Flexible back-contact solar cell module and manufacturing method therefor, and photovoltaic module

Abstract

Embodiments of the present invention relate to the technical field of flexible back-contact solar cell modules, and in particular to a flexible back-contact solar cell module and a manufacturing method therefor, and a photovoltaic module. The flexible back-contact solar cell module comprises: a cell substrate provided with a plurality of cell units, and a protection piece, wherein the back surface of the cell substrate is provided with electrode interconnection portions and electrode welding points; a flexible circuit board, wherein the front surface of the flexible circuit board is provided with patterned conductive circuits and butt-joint conductive portions, and is attached to the back surface of the cell substrate, and the butt-joint conductive portions at least partially cover the outer surfaces of the electrode welding points to form conductive contact portions; and insulating adhesive layers filled in gaps formed between the cell units and corresponding part of the flexible circuit board in the thickness direction and extending to cover the outer surfaces of the corresponding conductive contact portions. The embodiments of the present invention can avoid the problems of production defect rate increase and delamination caused by warping, markedly reduce power attenuation caused by bending and harsh environments, and achieve a simple manufacturing process, excellent weather resistance, and long service life.

Description

Flexible back contact solar cell module, manufacturing method thereof and photovoltaic assembly

[0001] Cross-reference to related applications

[0002] The present application claims priority to the Chinese patent application No. 2024104587225, filed on April 17, 2024, entitled "Flexible back contact solar cell module, manufacturing method thereof and photovoltaic assembly", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0003] The present disclosure belongs to the technical field of flexible back contact solar cell module, and particularly relates to a flexible back contact solar cell module, a manufacturing method thereof and a photovoltaic assembly. BACKGROUND

[0004] In recent years, the production technology of solar cells has been continuously improved, the production cost has been continuously reduced, the conversion efficiency has been continuously improved, and the application of solar cell power generation has become increasingly widespread and has become an important energy source for power supply. High-efficiency solar cells are the trend of future industry, which can not only increase the power generation per unit area, but also reduce the cost, thereby improving the additional value of module power generation. As one of the high-efficiency solar cells, the back contact solar cell moves all the electrodes on the front surface (i.e., the light receiving surface) to the back surface, so as to maximize the area of the front surface and improve the conversion efficiency of the cell. The key points for large-scale commercial production of back contact solar cells include how to efficiently and low-costly connect the back contact solar cells in series and in parallel to form a solar cell module, especially a flexible solar cell module. Unlike traditional solar silicon cells, the back contact solar cell needs to be welded by using a single-sided solder strip, which is easy to cause serious warping problems, thereby increasing the production failure rate and even causing the module to fail due to fragments or open circuit, which is one of the factors hindering the improvement of efficiency and reduction of cost. At the same time, the weather resistance of the existing flexible back contact solar cell module needs to be improved when used outdoors.

[0005] It should be noted that this part of the present disclosure only provides background technology related to the present disclosure, and does not necessarily constitute prior art or public knowledge. SUMMARY

[0006] The present disclosure aims to overcome the problem of the existing back contact solar cell that is prone to serious warping, thus leading to increased production failure rate and poor weather resistance, and to provide a flexible back contact solar cell module and a manufacturing method and photovoltaic module thereof, in which the cell units can be accurately aligned and stably connected with the flexible circuit board, and have good insulation and sealing properties, thus avoiding the problems of increased production failure rate and delamination due to warping, significantly reducing power attenuation under winding and harsh environment, and having simple manufacturing process, excellent weather resistance and long service life.

[0007] To achieve the above-mentioned purpose, in a first aspect, embodiments of the present disclosure provide a flexible back contact solar cell module, comprising a cell base body having a plurality of cell units and a protective sheet attached to the front surface of the cell base body, a split seam being formed between adjacent cell units, the back surface of the cell base body having an electrode interconnection part configured to connect electrodes between the cell units and / or lead out current, and a plurality of electrode pads provided on the electrode interconnection part, the flexible back contact solar cell module further comprising:

[0008] a flexible circuit board, the front surface of the flexible circuit board having a patterned conductive circuit and a corresponding conductive part provided on the conductive circuit to be electrically connected with the electrode pads, the front surface of the flexible circuit board being attached to the back surface of the cell base body, and the conductive part being at least partially wrapped around the outer surface of the electrode pads to form a conductive contact part;

[0009] an insulating adhesive layer, the insulating adhesive layer being filled into the gap formed between the cell units and the corresponding part of the flexible circuit board in the thickness direction and extending to wrap the outer surface of the corresponding conductive contact part; and in the thickness direction, the insulating adhesive layer at least extends to wrap the part of the corresponding cell unit located in the split seam, the height L of the wrapped part of the insulating adhesive layer located in the split seam of the corresponding cell unit satisfying L:T = 0.1-20:1, wherein T is the thickness of the conductive contact part.

[0010] In some preferred embodiments of the present disclosure, the thickness T of the conductive contact part is 30-100 μm, and the height L of the wrapped part of the insulating adhesive layer located in the split seam of the corresponding cell unit is 3-130 μm.

[0011] In some preferred embodiments of the present disclosure, in the width direction, the width d of the wrapped part of the insulating adhesive layer located in the split seam of the corresponding cell unit is 5%-50% of the width D of the split seam.

[0012] In some preferred embodiments of the present disclosure, the width D of the split seam between any adjacent cell units is 0.1 mm-30 mm.

[0013] In some preferred embodiments of the present disclosure, the insulating adhesive layers corresponding to adjacent battery units extend to each other along the width direction of the conductive contact portion.

[0014] In some preferred embodiments of the present disclosure, the protective sheet has protective sheet split line grooves corresponding to the overall pattern formed by the plurality of battery units and attached in alignment on the side of the protective sheet away from the battery base.

[0015] In some preferred embodiments of the present disclosure, the protective sheet is attached to the front side of the battery base by the adhesive layer.

[0016] In some preferred embodiments of the present disclosure, the height of the portion of the insulating adhesive layer between the battery unit and the flexible circuit board in the thickness direction is flush with the height of the conductive contact portion.

[0017] In some preferred embodiments of the present disclosure, the butt joint conductive portion is made of at least one material selected from the group consisting of tin paste, conductive adhesive, silver paste, and conductive copper paste.

[0018] In some preferred embodiments of the present disclosure, the butt joint conductive portion is a solder joint, a solder pad, or an adhesive layer.

[0019] In some preferred embodiments of the present disclosure, the pattern of the patterned conductive circuit corresponds to the arrangement of the plurality of battery units and the pattern formed by the series and parallel connection thereof.

[0020] In some preferred embodiments of the present disclosure, the flexible back contact solar cell module further has at least one of the following structures:

[0021] Structure one, the flexible circuit board comprises an insulating film, and the patterned conductive circuit is disposed on the insulating film;

[0022] Structure two, the split seam between each battery unit is filled with an insulating caulking adhesive;

[0023] Structure three, the thickness ratio of the flexible circuit board, the protective sheet, and the battery unit is 0.2-10:0.7-30:1;

[0024] Structure four, the thickness of the flexible circuit board is 30-230 μm, the thickness of the protective sheet is 0.1-1.5 mm, and the thickness of the battery unit is 50-150 μm;

[0025] Structure five, the conductive circuit is made of at least one material selected from the group consisting of copper, aluminum, nickel, tin, gold, and silver;

[0026] Structure six, the thickness of the conductive circuit is 10-200 μm.

[0027] In some preferred embodiments of the present disclosure, the flexible back contact solar cell module further comprises a first hot melt adhesive layer, a first flexible plate arranged in sequence on the outer surface of the protective sheet, and a second hot melt adhesive layer, a second flexible plate arranged in sequence on the back surface of the flexible circuit board.

[0028] In a second aspect, embodiments of the present disclosure provide a manufacturing method of a flexible back contact solar cell module, comprising the following steps:

[0029] S11, attaching a protective sheet to the front surface of the cell substrate and fixing it, thereby forming a glue-coated surface on the back surface of the cell substrate; wherein the front surface of the cell substrate is provided with a split seam to divide the cell substrate into a plurality of cell units, the back surface of the cell substrate has an electrode interconnection part configured to connect electrodes between cell units and / or lead out current, and a plurality of electrode pads arranged on the electrode interconnection part, the electrode pads including positive electrode pads and negative electrode pads, and the split seam is spaced apart from the positive electrode pads and the negative electrode pads on the corresponding cell unit;

[0030] S12, coating an insulating adhesive layer on the glue-coated surface, and making the insulating adhesive layer not cover the electrode pads, the coating area including the spacing between the cell split seam and the electrode pads on the corresponding cell unit and the area between the positive electrode pads and the negative electrode pads;

[0031] S13, providing a flexible circuit board, the front surface of the flexible circuit board having a patterned conductive circuit; forming a material required for the butt joint conductive part on the conductive circuit, the arrangement of the butt joint conductive part corresponding to the arrangement of the electrode pads;

[0032] S14, placing the back surface of the cell substrate obtained in S12 and the front surface of the flexible circuit board obtained in S13 in alignment, so that the butt joint conductive part is in contact with the electrode pads in alignment, and the positioning is achieved by the adhesion of the insulating adhesive layer, thereby forming a cell assembly;

[0033] S15, hot pressing the cell assembly, so that the butt joint conductive part melts to cover the corresponding electrode pads to form a conductive contact part to achieve stable electrical connection, and the insulating adhesive layer covers the outer surfaces on the opposite sides of the adjacent conductive contact parts, and the hot pressing conditions are controlled so that the insulating adhesive layer overflows into the split seam to cover the part of the side surface of the corresponding cell unit located in the split seam, and the coating thickness of the insulating adhesive layer is controlled so that the height L of the covered part of the insulating adhesive layer located in the split seam of the corresponding cell unit satisfies L:T = 0.1-20:1, wherein T is the thickness of the conductive contact part.

[0034] In some preferred embodiments of the present disclosure, the manufacturing method of the flexible back contact solar cell module further comprises: S16, sequentially stacking the first flexible plate, the first hot melt adhesive layer, the cell assembly, the second hot melt adhesive layer, and the second flexible plate, and then performing first lamination.

