In the electrification era, the demand for high-quality precision copper welding is crucial. Laser welding offers a promising solution for precise copper welds, whether joining copper-to-copper or copper-to-other materials. However, achieving top-notch welds is challenging due to copper's high reflectivity to infra-red lasers and the need for post-processing to maintain weld strength and integrity. This is what makes this research new as it focuses on a preliminary study examining a three-step process involving a green laser cleaning, then blue laser welding copper-to-stainless steel at continuous-wave (CW), emitting 1.5 kW at 455 nm wavelength. Then post processing the welded joint was conducted by laser peening with an novel ultra-portable laser shock processing system. The experimentation focused on 0.9 mm thick copper overlapped with a 0.3 mm thick stainless steel. Granular structures were evaluated, verified by its hardness, shear strength, and residual stresses. Results showed, surface roughness increased after laser cleaning, removing impurities and oxidation. Blue laser welding enhanced surface hardness, but introduced defects such as porosity and cracks in some instances. The triangular spot weld configuration provided effective in meeting industrial shear strength requirements and demonstrated that laser cleaning enhanced weld quality, with the highest shear strength followed by blue laser welding. Laser peening improved grain structure and hardness, but did not significantly increase shear strength. Residual stress analysis revealed that laser cleaning and welding induced tensile stresses, while laser peening alone induced compressive stress. Future studies will optimize these processes to improve copper weldability, structural integrity, and lifespan.