Single-side electrodeposition treatment on rolled copper foil to generate a dense black micron-scale alloy dendritic structure roughened film layer. Features ultra-high peel strength; low high-frequency loss; ultra-strong resistance to heat, humidity, and corrosion; low powder shedding and high cleanliness; combined matte and shielding effect; uniform etching supporting ultra-fine precision circuitry. Applications: new energy vehicles, power battery CCS integrated busbar FPC, on-board RF/radar FPC, on-board electronic controls, OBC, DC-DC internal flexible circuits; energy storage and photovoltaic high-power equipment; communications and consumer electronics high-end FPC, 5G RF modules, high-speed transmission flexible boards, foldable screens, high-end smartwatches, notebook internal precision flexible circuits, server and switch electromagnetic shielding flexible pads; medical precision electronics, medical imaging flexible circuits, testing equipment sensor flexible circuits; industrial high-end power equipment, high-frequency induction power supplies, inverter shielding flexible busbars, precision industrial control flexible acquisition circuits.