[0035] Optionally, the first lamination conditions comprise: pre-vacuumizing and vacuumizing for 100-900s, lamination pressure of 10-100kPa, lamination temperature of 140-165℃, and lamination time of 300-1200s.

[0036] In a third aspect, embodiments of the present disclosure provide a manufacturing method of a flexible back contact solar cell module, comprising the following steps:

[0037] S101, attaching a protective sheet to the front surface of a cell substrate and fixing the same to form a glue-coated surface on the back surface of the cell substrate; wherein the front surface of the cell substrate is provided with a split seam to divide the cell substrate into a plurality of cell units, the back surface of the cell substrate has an electrode interconnection part configured to connect electrodes between the cell units and / or lead out current, and a plurality of electrode pads are arranged on the electrode interconnection part, the electrode pads including positive electrode pads and negative electrode pads, and the split seam is spaced apart from the positive electrode pads and the negative electrode pads on the corresponding cell units;

[0038] S102, coating the glue-coated surface with a first insulating adhesive, and allowing the first insulating adhesive to not cover the electrode interconnection part, the coating area including the spacing between the cell split seam and the electrode pads on the corresponding cell units, so that the first insulating adhesive is located in the spacing;

[0039] S103, providing a flexible circuit board, the front surface of the flexible circuit board having a patterned conductive circuit; forming a material required for a butt joint conductive part on the conductive circuit, the arrangement of the butt joint conductive part corresponding to the arrangement of the electrode pads; and the flexible circuit board being provided with a through hole, the position of the through hole corresponding to the area between the positive electrode pads and the negative electrode pads in the cell unit;

[0040] S104, placing the back surface of the cell substrate obtained in S102 and the front surface of the flexible circuit board obtained in S103 in alignment, so that the butt joint conductive part is in alignment with the electrode pads and is in contact with the electrode pads, and the positioning is achieved by the adhesion of the first insulating adhesive, forming a cell assembly;

[0041] S105, hot-pressing the cell assembly, so that the butt joint conductive part melts to cover the corresponding electrode pads to form a conductive contact part to achieve stable electrical connection, and the first insulating adhesive covers one side of the outer surface of the adjacent conductive contact part;

[0042] S106, sequentially stack the first flexible plate, the first hot melt adhesive layer, the battery assembly after hot pressing, the second hot melt adhesive layer and the second flexible plate; then perform second lamination, in the second lamination process, the second hot melt adhesive layer is partially extruded through the through hole on the flexible circuit board to fill into the area between the positive electrode welding point and the negative electrode welding point of the corresponding battery cell after being hot melted, and further coat one side surface of the corresponding conductive contact part to form a second insulating adhesive, the second insulating adhesive and the first insulating adhesive form an insulating adhesive layer, and the conditions of the second lamination are controlled so that the second insulating adhesive and the first insulating adhesive overflow into the crack gap to coat the part of the corresponding battery cell located in the crack gap, and the coating thickness of the first insulating adhesive is controlled so that the height L of the coated part of the insulating adhesive layer located in the crack gap of the corresponding battery cell satisfies L:T = 0.1-20:1, wherein T is the thickness of the conductive contact part.

[0043] Optionally, the amount of the second hot melt adhesive layer used in S106 is 240-600g / m 2 .

[0044] In some preferred embodiments of the present disclosure, the flexible circuit board comprises an insulating film, and the patterned conductive circuit is arranged on the insulating film, and the through hole is formed in the insulating film.

[0045] In some preferred embodiments of the present disclosure, the conditions of the second lamination include: the lamination temperature is 140-165℃, the lamination pressure is not more than 4kPa, and the lamination time is 500-1500s.

[0046] In some preferred embodiments of the present disclosure, in the width direction, the surface area of the butt joint conductive part is 0.5-5 times the surface area of the electrode welding point.

[0047] In some preferred embodiments of the present disclosure, the thickness t of the insulating adhesive layer or the first insulating adhesive before hot pressing is adjusted according to the height h of the butt joint conductive part, and satisfies: t = 0.5h-1.2h, and optionally 0.5h-0.95h.

[0048] In some preferred embodiments of the present disclosure, S12 or S102 further comprises a pre-curing treatment after coating the insulating adhesive layer or the first insulating adhesive, so as to pre-cure it, and the pre-curing treatment comprises: baking at 50-200℃ for 1-10min.

[0049] In some preferred embodiments of the present disclosure, the pre-curing treatment makes the tensile force of the corresponding insulating adhesive not less than 0.6N, and the thickness of the corresponding insulating adhesive is 20-80μm.

[0050] In some preferred embodiments of the present disclosure, the hot-pressing conditions include a temperature of 140-180°C, a pressure of no more than 100 kPa, and a time of 200-1200 s.

[0051] In some preferred embodiments of the present disclosure, the process of attaching the protective sheet to the front of the battery substrate and fixing it includes:

[0052] S1.1, providing a battery substrate, the back of the battery substrate having an electrode interconnection part configured to connect electrodes between battery cells and / or lead out current, and a plurality of electrode pads provided on the electrode interconnection part, the electrode pads including positive electrode pads and negative electrode pads, the front of the battery substrate being scored with battery split line grooves, and in a direction parallel to the plane of the battery substrate, the battery split line grooves are spaced apart from the positive electrode pads and the negative electrode pads on the corresponding battery cells;

[0053] S1.2, providing a protective sheet;

[0054] S1.3, attaching the protective sheet to the front of the battery substrate and fixing it;

[0055] S1.4, splitting the battery substrate with the protective sheet attached, so that the battery substrate is split into a plurality of battery cells along the battery split line grooves, and then expanded to form split seams between adjacent battery cells; at this time, the back of the battery substrate forms a glue-coated surface.

[0056] In some preferred embodiments of the present disclosure, the method of manufacturing the flexible back-contact solar cell module further includes the step of providing a protective sheet in advance: on the side of the protective sheet away from the battery substrate, score protective sheet split line grooves corresponding to the battery split line grooves, and when the protective sheet is attached to the front of the battery substrate, make the protective sheet split line grooves coincide with the battery split line grooves.

[0057] In some preferred embodiments of the present disclosure, the method of manufacturing the flexible back-contact solar cell module further includes: after forming the battery assembly, filling the insulating caulking glue in the spacing area containing the split seam between each battery cell in a dispensing manner, and then performing the hot-pressing.

[0058] In some preferred embodiments of the present disclosure, the way of forming the material required for the butt joint conductive part on the conductive line includes printing, dispensing or coating, wherein the printing includes:

[0059] Step a, selecting an insulating film, and forming a patterned conductive line on the insulating film according to the arrangement of each battery cell and the pattern required for series and parallel connection;

[0060] Step b, select a metal screen plate, according to the setting position of the butt joint conductive part, open a mesh hole on the metal screen plate which corresponds to the arrangement of each electrode welding point in the battery base body and is permeable up and down;

[0061] Step c, install the metal screen plate on the printing machine, and place the flexible circuit board below the metal screen plate for alignment;

[0062] Step e, print the material required for the butt joint conductive part to form the butt joint conductive part which can be butt joint welded with each electrode welding point in the battery base body on the conductive circuit, and form the flexible circuit board.

[0063] In a fourth aspect, the embodiments of the present disclosure provide a flexible back contact solar cell module, which is prepared by the manufacturing method of the flexible back contact solar cell module according to the second aspect or the third aspect.

[0064] In a fifth aspect, the embodiments of the present disclosure provide a photovoltaic module, which comprises the flexible back contact solar cell module according to the first aspect, or the flexible back contact solar cell module according to the fourth aspect. Advantages:

[0065] The embodiments of the present disclosure realize stable electrical connection by the above technical solutions, especially by covering the butt joint conductive part of the flexible circuit board on the outer surface of the electrode welding point to form the conductive contact part. The conductive contact part is matched with the insulating adhesive layer with a specific structure, which not only improves the insulation effect between the positive electrode welding point and the negative electrode welding point in the battery cell, but also realizes accurate alignment and lamination between the battery cell and the flexible circuit board by the adhesion of the insulating adhesive layer, thereby achieving excellent sealing effect. In particular, the insulating adhesive layer covers the outer surface of the corresponding conductive contact part and extends at least to the part of the side surface of the corresponding battery cell located in the split seam, and the insulating adhesive layer fills the gap between the battery cell and the flexible circuit board at the same time, which not only realizes sealing and insulation to prevent short circuit, but also reduces the occurrence of warping problem, ensures excellent production yield, and improves the service life and photoelectric conversion efficiency of the battery cell. Moreover, the electrode welding point of the battery cell is well sealed and insulated, which avoids the erosion of the battery cell and its electrode welding point caused by external water vapor, significantly reduces the water vapor transmission rate, avoids the short circuit caused by the bubble in the outer surface packaging structure of the electrode welding point and the battery cell, and has good cold and hot impact resistance. In addition, the production yield is improved, and the weather resistance of the battery used outdoors is also greatly improved, and the service life is increased.

[0066] In the manufacturing method of the embodiment of the present disclosure, a gap is left between the split seam of the battery substrate and the positive electrode welding point and the negative electrode welding point on the corresponding battery cell in advance, and an insulating adhesive layer is formed in the area including the gap by using two different methods, so that the insulating adhesive layer is located on both sides of the electrode welding point. Through subsequent hot pressing and / or laminating, the electrode interconnection part and the butt joint conductive part are fixedly connected to form stable electrical connection, and the insulating adhesive layer covers the outer surface of the corresponding conductive contact part and at least extends to cover the part of the side surface of the corresponding battery cell located in the split seam. Good sealing and insulation effects are formed on the electrodes of the battery cell with different polarities, and good protection is provided for the electrode welding points of the battery cell. The erosion of the battery cell and its electrode welding points caused by external water vapor is avoided, the water vapor passing rate is significantly reduced, the short circuit caused by the bubble of the outer surface packaging structure of the electrode welding point and its battery cell is avoided, and the service life, production yield and photoelectric conversion efficiency of the battery cell are improved. Good cold and hot impact resistance performance is achieved. BRIEF DESCRIPTION OF DRAWINGS

[0067] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present disclosure, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0068] FIG. 1 is a cross-sectional view of a specific embodiment of the flexible back contact solar cell module of the present disclosure.

