• 한국표면공학회지
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• 제37권6호
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• pp.335-343
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• 2004

Bath stabilizers in the electroless nickel(EN) plating solution are known to prevent sudden bath decomposition and extend its lifetime. Further, every stabilizer has a different role and function in EN solution and it influences the surface structure. In this study, the effects of various stabilizers on the deposition rate, surface morphology, deposition content of phosphor and hardness were investigated.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 추계학술대회 논문집
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• pp.621-624
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• 1999

Metalization technology of the fine patterns by electroless plating is required in place of electrodeposition as high-density printed boards(PCR) become indispensable with the miniaturization of electronic components. Electroless nickel plating is a suitable diffusion barrier between conductor meta1s, such as Al and Cu and solder is essetional in electronic packaging in order to sustain a long period of service. Moreover, Electroless nickel has particular characteristics including non-magnetic property, amorphous structure. wear resistance, corrosion protection and thermal stability In this study fundamental aspects of electroless nickel deposition were studied with effort of complexeing agents of different kinds. Then the property of electroless deposit are controlled by the composition of the deposition solution the deposition condition such as temperature and pH value and so on. the characteristics of the deposits has been carried out.

• 한국표면공학회지
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• 제47권5호
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• pp.269-274
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• 2014

Electroless plating process as a solution deposition method is a viable means of preparing conductive metal films on non-conducting substrates through chemical reactions. In the present study, the preparation and properties of electroless Ni-plating on flexible silicone rubber are described. The process has been performed using a conventional Ni(P) chemical bath. Additives and complexing agents such as ammonium chloride and glycine were added and the reaction pH was controlled by NaOH aqueous solution. Ni deposition rate and crystallinity have been found to vary with pH and temperature of the plating bath. It was shown that Ni-films having the high crystallinity, enhanced adhesion and optimum electric conductivity were formed uniformly on silicone rubber substrates under pH 7 at $70^{\circ}C$. The conductive Ni-plated silicone rubber showed a high electromagnetic interference shielding effect in the 400 MHz-1 GHz range.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 춘계학술대회 논문집
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• pp.53-57
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• 2004

In this paper, we will present the Aspheric Surface Program for optical element. X-ray optical element designed to give a high resolution and reflectively in order to observe the living cell in the range of the water window. According to optical design, we developed the Aspheric Surface Program using the visual basic. Using the Aspheric Surface Program, we directly machined the electroless nickel bulk.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2007년도 추계학술발표대회 및
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• pp.29.2-29.2
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• 2007

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1507-1510
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• 2005

This study was carried out as a part of the research on the development of a maskless and electroless process for fabricating metal micro/nanostructures by using a nanoindenter and an electroless deposition technique. $2-\mu{m}-deep$ indentation tests on Ni and Cu samples were performed. The elastic recovery of the Ni and Cu was 9.30% and 9.53% of the maximum penetration depth, respectively. The hardness and the elastic modulus were 1.56 GPa and 120 GPa for Ni and 1.49 GPa and 100 GPa for Cu. The effect of single-point diamond machining conditions such as the Berkovich tip orientation (0, 45, and $90^{\circ}$) and the normal load (0.1, 0.3, 0.5, 1, 3, and 5 mN), on both the deformation behavior and the morphology of cutting traces (such as width and depth) was investigated by constant-load scratch tests. The tip orientation had a significant influence on the coefficient of friction, which varied from 0.52-0.66 for Ni and from 0.46-0.61 for Cu. The crisscross-pattern sample showed that the tip orientation strongly affects the surface quality of the machined area during scratching. A selective deposition of Cu at the pit-like defect on a p-type Si(111) surface was also investigated. Preferential deposition of the Cu occurred at the surface defect sites of silicon wafers, indicating that those defect sites act as active sites for the deposition reaction. The shape of the Cu-deposited area was almost the same as that of the residual stress field.

