Studies on solder self-alignment

Solder technologies are being used for precision-aligned optoelectronic assemblies. Two representative configurations for such assemblies are shown in this paper. In the first the assembly's component well is aligned to the substrate by the solder surface tension force. The second involves the use of mechanical stops that are pushed or pulled against each other by misaligned solder joints. The accuracies required for lateral alignments are in the range from 1 to 10 /spl mu/m. Our research studies are aimed at engineering soldering techniques for precision alignments by developing 1) CAD tools for solder designs and 2) CAM tools to optimize and control solder and process parameters for a fluxless soldering process.