• Journal of the Korea Academia-Industrial cooperation Society
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• v.1 no.1
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• pp.33-36
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• 2000

Auto DOME-reversing system had been installed in a vacuum coating chamber which decreased the coating time, the electric energy spending and the contamination by rotating and revilving substance. Auto multi coating with dual electron beam was accomplished and effective coating area was increased. The coating duration was decreased with 30%. the production efficiency were increased with 50%. Also the surface conductivity the coated film uniformity and anti-reflection capablity were also improved.

• Journal of the Korean Ceramic Society
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• v.34 no.1
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• pp.79-87
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• 1997

Anti-reflective and anti-static double layered films were prepared on the VDT panel by sol-gel spin-coating method. Their electrical, opticla, and mechanical properties were investigated. The outer SiO2 film with low re-fractive index was coated over the inner ATO(Antimony-doped Tin Oxide)-SiO2 film which was prepared by mixing ATO sol with SiO2 at molar ratio of 68:32 to satisfy the interference condition of double layers. The heat treatment was conducted at 45$0^{\circ}C$ for 30 min where residual organics were completely removed. The sheet resistance of ATO single layer showed the minimum value of 6$\times$107$\Omega$/$\square$ at 3 mol% addition of Sb and that of SiO2/ATO-SiO2 increased slightly with increasing SiO2 mol% up to 30 mol%, and then increased steeply to the value of 3$\times$108$\Omega$/$\square$ at 32 mol%. The reflectance of double layered films was about 0.64% at the wavelength of 550nm and the transmittance increased about 3.20%. The hardness of double layered films was almost the same as that of uncoated VDT panel, 471.4kg.f/mm2.

• Applied Chemistry for Engineering
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• v.26 no.4
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• pp.400-405
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• 2015

Traditional anti-reflective (AR) coating films prepared using tetraethylorthosilicate (TEOS) as a precursor absorbs water easily in addition to having a weak abrasion resistance. To improve the transmittance, hydrophobicity and abrasion resistance of AR coating film, various AR coating films were prepared using methyltrimethoxysilane (MTMS) as a precursor in addition to introducing a fluoroalkylsilane, acid catalyst, base catalyst and acid-base two step catalyst. The prepared AR coating films were then characterized by UV-Vis spectroscopy, contact angle analyzer, atomic force microscope (AFM), pencil scratch hardness test and cross-cut test. As a result, the transmittance of bare glass was 90.5%, while that of AR coating glass increased to 94.8% at curing temperature of $300^{\circ}C$. When the fluoroalkylsilane was added, the water contact angle of AR coating film increased from $96.3^{\circ}$ to $108^{\circ}$, indicating that the hydrophobicity of the film was greatly improved. The abrasion resistance of AR coating film was also improved by the acid catalyst, whereas the transmittance increased by the base catalyst. In the case of AR coating film prepared using an acid-base two step catalyzed reaction, both the transmittance and abrasion resistance of the film was synergistically enhanced as compared with those of AR coating films prepared without introduction of a catalyst.

• Transactions of the Korean hydrogen and new energy society
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• v.25 no.2
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• pp.145-150
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• 2014

This study investigates the preparation of anti-reflective (AR) coating film to improve the efficiency of solar cell. The AR coating film was successfully obtained by dip-coating with AR coatings prepared by sol-gel method. Fluoroalkylsilane was additionally introduced into the coatings to give the self-cleaning effect of AR coating film. We performed the abrasion test, pencil scratch hardness test and cross-cut test to identify the mechanical strength of AR coating film. As the results, the transmittance of AR coating films with 9.07, 18.13 and 27.20 of IPA/MTMS molar ratios were 93.1, 93.6 and 95.3%, respectively. The water contact angle and transmittance of AR coating film increased by the introduction of hydrophobicity. The prepared AR coating film shows the high level of abrasion, hardness and adhesion. The IPA/MTMS molar ratio of 27.20 and the withdrawing speed range of 0.20 ~ 0.28cm/sec are the optimal coating condition in terms of the transmittance and mechanical strength of AR coating film.

