Authors: Jim Kenny, Nils Arendt, Bernhard Wessling, and Karl Wengenroth Company: Enthone Inc., A Business of Cookson Electronics Date Published: 10/4/2009
Abstract: With the international implementation of lead-free technologies/processes use of Immersion Tin usage as a PWB final finish is expected to grow substantially in the near future. With the world-wide growing demand for Immersion Tin, the demands towards the product and process technology consequently increase significantly. Market leading OEMs require the surface finish to have higher tin thickness, improved solderability at multiple heat cycles and higher temperatures, perfect surface flatness, fine pitch compatibility, etc. Modern Immersion Tin technology can serve such requirements and has proven over several years its superior product and process advantages at market leading PCB manufacturers. New technology using unique Organic Metal technology in the immersion tin process allows for thinner tin coatings without sacrificing performance. The catalyst and passivation effect of the Organic Metal leads to a large grain size with a low affinity for oxidation or whiskers and high process reliability. The ability of a thin immersion tin to achieve comparable performance to thick immersion tin results in significant improvements in process costs, yields and environmental impact.
Key words: immersion tin, Organic Metal, surface finishes, thin tin