High power bc component and method of making the same

Abstract

This invention relates to the field of photovoltaic module manufacturing, specifically to a high-power BC module and its manufacturing method. The module includes multiple quadrature cell units formed by laser scribing, a back busbar disposed between adjacent cell strings, an alternating solder ribbon structure for electrically connecting the cell units, and an insulating adhesive layer. Each quadrature cell unit is composed of a single BC-type solar cell uniformly divided into four sub-cells along its length. The back busbar is disposed between the second and third rows of cell strings, and between the fourth and fifth rows of cell strings, and is hidden on the back of the module through folded wiring, maximizing the metal-free area on the front. The alternating solder ribbon structure uses flat solder ribbons made of tin-plated aluminum, with a width of 2mm and a thickness of 0.25mm, distributed on both sides of the cell in an alternating arrangement. This method can increase the output power of the BC module without significantly increasing the module size.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic module manufacturing, and more specifically, to a high-power BC module and its manufacturing method. Background Technology

[0002] With the accelerated transformation of the global energy structure, photovoltaic (PV) power generation technology has become a crucial pillar in the renewable energy sector. In recent years, the PV industry has driven improvements in module power output through continuous technological innovation. Key technological approaches include increasing cell size, optimizing optical materials, simplifying cell structures, and thinning silicon wafers. Regarding cell size, the industry has evolved from standard 156mm silicon wafers to larger sizes of 182mm and 210mm. In terms of optical performance, high-transmittance glass and anti-reflective coatings have become standard. Regarding cell structure, busbar-less (OBB) technology effectively reduces the front-side shading area. In silicon wafer processing, thinner silicon wafers (below 150μm) combined with half-cell / three-cell technology significantly reduce resistance loss.

[0003] Current mainstream manufacturing processes include various technologies such as laser welding, low-temperature lamination welding for full-screen displays, high-temperature welding for full-screen displays, and film-coated welding. Laser welding achieves localized connections through precise energy input control, low-temperature lamination welding uses special adhesive films for full-area bonding, high-temperature welding relies on traditional hot-melt welding strips, and film-coated welding combines physical coverage with electrical connection. While these processes improve the flatness of the module's appearance and local electrical performance, there is still room for optimization in core indicators such as current collection uniformity, voltage distribution balance, and carrier transport efficiency. In particular, when multiple advanced technologies are integrated, compatibility issues between subsystems can create new technological barriers.

[0004] The existing technology system faces multiple constraints: In terms of power output, simply increasing cell size exacerbates hot spot effects and makes system adaptation difficult, while the marginal benefits of optical and structural optimization are gradually decreasing; in terms of space utilization, traditional series-parallel layouts require reserving approximately 3-5% of the frame area for busbar routing, directly reducing the effective light-receiving area; in terms of electrical parameter matching, the open-circuit voltage generated by large-size multi-string cell combinations may exceed 1000V, exceeding the safe input range of conventional inverters; in terms of cost control, the cost of high-purity copper solder accounts for more than 15%, and the high-temperature welding process increases energy consumption and the risk of microcracks in silicon wafers. These factors collectively constrain the development of photovoltaic modules towards higher power density and lower levelized cost of electricity. Summary of the Invention

[0005] The purpose of this invention is to provide a high-power BC module and its manufacturing method, which can improve the output power of the BC module without significantly increasing the module size.

[0006] The technical solution of this invention is implemented as follows: A high-power BC module includes multiple quadrilateral cell cells formed by laser scribing, a back busbar disposed between adjacent cell strings, an alternating solder strip structure for electrically connecting the cell cells, and an insulating adhesive layer. The quad-cell battery unit is composed of a single BC-type solar cell that is uniformly divided into four sub-cells along the length direction to reduce the operating current and reduce resistance loss. The rear busbar is located between the second and third rows of battery strings and between the fourth and fifth rows of battery strings, and is hidden on the back of the module by folded wiring, maximizing the area without metal obstruction on the front and improving the cell area utilization rate to over 95.5%. The alternating solder strip structure uses flat solder strips made of tin-plated aluminum. The solder strips are 2mm wide and 0.25mm thick. They are distributed on the front and back of the battery cells and arranged in an alternating pattern to increase the electron collection area and reduce the series resistance.

[0007] Furthermore, the solder strip is a tin-plated aluminum strip, wherein the aluminum substrate surface is electroplated with a tin layer, and the tin layer is doped with copper element, wherein the mass percentage of copper element is 20wt%, and the copper powder particle size is 20–38μm.

