| About this Abstract |
| Meeting |
2010 TMS Annual Meeting & Exhibition
|
| Symposium
|
Pb-Free Solders and Emerging Interconnect and Packaging Technologies
|
| Presentation Title |
Solidification of the Sn-Cu-Ag Eutectic Alloy |
| Author(s) |
Yoshiko Takamatsu, Hisao Esaka, Kei Shinozuka |
| On-Site Speaker (Planned) |
Yoshiko Takamatsu |
| Abstract Scope |
At present Sn-Ag-Cu alloy is an important candidate for use as a Pb-free solder. In order to understand solidification process of Sn-Ag-Cu alloy, Sn-3.5Ag-0.5Cu and Sn-3.5Ag-1.5Cu have been prepared in this study. The specimens were quenched during solidification at a cooling rate of 3 K/min. In the case of Sn-3.5Ag-0.5Cu alloy, the Sn-Ag<SUB>3</SUB>Sn binary eutectic started to grow just after primary β-Sn dendrites nucleated. After growing of binary eutectic, Sn-Ag<SUB>3</SUB>Sn-Cu<SUB>6</SUB>Sn<SUB>5</SUB> ternary eutectic formed, though the volume fraction of Ag<SUB>3</SUB>Sn in ternary eutectic was small. It was found that the large undercooling was not necessary for Sn-Ag<SUB>3</SUB>Sn-Cu<SUB>6</SUB>Sn<SUB>5</SUB> ternary eutectic.
In the case of Sn-3.5Ag-1.5Cu alloy, no undercooling for primary Cu<SUB>6</SUB>Sn<SUB>5</SUB> and Ag3Sn was found, even though they were facet phases. However, there was a large undercooling for formation of β-Sn. Volume fraction of ternary eutectic was small compared with the estimation from equilibrium phase diagram. |
| Proceedings Inclusion? |
Planned: Journal of Electronic Materials |