Enhancement of the mechanical strength of Sn-3.0Ag-0.5Cu/Ni joints via doping minor Ni into solder alloy

•The shear strength of SnAgCu-Ni/Ni and SnAgCu-Ni/Cu joints were evaluated.•The microstructure of SnAgCu-Ni/Ni and SnAgCu-Ni/Cu joints were characterized.•(Cu,Ni)6Sn5 particles at fracture interface retarded the crack growth in the Ni-doped joints.•Particle-like (Cu,Ni)6Sn5 precipitates was not shown in the SnAgCu/Ni joints.•The formation of (Cu,Ni)6Sn5 IMC was attributed to Ni addition into solder alloy.