Showing papers on "Electroplating published in 2013"

Fundamental Aspects of Electrometallurgy

Abstract: 1. What is electrometallurgy. 2. Definitions, principles and concepts. 3. Surface morphology of metal electrodeposits. 4. The current distribution in electrochemical cells. 5. Electrodeposition at a periodically changing rate. 6. Electrowinning. 7. Electrorefining. 8. Optimum conditions for electroplating. 9. Electroplating and surface finishing. 10. Metal deposition without an external current. 11. Electrodeposition of metals from molten salts. 12. Environmental issues. Index.

Superhydrophobic copper mesh films with rapid oil/water separation properties by electrochemical deposition inspired from butterfly wing

Abstract: Inspired from butterfly wing, superhydrophobic copper mesh films were fabricated via a facile and environmental friendly method by electroplating Cu nanoparticles on the as-cleaned copper mesh films and followed by a thiol grafting. As-fabricated hierarchical structured copper mesh film showed efficient and rapid oil/water separation ability and could be repeatedly used for numerous times. The key parameters of the fabrication of suitable surface morphologies, including the electroplating time, current, electrolyte temperature, and electrolyte concentration, were particularly studied. The stability of as-prepared copper mesh film was also evaluated by compression, thermal, and ultrasonic tests.

Fully filamentized HTS coated conductor via striation and selective electroplating

Abstract: A simple, cost-effective method involving top-down mechanical scribing, oxidation and bottom-up electroplating has been successfully developed to fabricate fully filamentized HTS coated conductors. The copper stabilizer layer is selectively electroplated on the superconducting filaments while the striations remain copper-free due to the formation of a resistive oxide layer in between filaments by oxidation of the striated grooves at elevated temperature in oxygen atmosphere. Magnetization AC loss measurements, performed in a frequency range of 45–500 Hz at 77 K, confirmed the expected N-fold reduction in AC loss of the filamentized tapes with no significant degradation in critical current beyond that due to the material removal from the striations (N – number of filaments). A considerable reduction in coupling AC loss was observed after high temperature annealing/oxidation of the striated tapes. Furthermore, a significant reduction in eddy current loss was achieved with selective copper electroplating, as evidenced by analyzing the field and frequency dependence of magnetization AC loss, as well as by comparing the AC loss performance of striated samples to that of non-striated samples after electroplating of copper stabilizer.

Influence of the composite surface structure on the peel strength of metallized carbon fibre-reinforced epoxy

Abstract: In this work, the effect of mechanical pre-treatment on the surface structure of carbon fibre-reinforced epoxy composites and on its peel strength of electroless/electroplated copper was investigated. Sandblasting with Al 2 O 3 was used to pre-treat the composite surface. The parameters investigated were blasting time (3 s, 6 s and 9 s) and nozzle distance to substrate (300 mm and 500 mm). A two-step metallization process was used for depositing copper coatings on the pre-treated composite surface. First, an eletroless plating process was used to deposit a thin layer on the surface. Second, an electroplating process was used to reinforce the thickness of the coating. Increased blasting intensity leads to a significant increase in surface roughness, which promotes mechanical anchoring effects of the coating. Scanning electron microscopy images and contact angle measurements confirm the results of the surface roughness. The adhesion of sandblasted composites, characterized by measuring the peel strength, is 10 times higher compared to untreated specimens. In addition to the mechanical anchoring mechanism the exposure of carbon fibres on the surface due to the blasting process promoted a stronger bonding to copper, due to the higher, electrical conductivity of the fibres in comparison to the matrix.

Deep eutectic solvents (DESs) and the metal finishing industry: where are they now?

Abstract: The main focal area of the research into deep eutectic solvents (DESs) is currently the incorporation of metal ions into solution for metal deposition, metal dissolution, or metal processing. Although difficult to compete economically with existing electroplating systems for common metal applications, DESs can provide suitable media for the many technological goals of the industry.

