Byoun Young-Min, Noh Young-Tai, Kim Young-Geun, Ma Seung-Hwan, Kim Gwan-Hoon
Metal and Machinery Team, Korea Conformity Laboratories (KCL), 199 Gasan Digital 1-ro, Geumcheon-gu, Seoul, 08503, Korea.
JUNO CRAFT, 10220 Sandanfupyeong-gil, Iksan-si, Jeollabukdo, 54524, Korea.
J Nanosci Nanotechnol. 2018 Mar 1;18(3):2104-2108. doi: 10.1166/jnn.2018.14937.
Effect of pulse reverse current (PRC) method on brass coatings electroplated from gold solution was investigated by various plating parameters such as plating duration, the anodic duty cycle, the anodic current density and the cathodic current density. The reversed current results in a significant change in the morphology of electrodeposits, improvement of the overall current efficiency and reduction of deposit porosity. With longer pulses, hemispherical surface features are generated, while larger grains result from shorter pulse widths. The porosity of the plated samples is found to decrease compared with results at the same time-average plating rate obtained from DC or Pulse plating. A major impediment to reducing gold later thickness is the corrosion of the underlying substrate, which is affected by the porosity of the gold layer. Both the morphology and the hydrogen evolution reaction have significant impact on porosity. PRC plating affect hydrogen gold and may oxidize hydrogen produced during the cathodic portion of the waveform. Whether the dissolution of gold and oxidation of hydrogen occur depends on the type of plating bath and the plating conditions adapted. In reversed pulse plating, the amount of excess near-surface cyanide is changed after the cathodic current is applied, and the oxidation of gold under these conditions has not been fully addressed. The effects of the current density, pulse-reverse ratio and brightener concentration of the electroplating process were investigated and optimized for suitable performance.
通过电镀持续时间、阳极占空比、阳极电流密度和阴极电流密度等各种电镀参数，研究了脉冲反向电流（PRC）方法对从金溶液中电镀的黄铜涂层的影响。反向电流导致电沉积物的形态发生显著变化，提高了整体电流效率，并降低了沉积物孔隙率。脉冲持续时间越长，产生半球形表面特征，而脉冲宽度越短则导致晶粒越大。与直流或脉冲电镀在相同时间平均电镀速率下的结果相比，发现电镀样品的孔隙率降低。降低金镀层厚度的一个主要障碍是底层基材的腐蚀，这受到金层孔隙率的影响。形态和析氢反应都对孔隙率有重大影响。PRC电镀会影响金并可能氧化在波形阴极部分产生的氢。金的溶解和氢的氧化是否发生取决于电镀液的类型和所采用的电镀条件。在反向脉冲电镀中，施加阴极电流后近表面氰化物的过量量会发生变化，并且在这些条件下金的氧化尚未得到充分研究。研究并优化了电镀过程中电流密度、脉冲反向比和光亮剂浓度的影响，以获得合适的性能。
