• 산업공학
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• 제9권3호
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• pp.225-235
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• 1996

The SECS Ⅰ and Ⅱ Protocol has been widely used for the TFT LCD and semiconductor industry. This paper shows how the SECS protocol is implemented for data communications between the Host (CAM) and the TFT LCD equipments. In addition, this study introduces a way to apply the SECS protocol to the manufacturing systems control. It provides better throughput in terms of production and faster control of the automated TFT LCD manufacturing system by way of shortcut and distribution of control and data communications. The SECS protocol is successfully used for the control of the real TFT LCD manufacturing system.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.97.4-97
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• 2001

Recently, TFT LCD (thin film transistor liquid crystal display) manufacturing industry is more concerned with the ways of cleaning large TFT LCD´s with high pixed density than ever Ultrasonic cleaners with high frequencies like 1MHz (megasonic cleaners) are effective in removing very small particles without causing mechanical damage to the surface. In this study a megasonic cleaner for TFT LCD manufacturing process is developed and the performance is evaluated through experiments. The experimental results show that the developed magasonic cleaners is effective in removing very small particle from the LCD panel.

• 대한전기학회논문지:전력기술부문A
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• 제48권10호
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• pp.1303-1310
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• 1999

In this paper, the Timed Petri-Nets(TPN) modeling of Modular Cell Manufacturing Systems(MCMS) was investigated to overcome the limit of batch mode operation, which has been one of the most popular manufacturing types to produce an extensive industrial output and to be able to adopt to suitable and quickly changing manufacturing environments. A model of the MCMS was developed in reference to the actual TFT-LCD manufacturing system. TFT-LCD manufacturing system is not mass-productive in batch mode, but it operates in the form of MCMS which consists of a sequence of several cells with four processes of operation, including those of color filter(C/F), TFT, cell, and module. The cell process is further regrouped in those of Front-End and Back-End. For the Back-End cell process, it is reconstructed into a virtual model, consisting of three cells. The TPN modeling encompasses those properties, such as states and operations of machines, the number of buffers, and the processing time. The performance of the modeling was further examined in terms of scheduling system. The productivity in each cells was examined with respect to the change of failure rate of the cell machines and Automatic Guided Vehicles(AGV) using simulation by TPN.

• 한국컴퓨터정보학회논문지
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• 제12권4호
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• pp.249-256
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• 2007

본 논문에서는 휴대 가능한 중소형($4{\sim}9$인치 크기)의 정보단말기에 사용되는 TFT-LCD(Thin Film Transistor addressed -Liquid Crystal Display)의 LDI(LCD Driver Interface) 제어기(controller)를 제조사와 크기에 관계없이 사용할 수 있는 표준화된 범용 TFT-LCD의 LDI를 설계하고 FPGA(Field Programmable Gate Array)로 구현하였다. 설계한 LDI 제어기는 FPGA 테스트 보드(test board)에서 검증하였으며, 상업용 TFT-LCD 패널에서 시험결과 안정적으로 상호 동작하였다. 설계한 범용 LDI 제어기의 장점은 LCD의 제조사와 크기에 관계없이 그 동작을 표준화시켜 설계하였으므로 향후 모든 패널내의 SoG(System on a Glass) 모듈 설계에 적용할 수 있는 것이다. 그리고 기존의 방식에서는 LCD 제조사별, 패널 크기별로 별개의 LDI 제어기 칩을 개발하여 사용하지만, 설계한 LDI 제어기는 모든 휴대 가능한 중소형 패널을 구동시킬 수 있어서 IC의 공급가, AV 보드와 패널의 제조 원가 하락을 가져올 수 있으며 가까운 장래에는 보다 우수한 기능의 패널을 제작하기 위한 TFT-LCD 패널 모듈의 SoG 개발이 필연적으로 요구되고 있다. 연구결과는 TFT-LCD 패널을 더욱 소형화, 경량화 그리고 저가격화가 가능하여 기술 및 시장 경쟁력을 선점할 수 있다. 또한 향후 많은 수요가 예상되는 이동형 정보단말기에 사용되는 TFT-LCD 패널 모듈의 SoG IC(Integrated Circuit) 개발과 제작을 위한 기초 자료로서 활용될 수 있다.

• 대한전자공학회논문지SD
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• 제40권1호
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• pp.20-28
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• 2003

In this paper, we present results of the comparative analysis of the flicker phenomena in the poly-Si TFT-LCD and a-Si:H TFT-LCD arrays for the development and manufacturing of wide-area and high-quality TFT-LCD displays. We used four different types of TFTs; a-Si:H TFT, excimer laser annealed (ELA) poly-Si TFT, silicide mediated crystallization (SMC) poly-Si TFT, and counter-doped lateral body terminal (LBT), poly-Si TFT. We defined the electrical quantity of the flicker so that we could compare the flickers quantitatively for four different 40" UXGA TFT-LCDs. We identify three factors contributing to the flicker, such as charging time, kickback voltage and leakage current, and analyze how much each of three factors give rise to the flincker in the different TFT-LCD arrays. In addition, we suggest and show that, in the case of the poly-Si TFT-LCD arrays, the low-level (minimum) gate voltages should be carefully chosen to minimize the flicker because of their larger leakage currents compared with a-Si TFT-LCD arrays.

