• Journal of the Microelectronics and Packaging Society
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• v.18 no.4
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• pp.43-48
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• 2011

Electroless nickel platings on carbon substrate were investigated for porous MCFC electrode applications. Acidic bath and alkaline bath were used in electroless nickel plating on carbon substrates. The rate of electroless plating in alkaline bath was faster than that in acidic bath. As pH was increased, the deposition rate was increased in both baths and the content of phosphorus in nickel deposit was decreased. The residual stresses of nickel deposit from acidic bath showed the compressive stress and on the other hand those from alkaline bath showed the high tensile stress. High tensile internal stress in nickel deposit caused the cracks over pH 11. Thiourea was added to both acidic and alkaline bath. The deposition rate of nickel was increased upto 0.5 ppm of thiourea and decreased. The maximum concentration of thiourea for the electroless nickel plating on carbon substrate was 1.5 ppm in both acidic and alkaline bath. Succinic acid was added to acidic bath. Addition of succinic acid up to 5 g/L increased the deposition rate of nickel and beyond which the deposition rate was decreased and maintained.

• Journal of the Korean Electrochemical Society
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• v.3 no.4
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• pp.196-199
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• 2000

Electroless plating is the desirable surface treatment method which is being widely used to all kinds of material such as requiring corrosion resistance, wear resistance and conductivity, especially plating of nonconductive material. Electroless nickel deposit has particular characteristics including non-magnetic property, amorphous structure, wear resistance, corrosion protection and thermal stability. In this study, electroless nickel plating was studied with an change in hardness and corrosion resistance of electroless nickel-phosphorus deposit depending on heat treatment. The highest hardness value was obtained by heat treatment at $500^{\circ}C$ Corrosion resistance of deposit, which had been heated at $300^{\circ}C$, was excellent when it was immersed in 1M $H_2SO_4$ solution for 60 hrs.

• Korean Journal of Metals and Materials
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• v.48 no.1
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• pp.90-100
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• 2010

Micro-conductive patterns were microfabricated on an insulating substrate ($SiO_2$) surface by a selective electroless nickel plating process in order to investigate the formation of seed layers. To fabricate micro-conductive patterns, a thin layer of metal (Cu.Cr) was deposited in the desired micropattern using laser-induced forward transfer (LIFT). and above this layer, a second layer was plated by selective electroless plating. The LIFT process. which was carried out in multi-scan mode, was used to fabricate micro-conductive patterns via electroless nickel plating. This method helps to improve the deposition process for forming seed patterns on the insulating substrate surface and the electrical conductivity of the resulting patterns. This study analyzes the effect of seed pattern formation by LIFT and key parameters in electroless nickel plating during micro-conductive pattern fabrication. The effects of the process variables on the cross-sectional shape and surface quality of the deposited patterns are examined using field emission scanning electron microscopy (FE-SEM) and an optical microscope.

• Journal of the Microelectronics and Packaging Society
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• v.14 no.3
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• pp.21-27
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• 2007

Nickel bumps for ACF(anisotropic conductive film) flip chip application were fabricated by electroless and electro plating and their mechanical properties and impact reliability were examined through the compressive test, bump shear test and drop test. Stress-displacement curves were obtained from the load-displacement data in the compressive test using nano-indenter. Electroplated nickel bumps showed much lower elastic stress limits (70MPa) and elastic moduli ($7.8{\times}10^{-4}MPa/nm$) than electroless plated nickel bumps ($600-800MPa,\;9.7{\times}10^{-3}MPa/nm$). In the bump shear test, the electroless plated nickel bumps were deformed little by the test blade and bounded off from the pad at a low shear load, whereas the electroplated nickel bumps allowed large amount of plastic deformation and higher shear load. Both electroless and electro plated nickel bumps bonded by ACF flip chip method showed high impact reliability in the drop impact test.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.8
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• pp.27-33
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• 2004

The ultra-precision cutting is a key technique for the manufacture of optical components such as aluminium mirrors, electroless nickel mirror, plastic mirror in a variety of advanced science and technology applications. The paper presents experimental results of ultra-precision diamond fuming of electroless nickel materials. In general, the cutting condition such as feed rate and depth of rut, have effect on the surface roughness in ultra-precision diamond turning. To obtain an optimal cutting condition, we studied the effect of the cutting speed. the tool length, the tool nose radius, the feed rate and depth of cut on the surface roughness. So, the relationship of the surface roughness and cutting condition has been clarified. From the experimental results, the machined surface roughnesses were obtained less than 1nm rms.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.538-541
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• 2003

