresponding to the other solar cell 2, that is, the front electrode 2-1 of the first solar cell 2 is connected to the back electrode 2-2 of the other solar cell 2 through the metal wire 3, the interconnection pad 1-3, and the conductive pattern 1-2;

[0073] The front electrode 2-1 of the second solar cell 2 is connected to the interconnection pad 1-3 on the other side of the conductive pattern 1-2 through the metal wire 3, and the interconnection pad 1-3 can be connected to the conductive pattern 1-2 of the third solar cell, that is, the front electrode 2-1 of the second solar cell 2 is connected to the back electrode of the third solar cell through the metal wire 3, the interconnection pad 1-3, and the conductive pattern 1-2. Therefore, the interconnection of solar cells 2 can be realized by using the printed circuit board 1 and the metal wire 3; and so on, the series connection of n solar cells can be realized;

[0074] The nth interconnection pad is connected to the conductive pad 1-5 on the back of the printed circuit board 1 through the wire and the conductive hole 1-4, and the front electrode of the nth solar cell is led out to the conductive pad 1-5 on the back of the printed circuit board 1 through the nth interconnection pad, the conductive hole and the wire, thus completing the series connection of n solar cells.

[0075] This interconnection method can achieve the effect of battery series and parallel connection, by electrically connecting multiple interconnection pads 1-3 on the front side of the printed circuit board 1 through wires and conductive holes 1-4, and connecting to the conductive pads 1-5 on the back side of the printed circuit board 1, and the corresponding multiple conductive patterns 1-2 are connected to each other through wires and conductive holes 1-4, and connected to the conductive pads 1-3 of the printed circuit board 1.

[0076] By analogy, m solar cell strings can be connected in parallel.

[0077] In the above-mentioned solar cell interconnection process, the metal wire connecting the front electrode of the solar cell and the interconnection pad is realized by ball welding. A metal wire ball welding machine (wire welding machine) is used to weld the metal wire between the front electrode of the solar cell and the interconnection pad. The base plate temperature range during welding is 50-250°C, and the welding time range is 1-100ms. The metal interconnection wire takes gold wire as an example, and can also be aluminum wire, copper wire and other alloy wires. The shape of the metal interconnection wire is circular, elliptical, or square. The metal interconnection wire line shape can be arc-shaped, and the arc height is 50-500um.

[0078] During the welding process, the front electrode 2-1 of the solar cell 2 is used as the first welding point, and the interconnection pad 1-3 is used as the second welding point. The first welding point is welded before the second welding point. Figure 5 As shown; the interconnect pad 1-3 may also be used as the first welding point, the front electrode 2-1 of the solar cell 2 may be used as the second welding point, and the first welding point may be welded before the second welding point, such as Figure 6 As shown. According to different welding sequences, different arc shapes of welding wire can be formed to meet different usage requirements.

[0079] In the above-mentioned wire bonding process, in order to further improve the firmness of the wire bonding of the front electrode or the interconnection pad of the solar cell and avoid damage to the solar cell such as cracks and hidden cracks during the wire bonding process, before welding the interconnection wire, a gold ball 3-1 can be pre-planted at the welding wire of the front electrode 2-1 of the solar cell 2 and the welding wire of the interconnection pad, and then the wire bonding is performed on the planted gold ball 3-1 to complete the welding of the metal wire 3 between the front electrode 2-1 of the solar cell 2 and the interconnection pad 1-3, such as Figure 7 shown.

[0080] (5) Glue coating packaging

[0081] The printed circuit board 1 and the solar cell 2 interconnected in the above step 4 are packaged by glue coating, and the printed circuit board 1 is used as the backplane of the solar cell module. The packaging method is to use a glue coating device to evenly coat a layer of transparent protective glue 5 on the surface of the cell and the printed circuit board. The protective glue 5 can be epoxy resin glue, silicone or other types of transparent glue, and the coating thickness is 50um-5mm.

[0082] The epoxy resin glue has self-leveling ability. After a fixed volume of epoxy glue is injected, the glue quickly covers the entire printed circuit board and solar cell, and submerges the interconnecting metal wire 3 between the front electrode 2-1 of the solar cell 2 and the interconnecting pad 1-3. The viscosity of the epoxy resin glue ranges from 100-7000mPa.s / 25℃, the density is 0.9-1.5g / cm3, and the light transmittance is 70%-99%.

[0083] (6) Encapsulation glue curing

[0084] The sample that has been coated and packaged in step 5 is cured, so that the epoxy resin, the printed circuit board 1, and the solar cell 2 are integrated to form a solar cell module, the printed circuit board 1 is used as the back of the solar cell module, and the epoxy resin glue is used as the front of the solar cell module. The packaging glue is cured by one of room temperature curing, heating curing, and UV light curing. The room temperature curing time is 1-72 hours, the heating curing time is 10 minutes-480 minutes, the heating curing temperature is 50-180°C, the UV light curing wavelength is 355nm, and the UV light intensity is 1-300W / ㎡.