[0008] Furthermore, the cut surfaces of the quadruple battery cells are chemically passivated to form a dense oxide layer on the cut sidewalls. The passivation solution is a mixture of nitric acid, hydrogen peroxide, and alcohol in a volume ratio of HNO3:H2O2:alcohol = 4:4:92.

[0009] Furthermore, the insulating adhesive layer is made of silicone or acrylic pressure-sensitive adhesive material, printed on the edge area of ​​the battery cell, with a film thickness of 12μm, a sand thickness of 60μm, and a viscosity of 80–110dPas, to prevent leakage and short circuit.

[0010] Furthermore, the solder paste in the component has a melting point of 140°C, an alloy composition of Sn42Bi58, and 20wt% copper powder is added. The solder paste printing height is controlled at 140–180μm, and the viscosity is 900–1100dPas.

[0011] Furthermore, it also includes EPE type film as encapsulation material, the film being from the Foster or Swick brand; the front panel uses double-sided coated high-transparency glass produced by Rainbow or Xinfuxing, with a light transmittance ≥94%.

[0012] Furthermore, the overall dimensions of the component are 2382mm×1134mm, and it uses BC battery cells with a specification of 182.9mm×214.35mm. The battery cells are arranged in a multi-busbar staggered layout, and the non-active area is minimized by combining with the full-screen design.

[0013] A method for manufacturing the high-power BC module includes the following steps: S1: Use a screen to print insulating adhesive on the edge area of ​​the BC battery cell. The screen specifications are 450×450mm, tension 271N, mesh count 250, film thickness 12μm, sand thickness 60μm, squeegee length 235mm, angle 60°, printing pressure 50–70N, screen distance 1.2–2.5mm, compression 0.5–1.2mm, and printing speed 400–600mm / s. S2: Curing treatment of insulating adhesive; S3: Print low-temperature solder paste in the solder joint area of ​​the battery cell. The solder paste is Sn42Bi58 and doped with 20wt% copper powder. The printing parameters are the same as those in step S1: a 250 mesh screen with a film thickness of 12μm, a squeegee length of 225mm, an angle of 50°, and other parameters are the same as those in step S1. S4: Pre-curing of solder paste; S5: Use Deju pressure-sensitive adhesive for dispensing, with an adhesive dot diameter of 1.8mm and a distance of 1mm from the nearest solder joint. Then, heat at 80℃ for 10 seconds to complete the initial fixation. S6: Use laser equipment to cut the solar cell into quarters, set the thermal cracking power to 30-45%, the grooving power to 50-80%, the grooving length to 2-3mm, and the platform temperature to 50-70℃. S7: Immediately after dicing, introduce the passivation mechanism and spray a mixed passivation solution composed of HNO3:H2O2:ethanol = 4:4:92 onto a 0.2–0.1 mm wide area on both sides of the cut surface, and then dry it with hot air; S8: Arrange the alternating solder strips and the back busbars at predetermined positions, with the busbars placed between the second and third rows and the fourth and fifth rows of battery strings; S9: The laminated structure is fed into a laminator to complete the lamination welding, resulting in the final high-power BC module.

[0014] Furthermore, the passivation process described in step S7 is completed in real time in the passivation module integrated inside the string welding machine, realizing integrated online processing of "dicing-passivation-blowing".

[0015] Compared with the prior art, the beneficial effects of the present invention are: This solution adopts a "quadruple-segment + full-screen" structure. Each battery is divided into four segments, each with independent positive and negative output terminals. There are no metal grid lines or busbars obstructing the front, achieving a "full-screen" display. Furthermore, the busbars have been redesigned: horizontal busbars have been added between the second and third rows, and between the fourth and fifth rows. These busbars are no longer located at the module edges but are folded to the back to hide the wiring. This is achieved through flexible circuitry or FPC connections on the back, or by using U-shaped bent solder strips to guide the wiring to the back. This reduces front-side shading, improves light absorption, increases battery compactness, enhances area utilization, disperses current paths, and reduces localized heat generation. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This diagram shows a comparison between the conventional circuit of the existing BC component and the improved circuit of this solution. Figure 2 This is a diagram of the four-slice circuit structure of the present invention; Figure 3 This is an overall stack-up diagram of the BC component of the present invention; Figure 4 This is a conventional BC component stack-up diagram from the prior art. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments 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. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0019] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0020] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0021] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. In addition, the terms "first," "second," "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0022] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0023] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0024] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0025] Example 1: A high-power BC module A high-power BC module includes multiple quadrilateral cell cells formed by laser scribing, a back busbar disposed between adjacent cell strings, an alternating solder strip structure for electrically connecting the cell cells, and an insulating adhesive layer. The quad-cell battery unit is composed of a single BC-type solar cell that is uniformly divided into four sub-cells along the length direction to reduce the operating current and reduce resistance loss. The rear busbar is located between the second and third rows of battery strings and between the fourth and fifth rows of battery strings, and is hidden on the back of the component by folded wiring, maximizing the area on the front without metal obstruction. The alternating solder strip structure uses flat solder strips made of tin-plated aluminum. The solder strips are 2mm wide and 0.25mm thick. They are distributed on the front and back of the battery cells and arranged in an alternating pattern to increase the electron collection area and reduce the series resistance.

