Abnormal Cu3Sn growth through grain boundary penetration in space-confined Ni-Sn-Cu diffusion couples
Journal
Journal of Alloys and Compounds
Journal Volume
799
Pages
108-112
Date Issued
2019
Author(s)
Abstract
An abnormal growth of Cu3Sn through the grain boundaries of Cu6Sn5 formed in Ni/Sn/Cu ternary diffusion couples is reported in this study. The Ni/Sn/Cu diffusion couples are prepared by thermal compression bonding, with the Sn thickness controlled at 10 μm. The diffusion couples are aged at 200 °C for different periods of time. Due to the thinness of the initial Sn layer, the entire Sn layer ware converted into Cu6Sn5 and Cu3Sn only after 52 h or aging. At this stage, both compounds exhibit the layered structure. Afterward, as the reaction continues, Cu3Sn grows thicker at the expense of Cu6Sn5. Interestingly Cu3Sn now preferably grows along the grain boundaries of Cu6Sn5. The rationalization for this abnormal growth pattern is discussed.
SDGs
Publisher
Elsevier Ltd
Type
journal article