In order to achieve sustainable development goals, SDGs, decarbonization and low-carbonization are required. Electric and hybrid vehicles are indispensable for the conservation of natural environment, and the lightweight construction and the effective transfer of electricity become important. Thus, copper and aluminum have been becoming important materials because of their excellent electrical properties. However, in the welding of these materials, it is difficult to obtain strong joints, since there are problems in the brittle intermetallic compounds and the welding defects due to different melting points between copper and aluminum. Especially in joining of copper and aluminum by copper side irradiation, aluminum rich intermetallic compounds (IMC) shows brittle state, and mechanical strength decreases drastically. Therefore, mild heat input from copper to aluminum would be necessary to reduce the brittle IMC. Angled irradiation might result in the mild energy input to aluminum, because it can be expected that aluminum would be heated by the reflected light inside the keyhole generated in copper according to high light reflection of copper. In addition, stable welding can be expected by the superposed irradiation of blue and near-infrared lasers because of high light absorption rate of blue laser to copper. The angled and the superposed irradiation could achieve stable welding state, and the generation of aluminum rich IMC became smaller. Angled irradiation of near-infrared laser showed equivalent joining strength to the superposed irradiation of two wavelengths, and the combination of angled and superposed irradiation achieved the remarkable increase of joining strength in cross tensile test by 80%.