| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1642921 | Materials Letters | 2015 | 5 Pages |
Abstract
Microstructure development in solder joints between Sn-3.5Ag and Ni-based substrates has been widely reported. However, in the present study we illustrate a new phenomenon: that during soldering of Sn-3.5Ag to Ni or ENIG (electroless nickel, immersion gold), the bulk solder solidifies to contain a metastable eutectic consisting of βSn+Ag3Sn+NiSn4 instead of the βSn+Ag3Sn+Ni3Sn4, expected of equilibrium solidification. It is shown that metastable NiSn4 coarsens and then decomposes into Ni3Sn4 and βSn during aging at 150 and 200 °C and that coarsened NiSn4 particles deteriorate impact shear properties.
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Related Topics
Physical Sciences and Engineering
Materials Science
Nanotechnology
Authors
S.A. Belyakov, C.M. Gourlay,