About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
|
Phase Stability, Phase Transformations, and Reactive Phase Formation in Electronic Materials XXV
|
| Presentation Title |
Bismuth-Induced Microstructural and Property Changes in Eutectic Sn-Zn Alloy for Soldering Application |
| Author(s) |
Yu-An Shen, Hao-Zhe Kao |
| On-Site Speaker (Planned) |
Yu-An Shen |
| Abstract Scope |
Minor additions of Bi to eutectic Sn-9Zn alloy were investigated to improve its performance for soldering applications. Bi effectively refined the microstructure, enhanced tensile strength, and improved wettability on Cu substrates. The 3 wt% Bi alloy exhibited a reduced melting point of 187.9 °C and demonstrated significant aging-induced strengthening due to Bi redistribution and formation of a supersaturated solid solution. Reliable soldering to Cu was achieved at 210 °C, lower than the typical reflow temperature for Sn-3.5Ag, and interfacial intermetallic compound (Cu-Zn IMC) growth was significantly suppressed during the soldering. The improved alloy strength contributed to enhanced joint reliability. These findings highlight the promise of Bi-modified Sn-Zn solders for lead-free electronic packaging. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Joining, Phase Transformations, Mechanical Properties |