[0069] FIG. 2 is a cross-sectional view of a specific embodiment of the flexible back contact solar cell module of the present disclosure.

[0070] FIG. 3 is a structural schematic diagram of a battery substrate of the present disclosure.

[0071] FIG. 4 is a structural schematic diagram of a battery cell of the present disclosure.

[0072] FIG. 5 is a structural schematic diagram of a protective sheet of the present disclosure.

[0073] FIG. 6 is a structural schematic diagram of the battery substrate and the protective sheet of the present disclosure.

[0074] FIG. 7 is a structural schematic diagram of the present disclosure for coating an insulating adhesive layer on the coated surface.

[0075] FIG. 8 is a structural schematic diagram of the present disclosure for coating a first insulating adhesive on the coated surface.

[0076] FIG. 9 is a structural schematic diagram of a specific embodiment of a metal mesh plate of the present disclosure.

[0077] Fig. 10 is a structural diagram of a specific embodiment of the flexible circuit board of the present disclosure.

[0078] Fig. 11 is a structural diagram of the flexible circuit board and the battery cell and the alignment placement of the battery substrate thereof of the present disclosure.

[0079] Fig. 12 is a structural diagram of the flexible circuit board of the present disclosure provided with long strip through holes.

[0080] Fig. 13 is a structural diagram of the insulating adhesive layer coating of Comparative Example 3.

[0081] BRIEF DESCRIPTION OF THE DRAWINGS 1, battery substrate, 1-1, battery split line groove, 2, battery cell, 2-1, electrode interconnection, 2-2, electrode welding point, 3, insulating adhesive layer, 4, flexible circuit board, 4-1, PI insulating film, 4-2, copper layer, 4-3, soldering point, 4-4, long strip through hole, 5, metal screen, 5-1, screen hole, 6, protective sheet, 6-1, protective sheet split line, 7, first flexible plate, 8, first hot melt adhesive layer, 9, second hot melt adhesive layer, 10, second flexible plate, 11, adhesive layer, 12, caulking adhesive. DETAILED DESCRIPTION

[0082] In the present disclosure, the orientation words such as "upper", "lower", "left", "right" are generally understood in connection with the orientation shown in the drawings and the actual application, and "inner", "outer" refer to the inner and outer of the outline of the component.

[0083] In addition, the terms "first", "second" are only configured for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present disclosure, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified and limited.

[0084] In the present disclosure, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present disclosure can be understood according to the specific circumstances.

[0085] In the present disclosure, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0086] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein. Among them, the terms "optional" and "optional" all mean that they may be included or not (or may be present or not).

[0087] In the embodiments of the present disclosure, the area close to the battery base is considered as the inner side, and the area far from the battery base is considered as the outer side.

[0088] In a first aspect, an embodiment of the present disclosure provides a flexible back-contact solar cell module, comprising a battery substrate having a plurality of battery cells and a protective sheet attached to the front side of the battery substrate, with crack seams formed between adjacent battery cells. The back side of the battery substrate has an electrode interconnection portion configured to connect electrodes between battery cells and / or draw out current, as well as a plurality of electrode welding points arranged on the electrode interconnection portion.

[0089] It should be noted that the electrode interconnection portion described in the embodiment of the present disclosure includes a fine grid line electrode and a coarse grid line electrode (or main grid line electrode) provided in the battery, which is a prior art and will not be described in detail here. The electrode welding point (or pad) is provided at the intersection of the fine grid line electrode and the coarse grid line electrode and is configured to be a convergence. Several battery cells in the battery matrix are connected in series and parallel with each other, and can be specifically set according to needs.

[0090] The flexible back contact solar cell module further comprises:

[0091] a flexible circuit board, wherein the front surface of the flexible circuit board has a patterned conductive circuit and a docking conductive portion provided on the conductive circuit to electrically connect to the electrode welding point, the front surface of the flexible circuit board being attached to the back surface of the battery substrate, with the docking conductive portion at least partially covering the outer surface of the electrode welding point to form a conductive contact portion;

[0092] An insulating adhesive layer is filled in the gap formed between the battery cell and the corresponding partial flexible circuit board in the thickness direction and extends to cover the outer surface of the corresponding conductive contact part (optionally tightly covers the outer surface of the corresponding conductive contact part); and in the thickness direction, the insulating adhesive layer at least extends to cover the part of the side surface of the corresponding battery cell located in the split seam, and the height L of the covering part of the insulating adhesive layer located in the split seam of the corresponding battery cell satisfies L:T = 0.1-20:1, optionally 1-20:1, and more optionally 1.5-20:1, wherein T is the thickness of the conductive contact part.

[0093] The embodiments of the present disclosure adopt a suitable L:T range, which can not only ensure that the insulating adhesive layer covers at least the plated area of the back side of the split battery cell to avoid internal micro-short circuit caused by the side surface of the battery cell, but also facilitate the control of the coating process and the stability of the connection of the conductive contact part during hot pressing.

[0094] It can be understood that the embodiments of the present disclosure provide the butt joint conductive part on the front surface of the conductive circuit.

[0095] On the basis of satisfying the above L:T range, the specific values of L and T can be selected. In some preferred embodiments of the present disclosure, the thickness T of the conductive contact part is 30-100 μm, and the height L of the covering part of the insulating adhesive layer located in the split seam of the corresponding battery cell is 3-130 μm, optionally 10-130 μm.

[0096] The battery substrate of the embodiments of the present disclosure is a silicon-based battery. The size of the battery cell of the embodiments of the present disclosure can be determined according to actual needs.

[0097] In some preferred embodiments of the present disclosure, in the width direction, the width d of the covering part of the insulating adhesive layer located in the split seam of the corresponding battery cell is 5%-50% of the split seam width D, optionally 10%-50%, and optionally 20%-50%. The use of the insulating adhesive layer with a suitable width d to cover the battery cell can better control the consistency of the coating process and is more conducive to the stability of the production process, thereby further improving the temperature, humidity and heat resistance and waterproof performance of the flexible battery module.

[0098] In some preferred embodiments of the present disclosure, the width D of the split seam between any adjacent battery cells is 0.1 mm-30 mm, optionally 0.1 mm-8 mm, and optionally 0.1 mm-5 mm. The use of a suitable D is more conducive to the winding of the laminated product assembly, which reserves sufficient space to avoid the collision of the battery cells during winding and effectively releases the stress in the split seam area, thereby further avoiding the splitting phenomenon of the battery cells.

[0099] In some preferred embodiments of the present disclosure, in the width direction of the conductive contact part, the insulating adhesive layers corresponding to adjacent battery units extend to each other and connect to each other. By connecting the insulating adhesive layers corresponding to each battery unit to each other, the battery units can be kept in the same straight line, which is more conducive to accurate alignment and welding of the conductive contact part, avoids poor welding caused by inaccurate alignment, and further improves the reliability of the product and achieves better anti-winding performance.

[0100] In some preferred embodiments of the present disclosure, the side of the protective sheet away from the battery base has a protective sheet split line groove corresponding to and coinciding with the overall pattern formed by the plurality of battery units. This is more conducive to the battery units after the protective sheet is attached to accurately split along the preset battery split line groove to form individual battery units, further effectively reducing the risk of warping.

[0101] In some preferred embodiments of the present disclosure, the protective sheet is attached to the front of the battery base through the adhesive layer, which is more conducive to protecting the battery base and further avoiding the phenomenon of battery unit fragmentation during bending or winding, further improving the reliability and stability of the product.

[0102] In some preferred embodiments of the present disclosure, in the thickness direction, the height of the part of the insulating adhesive layer between the battery unit and the flexible circuit board is flush with the height of the conductive contact part, which is more conducive to improving the stability of the product and further avoiding the gap between the battery unit and the flexible circuit board, and the air in the gap is difficult to be evacuated, which may cause the risk of delamination during subsequent product bending and winding, further improving the reliability of the product.

[0103] The butt joint conductive part is configured to butt joint with the electrode welding point and is made of conductive material. In some preferred embodiments of the present disclosure, the butt joint conductive part is selected from at least one material selected from the group consisting of tin paste, conductive adhesive, silver paste, conductive copper paste, etc. The tin paste can be low-temperature tin paste.

[0104] In some preferred embodiments of the present disclosure, the butt joint conductive part is a welding point, a welding pad, or an adhesive layer.

[0105] In some preferred embodiments of the present disclosure, the pattern of the patterned conductive circuit corresponds to the arrangement of the plurality of battery units and the pattern formed by the series and parallel connection thereof, which is more conducive to accurate alignment of the electrode welding point and the butt joint conductive part and avoids the phenomenon of poor welding.

[0106] In some preferred embodiments of the present disclosure, the flexible circuit board includes an insulating film, and the patterned conductive circuit is arranged on the insulating film.

[0107] In some preferred embodiments of the present disclosure, the crack gaps between the individual battery cells are filled with insulating sealant, which is more conducive to improving the reliability of the battery assembly and further avoids the possibility that air remaining in the crack gaps affects the reliability and stability of the product due to the fact that the crack gaps are too small to be filled with the flowing hot melt adhesive during the lamination process.

[0108] Optionally, the insulating sealant can be any insulating adhesive, such as one or more of hot melt adhesive, silicone adhesive, EVA adhesive, POE adhesive, etc.

[0109] In some preferred embodiments of the present disclosure, the thickness ratio of the flexible circuit board, the protective sheet, and the battery cell is 0.2-10:0.7-30:1, optionally 0.2-4:0.7-30:1, and optionally 0.3-1.5:1-8:1. The appropriate thickness ratio matches the thickness of each layer, which is more conducive to achieving the protection of the battery cell and further improving the stability and reliability of the product during bending or winding.

