Growth behavior of Cu_6Sn_5 grains formed at an Sn3.5Ag/Cu interface

摘要

The growth behavior of Cu_6Sn_5 grains formed at an Sn3.5Ag/Cu interface was investigated. During soldering, Cu_5Sn_5 grains formed at the interface, showing a flattened ovoid shape. During solidification, Cu precipitated from molten solder in the form of Cu_6Sn_5, forming faceted surfaces on existing interfacial grains. The interfacial Cu_6Sn_5 morphology was unrelated to its crystal orientation, which was primarily dependent on reaction temperature. A reaction temperature of 240 ℃ led to an increase in (002) growth and a decrease in (101) growth with time. However, the (002) plane peak was not detected in the interfacial grains formed at a higher reaction temperature (280 ℃).