共查询到20条相似文献,搜索用时 15 毫秒
1.
Monoethanolamine (MEA)-complexed cupric ion solution was used as a non-ammoniacal solution for copper etching on printed circuit boards (PCB). The copper dissolution behaviour of this MEA-complexed cupric solution containing 1 M CuCl2 and 3.3 to 10 M MEA was studied by the potentiodynamic method at various temperatures (25–55 °C) and pH values (10–6.5). The effects of these factors on dissolution rate and etching factor of the copper patterns of PCBs were discussed. It was found that the highest corrosion current density (i
corr) was obtained with MEA concentration at about 5 M. Activation energies (E
a) of MEA-complexed cupric solutions were measured and the heat of adsorption (H
ads), which accounts for the chemisorption of the MEA ligands on the copper surface was calculated. H
ads was found to increase with solution containing excess MEA ([MEA] > 5 M), indicating the inhibition behaviour of MEA. Hence with lower pH, i
corr increased because the concentration of MEA ligands decreased due to acid reaction. The etching factor of copper patterns of PCBs with 75 m/75 m, line/space (L/S), were also tested by spray etching method. A high etching factor can be achieved for etchants containing high MEA concentration, which means MEA affects the etching factor since the inhibitive property of MEA reduces the undercut. Although the etching rate of MEA-complexed cupric etchant is still much lower than the ammoniacal etchant, the etching factor of the forward etchant (>3) is better than the latter (<2). 相似文献
2.
B. Stypuła J. Banaś M. Starowicz H. Krawiec A. Bernasik A. Janas 《Journal of Applied Electrochemistry》2006,36(12):1407-1414
The anodic behaviour of copper was investigated in ethanol solution containing LiClO4, LiCl electrolyte and water. The type of electrolyte and the water content influences the mechanism of the anodic process and the formation of anodic products. In LiClO4 electrolyte the dissolution of copper is related to the oxidation of Cu(I) to Cu(II). In solutions of LiCl the etching of copper begins with the creation of soluble complexes of Cu(I) with chloride ions and solvent molecules. At potentials above 0.4 V the formation of alkoxides was observed in both solutions, characterized by a yellow tint. On the other hand, above 0.8 V (i.e. above the equilibrium potential of alcohol oxidation) copper dissolution is accompanied by the formation of a blue colloidal suspension of Cu (II) copper salt. Anodic etching of copper in solutions containing 3% H2O at potentials higher than 0.4 V leads to the formation of colloidal suspension of copper oxide nanoparticles. 相似文献
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4.
An experimental study of the effect of SCN− ion concentration and laser bombardment intensity on the anodic dissolution of copper into an aqueous NaCl electrolyte is reported. The laser was used to accelerate the dissolution process. The results are analyzed in terms of power spectra, fractional Brownian motion theory and confocal image processing. An interpretation of the dynamic phenomena via the theory of nonlinear dynamics is also suggested. 相似文献
5.
F. K. Crundwell 《Electrochimica acta》1992,37(15):2707-2714
The electrodissolution of copper in hydrochloric acid solutions at the rotating ring-disk electrode was found to be controlled by both mass transfer and reaction in the apparent-Tafel region in HCl concentrations of between 0.1 and 1.0 M. The proposed mechanism describes the adsorption of CuClads on the corroding copper surface and the diffusion of CuCl−2 from the copper surface. The reaction in the limiting-current region was found to be controlled by the diffusion of Cl− to the copper surface through a porous CuCl layer that forms on the surface. The thickness of this porous layer is dependent on the stirring conditions, and independent of the Cl− concentration. Cu2+ is also produced at the Cu surface during electrodissolution. A mechanism describing the formation of a porous film of CuCl on the surface, the diffusion of Cl− through this film and the formation of Cu2+ has been proposed. 相似文献
6.
The oscillatory behaviour of the anodic dissolution of copper into an aqueous NaCl solution containing a small amount of thiocyanate ions has been studied experimentally in the absence and in the presence of a magnetic field. The latter has an inhibiting effect on the oscillation and, under specific conditions, it can fully suppress it. 相似文献
7.
Helen Harvey Mounir A. Malati 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1983,33(2):116-119
The zero order kinetics of the dissolution of CuO in ascorbic acid solution, acidified with HCl, was followed by measuring the absorbance of the coloured solution formed at 750 nm. From the variation of the logarithm of the rate constant with the reciprocal of the absolute temperature, an activation energy of 36 kJ mol-1 was calculated. The infrared spectrum of a solid isolated from the reaction mixture was compared with the spectrum of ascorbic acid. A tentative mechanism of the reaction is suggested. 相似文献
8.
