Preparation method of multi-slice, multi-main-grid, negative-spacing and zero-subfissure assembly

Abstract

The invention relates to the technical field of photovoltaic module preparation, and discloses a multi-fragment, multi-main-grid, negative-spacing and zero-subfissure module preparation method, which comprises the following steps: S1, cell pretreatment: scribing a whole crystalline silicon cell to obtain a multi-fragment cell, and cleaning and drying the scribed cell; s2, UV glue printing: UV curing heightening buffer glue is printed in the overlapping areas of the multiple fragmented battery pieces, and a preset printing pattern is formed; s3, curing the UV glue; s4, laying and embedding a welding strip; s5, stacking the battery pieces at negative intervals; and S6, packaging and laminating. The thickness of the UV curing heightening buffer glue is limited to be 0.05-0.3 mm, the UV curing heightening buffer glue is matched with the printed patterns which are formed by rectangular or multi-embossed connection at intervals, and meanwhile, an adaptive curing process and a welding strip embedding mode are adopted, so that hard contact between a welding strip and a battery piece during negative-distance stacking is effectively blocked, and the technical problem that the subfissure proportion of a conventional negative-distance assembly is too high is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of photovoltaic module preparation, in particular to a preparation method of a multi-slice, multi-busbar and negative spacing zero-hidden-crack module. BACKGROUND

[0002] With the increasing requirements of the photovoltaic industry on power generation efficiency and cost control, the multi-slice design can reduce the internal current loss of the cell, the multi-busbar structure can improve the current collection efficiency, and the negative spacing stacking can reduce the occupation of invalid space in the module and improve the power per unit area, so the module with the above characteristics becomes an important development direction of photovoltaic modules, and has important significance for promoting the high efficiency and miniaturization development of photovoltaic technology.

[0003] At present, the preparation of the multi-slice, multi-busbar and negative spacing module is mainly obtained by slicing the whole crystal silicon cell to obtain a multi-slice cell, setting a bonding or buffer structure in the overlapping area of the cell, and then performing solder strip laying, negative spacing stacking and subsequent encapsulation lamination to complete the preparation. In order to realize negative spacing stacking, the prior art usually applies a buffer adhesive layer in the overlapping area of the cell to try to relieve the stress in the stacking process. However, in the prior art, the thickness of the buffer adhesive layer lacks precise control, the printed pattern is usually a simple structure such as a continuous strip or a rectangle, and the curing process and solder strip embedding method are not adapted and coordinated, so that the adhesive layer cannot form a stable and effective buffer structure. In the negative spacing stacking process, the solder strip and the cell are easy to form direct hard contact, and the stress cannot be effectively dispersed and offset by the adhesive layer, which finally causes the high proportion of hidden cracks in the module, seriously affecting the structural stability, power generation performance and service life of the module. This problem has become a core bottleneck restricting the large-scale application of the multi-slice, multi-busbar and negative spacing module. SUMMARY

[0004] The present application provides a preparation method of a multi-slice, multi-busbar and negative spacing zero-hidden-crack module, which solves at least one technical problem in the background art.

[0005] To achieve the above purpose, the present application is implemented by the following technical scheme: a preparation method of a multi-slice, multi-busbar and negative spacing zero-hidden-crack module, comprising the following steps:

[0006] S1, cell pretreatment: slicing a whole crystal silicon cell to obtain a multi-slice cell, and cleaning and drying the sliced cell;

[0007] S2, UV glue printing: printing a UV curing cushion buffer adhesive on the overlapping area of the multi-slice cell to form a preset printing pattern, and the thickness of the UV curing cushion buffer adhesive is 0.05-0.3mm;

[0008] S3, UV glue curing: using a UV light source to cure the printed UV curing pad high buffer glue, to obtain a cured glue layer with a Shore hardness of 30-50, the thickness of the cured glue layer is greater than or equal to the diameter of the solder strip;

[0009] S4, solder strip laying and embedding: cutting the solder strip and laying it on the cured glue layer or embedding it in the semi-cured UV curing pad high buffer glue;

[0010] S5, negative interval stacking of battery pieces: stacking the multiple-piece battery pieces with completed solder strip laying according to the preset overlapping distance, so that the overlapping area corresponds to the cured glue layer;

[0011] S6, packaging and laminating: assembling the packaging material according to the preset order and then performing laminating treatment to obtain a zero-crack assembly.

[0012] By adopting the above technical solution, through S1 battery piece pretreatment, the multiple-piece battery pieces are obtained by slicing the whole piece of crystalline silicon battery piece and are cleaned and dried, which can remove impurities and debris on the surface of the battery piece after slicing, providing clean and stable surface conditions for the subsequent printing of UV curing pad high buffer glue;

[0013] S2, printing UV curing pad high buffer glue on the overlapping area of the multiple-piece battery piece and forming a preset printing pattern, the glue layer can build a buffer isolation structure during the subsequent battery piece stacking process to avoid direct contact between the solder strip and the battery piece;

[0014] S3, curing the UV curing pad high buffer glue to obtain a cured glue layer with a specific hardness, and controlling the thickness of the cured glue layer to be not less than the diameter of the solder strip, which can ensure that the glue layer has stable buffer support performance and provides a suitable bearing basis for the laying or embedding of the solder strip;

[0015] S4, laying the cut solder strip on the cured glue layer or embedding it in the semi-cured glue layer, so that the solder strip and the glue layer form a stable combination, ensuring the effectiveness of electrical connection while avoiding direct pressure on the battery piece by the solder strip through the glue layer isolation;

[0016] S5, stacking the battery pieces with negative interval according to the preset overlapping distance and making the overlapping area correspond to the cured glue layer, which can make the glue layer accurately play a buffering role and block the transmission of hard contact stress during negative interval stacking;

[0017] S6, assembling the packaging material according to the preset order and performing laminating treatment to complete the structure fixation and forming of the assembly;

[0018] The above steps work together to solve the technical problem of easy cracking during negative interval assembly stacking by constructing a glue layer buffer structure and accurately adapting each link, achieving a zero-crack assembly effect, and the precisely controlled glue layer setting can reduce the amount of UV curing pad high buffer glue, reducing raw material consumption.