• Journal of Korean Ophthalmic Optics Society
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• v.17 no.2
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• pp.119-126
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• 2012

Purpose: To study changes in coating and lens materials after chemically etched different polymer based glass lenses in short-term and ambient condition using hydrofluoric acid. Methods: Vinyl ester polymer (Lens A) and thiourethane polymer (Lens B), both dyed in gray 70%, were etched in hydrofluoric acid solution for 5, 10, or 15 min. The mechanical properties, degrees of damages in hard coating, anti-reflection coating, and other coatings, rates of refractive index and light transmission of both polymer types were evaluated. Results: Rates of refractive index of both lens types were not changed significantly after chemical etching. However, anti-reflection coatings and hard coatings were removed and lens surfaces were damaged. As a results, UV light transmission of lenses increased and mechanical properties decreased. Chemical etching notably changed various properties of thiourethane polymer materials. Conclusions: Depending on types of polymer materials, chemical reactions by hydrofluoric acid were dissimilar. Thus, various properties of les materials were altered differently.

• Applied Chemistry for Engineering
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• v.30 no.3
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• pp.358-364
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• 2019

To improve the optical characteristics and antifouling of anti-reflective coating (AR) films, various AR coating films were prepared by varying the mixing ratio of tetraethylorthosilicate (TEOS)/base and methyltrimethoxysilane (MTMS)/acid hybrid solution. Prepared AR coating films were characterized by UV-Vis spectroscopy, contact angle analyzer, atomic force microscope (AFM), FT-IR and pencil scratch hardness test. In an AR coating film that prepared from the hybrid solution with a 10 wt% MTMS/acid solution, the glass substrate showed an excellent optical property (97.2% transmittance), good antifouling ($121^{\circ}$ water contact angle and $90^{\circ}\;CH_2I_2$ contact angle) and moderate mechanical strength (pencil hardness of 4 H). In particular, it is considered that the good antifouling was due to the well dispersion of the methyl group ($-CH_3$), derived from a small amount of MTMS/acid solution in the hybrid solution, on the substrate surface. From results of the pencil hardness test, the mechanical strength of AR coating film was improved as the content of MTMS/acid solution increased.

• Journal of the Korean Ceramic Society
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• v.41 no.10 s.269
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• pp.766-770
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• 2004

High-transmittance film was coated by using spherical silica nano colloids. Silica colloid sol was preservred between two inclined slide glasses by capillary force, and particles were stacked to form a film onto the substrate as the upper glass was sliding. As the sliding speed increased, the thickness of the film decreased and light transmittance varied. The microstructure observed by SEM showed that silica particles were nearly close packed, which enabled the calculation of the effective refractive index of the film. The film thickness calculated from the wavelength of maximum transmittance and the effective refractive index was well coincided with the thickness observed by SEM and measured by profiler. The maximum transmittance of $94.7\%$ was obtained. This means that $97.4\%$ of transmittance or $1.3\%$ of reflectance can be achieved by simple process if both sides of the substrate are coated.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.472.2-472.2
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• 2014

현재 결정질 실리콘 태양전지의 전 후면 전극의 형성은 스크린 프린팅 방법이 주를 이루고 있다. 스크린 프린팅 방법은 쉽고 빠르게 인쇄가 가능한 반면 단가가 높고 금속 페이스트에 첨가된 여러 혼합물에 의해서 전극과 기판 사이의 저항이 크다는 단점이 있다. 본 논문에서는 도금을 이용하여 태양전지의 전극을 형성한 후 태양전지의 전기적 특성을 비교하였다. 또한 단일반사방지막($SiN_x$) 증착 후 도금을 이용한 전극 형성 시 반사방지막의 pin-hole에 의해 전극 이외의 표면에 도금이 되는 ghost plating 현상이 발생하게 되는데, 이를 방지하기 위해 thermal oxidation을 이용하여 SiO2/SiNx 이중반사 방지막을 증착함으로써 ghost plating을 최소화 시켰다. Ni을 이용하여 전극과 기판 사이의 저항을 낮추었으며, 주요 전극은 Cu 도금을 사용함으로써 단가를 낮추었으며 마지막으로 Cu전극의 산화를 방지하기 위해 Ag을 이용하여 얇게 도금하였다. 실험에 사용된 Si 웨이퍼 특성은 p-형, $156{\times}156mm2$, $200{\mu}m$, $0.5{\sim}3.0{\Omega}{\cdot}cm$ 이다. 웨이퍼는 표면조직화, p-n접합 형성, 반사방지막 코팅을 하였으며 스크린 프린팅 방법을 이용해 후면 전극을 인쇄하고 열처리 과정을 통해 전극을 형성하였다. 이 후 전면에 레이저를 이용해 전극 패턴을 형성한 후 도금을 실행하여 태양전지를 완성하였다. 완성된 태양전지는 솔라 시뮬레이터, QE 및 TLM패턴을 이용하여 전기적 특성을 분석하였으며, SEM과 linescan, 광학현미경 등을 이용하여 전극을 분석하였다.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.123-123
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• 2011

