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Indexed by:会议论文

Date of Publication:2017-01-01

Included Journals:EI、CPCI-S、Scopus

Page Number:1291-1295

Key Words:electromigration; Sn grain orientation; Ni substrate; dissolution; IMC precipitation

Abstract:The solid Sn exists in the beta-type possesses a body-centered tetragonal (BCT) structure. The diffusion coefficient of Ni atoms along the c-axis of Sn grains is about 3x10(4) times faster than the a-axis at 150 degrees C. Ni atoms show different EM characteristics in relation with beta-Sn crystallographic orientation in solder interconnect. The effects of Sn orientation on the dissolution of Ni substrate and intermetallic compounds (IMCs) precipitation during electro migration were investigated in the present work. When the c-axis of Sn grain was parallel to the electron flow direction, extensive Ni dissolution and massive (Ni,Cu)(3)Sn-4 IMC precipitation would occur due to the large diffusion flux of Ni atoms. When the c-axis of Sn grain was roughly perpendicular to the electron flow direction, the diffusion of Ni atoms was strongly retarded, resulting in little dissolution of Ni substrate and the precipitation of (Cu,Ni)(6)Sn-5 IMC in anode.