[0019] In the S1 step, the multi-sliced battery piece includes three-sliced, four-sliced or five-sliced, the number of main grid lines of the multi-sliced battery piece is 20BB-26BB, and the cleaning uses a mixed solution of deionized water and a neutral cleaning agent for ultrasonic cleaning for 10-15 minutes, followed by drying at 80-100℃ for 5-8 minutes.

[0020] By adopting the above technical solution, the whole piece of crystalline silicon battery piece is sliced to obtain a multi-sliced battery piece of three-sliced, four-sliced or five-sliced, the multi-sliced design can adapt to the subsequent assembly structure requirement of negative interval stacking; the number of main grid lines is set to 20BB-26BB, which can provide a matching electrical connection carrier for the subsequent laying and embedding of the solder strip, and ensure the adaptability of the electrical transmission channel; the battery piece after slicing is ultrasonically cleaned with a mixed solution of deionized water and a neutral cleaning agent, which can remove slicing debris, oil stains and other impurities attached to the surface of the battery piece, and drying can remove the residual moisture on the surface of the cleaned battery piece. The cleaning and drying steps work together to provide a clean and dry surface condition for the subsequent printing and attachment of the UV-cured pad height buffer glue in the overlapping area of the battery piece, improve the bonding stability of the glue layer and the battery piece, and indirectly ensure the construction effect of the subsequent buffer structure. At the same time, the adaptive main grid line number design can cooperate with the subsequent solder strip connection to ensure the stability of the electrical connection between the solder strip and the battery piece.

[0021] In the S2 step, the preset printing pattern is a spaced rectangular, and the thickness of the UV-cured pad height buffer glue after curing is 0.28-0.30mm, the width is 1-6mm, and the length is 160-180mm.

[0022] By adopting the above technical solution, the preset printing pattern is set to a spaced rectangular, which can form an adaptive buffer support structure in the overlapping area of the multi-sliced battery piece, providing a stable bearing interface for the subsequent laying of the solder strip, and at the same time, through the spaced layout, the glue layer is precisely adapted to the battery piece and the solder strip, and the direct hard contact between the solder strip and the battery piece in the negative interval stacking process is blocked; the UV-cured pad height buffer glue can completely cover the key stress parts in the overlapping area of the battery piece, ensuring the effective coverage range of the buffer effect, and the thickness parameter is within the interval of 0.05-0.3mm, which can control the usage of the UV-cured pad height buffer glue on the premise of ensuring that the buffer structure has sufficient support stability; the above printing pattern design and glue layer parameter work together to provide a structural basis for the subsequent curing to form a stable buffer glue layer with a Shore hardness of 30-50, directly helping to solve the technical problem of high hidden crack rate of conventional negative interval assemblies, while realizing reasonable control of the amount of glue.

[0023] In step S2, the preset printed pattern is a structure of multiple convex characters connected together. The thickness of the UV-cured padding buffer adhesive is 0.05-0.3mm, the length of the through part is 160-180mm and the width is 1-6mm, and the length of the protruding part is 0.5-3mm.

[0024] By adopting the above technical solution, the preset printed pattern is set as a structure of multiple convex characters connected together. The protruding part can provide a precise limiting and bearing interface for the subsequent splicing of the solder ribbon in the overlapping area of ​​the multi-segment battery cells. The penetrating part can ensure that the buffering effect covers the key stress parts of the overlapping area of ​​the battery cells. This structural design can build a stable buffer support system and prevent direct hard contact between the solder ribbon and the battery cells during negative pitch stacking. The thickness of the UV-cured cushioning adhesive is set in the range of 0.05-0.3mm, which can make the adhesive layer have suitable buffer support performance, while controlling the amount of adhesive used. The size setting of the penetrating part and the protruding part further ensures the compatibility of the adhesive layer with the battery cells and solder ribbons. The synergistic cooperation of the above printed pattern design and adhesive layer parameters provides a structural basis for the subsequent curing to form a stable cushioning adhesive layer with a Shore hardness of 30-50, directly helping to solve the technical problem of excessively high microcrack ratio in conventional negative pitch modules, while achieving reasonable control of adhesive usage.

[0025] In step S2, the UV-cured cushioning adhesive is an acrylic adhesive.

[0026] By adopting the above technical solution, acrylic adhesives are selected as UV-curing cushioning adhesives. These adhesives are compatible with UV curing processes and can stably form a cured adhesive layer that meets the requirements during subsequent UV curing treatment. At the same time, their own material properties can improve the bonding stability with the surface of the solar cells. In addition, the properties of acrylic adhesives can be combined with subsequent solder ribbon laying and embedding processes to ensure the stability of electrical connections between the solder ribbon, the adhesive layer, and the solar cells. This helps to solve the technical problem of excessively high microcrack ratio in conventional negative-pitch modules, and at the same time provides material support for the long-term structural stability and power generation performance of the modules.

[0027] The printing in step S2 is performed using a screen printing machine with a screen thickness of 120-135 μm, a printing speed of 4500-5000 mm / s, an acceleration of 6000-7000 mm / s, a deceleration of 6500-7000 mm / s, a printing pressure of 50-80 N, and a reflow speed of 400-500 mm / s. After printing, a squeegee is used to lightly press once along the printing direction to remove air and ensure uniform adhesive layer thickness.

