Indexed by:期刊论文
Date of Publication:2014-10-01
Journal:JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
Included Journals:SCIE、EI
Volume:25
Issue:10
Page Number:4538-4546
ISSN No.:0957-4522
Abstract:The growth behavior of Cu6Sn5 intermetallic compounds in rare earth (RE)-doped Sn-Cu solder alloys with an applied direct current (DC) has been in situ investigated using synchrotron radiation imaging technology. The morphological evolutions of Cu6Sn5 with various shapes of I-like, Y-like and bird-like are directly observed. After doping RE, the number of I-like and bird-like Cu6Sn5 is decreased, but the number of Y-like Cu6Sn5 is increased. The morphologies of Cu6Sn5 are more uniform and the mean lengths of Cu6Sn5 of different shapes are reduced in RE-doped alloys compared with that in RE-free alloys, which is attributed to the adsorption effect of RE. The growth orientation of Y-like Cu6Sn5 is changed after La is doped. Additionally, with an applied DC, the nucleation rate of Cu6Sn5 is increased and the growth rate is markedly enhanced resulting in the refinement of Cu6Sn5. Furthermore, the mechanisms of refinement caused by RE and DC are specifically discussed.