Root-cause Diagnosis of Blisters & Pits
镀层起泡与麻点的根因诊断树
标签：起泡, 麻点, 前处理, 析氢, 根因分析
镀层起泡四大根因按序排查：①前处理油膜或氧化膜残留——取起泡片复做除油、酸活化后再镀，若消失即前处理问题；②镀液有机污染——镀层背面有光泽的片状剥离，活性炭 3–5 g/L、50℃ 处理 2 h 后过滤；③镍底应力过大——瓦特浴中氯化镍超过 60 g/L 或糖精过量。麻点则看分布：集中于挂具上方为析氢滞留，加空气搅拌与润湿剂 0.5–1 mL/L；无规律散布查铁杂质（双氧水加活性炭除铁）与光泽剂过量。
Diagnose blisters in order: ① residual oil/oxide from pretreatment—replate a blistered coupon after full degrease and acid activation; ② organics in the bath—glossy-backed flakes point here, treat at 3–5 g/L activated carbon, 2 h at 50℃; ③ nickel-strike stress—Watts bath over 60 g/L nickel chloride or excess saccharin. For pits, read distribution: clustering above rack tips means hydrogen retention (air agitation plus wetter 0.5–1 mL/L); scattered pitting implicates iron contamination (peroxide-carbon treatment) or overdosed brightener.