• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.391-394
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• 2002

Transparent conductive oxides (TCO) are necessary as front electrode for most thin film solar cell. In our paper, transparent conducting aluminum-doped Zinc oxide films (ZnO:Al) were prepared by rf magnetron sputtering on glass (Corning 1737) substrate as a variation of the deposition condition. After deposition, the smooth ZnO:Al films were etched in diluted HCl (0.5%) to examine the electrical and surface morphology Properties as a variation of the time. The most important deposition condition of surface-textured ZnO films by chemical etching is the processing pressure and the substrate temperature. In low pressures (0.9 mTorr) and high substrate temperatures ($\leq$30$0^{\circ}C$), the surface morphology of films exhibits a more dense and compact film structure with effective light-trapping to apply the silicon thin film solar cells.

• Journal of the Korean Graphic Arts Communication Society
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• v.29 no.3
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• pp.17-30
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• 2011

The polarizer is an important optical element used in a variety of applications. Nano-wire grid polarizers in the form of sub-wavelength metallic gratings are an attractive alternative to conventional polarizers, because they provide high extinction ratio. This study has been carried out to fabrication of the 17inch area size nano-wire grid polarizer(NWGP) The master for NWGPs with a pitch of 200nm and the area size $730mm{\times}450mm$ were fabricated using laser interference lithography and aluminum sputtering and wet etching. And The NWGP fabrication process was using by the Roll to-Roll UV imprinting and was applied to flexible PET film. The results were a transmission of light (Tp) 46.7%, reflectance (Rs) 40.1% and Extinction ratio of above 16 for the visible light range.

• Journal of the Korean Chemical Society
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• v.64 no.3
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• pp.153-158
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• 2020

With the recent popularity of mobile devices, the demand for lithium-ion batteries is increasing. In this study, the surface treatment process for the development of the Al (aluminum) lead tab for positive electrode, a key component of the pouch-type lithium-ion battery, was investigated. Anodizing and sealing processes were tested as surface treatment techniques. It was found that only a sealing process is needed to obtain sufficient adhesive strength. In the present study, an adhesive strength of 17 N/12 mm was achieved by degreasing and etching pretreatment, followed by a sealing process of 10 min duration. This adhesive strength was greater than that achievable using Cr (chromium) surface treatment. Using various surface analysis techniques, the shape and composition of the surface before and after being subjected to the surface treatment were compared and analyzed. The results of this study are expected to contribute to the development of an eco-friendly lead tab.

• Journal of Korea Foundry Society
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• v.25 no.3
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• pp.134-141
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• 2005

To overcome the undesirable deformation, peeling off and geometrical restrictions which were mainly caused by differences in thermal expansion coefficients during the cladding of aluminum strip and stainless strip, new processing method based on vacuum die casting is designed and implemented in fabricating Al/Fe-17wt%Cr steel(stainless steel). To increase cast-bonding ability, the surface of Fe-17wt%Cr steel is electrochemically etched to have optimum pit size and density. The optimum conditions to generate best pit are as follows: Solution: 1 M $Fecl_{3}$+1 M Nacl, Addition: $CuCl_{2}+HCl$, Current density: 80 $mA/cm^{2}$, Total current: 400 $coulomb/cm^{2}$, AC frequency :60 Hz.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.77-78
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• 2006

We fabricated photonic crystals on GaAs and GaN substrates. After anodizing the aluminium thin film in electrochemical embient, the porous alumina was implemented to the mask for reactive ion beam etching process of GaAs wafer. And photonic crystals in GaN wafer were also fabricated using electron beam nano-lithography process. The coated PMMA thin film with 200 nm-thickness on GaN surface was patterned with triangular lattice and etched out the GaN surface by the inductively coupled plasma source. The fabricated GaAs and GaN photonic crystals provide the enhanced intensities of light emission for the wavelengths of 858 and 450 nm, respectively. We will present the detailed dimensions of photonic crystals from SEM and AFM measurements.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.09a
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• pp.29-34
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• 2005

A optical head unit for nano optical probe away was developed. The optical probe array is generated by Talbot effect. The shape and thickness of microlens array(MLA) were designed to minimize the spot size at the foci of MLA. To increase the optical efficiency of the system and obtain the large tolerance for fabrication, aperture size was theoretically optimized. Then microlens illuminated aperture array(MLIAA) as an optical head unit was fabricated using a ultra violet(UV) molding process on aluminum aperture array. In this process, Al aperture array was fabricated separately using the photolithography and reactive ion etching(RIE) process. Optical properties of the generated optical probes were measured and compared at Talbot distance from the aperture array having a diameter of $1{\mu}m$ and MLIAA.

