Laser-Assisted Soldering Techniques for Solar Cell Manufacturing

Photovoltaic module with improved soldering reliability through optimized laser welding. The module features a junction box with a plate that is precisely positioned to create a specific width ratio between the soldering seam in the first region and the direct weld in the second region. This deliberate width variation enables the laser welder to achieve optimal soldering performance while maintaining reliability. The module's design ensures that the soldering seam in the first region is narrower than the weld in the second region, preventing desoldering due to thermal shock.

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A low-temperature photovoltaic solder alloy for series welding of PERC, TOPcon, and HJT solar cells. The solder alloy combines a low melting point with high strength, enabling reliable welding of solar cells with thinned silicon wafers. The alloy composition includes Sb, Ni, Ge, In, and Co elements that enhance tensile strength and peeling force through solid solution strengthening and dispersion strengthening. The solder alloy is produced through a hot-dip coating process on copper substrates, providing a simple and cost-effective solution for series welding applications.

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Laser exposure solar cell welding device and photovoltaic module processing equipment that enables stable heat generation through a novel laser-based welding system. The device employs a laser system to provide controlled heat input during solar cell welding, eliminating the need for traditional welding lamps with filaments. This laser-based approach enables improved welding quality, reduced thermal management requirements, and lower equipment costs compared to conventional systems.

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A method for string welding interdigitated back contact (IBC) solar cells without using solder paste. The method employs a laser-based process that directly welds the solar cells together through their finger-like contacts, eliminating the need for solder paste. The laser welds the contacts together while maintaining the structural integrity of the solar cells, achieving efficient string welding of IBC solar cells without the environmental and operational drawbacks associated with traditional soldering methods.

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Low-temperature lead-free solder for photovoltaic cells that eliminates thermal expansion issues while maintaining environmental sustainability. The solder has a low melting point and coefficient of thermal expansion, enabling precise assembly of ultra-thin photovoltaic cells. The solder is prepared through a novel coating process that enhances its performance characteristics while maintaining environmental compliance.

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A welding method for photovoltaic cells and modules that enables reliable and efficient interconnection through solder joints. The method involves creating a solder layer on the cell substrate at a specific pad location, then lapping solder strips from adjacent cells to achieve precise contact. This approach enables precise soldering of adjacent cells while maintaining the required welding tension and minimizing solder wetting issues. The soldering process is performed through a controlled lapping sequence that ensures precise solder alignment and coverage, resulting in reliable electrical connections.

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Automated laser soldering system that enables precise and efficient welding of complex components by dynamically adjusting laser parameters based on the specific welding requirements. The system employs real-time monitoring of the welding process, including temperature and energy output, to automatically select optimal spot size and type for each weld joint. This enables precise control over solder placement, temperature management, and energy distribution, resulting in improved weld quality and reduced defects.

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A method to improve the quality and efficiency of soldering in photovoltaic modules without main grids. The method involves rolling the low-temperature solder strip with flux inside to release and attach flux to the strip surface. This pretreated strip is used to connect the photovoltaic cells instead of plain flux-containing strip. Rolling the strip before soldering increases tin wetting, flux migration, and oxide removal for better solder joints. The flux-coated strip also prevents brittleness issues.

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Tabbing device for solar cell module manufacturing that prevents over-soldering during the assembly process. The device incorporates a specialized heat shield with an integrated light transmission system that directs infrared radiation to the solar cells during soldering. The heat shield features an adjustable light path that can be configured to block or transmit infrared radiation depending on the cell's position on the conveyor. This dual-function design enables precise control over soldering areas while preventing overheating of non-soldered cells.

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A method for rapid laser soldering of materials using laser beams. The method employs a laser, a holder, a beam-guiding device, and a beam-focusing device to selectively solder specific areas of a material. The laser beam is directed through a beam-guiding device to precisely focus the laser energy onto the desired areas, while the beam-focusing device maintains optimal beam intensity and wavelength. This enables efficient laser soldering of specific regions of a material, eliminating the need for liquid soldering.

