Long-Length Coated Conductor Copper Plating Fabrication

Most application of high-temperature superconducting (HTS) wires require conductor engineering with respect to superior electric and mechanical properties and robustness. A long-length reel-to-reel Cu plating manufacturing technology was developed, tested, and transferred to the Bruker HTS production facility. Details of the design and the structure of the plating unit as well as plating results are reported. The pulse-plating technology provides a high quality of one- or two-sided metallic Cu layers on the surface of the pulsed laser deposition synthesized HTS tape. Acidic copper sulphate CuSO₄ has been tested to optimize and enhance the plating process with respect to the Cu deposition rate. Using reel-to-reel mode together with the 6-m-long plating apparatus, up to a 2000 m length conductor has been treated with our unique Cu-plating technique, yielding reproducible Cu stabilizer performance with deposition speeds of up to 50 m/h. The plating technology is considered to have a high flexibility in processing a metallic copper stabilizer of a thickness of 5-50 μm. The resulting Cu-layered conductor has allowed face-to-face standard soldered joints of 10^-7 Ωcm² resistance to become routine. This work describes the overall analysis of the constructed reel-to-reel plating unit and evaluates the final conductor properties.