| 摘要 |
A simple yet highly reliable technique for ejecting a droplet of heated solder, or other liquid conductive material, is described. Small droplets of an electrically-conductive liquid are ejected on-demand from a drop generator (100) operating on a magnetohydrodynamic principle. The drop generator (100) consists of two substantially parallel conductive paths (14, 16) separated by a thin electrically-insulating material (18). A channel (12) for the conductive liquid contains a drop ejecting orifice (20), and the conductive liquid in the channel forms a first (16) of these two parallel conductive paths. The other path (14) is either a solid conductor or a second channel filled with the conductive liquid. A current on the order of 10-1000 amperes is pulsed through the two parallel conductive paths, and the interaction of the magnetic fields generated by the electric currents through the parallel paths with these currents forces a droplet (24) of the conductive liquid through the orifice (20) in the first channel (16). By adjusting the duration and/or magnitude of the pulsed current, the droplet size may be carefully controlled. In the preferred embodiment, the drop generator (100) is in the form of a self-contained replaceable cartridge. |