[0026] The solder strip is a tin-plated aluminum strip, wherein the aluminum substrate surface is electroplated with a tin layer, and the tin layer is doped with copper element, the mass ratio of copper element is 20wt%, and the copper powder particle size is 20–38μm.

[0027] The cut surfaces of the four-segment battery cells are chemically passivated to form a dense oxide layer on the cut sidewalls. The passivation solution is a mixture of nitric acid, hydrogen peroxide, and alcohol in a volume ratio of HNO3:H2O2:alcohol = 4:4:92.

[0028] The insulating adhesive layer (or insulating film) is made of silicone or acrylic pressure-sensitive adhesive material, printed on the edge area of ​​the battery cell. The film thickness is 12μm, the sand thickness is 60μm, and the viscosity is 80–110dPas. It is used to prevent leakage and short circuit.

[0029] The solder paste in the component has a melting point of 140°C, an alloy composition of Sn42Bi58, and 20wt% copper powder. The solder paste printing height is controlled at 140–180μm, and the viscosity is 900–1100dPas.

[0030] The component also includes an EPE film as an encapsulation material, which is from the Foster or Swick brand; the front panel is made of double-sided coated high-transmittance glass produced by Rainbow or Xinfuxing, with a light transmittance of ≥94%.

[0031] The overall dimensions of the component are 2382mm×1134mm. It uses BC solar cells with a specification of 182.9mm×214.35mm. The solar cells are arranged in a multi-busbar staggered layout, and the non-active area is minimized by combining with the full-screen design.

[0032] Example 2: A high-power BC module and its manufacturing method Reference Figures 1-4 This embodiment provides a high-power back-contact (BC) photovoltaic module based on quad-cell cells, full-screen packaging, back-folded busbars, and passivated cut surfaces, as well as its fabrication method. The module is suitable for large-scale ground-mounted power plants and distributed rooftop systems, and features high power output, low cost, and strong low-voltage adaptability.

[0033] I. Material Preparation The following key materials were selected: Solar cell: P-type or N-type monocrystalline silicon back contact solar cell, measuring 182.2mm × 192.5mm, with no grid lines on the front and all electrodes located on the back; Insulating adhesive: High-temperature resistant epoxy insulating adhesive produced by Howell Corporation, with a viscosity of 95 dPa·s (measured at 25°C); Solder paste: Low-temperature alloy solder paste produced by Viteru Corporation, with Sn42Bi58 as the composition, melting point of about 140℃, and pre-doped with 20wt% spherical copper powder (T4 grade metal powder) with a particle size of 20–38μm, and used after being mixed evenly; the viscosity of the solder paste is controlled at 1000dPa·s; Solder strip: Yubang Company produces tin-plated aluminum solder strip with specifications of 0.25mm×2.0mm, which replaces the traditional 0.30mm×2.0mm pure copper solder strip; Busbar: Flat tin-plated copper busbars supplied by Talison, 4mm wide and 0.3mm thick, for multiple series-parallel connections; Adhesive film: EPE type co-extruded adhesive film (ethylene-methyl acrylate / EVA / POE three-layer structure) manufactured by Swick Corporation, with a thickness of 0.4mm; Glass: Double-sided anti-reflective (AR) coated ultra-clear patterned glass supplied by Xinfuxing Company, 3.2mm thick, with a light transmittance ≥94.2%; Passivation solution: Prepared on-site, it is made by mixing analytical grade nitric acid (HNO3), hydrogen peroxide (H2O2) and anhydrous ethanol in a volume ratio of 4:4:92, and should be prepared and used immediately. Pressure-sensitive adhesive: Deju Company's fast-curing pressure-sensitive adhesive is used for temporary fixation of battery cells.

