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Electromigration Studies of Sn(Cu) and Sn(Ni) Alloy Stripes

Published online by Cambridge University Press:  01 August 2005

C.C. Wei  and
C.Y. Liu
C.C. Wei
Affiliation:
Department of Chemical Engineering and Materials Engineering, National Central University, Chung-Li, Taiwan 320, Republic of China
C.Y. Liu*
Affiliation:
Department of Chemical Engineering and Materials Engineering, and Institute of Materials Science and Engineering, National Central University, Chung-Li, Taiwan 320, Republic of China
*
a) Address all correspondence to this author. e-mail: chengyi@cc.ncu.edu.tw.
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Abstract

Using Blech’s structure, we studied the electromigration (EM) behaviors of four different Sn(Cu) and Sn(Ni) alloys, which are Sn, Sn0.7Cu, Sn3.0Cu, and Sn1Ni. The order of the EM rates was determined to be Sn0.7Cu > Sn > Sn3Cu > Sn1Ni. We believe that the lower yielding strength and higher grain boundary density of Sn0.7Cu were the main reasons that Sn0.7Cu had the fastest EM rate. Moreover, we found that the addition at Ni could effectively retard EM. The critical products of Sn, Sn0.7Cu, and Sn3.0Cu, which were determined to be 1500, 500, and 1580 A/cm, respectively. The diffuse-effective charge (DZ*) values of the solder stripes from this present work have same order magnitude of the reported values, which were measured by using actual solder bumps.

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Journal of Materials Research , Volume 20 , Issue 8 , August 2005 , pp. 2072 - 2079
Copyright
Copyright © Materials Research Society 2005

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References

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