• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2017.05a
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• pp.120.2-120.2
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• 2017

본 연구에서는 고신뢰성 인쇄회로기판이나 플립칩 패키지에 적용되는 범프 표면처리에서 널리 사용되는, ENIG나 ENEPIG 대체를 위한 electroless Pd/immersion Au(EPIG)에 대하여 연구하였다. Transmission electron microscopy(TEM) 분석 결과 형성된 Au layer는 crystalline, Pd layer는 amorphous 임을 확인하였으며, 열처리 후 X-Ray photoelectron spectroscopy(XPS)를 통하여 EPIG층이 하부 copper의 확산방지막으로서 효과가 있음을 알 수 있었다. 또한, 비정질 Pd layer가 확산을 방지하기 위하여는 일정수준 이상의 두께가 필요하며, 그 두께는 35~65nm 수준임을 알 수 있었다.

• Journal of the Korean institute of surface engineering
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• v.23 no.4
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• pp.208-217
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• 1990

Electroless Ni-Cu-P plating was performed was performed to investigate for plating and changes in microhardness and corrosion rate of of electroless deposits depending on heat treatment. The activation energy for $75~85^{\circ}C$ were calculated to be 66.7KJ/mole. Plating rate increased to 34% with addition of 200ppm of NaF and 0.8ppm of thiourea to the bath. The highest hardness value was obtained by heat treatment deposits layer at$ 400^{\circ}C$, 1 hour. The increase in hardness of deposits by heating was confirmed to be associated with crystallization of the amorphous deposits. Corrosion resistance of deposir layer, which had been heated up to $300^{\circ}C$, was found to be exellent when immersed in 1N-H2SO4 solution, Change of the corrosion resistance seems to have some important bearing on content of amorpous, Ni3P and Cu3P.

• Korean Journal of Materials Research
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• v.22 no.7
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• pp.335-341
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• 2012

Recently, the demand for the miniaturization of printed circuit boards has been increasing, as electronic devices have been sharply downsized. Conventional multi-layered PCBs are limited in terms their use with higher packaging densities. Therefore, a build-up process has been adopted as a new multi-layered PCB manufacturing process. In this process, via-holes are used to connect each conductive layer. After the connection of the interlayers created by electro copper plating, the via-holes are filled with a conductive paste. In this study, a desmear treatment, electroless plating and electroplating were carried out to investigate the optimum processing conditions for Cu via filling on a PCB. The desmear treatment involved swelling, etching, reduction, and an acid dip. A seed layer was formed on the via surface by electroless Cu plating. For Cu via filling, the electroplating of Cu from an acid sulfate bath containing typical additives such as PEG(polyethylene glycol), chloride ions, bis-(3-sodiumsulfopropyl disulfide) (SPS), and Janus Green B(JGB) was carried out. The desmear treatment clearly removes laser drilling residue and improves the surface roughness, which is necessary to ensure good adhesion of the Cu. A homogeneous and thick Cu seed layer was deposited on the samples after the desmear treatment. The 2,2'-Dipyridyl additive significantly improves the seed layer quality. SPS, PEG, and JGB additives are necessary to ensure defect-free bottom-up super filling.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.10a
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• pp.203-206
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• 2004

Copper-based bulk amorphous alloy composite was synthesized by using the copper-coated $Cu_{54}Ni_{6}Zr_{22}Ti_{18}$ amorphous powder which was obtained by argon gas atomization. The amorphous powder having a super-cooled liquid region of 53 K was coated by crystalline copper by electroless coating. The consolidation was carried out by manufacturing performs and by the subsequent warm extrusion at 743 K. During the compression test at the room temperature, the composite containing a large fraction of crystalline copper displayed a larger plastic strain after yielding. FEM simulation revealed change in fracture modes in the composites depending on the amount of crystalline copper in the composites.

