Title :
On the formation of Cu-Ni-Sn ternary intermetallics in SMT solder joints
Author :
Xie, Xiaoming ; Xia, Yanhhua ; Chang, Junling
Author_Institution :
Shanghai Inst. of Microsyst. & Inf. Technol., Chinese Acad. of Sci., Shanghai, China
Abstract :
Formation of intermetallics for SnPb eutectic solder in a sandwich structure with one side copper pad/HASL finish and other side copper pad/NiAu finish was studied. The experimental results strongly indicate that the interface IMCs depends not only on the solder material and the metallization it reacted to but also on the metallization on the other side of the soldering interface. Copper can diffuse fast across the molten solder to react with nickel layer on the other side to form (CuNiSn) ternary alloy. Depending on the quantity of diffused copper, different types of IMCs are formed.
Keywords :
chemical interdiffusion; copper alloys; eutectic alloys; eutectic structure; interface structure; melting; metallisation; solders; tin compounds; HASL finish; SMT solder joints; SnPb eutectic solder; SnPb-CuNiSn; copper pad; intermetallic compounds; intermetallics formation; metallization reaction; sandwich structure; solder joint thickness; solder material; soldering interface; ternary alloy; ternary intermetallics; Copper; Gold; Intermetallic; Lead; Nickel; Optical microscopy; Scanning electron microscopy; Soldering; Surface finishing; Surface-mount technology;
Conference_Titel :
High Density Microsystem Design and Packaging and Component Failure Analysis, 2004. HDP '04. Proceeding of the Sixth IEEE CPMT Conference on
Print_ISBN :
0-7803-8620-5
DOI :
10.1109/HPD.2004.1346675
