Investigation on growth of the orientation-preferred Cu6Sn5 on (001)Cu during the temperature-increased multiple reflow process

Abstract The preferred orientation of Cu6Sn5 formed on (001) Cu single crystals has attracted great attention due to its feature of strong anisotropy. Lots of researchers believe that the formation of preferred orientation is closely related to the reaction temperature but do not have a unified conclusion. In this study, a temperature-increased multiple reflow process was designed and utilized to investigate the grain rotation and coarsening behavior of orientation-preferred Cu6Sn5 formed at the Sn-3Ag/(001)Cu interface. Results demonstrate that the temperature-increased multiple reflow process facilities the annexation and rotation of Cu6Sn5 grains as well as their morphology transformation from scalloped-type to small facet. The results have significant meaning in understanding and controlling the formation of Cu6Sn5 preferred orientation and improving the reliability of solder joints.