Lead-Free Soldering Alloys for Solar Cell Interconnection

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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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 lead-free solder ribbon for photovoltaic cells with reduced melting point and improved thermal expansion properties. The ribbon comprises a base layer with a lead-free solder layer, where the solder layer is applied to the base layer surface. This composition enables lower melting point soldering at elevated temperatures (up to 200°C) while maintaining excellent thermal expansion properties compared to traditional lead-based soldering. The lead-free solder layer ensures reliable bonding in ultra-thin photovoltaic cell applications, while the base layer provides a stable substrate surface for cell assembly.

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Sn-Ag-Cu-Bi lead-free solder alloy for electronic packaging applications, comprising a composition of 0.5-1.0 wt.% Bi, with the remainder being Sn-3.0Ag-0.5Cu. The alloy is prepared through a two-step process: smelting and casting of the bulk alloy, followed by solidification molding into a solder alloy. This composition provides improved electromigration resistance compared to traditional Sn-3.0Ag-0.5Cu solder while maintaining the original low melting point.

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Lead-free and antimony-free solder alloys, solder balls, and solder joints with improved mechanical strength and thermal cycle resistance, achieved through a novel composition that balances the constituent elements. The solder alloy composition of Ag: 3.5% by mass, Cu: 0.8% by mass, Bi: 2.0% by mass, Ni: 0.05% by mass, Ge: 0.003% by mass, and a balance of Sn was prepared. This composition achieves a melting point near 230°C and a tensile strength of 50 MPa or more, enabling reliable die bonding and solder joints in high-temperature applications.

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A lead-free solder alloy that provides superior thermal and creep resistance properties for electronic applications, particularly in extreme operating environments. The alloy achieves lower undercooling temperatures compared to traditional tin-lead alloys, resulting in improved microstructural refinement and strengthening mechanisms. This leads to enhanced creep resistance and improved performance under high-temperature conditions. The alloy composition balances the key elements of tin-silver-copper (SAC) with additional elements like bismuth, cobalt, and antimony, while maintaining the necessary tin content for soldering and joining applications.

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Lead-free solder containing 93-98% indium, 1-4% tin, and an addition metal with 0.05-6% total mass, which comprises at least one of silver, antimony, copper, or nickel. The addition metal is added in amounts between 0.05-6% of the total solder composition. This composition enables the production of lead-free solder with excellent electrical conductivity, mechanical properties, and thermal stability, particularly suitable for high-temperature applications.

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Lead-free solder alloy for solar cell substrates and liquid crystal substrates that combines the strength and durability of traditional lead-free solders with improved adhesion properties. The alloy comprises a base of Sn-Zn alloy with trace amounts of P, In, Bi, and Sb, with additional alloying of Al, Si, Cu, Ag, Ni, and glass. The alloy maintains its melting point at lower temperatures compared to conventional lead-free solders, while maintaining excellent solderability and adhesion characteristics. The alloy can be formed into a paste or rod for welding applications, with the paste decomposing to improve adhesion during soldering.

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Lead-free solder alloy that combines superior thermal cycle reliability and drop impact resistance. The alloy contains a balance of tin, copper, and other elements, with specific concentrations of germanium, phosphorus, and gallium. This composition enables reliable bonding in thermal and mechanical stress environments, while maintaining high wetting properties and preventing oxidation. The alloy can be used in semiconductor devices where lead-free soldering is required, particularly in applications where environmental concerns and cost savings are critical.

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A lead-free low-temperature solder alloy for photovoltaic ribbon coatings that combines high mechanical properties with improved wettability and reliability. The alloy contains 35-37% Bi, 1% Ag, 0.5% Ni, and the balance of Sn by weight percentage. The alloy achieves a melting point of 138°C, which is significantly lower than traditional Sn-Pb-based solder alloys. The alloy also exhibits excellent wetting characteristics and mechanical properties, making it suitable for high-temperature photovoltaic applications.

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Lead-free solder alloy for semiconductor devices with enhanced thermal stability, mechanical strength, and surface resistance. The alloy comprises silver (Ag), copper (Cu), bismuth (Bi), nickel (Ni), and tin (Sn) with controlled silver content between 2.8% and 3.5%. The alloy maintains excellent thermal cycling reliability, mechanical properties, and surface resistance even when soldering to complex pads and interfaces.

