Abstract
The microstructure of the eutectic SnBi/Cu interface was investigated by transmission electron microscopy to study the growth mechanisms of the intermetallic compounds (IMCs). Although the growth kinetics of the total IMC layer were similar, the individual Cu 3Sn layer grew faster on polycrystalline Cu than on single-crystal substrates. It was found that, on polycrystalline Cu, newly formed Cu 3Sn grains with a smaller grain size nucleated and grew at both the Cu/Cu 3Sn and Cu 3Sn/Cu 6Sn 5 interfaces during reflow and solid-state aging. The consumption of Cu 6Sn 5 to form Cu 3Sn was faster at the Cu 3Sn/Cu 6Sn 5 interface. While on single-crystal Cu new Cu 3Sn grains nucleated only at the Cu/Cu 3Sn interface, the directional growth of the initial columnar Cu 3Sn controlled the advance of the Cu 3Sn/ Cu 6Sn 5 interface.
Original language | English (US) |
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Pages (from-to) | 2579-2584 |
Number of pages | 6 |
Journal | Journal of Electronic Materials |
Volume | 38 |
Issue number | 12 |
DOIs | |
State | Published - Dec 2009 |
Externally published | Yes |
Keywords
- Diffusion
- Growth mechanism
- Interface
- Intermetallic compound (IMC)
- SnBi solder
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering
- Materials Chemistry