| About this Abstract |
| Meeting |
2024 TMS Annual Meeting & Exhibition
|
| Symposium
|
Electronic Packaging and Interconnection Materials
|
| Presentation Title |
Surface Precipitation and Growth Mechanisms of Bismuth Particles in Sn-Bi Solder |
| Author(s) |
John Wu, Amey Luktuke, Nikhilesh Chawla |
| On-Site Speaker (Planned) |
John Wu |
| Abstract Scope |
Bismuth is commonly used as an alloying addition to Pb-free solders to lower the solder alloy’s melting temperature and improve the joint strength. Our previous work on Sn7Bi has shown that with small concentrations of Bi, precipitation is driven by surface diffusion, and that bismuth particles will gather at the exposed surface. We have continued this work on binary Sn-7Bi to investigate the precise mechanisms of precipitation of the Bi particles. In this talk we report on a systematic observation of surface precipitation in Sn-7Bi solder alloy. Grain properties were first characterized with EBSD and EDS, followed with time-resolved imaging, using scanning electron microscopy. In particular, Bi precipitates along grain boundaries, at Cu6Sn5 particles or within individual grains. The nature of mechanisms associated with precipitation at these locations will be discussed. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Electronic Materials, Characterization, Solidification |