Compared with traditional copper alloy welding wires, welding rings, and welding strips,Copper solder pastethe combination with automatic dispensing equipment can automatically coat complex and irregular parts. The coated parts enter a continuous brazing furnace for brazing, achieving continuity and automation in the entire welding process. The joint strength of the welded parts is high, the weld seam is beautiful, and the corrosion resistance is good. However, the current copper solder paste has a high flux content, and fluoroborate is highly corrosive at high temperatures, which can cause excessive corrosion and damage to the welding area and brazing equipment. Parts need to be cleaned after welding, and the corrosive volatile substances during the welding process can bring a series of problems to the working environment and environmental protection.

Technical points: Technicians provide aCopper solder pastepreparation method, where the copper solder paste obtained by this method contains a small amount of flux, has significantly low corrosion on parts, low melting point, easy assembly, good fluidity, and strong bonding strength of the parts after welding, with minimal environmental harm. To achieve the above objectives, the preparation method of this copper solder paste adopts the following technical scheme: a copper solder paste includes the following weight parts of components: solder 70-85 parts, paste 15-22 parts, flux 5-8 parts, where the solder consists of 94-96% by weight tin, 3-4% by weight silver, and 1-1% by weight copper. The flux is selected from at least one of sebacic acid, succinic acid, and lauric acid; the paste includes the following weight percentages of components: polyethylene propylene 14-16%, solvent 65-95%, non-ionic surfactant 2-3%, activator 0.8-1.1%. The solder consists of 95% by weight tin, 4% by weight silver, and 1% by weight copper. The paste contains the following components: 15% by weight polyethylene propylene, 81% by weight solvent, 3% by weight non-ionic surfactant, and 1% by weight activator. The solvent is diethylene glycol monoethyl ether or propylene glycol monoethyl ether; the non-ionic surfactant is glycerol fatty acid ester; the activator is unsaturated fatty acid and/or animal oil. This copper solder paste includes the following weight parts of components: solder 75 parts, paste 18 parts, flux 7 parts. The preparation method for making copper solder paste includes the following steps: 1. Weigh each component in appropriate proportions from solder and paste; then melt each component in weighed paste and flux separately into paste and flux respectively; then weigh each component in appropriate proportions; 2. Add the weighed flux and solder to the paste and stir for 30-45 minutes until evenly mixed to obtain copper solder paste.

The advantages of the above preparation method are: using a small amount of flux that does not contain fluorinated substances; all organic materials are used which significantly reduce corrosion on parts; solder made from specific ratios of tin, silver, and copper results in low melting point for easy welding; additionally, unsaturated fatty acids and animal oils are added as activators during the preparation process of copper solder paste which greatly increases the bonding strength between flux and organic part surfaces, facilitating anti-peeling layers and over-tube for automated large-scale production providing technical assurance; by controlling parameters in the preparation method, the produced copper solder paste has better performance.Copper solder paste制备方法的优点是：使用少量的钎剂，使用的钎剂不含含氟物质，全部使用有机物质，对零件的腐蚀明显较低;焊料由特定比例的锡、银和铜制成，所得铜焊膏熔点低，易于焊接;此外，在铜焊膏的制备过程中加入了不饱和脂肪酸、动物油等活化剂，大大增加了钎料与有机零件表面的结合力，有利于铜焊膏的防脱层和过管，为自动化、规模化生产提供了技术保障;通过控制制备方法中的参数，制备的铜焊膏具有更好的性能。