Method and appts. for production of solder bumps

摘要

The method concerns production of solder bumps on one or several regions of a surface, in particular, electric contact surfaces, according to which solder material is brought into the required locations and melted by high-energy radiation. The method is characterised by the fact that the molten solder,while contracting into a globule as a result of its surface tension, wets a predetermined surface region and produces a bump whose shape is particularly suited for a soldered connection. The appts. includes a source of high-energy radiation, and solder material located in the immediate vicinity of the appropriate surface regions. The solder material is arranged so that a given surface region is wetted when the material is melted by radiation. The solder material is applied in the form of a fine-grained solder paste forming a layer with a thickness of 100-1000 mu m. The appts. includes means for forming a beam of high-energy radiation, as well as means for positioning and/or deflection of the beam. The energy source is laser, in particular, a Nd:YAG laser.