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A method for joining solar cells through a novel soldering process that addresses common issues associated with traditional soldering techniques. The method employs a modified solder alloy that incorporates metal powders during the molten state, which are then incorporated into the solder upon solidification. This approach eliminates the need for additional powder additions after soldering, eliminating the potential for partial chromatic aberration and improving weld quality.

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A lead-free solder strip for solar photovoltaic cells that enhances soldering performance and reliability through its unique composition. The solder strip comprises Sn-Bi alloy with an added layer of I2, which significantly improves solder wetting properties and reduces brittleness compared to traditional Sn-Pb solder. The I2 layer also enhances the solder's ability to form strong, full-flow joints in solar cells. The composition is achieved by combining Sn-Bi with I2 in a calculated weight ratio, with the added layer applied from the inside of the strip to the surface. This composition provides superior soldering performance, reliability, and durability for solar photovoltaic applications.

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Lead-free eutectic solder alloy containing zinc (Zn) as a main component and aluminum (Al) as an alloy metal. The alloy has a solidus temperature of 320-390°C, achieved through a single melting point. This characteristic enables high-temperature applications like die-attach electronics, where soldering temperatures typically range from 280°C to 400°C. The alloy's unique composition allows for improved thermal stability and reduced thermal expansion compared to traditional lead-containing eutectic solders.

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Pb-free solder alloy with improved wetting performance and environmental sustainability. The alloy contains 4-12% zinc, 0.5-4% bismuth, 0.5-5% indium, 0.005-0.5% phosphorus, 0.001-0.5% zirconium, and 0.001-0.5% silver, with the balance of tin. The composition provides excellent wetting characteristics, high melting point, and environmentally friendly properties.

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A lead-free solder alloy comprising Sn-Cu-Ni-In with improved performance characteristics compared to conventional Sn-Ag-Cu alloys. The alloy comprises 60 wt. % Sn, 20 wt. % Cu, 15 wt. % Ni, and 5 wt. % In, with the addition of Ce, Pr, Nd, Eu, Bi, Ge, and Ag in controlled proportions. The alloy achieves superior oxidation resistance, wettability, and corrosion resistance at elevated temperatures, making it suitable for high-performance electronic packaging applications.

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A lead-free solder alloy composition and manufacturing process that enables reliable performance in high-temperature and vibration environments. The composition comprises Sn-Bi-Cu, Sn-Ag-Bi, or Sn-Ag-Cu alloys with nano-sized ceramic additives. The ceramic additives, such as B, Ti, Al, V, Cr, Mn, Fe, Co, Ni, Zr, Nb, Mo, Y, La, Sn, Si, Ag, Bi, Cu, Au, Mg, Pd, Pt, or Zn, are dispersed in the molten solder alloy. The nano-dispersed ceramic particles enhance mechanical properties, particularly strength and toughness, while maintaining excellent wetting characteristics. This composition and process enable reliable soldering in demanding environments without compromising the solder's performance.

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Lead-free solder alloy composition with enhanced mechanical properties and improved wettability, comprising a lead-free solder alloy containing Sn and a high entropy alloy nanopowder. The composition includes an alloy solder containing Sn and a high entropy alloy nanopowder, with the high entropy alloy nanopowder having an average particle diameter of 10-500 nm.

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Lead-free solder alloy composition and manufacturing process that addresses environmental concerns associated with traditional lead-based solders. The composition comprises a Sn-Sb alloy solder with tungsten nanopowder surface coatings. The surface coatings, which are formed through plasma etching or sputtering, enhance solder wetting and intermetallic compound formation. The coatings are precisely controlled to achieve optimal performance while minimizing processing steps and material waste. The composition is manufactured through a single-step process that combines the solder alloy with the tungsten nanopowder coatings, resulting in a lead-free solder with improved wettability and mechanical properties.

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Lead-free solder alloy composition and manufacturing process that addresses environmental concerns by replacing lead with non-toxic elements while maintaining excellent solderability and mechanical properties. The composition comprises a lead-free solder alloy with a lead-free solder alloy composition and an intermetallic compound additive, which is added to the solder. The intermetallic compound additive, comprising metal nanoparticles, forms irregular microgrooves on the surface of the additive, enhancing bonding strength through increased wetting. The additive is prepared through a controlled process of metal nanoparticle formation using a rotating impeller and a rotating vessel. The resulting solder alloy composition is manufactured through a powder process, where the additive is mixed with the solder powder before forming the solder ball.