[0110] In some embodiments, the thickness of the flexible circuit board is 30-230 μm, optionally 30-100 μm.

[0111] In some embodiments, the thickness of the protective sheet is 0.1-1.5 mm, optionally 0.1-0.8 mm.

[0112] In some embodiments, the thickness of the battery cell is 50-150 μm.

[0113] The conductive circuit can be any material that is conducive to electricity. In some preferred embodiments of the present disclosure, the conductive circuit is selected from at least one of copper, aluminum, nickel, tin, gold, or silver.

[0114] In some preferred embodiments of the present disclosure, the thickness of the conductive circuit is 10-200 μm, more optionally 10-100 μm, and optionally 10-50 μm, which is more conducive to balancing the conductive requirement and weight requirement of the conductive circuit, i.e., in the case of meeting the conductive requirement, the thickness is thinned as much as possible to the lightest weight to reduce the overall weight of the flexible back contact solar cell module.

[0115] In some preferred embodiments of the present disclosure, the flexible back contact solar cell module further includes other conventional layers, such as a first hot melt adhesive layer, a first flexible plate arranged in sequence on the outer surface of the protective sheet, and a second hot melt adhesive layer, a second flexible plate arranged in sequence on the back surface of the flexible circuit board. The first flexible plate and the second flexible plate of the embodiments of the present disclosure can be, for example, a flexible material such as ETFE (ethylene-tetrafluoroethylene copolymer).

[0116] In a second aspect, embodiments of the present disclosure provide a manufacturing method of a flexible back contact solar cell module, comprising the following steps:

[0117] S11, attaching a protective sheet to the front surface of the cell substrate and fixing it, thereby forming a glue-coated surface on the back surface of the cell substrate; wherein the front surface of the cell substrate is provided with a split seam to divide the cell substrate into a plurality of cell units, the back surface of the cell substrate has an electrode interconnection part configured to connect the electrodes between the cell units and / or lead out current, and a plurality of electrode pads are arranged on the electrode interconnection part, the electrode pads including positive electrode pads and negative electrode pads, and the split seam is spaced apart from the positive electrode pads and the negative electrode pads on the corresponding cell units;

[0118] S12, coating an insulating glue layer on the glue-coated surface, and making the insulating glue layer not cover the electrode pads, the coating area including the spacing between the cell split seam and the electrode pads on the corresponding cell units and the area between the positive electrode pads and the negative electrode pads;

[0119] S13, providing a flexible circuit board, the front surface of the flexible circuit board having a patterned conductive circuit; forming the required materials for the butt joint conductive part on the conductive circuit, and the arrangement of the butt joint conductive part corresponding to the arrangement of the electrode pads;

[0120] S14, placing the back surface of the cell substrate obtained in S12 and the front surface of the flexible circuit board obtained in S13 in alignment, so that the butt joint conductive part is in contact with the electrode pads in alignment, and the positioning is realized by the adhesion of the insulating glue layer, thereby forming a cell assembly;

[0121] S15, hot pressing the cell assembly, so that the butt joint conductive part melts to cover the corresponding electrode pads to form a conductive contact part to realize stable electrical connection, and the insulating glue layer covers the outer surfaces on the opposite sides of the adjacent conductive contact parts, and the hot pressing conditions are controlled so that the insulating glue layer overflows into the split seam to cover the part of the side surface of the corresponding cell unit located in the split seam, and the coating thickness of the insulating glue layer is controlled so that the height L of the covered part of the insulating glue layer located in the split seam of the corresponding cell unit satisfies L:T = 0.1-20:1, wherein T is the thickness of the conductive contact part.

[0122] In the second aspect, the insulating adhesive layer is coated in the space left between the cell split line groove and the electrode welding points on the corresponding cell unit, and in the area between the positive electrode welding points and the negative electrode welding points, which can avoid the short circuit caused by the butt joint conductive part in the molten state connecting the positive electrode welding points and the negative electrode welding points under the pressure when the butt joint conductive part melts and covers the corresponding electrode welding points during hot pressing, or the flow to the side wall of the cell unit at the split seam position causing internal short circuit of the cell unit, and is more conducive to improving the yield of product production and ensuring the reliability of the product.

[0123] In some preferred embodiments of the second aspect of the present disclosure, the manufacturing method of the flexible back contact solar cell module further comprises: S16, sequentially stacking the first flexible plate, the first hot melt adhesive layer, the cell assembly, the second hot melt adhesive layer, and the second flexible plate, and then performing first lamination.

[0124] Optionally, the first lamination conditions include: pre-vacuum and vacuum time of 100-900s, lamination pressure of 10-100kPa, lamination temperature of 140-165℃, and lamination time of 300-1200s.

[0125] In a third aspect, the embodiments of the present disclosure provide another manufacturing method of a flexible back contact solar cell module, comprising the following steps:

[0126] S101, attaching a protective sheet to the front surface of the cell substrate and fixing it, thereby forming a glue coating surface on the back surface of the cell substrate; wherein the front surface of the cell substrate is provided with a split seam to divide the cell substrate into a plurality of cell units, the back surface of the cell substrate has an electrode interconnection part configured to connect the electrodes between the cell units and / or lead out the current, and a plurality of electrode welding points provided on the electrode interconnection part, the electrode welding points including positive electrode welding points and negative electrode welding points, and the split seam leaves a space between the corresponding positive electrode welding points and negative electrode welding points on the cell unit;

[0127] S102, coating the glue coating surface with a first insulating adhesive, and making the first insulating adhesive not cover the electrode interconnection part, the coating area including the space left between the cell split line groove and the electrode welding points on the corresponding cell unit, so that the first insulating adhesive is located in the space;

[0128] S103, providing a flexible circuit board, the front surface of the flexible circuit board having a patterned conductive circuit; forming the required material for the butt joint conductive part on the conductive circuit, the arrangement of the butt joint conductive part corresponding to the arrangement of the electrode welding points; and the flexible circuit board is provided with a through hole, the position of the through hole corresponding to the area between the positive electrode welding points and the negative electrode welding points in the cell unit;

[0129] S104, placing the back of the battery substrate obtained in S102 and the front of the flexible circuit board obtained in S103 in alignment, so that the butt joint conductive part is in contact with the electrode welding point in alignment, and positioning is achieved by the adhesion of the first insulating glue, forming a battery assembly;

[0130] S105, hot pressing the battery assembly, so that the butt joint conductive part melts to cover the corresponding electrode welding point to form a conductive contact part to achieve stable electrical connection, and the first insulating glue covers one side of the outer surface of the adjacent conductive contact part;

[0131] S106, sequentially stacking the first flexible plate, the first hot melt glue layer, the battery assembly after hot pressing, the second hot melt glue layer, and the second flexible plate; then performing second lamination, in which the second hot melt glue layer is hot fused and then partially extruded through the through hole on the flexible circuit board to fill the area between the positive electrode welding point and the negative electrode welding point in the corresponding battery cell, and then covers one side surface of the corresponding conductive contact part, forming a second insulating glue, the second insulating glue and the first insulating glue form an insulating glue layer, and the conditions of the second lamination are controlled so that the second insulating glue and the first insulating glue overflow into the crack gap and cover the part of the corresponding battery cell outside the crack gap, and the thickness of the first insulating glue is controlled so that the height L of the covered part of the insulating glue layer in the crack gap of the corresponding battery cell satisfies L:T = 0.1-20:1, where T is the thickness of the conductive contact part. The second insulating glue and the first insulating glue in S106 can be solidified to form an insulating glue layer after cooling.

[0132] In the third aspect, the amount of the second hot melt glue layer used in S106 is 240-600g / m 2 The appropriate amount of the second hot melt glue layer is more conducive to the extrusion of the appropriate part of the second hot melt glue layer through the through hole on the flexible circuit board to fill the area between the positive electrode welding point and the negative electrode welding point in the corresponding battery cell after hot fusion in the second lamination process, and a good balance between the extrusion amount and the amount of the second hot melt glue layer is achieved.

[0133] In the third aspect, the first insulating glue is coated in the space between the battery crack slot and the electrode welding point on the corresponding battery cell, and the second insulating glue formed in S106 is filled in the area between the positive electrode welding point and the negative electrode welding point, forming an overall insulating glue layer, which can fill the entire crack gap with insulating glue, avoiding air remaining in the crack gap, and more conducive to improving the reliability and long-term stability of the flexible back contact solar cell module.

[0134] In the third aspect, the thickness of the second hot melt adhesive layer is set in a suitable range, generally, the thickness is set in excess, so that part of the second hot melt adhesive layer is extruded through the through hole on the flexible circuit board to fill into the area between the positive electrode welding point and the negative electrode welding point of the corresponding battery cell after the second hot melt adhesive layer is hot melted during the second laminating process. The specific excess value can be selected according to actual needs.

[0135] In the second aspect of the embodiments of the present disclosure, the amount of the second hot melt adhesive layer used is 300-450 g / m 2 .

[0136] In some preferred embodiments of the third aspect of the present disclosure, the flexible circuit board comprises an insulating film, the patterned conductive circuit is arranged on the insulating film, and the through hole is formed on the insulating film, which is more conducive to completely filling the gap outside the conductive contact part area with hot melt insulating adhesive, and further avoids the possible occurrence of incomplete filling of insulating adhesive around the conductive contact part area.

[0137] In the second aspect and the third aspect, the gap between the split seam and the positive electrode welding point and the negative electrode welding point on the corresponding battery cell means that the gap between the split seam and the positive electrode welding point on the corresponding battery cell and the gap between the split seam and the negative electrode welding point on the corresponding battery cell are both left, and the specific size of the gap is only required to be sufficient for subsequent coating of the required amount of corresponding insulating adhesive.

[0138] In some preferred embodiments of the present disclosure, the conditions of the second laminating include that the laminating temperature is 140-165℃, the laminating pressure is not more than 4kPa, and the laminating time is 500-1500s.

[0139] In the present disclosure, the insulating adhesive layer or the first insulating adhesive on the gluing side can be coated by any coating method such as printing, dispensing or coating, which can be selected by those skilled in the art according to actual needs.

