以丙尔金为主盐的高纯度可焊性镀金工艺

Process for electroplating of highly pure and weldable gold coating using K{Au(I)[CH_2(CN)_2]}_2(C_6H_5O_7)·H_2O as main salt

以清洁环保的丙尔金[即一水合柠檬酸一钾二(丙二腈合金(I))]代替有毒氰化亚金钾为主盐,用市售的可焊性镀金工艺配方及规范,生产高纯度(99.99%)的金镀层。所得镀金层呈浅柠檬黄色、无色斑,比亚硫酸盐纯金层更均匀、致密,金线键合强度经高低温循环试验后稳定,与载体焊接牢固、无空穴,满足美国军标MIL-STD-883H–2010中方法2011.8──键合强度测试规范的性能要求。镀金液性能与亚硫酸盐纯金镀液相近。镀金液使用3年多后,不论是在加热状态或是长期放置都很稳定。

A highly pure （99.99%） gold coating was prepared by using environmentally friendly bis（malononitrile） gold（I） potassium citrate monohydrate as main salt in replace of toxic gold potassium cyanide based on the bath composition and operation parameters of a commercial weldable gold plating process. The obtained gold coating is pale lemon yellow and stain-free, and more uniform and compact than the pure gold coating prepared from a sulfite bath. The bonding strength of gold wire is stable after cyclic treatment between high and low temperatures, and is welded firmly without any seam to the carrier, meeting the requirement of U.S. military standard MlL-STD-883H-2010 Method 2011.8--Testing Specification of Bonding Strength. The properties of gold plating bath are similar to those of sulfite gold plating bath. The bath is stable whether it is heated or placed for long after using for more than 3 years.