알루미늄은 경량 금속으로 부식 저항력이 높아 철을 부식으로부터 보호하기 위한 표면처리 소재로 사용되고 있다. 철의 부식을 방지하기 위해서 알루미늄을 코팅하는 경우, 코팅 방법은 용융도금법이 주로 사용되고 있으며, 알루미늄을 빛의 반사막으로 활용하는 경우 진공 중에서 물리기상증착(physical vapor deposition; PVD)법을 사용하기도 한다. 알루미늄 박막을 물리기상 증착으로 코팅하면 박막성장 초기에 핵(nucleus)을 형성하고, 형성된 핵을 중심으로 주상정(column)으로 박막이 성장하는 것이 일반적이다. 알루미늄 박막의 주상정과 주상정 사이에 공극(pore)이 존재하기 때문에 알루미늄 박막을 부식방지 막으로 이용하기 위해서는 두께를 증가시켜야 한다. 본 연구에서는 스퍼터링(unbalanced magnetron sputtering)을 이용하여 치밀한 조직을 갖는 알루미늄 박막을 코팅할 수 있는 공정변수를 도출하고, 치밀한 알루미늄 조직이 철의 부식에 미치는 영향을 평가하였다. 기판은 냉연강판(cold rolled steel sheet)이 사용되었으며, 알루미늄 타겟의 크기는 직경 4 inch이었다. 알루미늄 박막의 미세조직과 밀도에 영향을 주는 공정변수를 확인하기 위해서 스퍼터링 파워, 공정 압력, 외부 자기장 세기 등의 조건을 변화시켜 코팅을 실시하였다. 알루미늄 박막의 밀도 변화에 가장 큰 영향을 준 공정변수는 외부 자기장의 세기와 방향이었다. 알루미늄 박막이 약 3 ${\mu}m$의 두께로 코팅된 냉연강판을 염수분무시험(salt spray test, 5% NaCl)으로 부식특성을 평가한 결과, 시험을 시작한 후 120시간 후에도 적청이 발생하지 않았다. 이러한 결과는 기존의 동일한 두께를 갖는 알루미늄이 코팅된 강판의 내부식 특성의 2배의 성능을 보여준다.

• Journal of Korean Ophthalmic Optics Society
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• v.16 no.3
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• pp.237-245
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• 2011

Purpose: The present study was conducted to investigate whether certain repeated physical and/or chemical stimuli added on ophthalmic lenses might induce any changes of the functions of lens coatings. Methods: The changes in lens surface, light transmittance, foggy duration, durability of ophthalmic lenses were determined after the application of tearing-off with tape, rubbing with acetone, soaking in acetone or distilled water of ophthalmic lens (CR-39 material) as physical and/or chemical stimuli. Results: The change of ophthalmic lens surface was detected after soaking in acetone for longer than 30 minutes by observing the lens surface to figure out the functional change of hard coating. The ophthalmic lens soaked in distilled water for 180 minutes showed little functional change of anti-reflection coating as 1% by measuring light transmittance of lens. However, the function of anti-reflection coating was almost disappeared after the ophthalmic lens was soaked in acetone for 60 minutes. The foggy duration of ophthalmic lens soaked in acetone was increased by estimating foggy duration of lens. The lens coating was shown to be defected when the pre-damaged ophthalmic lenses were torn off with tape, rubbed with acetone and soaked in distilled water or acetone by observing pre-damaged lens surface to evaluate its durability. Conclusions: The careful management during ophthalmic lens dispensing or usual eyeglass wearing is needed since the change in ophthalmic lens coatings was shown by repeated physical and/or chemical stimuli.