[0085] (7) After the curing is completed according to step 6, a solar cell module is obtained. Fig.10 shown.

[0086] Example 2

[0087] The difference between this embodiment and embodiment 1 is that in step 5, the printed circuit board and solar cell interconnected in step 4 are packaged by a laminating packaging method, and the laminating packaging method is to use a laminator to use the printed circuit board 1 as a backplane, and a transparent polymer material as an adhesive film and a front stop to package and protect the solar cell and the interconnection line. The specific steps of laminating packaging are as follows:

[0088] (1) First, apply transparent insulating glue 4 between the front electrode 2-1 of the solar cell 1 and the interconnection pad 1-3. Figure 8 As shown, the insulating glue 4 can be any one of epoxy resin glue, PSA, insulating tape, silicone, butyl rubber and other materials. The width of the insulating glue 4 is greater than or equal to the width of the metal wire 3 from the front electrode 2-1 of the solar cell 2 to the interconnection pad 1-3, and the height is greater than or equal to the arc height of the metal wire 3, so as to completely cover the metal wire 3. Fig. 9 As shown in the side view.

[0089] (2) Laying packaging materials to form a laminate, wherein the laminate is composed of a support substrate 8, a polytetrafluoroethylene cloth 7, a printed circuit board 1 and a solar cell 2 that have been interconnected, a transparent packaging film 5, a transparent front screen 6, and a polytetrafluoroethylene cloth 7 from bottom to top. Fig.11 shown.

[0090] The supporting carrier plate 8 can be an epoxy resin plate, glass, steel plate, etc., with a thickness of 1-5mm, used for lamination and support of the laminate; the transparent packaging film 5 material includes at least one of EVA polyethylene-polyvinyl acetate copolymer, POE (polyolefin elastomer), TPO (polyolefin thermoplastic elastomer), PVB (polyvinyl butyral ester), with a thickness of 10-1140um, and a transmittance of >85% in the light wavelength range of 350-1200nm; the transparent front screen includes at least one of transparent materials such as glass, ETFE, PET, PMMA, etc., with a material thickness of 10-5000um, and a transmittance of >85% in the light wavelength range of 350nm.

[0091] (3) Place the laminate into a laminator for lamination

[0092] With the support carrier 8 as the support, the laminate is placed in the laminator, and the lamination process is specifically as follows: close the upper cover of the laminator, heat the laminate, and control the temperature at 100-160°C; evacuate the upper vacuum chamber and the lower vacuum chamber, and the evacuation time is 10S-1000S; inflate the upper vacuum chamber, and keep the lower vacuum chamber in a vacuum state, so that the upper vacuum chamber maintains a pressure difference of 10-90KPa with the lower vacuum chamber, and the lamination time is 100-3600S; evacuate the upper vacuum chamber, and inflate the lower vacuum chamber to atmospheric pressure, open the upper cover of the laminator to take out the components, and complete the lamination of the components.

[0093] (4) Remove the module from the support plate 8 to obtain a solar cell module, such as Fig.12 shown.

[0094] Example 3

[0095] The difference between this embodiment and embodiments 1 and 2 is that in step 5, a transparent cover plate 6 is used to encapsulate the printed circuit board 1 and the solar cell 2 interconnected in step 4. The specific steps of encapsulating the transparent cover plate 7 are as follows:

[0096] (1) After step 4 of the embodiment is completed, a layer of sealing adhesive 9 is applied around the edges of the printed circuit board 1. The sealing adhesive 9 can be any one of materials with sealing and bonding functions such as silicone, epoxy resin glue, butyl glue, and tape. The sealing adhesive 9 can be transparent or other colors. The thickness of the sealing adhesive 9 is greater than the arc height of the metal wire 3 interconnecting the front electrode of the solar cell 2 and the interconnection pad on the printed circuit board 1. The width of the sealing adhesive 9 can be from 0.1 mm to any width of the edge of the solar cell and cannot cover the solar cell;

[0097] (2) A transparent cover plate 6 is attached to the sample coated with the sealing adhesive 9, so that the edge sealing adhesive material is closely attached to the transparent cover plate 6. The transparent cover plate 6 can be made of any material such as glass, PMMA, PC, etc., with a thickness of 50-3200 um. The space 10 between the transparent cover plate 6 and the solar cell 2 can be hollowed out, that is, a vacuum is formed, and can also be filled with gas according to actual needs, preferably inert gas or air, such as Fig.13 As shown, transparent glue material can also be filled, such as Fig.14 As shown, the transparent adhesive material can be any one of silicone, epoxy resin, silicone rubber and other transparent adhesive materials;