The electrochemical behaviour of copper has been investigated in different cupric complex solutions by cyclic voltammetry. In pyridinic and picolinic solutions the reduction of cupric complex occurred in two stages leading to Cu(I) and Cu(0), respectively. The electrodeposited copper is oxidized in two steps leading to Cu(I) and Cu(II) as in ammoniacal cupric complex solutions. In glycine, alanine, sulfamic acid and ethylenediamine solutions, the cuprous complex is an intermediate in the cupric complex reduction but it is not detected during the oxidation of the electrodeposited copper in these solutions. In EDTA and triethanolamine solutions, the cuprous complex is not observed. The rate of copper etching was determined in pyridinic and ammoniacal cupric solutions and was shown to be faster in ammoniacal cupric solutions than in the pyridinic solutions. 相似文献
9.
生物质是自然界中最丰富的可再生资源之一,将生物质转化为高附加值化工产品首先要进行生物质预处理,即利用物理、化学和生物等手段削弱细胞壁分子之间的作用,使生物质更容易降解。离子液体具有诸多优异的物理和化学性质,在众多领域引起了广泛关注,近年来在生物质预处理过程中同样展现出良好的效果。综述了近年来离子液体作为木质纤维素溶剂的主要研究成果,重点介绍了溶解机理方面相关研究。介绍了阴阳离子种类及氢键的影响,总结了木质纤维素与离子液体在分子水平上的相互作用机制,最后探讨了离子液体溶解生物质方面的发展前景。 相似文献
10.
采用实验室小型二维砂箱对地下水流动过程中甲基叔丁基醚(MTBE)溶解过程进行模拟实验,主要考察了非离子型表面活性剂聚乙氧基油酸山梨糖醇(Tween80)、阴离子表面活性剂十二烷基苯磺酸钠(SDBS)与助溶剂乙醇对MTBE溶解过程的影响。结果表明,Tween80在其临界胶束浓度(CMC)以上能够对MTBE起到增溶的效果而且在所研究浓度范围存在最佳增溶浓度10g/L;低于临界胶束浓度条件下的SDBS并没有增强MTBE迁移反而会延缓MTBE的溶解;乙醇可以增大MTBE的溶出浓度,而且随着含量提高增溶效果加强。通过比较各种条件下最佳的MTBE累积去除率可以得出,当MTBE去除率达到80%之前,对MTBE溶解增强效果由大到小顺序依次为:非离子型表面活性剂Tween80> 助溶剂乙醇> 水> 阴离子表面活性剂SDBS;而去除率80%以后,增溶效果的顺序则为乙醇> Tween80> 水> SDBS。 相似文献
11.
研究了一种无氰碱性镀铜工艺.运用循环伏安法和扫描电子显微镜研究了配方中三乙醇胺(4 mL/L)、硝酸铵(1.5g/L)、亚胺类物质hg01(1 mL/L)和吡啶类物质hg02(0.5 g/L)等4种添加剂的作用.结果表明:三乙醇胺能改善低电流密度处镀层质量;硝酸铵与铜离子结合能在较宽电流密度范围内参与阴极还原反应,有效抑制析氢反应;hg01优先吸附在阴极高电流密度处与铜离子产生强配合作用,能提高镀液的分散能力,有利于产生细微晶粒;hg02能在电极表面吸附,增大了铜沉积过程的极化作用,有效改善了中电流密度区镀层的整平性和脆性.X射线衍射研究表明,该铜镀层表现出(111)晶面的择优取向.该工艺具有良好的镀液及镀层性能,镀层厚度中等,适合用于铁基片上打底. 相似文献
12.
T. Z. Fahidy 《Journal of Applied Electrochemistry》1998,28(4):411-416
Queuing theory is applied to oscillatory phenomena encountered during anodic dissolution, with numerical illustration provided by a laboratory-scale copper dissolution process. The theory interprets oscillation as a two-phase process, where the first phase consists of ion arrival to the electrode and subsequent steps to form a solid deposit on it, and the second phase consists of the deposition process itself followed by partial dissolution of the deposit. The two phases correspond to the process of client-arrival and client-servicing in queuing theory. In particular, the M/M/1, the G/M/1 and the M/M/k queuing models are quantitatively compared in terms of queuing time and certain other queuing characteristics. 相似文献
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14.