• Resources Recycling
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• v.10 no.2
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• pp.27-33
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• 2001

Reusing of electroless Ni-Cu-P waste solution was investigated in the plating time, plating rate, solution composion and deposit. Plating time of nickel-catalytic surface took longer than that of zincated-catalytic surface. Initial solution with 50f) waste solution additive at batch type was possible to reusing of waste solution. Plating time of initial solution at continuous type took longer 10 times over than that of batch type. Plating time of 50% waste solution additive at continuous type took longer 3.7 times over than that of batch type. Component change of nickel-copper for electroless deposition was greatly affected by depolited inferiority and larger decreased plating rate.

• Journal of the Microelectronics and Packaging Society
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• v.11 no.2 s.31
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• pp.11-16
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• 2004

Electronic devices are getting smaller due to integration of electronic chip, and heat generated in electronic devices can cause loss of performance and/or reliability of the devices. In this research, metals such as gold, nickel and copper are plated onto a porous membrane by electroless plating method to make an efficient micro-heatsinks. Electroless plating includes sensitization and activation steps in pre-treatment steps. A polycarbonate(PC) membrane was sensitizied, activated and deposited in each metal solution for plating. Among manufactured microfibrils, heat transfer and radiation properties of Ni-microfibril with high surface area were more effective than those of $Au^-$ and Cu-microfibril.

• Journal of the Korean institute of surface engineering
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• v.45 no.1
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• pp.8-14
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• 2012

The effects of the alkali surface modification process on the adhesion strength between electroless-plated Cu and polyimide films were investigated. The polyimide surfaces were effectively modified by alkali surface treatments from the hydrophobic to the hydrophilic states, and it was confirmed by the results of the contact angle measurement. The surface roughness increased by alkali surface treatments and the adhesion strength was proportional to the surface roughness. The adhesion strength of Cu/polyimide interface treated by KOH + EDA (Ethylenediamine) was 874 gf/cm which is better than that treated by KOH and KOH + $KMnO_4$. The results of XPS spectra revealed that the alkali treatment formed oxygen functional groups such as carboxyl and amide groups on the polyimide films which is closely related to the interfacial bonding mechanism between electroless-plated Cu and polyimide films. It could be suggested that the species and contents of functional group on polyimide films, surface roughness and contact angle were related with the adhesion strength of Cu/polyimide in combination.

• Resources Recycling
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• v.12 no.1
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• pp.18-24
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• 2003

Reusing of electroless Ni-Cu-B waste solution was investigated in the plating time, plating rate, solution composition and deposit. Plating time of nickel-catalytic surface took longer than that of zincated-catalytic surface. Initial solution with 40% waste solution additive at batch type was possible to reusing of waste solution. Plating time of initial solution at continuous type took longer 6 times over than that of batch type. Plating time of 40% waste solution additive at continuous type took longer 2 times over than that of batch type. Component change of nickel-copper for electroless deposition was greatly affected by deposited inferiority and larger decreased plating rate.

• Journal of the Korean institute of surface engineering
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• v.46 no.1
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• pp.9-15
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• 2013

The effect of the additionally applied electrical current on the adhesion strength between electroless Cu and polyimide films was investigated. Peel tests were performed after applying electrical current within the range from 0.1 to 100 mA for the duration from 1 to 30 minutes. Sample with more than 1 mA of additional electrical current for 1 minute showed higher adhesion strength than that without additional electrical current. However, samples with 10 mA of additional electrical current for more than 10 miniutes showed the degradation of adhesion strength. Ra and RMS values of the peeled polyimide surface were proportional to the adhesion strength though there were no significant changes in the morphology of the peeled surfaces with varied amount and time-length of additional electrical current. Applying electrical current could increase the density of chemical bonding, which results in increase of the adhesion strength between copper and polyimide. However, in the case of applying additional electrical current for excessive amount or time, the degradation of the adhesion strength owing to the formation of copper oxide at the interface could occur.

• Proceedings of the Korean Fiber Society Conference
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• 2007.11a
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• pp.255-256
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• 2007