Effect of Cu addition on interfacial reaction between Sn–9Zn solder and Ag

The effect of Cu added eutectic Sn–9Zn solder reacting with the Ag substrate has been investigated in this study. Three Ag–Zn intermetallic compounds (IMCs), ∈–AgZn 3 , γ–Ag 5 Zn 8 , and ζ–AgZn, were formed on the Sn–9Zn/Ag interface at 260 °C. While Cu was gradually added to the Sn–9Zn alloy, microstructures of intermetallic compounds changed dramatically. The intermetallic compound microstructures became loose and Sn and Cu atoms in the Ag-Zn intermetallic compounds increased. If more than 3 wt% of Cu was added to the Sn-9Zn alloy, Ag-Sn intermetallic compounds were formed on the Ag surface and massive spalling of Ag–Zn IMC layers from the Ag surface occurred in a short reaction time.

[1]  Yee-Wen Yen,et al.  Interfacial reactions in Ag-Sn/Cu couples , 1999 .

[2]  Koichi Niihara,et al.  Wetting and interface microstructure between Sn–Zn binary alloys and Cu , 1998 .

[3]  Sinn-wen Chen,et al.  Interfacial reactions in the Sn-Ag/Au couples , 2001 .

[4]  King-Ning Tu,et al.  Ductile-to-brittle transition in Sn–Zn solder joints measured by impact test , 2004 .

[5]  Jun-Mo Yang,et al.  Analysis on interfacial reactions between Sn–Zn solders and the Au/Ni electrolytic-plated Cu pad , 2004 .

[6]  D. T. Hawkins,et al.  Selected values of the thermodynamic properties of binary alloys , 1973 .

[7]  D. Q. Yu,et al.  Investigation of interfacial microstructure and wetting property of newly developed Sn–Zn–Cu solders with Cu substrate , 2004 .

[8]  Jong-Kai Lin,et al.  Spalling of Cu3Sn intermetallics in high-lead 95Pb5Sn solder bumps on Cu under bump metallization during solid-state annealing , 2004 .

[9]  C. Kao,et al.  Volume effect on the soldering reaction between SnAgCu solders and Ni , 2005, Proceedings. International Symposium on Advanced Packaging Materials: Processes, Properties and Interfaces, 2005..

[10]  A. Berndt.  Binary phase diagrams , 1969 .

[11]  K. Suganuma,et al.  Interfaces in lead-free soldering , 2003 .

[12]  Katsuaki Suganuma,et al.  Heat resistance of Sn-9Zn solder/Cu interface with or without coating , 2000 .

[13]  Jenn-Ming Song,et al.  Role of Ag in the formation of interfacial intermetallic phases in Sn-Zn soldering , 2005 .

[14]  Chih-Ming Chen,et al.  Intermetallic compound formation and morphology evolution in the 95Pb5Sn flip-chip solder joint with Ti/Cu/Ni under bump metallization during reflow soldering , 2005 .

[15]  Kim,et al.  Kinetic analysis of the soldering reaction between eutectic SnPb alloy and Cu accompanied by ripening. , 1996, Physical review. B, Condensed matter.