复合光亮剂对盲孔填孔电镀铜的影响

Effect of composite brightener on blind via filling by copper electroplating

介绍了一种盲孔填孔电镀铜复合光亮剂,该光亮剂由抑制剂C(乙二醇与丙二醇的共聚物)、光亮剂B(N,N-二甲基二硫代羰基丙烷磺酸钠)和整平剂L(含氮杂环混合物)组成。先采用CVS(循环伏安剥离)法分析各添加剂对电镀速率的影响,以确定镀液中各组分有效浓度的分析方法。再通过全因子试验研究抑制剂C、光亮剂B和整平剂L对填孔率的影响。结果表明,光亮剂B和整平剂L用量对盲孔填孔效果的影响较大,抑制剂C的影响较小。在由210 g/L Cu SO_4·5H_2O、50 g/L H_2SO_4和50 mg/L氯离子组成的基础镀液中加入0.5 mL/L光亮剂B、10 mL/L整平剂L和15 mL/L抑制剂C时,填孔率大于90%,镀液通电量在200 A·h/L以内可达到良好的填孔效果。镀铜层的延展性和可靠性满足印制线路板(PCB)行业的应用要求。

A composite brightener composed of inhibitor C （copolymer of ethylene glycol and propylene glycol）, brightener B （sodium NcV-dimethyl-dithiocarbamyl propylsulfonate） and leveling agent L （a nitrogen-containing heterocyclic compound） for via filling by copper electroplating was introduced. The effects of different additives on electroplating rate were studied by CVS （cyclic voltammetric stripping） method to select the analysis methods of effective concentrations of different additives. The effects of inhibitor C, brightener B and leveling agent L on filling ratio were studied through full factorial test. The results showed that the blind via filling efficiency are greatly affected by both brightener B and leveling agent L, but slightly affected by inhibitor C. The filling ratio reaches 90% or above when adding 0.5 mL/L brightener B, 10 mL/L leveling agent L and 15 mL/L inhibitor C to the basic bath composed of 210 g/L CuSO4·5H2O, 50 g/L H2SO4 and 50 mg/L chloride ions. The filling effectiveness is good when the electric consumption is 200 A.h/L. The ductility and reliability of copper coating meet the application requirements of printed circuit board industry.