• Journal of Korean Ophthalmic Optics Society
• /
• v.7 no.2
• /
• pp.175-180
• /
• 2002

Use spctrophotometer to estimate thin film uniformity of lens, Compare, and analyze thin film uniformity availability selecting two peaks of Reflectance(R%) measuring on spectrum. Wavelength dependence's Reflectance in position of center, middle and edge of lens etc... obtain thin film's thickness (t) from Wavelength region (${\lambda}_1,{\lambda}_2$) of two peaks of Reflectance. $$t=\frac{1}{2(n^2-\sin^2{\theta})^{1/2}}{\times}\frac{{\lambda}_1{\lambda}_2}{{\lambda}_2-{\lambda}_1}$$ If Reflectance pattern is uniformity value in position of center middle of lens, edge etc... thin film has uniformity. Applied thin film uniformity estimation method to 1st layer $MgF_2$(n=1.38) coating lens. It was about thin film's thickness difference 360nm. Can analyze coating lens' thin film uniformity easily from Reflectance relationship measurement about Wavelength dependence.

• Bulletin of the Korean Chemical Society
• /
• v.32 no.5
• /
• pp.1483-1490
• /
• 2011

The protection effect of a $ZrO_2$ coating layer on a $LiCoO_2$ thin film was characterized. A wide and smooth $LiCoO_2$ thin film offers sufficient opportunity for careful observation of the reaction at the interface between cathode (coated and uncoated) and electrolyte. The formation of a $ZrO_2$ coating on a $LiCoO_2$ thin film was confirmed by secondary ion mass spectrometry. Scanning electron and atomic force microscopy were used to characterize the surface morphologies of coated and uncoated films before and after cycling. A $ZrO_2$-coated $LiCoO_2$ film showed a higher discharge capacity and rate capability than an uncoated film. This may be associated with a surface protection effect of the coating. The surface of a pristine film was damaged during cycling, whereas the coated film maintained a relatively clear surface under the same measurement conditions. This result clearly demonstrates the protection effect of a $ZrO_2$ coating on a $LiCoO_2$ thin film.

• Journal of Advanced Navigation Technology
• /
• v.17 no.5
• /
• pp.574-580
• /
• 2013

In this paper, The process of thin-film coating technology was applied to improve adhesion of the hardness thin film and nitride layer. This thin-film coating technology have formed composite thin-film to gain hardness and toughness used in press mold. The thin-film coating manufacturing technology increased vacuum present in the vacuum chamber and improved the throw ratio of the gun power using physical vapor deposition coating technology. Ti alloys target improved performance and surface material through the development of a composite film coating technology for various precision machining parts.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.34 no.5
• /
• pp.321-326
• /
• 2021

We fabricated BiAlO thin film by a solution process with a brush coating to be used as liquid crystal (LC) alignment layer. Solution-processed BiAlO was coated on the glass substrate by brush process. Prepared thin films were annealed at different temperatures of 80℃, 180℃, and 280℃. To verify whether the BiAlO film was formed properly, X-ray photoelectron spectroscopy analysis was performed on Bi and Al. Using a crystal rotation method by polarized optical microscopy, LC alignment state was evaluated. At the annealing temperature of 280℃, the uniform homogenous LC alignment was achieved. To reveal the mechanism of LC alignment by brush coating, field emission scanning electron microscope was used. Through this analysis, spin-coated and brush coated film surface were compared. It was revealed that physical anisotropy was induced by brush coating at a high annealing temperature. Particles were aligned in one direction along which brush coating was made, resulting in a physical anisotropy that affects a uniform LC alignment. Therefore, it was confirmed that brush coating combined with BiAlO thin film annealed at high temperature has a significant potential for LC alignment.

• Journal of the Semiconductor & Display Technology
• /
• v.13 no.1
• /
• pp.91-95
• /
• 2014

(F,Ga) co-doped ZnO thin film on glass substrate was fabricated via a simple non-alkoxide sol-gel spin-coating. Contrary to the F single doped ZnO thin film, the (F,Ga) co-doped thin film showed a significant reduce in electrical resistivity after a second post-heat-treatment in reducing environment. The resulting decrease in electrical resistivity with Ga co-doping is considered to be resulted from the increases both carrier density and mobility. The optical transmittance of the (F,Ga) co-doped thin film in the visible range showed higher transmittance with Ga co-doping compared with F single doped ZnO thin film.

