Stabilization of hexagonal Cu6(Sn,Zn)5 by minor Zn doping of Sn-based solder joints

doi:10.1016/j.scriptamat.2011.07.029

Scripta Materialia

Volume 65, Issue 9, November 2011, Pages 783-786

https://doi.org/10.1016/j.scriptamat.2011.07.029 Get rights and content

Cu₆Sn₅ is the dominant intermetallic compound at the Sn/Cu joint interface. The crystal structure of Cu₆Sn₅ varies with temperature. After reflow at 250 °C, interfacial Cu₆Sn₅ revealed a hexagonal structure (η-Cu₆Sn₅). During aging at 150 °C, hexagonal η-Cu₆Sn₅ transforms into monoclinic η′-Cu₆Sn₅. X-ray diffraction and differential scanning calorimetry analyses show that doping small amounts of Zn (0.8–2.1 at.%) into Cu₆(Sn,Zn)₅ can stabilize the hexagonal structure during the thermal aging process. Thermodynamic calculation also demonstrates that Zn stabilizes the hexagonal Cu₆(Sn,Zn)₅.

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Stabilization of hexagonal Cu6(Sn,Zn)5 by minor Zn doping of Sn-based solder joints

Mater. Sci. Eng. R: Rep.

Intermetallics

Scripta Mater.

Acta Mater.

J. Alloys Compd.

J. Electron. Mater.

Acta Mater.

J. Alloys Compd.

Calphad-Comput. Coupling Ph. Diagrams Thermochem.

Calphad-Comput. Coupling Ph. Diagrams Thermochem.

J. Alloys Compd.

Stabilization of hexagonal Cu₆(Sn,Zn)₅ by minor Zn doping of Sn-based solder joints