As electronic devices become more compact and power-dense, the reliability of solder
joints, particularly those using lead-free solders such as Sn−3.5Ag, faces significant
challenges due to electromigration (EM) and intermetallic compound (IMC) growth. This
study investigates the effects of high-current pulses (100−200 A) on Cu−Sn solder
joints, focusing on the impact of Fe nanoparticle (NP)-doped flux on mitigating electromigration
under accelerated conditions. Solder joints were subjected to pulsed current stressing
at a sample temperature of approximately 75∘C, and the resulting microstructural changes
were examined. Results showed significant IMC growth, particularly at the anode side
of solder joints, with morphological transitions from scalloped to planar IMC structures.
After pulsed current stressing, some joints exhibited IMC degradation at the cathode
side. The influence of Fe NP doping on EM effects was less clear, with variability
in the microstructural response observed across different solder bridges. These results
demonstrate that pulsed high-current loading induces distinct microstructural changes
and is a viable approach for studying accelerated electromigration.