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Lead-free solder alloy composition and manufacturing process that enables high-performance, lead-free soldering applications while minimizing environmental impact. The composition comprises a nano-particle additive, which when mixed with the solder alloy, enhances its wetting properties and mechanical properties. The nano-particle additive is specifically designed to promote uniform dispersion and strong intermetallic bonding between the solder metal and the nano-particle matrix. The composition is prepared through a controlled addition of the nano-particle material to the molten solder alloy, followed by processing into a solder alloy that exhibits superior wetting, strength, and ductility characteristics.

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Lead-free solder alloy composition and manufacturing process that addresses environmental concerns associated with traditional lead-based soldering. The composition and process incorporate tungsten nano-powder, which enhances soldering properties while preventing agglomeration. The nano-powder is coated with a metal layer to improve wettability and prevent cracking. The composition is prepared through a combination of nano-powder addition and metal coating, followed by molten solder processing. This approach enables the creation of lead-free solder alloys with superior ductility and toughness, while minimizing environmental risks associated with lead contamination.

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A lead-free solder alloy that suppresses erosion of both the soldering tip and solder bath during manual and dip soldering processes. The alloy composition includes Sn, Cu, V, and/or Fe in specific weight percentages, with the alloy being formulated to contain 0.1-2.0% Cu. The alloy's composition includes 0.001-0.5% V and 0.001-0.1% Fe. The alloy's unique composition, particularly the presence of V and Fe, provides enhanced wear resistance to both the soldering tip and solder bath, significantly improving solder joint reliability and workability.

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Solder composition for joining electronic components that suppresses gas generation during reflow and prevents voids in lead-free soldering applications. The composition contains a silicone oil component, a solder alloy, and a specific non-aqueous defoaming agent. The silicone oil enhances the solder's wetting properties and prevents volatile components in the flux from volatilizing, while the non-aqueous defoaming agent ensures effective removal of gas during reflow. The composition can be used in lead-free soldering applications where conventional fluxes and reflow conditions fail to prevent gas generation and voids.

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A lead-free solder alloy with improved solderability that achieves high solder wetting properties without compromising cost. The alloy contains 0.1-3% Cu, 0.001-0.1% P, 0.001-0.1% Ge, 0.1-4% Sn, and balances to 100%. This composition enables excellent soldering performance in conventional soldering processes, particularly in flow soldering applications, while maintaining the reliability and mechanical properties of lead-free soldering.

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Lead-free solder alloy comprising Sn, Bi, and any unavoidable impurities, with improved thermal stability and oxidation resistance compared to traditional lead-containing alloys. The alloy maintains high ductility and fracture toughness at elevated temperatures, particularly in high-temperature applications like electronics assembly. The alloy composition balances lead-free requirements with the beneficial properties of Bi and other elements.

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A low-silver lead-free solder alloy that combines the brazing and mechanical properties of traditional SnAgCu alloys with reduced silver content. The alloy incorporates trace amounts of nickel, germanium, and cerium to achieve significant silver reduction while maintaining high reliability. This composition enables the development of a low-cost, high-performance lead-free solder system for electronic assemblies.

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A lead-free soldering alloy comprising a Sn-Cu system that enhances the performance of lead-free soldering. The alloy includes a combination of Sn, Cu, and a specific alloying element that enhances the solder's wetting properties, strength, and oxidation resistance. The alloy's unique composition allows for improved wetting characteristics, better intermetallic compound formation, and enhanced post-heat treatment properties compared to conventional lead-free alloys.

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A lead-free solder alloy for photovoltaic welding strips that combines excellent brazing performance with low melting point properties. The alloy comprises Sn, Bi, and Sb with specific mass percentages, where Sb is incorporated to prevent burning during smelting. The composition is optimized to achieve high electrical conductivity, excellent soldering performance, and minimal thermal expansion mismatch between the ribbon and silicon wafer.

