The Experts below are selected from a list of 2043 Experts worldwide ranked by ideXlab platform

Wenbin Hu - One of the best experts on this subject based on the ideXlab platform.

  • role of additives in Electroless Copper Plating using hypophosphite as reducing agent
    Surface & Coatings Technology, 2012
    Co-Authors: Kechao Zhou, Wenbin Hu, Dou Zhang
    Abstract:

    Abstract In Electroless Copper Plating baths using hypophosphite as the reducing agent, nickel ions was used to catalyze hypophosphite oxidation. However, the color of the Copper deposits was dark or brown and the electrical resistivity was much higher than that obtained from formaldehyde baths. Polyethylene glycol (PEG) and K 4 Fe(CN) 6 were used to improve the microstructure and properties of Copper deposits obtained from Electroless Copper Plating bath using hypophosphite as the reducing agent. The effects of PEG concentration on the deposition rate, the microstructure, morphology and electrical resistivity of the Copper deposits, and the electrochemical reactions of hypophosphite (oxidation) and cupric ion (reduction) were investigated. The traces of hydrogen escaping from the deposits surface disappeared and the color of the Copper deposits changed from dark-brown to dark red when the PEG concentration was 1.67 × 10 − 5  M or more. The deposition rate increased and the electrical resistivity of the Copper deposits decreased slightly with the addition of PEG to the Plating solution. The electrical resistivity of Copper deposits decreased to 2.85 μΩ cm with 1.67 × 10 − 5  M PEG and 4.70 × 10 − 6  M K 4 Fe(CN) 6 in the bath. Larger grain size and higher (220) plane orientation were obtained with the increase of PEG concentration in the bath. The electrochemical current–voltage results showed that PEG accelerated the catalytic oxidation of hypophosphite at active nickel sites and had little effect on the reduction reaction of cupric ions on the deposit surface by adsorption on the electrode.

  • Role of additives in Electroless Copper Plating using hypophosphite as reducing agent
    Surface and Coatings Technology, 2012
    Co-Authors: Xueping Gan, Kechao Zhou, Wenbin Hu, Dou Zhang
    Abstract:

    In Electroless Copper Plating baths using hypophosphite as the reducing agent, nickel ions was used to catalyze hypophosphite oxidation. However, the color of the Copper deposits was dark or brown and the electrical resistivity was much higher than that obtained from formaldehyde baths. Polyethylene glycol (PEG) and K4Fe(CN)6were used to improve the microstructure and properties of Copper deposits obtained from Electroless Copper Plating bath using hypophosphite as the reducing agent. The effects of PEG concentration on the deposition rate, the microstructure, morphology and electrical resistivity of the Copper deposits, and the electrochemical reactions of hypophosphite (oxidation) and cupric ion (reduction) were investigated. The traces of hydrogen escaping from the deposits surface disappeared and the color of the Copper deposits changed from dark-brown to dark red when the PEG concentration was 1.67×10-5M or more. The deposition rate increased and the electrical resistivity of the Copper deposits decreased slightly with the addition of PEG to the Plating solution. The electrical resistivity of Copper deposits decreased to 2.85μΩ cm with 1.67×10-5M PEG and 4.70×10-6M K4Fe(CN)6in the bath. Larger grain size and higher (220) plane orientation were obtained with the increase of PEG concentration in the bath. The electrochemical current-voltage results showed that PEG accelerated the catalytic oxidation of hypophosphite at active nickel sites and had little effect on the reduction reaction of cupric ions on the deposit surface by adsorption on the electrode. © 2012 Elsevier B.V.

  • Electroless Copper Plating on pet fabrics using hypophosphite as reducing agent
    Surface & Coatings Technology, 2007
    Co-Authors: Yating Wu, Bin Shen, Wenbin Hu
    Abstract:

    Abstract Electroless Copper Plating on PET fabrics using hypophosphite as reducing agent was investigated. A continuous Copper deposition could be obtained as the nickel ion concentration and temperature were more than 0.0030 M and 65 °C, respectively. The deposition rate increased obviously with the increase of temperature, pH and nickel ion concentration. Potassium ferrocyanide (K4Fe(CN)6) was used to improve the properties of the Copper deposits. The addition of K4Fe(CN)6 to the Plating solution could reduce the deposition rate and make the deposits become more compact, which led to lower surface resistance of Copper-coated fabrics. The Copper deposit had an intensified (111) plane orientation with the addition of K4Fe(CN)6 to the Plating bath. The conductive fabrics could be prepared at the optimum condition with 0.0038M nickel ions and 2 ppm K4Fe(CN)6. As the Copper weight on the fabric was 40 g/m2, the shielding effectiveness (SE) of Copper-coated fabrics was more than 85 dB at frequency ranging from 100 MHz to 20 GHz.

