About this Abstract |
Meeting |
2021 TMS Annual Meeting & Exhibition
|
Symposium
|
Electronic Packaging and Interconnections 2021
|
Presentation Title |
Atomic Insights into the Role of Dopants in η-Cu6Sn5 toward Its Structural Stability |
Author(s) |
Wenhui Yang, Xuan Quy Tran, Tomokazu Yamamoto, Kazuhiro Nogita, Syo Matsumura |
On-Site Speaker (Planned) |
Wenhui Yang |
Abstract Scope |
Chemical modification using only small amounts of elements has proven to be an effective means to control the desired crystal structure of hexagonal η-Cu6Sn5 over a wide thermally operating window, typically found in Pb-free Sn-based soldering. Though appealing, the underlying mechanisms on the role of these dopants remain incomplete and their atomic arrangements within the η-Cu6Sn5 lattices have not yet been experimentally determined. In the current study, we directly reveal the atomic positions of Zn, In, and Sb at the Sn sites of η-Cu6Sn5 via XEDS maps utilizing advanced Cs-corrected STEM. The use of advanced statistical algorithms including Poisson NLPCA and lattice-averaging enables the fine resolution of weak XEDS maps from trace dopant elements. Our first-principles calculations further identify the influence of dopants at these atomic sites on the overall energetics, electronic structures, as well as local bonding environments, leading to the most favorable situations for η-Cu6Sn5 stabilization. |
Proceedings Inclusion? |
Planned: |