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Lead-free solder alloy for photovoltaic welding strips that provides improved brazing performance and reliability compared to traditional lead-based alloys. The alloy combines tin and bismuth to achieve a low melting point of 139°C, enabling efficient brazing of photovoltaic cells while maintaining high strength and thermal stability. The alloy's unique composition enables effective wetting of the copper substrate, forming a strong intermetallic bond during brazing. This leads to improved solder joint strength and thermal resistance, particularly during high-temperature welding processes. The alloy's low melting point also enables the use of conventional brazing techniques, eliminating the need for specialized equipment.

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Tin-zinc-based lead-free solder alloy for photovoltaic welding strips that offers improved electrical conductivity and soldering performance compared to traditional lead-based solders. The alloy contains zinc (3-9%), bismuth (1-5%), germanium (0.1-1%), cerium (0.1-1%), and tin (100%), with a composition that balances electrical conductivity, low melting point, and excellent soldering characteristics. The alloy enables reliable and efficient photovoltaic welding, particularly suitable for solar cell modules where precise thermal expansion matching is critical.

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A lead-free solder alloy with improved workability and fatigue resistance, developed through the optimization of a previously known lead-free soldering alloy. The alloy achieves superior soldering characteristics in low-temperature regions without adding lead, while maintaining high soldering performance and fatigue properties. The alloy's unique composition enables excellent flowability, dimensional stability, and mechanical properties at temperatures below 200°C, making it suitable for applications requiring low-temperature soldering.

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A solar cell solder that enables reliable and high-temperature soldering of solar cells. The solder comprises a solder alloy with a specific composition that provides optimal thermal conductivity and mechanical properties for high-temperature soldering applications. The solder alloy is formulated to achieve a balance between thermal conductivity, electrical conductivity, and mechanical strength, enabling reliable soldering of solar cells at elevated temperatures.

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A lead-free, antimony-free solder alloy comprising at least 74 wt. % tin, with a liquidus temperature of 210°C or less, and containing 0.05-0.25 wt. % nickel and the balance tin. This alloy achieves superior mechanical and thermal properties compared to conventional lead-based solder alloys while maintaining high solder wetting characteristics.

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A low-temperature alloy solder for photovoltaic cell welding that achieves improved electrical conductivity, tensile strength, and oxidation resistance. The solder composition is optimized to meet the requirements of solar cell welding without traditional lead-tin solder, enabling reliable ohmic contact between battery components and copper wires. The solder composition balances electrical conductivity, mechanical properties, and thermal stability, making it suitable for both traditional and solderless welding processes in solar cell manufacturing.

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Solder alloy and composition to prevent darkening of solder joints after soldering, particularly in lead-free soldering applications. The alloy contains a combination of Sn, Bi, and metals like Co or Ag. The alloy's unique composition enables effective suppression of oxidation and darkening of the solder joint, even when soldering with low halogen fluxes.

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A method for creating high-performance interconnections between solar cells in solar panels by incorporating platinum into a lead-free solder paste. The method involves adding platinum to a tin-silver-copper solder paste, which is then applied to the solar cell's busbars. The platinum-reinforced solder paste is then applied to the solar cell's metallic ribbons, and the solder paste is heated to form a strong, reliable interconnection. This approach addresses conventional soldering issues in solar cells by introducing a non-lead, non-toxic, and high-temperature-resistant soldering solution that enhances interconnection reliability and reduces electrical resistance.

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A lead-free solder alloy for electronic components that combines improved thermal stability with enhanced crack suppression properties. The alloy comprises Ag, Cu, and Sb in a composition range of 1-4 wt%, with additional Ni and Co content. The alloy exhibits superior thermal resistance and crack suppression capabilities compared to conventional lead-free solder alloys, particularly under extreme temperature and vibration conditions.

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Lead-free eutectic solder alloy comprising zinc (Zn) as the main component and aluminum (Al) as an alloying metal. The alloy has a eutectic temperature between 320 and 390 °C, measured by Differential Scanning Calorimetry (DSC) at a heating rate of 5 °C min-1.

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Lead-free eutectic solder alloy comprising zinc (Zn) as the main component and aluminum (Al) as an alloying metal. The alloy has a eutectic temperature of 320-390 °C measured by differential scanning calorimetry (DSC) at a heating rate of 5 °C min-1.

