| Autor: |
Qwan-Ho Chung, Kwang-Yoo Byun, Young-Bae Park, Seung-Taek Yang, Gi-Tae Lim, Jang-Hee Lee, Min Suk Suh |
| Rok vydání: |
2009 |
| Předmět: |
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| Zdroj: |
Journal of the Korean Physical Society. 54:1784-1792 |
| ISSN: |
0374-4884 |
| DOI: |
10.3938/jkps.54.1784 |
| Popis: |
The e ects of severe current crowding and Joule heating on the damage morphology and the electromigration parameters were evaluated for ip chip Sn-3.5Ag solder bumps with Cu underbump metallurgy. in-situ electromigration testing in a scanning electron microscope was performed to correlate the statistical lifetimes with the detailed microstructural characteristics. The highly accelerated test conditions used led to an activation energy of 1.63 eV and a current density exponent of 4.6, which can be attributed to severe current crowding and Joule heating e ects. Real-time microstructural analysis revealed that interfacial voids nucleated around corners of the under-bump metallurgy layer, where electrons entered from the chip or the substrate interconnect line to the solder bump and then grew along the Cu6Sn5/solder interface, irrespective of the current ow's direction. Accelerated growth of Kirkendall voids was also observed at the Cu3Sn/Cu interface and within Cu3Sn. However, electrical failure of the bump resulted from electromigration-induced interfacial void propagation along the Cu6Sn5/solder interface, which can be explained in terms of the large di erence in Cu di usion ux between the Cu-Sn intermetallic compound layer and the solder itself. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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