無電解Ni-Bめっきの初期析出におよぼす浴中化学種の影響

摘要

Important factors for fabricating thinner and more uniform films by electroless Ni-B plating using dimethylamine borane (DMAB) as the reducing agent were discussed. The number density of initial deposits was pointed out as the important factor for fabrication of thinner and more uniform films. Transmission electron microscope observations were performed for initial deposits plated from baths of different pH. The number density was lower in deposits plated from pH 9-10 than in those plated from pH 6-8. Dimethylamine produced through an oxidation reaction of a reducing agent (DMAB) prevents the initial deposition. Such a lower number density appeared in pH 9-10.rnNickel citrate - ammonia complex was formed under ammoniacal conditions. The nickel citrate - ammonia complex contributed to the increase in the number density of grains. It was possible to eliminate deposition prevention through the appropriate selection of nickel complexes. Results show that the initial deposition with higher number density of grains was achieved at all pH of Ni-B plating baths.%無電解こッケルめっきは，優れた機能を有することから自動車•機械産業•電子機器産業•半導体産業など幅広く用いられている。こッケルめっきの中でも,Ni-BめっきはNi-Pめっきと比較して，析出したままの硬度が高く，はんだ付け性•ボンディング特性が優れるなどの特徴があり，電子材料を中心とした幅広い分野に応用されている。これらの材料を構成する技術の進歩に伴い，Ni-Bめつきに対してもナノメートル領域にせまる微細化•薄膜化が要求されている。