Halogen-free solder paste and preparation method thereof

The invention provides a halogen-free solder paste and a preparation method thereof. The halogen-free solder paste is mainly used for preparing tin-based alloy solder paste. The solder paste comprises the following components by weight: 30 to 60 percent of rosin and/or rosin derivative, 2 to 20 percent of active agent, 3 to 12 percent of thixotropic agent, 0.3 to 2 percent high-efficient surfactant, 0.1 to 1.5 percent of corrosion inhibitor, and 30 to 60 percent of solvent, the sum of the portions of the above components is 100%. The solder paste is free of halogen, and a low-temperature emulsion and dispersion technology is carried out to the active agent during preparation process, thus realizing high activity and stability; the produced solder paste has high wettability, and can achieve the same welding effect as the effect of the halogen-containing product; after the welding is finished, the residue is more stable, and the reliability of the product is higher.