Abstract
This letter examines void nucleation and coalescence in Au-Al wire bonds using high-resolution transmission electron microscopy. It is found that void formation is not only attributed to Kirkendall-type migration as conventionally believed, but also due to volumetric shrinkage and intermetallic oxidation. A volumetric shrinkage of a few percent is associated with intermetallic growth and phase transformations. Intermetallic oxidation occurs at the intermetallics/alumina interface and the migration of oxygen towards the intermetallics leads to void growth and thickening of the surrounding oxide walls.
Original language | English |
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Pages (from-to) | 642-645 |
Number of pages | 4 |
Journal | Scripta Materialia |
Volume | 65 |
Issue number | 7 |
DOIs | |
Publication status | Published - Oct 2011 |