An electrochemical approach to total organic carbon control in printed circuit board copper sulfate plating baths Part II: Overall system

An electrochemical system for oxidative removal of high levels of total organic carbon (TOC) in printed circuit board (PCB) copper sulfate plating baths has been developed. These organic contaminants build-up over the course of pattern plating of PCBs, and at high concentrations they interfere with the quality of the plated copper. The chemistry of the electrochemical oxidation of the plating bath contaminants was qualitatively followed using high performance liquid chromatography (HPLC) and chemical oxygen demand (COD) measurements. A complete treatment system is described and rough calculations are given showing, for a given set of conditions, how the proper choice of electrode material and current density can minimize the system cost.     

柔性印刷电路板硫酸镍体系化学镀镍及镀层性能研究

分别以柔性印刷电路板(FPCB)和紫铜为基体,采用丁二酸钠-乙酸钠复合配位体系化学镀镍。通过正交试验对化学镀镍液进行优化,得到较优的配方为:NiSO₄·6H₂O 20 g/L,NaH₂PO₂·H₂O 10 g/L,CH₃COONa 9 g/L,丁二酸钠5 g/L,乳酸6 g/L,苹果酸4 g/L。采用该镀液在温度70°C、pH=5的条件下对FPCB化学镀镍70 min,所得镍镀层呈非晶态结构,厚度约为3μm,磷质量分数为7.263%,耐蚀性较优。