[0028] By adopting the above technical solution, UV-cured cushioning adhesive is printed using screen printing equipment, achieving precise printing and forming of the adhesive layer in the overlapping area of ​​the solar cells, ensuring that the adhesive layer meets the preset thickness and printing pattern requirements; after printing, a squeegee is used to lightly press once along the printing direction, which can remove air bubbles inside the adhesive layer, while ensuring uniform adhesive layer thickness, improving the bonding stability between the adhesive layer and the solar cells, solving the technical problem of excessively high microcrack ratio in conventional negative-pitch modules, and providing support for the long-term structural stability of the module in extreme environments.

[0029] In step S3, the surface of the battery cell is cleaned without dust before curing. The UV light source is a mercury lamp, xenon lamp, or LED lamp. The UV lamp box power is 55-67W, the UV lamp box opening time is 3.1-3.7s, and the UV welding time is 3.1-9.6s. When the preset printed pattern is a raised letter connection structure, a semi-curing treatment is performed first, and a full curing treatment is performed after the solder ribbons are embedded.

[0030] By adopting the above technical solutions, dust-free blowing is performed on the surface of the solar cells before curing to remove floating dust and impurities from the surface of the solar cells and the surrounding area of ​​the adhesive layer, thus preventing impurities from affecting the bonding stability between the adhesive layer and the solar cells. Using mercury lamps, xenon lamps, or LED lamps as UV light sources, and with the set UV lamp box power, UV lamp box opening time, and UV welding time parameters, precise curing of the UV-cured cushioning adhesive can be achieved, ensuring that the cured adhesive layer reaches the preset Shore hardness requirement, providing stable mechanical properties for the cushioning structure. When the preset printed pattern is a raised letter structure, a step-by-step curing method of semi-curing followed by full curing is adopted. The semi-cured state allows the adhesive layer to retain suitable flexibility, facilitating the subsequent embedding of the solder ribbon into the raised letter structure and achieving a tight fit. After the solder ribbon is embedded, full curing is performed, which further improves the bonding strength between the adhesive layer, solder ribbon, and solar cells, solving the technical problem of excessively high microcrack ratios in conventional negative-pitch modules, while providing process support for the long-term structural stability and power generation performance of the module.

[0031] In step S4, the specifications of the solder strip are ≤ Φ0.26mm. The cut solder strip end face is flat and burr-free. After cutting, the surface oxide layer is removed by wiping with alcohol. When the preset printed pattern is a spaced rectangle, the solder strip is directly attached to the top of the fully cured adhesive layer. When the preset printed pattern is a raised letter structure, the solder strip is embedded in the raised letter structure of the semi-cured adhesive layer. After embedding, the solder strip is lightly pressed to ensure tight adhesion with the adhesive layer.

[0032] By adopting the above technical solutions, limiting the specifications of the solder ribbon and performing end-face flattening and alcohol wiping to remove the surface oxide layer after cutting, it is possible to avoid scratching the battery cell or adhesive layer by burrs on the end face of the solder ribbon. At the same time, removing the oxide layer ensures the electrical connection performance between the solder ribbon and the battery cell. For different preset printed patterns, an appropriate solder ribbon laying method is adopted. When the preset printed pattern is a spaced rectangle, the solder ribbon is directly attached to the fully cured adhesive layer. When the preset printed pattern is a raised letter structure, the solder ribbon is embedded in the raised letter structure of the semi-cured adhesive layer and lightly pressed to ensure a tight fit. Both laying methods can enable the solder ribbon to achieve isolation from the battery cell through the adhesive layer, blocking the direct hard contact between the solder ribbon and the battery cell, while ensuring a stable bond between the solder ribbon and the adhesive layer.

[0033] In step S5, the preset overlap distance is a negative spacing. After the battery cells are fixed in position by the positioning fixture, they are stacked. During stacking, a uniform pressure of 0.1-0.3 MPa is applied and maintained for 10-20 seconds.

[0034] By adopting the above technical solution and setting the preset overlap distance to a negative spacing, the requirement for tight stacking of multiple battery cells can be met. After the battery cells are fixed in position by the positioning fixture, they can be stacked to ensure that the overlapping area of ​​the battery cells corresponds precisely to the cured adhesive layer, avoiding misalignment that could lead to failure of the buffer structure. Applying uniform pressure and maintaining it for a certain period of time during stacking can further improve the tightness of the bonding between the solder ribbon and the adhesive layer, and between the adhesive layer and the battery cells. At the same time, the cured adhesive layer can fully play its buffering role, blocking direct hard contact between the solder ribbon and the battery cells under the pressure generated by stacking at a negative spacing.

[0035] In step S6, the preset order is tempered glass, EVA film, stacked battery cell pack, EVA film, and backplate. After assembly, the assembly is first evacuated to ≤-0.09MPa and held for 3-5 minutes, and then laminated. The lamination temperature is 135-145℃, the pressure is 0.08-0.12MPa, and the time is 15-20 minutes.

[0036] By adopting the above technical solution, the encapsulation materials are assembled in a preset order: tempered glass, EVA film, stacked battery cells, EVA film, and backsheet. The tempered glass provides structural support, the EVA film achieves bonding and sealing between layers, and the backsheet provides protection, forming a comprehensive encapsulation protection for the stacked battery cells. After assembly, the assembly is first evacuated and kept for a certain period of time to remove air from the assembly, preventing air bubbles from forming during subsequent lamination and affecting the structural stability of the module. Subsequent lamination according to set parameters allows the EVA film to fully melt and solidify, achieving a tight bond between the encapsulation materials and the battery cells, fixing the overall structure of the module, and providing the final encapsulation guarantee for the long-term structural stability and power generation performance of the module.

[0037] This invention provides a method for fabricating a multi-segment, multi-gate, negative-pitch zero-microcrack component. It offers the following advantages:

[0038] 1. This invention limits the thickness of the UV-cured cushioning adhesive to 0.05-0.3mm, combines it with printed graphics of spaced rectangles or multiple convex characters, and employs a suitable curing process and solder ribbon embedding method to construct a stable buffer structure. This effectively blocks hard contact between the solder ribbon and the battery cells when stacked with negative spacing, solving the technical pain point of excessively high microcrack ratio in conventional negative spacing modules.

