Release Time:2019-03-12  Hits:

Indexed by: Conference Paper

Date of Publication: 2017-01-01

Included Journals: CPCI-S

Page Number: 1296-1299

Key Words: Electromigration; beta-Sn Grain orientation; Dissolution; Intermetallic compounds

Abstract: The effect of anisotropy in beta-Sn grain on electro migration (EM)-induced failure mechanism of the Ni/Sn-3.0Ag-0.5Cu/Ni-P solder interconnects was in situ investigated. Sn grain orientation was a crucial factor in dominating the EM behavior. When the c-axis of Sn grain was parallel to the electron flow direction, a larger EM flux was induced, resulting in an excessive dissolution of Ni at the cathode. Sn hillocks were squeezed out at intermetallic compounds (IMCs)/solder interface on the anode side to relieve surficial compressive stress in the current crowding regions. When the c-axis of beta-Sn grain was perpendicular to the electron flow direction, EM-induced void formation and propagation at the cathode resulted from the lower Ni diffusion flux. Furthermore, (Ni,Cu)(3)Sn-4-type IMCs precipitated along the c-axis in single beta-Sn grain in the bumps.