The addition of chromate to the leach liquor for the preparation of skeletal copper increases and stabilizes the copper surface area and slows the leaching rate. The kinetics have been studied using a rotating disc electrode (RDE) at 269–293 K in 2–8 M NaOH and 0–0.1 M Na2CrO4. The rate of leaching was found to be constant with time, with an activation energy of 74 ± 7 kJ mol–1. By monitoring the kinetics and free (mixed) corrosion potential, it was possible to elucidate the mechanistic effect of chromate causing the increased surface area. Chromate was found to deposit on the copper surface as chromium(III) oxide, hindering the leaching reaction as well as the dissolution/redeposition of copper, the main mechanism of structural formation/rearrangement for skeletal copper. This blocking of the surface resulted in a finer structure, with a corresponding larger surface area. It also stabilised the surface area by minimizing the rearrangement. The effect of chromate was found to reach a limit at around 0.03 M Na2CrO4. 相似文献
15.
Anodic dissolution behavior of titanium in chloride-containing ethylene glycol was examined using a rotating disk electrode. A potential-independent dissolution current flowed depending on the rotation speed, species and concentration of chloride salts. In solutions with lower concentrations of chloride, a potential-independent current was controlled not only by the mass transfer process but also by the charge transfer, and the kinetic-controlling current depends on solution conductivity. In concentrated chloride solutions, the current was controlled only by mass transfer process and decreased with increase in chloride concentration. A smaller current also flowed in a solution with a high concentration of titanium species. These results indicated that the diffusion-controlling species are titanium species, not chloride ions. Electrochemical impedance spectroscopy revealed that a titanium chloride salt layer, which maintains titanium species at a high concentration, accumulates a low charge (0.1 μF cm−2) and becomes thicker with increase in applied potential, is formed between the titanium substrate and diffusion layer during the mass transfer-controlling dissolution. 相似文献
16.
The dissolution of a massive chalcopyrite electrode (98.1% chalcopyrite, 1.9% siderite) was studied in 0.5 M sulfuric acid solution. Different anodic potentials were applied and the behavior of the electrode was observed by means of EIS, potentiodynamic, and Mott-Schottky techniques. Electrochemical impedance spectroscopy studies at open circuit potential (around −235 mV vs. MSE) proved the existence of a thin surface layer on the electrode. This layer was stable up to 100 mV vs. MSE and was assumed to be Cu1−xFe1−yS2 (y?x) based on reports from previous studies. By increasing the potential to the range of 100-300 mV vs. MSE, the previously formed layer partially dissolved and a second layer (Cu1−x−zS2) formed on the surface. Both of the layers showed the characteristics of passive layers at low potentiodynamic scan rate (0.05 mV s−1) while at high scan rates they acted like pseudo-passive layers. However, in the potential range of 300-420 mV vs. MSE, both of these surface layers dissolved and active dissolution of the electrode started. Further increase in potential caused the formation of a CuS layer which hindered the dissolution rate of the electrode. The formation of CuS is concomitant with Fe2(SO4)3 formation and the latter may act as a nucleation precursor for jarosite at higher potentials (around 750 mV vs. MSE). Jarosite precipitation on the electrode surface hindered the dissolution of chalcopyrite at higher potentials. Different equivalent electrochemical circuits were modeled for each potential range and the model regression results compared with the experimental results of EIS to determine the proposed sequence of chalcopyrite dissolution. 相似文献
17.
利用单因素法和正交设计法,研究pH、振荡温度和振荡时间对新型硅钙钾肥中硅溶出的影响,并模拟植物吸收养分,测定硅的累积溶出率,验证了其中硅的缓释性。 相似文献
18.
研究了化学镀铜溶液中稳定剂对铜沉积速率的影响,着重考虑主配位剂、副反应的抑制剂、甲醛捕获剂对化学镀铜的影响。结果表明,在基本配方8 g/L CuSO4.5H2O,3 g/L HCHO2,8 g/L EDTA7,.5 g/L NaOH,工艺参数pH=12.5,温度50℃,时间40 min的基础上,各种稳定剂的适宜用量为6 mL/L CH3OH、8 mg/L K4Fe(CN)6、6 mg/L 22,’-bipy。在最佳工艺下得到的镀层外观红亮,表面平整,晶粒细致,化学镀铜液稳定。 相似文献
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