• Journal of the Korean institute of surface engineering
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• v.36 no.3
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• pp.263-271
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• 2003

Optimal conditions of electroless nickel plating in acid baths has been studied for industrial applications of a developed EN solution. The phosphorus content in the deposition ranges from 8 to $12\;wt.\%$. The investigated EN plating parameters are ion concentrations of nickel and hypophosphite, concentration of reducing and complexing agent, temperature, and pH. The average plating rate of Ni-P deposition was ca. $14{\mu}m/h$. The EN solution used shows a deposition rate of $10{\mu}m/h$ up to seven metal turnovers.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2001.11a
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• pp.10-10
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• 2001

In this paper, initial depositing process of electroless Ni-Cu-P alloy was investigated by means of SEM, TEM and AES. The results show that the initial deposition is inhomogeneous and there exist different transition layers between different coatings and substrates, which are decided by the structures and compositions of the bath. For Ni-P binary alloy, its deposition takes place superiorly at grain boundary and on some grains with beneficial texture, the thickness of transition layer composed of Ni-Fe-P reaches 2000 angstrom. But during initiation of Ni-Cu-P trinary alloy, only at grain boundary is prIor to be deposited electrolessly, transited layer contains Ni-Fe-Cu-P and is decreased to about 500 angstrom. The structures of the films of Ni-P and Ni-Cu-P are crystalline at the initial depositing stage. The mechanisms of the process are put forward in this paper.

• Journal of the Korean institute of surface engineering
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• v.43 no.2
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• pp.111-120
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• 2010

In this study, the effects of multi-complex agents addition on characteristics of electroless Ni plating solution are investigated. The species and the concentration of complexing agents are major factors to control the deposition rate, P concentration, and surface morphology of plating films. Adipic acid increases the deposition rate in regardless of single- or mutli-complex agent addition. However, lactic acid effectively increases the deposition rate in case of multi-addition as the complex agents with adipic or sodium succinate acid. In addition, sodium citric acid and malic acid show good stabilizing effects of plating solution and lowering the deposition rate, because they have high complexibility. Therefore, it is suggested that the development of Ni-P plating solution suitable for diverse usages can be carried out systematically using the database from this study.

• Korean Journal of Metals and Materials
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• v.46 no.11
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• pp.725-729
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• 2008

Deposition characteristics of electroless plated Ni-W-P films were investigated for various complexing agents. Used complexing agents are sodium citrate, sodium gluconate and sodium malonate. In this study, the existing mixed potential theory could explain the overall mechanism of Ni-W-P electroless plating for all complexing agents. The deposition rate could be also expected by the theory. The deposited Ni-W-P films were evaluated in term of surface hardness and corrosion resistance. Microhardness of the deposit increased about 1,000 Hv after heat treatment for one hour at $400^{\circ}C$, because it was above the crystallization temperature of $Ni_3P$. The deposited Ni-W-P films can exhibit excellent corrosion resistance in using sodium malonate as a complexing agent, the other hand the using sodium gluconate was the worst corrosion resistance. The worst corrosion resistance was due to a large number of nano-sized pin-holes or small pores. The plating current at the mixed potential increases when the using sodium malonate as a complexing agent, it was explained by the cross section.

• Journal of the Korean institute of surface engineering
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• v.40 no.3
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• pp.131-137
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• 2007

The typical MCFC (molten carbonate fuel cell) anode is made of Ni-10%Cr alloy. The work of this paper is focused concerning long life of anode because Ni-10% Cr anode is suffering from sintering and creep behavior during cell operation. Therefore, Ni-coated Alumina powder($20{\mu}m$) was developed by electroless nickel plating. Optimum condition of electroless nickel coation on $20{\mu}m$ alumina is as follows: pH 11.7, temperature $65{\sim}80^{\circ}C$, powder amount $100cm^2/l$. The deposition rate for Ni-electroless plating was as a function of temperature and activation energy was evaluated by Arrhenius Equation thereby activation energy calculated slope of experimental data as 117.6 kJ/mol, frequency factor(A) was $6.28{\times}10^{18}hr^{-1}$, respectively.

