Abstract: A controlled amount of flux is applied to a circuit board (10) by first directing liquid flux through a nozzle (54) containing means for disintegrating the flux into a very fine fog of tiny flux droplets (62). The fog of flux droplets is injected into a laminar gas stream (52), thereby creating a laminar flux stream which is directed at the circuit board to coat the board with flux. As the flux spray is being directed at the circuit board, the concentration of flux solids on the board is being regulated, typically by controlling the rate of flux pumped into the nozzle.