Retarding electromigration on the Sn-Ag-Cu solder joints by micro-sized metal-particle reinforcement

Electromigration (EM) has become one of the reliability concerns to the fine pitch solder joint due to its increasing capacity to bear the high current density The EM effects on microstructure evolution of Sn-3.0Ag-0.5Cu+XNi (X=0, 0.05, 0.45, 2.0wt. %) solder joint was investigated. Findings of this study indicated that an appropriate addition of Ni element and moderate ambient temperature can alleviate EM damages in solder joint. The intermetallic compound layer which held a planar type and appropriate thickness improved the resistance of EM effects by suppressing the polarity effect. Ag
₃
Sn and the bulk IMCs also retard the effects from current stressing for the solder joint.