Copper Electrodeposition Research Articles

Roles and influencing mechanisms of guar gum and polyethylene glycol in copper electrodeposition

ABSTRACT In this paper, the effects of the organics guar gum and polyethylene glycol (PEG) additives on Cu electrodeposition cell voltage, energy consumption and surface morphology were evaluated. Furthermore, the influences of guar gum and PEG on the kinetics of Cu electrodeposition were investigated using electrochemical tests such as cyclic voltammetry (CV), linear sweep voltammetry (LSV) and Tafel linear fitting. The results indicated that adding 0.5 mg/L guar gum promoted the Cu electrodeposition. While indicating the lowest overpotential (10 and 100 mA cm−2 were −462 and −561 mV, respectively) and smaller Tafel slope of 50.37 mV dec−1. However, higher concentrations of guar gum and PEG increased cell voltage and energy consumption, with 900 mg/L PEG leading to a 61 kWh energy increase. Elevated organic levels in the electrolyte raised overpotential, inhibiting Cu deposition and causing surface roughness on Cu sheets.

Effect of additives on the microstructure and properties of pulsed electrodeposited copper foils

ABSTRACT A low-roughness ultra-thin copper foil was prepared by pulsed electrodeposition with a duty cycle 60%, pulse frequency of 600 Hz on titanium. The influence of sodium 3,3'-dithiodipropane sulphonate (SPS), hydroxyethyl cellulose (HEC), gelatin and collagen additives on the microstructure, mechanical properties and electrochemical behaviour of electrolytic copper foil was explored. Furthermore, the reaction mechanism of SPS and collagen additives on electrodeposited copper were discussed. The results showed that at 0.08 g L−1 collagen concentration, the lowest thickness, the highest microhardness and the optimal surface roughness were achieved (5.12 μm, 279.63 HV and 1.885 μm, respectively). X-ray diffraction results confirmed that electrolytic copper foils prepared when SPS was introduced into the blank solution had a preferred orientation of (220) texture, which benefitted from the synergistic effect of copper ions and additives. The intermediates formed by the additive and Cu+ occupied the active sites on the cathode surface that increased the nucleation sites for deposition. In addition, the formed complexes can act as a barrier to narrow ion deposition channels and inhibit the growth of Cu ions.

Predicting the surface roughness of an electrodeposited copper film using a machine learning technique

Predicting the surface roughness of an electrodeposited copper film using a machine learning technique

Electrochemical Growth of Copper Crystals on SPCE for Electrocatalysis Nitrate Reduction.

Copper is efficient, has a high conductivity (5.8 × 107 S/m), and is cost-effective. The use of copper-based catalysts is promising for the electrocatalytic reduction of nitrates. This work aims to grow and characterize copper micro-crystals on Screen-Printed Electrodes (SPEs) for NO3- reduction in water. Copper micro-crystals were grown by cyclic voltammetry. Different cycles (2, 5, 7, 10, 12, 15) of copper electrodeposition were investigated (potential ranges from -1.0 V to 0.0 V, scan rate of 0.1 V s-1). Electrodeposition generated different morphologies of copper crystals on the electrodes, as a function of the number of cycles, with various performances. The presence of numerous edges and defects in the copper micro-crystal structures creates highly reactive active sites, thus favoring nitrate reduction. The manufactured material can be successfully employed for environmental applications.

Potentiostatic electrodeposition of copper, indium, and cadmium sulfides for CO2 electroreduction: A path toward sustainable hydrogen generation

