Copper electroplating Solutions

Kim, B. C. Lee, I. H. Park, Y. H. Acid copper electroplating solution, especially useful in manufacture of semiconductor chip. Repub. Korean Kongkae Xaeho Kongbo KR 2004088322, 2004 Chem. Abstr. 2006, 145, 365094. 

Cadmium, cobalt, copper, and nickel sulfamates react with lower aHphatic aldehydes. These stable compositions are suitable for use ia electroplating solutions for deposition of the respective metal (see Electroplating). 

The sulphate bath The sulphate bath, the earliest of electroplating solutions and the simplest in composition, contains typically 150-250 g/1 of copper sulphate and 40-120 g/1 of sulphuric acid. The composition is not critical and the higher concentrations are used for plating at higher current densities, normally up to 6 A/dm. ... 

Other electroplating solutions Other solutions, which are more rarely used for plating copper, include the fluoborate bath, the amine bath, the sulphamate bath and the alkane sulphonate bath. 

How many electrons does a copper ion in copper sulfate solution take from a cathode in electroplating ... 

In a mixed copper-zinc solution of complex cyanide, however, the Cu ion concentration can be reduced to the order of lO mol/L and the concentration ratio (zinc ion)/(copper ion) will be made very large. A detailed calculation for this case is given by Faust in the 1974 edition of Modem Electroplating (1). It is shown there, and in detail below, that the copper cyanide complex is Cu(CN)3 , for which the dissociation value is known. The dissociation constant for the zinc cyanide complex, Zn(CN)4 , is also well known. Using those values that determine the fraction concentration of the free metal ion in solution and assuming an initial specific molar concentration, it is shown below that their respective reversible electrode potentials [see also Eq. (11.1)] can be brought together. 

Copper(l) cyanide is used in copper plating of nickel, chromium, zinc alloys, steel, and other metals or alloys. Such copper plating imparts brightness, smoothness, hardness, and strength. The cyanide solution employed for copper electroplating consists of copper cyanide and sodium cyanide. Other apph-cations of this compound are as an insecticide, a catalyst in polmerization, and as an antifouling agent in marine paints. 

Metal Coatings. Tellurium chlorides, as well as tellurium dioxide in hydrochloric acid solution, impart permanent and attractive black antique finish to silverware, aluminum, and brass. Anodized aluminum is colored dark gold by tellurium electro deposition. A solution containing sodium tellurate and copper ions forms a black or blue-black coating on ferrous and nonferrous metals and alloys. Addition of sodium tellurite improves the corrosion resistance of electroplated nickel. Tellurium diethyldithiocarbamate is an additive in bright copper electroplating (see Electroplating). 

Because of its poisonous nature, copper sulfate is used in the fungicide Bordeaux mixture, which is formed upon mixing copper sulfate solution with milk of lime and is added to water reservoirs to kill algae. It is also employed in electroplating and used as a mordant, germicide, and agent in engraving. 

Virgin ACFs, AW2001, supplied by Taiwan Carbon Co. was used in this work. To sensitize the surface of ACFs were immersed in a solution composed of acidified tin chloride solution at concentration of S g-f for 5 min at room temperature, and followed by a rinse with distilled water. The ACFs were successively subjected to a copper electroplating in copper plating solutions with varying treatment time. 

Solutions of acid copper sulfate (containing only chloride and carrier) were used as the copper electroplating bath. A piece of titanium mesh (diameter = 55 mm) coated with iridium oxide was used as an insoluble anode. The bath was pumped through the anode to the cathode under 1 l/min and controlled at 25 °C. The cathode rotating speed was maintained at 165 rpm. The copper electrodeposition tests were conducted under different electric field waveforms with an average cathodic current density of 25 to 32 ASF, which was controlled by the cell voltage. Samples were cross-sectioned with a focused ion beam scanning electron microscope (FIB-SEM) to inspect both the quality of the copper deposits in the trenches or via-holes. 

In order to increase the specific surface area and enhance the effectiveness/ activity of the porous electrodes, it is necessary to reduce the size of the pores, as well as the branches in the foam or agglomerates of copper grains in the honeycomb-Uke structures [26]. One of the ways to improve micro- and nanostructural characteristics of open porous electrodes is the addition of additives to the electroplating solution [26]. The decrease of diameter of holes, as well as the increase of their number in 3D foam copper structures, can be realized by the addition of acetic acid to the copper sulfate solution [26]. Also, the addition of chloride ions dramatically reduces the size of the copper branches in the walls of holes. The reduction in pore size is a result of lowering hydrophobic force of the generated hydrogen gas by adding bubble stabilizer (e.g., acetic acid) that suppresses the coalescence of bubbles, while the decrease in branch size in the foam wall is a consequence of the catalytic effect of chloride ions on the copper deposition reaction. 

The adsorbent SG(l)-TEPA-propyl is useful in adsorbing anionic copper cyanide complexes from electroplating solutions. Modeling this anionic adsorption phenomena requires the description of copper cyanide ion speciation in the aqueous solution, the acid-base characteristics of the adsorbent, and the complexation reactions between the copper cyanide anions and the protonated ligand sites. Details can be found elsewhere [5,30],... 

Electroplating is a useful process to produce thick metal structures on a substrate. Many metals such as copper (Cu), Au, and Ni can be electroplated. The substrate to be electroplated is immersed in an electroplating solution that contains a reducible form of the ion of the desired metal. The substrate is maintained at a negative potential (cathode) relative to an inert positive counter electrode (anode e.g., platinum). During the electroplating, electrons are supplied to the surface of the exposed metallic regions on the substrate, and the metal ions are reduced to their atomic form and subsequently deposited onto the substrate surface. 

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