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Formation mechanism of Sn-patch between SnAgCu solder and Ti/Ni(V)/Cu under bump metallization

Published online by Cambridge University Press:  31 January 2011

Jenq-Gong Duh*
Affiliation:
Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 300, Taiwan
Toung-Yi Shih
Affiliation:
Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 300, Taiwan; and United Microelectronics Corporation, Hsinchu 300, Taiwan
*
a) Address all correspondence to this author. e-mail: [email protected]
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Abstract

An Sn-patch formed in Ni(V)-based under bump metallization during reflow and aging. To elucidate the evolution of the Sn-patch, the detailed compositions and microstructure in Sn–Ag–Cu and Ti/Ni(V)/Cu joints were analyzed by a field emission electron probe microanalyzer (EPMA) and transmission electron microscope (TEM), respectively. There existed a concentration redistribution in the Sn-patch, and its microstructure also varied with aging. The Sn-patch consisted of crystalline Ni and an amorphous Sn-rich phase after reflow, whereas V2Sn3 formed with amorphous an Sn-rich phase during aging. A possible formation mechanism of the Sn-patch was proposed.

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Articles
Copyright
Copyright © Materials Research Society 2009

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