| About this Abstract |
| Meeting |
TMS Specialty Congress 2025
|
| Symposium
|
The 7th International Congress on 3D Materials Science (3DMS 2025)
|
| Presentation Title |
Observation of Thermal Fatigue-Induced Grain Rotation in Pb-Free Solder Joints by XSOL |
| Author(s) |
Jaemyung Kim, Yujiro Hayashi, Hiroaki Tatsumi, Hiroshi Nishikawa, Makina Yabashi |
| On-Site Speaker (Planned) |
Jaemyung Kim |
| Abstract Scope |
It is believed that the failure mechanism of Pb-free solder joints under thermal cycling is correlated with the rotation of β-Sn grains. However, destructive measurement methods have prevented understanding the original orientation of β-Sn grains before thermal cycling. While conventional X-ray-based orientation microscopies exist, they are limited to small cylindrical samples and are unsuitable for plate-like structures such as solder joints. As a result, no direct evidence of grain rotation has been available until now.
To overcome this limitation, we recently developed X-ray Scanning Orientation Laminography (XSOL), which enables orientation mapping of extended plate-like specimens. We applied XSOL to conduct nondestructive analysis of a 930-μm-thick plate containing solder joints. We observed that the β-Sn grains in the as-soldered joints exhibited random orientations, while the c-axis of the grains tended to align parallel to the Cu substrate after thermal cycling, providing direct evidence that grain rotation occurs due to thermal fatigue. |
| Proceedings Inclusion? |
Undecided |