Abstract We investigated the effect of Ag-coated multi-walled carbon nanotubes (Ag-MWCNT) on the microstructures and electromigration behaviors of a Sn58%Bi solder and organic solderability preservative (OSP) surface finished on the FR-4 printed circuit board (PCB) joint under a current stress of 3000 A/cm2 at 100 °C. Electromigration of Ag-MWCNT Sn58%Bi composite solder was investigated by daisy-chain test-kit. Reaction layers formed at the anode side and cathode side of the Sn58%Bi solder joints consisted of three microstructures; Bi-rich layer, Sn-rich layer, and intermetallic compounds (IMCs, Cu6Sn5 and Cu3Sn). The Bi-rich layer was mainly formed at the anode side in the couple of the Sn58%Bi solder joint with various times of applying current stress. The Bi-rich layer of the Ag-MWCNT Sn58%Bi composite solder joint was approximately 2 times thinner than that of the Sn58%Bi solder joint because the Ag-MWCNT acts as a diffusion barrier. Also, the Cu6Sn5 and Cu3Sn IMCs that formed at the interface between the Ag-MWCNT Sn58%Bi composite solder joints were thinner than those of the Sn58%Bi solder joints. The time to failure (TTF) was longest at the 0.05% Ag-MWCNT Sn58%Bi composite solder joint. Therefore, Ag MWCNT is expected to improve the reliability of electromigration in the Sn58%Bi composite solder joint.

中文翻译：

---

含银涂层多壁碳纳米管与 OSP 表面处理 PCB 的 Sn58%Bi 焊料的电迁移行为

摘要 我们研究了镀银多壁碳纳米管 (Ag-MWCNT) 对 FR-4 印刷电路板 (PCB) 表面处理的 Sn58%Bi 焊料和有机可焊性防腐剂 (OSP) 的微观结构和电迁移行为的影响。 ) 接头在 3000 A/cm2 电流应力下 100 °C。通过菊花链测试套件研究了 Ag-MWCNT Sn58%Bi 复合焊料的电迁移。在Sn58%Bi焊点的阳极侧和阴极侧形成的反应层由三种微结构组成；富铋层、富锡层和金属间化合物（IMC、Cu6Sn5 和 Cu3Sn）。富铋层主要形成在 Sn58%Bi 焊点的阳极侧，在不同时间施加电流应力的情况下。Ag-MWCNT Sn58%Bi 复合焊点的富铋层比 Sn58%Bi 焊点的富铋层薄约 2 倍，因为 Ag-MWCNT 充当扩散屏障。此外，在 Ag-MWCNT Sn58%Bi 复合焊点之间的界面处形成的 Cu6Sn5 和 Cu3Sn IMC 比 Sn58%Bi 焊点更薄。失效时间 (TTF) 在 0.05% Ag-MWCNT Sn58%Bi 复合焊点处最长。因此，Ag MWCNT 有望提高 Sn58%Bi 复合焊点中电迁移的可靠性。失效时间 (TTF) 在 0.05% Ag-MWCNT Sn58%Bi 复合焊点处最长。因此，Ag MWCNT 有望提高 Sn58%Bi 复合焊点中电迁移的可靠性。失效时间 (TTF) 在 0.05% Ag-MWCNT Sn58%Bi 复合焊点处最长。因此，Ag MWCNT 有望提高 Sn58%Bi 复合焊点中电迁移的可靠性。