The micro-structure and mechanical characteristics of the multi-layer nickel-plated copper foil welding by blue light laser with 450 nm were investigated. Nickel-plated copper foil with 20 layers were welded onto nickel-plated copper sheet with 0.5 mm

and the effects of different welding speeds on the weld morphology and tensile strength were investigated. The morphology on the weld failure mode and the micro morphology of the fracture were analyzed

and the electrical conductivity of the weld were tested. The results indicate that during the blue laser welding process

the depth of penetration is easily controlled.With the increase of welding speed

the weld penetration depth is gradually decreased

and the tensile strength of the weld is increased at first and then decreased.When the welding speed is 30 mm/s

the tensile strength of the weld reaches the maximum of 75 MPa. Blue laser can be successfully applied to the welding of multi-layer nickel-plated copper foil and laser welding leads to good mechanical properties.