Lead-free and halogen-free solder paste

Abstract

The present application relates to the technical field of welding materials, and particularly to a lead-free and halogen-free solder paste, including a solder alloy powder and a welding flux with a mass ratio of 85-90:10-15, the solder alloy powder is Sn-2.5Be-0.8Ag-0.5Cu alloy powder, and the welding flux includes the following components: itaconic acid, succinic acid, a surfactant, a thixotropic agent, modified rosin, a composite solvent, a corrosion inhibitor, and an acrylic type activator. Its preparation method includes the following steps: mixing the modified rosin, the composite solvent and the corrosion inhibitor, heating under stirring, cooling, adding itaconic acid, succinic acid and the acrylic type activator under stirring, cooling, adding the thixotropic agent for emulsification dispersion, adding the surfactant under stirring, grinding to obtain a welding flux after cooling, and stirring the solder alloy powder and the welding flux under vacuum to obtain the solder paste.

Dependencies are inferred from the claim text.