[0039] 2. This invention precisely controls the thickness of the UV-cured cushioning adhesive within the optimal range of 0.05-0.3mm. While ensuring zero microcracks, it significantly reduces the amount of adhesive used, directly lowering the cost of raw materials and resulting in significant economic benefits.

[0040] 3. The optimized adhesive layer buffer structure and supporting process of this invention avoid the problem of reduced current collection efficiency of the battery cells caused by microcracks. At the same time, the characteristics of acrylic UV adhesive and precise printing and curing parameters ensure the stability of electrical connection between the solder ribbon and the battery cells, so that the open circuit voltage, short circuit current and fill factor of the module are maintained at a high level, ensuring that the power generation performance meets the standards.

[0041] 4. This invention improves the bonding force between the adhesive layer and the battery cell through auxiliary processes such as post-printing scraper venting and pre-curing dust-free blowing. Combined with the limited adhesive layer hardness and structural design, the module can still maintain zero microcracks after extreme environmental tests such as high and low temperature cycling, and the power decay rate is controlled within a low range, effectively extending the service life of the module. Attached Figure Description

[0042] Figure 1 This is a flowchart of the method of the present invention;

[0043] Figure 2 This is a schematic diagram of the adhesive with rectangular spacing according to the present invention;

[0044] Figure 3 This is a schematic diagram of the adhesive used to connect multiple raised lines of characters according to the present invention;

[0045] Figure 4 Experimental data on the proportion of microcracks. Detailed Implementation

[0046] To better understand the above technical solutions, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0047] Example 1

[0048] This invention provides a method for fabricating a multi-segment, multi-gateway, negative-pitch zero-crack component, comprising the following steps:

[0049] S1. Cell pretreatment: The whole crystalline silicon cell is diced to obtain multiple diced cells. The diced cells are then cleaned and dried.

[0050] The multi-segmented solar cell is divided into three segments, and the number of main grid lines in the multi-segmented solar cell is 20BB. The stress is controlled during the dicing process to avoid the formation of initial microcracks in the solar cell. The cleaning process involves ultrasonic cleaning with a mixture of deionized water and neutral cleaning agent for 10 minutes, followed by drying at 80°C for 5 minutes.

[0051] S2, UV adhesive printing: UV-cured padding buffer adhesive is printed in the overlapping area of ​​the multi-segmented battery cells to form a preset printing pattern. The thickness of the UV-cured padding buffer adhesive is 0.05mm.

[0052] The preset printed graphic consists of multiple connected raised characters, with the through portion measuring 160mm in length and 1mm in width, and the protruding portion measuring 0.5mm in length. The UV-cured cushioning adhesive is an acrylic adhesive. Printing is performed using screen printing equipment with a screen thickness of 120µm, a printing speed of 4500mm / s, an acceleration of 6000mm / s, a deceleration of 6500mm / s, a printing pressure of 50N, and a return adhesive speed of 400mm / s. After printing, a squeegee is used to lightly press once along the printing direction to remove air and ensure uniform adhesive layer thickness.

[0053] S3, UV adhesive curing: The printed UV-curable padding buffer adhesive is cured using a UV light source to obtain a cured adhesive layer with a Shore hardness of 30. The thickness of the cured adhesive layer is greater than or equal to the diameter of the solder strip.

[0054] Before curing, the surface of the battery cell is cleaned without dust. The UV light source is a mercury lamp with a UV lamp box power of 55W, a UV lamp box opening time of 3.1s, and a UV welding time of 3.1s. Because the preset printed pattern is a convex connected structure, it is first semi-cured, and then fully cured after the solder ribbon is embedded.

[0055] S4. Welding ribbon laying and embedding: Cut the welding ribbon and lay it on the cured adhesive layer or embed it in the semi-cured UV-cured padding and cushioning adhesive.

[0056] The welding strip has a specification of Φ0.15mm. The cut welding strip has a flat end face without burrs. After cutting, the surface oxide layer is removed by wiping with alcohol. Since the preset printed pattern is a convex character structure, the welding strip is embedded in the convex character structure of the semi-cured adhesive layer. After embedding, the welding strip is lightly pressed to ensure a tight fit with the adhesive layer.

[0057] S5. Negative spacing stacking of battery cells: Stack the multi-segment battery cells with completed ribbon laying according to a preset overlap distance, so that the overlapping area corresponds completely with the cured adhesive layer;

[0058] The preset overlap distance is a negative spacing. The battery cells are stacked after being fixed in position by a positioning fixture. A uniform pressure of 0.1 MPa is applied and held for 10 seconds during stacking.

[0059] S6. Encapsulation and Lamination: After assembling the encapsulation materials in a preset order, lamination is performed to obtain a component with zero microcracks.

[0060] The preset order is tempered glass, EVA film, stacked battery cells, EVA film, and backplate. After assembly, the assembly is first evacuated to -0.09MPa and held for 3 minutes, and then laminated. The lamination process is carried out at a temperature of 135℃, a pressure of 0.08MPa, and a time of 15 minutes.

[0061] Example 2

[0062] This invention provides a method for fabricating a multi-segment, multi-gateway, negative-pitch zero-crack component, comprising the following steps:

[0063] S1. Cell pretreatment: The whole crystalline silicon cell is diced to obtain multiple diced cells. The diced cells are then cleaned and dried.

[0064] The multi-cell solar cell is a four-cell solar cell with 23BB main grid lines. The dicing process controls stress to prevent the solar cell from developing initial microcracks. The cleaning process involves ultrasonic cleaning with a mixture of deionized water and neutral cleaning agent for 12 minutes, followed by drying at 90°C for 6 minutes.