• 한국결정성장학회지
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• 제25권5호
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• pp.193-198
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• 2015

본 연구에서는 전자파 차폐형 MCT(multi cable transit)의 인서트블록에 사용되는 유연성 EPDM(ethylene propylene diene monomer)고무 상에 무전해 도금을 이용하여 니켈도금을 실시하였다. 도금욕의 공정변수 조절 즉 pH 및 온도에 따라 Ni 도금층의 결정성 및 부착력이 결정되었다. pH와 온도를 달리하여 합성 한 결과 pH 7 및 8, $60{\sim}70^{\circ}C$에서 얻은 도금막들에서 잘 발달된 결정상과 높은 전기 전도도를 가짐을 알 수 있었다. pH 7, $70^{\circ}C$에서 도금 시 가장 높은 부착력 및 전기전도도를 얻을 수 있었으며, 또한 400 MHz~1 GHz 범위에서 우수한 전자파 차단능을 얻을 수 있었다.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2009년도 춘계학술발표대회 논문집
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• pp.230-234
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• 2009

It is significant technique to increase competitiveness that solar cells have a high energy conversion efficiency and cost effectiveness. When making high efficiency crystalline Si solar cells, evaporated Ti/Pd/Ag contact system is widely used in order to reduce the electrical resistance of the contact fingers. However, the evaporation process is no applicable to mass production because high vacuum is needed. Furthermore, those metals are too expensive to be applied for terrestrial applications. Ni/Cu/Ag contact system of silicon solar cells offers a relatively inexpensive method of making electrical contact. Ni silicide formation is one of the indispensable techniques for Ni/Cu/Ag contact sytem. Ni was electroless plated on the front grid pattern, After Ni electroless plating, the cells were annealed by RTP(Rapid Thermal Process). Ni silicide(NiSi) has certain advantages over Ti silicide($TiSi_2$), lower temperature anneal, one step anneal, low resistivity, low silicon consumption, low film stress, absence of reaction between the annealing ambient. Ni/Cu/Ag metallization scheme is an important process in the direction of cost reduction for solar cells of high efficiency. In this article we shall report an investigation of rapid thermal silicidation of nickel on silngle crystalline silicon wafers in the annealing range of $350-390^{\circ}C$. The samples annealed at temperatures from 350 to $390^{\circ}C$ have been analyzed by SEM(Scanning Electron Microscopy).

• 마이크로전자및패키징학회지
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• 제12권1호
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• pp.41-46
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• 2005

무전해 Ni(P)과 솔더와의 반응 중 발견되는 취성파괴 현상과 계면 화학반응시의 금속간화합물 spalling과의 연관성을 전단 파괴실험을 통하여 체계적으로 연구하였다. 취성파괴는 무전해 Ni(P)과 Sn-3.5Ag 솔더와의 반응 후에만 나타났고 Sn-3.0Ag-0.5Cu 솔더와의 반응시에는 연성파괴만이 관찰되었다. Sn-3.0Ag-0.5Cu 솔더와의 반응시 $(Ni,Cu)_3Sn_4$와 $(Cu,Ni)_6Sn_5$의 삼성분계 금속간화합물이 생성되었고 spatting은 발생하지 않았다. 반면, Sn-3.5Ag 솔더와의 반응시에는 $Ni_3Sn_4$ 금속간화합물이 spatting된 솔더패드에서 취성파괴가 발생하였다. 파괴표면을 면밀히 분석한 결과 취성파괴는 $Ni_3Sn_4$ 금속간화합물과 Ni(P) 금속층 사이에 형성된 $Ni_3SnP$ 층에서 발생하는 것을 알 수 있었다. $Ni_3SnP$ 금속간화합물 층은 $Ni_3Sn_4$ 금속간화합물이 spatting되는 과정 중에 두껍게 성장하므로 무진해 Ni(P) 사용시 기계적 신뢰성을 보장하기 위해서는 금속간화합물의 spatting을 방지하는 것이 매우 중요하다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집C
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• pp.83-87
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• 2001

A 110 mm diameter aspheric metal secondary mirror for a test model of an earth observation satellite camera was fabricated by ultra-precision single point diamond turning (SPDT). Aluminum alloy for mirror substrates is known to be easily machinable, but not polishable due to its ductility. A harder material, Ni, is usually electrolessly coated on an Al substrate to increase the surface hardness for optical polishing. Aspheric metal secondary mirror without a conventional polishing process, the surface roughness of Ra=10nm, and the form error of $Ra={\lambda}/12({\lambda}=632nm)$ has been required. The purpose of this research is to find the optimum machining conditions for reflector cutting of electroless-Ni coated Al alloy and apply the SPDT technique to the manufacturing of ultra precision optical components of metal aspheric reflector.