基于稳健设计的ENEPIG印制板化学镀钯工艺研究

Study on electroless palladium plating for ENEPIG printed circuit board based on robust design

从化学镀钯反应机理入手,分析了影响化学镀钯质量的工艺参数,并运用DOE(试验设计)中的健壮设计实验方法,对这些参数进行了优化,获得了新型ENEPIG(化学镀镍、钯与浸金)印制电路板生产中化学镀钯的最优化工艺参数:氯化钯质量浓度2.2 g/L,次磷酸钠质量浓度13.2 g/L,氨水体积分数165 m L/L,温度55°C,p H 9.6,氯化铵质量浓度33 g/L。验证试验表明,应用优化后的化学镀钯工艺时,钯的沉积速率均值从原来的0.64 mg/(cm2·min)提升到4.83 mg/(cm2·min),分散度也有明显改善。经过大样本量验证,试验具有良好的重复性和再现性。

The process parameters affecting the quality of electroless palladium plating were analyzed based on the reaction mechanism of electroless palladium deposition and optimized by robust design, an approach of DOE （design of experiments）, for the production of novel ENEPIG （electroless nickel/electroless palladium/immersion gold） printed circuit boards as follows： PdC2 2.2 g/L, NaH2PO2·H2O 13.2 g/L, NH3·H2O 165 mL/L, NH4Cl 33 g/L, temperature 55 ℃, and pH 9.6. The result of verification test showed that the average deposition rate of palladium is raised from 0.64 mg/（cm^2·min） to 4.83 mg/（cm^2·min） after the optimization of electroless palladium plating process and the dispersion is significantly improved. The test has good repeatability and reproducibility during large sample size verification.