Catalyst For Electroless Plating Research Articles

Improved Plating Adhesion of Polyarylate Fibers via Supercritical CO2 and Impregnation of Slightly Soluble Oil on the Fiber Surface

There is a growing demand for conductive fibers with high bending resistance, particularly for applications, such as smart textiles and robot arms. The amount of fiber for such applications can be reduced using high-performance fibers with high tensile properties, such as polyaramid and polyarylate Vectran®). However, because such fibers are crystalline with rigid molecular structures, they poorly adhere to plated films; thus, the plated fibers exhibit poor bending fatigue resistance. To solve this problem, in this study, we expanded polyarylate fiber using supercritical CO2 (ScCO2) and impregnated it with a metal complex (palladium acetate), which acts as a catalyst for electroless plating to induce an anchoring effect. However, because polyarylate fiber has an extremely low polarity, it is difficult to uniformly impregnate it with many metal complexes, even with ScCO2. Generally, an organic solvent is added to tune the polarity of supercritical CO2; however, the metal complex penetrates the fiber, thereby reducing the amount of metal complex near the fiber surface. Therefore, we tuned the polarity of the surface by applying various oils to the fiber surface. The sample electroplated in ScCO2 with oil applied to its surface showed the highest bending fatigue resistance, followed by that treated in ScCO2 without oil, and the sample treated in an aqueous solution showed the lowest. Furthermore, we measured the interfacial adhesion strength of the samples using the microdroplet method, and the same trend was observed.

The Latest Trend of the Electroless Plating Catalyst

The Latest Trend of the Electroless Plating Catalyst

Deposition of Ni-Based Carbon Nanotube Composite Coatings By Using Laser Enhanced Electroless Plating

1 Introduction In recent years, the mask-less direct metal patterning on 3D shape plastic substrates has received considerable attention from the perspective of potential applications to such as 3D-molded interconnect device (3D-MID). 2-shot injection molding and Laser direct structuring (LDS) are the leading technology in this field. However, these technology are not direct metal patterning. In the case of LDS, The laser-activatable thermoplastic doped with a special additive was required for making a sensitized-activated surface by laser. When the thermoplastic was irradiation by laser beam, it was activated. A physical-chemical reaction forms metallic nuclei. These act as a catalyst for electroless plating. The metallization on activated pass was performed by electroless plating after laser-activation. Some recent researches have investigated the laser enhanced electroless plating and have reported that they could successfully and directly formed metal patterning on the plastic substrates by the laser enhanced electroless plating. The metallization on activated pass were performed by electroless plating after laser-activation. However, the effects of the laser wavelength and additives in plating bath is not clear. In this study, their effects on the laser enhanced electroless plating were investigated. Carbon nanotubes (CNTs) were used as additives for improving laser absorption. 2 Experimental Procedure Polyimide films as substrates were immersed in low phosphorus electroless nickel plating bath (Meltex, NI-426, 1-3% phosphorus). The polyimide films were not sensitized and were not activated. Laser beam irradiation performed on the substrates through quartz glass rods at room temperature. Laser wavelengths of 405nm, 532nm, 980nm were chosen. CNTs (Showa denko, VGCF-H, 0.4g/L) were added in the plating bath. 3. Results and discussion In the case of non-addition of CNTs, no nickel deposited on the polyimide film by laser irradiation of 405nm (0.15W), 532nm (1.5W), 980nm (6W) in wavelength. Non-deposition results from non-pretreatment, such as sensitizing and activating, and from the less laser absorption of substrates. In the case of addition of CNTs, Island-like nickel deposited on the polyimide films by using 980 nm Laser beam. The nickel deposits were nickel-based CNT composites. CNTs improved the absorption of Laser and led local heating on the substrates so that the composite coatings formed on the non-pretreated substrates. Figure 1

Reductive Nucleation of Palladium Nanoparticles on a Cycloolefin Polymer Surface Oxidized with Active Oxygen Species Generated by Vacuum Ultraviolet Excitation

Abstract The ability to reduce palladium (Pd) ions to Pd nanoparticles has been provided on the surface of cycloolefin polymer (COP). The origin of this reductive function is aldehyde and alcoholic hydroxy groups formed by oxidizing the COP surface with active oxygen species, which were generated through the irradiation of atmospheric oxygen and water molecules with vacuum ultraviolet light of 172 nm in wavelength. The Pd nanoparticles successfully served as catalysts for electroless plating.