[0065] S2, UV adhesive printing: UV-cured padding and buffering adhesive is printed in the overlapping area of ​​the multi-segmented battery cells to form a preset printing pattern. The thickness of the UV-cured padding and buffering adhesive is 0.29mm.

[0066] The preset printed pattern is a spaced rectangle; the UV-cured cushioning adhesive has a cured width of 3mm and a length of 170mm; the UV-cured cushioning adhesive is an acrylic adhesive; printing is done using screen printing equipment with a screen thickness of 125um, a printing speed of 4700mm / s, an acceleration of 6500mm / s, a deceleration of 6750mm / s, a printing pressure of 65N, and a reflow speed of 450mm / s; after printing, a squeegee is used to lightly press once along the printing direction to remove air and ensure uniform adhesive layer thickness.

[0067] S3, UV adhesive curing: The printed UV-curable padding buffer adhesive is cured using a UV light source to obtain a cured adhesive layer with a Shore hardness of 40. The thickness of the cured adhesive layer is greater than or equal to the diameter of the solder strip.

[0068] The process involves dust-free cleaning of the battery cell surface before curing; the UV light source is a xenon lamp, the UV lamp box power is 61W, the UV lamp box opening time is 3.4s, and the UV welding time is 6.3s.

[0069] S4. Welding ribbon laying and embedding: Cut the welding ribbon and lay it on the cured adhesive layer or embed it in the semi-cured UV-cured padding and cushioning adhesive.

[0070] The welding strip has a specification of Φ0.20mm. The cut welding strip has a flat end face without burrs. After cutting, the surface oxide layer is removed by wiping with alcohol. Since the preset printed pattern is a spaced rectangle, the welding strip is directly attached to the fully cured adhesive layer.

[0071] S5. Negative spacing stacking of battery cells: Stack the multi-segment battery cells with completed ribbon laying according to a preset overlap distance, so that the overlapping area corresponds completely with the cured adhesive layer;

[0072] The preset overlap distance is a negative spacing. The battery cells are stacked after being fixed in position by a positioning fixture. A uniform pressure of 0.2 MPa is applied and held for 15 seconds during stacking.

[0073] S6. Encapsulation and Lamination: After assembling the encapsulation materials in a preset order, lamination is performed to obtain a component with zero microcracks.

[0074] The preset order is tempered glass, EVA film, stacked battery cells, EVA film, and backplate. After assembly, the assembly is first evacuated to -0.09MPa and held for 4 minutes, and then laminated. The lamination process is carried out at a temperature of 140℃, a pressure of 0.10MPa, and a time of 17 minutes.

[0075] Example 3

[0076] This invention provides a method for fabricating a multi-segment, multi-gateway, negative-pitch zero-crack component, comprising the following steps:

[0077] S1. Cell pretreatment: The whole crystalline silicon cell is diced to obtain multiple diced cells. The diced cells are then cleaned and dried.

[0078] The multi-cell solar cell is a five-cell structure, and the number of main grid lines in the multi-cell solar cell is 26BB. The stress is controlled during the dicing process to avoid the formation of initial microcracks in the solar cell. The cleaning process involves ultrasonic cleaning with a mixture of deionized water and neutral cleaning agent for 15 minutes, followed by drying at 100°C for 8 minutes.

[0079] S2, UV adhesive printing: UV-cured padding and buffering adhesive is printed in the overlapping area of ​​the multi-segmented battery cells to form a preset printing pattern. The thickness of the UV-cured padding and buffering adhesive is 0.3mm.

[0080] The preset printed graphic consists of multiple connected raised characters, with the through portion measuring 180mm in length and 6mm in width, and the protruding portion measuring 3mm in length. The UV-cured cushioning adhesive is an acrylic adhesive. Printing is performed using screen printing equipment with a screen thickness of 135µm, a printing speed of 5000mm / s, an acceleration of 7000mm / s, a deceleration of 7000mm / s, a printing pressure of 80N, and a reflow speed of 500mm / s. After printing, a squeegee is used to lightly press once along the printing direction to remove air and ensure uniform adhesive layer thickness.

[0081] S3, UV adhesive curing: The printed UV-curable padding buffer adhesive is cured using a UV light source to obtain a cured adhesive layer with a Shore hardness of 50. The thickness of the cured adhesive layer is greater than or equal to the diameter of the solder strip.

[0082] Before curing, the surface of the battery cell is cleaned without dust. The UV light source is an LED lamp with a UV lamp box power of 67W, a UV lamp box opening time of 3.7s, and a UV welding time of 9.6s. Because the preset printed pattern is a convex connected structure, it is first semi-cured, and then fully cured after the solder ribbon is embedded.

[0083] S4. Welding ribbon laying and embedding: Cut the welding ribbon and lay it on the cured adhesive layer or embed it in the semi-cured UV-cured padding and cushioning adhesive.

[0084] The welding strip has a specification of Φ0.26mm. The cut welding strip has a flat end face without burrs. After cutting, the surface oxide layer is removed by wiping with alcohol. Since the preset printed pattern is a convex character structure, the welding strip is embedded in the convex character structure of the semi-cured adhesive layer. After embedding, the welding strip is lightly pressed to ensure a tight fit with the adhesive layer.

[0085] S5. Negative spacing stacking of battery cells: Stack the multi-segment battery cells with completed ribbon laying according to a preset overlap distance, so that the overlapping area corresponds completely with the cured adhesive layer;

[0086] The preset overlap distance is a negative spacing. The battery cells are stacked after being fixed in position by a positioning fixture. A uniform pressure of 0.3 MPa is applied and held for 20 seconds during stacking.

[0087] S6. Encapsulation and Lamination: After assembling the encapsulation materials in a preset order, lamination is performed to obtain a component with zero microcracks.

[0088] The preset order is tempered glass, EVA film, stacked battery cells, EVA film, and backplate. After assembly, the assembly is first evacuated to -0.09MPa and held for 5 minutes, and then laminated. The lamination process is carried out at a temperature of 145℃, a pressure of 0.12MPa, and a time of 20 minutes.

