• Advances in materials Research
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• v.2 no.4
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• pp.195-208
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• 2013

A comprehensive theory of the spin coating technique has been reviewed and the basic principles and parameters controlling the process are clearly highlighted, which include spin speed, spin time, acceleration and fume exhaust. The process generally involves four stages: a dispense stage, substrate acceleration stage, a stage of substrate spinning at a constant rate and fluid viscous forces dominate fluid thinning behaviour and a stage of substrate spinning at a constant rate and solvent evaporation dominates the coating thinning behaviour. The study also considered some common thin film defects associated with this technique, which include comet, striation, chucks marks environmental sensitivity and edge effect and possible remedies.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.35 no.1
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• pp.58-65
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• 2022

The field of liquid crystal display (LCD) is constantly in the spotlight and the process of depositing an alignment layer in the LCD manufacturing process is very important to obtain excellent performance such as low-power driving and high-speed response to improve LCD performance. Therefore, research on liquid crystal (LC) alignment is being actively conducted. When manufacturing LCD, it is necessary to consider the effect of the alignment layer thickness as one of the factors affecting various LCD performances. In addition, previous studies confirmed the LC alignment characteristics correlate with the rotation speed in the spin coating process. Therefore, the electro-optical properties of the LCD were investigated by manufacturing a polyimide alignment layer by varying the rotation speed in the spin coating process in this study. It was confirmed that the thickness of the polyimide alignment layer was controlled according to the spin coating conditions. The average transmittances of anti-parallel LC cells at the spin coating speed of 2,500 rpm and 3,000 rpm are about 60%, which indicates that the LC cell has relatively higher performance. At the spin coating speed of 3,000 rpm, the voltage-transmittance curve of twisted nematic (TN) LC cell was below 1.5 V, which means that the TN LC cell operated at a low power. In addition, high-speed operating characteristics were confirmed with a response time of less than 30 ms. From these derived data, we confirmed that the ideal spin coating speed is 3,000 rpm. And these results provide an optimized polyimide alignment layer process when considering enhanced future LCD manufacturing.

• Journal of the Semiconductor & Display Technology
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• v.2 no.1
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• pp.25-29
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• 2003

The fluid flow, mass transfer, heat transfer and film thickness variation during the spin coating process are numerically studied. The model is said to be I-dimensional because radial variations in film thickness, concentration and temperature are ignored. The finite difference method is employed to solve the equations that are simplified using the similarity transformation. In early time, the film thinning is due to the radial convective outflow. However that slows during the first seconds of spinning so the film thinning due to evaporation of solvent becomes sole. The time varing film thickness is analyzed according to the wafer spin speed, the various solvent fraction in the coating liquid, and the various solvent vapor fraction in the bulk of the overlying gas during the spin coating is estimated.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.11 no.4
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• pp.31-36
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• 2001

A spin coater is a machine to coat wafer or LCD display with thin film. Vibration in the spin coater may be one of main troubles in the coating process. In this paper, we focus on the difference between two spin coaters. Vibration sources are identified by experimental approach and are compared to find the difference between the two spin coaters. Also, the particle concentration is observed by laser particle counter (LPC) for the two spin coaters, when the spin coaxers are working. It is also considered whether the defect rate is proportional to the particle concentration. The result shows that particle generation in the coating process is related to excessive vibration of the spin coater shaft and the particles influence the defect rate of the thin film product.

• Environmental Engineering Research
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• v.24 no.4
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• pp.646-653
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• 2019

Recovery of valuable metals in the industrial wastewater and sludge has attracted an attention owing to limited metallic resources in the earth. In this study, we firstly fabricated Ti/Ir-Ru electrodes by spin coating technique for effective recovery of Cu in electrowinning process. Two different Ti/Ir-Ru electrodes were fabricated using 100 and 500 mM of precursors (i.e., Ir-Ru). SEM-EDX and AFM revealed that Ir and Ru were homogenously distributed on the surface of Ti plate by the spin coating, in particular the electrode prepared by 500 mM showed distinct boundary line between Ir-Ru layer and Ti substrate. XRD, XPS, and cyclic voltammetry also revealed that characteristics of IrO₂, RuO₂, and TiO₂ and its electrocatalytic property increased as the concentration of coating precursor increased. Finally, we carried out Cu recovery experiments using two Ti/Ir-Ru as anodes in electrowinning process, showing that both anodes showed a complete removal of Cu (1 and 10 g/L) within 6 h reaction, but much higher kinetic rate constant was obtained by the anode prepared by 500 mM. The findings in this study can provide a fundamental knowledge for surface characteristics of Ti/Ir-Ru electrode prepared by spin coating method and its potential feasibility for effective electrowinning process.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.6
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• pp.96-102
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• 2000