Fe-based surface activator for electroless nickel deposition on polyester: Application to electromagnetic shielding

The activation of the polyester (PET) by the solution of ferrous compound was examined as a palladium-free activation process. The principle of the process is based on the adsorption of Fe2+ on the substrate surface, reduction of Fe2+ into elementary substance Fe0, which is served as the catalyst for electroless plating. The Ni/PET composite can be obtained in three steps, namely: (i) the grafting of amino groups onto PET surface, (ii) the iron Fe0 seeding of the PET surface, and (iii) the nickel metallization using electroless plating bath. XPS, XRD, and AFM were used to characterize each step of the process. Adhesion of the nickel coating on PET was evaluated by a Scotch® tape test. Corrosive resistance of the Ni/PET composite was examined by a salty solution. The electromagnetic shielding effectiveness of the Ni/PET composite was more than 50dB at frequency ranging from 100 to 1000MHz. Comparing Fe2+ with Ni2+ as the metallic resource of the catalyst for electroless plating via the same process: the former resulting in a quicker nickel deposition rate and better nickel adhesion performance.

Electroless Plating Catalyst Performance of a Cationic Moiety Bearing Palladium Complex

Conventionally, in the electroless plating of resin, surface modification has been necessary to generate carboxylate moieties that enhances palladium catalyst adsorption. To further enhance palladium adsorption, a variety of Pd(II) amino acid complexes were synthesized, which bear a cationic pendant group with affinity for the carboxylate generated on the resin, and performance as an electroless plating catalyst evaluated. The Pd(II) complexes were characterized using UV-vis spectroscopy, revealing chelation of the amine and carboxylate groups of amino acids to Pd(II). For the Pd(II) complexes of Arginine or Lysine, affinity of the cationic pendant groups to resin surface carboxylate groups was suggested by enhanced Pd adsorption, c.a. 80 fold increase compared to complexes without cationic moieties. Furthermore, even under mild surface modification conditions with 0.5 mol/dm3 KOH, the Pd(II) complexed with Arginine or Lysine displayed performance as a electroless Ni catalyst, allowing for electolytic copper plated laminates of 1 kN/m adhesion strenghth.

Electroless plating of PVC plastic through new surface modification method applying a semi-IPN hydrogel film

A novel palladium-free surface activation process for electroless nickel plating was developed. This method applied a semi-Interpenetrating Polymer Network (semi-IPN) hydrogel film to modify the poly(vinyl chloride) (PVC) surface by chemical bonds. The activation process involved the formation of semi-IPN hydrogel film on the PVC surface and the immobilization of catalyst for electroless plating linking to the pretreated substrate via NNi chemical bond. The hydrogel layer was used as the chemisorption sites for nickel ions, and the catalyst could initiate the subsequent electroless nickel plating onto the PVC surface. Finally, a Ni–P layer was deposited on the nickel-activated PVC substrate by electroless plating technique. The composition and morphology of nickel-plated PVC foils were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). The results of SEM and XRD show that a compact and continuous Ni–P layer with amorphous nickel phase is formed on the PVC surface. EDS shows that the content of the nickel and the phosphorus in the deposits is 89.4wt.% and 10.6wt.%, respectively.

Iodine-aided palladium-free catalyzation process for durable electroless nickel plating on Kevlar® fiber

We report here a highly durable electroless nickel plating on Kevlar fiber through iodine-aided palladium-free catalyzation process. Kevlar was first treated with an iodine–potassium iodide aqueous solution to impart iodide component into the near fiber surface. The doped iodine was converted to silver iodide particles by treatment with silver nitrate aqueous solution, and subsequently silver iodide was reduced to silver metal particles. After electroless plating, a smooth nickel layer was evenly deposited on the fiber surface, which was resistant against sonication, tape peel-off, and alkaline corrosion tests. The silver particles formed on and near the fiber surface act as an anchor for the plated layer as well as a catalyst for electroless plating. Further investigation revealed that the use of an anionic surfactant during the catalyzation process enhanced the adhesive force of the plated layer with fiber surface. The plated fibers possessed high tensile strength, electrical conductivity, and ferromagnetic properties.