[0089] Comparative Example 1

[0090] The difference from Example 1 is that the thickness of the UV-cured cushioning adhesive in step S2 is 0.04 mm.

[0091] Comparative Example 2

[0092] The difference from Example 1 is that in step S2, the preset printing pattern is a continuous rectangle, rather than a structure of multiple convex characters connected together or spaced rectangles.

[0093] Comparative Example 3

[0094] The difference from Example 1 is that the Shore hardness of the cured adhesive layer in step S3 is 25.

[0095] Comparative Example 4

[0096] The difference from Example 1 is that the thickness of the cured adhesive layer in step S3 is 0.10 mm.

[0097] Comparative Example 5

[0098] The difference from Example 1 is that in step S3, when the preset printed graphic is a convex connected structure, it is directly subjected to complete curing.

[0099] Comparative Example 6

[0100] The difference from Example 1 is that in step S2, the preset printing pattern is a continuous strip, not an intermittent rectangle or a structure of multiple convex characters connected together.

[0101] Comparative Example 7

[0102] The difference from Example 1 is that the UV-cured cushioning adhesive in step S2 is an epoxy adhesive.

[0103] Comparative Example 8

[0104] The difference from Example 1 is that in step S2, after printing, the squeegee was not used to lightly press once along the printing direction to release air.

[0105] Comparative Example 9

[0106] The difference from Example 1 is that the surface of the battery cell was not cleaned in a dust-free manner before the curing process in step S3.

[0107] Experiment 1: Microcrack Proportion Detection Experiment

[0108] Referring to the microcrack detection method in GB / T 26944.3-2022 "Photovoltaic Modules Part 3: Structural Requirements", the module samples in Example 1 were selected, and fourteen groups (3000 samples per group) were set up according to different adhesive thicknesses (0.05-0.7mm). The whole cell of all samples was scanned using an EL electroluminescence analyzer to observe whether there were microcracks in the cells. The number of microcracks in each group was counted and the microcrack ratio was calculated (microcrack ratio = number of microcracked samples / total number of samples × 100%).

[0109] Experiment 2: Module Power Generation Performance Testing Experiment

[0110] Under standard test conditions (irradiance 1000W / m², ambient temperature 25℃, AM1.5 spectrum), a PV-6000 photovoltaic module power tester was used to test the power generation performance of 3000 module samples in each group of Examples 1-3 and Comparative Examples 1-9. The open-circuit voltage (Voc), short-circuit current (Isc), and maximum output power (Pmax) of each group of samples were recorded, and the fill factor (FF=Pmax / (Voc×Isc)) was calculated. The average value of each group of samples was taken as the test result.

[0111] Experiment 3: Reliability Verification Experiment After High and Low Temperature Cycling

[0112] Referring to GB / T 2423.22-2012 "Environmental Testing Part 2: Test Methods Test N: Temperature Change", high and low temperature cycling tests were conducted on 100 component samples from each group of Examples 1-3 and Comparative Examples 1-9. The test conditions were -40℃ (held for 1 hour) to 85℃ (held for 1 hour) as one cycle, and a total of 50 cycles were performed. After the test, the microcrack ratio was retested according to the method of Experiment 1, and the maximum output power was retested according to the standard test conditions of Experiment 2. The power attenuation rate was calculated (power attenuation rate = (initial Pmax - retested Pmax) / initial Pmax × 100%).

[0113] Table 2 Experimental data on the power generation performance of the components

[0114] Group Open-circuit voltage (Voc / V) Short-circuit current (Isc / A) Maximum output power (Pmax / W) Fill factor (FF) Example 1 32.6 12.8 385.2 0.93 Example 2 33.1 13.0 392.7 0.94 Example 3 33.5 13.2 398.4 0.94 Comparative Example 1 30.2 11.5 310.8 0.89 Comparative Example 2 29.8 11.2 301.5 0.88 Comparative Example 3 29.5 11.0 295.2 0.87 Comparative Example 4 28.7 10.6 298.5 0.72 Comparative Example 5 29.6 11.1 302.3 0.74 Comparative Example 6 29.9 11.3 312.3 0.75 Comparative Example 7 29.3 10.9 305.8 0.76 Comparative Example 8 31.5 12.2 352.6 0.85 Comparative Example 9 31.8 12.4 358.3 0.86

[0115] Table 3. Reliability verification experimental data after high and low temperature cycling.

[0116] Group Crack ratio after high-low temperature cycle (%) Power attenuation rate (%) Example 1 0 2.1 Example 2 0 1.9 Example 3 0 1.8 Comparative Example 1 25.7 12.5 Comparative Example 2 32.1 15.3 Comparative Example 3 36.4 16.8 Comparative Example 4 38.6 18.7 Comparative Example 5 32.4 16.3 Comparative Example 6 30.8 14.9 Comparative Example 7 35.2 17.5 Comparative Example 8 15.3 8.2 Comparative Example 9 13.7 7.8

[0117] Experimental conclusion:

[0118] As can be seen from the illustrations of Example 1, Comparative Example 1, and Table 1, the UV-cured cushioning adhesive thickness range of 0.05-0.3 mm defined in this invention is the core condition for achieving zero microcracks in negative-pitch modules. In the illustrations, tests one through six with an adhesive thickness of 0.05-0.3 mm showed a microcrack rate of 0 or only 0.01%, close to zero. Meanwhile, Table 2 shows that the maximum output power of Comparative Example 1 was only 310.8 W, a 23.9% decrease compared to 385.2 W in Example 1, confirming that deviations from this thickness range not only cause microcracks but also significantly reduce the module's power generation performance.