This study focuses on the potentiostatic electrodeposition of copper indium and cadmium sulfide (CuS, In2S3, and CdS) thin films on copper substrates, aiming to develop efficient electrocatalysts for the electrochemical reduction of CO2 and sustainable hydrogen generation. Utilizing Cu Kα radiation for X-ray diffraction (XRD) analysis, the crystal structures of the electrodeposited films were confirmed, revealing well-defined crystalline phases. The films exhibited average particle sizes of 55.99 nm for CuS, 50.37 nm for In2S3, and 63.51 nm for CdS. Cyclic voltammetry and chronoamperometry were employed to optimize the deposition parameters, ensuring efficient nucleation and growth of the metal sulfide films. The electrochemical performance of the synthesized electrocatalysts was rigorously tested, demonstrating their potential for CO2 reduction under optimized conditions with the highest efficiency for CdS electrodes. Additionally, the electrodeposited CuS and CdS are of the p-type, and In2S3 is of the n-type semiconductor were studied and verified by the Mott–Schottky test. CuS, In2S3, and CdS were found to have donor and acceptor concentrations (ND) of 1.68 × 106, 1.44 × 105, and 8.9 × 105 cm3, respectively. The photoelectrochemical measurements of the electrodeposited metal sulfides were studied at ambient temperature and under illumination, providing higher photocurrent responses for CdS and demonstrating its strong potential as a photoelectrode material for CO2 reduction. This work underscores the significance of facile electrochemical synthesis methods in developing cost-effective and scalable electrocatalysts, paving the way for their integration into photoelectrochemical systems for green energy applications.

Metallization of leaf-derived lignocellulose scaffolds for high-performance flexible electronics and oligodynamic disinfection

Vascular tubules in natural leaves form quasi-fractal networks that can be metallized. Traditional metallization techniques for these lignocellulose structures are complex, involving metal sputtering, nanoparticle solutions, or multiple chemical pretreatments. Here we present a novel, facile, and reliable method for metallizing leaf-derived lignocellulose scaffolds using silver microparticles. The method achieves properties on-par with the state-of-the-art, such as broadband optical transmittance of over 80%, sheet resistances below 1 Ω/sq., and a current-carrying capacity exceeding 6 A over a 2.5 × 2.5 cm² quasi-fractal electrode. We also demonstrate copper electrodeposition as a cost-effective approach towards fabricating such conductive, biomimetic quasi-fractals. Additionally, we show that these metallized structures can effectively eliminate pathogenic microorganisms like fecal coliforms and E. coli, which are bacterial indicators of microbiological contamination of water. We finally show that these oligodynamic properties can be significantly enhanced with a small externally applied voltage, indicating the noteworthy potential of such structures for water purification and pollution control.

Ultra-high flatness and conductivity of copper electrodeposits obtained by nano-twinned/fine-grained double layer electrodeposition

Electrodeposited copper (Cu) is utilized as an electrical interconnect material in electronic devices. In high-frequency signal transmission, the skin effect of current conduction is becoming more pronounced, necessitating higher requirements for conductor’s surface roughness and conductivity. In this study, we fabricate a double-layer copper (dl-Cu) consisting of highly flat fine-grained copper (fg-Cu) on top and perpendicular nano-twinned copper (pnt-Cu) at the bottom through two-step electrodeposition. The overall grain growth into large grains is achieved by annealing, and reverse dissolution before electrodeposition of fg-Cu is found to eliminate the interface of fg-Cu and pnt-Cu. The surface roughness of dl-Cu is only 4.65 nm, and the conductivity after annealing reaches 95.5 % of the international annealed copper standard.

Bisphenol A Polyoxyethylene Ether Sodium Sulfate as a New Leveler for Electrodeposition of Copper.

The electrochemical behavior of three types of bisphenol A polyoxyethylene ether sodium sulfate (BPA) is investigated through cyclic voltammetry striping tests. The results indicate that BPA-25 exhibited the most significant inhibition of Cu deposition. The nanotwinned Cu (nt-Cu) films are prepared by direct current electrodeposition in an acidic Cu sulfate bath containing a combination of conventional bath additives. Transmission electron microscopy (TEM) and cross-sectional scanning electron microscopy (SEM) results revealed that nt-Cu consisted of microcolumnar grains with high-density nanoscale coherent twin boundaries oriented parallel to the growth surface. The interaction between BPA-25 and the poly2-sulfur-2-propane sodium sulfonate (SPS) was further analyzed through galvanostatic measurements (GMs) and electron backscatter diffraction (EBSD). The results demonstrate that BPA-25 and SPS underwent competitive adsorption on the cathode surface, leading to the formation of nt-Cu. This growth mechanism provides a new perspective for the preparation of nt-Cu by using direct current electrodeposition.