• Industrial Engineering and Management Systems
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• 제8권3호
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• pp.148-154
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• 2009

In recent days, large-sized flat-panel display (FPD) has been increasingly applied to computer monitors and TVs. Mura defects, appearing as low contrast or non-uniform brightness region, sometimes occur in manufacturing of the Thin-Film Transistor Liquid-Crystal Displays (TFT-LCD). Implementation of automatic Mura inspection methods is necessary for TFT-LCD production. Various existing Mura detection methods based on regression diagnostics, surface fitting and data transformation have been presented with good performance. This paper proposes an efficient Mura detection method that is based on a regression diagnostics using studentized residuals for automatic Mura inspection of FPD. The input image is estimated by a linear model and then the studentized residuals are calculated for filtering Mura regions. After image dilation, the proposed threshold is determined for detecting the non-uniform brightness region in TFT-LCD by means of monitoring the every pixel in the image. The experimental results obtained from several test images are used to illustrate the effectiveness and efficiency of the proposed method for Mura detection.

• 산업공학
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• 제10권1호
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• pp.47-55
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• 1997

This paper deals with an assembly process of the TFT glasses and the color filters in LCD manufacturing. Two specific problems are presented and solved. One is a matching problem to find the best matches between a set of TFT glasses and a set of color filters, which result in the maximum number of good LCD assemblies. A simple mathematical model is constructed for this problem and an optimal solution can be obtained using an existing algorithm. The other is a main problem that requires a determination of an economic lot size of the color filters which are going to be assembled with a given set of TFT glasses. A Bayesian dynamic forecasting model is developed to predict the defective patterns of color filters. Based on the predicted defective rate of color filters, the minimum lot size of the color filters can be determined to minimize the probability of losing good TFT glasses and color filters.

• Journal of Information Display
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• 제11권2호
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• pp.49-51
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• 2010

Nanoimprint lithography (NIL) using ultraviolet (UV) rays is a technique in which unconventional lithographic patterns are formed on a substrate by curing a suitable liquid resist in contact with a transparent patterned mold, then releasing the freshly patterned material. Here, various solutions are introduced to achieve sufficient overlay accuracy and to overcome the technical challenges in resist patterning via UV imprinting. Moreover, resist patterning of all the layers in TFT and of the BM layer in CF was carried out using UV imprinting lithography to come up with a 12.1-inch TFT-LCD panel with a resolution of $1280{\times}800$ lines (125 ppi).

• 한국산학기술학회논문지
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• 제12권5호
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• pp.2038-2047
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• 2011

본 논문에서는 TFT-LCD(Thin Film Transistor-Liquid Crystal Display) 제조 공정 중 Module 공정의 Slim MES(Manufacturing Execution System)를 위한 생산계획 프레임워크(framework)개발에 관해 연구한다. TFT-LCD 제조 공정 중 Module 공정의 라인 구성 및 기능은 각 제조 현장마다 차이가 있다. 본 논문은 이러한 차이를 반영하는 제조현장 맞춤형 MES를 위한 생산계획 프레임워크를 제시한다. 먼저 TFT-LCD Module 공정의 분석을 통해 생산계획 프로세스를 파악한다. 그런 다음 현장 상황 제약조건을 반영한 수리적 모델링을 제시하고 이에 대한 최적 스케줄의 도출을 사례를 통해 제시한다. 또한 현장 상황을 반영한 디스패칭(dispatching) 룰에 의한 스케줄 생성 과정을 제시하고 성능실험 결과를 제시한다. 마지막으로 Slim MES를 위한 생산계획 프레임워크 설계 과정을 제시한다.

• Korea-Australia Rheology Journal
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• 제15권4호
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• pp.167-171
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• 2003

The backlight unit (BLU) is used as a light source of TFT liquid-crystalline-display (TFT-LCD) module. In this backlight unit, one of important components is the light guide, which is usually made of transparent polymers. Currently, the screen-printing method is mainly used for the light guide as a manufacturing process. However, it has limitation to the flexibility of three-dimensional optical design. In the present paper a new alternative manufacturing method for the light guide with low-cost is proposed. This manufacturing method is named as direct surface forming (DSF), which is very similar to the well-known hot embossing except for partial contact between mold and substrate. The results of this new manufacturing method are presented in terms of processing condition, dimensional accuracy, productivity, etc.