[0140] In some preferred embodiments of the present disclosure, in the width direction, the surface area of the butt joint conductive part is 0.5-5 times, optionally 1.3-5 times, and optionally 1.3-3.5 times the surface area of the electrode welding point, which can ensure the reliability of electrical connection while not sacrificing the flexibility of the assembly, and is more conducive to the large-scale production of flexible back contact solar cell modules. The balance of the two is particularly important, because too large butt joint conductive part can cause unnecessary rigidity, and too small conductive part can affect the electrical performance, therefore, it can achieve the best balance between the two aspects, thereby optimizing the overall performance of the product.

[0141] In some preferred embodiments of the present disclosure, the thickness t of the insulating adhesive layer or the first insulating adhesive before hot pressing is adjusted according to the height h of the butt joint conductive part, and satisfies: t = 0.5h-1.2h, optionally 0.5h-1.1h, optionally 0.5h-0.95h, optionally 0.6h-0.95h, more optionally 0.7h-0.9h. The thickness t of the insulating adhesive layer or the first insulating adhesive before hot pressing is set to be lower than the height h of the butt joint conductive part, which is conducive to the conductive connection. Then the two are made almost the same after hot pressing, which is more conducive to the high-quality connection of the butt joint conductive part and the electrode soldering point, and is more conducive to improving the electrical stability and physical structural integrity of the flexible back contact solar cell module, while promoting the efficiency of manufacturing and assembly, and effectively supporting the functional integration and large-scale production of the flexible back contact solar cell module.

[0142] In some preferred embodiments of the present disclosure, the pre-solidification treatment is further included in S12 or S102 after coating the insulating adhesive layer or the first insulating adhesive, so as to make it pre-solidified. The pre-solidification treatment in the embodiments of the present disclosure makes the insulating adhesive layer or the first insulating adhesive in a partially solidified state, which still has adhesion, so as to facilitate subsequent accurate alignment.

[0143] Optionally, the present disclosure does not pre-solidify the treatment, but directly aligns and places the corresponding insulating adhesive with the flexible circuit board after coating the corresponding insulating adhesive. The advantage is that the insulating adhesive is more firmly bonded and has greater pulling force.

[0144] In some preferred embodiments of the present disclosure, the pre-solidification treatment includes baking at 50-200°C for 1-10min.

[0145] In some preferred embodiments of the present disclosure, the pre-solidification treatment makes the pulling force of the corresponding insulating adhesive not less than 0.6N, optionally 0.6N-10N.

[0146] Optionally, the thickness of the corresponding insulating adhesive is 20-80μm.

[0147] In some preferred embodiments of the present disclosure, the conditions of the hot pressing include: temperature of 140-180°C, pressure not more than 100kPa, and time of 200-1200s.

[0148] The hot pressing in the embodiments of the present disclosure can be performed in a laminating device or a hot pressing device. When performed in a laminating device, it can also be optionally first vacuumed for 10-300s, and then hot pressed at the target temperature and pressure.

[0149] In some preferred embodiments of the present disclosure, the process of attaching and fixing the protective sheet on the front surface of the cell substrate to form the adhesive-coated surface on the back surface of the cell substrate includes:

[0150] S1.1, providing a battery base body, the back surface of the battery base body having an electrode interconnection part configured to connect electrodes between battery cells and / or lead out current, and a plurality of electrode pads provided on the electrode interconnection part, the electrode pads including positive electrode pads and negative electrode pads, the front surface of the battery base body being scored with battery cell splitting line grooves, and in a direction parallel to the plane of the battery base body, the battery cell splitting line grooves are each spaced apart from the positive electrode pads and the negative electrode pads on the corresponding battery cells;

[0151] S1.2, providing a protective sheet;

[0152] S1.3, attaching the protective sheet to the front surface of the battery base body and fixing it;

[0153] S1.4, splitting the battery base body with the protective sheet attached to form a plurality of battery cells along the battery cell splitting line grooves, and then expanding the spacing to form a splitting gap between adjacent battery cells; at this time, the back surface of the battery base body forms a glue-coated surface. By expanding the spacing, compared with directly connecting a plurality of battery cells in series and parallel to form a battery string, a gap is reserved between the battery cells, which is more conducive to releasing stress in the splitting gap area when the flexible back contact solar cell module is bent or wound, without damaging the battery cells.

[0154] It should be understood that expanding the spacing means that after splitting into a plurality of battery cells, the battery cells are connected adjacent to each other, and then expanded by a splitting machine to form a certain distance between the battery cells.

[0155] The material of the protective sheet can be any material that can protect the battery base body, such as glass sheet, silicone plate or acrylic plate, etc.

[0156] The way of scoring the battery cell splitting line grooves in the embodiments of the present disclosure can use laser.

[0157] Optionally, the process of attaching the protective sheet to the front surface of the battery base body and fixing it can be, for example, dropping or coating glue on the front surface of the battery base body or the non-cutting surface of the protective sheet, and aligning the non-cutting surface of the protective sheet with the front surface of the battery base body for attachment, so that the battery cell splitting line grooves coincide with the protective sheet splitting line grooves. Optionally, the glue used in the dropping or coating operation is optical silicone.

[0158] In some preferred embodiments of the present disclosure, the method for manufacturing the flexible back contact solar cell module further comprises the step of providing a protective sheet in advance: scoring protective sheet splitting line grooves corresponding to the battery cell splitting line grooves on the side of the protective sheet away from the battery base body, and aligning the protective sheet splitting line grooves with the battery cell splitting line grooves when the protective sheet is attached to the front surface of the battery base body.

[0159] The protective sheet can be scored by a laser scribe machine or a mechanical scribe machine.

[0160] In some preferred embodiments of the present disclosure, the method for manufacturing the flexible back contact solar cell module further comprises: after the cell assembly is formed, filling the insulating caulking glue in the interval area with the cell piece seam between the cell units in a dispensing manner, and then performing the hot pressing.

[0161] In some preferred embodiments of the present disclosure, the method for forming the material required for the butt joint conductive part on the conductive circuit comprises a printing method, a dispensing method or a coating method.

[0162] Optionally, the material required for the butt joint conductive part on the conductive circuit is printed, and specifically comprises:

[0163] Step a, selecting an insulating film, and forming a patterned conductive circuit on the insulating film according to the arrangement of the cell units and the pattern formed by the series and parallel connection of the cell units;

[0164] Step b, selecting a metal screen, and opening a mesh hole on the metal screen corresponding to the arrangement of the electrode welding points in the cell substrate and penetrating the mesh hole upward and downward according to the setting position of the butt joint conductive part;

[0165] Step c, installing the metal screen on the printing machine, and placing the flexible circuit board below the metal screen for alignment;

[0166] Step e, printing the material required for the butt joint conductive part, forming the butt joint conductive part capable of butt joint welding with the electrode welding points in the cell substrate on the conductive circuit, and forming the flexible circuit board. This printing method can more accurately control the printing area and size of the butt joint conductive part, and is more conducive to the accurate alignment of the butt joint conductive part and the electrode welding points.

[0167] Optionally, the insulating film can be an insulating film material such as PI.

[0168] Optionally, the metal screen in step b can be fixed in the screen frame by a steel wire screen, so as to be installed on the printing machine.

[0169] In the manufacturing method of the second aspect and the third aspect of the present disclosure, the insulating glue layers corresponding to the adjacent cell units near the outer side can be simultaneously coated under the same mesh hole by changing the printing screen used in the silk screen printing in S12 to print and coat the entire surface, or the insulating glue layers corresponding to the adjacent cell units can be extended to be connected in the width direction of the conductive contact part by optimizing the hot pressing parameters, i.e., adjusting the vacuum time in the condition of the hot pressing to make the corresponding insulating glue have better fluidity.

[0170] In the manufacturing method of the second aspect and the third aspect of the present disclosure, the amount of the corresponding insulating adhesive can be reduced by using the independent printing screen in S12, the corresponding insulating adhesive is not printed in a distance of 0.2-0.3 mm inward from the edge of the coating area close to the cell tab seam, and then the insulating adhesive is extruded into the side cell tab seam by hot pressing, so as to control the width d of the covering part of the insulating adhesive layer in the corresponding cell tab seam to be 10%-50% of the width D of the cell tab seam.

[0171] In the fourth aspect, the embodiments of the present disclosure provide a flexible back contact solar cell module, which is prepared by the manufacturing method of the flexible back contact solar cell module according to the second aspect or the third aspect. The structure and composition of the flexible back contact solar cell module are the same as those of the flexible back contact solar cell module according to the first aspect, and will not be repeated here.

[0172] In the fifth aspect, the embodiments of the present disclosure provide a photovoltaic module, which comprises the flexible back contact solar cell module according to the first aspect, or the flexible back contact solar cell module according to the fourth aspect.

[0173] The embodiments of the present disclosure are described in detail below, which are exemplary and are configured to explain the present disclosure, but cannot be understood as a limitation of the present disclosure.

[0174] Embodiment 1

[0175] A flexible back contact solar cell module is shown in FIG. 1, and the manufacturing method thereof specifically comprises the following steps:

[0176] S11:

[0177] S1.1, prepare a silicon-based back contact cell solar cell as a cell substrate 1;

[0178] The cell substrate 1 is laser-engraved with a cell tab line groove 1-1 on the front surface according to the arrangement of each cell unit 2 (the size specification of the cell unit 2 is 12 mm in length, 7.84 mm in width, and 130 μm in thickness), to form a plurality of cell units 2, forming a structure as shown in FIG. 3; the back surface of the cell substrate 1 has an electrode interconnection part 2-1 configured to connect and lead the current between the cell units 2, and a plurality of electrode soldering points 2-2 provided on the electrode interconnection part 2-1, the electrode soldering points 2-2 including positive electrode soldering points and negative electrode soldering points, as shown in FIG. 4; the cell tab line groove 1-1 is spaced apart from the positive electrode soldering points and the negative electrode soldering points on the corresponding cell unit 2;

[0179] S1.2, the protective sheet 6 (specifically, a glass sheet) is scored on one side according to the size of the battery cell 2 by a laser scribe machine to form a protective sheet crack line groove 6-1, as shown in FIG. 5. This side is the glass cutting surface, and the un-scored side is the non-cutting surface;

[0180] S1.3, glue is dropped on the front surface of the battery base 1, and the non-cutting surface of the protective sheet 6 is aligned and attached to the front surface of the battery base 1, so that the battery crack line groove 1-1 coincides with the protective sheet crack line groove 6-1, as shown in FIG. 6. The glue used is optical silicone glue;

[0181] S1.4, the battery base 1 with the protective sheet 6 attached is arranged at an expanded distance, so that the battery base 1 is cracked into individual battery cells 2, and the back surface of the battery cell 2 faces upward, forming a glue-coated surface after the expanded distance arrangement. The spacing between each battery cell 2 after the expanded distance arrangement (i.e., the width D of the crack gap) is 0.4 mm.

