METHOD OF DISPENSING MOLTEN SOLDER IN DROPS OF INCREASED STABILITY AND DEVICE FOR INCREASING STABILITY OF SOLDER DROPS

摘要

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.