A Black State from Reversible Copper Electrodeposition without Metal Additives

A Black State from Reversible Copper Electrodeposition without Metal Additives

Scaling analysis of electrodeposited copper and the influence of a modified polysaccharide on surface roughness

The influence of a commercially available modified polysaccharide (HydroStar®, Chemstar Chemical Products) on the roughness of short-term and small-scale copper electrodeposits was investigated using Atomic Force Microscopy (AFM), linear scan profilometry and scaling analysis. Copper was deposited on a 316L stainless steel cathode at 40 °C and 300 A m−2 from an electrolyte containing 40 g L−1 Cu2+, 170 g L−1 H2SO4, 1.5 g L−1 Fe3+, 15 mg L−1 Cl− and either 0, 10, 50 or 100 mg L−1 of HydroStar. Copper deposits produced between 15 and 25 min were imaged using AFM and 2D linear scan profilometry was used to gather surface features of copper samples produced in the range of 120 and 240 min. Scaling analysis was applied to quantify the surface characteristics of limiting roughness (δ) and critical length (LC) from which δ/LC was computed and related to the aspect ratio of surface features. All copper deposits showed a general rise in δ and LC with deposition time but the growth rates decreased when HydroStar was included in the electrolyte indicating that the additive lowers the vertical height of surface features as well as their widths. Furthermore, copper deposits were more consistently produced in the presence of HydroStar and, for a given value of limiting roughness, had surface features with wider base than those created in the absence of the additive. The results show that the modified polysaccharide acts to create smooth copper deposits by generating surface features with lower aspect ratios.

Electrolyte Solution Stirring Effect on Deposition Rate, Crystallographic Orientation, and Electrochemical Behaviour of Ni Film

Abstract Stirring the electrolyte meanwhile electrodeposition process is running may influence the properties of the forming films. In this work, the electrodeposition of copper (Cu) over aluminium (Al) alloy was performed. Subsequently, the electrodeposition of nickel (Ni) onto the formed Cu layer was conducted. In order to enhance the films properties, some various stirring speeds then are implied on the plating solution of the Ni electrodeposition process. The synthesized of Ni films were analysed by means of both X-ray diffraction (XRD) and a potentiostat equipment. The sample made shows different physical properties before and after electrodeposition based on sample weighed to examine the deposition rate. XRD patterns confirmed that all samples have a face-centered cubic (fcc) crystal structures with a space group of Fm-3m. Stirring speed play an important role of an inverse relationship with deposition rate, crystallite size, lattice strain, and corrosion rate. The sample that was made using the highest stirring speed yield a better corrosion resistance at around 0.239 mmpy due to less lattice strain.

Influence of Fe Ions on Anode Performance and the Mechanism of Action during Copper Electrowinning Process.

The performance of the anode varies from the impurity ions in the copper electrowinning process. This work focused on the variation of the electrochemical behavior of the Pb-0.06%Ca-1.2%Sn anode as the Fe ions (Fe3+ and/or Fe2+) existed in the electrolyte by electrochemical characterization. Copper electrodeposition experiments were conducted under a current density of 300 A/m2, with the Fe ion concentration in the electrolyte controlled within the range of 0 to 20 g/L and the Cu ion concentration maintained at 45 g/L at a temperature of 45 °C. The variation in the corrosion resistance, catalytic activity, and structural composition of the anode film layer was analyzed in-depth according to the presence of Fe ions. The results show that the structure of PbO2 on the surface of the film was changed as Fe ions doped into the anode film, and the oxygen evolution activity of the anode was also improved. However, the corrosion resistance decreased with increasing Fe3+ concentration. Furthermore, the addition of 2 g/L Fe2+ in the electrolyte containing 2 g/L Fe3+ led to an elevation in the corrosion resistance of the anode to some extent and further increased the oxygen evolution activity.