[0182] S12, a silk screen printing operation is used to coat an insulating glue layer 3 on the glue-coated surface. The insulating glue layer 3 is coated in the above-mentioned S1.1 reserved spacing and the area between the positive electrode welding point and the negative electrode welding point on the back surface of the battery cell 2. Only the positive electrode welding point and the negative electrode welding point are exposed and not coated. The insulating glue layer 3 is provided on both sides of the positive electrode welding point and the negative electrode welding point, as shown in FIG. 7 (the insulating glue layer 3 is coated in three strips), and the insulating glue layer does not cover the electrode welding points. The thickness of the insulating glue layer 3 is 30 μm.

[0183] S13, a flexible circuit board 4 is provided. The flexible circuit board 4 is printed with low-temperature tin paste to form tin welding points 4-3 as the butt joint conductive part according to the arrangement of each battery cell 2 of the battery base 1. In the width direction, the surface area of the butt joint conductive part is 1.5 times the surface area of the electrode welding point. In the thickness direction, the height h of the butt joint conductive part and the thickness t of the insulating glue layer satisfy: t = 0.8h. Specifically, a PI insulating film 4-1 (thickness 25 μm) is selected, and a patterned copper layer 4-2 (i.e., a conductive circuit) is formed on the PI insulating film 4-1 according to the arrangement of each battery cell 2 and the series-parallel connection requirement. The thickness of the copper layer 4-2 is 35 μm. b. A metal screen 5 is selected, and the metal screen 5 is fixed in a screen frame by a steel screen. c. According to the setting position of the butt joint conductive part, the upper and lower through holes 5-1 are formed on the metal screen 5, as shown in FIG. 9. d. The metal screen 5 is installed on a tin paste printing machine, and the flexible circuit board 4 is placed below the metal screen 5 for alignment. e. Low-temperature tin paste is used for printing to form tin welding points 4-3 on the copper layer 4-2, which can be aligned and welded with the positive and negative electrode welding points 2-2, as shown in FIG. 10. It is calculated that the thickness ratio of the flexible circuit board 4, the protective sheet 6, and the battery cell 2 is 0.46:3.08:1.

[0184] S14, the back of the battery cell 2 obtained in S12 is placed in alignment with the flexible circuit board 4 obtained in S13, as shown in FIG. 11, and positioning is achieved by adhesion of the insulating adhesive layer 3, forming a battery assembly. Then, the gap area between the battery cells 2, containing the tab seam, is filled with insulating caulking adhesive 12 (specifically, POE adhesive) in a dispensing manner.

[0185] S15, the battery assembly is hot-pressed, specifically, the battery assembly is placed in a laminating device, after vacuuming for 120 s, hot-pressing is performed at a laminating temperature of 180°C and a laminating pressure of 50 kPa for 240 s, so that the positive and negative electrode welding points 2-2 of each battery cell 2 are fixedly connected with the corresponding soldering points 4-3 to form stable electrical connections. During lamination of the battery assembly, the soldering points 4-3 melt at high temperature to cover the positive and negative electrode welding points 2-2 to form conductive contact portions, achieving stable electrical connections. At the same time, under the application of a certain pressure during the lamination process, the height of the soldering points 4-3 and the thickness of the insulating adhesive layer 3 can be adjusted to be the same, which not only avoids the flow of the melted soldering points 4-3 to the non-connection area (i.e., the area of the electrode with opposite polarity) during melting, but also makes the insulating adhesive layer 3 and the conductive contact portion at the same height. By controlling the thickness of the insulating adhesive layer applied in S12, the height L of the covered portion of the insulating adhesive layer 3 located in the tab seam of the corresponding battery cell 2 satisfies L:T = 2:1, where T is the thickness of the conductive contact portion and is 30 μm. By controlling the laminating pressure and the vacuuming time, the width d of the covered portion of the insulating adhesive layer 3 located in the tab seam of the corresponding battery cell 2 in the width direction is 30% of the width D of the tab seam.

[0186] S16, the first flexible plate 7, the first hot-melt adhesive layer 8, the battery assembly, the second hot-melt adhesive layer 9, and the second flexible plate 10 are sequentially laminated, and the amount of the second hot-melt adhesive layer 9 used is 380 g / m 2 , and a flexible back contact solar cell module is formed by first lamination. The conditions of the first lamination include: pre-vacuuming for 300 s, a laminating pressure of 50 kPa, a laminating temperature of 155°C, and a laminating time of 900 s.

[0187] Example 2

[0188] The method of Example 1 is referred to, except that, in the width direction of the conductive contact portion, the insulating adhesive layers corresponding to adjacent battery cells extend to each other for connection, as shown in FIG. 2. In order to meet this condition, the corresponding process needs to be adjusted: in S12, the printing screen used for screen printing is changed to print the entire adhesive layer, so that the insulating adhesive layers corresponding to adjacent battery cells near the outer side are coated at the same screen hole at the same time.

[0189] Example 3

[0190] A manufacturing method of a flexible back contact solar cell module, referring to the method of embodiment 1, the difference is that different insulating adhesive layer coating processes and subsequent processes are used, which are as follows:

[0191] S102 (alternative to S12 of embodiment 1), using screen printing to coat the adhesive side with the first insulating adhesive, the first insulating adhesive is coated in the above S1.1 reserved spacing, and is not coated in the area between the positive electrode welding point and the negative electrode welding point on the back of the cell unit, only the positive electrode welding point and the negative electrode welding point are exposed without coating, the outside of the positive electrode welding point and the negative electrode welding point is provided with the first insulating adhesive, as shown in Figure 8 (the first insulating adhesive is coated in two lines), and the insulating adhesive layer does not cover the electrode welding point. After coating, pre-curing operation is carried out, baking at 150℃ for 5min, so that the first insulating adhesive is in a semi-cured state. The pre-curing treatment makes the tensile force corresponding to the first insulating adhesive bonding 6N, and the thickness is 30μm.

[0192] S103, according to the S13 of embodiment 1, the difference is that a rectangular long hole 4-4 is opened on the PI insulating film, which corresponds to the area between the positive electrode welding point and the negative electrode welding point in the cell unit; as shown in Figure 12.

[0193] S106, according to the sequence of S16 of embodiment 1, the second lamination is carried out, the difference is that the lamination temperature is reduced to 145℃, the pressure value is reduced to 3.5kPa, the lamination time is 1200s, and the usage amount of the second hot melt adhesive layer is 500g / m 2 , that is, by reducing the lamination temperature and controlling the pressure value, the adhesive flow time of the hot melt adhesive is improved, so that part of the second hot melt adhesive layer melts and is extruded through the through hole on the flexible circuit board to fill into the area between the positive electrode welding point and the negative electrode welding point corresponding to the cell unit, and then coat one side surface of the corresponding conductive contact part, forming a second insulating adhesive, and the second insulating adhesive forms an insulating adhesive layer with the first insulating adhesive. In this method, the height L and width d of the coating part of the insulating adhesive layer in the corresponding cell unit crack gap are unchanged.

[0194] Embodiment 4

[0195] Referring to the method of embodiment 3, the difference is that in the width direction of the conductive contact part, the insulating adhesive layers corresponding to adjacent cell units extend to each other, as shown in Figure 2. In order to meet this condition, the corresponding process needs to be adjusted: adjust the screen printing of the insulating adhesive to print the entire area of the side area on both sides of the adjacent cell crack gap, or optimize the hot pressing parameters, lengthen the vacuum extraction time to make the adhesive have better flowability, so that the insulating adhesive can extend to each other.

[0196] Example 5

[0197] The method of Example 1 was followed, except that the width d of the covered portion of the insulating adhesive layer in the corresponding cell tab seam in the width direction was 10% of the tab seam width D. The process needed to be adjusted accordingly to meet this condition: an independent printing screen was used in S12 to reduce the amount of insulating adhesive, leaving a 0.3 mm distance inward from the edge of the coating area near the tab seam unprinted, and then extruded into the side tab seam by hot pressing.

[0198] Example 6

[0199] The method of Example 1 was followed, except that the hot pressing pressure was adjusted so that the height L of the covered portion of the insulating adhesive layer in the corresponding cell tab seam was 3 μm, and L:T was calculated to be 0.1:1. The printing screen was adjusted accordingly to meet this condition: leaving a 0.4 mm distance from the edge of the cell near the tab seam unprinted, and then extruded into the side by hot pressing.

[0200] Example 7

[0201] The method of Example 1 was followed, except that the width of the tab seam between adjacent cells was adjusted to be 10 mm.

[0202] Example 8

[0203] The method of Example 1 was followed, except that the thickness of the conductive circuit was adjusted to be 200 μm.

[0204] Example 9

[0205] The method of Example 1 was followed, except that the thickness t of the insulating adhesive layer before hot pressing was adjusted according to the height h of the butt conductive portion, t was 40 μm, and h was 38 μm. The structure of the resulting product, a flexible back contact solar cell module, was changed accordingly: the butt conductive portion did not completely cover the electrode solder point.

