A novel interface strengthening layer: Nanoscale AuCu super-structure formed during Au80Sn20/Cu rapid solidification soldering process

摘要

AbstractPhase composition and orientation of intermetallic compounds layers determine the functional and mechanical properties of solder joints. In this paper, interfacial reaction and strengthening mechanism of Au80Sn20/Cu joint by rapid solidification reflow soldering were studied. The Au80Sn20/Cu solder joint by rapid solidification reflow soldering exhibit a superior shear property, and the shear strength reaches up to 90MPa. It is found that a new nanoscale AuCu super-structure formed in the interfacial intermetallic compounds layer, which is coherent with the [001] Cu substrate. The orientation relationship of Cu matrix/interfacial intermetallic compounds is determined to be001Cu∥001AuCu∥2?42?3AuCu5Snand200Cu∥200AuCu∥101?0AuCu5Sn. Nanoscale AuCu super-structure influences the interface slip direction and provides interface misfit dislocation, hinder the dislocation movement, lead to the interface strengthening effect. Our finding on nanoscale AuCu super-structure formed during Au80Sn20/Cu soldering process not only sheds light on future research direction but also provides practical guidance to the engineers in solder industry.Graphical AbstractDisplay OmittedHighlights?The nanoscale AuCu super-structure formed in Au80Sn20/Cu soldering joint.?The