Fabrication of through alumina vias (TAV) by ultrasonic micromachining for advanced packaging applications

This article presents the fabrication of a high aspect ratio through alumina-vias (TAV) by combining ultrasonic micromachining (USM), electroless plating, and copper electrodeposition. Various horn designs, i.e., tapered, stepped, exponential, and hybrid horns, were analyzed to achieve a uniform longitudinal vibration in a 6 × 6 multi-tip tool assembly. The modal analysis determined the horn length, and harmonic analysis provided the stress distribution and vibrational amplitude. The tapered horn design was selected for its superior vibration amplification and reduced stresses. Finite element modeling predicted the geometric profiles of the microvias at various USM parameters. Experimental validation showed less than 5 % error in the depths of the microvias. Using the optimized USM parameters, a 6 × 6 array of blind and through-holes was created in a 3 mm thick alumina substrate with an average feed rate of 180 μm/min. The average tool wear was observed to be 0.5 mm when drilling through 3 mm thick alumina. Electroless deposition created a ∼100 nm seed layer on the alumina substrate and achieved good adhesion with via sidewalls. The through-holes were partially filled with a 60 μm thick copper layer by electrodeposition to create through-alumina vias (TAV) that can be used as 3D interconnects in the packaging of high-power electronics.

Copper‐graphene coatings for improving thermal shielding of CFRPs through electrodeposition techniques

AbstractToday, carbon fiber reinforced plastics (CFRPs) are materials of interest several industrial sectors because of their mechanical properties and low weight. However, applications in high‐temperature areas are limited because of thermal degradation. Thus, thin coatings acting as thermal shielding and ensuring the upkeep of CFRP structural stiffness are of high interest. This work presents an innovative approach to produce copper/graphene bilayer coatings through electrodeposition and electrophoretic deposition; it consists of laser pre‐treatment of the composite surface to remove the matrix layer exposing the carbon fibers, enabling the subsequent deposition. Bi‐layer graphene/copper coatings exhibit an enhancement in copper electrodeposition efficiency of more than 59% resulting in a 97% stiffness improvement compared to the single layer copper electroplating. All the obtained coatings were able to act as a thermal shield of the CFRPs, reducing the maximum temperature of the composite by more than 60%. In particular, due to the synergistic effect of copper and graphene, the GNPs‐Cu coating achieved the highest maximum temperature reduction (81%). Cross‐sectional analysis indicates severe delamination in uncoated CFRPs, whereas double‐layer coatings maintain structural integrity and prevent delamination even under high‐energy exposure. In addition, the coated composites exhibit a higher electrical conductivity compared to the laser cleaned CFRP, with the GNPs‐Cu coating that obtained a 90% enhancement because of the outstanding electrical properties of copper and graphene.Highlights The laser cleaning pretreatment allows the electrodepositions on CFRPs. The GNP‐Cu scenario achieves the highest deposition efficiency. A 97% stiffness improvement was achieved by GNPs‐Cu scenario. GNPs‐Cu coatings exhibit the utmost reduction in resistivity (98%). The GNPs‐Cu coating achieves the highest thermal shielding performance (81%).

Roles and influencing mechanisms of Fe2+ and Lix984 in copper electrodeposition

Roles and influencing mechanisms of Fe2+ and Lix984 in copper electrodeposition

Investigation of the effect of electrodeposited Cu from graphite wrapped in polypyrrole film formed by chemical oxidation

The metallization of graphite substrates is currently confronted by negative issues including insufficient adhesion and inherent instability. In an effort to surmount these challenges, a layer of conductive polypyrrole (PPy) film on a graphite surface is formed through simple polymerization, followed by an electroplating copper layer. The graphite enveloped by the PPy film, subjected to cyclic voltammetry (CV) and linear sweep voltammetry (LSV) analyses, demonstrates enhanced electrochemical activity and thus renders the more efficient electrodeposition of copper. Further investigation was conducted through orthogonal experiments to explore the optimal formulation of electroplating solutions containing popular additives including 3, 3′-dithiobis-1-propanesulfonic acid disodium salt (SPS), Janus Green B (JGB), and polyethylene glycol 8000 (PEG8000)., According to the optimal additive formulation, a dense copper layer with superior adhesion was electroplated on the graphite substrate employing PPy as an intermediate layer.

Clarifying the mechanism of actions of suppressor, brightener and sodium chloride in acid copper electrodeposition: A multidisciplinary approach for a many variable problem

Acid copper (AC) electrodeposition still a cardinal process for many fields, from electronic to decorative industries. Moreover, AC electroplating is a necessary step for Ni-free production cycles which are trending given the increased awareness of the toxicity of Ni2+ salts. State-of-the-art AC baths are formulated with a set of three organic additives, which are needed to achieve coatings with proper mechanical and optical features. However, despite the widespread use of these substances, their mechanism of action and the role of NaCl during the deposition are not clearly defined. A multidisciplinary approach has been employed to obtain insights on the mechanism of action of the organic additives on the Cu surface. This approach is based on electron microscopy electrochemical analysis supported by X-ray based techniques and computational calculations and simulations. An electrical field was included in molecular dynamics to delve the interactions between active species within the electrodeposition.

