盲孔填孔电镀铜添加剂的研究

Study on copper electroplating additives for blind via filling

介绍了一种盲孔电镀铜工艺,镀液组成和工艺条件为:CuSO4·5H2O 200 g/L,H2SO475 g/L,Cl 55 mg/L,抑制剂(乙二醇聚氧乙烯聚氧丙烯单丁醚)30 mL/L,整平剂(含氮杂环化合物)3 mL/L,加速剂(N,N二甲基二硫代羰基丙烷磺酸钠)2 mL/L,温度23°C,电流密度1.4 A/dm2,阴极摇摆16回/min,空气搅拌。研究了抑制剂、加速剂和整平剂对FR-4基材盲孔填孔效果的影响。结果表明,抑制剂和加速剂用量对盲孔填孔效果的影响较大,整平剂的影响较小。镀液中加入适宜含量的上述3种添加剂时,填孔效果良好,填孔率大于95%,所得铜镀层的延展性和可靠性满足印制电路板的应用要求。

A copper plating process for blind via filling was introduced. The bath composition and process conditions are as follows： CuSO4·5H2O 200 g/L, H2SO4 75 g/L, Cl- 55 mg/L, inhibitor （polyethylene-propylene glycol monobutyl ether） 30 mL/L, leveling agent （a nitrogen-containing heterocyclic compound） 3 mL/L, accelerator （sodium N,N-dimethyl- dithiocarbamylpropylsulfonate） 2 mL/L, temperature 23 ℃, current density 1.4 A/din2, cathode motion 16 times/rain, and air agitation. The influences of inhibitor, accelerator, and leveling agent on blind via filling effectiveness of FR-4 substrate were studied. The results showed that the dosages of inhibitor and accelerator have great effect on blind via filling, while the leveling agent has slight effect on it. The blind via filling quality is excellent with a filling ratio higher than 95% when the said three additives are added with a suitable amount to plating bath. The ductility and reliability of the copper coating obtained can meet the application requirements of printed circuit boards.