Effect of graphene doping on microstructural and mechanical properties of Sn–8Zn–3Bi solder joints together with electromigration analysis

•Graphene nanosheets are doped in Sn–8Zn–3Bi solder by mechanically dispersing.•The effect of electromigration is studied by a newly developed wire-type device.•In graphene doped solder, Zn-rich phases demonstrate a much finer microstructure.•The growth rate of the IMCs is hindered in the doped solder with quantification.•Shear strength and hardness have been improved with graphene reinforcement.