[0206] Example 10

[0207] The method of Example 1 was followed, except that in the manufacturing process, the amount of tin paste was controlled so that in the width direction, the surface area of the butt conductive portion was 4 times the surface area of the electrode solder point. The structure of the resulting product, a flexible back contact solar cell module, was changed accordingly: the butt conductive portion did not completely cover the electrode solder point.

[0208] Example 11

[0209] The method of Example 1 is referred to, except that in the manufacturing method, the amount of tin paste is controlled so that the surface area of the butt joint conductive part is less than the surface area of the electrode soldering point in the width direction, i.e. the surface area of the butt joint conductive part is 0.5 times the surface area of the electrode soldering point. The corresponding structure of the resulting product in the flexible back contact solar cell module changes to: the butt joint conductive part only partially covers the electrode soldering point.

[0210] Comparative Example 1

[0211] The method of Example 1 is referred to, except that the insulating adhesive layer only extends to the outer surface covering the corresponding conductive contact part, and does not extend to the part of the side surface of the corresponding cell unit located in the crack seam; the process that needs to be adjusted accordingly to meet this condition is: in S12, the printing screen used in screen printing is changed to reduce the amount of insulating adhesive, so that no insulating adhesive is printed within a distance of 0.5 mm from the edge of the coating area near the crack seam.

[0212] Comparative Example 2

[0213] The method of Example 1 is referred to, except that the hot pressing pressure is adjusted so that the height L of the insulating adhesive layer covering the part of the crack seam of the corresponding cell unit is L:T = 21.7:1, where T is the thickness of the conductive contact part. In order to meet this condition, the process that needs to be adjusted accordingly is to increase the coating thickness of the insulating adhesive to 50 μm, and at the same time increase the hot pressing pressure to 120 kPa, and the hot pressing time to 1200 s.

[0214] Comparative Example 3

[0215] The method of Example 1 is referred to, except that the insulating adhesive layer is only coated in the area between the positive electrode soldering point and the negative electrode soldering point in the cell unit, and the area near the crack on both sides is not coated with insulating adhesive, as shown in Figure 13.

[0216] Comparative Example 4

[0217] The method of Example 2 is referred to, except that in the manufacturing method, in the thickness direction, the height of the butt joint conductive part is greater than the thickness of the corresponding insulating adhesive by 20 μm. The structure of the resulting product in the flexible back contact solar cell module changes to: the insulating adhesive in the coated area is not filled, i.e. there is a certain gap between the insulating adhesive and the flexible circuit board without filling the insulating adhesive.

[0218] Test Example

[0219] The flexible back contact solar cell modules obtained in the above examples and comparative examples are tested for performance, and the results are shown in Table 1. Among them, the test method of each performance index is:

[0220] 1) winding test:

[0221] Test requirement: the conversion efficiency attenuation of the battery module is less than 5% after winding 5000 times.

[0222] Test process: the assembly is driven by a motor to perform winding and unwinding movement, one winding and unwinding movement is one test, and a total of 5000 winding tests are performed.

[0223] And observe whether delamination occurs on the appearance after winding test.

[0224] 2) -40℃ ~ 85℃ thermal cycle test:

[0225] Test standard and condition: tested according to IEC61215-2 2016 Ground Photovoltaic (PV) Module - Design Qualification and Type Approval; condition: high temperature 85℃, low temperature -40℃, cycle 200 times, 900h;

[0226] Test requirement: 3 times IEC standard, i.e. test 600 times;

[0227] Test result: after the test, there is no obvious abnormality such as corrosion, yellowing, discoloration, delamination, etc., there is no intermittent short circuit or leakage phenomenon during the test process, the insulation resistance meets the same requirements as the initial test, and the power attenuation is less than 5%;

[0228] 3) damp heat test:

[0229] Test standard and test condition: tested according to IEC61215-2 2016 Ground Photovoltaic (PV) Module - Design Qualification and Type Approval; condition: 85℃, 85% humidity cycle test, test 1000h;

[0230] Test requirement: 3 times IEC standard, i.e. test 3000h;

[0231] Test result: after the test, there is no obvious abnormality such as corrosion, yellowing, discoloration, delamination, etc., the insulation resistance meets the same requirements as the initial test, and the power attenuation is less than 5%.

[0232] Table 1

[0233] From the above results, compared with the comparative example, the battery cell can be accurately aligned and stably connected with the flexible circuit board by using the embodiment scheme of the present disclosure, and the insulation and sealing performance is good, which can avoid the problems of increased production failure rate and delamination due to warping, significantly reduce the power attenuation under winding and severe environment, and the manufacturing process is simple, and at the same time has excellent weather resistance and long service life.

[0234] Optionally, according to embodiments 1 and 5-11, the adoption of the optional specific structure and specific process solution of the present disclosure is more conducive to reducing the power attenuation under winding and harsh environment.

[0235] The above describes the preferred embodiments of the present disclosure, but the present disclosure is not limited thereto. Within the technical concept of the present disclosure, various simple modifications can be made to the technical solutions of the present disclosure, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be considered as disclosed by the present disclosure and fall within the protection scope of the present disclosure. Industrial applicability

[0236] The butt joint conductive part of the flexible circuit board is covered on the outer surface of the electrode welding point to form a conductive contact part to realize stable electrical connection. The conductive contact part is matched with the insulating adhesive layer with a specific structure, which not only improves the insulation effect between the positive electrode welding point and the negative electrode welding point in the battery cell, but also realizes accurate alignment and adhesion between the battery cell and the flexible circuit board to achieve excellent sealing effect. In particular, the insulating adhesive layer covers the outer surface of the corresponding conductive contact part and extends at least to the part of the side surface of the corresponding battery cell located in the split seam to cover the outer surface at an appropriate height. The insulating adhesive layer simultaneously fills the gap between the battery cell and the flexible circuit board, realizes sealing and insulation to prevent short circuit, reduces the occurrence of warping problem, ensures excellent production yield, improves the service life and photoelectric conversion efficiency of the battery cell; and it has a good sealing and insulation protection effect on the electrode welding point of the battery cell, avoids the erosion of external water vapor on the battery cell and its electrode welding point, significantly reduces the water vapor penetration rate, avoids the short circuit caused by the bubble in the outer surface packaging structure of the electrode welding point and the battery cell, and has good cold and hot impact resistance. While improving the production yield, it also greatly improves the weather resistance of the battery in outdoor use, increases the service life.

Claims

1. A flexible back contact solar cell module comprising a cell substrate having a plurality of cell units and a protective sheet attached to the front surface of the cell substrate, a split gap being formed between adjacent cell units, the back surface of the cell substrate having an electrode interconnection portion configured to electrically connect electrodes between the cell units and / or to draw current, and a plurality of electrode pads provided on the electrode interconnection portion, characterized in that, The flexible back contact solar cell module further comprises: A flexible circuit board, wherein the front surface of the flexible circuit board has a patterned conductive circuit and a docking conductive portion provided on the conductive circuit to electrically connect to the electrode welding point, the front surface of the flexible circuit board being attached to the back surface of the battery substrate, and the docking conductive portion at least partially covering the outer surface of the electrode welding point to form a conductive contact portion; An insulating adhesive layer fills the gap in the thickness direction formed between the battery cell and the corresponding portion of the flexible circuit board and extends to cover the outer surface of the corresponding conductive contact portion; and in the thickness direction, the insulating adhesive layer extends at least to cover the outside of the portion of the side surface of the corresponding battery cell located within the crack seam, and the height L of the covering portion of the insulating adhesive layer located within the crack seam of the corresponding battery cell satisfies L:T=0.1-20:1, where T is the thickness of the conductive contact portion.

2. The flexible back contact solar cell module according to claim 1, wherein, In the width direction, the width d of the covering portion of the insulating adhesive layer located within the corresponding battery cell split seam is 5%-50% of the split seam width D; and / or, The width D of the crack between any adjacent battery cells is 0.1 mm to 30 mm.

3. The flexible, back contact solar cell module of claim 1, wherein, In the width direction of the conductive contact portion, the insulating adhesive layers corresponding to adjacent battery cells extend to connect with each other; and / or, The thickness T of the conductive contact portion is 30-100 μm, and the height L of the covering portion of the insulating adhesive layer located within the corresponding battery cell split seam is 3-130 μm.

4. The flexible, back contact solar cell module of claim 1, wherein, The protective sheet has a side away from the battery substrate having a protective sheet splitting groove corresponding to and overlapping with the overall pattern formed by the plurality of battery cells; and / or, The protection sheet is attached to the front side of the battery substrate through an adhesive layer.

5. The flexible, back contact solar cell module of claim 1, wherein, In the thickness direction, the height of the portion of the insulating adhesive layer between the battery unit and the flexible circuit board is flush with the height of the conductive contact portion.

6. The flexible, back contact solar cell module of claim 1, wherein, The connecting conductive part is made of at least one material selected from solder paste, conductive glue, silver paste, and conductive copper paste, and the connecting conductive part is a solder point, a solder pad, or an adhesive layer; and / or, The pattern of the graphic conductive circuit corresponds to the pattern formed by the arrangement of a plurality of battery cells and their series and parallel connections. 7.The flexible back contact solar cell module according to claim 1 or 6, characterized in that, The flexible back contact solar cell module further has at least one of the following structures: Structure 1: The flexible circuit board includes an insulating film, and the patterned conductive circuit is provided on the insulating film; Structure 2: The cracks between each battery cell are filled with insulating caulking glue; Structure 3: The thickness ratio of the flexible circuit board, the protective sheet, and the battery cell is 0.2-10:0.7-30:1; Structure 4: The thickness of the flexible circuit board is 30-230 μm, the thickness of the protective sheet is 0.1-1.5 mm, and the thickness of the battery cell is 50-150 μm; Structure 5: The conductive circuit is selected from at least one of copper, aluminum, nickel, tin, gold, and silver; Structure 6: The thickness of the conductive circuit is 10-200 μm.

8. The flexible, back contact solar cell module of claim 1, wherein, The flexible back-contact solar cell module further includes a first hot melt adhesive layer and a first flexible board sequentially arranged on the outer surface of the protection sheet, and a second hot melt adhesive layer and a second flexible board sequentially arranged on the back side of the flexible circuit board.

