| abstract |
The invention describes a process for producing solder humps on one or more predetermined solderable or non-solderable regions of a surface, especially electrical connection surfaces, in which solder material for the humps to be made is applied in the immediate vicinity of the surface regions to be provided with solder humps, said solder material is melted by high-energy radiation in one or more spatially limited regions and the solder material melted at a spatially limited region and contracted into a solder bead wets a predetermined surface region, whereby a solder hump is formed, the shape of which is particularly suitable for making a soldered connection. The process of the invention can in particular be used in the same manner to provide non-solderable or difficultly solderable layers with a solderable coating on which the solder layer can be applied. According to the invention, preparing the solder material for a solder hump and melting it takes place in a single step, i.e. by melting the solder material in the laser beam and forming a solder bead. It is thus possible to make accurately shaped, extremely uniform solder humps rapidly and in selected locations. The selectivity of the process of the invention ensures that the temperature stress on neighbouring components or the substrates is comparatively very low. |