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A low-temperature solder alloy for photovoltaic applications that enables reliable stringing of solar cells through reduced welding temperatures. The alloy, comprising tin-lead-tin ternary alloy with indium addition, achieves a melting point of approximately 130°C, significantly lower than conventional tin-lead solder. The alloy's refined grain structure and improved grain boundary refinement properties enable enhanced bonding strength between the solder and the solar cell substrate, while maintaining sufficient wettability for efficient stringing.

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A method for laser beam soldering that enables high-quality connections while minimizing surface defects. The process employs a laser beam with two distinct focal planes: a large-area beam for the soldering area and a smaller-area beam for the seam root. This dual-beam configuration ensures direct heat transfer from the laser beam to the seam root, reducing edge notches and spatter compared to conventional single-beam systems. The smaller-area beam is positioned within the larger area beam, allowing precise control over the soldering process while maintaining optimal laser energy distribution.

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A low-temperature photovoltaic solder for high-efficiency solar cells that enables reliable connections at temperatures below 150°C. The solder comprises a combination of Sn, Bi, In, Zn, P alloy powder, graphene, thermosetting resin, curing agent, and organic acid. The alloy powder is prepared through atomization with precise composition and particle size control, while the thermosetting resin provides mechanical strength and thermal stability. The solder achieves high wetting properties and tensile strength while maintaining low oxidation resistance, making it suitable for photovoltaic module assembly at lower temperatures compared to traditional solders.

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A laser welding device that eliminates the complex and expensive tin ball feeding mechanism while maintaining high reliability. The device features a carrier tape with embedded solder inlays, where the solder is arranged in a sheet-like structure. The tape is conveyed by a carrier belt system, which transports the solder to the laser head. The laser melts and vaporizes the solder and tin, creating a molten jet that is directed to the welding area through a high-pressure gas system. This eliminates the need for individual tin ball feeding mechanisms, reducing production complexity and cost.

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Laser welding method and soldering machine that eliminates the traditional laser welding process's limitations by employing a novel laser welding technique that uses a high-temperature soldering process to create a permanent bond. The laser welding method involves melting the solder through a controlled laser energy density, rather than traditional molten soldering. This approach enables precise control over the soldering process, eliminating the structural damage typically associated with traditional laser welding. The soldering machine incorporates this laser welding method to create permanent solder joints, eliminating the need for flux and reducing environmental impact.

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A method and device for efficient solar cell welding that eliminates the need for manual positioning and double welding. The method employs a laser system that simultaneously heats multiple welding groups in a single pass, with each group's points aligned using a precision camera system. The laser's focused beam is directed through a beam expander and focusing lens to create precise spots that accurately target the welding points. This single-pass approach eliminates the need for manual positioning and double welding, significantly improving welding efficiency compared to conventional methods.

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A molten solder for photovoltaic modules that enables efficient bonding between electrode wires and semiconductor substrates. The solder composition combines tin (Sn) with indium (In) and lead (Pb) in a specific ratio, with a melting point between 181°C and 183°C, to achieve high bonding strength while minimizing thermal stress. The solder layer forms a strong bond with the electrode wire's conductive core, enabling reliable electrical connections between the wire and the semiconductor substrate.

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A method for welding heterojunction solar cells that improves yield and efficiency compared to existing methods. The method involves printing a thin layer of material on the welding points of the solar cells before welding. This adhesion layer helps bridge between the cells and the welding strip during welding, improving the connection and pull force. It allows welding at lower temperatures to avoid cell damage. The printed layer is made of a material like silver that melts earlier than the cell material. When the welding strip fuses with the cell, the printed layer connects them.

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A welding device for photovoltaic cells that enhances welding tension by optimizing soldering conditions. The device employs a controlled molten soldering process that prevents rapid solidification during the welding process. The molten solder is maintained at a stable temperature, allowing it to solidify slowly and evenly between the photovoltaic cell and the electrode. This controlled solidification prevents the formation of localized solder droplets that can compromise the welding process. The device enables stable and consistent soldering conditions, resulting in improved welding tension and overall cell performance.

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Laser beam soldering method for joining coated components with improved wetting and mechanical properties. The method employs a laser beam with a diameter ratio of at least 2.5 between the beam diameter and the filler material diameter, ensuring sufficient heating area for effective wetting and filling of the coating. This ratio enables the laser beam to penetrate the coating thickness and fill the gap between the components, resulting in improved connection quality compared to conventional laser brazing.

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