• Transactions of Materials Processing
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• v.21 no.5
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• pp.330-335
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• 2012

Roll formed steel bolts are electrodeposited with Zn-Ni to protect themselves from corrosion. However, white storage stain or white rust(corrosion) is found on Zn-Ni electrodeposited surface of steel bolts when they are exposed to moisture. In this paper a new process is introduced to protect Zn-Ni electrodeposited steel bolt from white storage stain or white rust for a long time under the salt spray test and high humidity test conditions. The better corrosion resistance could be gotten by the additional process of Ni-P electroless deposition and heat treatment to conventional manufacturing method of Zn-Ni coated steel bolt. The corrosion resistance of Zn-Al powder slurry coated steel bolt showed better than that of Zn-Ni electrodeposited one.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.10a
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• pp.25.2-25.2
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• 2011

Recently, thin film capacitors used for vehicle inverters are small size, high capacitance, fast response, and large capacitance. But its applications were made up of liquid as electrolyte, so its capacitors are limited to low operating temperature range and the polarity. This research proposes using Ni-P alloys by electroless plating as the electrode instead of liquid electrode. Our substrate has a high aspect ratio and complicated shape because of anodic aluminum oxide (AAO). We used AAO because film thickness and effective surface area are depended on for high capacitance. As the metal electrode instead of electrolyte is injected into AAO, the film capacitor has advantages high voltage, wide operating temperature, and excellent frequency property. However, thin film capacitor made by electroless-plated Ni on AAO for full-filling into etched tunnel was limited from optimizing the deposition process so as to prevent open-through pore structures at the electroless plating owing to complicated morphological structure. In this paper, the electroless plating parameters are controlled by temperature in electroless Ni plating for reducing reaction rate. The Electrical properties with I-V and capacitance density were measured. By using nickel electrode, the capacitance density for the etched and Ni electroless plated films was 100 nFcm-2 while that for a film without any etch tunnel was 12.5 nFcm-2. Breakdown voltage and leakage current are improved, as the properties of metal deposition by electroless plating. The synthesized final nanostructures were characterized by scanning electron microscopy (SEM).

• Korean Journal of Materials Research
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• v.14 no.8
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• pp.552-557
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• 2004

Thin Ni-B films, 1 ${\mu}m$ thick, were electrolessly deposited on Cu bus electrode fabricated by electro deposition. The purpose of these films is to encapsulate Cu electrodes for preventing Cu oxidation and to serve as a diffusion barrier against copper contamination of dielectric layer in AC-plasma display panel. The layers were heat treated at $580^{\circ}C$(baking temperature of dielectric layer) with and without pre-annealing at $300^{\circ}C$($Ni_{3}B$ formation temperature) for 30 minutes. In the layer with pre-annealing, amount of Cu diffusion was lower about 5 times than that in the layer without pre-annealing. The difference of Cu concentration could be attributed to Cu diffusion before $Ni_{3}B$ formation at grain boundaries. However, the diffusion behavior of the layer with pre-annealing was similar to that of the layer without pre-annealing after $Ni_{3}B$ formation. With increasing annealing time, Cu concentration of both layers increased due to grain growth.

• Journal of the Korean Ceramic Society
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• v.52 no.4
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• pp.264-268
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• 2015

Cu films were plated in an eco-friendly electroless bath (No-Formaldehyde) on Ni/screen printed Ag pattern/PET substrate. For electroless Cu plating, we used sodium-phosphinate ($NaH_2PO_2{\cdot}H_2O$) as reducing agent instead of Formaldehyde. All processes were carried out in electroless solution of pH 7 to minimize damage to the PET substrate. According to the increase of sodium-phosphinate, the deposition rate, the granule size, and rms roughness of the electroless Cu film increased and the Ni content also increased. The electroless Cu films plated using 0.280 M and 0.575 M solutions of sodium-phosphinate were made with Cu of 94 at.% and 82 at.%, respectively, with Ni and a small amount P. All electroless Cu plated films had typical FCC crystal structures, although the amount of co-deposited Ni changed according to the variation of the sodium-phosphinate contents. From these results, we concluded that a formation of higher purity Cu film without surface damage to the PET is possible by use of sodium-phosphinate at pH 7.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.4
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• pp.328-332
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• 2011

The formation of front metal contact silicon solar cells is required for low cost, low contact resistance to silicon surface. One of the front metal contacts is Ni/Cu plating that it is available to simply and inexpensive production to apply mass production. Ni is shown to be a suitable barrier to Cu diffusion into the silicon. The process of Ni electroless plating on front silicon surface is performed using a chemical bath. Additives and buffer agents such as ammonium chloride is added to maintain the stability and pH control of the bath. Ni deposition rate is found to vary with temperature, time, utilization of bath. The experimental result shown that Ni layer by SEM (scanning electron microscopy) and EDX analysis. Finally, plated Ni/Cu contact solar cell result in an efficiency of 17.69% on $2{\times}2\;cm^2$, Cz wafer.