[0119] As can be seen from Examples 1-3 and Comparative Example 2, and from Tables 2 and 3, the spaced rectangular or multiple convex lettering printed patterns defined in this invention are a key structural design to ensure the power generation performance and long-term reliability of negative-pitch modules. Table 2 shows that Comparative Example 2, using continuous rectangular patterns, has a maximum output power of only 301.5W and a fill factor of 0.88, which are 21.7% and 5.4% lower than those of Example 1 (385.2W and 0.93, respectively). Table 3 shows that Comparative Example 2 exhibits a microcrack rate of 32.1% and a power degradation rate of 15.3% after high and low temperature cycling, while Example 1 has a microcrack rate of 0% and a power degradation rate of only 2.1% after cycling. This confirms that deviating from the printed pattern design of this invention will not only directly reduce the power generation efficiency of the module but also exacerbate the risk of microcracks and performance degradation during long-term use.

[0120] Combining Examples 1-3 and Comparative Example 3 with Tables 2 and 3, it can be seen that the Shore hardness range of 30-50 for the cured adhesive layer defined in this invention is a core parameter for balancing the power generation performance and long-term stability of the module. Table 2 shows that the hardness of the cured adhesive layer in Comparative Example 3 is 25, with a maximum output power of only 295.2W and a fill factor of 0.87, which is a decrease of 23.4% and 6.5% compared to 385.2W and 0.93 in Example 1, respectively. Table 3 shows that after cycling, the microcrack rate of Comparative Example 3 reached 36.4%, and the power decay rate was 16.8%, while the microcrack rate of Examples 1-3 was 0% and the power decay rate was only 1.8-2.1%. This indicates that if the adhesive layer hardness deviates from the defined range, it will simultaneously deteriorate the power generation efficiency and long-term reliability of the module.

[0121] Combining Examples 1-3 and Comparative Example 4 with Tables 2 and 3, it can be seen that the adaptation requirement of the cured adhesive layer thickness being greater than or equal to the solder ribbon diameter, as defined in this invention, is a necessary condition for ensuring the power generation performance and structural stability of the module. Table 2 shows that in Comparative Example 4, the adhesive thickness is less than the solder ribbon diameter, resulting in a maximum output power of only 298.5W and a fill factor of 0.72, which are 22.5% and 22.6% lower than those of Example 1 (385.2W and 0.93, respectively). Table 3 shows that after cycling, Comparative Example 4 exhibits a microcrack rate of 38.6% and a power decay rate of 18.7%, while Examples 1-3 show a microcrack rate of 0% and a power decay rate of only 1.8-2.1% after cycling. This confirms that the lack of this adaptation requirement leads to microcracks caused by hard contact of the solder ribbon, and significantly reduces the power generation efficiency and long-term durability of the module.

[0122] Combining Examples 1-3 and Comparative Example 5 with Tables 2 and 3, it can be seen that the two-step curing method of semi-curing, solder ribbon integration, and complete curing used in this invention for the convex-shaped interconnected pattern is a key process to ensure module performance. Table 2 shows that Comparative Example 5, which directly undergoes complete curing, has a maximum output power of only 302.3W and a fill factor of 0.74, which is 21.5% and 20.4% lower than that of Example 1 (385.2W and 0.93, respectively). Table 3 shows that after cycling, Comparative Example 5 has a microcrack rate of 32.4% and a power decay rate of 16.3%, while Examples 1 and 3 have a microcrack rate of 0% and a power decay rate of only 2.1% and 1.8%, respectively. This indicates that an incorrect choice of curing method can simultaneously reduce module power generation efficiency and long-term resistance to microcracks.

[0123] Combining Examples 1-3 and Comparative Example 6 with Tables 2 and 3, it can be seen that the type of printed pattern defined in this invention is the core design for ensuring the power generation performance and long-term stability of the module. Table 2 shows that Comparative Example 6, using a continuous bar pattern, has a maximum output power of only 312.3W and a fill factor of 0.75, which is 18.9% and 19.4% lower than that of Example 1 (385.2W and 0.93, respectively). Table 3 shows that after cycling, Comparative Example 6 has a microcrack rate of 30.8% and a power decay rate of 14.9%, while Examples 1-3 have a microcrack rate of 0 and a power decay rate of only 1.8-2.1% after cycling. This confirms that deviating from the printed pattern of this invention will simultaneously weaken the power generation efficiency and long-term microcrack resistance of the module.

[0124] Combining Examples 1-3 and Comparative Example 7 with Tables 2 and 3, it can be seen that the acrylic UV-curable cushioning adhesive specified in this invention is the core material selection for ensuring module performance. Table 2 shows that Comparative Example 7, using an epoxy adhesive, has a maximum output power of only 305.8W and a filler factor of 0.76, which is a decrease of 20.6% and 18.3% compared to Example 1's 385.2W and 0.93, respectively. Table 3 shows that Comparative Example 7 had a microcrack rate of 35.2% and a power decay rate of 17.5% after cycling, while Examples 1-3 had a microcrack rate of 0% and a power decay rate of only 1.8-2.1% after cycling. This indicates that an incorrect selection of adhesive type can simultaneously reduce the module's power generation efficiency and long-term microcrack resistance.

[0125] As can be seen from Examples 1-3 and Comparative Example 8, and from Tables 2 and 3, the auxiliary process of light pressure venting of the scraper after printing in this invention is a crucial detail for ensuring component performance. Table 2 shows that Comparative Example 8, without this operation, had a maximum output power of 352.6W and a fill factor of 0.85, which are 8.5% and 8.6% lower than Example 1's 385.2W and 0.93, respectively. Table 3 shows that Comparative Example 8 had a microcrack rate of 15.3% and a power degradation rate of 8.2% after cycling, while Examples 1-3 had a microcrack rate of 0% and a power degradation rate of only 1.8-2.1% after cycling. This confirms that the absence of this auxiliary process slightly reduces power generation efficiency while increasing the risk of microcracks and performance degradation during long-term use.