  • Effects of K4Fe(CN)6 on Electroless Copper Plating using hypophosphite as reducing agent
    Journal of Applied Electrochemistry, 2007
    Co-Authors: Xueping Gan, Yating Wu, Lei Liu, Wenbin Hu
    Abstract:

    K4Fe(CN)6 was used to improve the microstructure and properties of Copper deposits obtained from hypophosphite baths. In Electroless Copper Plating solutions using hypophosphite as the reducing agent, nickel ions (0.0038 M with Ni2+/Cu2+ mole ratio 0.12) was used to catalyze hypophosphite oxidation. However, the color of the Copper deposits was dark or brown and its resistivity was much higher than that obtained in formaldehyde baths. The effects of K4Fe(CN)6 on the deposit composition, resistivity, structure, morphology and the electrochemical reactions of hypophosphite (oxidation) and cupric ion (reduction) have been investigated. The deposition rate and the resistivity of the Copper deposits decreased significantly with the addition of K4Fe(CN)6 to the Plating solution and the color of the deposits changed from dark-brown to Copper-bright with improved uniformity. The nickel and phosphorus content in the deposits also decreased slightly with the use of K4Fe(CN) 6. Smaller crystallite size and higher (111) plane orientation were obtained by addition of K4Fe(CN)6. The electrochemical current-voltage results show that K4Fe(CN)6 inhibited the catalytic oxidation of hypophosphite at active nickel sites and reduced the reduction reaction of cupric ions on the deposit surface by adsorption on the electrode. This results in lower deposition rate and a decrease in the mole ratio of NaH2PO2/CuSO4 consumed during Plating. © Springer Science+Business Media B.V. 2007.

Paul A Kohl - One of the best experts on this subject based on the ideXlab platform.

  • the deposition characteristics of accelerated nonformaldehyde Electroless Copper Plating
    Journal of The Electrochemical Society, 2003
    Co-Authors: Jun Li, Paul A Kohl
    Abstract:

    The deposition process of an Electroless Copper Plating solution using sodium citrate as the main complexing agent and sodium hypophosphite as the reducing agent has been investigated. The deposit composition, structure, and catalytic activity for the oxidation of hypophosphite during the process have been investigated. Formamidine disulfide (fd) has been shown to accelerate the deposition rate of the Electroless Plating just as it does with Electroless Plating solutions using N-(2-hydroxyethyl)ethylenediaminetriacetic acid trisodium salt hydrate (HEDTAI as the complexing agent. For solutions with the Cu 2+ /Ni 2+ mole ratio of 42, the deposition rate decreased with time and terminated after 90 min Plating because the surface catalytic activity of the deposit had decreased with thickness. A Copper deposit with total thickness of 6.48-6.59 μm was obtained after 90 min Plating. The decrease in the deposition rate with time was mitigated by decreasing the Cu 2+ /Ni 2+ mole ratio, holding the concentration of Copper ions constant. An optimized Electroless Copper Plating process with sustained deposition rate with time and high metal conductivity was developed. The bath was used in a fully additive high density wiring process.

  • the influence of 2 2 dipyridyl on non formaldehyde Electroless Copper Plating
    Copper interconnects new contact metallurgies structures and low-k interlevel dielectrics, 2003
    Co-Authors: Jun Li, Harley Hayden, Paul A Kohl
    Abstract:

    2,2'-dipyridyl was introduced to improve the microstructure and properties of the Copper deposits from Electroless Copper Plating using hypophosphite as the reducing agent. The influences of 2,2'-dipyridyl on the deposit composition, structure, properties, and the electrochemical reactions of hypophosphite oxidation and cupric ion reduction have been investigated. The results show that the Electroless deposition rate decreased significantly with the addition of 2,2'-dipyridyl in the Plating solution and the color of the deposits changed from dark brown to a semi-bright, pink-tint. The deposits became uniform and compact. The deposits had a decreased crystallite size and intensified (111) plane orientation with the addition of 2,2'-dipyridyl in the Plating bath. However, the resistivity and nickel content in the deposit were not effected by 2,2'-dipyridyl. The electrochemical measurements prove that 2,2'-dipyridyl inhibited significantly the catalytic oxidation of hypophosphite at the nickel active site on the deposit surface and increased the overpotential for cupric ion reduction, thus reducing the deposition rate and making the deposit become fine.

