Abstract
The growth model of the interfacial Cu6Sn5 compound at the circular Cu/Sn3.5Ag interface has been established in this work. The present developed growth model can predict well the interfacial Cu6Sn5 compound growth curve at the circular-interface. We found that the interfacial Cu6Sn5 compound growth rate at the circular-interface is slower than that at the planar-interface. The major factor for the slower interfacial Cu6Sn5 compound growth rate at the circular-interface attributes to the increase of the interfacial reaction area at the circular Cu6Sn5/solder interface with the annealing time. It causes a larger driving force for the interfacial Cu6Sn5 compound to dissolve into the solder matrix, which reduces the growth of the interfacial Cu6Sn5 compound layer. Moreover, the effect of the Ag concentration on the reaction mechanism for the circular reaction interface was also studied. For the Ag-rich Sn5Ag solder matrix, smaller Sn grain size (larger grain boundary density) was observed. The larger grain boundary density promotes more Cu dissolution from the interfacial Cu6Sn5 compound layer into the Sn5Ag solder matrix. Hence, the growth of the interfacial Cu6Sn5 compound layer in the Ag-rich Sn5Ag system is slightly slower than that of the Sn3.5Ag system.
Original language | English |
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Pages (from-to) | 25580-25588 |
Number of pages | 9 |
Journal | Journal of Materials Science: Materials in Electronics |
Volume | 33 |
Issue number | 34 |
DOIs | |
State | Published - Dec 2022 |