A metastable phase of tin in 3D integrated circuit solder microbumps

SCRIPTA MATERIALIA

卷:102

Article

Liu, Yingxia¹  Tamura, Nobumichi²  Kim, Doug Wook³  Gu, Sam³  Tu, K. N.¹ 

[1] Univ Calif Los Angeles, Dept Mat Sci & Engn, Los Angeles, CA 90095 USA

[2] Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Adv Light Source, Berkeley, CA 94720 USA

[3] Qualcomm, San Diego, CA 92121 USA

关键词: Lead-free solder;    Metastable phases;    Electronic packaging;    Joining;   

DOI  :  10.1016/j.scriptamat.2015.02.009

来源: Elsevier

【 摘 要 】

A metastable phase of Sn has been found to co-exist with beta-Sn in Pb-free SnAg microbumps in 3D integrated circuit technology. Synchrotron microbeam X-ray diffraction, high-resolution TEM imaging and selected-area electron diffraction were used to confirm the metastable phase, which has an orthorhombic lattice, with lattice parameter a = 0.635 nm, b = 0.639 nm, and c = 1.147 nm. Its composition is Sn containing a few percent of Ni. A higher rate of nucleation might have enabled its formation. (C) 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

【 授权许可】

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