[0034] II. Process Flow The process route of this plan is as follows: Insulating adhesive printing → curing → solder paste printing → curing → dispensing and positioning → heat curing → laser scribing → passivation treatment of cut surfaces → hot air drying → layout → placement of solder strips and busbars → lamination welding → post-processing (framing and junction box installation).

[0035] Step S1: Printing of insulating adhesive The operation is carried out using a fully automatic screen printing machine: Screen printing parameters: 450mm×450mm frame, tension 271N, mesh count 250, photosensitive film thickness 12μm, abrasive thickness 60μm; Scraper parameters: length 235mm, material polyurethane, hardness 80 Shore A, scraper angle 60° (relative to the screen plane). Printing parameters: pressure 60N, screen distance 1.8mm, compression 0.8mm, printing speed 500mm / s; Control the ambient temperature and humidity: temperature 23±2℃, relative humidity 45±5%RH; After printing, heat in an 80℃ oven for 10 minutes to complete the initial curing.

[0036] Step S2: Solder paste printing After changing the solder paste stencil on the same printing platform, continue the operation: The screen printing parameters are the same as above (250 mesh, film thickness 12μm). The scraper parameters are adjusted as follows: length 225mm, angle 50°; Solder paste printing height is controlled at 160μm (monitored online using a height gauge); Printing parameters: pressure 60N, screen distance 2.0mm, compression 1.0mm, speed 550mm / s; After printing, the product is also pre-cured at 80℃ for 10 seconds to prevent collapse during subsequent handling.

[0037] Step S3: Dispensing and Positioning To ensure that the solar cells do not shift during the laser scribing process, a dispensing machine is used to apply positioning adhesive dots on the edge of the cells. Use Deju pressure-sensitive adhesive; The diameter of the adhesive dots is set to 1.8mm; Two adhesive dots are placed on each side of each solar cell, 1mm away from the edge of the nearest pad. Immediately after dispensing, the glue dots enter the infrared heating channel and are heated at 80°C for 10 seconds to quickly set.

[0038] Step S4: Laser scribing A nanosecond pulsed green laser is used for four-segment cutting: the entire cell is evenly divided into four sub-cell units along its long side, each with a width of approximately 48.05 mm.

[0039] The parameters are set as follows: Thermal cracking power: 40%; grooving power: 70%; grooving length: 2.5mm; bearing platform temperature: 60℃; achieving controllable fracture and preventing microcracks from spreading to the battery body.

[0040] Step S5: Passivation treatment of the cut surface (core innovative step) Immediately after laser scribing, the cut surface is chemically passivated using a spray device integrated inside the welding machine: the nozzle is precisely aimed at the front and back areas of the cut edge, covering a width of 0.15mm; the passivation liquid (HNO3:H2O2:alcohol=4:4:92) is sprayed at a flow rate of 0.3mL / s for 3 seconds.

[0041] Reaction mechanism: Nitric acid oxidizes silicon on the surface to form a nanoscale SiO2 film, which effectively repairs lattice damage; hydrogen peroxide accelerates the oxidation process; alcohol promotes liquid evaporation and reduces residue; this process significantly reduces the surface state density (Dit), inhibits carrier recombination, and increases the open circuit voltage (Voc) and fill factor (FF).

[0042] Step S6: Hot air drying After passivation, the hot air system is activated for rapid drying: hot air temperature: 90℃, air speed: 3m / s, blowing time: 5 seconds, direction: oblique blowing, to ensure that the cut surface is completely dry and there is no liquid accumulation.

[0043] Step S7: Layout and Interconnection Structure Assembly The processed quarter-cell battery units are arranged according to a predetermined circuit topology: Adopting an alternating solder strip layout (e.g.) Figure 3 As shown in the figure, two solder strips are staggered to connect the positive and negative electrode pads of adjacent batteries, increasing the current collection area; Vertical busbars are installed at the inter-row positions between the second and third rows and between the fourth and fifth rows; The busbar extends from the front edge of the component, passes under the frame, and enters the rear wiring area, achieving "folded wiring" (e.g., Figure 3 (As shown), to avoid occupying the effective light-receiving area on the front.

[0044] Step S8: Lamination welding The laminated structure is fed into a laminator to complete the integrated encapsulation and welding: Lamination parameters: Temperature: First stage preheating at 100℃, second stage welding temperature ≤180℃; Time: Total duration 12 minutes, vacuum degree ≤50Pa; Pressure: 0.4Mpa.