9. A method of manufacturing a flexible back contact solar cell module, characterized by, The steps include: S11. Attaching and fixing the protective sheet to the front side of the battery substrate, thereby forming a glue-coated surface on the back side of the battery substrate; wherein the front side of the battery substrate is provided with a split seam to divide the battery substrate into a plurality of battery cells, and the back side of the battery substrate has an electrode interconnection portion configured to connect electrodes between the battery cells and / or extract current, and a plurality of electrode welding points provided on the electrode interconnection portion, the electrode welding points including a positive electrode welding point and a negative electrode welding point, and a gap is left between the split seam and the positive electrode welding point and the negative electrode welding point on the corresponding battery cell; S12, coating the coated surface with an insulating adhesive layer, ensuring that the insulating adhesive layer does not cover the electrode welding points, and the coated area includes the space between the battery split wire groove and the electrode welding point on the corresponding battery cell, and the area between the positive electrode welding point and the negative electrode welding point; S13. Providing a flexible circuit board, wherein the front side of the flexible circuit board has a patterned conductive circuit; forming materials required for the docking conductive portion on the conductive circuit, wherein the arrangement of the docking conductive portion corresponds to the arrangement of the electrode welding points; S14, aligning the back side of the battery substrate obtained in S12 with the front side of the flexible circuit board obtained in S13 so that the conductive portion and the electrode welding point are aligned and in contact, and positioning them by adhesion of the insulating adhesive layer to form a battery assembly; S15. Hot pressing the battery assembly to melt the docking conductive parts and cover the corresponding electrode welding points to form conductive contact parts to achieve stable electrical connection, and to cover the outer surfaces of the opposite sides of the adjacent conductive contact parts with the insulating adhesive layer. The hot pressing conditions are controlled so that the insulating adhesive layer overflows into the crack and covers the side surface of the corresponding battery cell located in the crack, and the coating thickness of the insulating adhesive layer is controlled so that the height L of the covered part of the insulating adhesive layer located in the crack of the corresponding battery cell satisfies L:T=0.1-20:1, wherein T is the thickness of the conductive contact part.

10. The method of manufacturing a flexible back contact solar cell module according to claim 9, wherein The manufacturing method of the flexible back-contact solar cell module also includes: S16, stacking the first flexible board, the first hot melt adhesive layer, the battery assembly, the second hot melt adhesive layer and the second flexible board in sequence, and then performing the first lamination; wherein the conditions for the first lamination include: pre-vacuuming and the vacuuming time is 100-900s, the lamination pressure is 10-100kPa, the lamination temperature is 140-165°C, and the lamination time is 300-1200s.

11. A method of manufacturing a flexible back contact solar cell module, characterized by, The steps include: S101. Attaching and fixing a protective sheet to the front face of a battery substrate, thereby forming a glue-coated surface on the back face of the battery substrate; wherein the front face of the battery substrate is provided with a split seam to divide the battery substrate into a plurality of battery cells, and the back face of the battery substrate has an electrode interconnection portion configured to connect electrodes between the battery cells and / or extract current, and a plurality of electrode welding points provided on the electrode interconnection portion, the electrode welding points including a positive electrode welding point and a negative electrode welding point, and a gap is left between the split seam and the positive electrode welding point and the negative electrode welding point on the corresponding battery cell; S102, applying a first insulating adhesive to the adhesive coating surface, ensuring that the first insulating adhesive does not cover the electrode interconnection portion, and the coating area includes the gap between the battery split wire groove and the electrode welding point on the corresponding battery cell, so that the first insulating adhesive is located within the gap; S103. Providing a flexible circuit board, wherein the front side of the flexible circuit board has a patterned conductive circuit; forming materials required for a docking conductive portion on the conductive circuit, wherein the arrangement of the docking conductive portion corresponds to the arrangement of the electrode welding points; and forming a through hole in the flexible circuit board, wherein the position of the through hole corresponds to the area between the positive electrode welding point and the negative electrode welding point in the battery cell; S104, aligning the back surface of the battery substrate obtained in S102 with the front surface of the flexible circuit board obtained in S103 so that the butting conductive portion and the electrode welding point are aligned and in contact, and positioning them by bonding with a first insulating adhesive to form a battery assembly; S105, hot pressing the battery assembly to melt the butted conductive portions and cover the corresponding electrode welding points to form conductive contact portions to achieve stable electrical connection, and coating the outer surface of one side of the adjacent conductive contact portions with the first insulating adhesive; S106. The first flexible board, the first hot melt adhesive layer, the hot-pressed battery assembly, the second hot melt adhesive layer, and the second flexible board are sequentially stacked; then a second lamination is performed, during which a portion of the second hot melt adhesive layer is melted and squeezed through the through hole on the flexible circuit board to fill the area between the positive electrode welding point and the negative electrode welding point in the corresponding battery cell, and then coated on a side surface of the corresponding conductive contact portion to form a second insulating adhesive. The second insulating adhesive and the first insulating adhesive form an insulating adhesive layer, and the conditions of the second lamination are controlled so that the second insulating adhesive and the first insulating adhesive overflow into the crack and coat the side of the corresponding battery cell located in the crack, and the coating thickness of the first insulating adhesive is controlled so that the height L of the coated portion of the insulating adhesive layer located in the crack of the corresponding battery cell satisfies L:T=0.1-20:1, where T is the thickness of the conductive contact portion.

12. The method of manufacturing a flexible back contact solar cell module according to claim 11, wherein The flexible circuit board includes an insulating film, the patterned conductive circuit is arranged on the insulating film, and the through hole is opened in the insulating film; and / or, The second lamination conditions include: lamination temperature of 140-165° C., lamination pressure not exceeding 4 kPa, and lamination time of 500-1500 s; and / or, The amount of the second hot melt adhesive layer used in S106 is 240-600 g / m 2 .

13. The method of manufacturing a flexible back contact solar cell module according to any one of claims 9-12, wherein, S12 or S102 further comprises a pre-curing process after the insulating adhesive layer or the first insulating adhesive layer is coated, so as to pre-cure the insulating adhesive layer or the first insulating adhesive layer, the pre-curing process comprises baking at 50-200℃ for 1-10min; the pre-curing process makes the bonding tensile force of the corresponding insulating adhesive layer not less than 0.6N, and the thickness of the corresponding insulating adhesive layer is 20-80μm.

14. The method of manufacturing a flexible back contact solar cell module according to any one of claims 9-12, wherein, In the width direction, the surface area of the butt joint conductive part is 0.5-5 times of the surface area of the electrode welding point; and / or, The thickness t of the insulating adhesive layer or the first insulating adhesive layer before hot pressing is adjusted according to the height h of the butt joint conductive part, and t=0.5h-1.2h is satisfied.

15. The method of manufacturing a flexible back contact solar cell module according to any one of claims 9-12, wherein, The conditions of the hot pressing include: temperature of 140-180℃, pressure not more than 100kPa, and time of 200-1200s.

16. The method of manufacturing a flexible back contact solar cell module according to any one of claims 9-12, wherein, The manufacturing method of the flexible back contact solar cell module further comprises a step of providing a protective sheet in advance: a protective sheet crack line groove corresponding to the cell crack line groove is engraved on the side of the protective sheet away from the cell base body, and the protective sheet crack line groove is coincided with the cell crack line groove when the protective sheet is attached to the front side of the cell base body. and / or, The manufacturing method of the flexible back contact solar cell module further comprises: after the cell assembly is formed, filling insulating caulking adhesive in the interval area between the cell units by dispensing, and then performing the hot pressing.

17. The method of manufacturing a flexible back contact solar cell module according to any one of claims 9-12, wherein, The process of attaching the protective sheet to the front side of the cell base body and performing the attachment and fixation, so as to form a coating side on the back side of the cell base body, comprises: S1.1, providing a cell base body, the back side of the cell base body has electrode interconnection parts configured to connect electrodes between cell units and / or lead out current, and a plurality of electrode welding points arranged on the electrode interconnection parts, the electrode welding points include positive electrode welding points and negative electrode welding points, the front side of the cell base body is engraved with a cell crack line groove, and in the direction parallel to the plane of the cell base body, the cell crack line groove is spaced apart from the positive electrode welding points and the negative electrode welding points on the corresponding cell unit; S1.2, providing a protective sheet; S1.3, attaching the protective sheet to the front side of the cell base body and performing the attachment and fixation; S1.4, cracking the cell base body with the protective sheet attached, so that the cell base body is cracked into a plurality of cell units along the cell crack line groove, and then the cell units are arranged with an expanded distance, so as to form a crack gap between adjacent cell units; at this time, the back side of the cell base body forms a coating side.

18. The method of manufacturing a flexible back contact solar cell module according to any one of claims 9-12, wherein, The material forming the butt joint conductive part on the conductive circuit includes printing, dispensing or coating, wherein the printing includes: Step a, selecting an insulating film, and forming a patterned conductive circuit on the insulating film according to the arrangement of each cell unit and the pattern required by series and parallel connection of the cell units; Step b, selecting a metal screen, and opening a mesh hole on the metal screen corresponding to the arrangement of each electrode welding point in the cell base body and penetrating the mesh hole up and down; Step c, installing the metal screen on the printing machine, and placing the flexible circuit board below the metal screen for alignment; Step d, dispensing the conductive adhesive on the conductive circuit of the insulating film, and then placing the flexible circuit board on the conductive adhesive to form the butt joint conductive part. Step e, printing the material required for the butt joint conductive part on the conductive circuit to form the butt joint conductive part capable of butt joint welding with the welding points of the electrodes in the battery matrix, and forming the flexible circuit board.

19. A flexible back contact solar cell module, characterized in that, The flexible back contact solar cell module is manufactured by the method of any one of claims 9-18.

20. A photovoltaic module, characterized by, The flexible back contact solar cell module comprises any one of claims 1-8, or the flexible back contact solar cell module of claim 19.

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