Characterisation of tin‒copper intermetallic growth in electrodeposited tin coatings using electrochemical oxidation techniques

摘要

In the present investigations electrochemical oxidation has allowed for the removal of tin from coatedcopper substrates permitting scanning electron microscopy to be employed to assess intermetalliccompound distribution and morphology. It was shown that the initial growth of intermetallic compoundwas not uniform, with its distribution dependent upon the grain structure of the copper substrate, andthe grain orientation and distribution within the tin coating. After a period of further nucleation andcoarsening, the intermetallic compound forms an almost complete layer along the interface. It isthought this uniform layer of intermetallic compound, formed soon after deposition, which may be responsiblefor this specific electrodeposited tin system having a low whiskering propensity.