[0045] During the soldering process, the Sn42Bi58-Cu composite solder paste fully wets the interface between the solder pad and the tin-plated aluminum solder ribbon, forming a stable metal bond. Due to the use of low-melting-point alloys and copper powder to enhance conductivity, good soldering quality can be achieved at lower temperatures, while reducing the risk of delamination caused by thermal stress.

[0046] Step S9: Post-processing After lamination, routine follow-up processes are carried out: cooling and shaping, trimming and trimming, installing aluminum alloy frame, installing junction box and crimping leads, and performing EL testing, IV testing and appearance inspection.

[0047] III. Performance Test Results The performance of the component (2382mm×1134mm, containing 60 quad-cell battery cells) prepared in this embodiment was evaluated under standard test conditions (STC: AM1.5G, 1000W / m², 25℃): The test results show that the component achieves significant power gain and cost reduction while maintaining reliability.

[0048] IV. Other Optional Implementation Methods (Variations) To demonstrate the broad applicability of this invention, several feasible variations are listed below: Variant 1: The battery size can be replaced with 182.9mm×214.35mm or other rectangular BC batteries, and it is still suitable for quarter-cutting; Variant 2: Isopropanol can be used instead of ethanol in the passivation solution, or the ratio can be adjusted to HNO3:H2O2:solvent = 3~5:3~5:90~94, which is still within the protection range; Variation 3: The copper powder doping ratio in the solder paste can be adjusted within the range of 15–25 wt%, and the powder diameter is controlled within 20–40 μm; Variation 4: The location of the busbar addition is not limited to the 2nd / 3rd row or the 4th / 5th row; it can also be flexibly set in the middle symmetrical position according to the number of strings. Variation 5: Passivation can be performed at a separate workstation and does not necessarily have to be integrated into the welding machine.

[0049] Variation 6: The four-slice method can be replaced with three-slice or five-slice, as long as it achieves the purpose of reducing current and increasing density; Variation 7: The width of the welding strip can be 1.8–2.2 mm, and the thickness can be 0.20–0.30 mm; Variation 8: The circuit structure described can be applied to other back electrode battery technologies such as TOPCon and HJT.

[0050] All such equivalent transformations or simple substitutions should be considered to fall within the protection scope of this invention.

[0051] In summary, this solution successfully addresses the limitations of existing BC modules, such as power growth constraints, high costs, and voltage incompatibility, through the introduction of multiple synergistic technological innovations, including four-segment current reduction, full-screen efficiency enhancement, rear-side folded busbar wiring, chemical passivation of the cut surfaces, and low-temperature composite solder paste soldering. The above embodiments fully demonstrate the technical feasibility and industrialization prospects of this invention.

[0052] Without creative effort, those skilled in the art can make adaptive adjustments to process parameters, material brands, equipment models, etc., according to actual production needs, and all such adjustments fall within the scope of protection of this solution.

[0053] Technical advantages of this solution: 1. "Four-segment + Full-screen" structure Each battery is divided into 4 small sections, each with an independent positive and negative output terminal, and there are no metal grid lines or busbars obstructing the front → achieving a "full screen".

[0054] 2. Busbar rearrangement A new horizontal busbar is added between the second and third rows and between the fourth and fifth rows. The busbar is no longer located at the edge of the component, but is folded to the back to hide the wiring. The implementation method is to connect it through the flexible circuit or FPC on the back, or to use U-shaped bent solder strip to pass through to the back.

[0055] Reduce front shading, improve light absorption, increase battery pack compactness, improve area utilization, disperse current paths, and reduce localized heat generation.

[0056] 3. Alternating double-welded strip structure (see...) Figure 3 ) Two sets of solder strips with different orientations are arranged alternately, one set is responsible for connecting odd-numbered rows and the other set is responsible for even-numbered rows, similar to a "Z" or "snake" series-parallel topology.

[0057] Advantages: Uniform current distribution, reduced series resistance, improved electron collection efficiency, and support for higher density arrangement.

