The flux composition probably by the Protecting agent - rosin, modified resin Activators - organic acids, organic salts The diffusing agent - surfactant Solvent - the high-boiling solvent Additives - matting agent, corrosion inhibitor composition Effect Removing oxide - active agents, such as organic acids Reduce the surface tension - organic acids, organic salts Auxiliary heat conduction - to prevent the local temperature is too large To the oil to increase the welding area - an organic solvent, a surface active agent - Rosin-type, high film-forming substances prevent reoxidation