▎ 摘　　要

NOVELTY - Preparation of black hole liquid, involves taking graphite plate as anode, titanium plate or graphite plate as cathode, using ultra-pure water or aqueous ammonia as electrolyte, electrolyzing, adding conductive agent and adhesive, and adjusting pH to 9-10. USE - The black hole liquid is used for processing surface of non-metal base material of printed circuit board or hole wall. ADVANTAGE - The conductive film layer has excellent adhesive force and conductivity.