Rha Sa-Kyun, Lee Youn-Seoung
J Nanosci Nanotechnol. 2015 Mar;15(3):2422-6. doi: 10.1166/jnn.2015.10253.
Area-selective copper deposition on screen printed Ag pattern/anodized Al/Al substrate was attempted using a neutral electroless plating processes for printed circuit boards (PCBs), according to a range of variation of pH 6.5-pH 8 at 70 °C. The utilized basic electroless solution consisted of copper(II) sulfate pentahydrate, sodium phosphinate monohydrate, sodium citrate tribasic dihydrate, ammonium chloride, and nickel(II) sulfate hexahydrate. The pH of the copper plating solutions was adjusted from pH 6.5 to pH 8 using NH4OH. Using electroless plating in pH 6.5 and pH 7 baths, surface damage to the anodized Al layer hardly occurred; the structure of the plated Cu-rich films was a typical fcc-Cu, but a small Ni component was co-deposited. In electroless plating at pH 8, the surface of the anodized Al layer was damaged and the Cu film was composed of a lot of Ni and P which were co-deposited with Cu. Finally, in a pH 7 bath, we can make a selectively electroless plated Cu film on a PCB without any lithography and without surface damage to the anodized Al layer.
采用用于印刷电路板（PCB）的中性化学镀工艺，在70°C下，根据pH值在6.5 - 8范围内的变化，尝试在丝网印刷的银图案/阳极氧化铝/铝基板上进行区域选择性铜沉积。所使用的碱性化学镀液由五水合硫酸铜、一水合次磷酸钠、二水合柠檬酸三钠、氯化铵和六水合硫酸镍组成。使用NH4OH将镀铜溶液的pH值从6.5调节到8。在pH值为6.5和7的镀液中进行化学镀时，阳极氧化铝层几乎没有发生表面损伤；镀覆的富铜膜结构为典型的面心立方铜，但有少量镍成分共沉积。在pH值为8的化学镀中，阳极氧化铝层的表面受到损伤，铜膜由大量与铜共沉积的镍和磷组成。最后，在pH值为7的镀液中，我们可以在不进行任何光刻且不对阳极氧化铝层造成表面损伤的情况下，在印刷电路板上制备出选择性化学镀铜膜。