Preparation and electrochemistry study of a new Ti-based PbO2 electrode with Ta-Ti-Sn(Ru)Ox interlayer in Cu electrowinning

Copper (Cu) is a crucial non-ferrous material, and in this research, a new composite layered anode, Ti/Ta-Ti-Sn(Ru)Ox/PbO2, was developed for the hydrometallurgical process. The anode was created using thermal decomposition and subsequent electrodeposition, with Ti serving as the matrix and Ta-Ti-Sn(Ru)Ox as the interlayer. The study identified that the optimal molar ratio of Ta:Ti was 4:1, the ideal number of coating layers was 3, and the preparation temperature was 550 °C. The addition of Sn element improved the bonding force of the coating, preventing it from detaching even if it fails, while the inclusion of Ru enhanced the electrode’s service life. Moreover, the deposited PbO2 layer demonstrated a rich porous structure. In a long-cycle copper electrodeposition application, anodes with optimal preparation parameters showed higher current efficiencies and reduced energy consumptions compared to the Ti/Sn-SbOx/PbO2 baseline electrode, energy consumption reduced by 220.8 kWh per ton of copper product. This research presents a valuable strategy for designing and constructing high-performance electrodes for nonferrous electrolysis and other similar applications.

Feasibility and Structural Transformation of Electrodeposited Copper Foils for Graphene Synthesis by Plasma‐Enhanced Chemical Vapor Deposition: Implications for High‐Frequency Applications

AbstractLarge‐area graphene is typically synthesized on rolled‐annealed copper foils, which require transferring to other substrates for applications. This study examines large‐area graphene growth on electrodeposited (ED) copper foils—used in lithium‐ion batteries and printed circuit boards—via plasma‐enhanced chemical vapor deposition (PECVD). It reveals that, for a set plasma power, a minimum growth time ensures full graphene coverage, leading to monolayer and then multilayer graphene, showing PECVD growth on ED copper is not self‐limited. The process also beneficially modifies the ED copper substrate, like removing the surface zinc layer and changing copper grain size and orientation, thus improving graphene growth. Additionally, the study includes high‐frequency scattering parameter (S‐parameter) measurements in a coplanar waveguide (CPW) system. This involves graphene on a sapphire substrate with a silver electrode. The S‐parameter data indicate that the CPW with graphene shows reduced insertion losses in high‐frequency circuits compared to those without graphene. This underscores graphene's role in reducing insertion losses between metallic and dielectric layers in high‐frequency settings, offering valuable insights for industrial and technological applications.

Novel suppressor for damascene copper electrodeposition: Thioether-modified polyether with enhanced adsorption through an adjustable synthesis strategy

The void-free deposition of small-sized and high-aspect ratio interconnect structures requires stronger suppressors than conventional polyethers. In this work, thioether was introduced into polyether to develop novel suppressors with improved adsorption on electrode. The structure of thioether-modified polyether can be easily tailored by choosing proper polyether and thiol compound, thus providing a simple way to regulate electrochemical properties of the suppressor. The electrochemical and copper filling performance related to the molecular structure of novel suppressors were systematically investigated. Thioether-modified polyether, which retains the strong polarizability of typical suppressor and exhibits high resistance to accelerator desorption, can significantly suppress copper deposition on feature sidewalls. This enabled defect-free filling of narrower features at a concentration much lower than the typical usage concentration of suppressor. The modified polyethers with ethylene-propylene-ethylene (EPE) oxide triblock ether chains exhibited higher polarization strength and concentration dependence, facilitating the higher deposition current at the bottom during filling. The length and block ratio of ether chain further influenced the anti-desorption ability of the modified polyether, thereby impacting their suppression on sidewalls, which is crucial in filling process. The convenient structural adjustments for thioether-modified polyether, combined with the derived structure-property relationship, contribute to the development of new suppressors with strong adsorption performance.