There are a set of flux soaking tanks at AB side of the equipment, and the bottom of the tank has auxiliary heating function, which can quickly concentrate the flux. The solder wire is coated on the surface through the flux bath. The flux in the bath is replenished by the flux tank in the cabinet, and a liquid level meter is installed in the replenishment tank, which can realize the alarm of the lower limit and remind to add flux. The capacity of the flux tank is 8L. Flux tank, pipeline and nozzle have anti-corrosion treatment.