Silver nanowire modified tin-silver-copper composite soldering paste and preparation method thereof

The invention relates to silver nanowire modified tin-silver-copper composite soldering paste and a preparation method thereof, and belongs to the technical field of welding. The silver nanowire modified tin-silver-copper composite soldering paste is composed of, by mass, 0.1%-0.4% of silver nanowires, 10%-20% of soldering flux and the balance Sn < 3.0 > Ag < 0.5 > Cu lead-free soldering flux, the silver nanowires account for 0.1%-0.4%, the soldering flux accounts for 10%-20%, and the Sn < 3.0 > Ag < 0.5 > Cu lead-free soldering flux accounts for 10%-20%. The soldering flux is composed of, by mass, 15%-20% of an active agent, 30%-35% of a film-forming agent, 1%-3% of a thixotropic agent, 1%-2% of a conditioning agent, 2%-3.5% of a surface active agent, 0.5%-1.5% of a corrosion inhibitor and a solvent. According to the method, the tin-silver-copper composite soldering paste is modified through the silver nanowires, the microstructure of a welding spot is refined, and the performance of the solder alloy is grea