[0126] Combining Examples 1-3 and Comparative Example 9 with Tables 2 and 3, it can be seen that the dust-free cleaning of the solar cells before curing is a key detail in ensuring module performance. Table 2 shows that Comparative Example 9 did not undergo this operation, and its maximum output power was 358.3W with a fill factor of 0.86, a decrease of 7.0% and 7.5% compared to Example 1's 385.2W and 0.93, respectively. Table 3 shows that after cycling, Comparative Example 9 had a microcrack rate of 13.7% and a power degradation rate of 7.8%, while Examples 1-3 had a microcrack rate of 0 and a power degradation rate of only 1.8-2.1% after cycling. This indicates that the absence of this pre-process slightly reduces power generation efficiency while increasing the risk of microcracks and performance degradation during long-term use.

[0127] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for fabricating a multi-segment, multi-gate, negative-pitch zero-microcrack component, characterized in that, Includes the following steps: S1. Cell pretreatment: The whole crystalline silicon cell is diced to obtain multiple diced cells. The diced cells are then cleaned and dried. S2, UV adhesive printing: UV-cured padding and buffering adhesive is printed in the overlapping area of ​​the multi-segmented battery cells to form a preset printing pattern. The thickness of the UV-cured padding and buffering adhesive is 0.05-0.3mm. S3, UV adhesive curing: The printed UV-curable padding buffer adhesive is cured using a UV light source to obtain a cured adhesive layer with a Shore hardness of 30-50. The thickness of the cured adhesive layer is greater than or equal to the diameter of the solder strip. S4. Welding ribbon laying and embedding: Cut the welding ribbon and lay it on the cured adhesive layer or embed it in the semi-cured UV-cured padding and cushioning adhesive. S5. Negative spacing stacking of battery cells: Stack the multi-segment battery cells with completed ribbon laying according to a preset overlap distance, so that the overlapping area corresponds completely with the cured adhesive layer; S6. Encapsulation and Lamination: After assembling the encapsulation materials in a preset order, lamination is performed to obtain a component with zero microcracks.

2. The method for fabricating a multi-segment, multi-gate, negative-pitch zero-microcrack component according to claim 1, characterized in that, In step S1, the multi-cell battery cell includes three-cell, four-cell, or five-cell cells. The number of main grid lines in the multi-cell battery cell is 20BB-26BB. The cleaning is performed by ultrasonic cleaning with a mixture of deionized water and neutral cleaning agent for 10-15 minutes, followed by drying at 80-100℃ for 5-8 minutes.

3. The method for fabricating a multi-segment, multi-gate, negative-pitch zero-microcrack component according to claim 1, characterized in that, In step S2, the preset printed pattern is a spaced rectangle, and the UV-cured padding buffer adhesive has a thickness of 0.28-0.30 mm, a width of 1-6 mm, and a length of 160-180 mm after curing.

4. The method for fabricating a multi-segment, multi-gate, negative-pitch zero-microcrack component according to claim 1, characterized in that, In step S2, the preset printed pattern is a structure of multiple convex characters connected together. The thickness of the UV-cured padding buffer adhesive is 0.05-0.3mm, the length of the through part is 160-180mm and the width is 1-6mm, and the length of the protruding part is 0.5-3mm.

5. The method for fabricating a multi-segment, multi-gate, negative-pitch zero-microcrack component according to claim 1, characterized in that, In step S2, the UV-cured cushioning adhesive is an acrylic adhesive.

6. The method for fabricating a multi-segment, multi-gate, negative-pitch zero-microcrack component according to claim 1, characterized in that, The printing in step S2 is performed using a screen printing machine with a screen thickness of 120-135 μm, a printing speed of 4500-5000 mm / s, an acceleration of 6000-7000 mm / s, a deceleration of 6500-7000 mm / s, a printing pressure of 50-80 N, and a reflow speed of 400-500 mm / s. After printing, a squeegee is used to lightly press once along the printing direction to remove air and ensure uniform adhesive layer thickness.

7. The method for fabricating a multi-segment, multi-gate, negative-pitch zero-microcrack component according to claim 1, characterized in that, In step S3, the surface of the battery cell is cleaned without dust before curing. The UV light source is a mercury lamp, xenon lamp, or LED lamp. The UV lamp box power is 55-67W, the UV lamp box opening time is 3.1-3.7s, and the UV welding time is 3.1-9.6s. When the preset printed pattern is a raised letter connection structure, a semi-curing treatment is performed first, and a full curing treatment is performed after the solder ribbons are embedded.

8. The method for fabricating a multi-segment, multi-gate, negative-pitch zero-microcrack component according to claim 1, characterized in that, In step S4, the specifications of the solder strip are ≤ Φ0.26mm. The cut solder strip end face is flat and burr-free. After cutting, the surface oxide layer is removed by wiping with alcohol. When the preset printed pattern is a spaced rectangle, the solder strip is directly attached to the top of the fully cured adhesive layer. When the preset printed pattern is a raised letter structure, the solder strip is embedded in the raised letter structure of the semi-cured adhesive layer. After embedding, the solder strip is lightly pressed to ensure tight adhesion with the adhesive layer.

9. The method for fabricating a multi-segment, multi-gate, negative-pitch zero-microcrack component according to claim 1, characterized in that, In step S5, the preset overlap distance is a negative spacing. After the battery cells are fixed in position by the positioning fixture, they are stacked. During stacking, a uniform pressure of 0.1-0.3 MPa is applied and maintained for 10-20 seconds.

10. The method for fabricating a multi-segment, multi-gate, negative-pitch zero-microcrack component according to claim 1, characterized in that, In step S6, the preset order is tempered glass, EVA film, stacked battery cell pack, EVA film, and backplate. After assembly, the assembly is first evacuated to ≤-0.09MPa and held for 3-5 minutes, and then laminated. The lamination temperature is 135-145℃, the pressure is 0.08-0.12MPa, and the time is 15-20 minutes.

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