Spinning mechanism is generally used in coasting process on grass plates. Rebounding PR(Photo Resist) which leads to occur inferiority of coating process is caused by vibrational energy of whole coating system. In this study, the sensitivity analysis is performed to analyze and reduce vibrational terms in the spin coating system. The sensitivity analysis is bared on the numerical expression of this system. By the bond graph method. power flow of each system is represented by some basic bond graph elements. Any energy domain system is modeled using the unified elements. The modelled spin coater system is verified with power spectrum data measured by FFT analyzer. As the results of verifying model parameters and sensitivity analysis, principal factors causing vibration phenomenon are mentioned. A study on vibration method in the spin coating system is discussed.

• Proceedings of the KSME Conference
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• 2001.11b
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• pp.59-64
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• 2001

The fluid flow, mass transfer and film thickness variation during a wafer spin coating process are numerically studied. Governing equations for the cylindrical coordinates are simplified using the similarity transformation and solved efficiently using the finite difference method. Concentration dependent viscosity and the binary diffusivity of the coating liquid are used in the analysis. The time variational velocity components of the coating liquid and the film thickness are analyzed according to the various spin speed. When the evaporation is considered, the flow decease in the early times due to the increase of the viscosity and the resultant flow resistance. Effects of the two film thinning mechanism, the flow-out and evaporation are also considered in the analysis.

• Transactions of the Society of Information Storage Systems
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• v.2 no.3
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• pp.178-183
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• 2006

A Blu-ray disc, which has a more than 25GB optical capacity, has been known as a promising next-generation optical disc format. It commonly has a 1.1 mm thick substrate and a 0.1 mm thick cover layer for beam transmitting and the protection of the reflecting surface. The cover layer is generally formed by the spin coating process. However, in conventional spin coating, small bumps are formed along the rim of the disc, which results in the fatal reading error. Numerical simulation of the thin film flow behaviors during spin coating with the commercial solver and optimal spinning conditions was obtained. Thickness distribution of the cover layer according to the variation of substrate's edge shape could be calculated as well. By modifying the shape of the substrate edge shape, the bumps along the disc rim could be minimized, and it was proved that the chamfered edge, around $5{\sim}10$ degree, is the simplest and most effective way to minimize the bumps.

• Journal of IKEEE
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• v.27 no.1
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• pp.78-84
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• 2023

In this paper, front color glass for Building Integrated Photovoltaic (BIPV) system was implemented by spin coating method using color solution. Solutions suitable for color solutions were investigated using pearlescent pigments and various solutions to implement color glass. One of investigated solutions, NOA 63 and NOA 65, which are ultraviolet light curing agents, were able to implement color glass with superior coating properties and color reproducibility than other solutions. Color glass realized by spin coating with a NOA 65 based color solution showed high transmittance of 86% in the visible and near-infrared wavelength bands, and the change in optical properties of color glass over time was insignificant, making it a suitable material for realizing color glass for BIPV Suitable as a color solution. The solution process method using the spin coating method is expected to facilitate the manufacturing process of front color glass for BIPV as it can produce color glass more easily and quickly than the existing physical deposition method or color glass manufacturing process using nanoparticles.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.05a
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• pp.113-116
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• 2005

In this paper, a computational and experimental analysis about the flow behavior of thin polymer film in the spin coating process for stable cover layer coating of a blu-ray disc is described. The blu-ray disc, a next-generation optical disc format over 25GB, consists of a 1.1mm thick substrate and a 0.1mm tick cover layer. Generally, cover layer on the blu-ray disc is made by the polymer spin coating process. However, it is hard to secure sufficient coating uniformity around the rim on the cover layer. In order to get the uniform thickness deviation and to minimize the bead around the rim, the edge of the disc substrate can be modified into various shapes around the rim on the disc and analyzed with various parameters, such as surface tension, viscosity, and rotation speed, etc. The optimal shape of the rim was tried to get by 3 dimensional computer simulation of the polymer expulsion process.