Adherent metal oxide coating forming a high surface area electrode

Abstract: An implantable electrode and method for manufacturing the electrode wherein the electrode has a strong, adherent surface coating of iridium oxide or titanium nitride on a platinum surface, which demonstrates an increase in surface area of at least five times when compared to smooth platinum of the same geometry. The iridium oxide coating may be formed on platinum by a physical deposition process, such as sputtering. The process of electroplating the iridium oxide surface coating is accomplished by voltage control processes. A gradient coating of iridium oxide ranging in composition from essentially pure platinum to essentially pure iridium oxide is produced by sputtering.

Copper@carbon coaxial nanowires synthesized by hydrothermal carbonization process from electroplating wastewater and their use as an enzyme-free glucose sensor

Abstract: In the pursuit of electrocatalysts with great economic and ecological values for non-enzymatic glucose sensors, one-dimensional copper@carbon (Cu@C) core–shell coaxial nanowires (NWs) have been successfully prepared via a simple continuous flow wet-chemistry approach from electroplating wastewater. The as-obtained products were characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, selected area electron diffraction, energy dispersive X-ray spectroscopy and Raman spectroscopy. The electrocatalytic activity of the modified electrodes by Cu@C NWs towards glucose oxidation was investigated by cyclic voltammetry and chronoamperometry. It was found that the as-obtained Cu@C NWs showed good electrochemical properties and could be used as an electrochemical sensor for the detection of glucose molecules. Compared to the other electrodes including the bare Nafion/glassy carbon electrode (GCE) and several hot hybrid nanostructures modified GCE, a substantial decrease in the overvoltage of the glucose oxidation was observed at the Cu@C NWs electrodes with oxidation starting at ca. 0.20 V vs. Ag/AgCl (3 M KCl). At an applied potential of 0.65 V, Cu@C NWs electrodes had a high and reproducible sensitivity of 437.8 µA cm−2 mM−1 to glucose. Linear responses were obtained with a detection limit of 50 nM. More importantly, the proposed electrode also had good stability, high resistance against poisoning by chloride ion and commonly interfering species. These good analytical performances make Cu@C NWs promising for the future development of enzyme-free glucose sensors.

The process of electroplating with Cu on the surface of Mg–Li alloy

Abstract: Mg–Li alloy is a potential applied material because of its ultra-low density. Its poor corrosion and wear resistance hinder the expansive applications. In this research, an electroplating mean was carried to obtain a Cu-coating on the Mg–Li alloy. The main factors that influence the electroplating effect were examined through orthogonal experiments, and the determined optimum processing parameters by electrochemical tests are as follows: concentration of main salt is 50 g/L, current density is 2 A/dm 2 , solution temperature is 40 °C and electroplating time is 30 min, respectively. Afterwards, surface and cross-section morphology feature and elemental composition were characterized by SEM and EDS, and surface phase composition was characterized by XRD. Corrosion resistance and adhesion property of the coating were investigated by electrochemical tests and cross-cut tests. Results show that there exists the uniform, dense and pure Cu coating with nodular structures on the surface of Mg–Li alloy. Meanwhile, the corrosion resistance and adhesion properties are improved and the hardness value is increased after electroplating with Cu, which concludes that the coating can provide protection for Mg–Li alloys.

Simulation and fabrication of two Cu TSV electroplating methods for wafer-level 3D integrated circuits packaging

Abstract: Three-dimensional (3-D) integration and packaging with through silicon via (TSV) is an emerging trend for overcoming the limitation of integration scale in Micro-electro-mechanical systems (MEMS) packaging. It is helpful for the realization of high density and reliability of micro-devices and sensors. The technology of fabricating copper (Cu) TSVs by electroplating is applied to provide communication links in vertical direction. The fabrication of defect-free and time-saving TSV is our destination. In this paper, the Cu deposition mechanism was analyzed and the process was expressed by a series of electrochemical equations. Finite element models were built to simulate two different kinds of Cu electroplating processes in through-hole via. 100 mm diameter and 370 μm thick polished silicon wafers were chosen in experiments. Under the guidance of the simulation results, defect-free Cu TSVs were obtained by using double-sided and bottom-up electroplating methods respectively. Electrolyte additives affected the Cu deposition velocity and direction to a certain extent. Comparing the two electroplating methods, we found that double-sided electroplating is economical and time-saving. While, bottom-up electroplating has the capability in filling the through-holes whose aspect ratio are greater than 10:1. It only took about 2.5 h and 3.5 h to obtain the intact Cu TSVs by using double-sided and bottom-up electroplating methods respectively. Finally, Cu TSVs were successfully applied to the Wafer Level Packaging (WLP) Pirani vacuum gauges for the vacuum packaging of MEMS. The vertical leakage rate of bonding samples ranged from 1.0E-9 Pa m 3 /s to 4.5E-8 Pa m 3 /s, which were measured by helium leak detector.

