Annealing to Reduce Ozidation of Solder Powder during Storage
Solder powders form the basis of the mixtures of solder and flux that are reflowed to produce the electrically conductive bonds joining components to a printed circuit board in the manufacture of electronic circuits. To be effective soldering agents, the powders must be protected from oxidation. This is especially important for fine solder powders with a high ratio of surface area to volume. Gas atomisation can produce solder powders with very low levels of oxide contamination, but these powders can degrade in storage. Earlier published reports have suggested that annealing lead/tin solder powder in a hydrogen atmosphere could reduce the subsequent oxidation rate during storage. In the work reported here, we set out to discover whether applying the same process to tin/silver/copper solder powders would produce a similar result. We also wanted to explore the role of hydrogen in the annealing process. Because there wasnt enough oxide in our solder samples, weight changes were unable to confirm any benefits from hydrogen in reducing oxides, although surface oxide measurements suggested a slight oxide reduction. Hydrogen annealing seems to make matters worse as the solder oxidised more rapidly when stored and more oxide was produced than for untreated powder. Annealing in nitrogen, however, provides an improvement over untreated powder with less oxide being formed during storage.
solder annealing hydrogen nitrogen ozidation storage
Paul Stratton Michael Graf Edward Feng
Linde Gas,Sheffield,UK Linde Gas,Unterschleissheim,Germany Linde Gas,Shanghai,China
国际会议
The Fourth Asian Conference on Heat Treatment and Surface Engineering(第四届亚洲热处理及表面工程大会)
北京
英文
277-280
2009-10-27（万方平台首次上网日期，不代表论文的发表时间）