Microstructure induced galvanic corrosion evolution of SAC305 solder alloys in simulated marine atmosphere
来源期刊：JOURNAL OF MATERIALS SCIENCE TECHNOLOG2020年第16期
论文作者：Mingna Wang Chuang Qiao Xiaolin Jiang Long Hao Xiahe Liu
文章页码：40 - 53
摘 要：Motivated by the increasing use of Sn-3.0 Ag-0.5 Cu（SAC305） solder in electronics worked in marine atmospheric environment and the uneven distribution of Ag3Sn and Cu6Sn5 intermetallic compounds（IMCs） in β-Sn matrix, comb-like electrodes have been designed for in-situ EIS measurements to study the microstructure induced galvanic corrosion evolution of SAC305 solder in simulated marine atmosphere with high-temperature and high-humidity. Results indicate that in-situ EIS measurement by comb-like electrodes is an effective method for corrosion evolution behavior study of SAC305 solder. Besides, the galvanic effect between Ag3Sn IMCs and β-Sn matrix can aggravate the corrosion of both as-received and furnace-cooled SAC305 solder as the exposure time proceeds in spite of the presence of corrosion product layer. Pitting corrosion can be preferentially found on furnace-cooled SAC305 with larger Ag3Sn grain size. Moreover, the generated inner stress during phases transformation process with Sn3O（OH）2Cl2 as an intermediate and the possible hydrogen evolution at local acidified sites are supposed to be responsible for the loose, porous, cracked, and non-adherent corrosion product layer. These findings clearly demonstrate the corrosion acceleration behavior and mechanism of SAC305 solder, and provide potential guidelines on maintenance of microelectronic devices for safe operation and longer in-service duration.
Mingna Wang1，Chuang Qiao2,3，Xiaolin Jiang2，Long Hao3,4，Xiahe Liu2
1. Department of Physics, Hebei Normal University of Science & Technology2. School of Metallurgy, Northeastern University3. Environmental Corrosion Centre of Materials, Institute of Metal Research, Chinese Academy of Sciences4. School of Material Science and Engineering, University of Science and Technology of China
摘 要：Motivated by the increasing use of Sn-3.0 Ag-0.5 Cu（SAC305） solder in electronics worked in marine atmospheric environment and the uneven distribution of Ag3Sn and Cu6Sn5 intermetallic compounds（IMCs） in β-Sn matrix, comb-like electrodes have been designed for in-situ EIS measurements to study the microstructure induced galvanic corrosion evolution of SAC305 solder in simulated marine atmosphere with high-temperature and high-humidity. Results indicate that in-situ EIS measurement by comb-like electrodes is an effective method for corrosion evolution behavior study of SAC305 solder. Besides, the galvanic effect between Ag3Sn IMCs and β-Sn matrix can aggravate the corrosion of both as-received and furnace-cooled SAC305 solder as the exposure time proceeds in spite of the presence of corrosion product layer. Pitting corrosion can be preferentially found on furnace-cooled SAC305 with larger Ag3Sn grain size. Moreover, the generated inner stress during phases transformation process with Sn3O（OH）2Cl2 as an intermediate and the possible hydrogen evolution at local acidified sites are supposed to be responsible for the loose, porous, cracked, and non-adherent corrosion product layer. These findings clearly demonstrate the corrosion acceleration behavior and mechanism of SAC305 solder, and provide potential guidelines on maintenance of microelectronic devices for safe operation and longer in-service duration.
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