Abstract: A method and system for introducing flux onto at least one surface of a solder pump achieve their objects as follows. A solder pump nozzle is submerged into a flux reservoir. In response to such submersion, the flux in the reservoir is actively introduced into the solder pump nozzle. In one embodiment, the active introduction is achieved by creating a negative pressure in a solder pump nozzle such that flux fills a vacated volume. The created negative pressure is produced by moving a solder column, contained within the solder pump nozzle, under the influence of an applied electric current and an applied magnetic field.

Abstract: The size and shape of molten solder droplets ejected from a nozzle of a droplet pump are stabilized using flux transported into the aperture region of the nozzle through which the droplets are ejected. The flux is periodically replenished as necessary to remove solder oxides and dross, as well as to lubricate the aperture. The flux may be deposited by spraying onto the nozzle, submersion of the nozzle, contact of the nozzle to a flux film, contact of the nozzle with an intermediate transfer medium, or through injection internal to the nozzle assembly. Fluxes exhibiting high activity and high thermal stability at elevated temperatures are preferred.