[0098] (3) curing the edge sealant 9 or the filling glue to form a solar cell module;

[0099] Example 4

[0100] The difference between this embodiment and embodiment 3 is that, in step 5, when the printed circuit board 1 and the solar cell 2 interconnected in step 4 are packaged by means of a transparent cover plate 6, a transparent adhesive material 5 is coated on the surface of the printed circuit board 1, the solar cell 2, and the interconnection metal wire 3, and the thickness of the transparent adhesive material 5 is higher than the arc height of the interconnection metal wire between the front electrode of the solar cell and the interconnection pad on the printed circuit board;

[0101] On the sample coated with the transparent adhesive material 5, a transparent cover plate 6 is attached so that the transparent cover plate 6 is completely attached to the transparent adhesive material 5. The transparent cover plate 6 can be made of any material such as glass, PMMA, PC, etc., with a thickness of 50-3200um. Fig.15 shown.

[0102] The transparent adhesive material 5 is cured to form a solar cell module.

[0103] The above embodiments are merely illustrative of the principles and structures of the present invention, and are not intended to limit the present invention. It should be understood by those skilled in the art that any changes and improvements made to the present invention without departing from the overall concept of the present invention are within the scope of the present invention. The scope of protection of the present invention shall be subject to the scope defined by the claims of this application.

Claims

1. A solar cell interconnection structure, comprising: A printed circuit board, the printed circuit board comprising a substrate, a front side of the substrate being provided with a conductive pattern, interconnection pads, and conductive holes, a back side of the substrate being provided with conductive pads, and the conductive pads being connected to the conductive pattern and interconnection pads on the front side of the substrate through wires and conductive holes; At least one solar cell unit is arranged on the front side of the printed circuit board, the solar cell unit comprises an upper electrode and a lower electrode, the lower electrode of the solar cell is connected to the conductive pattern on the printed circuit board, and the upper electrode is connected to the interconnection pad on the printed circuit board; in, A group of solar cell units are connected in series and parallel through interconnection lines on a printed circuit board to form a solar cell assembly, and the conductive pads on the back of the substrate form external positive and negative electrodes of the group of solar cell assemblies; Wherein, the interconnect pad connected to the upper electrode of one solar cell unit on the printed circuit board is connected to the conductive pattern corresponding to another solar cell unit to realize the series connection of multiple solar cells; or The plurality of interconnect pads on the front side of the printed circuit board are electrically connected through wires and / or conductive holes, and the corresponding plurality of conductive patterns are electrically connected through wires and / or conductive holes, thereby realizing parallel connection of the plurality of battery cells.

2. The solar cell interconnection structure according to claim 1, wherein the upper electrode of the solar cell unit is connected to the interconnection pad by a metal wire.

3. The solar cell interconnection structure according to claim 1, wherein the solar cell unit is attached to the conductive pattern of the printed circuit board through a conductive material, so that the lower electrode of the solar cell forms a circuit connection with the conductive pattern of the printed circuit board.

4. The solar cell interconnection structure according to claim 1, wherein a transparent insulating glue is provided between the front electrode of the solar cell and the interconnection pad, the transparent insulating glue covers the metal wire, the width of the transparent insulating glue is greater than or equal to the width of the metal wire from the front electrode of the solar cell to the interconnection pad, and the height is greater than or equal to the arc height of the metal wire.

5. The solar cell interconnection structure according to claim 1, wherein a cell positioning frame or a positioning mark is provided on the conductive pattern on the front side of the printed circuit board, and the solar cell is mounted according to the positioning frame or the positioning mark.

6. A solar cell assembly comprising: The solar cell interconnection structure according to any one of claims 1 to 5; and A transparent encapsulation layer is arranged on one side of the solar cell unit of the solar cell interconnection structure to encapsulate multiple solar cell units into an integral solar cell assembly.

7. The solar cell assembly according to claim 6, wherein the transparent encapsulation layer comprises a transparent adhesive film, and the transparent adhesive film is coated on the entire printed circuit board on one side of the solar cell unit.

8. The solar cell assembly according to claim 7, wherein the transparent encapsulation layer further comprises a transparent cover plate disposed above the transparent adhesive film.

9. The solar cell assembly according to claim 6, wherein the transparent encapsulation layer comprises a sealing adhesive and a transparent cover plate, the sealing adhesive is applied on the periphery of the printed circuit board, and the transparent cover plate is bonded to the printed circuit board by the sealing adhesive.

10. The solar cell assembly according to claim 9, wherein the space between the transparent cover plate and the solar cell is a vacuum structure or filled with transparent glue or gas.

11. The solar cell module according to claim 10, wherein the gas is air or an inert gas.

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