Highly adhesive metal plating on Zylon® fiber via iodine pretreatment

Highly adhesive metal plating was performed on poly(p-phenylene-2,6-benzobisoxazole) fiber named Zylon® via iodine pretreatment followed by electroless plating. First, iodine components were selectively doped into the inner part of the fiber near the surface through iodine vapor exposure. The doped iodine was converted to palladium iodide particles by treating with palladium chloride solution. After the reduction of the iodide to metal palladium particles, electroless copper plating was conducted on the fiber. A uniform copper layer was deposited on the fiber surface and exhibited high durability in durability tests such as ultrasonic exposure, tape peeling-off, and corrosion in NaCl solution. This durability was attributed to the palladium particles formed at the fiber surface that served as an anchor for the plated layer as well as an electroless plating catalyst. The plated fibers also possessed electrical conductivity. Although the tensile strength of the Zylon® fiber decreased from 5.8 to 4.9GPa after undergoing the pretreatment and plating processes, the light shielding effect improved the light resistance of the plated fibers in terms of tensile properties. After 18days of xenon lamp exposure, the plated fibers retained 74% of its initial strength, whereas that of untreated fibers decreased to 43%.

Evaluation of Tin-Copper Mixed Catalyst for the Replacement of Tin- Palladium Mixed Catalyst for Electroless Plating

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Ｐｄ混合触媒に代わる無電解めっき用Ｃｕ混合触媒の検討

Ｐｄ混合触媒に代わる無電解めっき用Ｃｕ混合触媒の検討

Thin Pd membrane on α-Al 2O 3 hollow fiber substrate without any interlayer by electroless plating combined with embedding Pd catalyst in polymer template

Palladium acetate and poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) were dissolved in chloroform to form a homogeneous solution. Using this solution, thin polymer template film with embedded Pd catalyst was coated on a porous α-Al 2O 3 hollow fiber substrate. The Pd in the template film was used as the catalyst for electroless plating of Pd membranes. After the template was removed by heat treatment, the thin Pd membranes without any intermediate layers and substrate penetration were synthesized successfully. The as-synthesized Pd composite membranes of thickness less than 5 μm not only have a very high hydrogen permeance/permeability but also have a good hydrogen selectivity. Moreover, the good membrane stability was verified by the long-term operation under the condition of hydrogen permeation and the gas exchange cycles between pure hydrogen and pure helium. The good membrane stability was interpreted by estimating the shear stress of the special membrane configuration with small gap between Pd membrane and porous substrate layer.

A Simple Photomask with Photoresist Mask Layer for Ultraviolet-Photolithography and Its Application for Selectively Photochemical Surface Modification of Polymers

According to ultraviolet (UV) spectroscopic studies, a positive AZ photoresist film thicker than 10 (m can hardly transmit UV lights of wavelengths 200–285 nm. A simple photomask for UV photolithography was prepared using a quartz glass plate coated with a light-obstructing film of positive AZ photoresist, and the quality of the photomask and fidelity of the pattern transferred by the photomask were evaluated. The developed AZ photoresist photomask was used for fabrication of gold microelectrode on polycarbonate (PC) sheets. PC sheetswere exposed to the UV lights emitted from a low-pressure mercury lamp and passed through the photomask. The PC sheets were subjected to selective surface photolysis in the exposed area. After a series of wet chemical reactions, nano gold particles serving as the catalyst for electroless plating were deposited on the irradiated area. Gold microelectrodes were then generated by immersing the selectively activated PC sheet in an electroless gold plating bath for a specific time. Without need for a clean room, the photomasks can be prepared by a chemist in a common chemical laboratory with low-cost materials and simple procedures.

Electroless Copper Plating onto Polyimide Using Polymer Nanosheet as a Nano-Adhesive

In this paper, we describe a technique to prepare a copper layer on polyimide film using a polymer nanosheet as a nano-adhesion. We employ two kinds of functional polymer nanosheets: one works as an adhesion layer and the other works as a template layer to adsorb gold nanoparticles, which works as a catalyst for the electroless plating. The photoreactive polymer nanosheet was used to increase the adhesion force between the copper layer and polyimide. Furthermore, the cationic polymer nanosheets were used to adsorb a gold catalyst for electroless copper plating. Applying the technique, electroless plated copper was attached strongly onto polyimide film. Micrometer copper lines were fabricated by photopatterning the polymer nanosheets. The process using polymer nanosheets as an adhesive required no surface modification of polyimide substrate and enabled microscale copper line fabrication without discharging harmful waste. Consequently, the technique is useful for next-generation flexible printed board fabrication.