• Conservation Science in Museum
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• v.27
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• pp.67-90
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• 2022

A C-46 transport aircraft, which can be thought of as a large cultural heritage item from the modern period, was subjected to paint analysis and conservation treatment in preparation for its exhibition. The C-46 is the first aircraft ever dispatched to overseas combat zones by the Korean Air Force and carried out missions during the Vietnam War. The aircraft is mainly made of aluminum and shows signs of corrosion on its surface, including pitting and etching, as well as gray and white powdery attachments. In the analysis of the paint, diatomite(SiO₂·nH₂O) was confirmed in the red paint, titanium dioxide(TiO₂) was identified in the white paint, black iron oxide(Fe₃O₄) was detected in the black paint, and colcothar(Fe₃O₄) mixed with putty was confirmed in the blue paint. Infrared spectroscopy revealed the use of alkyd resin in the paint on the main body and nitrocellulose in the Taegeuk pattern. During the conservation treatment, mechanical cleaning, such as sanding, was conducted to remove paint and varnish from the surface. Corrosion was removed by sanding and cleaning with chemical solvents, and new paints and varnishes were applied. Through the paint analysis and conservation treatment, the aircraft was made available for exhibition in a stable condition.

• Korean Journal of Materials Research
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• v.10 no.5
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• pp.369-374
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• 2000

In order to investigate the effects of addition of 1M sulfuric acid to the etching solution or 1M hydrochloric acid on the etching behavior of aluminum foil for electrolytic capacitors, the changes in the density of etch pit, the length and diameter of etch tunnels and the capacitance were analyzed using SEM, TEM, LCR meter etc. Sulfate ion as a corrosion inhibitor was contributed to the increase of the surface area comparing with chloride ion. By adding sul-furic acid the density of etch pit and the length of etched tunnel increased and the diameter of the tunnel decreased, resulting in the increase of capacitance. It was also shown that the capacitance decreased when the current density was below $0.9A/\textrm{cm}^2$, while remarkably increased in the other case.

• Journal of Electrical Engineering and Technology
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• v.4 no.4
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• pp.546-551
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• 2009

In this paper, we describe a self-aligned fabrication method for a nano-patterned bottom electrode using flood exposure from the backside. Misalignments between layers could cause the final devices to fail after the fabrication of the nano-scale bottom electrodes. A self-alignment was exploited to embed the bottom electrode inside the glass substrate. Aluminum patterns act as a dry etching mask to fabricate glass trenches as well as a self-aligned photomask during the flood exposure from the backside. The patterned photoresist (PR) has a negative sidewall slope using the flood exposure. The sidewall slopes of the glass trench and the patterned PR were $54.00^{\circ}$ and $63.47^{\circ}$, respectively. The negative sidewall enables an embedment of a gold layer inside $0.7{\mu}m$ wide glass trenches. Gold residues on the trench edges were removed by the additional flood exposure with wet etching. The sidewall slopes of the patterned PR are related to the slopes of the glass trenches. Nano-scale bottom electrodes inside the glass trenches will be used in beam resonators operating at high resonant frequencies.

• The Journal of Korean Academy of Prosthodontics
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• v.25 no.1
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• pp.303-316
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• 1987

The purpose f this study was to evaluate the effect of resin film thickness on the tensile bond strength and to compare the tensile bond strengths of 4 differently treated metal surfaces. For the experiment, seventy metal specimens were cast with Verabond and divided into I, II, III, groups. The metal specimens in group I were electrolytically etched and cemented with Panavia under finger pressure. Cement film thickness was regulated with metal spacers. The metal specimens in Group II were treated by 4 methods, such as electrolytic etching method, salt-roughened method, EZ-oxisor method , chemical etching method and cemented with Panavia. In group III, electrolytically etched metal specimens were cemented with Hy-Bond. The etched surface of metal specimens and the cement film thickness were examined under the scanning electron microscope. Results were as follows; 1. The tensile bond strength showed no significant difference between $30{\mu}m,\;80{\mu}m,\;130{\mu}m$ film thicknessspecimens. 2. There was no significant difference in the tensile bond strength between the 4 differently treated metal specimens. 3. The tensile bond strength showed significant difference between Panavia and Hy-Bond. 4. Scanning electron microscope photograph revealed that tile interdendritic eutectic was removed in electrolytically etched metal surfaces hilt even dendritic arm was removed in Chemically etched metal surfaces. 5. The metal surfaces which were air-abraded with $50{\mu}m$ aluminum oxide showed roughness and small crack on scanning electron microscope photograph.