Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1623259 | Journal of Alloys and Compounds | 2009 | 8 Pages |
Growth kinetics and interfacial morphologies of the intermetallic compounds (IMCs) between single crystal Ag and Sn–4Ag, Sn–3Cu and Sn–37Pb solders were investigated by solid-state aging at 160 °C and liquid-state aging at 260 °C. Isothermal equation of chemical reaction and phase diagrams were used to explain the effects of Ag, Cu and Pb on the growth kinetics of IMCs under solid-state and liquid-state aging conditions. The diffusion coefficients for the three solder joints of Sn–4Ag/Ag, Sn–3Cu/Ag and Sn–37Pb/Ag were calculated after solid-state and liquid-state aging. It is found that Pb can effectively retard the growth of IMCs during liquid-state aging but has little influence on the growth rate of IMCs during the solid-state aging. Some local small cracks were frequently observed in the Cu6Sn5 particles near interfaces of the Sn–3Cu/Ag solder joints after solid-state aging for several days. However, there were no such local small cracks when solders or interfaces did not contain the Cu6Sn5 particles after the same aging time.