Tris(hydroxymethyl)phosphine-Capped Gold Particles Templated by DNA as Nanowire Precursors

Tris(hydroxymethyl)phosphine-capped gold nanoparticles (ca. 1−2 nm diameter) bind densely to DNA, although both species are negatively charged. The particles are also active catalysts for electroless plating of gold. Electroless plating after adsorption to calf thymus DNA immobilized on silicon provides nanowires as narrow as ca. 30−40 nm and electrical conductivities ca. one-thousandth that of bulk gold. Here we summarize our physical characterization of the particles and their DNA conjugates and initial electrical measurements after plating.

Characterisation of a PdCl 2/SnCl 2 electroless plating catalyst system adsorbed on barium titanate-based electroactive ceramics

A PdCl 2/SnCl 2 metallisation catalyst system, of the type used to activate non-conducting surfaces for electroless metal deposition, has been characterised by X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The substrate is a barium titanate (BaTiO 3)-based electroactive ceramic of the type used in the fabrication of multilayer ceramic capacitors (MLCC). The treatment of the substrate surface with the PdCl 2/SnCl 2 “sensitiser” solution leads to the adsorption of catalytically inactive compounds of palladium and tin. Subsequent treatment of this surface with an “accelerator” solution removes excess oxides, hydroxides and salts of tin thereby leaving the active catalyst species, Pd x Sn y , on the surface. Such sites, on exposure to the appropriete electroless plating bath, are then responsible for the metal deposition. In this study, the chemical state and relative quantities of the various surface species present after each of the processing stages have been determined by XPS. The surface roughness of the substrate results in less of the tin compounds present thereon being removed on washing the catalysed surface in the accelerator solution than normally reported for such systems, thereby affecting the measured Pd: Sn ratio. SEM studies show that the accelerator solution treatment generates crystalline areas, which may be a result of coagulation of the Pd x Sn y particles present, in the otherwise amorphous catalyst coating.

Effect of Selected Metals on Electroless Plating Catalyst

SUMMARYA hydrous melt catalyst synthesis method was used to prepare materials having large amounts of copper or tin (IV). Both additives are of commercial interest. Absorption studies showed that neither had an effect on catalyst deposition on a plastic substrate. Their effect on catalyst synthesis is discussed.

Photo‐Selective Electroless Metal Deposition Following Light Absorption by Titanate Ceramics

Light absorption by titanate ceramics which have been pretreated with a Sn+2 containing solution can deactivate an electroless plating catalyst providing that photo‐exposure occurs in an containing ambient. Conditions are described whereby a lead zirconate‐titanate ceramic can be photopatterned by a brief exposure to a 365 nm wavelength lamp using a Mylar photomask and electroless Ni plated to yield a Ni pattern on the ceramic. Line/space resolution exceeding 0.05 mm is attainable.

Organometallic chemical vapor deposition of cobalt and formation of cobalt disilicide

The deposition of Co thin films by organometallic chemical vapor deposition is reported. Co is of interest in very large scale integration technology as a catalyst for electroless plating of other metals and as a precursor to formation of CoSi2. High purity, conformal films of Co are deposited by pyrolysis of Co2(CO)8 at 200 °C in vacuum. These films exhibit electrical resistivities of 5–10 μΩ cm and excellent adhesion to Si and SiO2. CoSi2 is formed by heating the samples at 700 °C. The CoSi2 films resulting from reaction of the Co films with the Si substrate contain larger grains than the starting film and exhibit electrical resistivities of ∼13–37 μΩ cm. Selective formation of CoSi2 on patterned test wafers shows similar attributes.

Behavior of Pd/Sn and Pd Catalysts for Electroless Plating on Different Substrates Investigated by Means of Rutherford Backscattering Spectroscopy

Two catalytic systems for electroless metal deposition have been investigated by means of Rutherford backscattering spectrometry (RBS). The well‐known tin sensitizer, palladium activator, two‐step catalyst had the main emphasis, but also a commercial one based on evaporated palladium was examined. The behavior of the two‐step catalyst was largely dependent on the substrates used. On , the Sn:Pd ratio was 1:1 with each. On carbon substrates, the Sn:Pd ratio was 1:4 with and . Both these results violate the simple reaction mechanism described by the equation . The commercial catalyst on polyimide containing on the surface behaved differently compared to the two‐step catalyst by diffusing into the deposited layer and thereby influencing its deposition rate.