The increasing electrification of automotive powertrains demands reliable, high‑precision joining technologies, particularly for inverter and power module production. As power electronic converters become more compact and achieve higher power densities, joining processes must minimize heat input due to the proximity of temperature sensitive components. Blue laser radiation at 445 nm enables efficient energy coupling into copper, offering a promising route to stable, low defect micro welds for power electronics interconnects. This work examines micro lap welding of 0.3 mm oxygen‑free copper (Cu‑OF) foils to an active metal brazed (AMB) substrate carrying a copper layer, using a 445 nm laser source focused to 92 µm spot size. The welding process benefits from good absorption of the blue wavelength with small focus diameter. Investigates on how process parameters affect bond formation in Cu foil to AMB joints are performed. The analysis considers lack of fusion versus full penetration, the onset of porosity, and the resulting weld geometry while limiting thermal load on the substrate. Bond integrity at the Cu ceramic interface is assessed by scanning acoustic microscopy to detect delamination and subsurface cracks. Post process characterization includes metallographic cross sections and optical profilometry. Mechanical performance is evaluated by tensile strength testing, relating failure load and fracture location to weld geometry and interface condition.