Motivated by the increasing use of Sn-3.0Ag-0.5Cu (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.

归因于在海洋大气环境中工作的电子产品中Sn-3.0Ag-0.5Cu（SAC305）焊料的日益使用以及Ag- ₃ Sn和Cu ₆ Sn ₅金属间化合物（IMC）在β- Sn基体中的不均匀分布。已设计了类似的电极用于原位EIS测量，以研究在高温高湿的模拟海洋环境中SAC305焊料的微观结构引起的电化腐蚀演变。结果表明，通过梳状电极进行现场EIS测量是研究SAC305焊料腐蚀行为的有效方法。此外，Ag ₃ Sn IMC与β之间的电化作用尽管存在腐蚀产物层，但随着暴露时间的延长，-Sn基体会加剧原样和炉冷的SAC305焊料的腐蚀。优先在较大的Ag ₃ Sn晶粒尺寸的炉冷SAC305上发现点蚀。此外，Sn ₃ O（OH）₂ Cl ₂在相变过程中产生的内应力作为中间产物，可能会在局部酸化位置放出氢气，这是造成松散，多孔，破裂和不粘附的腐蚀产物层的原因。这些发现清楚地证明了SAC305焊料的腐蚀加速行为和机理，并为维护微电子器件提供了潜在的指导方针，以确保安全操作和延长使用寿命。