  • the acceleration of nonformaldehyde Electroless Copper Plating
    Journal of The Electrochemical Society, 2002
    Co-Authors: Jun Li, Paul A Kohl
    Abstract:

    Nonformaldehyde, low pH (compared to highly alkaline bath) Electroless Copper Plating has been investigated. Thiourea and its derivatives have been shown to increase the deposition rate of Electroless Copper Plating solutions using HEDTA [N-(2-hydroxyethyl)ethylenediaminetriacetic acid trisodium salt hydrate] as the complexing agent and sodium hypophosphite as the reducing agent. A thiourea concentration of 1.0 ppm produced a fourfold increase in the deposition rate of Copper from about 1 to 4 μm/h. The effect of thiourea on the electrochemical reactions, and the crystal structures and electrical properties of the Copper deposits were examined. A small amount of thiourea, or its derivatives, in the Electroless Copper solution improves the catalytic activity of the Copper surface for the oxidation of hypophosphite, resulting in a higher Electroless deposition rate. The thiourea also increases the growth colony size of the Copper deposits and improves its conductivity. A reaction mechanism is proposed to describe the function of the thiourea and its derivatives on the process.

Jun Li - One of the best experts on this subject based on the ideXlab platform.

  • the deposition characteristics of accelerated nonformaldehyde Electroless Copper Plating
    Journal of The Electrochemical Society, 2003
    Co-Authors: Jun Li, Paul A Kohl
    Abstract:

    The deposition process of an Electroless Copper Plating solution using sodium citrate as the main complexing agent and sodium hypophosphite as the reducing agent has been investigated. The deposit composition, structure, and catalytic activity for the oxidation of hypophosphite during the process have been investigated. Formamidine disulfide (fd) has been shown to accelerate the deposition rate of the Electroless Plating just as it does with Electroless Plating solutions using N-(2-hydroxyethyl)ethylenediaminetriacetic acid trisodium salt hydrate (HEDTAI as the complexing agent. For solutions with the Cu 2+ /Ni 2+ mole ratio of 42, the deposition rate decreased with time and terminated after 90 min Plating because the surface catalytic activity of the deposit had decreased with thickness. A Copper deposit with total thickness of 6.48-6.59 μm was obtained after 90 min Plating. The decrease in the deposition rate with time was mitigated by decreasing the Cu 2+ /Ni 2+ mole ratio, holding the concentration of Copper ions constant. An optimized Electroless Copper Plating process with sustained deposition rate with time and high metal conductivity was developed. The bath was used in a fully additive high density wiring process.

  • the influence of 2 2 dipyridyl on non formaldehyde Electroless Copper Plating
    Copper interconnects new contact metallurgies structures and low-k interlevel dielectrics, 2003
    Co-Authors: Jun Li, Harley Hayden, Paul A Kohl
    Abstract:

    2,2'-dipyridyl was introduced to improve the microstructure and properties of the Copper deposits from Electroless Copper Plating using hypophosphite as the reducing agent. The influences of 2,2'-dipyridyl on the deposit composition, structure, properties, and the electrochemical reactions of hypophosphite oxidation and cupric ion reduction have been investigated. The results show that the Electroless deposition rate decreased significantly with the addition of 2,2'-dipyridyl in the Plating solution and the color of the deposits changed from dark brown to a semi-bright, pink-tint. The deposits became uniform and compact. The deposits had a decreased crystallite size and intensified (111) plane orientation with the addition of 2,2'-dipyridyl in the Plating bath. However, the resistivity and nickel content in the deposit were not effected by 2,2'-dipyridyl. The electrochemical measurements prove that 2,2'-dipyridyl inhibited significantly the catalytic oxidation of hypophosphite at the nickel active site on the deposit surface and increased the overpotential for cupric ion reduction, thus reducing the deposition rate and making the deposit become fine.

  • the acceleration of nonformaldehyde Electroless Copper Plating
    Journal of The Electrochemical Society, 2002
    Co-Authors: Jun Li, Paul A Kohl
    Abstract:

    Nonformaldehyde, low pH (compared to highly alkaline bath) Electroless Copper Plating has been investigated. Thiourea and its derivatives have been shown to increase the deposition rate of Electroless Copper Plating solutions using HEDTA [N-(2-hydroxyethyl)ethylenediaminetriacetic acid trisodium salt hydrate] as the complexing agent and sodium hypophosphite as the reducing agent. A thiourea concentration of 1.0 ppm produced a fourfold increase in the deposition rate of Copper from about 1 to 4 μm/h. The effect of thiourea on the electrochemical reactions, and the crystal structures and electrical properties of the Copper deposits were examined. A small amount of thiourea, or its derivatives, in the Electroless Copper solution improves the catalytic activity of the Copper surface for the oxidation of hypophosphite, resulting in a higher Electroless deposition rate. The thiourea also increases the growth colony size of the Copper deposits and improves its conductivity. A reaction mechanism is proposed to describe the function of the thiourea and its derivatives on the process.

Attaphon Kaewvilai - One of the best experts on this subject based on the ideXlab platform.

