不同体系925银化学蚀刻工艺的研究

Study on different chemical etching systems for 925 silver

以蚀刻速率为主要指标,对比研究了硝酸体系、过硫酸钠-硫酸体系、过氧化氢-硫酸体系和自配复杂体系蚀刻液对925银的蚀刻能力,得到了几种满足不同应用的蚀刻液配方。适用于深蚀或镂空蚀的蚀刻液有质量分数为40%~50%的室温硝酸溶液,以及自配复杂体系（温度30℃）—硝酸25%（均为质量分数）,硫酸20%,过氧化氢15%,硝酸铵4%,草酸1%,水余量。适用于浅蚀的蚀刻液有：过硫酸钠-硫酸体系（温度50℃）——过硫酸钠150 g/L,硫酸体积分数2%;过氧化氢-硫酸体系（温度30℃）——过氧化氢质量分数30%,硫酸质量分数20%,水余量;自配复杂体系（温度30℃）——硝酸15%（均为质量分数）,硫酸15%,过氧化氢20%,硝酸铵4%,草酸1%,水余量。

The etching capability of several kinds of etching solutions including nitric acid system, sodium persulfate-sulfuric acid system, hydrogen peroxide-sulfuric acid system and the home-developed multicomponent system for 925 silver was comparatively studied using etching rate as the main evaluation index. Several formulations of etching solution meeting different application requirements were obtained. The etching solutions suitable for deep or hollow etching of 925 silver are： （1） 40-50wt% nitric acid used at room temperature; and （2） home-developed multicomponent system comprising nitric acid 25wt%, sulfuric acid 20wt%, hydrogen peroxide 15wt%, ammonium nitrate 4wt%, oxalic acid lwt%, and water balance used at 30℃. The etching solutions suitable for shallow etching are： （1） sodium persulfate-sulfuric acid system comprising sodium persulfate 150 g/L and sulfuric acid 2vo1% used at 50℃; （2） hydrogen peroxide-sulfuric acid system comprising hydrogen peroxide 30wt%, sulfuric acid 20wt%, and water balance used at 30 ℃; and （3） home-developed multicomponent system comprising nitric acid 15wt%, sulfuric acid 15wt%, hydrogen peroxide 20wt%, ammonium nitrate 4wt%, oxalic acid 1 wt%, and water balance used at 30℃