The invention provides a preformed
soldering terminal with
halogen-free
soldering fluxes coated on the surfaces, and the performed
soldering terminal is good in soldering performance, and the quantity of the soldering fluxes can be controlled easily. A soldering flux
coating is formed by the method that the preformed soldering terminal is wetted by
halogen-free liquid soldering fluxes and then dried, the
halogen-free liquid soldering fluxes are composed of the following components by weight: 35-42% of carrier, 1.0-1.4% of surface
wetting agent, 0.5-1.2% of leveling agent, 0.3-0.5% of
active agent, 0.1-1.0% of resin film-forming agent, 0.15-1.2% of
thickening agent, and the balance is organic solvents. The carrier is
rosin, the surface
wetting agent is T-80, TX-100 and Span60, the leveling agent is OP-10, the
active agent is
oxalic acid,
salicylic acid and
malic acid, the resin film-forming agent is
polybutadiene and
polyurethane, the
thickening agent is hydrogenated
castor oil, and the
organic solvent is
alcohol or
ketone which is lower than 110 DEG C in
boiling point. The weight of the preformed soldering terminal with the halogen-free soldering fluxes coated on the surfaces is regarded as a standard, the content of the soldering flux
coating is 0.2-5.0%, and the preformed soldering terminal with the halogen-free soldering fluxes coated on the surfaces is suitable for soldering of packaging of electronic components.