In situ study on the increase of intermetallic compound thickness at anode of molten tin due to electromigration of copper

Synchrotron radiation imaging technology was applied for in situ observation of the growth of Cu6Sn5 intermetallic compounds at the anode in Cu/molten Sn/Cu joint undergoing electromigration. For current density of 0.6 × 103 A/cm2, temperature of 250 °C and reflow heating time of 1 h, thickness of the compound was obtained as 110 μm. The thickness growth was observed to have linear dependence with time. The numerical model for diffusion and electromigration of the copper species was implemented using the finite volume method.