Electromigration failure in flip chip solder joints due to rapid dissolution of copper
Journal
Journal of Materials Research
Journal Volume
18
Journal Issue
11
Pages
2544-2548
Date Issued
2003
Author(s)
Abstract
An electromigration failure mechanism in flip chip solder joints is reported in this communication. The solder joints failed by a very rapid, asymmetrical, and localized dissolution of the Cu metallization on the cathode side. The average dissolution rate was about 1 μm/min. The dissolved Cu included not only the Cu under bump metallurgy but also the on-chip Cu conducting trace. From the location and geometry of the dissolved Cu, it can be concluded that current crowding plays a critical role in the rapid dissolution. The dissolved Cu atoms were driven to the anode side by electromigration, and a large amount of Cu6Sn5 was formed there.
Publisher
Materials Research Society
Type
journal article