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A lead-free solder alloy and solder paste for electronic devices that achieves high strength, fatigue resistance, and void suppression. The solder alloy contains tin, silver, copper, bismuth, nickel, and cobalt, with specific composition limits. The solder paste is formulated with this alloy and is used for joining electronic components. The solder paste enables reliable solder joints in devices where lead-free requirements are critical, while maintaining excellent mechanical properties, thermal fatigue resistance, and void suppression.

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A lead-free soldering alloy, solder material, and joining structure object that enables precise control of electro migration in solder joints. The alloy, solder material, and joining structure object are designed to minimize the generation of high-density current and electron migration in soldered joints, particularly in very small solder joints. The alloy and solder material contain elements that suppress the migration phenomenon, while the joining structure object features a unique design that enables precise control over the soldering process. The design incorporates features such as precisely controlled current paths, optimized joint geometry, and enhanced soldering parameters that prevent excessive current flow and electron migration.

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A lead-free tin-silver alloy plating layer composition for soldering applications, particularly in solar cells, that significantly improves electrical conductivity while maintaining cost-effectiveness. The composition comprises 16-40% zinc, 0.1-1% silver, 0.01-0.3% aluminum, 0.001-0.01% phosphorus, 0.001-0.5% bismuth, and the balance tin. This composition enables excellent solderability and conductivity while reducing manufacturing costs compared to traditional lead-based soldering systems.

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A lead-free solder containing cerium and cesium, with a melting point below 100°C, is achieved through a novel preparation method that replaces traditional lead with these elements. The cerium-cesium alloy enhances solder ductility and reduces melting point compared to traditional lead-tin alloys. The preparation method involves the controlled addition of cesium and cerium to a zinc-tin alloy, resulting in a lead-free solder with improved performance characteristics.

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Environmentally friendly lead-free solder with improved performance and cost-effectiveness. The solder composition combines lanthanum, zinc, and cesium in a tin-based alloy, achieving a melting point below 200°C while maintaining excellent ductility and mechanical properties. The lanthanum content enhances solder ductility, while cesium improves lead-free solder performance. The composition can be formulated to meet industry standards for lead-free soldering materials, with the lanthanum content ranging from 0.05% to 5%.

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A lead-free soldering alloy that combines excellent welding performance, environmental protection, and low-cost production while avoiding the drawbacks of lead-based solders. The alloy comprises lanthanum, zinc, and tin with specific composition percentages, specifically 0.05-10% lanthanum, 0.05-10% zinc, and the remaining percentage consisting of tin. This composition range results in a solder with improved ductility, reduced melting point, and enhanced weldability compared to traditional lead-free solders. The alloy is suitable for welding applications requiring environmental protection and low-cost production.

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A lead-free solder material that combines the benefits of praseodymium-doped zinc-tin alloys with improved welding performance and environmental sustainability. The solder composition includes praseodymium (Pr), cesium (Cs), zinc (Zn), and tin (Sn), with specific percentages ranging from 0.2% to 10% Pr and Cs. This composition maintains the solder's ductility and melting point while eliminating lead, making it suitable for welding applications without compromising health or environmental standards. The solder's composition and preparation method enable low-cost production while achieving superior performance compared to existing lead-free alternatives.

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Cerium-zinc lead-free solder with improved welding performance and environmental properties. The solder contains cerium, zinc, tin, and rubidium, with specific composition ranges that balance strength, ductility, and melting point. The composition enables lead-free solder that meets stringent environmental standards while maintaining reliable welding performance and mechanical properties. The cerium content enhances solder ductility and reduces melting point compared to traditional lead-free solders. The composition also meets the requirement of lead content below 0.1%. The solder is prepared through a controlled addition of cerium and zinc to the lead-free alloy, eliminating the need for lead elements.

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Lead-free solder for wave soldering and PCB assembly applications that offers superior oxidation resistance and thermal stability compared to conventional lead-free alloys. The solder comprises a copper-tin binary alloy, a nickel-tin binary alloy, and a tin-silver binary alloy. The alloy is produced through a single-step manufacturing process that eliminates the need for complex eutectic alloy processing. The resulting solder has excellent oxidation resistance properties, enabling reliable soldering of sensitive electronic components, and superior thermal stability, ensuring reliable performance in high-temperature environments.

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