• Journal of the Korean Society for Precision Engineering
• /
• v.27 no.12
• /
• pp.28-32
• /
• 2010

Technical demands for aspheric glass lens formed in market increases its application from simple camera lens module to fiber optics connection module in optical engineering. WC is often used as a metal core of the aspheric glass lens, but the long life time is issued because it fabricated in high temperature and high pressure environment. High hard thin film coating of lens core increases the core life time critically. Diamond Like Carbon(DLC) thin film coating shows very high hardness and low surface roughness, i.e. low friction between a glass lens and a metal core, and thus draw interests from an optical manufacturing industry. In addition, DLC thin film coating can removed by etching process and deposit the film again, which makes the core renewable. In this study, DLC films were deposited on the SiC ceramic core. The process variable in FVA(Filtered Vacuum Arc) method was the substrate bias-voltage. Deposited thin film was evaluated by raman spectroscopy, AFM and nano indenter and measured its crystal structure, surface roughness, and hardness. After applying optimum thin film condition, the life time and crystal structure transition of DLC thin film was monitored.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.24 no.10
• /
• pp.812-816
• /
• 2011

An optical lens is usually produced in the manner of high temperature compression molding with tungsten carbide alloy molding cores, it is necessary to develop and study technology for super-precision processing of molding cores and coating the core surface. As main methods used in surface improvement technologies using thin film, DLC present high hardness, chemical stability, and outstanding durability of abrasion to be extensively applied in various industrial fields. In this study, the effect of DLC coating of a thin film by means of the FVAS (filtered vacuum arc source) analyzed the characteristics of thin film. Surface roughness before and after DLC coating was measured and the result showed that the surface roughness was improved after coating as compared to before coating. In conclusion, it was observed that DLC coating of the ultra hard alloy core surface for molding had an effect on improving the surface roughness and shape of the core surface. It is considered that this will have an effect on improving abrasion resistance and the service life of the core surface.

• Journal of ILASS-Korea
• /
• v.18 no.3
• /
• pp.146-154
• /
• 2013

The flow of a liquid film on spin coating is investigated in the case that the fixed volume of a liquid is placed on the center of a stationary disk. Thin film equations that are well approximated when the characteristic length in the vertical direction is much smaller than that in the radial direction (${\varepsilon}{\ll}1$) and have already been proposed in the work of T.-S. Kim & M.-U. Kim (2009), are used. The differential equation that governs the free surface of a liquid when ${\varepsilon}{\ll}1$ and ${\varepsilon}Re{\ll}1$ is also derived. The basic flow is analyzed using the thin film equations and their results are compared to the results of Navier-Stokes equations.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2004.10a
• /
• pp.1344-1347
• /
• 2004

Recently, Study on measuring property of a micro thin film(nm ～ hundreds of ) under Thermal Mechanical loading. In this work, We perform tensile test at high temperature(1200 ) to investigate mechanical properties of alumina TGO formed under Thermal Barrier Coating. We used Digital Image Correlation method for measuring displacement, and We presented a method of tensile test for thin film at high temperature.

• Journal of the Semiconductor & Display Technology
• /
• v.23 no.1
• /
• pp.88-91
• /
• 2024

The europium doped yttrium oxide (Y₂O₃:Eu³⁺) thin film was formed on a Si substrate by the conventional spin-coating process followed by rapid thermal annealing (RTA) treatment. The spinning profiles such as rotation speed, acceleration and holding times were controlled during the spin-coating process for the best condition of the Y₂O₃:Eu³⁺ thin film. The RTA treatment was conducted for several temperature in order to crystallize the spin coated film. The Y₂O₃:Eu³⁺ thin film presented best performance in the conditions of 4000 rpm, 30 s and 10 s of rotation speed, acceleration time and holding time, respectively, at a fixed RTA temperature of 900 ℃.