Plating bath and method

Abstract: Tin-silver alloy electroplating baths having certain amine-oxide surfactants and methods of electrodepositing a tin-silver-containing layer using these baths are disclosed. Such electroplating baths are useful to provide tin-silver solder deposits having reduced void formation and improved within-die uniformity.

Electrochemical deposition and evaluation of electrically conductive polymer coating on biodegradable magnesium implants for neural applications.

Abstract: In an attempt to develop biodegradable, mechanically strong, biocompatible, and conductive nerve guidance conduits, pure magnesium (Mg) was used as the biodegradable substrate material to provide strength while the conductive polymer, poly(3,4-ethylenedioxythiophene) (PEDOT) was used as a conductive coating material to control Mg degradation and improve cytocompatibility of Mg substrates. This study explored a series of electrochemical deposition conditions to produce a uniform, consistent PEDOT coating on large three-dimensional Mg samples. A concentration of 1 M 3,4-ethylenedioxythiophene in ionic liquid was sufficient for coating Mg samples with a size of 5 × 5 × 0.25 mm. Both cyclic voltammetry (CV) and chronoamperometry coating methods produced adequate coverage and uniform PEDOT coating. Low-cost stainless steel and copper electrodes can be used to deposit PEDOT coatings as effectively as platinum and silver/silver chloride electrodes. Five cycles of CV with the potential ranging from -0.5 to 2.0 V for 200 s per cycle were used to produce consistent coatings for further evaluation. Scanning electron micrographs showed the micro-porous structure of PEDOT coatings. Energy dispersive X-ray spectroscopy showed the peaks of sulfur, carbon, and oxygen, indicating sufficient PEDOT coating. Adhesion strength of the coating was measured using the tape test following the ASTM-D 3359 standard. The adhesion strength of PEDOT coating was within the classifications of 3B to 4B. Tafel tests of the PEDOT coated Mg showed a corrosion current (I(CORR)) of 6.14 × 10(-5) A as compared with I(CORR) of 9.08 × 10(-4) A for non-coated Mg. The calculated corrosion rate for the PEDOT coated Mg was 2.64 mm/year, much slower than 38.98 mm/year for the non-coated Mg.

Effect of electrodeposition parameters on chemical and morphological characteristics of Cu–Sn coatings from a methanesulfonic acid electrolyte

Abstract: Currently Cu–Sn coatings are widely used in numerous commercial productions in replacement of Ni layers especially for decorative arts. In recent decades, researchers are exploring more environment-friendly baths to deposit Cu–Sn coatings to substitute CN − electrolyte which has been widely used as conventional electroplating baths for industrial applications. This paper investigated Cu–Sn deposition from a methanesulfonic acid based bath studying the optimization of deposition parameters. Film composition was varied by changing current density, which leads to a difference in color and final properties. Usually lifetime of tin containing baths is limited because the composition of deposited films has poor stability. In this work the effect of deposition parameters and anode materials on bath and deposits stability is evaluated. In particular, the application of pulse current was considered to improve the quality of coatings at fixed duty cycle while deposition frequency was varied. The coatings deposited under different conditions were compared in term of microstructure and corrosion behavior.

