| About this Abstract |
| Meeting |
2021 TMS Annual Meeting & Exhibition
|
| Symposium
|
Phase Stability, Phase Transformations, and Reactive Phase Formation in Electronic Materials XX
|
| Presentation Title |
Thermomigration Failure Induced by Surface Diffusion of Sn on Ni/Cu Metallization in Microbumps for 2.5-dimensional Integrated Circuits Packaging |
| Author(s) |
Wei-Dung Tsai, Chen Wei Lee, Fan-Yi Ouyang |
| On-Site Speaker (Planned) |
Wei-Dung Tsai |
| Abstract Scope |
The 2.5D-IC packaging can integrate the different Si chips placed horizontally on a Si interposer to achieve heterogeneous integration, and microbumps have been adopted as the vertical interconnects between chips and interposer. The Joule heating from the powered chip may transfer horizontally by interposer to the neighboring un-powered chip, and creates a large temperature gradient.In this study, an electromigration-induced failure was investigated under a current density of 5.4×〖10〗^4 A/〖cm〗^2 at 150°C. However, the micro joints in the neighboring un-powered chip has more serious thermomigration-induced failure because Sn atoms tend to migrate along the surface of Ni/Cu metallization under temperature gradient, and form Ni3Sn4 and Cu3Sn IMCs, respectively. When the Sn diffuses away from solders, necking or significant voids formation occurs in the solder layer of micro bumps, weakening the electrical and mechanical properties. Thus this new thermomigration-induced failure mode will become even significantly in micro joint for 2.5D-IC packaging. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Electronic Materials, Electrometallurgy, Phase Transformations |