Ion migration and corrosion behavior in Ag-4Pd alloy wires with fine and coarse grains in the outer regions were evaluated with water drop tests. The results from the in situ observations and measurements of Ag ion migration in both Ag-4Pd bonding wires indicated that the fine-grained wire had much shorter times of dendrite contact and short circuit than those of coarse-grained wire for various wire spaces. It was obvious that grain refinement in Ag-4Pd alloy wires accelerated the ion migration of Ag-4Pd alloy wires. Electrochemical polarization tests confirmed that the passive film on fine-grained Ag-4Pd wire was easily broken down, leading to a higher Ag dissolution tendency than that of coarse-grained wire. Although an annealing twin-rich Ag-4Pd alloy wire was shown to enhance the thermal stability of the grain structure and mechanical properties, the large number of twins had no influence on the formation of Ag dendrites on the cathode and Ag₂O oxide on the anode of the coarse-grained Ag-4Pd wire couple during ion migration.

通过水滴试验评估了在外部区域具有细晶粒和粗晶粒的 Ag-4Pd 合金线中的离子迁移和腐蚀行为。两种 Ag-4Pd 键合线中 Ag 离子迁移的原位观察和测量结果表明，对于各种线间距，细晶粒线的枝晶接触和短路时间比粗晶粒线短得多。很明显，Ag-4Pd 合金线的晶粒细化加速了 Ag-4Pd 合金线的离子迁移。电化学极化测试证实，细晶粒Ag-4Pd线上的钝化膜很容易被破坏，导致比粗晶粒线更高的Ag溶解趋势。离子迁移过程中粗粒 Ag-4Pd 线对阳极上的₂ O 氧化物。