  • Electroless Copper Plating on nano silver activated glass substrate a single step activation
    Surface & Coatings Technology, 2017
    Co-Authors: Attaphon Kaewvilai, Romchalee Tanathakorn, Apirat Laobuthee, Watcharee Rattanasakulthong, Aphichart Rodchanarowan
    Abstract:

    Abstract The Electroless Copper Plating on non-conductive glass substrates by nano-silver activation was studied instead of the conventional two-stepped pre-treatment processes (SnCl 2 sensitization and PdCl 2 activation). The glass substrate was prepared by polishing with 400 grit silicon carbide abrasive paper and then activated by dipping into Ag(I)-benzoxanine solution to obtain the dispersed nano-silver particles on the surface. The results from SEM, XRD, XRF and TEM illustrated that nano-metallic Ag was successfully prepared and coated on glass substrate. The nano-silver activated glass substrates were then used to study the following parameters: Plating time, temperature and concentration of additive gelatin. According to SEM and AFM observation, the Cu film was uniformly grown, smooth and dense of particles. The crystallized sizes of silver and Copper on the substrate were calculated by Scherrer's equation, and found to be 45 and 85 nm, respectively. In addition, the adhesion of the deposited Copper was conducted by using the tape-test technique according to ASTM D3359-02.

Dou Zhang - One of the best experts on this subject based on the ideXlab platform.

  • role of additives in Electroless Copper Plating using hypophosphite as reducing agent
    Surface & Coatings Technology, 2012
    Co-Authors: Kechao Zhou, Wenbin Hu, Dou Zhang
    Abstract:

    Abstract In Electroless Copper Plating baths using hypophosphite as the reducing agent, nickel ions was used to catalyze hypophosphite oxidation. However, the color of the Copper deposits was dark or brown and the electrical resistivity was much higher than that obtained from formaldehyde baths. Polyethylene glycol (PEG) and K 4 Fe(CN) 6 were used to improve the microstructure and properties of Copper deposits obtained from Electroless Copper Plating bath using hypophosphite as the reducing agent. The effects of PEG concentration on the deposition rate, the microstructure, morphology and electrical resistivity of the Copper deposits, and the electrochemical reactions of hypophosphite (oxidation) and cupric ion (reduction) were investigated. The traces of hydrogen escaping from the deposits surface disappeared and the color of the Copper deposits changed from dark-brown to dark red when the PEG concentration was 1.67 × 10 − 5  M or more. The deposition rate increased and the electrical resistivity of the Copper deposits decreased slightly with the addition of PEG to the Plating solution. The electrical resistivity of Copper deposits decreased to 2.85 μΩ cm with 1.67 × 10 − 5  M PEG and 4.70 × 10 − 6  M K 4 Fe(CN) 6 in the bath. Larger grain size and higher (220) plane orientation were obtained with the increase of PEG concentration in the bath. The electrochemical current–voltage results showed that PEG accelerated the catalytic oxidation of hypophosphite at active nickel sites and had little effect on the reduction reaction of cupric ions on the deposit surface by adsorption on the electrode.

  • Role of additives in Electroless Copper Plating using hypophosphite as reducing agent
    Surface and Coatings Technology, 2012
    Co-Authors: Xueping Gan, Kechao Zhou, Wenbin Hu, Dou Zhang
    Abstract:

    In Electroless Copper Plating baths using hypophosphite as the reducing agent, nickel ions was used to catalyze hypophosphite oxidation. However, the color of the Copper deposits was dark or brown and the electrical resistivity was much higher than that obtained from formaldehyde baths. Polyethylene glycol (PEG) and K4Fe(CN)6were used to improve the microstructure and properties of Copper deposits obtained from Electroless Copper Plating bath using hypophosphite as the reducing agent. The effects of PEG concentration on the deposition rate, the microstructure, morphology and electrical resistivity of the Copper deposits, and the electrochemical reactions of hypophosphite (oxidation) and cupric ion (reduction) were investigated. The traces of hydrogen escaping from the deposits surface disappeared and the color of the Copper deposits changed from dark-brown to dark red when the PEG concentration was 1.67×10-5M or more. The deposition rate increased and the electrical resistivity of the Copper deposits decreased slightly with the addition of PEG to the Plating solution. The electrical resistivity of Copper deposits decreased to 2.85μΩ cm with 1.67×10-5M PEG and 4.70×10-6M K4Fe(CN)6in the bath. Larger grain size and higher (220) plane orientation were obtained with the increase of PEG concentration in the bath. The electrochemical current-voltage results showed that PEG accelerated the catalytic oxidation of hypophosphite at active nickel sites and had little effect on the reduction reaction of cupric ions on the deposit surface by adsorption on the electrode. © 2012 Elsevier B.V.