Ultra-precision machining was carried out on a electroless nickel materials using single crystal diamond tools. The effects of the cutting velocity, the tool length, the tool nose radius, the feed rate and depth of cut on the surface roughness were studied. In this paper, the cutting condition for getting nano order smooth surface of electroless nickel have been examined experimentally by the ultra-precision machine and single crystal diamond tools. And also. the surface roughness was measured by the three dimension

• Journal of the Korean institute of surface engineering
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• v.43 no.3
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• pp.142-147
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• 2010

We evaluated characteristics of ENEPIG (Electroless Nickel Electroless Palladium Immersion Gold) surface treatment for mobile equipment that requires high reliability, in addition to investigating surface treatment processes for semiconductor boards that require high reliability such as regular PCB-package systems, board-on-chip, chip-scaled package (CSP), etc and application for semiconductor package board of SIP, BOC. As a result, it appeared that ENEPIG has superior properties compared to ENIG surface treatment in corrosion resistance, solder junction, wetting, etc. We anticipate that these results will be able to lend credibility to ENEPIG as a low-cost alternative for producing mobile devices such as the cell phones, especially when applied to mass production.

• Applied Chemistry for Engineering
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• v.25 no.3
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• pp.268-273
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• 2014

In this study, multi-walled carbon nanotubes (MWCNT) were treated with nickel by electroless plating method for improving electromagnetic interference (EMI) shielding performance of MWCNT. The physical properties of electroless plated MWCNT were analyzed by using ultra-high resolution scanning electron microscope (UHR-SEM), thermogravimetry (TGA), sheet resistance analyzer and EMI shielding analyzer. EMI shielding efficiencies of nickel electroless plated MWCNT were measured to be 16 dB from 800 MHz band, which was 1.6 times increased compared to that of the activated MWCNT. Also, the average sheet resistance of nickel electroless plated MWCNT was measured to be $70{\Omega}/sq$, which was 56% decreased compared to that of the activated MWCNT. This result could be attributed to the plating morphology on the surface of MWCNT. This result could be attributed to uniformity of plating morphology on the surface, which has more effect on EMI shielding efficiency than the amount of nickel plating.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.6
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• pp.367-374
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• 2000

This paper presents a method to fabricate freestanding structures by (100) silicon anisotropic etching and nickel electroless plating. The electroless plating process is simpler than the electroplating, and provides good coating uniformity and improved mechanical properties. Furthermore, the (100) silicon anisotropic etching in KOH solution with being aligned to <100> direction provides vertical (100) sidewalls on etched (100) surface. In this paper, the effects of the nickel electroless plating condition on the properties of electroless plated metal structures are investigated to apply fabrication of micro structures and then various micro structures are fabricated by nickel electroless plating. And then, the structures are released by silicon anisotropic etching in KOH solution with a large gap between the structure and the substrate. The fabricated cantilever structures are $210\mum$. wide, $5\mum$. thick and $15\mum$. over the silicon substrate, and the comb structure has the comb electrodes which are $4\mum$. wide and $4.3\mum$. thick separated by$1\mum$. It is released by silicon anisotropic etching in KOH solution. The gap between the structure and the substrate is $2.5\mum$.

• Journal of the Korean institute of surface engineering
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• v.19 no.3
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• pp.109-120
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• 1986

The electroless nickel plating on high alumina ceramics was performed in the bath containing nickel chloride, sodium hypophosphite and mono- or bi-carboxylic acid as a complexing agent in order to examine the empirical rate law as well as the effects of the complexing agent, plating temperature and pH on the rate of deposition. Adding the carboxylic acid to the plating bath, the rate of deposition was increased considerably, and each of the complexing agents showed a maximum deposition rate plateau around a particular concentration of the complexing agent. The rate of deposition was increased with increasing either temperature or pH, but microstructure of the surface became more rough. Furthermore, empirical rate law of the elecltroless nickel deposition on high alumina ceramics was discussed with the activation energy and other rate parameters calculated.