Influence of Bonding Conditions on Low-temperature Solid-state Bonding of Cobalt Based Nanocones

With the miniaturization of integrated circuits, high processing temperature in mass reflow leads to more interface failure, high thermal stress and other reliability problems. Low-temperature solid-state bonding technology is potential in future 3D packaging due to its low processing temperature, high packaging density and simple post-processing. Cobalt is a promising barrier material with high hardness and electromigration resistance. Therefore, Co based nanocones prepared by electrodeposition for low-temperature solid-state bonding have a promising application. It is vital to explore the effect of bonding conditions on its bonding effect. In this paper, Co based nanocones were fabricated by electrodeposition, which were then applied in low-temperature solid-state bonding. The obtained solder joint cross-section morphology and the surface of the solder joint after shearing were characterized by SEM. The shear strength of solder joints was tested under different bonding temperatures and pressures. On the basis of above work, 190℃, 1000 gf and 150 s were determined as the appropriate low temperature bonding conditions in this experiment, and the corresponding shear strength of solder joint reached 48.99 MPa, which provides reference for the practical industrial application of low-temperature solid-state bonding of cobalt based nanocones in the future.