[0058] 4. Voltage regulation mechanism The total voltage of the components can be actively reduced by: dividing the components into quarters → doubling the number of cells in a single string → reducing the number of series strings; adding parallel circuits in the middle → achieving "series-parallel hybrid" and forming more parallel branches, thus reducing the output voltage.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-power BC module, characterized in that, It includes multiple quadrilateral battery cells formed by laser scribing, a back busbar disposed between adjacent battery strings, an alternating solder strip structure for electrically connecting each battery cell, and an insulating adhesive layer; The quad-cell battery unit is composed of a single BC-type solar cell that is uniformly divided into four sub-cells along the length direction to reduce the operating current and reduce resistance loss. The rear busbar is located between the second and third rows of battery strings and between the fourth and fifth rows of battery strings, and is hidden on the back of the component by folded wiring, maximizing the area on the front without metal obstruction. The alternating solder strip structure uses flat solder strips made of tin-plated aluminum. The solder strips are 2mm wide and 0.25mm thick. They are distributed on the front and back of the battery cells and arranged in an alternating pattern to increase the electron collection area and reduce the series resistance.

2. The high-power BC module according to claim 1, characterized in that, The solder strip is a tin-plated aluminum strip, wherein the aluminum substrate surface is electroplated with a tin layer, and the tin layer is doped with copper element, the mass ratio of copper element is 20wt%, and the copper powder particle size is 20–38μm.

3. The high-power BC module according to claim 1 or 2, characterized in that, The cut surfaces of the four-segment battery cells are introduced with a passivation solution for chemical passivation treatment, forming a dense oxide layer on the cut sidewalls. The passivation solution is a mixture of nitric acid, hydrogen peroxide, and alcohol in a volume ratio of HNO3:H2O2:alcohol = 4:4:

92.

4. The high-power BC module according to claim 1, characterized in that, The insulating adhesive layer is made of silicone or acrylic pressure-sensitive adhesive material, printed on the edge area of ​​the battery cell, with a film thickness of 12μm, a sand thickness of 60μm, and a viscosity of 80–110dPas, to prevent leakage and short circuit.

5. The high-power BC module according to claim 1, characterized in that, The solder paste in the component has a melting point of 140°C, an alloy composition of Sn42Bi58, and 20wt% copper powder. The solder paste printing height is controlled at 140–180μm, and the viscosity is 900–1100dPas.

6. The high-power BC module according to claim 1, characterized in that, It also includes EPE type film as encapsulation material, the film being from the Foster or Swick brand; the front panel uses double-sided coated high-transparency glass produced by Rainbow or Xinfuxing, with a light transmittance ≥94%.

7. The high-power BC module according to claim 1, characterized in that, The overall dimensions of the component are 2382mm×1134mm. It uses BC solar cells with a specification of 182.9mm×214.35mm. The solar cells are arranged in a multi-busbar staggered layout, and the non-active area is minimized by combining with the full-screen design.

8. A method for manufacturing a high-power BC module as described in any one of claims 1 to 7, characterized in that, Includes the following steps: S1: Use a screen to print insulating adhesive on the edge area of ​​the BC solar cell. The screen size is 450×450mm, tension is 271N, mesh count is 250, film thickness is 12μm, sand thickness is 60μm, squeegee length is 235mm, angle is 60°, printing pressure is 50–70N, screen distance is 1.2–2.5mm, compression is 0.5–1.2mm, and printing speed is 400–600mm / s. S2: Curing treatment of insulating adhesive; S3: Print low-temperature solder paste in the solder joint area of ​​the battery cell. The solder paste is Sn42Bi58 and doped with 20wt% copper powder. The printing parameters are the same as those of a 250-mesh screen with a film thickness of 12μm, a squeegee length of 225mm, and an angle of 50°. S4: Pre-curing of solder paste; S5: Pressure-sensitive adhesive is used for dispensing. The diameter of the adhesive dot is 1.8mm and the distance from the nearest solder joint is 1mm. Then, it is heated at 80℃ for 10 seconds to complete the initial fixation. S6: Use laser equipment to cut the solar cell into quarters, set the thermal cracking power to 30-45%, the grooving power to 50-80%, the grooving length to 2-3mm, and the platform temperature to 50-70℃. S7: Immediately after dicing, the cut surface is introduced into the passivation mechanism for passivation treatment. A mixed passivation solution consisting of HNO3:H2O2:ethanol = 4:4:92 is sprayed onto a 0.2–0.1 mm wide area on both sides of the cut surface, and then dried with hot air. S8: Arrange the alternating solder strips and the back busbars at predetermined positions, with the busbars placed between the second and third rows and the fourth and fifth rows of battery strings; S9: The laminated structure is fed into a laminator to complete the lamination welding, resulting in the final high-power BC module.

9. The manufacturing method according to claim 8, characterized in that, In step S7, the passivation process is completed in real time in the passivation module integrated inside the string welding machine.

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