A simple method for acrylonitrile butadiene styrene metallization

Abstract: The metallization of acrylonitrile butadiene styrene (ABS) has been achieved using a new direct plating process that consisted of a previous treatment by polypyrrole (PPy) to transform the plastic conductor followed by direct copper electroplating. The deposition of PPy on ABS samples is reached chemically in a solution of pyrrole and iron(III) chloride as oxidant. The PPy synthesized is adherent to the plastic surfaces. Adherent copper layers with different thicknesses have been obtained on PPy/ABS at different electrolysis time. Energy dispersive X-ray spectroscopy (EDS) analysis revealed that copper is deposited on PPy/ABS surface. SEM analysis shows that increasing the electrolysis time increases the copper coating thickness.

In Situ Formation of Anticorrosive Mg-Al Layered Double Hydroxide-Containing Magnesium Hydroxide Film on Magnesium Alloy by Steam Coating

Abstract: In the 21st century, global warming has become a major issue worldwide. To mitigate global warming, technological developments such as improving fuel efficiencies and reducing CO2 emissions are essential. A reduction in material weight is one means to improve fuel efficiencies; thus, lightweight metals and alloys are becoming increasingly important. Among various lightweight metals, Mg alloys are expected to be used in the manufacturing of structural components for aircraft, automotive, electronics, and construction industries because of superior physical and mechanical properties such as good electromagnetic shielding, and high strength/weight ratio. 1,2 Poor corrosion resistance of these metals, however, hinders their use on a larger scale. To improve corrosion resistance, various surface treatments such as physical vapor deposition, anodic oxidation, electroplating, sol-gel coating, and chemical conversions have been developed. 3–8 Among these, chemical conversion and anodic oxidation have been developed for practical application in the case of large-size Mg components such as automotive components, because of the simple and low-cost process. However, these methods require treatment of liquid waste before disposal, and thus, there exists the risk of environmental pollution due to heavy metal ions. Therefore, an environmentally friendly surface treatment method suitable for large-size Mg components is highly desirable. In the field of corrosion protection, studies on micro and nanoreservoirs for intercalation or encapsulation of corrosion inhibitors with controlled release depending on environmental conditions such as pH 9 and the presence of aggressive species 10 have been developed. Layered double hydroxides (LDHs) have been used as nanoreservoirs because they consist of mixed metal and positively charged hydroxide layers separated by anions and water molecules. Several researchers have focused on the anticorrosion properties of LDH loaded materials. 11–13 The main role of LDHs is the storage and release of inhibitors on demand as a result of anion exchange between inhibiting species and corrosion-relevant anions such as chloride anions. 14 It has been reported that LDHs without any corrosion inhibitor-loaded film could substantially improve corrosion protection. In this case, the entrapment of corrosion-relevant anions in LDHs could play an important role in delaying coating degradation. Thus, LDHs are considered to be effective agents for delaying the corrosion reaction. In this letter, we report a novel, environmentally friendly, inexpensive, and simple steam-coating method for the in-situ formation of an anticorrosive Mg–Al LDH-containing magnesium hydroxide film on large-size Mg alloy AZ31. Mg alloy AZ31 (nominal composition: 3% Al, 1% Zn, 0.3% Mn, and balance Mg) specimens with sizes of 500 × 500 × 1.5 mm were used as the substrate. Substrates were ultrasonically cleaned in absolute ethanol for 10 min. The steam coating was performed using a horizontal autoclave made of stainless steel with a volume

Effect of Dextrin and Thiourea Additives on the Zinc Electroplated Mild Steel in Acid Chloride Solution

Abstract: The performance effects of thiourea and dextrin as addition agents on the electroplating of zinc on mild steel in acid chloride solution were experimentally investigated. The experiments were performed under different additive concentrations, different plating time and fixed pH conditions. The zinc electroplating on mild steel was performed using a DC – supply at defined operating parameters. The surface of the plated steel was examined using scanning electron microscopy (SEM) for surface morphology; and Energy Dispersive Spectroscopy (EDS) for surface elemental composition analysis. Different surface characteristics were obtained depending upon the concentration of the additive and the plating time. The corrosion resistance of the plated surface was determined by gravimetric method. The quality of the electro-deposition of zinc was good as indicated by the microstructural feature of the plated surface. The electrodeposition process was sensitive to changes in additive concentration and plating time. Variations in the plating parameters produced entirely new and different surface morphology.