Crystallographic Characteristic Effect of Cu Substrate on Serrated Cathode Dissolution in Cu/Sn–3.0Ag–0.5Cu/Cu Solder Joints during Electromigration

Autor: Wu Yue, Chao Ding, Hongbo Qin, Chenggong Gong, Junxi Zhang
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Zdroj: Materials, Vol 14, Iss 10, p 2486 (2021)
Druh dokumentu: article
ISSN: 1996-1944
DOI: 10.3390/ma14102486
Popis: The crystallographic characteristic effect of Cu substrate on cathode dissolution behavior in line-type Cu/Sn–3.0Ag–0.5Cu (SAC305)/Cu solder joints during electromigration (EM) was investigated by scanning electron microscope (SEM), electron backscatter diffraction (EBSD), and first-principles calculations. The SEM and EBSD results show that the crystallographic characteristic of Cu substrate is crucial to cathode dissolution behavior under a direct current of 1.5 × 104 A/cm2 at 125 °C ± 2 °C. When the (001) plane of copper grain adjacent to the Cu3Sn/Cu interface is perpendicular or nearly perpendicular to the current direction, local cathode dissolution tips are easily formed, whereas the (111) plane remains mostly undissolved, which finally leads to the inhomogeneous cathode serrated dissolution in the substrate. The first-principles calculation results reveal that the different surface energies and energy barriers of the different crystallographic planes of Cu grains in the substrate are responsible for the local cathode dissolution tips. Adjusting the copper grain in a substrate to a crystal plane or direction that is difficult to dissolve during EM is a promising method for improving the reliability of solder joints in the future.
Databáze: Directory of Open Access Journals
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