• Journal of computational fluids engineering
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• v.8 no.2
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• pp.33-41
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• 2003

A simplified simulation model is designed to investigate the vacuum-driven bonding of glass panels in the cell process for LCD manufacturing. The bonding process is modelled by the transient flow of a weakly-compressible fluid in a very thin channel between two horizontal glass panels. An order of magnitude scaling analysis is conducted based on the characteristic feature of the channel of which height is much smaller than the horizontal length scales. It is revealed that the flow in the channel is represented by a Poiseuille flow of a compressible fluid. A finite volume model has been constructed to acquire the numerical solution to the derived simplified equations. For a simple test problem of pressure-driven microchannel flow, an assessment is made of the accuracy and validity of the proposed model. The basic aspects of vacuum-driven bonding are examined numerically, and the applicability of the present simulation model is illustrated.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.5
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• pp.162-165
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• 2007

TFT-LCD process has two advantages as compared with the semiconductor-process. It is that cycle time is short and number of the final products are small. But it needs complicated inspection / assembly line to be treated manually and much higher labor costs in the TFT-LCD process. Also, It is necessary to build PICS(Production Information and Control System) which is automated and intelligent. In this paper, an automated process of LCD module assembly line that can increase productivity and reduce the cost of production to strengthen the competitiveness corresponding with global market is planned in comparison with its manual/semi-auto. It is noted that The automated line for COG$\sim$FOG process replacing with the existing facilities had the following effects; the productivity is increased to about 1.5 times and labor cost reduced 85%. In addition, whole assembly line can be short and simple.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.04a
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• pp.73-77
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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.

• Fire Science and Engineering
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• v.26 no.5
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• pp.41-47
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• 2012

As a core process in the manufacture of state-of-the-art industrial technologies such as semiconductor and LCD, a clean room is the most important process which can affect the performance and quality of products drastically. Nevertheless, scientific research on comprehensive safety measures from a fire protection standpoint is not being carried out in Korea. This study aims to derive measures to improve smoke control systems by identifying performance and problems of smoke systems installed in clean rooms as an LCD manufacturing process and analyzing fire and evacuation simulations considering several scenarios. As a result of analysis of fires and smoke in a clean roomas an LCD manufacturing process, it is found to be necessary to stop air handling units through interlocking in case of a fire and exhaust smoke out of the room through the top of FAB in consideration of buoyancy of smoke. It is also found to be necessary to install quick response sprinkler heads and accessories to accelerate the response time, because the heat-accumulating performance of sprinkler heads decreases in this application. Despite its low density of dwelling due to the automation process, clean room is characterized by an array of complex production equipment and working environment requiring dustproof clothes, which makes it difficult to acquire evacuation safety performance. Thus, thorough control of danger factors in processes and periodic education and training are required. It is also necessary to establish a level of domestic technologies equivalent to the level of standards of advanced countries in fire protection.

• Journal of Industrial Technology
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• v.31 no.A
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• pp.53-57
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• 2011

Recently due to dramatically increasing demand of liquid crystal display (LCD) panel in IT industry, the used LCD panel glass has been wasted from electronic items, and also panel glass of poor quality during manufacturing process. The wasted LCD panel glass was crushed in the range of 0.42 to 2mm and evaluated for its usefulness as a aggregate in production of cement concrete brick. Cement concrete specimens with various mixing ratios of weathered granite soil, LCD panel glass and cement were cured in wetness for 7 days at $40^{\circ}C$ and then tested for uniaxial comprehensive strength (UCS)(KS F 4004 method). Specimen with a mixing ratio, 1:6:3, of weathered granite, LCD panel glass and cement, respectively, showed the highest average in the UCS test($26.51N/mm^2$). It is much higher than that of commercial brick without glass($17.00N/mm^2$). Conclusively waste LCD panel glass can be reutilized economically as a raw building material of good quality.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.2
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• pp.31-37
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• 2015

Recently, mobile phones have become necessary tools for everyday life. In this study, a device that can serve as a separation between a touch panel and an LCD module in a mobile phone was devised for mass repair processes at a smaill business. We used a wire cutting method to separate the bonding plate area between the modules. The device is composed of DC motors and stepping motors that can deliver a precise cutting motion. The motor control system is connected by individual control modules to a CAN network. The developed device showed excellent performance at high temperature conditions.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.10a
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• pp.221-224
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• 2003

Recently, the market share of the thin-film-transistor liquid-crystalline-display (TFT-LCD) is growing rapidly in display device market. The backlight unit is used as a light source of TFT-LCD module. A light-guide is one of several important components of backlight unit. The manufacturing technology and optical system design of the light guide is very sensitive to quality and cost of the TFT-LCD module. In the present study a new manufacturing method which is called as direct surface forming(DSF) has been tested under various conditions. The result of this test, V-groove pattern shows different shapes depends on the temperature of mold surface, contact time of mold and depth of V-groove.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.34 no.1
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• pp.42-51
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• 2011

Poisson model and Gamma-Poisson model are popularly used to analyze statistical behavior from defective data. The methods are based on binary criteria, that is, good or failure. However, manufacturing industries prefer polytomous criteria for classifying manufactured products due to flexibility of marketing. In this paper, I introduce two multivariate Gamma-Poisson(MGP) models and estimation methods of the parameters in the models, which are able to handle polytomous data. The models and estimators are verified on defective pixels of LCD manufacturing. Experimental results show that both the independent MGP model and the multinomial MGP model have excellent performance in terms of mean absolute deviation and the choice of method depends on the purpose of use.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.641-648
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• 2007

Computational rotor dynamic analyses of designed composite roller for large LCD panel manufacturing process have been conducted. The present computational method is based on the general finite element method with rotating gyroscopic effects. General purpose commercial finite element code, with special rotordynamics analysis module is applied. For the purpose of numerical verification, comparison study for a benchmark dual rotor model with support bearings is also presented. Detailed finite element models for composite roller with different length are constructed and analyzed considering gravity effect in order to investigate vibration characteristics in actual operation environment. As results of the present study, rotor stability diagrams and mass unbalance responses are presented for different rotating conditions.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.698-700
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• 2003

LGP (Light-Guide Panel) of TFT-LCD Backligh/Frontlight is one of the major components which affect on the product quality of LCD. Since the brightness distribution of LGP is sensitive to the process error in manufacturing, the optical characteristics such as reflection and absorption of LGP pattern should be modeled including the process error. LGP is developed by using the fast and reliable design technology, which uses the concept of the inverse-design, makes the model on the characteristics of uncertainty in the manufacturing process, and designs the dispersion pattern analytically without try-and-error by using an artificial intelligence. The PEA(Process-Error-Adaptive) design gives the best solution in handling the process error. The offset of target in feedback system makes such the best pattern design possible that the brightness distribution is nearly same (more than 90%) with target in regardless of the miscellaneous errors in mass production. The present design method has been also applied to frontlight and multi-side-lamp(eg., four-side-four-lamp) backlight.